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Sample records for submicrometer fiber populations

  1. Filtration of submicrometer particles by pelagic tunicates.

    Science.gov (United States)

    Sutherland, Kelly R; Madin, Laurence P; Stocker, Roman

    2010-08-24

    Salps are common in oceanic waters and have higher per-individual filtration rates than any other zooplankton filter feeder. Although salps are centimeters in length, feeding via particle capture occurs on a fine, mucous mesh (fiber diameter d approximately 0.1 microm) at low velocity (U = 1.6 +/- 0.6 cmxs(-1), mean +/- SD) and is thus a low Reynolds-number (Re approximately 10(-3)) process. In contrast to the current view that particle encounter is dictated by simple sieving of particles larger than the mesh spacing, a low-Re mathematical model of encounter rates by the salp feeding apparatus for realistic oceanic particle-size distributions shows that submicron particles, due to their higher abundances, are encountered at higher rates (particles per time) than larger particles. Data from feeding experiments with 0.5-, 1-, and 3-microm diameter polystyrene spheres corroborate these findings. Although particles larger than 1 microm (e.g., flagellates, small diatoms) represent a larger carbon pool, smaller particles in the 0.1- to 1-microm range (e.g., bacteria, Prochlorococcus) may be more quickly digestible because they present more surface area, and we find that particles smaller than the mesh size (1.4 microm) can fully satisfy salp energetic needs. Furthermore, by packaging submicrometer particles into rapidly sinking fecal pellets, pelagic tunicates can substantially change particle-size spectra and increase downward fluxes in the ocean.

  2. High dietary fiber intake prevents stroke at a population level.

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    Casiglia, Edoardo; Tikhonoff, Valérie; Caffi, Sandro; Boschetti, Giovanni; Grasselli, Carla; Saugo, Mario; Giordano, Nunzia; Rapisarda, Valentina; Spinella, Paolo; Palatini, Paolo

    2013-10-01

    This research was aimed at clarifying whether high dietary fiber intake has an impact on incidence and risk of stroke at a population level. In 1647 unselected subjects, dietary fiber intake (DFI) was detected in a 12-year population-based study, using other dietary variables, anagraphics, biometrics, blood pressure, heart rate, blood lipids, glucose, insulin, uricaemia, fibrinogenaemia, erytrosedimentation rate, diabetes, insulin resistance, smoking, pulmonary disease and left ventricular hypertrophy as covariables. In adjusted Cox models, high DFI reduced the risk of stroke. In analysis based on quintiles of fiber intake adjusted for confounders, HR for incidence of stroke was lower when the daily intake of soluble fiber was >25 g or that of insoluble fiber was >47 g. In multivariate analyses, using these values as cut-off of DFI, the risk of stroke was lower in those intaking more that the cut-off of soluble (HR 0.31, 0.17-0.55) or insoluble (HR 0.35, 0.19-0.63) fiber. Incidence of stroke was also lower (-50%, p dietary DFI is inversely and independently associated to incidence and risk of stroke in general population. Copyright © 2012 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  3. Population genetic structure in natural and reintroduced beaver (Castor fiber populations in Central Europe

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    Kautenburger, R.

    2008-12-01

    Full Text Available Castor fiber Linnaeus, 1758 is the only indigenous species of the genus Castor in Europe and Asia. Due to extensive hunting until the beginning of the 20th century, the distribution of the formerly widespread Eurasian beaver was dramatically reduced. Only a few populations remained and these were in isolated locations, such as the region of the German Elbe River. The loss of genetic diversity in small or captive populations throughgenetic drift and inbreeding is a severe conservation problem. However, the reintroduction of beaver populations from several regions in Europe has shown high viability and populations today are growing fast. In the present study we analysed the population genetic structure of a natural and two reintroduced beaver populations in Germany and Austria. Furthermore, we studied the genetic differentiation between two beaver species, C. fiber and the American beaver (C. canadensis, using RAPD (Random Amplified Polymorphic DNA as a genetic marker. The reintroduced beaver populations of different origins and the autochthonous population of the Elbe River showed a similar low genetic heterogeneity. There was an overall high genetic similarity in the species C. fiber, and no evidence was found for a clear subspecific structure in the populations studied.

  4. Fiber

    Science.gov (United States)

    ... fiber you get from the food. Fiber-rich foods offer health benefits when eaten raw or cooked. Alternative Names Diet - fiber; Roughage; Bulk; Constipation - fiber Patient Instructions Constipation - ...

  5. Submicrometer grating light bar for a color-separation backlight.

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    Liu, Chun-Wei; Lee, Chi-Hung; Yang, Tzu-Chun; Ting, Chia-Jen; Lin, Tsung-Hsin; Lin, Shih-Chieh

    2013-05-20

    A light bar patterned using a submicrometer grating was designed to replace conventional dye color filters for color liquid crystal displays. The light bar generates color rays by transmitting them from side-lit color light-emitting diodes through the submicrometer grating. These angular color rays are then redirected by a V-grooved light guide, and then converged by a lens array and mapped to corresponding subpixel positions to efficiently display color images. The results show that 106% of the National Television System Committee (NTSC) color space in a blue-green-red-green (B-G-R-G) repeating pattern display pixel layout can be achieved.

  6. Hygroscopic growth of sub-micrometer and one-micrometer aerosol particles measured during ACE-Asia

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    A. Massling

    2007-06-01

    Full Text Available Hygroscopic properties of aerosol particles in the sub-micrometer and one-micrometer size ranges were measured during the ACE-Asia study (Aerosol Characterization Experiment-Asia in spring 2001. The measurements took place off the coasts of Japan, Korea, and China. All instruments contributing to this study were deployed in a container on the forward deck of the NOAA Research Vessel Ronald H. Brown. Air masses with primarily marine influence and air masses from the Asian continent affected by both anthropogenic sources and by the transport of desert dust aerosol were encountered during the cruise.

    Results showed very different hygroscopic behavior in the sub-micrometer size range compared to the one-micrometer size range. In general, for all continentally influenced air masses, the one-micrometer particle population was characterized by two different particle groups – a nearly hydrophobic fraction with growth factors around 1.0 representative of dust particles and a sea salt fraction with hygroscopic growth factors around 2.0. The number fraction of dust particles was generally about 60% independent of long-range air mass origin.

    For sub-micrometer particles, a dominant, more hygroscopic particle fraction with growth factors between 1.5 and 1.9 (depending on dry particle size consistent with ammonium sulfate or non-neutralized sulfates as major component was always found. In marine air masses and for larger sizes within the sub-micrometer range (Dp=250 and 350 nm, a sea salt fraction with growth factors between 2.0 and 2.1 was also observed. For all other air masses, the more hygroscopic particle fraction in the sub-micrometer size range was mostly accompanied by a less hygroscopic particle fraction with growth factors between 1.20 and 1.55 depending on both the continental sources and the dry particle size. Number fractions of this particle group varied between 4 and 39% depending on dry particle size and air mass

  7. Development of an ordered array of optoelectrochemical individually readable sensors with submicrometer dimensions: application to remote electrochemiluminescence imaging.

    Science.gov (United States)

    Chovin, Arnaud; Garrigue, Patrick; Vinatier, Philippe; Sojic, Neso

    2004-01-15

    A novel array of optoelectrochemical submicrometer sensors for remote electrochemiluminescence (ECL) imaging is presented. This device was fabricated by chemical etching of a coherent optical fiber bundle to produce a nanotip array. The surface of the etched bundle was sputter-coated with a thin layer of indium tin oxide in order to create a transparent and electrically conductive surface that is insulated eventually by a new electrophoretic paint except for the apex of the tip. These fabrication steps produced an ordered array of optoelectrochemical sensors with submicrometer dimensions that retains the optical fiber bundle architecture. The electrochemical behavior of the sensor array was independently characterized by cyclic voltammetry and ECL experiments. The steady-state current indicates that the sensors are diffusively independent. This sensor array was further studied with a co-reactant ECL model system, such as Ru(bpy)(3)(2+)/TPrA. We clearly observed an ordered array of individual ECL micrometer spots, which corresponds to the sensor array structure. While the sensors of the array are not individually addressable electrochemically, we could establish that the sensors are optically independent and individually readable. Finally, we show that remote ECL imaging is performed quantitatively through the optoelectrochemical sensor array itself.

  8. Human atlas of the cardiac fiber architecture: study on a healthy population.

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    Lombaert, Herve; Peyrat, Jean-Marc; Croisille, Pierre; Rapacchi, Stanislas; Fanton, Laurent; Cheriet, Farida; Clarysse, Patrick; Magnin, Isabelle; Delingette, Hervé; Ayache, Nicholas

    2012-07-01

    Cardiac fibers, as well as their local arrangement in laminar sheets, have a complex spatial variation of their orientation that has an important role in mechanical and electrical cardiac functions. In this paper, a statistical atlas of this cardiac fiber architecture is built for the first time using human datasets. This atlas provides an average description of the human cardiac fiber architecture along with its variability within the population. In this study, the population is composed of ten healthy human hearts whose cardiac fiber architecture is imaged ex vivo with DT-MRI acquisitions. The atlas construction is based on a computational framework that minimizes user interactions and combines most recent advances in image analysis: graph cuts for segmentation, symmetric log-domain diffeomorphic demons for registration, and log-Euclidean metric for diffusion tensor processing and statistical analysis. Results show that the helix angle of the average fiber orientation is highly correlated to the transmural depth and ranges from -41° on the epicardium to +66° on the endocardium. Moreover, we find that the fiber orientation dispersion across the population (±13°) is lower than for the laminar sheets (±31°) . This study, based on human hearts, extends previous studies on other mammals with concurring conclusions and provides a description of the cardiac fiber architecture more specific to human and better suited for clinical applications. Indeed, this statistical atlas can help to improve the computational models used for radio-frequency ablation, cardiac resynchronization therapy, surgical ventricular restoration, or diagnosis and followups of heart diseases due to fiber architecture anomalies.

  9. Effects of different sources of physically effective fiber on rumen microbial populations.

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    Shaw, C N; Kim, M; Eastridge, M L; Yu, Z

    2016-03-01

    Physically effective fiber is needed by dairy cattle to prevent ruminal acidosis. This study aimed to examine the effects of different sources of physically effective fiber on the populations of fibrolytic bacteria and methanogens. Five ruminally cannulated Holstein cows were each fed five diets differing in physically effective fiber sources over 15 weeks (21 days/period) in a Latin Square design: (1) 44.1% corn silage, (2) 34.0% corn silage plus 11.5% alfalfa hay, (3) 34.0% corn silage plus 5.1% wheat straw, (4) 36.1% corn silage plus 10.1% wheat straw, and (5) 34.0% corn silage plus 5.5% corn stover. The impact of the physically effective fiber sources on total bacteria and archaea were examined using denaturing gradient gel electrophoresis. Specific real-time PCR assays were used to quantify total bacteria, total archaea, the genus Butyrivibrio, Fibrobacter succinogenes, Ruminococcus albus, Ruminococcus flavefaciens and three uncultured rumen bacteria that were identified from adhering ruminal fractions in a previous study. No significant differences were observed among the different sources of physical effective fiber with respect to the microbial populations quantified. Any of the physically effective fiber sources may be fed to dairy cattle without negative impact on the ruminal microbial community.

  10. Environmental concentrations of fibers with fluoro-edenitic composition and population exposure in Biancavilla (Sicily, Italy

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    Biagio Maria Bruni

    2014-06-01

    Full Text Available INTRODUCTION. The town of Biancavilla (Sicily was included in the National Priorities List of Contaminated Sites due to environmental dispersion of amphibole fibers owing to the extraction of materials from a local quarry. The present report summarizes results from several, hitherto unpublished, environmental surveys carried out in the area, as well as from published analyses of the chemistry and composition of fibers. METHODS. Data included here comprises environmental fiber concentrations by scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS analysis in soil, indoor and outdoor air, personal monitoring, as well as a chemical characterization of the fibers. The full chemical structure and spectroscopic characterization of fibers were obtained through a multi-analytical approach: SEM-EDS, X-ray powder diffraction (XRPD, as well as Mössbauer (MS and Fourier transform infrared (FT-IR spectroscopies. RESULTS. Data analyzed provided a spatial and temporal picture of fiber concentrations in Biancavilla, and a qualitative assessment of population exposure. Results suggest that until 2000, the population had been exposed to high levels of amphibole fibers. Mitigation measures adopted since 2001, gradually reduced exposure levels to about 0.10.4 ff/l. Previous studies on fibrous amphiboles from Biancavilla reported considerable chemical variability. Differences in composition, especially concerning the presence of Si, Ca, Fe, and Na, were found both within and between samples. Compared to the previously investigated prismatic fluoro-edenite, these fibrous fluorine amphiboles consistently showed higher average values of Si and Fe content, whereas Ca was significantly lower, which we consider a distinctive characteristic of the fluorine fibrous variety. CONCLUSIONS. The population of Biancavilla had been highly exposed to a suite of fibrous amphiboles for over 50 years. Dust mitigation measures have gradually reduced exposure, but

  11. Physical activity and dietary fiber determine population body fat levels : The Seven Countries Study

    NARCIS (Netherlands)

    Kromhout, D.; Bloemberg, B; Seidell, J. C.; Nissinen, A.; Menotti, A.

    2001-01-01

    BACKGROUND: A global epidemic of obesity is developing. Current prevalence rates are about 20-25% in American adults and 15-20% in Europeans. OBJECTIVE: We investigated the association between population levels of physical activity, dietary fat, dietary fiber and indicators of body fat. DESIGN:

  12. Physical activity and dietary fiber determine population body fat levels : the Seven Countries Study

    NARCIS (Netherlands)

    Kromhout, D.; Bloemberg, B; Seidell, J C; Nissinen, A.; Menotti, A.

    BACKGROUND: A global epidemic of obesity is developing. Current prevalence rates are about 20-25% in American adults and 15-20% in Europeans. OBJECTIVE: We investigated the association between population levels of physical activity, dietary fat, dietary fiber and indicators of body fat. DESIGN:

  13. Development and viability of a translocated beaver Castor fiber population in the Netherlands

    NARCIS (Netherlands)

    Nolet, B.A.; Baveco, J.M.

    1996-01-01

    We monitored survival, reproduction and emigration of a translocated beaver Castor fiber population in the Netherlands for five years and used a stochastic model to assess its viability. Between 1988 and 1991, 42 beavers were released in the Biesbosch National Park. The mortality was initially high

  14. Fiber

    Science.gov (United States)

    ... white toast. Lunch and Dinner: Make sandwiches with whole-grain breads (rye, oat, or wheat) instead of white. Make a fiber-rich sandwich with whole-grain bread, peanut butter, and bananas. Use whole-grain spaghetti ...

  15. Gas-Filled Hollow Core Fiber Lasers Based on Population Inversion

    Science.gov (United States)

    2013-12-05

    solid-core fiber laser systems. Gas- filled hollow-core fiber lasers based on population inversion from acetylene (12C2H2) and hydrogen cyanide (HCN...via first order rotational- vibrational overtones near 1.5 μm using 1-ns duration pulses from a home-built optical parametric amplifier. Narrow-band...laser emission peaks in the 3-μm region corresponding to the ΔJ = ±1 dipole allowed rotational transitions between the pumped vibrational overtone

  16. The function of sensory nerve fibers in lumbar radiculopathy. Use of quantitative sensory testing in the exploration of different populations of nerve fibers and dermatomes.

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    Nygaard, O P; Mellgren, S I

    1998-02-01

    The function of sensory nerve fibers in patients with lumbar radiculopathy and in control individuals was evaluated using quantitative sensory testing. To investigate the effect of lumbar nerve root compression on different populations of nerve fibers and to explore the function of sensory nerve fibers in neighboring nerve roots not involved in the mechanical compression. Results from experimental and clinical studies indicate that chronic compression of lumbar nerve roots affects the large myelinated nerve fibers. The majority of nerve fibers involved in the sensation of pain, however, are small afferent nerve fibers. It is therefore of interest to study the effect of compression on large and small sensory afferent channels. Several authors have elucidated the biochemical interaction between disc tissue and nerve roots. Chemical substances in the epidural space can reach the nerve fibers in nerve roots at the same or neighboring lumbar segments. In this way, fibers not involved in the mechanical compression may be affected. The small nerve fibers were studied using tests for thermal thresholds (thermotest), and the large myelinated fibers were studied by vibrametry. Forty-two patients were investigated in the symptomatic and the asymptomatic leg, and the results were compared with those of 21 healthy individuals. The thresholds of cold, warmth, and vibration were significantly increased in the dermatome of the compressed nerve root, indicating that large and small sensory nerve fibers were affected. Further, the thresholds were significantly increased in the neighboring dermatomes in the symptomatic and the asymptomatic leg. Large and small sensory afferent nerve fibers are affected in lumbar radiculopathy. The increase in sensation thresholds in the ipsilateral neighboring dermatome and in the dermatomes in the asymptomatic leg indicates that adjacent nerve roots are involved in the pathophysiology of sciatica in patients with lumbar disc herniation.

  17. Dimensional measurements with submicrometer uncertainty in production environment

    DEFF Research Database (Denmark)

    De Chiffre, L.; Gudnason, M. M.; Madruga, D.

    2015-01-01

    The work concerns a laboratory investigation of a method to achieve dimensional measurements with submicrometer uncertainty under conditions that are typical of a production environment. The method involves the concurrent determination of dimensions and material properties from measurements carried...... out over time. A laboratory set-up was developed comprising a pair of electronic probes mounted on a Zerodur block featuring near zero thermal expansion. Three temperature sensors, data acquisition system, and a temperature regulated plate for heating the workpiece were implemented. Investigations...... gauge blocks along with their uncertainties were estimated directly from the measurements. The length of the two workpieces at the reference temperature of 20 °C was extrapolated from the measurements and compared to certificate values. The investigations have documented that the developed approach...

  18. Three-dimensional structure of brain tissue at submicrometer resolution

    Energy Technology Data Exchange (ETDEWEB)

    Saiga, Rino; Mizutani, Ryuta, E-mail: ryuta@tokai-u.jp [Department of Applied Biochemistry, Tokai University, Hiratsuka, Kanagawa 259-1292 (Japan); Inomoto, Chie; Takekoshi, Susumu; Nakamura, Naoya; Tsuboi, Akio; Osawa, Motoki [Tokai University School of Medicine, Isehara, Kanagawa 259-1193 (Japan); Arai, Makoto; Oshima, Kenichi; Itokawa, Masanari [Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-8506 (Japan); Uesugi, Kentaro; Takeuchi, Akihisa; Terada, Yasuko; Suzuki, Yoshio [Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), Sayo, Hyogo 679-5198 (Japan)

    2016-01-28

    Biological objects are composed of submicrometer structures such as cells and organelles that are essential for their functions. Here, we report on three-dimensional X-ray visualization of cells and organelles at resolutions up to 100 nm by imaging microtomography (micro-CT) equipped with Fresnel zone plate optics. Human cerebral tissue, fruit fly cephalic ganglia, and Escherichia coli bacteria labeled with high atomic-number elements were embedded in epoxy resin and subjected to X-ray microtomography at the BL37XU and BL47XU beamlines of the SPring-8 synchrotron radiation facility. The obtained results indicated that soft tissue structures can be visualized with the imaging microtomography.

  19. Low LET protons focused to submicrometer shows enhanced radiobiological effectiveness.

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    Schmid, T E; Greubel, C; Hable, V; Zlobinskaya, O; Michalski, D; Girst, S; Siebenwirth, C; Schmid, E; Molls, M; Multhoff, G; Dollinger, G

    2012-10-07

    This study shows that enhanced radiobiological effectiveness (RBE) values can be generated focusing low linear energy transfer (LET) radiation and thus changing the microdose distribution. 20 MeV protons (LET = 2.65 keV µm(-1)) are focused to submicrometer diameter at the ion microprobe superconducting nanoprobe for applied nuclear (Kern) physics experiments of the Munich tandem accelerator. The RBE values, as determined by measuring micronuclei (RBE(MN) = 1.48 ± 0.07) and dicentrics (RBE(D) = 1.92 ± 0.15), in human-hamster hybrid (A(L)) cells are significantly higher when 117 protons were focused to a submicrometer irradiation field within a 5.4 × 5.4 µm(2) matrix compared to quasi homogeneous in a 1 × 1 µm(2) matrix applied protons (RBE(MN) = 1.28 ± 0.07; RBE(D) = 1.41 ± 0.14) at the same average dose of 1.7 Gy. The RBE values are normalized to standard 70 kV (dicentrics) or 200 kV (micronuclei) x-ray irradiation. The 117 protons applied per point deposit the same amount of energy like a (12)C ion with 55 MeV total energy (4.48 MeV u(-1)). The enhancements are about half of that obtained for (12)C ions (RBE(MN) = 2.20 ± 0.06 and RBE(D) = 3.21 ± 0.10) and they are attributed to intertrack interactions of the induced damages. The measured RBE values show differences from predictions of the local effect model (LEM III) that is used to calculate RBE values for irradiation plans to treat tumors with high LET particles.

  20. Random or selective neuroanatomical connectivity. Study of the distribution of fibers over two populations of identified interneurons in cerebral cortex

    NARCIS (Netherlands)

    Vinkenoog, M.; van den Oever, M.C.; Uylings, H.B.M.; Wouterlood, F.G.

    2005-01-01

    We present a neuroanatomical tracing method in a stereological approach to study the proportional distribution of fibers of a particular projection over two chemically different populations of neurons. The fiber projection from the presubiculum to the medial division of the entorhinal cortex of the

  1. Focusing of sub-micrometer particles and bacteria enabled by two-dimensional acoustophoresis

    DEFF Research Database (Denmark)

    Antfolk, M.; Muller, Peter Barkholt; Augustsson, P.

    2014-01-01

    particles as small as 0.5 μm in diameter in microchannels of square or rectangular cross sections, is demonstrated. Numerical analysis was used to determine generic transverse particle trajectories in the channels, which revealed spiral-shaped trajectories of the sub-micrometer particles towards the center......Handling of sub-micrometer bioparticles such as bacteria are becoming increasingly important in the biomedical field and in environmental and food analysis. As a result, there is an increased need for less labor-intensive and time-consuming handling methods. Here, an acoustophoresis......-based microfluidic chip that uses ultrasound to focus sub-micrometer particles and bacteria, is presented. The ability to focus sub-micrometer bioparticles in a standing one-dimensional acoustic wave is generally limited by the acoustic-streaming-induced drag force, which becomes increasingly significant the smaller...

  2. About scavenging of near-water submicrometer aerosol in Arctic and Sub-Arctic regions

    Science.gov (United States)

    Polkin, V. V.; Polkin, Vas. V.

    2014-11-01

    Situations with scavenging of submicrometer aerosol particles by precipitation are analyzed. Experiments were carries out in Arctic region (NABOS expedition) onboard research vessels "Akademik Fedorov" and "Professor Khlyustin" in August-September 2013.

  3. Quantifying the Hygroscopic Growth of Individual Submicrometer Particles with Atomic Force Microscopy.

    Science.gov (United States)

    Morris, Holly S; Estillore, Armando D; Laskina, Olga; Grassian, Vicki H; Tivanski, Alexei V

    2016-04-05

    method, regardless of particle composition but area equivalent derived GFs varied for different chemical systems. Furthermore, the NaCl and MA mixture was substrate-deposited both wet and dry, revealing that the hydration state of the particle at the time of impaction influences how the particle grows on the substrate upon water uptake. Most importantly, for the binary mixtures it is shown here that different populations of particles can be distinguished with AFM, an individual particle method, whereas HTDMA sees the ensemble average. Overall, this study establishes the methodology of using AFM to accurately quantify the water uptake of individual submicrometer particles at ambient conditions over a wide range of RH values. Furthermore, the importance of single particle AFM analysis is demonstrated.

  4. Meta-analysis of cotton fiber quality QTLs across diverse environments in a Gossypium hirsutum x G. barbadense RIL population

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    Giband Marc

    2010-06-01

    Full Text Available Abstract Background Cotton fibers (produced by Gossypium species are the premier natural fibers for textile production. The two tetraploid species, G. barbadense (Gb and G. hirsutum (Gh, differ significantly in their fiber properties, the former having much longer, finer and stronger fibers that are highly prized. A better understanding of the genetics and underlying biological causes of these differences will aid further improvement of cotton quality through breeding and biotechnology. We evaluated an inter-specific Gh × Gb recombinant inbred line (RIL population for fiber characteristics in 11 independent experiments under field and glasshouse conditions. Sites were located on 4 continents and 5 countries and some locations were analyzed over multiple years. Results The RIL population displayed a large variability for all major fiber traits. QTL analyses were performed on a per-site basis by composite interval mapping. Among the 651 putative QTLs (LOD > 2, 167 had a LOD exceeding permutation based thresholds. Coincidence in QTL location across data sets was assessed for the fiber trait categories strength, elongation, length, length uniformity, fineness/maturity, and color. A meta-analysis of more than a thousand putative QTLs was conducted with MetaQTL software to integrate QTL data from the RIL and 3 backcross populations (from the same parents and to compare them with the literature. Although the global level of congruence across experiments and populations was generally moderate, the QTL clustering was possible for 30 trait x chromosome combinations (5 traits in 19 different chromosomes where an effective co-localization of unidirectional (similar sign of additivity QTLs from at least 5 different data sets was observed. Most consistent meta-clusters were identified for fiber color on chromosomes c6, c8 and c25, fineness on c15, and fiber length on c3. Conclusions Meta-analysis provided a reliable means of integrating phenotypic and

  5. Evaluating Glaucomatous Retinal Nerve Fiber Damage by GDx VCC Polarimetry in Taiwan Chinese Population

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    Chen, Hsin-Yi; Huang, Mei-Ling; Huang, Wei-Cheng

    2010-01-01

    Purpose To study the capability of scanning laser polarimetry with variable corneal compensation (GDx VCC) to detect differences in retinal nerve fiber layer thickness between normal and glaucomatous eyes in a Taiwan Chinese population. Methods This study included 44 normal eyes and 107 glaucomatous eyes. The glaucomatous eyes were divided into three subgroups on the basis of its visual field defects (early, moderate, severe). Each subject underwent a GDx-VCC exam and visual field testing. The area under the receiver-operating characteristic curve (AROC) of each relevant parameter was used to differentiate normal from each glaucoma subgroup, respectively. The correlation between visual field index and each parameter was evaluated for the eyes in the glaucoma group. Results For normal vs. early glaucoma, the parameter with the best AROC was Nerve fiber indicator (NFI) (0.942). For normal vs. moderate glaucoma, the parameter showing the best AROC was NFI (0.985). For normal vs. severe glaucoma, the parameter that had the best AROC was NFI (1.000). For early vs. moderate glaucoma, the parameter with the best AROC was NFI (0.732). For moderate vs. severe, the parameter showing the best AROC was temporal-superior-nasal-inferior-temporal average (0.652). For early vs. severe, the parameter with the best AROC was NFI (0.852). Conclusions GDx-VCC-measured parameters may serve as a useful tool to distinguish normal from glaucomatous eyes; in particular, NFI turned out to be the best discriminating parameter.

  6. Hydrogen template assisted electrodeposition of sub-micrometer wires composing honeycomb-like porous Pb films

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    Cherevko, Serhiy; Xing, Xiaoli; Chung, Chan-Hwa

    2011-07-01

    High surface area porous Pb films are electrodeposited using a hydrogen bubble dynamic template. The influence of the experimental parameters on the morphology features such as the pore size, wall thickness, and sub-micrometer size features is investigated. Two structural transformations between sub-micrometer wires and particles obtained by adjusting the HClO4 concentration are observed. At a low HClO4 concentration, the growth of sub-micrometer wires is favored. The deposition of particles or wires covered by particles is observed at higher H+ concentrations. The addition of sodium citrate as an additive facilitates the preservation of Pb in the form of wires. Adjusting the concentration of Pb(ClO4)2·3H2O influences the mass transfer of Pb and affects its morphology. At low concentrations, the deposition of porous Pb films composed of porous wires is shown. The additional deposition of particles on wires is observed at high concentrations. The formation process of honeycomb-like porous structures is revealed by analysis of films deposited during different deposition time. The influence of the current density on the micro and sub-micrometer scale morphologies is presented.

  7. Hygroscopic behavior of individual submicrometer particles studied by X-ray spectromicroscopy.

    Science.gov (United States)

    Ghorai, Suman; Tivanski, Alexei V

    2010-11-15

    A novel application of single particle scanning transmission X-ray microscopy (STXM) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy is presented for quantitative analysis of hygroscopic properties and phase transitions of individual submicrometer particles. The approach utilizes the exposure of substrate-deposited individual particles to water vapor at different relative humidity followed by STXM/NEXAFS spectromicroscopy analysis. The hygroscopic properties of atmospherically relevant NaCl, NaBr, NaI, and NaNO(3) submicrometer particles were measured to evaluate the utility of the approach. An analytical approach for quantification of a water-to-solute ratio within an individual submicrometer particle during hydration and dehydration cycles is presented. The results for the deliquescence and efflorescence phase transitions and quantitative measurements of water-to-solute ratios are found in excellent agreement with available literature data. Oxygen K-edge NEXAFS spectra of submicrometer sodium halide droplets are reported along with a unique experimental observation of the formation of the halide-water anionic complex in NaBr and NaI microdimensional droplets. The analytical approach provides a unique opportunity for spectromicroscopy studies of water uptake on environmental particles collected in both laboratory and field studies.

  8. Dietary fiber intake of the U.S. population, What We Eat in America, NHANES 2009-2010

    Science.gov (United States)

    The purpose of this report is to present data on the dietary fiber intake of the U.S. population and the food categories that contribute to total intake. The dietary intake data were from a twenty-four hour recall provided by 9,042 individuals ages two and older, except breast-fed children, who par...

  9. Morphometric analysis of the fiber populations of the rat sciatic nerve, its spinal roots, and its major branches

    NARCIS (Netherlands)

    Prodanov, D.P.; Feierabend, H.K.P.

    2007-01-01

    Correspondence between the nerve composition and the functional characteristics of its fiber populations is not always evident. To investigate such correspondence and to give a systematic picture of the morphology of the rat hind limb nerves, extensive morphometric study was performed on the sciatic

  10. M&A For Lithography Of Sparse Arrays Of Sub-Micrometer Features

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    Brueck, Steven R.J.; Chen, Xiaolan; Zaidi, Saleem; Devine, Daniel J.

    1998-06-02

    Methods and apparatuses are disclosed for the exposure of sparse hole and/or mesa arrays with line:space ratios of 1:3 or greater and sub-micrometer hole and/or mesa diameters in a layer of photosensitive material atop a layered material. Methods disclosed include: double exposure interferometric lithography pairs in which only those areas near the overlapping maxima of each single-period exposure pair receive a clearing exposure dose; double interferometric lithography exposure pairs with additional processing steps to transfer the array from a first single-period interferometric lithography exposure pair into an intermediate mask layer and a second single-period interferometric lithography exposure to further select a subset of the first array of holes; a double exposure of a single period interferometric lithography exposure pair to define a dense array of sub-micrometer holes and an optical lithography exposure in which only those holes near maxima of both exposures receive a clearing exposure dose; combination of a single-period interferometric exposure pair, processing to transfer resulting dense array of sub-micrometer holes into an intermediate etch mask, and an optical lithography exposure to select a subset of initial array to form a sparse array; combination of an optical exposure, transfer of exposure pattern into an intermediate mask layer, and a single-period interferometric lithography exposure pair; three-beam interferometric exposure pairs to form sparse arrays of sub-micrometer holes; five- and four-beam interferometric exposures to form a sparse array of sub-micrometer holes in a single exposure. Apparatuses disclosed include arrangements for the three-beam, five-beam and four-beam interferometric exposures.

  11. Consumo de fibras alimentares em população adulta Dietary fiber consumption in an adult population

    Directory of Open Access Journals (Sweden)

    Lúcia Leal de Mattos

    2000-02-01

    Full Text Available OBJETIVO: As fibras alimentares estão entre os principais fatores da alimentação na prevenção de doenças crônicas. Por isso, objetivou-se estimar o consumo médio diário de fibras alimentares totais, insolúveis e solúveis, nas refeições de uma população de área metropolitana. MÉTODOS: Foi estudada uma amostra da população do Município de Cotia, SP, composta por 559 indivíduos com mais de 20 anos. O consumo alimentar foi obtido pelo método de história alimentar - dieta habitual. Foram identificadas as fontes de fibras nas refeições: desjejum, almoço e jantar. Com base na porção média, os alimentos foram classificados quanto ao conteúdo de fibras como: muito alto (7 g ou mais; alto (4,5 g a 6,9 g; moderado (2,4 g a 4,4 g e baixo (OBJECTIVE: The dietary fiber has emerged as a leading dietary factor in the prevention and treatment of chronic diseases. I was estimated the average consumption of total dietary fiber (DF, insoluble fiber (IF and soluble fiber (SF in the meals of both sex adults from the town of Cotia, a metropolitan area in S. Paulo State, Brazil. METHODS: A population sample of Cotia country, S. Paulo (Brazil, consisted of 559 adults older than 20 years old, was studied. Food consumption was assessed by the dietary history habits. The amount of dietary fiber in each meal (breakfast, lunch and diner was estimated by the serving size. The foods were classified according to their fiber content in Very High (7 g or more, High (4.5 to 6.9, Moderate (2.4 to 4.4 and Low (<2.4. RESULTS: The average population's consumption of dietary fiber was of 24 g/day, with an average consumption of insoluble fiber of 17 g/day and soluble of 7 g/day. Among women, the average consumption was 20 g/day and among men 29 g/day (p<0.01. Most of the foods in their diet were classified as having a low content of dietary fiber. Beans were the most important dietary fiber source in the population diet. Lunch and diner were the meal with

  12. Morgellons disease: Analysis of a population with clinically confirmed microscopic subcutaneous fibers of unknown etiology.

    Science.gov (United States)

    Savely, Virginia R; Stricker, Raphael B

    2010-05-13

    Morgellons disease is a controversial illness in which patients complain of stinging, burning, and biting sensations under the skin. Unusual subcutaneous fibers are the unique objective finding. The etiology of Morgellons disease is unknown, and diagnostic criteria have yet to be established. Our goal was to identify prevalent symptoms in patients with clinically confirmed subcutaneous fibers in order to develop a case definition for Morgellons disease. Patients with subcutaneous fibers observed on physical examination (designated as the fiber group) were evaluated using a data extraction tool that measured clinical and demographic characteristics. The prevalence of symptoms common to the fiber group was then compared with the prevalence of these symptoms in patients with Lyme disease and no complaints of skin fibers. The fiber group consisted of 122 patients. Significant findings in this group were an association with tick-borne diseases and hypothyroidism, high numbers from two states (Texas and California), high prevalence in middle-aged Caucasian women, and an increased prevalence of smoking and substance abuse. Although depression was noted in 29% of the fiber patients, pre-existing delusional disease was not reported. After adjusting for nonspecific symptoms, the most common symptoms reported in the fiber group were: crawling sensations under the skin; spontaneously appearing, slow-healing lesions; hyperpigmented scars when lesions heal; intense pruritus; seed-like objects, black specks, or "fuzz balls" in lesions or on intact skin; fine, thread-like fibers of varying colors in lesions and intact skin; lesions containing thick, tough, translucent fibers that are highly resistant to extraction; and a sensation of something trying to penetrate the skin from the inside out. This study of the largest clinical cohort reported to date provides the basis for an accurate and clinically useful case definition for Morgellons disease.

  13. Injection molding of nanopatterned surfaces in the sub-micrometer range with induction heating aid

    DEFF Research Database (Denmark)

    Menotti, Stefano; Hansen, Hans Nørgaard; Bissacco, Giuliano

    2014-01-01

    Replication of sub-micrometer structures by injection molding leads to special requirements for the mold in order to ensure proper replica and acceptable cycle time. This paper investigates the applicability of induction heating embedded into the mold for the improvement of nanopattern replication....... A tool insert having a surface containing functional geometries in the sub-micrometer range was produced using aluminum anodization and nickel electroplating. In order to provide elevated mold temperatures necessary for the complete replica of the pattern, a new mold setup was developed, which allows...... rapid heating of the cavity wall using an induction heating system. Temperature was measured using a thermocouple placed in the mold insert. The system was used to heat up the cavity wall with heating rates of up to 10 K/s. Acrylonitrile butadiene styrene (ABS) and polycarbonate (PC) were used...

  14. Submicrometer particles and their effects on the association between air temperature and mortality in Brisbane, Australia.

    Science.gov (United States)

    Wang, Lina; Tong, Shilu; Toloo, Ghasem Sam; Yu, Weiwei

    2014-01-01

    Air temperature and pollution can jointly affect human health. Submicrometer particles appearing to have particularly harmful effects compared with the coarse ones. However, little is known about how the association between temperature and mortality is affected by these particles. This study examined the association between air temperature and mortality before and after adjustment for particle concentrations among different age and disease groups from 1995 to 2000 in Brisbane, Australia. The monitoring of particle size distribution within the 15-750nm range was carried out by a Scanning Mobility Particle Sizer. Corresponding climate and air pollutant data were collected from relevant government agencies. The association between temperature and mortality was quantified using a Poisson time-series model within a distributed lag non-linear modelling framework. The results showed that the effects of air temperature on mortality were lower among the elderly and people with respiratory diseases, and greater among people with cardiovascular diseases after controlling for submicrometer particle concentrations. Submicrometer particles seem to be an important confounder for the temperature-mortality relationship, particularly among vulnerable groups, and should be taken into account when assessing the impacts of air temperature on human health. Crown Copyright © 2013 Published by Elsevier Inc. All rights reserved.

  15. Morgellons disease: Analysis of a population with clinically confirmed microscopic subcutaneous fibers of unknown etiology

    Directory of Open Access Journals (Sweden)

    Virginia R Savely

    2010-05-01

    Full Text Available Virginia R Savely1, Raphael B Stricker21TBD Medical Associates, San Francisco, CA, USA; 2International Lyme and Associated Diseases Society, Bethesda, MD, USABackground: Morgellons disease is a controversial illness in which patients complain of stinging, burning, and biting sensations under the skin. Unusual subcutaneous fibers are the unique objective finding. The etiology of Morgellons disease is unknown, and diagnostic criteria have yet to be established. Our goal was to identify prevalent symptoms in patients with clinically confirmed subcutaneous fibers in order to develop a case definition for Morgellons disease.Methods: Patients with subcutaneous fibers observed on physical examination (designated as the fiber group were evaluated using a data extraction tool that measured clinical and demographic characteristics. The prevalence of symptoms common to the fiber group was then compared with the prevalence of these symptoms in patients with Lyme disease and no complaints of skin fibers.Results: The fiber group consisted of 122 patients. Significant findings in this group were an association with tick-borne diseases and hypothyroidism, high numbers from two states (Texas and California, high prevalence in middle-aged Caucasian women, and an increased prevalence of smoking and substance abuse. Although depression was noted in 29% of the fiber patients, pre-existing delusional disease was not reported. After adjusting for nonspecific symptoms, the most common symptoms reported in the fiber group were: crawling sensations under the skin; spontaneously appearing, slow-healing lesions; hyperpigmented scars when lesions heal; intense pruritus; seed-like objects, black specks, or “fuzz balls” in lesions or on intact skin; fine, thread-like fibers of varying colors in lesions and intact skin; lesions containing thick, tough, translucent fibers that are highly resistant to extraction; and a sensation of something trying to penetrate the skin from

  16. Retinal nerve fiber layer thickness in normal Indian pediatric population measured with optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Neelam Pawar

    2014-01-01

    Full Text Available Purpose: To measure the peripapillary retinal nerve fiber layer (RNFL thickness in normal Indian pediatric population. Subjects and Methods: 120 normal Indian children ages 5-17 years presenting to the Pediatric Clinic were included in this observational cross-sectional study. RNFL thickness was measured with stratus optical coherence tomography (OCT. Children with strabismus or amblyopia, with neurological, metabolic, vascular, or other disorders and those with abnormal optic discs were excluded. One eye of each subject was randomly selected for statistical analysis. The effect of age, refraction and gender on RNFL thickness was investigated statistically. Result: OCT measurements were obtained in 120 of 130 (92.3% subjects. Mean age was 10.8 ± 3.24 years (range 5-17. Average RNFL thickness was (± SD 106.11 ± 9.5 μm (range 82.26-146.25. The RNFL was thickest inferiorly (134.10 ± 16.16 μm and superiorly (133.44 ± 15.50 μm, thinner nasally (84.26 ± 16.43 μm, and thinnest temporally (70.72 ± 14.80 μm. In univariate regression analysis, age had no statistical significant effect on RNFL thickness (P = 0.7249 and refraction had a significant effect on RNFL thickness (P = 0.0008. Conclusion: OCT can be used to measure RNFL thickness in children. Refraction had an effect on RNFL thickness. In normal children, variation in RNFL thickness is large. The normative data provided by this study may assist in identifying changes in RNFL thickness in Indian children.

  17. QTL analysis of cotton fiber length in advanced backcross populations derived from a cross between Gossypium hirsutum and G. mustelinum.

    Science.gov (United States)

    Wang, Baohua; Draye, Xavier; Zhuang, Zhimin; Zhang, Zhengsheng; Liu, Min; Lubbers, Edward L; Jones, Don; May, O Lloyd; Paterson, Andrew H; Chee, Peng W

    2017-06-01

    QTLs for fiber length mapped in three generations of advanced backcross populations derived from crossing Gossypium hirsutum and Gossypium mustelinum showed opportunities to improve elite cottons by introgression from wild relatives. The molecular basis of cotton fiber length in crosses between Gossypium hirsutum and Gossypium mustelinum was dissected using 21 BC 3 F 2 and 12 corresponding BC 3 F 2:3 and BC 3 F 2:4 families. Sixty-five quantitative trait loci (QTLs) were detected by one-way analysis of variance. The QTL numbers detected for upper-half mean length (UHM), fiber uniformity index (UI), and short fiber content (SFC) were 19, 20, and 26 respectively. Twenty-three of the 65 QTLs could be detected at least twice near adjacent markers in the same family or near the same markers across different families/generations, and 32 QTLs were detected in both one-way variance analyses and mixed model-based composite interval mapping. G. mustelinum alleles increased UHM and UI and decreased SFC for five, one, and one QTLs, respectively. In addition to the main-effect QTLs, 17 epistatic QTLs were detected which helped to elucidate the genetic basis of cotton fiber length. Significant among-family genotypic effects were detected at 18, 16, and 16 loci for UHM, UI, and SFC, respectively. Six, two, and two loci showed genotype × family interaction for UHM, UI and SFC, respectively, illustrating complexities that might be faced in introgression of exotic germplasm into cultivated cotton. Co-location of many QTLs for UHM, UI, and SFC accounted for correlations among these traits, and selection of these QTLs may improve the three traits simultaneously. The simple sequence repeat (SSR) markers associated with G. mustelinum QTLs will assist breeders in transferring and maintaining valuable traits from this exotic source during cultivar development.

  18. Submicrometer Hollow Bioglass Cones Deposited by Radio Frequency Magnetron Sputtering: Formation Mechanism, Properties, and Prospective Biomedical Applications.

    Science.gov (United States)

    Popa, A C; Stan, G E; Besleaga, C; Ion, L; Maraloiu, V A; Tulyaganov, D U; Ferreira, J M F

    2016-02-01

    This work reports on the unprecedented magnetron sputtering deposition of submicrometric hollow cones of bioactive glass at low temperature in the absence of any template or catalyst. The influence of sputtering conditions on the formation and development of bioglass cones was studied. It was shown that larger populations of well-developed cones could be achieved by increasing the argon sputtering pressure. A mechanism describing the growth of bioglass hollow cones is presented, offering the links for process control and reproducibility of the cone features. The composition, structure, and morphology of the as-synthesized hollow cones were investigated by energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), grazing incidence geometry X-ray diffraction (GIXRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM)-selected area electron diffraction (SAED). The in vitro biological performance, assessed by degradation tests (ISO 10993-14) and cytocompatibility assays (ISO 10993-5) in endothelial cell cultures, was excellent. This allied with resorbability and the unique morphological features make the submicrometer hollow cones interesting candidate material devices for focal transitory permeabilization of the blood-brain barrier in the treatment of carcinoma and neurodegenerative disorders.

  19. Usual Intake of Added Sugars and Saturated Fats Is High while Dietary Fiber Is Low in the Mexican Population.

    Science.gov (United States)

    López-Olmedo, Nancy; Carriquiry, Alicia L; Rodríguez-Ramírez, Sonia; Ramírez-Silva, Ivonne; Espinosa-Montero, Juan; Hernández-Barrera, Lucia; Campirano, Fabricio; Martínez-Tapia, Brenda; Rivera, Juan A

    2016-09-01

    The Mexican National Health and Nutrition Survey (ENSANUT) was carried out in 2012. Information from the survey is used to design and evaluate food and nutrition policies in Mexico. The objective of this study was to estimate the usual intake of energy and macronutrients in the Mexican population by using the ENSANUT 2012. Twenty-four-hour recall interviews were administered to a nationally representative subsample of 10,096 individuals aged ≥1 y from the ENSANUT 2012. Usual intake distributions and the prevalence of inadequate intakes were estimated by using the Iowa State University method. Student's t tests and tests on the equality of proportions were used to compare usual intakes and prevalence of inadequacy across socioeconomic status, area (rural or urban), and region of residence (North, Center, or South). Energy and macronutrient intakes and indicators of dietary adequacy are presented for children (ages 1-4 y and 5-11 y), adolescents (12-19 y), and adults (≥20 y). At the national level, the estimated mean fiber intake was below the Adequate Intake for all population subgroups, suggesting inadequacies. The estimated proportion with a usual added sugars intake of >10% of total energy intake was >64% in all age groups. The proportion with a usual saturated fat intake of >10% of total energy intake was estimated to be >78% in children, >66% in adolescents, and >50% in adults. Overall, fiber intake was lower and intakes of saturated fat and added sugars were higher in urban compared with rural areas, in the North compared with South regions, and among those with high compared with low socioeconomic status (P Fiber intake is lower and added sugar and saturated fat intakes are higher than recommended for >50% of the Mexican population aged ≥1 y. These results highlight the importance of improving the diets of the overall population to reduce the risk of noncommunicable chronic diseases. © 2016 American Society for Nutrition.

  20. Impact of Chinese anthropogenic emissions on submicrometer aerosol concentration at Mt. Tateyama, Japan

    Directory of Open Access Journals (Sweden)

    H. Iida

    2009-12-01

    Full Text Available Rapid Asian economic development might engender secondary impacts of atmospheric aerosol particles over the western Pacific after conversion of gaseous pollutants such as SO2. To elucidate changes in aerosol concentrations in leeward areas undergoing remarkable industrialization, the number-size distributions of submicrometer (0.3–1.0 μm aerosols were measured at Murododaira (36.6° N, 137.6° E, 2450 m a.s.l. on the western flank of Mount Tateyama in central Japan during January 1999–February 2009. Nighttime data obtained from 2400 to 0500 were used to analyze free-tropospheric aerosol concentration. Monthly average volume concentrations were calculated for months with >50% daily data coverage. Volume concentrations of submicrometer aerosols were high in spring to early summer and low in winter. Significant increasing trends at 95% confidence levels were found for volume concentrations in winter–spring. Simulated monthly anthropogenic aerosol concentrations at Mt. Tateyama from results of regional aerosol modeling with emission inventory up to 2005 showed seasonal variation and winter–spring increasing trends similar to those of observed aerosol concentration. According to the model analyses, the contribution of anthropogenic aerosol concentrations derived from China was high during winter–spring (60–80% of total anthropogenic aerosols at Mt. Tateyama. This accords with the increasing trend observed for winter–spring. Because SO42− is the dominant component of total anthropogenic aerosols, these results suggest that increasing anthropogenic emissions, especially for SO2, in China, engender enhancement of submicrometer-diameter aerosols over Japan during winter–spring.

  1. Multimaterial preform coextrusion for robust chalcogenide optical fibers and tapers.

    Science.gov (United States)

    Tao, Guangming; Shabahang, Soroush; Banaei, Esmaeil-Hooman; Kaufman, Joshua J; Abouraddy, Ayman F

    2012-07-01

    The development of robust infrared fibers is crucial for harnessing the capabilities of new mid-infrared lasers. We present a novel approach to the fabrication of chalcogenide glass fiber preforms: one-step multimaterial extrusion. The preform consists of a glass core and cladding surrounded by a built-in, thermally compatible, polymer jacket for mechanical support. Using this approach we extrude several preform structures and draw them into robust composite fibers. Furthermore, the polymer cladding allows us to produce robust tapers with submicrometer core diameter.

  2. Morgellons disease: Analysis of a population with clinically confirmed microscopic subcutaneous fibers of unknown etiology

    OpenAIRE

    Virginia R Savely; Raphael B Stricker

    2010-01-01

    Virginia R Savely1, Raphael B Stricker21TBD Medical Associates, San Francisco, CA, USA; 2International Lyme and Associated Diseases Society, Bethesda, MD, USABackground: Morgellons disease is a controversial illness in which patients complain of stinging, burning, and biting sensations under the skin. Unusual subcutaneous fibers are the unique objective finding. The etiology of Morgellons disease is unknown, and diagnostic criteria have yet to be established. Our goal was to identify prevalen...

  3. Dietary fiber intake and risk of cardiovascular disease in the Japanese population: the Japan Public Health Center-based study cohort.

    Science.gov (United States)

    Kokubo, Y; Iso, H; Saito, I; Yamagishi, K; Ishihara, J; Inoue, M; Tsugane, S

    2011-11-01

    There has been no study with regard to the association between dietary fibers and the incidence of stroke and coronary heart disease (CHD) in Asia. We investigated the association between dietary fiber and the risk of cardiovascular disease (CVD), which we defined as stroke or CHD, in a Japanese population. We studied 86 387 Japanese subjects (age 45-65 years, without CVD or cancer in 1995 as Cohort I and in 1998 as Cohort II) and used a self-administered questionnaire to follow-up the participants until the end of 2004. Dietary fiber intake was estimated from food-frequency questionnaires comprising 138 food items. After 899 141 person-years of follow-up, we documented the incidence of 2553 strokes and 684 cases of CHD. Multivariable-adjusted hazard ratios (95% confidence intervals (CIs)) of CVD for the third to fifth quintiles of total fiber were 0.79 (0.63-0.99), 0.70 (0.54-0.89) and 0.65 (0.48-0.87) in women, respectively, compared with the lowest quintile. Total fiber intake was inversely associated with the incidence of stroke, either cerebral infarction or intracerebral hemorrhage in women. The results for insoluble fiber in women were similar to those for total fiber, whereas those for soluble fiber were weak. An inverse association of total fiber with CVD was observed primarily in non-smokers (P for trend=0.045 and 0.001) and not in smokers (probability values for interaction between total fiber and smoking were 0.06 and 0.01 in men and women, respectively). Higher total dietary fiber was associated with reduced risk of CVD in Japanese non-smokers.

  4. Effects of Carbohydrate and Dietary Fiber Intake, Glycemic Index and Glycemic Load on HDL Metabolism in Asian Populations.

    Science.gov (United States)

    Yanai, Hidekatsu; Katsuyama, Hisayuki; Hamasaki, Hidetaka; Abe, Shinichi; Tada, Norio; Sako, Akahito

    2014-10-01

    High-density lipoprotein (HDL) is a lipoprotein which has anti-atherogenic property by reverse cholesterol transport from the peripheral tissues to liver. Low HDL-cholesterol (HDL-C) levels are associated with the development of coronary artery diseases (CADs). Various epidemiological studies have suggested that the development of CAD increase in individuals with less than 40 mg/dL of HDL-C. In spite of accumulation of evidences which suggest a significant association between low HDL-C and cardiovascular diseases, effects of dietary factors on HDL metabolism remained largely unknown. There may be interracial differences in effects of dietary factors on HDL metabolism. Here we reviewed published articles about effects of carbohydrate and dietary fiber intake, glycemic index (GI) and glycemic load (GL), on HDL-C metabolism, regarding meta-analyses and clinical studies performed in Asian population as important articles. Low carbohydrate intake, GI and GL may be beneficially associated with HDL metabolism. Dietary fiber intake may be favorably associated with HDL metabolism in Asian populations.

  5. Discharge from total populations of Ia and II afferent fibers in the cat's deefferented medial gastrocnemius muscle during static stretch.

    Science.gov (United States)

    Botterman, B R; Eldred, E

    1983-04-01

    Estimates were made of the changing volumes of discharge arising from the total populations of Ia and II spindle afferent fibers in the cat's deefferented medial gastrocnemius as the muscle was extended stepwise over its excursion range. The estimates were based on values reported elsewhere for (i) the incidence of active units and (ii) their rates of discharge at static muscle lengths normalized against the excursion range of the particular muscle, together with (iii) the numbers of Ia and II afferent fibers in the medial gastrocnemius as derived from a critical review of published information. Curves representing the total discharge of the two afferent types are similar and show three phases: an initial level of spontaneous activity, a somewhat curvilinear rise associated with early recruitment of units during stretch, and rectilinear increase after full recruitment. There was no appearance of saturation. Completion of recruitment of both types of units occurred about halfway in the extension range of the passive muscle. Over most of the excursion range, inflow from the group II population was about one-third greater than that from the Ia units.

  6. Direct Surface Tension Measurements of Individual Sub-Micrometer Particles Using Atomic Force Microscopy.

    Science.gov (United States)

    Lee, Hansol D; Estillore, Armando D; Morris, Holly S; Ray, Kamal K; Alejandro, Aldair; Grassian, Vicki H; Tivanski, Alexei V

    2017-11-02

    Understanding the role of sea spray aerosol (SSA) on climate and the environment is of great interest due to their high number concentration throughout the Earth's atmosphere. Despite being of fundamental importance, direct surface tension measurements of SSA relevant sub-micrometer particles are rare, largely due to their extremely small volumes. Herein, atomic force microscopy (AFM) is used to directly measure the surface tension of individual sub-micrometer SSA particle mimics at ambient temperature and varying relative humidity (RH). Specifically, we probed both atmospherically relevant and fundamentally important model systems including electrolyte salts, dicarboxylic acids, and saccharides as single components and mixtures. Our results show that the single particle surface tension depends on RH or solute mole percentage and chemical composition. Moreover, for liquid droplets at and below 100 Pa s in viscosity, or at corresponding RH, we show good agreement between the AFM single particle and the bulk solution surface tension measurements at overlapping concentration ranges. Thus, direct surface tension measurements of individual particles using AFM is shown over a wide range of chemical systems as a function of RH, solute mole percentage, and viscosity than previously reported.

  7. Sub-micrometer adhesion modulation on polymer surfaces containing gratings produced by two-beam interference

    Energy Technology Data Exchange (ETDEWEB)

    Csete, M. [Department of Optics and Quantum Electronics, University of Szeged, Dom ter 9, H-6720 Szeged (Hungary)]. E-mail: mcsete@sol.cc.u-szeged.hu; Kresz, N. [Department of Optics and Quantum Electronics, University of Szeged, Dom ter 9, H-6720 Szeged (Hungary); Vass, Cs. [Department of Optics and Quantum Electronics, University of Szeged, Dom ter 9, H-6720 Szeged (Hungary); Kurdi, G. [Research Group on Laser Physics, University of Szeged, Dom ter 9, H-6720 Szeged (Hungary); Heiner, Zs. [Department of Optics and Quantum Electronics, University of Szeged, Dom ter 9, H-6720 Szeged (Hungary); Deli, M. [Laboratory of Molecular Neurobiology, Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences, Temesvari krt. 62, H-6726 Szeged (Hungary); Bor, Zs. [Department of Optics and Quantum Electronics, University of Szeged, Dom ter 9, H-6720 Szeged (Hungary); Marti, O. [Department of Experimental Physics, University of Ulm, Albert Einstein Allee 11, D-89069 Ulm (Germany)

    2005-12-15

    Grating-like structures having a period of 416 nm were produced on the surface of poly-carbonate films by two-beam interference realized by the fourth harmonic of Nd:Yag laser. The period of the structures was half of that the applied master grating, the ratio of the width of the valleys to the period was tuned by the intensity, the depth of the modulation was increased by the number of laser pulses. Pulsed force mode atomic force microscopy was applied to study the topography and the adhesion on structured surfaces with sub-micrometer resolution. The adhesion modulation caused by the topography was calculated along line cross-sections of the AFM pictures taking into account the tip and surface geometry. The separation of the effects of the topography and the laser-induced material changes proved that the adhesion is increased at the areas illuminated by laser beam having a fluence above the melting threshold. The laser-induced material changes cause an additional adhesion increase at the valleys of the structure. It was shown that the adherence of albumin results in dense packing on poly-carbonate surface parts having sub-micrometer periodic adhesion modulation.

  8. Reaction of iodine atoms with submicrometer squalane and squalene droplets: mechanistic insights into heterogeneous reactions.

    Science.gov (United States)

    Popolan-Vaida, Denisia M; Wilson, Kevin R; Leone, Stephen R

    2014-11-13

    The gas-phase reaction of iodine atoms with hydrocarbon molecules is energetically unfavorable, and there is no direct evidence for iodinated product formation by either H abstraction or I addition reactions at ambient temperature. Here we consider the possible heterogeneous reaction of I atoms with submicrometer droplets composed of a saturated alkane, squalane (Sq), and an unsaturated alkene, squalene (Sqe). The investigations are performed in an atmospheric pressure photochemical flow tube reactor in conjunction with a vacuum ultraviolet photoionization aerosol mass spectrometer and a scanning mobility particle sizer. Squalane, a branched alkane, is unreactive toward I atoms within the signal-to-noise, and an upper limit of the effective reactive uptake coefficient is estimated to be γI(Sq) ≤ 8.58 × 10(–7). In contrast, the reaction of I atoms with unsaturated submicrometer squalene droplets results in observable iodinated squalene products. The effective reactive uptake coefficient of I atom with squalene particles is determined to be γI(Sqe) = (1.20 ± 0.52) × 10(–4) at an average I concentration of 1.5 × 10(14) molecules·cm(–3).

  9. Thermoelectric properties of Si/CoSi2 sub-micrometer composites prepared by melt-spinning technique

    Science.gov (United States)

    Xie, Jun; Ohishi, Yuji; Ichikawa, Satoshi; Muta, Hiroaki; Kurosaki, Ken; Yamanaka, Shinsuke

    2017-05-01

    We here report on the influence of CoSi2 precipitates on the thermoelectric properties of heavily doped p-type Si. A simple self-assembly process using a melt-spinning technique followed by spark plasma sintering is introduced to prepare bulk Si/CoSi2 composites with a nominal composition of (Si0.99B0.01)95Co5. Scanning and transmission electron microscopy observations present clear evidence of a sub-micrometer CoSi2 phase with a size ranging from 50 to 500 nm. These sub-micrometer precipitates resulted in a retention of the high electrical performance of heavily doped Si, while simultaneously reducing thermal conductivity by over 20% compared to a coarse CoSi2 phase (1-10 μm) in a comparative sample prepared by arc melting and spark plasma sintering. As a result, a figure of merit ZT value of 0.21 at 1073 K was achieved in the sub-micrometer Si/CoSi2, an increase of 16% compared with the ZT value for homogeneous p-type Si with a similar carrier concentration. This suggests that the self-assembled sub-micrometer inclusions effectively enhanced the thermoelectric performance of Si-based thermoelectric materials.

  10. Seasonal variation of aliphatic amines in marine sub-micrometer particles at the Cape Verde islands

    Directory of Open Access Journals (Sweden)

    H. Herrmann

    2009-12-01

    Full Text Available Monomethylamine (MA, dimethylamine (DMA and diethylamine (DEA were detected at non-negligible concentrations in sub-micrometer particles at the Cap Verde Atmospheric Observatory (CVAO located on the island of São Vicente in Cape Verde during algal blooms in 2007. The concentrations of these amines in five stage impactor samples ranged from 0–30 pg m−3 for MA, 130–360 pg m−3 for DMA and 5–110 pg m−3 for DEA during the spring bloom in May 2007 and 2–520 pg m−3 for MA, 100–1400 pg m−3 for DMA and 90–760 pg m−3 for DEA during an unexpected winter algal bloom in December 2007. Anomalously high Saharan dust deposition and intensive ocean layer deepening were found at the Atmospheric Observatory and the associated Ocean Observatory during algal bloom periods. The highest amine concentrations in fine particles (impactor stage 2, 0.14–0.42 μm indicate that amines are likely taken up from the gas phase into the acidic sub-micrometer particles. The contribution of amines to the organic carbon (OC content ranged from 0.2–2.5% C in the winter months, indicating the importance of this class of compounds to the carbon cycle in the marine environment. Furthermore, aliphatic amines originating from marine biological sources likely contribute significantly to the nitrogen content in the marine atmosphere. The average contribution of the amines to the detected nitrogen species in sub-micrometer particles can be non-negligible, especially in the winter months (0.1% N–1.5% N in the sum of nitrate, ammonium and amines. This indicates that these smaller aliphatic amines can be important for the carbon and the nitrogen cycles in the remote marine environment.

  11. Quantification of retinal nerve fiber layer thickness using spectral domain optical coherence tomography in normal Indian population

    Directory of Open Access Journals (Sweden)

    Tarannum Mansoori

    2012-01-01

    Full Text Available The purpose of this study was to measure peripapillary retinal nerve fiber layer thickness (RNFLT using spectral domain optical coherence tomography (SD-OCT in normal Indian eyes, for which, 210 normal volunteers were recruited. One eye of each subject underwent RNFL scanning at 3.4 mm circle diameter around optic nerve using SD OCT. The data were analyzed to determine RNFLT in the sample population and its variation with age and gender. The average peripapillary RNFLT was 114.03 ± 9.59 μm. There was no effect of gender on RNFLT parameters. Age had significant negative correlation with average (P = 0.005, superior (P = 0.04, temporal (P = 0.049, and nasal quadrants (P = 0.01 RNFLT. Inferior quadrant RNFLT also had a negative correlation with age, but it was not statistically significant (P = 0.15.

  12. Electro-optical and dielectric characterization of submicrometer-sized PDLC films

    Science.gov (United States)

    Krishna Koduru, Hari

    2017-01-01

    This report concerns thin films (25 µm thickness) of polymer-dispersed liquid crystal (PDLC) composites having submicrometer-sized nematic liquid crystal domains. Such PDLC films were prepared by performing photo-induced phase separation of mixed soft material composed from the room-temperature nematic liquid crystal 4-n-heptyl cyanobiphenyl (7CB) and photo-curable polymer NOA-65. Being of interest for electro-optical (EO) and other applications driven by alternating-current electric field, the produced composites were studied by EO measurements and complex impedance spectroscopy. For the examined soft-solid composite material with a large content of submicro-confined nematic, was obtained information about the dielectric permittivity and molecular dynamics, useful for practice.

  13. Formation and Order Enhancement of submicrometer and nanoscale features in thin films

    Science.gov (United States)

    Lau, Cindy Yee Cin

    The wide applications of two-dimensionally ordered submicrometer features have stimulated the development of cheap and fast fabrication techniques throughout the years. We showed that electrohydrodynamic patterning, which is known to produce ordered pillar arrays on polymer thin film at micrometer scale, could be extended to create submicrometer features as small as 351 +/- 78 nm quickly and economically. However, the dielectric breakdown of polymer imposed a fundamental limit on further reducing the feature size to nanoscale. We overcame the limited resolution by bottom-up colloidal assemblies which used nanoparticles between 49.8 +/- 8.7 nm and 117.6 +/- 6.7 nm as building blocks. By employing flow-coating deposition, we were able to control the deposited amount and achieve large area of uniform colloidal film easily. However, the single crystalline domain of a close-packed monolayer remained limited due to the restricted time for ordering through lateral capillary pressure before the particles were in contact. That motivated the deposition of initially ordered colloidal dispersions, attained through deionizing the solutions to extend electrostatic double layers for long-range repulsion. Although the deposited amount agreed reasonably well with our model adapted for a power-law fluid, the shear-thinning viscosity and final structure both revealed that the initial order was destroyed at high shear. On the other hand, the particle order was partially sustained during low shear depositions, yet the domain size was not particularly extensive. We attributed the limited order to the high compressibility of double layer during the evaporation phase. To improve the order of a colloidal monolayer, we investigated the effect of excess free ligands on 8.0 +/- 0.3 nm gold nanoparticles deposited by the Langmuir-Blodgett technique. We showed that the excess ligands, oleylamine, not only improved the order of particles that were deposited together with them, but could also

  14. Secondary submicrometer impact cratering on the surface of asteroid 25143 Itokawa

    Science.gov (United States)

    Harries, Dennis; Yakame, Shogo; Karouji, Yuzuru; Uesugi, Masayuki; Langenhorst, Falko

    2016-09-01

    Particle RA-QD02-0265 returned by the Hayabusa spacecraft from near-Earth asteroid 25143 Itokawa displayed a unique abundance of submicrometer-sized (≤500 nm) impact craters, which are rarely observed among the Hayabusa samples. The particle consists of intensely twinned diopside that was subjected to a large-scale shock event before exposure to the space environment on the surface of 25143 Itokawa. Intense (sub-)micrometer-scale impact cratering may suggest a long surface exposure and, hence, a long residence time of regolith material on the surface of small asteroids, bearing implications for the dynamical evolution of these bodies. However, our combined FE-SEM and FIB/TEM study shows that the degree of solar wind-induced space weathering and the accumulation of solar flare tracks are not exceptionally different from other Hayabusa particles with surface exposure ages estimated to be less than 1 ka. A 500 nm wide crater on the surface of RA-QD02-0265 exhibits microstructural damage to a depth of 400 nm below its floor and contains residues of Fe-Ni metal, excluding a formation by space craft exhausts or curatorial handling. The geometrical clustering among the 15 craters is unlikely random, and we conclude that the craters have formed through the impacts of secondary projectiles (at least partially Fe-Ni metal) created in a nearby (micro-)impact event. Besides structural damage by the solar wind and deposition of impact-generated melts and vapors, secondary impact cratering on the submicrometer-scale is another potential mechanism to modify the spectral properties of individual regolith grains. The lack of extensively exposed regolith grains supports a dynamic regolith on the surface of 25143 Itokawa.

  15. Highly thermally conductive and mechanically strong graphene fibers.

    Science.gov (United States)

    Xin, Guoqing; Yao, Tiankai; Sun, Hongtao; Scott, Spencer Michael; Shao, Dali; Wang, Gongkai; Lian, Jie

    2015-09-04

    Graphene, a single layer of carbon atoms bonded in a hexagonal lattice, is the thinnest, strongest, and stiffest known material and an excellent conductor of heat and electricity. However, these superior properties have yet to be realized for graphene-derived macroscopic structures such as graphene fibers. We report the fabrication of graphene fibers with high thermal and electrical conductivity and enhanced mechanical strength. The inner fiber structure consists of large-sized graphene sheets forming a highly ordered arrangement intercalated with small-sized graphene sheets filling the space and microvoids. The graphene fibers exhibit a submicrometer crystallite domain size through high-temperature treatment, achieving an enhanced thermal conductivity up to 1290 watts per meter per kelvin. The tensile strength of the graphene fiber reaches 1080 megapascals. Copyright © 2015, American Association for the Advancement of Science.

  16. Dietary fiber intake and risk of cardiovascular disease in the Japanese population: the Japan Public Health Center-based study cohort

    OpenAIRE

    Kokubo, Y; ISO, H; Saito, I; Yamagishi, K.; Ishihara, J.; Inoue, M.; Tsugane, S

    2011-01-01

    Background/Objectives:There has been no study with regard to the association between dietary fibers and the incidence of stroke and coronary heart disease (CHD) in Asia. We investigated the association between dietary fiber and the risk of cardiovascular disease (CVD), which we defined as stroke or CHD, in a Japanese population.Subjects/Methods:We studied 86 387 Japanese subjects (age 45–65 years, without CVD or cancer in 1995 as Cohort I and in 1998 as Cohort II) and used a self-administered...

  17. Performance of combination drug and hygroscopic excipient submicrometer particles from a softmist inhaler in a characteristic model of the airways.

    Science.gov (United States)

    Longest, P Worth; Tian, Geng; Li, Xiang; Son, Yoen-Ju; Hindle, Michael

    2012-12-01

    Excipient enhanced growth (EEG) of inhaled submicrometer pharmaceutical aerosols is a recently proposed method intended to significantly reduce extrathoracic deposition and improve lung delivery. The objective of this study was to evaluate the size increase of combination drug and hygroscopic excipient particles in a characteristic model of the airways during inhalation using both in vitro experiments and computational fluid dynamic (CFD) simulations. The airway model included a characteristic mouth-throat (MT) and upper tracheobronchial (TB) region through the third bifurcation and was enclosed in a chamber geometry used to simulate the thermodynamic conditions of the lungs. Both in vitro results and CFD simulations were in close agreement and indicated that EEG delivery of combination submicrometer particles could nearly eliminate MT deposition for inhaled pharmaceutical aerosols. Compared with current inhalers, the proposed delivery approach represents a 1-2 order of magnitude reduction in MT deposition. Transient inhalation was found to influence the final size of the aerosol based on changes in residence times and relative humidity values. Aerosol sizes following EEG when exiting the chamber (2.75-4.61 μm) for all cases of initial submicrometer combination particles were equivalent to or larger than many conventional pharmaceutical aerosols that frequently have MMADs in the range of 2-3 μm.

  18. Characterization of dual-phase steel microstructure by combined submicrometer EBSD and EPMA carbon measurements.

    Science.gov (United States)

    Pinard, Philippe T; Schwedt, Alexander; Ramazani, Ali; Prahl, Ulrich; Richter, Silvia

    2013-08-01

    Electron backscatter diffraction (EBSD) and electron probe microanalysis (EPMA) measurements are combined to characterize an industrial produced dual-phase steel containing some bainite fraction. High-resolution carbon mappings acquired on a field emission electron microprobe are utilized to validate and improve the identification of the constituents (ferrite, martensite, and bainite) performed by EBSD using the image quality and kernel average misorientation. The combination eliminates the ambiguity between the identification of bainite and transformation-induced dislocation zones, encountered if only the kernel average misorientation is considered. The detection of carbon in high misorientation regions confirms the presence of bainite. These results are corroborated by secondary electron images after nital etching. Limitations of this combined method due to differences between the spatial resolution of EBSD and EPMA are assessed. Moreover, a quantification procedure adapted to carbon analysis is presented and used to measure the carbon concentration in martensite and bainite on a submicrometer scale. From measurements on reference materials, this method gives an accuracy of 0.02 wt% C and a precision better than 0.05 wt% C despite unavoidable effects of hydrocarbon contamination.

  19. Sub-micrometer resolution proximity X-ray microscope with digital image registration.

    Science.gov (United States)

    Chkhalo, N I; Pestov, A E; Salashchenko, N N; Sherbakov, A V; Skorokhodov, E V; Svechnikov, M V

    2015-06-01

    A compact laboratory proximity soft X-ray microscope providing submicrometer spatial resolution and digital image registration is described. The microscope consists of a laser-plasma soft X-ray radiation source, a Schwarzschild objective to illuminate the test sample, and a two-coordinate detector for image registration. Radiation, which passes through the sample under study, generates an absorption image on the front surface of the detector. Optical ceramic YAG:Ce was used to convert the X-rays into visible light. An image was transferred from the scintillator to a charge-coupled device camera with a Mitutoyo Plan Apo series lens. The detector's design allows the use of lenses with numerical apertures of NA = 0.14, 0.28, and 0.55 without changing the dimensions and arrangement of the elements of the device. This design allows one to change the magnification, spatial resolution, and field of view of the X-ray microscope. A spatial resolution better than 0.7 μm and an energy conversion efficiency of the X-ray radiation with a wavelength of 13.5 nm into visible light collected by the detector of 7.2% were achieved with the largest aperture lens.

  20. Evolution of Submicrometer Organic Aerosols during a Complete Residential Coal Combustion Process.

    Science.gov (United States)

    Zhou, Wei; Jiang, Jingkun; Duan, Lei; Hao, Jiming

    2016-07-19

    In the absence of particulate matter (PM) control devices, residential coal combustion contributes significantly to ambient PM pollution. Characterizing PM emissions from residential coal combustion with high time resolution is beneficial for developing control policies and evaluating the environmental impact of PM. This study reports the evolution of submicrometer organic aerosols (OA) during a complete residential coal combustion process, that is, from fire start to fire extinction. Three commonly used coal types (bituminous, anthracite, and semicoke coals) were evaluated in a typical residential stove in China. For all three types of coal, the OA emission exhibited distinct characteristics in the four stages, that is, ignition, fierce combustion, relatively stable combustion, and ember combustion. OA emissions during the ignition stage accounted for 58.2-85.4% of the total OA emission of a complete combustion process. The OA concentration decreased rapidly during the fierce combustion stage and remained low during the relatively stable combustion stage. During these two stages, a significant ion peak of m/z 73 from organic acids were observed. The degree of oxidation of the OA increased from the first stage to the last stage. Implications for ambient OA source-apportionment and residential PM emission characterization and control are discussed.

  1. Single molecule analysis of bacterial polymerase chain reaction products in submicrometer fluidic channels.

    Science.gov (United States)

    Stavis, Samuel M; Corgié, Stéphane C; Cipriany, Benjamin R; Craighead, Harold G; Walker, Larry P

    2007-09-20

    Laser induced fluorescence in submicrometer fluidic channels was used to characterize the synthesis of polymerase chain reaction (PCR) products from a model bacterial system in order to explore the advantages and limitations of on chip real time single molecule PCR analysis. Single oligonucleotide universal bacterial primers and PCR amplicons from the 16S rDNA of Thermobifida fusca (325 bp) were directly detected at all phases of the reaction with low sample consumption and without post-amplification purification or size screening. Primers were fluorescently labeled with single Alexa Fluor 488 or Alexa Fluor 594 fluorophores, resulting in double labeled, two color amplicons. PCR products were driven electrokinetically through a fused silica channel with a 250 nm by 500 nm rectangular cross section. Lasers with 488 nm and 568 nm wavelengths were focused and overlapped on the channel for fluorescence excitation. All molecules entering the channel were rapidly and uniformly analyzed. Photon burst analysis was used to detect and identify individual primers and amplicons, and fluorescence correlation and cross-correlation spectroscopy were used to account for analyte flow speed. Conventional gel and capillary electrophoresis were also used to characterize the PCR amplification, and the results of differences in detection sensitivity and analyte discrimination were examined. Limits were imposed by the purity and labeling efficiency of the PCR reagents, which must be improved in parallel with increases in detection sensitivity.

  2. A linear piezoelectric stepper motor with submicrometer step size and centimeter travel range.

    Science.gov (United States)

    Judy, J W; Polla, D L; Robbins, W P

    1990-01-01

    A linear stepper motor capable of submicrometer controlled movement has been constructed using the piezoelectric material lead zirconate titanate (PZT). This motor consists of a 25.4-mmx12.7-mmx1.6-mm piezoelectric driving element connected between a glider base and an attached load. The device is inset in a trench to constrain motion to one dimension. An electrode on the bottom of the glider is used with an electrode on the top of the trench to implement an electrostatic clamp. This clamp enables the stepper motor to climb slopes of up to 12 degrees , whereas without the clamp only slopes of 6 degrees or less are tolerated. A linear inertial sliding motion can be achieved by expanding and contracting the piezoelectric bar, but the addition of the electrostatic clamp enhances the movement capabilities of the glider by the periodic clamping and unclamping of the glider. Glider velocities of 5.7-476 mum/s are measured by timing the movement of the glider over a 1.0-mm portion of the track through an optical microscope. Displacement steps of 0.07-1.1 mum are calculated by dividing the measured glider velocity by the frequency of the applied voltage pulses. Displacement step size and glider velocity are controlled by the application of PZT extension voltages ranging from +/-(60-340) V.

  3. High Gain Submicrometer Optical Amplifier at Near-Infrared Communication Band.

    Science.gov (United States)

    Wang, Xiaoxia; Zhuang, Xiujuan; Yang, Sen; Chen, Yu; Zhang, Qinglin; Zhu, Xiaoli; Zhou, Hong; Guo, Pengfei; Liang, Junwu; Huang, Yu; Pan, Anlian; Duan, Xiangfeng

    2015-07-10

    Nanoscale near-infrared optical amplification is important but remains a challenge to achieve. Here we report a unique design of silicon and erbium silicate core-shell nanowires for high gain submicrometer optical amplification in the near-infrared communication band. The high refraction index silicon core is used to tightly confine the optical field within the submicron structures, and the single crystalline erbium-ytterbium silicates shell is used as the highly efficient gain medium. Both theoretical and experimental results show that, by systematically tuning the core diameter and shell thickness, a large portion of the optical power can be selectively confined to the erbium silicate shell gain medium to enable a low loss waveguide and high gain optical amplifier. Experimental results further demonstrate that an optimized core-shell nanowire can exhibit an excellent net gain up to 31  dB mm(-1), which is more than 20 times larger than the previously reported best results on the micron-scale optical amplifiers.

  4. Associations of soluble fiber, whole fruits/vegetables, and juice with plasma Beta-carotene concentrations in a free-living population of breast cancer survivors.

    Science.gov (United States)

    Kolodziejczyk, Julia K; Flatt, Shirley W; Natarajan, Loki; Patterson, Ruth; Pierce, John P; Norman, Gregory J

    2012-01-01

    Soluble fiber and the physical state of fruits/vegetables affect plasma ß-carotene concentrations; however, most of this research was conducted in laboratory-based settings. These analyses investigated the relationship between soluble fiber and juiced versus whole fruits/vegetables to plasma ß-carotene concentrations in a free-living population. This cross-sectional analysis used 12-month follow-up data from the Women's Healthy Eating & Living Study (1995-2006), a study to improve diet in breast cancer survivors in the Western United States. The dietary nutrients considered in this analysis included intake of soluble fiber (g), ß-carotene from fruit/vegetable juice (mg), and ß-carotene from whole fruits/vegetables (mg). A linear regression model was used to assess the relationship of the variables to plasma ß-carotene concentrations. Out of 3,088 women enrolled in the Women's Healthy Eating & Living Study, 2,397 women had complete data (mean age = 54). The final model accounted for approximately 49% of the explained variance in plasma ß-carotene concentrations. Fruit/vegetable juice had the largest positive relation to plasma ß-carotene concentrations (standardized parameter estimate = 0.23, p vegetables (standardized parameter estimate = 0.09, p fiber may inhibit ß-carotene absorption; therefore, consumption of juice may increase plasma ß-carotene concentrations more than whole fruits/vegetables in free-living populations.

  5. Realization of fiber-based laser Doppler vibrometer with serrodyne frequency shifting.

    Science.gov (United States)

    Li, Yanlu; Meersman, Stijn; Baets, Roel

    2011-06-10

    We demonstrate a laser Doppler vibrometer (LDV) based on the serrodyne frequency shifting technique. A proof-of-principle system is implemented on the basis of fiber-optic components but opens the way toward an ultracompact integrated LDV system on a silicon chip. With a low laser power of 50  μW, the serrodyne LDV was able to measure submicrometer vibrations with frequencies in the audio range.

  6. Effects of Carbohydrate and Dietary Fiber Intake, Glycemic Index and Glycemic Load on HDL Metabolism in Asian Populations

    National Research Council Canada - National Science Library

    Yanai, Hidekatsu; Katsuyama, Hisayuki; Hamasaki, Hidetaka; Abe, Shinichi; Tada, Norio; Sako, Akahito

    2014-01-01

    .... There may be interracial differences in effects of dietary factors on HDL metabolism. Here we reviewed published articles about effects of carbohydrate and dietary fiber intake, glycemic index (GI) and glycemic load (GL...

  7. Ten-year trends in fiber and whole grain intakes and food sources for the United States population: National Health and Nutrition Examination Survey 2001-2010.

    Science.gov (United States)

    McGill, Carla R; Fulgoni, Victor L; Devareddy, Latha

    2015-02-09

    Current U.S. dietary guidance includes recommendations to increase intakes of both dietary fiber and whole grain (WG). This study examines fiber and WG intakes, food sources and trends from 2001 to 2010 based on National Health and Nutrition Examination Survey (NHANES) data for children/adolescents (n=14,973) and adults (n=24,809). Mean fiber intake for children/adolescents was 13.2 (±0.1) g/day. Mean fiber intake for adults 19-50 years (y) was 16.1 (±0.2) g/day and for adults 51+ was 16.1 (±0.2) g/day. There were significant increases in fiber intake from 2001-2010 for children/adolescents and for adults 51+y. Mean WG intake for children/adolescents was 0.52 (±0.01) oz eq/day. Mean WG intake for adults 19-50 y was 0.61 (±0.02) oz eq/day and for adults 51+0.86 (±0.02) oz eq/day. There were no significant changes in WG intake for any age group from 2001-2010. The main food groups contributing to dietary fiber intake for children/adolescents were vegetables (16.6%), grain mixtures (16.3%), other foods (15.8%) and fruits (11.3%). For adults 19+y, the main sources of dietary fiber were vegetables (22.6%), other foods (14.3%), grain mixtures (12.0%) and fruits (11.1%). Major WG sources for children/adolescents included ready-to-eat cereals (RTEC) (31%), yeast breads/rolls (21%) and crackers and salty grain snacks (21%). The main sources of WG for adults 19+ were yeast breads/rolls (27%), RTEC (23%) and pastas/cooked cereals/rice (21%). Recommending cereals, breads and grain mixtures with higher contents of both dietary fiber and WG, along with consumer education, could increase intakes among the United States (U.S.) population.

  8. Ten-Year Trends in Fiber and Whole Grain Intakes and Food Sources for the United States Population: National Health and Nutrition Examination Survey 2001–2010

    Directory of Open Access Journals (Sweden)

    Carla R. McGill

    2015-02-01

    Full Text Available Current U.S. dietary guidance includes recommendations to increase intakes of both dietary fiber and whole grain (WG. This study examines fiber and WG intakes, food sources and trends from 2001 to 2010 based on National Health and Nutrition Examination Survey (NHANES data for children/adolescents (n = 14,973 and adults (n = 24,809. Mean fiber intake for children/adolescents was 13.2 (±0.1 g/day. Mean fiber intake for adults 19–50 years (y was 16.1 (±0.2 g/day and for adults 51+ was 16.1 (±0.2 g/day. There were significant increases in fiber intake from 2001–2010 for children/adolescents and for adults 51+ y. Mean WG intake for children/adolescents was 0.52 (±0.01 oz eq/day. Mean WG intake for adults 19–50 y was 0.61 (±0.02 oz eq/day and for adults 51+ 0.86 (±0.02 oz eq/day. There were no significant changes in WG intake for any age group from 2001–2010. The main food groups contributing to dietary fiber intake for children/adolescents were vegetables (16.6%, grain mixtures (16.3%, other foods (15.8% and fruits (11.3%. For adults 19+ y, the main sources of dietary fiber were vegetables (22.6%, other foods (14.3%, grain mixtures (12.0% and fruits (11.1%. Major WG sources for children/adolescents included ready-to-eat cereals (RTEC (31%, yeast breads/rolls (21% and crackers and salty grain snacks (21%. The main sources of WG for adults 19+ were yeast breads/rolls (27%, RTEC (23% and pastas/cooked cereals/rice (21%. Recommending cereals, breads and grain mixtures with higher contents of both dietary fiber and WG, along with consumer education, could increase intakes among the United States (U.S. population.

  9. X-Ray Nanofocus CT: Visualising Of Internal 3D-Structures With Submicrometer Resolution

    Science.gov (United States)

    Weinekoetter, Christian

    2008-09-01

    High-resolution X-ray Computed Tomography (CT) allows the visualization and failure analysis of the internal micro structure of objects—even if they have complicated 3D-structures where 2D X-ray microscopy would give unclear information. During the past several years, computed tomography has progressed to higher resolution and quicker reconstruction of the 3D-volume. Most recently it even allows a three-dimensional look into the inside of materials with submicron resolution. With the use of nanofocus® tube technology, nanoCT®-systems are pushing forward into application fields that were exclusive to high cost and rare available synchrotron techniques. The study was performed with the new nanotom, a very compact laboratory system which allows the analysis of samples up to 120 mm in diameter and weighing up to 1 kg with exceptional voxel-resolution down to volumes, the nanotom® includes a variety of effective software tools to reduce ring-artefacts and correct beam hardenings or drift effects which occurred during data acquisition. The resulting CT volume data set can be displayed in various ways, for example by virtual slicing and sectional views in any direction of the volume. By the fact that this requires only a mouse click, this technique will substitute destructive mechanical slicing and cutting in many applications. The initial CT results obtained with the nanotom® demonstrate that it is now possible to analyze the three-dimensional micro structure of materials and small objects with submicrometer resolution. Any internal difference in material, density or porosity within a sample can be visualized and data like distances can be measured. NanoCT® widely expands the spectrum of detectable micro-structures. The nanotom® opens a new dimension of 3D-microanalysis and will replace more destructive methods—saving costs and time per sample inspected.

  10. Zro2 Thin-Film-Based Sapphire Fiber Temperature Sensor

    OpenAIRE

    Wang, Jiajun; Lally, Evan M; Wang, Xiaoping; Gong, Jianmin; Pickrell, Gary R.; Wang, Anbo

    2012-01-01

    A submicrometer-thick zirconium dioxide film was deposited on the tip of a polished C-plane sapphire fiber to fabricate a temperature sensor that can work to an extended temperature range. Zirconium dioxide was selected as the thin film material to fabricate the temperature sensor because it has relatively close thermal expansion to that of sapphire, but more importantly it does not react appreciably with sapphire up to 1800 degrees C. In order to study the properties of the deposited thin fi...

  11. Scatterometry for semiconductor sub-micrometer and nanometer critical dimension metrology

    Science.gov (United States)

    Al-Assaad, Rayan M.

    Scatterometry1 is one optical measurement technique that has been explored extensively for semiconductor sub-micrometer dimensional metrology. The technique refers to the measurements of reflected power upon the interaction of an incident beam with some periodic surface (grating). The characteristics of the diffractive surface affect directly the acquired measurements. Therefore it is possible to resolve some information about the grating line profile and dimensions from the measurements, which is referred to as the inverse scatterometry problem. As technology is continuously pushing lithographic processes to sub-nanometer precision2, aspects of the inverse scatterometry problem related to the accurate estimation and modeling of errors and the enhancement of the optimization methods become of great importance. For this purpose the effects of measurement errors on the estimated grating profile are analyzed in this dissertation and optimization methods are proposed to improve the accuracies in the estimated geometrical parameters for various grating profiles in real experimental conditions. A technique based on the information content analysis of the measurement data is further suggested to reduce the number of measurements required without the loss in the solution accuracies resulting in lower cost and more suitable real time implementation. Theoretical and experimental results are presented to validate these studies where the solutions to the profile parameters are accomplished by implementing a linear regression technique3. In addition a new scheme is proposed to address resolving more difficult profile parameters with sub-wavelength dimensions (sub-100 nm) that are until now subject to ongoing investigation with inconclusive results. The proposed approach consists of using a large number of angular reflectance measurements with linearly polarized TM incidence. In the case where the profile dimensions are many times smaller than the light wavelength, the parameter

  12. Surface organic monolayers control the hygroscopic growth of submicrometer particles at high relative humidity.

    Science.gov (United States)

    Ruehl, Christopher R; Wilson, Kevin R

    2014-06-05

    Although many organic molecules commonly found in the atmosphere are known to be surface-active in macroscopic aqueous solutions, the impact of surface partitioning of organic molecules to a microscopic aqueous droplet interface remains unclear. Here we measure the droplet size formed, at a relative humidity (∼99.9%) just below saturation, on submicrometer particles containing an ammonium sulfate core and an organic layer of a model compound of varying thickness. The 12 model organic compounds are a series of dicarboxylic acids (C3 to C10), cis-pinonic, oleic, lauric, and myristic acids, which represent a broad range in solubility from miscible (malonic acid) to insoluble. The variation in droplet size with increasing organic aerosol fraction cannot be explained by assuming the organic material is dissolved in the bulk droplet. Instead, the wet droplet diameters exhibit a complex and nonlinear dependence on organic aerosol volume fraction, leading to hygroscopic growth that is in some cases smaller and in others larger than that predicted by bulk solubility alone. For palmitic and stearic acid, small droplets at or below the detection limit of the instrument are observed, indicating significant kinetic limitations for water uptake, which are consistent with mass accommodation coefficients on the order of 10(-4). A model based on the two-dimensional van der Waals equation of state is used to explain the complex droplet growth with organic aerosol fraction and dry diameter. The model suggests that mono- and dicarboxylic acids with limited water solubility partition to the droplet surface and reduce surface tension only after a two-dimensional condensed monolayer is formed. Two relatively soluble compounds, malonic and glutaric acid, also appear to form surface phases, which increase hygroscopicity. There is a clear alternation in the threshold for droplet growth observed for odd and even carbon number diacids, which is explained in the model by differences in the

  13. Fiber webs

    Science.gov (United States)

    Roger M. Rowell; James S. Han; Von L. Byrd

    2005-01-01

    Wood fibers can be used to produce a wide variety of low-density three-dimensional webs, mats, and fiber-molded products. Short wood fibers blended with long fibers can be formed into flexible fiber mats, which can be made by physical entanglement, nonwoven needling, or thermoplastic fiber melt matrix technologies. The most common types of flexible mats are carded, air...

  14. Focusing and imaging with increased numerical apertures through multimode fibers with micro-fabricated optics

    KAUST Repository

    Bianchi, Silvio

    2013-01-01

    The use of individual multimode optical fibers in endoscopy applications has the potential to provide highly miniaturized and noninvasive probes for microscopy and optical micromanipulation. A few different strategies have been proposed recently, but they all suffer from intrinsically low resolution related to the low numerical aperture of multimode fibers. Here, we show that two-photon polymerization allows for direct fabrication of micro-optics components on the fiber end, resulting in an increase of the numerical aperture to a value that is close to 1. Coupling light into the fiber through a spatial light modulator, we were able to optically scan a submicrometer spot (300 nm FWHM) over an extended region, facing the opposite fiber end. Fluorescence imaging with improved resolution is also demonstrated. © 2013 Optical Society of America.

  15. Synthesis and Characterization of Zirconium Tungstate Ultra-Thin Fibers

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lifeng [South Dakota School of Mines and Technology; Howe, Jane Y [ORNL; Fong, Hao [South Dakota School of Mines and Technology; Zhang, Yan [Anhui Normal University, People' s Republic of China

    2009-01-01

    This study reports an innovative method of electrospinning followed by pyrolysis to synthesize zirconium tungstate (ZrW2O8), a material with negative coefficient of thermal expansion (CTE), in ultra-thin fiber form. Morphologies and microstructures of the as-electrospun precursor fibers, the heat-treated intermediate fibers, and the final ZrW2O8 ultra-thin fibers were characterized by SEM, XRD, and TEM. The ZrW2O8 ultra-thin fibers had diameters in the sub-micrometer range with aspect ratios larger than 100; these fibers were polycrystalline, and consisted of single crystalline ZrW2O8 crystallites with sizes of 30-50 nm and surface roughness of several nanometers. The ZrW2O8 ultra-thin fibers are expected to outperform spherically, cylindrically, and/or irregularly shaped polycrystalline ZrW2O8 particles for the development of composites with precisely controlled CTEs. Additionally, this reported method could be utilized as a general approach to convert nano-scaled inorganic particles into fibers.

  16. Natural fibers

    Science.gov (United States)

    Craig M. Clemons; Daniel F. Caulfield

    2005-01-01

    The term “natural fibers” covers a broad range of vegetable, animal, and mineral fibers. However, in the composites industry, it usually refers to wood fiber and agrobased bast, leaf, seed, and stem fibers. These fibers often contribute greatly to the structural performance of the plant and, when used in plastic composites, can provide significant reinforcement. Below...

  17. Influence of short chain organic acids and bases on the wetting properties and surface energy of submicrometer ceramic powders.

    Science.gov (United States)

    Neirinck, Bram; Soccol, Dimitri; Fransaer, Jan; Van der Biest, Omer; Vleugels, Jef

    2010-08-15

    The effect of short chained organic acids and bases on the surface energy and wetting properties of submicrometer alumina powder was assessed. The surface chemistry of treated powders was determined by means of Diffuse Reflectance Infrared Fourier Transform spectroscopy and compared to untreated powder. The wetting of powders was measured using a modified Washburn method, based on the use of precompacted powder samples. The geometric factor needed to calculate the contact angle was derived from measurements of the porous properties of the powder compacts. Contact angle measurements with several probe liquids before and after modification allowed a theoretical estimation of the surface energy based on the surface tension component theory. Trends in the surface energy components were linked to observations in infrared spectra. The results showed that the hydrophobic character of the precompacted powder depends on both the chain length and polar group of the modifying agent. Copyright 2010 Elsevier Inc. All rights reserved.

  18. Evaluation of retinal nerve fiber layer thickness parameters in myopic population using scanning laser polarimetry (GDxVCC).

    Science.gov (United States)

    Dada, Tanuj; Aggarwal, A; Bali, S J; Sharma, A; Shah, B M; Angmo, D; Panda, A

    2013-01-01

    Myopia presents a significant challenge to the ophthalmologist as myopic discs are often large, tilted, with deep cups and have a thinner neuroretinal rim all of which may mimic glaucomatous optic nerve head changes causing an error in diagnosis. To evaluate the retinal fiber layer (RNFL) thickness in low, moderate and high myopia using scanning laser polarimetry with variable corneal compensation (GDxVCC). One hundred eyes of 100 emmetropes, 30 eyes of low myopes (0 to - 4 D spherical equivalent(SE), 45 eyes with moderate myopia (- 4 to - 8D SE), and 30 eyes with high myopia (- 8 to - 15D SE) were subjected to retinal nerve fiber layer assessment using the scanning laser polarimetry (GDxVCC) in all subjects using the standard protocol. Subjects with IOP > 21 mm Hg, optic nerve head or visual field changes suggestive of glaucoma were excluded from the study. The major outcome parameters were temporal-superior-nasal-inferiortemporal (TSNIT) average, the superior and inferior average and the nerve fibre indicator (NFI). The TSNIT average (p = 0.009), superior (p = 0.001) and inferior average (p = 0.008) were significantly lower; the NFI was higher (P less than 0.001) in moderate myopes as compared to that in emmetropes. In high myopia the RNFL showed supranormal values; the TSNIT average, superior and inferior average was significantly higher(p less than 0.001) as compared to that in emmetropes. The RNFL measurements on scanning laser polarimetry are affected by the myopic refractive error. Moderate myopes show a significant thinning of the RNFL. In high myopia due to peripapillary chorioretinal atrophy and contribution of scleral birefringence, the RNFL values are abnormally high. These findings need to be taken into account while assessing and monitoring glaucoma damage in moderate to high myopes on GDxVCC. © NEPjOPH.

  19. Dislocation density and Burgers vector population in fiber-textured Ni thin films determined by high-resolution X-ray line profile analysis

    DEFF Research Database (Denmark)

    Csiszár, Gábor; Pantleon, Karen; Alimadadi, Hossein

    2012-01-01

    Nanocrystalline Ni thin films have been produced by direct current electrodeposition with different additives and current density in order to obtain 〈100〉, 〈111〉 and 〈211〉 major fiber textures. The dislocation density, the Burgers vector population and the coherently scattering domain size...... distribution are determined by high-resolution X-ray diffraction line profile analysis. The substructure parameters are correlated with the strength of the films by using the combined Taylor and Hall-Petch relations. The convolutional multiple whole profile method is used to obtain the substructure parameters...... in the different coexisting texture components. A strong variation of the dislocation density is observed as a function of the deposition conditions....

  20. Fiber biology

    Science.gov (United States)

    Cotton fiber cells arising from seed epidermis is the most important agricultural textile commodity in the world. To produce fully mature fibers, approximately two months of fiber developmental process are required. The timing of four distinctive fiber development stages consisting of initiation, ...

  1. Comparison of diagnostic capability of macular ganglion cell complex and retinal nerve fiber layer among primary open angle glaucoma, ocular hypertension, and normal population using Fourier-domain optical coherence tomography and determining their functional correlation in Indian population

    Directory of Open Access Journals (Sweden)

    Nabanita Barua

    2016-01-01

    Full Text Available Context: Analysis of diagnostic ability of macular ganglionic cell complex and retinal nerve fiber layer (RNFL in glaucoma. Aim: To correlate functional and structural parameters and comparing predictive value of each of the structural parameters using Fourier-domain (FD optical coherence tomography (OCT among primary open angle glaucoma (POAG and ocular hypertension (OHT versus normal population. Setting and Design: Single centric, cross-sectional study done in 234 eyes. Materials and Methods: Patients were enrolled in three groups: POAG, ocular hypertensive and normal (40 patients in each group. After comprehensive ophthalmological examination, patients underwent standard automated perimetry and FD-OCT scan in optic nerve head and ganglion cell mode. The relationship was assessed by correlating ganglion cell complex (GCC parameters with mean deviation. Results were compared with RNFL parameters. Statistical Analysis: Data were analyzed with SPSS, analysis of variance, t-test, Pearson′s coefficient, and receiver operating curve. Results: All parameters showed strong correlation with visual field (P 0.5 when compared with other parameters. None of the parameters showed significant diagnostic capability to detect OHT from normal population. In diagnosing early glaucoma from OHT and normal population, only inferior GCC had statistically significant AUC value (0.715. Conclusion: In this study, GCC and RNFL parameters showed equal predictive capability in perimetric versus normal group. In early stage, inferior GCC was the best parameter. In OHT population, single day cross-sectional imaging was not valuable.

  2. [Population-genetic structure of beaver (Castor fiber L., 1758) communities and estimation of effective reproductive size Ne of an elementary population].

    Science.gov (United States)

    2004-07-01

    The absence of panmixia at all hierarchical levels of the European beaver communities down to individual families implies a complex organization of the population-genetic structures of the species, in particular, a large intergroup component of gene diversity in the populations. Testing this assumption by analysis of 39 allozyme loci in the communities of reintroduced beaver from the Vyatka river basin (Kirov oblast) has shown that only the beaver colonies exhibit high intergroup gene diversity (Gst = 0.32) whereas this parameter is much lower when estimated among beaver groups from individual Vyatka River tributaries and among localities of one of the tributaries (0.07 and 0.11, respectively). The data suggesting genetic heterogeneity among individual settles within colonies have been obtained. The factors affecting the structure of the beaver communities of the lower hierarchical ranks are considered: the common origin, founder effect, selection, gene drift, assortative mating, and social and behavior features of the species. The conclusion is drawn that the founder effect could be the primary factor of population differentiation only at the time of their formation. The heterogeneity among colonies and among settles is maintained largely by isolation of colonies from one another. The strong interspecific competition for food resources, which is behaviorally implemented in the species at the level of minimal structural units (individual settles) creates a profound and unique population-genetic subdivision of the species. These results substantiate the suggestion that an elementary population (micropopulation) of European beaver is a colony, i.e., a set of related settles of different types. Based on ecological and genetic parameters, the effective reproductive size Ne of the minimum beaver population was estimated to be equal to three animals. This extremely low value of effective reproductive population size largely explains the high tolerance of European beaver

  3. Fiber Amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten

    2017-01-01

    The chapter provides a discussion of optical fiber amplifiers and through three sections provides a detailed treatment of three types of optical fiber amplifiers, erbium doped fiber amplifiers (EDFA), Raman amplifiers, and parametric amplifiers. Each section comprises the fundamentals including...... the basic physics and relevant in-depth theoretical modeling, amplifiers characteristics and performance data as a function of specific operation parameters. Typical applications in fiber optic communication systems and the improvement achievable through the use of fiber amplifiers are illustrated....

  4. Statistical analysis and parameterization of the hygroscopic growth of the sub-micrometer urban background aerosol in Beijing

    Science.gov (United States)

    Wang, Yu; Wu, Zhijun; Ma, Nan; Wu, Yusheng; Zeng, Limin; Zhao, Chunsheng; Wiedensohler, Alfred

    2018-02-01

    The take-up of water of aerosol particles plays an important role in heavy haze formation over North China Plain, since it is related with particle mass concentration, visibility degradation, and particle chemistry. In the present study, we investigated the size-resolved hygroscopic growth factor (HGF) of sub-micrometer aerosol particles (smaller than 350 nm) on a basis of 9-month Hygroscopicity-Tandem Differential Mobility Analyzer measurement in the urban background atmosphere of Beijing. The mean hygroscopicity parameter (κ) values derived from averaging over the entire sampling period for particles of 50 nm, 75 nm, 100 nm, 150 nm, 250 nm, and 350 nm in diameters were 0.14 ± 0.07, 0.17 ± 0.05, 0.18 ± 0.06, 0.20 ± 0.07, 0.21 ± 0.09, and 0.23 ± 0.12, respectively, indicating the dominance of organics in the sub-micrometer urban aerosols. In the spring, summer, and autumn, the number fraction of hydrophilic particles increased with increasing particle size, resulting in an increasing trend of overall particle hygroscopicity with enhanced particle size. Differently, the overall mean κ values peaked in the range of 75-150 nm and decreased for particles larger than 150 nm in diameter during wintertime. Such size-dependency of κ in winter was related to the strong primary particle emissions from coal combustion during domestic heating period. The number fraction of hydrophobic particles such as freshly emitted soot decreased with increasing PM2.5 mass concentration, indicating aged and internal mixed particles were dominant in the severe particulate matter pollution. Parameterization schemes of the HGF as a function of relative humidity (RH) and particle size between 50 and 350 nm were determined for different seasons and pollution levels. The HGFs calculated from the parameterizations agree well with the measured HGFs at 20-90% RH. The parameterizations can be applied to determine the hygroscopic growth of aerosol particles at ambient conditions for the area

  5. Populism

    OpenAIRE

    Abts, Koenraad; Van Kessel, Stijn

    2015-01-01

    Populism is a concept applied to a wide range of political movements and actors across the globe. There is, at the same time, considerable confusion about the attributes and manifestation of populism, as well as its impact on democracy. This contribution identifies the defining elements of the populist ideology and discusses the varieties in which populism manifests itself, for instance as a component of certain party families. We finally discuss various normative interpretations of populism,...

  6. An optimized histochemical method to assess skeletal muscle glycogen and lipid stores reveals two metabolically distinct populations of type I muscle fibers

    DEFF Research Database (Denmark)

    Prats Gavalda, Clara; Gomez-Cabello, Alba; Nordby, Pernille

    2013-01-01

    Skeletal muscle energy metabolism has been a research focus of physiologists for more than a century. Yet, how the use of intramuscular carbohydrate and lipid energy stores are coordinated during different types of exercise remains a subject of debate. Controversy arises from contradicting data...... distinct myosin heavy chain I expressing fibers: I-1 fibers have a smaller crossectional area, a higher density of lipid droplets, and a tendency to lower glycogen content compared to I-2 fibers. Type I-2 fibers have similar lipid content than IIA. Exhaustive exercise lead to glycogen depletion in type IIA...... and IIX fibers, a reduction in lipid droplets density in both type I-1 and I-2 fibers, and a decrease in the size of lipid droplets exclusively in type I-1 fibers....

  7. Highly Localized Acoustic Streaming and Size-Selective Submicrometer Particle Concentration Using High Frequency Microscale Focused Acoustic Fields.

    Science.gov (United States)

    Collins, David J; Ma, Zhichao; Ai, Ye

    2016-05-17

    Concentration and separation of particles and biological specimens are fundamental functions of micro/nanofluidic systems. Acoustic streaming is an effective and biocompatible way to create rapid microscale fluid motion and induce particle capture, though the >100 MHz frequencies required to directly generate acoustic body forces on the microscale have traditionally been difficult to generate and localize in a way that is amenable to efficient generation of streaming. Moreover, acoustic, hydrodynamic, and electrical forces as typically applied have difficulty manipulating specimens in the submicrometer regime. In this work, we introduce highly focused traveling surface acoustic waves (SAW) at high frequencies between 193 and 636 MHz for efficient and highly localized production of acoustic streaming vortices on microfluidic length scales. Concentration occurs via a novel mechanism, whereby the combined acoustic radiation and streaming field results in size-selective aggregation in fluid streamlines in the vicinity of a high-amplitude acoustic beam, as opposed to previous acoustic radiation induced particle concentration where objects typically migrate toward minimum pressure locations. Though the acoustic streaming is induced by a traveling wave, we are able to manipulate particles an order of magnitude smaller than possible using the traveling wave force alone. We experimentally and theoretically examine the range of particle sizes that can be captured in fluid streamlines using this technique, with rapid particle concentration demonstrated down to 300 nm diameters. We also demonstrate that locations of trapping and concentration are size-dependent, which is attributed to the combined effects of the acoustic streaming and acoustic forces.

  8. A method to transfer an individual graphene flake to a target position with a precision of sub-micrometer

    Science.gov (United States)

    Wang, Yubing; Yin, Weihong; Han, Qin; Yang, Xiaohong; Ye, Han; Lü, Qianqian; Yin, Dongdong

    2017-04-01

    Graphene field-effect transistors have been intensively studied. However, in order to fabricate devices with more complicated structures, such as the integration with waveguide and other two-dimensional materials, we need to transfer the exfoliated graphene samples to a target position. Due to the small area of exfoliated graphene and its random distribution, the transfer method requires rather high precision. In this paper, we systematically study a method to selectively transfer mechanically exfoliated graphene samples to a target position with a precision of sub-micrometer. To characterize the doping level of this method, we transfer graphene flakes to pre-patterned metal electrodes, forming graphene field-effect transistors. The hole doping of graphene is calculated to be 2.16 × {10}12{{{cm}}}-2. In addition, we fabricate a waveguide-integrated multilayer graphene photodetector to demonstrate the viability and accuracy of this method. A photocurrent as high as 0.4 μA is obtained, corresponding to a photoresponsivity of 0.48 mA/W. The device performs uniformly in nine illumination cycles. Project supported by the National Key Research and Development Program of China (No. 2016YFB0402404), the High-Tech Research and Development Program of China (Nos. 2013AA031401, 2015AA016902, 2015AA016904), and the National Natural Foundation of China (Nos. 61674136, 61176053, 61274069, 61435002).

  9. Interocular symmetry of retinal nerve fiber layer and optic nerve head parameters measured by Cirrus high-definition optical coherence tomography in a normal pediatric population.

    Science.gov (United States)

    Pawar, Neelam; Maheshwari, Devendra; Ravindran, Meenakshi; Ramakrishnan, Renagappa

    2017-10-01

    To determine interocular differences in the retinal nerve fiber layer (RNFL) and optic nerve head (ONH) parameters in a pediatric population using Cirrus high-definition optical coherence tomography (HD-OCT). Seventy normal Indian children aged 5-17 years presenting to the Pediatric Clinic were included in this observational cross-sectional study. All subjects underwent a comprehensive ophthalmologic examination and an evaluation of the RNFL and ONH by Cirrus HD-OCT. Differences between the right and left eyes were calculated and values were compared by means of a paired t-test. Subjects were also divided into two groups based on age (under or over 10 years of age). Interocular differences in RNFL and ONH parameters together with sex and age variations for these differences were determined. The mean age of studied pediatric population was 11.83 ± 3.3 years (range 5-17). Average RNFL thickness was 94.46 ± 8.7 μm (± SD) (range 77-111). Differences in the average RNFL between right and left eyes were not statistically significant (P = 0.060). Superior quadrant RNFL was thicker in the left eye and temporal quadrant was thicker in the right eye. Among ONH parameters, there were no statistically significant differences in any parameters, except vertical cup-disc (CD) ratio which was significant (P = 0.007). The 2.5%-97.5% limits of asymmetry were 9 μm for average RNFL, 0.14 for average CD ratio, and 0.22 for vertical CD ratio. Mean interocular RNFL thickness differences in superior, superior nasal, and temporal superior quadrants were 10.61 (P population. The normal interocular RNFL asymmetry should not exceed 9 μm and vertical CD ratio beyond 0.22 should be considered for further investigations. The physiologic asymmetry provided by this study may assist in identifying changes in RNFL thickness and ONH parameters in pediatric glaucoma and ONH disorders.

  10. Dietary Fiber

    Science.gov (United States)

    Fiber is a substance in plants. Dietary fiber is the kind you eat. It's a type of carbohydrate. You may also see it listed on a food label as soluble ... types have important health benefits. Good sources of dietary fiber include Whole grains Nuts and seeds Fruit and ...

  11. Teores de fibra e rendimento de grãos em populações de feijão Fiber content and yield grain in common bean populations

    Directory of Open Access Journals (Sweden)

    Patrícia Medianeira Grigoletto Londero

    2008-02-01

    Full Text Available O desenvolvimento de cultivares de feijão com alto potencial de produtividade e maior teor de fibra é desejável, por isso objetivou-se neste trabalho investigar a presença de variabilidade genética para o teor de fibra e para o rendimento de grãos em populações segregantes de feijão do grupo preto. Os cruzamentos possíveis entre os genitores CNFP 8100, FT 96-1282, Varre-Sai e BRS Valente foram realizados em casa-de-vegetação. As populações obtidas (F1, F1 recíprocos, F2 e RC e os genitores foram avaliados a campo durante a primavera/verão de 2003/04, em delineamento de blocos ao acaso. Apesar de ter-se utilizado genitores contrastantes para teor de fibra bruta, definidos em experimento prévio, não foram detectadas diferenças significativas para fibra bruta, fibra solúvel, fibra insolúvel, fibra alimentar total e rendimento de grãos. Assim, não foi possível obter populações segregantes com variabilidade genética, a partir dos cruzamentos entre os genitores CNFP 8100, FT 96-1282, BRS Valente e Varre-Sai. As populações obtidas apresentaram altos teores de fibra alimentar solúvel, insolúvel e total.The development of bean cultivars with high grain yield and high dietary fiber content is desirable, thus objective of this study was to evaluate genetic variability for fiber content and grain yield in segregant populations of the black common bean. Crossings were performed inside a greenhouse among the parents CNFP 8100, FT 96-1282, Varre Sai and BRS Valente. The populations obtained (F1, F1 reciprocals, F2 and RC and parents were assessed in the field during spring/summer 2003/04, using a complete randomized blocks experimental design. Significant differences were not obtained for crude fiber, soluble fiber, insoluble fiber, dietary fiber and grain yield, although contrast parents were used. In this go, it was not possible to obtain segregant populations with genetic variability of the crossing among the parents CNFP 8100

  12. Water Fibers

    CERN Document Server

    Douvidzon, Mark L; Martin, Leopoldo L; Carmon, Tal

    2016-01-01

    Fibers constitute the backbone of modern communication and are used in laser surgeries; fibers also genarate coherent X-ray, guided-sound and supercontinuum. In contrast, fibers for capillary oscillations, which are unique to liquids, were rarely considered in optofluidics. Here we fabricate fibers by water bridging an optical tapered-coupler to a microlensed coupler. Our water fibers are held in air and their length can be longer than a millimeter. These hybrid fibers co-confine two important oscillations in nature: capillary- and electromagnetic-. We optically record vibrations in the water fiber, including an audio-rate fundamental and its 3 overtones in a harmonic series, that one can hear in soundtracks attached. Transforming Micro-Electro-Mechanical-Systems [MEMS] to Micro-Electro-Capillary-Systems [MECS], boosts the device softness by a million to accordingly improve its response to minute forces. Furthermore, MECS are compatible with water, which is a most important liquid in our world.

  13. Relationships between submicrometer particulate air pollution and air mass history in Beijing, China, 2004 2006

    Science.gov (United States)

    Wehner, B.; Birmili, W.; Ditas, F.; Wu, Z.; Hu, M.; Liu, X.; Mao, J.; Sugimoto, N.; Wiedensohler, A.

    2008-10-01

    The Chinese capital Beijing is one of the global megacities where the effects of rapid economic growth have led to complex air pollution problems that are not well understood. In this study, ambient particle number size distributions in Beijing between 2004 and 2006 are analysed as a function of regional meteorological transport. An essential result is that the particle size distribution in Beijing depends to large extent on the history of the synoptic scale air masses. A first approach based on manual back trajectory classification yielded differences in particulate matter mass concentration by a factor of two between four different air mass categories, including three main wind directions plus the case of stagnant air masses. A back trajectory cluster analysis refined these results, yielding a total of six trajectory clusters. Besides the large scale wind direction, the transportation speed of an air mass was found to play an essential role on the PM concentrations in Beijing. Slow-moving air masses were shown to be associated with an effective accumulation of surface-based anthropogenic emissions due to both, an increased residence time over densely populated land, and their higher degree of vertical stability. For the six back trajectory clusters, differences in PM1 mass concentrations by a factor of 3.5, in the mean air mass speed by a factor of 6, and in atmospheric visibility by a factor of 4 were found. The main conclusion is that the air quality in Beijing is not only degraded by anthropogenic aerosol sources from within the megacity, but also by sources across the entire Northwest China plain depending on the meteorological situation.

  14. Relationships between submicrometer particulate air pollution and air mass history in Beijing, China, 2004-2006

    Science.gov (United States)

    Wehner, B.; Birmili, W.; Ditas, F.; Wu, Z.; Hu, M.; Liu, X.; Mao, J.; Sugimoto, N.; Wiedensohler, A.

    2008-06-01

    The Chinese capital Beijing is one of the global megacities where the effects of rapid economic growth have led to complex air pollution problems that are not well understood. In this study, ambient particle number size distributions in Beijing between 2004 and 2006 are analysed as a function of regional meteorological transport. An essential result is that the particle size distribution in Beijing depends to large extent on the history of the synoptic scale air masses. A first approach based on manual back trajectory classification yielded differences in particulate matter mass concentration (PM1 and PM10) by a factor of two between four different air mass categories, including three main wind directions plus the case of stagnant air masses. A back trajectory cluster analysis refined these results, yielding a total of six trajectory clusters. Besides the large scale wind direction, the transportation speed of an air mass was found to play an essential role on the PM concentrations in Beijing. Slow-moving air masses were shown to be associated with an effective accumulation of surface-based anthropogenic emissions due to both, an increased residence time over densely populated land, and their higher degree of vertical stability. For the six back trajectory clusters, differences in PM1 mass concentrations by a factor of 3.5, in the mean air mass speed by a factor of 6, and in atmospheric visibility by a factor of 4 were found. The main conclusion is that the air quality in Beijing is not only degraded by anthropogenic aerosol sources from within the megacity, but also by sources across the entire Northwest China plain depending on the meteorological situation.

  15. Cardiovascular benefits of dietary fiber.

    Science.gov (United States)

    Satija, Ambika; Hu, Frank B

    2012-12-01

    The relationship between dietary fiber and risk of cardiovascular disease (CVD) has been extensively studied. There is considerable epidemiological evidence indicating an inverse association between dietary fiber intake and CVD risk. The association has been found to be stronger for cereal fiber than for fruit or vegetable fiber, and several studies have also found increased whole grain consumption to be associated with CVD risk reduction. In light of this evidence, recent US dietary guidelines have endorsed increased consumption of fiber rich whole grains. Regular consumption of dietary fiber, particularly fiber from cereal sources, may improve CVD health through multiple mechanisms including lipid reduction, body weight regulation, improved glucose metabolism, blood pressure control, and reduction of chronic inflammation. Future research should focus on various food sources of fiber, including different types of whole grains, legumes, fruits, vegetables, and nuts, as well as resistant starch in relation to CVD risk and weight control; explore the biological mechanisms underlying the cardioprotective effect of fiber-rich diets; and study different ethnic groups and populations with varying sources of dietary fiber.

  16. Hygroscopicity of the submicrometer aerosol at the high-alpine site Jungfraujoch, 3580 m a.s.l., Switzerland

    Directory of Open Access Journals (Sweden)

    S. Sjogren

    2008-09-01

    Full Text Available Data from measurements of hygroscopic growth of submicrometer aerosol with a hygroscopicity tandem differential mobility analyzer (HTDMA during four campaigns at the high alpine research station Jungfraujoch, Switzerland, are presented. The campaigns took place during the years 2000, 2002, 2004 and 2005, each lasting approximately one month. Hygroscopic growth factors (GF, i.e. the relative change in particle diameter from dry diameter, D0, to diameter measured at higher relative humidity, RH are presented for three distinct air mass types, namely for: 1 free tropospheric winter conditions, 2 planetary boundary layer influenced air masses (during a summer period and 3 Saharan dust events (SDE. The GF values at 85% RH (D0=100 nm were 1.40±0.11 and 1.29±0.08 for the first two situations while for SDE a bimodal GF distribution was often found. No phase changes were observed when the RH was varied between 10–90%, and the continuous water uptake could be well described with a single-parameter empirical model. The frequency distributions of the average hygroscopic growth factors and the width of the retrieved growth factor distributions (indicating whether the aerosol is internally or externally mixed are presented, which can be used for modeling purposes.

    Measurements of size resolved chemical composition were performed with an aerosol mass spectrometer in parallel to the GF measurements. This made it possible to estimate the apparent ensemble mean GF of the organics (GForg using inverse ZSR (Zdanovskii-Stokes-Robinson modeling. GForg was found to be ~1.20 at aw=0.85, which is at the upper end of previous laboratory and field data though still in agreement with the highly aged and oxidized nature of the Jungfraujoch aerosol.

  17. Fabrication of sub-micrometer PMOSFETs with sub-100 nm p sup + -n shallow junctions using Group III dual ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Lin, C.-M. (Intel Corp., Santa Clara, CA (USA)); Steckl, A.J. (Cincinnati Univ., OH (USA). Dept. of Electrical and Computer Engineering)

    1990-04-01

    Fabrication of sub-micrometer PMOSFETs with sub-100 nm p{sup +}-n source/drain junctions using all Group III ({sup 69}Ga, {sup 115}In, {sup 11}B, {sup 49}BF{sub 2}) dual ion implantation is reported. We have obtained low leakage p{sup +}-n shallow junctions with a depth less than 70 nm by implanting various combinations of Group III species in conjunction with low temperature rapid thermal annealing (25/3 keV Ga/B implant annealed at 600{sup 0}C for 30 s; 50/5 keV and 30/3 keV, In/B implants annealed at 900{sup 0}C for 10 s). Sub-micrometer (0.6-0.95 {mu}m) PMOSFETs have been fabricated with this technique. The Ga/B-implanted transistors exhibit a subthreshold slope of 95-105 mV/decade and yield a maximum transconductance of 35-45 mS/mm. The corresponding values for the In/B-implanted FETs are 100-110 mV/decade and 30-40 mS/mm. (author).

  18. [Carbohydrates and fiber].

    Science.gov (United States)

    Lajolo, F M; de Menezes, E W; Filisetti-Cozzi, T M

    1988-09-01

    Dietary carbohydrates comprise two fractions that may be classified as digestible, and which are useful as energy sources (simple and complex carbohydrates) and fiber, which is presumed to be of no use to the human body. There are insufficient epidemiologic data on the metabolic effects of simple carbohydrates and it is not advisable to make quantitative recommendations of intake. It is questionable to recommend in developing countries that a fixed proportion of dietary energy be derived from simple sugars, due to the high prevalence of deficient energy intake, cultural habits, and regional differences in food intake and physical activity. In relation to recommendations of complex carbohydrates, it should be considered that their absorption is influenced by many factors inherent to the individual and to the foods. Fiber is defined as a series of different substances derived from tissue structures, cellular residues and undigested chemical substances that may be partially utilized after intestinal bacteria have acted on them. There is not a clear definition of the chemical composition of fiber, but it consists mainly of polysaccharides (such as cellulose, hemicellulose and pectins), lignin and end products of the interactions of various food components. The effects of fiber, such as control of food intake, regulation of gastrointestinal transit, post-prandial blood concentrations of cholesterol, glucose and insulin, flatulence and alterations in nutrient bioavailability are due to various physical properties inherent to its chemical components. Impairment of nutrient absorption may be harmful, mainly among populations whose food intake is lower than their energy needs, and with a high fiber content. This may be particularly important in pregnant women, growing children and the elderly, and should be considered when making nutrient recommendations. A precise knowledge of fiber is also important to calculate the real energy value of foods, mainly for two reasons: 1

  19. Total dietary fiber intakes in the US population are related to whole grain consumption: results from the National Health and Nutrition Examination Survey 2009 to 2010.

    Science.gov (United States)

    Reicks, Marla; Jonnalagadda, Satya; Albertson, Ann M; Joshi, Nandan

    2014-03-01

    Whole grain (WG) foods have been shown to reduce chronic disease risk and overweight. Total dietary fiber is associated with WG and its health benefits. The purpose was to determine whether associations exist between WG intake (no-WG intake, 0 ounce equivalent [oz eq]; low, >0-dietary fiber intake among Americans 2 years and older. One-day food intake data from the US National Health and Nutrition Examination Survey 2009 to 2010 (n = 9042) showed that only 2.9% and 7.7% of children/adolescents (2-18 years) and adults (≥19 years) consumed at least 3 WG oz eq/d, respectively. For children/adolescents and adults, individuals in the high WG intake group were 59 and 76 times more likely to fall in the third fiber tertile, respectively, compared with those with no-WG intake. Total dietary fiber intake from food sources varied by WG intake group for children/adolescents and adults with more total dietary fiber consumed from ready-to-eat (RTE) and hot cereals and yeast breads/rolls in the high WG intake group compared with the no-WG intake group. Major WG sources for children/adolescents and adults included yeast bread/rolls (24% and 27%, respectively), RTE cereals (25% and 20%, respectively), and oatmeal (12% and 21%, respectively). Among those with the highest WG intake, WG RTE cereal with no added bran was the greatest contributor to total dietary fiber compared with other RTE cereal types. Whole grain foods make a substantial contribution to total dietary fiber intake and should be promoted to meet recommendations. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  20. An optimized histochemical method to assess skeletal muscle glycogen and lipid stores reveals two metabolically distinct populations of type I muscle fibers.

    Directory of Open Access Journals (Sweden)

    Clara Prats

    Full Text Available Skeletal muscle energy metabolism has been a research focus of physiologists for more than a century. Yet, how the use of intramuscular carbohydrate and lipid energy stores are coordinated during different types of exercise remains a subject of debate. Controversy arises from contradicting data from numerous studies, which used different methodological approaches. Here we review the "pros and cons" of previously used histochemical methods and describe an optimized method to ensure the preservation and specificity of detection of both intramyocellular carbohydrate and lipid stores. For optimal preservation of muscle energy stores, air drying cryosections or cycles of freezing-thawing need to be avoided. Furthermore, optimization of the imaging settings in order to specifically image intracellular lipid droplets stained with oil red O or Bodipy-493/503 is shown. When co-staining lipid droplets with associated proteins, Bodipy-493/503 should be the dye of choice, since oil red O creates precipitates on the lipid droplets blocking the light. In order to increase the specificity of glycogen stain, an antibody against glycogen is used. The resulting method reveals the existence of two metabolically distinct myosin heavy chain I expressing fibers: I-1 fibers have a smaller crossectional area, a higher density of lipid droplets, and a tendency to lower glycogen content compared to I-2 fibers. Type I-2 fibers have similar lipid content than IIA. Exhaustive exercise lead to glycogen depletion in type IIA and IIX fibers, a reduction in lipid droplets density in both type I-1 and I-2 fibers, and a decrease in the size of lipid droplets exclusively in type I-1 fibers.

  1. Dietary magnesium and fiber intakes and inflammatory and metabolic indicators in middle-aged subjects from a population-based cohort.

    Science.gov (United States)

    Bo, Simona; Durazzo, Marilena; Guidi, Sabrina; Carello, Monica; Sacerdote, Carlotta; Silli, Barbara; Rosato, Rosalba; Cassader, Maurizio; Gentile, Luigi; Pagano, Gianfranco

    2006-11-01

    Type 2 diabetes (DM), metabolic syndrome (MetS), and inflammation are linked to reduced magnesium and fiber intakes; these associations are attenuated by adjustment for each of these nutrients. We investigated the association among magnesium and fiber intakes, metabolic variables, and high-sensitivity C-reactive protein (hs-CRP) values. Cross-sectional analyses were performed in a representative cohort of 1653 adults and in a subgroup with normal body mass index without dysmetabolisms (n = 205). A validated semiquantitative food-frequency questionnaire was used; magnesium intake was computed by multiplying its content in each food by the frequency of food consumption. The prevalence of DM, MetS, and hs-CRP >/= 3 mg/L significantly decreased from the lowest to the highest tertile of magnesium and fiber intakes. Subjects within the lowest tertiles of magnesium and fiber intakes were 3-4 times as likely to have DM, MetS, and hs-CRP >/= 3 mg/L, after multiple adjustments. After the analysis was additionally controlled for fiber intake, associations with hs-CRP >/= 3 mg/L proved to be significant (odds ratio: 2.05; 95% CI: 1.30, 3.25), whereas reduced magnesium intake and DM and MetS were no longer significant. The lowest tertile of fiber intake remained associated with DM, hs-CRP >/= 3 mg/L, and MetS after adjustments for multiple confounders and magnesium intake. In the lean, healthy subject subgroup, hs-CRP values were inversely associated with magnesium and fiber intakes in a multivariate model (P /= 3 mg/L in both the entire cohort and healthy persons.

  2. Optical Fibers

    Science.gov (United States)

    Ghatak, Ajoy; Thyagarajan, K.

    With the development of extremely low-loss optical fibers and their application to communication systems, a revolution has taken fiber glass place during the last 40 years. In 2001, using glass fibers as the transmission medium and lightwaves as carrier wave waves, information was transmitted at a rate more than 1 Tbit/s (which is roughly equivalent to transmission of about 15 million simultaneous telephone conversations) through one hair thin optical fiber. Experimental demonstration of transmission at the rate of 14 Tbit/s over a 160 km long single fiber was demonstrated in 2006, which is equivalent to sending 140 digital high definition movies in 1 s. Very recently record transmission of more than 100 Tbit/s over 165 km single mode fiber has been reported. These can be considered as extremely important technological achievements. In this chapter we will discuss the propagation characteristics of optical fibers with special applications to optical communication systems and also present some of the noncommunication applications such as sensing.

  3. Vacuum fiber-fiber coupler

    Science.gov (United States)

    Heinrici, Axel; Bjelajac, Goran; Jonkers, Jeroen; Jakobs, Stefan; Olschok, Simon; Reisgen, Uwe

    2017-02-01

    Research and development carried out by the ISF Welding and Joining Institute of RWTH Aachen University has proven that combining high power laser and low vacuum atmosphere provides a welding performance and quality, which is comparable to electron beam welding. The developed welding machines are still using a beam forming which takes place outside the vacuum and the focusing laser beam has to be introduced to the vacuum via a suitable window. This inflexible design spoils much of the flexibility of modern laser welding. With the target to bring a compact, lightweight flying optics with flexible laser transport fibers into vacuum chambers, a high power fiber-fiber coupler has been adapted by II-VI HIGHYAG that includes a reliable vacuum interface. The vacuum-fiber-fiber coupler (V-FFC) is tested with up to 16 kW sustained laser power and the design is flexible in terms of a wide variety of laser fiber plug systems and vacuum flanges. All that is needed to implement the V-FFC towards an existing or planned vacuum chamber is an aperture of at least 100 mm (4 inch) diameter with any type of vacuum or pressure flange. The V-FFC has a state-of-the-art safety interface which allows for fast fiber breakage detection for both fibers (as supported by fibers) by electric wire breakage and short circuit detection. Moreover, the System also provides connectors for cooling and electric signals for the laser beam optics inside the vacuum. The V-FFC has all necessary adjustment options for coupling the laser radiation to the receiving fiber.

  4. High-Definition Fiber Tractography in Evaluation and Surgical Planning of Thalamopeduncular Pilocytic Astrocytomas in Pediatric Population: Case Series and Review of Literature.

    Science.gov (United States)

    Celtikci, Emrah; Celtikci, Pinar; Fernandes-Cabral, David Tiago; Ucar, Murat; Fernandez-Miranda, Juan Carlos; Borcek, Alp Ozgun

    2017-02-01

    Thalamopeduncular tumors (TPTs) of childhood present a challenge for neurosurgeons due to their eloquent location. Preoperative fiber tracking provides total or near-total resection, without additional neurologic deficit. High-definition fiber tractography (HDFT) is an advanced white matter imaging technique derived from magnetic resonance imaging diffusion data, shown to overcome the limitations of diffusion tensor imaging. We aimed to investigate alterations of corticospinal tract (CST) and medial lemniscus (ML) caused by TPTs and to demonstrate the application of HDFT in preoperative planning. Three pediatric patients with TPTs were enrolled. CSTs and MLs were evaluated for displacement, infiltration, and disruption. The relationship of these tracts to tumors was identified and guided surgical planning. Literature was reviewed for publications on pediatric thalamic and TPTs that used diffusion imaging. Two patients had histologic diagnosis of pilocytic astrocytoma. One patient whose imaging suggested a low-grade glioma was managed conservatively. All tracts were displaced (1 CST anteriorly, 2 CSTs, 1 ML anteromedially, 1 ML medially, and 1 ML posteromedially). Literature review revealed 2 publications with 15 pilocytic astrocytoma cases, which investigated CST only. The condition of sensory pathway or anteromedial displacement of the CST in these tumors was not reported previously. Displacement patterns of the perilesional fiber bundles by TPTs are not predictable. Fiber tracking, preferably HDFT, should be part of preoperative planning to achieve maximal extent of resection for longer survival rates in this young group of patients, while preserving white matter tracts and thus quality of life. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Simulating aerosol microphysics with the ECHAM4/MADE GCM – Part II: Results from a first multiannual simulation of the submicrometer aerosol

    Directory of Open Access Journals (Sweden)

    A. Lauer

    2006-01-01

    Full Text Available First results of a multiannual integration with the new global aerosol model system ECHAM4/MADE are presented. This model system enables simulations of the particle number concentration and size-distribution, which is a fundamental innovation compared to previous global model studies considering aerosol mass cycles only. The data calculated by the model provide detailed insights into the properties of the global submicrometer aerosol regarding global burden, chemical composition, atmospheric residence time, particle number concentration and size-distribution. The aerosol components considered by the model are sulfate (SO4, nitrate (NO3, ammonium (NH4, black carbon (BC, organic matter (OM, mineral dust, sea salt and aerosol water. The simulated climatological annual mean global atmospheric burdens (residence times of the dominant submicrometer aerosol components are 2.25 Tg (4.5 d for SO4, 0.46 Tg (4.5 d for NH4, 0.26 Tg (6.6 d for BC, and 1.77 Tg (6.5 d for OM. The contributions of individual processes such as emission, nucleation, condensation or dry and wet deposition to the global sources and sinks of specific aerosol components and particle number concentration are quantified. Based on this analysis, the significance of aerosol microphysical processes (nucleation, condensation, coagulation is evaluated by comparison to the importance of other processes relevant for the submicrometer aerosol on the global scale. The results reveal that aerosol microphysics are essential for the simulation of the particle number concentration and important but not vital for the simulation of particle mass concentration. Hence aerosol microphysics should be taken into account in simulations of atmospheric processes showing a significant dependence on aerosol particle number concentration. The analysis of the vertical variation of the microphysical net production and net depletion rates performed for particle number concentration, sulfate mass and black carbon

  6. A simple sheathless CE-MS interface with a sub-micrometer electrical contact fracture for sensitive analysis of peptide and protein samples

    DEFF Research Database (Denmark)

    Nguyen, Tam T. T. N.; Petersen, Nickolaj J.; Rand, Kasper Dyrberg

    2016-01-01

    of forming a sub-micrometer fracture directly in the capillary. The simple interface design allowed the generation of a stable ESI spray capable of ionization at low nanoliter flow-rates (45–90 nL/min) for high sensitivity MS analysis of challenging samples like those containing proteins and peptides...... profile was achieved and comparable sequence coverage was obtained by the CE-MS method (73%) compared to a representative UPLC-MS method (77%). The CE-MS interface was subsequently used to analyse a more complex sample of pharmaceutically relevant human proteins including insulin, tissue factor and α......Online coupling of capillary electrophoresis (CE) to electrospray ionization mass spectrometry (MS) has shown considerable potential, however, technical challenges have limited its use. In this study, we have developed a simple and sensitive sheathless CE-MS interface based on the novel concept...

  7. Low-fiber diet

    Science.gov (United States)

    ... residue; Low-fiber diet; Fiber restricted diet; Crohn disease - low fiber diet; Ulcerative colitis - low fiber diet; ... pulp: Yellow squash (without seeds) Spinach Pumpkin Eggplant Potatoes, without skin Green beans Wax beans Asparagus Beets ...

  8. Soluble vs. insoluble fiber

    Science.gov (United States)

    Insoluble vs. soluble fiber; Fiber - soluble vs. insoluble ... There are 2 different types of fiber -- soluble and insoluble. Both are important for health, digestion, and preventing diseases. Soluble fiber attracts water and turns to gel during digestion. This slows ...

  9. Fiber resources

    Science.gov (United States)

    P. J. Ince

    2004-01-01

    In economics, primary inputs or factors of production define the term ‘resources.’ Resources include land resources (plants, animals, and minerals), labor, capital, and entrepreneurship. Almost all pulp and paper fiber resources are plant materials obtained from trees or agricultural crops. These resources encompass plant materials harvested directly from the land (...

  10. Infrared Optical Properties of β-Spodumene Solid Solution Glass-Ceramic for Fiber-Optic Devices

    Science.gov (United States)

    Sakamoto, Akihiko; Yamamoto, Shigeru

    2006-09-01

    The IR optical properties of an opaque β-spodumene solid solution (s.s.) glass-ceramic for fiber-optic devices were studied in relation to its refractive indices in both crystalline and glass phases. We investigated the refractive indices of both phases on the basis of IR transmittance change due to the structural relaxation of the glass phase. The refractive indices of this β-spodumene s.s. glass-ceramic at a wavelength of 1550 nm in the crystalline and glass phases were first determined to be 1.530 and 1.495, respectively. It was found from the refractive index data that the optical scattering intensity of this glass-ceramic approximately follows the Rayleigh-Gans model. We also demonstrated that the inner diameter of an opaque glass-ceramic capillary used in optical fiber connectors can be optically measured with a sub-micrometer accuracy using an IR laser.

  11. Start codon targeted (SCoT) polymorphism reveals genetic diversity in wild and domesticated populations of ramie (Boehmeria nivea L. Gaudich.), a premium textile fiber producing species

    Science.gov (United States)

    Satya, Pratik; Karan, Maya; Jana, Sourav; Mitra, Sabyasachi; Sharma, Amit; Karmakar, P.G.; Ray, D.P.

    2015-01-01

    Twenty-four start codon targeted (SCoT) markers were used to assess genetic diversity and population structure of indigenous, introduced and domesticated ramie (Boehmeria nivea L. Gaudich.). A total of 155 genotypes from five populations were investigated for SCoT polymorphism, which produced 136 amplicons with 87.5% polymorphism. Polymorphism information content and resolving power of the SCoT markers were 0.69 and 3.22, respectively. The Indian ramie populations exhibited high SCoT polymorphism (> 50%), high genetic differentiation (GST = 0.27) and moderate gene flow (Nm = 1.34). Analysis of molecular variance identified significant differences for genetic polymorphism among the populations explaining 13.1% of the total variation. The domesticated population exhibited higher genetic polymorphism and heterozygosity compared to natural populations. Cluster analysis supported population genetic analysis and suggested close association between introduced and domesticated genotypes. The present study shows effectiveness of employing SCoT markers in a cross pollinated heterozygous species like Boehmeria, and would be useful for further studies in population genetics, conservation genetics and cultivar improvement. PMID:25750860

  12. Frequency of micronuclei and other biomarkers of DNA damage in populations exposed to dusts, asbestos and other fibers. A systematic review.

    Science.gov (United States)

    Bonassi, Stefano; Milić, Mirta; Neri, Monica

    Airborne particles are small, solid particles projected into the air either by natural forces, or by mechanical or man-made processes, and include fibers and dusts. Their toxicity is usually subsequent to inhalation and can lead to pulmonary dysfunctions and diseases, including cancer. Cytochalasin B blocked micronucleus assay in lymphocytes (L-CBMN) has been shown as a sensitive and reliable technique in assessing genotoxic exposure, An extensive search of the PubMed and Web of Science databases allowed retrieval of 18 articles on occupational or environmental exposure evaluating L-CBMN in subjects exposed to fibers or dusts (asbestos, silica, rockwool, beryllium, tobacco, and wood). For each study, mean L-CBMN levels were compared in exposed subjects vs. unexposed controls providing a point estimate, the Mean Ratio (MR). The high heterogeneity among retrieved studies and their relatively limited number did not allow a quantitative meta-analysis. However, the inter-quartile range of all MRs fell within the interval between 1.25 and 2.23, supporting the hypothesis that exposure to airborne particles increases DNA damage, although mechanisms of genotoxicity should be further investigated. A borderline significant correlation was found with SCE, but not with chromosome aberrations or comet assay. Future research should focus on exposure assessment, in order to perform proper dose-response studies and disentangle the effect of different compounds in mixed exposures. To fully exploit the cytome assay, L-CBMN frequency should be integrated with other endpoints, such as nucleoplasmic bridges and nuclear buds. The use of alternative tissues, such as nasal and buccal mucosa, and the implementation of other cytogenetic assay, may help to understand the effects of this exposure. Copyright © 2016. Published by Elsevier B.V.

  13. Novel method for carbon nanofilament growth on carbon fibers

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Johathan [Los Alamos National Laboratory; Luhrs, Claudia [UNM MECH.ENG.; Terani, Mehran [UNM MECH.ENG.; Al - Haik, Marwan [UNM MECH.ENG.; Garcia, Daniel [UNM MECH.ENG.; Taha, Mahmoud R [UNM MECH.ENG.

    2009-01-01

    with smooth walls and low impurity content were grown. Carbon nanofibers were also grown on a carbon fiber cloth using plasma enhanced chemical vapor deposition (CVD) from a mixture of acetylene and ammonia. In this case, a cobalt colloid was used to achieve a good coverage of nanofibers on carbon fibers in the cloth. Caveats to CNT growth include damage in the carbon fiber surface due to high-temperatures (>800 C). More recently, Qu et al. reported a new method for uniform deposition of CNT on carbon fibers. However, this method requires processing at 1100 C in the presence of oxygen and such high temperature is anticipated to deepen the damage in the carbon fibers. In the present work, multi-scale filaments (herein, linear carbon structures with multi-micron diameter are called 'fibers', all structures with sub-micron diameter are called 'filaments') were created with a low temperature (ca. 550 C) alternative to CVD growth of CNTs. Specifically, nano-scale filaments were rapidly generated (> 10 microns/hour) on commercial micron scale fibers via catalytic (Pd particles) growth from a fuel rich combustion environment at atmospheric pressure. This atmospheric pressure process, derived from the process called Graphitic Growth by Design (GSD), is rapid, the maximum temperature low enough (below 700 C) to avoid structural damage and the process inexpensive and readily scalable. In some cases, a significant and unexpected aspect of the process was the generation of 'three scale' materials. That is, materials with these three size characteristics were produced: (1) micrometer scale commercial PAN fibers, (2) a layer of 'long' sub-micrometer diameter scale carbon filaments, and (3) a dense layer of 'short' nanometer diameter filaments.

  14. Native and thermally modified protein-polyphenol coassemblies: lactoferrin-based nanoparticles and submicrometer particles as protective vehicles for (-)-epigallocatechin-3-gallate.

    Science.gov (United States)

    Yang, Wei; Xu, Chenqi; Liu, Fuguo; Yuan, Fang; Gao, Yanxiang

    2014-11-05

    The interactions between native, thermally modified lactoferrin (LF) and (-)-epigallocatechin-3-gallate (EGCG) at pH 3.5, 5.0, and 6.5 were investigated. Turbidity, particle size, and charge of LF-EGCG complexes were mainly dominated by pH value and secondary structure of protein. At pH 3.5 and 5.0, LF-EGCG complexes were nanoparticles which had high ζ-potential, small size, and soluble state. At pH 6.5, they were submicrometer particles which exhibited low ζ-potential, large size, and insoluble state. The infrared spectra of freeze-dried LF-EGCG complexes showed that they were different from LF and EGCG alone. Far-UV CD results indicated that heat denaturation might irreversibly alter the secondary structure of LF and EGCG induced a progressive increase in the proportion of α-helix structure at the cost of β-sheet and unordered coil structure of LF at pH 3.5, 5.0, and 6.5. EGCG exhibited a strong affinity for native LF but a weak affinity for thermally modified LF at pH 5.0 and 6.5. An inverse result was observed at pH 3.5. These results could have potential for the development of food formulations based on LF as a carrier of bioactive compounds.

  15. Cellular structure of the healthy and keratoconic human cornea imaged in-vivo with sub-micrometer axial resolution OCT(Conference Presentation)

    Science.gov (United States)

    Bizheva, Kostadinka; Tan, Bingyao; Mason, Erik; Carter, Kirsten; Haines, Lacey; Sorbara, Luigina

    2017-02-01

    Keratoconus causes progressive morphological changes in the corneal epithelium (EPI), Bowman's membrane (BM) and anterior stroma. However, it is still not well understood if KC originates in the corneal epithelium and propagates to the anterior stroma through disruptions of the BM, or vice versa. In this study we used a sub-micrometer axial resolution OCT system to image in-vivo the cellular structure of the EPI layer and the fibrous structure of the BM and the anterior stroma in mild to advanced keratoconics, as well as healthy subjects. The imaging study was approved by the University of Waterloo Human Research Ethics Committee. The OCT system operates in the 800 nm spectral region at 34 kHz image acquisition rate and provides 0.95 um axial and < 2 um lateral resolution in corneal tissue, which is sufficient to visualize the cellular structure of the corneal epithelium and the fibrous structure of the BM. In some subjects, localized thinning and thickening of the EPI layer was observed, while there was no visible damage to the BM or anterior stroma. In other subjects, localized breakage of the stromal collagen fibrils was observed with no significant morphological changes of the corneal EPI.

  16. Benefits of dietary fiber in clinical nutrition.

    Science.gov (United States)

    Klosterbuer, Abby; Roughead, Zamzam Fariba; Slavin, Joanne

    2011-10-01

    Dietary fiber is widely recognized as an important part of a healthy diet and is a common addition to enteral nutrition (EN) formulas. Fiber sources differ in characteristics such as solubility, fermentability, and viscosity, and it is now well known that different types of fiber exert varying physiological effects in the body. Clinical studies suggest fiber can exert a wide range of benefits in areas such as bowel function, gut health, immunity, blood glucose control, and serum lipid levels. Although early clinical nutrition products contained fiber from a single source, it is now thought that blends of fiber from multiple sources more closely resemble a regular diet and may provide a greater range of benefits for the patient. Current recommendations support the use of dietary fiber in clinical nutrition when no contraindications exist, but little information exists about which types and combinations of fibers provide the relevant benefit in certain patient populations. This article summarizes the different types of fiber commonly added to EN products and reviews the current literature on the use of fiber blends in clinical nutrition.

  17. Characterizing axonal myelination within the healthy population: a tract-by-tract mapping of effects of age and gender on the fiber g-ratio.

    Science.gov (United States)

    Cercignani, Mara; Giulietti, Giovanni; Dowell, Nick G; Gabel, Matt; Broad, Rebecca; Leigh, P Nigel; Harrison, Neil A; Bozzali, Marco

    2017-01-01

    The g-ratio, equal to the ratio of the inner-to-outer diameter of a myelinated axon, is associated with the speed of conduction, and thus reflects axonal function and integrity. It is now possible to estimate an "aggregate" g-ratio in vivo using MRI. The aim of this study was to assess the variation of the MRI-derived fiber g-ratio in the brain of healthy individuals, and to characterize its variation across the lifespan. Thirty-eight healthy participants, aged between 20 and 76, were recruited. Whole-brain g-ratio maps were computed and analyzed voxel-wise. Median tract g-ratio values were also extracted. No significant effect of gender was found, whereas age was found to be significantly associated with the g-ratio within the white matter. The tract-specific analysis showed this relationship to follow a nearly-linear increase, although the slope appears to slow down slightly after the 6th decade of life. The most likely interpretation is a subtle but consistent reduction in myelin throughout adulthood, with the density of axons beginning to decrease between the 4th and 5th decade. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Photonic crystal fibers -

    DEFF Research Database (Denmark)

    Libori, Stig E. Barkou

    2002-01-01

    During this ph.d. work, attention has been focused on understanding and analyzing the modal behavior of micro-structured fibers. Micro-structured fibers are fibers with a complex dielectric toplogy, and offer a number of novel possibilities, compared to standard silica based optical fibers....... The thesis focuses on understanding the basic mechanisms controlling the modal properties of micro-structured fibers. One important sub-class of micro-structured fibers are fibers that guide light by index effects similar to those index effects that ensure guidance of light in standard optical fibers....... Such micro-structured fibers are the ones most often trated in literature concerning micro-structured fibers. These micro-structured fibers offer a whole range of novel wave guiding characteristics, including the possibility of fibers that guide only one mode irrespective of the frequency of light...

  19. Photonic Bandgap Fibers

    DEFF Research Database (Denmark)

    Barkou, Stig Eigil; Broeng, Jes; Bjarklev, Anders Overgaard

    1999-01-01

    Photonic bandgap fibers are describes using a new Kagomé cladding structure. These fibers may potentially guide light in low-index regions. Such fibers offer new dispersion properties, and large design flexibility.......Photonic bandgap fibers are describes using a new Kagomé cladding structure. These fibers may potentially guide light in low-index regions. Such fibers offer new dispersion properties, and large design flexibility....

  20. Sub-Micrometer Magnetic Nanocomposites: Insights into the Effect of Magnetic Nanoparticles Interactions on the Optimization of SAR and MRI Performance.

    Science.gov (United States)

    Grillo, Renato; Gallo, Juan; Stroppa, Daniel G; Carbó-Argibay, Enrique; Lima, Renata; Fraceto, Leonardo F; Bañobre-López, Manuel

    2016-10-05

    There is increasing interest in the development of new magnetic polymeric carriers for biomedical applications such as trigger-controlled drug release, magnetic hyperthermia (MH) for the treatment of cancer, and as contrast agents in magnetic resonance imaging (MRI). This work describes the synthesis of sub-micrometer and magnetic polymer nanocomposite capsules (MPNCs) by combining in one single platform the biodegradable polymer poly-ε-caprolactone (PCL) and different concentrations of ∼8 nm oleic acid (OA)-functionalized magnetite nanoparticles (Fe3O4@OA), employing the oil-in-water emulsion/solvent evaporation method. The MPNCs showed a significant increase in particle size from ∼400 to ∼800 nm as the magnetic loading in the organic-inorganic hybrids increases from 1.0% to 10%. The MPNCs presented high incorporation efficiency of Fe3O4@OA nanoparticles, good colloidal stability, and super-paramagnetic properties. Interestingly, electron microscopy results showed that the Fe3O4@OA nanoparticles were preferentially located at the surface of the capsules. Evaluation of the magnetic properties showed that the saturation magnetization and the blocking temperature of the MPNCs samples increased as a function of the Fe3O4@OA loading. All the MPNCs exhibited heating when subjected to MH, and showed good specific absorption rates. Use of the formulations decreased the longitudinal (T1) and transverse (T2) relaxation times of water protons' nuclei, with excellent transverse relaxivity (r2) values, especially in the case of the formulation with lowest Fe3O4@OA loading. Furthermore, the MPNCs-cell interaction was studied, and MPNCs showed lower cellular toxicity to normal cells compared to cancer cells. These findings help in understanding the relationships between magnetic nanoparticles and polymeric capsules, opening perspectives for their potential clinical uses as simultaneous heating sources and imaging probes in MH and MRI, respectively.

  1. An integrated experimental-modeling approach to study the acid leaching behavior of lead from sub-micrometer lead silicate glass particles

    Energy Technology Data Exchange (ETDEWEB)

    Elteren, Johannes T. van, E-mail: elteren@ki.si [Analytical Chemistry Laboratory, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Grilc, Miha [Laboratory of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Beeston, Michael P. [Analytical Chemistry Laboratory, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); TSI GmbH, Neuköllner Str. 4, 52068 Aachen (Germany); Reig, Milagros Santacatalina [General Foundation, University of Alicante, E-03690 San Vicente del Raspeig (Alicante) (Spain); Department of Chemical Engineering, University of Alicante, P.O. Box 99, E-03080 Alicante (Spain); Grgić, Irena [Analytical Chemistry Laboratory, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia)

    2013-11-15

    Highlights: • Generation of particles by laser ablation of lead silicate glass. • Collection of particles on filters and continuous acid leaching and ICP-MS monitoring. • Fitting of the lead leaching profile to a mathematical intraparticle diffusion model. • Extraction of individual leaching profiles for selected mono-dispersed size fractions. • Leaching kinetics is based on ion-exchange and correlated with particle size. -- Abstract: This work focuses on the development of a procedure to study the mechanism of leaching of lead from sub-micrometer lead glass particles using 0.3 mol l{sup −1} HNO{sub 3} as a leachant. Glass particles with an effective size distribution range from 0.05 to 1.4 μm were generated by laser ablation (213 nm Nd:YAG laser) and collected on an inline 0.2 μm syringe filter. Subsequently, the glass particles on the filter were subjected to online leaching and continuous monitoring of lead (Pb-208) in the leachate by quadrupole ICP-MS. The lead leaching profile, aided by the particle size distribution information from cascade impaction, was numerically fitted to a mathematical model based on the glass intraparticle diffusion, liquid film distribution and thermodynamic glass-leachant distribution equilibrium. The findings of the modeling show that the rate-limiting step of leaching is the migration of lead from the core to the surface of the glass particle by an ion-exchange mechanism, governed by the apparent intraparticle lead diffusivity in glass which was calculated to be 3.1 × 10{sup −18} m{sup 2} s{sup −1}. Lead leaching is illustrated in the form of graphs and animations of intraparticle lead release (in time and intraparticle position) from particles with sizes of 0.1 and 0.3 μm.

  2. Photonic crystal fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Hansen, K P; Nielsen, M D

    2003-01-01

    Photonic crystal fibers having a complex microstructure in the transverse plane constitute a new and promising class of optical fibers. Such fibers can either guide light through total internal reflection or the photonic bandgap effect, In this paper, we review the different types and applications...... of photonic crystal fibers with particular emphasis on recent advances in the field....

  3. Fiber optic temperature sensor

    Science.gov (United States)

    Sawatari, Takeo (Inventor); Gaubis, Philip A. (Inventor)

    2000-01-01

    A fiber optic temperature sensor uses a light source which transmits light through an optical fiber to a sensor head at the opposite end of the optical fiber from the light source. The sensor head has a housing coupled to the end of the optical fiber. A metallic reflective surface is coupled to the housing adjacent the end of the optical fiber to form a gap having a predetermined length between the reflective surface and the optical fiber. A detection system is also coupled to the optical fiber which determines the temperature at the sensor head from an interference pattern of light which is reflected from the reflective surface.

  4. Romanian knowledge and attitudes regarding dietary fibers

    Directory of Open Access Journals (Sweden)

    Monica TARCEA

    2016-11-01

    Full Text Available Introduction: Presently, the scientists recognize the health benefits of food fibers in the menu and also plant food sources are at high interest both for general population and food companies. The food companies are responsible for a clear nutrition labelling that will assist consumers to make informed and healthy choices and health providers has to inform the population about the benefits of fibers. The aim of our study was to evaluate the Romanian knowledge and attitudes regarding dietary fibers from food products. Materials and methods: We made a qualitative survey based on a questionnaire applied in 2015, over a period of 6 months, over 670 Romanian consumers. It was focused on testing the attitudes and knowledge towards ingestion of foods rich in fibers. For all data analysis we used the software SPSS, from IBM Inc. Results and Discussions: Our results showed that the knowledge about dietary fibers and also the ingestion of food products rich in fibers were low, and most of the subjects didn’t have any interest to read the nutritional information from food labels related to fibers. The female participants ate more whole grains and fruits than males and pay more attention to food labelling, the Romanian people prefer to stay and eat home than at restaurants especially in rural areas, and the knowledge about fibers benefits was significantly related to education and urban location. Conclusion: We underline the needs for more efficient community interventions and proper information about the importance of dietary fibers for our health and also to improve and disseminate our nutritional standards and diet recommendation among population.

  5. Amplitude-modulated fiber-ring laser

    DEFF Research Database (Denmark)

    Caputo, J. G.; Clausen, Carl A. Balslev; Sørensen, Mads Peter

    2000-01-01

    Soliton pulses generated by a fiber-ring laser are investigated by numerical simulation and perturbation methods. The mathematical modeling is based on the nonlinear Schrödinger equation with perturbative terms. We show that active mode locking with an amplitude modulator leads to a self-starting......Soliton pulses generated by a fiber-ring laser are investigated by numerical simulation and perturbation methods. The mathematical modeling is based on the nonlinear Schrödinger equation with perturbative terms. We show that active mode locking with an amplitude modulator leads to a self......-starting of stable solitonic pulses from small random noise, provided the modulation depth is small. The perturbative analysis leads to a nonlinear coupled return map for the amplitude, phase, and position of the soliton pulses circulating in the fiber-ring laser. We established the validity of this approach...

  6. Optical Fiber Fusion Splicing

    CERN Document Server

    Yablon, Andrew D

    2005-01-01

    This book is an up-to-date treatment of optical fiber fusion splicing incorporating all the recent innovations in the field. It provides a toolbox of general strategies and specific techniques that the reader can apply when optimizing fusion splices between novel fibers. It specifically addresses considerations important for fusion splicing of contemporary specialty fibers including dispersion compensating fiber, erbium-doped gain fiber, polarization maintaining fiber, and microstructured fiber. Finally, it discusses the future of optical fiber fusion splicing including silica and non-silica based optical fibers as well as the trend toward increasing automation. Whilst serving as a self-contained reference work, abundant citations from the technical literature will enable readers to readily locate primary sources.

  7. The ISNT Rule: How Often Does It Apply to Disc Photos and Retinal Nerve Fiber Layer Measurements in the Normal Population.

    Science.gov (United States)

    Yi-Chieh Poon, Linda; Solá-Del Valle, David; Turalba, Angela V; Falkenstein, Iryna A; Horsley, Michael; Kim, Julie H; Song, Brian J; Takusagawa, Hana L; Wang, Kaidi; Chen, Teresa C

    2017-09-22

    To determine what percentage of normal eyes follow the ISNT rule, and whether ISNT rule variants may be more generalizable to the normal population. Cross-sectional study. Setting: Institutional setting. 110 normal subjects. Neuroretinal rim assessments from disc photos and RNFL thickness measurements from spectral domain OCT. The percentages of subjects that obeyed the ISNT rule and its variants. The ISNT rule is only valid for 37.0% of disc photo rim assessments and 43.8% of RNFL measurements. Deviation of the nasal sector from the expected ISNT pattern was a major cause for the ISNT rule not being obeyed for both rim and RNFL assessments. Specifically, 10.9% of subjects had wider nasal rims than the inferior rims, 29.4% had wider nasal rims than the superior rims, 14.7% had narrower nasal rims than the temporal rims, and 42.9% had thinner nasal RNFLs compared to the temporal quadrant. Exclusion of the nasal quadrant from the ISNT rule significantly increased the validity of ISNT variant rules, with 70.9% and 76.4% of disc photos following the IST rule and the IS rule, respectively. Similarly, for RNFL thickness, 70.9% and 71.8% of patients followed the IST and IS rule, respectively. The ISNT rule is only valid for about a third of disc photos and less than half of RNFL measurements in normal patients. ISNT rule variants, such as the IST and IS rule, may be considered, as they are valid in over 70% of patients. Copyright © 2017. Published by Elsevier Inc.

  8. Nonlinear Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Hansen, Kim Per

    2004-01-01

    Despite the general recession in the global economy and the collapse of the optical telecommunication market, research within specialty fibers is thriving. This is, more than anything else, due to the technology transition from standard all-glass fibers to photonic crystal fibers, which, instead...... in 1996, and are today on their way to become the dominating technology within the specialty fiber field. Whether they will replace the standard fiber in the more traditional areas like telecommunication transmission, is not yet clear, but the nonlinear photonic crystal fibers are here to stay....

  9. Reducing fiber cross-talk in mineral fiber arrays

    OpenAIRE

    Daniel Lee Stark

    2017-01-01

    Monocentric optics replace current systems with diffraction limited performance. The fiber arrays have been the issue. Commercial expensive fiber arrays are available, but enhanced mineral fiber arrays offer very inexpensive fiber arrays.

  10. Distribution of fiber types in locomotory muscles of dogs.

    Science.gov (United States)

    Armstrong, R B; Saubert, C W; Seeherman, H J; Taylor, C R

    1982-01-01

    The distribution of Type I and Type II fibers, as determined from histochemical estimation of myofibrillar ATPase activity, was studied within and among the locomotory muscles of the forelimb, trunk, and hindlimb of three mongrel dogs. All Type II fibers had high oxidative capacities as estimated from the histochemical assay for reduced nicotinamide adenine dinucleotide tetrazolium reductase, so they were not further divided into subpopulations. Furthermore, Type I and Type II fibers had similar oxidative potentials as indicated by both histochemistry and biochemistry. Type I fiber populations ranged between 14% and 100% in the muscles sampled. The highest percentages of Type I fibers were found in deep muscles of physiological extensor groups in the arm and thigh that serve to resist gravity (antigravity muscles) when the dog is in the quadrupedal standing position. More superficial muscles in these same groups had fewer Type I fibers. The patterns of Type I fiber distribution among muscles in the antigravity groups of the forearm and leg were the opposite of those in the arm and thigh, with the more superficial muscles of the distal limb segments having more Type I fibers than the deeper muscles. In all limb segments, muscle groups that do not serve to resist gravity did not show as much intermuscular variation. Type I fiber populations in these muscles did not exceed 50%. A stratification of fiber types also existed within muscles, both in extensor and flexor groups, with the deeper portions of the muscles having more Type I fibers than the more superficial portions.

  11. Physical properties of the sub-micrometer aerosol over the Amazon rain forest during the wet-to-dry season transition - comparison of modeled and measured CCN concentrations

    Directory of Open Access Journals (Sweden)

    J. Rissler

    2004-01-01

    Full Text Available Sub-micrometer atmospheric aerosol particles were studied in the Amazon region, 125 km northeast of Manaus, Brazil (-1°55.2'S, 59°28.1'W. The measurements were performed during the wet-to-dry transition period, 4-28 July 2001 as part of the LBA (Large-Scale Biosphere Atmosphere Experiment in Amazonia CLAIRE-2001 (Cooperative LBA Airborne Regional Experiment experiment. The number size distribution was measured with two parallel differential mobility analyzers, the hygroscopic growth at 90% RH with a Hygroscopic Tandem Mobility Analyzer (H-TDMA and the concentrations of cloud condensation nuclei (CCN with a cloud condensation nuclei counter. A model was developed that uses the H-TDMA data to predict the number of soluble molecules or ions in the individual particles and the corresponding minimum particle diameter for activation into a cloud droplet at a certain supersaturation. Integrating the number size distribution above this diameter, CCN concentrations were predicted with a time resolution of 10 min and compared to the measured concentrations. During the study period, three different air masses were identified and compared: clean background, air influenced by aged biomass burning, and moderately polluted air from recent local biomass burning. For the clean period 2001, similar number size distributions and hygroscopic behavior were observed as during the wet season at the same site in 1998, with mostly internally mixed particles of low diameter growth factor (~1.3 taken from dry to 90% RH. During the periods influenced by biomass burning the hygroscopic growth changed slightly, but the largest difference was seen in the number size distribution. The CCN model was found to be successful in predicting the measured CCN concentrations, typically within 25%. A sensitivity study showed relatively small dependence on the assumption of which model salt that was used to predict CCN concentrations from H-TDMA data. One strength of using H-TDMA data

  12. Ceramic fiber reinforced filter

    Science.gov (United States)

    Stinton, David P.; McLaughlin, Jerry C.; Lowden, Richard A.

    1991-01-01

    A filter for removing particulate matter from high temperature flowing fluids, and in particular gases, that is reinforced with ceramic fibers. The filter has a ceramic base fiber material in the form of a fabric, felt, paper of the like, with the refractory fibers thereof coated with a thin layer of a protective and bonding refractory applied by chemical vapor deposition techniques. This coating causes each fiber to be physically joined to adjoining fibers so as to prevent movement of the fibers during use and to increase the strength and toughness of the composite filter. Further, the coating can be selected to minimize any reactions between the constituents of the fluids and the fibers. A description is given of the formation of a composite filter using a felt preform of commercial silicon carbide fibers together with the coating of these fibers with pure silicon carbide. Filter efficiency approaching 100% has been demonstrated with these filters. The fiber base material is alternately made from aluminosilicate fibers, zirconia fibers and alumina fibers. Coating with Al.sub.2 O.sub.3 is also described. Advanced configurations for the composite filter are suggested.

  13. Rockslide deformation monitoring with fiber optic strain sensors

    Directory of Open Access Journals (Sweden)

    J. R. Moore

    2010-02-01

    Full Text Available With micro-strain resolution and the capability to sample at rates of 100 Hz and higher, fiber optic (FO strain sensors offer exciting new possibilities for in-situ landslide monitoring. Here we describe a new FO monitoring system based on long-gauge fiber Bragg grating sensors installed at the Randa Rockslide Laboratory in southern Switzerland. The new FO monitoring system can detect sub-micrometer scale deformations in both triggered-dynamic and continuous measurements. Two types of sensors have been installed: (1 fully embedded borehole sensors and (2 surface extensometers. Dynamic measurements are triggered by sensor deformation and recorded at 100 Hz, while continuous data are logged every 5 min. Deformation time series for all sensors show displacements consistent with previous monitoring. Accelerated shortening following installation of the borehole sensors is likely related to long-term shrinkage of the grout. A number of transient signals have been observed, which in some cases were large enough to trigger rapid sampling. The combination of short- and long-term observation offers new insight into the deformation process. Accelerated surface crack opening in spring is shown to have a diurnal trend, which we attribute to the effect of snowmelt seeping into the crack void space and freezing at night to generate pressure on the crack walls. Controlled-source tests investigated the sensor response to dynamic inputs, which compared an independent measure of ground motion against the strain measured across a surface crack. Low frequency signals were comparable but the FO record suffered from aliasing, where undersampling of higher frequency signals generated spectral peaks not related to ground motion.

  14. Shaped fiber composites

    Energy Technology Data Exchange (ETDEWEB)

    Kinnan, Mark K.; Roach, Dennis P.

    2017-12-05

    A composite article is disclosed that has non-circular fibers embedded in a polymer matrix. The composite article has improved damage tolerance, toughness, bending, and impact resistance compared to composites having traditional round fibers.

  15. High-fiber foods

    Science.gov (United States)

    ... that have higher amounts of fiber, such as whole-wheat bread versus white bread. ... cereals, such as oatmeal and farina (Cream of Wheat) Whole-grain breads Brown rice Popcorn High-fiber cereals, such as ...

  16. Fiber Optics Instrumentation Development

    Science.gov (United States)

    Chan, Patrick Hon Man; Parker, Allen R., Jr.; Richards, W. Lance

    2010-01-01

    This is a general presentation of fiber optics instrumentation development work being conducted at NASA Dryden for the past 10 years and recent achievements in the field of fiber optics strain sensors.

  17. Superlattice Microstructured Optical Fiber

    Directory of Open Access Journals (Sweden)

    Ming-Leung Vincent Tse

    2014-06-01

    Full Text Available A generic three-stage stack-and-draw method is demonstrated for the fabrication of complex-microstructured optical fibers. We report the fabrication and characterization of a silica superlattice microstructured fiber with more than 800 rhomboidally arranged air-holes. A polarization-maintaining fiber with a birefringence of 8.5 × 10−4 is demonstrated. The birefringent property of the fiber is found to be highly insensitive to external environmental effects, such as pressure.

  18. Fundamentals of fiber lasers and fiber amplifiers

    CERN Document Server

    Ter-Mikirtychev, Valerii (Vartan)

    2014-01-01

    This book covers the fundamental aspects of fiber lasers and fiber amplifiers, and includes a wide range of material from laser physics fundamentals to state-of-the-art topics in this rapidly growing field of quantum electronics. Emphasis is placed on the nonlinear processes taking place in fiber lasers and amplifiers, their similarities, differences to, and their advantages over other solid-state lasers. The reader will learn basic principles of solid-state physics and optical spectroscopy of laser active centers in fibers, main operational laser regimes, and practical recommendations and suggestions on fiber laser research, laser applications, and laser product development. The book will be useful for students, researchers, and professionals who work with lasers, in the optical communications, chemical and biological industries, etc.

  19. Fiber optic coupled optical sensor

    Science.gov (United States)

    Fleming, Kevin J.

    2001-01-01

    A displacement sensor includes a first optical fiber for radiating light to a target, and a second optical fiber for receiving light from the target. The end of the first fiber is adjacent and not axially aligned with the second fiber end. A lens focuses light from the first fiber onto the target and light from the target onto the second fiber.

  20. Mineral Fiber Toxicology

    Science.gov (United States)

    The chemical and physical properties of different forms of mineral fibers impact biopersistence and pathology in the lung. Fiber chemistry, length, aspect ratio, surface area and dose are critical factors determining mineral fiber-associated health effects including cancer and as...

  1. Fiber Lasers V

    DEFF Research Database (Denmark)

    Hansen, Kim P.; Olausson, Christina Bjarnal Thulin; Broeng, Jes

    2008-01-01

    High-power fiber lasers and amplifiers have gained tremendous momentum in the last five years, and many of the traditional manufactures of gas and solid-state lasers are pursuing the attractive fiber-based systems, which are now displacing the old technology in many areas. High-power fiber laser ...

  2. Resonant filtered fiber amplifiers

    DEFF Research Database (Denmark)

    Alkeskjold, Thomas Tanggaard; Laurila, Marko; Olausson, Christina Bjarnal Thulin

    2013-01-01

    In this paper we present our recent result on utilizing resonant/bandgap fiber designs to achieve high performance ytterbium doped fiber amplifers for achieving diffraction limited beam quality in large mode area fibers, robust bending performance and gain shaping for long wavelength operation...

  3. Variability and interrelation of yield components in fiber hemp

    Directory of Open Access Journals (Sweden)

    Sikora Vladimir

    2011-01-01

    Full Text Available Variability and interrelation of yield components in fiber hemp were analysed in field experiments. This research included 20 commercial varieties currently being cultivated in Europe. Significant variability was determined for plant height, stem yield, fiber content and fiber yield, so these materials can be useful as a good base for future fiber hemp breeding and production improvement. Stem diameter was predominantly determined by ecological factors, and genetic background of examined varieties had small influence on expression of this trait. Regarding expression of other yield components, influence of genetic factors was more important than environmental conditions. Correlation between analyzed traits shows that high stem and fiber yield are achieved in higher populations of fiber hemp with thicker stem. Fiber content increased with stem thickness increase.

  4. Airclad fiber laser technology

    DEFF Research Database (Denmark)

    Hansen, Kim P.; Olausson, Christina Bjarnal Thulin; Broeng, Jes

    2008-01-01

    High-power fiber lasers and amplifiers have gained tremendous momentum in the last five years, and many of the traditional manufactures of gas and solid-state lasers are pursuing the attractive fiber-based systems, which are now displacing the old technology in many areas. High-power fiber laser...... systems require specially designed fibers with large cores and good power handling capabilities - requirements that are all met by the airclad fiber technology. In the present paper we go through many of the building blocks needed to build high-power systems and we show an example of a complete airclad...... laser system. We present the latest advancements within airclad fiber technology including a new 70 μm single-mode polarization-maintaining rod-type fiber capable of amplifying to MW power levels. Furthermore we describe the novel airclad based pump combiners and their use in a completely monolithic 350...

  5. Airclad fiber laser technology

    DEFF Research Database (Denmark)

    Hansen, Kim P.; Olausson, Christina Bjarnal Thulin; Broeng, Jes

    2011-01-01

    High-power fiber lasers and amplifiers have gained tremendous momentum in the last 5 years. Many of the traditional manufacturers of gas and solid-state lasers are now pursuing the fiber-based systems, which are displacing the conventional technology in many areas. High-power fiber laser systems...... require reliable fibers with large cores, stable mode quality, and good power handling capabilities-requirements that are all met by the airclad fiber technology. In the present paper we go through many of the building blocks needed to build high-power systems and we show an example of a complete airclad...... laser system. We present the latest advancements within airclad fiber technology including a new 100 m single-mode polarization-maintaining rod-type fiber capable of amplifying to megawatt power levels. Furthermore, we describe the novel airclad-based pump combiners and their use in a completely...

  6. ZrO2 thin-film-based sapphire fiber temperature sensor.

    Science.gov (United States)

    Wang, Jiajun; Lally, Evan M; Wang, Xiaoping; Gong, Jianmin; Pickrell, Gary; Wang, Anbo

    2012-04-20

    A submicrometer-thick zirconium dioxide film was deposited on the tip of a polished C-plane sapphire fiber to fabricate a temperature sensor that can work to an extended temperature range. Zirconium dioxide was selected as the thin film material to fabricate the temperature sensor because it has relatively close thermal expansion to that of sapphire, but more importantly it does not react appreciably with sapphire up to 1800 °C. In order to study the properties of the deposited thin film, ZrO2 was also deposited on C-plane sapphire substrates and characterized by x-ray diffraction for phase analysis as well as by atomic force microscopy for analysis of surface morphology. Using low-coherence optical interferometry, the fabricated thin-film-based sapphire fiber sensor was tested in the lab up to 1200 °C and calibrated from 200° to 1000 °C. The temperature resolution is determined to be 5.8 °C when using an Ocean Optics USB4000 spectrometer to detect the reflection spectra from the ZrO2 thin-film temperature sensor.

  7. Electrohydrodynamic atomization: an approach to growing continuous self-supporting polymeric fibers.

    Science.gov (United States)

    Jayasinghe, S N; Sullivan, A C

    2006-02-16

    The investigation presented in this paper illustrates a technique for growing in-situ polymerized networks, forming scaffold-like structures usually formed by means of electrospinning. The technique of jet atomization employing electrohydrodynamics is a manifestation of electrospinning. However, we show for the first time that using this technique where individual droplets are generated, a continuous self-supporting submicrometer web-like structure can be grown whereby fragments of the structure are delivered in the droplets and polymerize on the surface of the growing structure via polycondensation. The development of these growing fibers into web structures is a direct result of the processing route together with the excellent tailor-made cross-linking nature of the resin. An operational map is generated to identify a parametric space in which the stable cone-jet mode of electrohydrodynamic atomization prevails for generating the finest droplets. A statistical analysis on the formed fibers for a given time and electrospray condition is presented together with optical micrographs of the structure, which concludes the discussion in this paper.

  8. Efficiency of erbium 3-µm crystal and fiber lasers

    NARCIS (Netherlands)

    Pollnau, Markus; Spring, R.; Ghisler, C.; Wittwer, S.; Lüthy, W.; Weber, H.P.

    1996-01-01

    The population dynamics of erbium 3-μm crystal and fiber lasers are compared experimentally and theoretically. Laser slope efficiencies of 40% in Er:LiYF4 and 23% in a fluorozirconate fiber are experimentally demonstrated under Ti:sapphire pumping. These are both to our knowledge the highest values

  9. Hierarchically Structured Electrospun Fibers

    Directory of Open Access Journals (Sweden)

    Nicole E. Zander

    2013-01-01

    Full Text Available Traditional electrospun nanofibers have a myriad of applications ranging from scaffolds for tissue engineering to components of biosensors and energy harvesting devices. The generally smooth one-dimensional structure of the fibers has stood as a limitation to several interesting novel applications. Control of fiber diameter, porosity and collector geometry will be briefly discussed, as will more traditional methods for controlling fiber morphology and fiber mat architecture. The remainder of the review will focus on new techniques to prepare hierarchically structured fibers. Fibers with hierarchical primary structures—including helical, buckled, and beads-on-a-string fibers, as well as fibers with secondary structures, such as nanopores, nanopillars, nanorods, and internally structured fibers and their applications—will be discussed. These new materials with helical/buckled morphology are expected to possess unique optical and mechanical properties with possible applications for negative refractive index materials, highly stretchable/high-tensile-strength materials, and components in microelectromechanical devices. Core-shell type fibers enable a much wider variety of materials to be electrospun and are expected to be widely applied in the sensing, drug delivery/controlled release fields, and in the encapsulation of live cells for biological applications. Materials with a hierarchical secondary structure are expected to provide new superhydrophobic and self-cleaning materials.

  10. Multicolor, Fluorescent Supercapacitor Fiber.

    Science.gov (United States)

    Liao, Meng; Sun, Hao; Zhang, Jing; Wu, Jingxia; Xie, Songlin; Fu, Xuemei; Sun, Xuemei; Wang, Bingjie; Peng, Huisheng

    2017-10-05

    Fiber-shaped supercapacitors have attracted broad attentions from both academic and industrial communities due to the demonstrated potentials as next-generation power modules. However, it is important while remains challenging to develop dark-environment identifiable supercapacitor fibers for enhancement on operation convenience and security in nighttime applications. Herein, a novel family of colorful fluorescent supercapacitor fibers has been produced from aligned multi-walled carbon nanotube sheets. Fluorescent dye particles are introduced and stably anchored on the surfaces of aligned multi-walled carbon nanotubes to prepare hybrid fiber electrodes with a broad range of colors from red to purple. The fluorescent component in the dye introduces fluorescent indication capability to the fiber, which is particularly promising for flexible and wearable devices applied in dark environment. In addition, the colorful fluorescent supercapacitor fibers also maintain high electrochemical performance under cyclic bending and charge-discharge processes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Continuous Fiber Ceramic Composites

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-09-01

    Fiber-reinforced ceramic composites demonstrate the high-temperature stability of ceramics--with an increased fracture toughness resulting from the fiber reinforcement of the composite. The material optimization performed under the continuous fiber ceramic composites (CFCC) included a series of systematic optimizations. The overall goals were to define the processing window, to increase the robustinous of the process, to increase process yield while reducing costs, and to define the complexity of parts that could be fabricated.

  12. Oriented Fiber Filter Media

    OpenAIRE

    R. Bharadwaj; A. Patel, S. Chokdeepanich, Ph.D.; G.G. Chase, Ph.D.

    2008-01-01

    Coalescing filters are widely used throughout industry and improved performance will reduce droplet emissions and operating costs. Experimental observations show orientation of micro fibers in filter media effect the permeability and the separation efficiency of the filter media. In this work two methods are used to align the fibers to alter the filter structure. The results show that axially aligned fiber media improve quality factor on the order of 20% and cutting media on an angle from a t...

  13. Agave Americana Leaf Fibers

    Directory of Open Access Journals (Sweden)

    Ashish Hulle

    2015-02-01

    Full Text Available The growing environmental problems, the problem of waste disposal and the depletion of non-renewable resources have stimulated the use of green materials compatible with the environment to reduce environmental impacts. Therefore, there is a need to design products by using natural resources. Natural fibers seem to be a good alternative since they are abundantly available and there are a number of possibilities to use all the components of a fiber-yielding crop; one such fiber-yielding plant is Agave Americana. The leaves of this plant yield fibers and all the parts of this plant can be utilized in many applications. The “zero-waste” utilization of the plant would enable its production and processing to be translated into a viable and sustainable industry. Agave Americana fibers are characterized by low density, high tenacity and high moisture absorbency in comparison with other leaf fibers. These fibers are long and biodegradable. Therefore, we can look this fiber as a sustainable resource for manufacturing and technical applications. Detailed discussion is carried out on extraction, characterization and applications of Agave Americana fiber in this paper.

  14. Add Fiber without Extra Calories

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_166315.html Add Fiber Without Extra Calories How to fill up, not ... 6, 2017 (HealthDay News) -- Are you getting enough fiber in your diet? According to the National Fiber ...

  15. Soluble and insoluble fiber (image)

    Science.gov (United States)

    ... stool. There are two types of dietary fiber, soluble and insoluble. Soluble fiber retains water and turns to gel during ... and nutrient absorption from the stomach and intestine. Soluble fiber is found in foods such as oat ...

  16. Applications of nonlinear fiber optics

    CERN Document Server

    Agrawal, Govind

    2008-01-01

    * The only book describing applications of nonlinear fiber optics * Two new chapters on the latest developments: highly nonlinear fibers and quantum applications* Coverage of biomedical applications* Problems provided at the end of each chapterThe development of new highly nonlinear fibers - referred to as microstructured fibers, holey fibers and photonic crystal fibers - is the next generation technology for all-optical signal processing and biomedical applications. This new edition has been thoroughly updated to incorporate these key technology developments.The bo

  17. Super capacitor with fibers

    Science.gov (United States)

    Farmer, Joseph Collin; Kaschmitter, James

    2015-02-17

    An electrical cell apparatus includes a first current collector made of a multiplicity of fibers, a second current collector spaced from the first current collector; and a separator disposed between the first current collector and the second current collector. The fibers are contained in a foam.

  18. Fiber Sensor Technology Today

    Science.gov (United States)

    Hotate, Kazuo

    2006-08-01

    Fiber sensor technologies are overviewed. Since the early 1970s, this field has been developed, on the basis of the same devices and photonic principles as fiber communication technologies. Besides simple configurations, in which the fiber acts only as a data transmission line, sophisticated configurations have also been developed, in which the fiber is used as a device to realize unique sensing mechanisms. The fiber optic gyroscope (FOG) is a good example, and has been developed as an absolute rotation sensor used, for example, for navigation and/or attitude control applications. Compared with traditional spinning-mass gyroscopes, the FOG has advantages, such as a short warming-up time, a light weight, and easy handling. A Japanese satellite, which was launched in August 2005 with a mission to observe the aurora, is controlled with a FOG. The FOG has also been used in consumer applications, such as the camera stabilizer, radio-controlled (RC) helicopter navigation, and the control of humanoid robots. Recently, distributed and multiplexed sensing schemes, in particular, have been studied and developed, in which a long fiber acts like a “nerve” for feeling the strain and/or the temperature distribution along the fiber. Performances of artificial nerve systems have markedly improved within the last couple of years, in spatial resolution and measurement speed. By embedding the “fiber-optic nerve system” in aircraft wings, bridges and tall buildings, these materials and structures can sense damage to prevent disasters.

  19. Fiber reinforced engineering plastics

    Science.gov (United States)

    Daniel F. Caulfield; Rodney E. Jacobson; Karl D. Sears; John H. Underwood

    2001-01-01

    Although natural fiber reinforced commodity thermoplastics have a wide range of nonstructural applications in the automotive and decking industries, there have been few reports of cellulosic fiber-reinforced engineering thermoplastics. The commonly held belief has been that the only thermoplastics amenable to natural-fibre reinforcement are limited to low-melting (...

  20. High-density multicore fibers

    DEFF Research Database (Denmark)

    Takenaga, K.; Matsuo, S.; Saitoh, K.

    2016-01-01

    High-density single-mode multicore fibers were designed and fabricated. A heterogeneous 30-core fiber realized a low crosstalk of −55 dB. A quasi-single-mode homogeneous 31-core fiber attained the highest core count as a single-mode multicore fiber.......High-density single-mode multicore fibers were designed and fabricated. A heterogeneous 30-core fiber realized a low crosstalk of −55 dB. A quasi-single-mode homogeneous 31-core fiber attained the highest core count as a single-mode multicore fiber....

  1. Raman fiber lasers

    CERN Document Server

    2017-01-01

    This book serves as a comprehensive, up-to-date reference about this cutting-edge laser technology and its many new and interesting developments. Various aspects and trends of Raman fiber lasers are described in detail by experts in their fields. Raman fiber lasers have progressed quickly in the past decade, and have emerged as a versatile laser technology for generating high power light sources covering a spectral range from visible to mid-infrared. The technology is already being applied in the fields of telecommunication, astronomy, cold atom physics, laser spectroscopy, environmental sensing, and laser medicine. This book covers various topics relating to Raman fiber laser research, including power scaling, cladding and diode pumping, cascade Raman shifting, single frequency operation and power amplification, mid-infrared laser generation, specialty optical fibers, and random distributed feedback Raman fiber lasers. The book will appeal to scientists, students, and technicians seeking to understand the re...

  2. Python fiber optic seal

    Energy Technology Data Exchange (ETDEWEB)

    Ystesund, K.; Bartberger, J.; Brusseau, C.; Fleming, P.; Insch, K.; Tolk, K.

    1993-08-01

    Sandia National Laboratories has developed a high security fiber optic seal that incorporates tamper resistance features that are not available in commercial fiber optic seals. The Python Seal is a passive fiber optic loop seal designed to give indication of unauthorized entry. The seal includes a fingerprint feature that provides seal identity information in addition to the unique fiber optic pattern created when the seal is installed. The fiber optic cable used for the seal loop is produced with tamper resistant features that increase the difficulty of attacking that component of a seal. A Seal Reader has been developed that will record the seal signature and the fingerprint feature of the seal. A Correlator software program then compares seal images to establish a match or mismatch. SNL is also developing a Polaroid reader to permit hard copies of the seal patterns to be obtained directly from the seal.

  3. Green insulation: hemp fibers

    Energy Technology Data Exchange (ETDEWEB)

    Anon

    2011-09-15

    Indian hemp (Cannabis indica) is known for its psychotropic values and it is banned in most countries. However, industrial hemp (Cannabis sativa) is known for its tough fibers. Several manufactures in Europe including, small niche players, have been marketing hemp insulation products for several years. Hemp is a low environmental impact material. Neither herbicide nor pesticide is used during the growth of hemp. The fibers are extracted in a waste-free and chemical-free mechanical process. Hemp can consume CO2 during its growth. In addition, hemp fiber can be disposed of harmlessly by composting or incineration at the end of its life. Hemp fibers are processed and treated only minimally to resist rot and fungal activity. There is little health risk when producing and installing the insulation, thanks to the absence of toxic additive. Its thermal resistance is comparable to mineral wool. But the development and marketing of hemp fibers may be restricted in North America.

  4. Fiber optic hydrophone

    Science.gov (United States)

    Kuzmenko, P.J.; Davis, D.T.

    1994-05-10

    A miniature fiber optic hydrophone based on the principles of a Fabry-Perot interferometer is disclosed. The hydrophone, in one embodiment, includes a body having a shaped flexible bladder at one end which defines a volume containing air or suitable gas, and including a membrane disposed adjacent a vent. An optical fiber extends into the body with one end terminating in spaced relation to the membrane. Acoustic waves in the water that impinge on the bladder cause the pressure of the volume therein to vary causing the membrane to deflect and modulate the reflectivity of the Fabry-Perot cavity formed by the membrane surface and the cleaved end of the optical fiber disposed adjacent to the membrane. When the light is transmitted down the optical fiber, the reflected signal is amplitude modulated by the incident acoustic wave. Another embodiment utilizes a fluid filled volume within which the fiber optic extends. 2 figures.

  5. Compound Droplets on Fibers.

    Science.gov (United States)

    Weyer, Floriane; Ben Said, Marouen; Hötzer, Johannes; Berghoff, Marco; Dreesen, Laurent; Nestler, Britta; Vandewalle, Nicolas

    2015-07-21

    Droplets on fibers have been extensively studied in the recent years. Although the equilibrium shapes of simple droplets on fibers are well established, the situation becomes more complex for compound fluidic systems. Through experimental and numerical investigations, we show herein that compound droplets can be formed on fibers and that they adopt specific geometries. We focus on the various contact lines formed at the meeting of the different phases and we study their equilibrium state. It appears that, depending on the surface tensions, the triple contact lines can remain separate or merge together and form quadruple lines. The nature of the contact lines influences the behavior of the compound droplets on fibers. Indeed, both experimental and numerical results show that, during the detachment process, depending on whether the contact lines are triple or quadruple, the characteristic length is the inner droplet radius or the fiber radius.

  6. Method for the preparation of carbon fiber from polyolefin fiber precursor, and carbon fibers made thereby

    Science.gov (United States)

    Naskar, Amit Kumar; Hunt, Marcus Andrew; Saito, Tomonori

    2015-08-04

    Methods for the preparation of carbon fiber from polyolefin fiber precursor, wherein the polyolefin fiber precursor is partially sulfonated and then carbonized to produce carbon fiber. Methods for producing hollow carbon fibers, wherein the hollow core is circular- or complex-shaped, are also described. Methods for producing carbon fibers possessing a circular- or complex-shaped outer surface, which may be solid or hollow, are also described.

  7. Position of the American Dietetic Association: health implications of dietary fiber.

    Science.gov (United States)

    Slavin, Joanne L

    2008-10-01

    It is the position of the American Dietetic Association that the public should consume adequate amounts of dietary fiber from a variety of plant foods. Populations that consume more dietary fiber have less chronic disease. In addition, intake of dietary fiber has beneficial effects on risk factors for developing several chronic diseases. Dietary Reference Intakes recommend consumption of 14 g dietary fiber per 1,000 kcal, or 25 g for adult women and 38 g for adult men, based on epidemiologic studies showing protection against cardiovascular disease. Appropriate kinds and amounts of dietary fiber for children, the critically ill, and the very old are unknown. The Dietary Reference Intakes for fiber are based on recommended energy intake, not clinical fiber studies. Usual intake of dietary fiber in the United States is only 15 g/day. Although solubility of fiber was thought to determine physiological effect, more recent studies suggest other properties of fiber, perhaps fermentability or viscosity are important parameters. High-fiber diets provide bulk, are more satiating, and have been linked to lower body weights. Evidence that fiber decreases cancer is mixed and further research is needed. Healthy children and adults can achieve adequate dietary fiber intakes by increasing variety in daily food patterns. Dietary messages to increase consumption of high-fiber foods such as whole grains, legumes, fruits, and vegetables should be broadly supported by food and nutrition professionals. Consumers are also turning to fiber supplements and bulk laxatives as additional fiber sources. Few fiber supplements have been studied for physiological effectiveness, so the best advice is to consume fiber in foods. Look for physiological studies of effectiveness before selecting functional fibers in dietetics practice.

  8. Fiber optic spanner

    Science.gov (United States)

    Black, Bryan; Mohanty, Samarendra

    2011-10-01

    Rotation is a fundamental function in nano/biotechnology and is being useful in a host of applications such as pumping of fluid flow in microfluidic channels for transport of micro/nano samples. Further, controlled rotation of single cell or microscopic object is useful for tomographic imaging. Though conventional microscope objective based laser spanners (based on transfer of spin or orbital angular momentum) have been used in the past, they are limited by the short working distance of the microscope objective. Here, we demonstrate development of a fiber optic spanner for rotation of microscopic objects using single-mode fiber optics. Fiber-optic trapping and simultaneous rotation of pin-wheel structure around axis perpendicular to fiber-optic axis was achieved using the fiber optic spanner. By adjusting the laser beam power, rotation speed of the trapped object and thus the microfluidic flow could be controlled. Since this method does not require special optical or structural properties of the sample to be rotated, three-dimensional rotation of a spherical cell could also be controlled. Further, using the fiber optic spanner, array of red blood cells could be assembled and actuated to generate vortex motion. Fiber optical trapping and spinning will enable physical and spectroscopic analysis of microscopic objects in solution and also find potential applications in lab- on-a-chip devices.

  9. Fiber optic hydrogen sensor

    Science.gov (United States)

    Buchanan, B.R.; Prather, W.S.

    1991-01-01

    Apparatus and method for detecting a chemical substance by exposing an optic fiber having a core and a cladding to the chemical substance so that the chemical substance can be adsorbed onto the surface of the cladding. The optic fiber is coiled inside a container having a pair of valves for controlling the entrance and exit of the substance. Light from a light source is received by one end of the optic fiber, preferably external to the container, and carried by the core of the fiber. Adsorbed substance changes the transmissivity of the fiber as measured by a spectrophotometer at the other end, also preferably external to the container. Hydrogen is detected by the absorption of infrared light carried by an optic fiber with a silica cladding. Since the adsorption is reversible, a sensor according to the present invention can be used repeatedly. Multiple positions in a process system can be monitored using a single container that can be connected to each location to be monitored so that a sample can be obtained for measurement, or, alternatively, containers can be placed near each position and the optic fibers carrying the partially-absorbed light can be multiplexed for rapid sequential reading, by a single spectrophotometer.

  10. Fiber Bragg grating inscription in optical multicore fibers

    Science.gov (United States)

    Becker, Martin; Elsmann, Tino; Lorenz, Adrian; Spittel, Ron; Kobelke, Jens; Schuster, Kay; Rothhardt, Manfred; Latka, Ines; Dochow, Sebastian; Bartelt, Hartmut

    2015-09-01

    Fiber Bragg gratings as key components in telecommunication, fiber lasers, and sensing systems usually rely on the Bragg condition for single mode fibers. In special applications, such as in biophotonics and astrophysics, high light coupling efficiency is of great importance and therefore, multimode fibers are often preferred. The wavelength filtering effect of Bragg gratings in multimode fibers, however is spectrally blurred over a wide modal spectrum of the fiber. With a well-designed all solid multicore microstructured fiber a good light guiding efficiency in combination with narrow spectral filtering effect by Bragg gratings becomes possible.

  11. Kinetics of stress fibers

    Energy Technology Data Exchange (ETDEWEB)

    Stachowiak, Matthew R; O' Shaughnessy, Ben [Department of Chemical Engineering, Columbia University, New York, NY 10027 (United States)], E-mail: bo8@columbia.edu

    2008-02-15

    Stress fibers are contractile cytoskeletal structures, tensile actomyosin bundles which allow sensing and production of force, provide cells with adjustable rigidity and participate in various processes such as wound healing. The stress fiber is possibly the best characterized and most accessible multiprotein cellular contractile machine. Here we develop a quantitative model of the structure and relaxation kinetics of stress fibers. The principal experimentally known features are incorporated. The fiber has a periodic sarcomeric structure similar to muscle fibers with myosin motor proteins exerting contractile force by pulling on actin filaments. In addition the fiber contains the giant spring-like protein titin. Actin is continuously renewed by exchange with the cytosol leading to a turnover time of several minutes. In order that steady state be possible, turnover must be regulated. Our model invokes simple turnover and regulation mechanisms: actin association and dissociation occur at filament ends, while actin filament overlap above a certain threshold in the myosin-containing regions augments depolymerization rates. We use the model to study stress fiber relaxation kinetics after stimulation, as observed in a recent experimental study where some fiber regions were contractile and others expansive. We find that two distinct episodes ensue after stimulation: the turnover-overlap system relaxes rapidly in seconds, followed by the slow relaxation of sarcomere lengths in minutes. For parameter values as they have been characterized experimentally, we find the long time relaxation of sarcomere length is set by the rate at which actin filaments can grow or shrink in response to the forces exerted by the elastic and contractile elements. Consequently, the stress fiber relaxation time scales inversely with both titin spring constant and the intrinsic actin turnover rate. The model's predicted sarcomere velocities and contraction-expansion kinetics are in good

  12. Characteristics research on self-amplified distributed feedback fiber laser

    Science.gov (United States)

    Song, Zhiqiang; Qi, Haifeng; Guo, Jian; Wang, Chang; Peng, Gangding

    2014-09-01

    A distributed feedback (DFB) fiber laser with a ratio of the backward to forward output power of 1:100 was composed by a 45-mm-length asymmetrical phase-shifted fiber grating fabricated on the 50-mm erbium-doped photosensitive fiber. Forward output laser was amplified using a certain length of Nufern EDFL-980-Hp erbium-doped fiber to absorb the surplus pump power after the active phase-shifted fiber grating and get population inversion. By using OptiSystem software, the best fiber length of the EDFL to get the highest gain was simulated. In order to keep the amplified laser with the narrow line-width and low noise, a narrow-band light filter consisting of a fiber Bragg grating (FBG) with the same Bragg wavelength as the laser and an optical circulator was used to filter the amplified spontaneous emission (ASE) noise of the out-cavity erbium-doped fiber. The designed laser structure sufficiently utilized the pump power, and a DFB fiber laser with the 32.5-mW output power, 11.5-kHz line width, and -87-dB/Hz relative intensity noise (RIN) at 300 mW of 980 nm pump power was brought out.

  13. Nonlinear fiber optics

    CERN Document Server

    Agrawal, Govind P

    2001-01-01

    The Optical Society of America (OSA) and SPIE - The International Society for Optical Engineering have awarded Govind Agrawal with an honorable mention for the Joseph W. Goodman Book Writing Award for his work on Nonlinear Fiber Optics, 3rd edition.Nonlinear Fiber Optics, 3rd Edition, provides a comprehensive and up-to-date account of the nonlinear phenomena occurring inside optical fibers. It retains most of the material that appeared in the first edition, with the exception of Chapter 6, which is now devoted to the polarization effects relevant for light propagation in optical

  14. Birefringent hollow core fibers

    DEFF Research Database (Denmark)

    Roberts, John

    2007-01-01

    Hollow core photonic crystal fiber (HC-PCF), fabricated according to a nominally non-birefringent design, shows a degree of un-controlled birefringence or polarization mode dispersion far in excess of conventional non polarization maintaining fibers. This can degrade the output pulse in many...... and an increased overlap between the polarization modes at the glass interfaces. The interplay between these effects leads to a wavelength for optimum polarization maintenance, lambda(PM), which is detuned from the wavelength of highest birefringence. By a suitable fiber design involving antiresonance of the core...

  15. QUARTZ FIBER ELECTROSCOPES

    Science.gov (United States)

    Henderson, R.P.

    1957-09-17

    An instrument carried unobtrusively about the person such as in a finger ring to indicate when that person has been exposed to an unusual radiation hazard is described. A metallized quartz fiber is electrically charged to indicate a full scale reading on an etched glass background. The quartz fiber and the scale may be viewed through a magnifying lens for ease of reading. Incident radiation will ionize gaseous particles in the sealed structure thereby allowing the charge to leak off the quartz fiber with its resulting movement across the scale proportionally indicating the radiation exposure.

  16. Public health implications of dietary fiber intake to reduce the cost of chronic diseases

    OpenAIRE

    Fazakas, Z; Tarcea, M; Szucs, V; Zsolt, K; Eniko, NN; Guiné, R

    2016-01-01

    Objective: To assess the epidemiological evidence on dietary fiber intake and chronic diseases and make public health recommendations for the population in Romania based on their consumption. Populations that consume more dietary fiber from cereals, fruits and vegetables have less chronic disease. Dietary Reference Intakes recommend consumption of 14 g dietary fiber per 1,000 kcal, or 25 g for adult women and 38 g for adult men, based on epidemiologic studies showing protection against ca...

  17. Tunable femtosecond Cherenkov fiber laser

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Svane, Ask Sebastian; Lægsgaard, Jesper

    2014-01-01

    We demonstrate electrically-tunable femtosecond Cherenkov fiber laser output at the visible range. Using an all-fiber, self-starting femtosecond Yb-doped fiber laser as the pump source and nonlinear photonic crystal fiber link as the wave-conversion medium, ultrafast, milliwatt-level, tunable...

  18. Carbon Fiber Risk Analysis. [conference

    Science.gov (United States)

    1979-01-01

    The scope and status of the effort to assess the risks associated with the accidental release of carbon/graphite fibers from civil aircraft is presented. Vulnerability of electrical and electronic equipment to carbon fibers, dispersal of carbon fibers, effectiveness of filtering systems, impact of fiber induced failures, and risk methodology are among the topics covered.

  19. Fiber bundle phase conjugate mirror

    Science.gov (United States)

    Ward, Benjamin G.

    2012-05-01

    An improved method and apparatus for passively conjugating the phases of a distorted wavefronts resulting from optical phase mismatch between elements of a fiber laser array are disclosed. A method for passively conjugating a distorted wavefront comprises the steps of: multiplexing a plurality of probe fibers and a bundle pump fiber in a fiber bundle array; passing the multiplexed output from the fiber bundle array through a collimating lens and into one portion of a non-linear medium; passing the output from a pump collection fiber through a focusing lens and into another portion of the non-linear medium so that the output from the pump collection fiber mixes with the multiplexed output from the fiber bundle; adjusting one or more degrees of freedom of one or more of the fiber bundle array, the collimating lens, the focusing lens, the non-linear medium, or the pump collection fiber to produce a standing wave in the non-linear medium.

  20. Fiber Optics: No Illusion.

    Science.gov (United States)

    American School and University, 1983

    1983-01-01

    A campus computer center at Hofstra University (New York) that holds 70 terminals for student use was first a gymnasium, then a language laboratory. Strands of fiber optics are used for the necessary wiring. (MLF)

  1. Ways to Boost Fiber

    Science.gov (United States)

    ... Workout Nutrition Timing Your Pre- and Post-Workout Nutrition weights and fruits Building Muscle on a Vegetarian Diet For Kids For Parents For Men For Women For Seniors Easy Ways to Boost Fiber in Your Daily ...

  2. Fiber optic data transmission

    Science.gov (United States)

    Shreve, Steven T.

    1987-01-01

    The Ohio University Avionics Engineering Center is currently developing a fiber optic data bus transmission and reception system that could eventually replace copper cable connections in airplanes. The original form of the system will transmit information from an encoder to a transponder via a fiber optic cable. An altimeter and an altitude display are connected to a fiber optic transmitter by copper cable. The transmitter converts the altimetry data from nine bit parallel to serial form and send these data through a fiber optic cable to a receiver. The receiver converts the data using a cable similar to that used between the altimeter and display. The transmitting and receiving ends also include a display readout. After completion and ground testing of the data bus, the system will be tested in an airborne environment.

  3. Fiber optics standard dictionary

    CERN Document Server

    Weik, Martin H

    1997-01-01

    Fiber Optics Vocabulary Development In 1979, the National Communications System published Technical InfonnationBulle­ tin TB 79-1, Vocabulary for Fiber Optics and Lightwave Communications, written by this author. Based on a draft prepared by this author, the National Communications System published Federal Standard FED-STD-1037, Glossary of Telecommunications Terms, in 1980 with no fiber optics tenns. In 1981, the first edition of this dictionary was published under the title Fiber Optics and Lightwave Communications Standard Dictionary. In 1982, the then National Bureau of Standards, now the National Institute of Standards and Technology, published NBS Handbook 140, Optical Waveguide Communications Glossary, which was also published by the General Services Admin­ istration as PB82-166257 under the same title. Also in 1982, Dynamic Systems, Inc. , Fiberoptic Sensor Technology Handbook, co-authored and edited by published the this author, with an extensive Fiberoptic Sensors Glossary. In 1989, the handbook w...

  4. Hybrid photonic crystal fiber

    National Research Council Canada - National Science Library

    Arismar Cerqueira S. Jr; F. Luan; C. M. B. Cordeiro; A. K. George; J. C. Knight

    2006-01-01

    We present a hybrid photonic crystal fiber in which a guided mode is confined simultaneously by modified total internal reflection from an array of air holes and antiresonant reflection from a line...

  5. Fiber optic gas sensor

    Science.gov (United States)

    Chen, Peng (Inventor); Buric, Michael P. (Inventor); Swinehart, Philip R. (Inventor); Maklad, Mokhtar S. (Inventor)

    2010-01-01

    A gas sensor includes an in-fiber resonant wavelength device provided in a fiber core at a first location. The fiber propagates a sensing light and a power light. A layer of a material is attached to the fiber at the first location. The material is able to absorb the gas at a temperature dependent gas absorption rate. The power light is used to heat the material and increases the gas absorption rate, thereby increasing sensor performance, especially at low temperatures. Further, a method is described of flash heating the gas sensor to absorb more of the gas, allowing the sensor to cool, thereby locking in the gas content of the sensor material, and taking the difference between the starting and ending resonant wavelengths as an indication of the concentration of the gas in the ambient atmosphere.

  6. Raman Scattering of Inorganic Fibers

    OpenAIRE

    SASAKI, Yoshiro; Sato, Mitsuhiko; OKAMURA, Kiyohito; NISHINA, Yuichiro

    1985-01-01

    We have examined evolution of Raman spectra of carbon fibers and SiC fibers through structural transformations caused by heat treatment. Raman spectra of the SiC fibers indicate that the fibers consist of amorphous or microcrystalline SiC and graphitic microcrystals. We discuss the correlation between the tensile strength of the fibers and their microscopic structure deduced from the Raman data.

  7. Health benefits of dietary fiber

    OpenAIRE

    Anderson, JW; Baird, P.; Davis, RH; Ferreri, S.; Knudtson, M.; Koraym, A; Waters, V; Williams, CL

    2009-01-01

    Dietary fiber intake provides many health benefits. However, average fiber intakes for US children and adults are less than half of the recommended levels. Individuals with high intakes of dietary fiber appear to be at significantly lower risk for developing coronary heart disease, stroke, hypertension, diabetes, obesity, and certain gastrointestinal diseases. Increasing fiber intake lowers blood pressure and serum cholesterol levels. Increased intake of soluble fiber improves glycemia and in...

  8. Radiation Damage of Quartz Fibers

    OpenAIRE

    Hagopian, V

    1999-01-01

    Quartz fibers are used in high energy physics experiments as the active medium in high radiation area calorimetry. Quartz fibers are also used in the transmission of optical signals. Even though quartz does not damage by moderate amounts of irradiation, the clad of the fibers and the protective coating ( buffer) do damage reducing light transmission. Various types of quartz fibers have been irradiated and measured for light transmission. The most radiation hard quartz fibers are those with qu...

  9. Fiber optics welder

    Science.gov (United States)

    Higgins, R.W.; Robichaud, R.E.

    A system is described for welding fiber optic waveguides together. The ends of the two fibers to be joined together are accurately, collinearly aligned in a vertical orientation and subjected to a controlled, diffuse arc to effect welding and thermal conditioning. A front-surfaced mirror mounted at a 45/sup 0/ angle to the optical axis of a stereomicroscope mounted for viewing the junction of the ends provides two orthogonal views of the interface during the alignment operation.

  10. Brominated graphitized carbon fibers

    Science.gov (United States)

    Hung, Ching-Cheh (Inventor)

    1991-01-01

    Low cost, high break elongation graphitized carbon fibers having low degree of graphitization are inert to bromine at room or higher temperatures, but are brominated at -7 to 20 C, and then debrominated at ambient. Repetition of this bromination-debromination process can bring the bromine content to 18 percent. Electrical conductivity of the brominated fibers is three times of the before-bromination value.

  11. Infrared fiber optic materials

    Science.gov (United States)

    Feigelson, Robert S.

    1987-01-01

    The development of IR fiber optics for use in astronomical and other space applications is summarized. Candidate materials were sought for use in the 1 to 200 micron and the 200 to 1000 micron wavelength range. Synthesis and optical characterization were carried out on several of these materials in bulk form. And the fabrication of a few materials in single crystal fiber optic form were studied.

  12. Electrospun Amplified Fiber Optics

    OpenAIRE

    Morello, Giovanni; Camposeo, Andrea; Moffa, Maria; Pisignano, Dario

    2015-01-01

    A lot of research is focused on all-optical signal processing, aiming to obtain effective alternatives to existing data transmission platforms. Amplification of light in fiber optics, such as in Erbium-doped fiber amplifiers, is especially important for an efficient signal transmission. However, the complex fabrication methods, involving high-temperature processes performed in highly pure environment, slow down the fabrication and make amplified components expensive with respect to an ideal, ...

  13. Thermodynamics of fiber bundles

    OpenAIRE

    Pride, Steven R.; Toussaint, Renaud

    2002-01-01

    A recent theory that determines the properties of disordered solids as the solid accumulates damage is applied to the special case of fiber bundles with global load sharing and is shown to be exact in this case. The theory postulates that the probability of observing a given emergent damage state is obtained by maximizing the emergent entropy as defined by Shannon subject to energetic constraints. This theory yields the known exact results for the fiber-bundle model with global load sharing a...

  14. Graphite Fibers from Pitch

    Science.gov (United States)

    1976-09-01

    filtering it through the screen. The first filter cake usually shrinks away from the ring upon drying; the crack is filled up by a second filtration ...structures. 9 Magnetoresistance perpendicular to the axis of Type P fibers with different structures and thermal history . 10 Magnetoresistance...parallel to the axis of Type P fibers with different structures and thermal history . 11 Plot of the transverse magnetoresistance versus the resistivity

  15. Fiber optic detector

    Energy Technology Data Exchange (ETDEWEB)

    Partin, J.K.; Ward, T.E.; Grey, A.E.

    1990-12-31

    This invention is comprised of a portable fiber optic detector that senses the presence of specific target chemicals by exchanging the target chemical for a fluorescently-tagged antigen that is bound to an antibody which is in turn attached to an optical fiber. Replacing the fluorescently-tagged antigen reduces the fluorescence so that a photon sensing detector records the reduced light level and activates an appropriate alarm or indicator.

  16. Extending fiber resources : fiber loading recycled fiber and mechanical pulps for lightweight, high opacity paper

    Science.gov (United States)

    Marguerite Sykes; John Klungness; Freya Tan; Mathew Stroika; Said Abubakr

    1999-01-01

    Production of a lightweight, high opacity printing paper is a common goal of papermakers using virgin or recycled fibers. Fiber loading is an innovative, commercially viable process that can substantially upgrade and extend most types of wood fibers. Fiber loading, a process carried out at high consistency and high alkalinity, precipitates calcium carbonate (PCC) in...

  17. Electrospun amplified fiber optics.

    Science.gov (United States)

    Morello, Giovanni; Camposeo, Andrea; Moffa, Maria; Pisignano, Dario

    2015-03-11

    All-optical signal processing is the focus of much research aiming to obtain effective alternatives to existing data transmission platforms. Amplification of light in fiber optics, such as in Erbium-doped fiber amplifiers, is especially important for efficient signal transmission. However, the complex fabrication methods involving high-temperature processes performed in a highly pure environment slow the fabrication process and make amplified components expensive with respect to an ideal, high-throughput, room temperature production. Here, we report on near-infrared polymer fiber amplifiers working over a band of ∼20 nm. The fibers are cheap, spun with a process entirely carried out at room temperature, and shown to have amplified spontaneous emission with good gain coefficients and low levels of optical losses (a few cm(-1)). The amplification process is favored by high fiber quality and low self-absorption. The found performance metrics appear to be suitable for short-distance operations, and the large variety of commercially available doping dyes might allow for effective multiwavelength operations by electrospun amplified fiber optics.

  18. Sub-micrometer 20MeV protons or 45MeV lithium spot irradiation enhances yields of dicentric chromosomes due to clustering of DNA double-strand breaks.

    Science.gov (United States)

    Schmid, T E; Friedland, W; Greubel, C; Girst, S; Reindl, J; Siebenwirth, C; Ilicic, K; Schmid, E; Multhoff, G; Schmitt, E; Kundrát, P; Dollinger, G

    2015-11-01

    In conventional experiments on biological effects of radiation types of diverse quality, micrometer-scale double-strand break (DSB) clustering is inherently interlinked with clustering of energy deposition events on nanometer scale relevant for DSB induction. Due to this limitation, the role of the micrometer and nanometer scales in diverse biological endpoints cannot be fully separated. To address this issue, hybrid human-hamster AL cells have been irradiated with 45MeV (60keV/μm) lithium ions or 20MeV (2.6keV/μm) protons quasi-homogeneously distributed or focused to 0.5×1μm(2) spots on regular matrix patterns (point distances up to 10.6×10.6μm), with pre-defined particle numbers per spot to provide the same mean dose of 1.7Gy. The yields of dicentrics and their distribution among cells have been scored. In parallel, track-structure based simulations of DSB induction and chromosome aberration formation with PARTRAC have been performed. The results show that the sub-micrometer beam focusing does not enhance DSB yields, but significantly affects the DSB distribution within the nucleus and increases the chance to form DSB pairs in close proximity, which may lead to increased yields of chromosome aberrations. Indeed, the experiments show that focusing 20 lithium ions or 451 protons per spot on a 10.6μm grid induces two or three times more dicentrics, respectively, than a quasi-homogenous irradiation. The simulations reproduce the data in part, but in part suggest more complex behavior such as saturation or overkill not seen in the experiments. The direct experimental demonstration that sub-micrometer clustering of DSB plays a critical role in the induction of dicentrics improves the knowledge on the mechanisms by which these lethal lesions arise, and indicates how the assumptions of the biophysical model could be improved. It also provides a better understanding of the increased biological effectiveness of high-LET radiation. Copyright © 2015 Elsevier B.V. All

  19. Cellulosic Fibers: Effect of Processing on Fiber Bundle Strength

    DEFF Research Database (Denmark)

    Thygesen, Anders; Madsen, Bo; Thomsen, Anne Belinda

    2011-01-01

    A range of differently processed cellulosic fibers from flax and hemp plants were investigated to study the relation between processing of cellulosic fibers and fiber bundle strength. The studied processing methods are applied for yarn production and include retting, scutching, carding, and cotto......A range of differently processed cellulosic fibers from flax and hemp plants were investigated to study the relation between processing of cellulosic fibers and fiber bundle strength. The studied processing methods are applied for yarn production and include retting, scutching, carding...

  20. Chaotic dynamics in erbium-doped fiber ring lasers

    Science.gov (United States)

    Abarbanel, Henry D. I.; Kennel, Matthew B.; Buhl, Michael; Tureman Lewis, Clifford

    1999-09-01

    Chaotically oscillating rare-earth-doped fiber ring lasers (DFRLs) may provide an attractive way to exploit the broad bandwidth available in an optical communications system. Recent theoretical and experimental investigations have successfully shown techniques to modulate information onto the wide-band chaotic oscillations, transmit that signal along an optical fiber, and demodulate the information at the receiver. We develop a theoretical model of a DFRL and discuss an efficient numerical simulation which includes intrinsic linear and nonlinear induced birefringence, both transverse polarizations, group velocity dispersion, and a finite gain bandwidth. We analyze first a configuration with a single loop of optical fiber containing the doped fiber amplifier, and then, as suggested by Roy and VanWiggeren, we investigate a system with two rings of optical fiber-one made of passive fiber alone. The typical round-trip time for the passive optical ring connecting the erbium-doped amplifier to itself is 200 ns, so ~105 round-trips are required to see the slow effects of the population inversion dynamics in this laser system. Over this large number of round-trips, physical effects like GVD and the Kerr nonlinearity, which may appear small at our frequencies and laser powers via conventional estimates, may accumulate and dominate the dynamics. We demonstrate from our model that chaotic oscillations of the ring laser with parameters relevant to erbium-doped fibers arises from the nonlinear Kerr effect and not from interplay between the atomic population inversion and radiation dynamics.

  1. Man-made mineral fibers and interstitial lung diseases.

    Science.gov (United States)

    Fireman, Elizabeth

    2014-03-01

    Manufactured (artificial) fibers represent an important and continuously growing volume among substitutes to natural fibers. A major proportion of the population in an industrialized society has been, is, or will be in contact with these fibers. The fibrous configuration of asbestos is well recognized as being an important parameter in toxicity, and now that of synthetic fibers is also suspected of inducing serious health effects on the respiratory system. There is an ongoing debate about the actual fibrogenic effect of these man-made mineral fibers (MMMFs) in humans. Several case reports have demonstrated the biopersistance of MMMFs in the lung of workers who were exposed to rock wool or fiberglass for long periods of time and were diagnosed with interstitial pulmonary fibrosis. A 20-year follow up also identified refractory ceramic fibers in workers' lung tissue, with significant association between cumulative fiber exposure and radiographic pleural changes. Newly emerging man-made fiber industries appear to induce new types of occupational diseases. Exposure of workers in MMMFs production plants is correlated to high risk for developing pneumoconiosis. Large epidemiological studies are needed in order to determine dose metrics for risk assessment and management.

  2. Characteristics research of self-amplified distributed feedback fiber laser

    Science.gov (United States)

    Song, Zhiqiang; Qi, Haifeng; Guo, Jian; Wang, Chang; Peng, Gangding

    2013-09-01

    A distributed feedback (DFB) fiber laser with a ratio of backward to forward output power of 1:100 was composed by a 45mm length asymmetrical phase-shifted fiber grating fabricated on 50mm erbium-doped photosensitive fiber. Forward output laser was amplified using a certain length of Nufern EDFL980-Hp erbium-doped fiber to absorb surplus pump power after the active phase-shifted fiber grating and get population inversion. Using OptiSystem software, the best fiber length of the EDFL to get the highest gain was simulated. In order to keep the amplified laser with narrow line-width and low noise, a narrow-band light filter consisted of a FBG with the same Bragg wavelength as the laser and an optical circulator was used to filter the ASE noise of the out-cavity erbium-doped fiber. The designed laser structure sufficiently utilized the pump power, a DFB fiber laser of 32.5mW output power, 11.5 kHz line width, and -87dB/Hz relative intensity noise (RIN) at 300mW of 980 nm pump power was brought out.

  3. Detailed investigation of submicrometer-sized grains of chemically sprayed (Sn{sub 1-x}Al{sub x}, O{sub 2}) (0 {<=} x {<=} 0.085) thin films

    Energy Technology Data Exchange (ETDEWEB)

    Benhaliliba, M., E-mail: mbenhaliliba@gmail.com [Physics Department, Science Faculty, Oran University of Sciences and Technology, USTOMB, BP1505 Oran (Algeria); Benouis, C.E., E-mail: babimo14@yahoo.fr [Physics Department, Science Faculty, Oran University of Sciences and Technology, USTOMB, BP1505 Oran (Algeria); Yakuphanoglu, F. [Firat University, Physics Department, Faculty of Sciences and Arts, 23119 Elazig (Turkey); Tiburcio-Silver, A. [ITT-DIEE, Apdo, Postal 20, Metepec 3, 52176 Estado de Mexico (Mexico); Aydin, C. [Firat University, Physics Department, Faculty of Sciences and Arts, 23119 Elazig (Turkey); Hamzaoui, S. [Laboratoire de Microscope Electronique et Sciences des Materiaux, USTOMB, BP1505 Oran (Algeria); Mouffak, Z. [Department of Electrical and Computer Engineering, California State University, Fresno, CA (United States)

    2012-06-25

    Highlights: Black-Right-Pointing-Pointer The pure and Al doped SnO{sub 2} nanostructures are chemically sprayed from (SnCl{sub 4}{center_dot}5H{sub 2}O) as starting material and aluminum (3+) chloride (AlCl{sub 3}) as doping source. Black-Right-Pointing-Pointer The X-rays of these nanostructures were analyzed and largely investigated. Further more details were obtained. Black-Right-Pointing-Pointer Al doped SnO{sub 2} nanostructures can be prepared by spray pyrolysis for advanced technological applications such as sensors. Black-Right-Pointing-Pointer Pictures and parameters of AFM analysis were described, several results for advanced and applied physics and technology were revealed. - Abstract: In this study, the submicrometer-sized grains of chemically sprayed tin oxide, SnO{sub 2}, were largely investigated. The films (Sn{sub 1-x}O{sub 2}, Al{sub x}), with x = 0-0.085 were grown by spray pyrolysis onto glass at a fixed temperature of 300 Degree-Sign C. Structural, optical, electrical and morphological properties were studied. These films are polycrystalline in nature with a tetragonal crystalline structure, and exhibited a preferred orientation along the (2 0 0) planes. Atomic force microscope (AFM) analysis demonstrated a nano-grain structure. Our nanostructured films revealed high transparency in the visible and infra-red spectra and an electrical resistivity that ranged from 1 to1000 {Omega} cm.

  4. Fiber-reinforced technology in multidisciplinary chairside approaches

    OpenAIRE

    Arhun Neslihan; Arman Ayca

    2008-01-01

    There is an increasing demand to improve dentofacial esthetics in the adult population. This demand usually requires a close collaboration within the various disciplines of dentistry and the patient at every stage of the therapy. The materials and techniques used by these interdisciplinary clinicians must be conservative and minimally invasive. Fiber-reinforced composite technology offers such solutions for chairside applications. This case report presents two cases where fiber-reinforced rib...

  5. Fiber-optic technology review

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, P.B.

    1980-01-01

    A history of fiber technology is presented. The advantages of fiber optics are discussed (bandwidth, cost, weight and size, nonmetallic construction and isolation). Some aspects of the disadvantages of fiber systems briefly discussed are fiber and cable availability, fiber components, radiation effects, receivers and transmitters, and material dispersion. Particular emphasis over the next several years will involve development of fibers and systems optimized for use at wavelengths near 1.3 ..mu..m and development of wavelengths multiplexers for simultaneous system operation at several wavelengths.

  6. Position of the Academy of Nutrition and Dietetics: Health Implications of Dietary Fiber.

    Science.gov (United States)

    Dahl, Wendy J; Stewart, Maria L

    2015-11-01

    It is the position of the Academy of Nutrition and Dietetics that the public should consume adequate amounts of dietary fiber from a variety of plant foods. Dietary fiber is defined by the Institute of Medicine Food Nutrition Board as "nondigestible carbohydrates and lignin that are intrinsic and intact in plants." Populations that consume more dietary fiber have less chronic disease. Higher intakes of dietary fiber reduce the risk of developing several chronic diseases, including cardiovascular disease, type 2 diabetes, and some cancers, and have been associated with lower body weights. The Adequate Intake for fiber is 14 g total fiber per 1,000 kcal, or 25 g for adult women and 38 g for adult men, based on research demonstrating protection against coronary heart disease. Properties of dietary fiber, such as fermentability and viscosity, are thought to be important parameters influencing the risk of disease. Plant components associated with dietary fiber may also contribute to reduced disease risk. The mean intake of dietary fiber in the United States is 17 g/day with only 5% of the population meeting the Adequate Intake. Healthy adults and children can achieve adequate dietary fiber intakes by increasing their intake of plant foods while concurrently decreasing energy from foods high in added sugar and fat, and low in fiber. Dietary messages to increase consumption of whole grains, legumes, vegetables, fruits, and nuts should be broadly supported by food and nutrition practitioners. Copyright © 2015 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  7. Carbon Fiber Composites

    Science.gov (United States)

    1997-01-01

    HyComp(R), Inc. development a line of high temperature carbon fiber composite products to solve wear problems in the harsh environment of steel and aluminum mills. WearComp(R), self-lubricating composite wear liners and bushings, combines carbon graphite fibers with a polyimide binder. The binder, in conjunction with the fibers, provides the slippery surface, one that demands no lubrication, yet wears at a very slow rate. WearComp(R) typically lasts six to ten times longer than aluminum bronze. Unlike bronze, WearComp polishes the same surface and imparts a self-lube film for years of service. It is designed for continuous operation at temperatures of 550 degrees Fahrenheit and can operate under high compressive loads.

  8. Multibeam fiber laser cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove; Hansen, Klaus Schütt; Nielsen, Jakob Skov

    2009-01-01

    The appearance of the high power high brilliance fiber laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating Cutting laser, the CO2 laser. However, quality problems in fiber......-laser cutting have until now limited its application to metal cutting. In this paper the first results of proof-of-principle Studies applying a new approach (patent pending) for laser cutting with high brightness and short wavelength lasers will be presented. In the approach, multibeam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from two single mode fiber lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W...

  9. Carving fiber-top optomechanical transducers from an optical fiber

    NARCIS (Netherlands)

    Deladi, S.; Iannuzzi, D.; Gadgil, V.J.; Schreuders, H.; Elwenspoek, Michael Curt

    2006-01-01

    In a recent paper (Iannuzzi et al 2006 Monolithic fiber-top sensor for critical environments and standard applications Appl. Phys. Lett. 88 053501) we have presented the principle of the fiber-top position sensor, having a monolytical structure carved out of a single-mode optical fiber. The device

  10. Monolithic Yb-fiber femtosecond laser using photonic crystal fiber

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

    2008-01-01

    We demonstrate, both experimentally and theoretically, an environmentally stable monolithic all-PM modelocked femtosecond Yb-fiber laser, with laser output pulse compressed in a spliced-on low-loss hollow-core photonic crystal fiber. Our laser provides direct fiber-end delivery of 4 nJ pulses...

  11. Single fiber pullout from hybrid fiber reinforced concrete

    NARCIS (Netherlands)

    Markovich, I.; Van Mier, J.G.M.; Walraven, J.C.

    2001-01-01

    Hybrid fiber reinforcement can be very efficient for improving the tensile response of the composite. In such materials, fibers of different geometries can act as bridging mechanisms over cracks of different widths. The fiber bridging efficiency depends on the interface properties, which makes

  12. Fluoride glass fiber optics

    CERN Document Server

    Aggarwal, Ishwar D

    1991-01-01

    Fluoride Glass Fiber Optics reviews the fundamental aspects of fluoride glasses. This book is divided into nine chapters. Chapter 1 discusses the wide range of fluoride glasses with an emphasis on fluorozirconate-based compositions. The structure of simple fluoride systems, such as BaF2 binary glass is elaborated in Chapter 2. The third chapter covers the intrinsic transparency of fluoride glasses from the UV to the IR, with particular emphasis on the multiphonon edge and electronic edge. The next three chapters are devoted to ultra-low loss optical fibers, reviewing methods for purifying and

  13. Optical fiber rotation sensing

    CERN Document Server

    Burns, William K; Kelley, Paul

    1993-01-01

    Optical Fiber Rotation Sensing is the first book devoted to Interferometric Fiber Optic Gyros (IFOG). This book provides a complete overview of IFOGs, beginning with a historical review of IFOG development and including a fundamental exposition of basic principles, a discussion of devices and components, and concluding with industry reports on state-of-the-art activity. With several chapters contributed by principal developers of this solid-state device, the result is an authoritative work which will serve as the resource for researchers, students, and users of IFOGs.* * State-of-t

  14. Optical fiber telecommunications IIIb

    CERN Document Server

    Koch, Thomas L

    2012-01-01

    Updated to include the latest information on light wave technology, Optical Fiber Telecommunication III, Volumes A & B are invaluable for scientists, students, and engineers in the modern telecommunications industry. This two-volume set includes the most current research available in optical fiber telecommunications, light wave technology, and photonics/optoelectronics. The authors cover important background concepts such as SONET, coding device technology, andWOM components as well as projecting the trends in telecommunications for the 21st century.Key Features* One of the hottest subjects of

  15. Nonlinear fiber optics

    CERN Document Server

    Agrawal, Govind

    2012-01-01

    Since the 4e appeared, a fast evolution of the field has occurred. The 5e of this classic work provides an up-to-date account of the nonlinear phenomena occurring inside optical fibers, the basis of all our telecommunications infastructure as well as being used in the medical field. Reflecting the big developments in research, this new edition includes major new content: slow light effects, which offers a reduction in noise and power consumption and more ordered network traffic-stimulated Brillouin scattering; vectorial treatment of highly nonlinear fibers; and a brand new chapter o

  16. Fiber MOPA for Ascends Project

    Data.gov (United States)

    National Aeronautics and Space Administration — CO2 sensing using absorption bands near 1570nm is very attractive by taking advantage of the mature fiber-amplifier technology derived from fiber-optic telecom...

  17. Fiber and Prebiotics: Mechanisms and Health Benefits

    OpenAIRE

    Slavin, Joanne

    2013-01-01

    The health benefits of dietary fiber have long been appreciated. Higher intakes of dietary fiber are linked to less cardiovascular disease and fiber plays a role in gut health, with many effective laxatives actually isolated fiber sources. Higher intakes of fiber are linked to lower body weights. Only polysaccharides were included in dietary fiber originally, but more recent definitions have included oligosaccharides as dietary fiber, not based on their chemical measurement as dietary fiber b...

  18. Dietary fiber, kidney function, inflammation, and mortality risk.

    Science.gov (United States)

    Xu, Hong; Huang, Xiaoyan; Risérus, Ulf; Krishnamurthy, Vidya M; Cederholm, Tommy; Arnlöv, Johan; Lindholm, Bengt; Sjögren, Per; Carrero, Juan Jesús

    2014-12-05

    In the United States population, high dietary fiber intake has been associated with a lower risk of inflammation and mortality in individuals with kidney dysfunction. This study aimed to expand such findings to a Northern European population. Dietary fiber intake was calculated from 7-day dietary records in 1110 participants aged 70-71 years from the Uppsala Longitudinal Study of Adult Men (examinations performed during 1991-1995). Dietary fiber was adjusted for total energy intake by the residual method. Renal function was estimated from the concentration of serum cystatin C, and deaths were registered prospectively during a median follow-up of 10.0 years. Dietary fiber independently and directly associated with eGFR (adjusted difference, 2.6 ml/min per 1.73 m(2) per 10 g/d higher; 95% confidence interval [95% CI], 0.3 to 4.9). The odds of C-reactive protein >3 mg/L were lower (linear trend, P=0.002) with higher fiber quartiles. During follow-up, 300 participants died (incidence rate of 2.87 per 100 person-years at risk). Multiplicative interactions were observed between dietary fiber intake and kidney dysfunction in the prediction of mortality. Higher dietary fiber was associated with lower mortality in unadjusted analysis. These associations were stronger in participants with kidney dysfunction (eGFRdietary fiber was associated with better kidney function and lower inflammation in community-dwelling elderly men from Sweden. High dietary fiber was also associated with lower (cancer) mortality risk, especially in individuals with kidney dysfunction. Copyright © 2014 by the American Society of Nephrology.

  19. Advances on Optical Fiber Sensors

    Directory of Open Access Journals (Sweden)

    Luciano Mescia

    2013-12-01

    Full Text Available In this review paper some recent advances on optical fiber sensors are reported. In particular, fiber Bragg grating (FBG, long period gratings (LPGs, evanescent field and hollow core optical fiber sensors are mentioned. Examples of recent optical fiber sensors for the measurement of strain, temperature, displacement, air flow, pressure, liquid-level, magnetic field, and the determination of methadone, hydrocarbons, ethanol, and sucrose are briefly described.

  20. Boron nitride converted carbon fiber

    Science.gov (United States)

    Rousseas, Michael; Mickelson, William; Zettl, Alexander K.

    2016-04-05

    This disclosure provides systems, methods, and apparatus related to boron nitride converted carbon fiber. In one aspect, a method may include the operations of providing boron oxide and carbon fiber, heating the boron oxide to melt the boron oxide and heating the carbon fiber, mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide, and converting at least a portion of the carbon fiber to boron nitride.

  1. Fiber-Reinforced Slip Castings

    Science.gov (United States)

    Blome, J. C.; Drennan, D. N.; Keeser, H. M.

    1982-01-01

    Addition of silica fibers greatly reduces shrinkage and cracking during casting of ceramics. Fiber-reinforced slip-cast silica ceramics are also tougher and have lower dielectric loss. Silica fibers are hyperpure material containing only 1 part per million total metal-ion impurities. Hyperpure fibers ensure high reflectance and allow casting to be fired at temperature greater than 2,200 degrees F without loss of strength from devitrification.

  2. Polymer Bonding of Optical Fibers

    Science.gov (United States)

    Goss, W.; Nelson, M. D.

    1983-01-01

    Optical waveguies coupled through their sides. In fiber etching process bonded length for coupling determined by observing optical output powers in two fibers. Surface tension of etchant remaining between two fibes holds then in contact when raised from solution for power measurement. When fibers reimmersed, they separate allowing free access by etchant.

  3. Photonic-crystal fibers gyroscope

    Directory of Open Access Journals (Sweden)

    Ali Muse Haider

    2015-01-01

    Full Text Available In this paper we proposed to use of a photonic crystal fiber with an inner hollow defect. The use of such fibers is not affected by a material medium on the propagation of optical radiation. Photonic crystal fibers present special properties and capabilities that lead to an outstanding potential for sensing applications

  4. Short fiber reinforced thermoplastic blends

    NARCIS (Netherlands)

    Malchev, P.G.

    2008-01-01

    The present thesis investigates the potential of short fiber reinforced thermoplastic blends, a combination of an immiscible polymer blend and a short fiber reinforced composite, to integrate the easy processing solutions available for short fiber reinforced composites with the high mechanical

  5. Mid-infrared fiber lasers

    NARCIS (Netherlands)

    Pollnau, Markus; Jackson, Stuart D.; Sorokina, I.T.; Vodopyanov, K.L.

    2003-01-01

    The current state of the art in mid-infrared fiber lasers is reviewed in this chapter. The relevant fiber-host materials such as silicates, fluorides, chalcogenides, and ceramics, the fiber, pump, and resonator geometries, and the spectroscopic properties of rare-earth ions are introduced. Lasers at

  6. Neuroanatomic Fiber Orientation Maps (FOMs)

    DEFF Research Database (Denmark)

    Axer, Hubertus; Jantzen, Jan; Grässel, David

    2002-01-01

    A new neuroanatomic method is described which allows to map the orientation of central nervous fibers in gross histological sections. Polarised light is used to calculate the angle of inclination and direction of the fibers in each pixel. Serial fiber orientation maps (FOMs) can be aligned and 3D...

  7. Aerogel-clad optical fiber

    Science.gov (United States)

    Sprehn, Gregory A.; Hrubesh, Lawrence W.; Poco, John F.; Sandler, Pamela H.

    1997-01-01

    An optical fiber is surrounded by an aerogel cladding. For a low density aerogel, the index of refraction of the aerogel is close to that of air, which provides a high numerical aperture to the optical fiber. Due to the high numerical aperture, the aerogel clad optical fiber has improved light collection efficiency.

  8. Fabrication of Optical Fiber Devices

    Science.gov (United States)

    Andres, Miguel V.

    In this paper we present the main research activities of the Laboratorio de Fibras Opticas del Instituto de Ciencia de los Materiales de la Universidad de Valencia. We show some of the main results obtained for devices based on tapered fibers, fiber Bragg gratings, acousto-optic effects and photonic crystal fibers.

  9. Optical fiber sensors measurement system and special fibers improvement

    Science.gov (United States)

    Jelinek, Michal; Hrabina, Jan; Hola, Miroslava; Hucl, Vaclav; Cizek, Martin; Rerucha, Simon; Lazar, Josef; Mikel, Bretislav

    2017-06-01

    We present method for the improvement of the measurement accuracy in the optical frequency spectra measurements based on tunable optical filters. The optical filter was used during the design and realization of the measurement system for the inspection of the fiber Bragg gratings. The system incorporates a reference block for the compensation of environmental influences, an interferometric verification subsystem and a PC - based control software implemented in LabView. The preliminary experimental verification of the measurement principle and the measurement system functionality were carried out on a testing rig with a specially prepared concrete console in the UJV Řež. The presented system is the laboratory version of the special nuclear power plant containment shape deformation measurement system which was installed in the power plant Temelin during last year. On the base of this research we started with preparation other optical fiber sensors to nuclear power plants measurement. These sensors will be based on the microstructured and polarization maintaining optical fibers. We started with development of new methods and techniques of the splicing and shaping optical fibers. We are able to made optical tapers from ultra-short called adiabatic with length around 400 um up to long tapers with length up to 6 millimeters. We developed new techniques of splicing standard Single Mode (SM) and Multimode (MM) optical fibers and splicing of optical fibers with different diameters in the wavelength range from 532 to 1550 nm. Together with development these techniques we prepared other techniques to splicing and shaping special optical fibers like as Polarization-Maintaining (PM) or hollow core Photonic Crystal Fiber (PCF) and theirs cross splicing methods with focus to minimalize backreflection and attenuation. The splicing special optical fibers especially PCF fibers with standard telecommunication and other SM fibers can be done by our developed techniques. Adjustment

  10. Funky inorganic fibers

    NARCIS (Netherlands)

    de Wit, Patrick

    2017-01-01

    Inorganic porous hollow fibers (IPHF) are interesting for various applications that can benefit from a high surface-area-to-volume ratio. Examples include membranes, catalysts, electrodes, and combinations of these. The thesis starts with providing an overview of conceivable materials of which IPHF

  11. Bluebonnet Fiber Collages

    Science.gov (United States)

    Sterling, Joan

    2009-01-01

    This article presents a lesson that uses stitching and applique techniques to create a fiber collage in which every child is successful with high-quality work. This lesson was inspired by Tomie dePaola's "The Legend of the Bluebonnet." The back cover had a lovely illustration of the bluebonnet flower the author thought would translate easily to a…

  12. Infrared Fiber Optic Sensors

    Science.gov (United States)

    1997-01-01

    Successive years of Small Business Innovation Research (SBIR) contracts from Langley Research Center to Sensiv Inc., a joint venture between Foster-Miller Inc. and Isorad, Ltd., assisted in the creation of remote fiber optic sensing systems. NASA's SBIR interest in infrared, fiber optic sensor technology was geared to monitoring the curing cycles of advanced composite materials. These funds helped in the fabrication of an infrared, fiber optic sensor to track the molecular vibrational characteristics of a composite part while it is being cured. Foster-Miller ingenuity allowed infrared transmitting optical fibers to combine with Fourier Transform Infrared spectroscopy to enable remote sensing. Sensiv probes operate in the mid-infrared range of the spectrum, although modifications to the instrument also permits its use in the near-infrared region. The Sensiv needle-probe is built to be placed in a liquid or powder and analyze the chemicals in the mixture. Other applications of the probe system include food processing control; combustion control in furnaces; and maintenance problem solving.

  13. Interferometric fiber optic sensors.

    Science.gov (United States)

    Lee, Byeong Ha; Kim, Young Ho; Park, Kwan Seob; Eom, Joo Beom; Kim, Myoung Jin; Rho, Byung Sup; Choi, Hae Young

    2012-01-01

    Fiber optic interferometers to sense various physical parameters including temperature, strain, pressure, and refractive index have been widely investigated. They can be categorized into four types: Fabry-Perot, Mach-Zehnder, Michelson, and Sagnac. In this paper, each type of interferometric sensor is reviewed in terms of operating principles, fabrication methods, and application fields. Some specific examples of recently reported interferometeric sensor technologies are presented in detail to show their large potential in practical applications. Some of the simple to fabricate but exceedingly effective Fabry-Perot interferometers, implemented in both extrinsic and intrinsic structures, are discussed. Also, a wide variety of Mach-Zehnder and Michelson interferometric sensors based on photonic crystal fibers are introduced along with their remarkable sensing performances. Finally, the simultaneous multi-parameter sensing capability of a pair of long period fiber grating (LPG) is presented in two types of structures; one is the Mach-Zehnder interferometer formed in a double cladding fiber and the other is the highly sensitive Sagnac interferometer cascaded with an LPG pair.

  14. Interferometric Fiber Optic Sensors

    Directory of Open Access Journals (Sweden)

    Hae Young Choi

    2012-02-01

    Full Text Available Fiber optic interferometers to sense various physical parameters including temperature, strain, pressure, and refractive index have been widely investigated. They can be categorized into four types: Fabry-Perot, Mach-Zehnder, Michelson, and Sagnac. In this paper, each type of interferometric sensor is reviewed in terms of operating principles, fabrication methods, and application fields. Some specific examples of recently reported interferometeric sensor technologies are presented in detail to show their large potential in practical applications. Some of the simple to fabricate but exceedingly effective Fabry-Perot interferometers, implemented in both extrinsic and intrinsic structures, are discussed. Also, a wide variety of Mach-Zehnder and Michelson interferometric sensors based on photonic crystal fibers are introduced along with their remarkable sensing performances. Finally, the simultaneous multi-parameter sensing capability of a pair of long period fiber grating (LPG is presented in two types of structures; one is the Mach-Zehnder interferometer formed in a double cladding fiber and the other is the highly sensitive Sagnac interferometer cascaded with an LPG pair.

  15. High Power Fiber Lasers

    Science.gov (United States)

    2012-08-02

    Optics, Information and Photonics, University of Erlangen- Nuremberg , Germany, June 2007. INVITED 14. A. Siegman, “Index Antiguided Optical Fibers and...Lasers” seminar given at the Institute for Optics, Information and Photonics, University of Erlangen- Nuremberg , Germany, June 2007. INVITED 14. A

  16. The dentate mossy fibers

    DEFF Research Database (Denmark)

    Blaabjerg, Morten; Zimmer, Jens

    2007-01-01

    and taking interesting turns, the mossy fibers display a number of unique features with regard to axonal projections, terminal structures and synaptic contacts, development and variations among species and strains, as well as to normal occurring and lesion-induced plasticity and neural transplantation...

  17. Hyaluronic Acid/PLGA Core/Shell Fiber Matrices Loaded with EGCG Beneficial to Diabetic Wound Healing.

    Science.gov (United States)

    Shin, Yong Cheol; Shin, Dong-Myeong; Lee, Eun Ji; Lee, Jong Ho; Kim, Ji Eun; Song, Sung Hwa; Hwang, Dae-Youn; Lee, Jun Jae; Kim, Bongju; Lim, Dohyung; Hyon, Suong-Hyu; Lim, Young-Jun; Han, Dong-Wook

    2016-12-01

    During the last few decades, considerable research on diabetic wound healing strategies has been performed, but complete diabetic wound healing remains an unsolved problem, which constitutes an enormous biomedical burden. Herein, hyaluronic acid (HA)/poly(lactic-co-glycolic acid, PLGA) core/shell fiber matrices loaded with epigallocatechin-3-O-gallate (EGCG) (HA/PLGA-E) are fabricated by coaxial electrospinning. HA/PLGA-E core/shell fiber matrices are composed of randomly-oriented sub-micrometer fibers and have a 3D porous network structure. EGCG is uniformly dispersed in the shell and sustainedly released from the matrices in a stepwise manner by controlled diffusion and PLGA degradation over four weeks. EGCG does not adversely affect the thermomechanical properties of HA/PLGA-E matrices. The number of human dermal fibroblasts attached on HA/PLGA-E matrices is appreciably higher than that on HA/PLGA counterparts, while their proliferation is steadily retained on HA/PLGA-E matrices. The wound healing activity of HA/PLGA-E matrices is evaluated in streptozotocin-induced diabetic rats. After two weeks of surgical treatment, the wound areas are significantly reduced by the coverage with HA/PLGA-E matrices resulting from enhanced re-epithelialization/neovascularization and increased collagen deposition, compared with no treatment or HA/PLGA. In conclusion, the HA/PLGA-E matrices can be potentially exploited to craft strategies for the acceleration of diabetic wound healing and skin regeneration. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Congenital fiber type disproportion.

    Science.gov (United States)

    Kissiedu, Juliana; Prayson, Richard A

    2016-04-01

    Type I muscle fiber atrophy in childhood can be encountered in a variety of neuromuscular disorders. Congenital fiber type disproportion (CFTD) is one such condition which presents as a nonprogressive muscle weakness. The diagnosis is often made after excluding other differential diagnostic considerations. We present a 2-year-9-month-old full term boy who presented at 2 months with an inability to turn his head to the right. Over the next couple of years, he showed signs of muscle weakness, broad based gait and a positive Gower's sign. He had normal levels of creatine kinase and normal electromyography. A biopsy of the vastus lateralis showed a marked variation in muscle fiber type. The adenosine triphosphate (ATP)-ase stains highlighted a marked type I muscle atrophy with rare scattered atrophic type II muscle fibers. No abnormalities were observed on the nicotinamide adenine dinucleotide (NADH), succinate dehydrogenase (SDH) or cytochrome oxidase stained sections. Ragged red fibers were not present on the trichrome stain. Abnormalities of glycogen or lipid deposition were not observed on the periodic acid-Schiff or Oil-Red-O stains. Immunostaining for muscular dystrophy associated proteins showed normal staining. Ultrastructural examination showed a normal arrangement of myofilaments, and a normal number and morphology for mitochondria. A diagnosis of CFTD was made after excluding other causes of type I atrophy including congenital myopathy. The lack of specific clinical and genetic disorder associated with CFTD suggests that it is a spectrum of a disease process and represents a diagnosis of exclusion. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Health Benefits of Fiber Fermentation.

    Science.gov (United States)

    Dahl, Wendy J; Agro, Nicole C; Eliasson, Åsa M; Mialki, Kaley L; Olivera, Joseph D; Rusch, Carley T; Young, Carly N

    2017-02-01

    Although fiber is well recognized for its effect on laxation, increasing evidence supports the role of fiber in the prevention and treatment of chronic disease. The aim of this review is to provide an overview of the health benefits of fiber and its fermentation, and describe how the products of fermentation may influence disease risk and treatment. Higher fiber intakes are associated with decreased risk of cardiovascular disease, type 2 diabetes, and some forms of cancer. Fiber may also have a role in lowering blood pressure and in preventing obesity by limiting weight gain. Fiber is effective in managing blood glucose in type 2 diabetes, useful for weight loss, and may provide therapeutic adjunctive roles in kidney and liver disease. In addition, higher fiber diets are not contraindicated in inflammatory bowel disease or irritable bowel syndrome and may provide some benefit. Common to the associations with disease reduction is fermentation of fiber and its potential to modulate microbiota and its activities and inflammation, specifically the production of anti-inflammatory short chain fatty acids, primarily from saccharolytic fermentation, versus the deleterious products of proteolytic activity. Because fiber intake is inversely associated with all-cause mortality, mechanisms by which fiber may reduce chronic disease risk and provide therapeutic benefit to those with chronic disease need further elucidation and large, randomized controlled trials are needed to confirm causality.Teaching Points• Strong evidence supports the association between higher fiber diets and reduced risk of cardiovascular disease, type 2 diabetes, and some forms of cancer.• Higher fiber intakes are associated with lower body weight and body mass index, and some types of fiber may facilitate weight loss.• Fiber is recommended as an adjunctive medical nutritional therapy for type 2 diabetes, chronic kidney disease, and certain liver diseases.• Fermentation and the resulting shifts in

  20. Space-propagation model of Tm-doped fiber laser.

    Science.gov (United States)

    Lü, Haibin; Zhou, Pu; Wang, Xiaolin; Jiang, Zongfu

    2012-11-01

    In this paper, we propose the space-propagation model for the Tm-doped fiber laser. This model builds the space-propagation equations for the population densities at different energy levels as well as the pump and laser powers. Compared to the conventional models, this model has significant advantage in reducing the computing time significantly when the steady-state population density rate equations cannot be solved analytically. On the basis of the model, the power characteristic and optimization for the Tm-doped fiber laser are investigated. Excellent agreements are achieved between the numerical simulation and experimental results.

  1. Comparative study of sub-micrometer polymeric structures: Dot-arrays, linear and crossed gratings generated by UV laser based two-beam interference, as surfaces for SPR and AFM based bio-sensing

    Energy Technology Data Exchange (ETDEWEB)

    Csete, M. [Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Dom ter 9 (Hungary)], E-mail: mcsete@physx.u-szeged.hu; Sipos, A.; Kohazi-Kis, A.; Szalai, A.; Szekeres, G.; Mathesz, A.; Csako, T.; Osvay, K.; Bor, Zs. [Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Dom ter 9 (Hungary); Penke, B. [Department of Medical Chemistry, University of Szeged, H-6720 Szeged, Dom ter 9 (Hungary); Deli, M.A.; Veszelka, Sz. [Laboratory of Molecular Neurobiology, Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences, H-6726 Szeged, Temesvari Krt. 62 (Hungary); Schmatulla, A.; Marti, O. [Department of Experimental Physics, University of Ulm, D-89069 Ulm, Albert Einstein Allee 12 (Germany)

    2007-12-15

    Two-dimensional gratings are generated on poly-carbonate films spin-coated onto thin gold-silver bimetallic layers by two-beam interference method. Sub-micrometer periodic polymer dots and stripes are produced illuminating the poly-carbonate surface by p- and s-polarized beams of a frequency quadrupled Nd:YAG laser, and crossed gratings are generated by rotating the substrates between two sequential treatments. It is shown by pulsed force mode atomic force microscopy that the mean value of the adhesion is enhanced on the dot-arrays and on the crossed gratings. The grating-coupling on the two-dimensional structures results in double peaks on the angle dependent resonance curves of the surface plasmons excited by frequency doubled Nd:YAG laser. The comparison of the resonance curves proves that a surface profile ensuring minimal undirected scattering is required to optimize the grating-coupling, in addition to the minimal modulation amplitude, and to the optimal azimuthal orientation. The secondary minima are the narrowest in presence of linear gratings on multi-layers having optimized composition, and on crossed structures consisting of appropriately oriented polymer stripes. The large coupling efficiency and adhesion result in high detection sensitivity on the crossed gratings. Bio-sensing is realized by monitoring the rotated-crossed grating-coupled surface plasmon resonance curves, and detecting the chemical heterogeneity by tapping-mode atomic force microscopy. The interaction of Amyloid-{beta} peptide, a pathogenetic factor in Alzheimer disease, with therapeutical molecules is demonstrated.

  2. Muscle Fiber Conduction Velocity, Muscle Fiber Composition, and Power Performance.

    Science.gov (United States)

    Methenitis, Spyridon; Karandreas, Nikolaos; Spengos, Konstantinos; Zaras, Nikolaos; Stasinaki, Angeliki-Nikoletta; Terzis, Gerasimos

    2016-09-01

    The aim of this study was to explore the relationship between muscle fiber conduction velocity (MFCV), fiber type composition, and power performance in participants with different training background. Thirty-eight young males with different training background participated: sedentary (n = 10), endurance runners (n = 9), power trained (n = 10), and strength trained (n = 9). They performed maximal countermovement jumps (CMJ) and maximal isometric leg press for the measurement of the rate of force development (RFD). Resting vastus lateralis MFCV was measured with intramuscular microelectrodes on a different occasion, whereas muscle fiber type and cross-sectional area (CSA) of vastus lateralis were evaluated through muscle biopsies 1wk later. MFCV, CMJ power, RFD, and % CSA of type II and type IIx fibers were higher for the power-trained group (P power participants. Close correlations were found between MFCV and fiber CSA as well as the % CSA of all fiber types as well as with RFD and CMJ power (r = 0.712-0.943, P power performance. Significant models for the prediction of the % CSA of type IIa and type II as well as the CSA of all muscle fibers based upon MFCV, RFD, and CMJ were revealed (P = 0.000). MFCV is closely associated with muscle fiber % CSA. RFD and jumping power are associated with the propagation of the action potentials along the muscle fibers. This link is regulated by the size and the distribution of type II, and especially type IIx muscle fibers.

  3. Multispot fiber laser welding

    DEFF Research Database (Denmark)

    Schutt Hansen, Klaus

    This dissertation presents work and results achieved in the field of multi beam fiber laser welding. The project has had a practical approach, in which simulations and modelling have been kept at a minimum. Different methods to produce spot patterns with high power single mode fiber lasers have...... been examined and evaluated. It is found that both diamond turned DOE’s in zinc sulphide and multilevel etched DOE’s (Diffractive Optical Elements) in fused silica have a good performance. Welding with multiple beams in a butt joint configuration has been tested. Results are presented, showing it has...... been possible to control the welding width in incremental steps by adding more beams in a row. The laser power was used to independently control the keyhole and consequently the depth of fusion. An example of inline repair of a laser weld in butt joint configuration was examined. Zinc powder was placed...

  4. Bidirectional multimode fiber interconnection

    Science.gov (United States)

    Michalzik, Rainer; Kern, Alexander; Wahl, Dietmar

    2012-03-01

    We summarize the properties of 850nm wavelength AlGaAs/GaAs-based transceiver chips, monolithically integrating vertical-cavity surface-emitting lasers (VCSELs) and metal-semiconductor-metal (MSM) or PIN-type (p-doped-intrinsic-n-doped) photodiodes. Different chip designs enable half- and full-duplex bidirectional optical interconnection at multiple Gbit/s data rate over a single butt-coupled glass or polymer-clad optical fiber with core diameters ranging from 50 to 200 μm. The chips at both fiber ends are nominally identical and no external optics is required, which leads to lower cost in addition to volume and weight reduction. The commercial availability of such chips would directly enable applications in data communication and sensing networks in various environments such as automotive, home, industrial, in-building, or medical.

  5. Optical fiber communications

    CERN Document Server

    Keiser, Gerd

    2008-01-01

    The fourth edition of this popular text and reference book presents the fundamental principles for understanding and applying optical fiber technology to sophisticated modern telecommunication systems. Optical-fiber-based telecommunication networks have become a major information-transmission-system, with high capacity links encircling the globe in both terrestrial and undersea installations. Numerous passive and active optical devices within these links perform complex transmission and networking functions in the optical domain, such as signal amplification, restoration, routing, and switching. Along with the need to understand the functions of these devices comes the necessity to measure both component and network performance, and to model and stimulate the complex behavior of reliable high-capacity networks.

  6. Optical fiber smartphone spectrometer.

    Science.gov (United States)

    Hossain, Md Arafat; Canning, John; Cook, Kevin; Jamalipour, Abbas

    2016-05-15

    An optical fiber-based smartphone spectrometer incorporating an endoscopic fiber bundle is demonstrated. The endoscope allows transmission of the smartphone camera LED light to a sample, removing complications from varying background illumination. The reflected spectra collected from a surface or interface is dispersed onto the camera CMOS using a reflecting diffraction grating. A spectral resolution as low as δλ∼2.0  nm over a bandwidth of Δλ∼250  nm is obtained using a slit width, ωslit=0.7  mm. The instrument has vast potential in a number of industrial applications including agricultural produce analysis. Spectral analysis of apples shows straightforward measurement of the pigments anthocyanins, carotenoid, and chlorophyll, all of which decrease with increasing storage time.

  7. Higher Order Mode Fibers

    DEFF Research Database (Denmark)

    Israelsen, Stine Møller

    This PhD thesis considers higher order modes (HOMs) in optical fibers. That includes their excitation and characteristics. Within the last decades, HOMs have been applied both for space multiplexing in optical communications, group velocity dispersion management and sensing among others....... The research presented in this thesis falls in three parts. In the first part, a first time demonstration of the break of the azimuthal symmetry of the Bessel-like LP0X modes is presented. This effect, known as the bowtie effect, causes the mode to have an azimuthal dependence as well as a quasi......-radial polarization as opposed to the linear polarization of the LP0X modes. The effect is investigated numerically in a double cladding fiber with an outer aircladding using a full vectorial modesolver. Experimentally, the bowtie modes are excited using a long period grating and their free space characteristics...

  8. Relative validity and reproducibility of a food frequency questionnaire to assess dietary fiber intake in Danish adults

    DEFF Research Database (Denmark)

    Vuholm, Stine; Lorenzen, Janne Kunchel; Kristensen, Mette Bredal

    2014-01-01

    Background: Differences in habitual dietary fiber intake may modify effects of dietary fiber interventions, thus measurement of habitual dietary fiber intake is relevant to apply in intervention studies on fiber-rich foods, and food frequency questionnaire (FFQ) is a commonly used method. Rye bread...... is the major contributor of dietary fiber in the Danish population, and a nation-specific FFQ is therefore needed. Objective: The aim of this study was to assess the relative validity and reproducibility of a self-administered quantitative FFQ designed to assess total dietary fiber intake among Danish adults...... months later. Results: Estimates of mean dietary fiber intake were 24.999.8 and 28.199.4 g/day when applying the FFQ and DR, respectively, where FFQ estimates were 12% lower (pB0.001). Pearson’s correlation coefficient between the estimated dietary fiber intake of the two methods was r0.63 (pB0...

  9. Antimicrobial Acrylic Fiber

    Science.gov (United States)

    2006-08-01

    the spinneret fitted with a 325 mesh wire screen filter inside. Extrusion conditions were as follows: 2 Process: dry-jet wet spinning...crude nonwoven fabric (one inch square), treated samples were challenged with Staphylococcus aureus (ATCC 6538) using a modified AATCC Test Method 100...obtained chlorine after chlorination. The fibers were formed into a nonwoven matt which upon chlorination with 10% household bleach became

  10. Dietary fiber analysis of common pulses using AOAC 2011.25: Implications for human health

    Science.gov (United States)

    Dietary fiber is an important non-nutritive component of food and is believed to have various benefits to human health. In many countries, such as the United States and Canada, the intake of dietary fiber is 50 to 70% below recommended levels in greater than 95% of the population. We recently adva...

  11. Lower intake of magnesium and dietary fiber increases the incidence of type 2 diabetes in Taiwanese

    Directory of Open Access Journals (Sweden)

    Lu-Chen Weng

    2012-11-01

    Conclusion: Lower magnesium, lower total dietary fiber intake, or lower intake of both was associated with higher risk of diabetes in the Taiwanese population. Clinical trials are required to confirm the protective effects of the adequate intake of fiber, magnesium, and/or their combination.

  12. Alternative Dietary Fiber Sources in Companion Animal Nutrition

    Directory of Open Access Journals (Sweden)

    George C. Fahey, Jr.

    2013-08-01

    Full Text Available The US has a pet population of approximately 70 million dogs and 74 million cats. Humans have developed a strong emotional bond with companion animals. As a consequence, pet owners seek ways to improve health, quality of life and longevity of their pets. Advances in canine and feline nutrition have contributed to improved longevity and well-being. Dietary fibers have gained renewed interest in the pet food industry, due to their important role in affecting laxation and stool quality. More recently, because of increased awareness of the beneficial effects of dietary fibers in health, as well as the popularity of functional foods and holistic and natural diets, alternative and novel carbohydrates have become widespread in human and pet nutrition. Fiber sources from cereal grains, whole grains and fruits have received increasing attention by the pet food industry and pet owners. While limited scientific information is available on the nutritional and nutraceutical properties of alternative fiber sources, studies indicate that corn fiber is an efficacious fiber source for pets, showing no detrimental effects on palatability or nutrient digestibility, while lowering the glycemic response in adult dogs. Fruit fiber and pomaces have good water-binding properties, which may be advantageous in wet pet food production, where a greater water content is required, along with low water activity and a firm texture of the final product. Rice bran is a palatable fiber source for dogs and may be an economical alternative to prebiotic supplementation of pet foods. However, it increases the dietary requirement of taurine in cats. Barley up to 40% in a dry extruded diet is well tolerated by adult dogs. In addition, consumption of complex carbohydrates has shown a protective effect on cardiovascular disease and oxidative stress. Alternative fiber sources are suitable ingredients for pet foods. They have been shown to be nutritionally adequate and to have potential

  13. Alternative dietary fiber sources in companion animal nutrition.

    Science.gov (United States)

    de Godoy, Maria R C; Kerr, Katherine R; Fahey, George C

    2013-08-06

    The US has a pet population of approximately 70 million dogs and 74 million cats. Humans have developed a strong emotional bond with companion animals. As a consequence, pet owners seek ways to improve health, quality of life and longevity of their pets. Advances in canine and feline nutrition have contributed to improved longevity and well-being. Dietary fibers have gained renewed interest in the pet food industry, due to their important role in affecting laxation and stool quality. More recently, because of increased awareness of the beneficial effects of dietary fibers in health, as well as the popularity of functional foods and holistic and natural diets, alternative and novel carbohydrates have become widespread in human and pet nutrition. Fiber sources from cereal grains, whole grains and fruits have received increasing attention by the pet food industry and pet owners. While limited scientific information is available on the nutritional and nutraceutical properties of alternative fiber sources, studies indicate that corn fiber is an efficacious fiber source for pets, showing no detrimental effects on palatability or nutrient digestibility, while lowering the glycemic response in adult dogs. Fruit fiber and pomaces have good water-binding properties, which may be advantageous in wet pet food production, where a greater water content is required, along with low water activity and a firm texture of the final product. Rice bran is a palatable fiber source for dogs and may be an economical alternative to prebiotic supplementation of pet foods. However, it increases the dietary requirement of taurine in cats. Barley up to 40% in a dry extruded diet is well tolerated by adult dogs. In addition, consumption of complex carbohydrates has shown a protective effect on cardiovascular disease and oxidative stress. Alternative fiber sources are suitable ingredients for pet foods. They have been shown to be nutritionally adequate and to have potential nutraceutical

  14. [Small fiber neuropathy].

    Science.gov (United States)

    Langlois, V; Bedat Millet, A-L; Lebesnerais, M; Miranda, S; Marguet, F; Benhamou, Y; Marcorelles, P; Lévesque, H

    2017-04-11

    Small fiber neuropathy (SFN) is still unknown. Characterised by neuropathic pain, it typically begins by burning feet, but could take many other expression. SFN affects the thinly myelinated Aδ and unmyelinated C-fibers, by an inherited or acquired mechanism, which could lead to paresthesia, thermoalgic disorder or autonomic dysfunction. Recent studies suggest the preponderant role of ion channels such as Nav1.7. Furthermore, erythromelalgia or burning mouth syndrome are now recognized as real SFN. Various aetiologies of SFN are described. It could be isolated or associated with diabetes, impaired glucose metabolism, vitamin deficiency, alcohol, auto-immune disease, sarcoidosis etc. Several mutations have recently been identified, like Nav1.7 channel leading to channelopathies. Diagnostic management is based primarily on clinical examination and demonstration of small fiber dysfunction. Laser evoked potentials, Sudoscan®, cutaneous biopsy are the main test, but had a difficult access. Treatment is based on multidisciplinary management, combining symptomatic treatment, psychological management and treatment of an associated etiology. Copyright © 2017 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  15. [Muscle fiber atrophy].

    Science.gov (United States)

    Nonaka, Ikuya

    2012-01-01

    Muscle fibers have been classified into two major forms of red (slow twitch) and white (fast twitch) muscles. The red muscle utilizes lipid as energy source through mitochondrial metabolism and function to sustain the position against gravity (sometimes called as antigravity muscle). Under microgravity the red muscle is selectively involved. In our unloading study by hindlimb suspension experiment on rats, the one of the representative red muscle of soleus muscle underwent rapid atrophy; they reduced their weights about 50% after 2 week-unloading. In addition, myofibrils were occasionally markedly disorganized with selective thin filament loss. Mitochondria in the degenerated area were decreased in number. The white muscle fibers in the soleus muscle had mostly transformed to the red ones. It took about 1 month to recover morphologically. The satellite cell playing a major role in muscle regeneration was not activated. There still remained unsolved what are the mechanosensors to keep muscle function under normal gravity. Dr Nikawa's group proposed that one of ubiquitin ligases, Cbl-b is activated under microgravity and induces muscle fiber degeneration. There might be many factors to induce muscle atrophy and degeneration under microgravity. Further study is necessary to explore the pathomechanism of muscle atrophy in disused and under immobility conditions.

  16. Green Fiber Bottle

    DEFF Research Database (Denmark)

    Didone, Mattia; Tosello, Guido

    The ambition of the Green Fiber Bottle (GFB) project is to manufacture a fully biodegradable bottle. Carlsberg is the intended end user, and they aim to package their beer in the new bottle. The new product is intended to replace the existing plastic and glass bottles, and thus reducing their imp......The ambition of the Green Fiber Bottle (GFB) project is to manufacture a fully biodegradable bottle. Carlsberg is the intended end user, and they aim to package their beer in the new bottle. The new product is intended to replace the existing plastic and glass bottles, and thus reducing...... their impact on the environment, especially the oceans. For example, the life span of a plastic bottle in the ocean is 500 years, and during its degradation, the plastic is reduced to micro pieces, which causes the starvation of several marine animals. The new bottle is completely made from molded paper pulp......, which is a renewable resource. Nevertheless, due to food and drugs limitations, only virgin paper fibers must be employed in the production. The bottle could then be left to biodegrade in nature or enter a recycle system, along with other paper-based product. In order to contain the liquid, the bottle...

  17. Do fiber and psyllium fiber improve diabetic metabolism?

    Science.gov (United States)

    Hall, Micki; Flinkman, Tanis

    2012-07-01

    Increasing numbers of elderly individuals with diabetes look for natural means to manage their disease to reduce diabetes-related complications. The American Diabetes Association recommends a goal of 25 g to 35 g dietary fiber daily for a healthy diet. This review focuses on recent research that explores the utility of fiber and psyllium fiber in improving glucose control in patients with diabetes mellitus (DM). Fiber studies show decreased glucose concentrations and decreasing all-cause mortality. Small studies looking at psyllium fiber, in particular, have shown it to be associated with lower mean daily glucose concentrations, lower postmeal glucose concentrations, fewer hypoglycemic events, lower A1C levels, and lower insulin concentrations in people with DM. Results, as well as strengths and weaknesses of the studies, are presented. Considering the available research, we recommend elderly patients who are not able to meet their fiber goals by dietary intake consider psyllium supplementation.

  18. FIBER ORIENTATION IN INJECTION MOLDED LONG CARBON FIBER THERMOPLASTIC COMPOSITES

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jin; Nguyen, Ba Nghiep; Mathur, Raj N.; Sharma, Bhisham; Sangid, Michael D.; Costa, Franco; Jin, Xiaoshi; Tucker III, Charles L.; Fifield, Leonard S.

    2015-03-23

    A set of edge-gated and center-gated plaques were injection molded with long carbon fiber-reinforced thermoplastic composites, and the fiber orientation was measured at different locations of the plaques. Autodesk Simulation Moldflow Insight (ASMI) software was used to simulate the injection molding of these plaques and to predict the fiber orientation, using the anisotropic rotary diffusion and the reduced strain closure models. The phenomenological parameters of the orientation models were carefully identified by fitting to the measured orientation data. The fiber orientation predictions show very good agreement with the experimental data.

  19. Thulium-doped optical fibers for fiber lasers

    Science.gov (United States)

    Kamrádek, M.; Aubrecht, J.; Peterka, P.; Podrazký, O.; Honzátko, P.; Cajzl, J.; Mrázek, J.; Kubeček, V.; Kašík, I.

    2017-12-01

    We present preparation and characterization of thulium-doped silica-based optical fibers for fiber lasers. The fibers were prepared by modified chemical vapor deposition process and doped with alumina and thulium ions. Alumina co-doping was achieved through two different methods - solution doping and nanoparticle doping method. Prepared preforms were characterized in terms of refractive index profiles and dopants distribution. For the drawn fibers, their spectral attenuation, fluorescence lifetime and laser performance were measured. In the case of nanoparticle doping, better laser characteristics were observed. Discussion and explanation of the trends for laser efficiency improvement is given.

  20. Optical fiber networks for remote fiber optic sensors.

    Science.gov (United States)

    Fernandez-Vallejo, Montserrat; Lopez-Amo, Manuel

    2012-01-01

    This paper presents an overview of optical fiber sensor networks for remote sensing. Firstly, the state of the art of remote fiber sensor systems has been considered. We have summarized the great evolution of these systems in recent years; this progress confirms that fiber-optic remote sensing is a promising technology with a wide field of practical applications. Afterwards, the most representative remote fiber-optic sensor systems are briefly explained, discussing their schemes, challenges, pros and cons. Finally, a synopsis of the main factors to take into consideration in the design of a remote sensor system is gathered.

  1. All-Fiber Raman Probe

    DEFF Research Database (Denmark)

    Brunetti, Anna Chiara

    by means of fiber components. Assuming the possibility to use a fiber laser with a fundamental radiation at 1064nm, in-fiber efficient second harmonic generation is achieved by optically poling the core of the waveguide delivering the excitation light to the sample. In this way, Raman spectroscopy...... of the collected Raman scattering from the inner-cladding region of the double-clad fiber, thus replacing the bulk dichroic component normally used to demultiplex the pump and Raman signal. A tunable Rayleigh-rejection filter based on a liquid filled-photonic bandgap fiber is also demonstrated in this work......The design and development of an all-in-fiber probe for Raman spectroscopy are presented in this Thesis. Raman spectroscopy is an optical technique able to probe a sample based on the inelastic scattering of monochromatic light. Due to its high specificity and reliability and to the possibility...

  2. Multichannel laser-fiber vibrometer

    Science.gov (United States)

    Dudzik, Grzegorz; Waz, Adam; Kaczmarek, Pawel; Antonczak, Arkadiusz; Sotor, Jaroslaw; Krzempek, Karol; Sobon, Grzegorz; Abramski, Krzysztof M.

    2013-01-01

    For the last few years we were elaborating the laser-fiber vibrometer working at 1550 nm. Our main stress was directed towards different aspects of research: analysis of scattered light, efficient photodetection, optimization of the fiber-free space interfaces and signal processing. As a consequence we proposed the idea of a multichannel fiber vibrometer based on well developed telecommunication technique - Wavelength Division Multiplexing (WDM). One of the most important parts of a fiber-laser vibrometer is demodulation electronic section. The distortion, nonlinearity, offset and added noise of measured signal come from electronic circuits and they have direct influence on finale measuring results. We present the results of finished project "Developing novel laser-fiber monitoring technologies to prevent environmental hazards from vibrating objects" where we have constructed a 4-channel WDM laser-fiber vibrometer.

  3. Fiber optic sensor and method for making

    Science.gov (United States)

    Vartuli, James Scott; Bousman, Kenneth Sherwood; Deng, Kung-Li; McEvoy, Kevin Paul; Xia, Hua

    2010-05-18

    A fiber optic sensor including a fiber having a modified surface integral with the fiber wherein the modified surface includes an open pore network with optical agents dispersed within the open pores of the open pore network. Methods for preparing the fiber optic sensor are also provided. The fiber optic sensors can withstand high temperatures and harsh environments.

  4. Producing Silicon Carbide/Silicon Nitride Fibers

    Science.gov (United States)

    1986-01-01

    Manufacturing process makes CxSiyNz fibers. Precursor fibers spun from extruding machine charged with polycarbosilazane resin. When pyrolyzed, resin converted to cross-linked mixture of silicon carbide and silicon nitride, still in fiber form. CxSiyNz fibers promising substitutes for carbon fibers in high-strength, low-weight composites where high electrical conductivity unwanted.

  5. Electrochromic fiber-shaped supercapacitors.

    Science.gov (United States)

    Chen, Xuli; Lin, Huijuan; Deng, Jue; Zhang, Ye; Sun, Xuemei; Chen, Peining; Fang, Xin; Zhang, Zhitao; Guan, Guozhen; Peng, Huisheng

    2014-12-23

    An electrochromic fiber-shaped super-capacitor is developed by winding aligned carbon nanotube/polyaniline composite sheets on an elastic fiber. The fiber-shaped supercapacitors demonstrate rapid and reversible chromatic transitions under different working states, which can be directly observed by the naked eye. They are also stretchable and flexible, and are woven into textiles to display designed signals in addition to storing energy. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Fiber Sagnac interferometer temperature sensor

    Energy Technology Data Exchange (ETDEWEB)

    Starodumov, A.N.; Zenteno, L.A.; Monzon, D.; De La Rosa, E. [Centro de Investigaciones en Optica, 37150 Leon, Gto (Mexico)

    1997-01-01

    A modified Sagnac interferometer-based fiber temperature sensor is proposed. Polarization independent operation and high temperature sensitivity of this class of sensors make them cost effective instruments for temperature measurements. A comparison of the proposed sensor with Bragg grating and long-period grating fiber sensors is derived. A temperature-induced spectral displacement of 0.99 nm/K is demonstrated for an internal stress birefringent fiber-based Sagnac interferometer. {copyright} {ital 1997 American Institute of Physics.}

  7. Production and Characterization of Activated Carbon Fiber from Textile PAN Fiber

    OpenAIRE

    Amaral Junior,Miguel Angelo do; Matsushima,Jorge Tadao; Rezende,Mirabel Cerqueira; Gonçalves,Emerson Sarmento; Marcuzzo,Jossano Saldanha; Baldan,Maurício Ribeiro

    2017-01-01

    ABSTRACT: This paper presents the preparation and characterization of carbon fiber felt and activated carbon fiber felt from textile polyacrylonitrile fiber. Carbon fibers are usually related to aircraft manufacturing or high mechanical purposes. Activated carbon fibers are known as excellent adsorbent materials. Despite all advantages, carbon fiber and activated carbon fiber are expensive materials because of their raw material cost. On the other hand, in this study, carbon fiber felt and ac...

  8. Fiber-Optic Sensor Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Constructs and evaluates fiber-optic sensors for a variety of measurands. These measurands include acoustic, pressure, magnetic, and electric field as well...

  9. Thermal properties of Fiber ropes

    DEFF Research Database (Denmark)

    Bossolini, Elena; Nielsen, Ole Wennerberg; Oland, Espen

    There is a trend within the oil and gas market to shift from steel wire ropes to fiber ropes for lifting, hoisting and mooring applications. The cost of fiber ropes is about 2-3 times that of steel wire ropes, but the natural buoyancy of fiber ropes reduces the overall weight resulting in smaller....... This means that the rope is discarded before it is necessary, increasing the overall life-cycle costs. The offshore industry wants a better monitoring system to understand when the fiber rope must be replaced....

  10. Capillary stretching of elastic fibers

    Science.gov (United States)

    Protiere, Suzie; Stone, Howard A.; Duprat, Camille

    2014-11-01

    Fibrous media consisting of constrained flexible fibers can be found in many engineered systems (membranes in filters, woven textile, matted paper). When such materials interact with a liquid, the presence of liquid/air interfaces induces capillary forces that deform the fibers. To model this interaction we study the behaviour of a finite volume of liquid deposited on two parallel flexible fibers clamped at both ends. A tension along the fibers is imposed and may be varied. We show that the system undergoes various morphological changes as the interfiber distance, the elasticity and the tension of the fibers are varied. For a certain range of parameters, the liquid spreads along the fibers and pulls them together, leading to the ``zipping'' of the fibers. This capillary adhesion can then be enhanced or reduced by changing the tension within the fibers. We will show that balancing stretching and capillary forces allows the prediction of this transition as well as the conditions for which detachment of the fibers occurs. These results may be used to prevent the clogging of fibrous membranes or to optimize the capture of liquids.

  11. Broadband terahertz fiber directional coupler

    DEFF Research Database (Denmark)

    Nielsen, Kristian; Rasmussen, Henrik K.; Jepsen, Peter Uhd

    2010-01-01

    We present the design of a short broadband fiber directional coupler for terahertz (THz) radiation and demonstrate a 3 dB coupler with a bandwidth of 0:6 THz centered at 1:4 THz. The broadband coupling is achieved by mechanically downdoping the cores of a dual-core photonic crystal fiber by micro......We present the design of a short broadband fiber directional coupler for terahertz (THz) radiation and demonstrate a 3 dB coupler with a bandwidth of 0:6 THz centered at 1:4 THz. The broadband coupling is achieved by mechanically downdoping the cores of a dual-core photonic crystal fiber...

  12. Annealing of silicon optical fibers

    Science.gov (United States)

    Gupta, N.; McMillen, C.; Singh, R.; Podila, R.; Rao, A. M.; Hawkins, T.; Foy, P.; Morris, S.; Rice, R.; Poole, K. F.; Zhu, L.; Ballato, J.

    2011-11-01

    The recent realization of silicon core optical fibers has the potential for novel low insertion loss rack-to-rack optical interconnects and a number of other uses in sensing and biomedical applications. To the best of our knowledge, incoherent light source based rapid photothermal processing (RPP) was used for the first time to anneal glass-clad silicon core optical fibers. X-ray diffraction examination of the silicon core showed a considerable enhancement in the length and amount of single crystallinity post-annealing. Further, shifts in the Raman frequency of the silicon in the optical fiber core that were present in the as-drawn fibers were removed following the RPP treatment. Such results indicate that the RPP treatment increases the local crystallinity and therefore assists in the reduction of the local stresses in the core, leading to more homogenous fibers. The dark current-voltage characteristics of annealed silicon optical fiber diodes showed lower leakage current than the diodes based on as-drawn fibers. Photons in UV and vacuum ultraviolet (VUV) regions play a very important role in improving the bulk and carrier transport properties of RPP-treated silicon optical fibers, and the resultant annealing permits a path forward to in situ enhancement of the structure and properties of these new crystalline core optical fibers.

  13. Power Scaling Fiber Amplifiers Using Very-Large-Mode-Area Fibers

    Science.gov (United States)

    2016-02-23

    expected resilience to TMI. 15. SUBJECT TERMS Fiber amplifier, high power laser, thermal mode instability, large-mode-area fiber, ytterbium- doped ...18 6.2 Cladded Linear Index Graded (CLING) Fiber ........................................................ 20 6.3 Trefoil Fiber...conventional LMA fiber............ 20 13. Comparison of modes between step-index and graded -index fibers........................... 21 14. Modes of a LING

  14. Evidence mapping: dietary fiber interventions and bone health outcomes

    Science.gov (United States)

    The prevalence of osteoporosis and low bone mass is expected to increase as the United States population ages. High dietary fiber intake has previously been implicated as a risk factor for bone health by binding calcium and thereby reducing its intestinal absorption; however, more recently, interven...

  15. Scintillating fiber detector

    CERN Document Server

    Vozak, Matous

    2016-01-01

    NA61 is one of the physics experiments at CERN dedicated to study hadron states coming from interactions of SPS beams with various targets. To determine the position of a secondary beam, three proportional chambers are placed along the beamline. However, these chambers tend to have slow response. In order to obtain more precise time information, use of another detector is being considered. Fast response and compact size is making scintillation fiber (SciFi) with silicon photomultiplier (Si-PM) read out a good candidate. This report is focused on analysing data from SciFi collected in a test beam at the beginning of July 2016.

  16. Fiber sample presentation system for spectrophotometer cotton fiber color measurements

    Science.gov (United States)

    The Uster® High Volume Instrument (HVI) is used to class U.S. cotton for fiber color, yielding the industry accepted, cotton-specific color parameters Rd and +b. The HVI examines a 9 square inch fiber sample, and it is also used to test large AMS standard cotton “biscuits” or rectangles. Much inte...

  17. Coating Carbon Fibers With Platinum

    Science.gov (United States)

    Effinger, Michael R.; Duncan, Peter; Coupland, Duncan; Rigali, Mark J.

    2007-01-01

    A process for coating carbon fibers with platinum has been developed. The process may also be adaptable to coating carbon fibers with other noble and refractory metals, including rhenium and iridium. The coated carbon fibers would be used as ingredients of matrix/fiber composite materials that would resist oxidation at high temperatures. The metal coats would contribute to oxidation resistance by keeping atmospheric oxygen away from fibers when cracks form in the matrices. Other processes that have been used to coat carbon fibers with metals have significant disadvantages: Metal-vapor deposition processes yield coats that are nonuniform along both the lengths and the circumferences of the fibers. The electrical resistivities of carbon fibers are too high to be compatible with electrolytic processes. Metal/organic vapor deposition entails the use of expensive starting materials, it may be necessary to use a furnace, and the starting materials and/or materials generated in the process may be hazardous. The present process does not have these disadvantages. It yields uniform, nonporous coats and is relatively inexpensive. The process can be summarized as one of pretreatment followed by electroless deposition. The process consists of the following steps: The surfaces of the fiber are activated by deposition of palladium crystallites from a solution. The surface-activated fibers are immersed in a solution that contains platinum. A reducing agent is used to supply electrons to effect a chemical reduction in situ. The chemical reduction displaces the platinum from the solution. The displaced platinum becomes deposited on the fibers. Each platinum atom that has been deposited acts as a catalytic site for the deposition of another platinum atom. Hence, the deposition process can also be characterized as autocatalytic. The thickness of the deposited metal can be tailored via the duration of immersion and the chemical activity of the solution.

  18. Carbon Fiber Biocompatibility for Implants.

    Science.gov (United States)

    Petersen, Richard

    Carbon fibers have multiple potential advantages in developing high-strength biomaterials with a density close to bone for better stress transfer and electrical properties that enhance tissue formation. As a breakthrough example in biomaterials, a 1.5 mm diameter bisphenol-epoxy/carbon-fiber-reinforced composite rod was compared for two weeks in a rat tibia model with a similar 1.5 mm diameter titanium-6-4 alloy screw manufactured to retain bone implants. Results showed that carbon-fiber-reinforced composite stimulated osseointegration inside the tibia bone marrow measured as percent bone area (PBA) to a great extent when compared to the titanium-6-4 alloy at statistically significant levels. PBA increased significantly with the carbon-fiber composite over the titanium-6-4 alloy for distances from the implant surfaces of 0.1 mm at 77.7% vs. 19.3% (p carbon fiber properties that increased PBA for enhanced implant osseointegration. Carbon fibers acting as polymer coated electrically conducting micro-biocircuits appear to provide a biocompatible semi-antioxidant property to remove damaging electron free radicals from the surrounding implant surface. Further, carbon fibers by removing excess electrons produced from the cellular mitochondrial electron transport chain during periods of hypoxia perhaps stimulate bone cell recruitment by free-radical chemotactic influences. In addition, well-studied bioorganic cell actin carbon fiber growth would appear to interface in close contact with the carbon-fiber-reinforced composite implant. Resulting subsequent actin carbon fiber/implant carbon fiber contacts then could help in discharging the electron biological overloads through electrochemical gradients to lower negative charges and lower concentration.

  19. Optical Fiber Embedded in Epoxy Glass Unidirectional Fiber Composite System.

    Science.gov (United States)

    Severin, Irina; El Abdi, Rochdi; Corvec, Guillaume; Caramihai, Mihai

    2013-12-20

    We aimed to embed silica optical fibers in composites (epoxy vinyl ester matrix reinforced with E-glass unidirectional fibers in mass fraction of 60%) in order to further monitor the robustness of civil engineering structures (such as bridges). A simple system was implemented using two different silica optical fibers (F1-double coating of 172 µm diameter and F2-single coating of 101.8 µm diameter respectively). The optical fibers were dynamically tensile tested and Weibull plots were traced. Interfacial adhesion stress was determined using pull-out test and stress values were correlated to fracture mechanisms based on SEM observations. In the case of the optical fiber (OF) (F1)/resin system and OF (F1)/composite system, poor adhesion was reported that may be correlated to interface fracture at silica core level. Relevant applicable results were determined for OF (F2)/composite system.

  20. Homogenization of long fiber reinforced composites including fiber bending effects

    DEFF Research Database (Denmark)

    Poulios, Konstantinos; Niordson, Christian Frithiof

    2016-01-01

    This paper presents a homogenization method, which accounts for intrinsic size effects related to the fiber diameter in long fiber reinforced composite materials with two independent constitutive models for the matrix and fiber materials. A new choice of internal kinematic variables allows...... to maintain the kinematics of the two material phases independent from the assumed constitutive models, so that stress-deformation relationships, can be expressed in the framework of hyper-elasticity and hyper-elastoplasticity for the fiber and the matrix materials respectively. The bending stiffness...... of the reinforcing fibers is captured by higher order strain terms, resulting in an accurate representation of the micro-mechanical behavior of the composite. Numerical examples show that the accuracy of the proposed model is very close to a non-homogenized finite-element model with an explicit discretization...

  1. Actively doped solid core Photonic Bandgap Fiber

    DEFF Research Database (Denmark)

    Broeng, Jes; Olausson, Christina Bjarnal Thulin; Lyngsøe, Jens Kristian

    2010-01-01

    Solid photonic bandgap fibers offer distributed spectral filtering with extraordinary high suppression. This opens new possibilities of artificially tailoring the gain spectrum of fibers. We present record-performance of such fibers and outline their future applications....

  2. Polymer optical fiber bragg grating sensors

    DEFF Research Database (Denmark)

    Stefani, Alessio; Yuan, Scott Wu; Andresen, Søren

    2010-01-01

    Fiber-optical accelerometers based on polymer optical fiber Bragg gratings are reported. We have written fiber Bragg gratings for 1550 nm and 850 nm operations, characterized their temperature and strain response, and tested their performance in a prototype accelerometer....

  3. Dietary Fiber: Essential for a Healthy Diet

    Science.gov (United States)

    ... fiber is found in oats, peas, beans, apples, citrus fruits, carrots, barley and psyllium. Insoluble fiber. This ... in different plant foods. To receive the greatest health benefit, eat a wide variety of high-fiber foods. ...

  4. Optical Limiting in Photonic Crystal Fibers

    National Research Council Canada - National Science Library

    Bloemer, Mark; Scalora, Michael; Davenport, Wayne; Poliakov, Evgeni; Konorov, S. O; Sidorov-Biryukov, D. A; Serebryannikov, E. E; Zheltikov, A. M; Miles, R. B; Bugar, I

    2004-01-01

    .... We have shown that the limiting energy depends on the effective mode area of the fiber, the passband width of the propagating fiber mode, the length of the fiber, and the nonlinear refractive index of the gas (or other material...

  5. Photonic crystal fibers: fundamentals to emerging applications

    DEFF Research Database (Denmark)

    Bjarklev, Anders Overgaard

    2005-01-01

    A review of the fundamental properties of photonic crystal fibers is presented. Special focus is held on the emerging fields of application within areas such as actively controlled fiber devices and high-power fiber lasers.......A review of the fundamental properties of photonic crystal fibers is presented. Special focus is held on the emerging fields of application within areas such as actively controlled fiber devices and high-power fiber lasers....

  6. Continuous method of producing silicon carbide fibers

    Science.gov (United States)

    Barnard, Thomas Duncan (Inventor); Nguyen, Kimmai Thi (Inventor); Rabe, James Alan (Inventor)

    1999-01-01

    This invention pertains to a method for production of polycrystalline ceramic fibers from silicon oxycarbide (SiCO) ceramic fibers wherein the method comprises heating an amorphous ceramic fiber containing silicon and carbon in an inert environment comprising a boron oxide and carbon monoxide at a temperature sufficient to convert the amorphous ceramic fiber to a polycrystalline ceramic fiber. By having carbon monoxide present during the heating of the ceramic fiber, it is possible to achieve higher production rates on a continuous process.

  7. Photonic crystal fiber modelling and applications

    DEFF Research Database (Denmark)

    Bjarklev, Anders Overgaard; Broeng, Jes; Libori, Stig E. Barkou

    2001-01-01

    Photonic crystal fibers having a microstructured air-silica cross section offer new optical properties compared to conventional fibers for telecommunication, sensor, and other applications. Recent advances within research and development of these fibers are presented.......Photonic crystal fibers having a microstructured air-silica cross section offer new optical properties compared to conventional fibers for telecommunication, sensor, and other applications. Recent advances within research and development of these fibers are presented....

  8. High-birefringent photonic crystal fiber

    DEFF Research Database (Denmark)

    Libori, Stig E. Barkou; Broeng, Jes; Knudsen, Erik

    2001-01-01

    A highly birefringent photonic crystal fiber design is analysed. Birefringence up to 10-3 is found. Random fluctuations in the cladding design are analysed, and the fiber is found to be a feasible polarization maintaining fiber.......A highly birefringent photonic crystal fiber design is analysed. Birefringence up to 10-3 is found. Random fluctuations in the cladding design are analysed, and the fiber is found to be a feasible polarization maintaining fiber....

  9. Quantitive DNA Fiber Mapping

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Chun-Mei; Wang, Mei; Greulich-Bode, Karin M.; Weier, Jingly F.; Weier, Heinz-Ulli G.

    2008-01-28

    Several hybridization-based methods used to delineate single copy or repeated DNA sequences in larger genomic intervals take advantage of the increased resolution and sensitivity of free chromatin, i.e., chromatin released from interphase cell nuclei. Quantitative DNA fiber mapping (QDFM) differs from the majority of these methods in that it applies FISH to purified, clonal DNA molecules which have been bound with at least one end to a solid substrate. The DNA molecules are then stretched by the action of a receding meniscus at the water-air interface resulting in DNA molecules stretched homogeneously to about 2.3 kb/{micro}m. When non-isotopically, multicolor-labeled probes are hybridized to these stretched DNA fibers, their respective binding sites are visualized in the fluorescence microscope, their relative distance can be measured and converted into kilobase pairs (kb). The QDFM technique has found useful applications ranging from the detection and delineation of deletions or overlap between linked clones to the construction of high-resolution physical maps to studies of stalled DNA replication and transcription.

  10. Low-Loss Fiber Waveguides.

    Science.gov (United States)

    1980-10-01

    quality. Ion exchange will be attempted using liquid (e.g., HBr ) and gas phase chemistry on extruded KRS-5 fiber. The fiber developed, both clad and...glasses, mechanisms which give rise td these fluctuations include: density variations resulting from the frozen-in, random variations in dielectric

  11. Handbook of fiber optics theory and applications

    CERN Document Server

    Yeh, Chai

    2013-01-01

    Dr. Yeh supplies a firm theoretical foundation in such topics as propagation of light through fibers, fiber fabrication, loss mechanisms, and dispersion properties. He then expands from this into such practical areas as fiber splicing, measuring loss in fibers, fiber-based communications networks, remote fiber sensors, and integrated optics. Whether involved in fiber optics research, design, or practical implementation of systems, this handbook will be extremely useful.Key Features* Here is a comprehensive, ""one-stop"" reference with state-of-the-art information on fiber optics Included is da

  12. Fiber-reinforced syntactic foams

    Science.gov (United States)

    Huang, Yi-Jen

    Long fibers are generally preferred for reinforcing foams for performance reasons. However, uniform dispersion is difficult to achieve because they must be mixed with liquid resin prior to foam expansion. New approaches aiming to overcome such problem have been developed at USC's Composites Center. Fiber-reinforced syntactic foams with long fibers (over 6 mm in length) manufactured at USC's Composites Center have achieved promising mechanical properties and demonstrated lower density relative to conventional composite foams. Fiber-reinforced syntactic foams were synthesized from thermosetting polymeric microspheres (amino and phenolic microspheres), as well as thermoplastic PVC heat expandable microspheres (HEMs). Carbon and/or aramid fibers were used to reinforce the syntactic foams. Basic mechanical properties, including shear, tensile, and compression, were measured in syntactic foams and fiber-reinforced syntactic foams. Microstructure and crack propagation behavior were investigated by scanning electron microscope and light microscopy. Failure mechanisms and reinforcing mechanisms of fiber-reinforced syntactic foams were also analyzed. As expected, additions of fiber reinforcements to foams enhanced both tensile and shear properties. However, only limited enhancement in compression properties was observed, and fiber reinforcement was of limited benefit in this regard. Therefore, a hybrid foam design was explored and evaluated in an attempt to enhance compression properties. HEMs were blended with glass microspheres to produce hybrid foams, and hybrid foams were subsequently reinforced with continuous aramid fibers to produce fiber-reinforced hybrid foams. Mechanical properties of these foams were evaluated. Findings indicated that the production of hybrid foams was an effective way to enhance the compressive properties of syntactic foams, while the addition of fiber reinforcements enhanced the shear and tensile performance of syntactic foams. Another approach

  13. Sensored fiber reinforced polymer grate

    Science.gov (United States)

    Ross, Michael P.; Mack, Thomas Kimball

    2017-08-01

    Various technologies described herein pertain to a sensored grate that can be utilized for various security fencing applications. The sensored grate includes a grate framework and an embedded optical fiber. The grate framework is formed of a molded polymer such as, for instance, molded fiber reinforced polymer. Further, the grate framework includes a set of elongated elements, where the elongated elements are spaced to define apertures through the grate framework. The optical fiber is embedded in the elongated elements of the grate framework. Moreover, bending or breaking of one or more of the elongated elements can be detected based on a change in a characteristic of input light provided to the optical fiber compared to output light received from the optical fiber.

  14. Oxide Fiber Targets at ISOLDE

    CERN Document Server

    Köster, U; Carminati, D; Catherall, R; Cederkäll, J; Correia, J G; Crepieux, B; Dietrich, M; Elder, K; Fedosseev, V; Fraile-Prieto, L M; Franchoo, S; Fynbo, H O U; Georg, U; Giles, T; Joinet, A; Jonsson, O C; Kirchner, R; Lau, C; Lettry, Jacques; Maier, H J; Mishin, V I; Oinonen, M; Peräjärvi, K; Ravn, H L; Rinaldi, T; Santana-Leitner, M; Wahl, U; Weissman, L

    2003-01-01

    Many elements are rapidly released from oxide matrices. Some oxide powder targets show a fast sintering, thus losing their favorable release characteristics. Loosely packed oxyde fiber targets are less critical since they may maintain their open structure even when starting to fuse together at some contact points. The experience with various oxyde fiber targets (titania, zirconia, ceria and thoria) used in the last years at ISOLDE is reviewed. For short-lived isotopes of Cu, Ga and Xe the zirconia and ceria targets respectively provided significantly higher yields than any other target (metal foils, oxide powders, etc.) tested before. Titania fibers, which were not commercially available, were produced in a relic process by impregnation of a rayon felt in a titanium chloride solution and subsequent calcination by heating the dried felt in air. Thoria fibers were obtained either by the same process or by burning commercial gas lantern mantle cloth. In the future a beryllia fiber target could be used to produce...

  15. High-stability polymer optical fiber with Rhodamine-doped cladding for fiber light systems

    Science.gov (United States)

    Jaramillo-Ochoa, L.; Narro-García, R.; Ocampo, M. A.; Quintero-Torres, R.

    2016-09-01

    In this work, the photodegradation of a polymer optical fiber with Rhodamine doped cladding as a function of illumination time and excitation intensity is presented. To show the effect of photodegradation on different bulk geometries and environments, the photodegradation from a dye doped preform and a PMMA thick film is also evaluated. The reversible and the irreversible degradation of the florescent material were quantified under an established excitation scheme. To this purpose, a four-level system to model the photodegradation rates and its relation with the population of the states is presented and it is used to justify a possible underlying mechanism. The obtained results suggest an increase of one order of magnitude in the stability (lifetime) of the polymer optical fiber with respect to the preform or the thick film geometry stability.

  16. Fiber-reinforced technology in multidisciplinary chairside approaches.

    Science.gov (United States)

    Arhun, Neslihan; Arman, Ayca

    2008-01-01

    There is an increasing demand to improve dentofacial esthetics in the adult population. This demand usually requires a close collaboration within the various disciplines of dentistry and the patient at every stage of the therapy. The materials and techniques used by these interdisciplinary clinicians must be conservative and minimally invasive. Fiber-reinforced composite technology offers such solutions for chairside applications. This case report presents two cases where fiber-reinforced ribbon and composite complex was used in a multidisciplinary approach to improve esthetics.

  17. Fiber-reinforced technology in multidisciplinary chairside approaches

    Directory of Open Access Journals (Sweden)

    Arhun Neslihan

    2008-01-01

    Full Text Available There is an increasing demand to improve dentofacial esthetics in the adult population. This demand usually requires a close collaboration within the various disciplines of dentistry and the patient at every stage of the therapy. The materials and techniques used by these interdisciplinary clinicians must be conservative and minimally invasive. Fiber-reinforced composite technology offers such solutions for chairside applications. This case report presents two cases where fiber-reinforced ribbon and composite complex was used in a multidisciplinary approach to improve esthetics.

  18. Phase Planning for Overall Copper-Fiber Switch-over

    DEFF Research Database (Denmark)

    Gutierrez Lopez, Jose Manuel; Jensen, Michael; Andreasen, Morten Henius

    2013-01-01

    This paper introduces a phase planning concept to the imminent copper-fiber switch-over action. Traditional copper loops are to be replaced by modern fiber lines in order to keep up with the current evolution of data communications. This work proposes two novel approaches of how to schedule...... this transition by systematically selecting the most attractive areas, in terms of economic efficiency, to be upgraded first. These are alternatively based on 1) distance to the access point and 2)population density, and the overall plan is divided into three phases. In both cases the final network solution...

  19. Crude fiber determination using ceramic fiber to replace asbestos.

    Science.gov (United States)

    Knox, R L; Engvall, D S; Ginther, B E

    1982-09-01

    Crude fiber was determined in a wide range of feed products by a method which specifies ceramic fiber as a filter medium instead of the more hazardous and difficult to obtain asbestos. Results correlated well with those obtained by using AOAC official final action method 7.061-7.065 (correlation coefficient, 0.9994). For 8 samples, the coefficients of variation ranged from 0.74 to 4.80%. Compared with the AOAC method the proposed method showed a slight negative bias of 0.1%. Compared with asbestos, ceramic fiber was easier to prepare for use, filtering was faster, and samples bumped less.

  20. Continuously tunable wideband semiconductor fiber-ring laser

    Science.gov (United States)

    Mao, Xuefeng; Zhao, Shiwei; Yuan, Suzhen; Wang, Xiaofa; Zheng, Peichao

    2017-08-01

    We demonstrate a wideband tunable semiconductor fiber-ring laser that can be continuously tuned from 1498 nm to 1623 nm. The proposed laser uses a semiconductor optical amplifier (SOA) as a gain medium and a fiber Fabry-Perot tunable filter as a selective wavelength filter. The optimized drive current of the SOA and the output coupling ratio are obtained by experimental research. This laser has a simple configuration, low threshold, flat laser output power and high optical signal-to-noise ratio.

  1. Ceramic fiber filter technology

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, B.L.; Janney, M.A.

    1996-06-01

    Fibrous filters have been used for centuries to protect individuals from dust, disease, smoke, and other gases or particulates. In the 1970s and 1980s ceramic filters were developed for filtration of hot exhaust gases from diesel engines. Tubular, or candle, filters have been made to remove particles from gases in pressurized fluidized-bed combustion and gasification-combined-cycle power plants. Very efficient filtration is necessary in power plants to protect the turbine blades. The limited lifespan of ceramic candle filters has been a major obstacle in their development. The present work is focused on forming fibrous ceramic filters using a papermaking technique. These filters are highly porous and therefore very lightweight. The papermaking process consists of filtering a slurry of ceramic fibers through a steel screen to form paper. Papermaking and the selection of materials will be discussed, as well as preliminary results describing the geometry of papers and relative strengths.

  2. Carbon Fiber from Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Milbrandt, Anelia [Clean Energy Manufacturing Analysis Center, Godlen, CO (United States); Booth, Samuel [Clean Energy Manufacturing Analysis Center, Godlen, CO (United States)

    2016-09-01

    Carbon fiber (CF), known also as graphite fiber, is a lightweight, strong, and flexible material used in both structural (load-bearing) and non-structural applications (e.g., thermal insulation). The high cost of precursors (the starting material used to make CF, which comes predominately from fossil sources) and manufacturing have kept CF a niche market with applications limited mostly to high-performance structural materials (e.g., aerospace). Alternative precursors to reduce CF cost and dependence on fossil sources have been investigated over the years, including biomass-derived precursors such as rayon, lignin, glycerol, and lignocellulosic sugars. The purpose of this study is to provide a comprehensive overview of CF precursors from biomass and their market potential. We examine the potential CF production from these precursors, the state of technology and applications, and the production cost (when data are available). We discuss their advantages and limitations. We also discuss the physical properties of biomass-based CF, and we compare them to those of polyacrylonitrile (PAN)-based CF. We also discuss manufacturing and end-product considerations for bio-based CF, as well as considerations for plant siting and biomass feedstock logistics, feedstock competition, and risk mitigation strategies. The main contribution of this study is that it provides detailed technical and market information about each bio-based CF precursor in one document while other studies focus on one precursor at a time or a particular topic (e.g., processing). Thus, this publication allows for a comprehensive view of the CF potential from all biomass sources and serves as a reference for both novice and experienced professionals interested in CF production from alternative sources.

  3. Dissecting Regional Variations in Stress Fiber Mechanics in Living Cells with Laser Nanosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, Kandice; Boudreau, Aaron; Bissell, Mina J; Kumar, Sanjay

    2010-03-02

    The ability of a cell to distribute contractile stresses across the extracellular matrix in a spatially heterogeneous fashion underlies many cellular behaviors, including motility and tissue assembly. Here we investigate the biophysical basis of this phenomenon by using femtosecond laser nanosurgery to measure the viscoelastic recoil and cell-shape contributions of contractile stress fibers (SFs) located in specific compartments of living cells. Upon photodisruption and recoil, myosin light chain kinase-dependent SFs located along the cell periphery display much lower effective elasticities and higher plateau retraction distances than Rho-associated kinase-dependent SFs located in the cell center, with severing of peripheral fibers uniquely triggering a dramatic contraction of the entire cell within minutes of fiber irradiation. Image correlation spectroscopy reveals that when one population of SFs is pharmacologically dissipated, actin density flows toward the other population. Furthermore, dissipation of peripheral fibers reduces the elasticity and increases the plateau retraction distance of central fibers, and severing central fibers under these conditions triggers cellular contraction. Together, these findings show that SFs regulated by different myosin activators exhibit different mechanical properties and cell shape contributions. They also suggest that some fibers can absorb components and assume mechanical roles of other fibers to stabilize cell shape.

  4. Dimensional stability of natural fibers

    Energy Technology Data Exchange (ETDEWEB)

    Driscoll, Mark S. [Ultraviolet Light/Electron Beam (UV/EB) Technology Center, State University of New York College of Environmental Science and Forestry (SUNY-ESF), 1 Forestry Drive, Syracuse, NY 13210 (United States); Smith, Jennifer L.; Woods, Sean; Tiss, Kenneth J. [Ultraviolet Light/Electron Beam (UV/EB) Technology Center, State University of New York College of Environmental Science and Forestry (SUNY-ESF), 1 Forestry Drive, Syracuse, NY 13210 and Sustainable Construction Management and Engineering, SUNY-ESF (United States); Larsen, L. Scott [New York State Energy Research and Development Authority (NYSERDA), 17 Columbia Circle, Albany, NY 12203 (United States)

    2013-04-19

    One of the main problems associated with the use of natural fibers as reinforcing agents in composites is their uptake of moisture. Many natural fibers are lignocellulosic, which causes them to swell and shrink as the amount of available moisture changes. Swelling and shrinking can cause composites to prematurely fail. This paper presents the results of a preliminary study that considers the use of two different low molecular weight monomers, hydroxyethyl methacrylate (HEMA) and hydroxyethyl acrylate (HEA), polymerized by electron beam ionizing radiation, to dimensionally stabilize natural fibers. Eight different treatments consisting of varying amounts of monomer, encapsulating agent, and cross-linkers, were evaluated for their ability to dimensionally stabilize sisal fiber. Results indicate that both polymerized HEA and HEMA can reduce the swelling of sisal fiber. The effectiveness of HEA and HEMA can be further enhanced with the use of a cross-linker (SR 454). The use of hydroxylated monomers to dimensionally stabilize natural fibers may play an important role in reducing delamination and improving fiber-resin adhesion in composites.

  5. Dietary protein and soluble fiber reduce ambulatory blood pressure in treated hypertensives.

    Science.gov (United States)

    Burke, V; Hodgson, J M; Beilin, L J; Giangiulioi, N; Rogers, P; Puddey, I B

    2001-10-01

    In population studies, higher blood pressure has been associated with lower intake of protein and, possibly, lower fiber consumption. In the present randomized controlled trial, we sought to determine whether dietary protein and fiber had additive effects on blood pressure reduction in hypertensives. Treated hypertensive patients changed for 4 weeks (familiarization) to a diet low in protein (12.5% energy) and fiber (15 g/d). Patients (n=41) were then randomized to 1 of 4 groups in an 8-week factorial study of parallel design in which they continued the low-protein, low-fiber diet alone or had supplements of soy protein to increase protein intake to 25% energy, of psyllium to provide an additional 12 g soluble fiber/d, or of both protein and fiber. The 24-hour ambulatory blood pressure was compared from the end of familiarization to the end of intervention. In the 36 subjects who provided complete data, protein and fiber had significant additive effects to lower 24-hour and awake systolic blood pressure. Relative to control subjects, the net reduction in 24-hour systolic blood pressure was 5.9 mm Hg with fiber and with protein. Findings were independent of age, gender, and change in weight, alcohol intake, or urinary sodium and potassium. Relative to reduced fiber and protein intake, dietary protein and soluble fiber supplements lower blood pressure additively in hypertensives. These findings have important implications for the prevention and management of hypertension, particularly in populations in which high blood pressure is prevalent in association with diets low in protein, fiber, or both.

  6. Yb-doped polarizing fiber

    Science.gov (United States)

    Gillooly, A.; Webb, A. S.; Favero, F. C.; Bouchan, T.; Cooper, L. J.; Read, D.; Hill, M.

    2017-02-01

    An ytterbium (Yb) doped polarizing fiber is demonstrated. The fiber offers the opportunity to build all-fiber lasers with single polarization output and without the need for free-space polarizing components. Traditional single polarization fiber lasers utilize polarization-maintaining (PM) gain fiber with a single polarization stimulation signal. Whilst this results in an approximation to a single polarization laser, the spontaneous emission from the unstimulated polarization state limits the polarization extinction ratio (PER). The PER is further limited as the stimulated signal is prone to crosstalk. Furthermore, controlling amplitude modulation of the stimulated signal is critical for maximizing the peak power of an optical pulse, particularly for high energy lasers. If light is allowed to leak in to the unstimulated axis it will travel at a different velocity to the stimulated axis and can cross-couple back into the signal axis, creating an interference effect which leads to amplitude modulation on the signal pulse. Single-polarization Yb-doped fiber ensures that light on the fast axis is constantly attenuated; ensuring that light on the unstimulated axis cannot propagate and thus cannot degrade the PER or create amplitude modulation. In this paper we report on, to the best of our knowledge, the first demonstration of a single polarization Yb-doped bowtie optical fiber manufactured using a combination of Modified Chemical Vapor Deposition (MCVD) and rare-earth solution doping technology. The fiber has a single-polarization window of 80nm at the operating wavelength of 1060nm and a PER of >18dB. The fabrication and characterization of the fiber is reported.

  7. In Vitro Degradation and Fermentation of Three Dietary Fiber Sources by Human Colonic Bacteria

    Science.gov (United States)

    Bliss, Donna Z.; Weimer, Paul J.; Jung, Hans-Joachim G.; Savik, Kay

    2013-01-01

    Although clinical benefits of dietary fiber supplementation seem to depend partially on the extent of fiber degradation and fermentation by colonic bacteria, little is known about the effect of supplemental fiber type on bacterial metabolism. In an experiment using a non-adapted human bacterial population from three normal subjects, extent of in vitro fermentation was greater for gum arabic (GA) than for psyllium (PSY), which was greater than that for carboxymethylcellulose (CMC). In a separate experiment, in vitro incubation with feces from 52 subjects with fecal incontinence, before and after random assignment to and consumption of one of three fiber (GA, PSY, or CMC) supplements or a placebo for 20-21d, indicated that prior consumption of a specific fiber source did not increase its degradation by fecal bacteria. Results suggest that the colonic microbial community enriched on a particular fiber substrate can rapidly adapt to the presentation of a new fiber substrate. Clinical implications of the findings are that intake of a fiber source by humans is not expected to result in bacterial adaptation that would require continually larger and eventually intolerable amounts of fiber to achieve therapeutic benefits. PMID:23556460

  8. In vitro degradation and fermentation of three dietary fiber sources by human colonic bacteria.

    Science.gov (United States)

    Bliss, Donna Z; Weimer, Paul J; Jung, Hans-Joachim G; Savik, Kay

    2013-05-15

    Although clinical benefits of dietary fiber supplementation seem to depend partially on the extent of fiber degradation and fermentation by colonic bacteria, little is known about the effect of supplemental fiber type on bacterial metabolism. In an experiment using a nonadapted human bacterial population from three normal subjects, the extent of in vitro fermentation was greater for gum arabic (GA) than for psyllium (PSY), which was greater than that for carboxymethylcellulose (CMC). In a separate experiment, in vitro incubation with feces from 52 subjects with fecal incontinence, before and after random assignment to and consumption of one of three fiber (GA, PSY, or CMC) supplements or a placebo for 20-21 days, indicated that prior consumption of a specific fiber source did not increase its degradation by fecal bacteria. Results suggest that the colonic microbial community enriched on a particular fiber substrate can rapidly adapt to the presentation of a new fiber substrate. Clinical implications of the findings are that intake of a fiber source by humans is not expected to result in bacterial adaptation that would require continually larger and eventually intolerable amounts of fiber to achieve therapeutic benefits.

  9. All-Fiber Components for Micro-Structured Fibers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose new concepts for developing components for high performance space based Lidar systems. While it is generally recognized that photonic crystal fiber...

  10. Fiber composite materials: A survey of fiber matrix interface mechanics

    Science.gov (United States)

    Chamis, C. C.

    1973-01-01

    Report is described which discusses mechanism of load transfer from matrix to fiber through interface and effects of interface on composite structural integrity. Theoretical considerations are supplemented with experimental data. General trends and significant points are illustrated graphically.

  11. Optical Fiber Sensors Based on Fiber Ring Laser Demodulation Technology.

    Science.gov (United States)

    Xie, Wen-Ge; Zhang, Ya-Nan; Wang, Peng-Zhao; Wang, Jian-Zhang

    2018-02-08

    A review for optical fiber sensors based on fiber ring laser (FRL) demodulation technology is presented. The review focuses on the principles, main structures, and the sensing performances of different kinds of optical fiber sensors based on FRLs. First of all, the theory background of the sensors has been discussed. Secondly, four different types of sensors are described and compared, which includes Mach-Zehnder interferometer (MZI) typed sensors, Fabry-Perot interferometer (FPI) typed sensors, Sagnac typed sensors, and fiber Bragg grating (FBG) typed sensors. Typical studies and main properties of each type of sensors are presented. Thirdly, a comparison of different types of sensors are made. Finally, the existing problems and future research directions are pointed out and analyzed.

  12. Advanced Optical Fibers for High power Fiber lasers

    Science.gov (United States)

    2015-08-24

    unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. propagation of a higher-order mode in a...demonstrated high efficiency and excellent mode quality (see Figure 27(b) and (c)). The fiber also demonstrated robust single- mode behavior near the short...core chirally coupled core optical fibers,” PhotonicsWest, paper 8237-59, 2012. [45] T. A. Birks, G. J. Pearce, D. M. Bird , “Approximate band structure

  13. Silicon photonics for multicore fiber communication

    DEFF Research Database (Denmark)

    Ding, Yunhong; Kamchevska, Valerija; Dalgaard, Kjeld

    2016-01-01

    We review our recent work on silicon photonics for multicore fiber communication, including multicore fiber fan-in/fan-out, multicore fiber switches towards reconfigurable optical add/drop multiplexers. We also present multicore fiber based quantum communication using silicon devices....

  14. Digital signal processing for fiber nonlinearities [Invited

    DEFF Research Database (Denmark)

    Cartledge, John C.; Guiomar, Fernando P.; Kschischang, Frank R.

    2017-01-01

    This paper reviews digital signal processing techniques that compensate, mitigate, and exploit fiber nonlinearities in coherent optical fiber transmission systems......This paper reviews digital signal processing techniques that compensate, mitigate, and exploit fiber nonlinearities in coherent optical fiber transmission systems...

  15. Climbing fiber signaling and cerebellar gain control

    NARCIS (Netherlands)

    G. Ohtsuki (Gen); C. Piochon (Claire); C.R.W. Hansel (Christian)

    2009-01-01

    textabstractThe physiology of climbing fiber signals in cerebellar Purkinje cells has been studied since the early days of electrophysiology. Both the climbing fiber-evoked complex spike and the role of climbing fiber activity in the induction of long-term depression (LTD) at parallel fiber-Purkinje

  16. Influence of fiber quality on draftometer measurements

    Science.gov (United States)

    Fiber-to-fiber and fiber-to-machine friction play an important role in determining textile processing efficiency and end-product quality. A process, known as drafting, is used to control the attenuation of the fiber mass being processed in carding, drawing and spinning. The amount of attenuation t...

  17. Genome Regions Associated with Functional Performance of Soybean Stem Fibers in Polypropylene Thermoplastic Composites.

    Science.gov (United States)

    Reinprecht, Yarmilla; Arif, Muhammad; Simon, Leonardo C; Pauls, K Peter

    2015-01-01

    Plant fibers can be used to produce composite materials for automobile parts, thus reducing plastic used in their manufacture, overall vehicle weight and fuel consumption when they replace mineral fillers and glass fibers. Soybean stem residues are, potentially, significant sources of inexpensive, renewable and biodegradable natural fibers, but are not curretly used for biocomposite production due to the functional properties of their fibers in composites being unknown. The current study was initiated to investigate the effects of plant genotype on the performance characteristics of soybean stem fibers when incorporated into a polypropylene (PP) matrix using a selective phenotyping approach. Fibers from 50 lines of a recombinant inbred line population (169 RILs) grown in different environments were incorporated into PP at 20% (wt/wt) by extrusion. Test samples were injection molded and characterized for their mechanical properties. The performance of stem fibers in the composites was significantly affected by genotype and environment. Fibers from different genotypes had significantly different chemical compositions, thus composites prepared with these fibers displayed different physical properties. This study demonstrates that thermoplastic composites with soybean stem-derived fibers have mechanical properties that are equivalent or better than wheat straw fiber composites currently being used for manufacturing interior automotive parts. The addition of soybean stem residues improved flexural, tensile and impact properties of the composites. Furthermore, by linkage and in silico mapping we identified genomic regions to which quantitative trait loci (QTL) for compositional and functional properties of soybean stem fibers in thermoplastic composites, as well as genes for cell wall synthesis, were co-localized. These results may lead to the development of high value uses for soybean stem residue.

  18. Genome Regions Associated with Functional Performance of Soybean Stem Fibers in Polypropylene Thermoplastic Composites.

    Directory of Open Access Journals (Sweden)

    Yarmilla Reinprecht

    Full Text Available Plant fibers can be used to produce composite materials for automobile parts, thus reducing plastic used in their manufacture, overall vehicle weight and fuel consumption when they replace mineral fillers and glass fibers. Soybean stem residues are, potentially, significant sources of inexpensive, renewable and biodegradable natural fibers, but are not curretly used for biocomposite production due to the functional properties of their fibers in composites being unknown. The current study was initiated to investigate the effects of plant genotype on the performance characteristics of soybean stem fibers when incorporated into a polypropylene (PP matrix using a selective phenotyping approach. Fibers from 50 lines of a recombinant inbred line population (169 RILs grown in different environments were incorporated into PP at 20% (wt/wt by extrusion. Test samples were injection molded and characterized for their mechanical properties. The performance of stem fibers in the composites was significantly affected by genotype and environment. Fibers from different genotypes had significantly different chemical compositions, thus composites prepared with these fibers displayed different physical properties. This study demonstrates that thermoplastic composites with soybean stem-derived fibers have mechanical properties that are equivalent or better than wheat straw fiber composites currently being used for manufacturing interior automotive parts. The addition of soybean stem residues improved flexural, tensile and impact properties of the composites. Furthermore, by linkage and in silico mapping we identified genomic regions to which quantitative trait loci (QTL for compositional and functional properties of soybean stem fibers in thermoplastic composites, as well as genes for cell wall synthesis, were co-localized. These results may lead to the development of high value uses for soybean stem residue.

  19. Molecular mechanisms of fiber differential development between G. barbadense and G. hirsutum revealed by genetical genomics.

    Directory of Open Access Journals (Sweden)

    Xiangdong Chen

    Full Text Available Cotton fiber qualities including length, strength and fineness are known to be controlled by genes affecting cell elongation and secondary cell wall (SCW biosynthesis, but the molecular mechanisms that govern development of fiber traits are largely unknown. Here, we evaluated an interspecific backcrossed population from G. barbadense cv. Hai7124 and G. hirsutum acc. TM-1 for fiber characteristics in four-year environments under field conditions, and detected 12 quantitative trait loci (QTL and QTL-by-environment interactions by multi-QTL joint analysis. Further analysis of fiber growth and gene expression between TM-1 and Hai7124 showed greater differences at 10 and 25 days post-anthesis (DPA. In this two period important for fiber performances, we integrated genome-wide expression profiling with linkage analysis using the same genetic materials and identified in total 916 expression QTL (eQTL significantly (P<0.05 affecting the expression of 394 differential genes. Many positional cis-/trans-acting eQTL and eQTL hotspots were detected across the genome. By comparative mapping of eQTL and fiber QTL, a dataset of candidate genes affecting fiber qualities was generated. Real-time quantitative RT-PCR (qRT-PCR analysis confirmed the major differential genes regulating fiber cell elongation or SCW synthesis. These data collectively support molecular mechanism for G. hirsutum and G. barbadense through differential gene regulation causing difference of fiber qualities. The down-regulated expression of abscisic acid (ABA and ethylene signaling pathway genes and high-level and long-term expression of positive regulators including auxin and cell wall enzyme genes for fiber cell elongation at the fiber developmental transition stage may account for superior fiber qualities.

  20. Genome Regions Associated with Functional Performance of Soybean Stem Fibers in Polypropylene Thermoplastic Composites

    Science.gov (United States)

    Reinprecht, Yarmilla; Arif, Muhammad; Simon, Leonardo C.; Pauls, K. Peter

    2015-01-01

    Plant fibers can be used to produce composite materials for automobile parts, thus reducing plastic used in their manufacture, overall vehicle weight and fuel consumption when they replace mineral fillers and glass fibers. Soybean stem residues are, potentially, significant sources of inexpensive, renewable and biodegradable natural fibers, but are not curretly used for biocomposite production due to the functional properties of their fibers in composites being unknown. The current study was initiated to investigate the effects of plant genotype on the performance characteristics of soybean stem fibers when incorporated into a polypropylene (PP) matrix using a selective phenotyping approach. Fibers from 50 lines of a recombinant inbred line population (169 RILs) grown in different environments were incorporated into PP at 20% (wt/wt) by extrusion. Test samples were injection molded and characterized for their mechanical properties. The performance of stem fibers in the composites was significantly affected by genotype and environment. Fibers from different genotypes had significantly different chemical compositions, thus composites prepared with these fibers displayed different physical properties. This study demonstrates that thermoplastic composites with soybean stem-derived fibers have mechanical properties that are equivalent or better than wheat straw fiber composites currently being used for manufacturing interior automotive parts. The addition of soybean stem residues improved flexural, tensile and impact properties of the composites. Furthermore, by linkage and in silico mapping we identified genomic regions to which quantitative trait loci (QTL) for compositional and functional properties of soybean stem fibers in thermoplastic composites, as well as genes for cell wall synthesis, were co-localized. These results may lead to the development of high value uses for soybean stem residue. PMID:26167917

  1. Matters of fiber size and myonuclear domain

    DEFF Research Database (Denmark)

    Karlsen, Anders; Couppé, Christian; Andersen, Jesper L.

    2015-01-01

    INTRODUCTION: The relationship between fiber size and myonuclear content is understood poorly. METHODS: Biopsy cross-sections from young and old trained and untrained healthy individuals were analyzed for fiber area and myonuclei, and 2 fiber size-dependent cluster analyses were performed. RESULTS...... in fibers type II fibers below 3,000 μm(2) was observed in the old. DISCUSSION: These findings suggest that age-related reductions in myonuclear domain size could be explained by a larger proportion of small fibers and highlight the usefulness of fiber size...

  2. Ethanol extraction of phytosterols from corn fiber

    Science.gov (United States)

    Abbas, Charles; Beery, Kyle E.; Binder, Thomas P.; Rammelsberg, Anne M.

    2010-11-16

    The present invention provides a process for extracting sterols from a high solids, thermochemically hydrolyzed corn fiber using ethanol as the extractant. The process includes obtaining a corn fiber slurry having a moisture content from about 20 weight percent to about 50 weight percent solids (high solids content), thermochemically processing the corn fiber slurry having high solids content of 20 to 50% to produce a hydrolyzed corn fiber slurry, dewatering the hydrolyzed corn fiber slurry to achieve a residual corn fiber having a moisture content from about 30 to 80 weight percent solids, washing the residual corn fiber, dewatering the washed, hydrolyzed corn fiber slurry to achieve a residual corn fiber having a moisture content from about 30 to 80 weight percent solids, and extracting the residual corn fiber with ethanol and separating at least one sterol.

  3. Thermoplastic-carbon fiber hybrid yarn

    Science.gov (United States)

    Ketterer, M. E.

    1984-01-01

    Efforts were directed to develop processing methods to make carbon fiber/thermoplastic fiber preforms that are easy to handle and drapeable, and to consolidate them into low void content laminates. The objectives were attained with the development of the hybrid yarn concept; whereby, thermoplastic fiber can be intimately intermixed with carbon fiber into a hybrid yarn. This was demonstrated with the intermixing of Celion 3000 with a Celanese liquid crystal polymer fiber, polybutylene terepthalate fiber, or polyetheretherketone fiber. The intermixing of the thermoplastic matrix fiber and the reinforcing carbon fiber gives a preform that can be easily fabricated into laminates with low void content. Mechanical properties of the laminates were not optimized; however, initial results indicated properties typical of a thermoplastic/carbon fiber composites prepared by more conventional methods.

  4. High performance polyethylene nanocomposite fibers

    Directory of Open Access Journals (Sweden)

    A. Dorigato

    2012-12-01

    Full Text Available A high density polyethylene (HDPE matrix was melt compounded with 2 vol% of dimethyldichlorosilane treated fumed silica nanoparticles. Nanocomposite fibers were prepared by melt spinning through a co-rotating twin screw extruder and drawing at 125°C in air. Thermo-mechanical and morphological properties of the resulting fibers were then investigated. The introduction of nanosilica improved the drawability of the fibers, allowing the achievement of higher draw ratios with respect to the neat matrix. The elastic modulus and creep stability of the fibers were remarkably improved upon nanofiller addition, with a retention of the pristine tensile properties at break. Transmission electronic microscope (TEM images evidenced that the original morphology of the silica aggregates was disrupted by the applied drawing.

  5. Oxide fiber targets at ISOLDE

    DEFF Research Database (Denmark)

    Köster, U.; Bergmann, U.C.; Carminati, D.

    2003-01-01

    Many elements are rapidly released from oxide matrices. Some oxide powder targets show a fast sintering, thus losing their favorable release characteristics. Loosely packed oxide fiber targets are less critical since they may maintain their open structure even when starting to fuse together at some...... contact points. The experience with various oxide fiber targets (titania, zirconia, ceria and thoria) used in the last years at ISOLDE is reviewed. For short-lived isotopes of Cu, Ga and Xe the zirconia and ceria targets respectively provided significantly higher yields than any other target (metal foils......, oxide powders, etc.) tested before. Titania fibers, which were not commercially available, were produced in a relic process by impregnation of a rayon felt in a titanium chloride solution and subsequent calcination by heating the dried felt in air. Thoria fibers were obtained either by the same process...

  6. Carbon Fiber Technology Facility (CFTF)

    Data.gov (United States)

    Federal Laboratory Consortium — Functionally within the MDF, ORNL operates DOE’s unique Carbon Fiber Technology Facility (CFTF)—a 42,000 ft2 innovative technology facility and works with leading...

  7. Nanomechanics of electrospun phospholipid fiber

    DEFF Research Database (Denmark)

    Mendes, Ana Carina Loureiro; Nikogeorgos, Nikolaos; Lee, Seunghwan

    2015-01-01

    Electrospun asolectin phospholipid fibers were prepared using isooctane as a solvent and had an average diameter of 6.1 +/- 2.7 mu m. Their mechanical properties were evaluated by nanoindentation using Atomic Force Microscopy, and their elastic modulus was found to be approximately 17.2 +/- 1MPa....... At a cycle of piezo expansion-retraction (loading-unloading) of a silicon tip on a fiber, relatively high adhesion was observed during unloading. It is proposed that this was primarily due to molecular rearrangements at the utmost layers of the fiber caused by the indentation of the hydrophilic tip....... The phospholipid fibers were shown to be stable in ambient conditions, preserving the modulus of elasticity up to 24 h. (c) 2015 AIP Publishing LLC....

  8. Application of Fiber Optic Instrumentation

    Science.gov (United States)

    Richards, William Lance; Parker, Allen R., Jr.; Ko, William L.; Piazza, Anthony; Chan, Patrick

    2012-01-01

    Fiber optic sensing technology has emerged in recent years offering tremendous advantages over conventional aircraft instrumentation systems. The advantages of fiber optic sensors over their conventional counterparts are well established; they are lighter, smaller, and can provide enormous numbers of measurements at a fraction of the total sensor weight. After a brief overview of conventional and fiber-optic sensing technology, this paper presents an overview of the research that has been conducted at NASA Dryden Flight Research Center in recent years to advance this promising new technology. Research and development areas include system and algorithm development, sensor characterization and attachment, and real-time experimentally-derived parameter monitoring for ground- and flight-based applications. The vision of fiber optic smart structure technology is presented and its potential benefits to aerospace vehicles throughout the lifecycle, from preliminary design to final retirement, are presented.

  9. Studies on scintillating fiber response

    Energy Technology Data Exchange (ETDEWEB)

    Albers, D. [Bonn Univ. (Germany). Inst. fuer Strahlen- und Kernphysik; Bisplinghoff, J.; Bollmann, R.; Buesser, K.; Cloth, P.; Diehl, O.; Dohrmann, F.; Drueke, V.; Engelhardt, H.P.; Ernst, J.; Eversheim, P.D.; Filges, D.; Gasthuber, M.; Gebel, R.; Greiff, J.; Gross, A.; Gross-Hardt, R.; Heine, A.; Heider, S.; Hinterberger, F.; Igelbrink, M.; Jahn, R.; Jeske, M.; Langkau, R.; Lindlein, J.; Maier, R.; Maschuw, R.; Mayer-Kuckuk, T.; Mertler, G.; Metsch, B.; Mosel, F.; Mueller, M.; Muenstermann, M.; Paetz genannt Schieck, H.; Petry, H.R.; Prasuhn, D.; Rohdjess, H.; Rosendaal, D.; Ross, U.; Rossen, P. von; Scheid, H.; Schirm, N.; Schulz-Rojahn, M.; Schwandt, F.; Scobel, W.; Steeg, B.; Sterzenbach, G.; Trelle, H.J.; Wellinghausen, A.; Wiedmann, W.; Woller, K.; Ziegler, R. [Institut fuer Strahlen- und Kernphysik, Universitaet Bonn, Bonn (Germany)]|[1. Institut fuer Experimentalphysik, Universitaet Hamburg, Hamburg (Germany)]|[Institut fuer Kernphysik, KFA, Juelich (Germany)]|[Institut fuer Theor. Kernphysik, Universitaet Bonn, Bonn (Germany)]|[Institut fuer Kernphysik, Universitaet Koeln, Koeln (Germany)

    1995-03-11

    Scintillating fibers of type Bicron BCF-12 with 2 x 2 mm{sup 2} cross section, up to 600 mm length, and PMMA cladding have been tested, in conjunction with the multi-channel photomultiplier Hamamatsu R 4760, with minimum ionizing electrons. The impact of cladding, extramural absorbers and/or wrapping on the light attenuation and photoelectron yield is studied in detail. Fibers have been circularly bent with radii of 171 mm and arranged in two layers to bundles forming granulated scintillator rings. Their performance in the EDDA experiment at COSY for detection of high energy protons revealed typically more than 9 (6) photoelectrons per fiber from bundles with (without) mirror on the rear side, guaranteeing detection efficiencies >99% and full compatibility with corresponding solid scintillator rings. The time resolution of 3.4 ns FWHM per fiber read out is essentially due to the R 4760. (orig.).

  10. Studies on scintillating fiber response

    Science.gov (United States)

    Albers, D.; Bisplinghoff, J.; Bollmann, R.; Büßer, K.; Cloth, P.; Diehl, O.; Dohrmann, F.; Drüke, V.; Engelhardt, H. P.; Ernst, J.; Eversheim, P. D.; Filges, D.; Gasthuber, M.; Gebel, R.; Greiff, J.; Groß, A.; Groß-Hardt, R.; Heine, A.; Heider, S.; Hinterberger, F.; Igelbrink, M.; Jahn, R.; Jeske, M.; Langkau, R.; Lindlein, J.; Maier, R.; Maschuw, R.; Mayer-Kuckuk, T.; Mertler, G.; Metsch, B.; Mosel, F.; Müller, M.; Münstermann, M.; Paetz gen. Schieck, H.; Petry, H. R.; Prasuhn, D.; Rohdjeß, H.; Rosendaal, D.; Roß, U.; von Rossen, P.; Scheid, H.; Schirm, N.; Schulz-Rojahn, M.; Schwandt, F.; Scobel, W.; Steeg, B.; Sterzenbach, G.; Trelle, H. J.; Wellinghausen, A.; Wiedmann, W.; Woller, K.; Ziegler, R.

    1996-02-01

    Scintillating fibers of type Bicron BCF-12 with 2 × 2 mm 2 cross section, up to 600 mm length, and PMMA cladding have been tested, in conjunction with the multi-channel photomultiplier Hamamatsu R 4760, with minimum ionizing electrons. The impact of cladding, extramural absorbers and/or wrapping on the light attenuation and photoelectron yield is studied in detail. Fibers have been circularly bent with radii of 171 mm and arranged in two layers to bundles forming granulated scintillator rings. Their performance in the EDDA experiment at COSY for detection of high energy protons revealed typically more than 9 (6) photoelectrons per fiber from bundles with (without) mirror on the rear side, guaranteeing detection efficiencies >99% and full compatibility with corresponding solid scintillator rings. The time resolution of 3.4 ns FWHM per fiber read out is essentially due to the R 4760.

  11. Submicron Surface-Patterned Fibers and Textiles

    Science.gov (United States)

    2016-11-04

    The patterned fiber surface behaves as an optical diffraction grating when the feature size is comparable with visible light wavelengths. A red laser...the optical fiber gratings For the first diffraction order of the micron and submicron patterned fiber , we utilize the formula α tanh (where s...e) SEM images of patterned PMMA fiber are depicted. The inset shows the cross- section of this fiber . Submitted to 20 Figure S3

  12. Safely splicing glass optical fibers

    Science.gov (United States)

    Korbelak, K.

    1980-01-01

    Field-repair technique fuses glass fibers in flammable environment. Apparatus consists of v-groove vacuum chucks on manipulators, high-voltage dc power supply and tungsten electrodes, microscope to observe joint alignment and fusion, means of test transmission through joint. Apparatus is enclosed in gas tight bos filled with inert gas during fusion. About 2 feet of fiber end are necessary for splicing.

  13. Progress In IR Optical Fibers

    Science.gov (United States)

    Hartouni, E.; Hulderman, F.; Guiton, T.

    1984-12-01

    A quantitative assessment of bulk chalcogenide glass material properties was conducted for the As-S, As-Se, As-Se-Te, Ge-As-Se, and Ge-As-Te glass systems. The promising glass candidates were subsequently drawn into optical fibers by the crucible technique, and fiber attenuation losses were measured at wavelengths of He:Ne and CO2 laser sources.

  14. Fundamentals of plastic optical fibers

    CERN Document Server

    Koike, Yasuhiro

    2014-01-01

    Polymer photonics is an interdisciplinary field which demands excellence both in optics (photonics) and materials science (polymer). However, theses disciplines have developed independently, and therefore the demand for a comprehensive work featuring the fundamentals of photonic polymers is greater than ever.This volume focuses on Polymer Optical Fiber and their applications. The first part of the book introduces typical optical fibers according to their classifications of material, propagating mode, and structure. Optical properties, the high bandwidth POF and transmission loss are discussed,

  15. Small Business Innovations (Fiber Optics)

    Science.gov (United States)

    1991-01-01

    Foster-Miller, Inc. Waltham, MA developed the In-Situ Fiber Optic Polymer Reaction Monitor which could lead to higher yields and lower costs in complex composite manufacturing. The monitor, developed under a Small Business Innovation Research (SBIR) contract with Langley Research Center, uses an infrared, fiber optic sensor to track the molecular vibrational characteristics of a composite part while it is being cured. It is the first analytical system capable of directly measuring the chemistry of advanced composite materials.

  16. Dietary Fibers and Cardiometabolic Diseases

    OpenAIRE

    Nicolantonio D’Orazio; Luca Scotti; Salvatore Cusenza; Eugenio Gemello; Barbara Di Bello; Valeriana Sblendorio; Graziano Riccioni

    2012-01-01

    The high prevalence of cardiovascular disease (CVD) is largely attributable to the contemporary lifestyle that is often sedentary and includes a diet high in saturated fats and sugars and low ingestion of polyunsaturated fatty acids (PUFAs), fruit, vegetables, and fiber. Experimental data from both animals and humans suggest an association between increased dietary fiber (DF) intakes and improved plasma lipid profiles, including reduced low density lipoprotein cholesterol (LDL-C) concentratio...

  17. Fiber coupler end face wavefront surface metrology

    Science.gov (United States)

    Compertore, David C.; Ignatovich, Filipp V.; Marcus, Michael A.

    2015-09-01

    Despite significant technological advances in the field of fiber optic communications, one area remains surprisingly `low-tech': fiber termination. In many instances it involves manual labor and subjective visual inspection. At the same time, high quality fiber connections are one of the most critical parameters in constructing an efficient communication link. The shape and finish of the fiber end faces determines the efficiency of a connection comprised of coupled fiber end faces. The importance of fiber end face quality becomes even more critical for fiber connection arrays and for in the field applications. In this article we propose and demonstrate a quantitative inspection method for the fiber connectors using reflected wavefront technology. The manufactured and polished fiber tip is illuminated by a collimated light from a microscope objective. The reflected light is collected by the objective and is directed to a Shack-Hartmann wavefront sensor. A set of lenses is used to create the image of the fiber tip on the surface of the sensor. The wavefront is analyzed by the sensor, and the measured parameters are used to obtain surface properties of the fiber tip, and estimate connection loss. For example, defocus components in the reflected light indicate the presence of bow in the fiber end face. This inspection method provides a contact-free approach for quantitative inspection of fiber end faces and for estimating the connection loss, and can potentially be integrated into a feedback system for automated inspection and polishing of fiber tips and fiber tip arrays.

  18. Fiber Based Dispersion Compensation

    CERN Document Server

    Ramachandran, Siddharth

    2007-01-01

    Dispersion management is a critical design criterion that characterizes the performance of an optical network, and has impacted almost every aspect of the physical layer of an optical transmission line. The past 10 years have seen an explosion in the variety of device effects exploited to obtain optimal performance from dispersion compensators, and this is the first book that deals exclusively with this technology. It starts with an exposition on the fundamental physics underlying dispersion and its effects on optical pulses, followed by at least one chapter devoted to each of the fiber-based dispersion-compensating devices that have either been deployed or are considered as serious candidates for future networks. The final section of this book then describes the systems-level impact of these devices, hence providing a one-stop reference for all aspects of optical-communication-network design pertaining to dispersion-management. Each chapter is written by the leading experts in the field, drawn from both acad...

  19. Photonic bandgap fiber lasers and multicore fiber lasers for next generation high power lasers

    DEFF Research Database (Denmark)

    Shirakawa, A.; Chen, M.; Suzuki, Y.

    2014-01-01

    Photonic bandgap fiber lasers are realizing new laser spectra and nonlinearity mitigation that a conventional fiber laser cannot. Multicore fiber lasers are a promising tool for power scaling by coherent beam combination. © 2014 OSA....

  20. Hybrid Effect Evaluation of Steel Fiber and Carbon Fiber on the Performance of the Fiber Reinforced Concrete

    Science.gov (United States)

    Song, Weimin; Yin, Jian

    2016-01-01

    Fiber reinforcement is an important method to enhance the performance of concrete. In this study, the compressive test and impact test were conducted, and then the hybrid effect between steel fiber (SF) and carbon fiber (CF) was evaluated by employing the hybrid effect index. Compressive toughness and impact toughness of steel fiber reinforced concrete (SFRC), carbon fiber reinforced concrete (CFRC) and hybrid fiber reinforced concrete (HFRC) were explored at steel fiber volume fraction 0.5%, 1%, 1.5% and carbon fiber 0.1%, 0.2%, 0.3%. Results showed that the addition of steel fiber and carbon fiber can increase the compressive strength. SF, CF and the hybridization between them could increase the compressive toughness significantly. The impact test results showed that as the volume of fiber increased, the impact number of the first visible crack and the ultimate failure also increased. The improvement of toughness mainly lay in improving the crack resistance after the first crack. Based on the test results, the positive hybrid effect of steel fiber and carbon fiber existed in hybrid fiber reinforced concrete. The relationship between the compressive toughness and impact toughness was also explored. PMID:28773824

  1. Hybrid Effect Evaluation of Steel Fiber and Carbon Fiber on the Performance of the Fiber Reinforced Concrete.

    Science.gov (United States)

    Song, Weimin; Yin, Jian

    2016-08-18

    Fiber reinforcement is an important method to enhance the performance of concrete. In this study, the compressive test and impact test were conducted, and then the hybrid effect between steel fiber (SF) and carbon fiber (CF) was evaluated by employing the hybrid effect index. Compressive toughness and impact toughness of steel fiber reinforced concrete (SFRC), carbon fiber reinforced concrete (CFRC) and hybrid fiber reinforced concrete (HFRC) were explored at steel fiber volume fraction 0.5%, 1%, 1.5% and carbon fiber 0.1%, 0.2%, 0.3%. Results showed that the addition of steel fiber and carbon fiber can increase the compressive strength. SF, CF and the hybridization between them could increase the compressive toughness significantly. The impact test results showed that as the volume of fiber increased, the impact number of the first visible crack and the ultimate failure also increased. The improvement of toughness mainly lay in improving the crack resistance after the first crack. Based on the test results, the positive hybrid effect of steel fiber and carbon fiber existed in hybrid fiber reinforced concrete. The relationship between the compressive toughness and impact toughness was also explored.

  2. Fiber reinforced hybrid phenolic foam

    Science.gov (United States)

    Desai, Amit

    Hybrid composites in recent times have been developed by using more than one type of fiber reinforcement to bestow synergistic properties of the chosen filler and matrix and also facilitating the design of materials with specific properties matched to end use. However, the studies for hybrid foams have been very limited because of problems related to fiber dispersion in matrix, non uniform mixing due to presence of more than one filler and partially cured foams. An effective approach to synthesize hybrid phenolic foam has been proposed and investigated here. Hybrid composite phenolic foams were reinforced with chopped glass and aramid fibers in varied proportions. On assessing mechanical properties in compression and shear several interesting facts surfaced but overall hybrid phenolic foams exhibited a more graceful failure, greater resistance to cracking and were significantly stiffer and stronger than foams with only glass and aramid fibers. The optimum fiber ratio for the reinforced hybrid phenolic foam system was found to be 1:1 ratio of glass to aramid fibers. Also, the properties of hybrid foam were found to deviate from rule of mixture (ROM) and thus the existing theories of fiber reinforcement fell short in explaining their complex behavior. In an attempt to describe and predict mechanical behavior of hybrid foams a statistical design tool using analysis of variance technique was employed. The utilization of a statistical model for predicting foam properties was found to be an appropriate tool that affords a global perspective of the influence of process variables such as fiber weight fraction, fiber length etc. on foam properties (elastic modulus and strength). Similar approach could be extended to study other fiber composite foam systems such as polyurethane, epoxy etc. and doing so will reduce the number of experimental iterations needed to optimize foam properties and identify critical process variables. Diffusivity, accelerated aging and flammability

  3. Fiber optic muzzle brake tip for reducing fiber burnback and stone retropulsion during thulium fiber laser lithotripsy

    Science.gov (United States)

    Hutchens, Thomas C.; Gonzalez, David A.; Irby, Pierce B.; Fried, Nathaniel M.

    2017-01-01

    The experimental thulium fiber laser (TFL) is being explored as an alternative to the current clinical gold standard Holmium:YAG laser for lithotripsy. The near single-mode TFL beam allows coupling of higher power into smaller optical fibers than the multimode Holmium laser beam profile, without proximal fiber tip degradation. A smaller fiber is desirable because it provides more space in the ureteroscope working channel for increased saline irrigation rates and allows maximum ureteroscope deflection. However, distal fiber tip burnback increases as fiber diameter decreases. Previous studies utilizing hollow steel sheaths around recessed distal fiber tips reduced fiber burnback but increased stone retropulsion. A "fiber muzzle brake" was tested for reducing both fiber burnback and stone retropulsion by manipulating vapor bubble expansion. TFL lithotripsy studies were performed at 1908 nm, 35 mJ, 500 μs, and 300 Hz using a 100-μm-core fiber. The optimal stainless steel muzzle brake tip tested consisted of a 1-cm-long, 560-μm-outer-diameter, 360-μm-inner-diameter tube with a 275-μm-diameter through hole located 250 μm from the distal end. The fiber tip was recessed a distance of 500 μm. Stone phantom retropulsion, fiber tip burnback, and calcium oxalate stone ablation studies were performed ex vivo. Small stones with a mass of 40±4 mg and 4-mm-diameter were ablated over a 1.5-mm sieve in 25±4 s (n=10) without visible distal fiber tip burnback. Reduction in stone phantom retropulsion distance by 50% and 85% was observed when using muzzle brake tips versus 100-μm-core bare fibers and hollow steel tip fibers, respectively. The muzzle brake fiber tip simultaneously provided efficient stone ablation, reduced stone retropulsion, and minimal fiber degradation during TFL lithotripsy.

  4. Photonic bandgap fiber lasers and multicore fiber lasers for next generation high power lasers

    DEFF Research Database (Denmark)

    Shirakawa, A.; Chen, M.; Suzuki, Y.

    2014-01-01

    Photonic bandgap fiber lasers are realizing new laser spectra and nonlinearity mitigation that a conventional fiber laser cannot. Multicore fiber lasers are a promising tool for power scaling by coherent beam combination. © 2014 OSA.......Photonic bandgap fiber lasers are realizing new laser spectra and nonlinearity mitigation that a conventional fiber laser cannot. Multicore fiber lasers are a promising tool for power scaling by coherent beam combination. © 2014 OSA....

  5. Method for the preparation of carbon fiber from polyolefin fiber precursor

    Energy Technology Data Exchange (ETDEWEB)

    Naskar, Amit Kumar; Hunt, Marcus Andrew; Saito, Tomonori

    2017-11-28

    Methods for the preparation of carbon fiber from polyolefin fiber precursor, wherein the polyolefin fiber precursor is partially sulfonated and then carbonized to produce carbon fiber. Methods for producing hollow carbon fibers, wherein the hollow core is circular- or complex-shaped, are also described. Methods for producing carbon fibers possessing a circular- or complex-shaped outer surface, which may be solid or hollow, are also described.

  6. Advanced ultrafast fiber laser sources enabled by fiber nonlinearities

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei

    2017-05-15

    Development of high power/energy ultrafast fiber lasers for scientific research and industrial applications is one of the most exciting fields in ultrafast optics. This thesis demonstrated new means to improve two essential properties - which are indispensable for novel applications such as high-harmonic generation (HHG) and multiphoton microscopy (MPM) - of an ultrafast fiber laser system: energy scaling capability and wavelength tunability. High photon-flux extreme ultraviolet sources enabled by HHG desire high power (>100 W), high repetition-rate (>1 MHz) ultrafast driving laser sources. We have constructed from scratch a high-power Yb-fiber laser system using the well-known chirped-pulse amplification (CPA) technique. Such a CPA system capable of producing ∝200-W average power consists of a monolithic Yb-fiber oscillator, an all-fiber stretcher, a pre-amplifier chain, a main amplifier constructed from rode-type large pitch fiber, and a diffraction-grating based compressor. To increase the HHG efficiency, ultrafast pulses with duration <60 fs are highly desired. We proposed and demonstrated a novel amplification technique, named as pre-chirp managed amplification (PCMA). We successfully constructed an Yb-fiber based PCMA system that outputs 75-MHz spectrally broadened pulses with >130-W average power. The amplified pulses are compressed to 60-fs pulses with 100-W average power, constituting a suitable HHG driving source. MPM is a powerful biomedical imaging tool, featuring larger penetration depth while providing the capability of optical sectioning. Although femtosecond solid-state lasers have been widely accepted as the standard option as MPM driving sources, fiber-based sources have received growing research efforts due to their superior performance. In the second part of this thesis, we both theoretically and experimentally demonstrated a new method of producing wavelength widely tunable femtosecond pulses for driving MPM. We employed self-phase modulation

  7. Population dynamics of two beaver species in Finland inferred from citizen‐science census data

    National Research Council Canada - National Science Library

    Brommer, J. E; Alakoski, R; Selonen, V; Kauhala, K

    2017-01-01

    ...‐census open population N‐mixture model, which was recently developed to handle such challenging census data, to describe the dynamics in the Finnish population sizes of the reintroduced native Eurasian beaver ( Castor fiber...

  8. Bonding Properties of Basalt Fiber and Strength Reduction According to Fiber Orientation.

    Science.gov (United States)

    Choi, Jeong-Il; Lee, Bang Yeon

    2015-09-30

    The basalt fiber is a promising reinforcing fiber because it has a relatively higher tensile strength and a density similar to that of a concrete matrix as well as no corrosion possibility. This study investigated experimentally the bonding properties of basalt fiber with cementitious material as well as the effect of fiber orientation on the tensile strength of basalt fiber for evaluating basalt fiber's suitability as a reinforcing fiber. Single fiber pullout tests were performed and then the tensile strength of fiber was measured according to fiber orientation. The test results showed that basalt fiber has a strong chemical bond with the cementitious matrix, 1.88 times higher than that of polyvinyl alcohol fibers with it. However, other properties of basalt fiber such as slip-hardening coefficient and strength reduction coefficient were worse than PVA and polyethylene fibers in terms of fiber bridging capacity. Theoretical fiber-bridging curves showed that the basalt fiber reinforcing system has a higher cracking strength than the PVA fiber reinforcing system, but the reinforcing system showed softening behavior after cracking.

  9. Measuring shear modulus of individual fibers

    Science.gov (United States)

    Behlow, Herbert; Saini, Deepika; Oliviera, Luciana; Skove, Malcolm; Rao, Apparao

    2014-03-01

    Fiber technology has advanced to new heights enabling tailored mechanical properties. For reliable fiber applications their mechanical properties must be well characterized at the individual fiber level. Unlike the tensile modulus, which can be well studied in a single fiber, the present indirect and dynamic methods of measuring the shear properties of fibers suffer from various disadvantages such as the interaction between fibers and the influence of damping. In this talk, we introduce a quasi-static method to directly measure the shear modulus of a single micron-sized fiber. Our simple and inexpensive setup yields a shear modulus of 16 and 2 GPa for a single IM7 carbon fiber and a Kevlar fiber, respectively. Furthermore, our setup is also capable of measuring the creep, hysteresis and the torsion coefficient, and examples of these will be presented.

  10. All fiber passively Q-switched laser

    Science.gov (United States)

    Soh, Daniel B. S.; Bisson, Scott E

    2015-05-12

    Embodiments relate to an all fiber passively Q-switched laser. The laser includes a large core doped gain fiber having a first end. The large core doped gain fiber has a first core diameter. The laser includes a doped single mode fiber (saturable absorber) having a second core diameter that is smaller than the first core diameter. The laser includes a mode transformer positioned between a second end of the large core doped gain fiber and a first end of the single mode fiber. The mode transformer has a core diameter that transitions from the first core diameter to the second core diameter and filters out light modes not supported by the doped single mode fiber. The laser includes a laser cavity formed between a first reflector positioned adjacent the large core doped gain fiber and a second reflector positioned adjacent the doped single mode fiber.

  11. Harnessing the fiber fuse for sensing applications.

    Science.gov (United States)

    Lin, Guei-Ru; Baiad, Mohamad Diaa; Gagne, Mathieu; Liu, Wen-Fung; Kashyap, Raman

    2014-04-21

    A simple refractive index sensor based on a small section of fiber damaged by the fiber fuse is proposed and demonstrated with a sensitivity of 350.58 nm/refractive index unit (RIU). For comparison, a hetero-core structure fiber sensor composed of a short no-core fiber (NCF) sandwiched between two pieces of single-mode fibers is demonstrated with a sensitivity of 157.29 nm/RIU. The fiber fuse technique can allow mass production of sensors by incorporating small sections of the damaged fiber of any type into each device. We believe this is the first application of the periodic damage tracks in optical fibers formed by the fiber fuse.

  12. Polymer fiber waveguides for terahertz radiation

    DEFF Research Database (Denmark)

    Nielsen, Kristian

    is taken from microstructured polymer optical fibers (mPOFs) used at optical wavelengths for sensing and communication. The fibers investigated can be divided into two groups, the solid core fibers and the hollow core fibers. The solid core fibers offer the broadest bandwidth with the best dispersion....... The polymer material with lowest loss is Topas and all the solid core fibers are manufactured using this material. The polymer PMMA however has higher refractive index along with higher loss, and this higher refractive index is utilized to achieve a large bandwidth hollow core fiber with a low air......Terahertz radiation offers many exciting applications noticeably in spectroscopy and it is showing promising results in imaging, mainly for security applications. In this project the study of using structured polymer fibers for THz waveguiding is presented. The inspiration for the THz fiber...

  13. Morphological and neurochemical differences in peptidergic nerve fibers of the mouse vagina.

    Science.gov (United States)

    Barry, Christine M; Ji, Esther; Sharma, Harman; Beukes, Lara; Vilimas, Patricia I; DeGraaf, Yvette C; Matusica, Dusan; Haberberger, Rainer V

    2017-07-01

    The vagina is innervated by a complex arrangement of sensory, sympathetic, and parasympathetic nerve fibers that contain classical transmitters plus an array of neuropeptides and enzymes known to regulate diverse processes including blood flow and nociception. The neurochemical characteristics and distributions of peptide-containing nerves in the mouse vagina are unknown. This study used multiple labeling immunohistochemistry, confocal maging and analysis to investigate the presence and colocalization of the peptides vasoactive intestinal polypeptide (VIP), calcitonin-gene related peptide (CGRP), substance P (SP), neuropeptide tyrosine (NPY), and the nitric oxide synthesizing enzyme neuronal nitric oxide synthase (nNOS) in nerve fibers of the murine vaginal wall. We compared cervical and vulvar areas of the vagina in young nullipara and older multipara C57Bl/6 mice, and identified differences including that small ganglia were restricted to cervical segments, epithelial fibers were mainly present in vulvar segments and most nerve fibers were found in the lamina propria of the cervical region of the vagina, where a higher number of fibers containing immunoreactivity for VIP, CGRP, SP, or nNOS were found. Two populations of VIP-containing fibers were identified: fibers containing CGRP and fibers containing VIP but not CGRP. Differences between young and older mice were present in multiple layers of the vaginal wall, with older mice showing overall loss of innervation of epithelium of the proximal vagina and reduced proportions of VIP, CGRP, and SP containing nerve fibers in the distal epithelium. The distal vagina also showed increased vascularization and perivascular fibers containing NPY. Immunolabeling of ganglia associated with the vagina indicated the likely origin of some peptidergic fibers. Our results reveal regional differences and age- or parity-related changes in innervation of the mouse vagina, effecting the distribution of neuropeptides with diverse roles

  14. 1940 nm all-fiber Q-switched fiber laser

    Science.gov (United States)

    Ahmadi, P.; Estrada, A.; Katta, N.; Lim, E.; McElroy, A.; Milner, T. E.; Mokan, V.; Underwood, M.

    2017-02-01

    We present development of a nanosecond Q-switched Tm3+-doped fiber laser with 16 W average power and 4.4 kW peak power operating at 1940 nm. The laser has a master oscillator power amplifier design, and uses large mode area Tm3+-doped fibers as the gain medium. Special techniques are used to splice Tm3+-doped fibers to minimize splice loss. The laser design is optimized to reduce non-linear effects, including modulation instability. Pulse width broadening due to high gain is observed and studied in detail. Medical surgery is a field of application where this laser may be able to improve clinical practice. The laser together with scanning galvanometer mirrors is used to cut precisely around small footprint vessels in tissue phantoms without leaving any visible residual thermal damage. These experiments provide proof-of-principle that this laser has promising potential in the laser surgery application space.

  15. Fiber-Optic Vibration Sensor Based on Multimode Fiber

    Directory of Open Access Journals (Sweden)

    I. Lujo

    2008-06-01

    Full Text Available The purpose of this paper is to present a fiberoptic vibration sensor based on the monitoring of the mode distribution in a multimode optical fiber. Detection of vibrations and their parameters is possible through observation of the output speckle pattern from the multimode optical fiber. A working experimental model has been built in which all used components are widely available and cheap: a CCD camera (a simple web-cam, a multimode laser in visible range as a light source, a length of multimode optical fiber, and a computer for signal processing. Measurements have shown good agreement with the actual frequency of vibrations, and promising results were achieved with the amplitude measurements although they require some adaptation of the experimental model. Proposed sensor is cheap and lightweight and therefore presents an interesting alternative for monitoring large smart structures.

  16. Modulation-frequency-controlled change from sub- to superluminal regime in highly doped erbium fibers.

    Science.gov (United States)

    Melle, Sonia; Calderón, Oscar G; Caro, Cesar E; Cabrera-Granado, E; Antón, M A; Carreño, F

    2008-04-15

    We report a change from sub- to superluminal propagation upon increasing the modulation frequency of an amplitude-modulated 1,550 nm signal when propagating through highly doped erbium fibers pumped at 980 nm. We show that the interplay between the pump absorption and the pump-power broadening of the spectral hole induced by coherent population oscillations may drastically affect the fractional advancement or delay of the signal for the considered fibers.

  17. Lower intake of magnesium and dietary fiber increases the incidence of type 2 diabetes in Taiwanese

    OpenAIRE

    Weng, Lu-Chen; Lee, Ni-Jen; Yeh, Wen-Ting; Ho, Low-Tone; Pan, Wen-Harn

    2012-01-01

    Several studies have indicated an inverse association between the incidence of diabetes mellitus and magnesium and dietary fiber intake. Few studies have examined both of these associations together, not to mention in Asian populations with prospective study design. We therefore aimed to study how dietary magnesium and fiber intake levels affect diabetes incidence separately or in combination, in a prospective study in Taiwan. Methods: The study subjects were recruited for a longitudinal s...

  18. Excess protein intake relative to fiber and cardiovascular events in elderly men with chronic kidney disease

    OpenAIRE

    Xu, Hong; Rossi, Megan; Campbell, Katrina L; Sencion, Gloria Lissete; Ärnlöv, Johan; Cederholm, Tommy; Sjögren, Per; Risérus, Ulf; Lindholm, Bengt; Carrero, Juan Jesús

    2016-01-01

    AbstractBackground and Aims The elevated cardiovascular (CVD) risk observed in chronic kidney disease (CKD) may be partially alleviated through diet. While protein intake may link to CVD events in this patient population, dietary fiber has shown cardioprotective associations. Nutrients are not consumed in isolation; we hypothesize that CVD events in CKD may be associated with dietary patterns aligned with an excess of dietary protein relative to fiber. Methods and Results Prospective cohort s...

  19. Characterization of Hypercontracted Fibers in Skeletal Muscle of Domestic Turkey (Meleagris Gallopavo)

    OpenAIRE

    A. Sosnicki; Cassens, R. G.; McIntyre, D. R.; Vimini, R. J.; Greaser, M L

    1988-01-01

    Several different muscles from a population of thirty Large White male turkeys were studied by histological and histochemical methods, and a high incidence of hypercontracted fibers was noted . The fibers were characterized in cross-section by an apparent swelling, a rounded rather than polygonal shape and a homogenous appearance. They were eosinophilic, positive to Gomori-trichrome and appeared to have an elevated lipid content. An unusual histochemical profile was noted. It was postulated t...

  20. Blood glucose response to pea fiber

    DEFF Research Database (Denmark)

    Hamberg, O; Rumessen, J J; Gudmand-Høyer, E

    1989-01-01

    Two new fiber types, pea fiber (PF) and sugar beet fiber (BF), were compared with wheat bran (WB) to investigate the effect on postprandial blood glucose and serum insulin responses in normal subjects. The control meal consisted of 150 g ground beef mixed with 50 g glucose and 20 g lactulose. Only...... addition of PF (15 g pure fiber) reduced the area under the incremental blood glucose curve significantly (by 65%, p less than 0.05). None of the fibers affected the area under the insulin-response curve significantly although it was reduced by all fibers. Mouth-to-cecum transit time, assessed...

  1. Preliminary characterization of glass fiber sizing

    DEFF Research Database (Denmark)

    Petersen, Helga Nørgaard; Kusano, Yukihiro; Brøndsted, Povl

    2013-01-01

    Glass fiber surfaces are treated with sizing during manufacturing. Sizing consists of several components, including a film former and a silane coupling agent that is important for adhesion between glass fibers and a matrix. Although the sizing highly affects the composite interface and thus...... the strength of the composites, little is known about the structure and chemistry of the sizing. A part of sizing was extracted by soxhlet extraction. The fibers were subsequently burned and some fibers were merely burned for analysis of glass fiber and sizing. The results showed that the analyzed fibers had...

  2. Photonic Crystal Fibers for Sensing Applications

    Directory of Open Access Journals (Sweden)

    Ana M. R. Pinto

    2012-01-01

    Full Text Available Photonic crystal fibers are a kind of fiber optics that present a diversity of new and improved features beyond what conventional optical fibers can offer. Due to their unique geometric structure, photonic crystal fibers present special properties and capabilities that lead to an outstanding potential for sensing applications. A review of photonic crystal fiber sensors is presented. Two different groups of sensors are detailed separately: physical and biochemical sensors, based on the sensor measured parameter. Several sensors have been reported until the date, and more are expected to be developed due to the remarkable characteristics such fibers can offer.

  3. Simulation of Compressive Failure in Fiber Composites

    DEFF Research Database (Denmark)

    Veluri, Badrinath; Jensen, Henrik Myhre

    Kinkband formation is a non-linear phenomenon involving interacting effects of non-linear material behavior of the matrix materials and fiber buckling including fiber misalignment in fiber composites under compressive loading. Taking into account the non-linearties of the constituents a constitut......Kinkband formation is a non-linear phenomenon involving interacting effects of non-linear material behavior of the matrix materials and fiber buckling including fiber misalignment in fiber composites under compressive loading. Taking into account the non-linearties of the constituents...

  4. Carbon nanotube fiber spun from wetted ribbon

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yuntian T; Arendt, Paul; Zhang, Xiefei; Li, Qingwen; Fu, Lei; Zheng, Lianxi

    2014-04-29

    A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

  5. Continuous Fiber Ceramic Composites (CFCC)

    Energy Technology Data Exchange (ETDEWEB)

    R. A. Wagner

    2002-12-18

    This report summarizes work to develop CFCC's for various applications in the Industries of the Future (IOF) and power generation areas. Performance requirements range from relatively modest for hot gas filters to severe for turbine combustor liners and infrared burners. The McDermott Technology Inc. (MTI) CFCC program focused on oxide/oxide composite systems because they are known to be stable in the application environments of interest. The work is broadly focused on dense and porous composite systems depending on the specific application. Dense composites were targeted at corrosion resistant components, molten aluminum handling components and gas turbine combustor liners. The development work on dense composites led to significant advances in fiber coatings for oxide fibers and matrix densification. Additionally, a one-step fabrication process was developed to produce low cost composite components. The program also supported key developments in advanced oxide fibers that resulted in an improved version of Nextel 610 fiber (commercially available as Nextel 650) and significant progress in the development of a YAG/alumina fiber. Porous composite development focused on the vacuum winding process used to produce hot gas filters and infrared burner components.

  6. Electron microscopy study of refractory ceramic fibers.

    Science.gov (United States)

    MacKinnon, P A; Lentz, T J; Rice, C H; Lockey, J E; Lemasters, G K; Gartside, P S

    2001-10-01

    In epidemiological studies designed to identify potential health risks of exposures to synthetic vitreous fibers, the characterization of airborne fiber dimensions may be essential for assessing mechanisms of fiber toxicity. Toward this end, air sampling was conducted as part of an industry-wide study of workers potentially exposed to airborne fibrous dusts during the manufacture of refractory ceramic fibers (RCF) and RCF products. Analyses of a subset of samples obtained on the sample filter as well as on the conductive sampling cowl were performed using both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to characterize dimensions of airborne fibers. Comparison was made of bivariate fiber size distributions (length and diameter) from air samples analyzed by SEM and by TEM techniques. Results of the analyses indicate that RCF size distributions include fibers small enough in diameter (fibers (> 60 microm) may go undetected by TEM, as evidenced by the proportion of fibers in this category for TEM and SEM analyses (1% and 5%, respectively). Limitations of the microscopic techniques and differences in fiber-sizing rules for each method are believed to have contributed to the variation among fiber-sizing results. It was concluded from these data that further attempts to characterize RCF exposure in manufacturing and related operations should include analysis by TEM and SEM, since the smallest diameter fibers are not resolved with SEM and the fibers of longer length are not sized by TEM.

  7. Signal propagation in nerve fiber

    Science.gov (United States)

    Zayko, Yuriy N.

    2007-05-01

    In this paper the problem of signal propagation in nerve fiber is considered. Ohm losses and heat processes were taken into account. These permit to combine the two stages (metabolic and non-metabolic) of propagation and Na + and K + ions transmission through cell membrane due propagation. Electrodynamics of nerve fiber with losses is described by telegraph equations. Heat processes in fiber are described by an equation of entropy transfer. Ion motion at metabolic stage against the electro-chemical potential is described by negative conductance, responsible for the escape flow. The running- wave-type solutions of these equations are studied. An integral and an explicit solution of the given system are obtained. The solution represented by a series of quasi-harmonic pulses is investigated numerically. This proves the applicability of telegraph equation to the problem considered. Different types of solitary waves corresponding to various types of conductivity are also investigated.

  8. Optical Fiber Grating based Sensors

    DEFF Research Database (Denmark)

    Michelsen, Susanne

    2003-01-01

    In this thesis differenct optical fiber gratings are used for sensor purposes. If a fiber with a core concentricity error (CCE) is used, a directional dependent bend sensor can be produced. The CCE direction can be determined by means of diffraction. This makes it possible to produce long......-period gratings in a fiber with a CCE direction parallel or perpendicular to the writing direction. The maximal bending sensitivity is independent on the writing direction, but the detailed bending response is different in the two cases. A temperature and strain sensor, based on a long-period grating and two...... sampled gratings, was produced and investigated. It is based on the different temperature and strain response of these gratings. Both a transfer matrix method and an overlap calculation is performed to explain the sensor response. Another type of sensor is based on tuning and modulation of a laser...

  9. Scalar - vector soliton fiber lasers

    CERN Document Server

    Wu, Zhichao; Li, Lei; Luo, Yiyang; Tang, Dingyuan; Shen, Deyuan; Tang, Ming; Fu, Songnian; Zhao, Luming

    2016-01-01

    Rapid progress in passively mode-locked fiber lasers is currently driven by the recent discovery of vector feature of mode-locking pulses, namely, the group velocity-locked vector solitons, the phase locked vector solitons, and the high-order vector solitons. Those vector solitons are fundamentally different from the previously known scalar solitons. Here, we report a fiber laser where the mode-locked pulse evolves as a vector soliton in the strong birefringent segment and is transformed into a regular scalar soliton after the polarizer within the laser cavity. The existence of solutions in a polarization-dependent cavity comprising a periodic combination of two distinct nonlinear waves is novel and likely to be applicable to various other nonlinear systems. For very large local birefringence, our laser approaches the working regime of vector soliton lasers, while it approaches scalar soliton fiber lasers under the conditions of very small birefringence.

  10. A helical scintillating fiber hodoscope

    Energy Technology Data Exchange (ETDEWEB)

    Altmeier, M.; Bauer, F.; Bisplinghoff, J.; Bissel, T.; Bollmann, R.; Busch, M.; Buesser, K.; Colberg, T.; Demiroers, L.; Diehl, O.; Dohrmann, F.; Engelhardt, H.P.; Eversheim, P.D.; Felden, O.; Gebel, R.; Glende, M.; Greiff, J.; Gross, A.; Gross-Hardt, R.; Hinterberger, F.; Jahn, R.; Jeske, M.; Jonas, E.; Krause, H.; Lahr, U.; Langkau, R.; Lindemann, T.; Lindlein, J.; Maier, R.; Maschuw, R.; Mayer-Kuckuck, T.; Meinerzhagen, A.; Naehle, O.; Pfuff, M.; Prasuhn, D.; Rohdjess, H.; Rosendaal, D.; Rossen, P. von; Sanz, B.; Schirm, N.; Schulz-Rojahn, M.; Schwarz, V.; Scobel, W.; Thomas, S.; Trelle, H.J.; Weise, E.; Wellinghausen, A.; Wiedmann, W.; Woller, K.; Ziegler, R

    1999-07-21

    A novel scintillating fiber hodoscope in helically cylindric geometry has been developed for detection of low multiplicity events of fast protons and other light charged particles in the internal target experiment EDDA at the Cooler Synchrotron COSY. The hodoscope consists of 640 scintillating fibers (2.5 mm diameter), arranged in four layers surrounding the COSY beam pipe. The fibers are helically wound in opposing directions and read out individually using 16-channel photomultipliers connected to a modified commercial encoding system. The detector covers an angular range of 9 deg. {<=}{theta}{<=}72 deg. and 0 deg. {<=}phi (cursive,open) Greek{<=}360 deg. in the lab frame. The detector length is 590 mm, the inner diameter 161 mm. Geometry and granularity of the hodoscope afford a position resolution of about 1.3 mm. The detector design took into consideration a maximum of reliability and a minimum of maintenance. An LED array may be used for monitoring purposes. (author)

  11. A helical scintillating fiber hodoscope

    CERN Document Server

    Altmeier, M; Bisplinghoff, J; Bissel, T; Bollmann, R; Busch, M; Büsser, K; Colberg, T; Demiroers, L; Diehl, O; Dohrmann, F; Engelhardt, H P; Eversheim, P D; Felden, O; Gebel, R; Glende, M; Greiff, J; Gross, A; Gross-Hardt, R; Hinterberger, F; Jahn, R; Jeske, M; Jonas, E; Krause, H; Lahr, U; Langkau, R; Lindemann, T; Lindlein, J; Maier, R; Maschuw, R; Mayer-Kuckuck, T; Meinerzhagen, A; Naehle, O; Pfuff, M; Prasuhn, D; Rohdjess, H; Rosendaal, D; Von Rossen, P; Sanz, B; Schirm, N; Schulz-Rojahn, M; Schwarz, V; Scobel, W; Thomas, S; Trelle, H J; Weise, E; Wellinghausen, A; Wiedmann, W; Woller, K; Ziegler, R

    1999-01-01

    A novel scintillating fiber hodoscope in helically cylindric geometry has been developed for detection of low multiplicity events of fast protons and other light charged particles in the internal target experiment EDDA at the Cooler Synchrotron COSY. The hodoscope consists of 640 scintillating fibers (2.5 mm diameter), arranged in four layers surrounding the COSY beam pipe. The fibers are helically wound in opposing directions and read out individually using 16-channel photomultipliers connected to a modified commercial encoding system. The detector covers an angular range of 9 deg. <= THETA<=72 deg. and 0 deg. <=phi (cursive,open) Greek<=360 deg. in the lab frame. The detector length is 590 mm, the inner diameter 161 mm. Geometry and granularity of the hodoscope afford a position resolution of about 1.3 mm. The detector design took into consideration a maximum of reliability and a minimum of maintenance. An LED array may be used for monitoring purposes. (author)

  12. A helical scintillating fiber hodoscope

    Science.gov (United States)

    Altmeier, M.; Bauer, F.; Bisplinghoff, J.; Bissel, T.; Bollmann, R.; Busch, M.; Büßer, K.; Colberg, T.; Demirörs, L.; Diehl, O.; Dohrmann, F.; Engelhardt, H. P.; Eversheim, P. D.; Felden, O.; Gebel, R.; Glende, M.; Greiff, J.; Groß, A.; Groß-Hardt, R.; Hinterberger, F.; Jahn, R.; Jeske, M.; Jonas, E.; Krause, H.; Lahr, U.; Langkau, R.; Lindemann, T.; Lindlein, J.; Maier, R.; Maschuw, R.; Mayer-Kuckuck, T.; Meinerzhagen, A.; Nähle, O.; Pfuff, M.; Prasuhn, D.; Rohdjeß, H.; Rosendaal, D.; von Rossen, P.; Sanz, B.; Schirm, N.; Schulz-Rojahn, M.; Schwarz, V.; Scobel, W.; Thomas, S.; Trelle, H. J.; Weise, E.; Wellinghausen, A.; Wiedmann, W.; Woller, K.; Ziegler, R.; EDDA Collaboration

    1999-07-01

    A novel scintillating fiber hodoscope in helically cylindric geometry has been developed for detection of low multiplicity events of fast protons and other light charged particles in the internal target experiment EDDA at the Cooler Synchrotron COSY. The hodoscope consists of 640 scintillating fibers (2.5 mm diameter), arranged in four layers surrounding the COSY beam pipe. The fibers are helically wound in opposing directions and read out individually using 16-channel photomultipliers connected to a modified commercial encoding system. The detector covers an angular range of 9°⩽ Θ⩽72° and 0°⩽ ϕ⩽360° in the lab frame. The detector length is 590 mm, the inner diameter 161 mm. Geometry and granularity of the hodoscope afford a position resolution of about 1.3 mm. The detector design took into consideration a maximum of reliability and a minimum of maintenance. An LED array may be used for monitoring purposes.

  13. Building polymer fiber optic network

    Science.gov (United States)

    Bienias, P.; Bereś-Pawlik, E.

    2015-09-01

    The paper describes an investigation of transmission in LAN with using polymer optical fiber (POF). There were used two kinds of POF, step index plastic optical fiber (SI-POF) and graded index plastic optical fiber (GI-POF). Furthermore, the paper include a comparison between SI-POF and GI-POF and possibilities of using them. For the project's needs, new type of couplers has been designed and built, optimization has been performed to obtain the best parameters for designed couplers. Additionally, the coupler has been built from the same material, which GI-POF - PMMA is made of. Moreover, CWDM (Coarse Wavelength Division Multiplexing) transmissions is investigated to improve the network capacity.

  14. Study on Mechanical Properties of Hybrid Fiber Reinforced Concrete

    Science.gov (United States)

    He, Dongqing; Wu, Min; Jie, Pengyu

    2017-12-01

    Several common high elastic modulus fibers (steel fibers, basalt fibers, polyvinyl alcohol fibers) and low elastic modulus fibers (polypropylene fiber) are incorporated into the concrete, and its cube compressive strength, splitting tensile strength and flexural strength are studied. The test result and analysis demonstrate that single fiber and hybrid fiber will improve the integrity of the concrete at failure. The mechanical properties of hybrid steel fiber-polypropylene fiber reinforced concrete are excellent, and the cube compressive strength, splitting tensile strength and flexural strength respectively increase than plain concrete by 6.4%, 3.7%, 11.4%. Doped single basalt fiber or polypropylene fiber and basalt fibers hybrid has little effect on the mechanical properties of concrete. Polyvinyl alcohol fiber and polypropylene fiber hybrid exhibit ‘negative confounding effect’ on concrete, its splitting tensile and flexural strength respectively are reduced by 17.8% and 12.9% than the single-doped polyvinyl alcohol fiber concrete.

  15. Lab-on-fiber technology

    CERN Document Server

    Cusano, Andrea; Crescitelli, Alessio; Ricciardi, Armando

    2014-01-01

    This book focuses on a research field that is rapidly emerging as one of the most promising ones for the global optics and photonics community: the "lab-on-fiber" technology. Inspired by the well-established 'lab on-a-chip' concept, this new technology essentially envisages novel and highly functionalized devices completely integrated into a single optical fiber for both communication and sensing applications.Based on the R&D experience of some of the world's leading authorities in the fields of optics, photonics, nanotechnology, and material science, this book provides a broad and accurate de

  16. Fiber Bragg Grating Based Thermometry

    CERN Document Server

    Ahmed, Zeeshan; Guthrie, William; Quintavalle, John

    2016-01-01

    In recent years there has been considerable interest in developing photonic temperature sensors such as the Fiber Bragg gratings (FBG) as an alternative to resistance thermometry. In this study we examine the thermal response of FBGs over the temperature range of 233 K to 393 K. We demonstrate, in a hermetically sealed dry Argon environment, that FBG devices show a quadratic dependence on temperature with expanded uncertainties (k = 2) of ~500 mK. Our measurements indicate that the combined measurement uncertainty is dominated by uncertainty in determining the peak center fitting and by thermal aging of polyimide coated fibers.

  17. Polarization-preserving holey fibers

    DEFF Research Database (Denmark)

    Broeng, Jes; Mogilevtsev, Dmitri; Libori, Stig E. Barkou

    2001-01-01

    In this work we suggest and discuss a microstructure of air capillaries with elliptical cross-section in a tread of glass that gives opportunity for Creation of polarization-preserving fiber with very small beat length between the fundamental modes of different polarization......In this work we suggest and discuss a microstructure of air capillaries with elliptical cross-section in a tread of glass that gives opportunity for Creation of polarization-preserving fiber with very small beat length between the fundamental modes of different polarization...

  18. Theory of fiber reinforced materials

    Science.gov (United States)

    Hashin, Z.

    1972-01-01

    A unified and rational treatment of the theory of fiber reinforced composite materials is presented. Fundamental geometric and elasticity considerations are throughly covered, and detailed derivations of the effective elastic moduli for these materials are presented. Biaxially reinforced materials which take the form of laminates are then discussed. Based on the fundamentals presented in the first portion of this volume, the theory of fiber-reinforced composite materials is extended to include viscoelastic and thermoelastic properties. Thermal and electrical conduction, electrostatics and magnetostatics behavior of these materials are discussed. Finally, a brief statement of the very difficult subject of physical strength is included.

  19. Coupling to photonic crystal fibers

    DEFF Research Database (Denmark)

    Hougaard, Kristian G.; Bjarklev, Anders Overgaard; Knudsen, Erik

    2002-01-01

    In this work we have analyzed the correspondence between the fundamental mode of PCFs and Gaussian modes as a function of frequency, pitch, and air hole size. Such analysis provides insight into design space regions of PCFs, where low-loss coupling to standard fibers may be obtained.......In this work we have analyzed the correspondence between the fundamental mode of PCFs and Gaussian modes as a function of frequency, pitch, and air hole size. Such analysis provides insight into design space regions of PCFs, where low-loss coupling to standard fibers may be obtained....

  20. Fiber tractography using machine learning.

    Science.gov (United States)

    Neher, Peter F; Côté, Marc-Alexandre; Houde, Jean-Christophe; Descoteaux, Maxime; Maier-Hein, Klaus H

    2017-09-01

    We present a fiber tractography approach based on a random forest classification and voting process, guiding each step of the streamline progression by directly processing raw diffusion-weighted signal intensities. For comparison to the state-of-the-art, i.e. tractography pipelines that rely on mathematical modeling, we performed a quantitative and qualitative evaluation with multiple phantom and in vivo experiments, including a comparison to the 96 submissions of the ISMRM tractography challenge 2015. The results demonstrate the vast potential of machine learning for fiber tractography. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Dietary fibers and cardiometabolic diseases.

    Science.gov (United States)

    Riccioni, Graziano; Sblendorio, Valeriana; Gemello, Eugenio; Di Bello, Barbara; Scotti, Luca; Cusenza, Salvatore; D'Orazio, Nicolantonio

    2012-01-01

    The high prevalence of cardiovascular disease (CVD) is largely attributable to the contemporary lifestyle that is often sedentary and includes a diet high in saturated fats and sugars and low ingestion of polyunsaturated fatty acids (PUFAs), fruit, vegetables, and fiber. Experimental data from both animals and humans suggest an association between increased dietary fiber (DF) intakes and improved plasma lipid profiles, including reduced low density lipoprotein cholesterol (LDL-C) concentrations. These observations underline that the intake of DF may protect against heart disease and stroke.

  2. Dietary Fibers and Cardiometabolic Diseases

    Directory of Open Access Journals (Sweden)

    Nicolantonio D’Orazio

    2012-02-01

    Full Text Available The high prevalence of cardiovascular disease (CVD is largely attributable to the contemporary lifestyle that is often sedentary and includes a diet high in saturated fats and sugars and low ingestion of polyunsaturated fatty acids (PUFAs, fruit, vegetables, and fiber. Experimental data from both animals and humans suggest an association between increased dietary fiber (DF intakes and improved plasma lipid profiles, including reduced low density lipoprotein cholesterol (LDL-C concentrations. These observations underline that the intake of DF may protect against heart disease and stroke.

  3. Adaptation of the AOAC 2011.25 integrated total dietary fiber assay to determine the dietary fiber and oligosaccharide content of dry edible beans.

    Science.gov (United States)

    Kleintop, Adrienne E; Echeverria, Dimas; Brick, Leslie A; Thompson, Henry J; Brick, Mark A

    2013-10-09

    Dietary fiber (DF) has important health benefits in the human diet. Developing dry edible bean (Phaseolus vulgaris L.) cultivars with improved DF and reduced nondigestible oligosaccharide content is an important goal for dry bean breeders to increase consumer acceptance. To determine if genetic variation exists among dry bean cultivars for DF, two populations of diverse dry bean cultivars/lines that represent two centers of dry bean domestication were evaluated for dietary fiber using the Integrated Total Dietary Fiber Assay (AOAC 2011.25). This assay was adapted to measure water insoluble dietary fiber, water soluble dietary fiber, oligosaccharides raffinose and stachyose, and the calculated total dietary fiber (TDF) content of cooked dry bean seed. The AOAC 2011.25 protocol was modified by using a quick, simple, and sensitive high-performance liquid chromatography method paired with an electrochemical detection method to separate and quantify specific oligosaccharides, and using duplicate samples as replicates to generate statistical information. The TDF of dry bean entries ranged from 20.0 to 27.0% in population I and from 20.6 to 25.7% in population II. Total oligosaccharides ranged from 2.56 to 4.65% in population I and from 2.36 to 3.84% in population II. The results suggest that significant genetic variation exists among dry bean cultivars/lines to allow for genetic selection for improved DF content in dry beans and that the modifications to the AOAC 2011.25 method were suitable for estimating DF in cooked dry edible beans.

  4. Fiber facet gratings for high power fiber lasers

    Science.gov (United States)

    Vanek, Martin; Vanis, Jan; Baravets, Yauhen; Todorov, Filip; Ctyroky, Jiri; Honzatko, Pavel

    2017-12-01

    We numerically investigated the properties of diffraction gratings designated for fabrication on the facet of an optical fiber. The gratings are intended to be used in high-power fiber lasers as mirrors either with a low or high reflectivity. The modal reflectance of low reflectivity polarizing grating has a value close to 3% for TE mode while it is significantly suppressed for TM mode. Such a grating can be fabricated on laser output fiber facet. The polarizing grating with high modal reflectance is designed as a leaky-mode resonant diffraction grating. The grating can be etched in a thin layer of high index dielectric which is sputtered on fiber facet. We used refractive index of Ta2O5 for such a layer. We found that modal reflectance can be close to 0.95 for TE polarization and polarization extinction ratio achieves 18 dB. Rigorous coupled wave analysis was used for fast optimization of grating parameters while aperiodic rigorous coupled wave analysis, Fourier modal method and finite difference time domain method were compared and used to compute modal reflectance of designed gratings.

  5. IMPROVED SPECTROPHOTOMETER FIBER SAMPLING SYSTEM FOR COTTON FIBER COLOR MEASUREMENTS

    Science.gov (United States)

    Cotton in the U.S. is classified for color using the Uster® High Volume Instrument (HVI), and the parameters Rd and +b are used to designate color grades for cotton fiber. However, Rd and +b are cotton-specific color parameters, and the need existed to demonstrate the relationships of Rd and +b to...

  6. Monolithic thulium-doped fiber laser

    Science.gov (United States)

    Aubrecht, J.; Peterka, P.; Honzátko, P.; Todorov, F.; Podrazký, O.; Kamrádek, M.; Proboštová, J.; Kašík, I.

    2017-12-01

    In this contribution we report and discuss the results of laser characterizations of experimental thulium-doped optical fibers. These active fibers were fabricated in house and were tested in two laser systems to verify their characteristics. The first one, a monolithic fiber laser, was of great interest to us due to its potentially lower overall resonator losses, improved laser lifetime and better robustness. The compact laser cavities with a Bragg gratings inscribed directly into the active optical fiber differs to the second laser system where the Bragg gratings were inscribed into a passive fiber which had to be spliced to the active fiber. The tested fibers were manufactured by the modified chemical vapor deposition method and a solution-doping of thulium ions with Al2O3 or alumina nanoparticles, respectively. We focused on comparison of laser output powers, slope efficiencies, and laser thresholds for particular thulium-doped fiber in different laser configurations.

  7. One Man's Trash Is Another's Fiber

    Science.gov (United States)

    ... fullstory_165988.html One Man's Trash Is Another's Fiber Wasted food in U.S. would reduce nutritional shortfalls, ... grams of protein; 5.9 grams of dietary fiber; 1.7 micrograms of vitamin D; 286 milligrams ...

  8. Textile composites based on natural fibers

    CSIR Research Space (South Africa)

    Li, Yan

    2009-04-01

    Full Text Available composites based on natural fibers are investigated, which includes the manufacuring techniques, fracture and mechanical properties and other behaviours. Consolidation and permeability of the textiles based on natural fibers are specially addressed...

  9. Multi-core fiber undersea transmission systems

    DEFF Research Database (Denmark)

    Nooruzzaman, Md; Morioka, Toshio

    2017-01-01

    Various potential architectures of branching units for multi-core fiber undersea transmission systems are presented. It is also investigated how different architectures of branching unit influence the number of fibers and those of inline components....

  10. Photonics and Fiber Optics Processor Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Photonics and Fiber Optics Processor Lab develops, tests and evaluates high speed fiber optic network components as well as network protocols. In addition, this...

  11. Properties of Fiber Reinforced Polymer Concrete

    National Research Council Canada - National Science Library

    Marinela Bărbuţă; Maria Harja

    2008-01-01

    .... In the composition were introduced near the fly ash, used as filler, the cellulose fibers. The mechanical characteristics such as compressive strength, flexural strength and split tensile strength of polymer concrete with fibers were investigated...

  12. Generation of non-overlapping fiber architecture

    DEFF Research Database (Denmark)

    Chapelle, Lucie; Lévesque, M.; Brøndsted, Povl

    2015-01-01

    step toward the computation of their physical properties. In this work, a realistic 3D model is developed to describe the architecture of a complex fiber structure. The domain of application of the model could include natural fibers composites, wood fibers materials, papers, mineral and steel wools......Numerical models generating actual fiber architecture by including parameters such as the fiber geometry and arrangement are a powerful tool to explore the relation between the fiber architecture and mechanical properties. The generation of virtual architectures of fibrous materials is the first......: a repulsion force to suppress the overlap between two fibers and a bending and stretching force to ensure that the fiber structure is kept unchanged. The model can be used as the geometrical basis for further finite-element modelling....

  13. Thermoresponsive electrospun fibers for water harvesting applications

    Science.gov (United States)

    Thakur, Neha; Baji, Avinash; Ranganath, Anupama Sargur

    2018-03-01

    Temperature triggered switchable cellulose acetate-poly(N-isopropylacrylamide) (CA-PNIPAM) core-shell and blend nanofibers are fabricated for controlled moisture harvesting applications. Core-shell fibers are fabricated using a co-axial electrospinning setup whereas the conventional electrospinning setup is employed for fabricating the blend fibers. Investigation of their wettability behaviour demonstrated that the blend fibers are superhydrophilic whereas the core-shell fibers are hydrophilic at ambient temperature. Furthermore, both the samples have an ability to switch between the two states viz. hydrophilic to hydrophobic state based on thermal stimulus. The core-shell fibers are shown to have higher moisture sorption ability compared to the blend fibers. This study investigates the mechanism behind the switchable wettability behaviour of the core-shell fibers and demonstrates the crucial role played by the functional groups present on the surface layer of fibers in governing their moisture collection efficiency.

  14. Compression Behavior of High Performance Polymeric Fibers

    National Research Council Canada - National Science Library

    Kumar, Satish

    2003-01-01

    Hydrogen bonding has proven to be effective in improving the compressive strength of rigid-rod polymeric fibers without resulting in a decrease in tensile strength while covalent crosslinking results in brittle fibers...

  15. Fermentation of Ammonia Fiber Expansion Treated and Untreated Barley Straw in a Rumen Simulation Technique using Rumen Inoculum from Cattle with Slow Versus Fast Rate of Fiber Disappearance

    Directory of Open Access Journals (Sweden)

    Karen Ann Beauchemin

    2016-11-01

    Full Text Available The purpose of this study was to determine the effect of rumen inoculum from heifers with fast vs. slow rate of in situ fiber digestion on the fermentation of complex versus easily digested fiber sources in the forms of untreated and Ammonia Fiber Expansion (AFEX treated barley straw, respectively, using an artificial rumen simulation technique (Rusitec. In situ fiber digestion was measured in a previous study by incubating untreated barley straw in the rumen of sixteen heifers fed a diet consisting of 700 g/kg barley straw and 300 g/kg concentrate. The two heifers with fastest rate of digestion (Fast > 4.18 % h-1 and the two heifers with the slowest rate of digestion (Slow 0.05 methane per gram of digested material for both untreated and AFEX straw, and reduced (interaction, P < 0.05 acetate: propionate ratio for untreated straw. Greater relative populations of Ruminococcus albus (P < 0.05 and increased microbial N production (P = 0.045 were observed in Fast rumen inoculum. AFEX straw in Fast inoculum had greater total bacterial populations than Slow, but for untreated straw this result was reversed (interaction, P = 0.013. These findings indicate that differences in microbial populations in rumen fluid contribute to differences in the capacity of rumen inoculum to digest fiber.

  16. Mechanical properties of flax fibers and their composites

    OpenAIRE

    Sparnins, Edgars

    2006-01-01

    Flax fibers, along with a number of other natural fibers, are being considered as an environmentally friendlier alternative of synthetic fibers in fiber-reinforced polymer composites. A common feature of natural fibers is a much higher variability of mechanical properties. This necessitates study of the flax fiber strength distribution and efficient experimental methods for its determination. Elementary flax fibers of different gauge lengths are tested by single fiber tension in order to obta...

  17. Lower intake of magnesium and dietary fiber increases the incidence of type 2 diabetes in Taiwanese.

    Science.gov (United States)

    Weng, Lu-Chen; Lee, Ni-Jen; Yeh, Wen-Ting; Ho, Low-Tone; Pan, Wen-Harn

    2012-11-01

    Several studies have indicated an inverse association between the incidence of diabetes mellitus and magnesium and dietary fiber intake. Few studies have examined both of these associations together, not to mention in Asian populations with prospective study design. We therefore aimed to study how dietary magnesium and fiber intake levels affect diabetes incidence separately or in combination, in a prospective study in Taiwan. The study subjects were recruited for a longitudinal study, CardioVascular Disease risk FACtor Two-township Study cycle 2 from November 1990. Data from complete baseline information on dietary and biochemical profile and at least one additional follow-up visit were gathered on a total of 1604 healthy subjects aged 30 years and over. Cox proportional hazard model was used to study the association between diabetes incidence and dietary magnesium and fiber intake level estimated from a food frequency questionnaire. A total of 141 diabetes mellitus events were identified and confirmed during the 4.6 years of follow-up (7365.1 person-years). A significantly higher diabetes risk was observed for people in the lowest quintile of total dietary fiber intake (hazard ratio = 2.04; 95% CI = 1.17-3.53) and magnesium intake (hazard ratio = 2.61; 95% CI = 1.42-4.79) compared with the highest quintile after adjusting for traditional cardiovascular disease risk factors. Similar inverse associations for total dietary fiber were also shown for vegetable fiber and fruit fiber. Lower magnesium, lower total dietary fiber intake, or lower intake of both was associated with higher risk of diabetes in the Taiwanese population. Clinical trials are required to confirm the protective effects of the adequate intake of fiber, magnesium, and/or their combination. Copyright © 2012. Published by Elsevier B.V.

  18. Genetic mapping and comparative analysis of seven mutants related to seed fiber development in cotton.

    Science.gov (United States)

    Rong, Junkang; Pierce, Gary J; Waghmare, Vijay N; Rogers, Carl J; Desai, Aparna; Chee, Peng W; May, O Lloyd; Gannaway, John R; Wendel, Jonathan F; Wilkins, Thea A; Paterson, Andrew H

    2005-10-01

    Mapping of genes that play major roles in cotton fiber development is an important step toward their cloning and manipulation, and provides a test of their relationships (if any) to agriculturally-important QTLs. Seven previously identified fiber mutants, four dominant (Li (1), Li (2), N (1) and Fbl) and three recessive (n (2), sma-4(h (a)), and sma-4(fz)), were genetically mapped in six F(2) populations comprising 124 or more plants each. For those mutants previously assigned to chromosomes by using aneuploids or by linkage to other morphological markers, all map locations were concordant except n (2), which mapped to the homoeolog of the chromosome previously reported. Three mutations with primary effects on fuzz fibers (N (1), Fbl, n (2)) mapped near the likelihood peaks for QTLs that affected lint fiber productivity in the same populations, perhaps suggesting pleiotropic effects on both fiber types. However, only Li (1) mapped within the likelihood interval for 191 previously detected lint fiber QTLs discovered in non-mutant crosses, suggesting that these mutations may occur in genes that played early roles in cotton fiber evolution, and for which new allelic variants are quickly eliminated from improved germplasm. A close positional association between sma-4(h ( a )), two leaf and stem-borne trichome mutants (t (1) , t (2)), and a gene previously implicated in fiber development, sucrose synthase, raises questions about the possibility that these genes may be functionally related. Increasing knowledge of the correspondence of the cotton and Arabidopsis genomes provides several avenues by which genetic dissection of cotton fiber development may be accelerated.

  19. Experimental Study of Fiber Length and Orientation in Injection Molded Natural Fiber/Starch Acetate Composites

    Directory of Open Access Journals (Sweden)

    Heidi Peltola

    2011-01-01

    Full Text Available Composite compounds based on triethyl citrate plasticized starch acetate and hemp and flax fibers were prepared by melt processing. Plasticizer contents from 20 to 35 wt% and fiber contents of 10 and 40 wt% were used. The compounded composites were injection molded to tensile test specimens. The effect of processing, melt viscosity and fiber type on the fiber length was investigated. The lengths of fully processed fibers were determined by dissolving the matrix and measuring the length of the remaining fibers by microscope analysis. A clear reductive effect of the processing on the fiber length was noticed. A reduction of fiber length along the increasing fiber content and the decreasing plasticizer content was also detected. This reduction originated from the increasing shear forces during compounding, which again depended on the increased viscosity of the material. Hemp fibers were shown to remain longer and fibrillate more than flax fibers, leading to higher aspect ratio. Thus, the reinforcement efficiency of hemp fibers by the processing was improved, in contrast with flax fibers. In addition, the analysis of fiber dispersion and orientation showed a good dispersion of fibers in the matrix, and a predominant orientation of the fibers in the melt flow direction.

  20. Identifying Practical Solutions to Meet America’s Fiber Needs: Proceedings from the Food & Fiber Summit

    Directory of Open Access Journals (Sweden)

    Amy R. Mobley

    2014-07-01

    Full Text Available Fiber continues to be singled out as a nutrient of public health concern. Adequate intakes of fiber are associated with reduced risk for cardiovascular disease, cancer, diabetes, certain gastrointestinal disorders and obesity. Despite ongoing efforts to promote adequate fiber through increased vegetable, fruit and whole-grain intakes, average fiber consumption has remained flat at approximately half of the recommended daily amounts. Research indicates that consumers report increasingly attempting to add fiber-containing foods, but there is confusion around fiber in whole grains. The persistent and alarmingly low intakes of fiber prompted the “Food & Fiber Summit,” which assembled nutrition researchers, educators and communicators to explore fiber’s role in public health, current fiber consumption trends and consumer awareness data with the objective of generating opportunities and solutions to help close the fiber gap. The summit outcomes highlight the need to address consumer confusion and improve the understanding of sources of fiber, to recognize the benefits of various types of fibers and to influence future dietary guidance to provide prominence and clarity around meeting daily fiber recommendations through a variety of foods and fiber types. Potential opportunities to increase fiber intake were identified, with emphasis on meal occasions and food categories that offer practical solutions for closing the fiber gap.

  1. Hybrid fiber reinforced self-compacting concrete: fiber synergy at low ...

    African Journals Online (AJOL)

    In most cases, fiber reinforced self-compacting concrete (FRSCC) contains only one type of fiber. The use of two or more types of fibers in a suitable combination may potentially not only improve the overal properties of self-compacting concrete, but may also result in performance synergie. The combining of fibers, often ...

  2. Numerical approach to inter-fiber flow in nonwovens with super absorbent fibers

    Directory of Open Access Journals (Sweden)

    Ding Zhi-Rong

    2017-01-01

    Full Text Available This paper establishes a 3-D numerical model for inter-fiber flows in non-woven materials composed of super absorbent fibers. The velocity distribution of the inter-fiber flow is obtained. The effects of absorbent fibers and geometrical structure of non-woven fabrics on flow properties are analyzed.

  3. 16 CFR 303.23 - Textile fiber products containing superimposed or added fibers.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Textile fiber products containing superimposed or added fibers. 303.23 Section 303.23 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULES AND REGULATIONS UNDER THE TEXTILE FIBER PRODUCTS IDENTIFICATION ACT § 303.23 Textile fiber products containing...

  4. Electrically tunable Yb-doped fiber laser based on a liquid crystal photonic bandgap fiber device

    DEFF Research Database (Denmark)

    Olausson, Christina Bjarnal Thulin; Scolari, Lara; Wei, Lei

    2010-01-01

    We demonstrate electrical tunability of a fiber laser using a liquid crystal photonic bandgap fiber. Tuning of the laser is achieved by combining the wavelength filtering effect of a tunable liquid crystal photonic bandgap fiber device with an ytterbium-doped photonic crystal fiber. We fabricate...

  5. Identifying Practical Solutions to Meet America’s Fiber Needs: Proceedings from the Food & Fiber Summit

    Science.gov (United States)

    Mobley, Amy R.; Jones, Julie Miller; Rodriguez, Judith; Slavin, Joanne; Zelman, Kathleen M.

    2014-01-01

    Fiber continues to be singled out as a nutrient of public health concern. Adequate intakes of fiber are associated with reduced risk for cardiovascular disease, cancer, diabetes, certain gastrointestinal disorders and obesity. Despite ongoing efforts to promote adequate fiber through increased vegetable, fruit and whole-grain intakes, average fiber consumption has remained flat at approximately half of the recommended daily amounts. Research indicates that consumers report increasingly attempting to add fiber-containing foods, but there is confusion around fiber in whole grains. The persistent and alarmingly low intakes of fiber prompted the “Food & Fiber Summit,” which assembled nutrition researchers, educators and communicators to explore fiber’s role in public health, current fiber consumption trends and consumer awareness data with the objective of generating opportunities and solutions to help close the fiber gap. The summit outcomes highlight the need to address consumer confusion and improve the understanding of sources of fiber, to recognize the benefits of various types of fibers and to influence future dietary guidance to provide prominence and clarity around meeting daily fiber recommendations through a variety of foods and fiber types. Potential opportunities to increase fiber intake were identified, with emphasis on meal occasions and food categories that offer practical solutions for closing the fiber gap. PMID:25006857

  6. Optical fiber strain sensor using fiber resonator based on frequency comb Vernier spectroscopy

    DEFF Research Database (Denmark)

    Zhang, Liang; Lu, Ping; Chen, Li

    2012-01-01

    A novel (to our best knowledge) optical fiber strain sensor using a fiber ring resonator based on frequency comb Vernier spectroscopy is proposed and demonstrated. A passively mode-locked optical fiber laser is employed to generate a phased-locked frequency comb. Strain applied to the optical fiber...

  7. Dispersion properties of photonic bandgap guiding fibers

    DEFF Research Database (Denmark)

    Barkou, Stig Eigil; Broeng, Jes; Bjarklev, Anders Overgaard

    1999-01-01

    We investigate low-index core photonic crystal fibers. Dispersion properties very different from standard fibers are found. Both Zero dispersion are very large dispersion is shown possible at 1550 nm wavelength.......We investigate low-index core photonic crystal fibers. Dispersion properties very different from standard fibers are found. Both Zero dispersion are very large dispersion is shown possible at 1550 nm wavelength....

  8. High Power Performance of Rod Fiber Amplifiers

    DEFF Research Database (Denmark)

    Johansen, Mette Marie; Michieletto, Mattia; Kristensen, Torben

    2015-01-01

    An improved version of the DMF rod fiber is tested in a high power setup delivering 360W of stable signal power. Multiple testing degrades the fiber and transverse modal instability threshold from >360W to ~290W.......An improved version of the DMF rod fiber is tested in a high power setup delivering 360W of stable signal power. Multiple testing degrades the fiber and transverse modal instability threshold from >360W to ~290W....

  9. Polarization properties of photonic bandgap fibers

    DEFF Research Database (Denmark)

    Broeng, Jes; Libori, Stig E. Barkou; Bjarklev, Anders Overgaard

    2000-01-01

    We present the first analysis of polarization properties of photonic bandgap fibers. Strong birefringence may be obtained for modest non-uniformities in and around the core region, suggesting the use of photonic bandgap fibers as polarization maintaining components.......We present the first analysis of polarization properties of photonic bandgap fibers. Strong birefringence may be obtained for modest non-uniformities in and around the core region, suggesting the use of photonic bandgap fibers as polarization maintaining components....

  10. Catching Attention in Fiber Optics Class

    OpenAIRE

    Kezerashvili, R. Ya.; Leng, L.

    2004-01-01

    Following a brief review on the history and the current development of fiber optics, the significance of teaching fiber optics for science and non-science major college students is addressed. Several experimental demonstrations designed to aid the teaching and learning process in fiber optics lectures are presented. Sample laboratory projects are also proposed to help the students to understand the physical principles of fiber optics.

  11. Mechanical characterization of fiber reinforced Polymer Concrete

    OpenAIRE

    Reis,João Marciano Laredo dos

    2005-01-01

    A comparative study between epoxy Polymer Concrete plain, reinforced with carbon and glass fibers and commercial concrete mixes was made. The fibers are 6 mm long and the fiber content was 2% and 1%, respectively, in mass. Compressive tests were performed at room temperature and load vs. displacement curves were plotted up to failure. The carbon and glass fibers reinforcement were randomly dispersed into the matrix of polymer concrete. An increase in compressive properties was observed as fun...

  12. In-line fiber optic interferometric sensors in single-mode fibers.

    Science.gov (United States)

    Zhu, Tao; Wu, Di; Liu, Min; Duan, De-Wen

    2012-01-01

    In-line fiber optic interferometers have attracted intensive attention for their potential sensing applications in refractive index, temperature, pressure and strain measurement, etc. Typical in-line fiber-optic interferometers are of two types: Fabry-Perot interferometers and core-cladding-mode interferometers. It's known that the in-line fiber optic interferometers based on single-mode fibers can exhibit compact structures, easy fabrication and low cost. In this paper, we review two kinds of typical in-line fiber optic interferometers formed in single-mode fibers fabricated with different post-processing techniques. Also, some recently reported specific technologies for fabricating such fiber optic interferometers are presented.

  13. Microscopic observations during longitudinal compression loading of single pulp fibers

    Science.gov (United States)

    Irving B. Sachs

    1986-01-01

    Paperboard components (linerboard adn corrugating medium) fail in edgewise compression because of failure of single fibers, as well as fiber-to-fiber bonds. While fiber-to-fiber-bond failure has been studied extensively, little is known about the longitudinal compression failure of a single fiber. In this study, surface alterations on single loblolly pine kraft pulp...

  14. Yield and fiber quality properties of cotton (Gossypium hirsutum L ...

    African Journals Online (AJOL)

    Jane

    2011-10-03

    Oct 3, 2011 ... negatively affected by water stress treatment. Fiber length, fiber strength, fiber fineness and fiber elongation were decreased, while fiber uniformity was not affected by water stress treatment. Key words: Cotton, yield, fiber quality properties, water stress, non-stress. INTRODUCTION. Water stress is the most ...

  15. Dynamic Characterization of Polymer Optical Fibers

    DEFF Research Database (Denmark)

    Stefani, Alessio; Andresen, Søren; Yuan, Wu

    2012-01-01

    With the increasing interest in fiber sensors based on polymer optical fibers, it becomes fundamental to determine the real applicability and reliability of this type of sensor. The viscoelastic nature of polymers gives rise to questions about the mechanical behavior of the fibers. In particular...

  16. Single-Crystal Germanium Core Optoelectronic Fibers

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Xiaoyu [Department of Materials Science and Engineering, Materials Research Institute, Pennsylvania State University, University Park PA 16802 USA; Page, Ryan L. [Department of Materials Science and Engineering, Materials Research Institute, Pennsylvania State University, University Park PA 16802 USA; Chaudhuri, Subhasis [Department of Chemistry, Pennsylvania State University, University Park PA 16802 USA; Liu, Wenjun [Advanced Photon Source, Argonne National Laboratory, Argonne IL 60439 USA; Yu, Shih-Ying [Department of Materials Science and Engineering, Materials Research Institute, Pennsylvania State University, University Park PA 16802 USA; Mohney, Suzanne E. [Department of Materials Science and Engineering, Materials Research Institute, Pennsylvania State University, University Park PA 16802 USA; Badding, John V. [Department of Materials Science and Engineering, Materials Research Institute, Pennsylvania State University, University Park PA 16802 USA; Department of Chemistry, Pennsylvania State University, University Park PA 16802 USA; Department of Physics, Pennsylvania State University, University Park PA 16802 USA; Gopalan, Venkatraman [Department of Materials Science and Engineering, Materials Research Institute, Pennsylvania State University, University Park PA 16802 USA

    2016-09-19

    Synthesis and fabrication of high-quality, small-core single-crystal germanium fibers that are photosensitive at the near-infrared and have low optical losses ≈1 dB cm-1 at 2 μm are reported. These fibers have potential applications in fiber-based spectroscopic imaging, nonlinear optical devices, and photodetection at the telecommunication wavelengths.

  17. Mode field diameter preserving fiber tapers

    DEFF Research Database (Denmark)

    Noordegraaf, Danny; Maack, M. D.; Skovgaard, P. M. W.

    2011-01-01

    concentric dual-core fibers, which couple light from an inner core to an outer core through a taper. Fibers with a 6 μm MFD feedthrough and a 15 μm polarization maintaining feedthrough are demonstrated experimentally. Simulations of the MFD in the tapered dual-core fibers are also presented....

  18. Engineering modes in optical fibers with metamaterial

    DEFF Research Database (Denmark)

    Yan, Min; Mortensen, Asger; Qiu, Min

    2009-01-01

    In this paper, we report a preliminary theoretical study on optical fibers with fine material inclusions whose geometrical inhomogeneity is almost indistinguishable by the operating wavelength.We refer to such fibers as metamaterial optical fibers, which can conceptually be considered as an exten...

  19. Single curved fiber sedimentation under gravity

    Science.gov (United States)

    Xiaoying Rong; Dewei Qi; Guowei He; Jun Yong Zhu; Tim Scott

    2008-01-01

    Dynamics of single curved fiber sedimentation under gravity are simulated by using the lattice Boltzmann method. The results of migration and rotation of the curved fiber at different Reynolds numbers are reported. The results show that the rotation and migration processes are sensitive to the curvature of the fiber.

  20. Gemini Fiber for Interferometry and Sensing Applications

    Directory of Open Access Journals (Sweden)

    E. Zetterlund

    2009-01-01

    Full Text Available A novel type of fiber for sensing applications is introduced based on a plurality of individual fiber preforms drawn together but maintaining their original shape. The individual cores of the Gemini fiber can be addressed at input and output ends through splicing to stand-alone fibers. Thermal coupling between cores is sufficient to eliminate relative thermal effects. Fabrication, coupling and fiber Bragg grating (FBG studies are discussed. The possibility to connect in a single splice more than one fiber to the Gemini fiber is introduced as being highly advantageous. A conventional splicer can be used, the loss is acceptable and the operation takes minutes. Sensing with Gemini fibers is discussed mainly with the incorporation of fiber Bragg gratings. Another advantage of the concept of the Gemini fiber discussed is the possibility to make monolithic fiber interferometers of nearly equal arm lengths. A large number of new options are opened by the monolithic multicore fiber design, where access to individual cores is straightforward.

  1. Simulation of Glass Fiber Forming Processes

    DEFF Research Database (Denmark)

    Von der Ohe, Renate

    Two glass fiber forming processes have been simulated using FEM, which are the drawing of continuous glass fibers for reinforcement purposes and the spinning of discontinuous glass fibers - stone wool for insulation. The aim of this work was to set up a numerical model for each process, and to use...

  2. 40 CFR 721.2800 - Erionite fiber.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Erionite fiber. 721.2800 Section 721... Erionite fiber. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance, erionite fiber (CAS No. 66733-21-9 (when an exact molecular formula is known) and 12510-42-8...

  3. Kenaf fiber-reinforced copolyester biocomposites

    CSIR Research Space (South Africa)

    Mokhothu, Thabang H

    2011-12-01

    Full Text Available In this study the morphology and properties of a biodegradable aliphatic–aromatic copolyester mixed with kenaf fiber were investigated. Untreated kenaf fiber, as well as kenaf fiber treated with NaOH, and with NaOH followed by silane coupling agent...

  4. Advances in mid-infrared fiber lasers

    NARCIS (Netherlands)

    Pollnau, Markus; Jackson, S.D.; Ebrahim-Zadeh, M.; Sorokina, I.T.

    The current state of the art in mid-infrared fiber laser research is reviewed. The relevant glass and ceramic fiber host matkrials and the fiber, pump, and resonator geometries are introduced. Lasers operating on transitions ranging from 1.9 to 4 pm occurring in the rare-earth-ions $Tm^{3+}$,

  5. All-fiber femtosecond Cherenkov source

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Møller, Uffe Visbech

    2013-01-01

    An all-fiber femtosecond Cherenkov radiation source is demonstrated for the first time, to the best of our knowledge. Using a stable monolithic femtosecond Ybdoped fiber laser as the pump source, and the combination of photonic crystal fibers as the wave-conversion medium, we have generated tunable...

  6. Palm date fibers: analysis and enzymatic hydrolysis.

    Science.gov (United States)

    Shafiei, Marzieh; Karimi, Keikhosro; Taherzadeh, Mohammad J

    2010-11-01

    Waste palm dates were subjected to analysis for composition and enzymatic hydrolysis of their flesh fibers. The fruit contained 32% glucose and 30% fructose, while the water-insoluble fibers of its flesh consisted of 49.9% lignin and 20.9% polysaccharides. Water-insoluble fibers were settled to 55% of its initial volume in 12 h. The presence of skin and flesh colloidal fibers results in high viscosity and clogging problems during industrial processes. The settling velocity of the fibers was improved by enzymatic hydrolysis. Hydrolysis resulted in 84.3% conversion of the cellulosic part of the fibers as well as reducing the settling time to 10 minutes and the final settled volume to 4% of the initial volume. It implies easier separation of the fibers and facilitates fermentation processes in the corresponding industries. Two kinds of high- and low-lignin fibers were identified from the water-insoluble fibers. The high-lignin fibers (75% lignin) settled easily, while the low-lignin fibers (41.4% lignin) formed a slurry suspension which settled very slowly. The hydrophilicity of these low-lignin fibers is the major challenge of the industrial processes.

  7. Palm Date Fibers: Analysis and Enzymatic Hydrolysis

    Directory of Open Access Journals (Sweden)

    Mohammad J. Taherzadeh

    2010-11-01

    Full Text Available Waste palm dates were subjected to analysis for composition and enzymatic hydrolysis of their flesh fibers. The fruit contained 32% glucose and 30% fructose, while the water-insoluble fibers of its flesh consisted of 49.9% lignin and 20.9% polysaccharides. Water-insoluble fibers were settled to 55% of its initial volume in 12 h. The presence of skin and flesh colloidal fibers results in high viscosity and clogging problems during industrial processes. The settling velocity of the fibers was improved by enzymatic hydrolysis. Hydrolysis resulted in 84.3% conversion of the cellulosic part of the fibers as well as reducing the settling time to 10 minutes and the final settled volume to 4% of the initial volume. It implies easier separation of the fibers and facilitates fermentation processes in the corresponding industries. Two kinds of high- and low-lignin fibers were identified from the water-insoluble fibers. The high-lignin fibers (75% lignin settled easily, while the low-lignin fibers (41.4% lignin formed a slurry suspension which settled very slowly. The hydrophilicity of these low-lignin fibers is the major challenge of the industrial processes.

  8. Electrospinning of ultra-thin polymer fibers

    NARCIS (Netherlands)

    Jaeger, Raimund; Bergshoef, M.M.; Batlle, C.M.; Martin i Batlle, C.; Schönherr, Holger; Vancso, Gyula J.

    1998-01-01

    The electrospinning technique was used to spin ultra-thin fibers from several polymer/solvent systems. The diameter of the electrospun fibers ranged from 16 nm to 2 μm. The morphology of these fibers was investigated with an atomic force microscope (AFM) and an optical microscope. Polyethylene

  9. Multifunctional Next Generation Carbon Nanotube Super Fibers

    National Research Council Canada - National Science Library

    Ait-Haddou, Hassan

    2005-01-01

    The goal of this program was to produce continuous strong CNT-based fibers. The production of continuous fibers was met and we have matched 2/3 of the strength of what has been previously reported with CNT-PAN fibers...

  10. Career Directions--Fiber Optic Installer

    Science.gov (United States)

    Tech Directions, 2012

    2012-01-01

    Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of light through an optical fiber that is roughly the diameter of a human hair. The light forms an electromagnetic carrier wave that is modulated to carry information. Each optical fiber is capable of carrying an enormous amount of…

  11. Microtubule Sliding within the Bridging Fiber Pushes Kinetochore Fibers Apart to Segregate Chromosomes.

    Science.gov (United States)

    Vukušić, Kruno; Buđa, Renata; Bosilj, Agneza; Milas, Ana; Pavin, Nenad; Tolić, Iva M

    2017-10-09

    During cell division, mitotic spindle microtubules segregate chromosomes by exerting forces on kinetochores. What forces drive chromosome segregation in anaphase remains a central question. The current model for anaphase in human cells includes shortening of kinetochore fibers and separation of spindle poles. Both processes require kinetochores to be linked with the poles. Here we show, by combining laser ablation, photoactivation, and theoretical modeling, that kinetochores can separate without any attachment to one spindle pole. This separation requires the bridging fiber, a microtubule bundle that connects sister kinetochore fibers. Bridging fiber microtubules in intact spindles slide apart with kinetochore fibers, indicating strong crosslinks between them. We conclude that sliding of microtubules within the bridging fibers drives pole separation and pushes kinetochore fibers poleward by the friction of passive crosslinks between these fibers. Thus, sliding within the bridging fiber works together with the shortening of kinetochore fibers to segregate chromosomes. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  12. Using a Fiber Loop and Fiber Bragg Grating as a Fiber Optic Sensor to Simultaneously Measure Temperature and Displacement

    Directory of Open Access Journals (Sweden)

    Hsu-Chih Cheng

    2013-05-01

    Full Text Available This study integrated a fiber loop manufactured by using commercial fiber (SMF-28, Corning and a fiber Bragg grating (FBG to form a fiber optic sensor that could simultaneously measure displacement and temperature. The fiber loop was placed in a thermoelectric cooling module with FBG affixed to the module, and, consequently, the center wavelength displacement of FBG was limited by only the effects of temperature change. Displacement and temperature were determined by measuring changes in the transmission of optical power and shifts in Bragg wavelength. This study provides a simple and economical method to measure displacement and temperature simultaneously.

  13. Hollow-Core Fiber Lamp

    Science.gov (United States)

    Yi, Lin (Inventor); Tjoelker, Robert L. (Inventor); Burt, Eric A. (Inventor); Huang, Shouhua (Inventor)

    2016-01-01

    Hollow-core capillary discharge lamps on the millimeter or sub-millimeter scale are provided. The hollow-core capillary discharge lamps achieve an increased light intensity ratio between 194 millimeters (useful) and 254 millimeters (useless) light than conventional lamps. The capillary discharge lamps may include a cone to increase light output. Hollow-core photonic crystal fiber (HCPCF) may also be used.

  14. Fiber optics physics and technology

    CERN Document Server

    Mitschke, Fedor

    2016-01-01

    This book tells you all you want to know about optical fibers: Their structure, their light-guiding mechanism, their material and manufacture, their use. It began with telephone, then came telefax and email. Today we use search engines, music downloads and internet videos, all of which require shuffling of bits and bytes by the zillions. The key to all this is the conduit: the line which is designed to carry massive amounts of data at breakneck speed. In their data carrying capacity optical fiber lines beat all other technologies (copper cable, microwave beacons, satellite links) hands down, at least in the long haul; wireless devices rely on fibers, too. Several effects tend to degrade the signal as it travels down the fiber: they are spelled out in detail. Nonlinear processes are given due consideration for a twofold reason: On the one hand they are fundamentally different from the more familiar processes in electrical cable. On the other hand, they form the basis of particularly interesting and innovative ...

  15. Oceanic Applications of Fiber Optics

    Science.gov (United States)

    1991-12-01

    theoretical performance of the optical hydrophone is 0 dB RE Qoherent Sensors IpPa [141. The Navy is investing heavily in fiber optic sensor While relatively...frequencies. The expected resolutions down to 0.5 degrees. theoretical performance of the optical hydrophone is 0 dB RE Coherent Sensors IpPa [14]. The Navy is

  16. A compact optical fiber positioner

    Science.gov (United States)

    Hu, Hongzhuan; Wang, Jianping; Liu, Zhigang; Zhou, Zengxiang; Zhai, Chao; Chu, Jiaru

    2016-07-01

    In this paper, a compact optical fiber positioner is proposed, which is especially suitable for small scale and high density optical fiber positioning. Based on the positioning principle of double rotation, positioner's center shaft depends on planetary gear drive principle, meshing with the fixed annular gear central motor gear driving device to rotate, and the eccentric shaft rotated driving by a coaxial eccentric motor, both center and the eccentric shaft are supported by a rolling bearings; center and eccentric shaft are both designed with electrical zero as a reference point, and both of them have position-limiting capability to ensure the safety of fiber positioning; both eccentric and center shaft are designed to eliminating clearance with spring structure, and can eliminate the influence of gear gap; both eccentric and center motor and their driving circuit can be installed in the positioner's body, and a favorable heat sink have designed, the heat bring by positioning operation can be effectively transmit to design a focal plane unit through the aluminum component, on sleeve cooling spiral airway have designed, when positioning, the cooling air flow is inlet into install hole on the focal plate, the cooling air flow can effectively take away the positioning's heat, to eliminate the impact of the focus seeing. By measuring position device's sample results show that: the unit accuracy reached 0.01mm, can meet the needs of fiber positioning.

  17. Fiber Bragg distributed chemical sensor

    NARCIS (Netherlands)

    Boersma, A.; Saalmink, M.; Lucassen, T.; Wiegersma, S.; Jansen, T.H.; Jansen, R.; Cheng, L.K.

    2011-01-01

    A distributed chemical sensor is developed by coating multiple Bragg gratings in a single glass fiber with chemical responsive coatings. The composition of the coating is tuned to the target chemicals to be measured and the optical response of the coated grating is optimized by changing the coating

  18. Monolithic fiber optic sensor assembly

    Science.gov (United States)

    Sanders, Scott

    2015-02-10

    A remote sensor element for spectrographic measurements employs a monolithic assembly of one or two fiber optics to two optical elements separated by a supporting structure to allow the flow of gases or particulates therebetween. In a preferred embodiment, the sensor element components are fused ceramic to resist high temperatures and failure from large temperature changes.

  19. Cylindrical Piezoelectric Fiber Composite Actuators

    Science.gov (United States)

    Allison, Sidney G.; Shams, Qamar A.; Fox, Robert L.

    2008-01-01

    The use of piezoelectric devices has become widespread since Pierre and Jacques Curie discovered the piezoelectric effect in 1880. Examples of current applications of piezoelectric devices include ultrasonic transducers, micro-positioning devices, buzzers, strain sensors, and clocks. The invention of such lightweight, relatively inexpensive piezoceramic-fiber-composite actuators as macro fiber composite (MFC) actuators has made it possible to obtain strains and displacements greater than those that could be generated by prior actuators based on monolithic piezoceramic sheet materials. MFC actuators are flat, flexible actuators designed for bonding to structures to apply or detect strains. Bonding multiple layers of MFC actuators together could increase force capability, but not strain or displacement capability. Cylindrical piezoelectric fiber composite (CPFC) actuators have been invented as alternatives to MFC actuators for applications in which greater forces and/or strains or displacements may be required. In essence, a CPFC actuator is an MFC or other piezoceramic fiber composite actuator fabricated in a cylindrical instead of its conventional flat shape. Cylindrical is used here in the general sense, encompassing shapes that can have circular, elliptical, rectangular or other cross-sectional shapes in the planes perpendicular to their longitudinal axes.

  20. Performance Assessment of Discontinuous Fibers in Fiber Reinforced Concrete: Current State-of-the-Art

    Science.gov (United States)

    2017-07-01

    ER D C/ G SL T R- 17 -1 9 Performance Assessment of Discontinuous Fibers in Fiber-Reinforced Concrete: Current State-of-the- Art G eo te...Discontinuous Fibers in Ultra-High Performance Fiber-Reinforced Concrete: Current State-of-the- Art Charles A. Burchfield Geotechnical and...Finally, a summary of the current state-of-the- art and future research recommendations will be discussed in Chapter 4. 1.1 Fiber-reinforced concrete

  1. Soliton transmission and supercontinuum generation in holey fiber using a diode pumped ytterbium fiber source

    OpenAIRE

    Price, Jonathan H.V.; Belardi, W.; Monro, T.M.; Malinowski, A.; Piper, A.; Richardson, D.J.

    2002-01-01

    We report linear dispersion compensation, soliton pulse formation, soliton compression, and ultra-broad supercontinuum generation in a holey fiber with anomalous dispersion at wavelengths above 800nm. The holey fiber was seeded with ultrashort pulses from a diode pumped, Ytterbium (Yb)-doped fiber source operating at 1.06µm. The results highlight the compatibility of the rapidly developing holey fiber technology with short pulse Yb-doped fiber lasers for wide application.

  2. Carbon Fiber Reinforced Polymer with Shredded Fibers: Quasi-Isotropic Material Properties and Antenna Performance

    OpenAIRE

    Gerald Artner; Gentner, Philipp K.; Johann Nicolics; Mecklenbräuker, Christoph F.

    2017-01-01

    A carbon fiber reinforced polymer (CFRP) laminate, with the top layer consisting of shredded fibers, is proposed and manufactured. The shredded fibers are aligned randomly on the surface to achieve a more isotropic conductivity, as is desired in antenna applications. Moreover, fiber shreds can be recycled from carbon fiber composites. Conductivity, permittivity, and permeability are obtained with the Nicolson-Ross-Weir method from material samples measured inside rectangular waveguides in the...

  3. FIBER LASER CONSTRUCTION AND THEORY INCLUDING FIBER BRAGG GRATINGS Photonic Crystal Fibers (PCFs) and applications of gas filled PCFs

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, Jacob O. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-08

    The principles used in fiber lasers have been around for a while but it is only within the past few years that fiber lasers have become commercially available and used in high power laser applications. This paper will focus on the basic design principles of fiber lasers, including fiber Bragg gratings, principles of operation, and forms of non-linear effects. It will describe the type and associated doping of the fiber used and difficult designs used to guide energy from the pump to the active medium. Topics covered include fiber laser design, fiber Bragg gratings, materials used, differences in quantum energy loss, thermo-optical effects, stimulated Raman scattering, Brillouin scattering, photonic crystal fibers and applications of gas filled Photonic Crystal Fibers (PCFs). Thanks to fiber lasers, the energy required to produce high power lasers has greatly dropped and as such we can now produce kW power using a standard 120V 15A circuit. High power laser applications are always requiring more power. The fiber laser can now deliver the greater power that these applications demand. Future applications requiring more power than can be combined using standard materials or configurations will need to be developed to overcome the high energy density and high non-linear optical scattering effects present during high power operations.

  4. Fiber design and realization of point-by-point written fiber Bragg gratings in polymer optical fibers

    DEFF Research Database (Denmark)

    Stefani, Alessio; Stecher, Matthias; Town, Graham E.

    2012-01-01

    and realization of a microstructured polymer optical fiber made of PMMA for direct writing of FBGs. The fiber was designed specifically to avoid obstruction of the writing beam by air-holes. The realized fiber has been used to point-by-point write a 5 mm long fourth order FBG with a Bragg wavelength of 1518 nm......An increasing interest in making sensors based on fiber Bragg gratings (FBGs) written in polymer optical fibers (POFs) has been seen recently. Mostly microstructured POFs (mPOFs) have been chosen for this purpose because they are easier to fabricate compared, for example, to step index fibers....... The grating was inspected under Differential Interferometric Contrast microscope and the reflection spectrum was measured. This is, to the best of our knowledge, the first FBGs written into a mPOF with the point-by-point technique and also the fastest ever written into a polymer optical fiber, with less than...

  5. Orange fiber laser for ophthalmology

    Science.gov (United States)

    Adachi, M.; Kojima, K.; Hayashi, K.

    2007-02-01

    For the light source of photocoagulators for ophthalmology, orange laser is more suitable than green laser because of low scattering loss by the crystalline lens, and low absorption by xanthophylls in the retina. We developed two orange fiber lasers (580 nm and 590 nm) to investigate the effect depending on the difference in the range of orange. The 580nm laser is composed of a 1160 nm fiber laser and a Periodically Polled Lithium Niobate (PPLN) crystal for second harmonic generation. The 1160 nm fiber laser beam is focused into the MgO-doped PPLN crystal whose length is 30 mm with 3-pass configuration. Continuous-wave 1.3 W output power of 580 nm was obtained with 5.8 W input power of 1160nm for the first time. The conversion efficiency was 22%. The band width of the second harmonic was 0.006 nm (FWHM). The 590 nm laser is almost the same as 580 nm laser source. In this case we used a Raman shift fiber to generate 1180 nm, and the output power of 590 nm was 1.4 W. We developed an evaluation model of photocoagulator system using these two laser sources. A 700 mW coagulation output power was obtained with this orange fiber laser photocoagulator system. This is enough power for the eye surgery. We have the prospect of the maintenance-free, long-life system that is completely air-cooled. We are planning to evaluate this photocoagulator system in order to investigate the difference between the two wavelengths at the field test.

  6. Stretching single fibrin fibers hampers their lysis.

    Science.gov (United States)

    Li, Wei; Lucioni, Tomas; Li, Rongzhong; Bonin, Keith; Cho, Samuel S; Guthold, Martin

    2017-09-15

    Blood clots, whose main structural component is a mesh of microscopic fibrin fibers, experience mechanical strain from blood flow, clot retraction and interactions with platelets and other cells. We developed a transparent, striated and highly stretchable substrate made from fugitive glue (a styrenic block copolymer) to investigate how mechanical strain affects lysis of single, suspended fibrin fibers. In this suspended fiber assay, lysis manifested itself by fiber elongation, thickening (disassembly), fraying and collapse. Stretching single fibrin fibers significantly hampered their lysis. This effect was seen in uncrosslinked and crosslinked fibers. Crosslinking (without stretching) also hampered single fiber lysis. Our data suggest that strain is a novel mechanosensitive factor that regulates blood clot dissolution (fibrinolysis) at the single fiber level. At the molecular level of single fibrin molecules, strain may distort, or hinder access to, plasmin cleavage sites and thereby hamper lysis. Fibrin fibers are the major structural component of a blood clot. We developed a highly stretchable substrate made from fugitive glue and a suspended fibrin fiber lysis assay to investigate the effect of stretching on single fibrin fibers lysis. The key findings from our experiments are: 1) Fibers thicken and elongate upon lysis; 2) stretching strongly reduces lysis; 3) this effect is more pronounced for uncrosslinked fibers; and 4) stretching fibers has a similar effect on reducing lysis as crosslinking fibers. At the molecular level, strain may distort plasmin cleavage sites, or restrict access to those sites. Our results suggest that strain may be a novel mechanobiological factor that regulates fibrinolysis. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  7. Characterization of polymer concrete with natural fibers

    Science.gov (United States)

    Barbuta, M.; Serbanoiu, A. A.; Teodorescu, R.; Rosca, B.; Mitroi, R.; Bejan, G.

    2017-09-01

    In the study are presented the experimental results obtained for polymer concrete prepared with epoxy resin, aggregates, fly ash as filler and two types of fibers: wool and hemp. The influence of type and dosage of fibers were studied. The density and mechanical characteristics were determined: compressive strength, flexural strength and split tensile strength. For both types of fibers, with increasing the fiber dosage the density decreases. The studied dosages had not an important influence on mechanical strengths. The fibers improved especially the tensile strength and the compressive strength presented generally smaller values than the control mix.

  8. Silicon carbide fibers and articles including same

    Science.gov (United States)

    Garnier, John E; Griffith, George W

    2015-01-27

    Methods of producing silicon carbide fibers. The method comprises reacting a continuous carbon fiber material and a silicon-containing gas in a reaction chamber at a temperature ranging from approximately 1500.degree. C. to approximately 2000.degree. C. A partial pressure of oxygen in the reaction chamber is maintained at less than approximately 1.01.times.10.sup.2 Pascal to produce continuous alpha silicon carbide fibers. Continuous alpha silicon carbide fibers and articles formed from the continuous alpha silicon carbide fibers are also disclosed.

  9. Methods for producing silicon carbide fibers

    Science.gov (United States)

    Garnier, John E.; Griffith, George W.

    2016-03-01

    Methods of producing silicon carbide fibers. The method comprises reacting a continuous carbon fiber material and a silicon-containing gas in a reaction chamber at a temperature ranging from approximately 1500.degree. C. to approximately 2000.degree. C. A partial pressure of oxygen in the reaction chamber is maintained at less than approximately 1.01.times.10.sup.2 Pascal to produce continuous alpha silicon carbide fibers. Continuous alpha silicon carbide fibers and articles formed from the continuous alpha silicon carbide fibers are also disclosed.

  10. Nonlinear fiber optics formerly quantum electronics

    CERN Document Server

    Agrawal, Govind

    1995-01-01

    The field of nonlinear fiber optics has grown substantially since the First Edition of Nonlinear Fiber Optics, published in 1989. Like the First Edition, this Second Edition is a comprehensive, tutorial, and up-to-date account of nonlinear optical phenomena in fiber optics. It synthesizes widely scattered research material and presents it in an accessible manner for students and researchers already engaged in or wishing to enter the field of nonlinear fiber optics. Particular attention is paid to the importance of nonlinear effects in the design of optical fiber communication systems. This is

  11. Optical Fiber Grating Hydrogen Sensors: A Review.

    Science.gov (United States)

    Dai, Jixiang; Zhu, Li; Wang, Gaopeng; Xiang, Feng; Qin, Yuhuan; Wang, Min; Yang, Minghong

    2017-03-12

    In terms of hydrogen sensing and detection, optical fiber hydrogen sensors have been a research issue due to their intrinsic safety and good anti-electromagnetic interference. Among these sensors, hydrogen sensors consisting of fiber grating coated with sensitive materials have attracted intensive research interests due to their good reliability and distributed measurements. This review paper mainly focuses on optical fiber hydrogen sensors associated with fiber gratings and various materials. Their configurations and sensing performances proposed by different groups worldwide are reviewed, compared and discussed in this paper. Meanwhile, the challenges for fiber grating hydrogen sensors are also addressed.

  12. Integrated optics for fiber optic sensors

    Science.gov (United States)

    Minford, W. J.; Depaula, R. P.

    1991-01-01

    Recent progress achieved in the field of fiber-optic sensor applications is discussed with emphasis placed on LiNbO3-based integrated optics (IO). Particular consideration is given to advanced electromagnetic-field sensors, an integrated laser vibrometer system, and a fiber-optic gyroscope system. It is shown that the multifunction IO chips have enabled high perforamance fiber-optic sensors (e.g., fiber-optic gyros), provided advanced and unique signal processing capabilities and advanced architectures, and have a potential of making fiber-optic sensors at low cost.

  13. Of masers, lasers and optical fiber

    Energy Technology Data Exchange (ETDEWEB)

    Stiglitz, M.R.; Blanchard, C.

    1991-07-01

    A review is presented of the development and evolution of fiber optics, lasers, and masers. It is noted that lasers and masers are based on quantum mechanical principles in which energy is transferred from a pump source to a paramagnetic material. Attention is given to gas lasers, liquid lasers (dye lasers), semiconductor lasers, and CW lasers. Also condsidered are materials used in the fabrication of optical fibers, optical fiber configurations, step-index multimode fibers, depletion layer photodiodes, and undersea fiber-optic communications links. 8 refs.

  14. Of masers, lasers and optical fiber

    Science.gov (United States)

    Stiglitz, Martin R.; Blanchard, Christine

    1991-07-01

    A review is presented of the development and evolution of fiber optics, lasers, and masers. It is noted that lasers and masers are based on quantum mechanical principles in which energy is transferred from a pump source to a paramagnetic material. Attention is given to gas lasers, liquid lasers (dye lasers), semiconductor lasers, and CW lasers. Also condsidered are materials used in the fabrication of optical fibers, optical fiber configurations, step-index multimode fibers, depletion layer photodiodes, and undersea fiber-optic communications links.

  15. Optical fibers and RF a natural combination

    CERN Document Server

    Romeiser, Malcolm

    2004-01-01

    The optical fiber industry has experienced a period of consolidation and reorganization and is now poised for a new surge in growth. To take advantage of that growth, and to respond to the demand to use fiber more efficiently, designers need a better understanding of fiber optics. Taking the approach that optical fibers are an extension of RF-based communications, the author explains basic optical concepts, applications, and systems; the nature and performance characteristics of optical fibers; and optical sources, connectors and splices. Subsequent chapters explore current applications of fib

  16. Properties of Fiber Reinforced Polymer Concrete

    Directory of Open Access Journals (Sweden)

    Marinela Bărbuţă

    2008-01-01

    Full Text Available Polymer concrete is a composite material realized with resin and aggregates. In the present study the epoxy resin was used for binding the aggregates. In the composition were introduced near the fly ash, used as filler, the cellulose fibers. The mechanical characteristics such as compressive strength, flexural strength and split tensile strength of polymer concrete with fibers were investigated. The fiber percentage was constant, the epoxy resin and the filler dosages were varied. The cellulose fiber had not improved the mechanical characteristics of the polymer concrete in comparison to that of polymer concrete without cellulose fibers.

  17. Dietary fiber intake and depressive symptoms in Japanese employees: The Furukawa Nutrition and Health Study.

    Science.gov (United States)

    Miki, Takako; Eguchi, Masafumi; Kurotani, Kayo; Kochi, Takeshi; Kuwahara, Keisuke; Ito, Rie; Kimura, Yasumi; Tsuruoka, Hiroko; Akter, Shamima; Kashino, Ikuko; Kabe, Isamu; Kawakami, Norito; Mizoue, Tetsuya

    2016-05-01

    Dietary fiber may play a favorable role in mood through gut microbiota, but epidemiologic evidence linking mood to dietary fiber intake is scarce in free-living populations. We investigated cross-sectionally the associations of dietary intakes of total, soluble, insoluble, and sources of fiber with depressive symptoms among Japanese workers. Participants were 1977 employees ages 19-69 y. Dietary intake was assessed via a validated, brief self-administered diet history questionnaire. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale. Logistic regression was used to estimate odds ratios of depressive symptoms adjusted for a range of dietary and non-dietary potential confounders. Dietary fiber intake from vegetables and fruits was significantly inversely associated with depressive symptoms. The multivariable-adjusted odds ratios (95% confidence intervals) for the lowest through the highest tertile of vegetable and fruit fiber were 1.00 (reference), 0.80 (0.60-1.05), and 0.65 (0.45-0.95), respectively (P for trend = 0.03). Dietary intake of total, soluble, insoluble, and cereal fiber was not associated with depressive symptoms. Higher dietary fiber intake from vegetables and fruits may be associated with lower likelihood of having depressive symptoms. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Cornea nerve fiber quantification and construction of phenotypes in patients with fibromyalgia.

    Science.gov (United States)

    Oudejans, Linda; He, Xuan; Niesters, Marieke; Dahan, Albert; Brines, Michael; van Velzen, Monique

    2016-03-23

    Cornea confocal microscopy (CCM) is a novel non-invasive method to detect small nerve fiber pathology. CCM generally correlates with outcomes of skin biopsies in patients with small fiber pathology. The aim of this study was to quantify the morphology of small nerve fibers of the cornea of patients with fibromyalgia in terms of density, length and branching and further phenotype these patients using standardized quantitative sensory testing (QST). Small fiber pathology was detected in the cornea of 51% of patients: nerve fiber length was significantly decreased in 44% of patients compared to age- and sex-matched reference values; nerve fiber density and branching were significantly decreased in 10% and 28% of patients. The combination of the CCM parameters and sensory tests for central sensitization, (cold pain threshold, mechanical pain threshold, mechanical pain sensitivity, allodynia and/or windup), yielded four phenotypes of fibromyalgia patients in a subgroup analysis: one group with normal cornea morphology without and with signs of central sensitization, and a group with abnormal cornea morphology parameters without and with signs of central sensitization. In conclusion, half of the tested fibromyalgia population demonstrates signs of small fiber pathology as measured by CCM. The four distinct phenotypes suggest possible differences in disease mechanisms and may require different treatment approaches.

  19. In Vivo Microscopy Reveals Extensive Embedding of Capillaries within the Sarcolemma of Skeletal Muscle Fibers

    Science.gov (United States)

    Glancy, Brian; Hsu, Li-Yueh; Dao, Lam; Bakalar, Matthew; French, Stephanie; Chess, David J.; Taylor, Joni L.; Picard, Martin; Aponte, Angel; Daniels, Mathew P.; Esfahani, Shervin; Cushman, Samuel; Balaban, Robert S.

    2013-01-01

    Objective To provide insight into mitochondrial function in vivo, we evaluated the 3D spatial relationship between capillaries, mitochondria, and muscle fibers in live mice. Methods 3D volumes of in vivo murine Tibialis anterior muscles were imaged by multi-photon microscopy (MPM). Muscle fiber type, mitochondrial distribution, number of capillaries, and capillary-to-fiber contact were assessed. The role of myoglobin-facilitated diffusion was examined in myoglobin knockout mice. Distribution of GLUT4 was also evaluated in the context of the capillary and mitochondrial network. Results MPM revealed that 43.6 ± 3.3% of oxidative fiber capillaries had ≥ 50% of their circumference embedded in a groove in the sarcolemma, in vivo. Embedded capillaries were tightly associated with dense mitochondrial populations lateral to capillary grooves and nearly absent below the groove. Mitochondrial distribution, number of embedded capillaries, and capillary-to-fiber contact were proportional to fiber oxidative capacity and unaffected by myoglobin knockout. GLUT4 did not preferentially localize to embedded capillaries. Conclusions Embedding capillaries in the sarcolemma may provide a regulatory mechanism to optimize delivery of oxygen to heterogeneous groups of muscle fibers. We hypothesize that mitochondria locate to paravascular regions due to myofibril voids created by embedded capillaries, not to enhance the delivery of oxygen to the mitochondria. PMID:25279425

  20. Can increased spatial resolution solve the crossing fiber problem for diffusion MRI?

    Science.gov (United States)

    Schilling, Kurt; Gao, Yurui; Janve, Vaibhav; Stepniewska, Iwona; Landman, Bennett A; Anderson, Adam W

    2017-09-15

    It is now widely recognized that voxels with crossing fibers or complex geometrical configurations present a challenge for diffusion MRI (dMRI) reconstruction and fiber tracking, as well as microstructural modeling of brain tissues. This "crossing fiber" problem has been estimated to affect anywhere from 30% to as many as 90% of white matter voxels, and it is often assumed that increasing spatial resolution will decrease the prevalence of voxels containing multiple fiber populations. The aim of this study is to estimate the extent of the crossing fiber problem as we progressively increase the spatial resolution, with the goal of determining whether it is possible to mitigate this problem with higher resolution spatial sampling. This is accomplished using ex vivo MRI data of the macaque brain, followed by histological analysis of the same specimen to validate these measurements, as well as to extend this analysis to resolutions not yet achievable in practice with MRI. In both dMRI and histology, we find unexpected results: the prevalence of crossing fibers increases as we increase spatial resolution. The problem of crossing fibers appears to be a fundamental limitation of dMRI associated with the complexity of brain tissue, rather than a technical problem that can be overcome with advances such as higher fields and stronger gradients. Copyright © 2017 John Wiley & Sons, Ltd.

  1. Relative validity and reproducibility of a food frequency questionnaire to assess dietary fiber intake in Danish adults.

    Science.gov (United States)

    Vuholm, Stine; Lorenzen, Janne K; Kristensen, Mette

    2014-01-01

    Differences in habitual dietary fiber intake may modify effects of dietary fiber interventions, thus measurement of habitual dietary fiber intake is relevant to apply in intervention studies on fiber-rich foods, and food frequency questionnaire (FFQ) is a commonly used method. Rye bread is the major contributor of dietary fiber in the Danish population, and a nation-specific FFQ is therefore needed. The aim of this study was to assess the relative validity and reproducibility of a self-administered quantitative FFQ designed to assess total dietary fiber intake among Danish adults. In order to assess the relative validity of the FFQ, a total of 125 participants completed both a 7-day weighed dietary recording (DR) and an FFQ consisting of 60 questions. To evaluate the reproducibility of the FFQ, a sub-group of 12 participants subsequently completed an FFQ approximately 6 months later. Estimates of mean dietary fiber intake were 24.9±9.8 and 28.1±9.4 g/day when applying the FFQ and DR, respectively, where FFQ estimates were ~12% lower (pfiber intake of the two methods was r=0.63 (pfiber intake (g/day), adequate ranking of subjects according to their dietary fiber intake, and good reproducibility. The FFQ is therefore believed to be a valuable tool for epidemiology and screening in human interventions, where intake of dietary fibers is of specific interest.

  2. Population Research.

    Science.gov (United States)

    National Inst. of Child Health and Human Development (NIH), Bethesda, MD.

    The scope of population research as carried on by the National Institute of Child Health and Human Development (NICHD) is set forth in this booklet. Population problems of the world, United States, and the individual are considered along with international population policies based on voluntary family planning programs. NICHD goals for biological…

  3. Manipulation of Bioprocess in Rumen to Improve Fiber Feed Utilization

    Directory of Open Access Journals (Sweden)

    Wisri Puastuti

    2009-12-01

    Full Text Available Ruminant has a unique digestive organ that has big capacity to digest fiber. The digestive process includes the interaction of feed, rumen microbe and animal itself. Fementative digestion gives an advantage for ruminant as majority of feed consists of fiber, i.e: cellulose, hemi cellulose and xylan. Rumen microbes have an important role to digest fiber. Rumen microbes could be manipulated by several strategies to increase microbial protein synthesis and microbial activity. Feed supplement could stimulate growth and activity of rumen microbes, while buffer could stabilize the rumen pH and also the fermentation. Defaunating agent was given to control the existence of rumen microfauna (protozoa so increase the population of bacteria. Essensial amino acid was used as a growth factor of rumen microbe the amino acid or its precursor could be given as supplementation. Feeding probiotic could maintain anaerob condition in the rumen, and caused population and activity of rumen microbe increased. Addition of micro mineral or enzyme could improve the fermentation and feed degradation in the rumen, hence, improved feed intake and animal productivity.

  4. Quantifying variation in human scalp hair fiber shape and pigmentation.

    Science.gov (United States)

    Lasisi, Tina; Ito, Shosuke; Wakamatsu, Kazumasa; Shaw, Colin N

    2016-06-01

    This study aims to evaluate the use of quantitative methods of measuring variation in scalp hair fiber shape and pigmentation and carry out exploratory data analysis on a limited sample of individuals from diverse populations in order to inform future avenues of research for the evolution of modern human hair variation. Cross-sectional area and shape and average curvature of scalp hair fibers were quantified using ImageJ. Pigmentation was analyzed using chemical methods estimating total melanin content through spectrophotometric methods, and eumelanin and pheomelanin content through HLPC analysis of melanin-specific degradation products. The initial results reinforced findings from earlier, traditional studies. African and African Diaspora scalp hair was significantly curled, (East) Asian hair was significantly thick, and European hair was significantly lighter in color. However, pigmentation analyses revealed a high level of variability in the melanin content of non-European populations and analysis of curvature found a large range of variation in the average curvature of East African individuals. Overall, these results suggest the usefulness of chemical methods for the elucidation of nonperceptible differences in scalp hair color and highlight the need for improvements in our assessment and understanding of hair fiber curvature. Am J Phys Anthropol 160:341-352, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. A chip of fiber optical trap

    Science.gov (United States)

    Su, Heming; Hu, Huizhu; Zhang, Lei; Ge, Xiaojia; Shen, Yu

    2016-10-01

    A chip of fiber optical trap paves the way to realize the miniaturization and portability of devices based on dual beam optical trap, without loss of stability. We have designed two types of chip of fiber optical trap according to our theoretical simulation. The first one integrates dual beam optical trap with microfluidic chip, called a chip of semi-sealing fiber optical trap. It is generally used in chemical, biological, medical and other high-throughput experiments. The second one is a chip of full-sealing fiber optical trap. It is used to measure precisely the coefficient of viscosity or the Brownian movement of micro-object's in liquid. This paper focuses on the chip of fiber optical trap. We present two types of chips of fiber optical trap and detail their designs, fabrication and validation. The chip of semi-sealing fiber optical trap is integrated with optical fiber and microfluidic chip made of polydimethylsiloxane (PDMS). We have achieved the micro-sized alignment of optical paths and the trapping of micro-sized particles in the chip of semi-sealing fiber optical trap. In addition, it is easy to fabrication and clean. The chip of full-sealing fiber optical trap was based on a cubic micro-cavity made by a rectangular capillary tube and sealed by PDMS. We have achieved micro-sized alignment accuracy, high trapping efficiency and better trapping stability in the chip of full-sealing fiber optical trap as well.

  6. Fabrication of miniature fiber-optic temperature sensors

    Science.gov (United States)

    Zhu, Yizheng; Wang, Anbo

    2010-07-27

    A method of coupling a silica fiber and a sapphire fiber includes providing a silica fiber having a doped core and a cladding layer, with the doped core having a prescribed diameter, providing a sapphire fiber having a diameter less than the doped core, placing an end of the sapphire fiber in close proximity to an end of the silica fiber, applying a heat source to the end of silica fiber and introducing the end of sapphire fiber into the heated doped core of the silica fiber to produce a coupling between the silica and sapphire fibers.

  7. Mechanical Properties Optimization of Fiber Reinforced Foam Concrete

    Directory of Open Access Journals (Sweden)

    Yu Lei

    2016-01-01

    Full Text Available 3 factors including fiber kind, fiber content and fiber mix-ability are selected to optimizing mechanical properties of foam concrete. By orthogonal experiment design, compression and flexural stress and strain of specimens from different fiber added ways were test. Range analysis and factor levels analysis show the best fiber added way. Test shows that fiber content is the most important factor to flexural stress. Next one is fiber kind and the third is fiber mix-ability. Fiber kind is the most important factor to stress curves. Fiber is not good for compression strength but good for flexural strength.

  8. Prebiotics, Fermentable Dietary Fiber, and Health Claims.

    Science.gov (United States)

    Delcour, Jan A; Aman, Per; Courtin, Christophe M; Hamaker, Bruce R; Verbeke, Kristin

    2016-01-01

    Since the 1970s, the positive effects of dietary fiber on health have increasingly been recognized. The collective term "dietary fiber" groups structures that have different physiologic effects. Since 1995, some dietary fibers have been denoted as prebiotics, implying a beneficial physiologic effect related to increasing numbers or activity of the gastrointestinal microbiota. Given the complex composition of the microbiota, the demonstration of such beneficial effects is difficult. In contrast, an exploration of the metabolites of dietary fiber formed as a result of its fermentation in the colon offers better perspectives for providing mechanistic links between fiber intake and health benefits. Positive outcomes of such studies hold the promise that claims describing specific health benefits can be granted. This would help bridge the "fiber gap"-that is, the considerable difference between recommended and actual fiber intakes by the average consumer. © 2016 American Society for Nutrition.

  9. Dietary fiber and blood pressure control.

    Science.gov (United States)

    Aleixandre, A; Miguel, M

    2016-04-01

    In the past few years, new strategies to control blood pressure levels are emerging by developing new bioactive components of foods. Fiber has been linked to the prevention of a number of cardiovascular diseases and disorders. β-Glucan, the main soluble fiber component in oat grains, was initially linked to a reduction in plasma cholesterol. Several studies have shown afterward that dietary fiber may also improve glycaemia, insulin resistance and weight loss. The effect of dietary fiber on arterial blood pressure has been the subject of far fewer studies than its effect on the above-mentioned variables, but research has already shown that fiber intake can decrease arterial blood pressure in hypertensive rats. Moreover, certain fibers can improve arterial blood pressure when administered to hypertensive and pre-hypertensive subjects. The present review summarizes all those studies which attempt to establish the antihypertensive effects of dietary fiber, as well as its effect on other cardiovascular risk factors.

  10. Attenuation in silica-based optical fibers

    DEFF Research Database (Denmark)

    Wandel, Marie Emilie

    2006-01-01

    In this thesis on attenuation in silica based optical fibers results within three main topics are reported. Spectral attenuation measurements on transmission fibers are performed in the wide wavelength range 290 nm – 1700 nm. The measured spectral attenuation is analyzed with special emphasis...... on absorption peaks in order to investigate the cause of an unusual high attenuation in a series of transmission fibers. Strong indications point to Ni2+ in octahedral coordination as being the cause of the high attenuation. The attenuation of fibers having a high core refractive index is analyzed and the cause...... of the high attenuation measured in such fibers is described as being due to scattering of light on fluctuations of the core diameter. A novel semi-empirical model for predicting the attenuation of high index fibers is presented. The model is shown to be able to predict the attenuation of high index fibers...

  11. Degradation Behavior of Thermal Stabilized Polyacrylonitrile Fibers

    Directory of Open Access Journals (Sweden)

    LEI Shuai

    2017-05-01

    Full Text Available In the temperature range of 300-800℃, 40%-50% of the mass lost during the processing of polyacrylonitrile based carbon fiber (PANCF. Understanding the degradation behavior will be valuable in understanding the formation mechanism of pseudo-graphite structure, and providing theoretic basis for producing high performance carbon fiber and increasing the carbonization yield. The simulation of the degradation progress was carried out on the thermogravimetric analyzer (TGA, the results show that there are two degradation steps for PAN fiber stabilized in air, and controlled by cyclization coefficient and oxygen content. The cyclization coefficient and oxygen content are effective to the density of carbon fiber by influencing the degradation behavior, which cause defects in the fiber. The higher cyclization coefficient leads to form less structural defects and higher density of the fiber; on the contrary, the higher oxygen content leads to form more structural defects and lower density of the fiber.

  12. Electrical Properties of Carbon Fiber Support Systems

    CERN Document Server

    Cooper, W; Demarteau, M; Fast, J; Hanagaki, K; Johnson, M; Kuykendall, W; Lubatti, H; Matulik, M; Nomerotski, A; Quinn, B; Wang, J

    2005-01-01

    Carbon fiber support structures have become common elements of detector designs for high energy physics experiments. Carbon fiber has many mechanical advantages but it is also characterized by high conductivity, particularly at high frequency, with associated design issues. This paper discusses the elements required for sound electrical performance of silicon detectors employing carbon fiber support elements. Tests on carbon fiber structures are presented indicating that carbon fiber must be regarded as a conductor for the frequency region of 10 to 100 MHz. The general principles of grounding configurations involving carbon fiber structures will be discussed. To illustrate the design requirements, measurements performed with a silicon detector on a carbon fiber support structure at small radius are presented. A grounding scheme employing copper-kapton mesh circuits is described and shown to provide adequate and robust detector performance.

  13. All-fiber femtosecond Cherenkov radiation source

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Møller, Uffe

    2012-01-01

    An all-fiber femtosecond source of spectrally isolated Cherenkov radiation is reported, to the best of our knowledge, for the first time. Using a monolithic, self-starting femtosecond Yb-doped fiber laser as the pump source and the combination of photonic crystal fibers as the wave-conversion med......An all-fiber femtosecond source of spectrally isolated Cherenkov radiation is reported, to the best of our knowledge, for the first time. Using a monolithic, self-starting femtosecond Yb-doped fiber laser as the pump source and the combination of photonic crystal fibers as the wave......-conversion medium, we demonstrate milliwatt-level, stable, and tunable Cherenkov radiation at visible wavelengths 580–630 nm, with pulse duration of sub-160-fs, and the 3 dB spectral bandwidth not exceeding 36 nm. Such an all-fiber Cherenkov radiation source is promising for practical applications in biophotonics...

  14. Fiber cavities with integrated mode matching optics.

    Science.gov (United States)

    Gulati, Gurpreet Kaur; Takahashi, Hiroki; Podoliak, Nina; Horak, Peter; Keller, Matthias

    2017-07-17

    In fiber based Fabry-Pérot Cavities (FFPCs), limited spatial mode matching between the cavity mode and input/output modes has been the main hindrance for many applications. We have demonstrated a versatile mode matching method for FFPCs. Our novel design employs an assembly of a graded-index and large core multimode fiber directly spliced to a single mode fiber. This all-fiber assembly transforms the propagating mode of the single mode fiber to match with the mode of a FFPC. As a result, we have measured a mode matching of 90% for a cavity length of ~400 μm. This is a significant improvement compared to conventional FFPCs coupled with just a single mode fiber, especially at long cavity lengths. Adjusting the parameters of the assembly, the fundamental cavity mode can be matched with the mode of almost any single mode fiber, making this approach highly versatile and integrable.

  15. The Bushbaby Optic Nerve: Fiber Count and Fiber Diameter Spectrum

    Science.gov (United States)

    1986-03-01

    The identification of unmyelinated axons was based primariliy on the shape or the axon, its membrane thickness, and the axoplasmic contents ( Maturana ...studies of the optic nerve that axons are not rigid, circular tubes ( Maturana , 1959). They do not traverse the length of the optic nerve in register...fascicles as in most vertebrates (turtle: Fulbrook and Granda, 1978; pigeon: Binggelli and Paule, 1969; frog: Maturana , 1959). Nerve Fiber Total Counts

  16. Dietary fiber intake is associated with reduced risk of mortality from cardiovascular disease among Japanese men and women.

    Science.gov (United States)

    Eshak, Ehab S; Iso, Hiroyasu; Date, Chigusa; Kikuchi, Shogo; Watanabe, Yoshiyuki; Wada, Yasuhiko; Wakai, Kenji; Tamakoshi, Akiko

    2010-08-01

    Dietary fiber protects against coronary heart disease (CHD), but evidence in Asia is limited. We examined the association between dietary fiber intake and mortality from cardiovascular disease (CVD) in a Japanese population in a prospective study of 58,730 Japanese men and women aged 40-79 y in which dietary fiber intake was determined by a self-administered FFQ. The participants were followed up from 1988-1990 to the end of 2003. Hazard ratios (HR) and 95% CI of mortality were calculated per quintile of fiber intake. During the 14-y follow-up, a total of 2080 CVD deaths (983 strokes, 422 CHD, and 675 other CVD) were documented. Total, insoluble, and soluble dietary fiber intakes were inversely associated with risk of mortality from CHD and total CVD for both men and women. For men, the multivariable HR (95% CI) for CHD in the highest vs. the lowest quintiles were 0.81 [(95% CI, 0.61-1.09); P-trend = 0.02], 0.48 [(95% CI, 0.27-0.84); P-trend fiber, respectively. The respective HR (95% CI) for women were 0.80 [(95% CI, 0.57-0.97); P-trend = 0.01], 0.49 [(95% CI, 0.27-0.86); P-trend = 0.004], and 0.72 [(95% CI, 0.34-0.99); P-trend = 0.03], respectively. For fiber sources, intakes of fruit and cereal fibers but not vegetable fiber were inversely associated with risk of mortality from CHD. In conclusion, dietary intakes of fiber, both insoluble and soluble fibers, and especially fruit and cereal fibers, may reduce risk of mortality from CHD.

  17. Coexistence of High-Bit-Rate Quantum Key Distribution and Data on Optical Fiber

    Directory of Open Access Journals (Sweden)

    K. A. Patel

    2012-11-01

    Full Text Available Quantum key distribution (QKD uniquely allows the distribution of cryptographic keys with security verified by quantum mechanical limits. Both protocol execution and subsequent applications require the assistance of classical data communication channels. While using separate fibers is one option, it is economically more viable if data and quantum signals are simultaneously transmitted through a single fiber. However, noise-photon contamination arising from the intense data signal has severely restricted both the QKD distances and secure key rates. Here, we exploit a novel temporal-filtering effect for noise-photon rejection. This allows high-bit-rate QKD over fibers up to 90 km in length and populated with error-free bidirectional Gb/s data communications. With a high-bit rate and range sufficient for important information infrastructures, such as smart cities and 10-Gbit Ethernet, QKD is a significant step closer toward wide-scale deployment in fiber networks.

  18. Additives in fibers and fabrics.

    Science.gov (United States)

    Barker, R H

    1975-01-01

    The additives and contaminants which occur in textile fibers vary widely, depending on the type of fiber and the pretreatment which it has received. Synthetic fibers such as nylon and polyester contain trace amounts of contaminants such as catalysts and catalyst deactivators which remain after the synthesis of the basic polymers. In addition, there are frequently a number of materials which are added to perform specific functions in almost all man-made fibers. Examples of these would include traces of metals or metal salts used as tracers for identification of specific lots of fiber, TiO2 or similar materials added as delustrants, and a host of organic species added for such special purposes as antistatic agents or flame retardants. There may also be considerable quantities of residual monomer or small oligomers dissolved in the polymer matrix. The situation becomes even more complex after the fibers are converted into fabric form. Numerous materials are applied at various stages of fabric preparation to act as lubricants, sizing agents, antistats, bleaches, and wetting agents to facilitate the processing, but these are normally removed before the fabric reaches the cutters of the ultimate consumers and therefore usually do not constitute potential hazards. However, there are many other chemical agents which are frequently added during the later stages of fabric preparation and which are not designed to be removed. Aside from dyes and printing pigments, the most common additive for apparel fabrics is a durable press treatment. This generally involves the use of materials capable of crosslinking cellulosics by reacting through such functions as N-methylolated amides or related compounds such as ureas and carbamates. These materials pose some potential hazards due to both the nitrogenous bases and the formaldehyde which they usually release. There is usually also some residual catalyst in fabrics which have received such treatments. Other types of chemical treatments

  19. Single Muscle Fiber Proteomics Reveals Fiber-Type-Specific Features of Human Muscle Aging

    Directory of Open Access Journals (Sweden)

    Marta Murgia

    2017-06-01

    Full Text Available Skeletal muscle is a key tissue in human aging, which affects different muscle fiber types unequally. We developed a highly sensitive single muscle fiber proteomics workflow to study human aging and show that the senescence of slow and fast muscle fibers is characterized by diverging metabolic and protein quality control adaptations. Whereas mitochondrial content declines with aging in both fiber types, glycolysis and glycogen metabolism are upregulated in slow but downregulated in fast muscle fibers. Aging mitochondria decrease expression of the redox enzyme monoamine oxidase A. Slow fibers upregulate a subset of actin and myosin chaperones, whereas an opposite change happens in fast fibers. These changes in metabolism and sarcomere quality control may be related to the ability of slow, but not fast, muscle fibers to maintain their mass during aging. We conclude that single muscle fiber analysis by proteomics can elucidate pathophysiology in a sub-type-specific manner.

  20. Comparison of F-12 aramid fiber with domestic armid fiber III on surface feature

    Science.gov (United States)

    Zhang, Shu-hui; He, Guo-qiang; Liang, Guo-zheng; Cui, Hong; Zhang, Wei; Wang, Bin

    2010-01-01

    A comparison of F-12 aramid fiber with domestic armid fiber III (DAF III) on surface feature was carried out by scanning electron microscope (SEM), atomic force microscopy (AFM), elements analysis and X-ray Photoelectron Spectroscopy (XPS) analysis. It is found that the two aramid fibers are of "skin-core" structure and fibrillar structure. The microfibrils orient along the fiber axis and rather poorly bond in transverse direction. Many defects exist on the surface of two fibers. Carbon, hydrogen, nitrogen and oxygen are the major elements of two aramid fiber. The element content of the same aramid fiber from surface to interior is different. The surface carbon contents of F-12 aramid fiber and DAF III are increased by 10.75% and 9.95% than those in fiber interior respectively, the surface nitrogen content decreased by 9.72% and 27.02% respectively, and the surface oxygen content increased by 13.99% and 37.95% respectively.

  1. Fluoro-edenite Fibers Induce Expression of Hsp70 and Inflammatory Response

    Directory of Open Access Journals (Sweden)

    Michael Balazy

    2007-09-01

    Full Text Available Many asbestos-like mineral fibers have been detected in the air of mountainous and volcanic areas of Italy and other parts of the world. These fibers have been suspected to be the cause of increased incidences of lung cancer and other lung diseases in these areas. However, the mechanisms of the cellular response and defense following exposure to these microscopic fibers have not been characterized. We continue to study these mechanisms to be able to propose preventive strategies in large populations. The objective of the present study was to determine comparatively biological responses of mesothelial Met-5A and monocyte-macrophage J774 cells following exposure to two types of fluoro-edenite fibers having low and high iron content (labeled 19 and 27, respectively obtained from Biancavilla (Sicily, Italy. The reference fiber was a non-iron fibrous tremolite from Val di Susa (Piemonte, Italy. The cells were treated with 5, 50, and 100 μg of fibrous matter per 1 ml for 72 hr. We identified several key mechanisms by which cells responded and counteracted the injury induced by these fibers. The fibers caused induction of the heat shock protein 70 (Hsp70, stimulated formation of reactive oxygen species (detected by using DCFH-DA as a fluorescent probe and NO• (measured as nitrite. Exposure of cells to the fibers induced lactate dehydrogenase activity and decreased viability. The fluoro-endenite type 27 was the most potent fiber tested, which indicated that iron and possibly manganese contribute significantly to this fiber toxicity. The J774 cells were more sensitive to fluoro-edenite than Met-5A cells suggesting that the primary site of the fiberinduced inflammatory response could be the macrophage rather than the pulmonary epithelium. Fluoro-edenite produces more biological alterations with respect to non-iron tremolite. Hsp70 and free radicals could be important factors in the context of mineral fiber-induced acute lung injury

  2. Hollow steel tips for reducing distal fiber burn-back during thulium fiber laser lithotripsy.

    Science.gov (United States)

    Hutchens, Thomas C; Blackmon, Richard L; Irby, Pierce B; Fried, Nathaniel M

    2013-07-01

    The use of thulium fiber laser (TFL) as a potential alternative laser lithotripter to the clinical holmium:YAG laser is being studied. The TFL's Gaussian spatial beam profile provides efficient coupling of higher laser power into smaller core fibers without proximal fiber tip degradation. Smaller fiber diameters are more desirable, because they free up space in the single working channel of the ureteroscope for increased saline irrigation rates and allow maximum ureteroscope deflection. However, distal fiber tip degradation and "burn-back" increase as fiber diameter decreases due to both excessive temperatures and mechanical stress experienced during stone ablation. To eliminate fiber tip burn-back, the distal tip of a 150-μm core silica fiber was glued inside 1-cm-long steel tubing with fiber tip recessed 100, 250, 500, 1000, or 2000 μm inside the steel tubing to create the hollow-tip fiber. TFL pulse energy of 34 mJ with 500-μs pulse duration and 150-Hz pulse rate was delivered through the hollow-tip fibers in contact with human calcium oxalate monohydrate urinary stones during ex vivo studies. Significant fiber tip burn-back and degradation was observed for bare 150-μm core-diameter fibers. However, hollow steel tip fibers experienced minimal fiber burn-back without compromising stone ablation rates. A simple, robust, compact, and inexpensive hollow fiber tip design was characterized for minimizing distal fiber burn-back during the TFL lithotripsy. Although an increase in stone retropulsion was observed, potential integration of the hollow fiber tip into a stone basket may provide rapid stone vaporization, while minimizing retropulsion.

  3. Erbium Doped Fiber Optic Gravimeter

    Science.gov (United States)

    Pérez-Sánchez, G. G.; Pérez-Torres, J. R.; Flores-Bravo, J. A.; Álvarez-Chávez, J. A.; Martínez-Piñón, F.

    2017-01-01

    Gravimeters are devices that can be used in a wide range of applications, such as mining, seismology, geodesy, archeology, geophysics and many others. These devices have great sensibility, which makes them susceptible to external vibrations like electromagnetic waves. There are several technologies regarding gravimeters that are of use in industrial metrology. Optical fiber is immune to electromagnetic interference, and together with long period gratings can form high sensibility sensors of small size, offering advantages over other systems with different technologies. This paper shows the development of an optical fiber gravimeter doped with Erbium that was characterized optically for loads going from 1 to 10 kg in a bandwidth between 1590nm to 1960nm, displaying a weight linear response against power. Later on this paper, the experimental results show that the previous described behavior can be modeled as characteristic function of the sensor.

  4. Peculiarities of carbon fiber drilling

    Directory of Open Access Journals (Sweden)

    Ruslan Yu. Melentiev

    2014-12-01

    Full Text Available At polymeric composite materials (PCM machining we face a number of specific features. The research refers to PCMs classification, exposing an overview of known specific features described in the latest advances and techniques to improve the quality and efficiency in PCM processing. To study the carbon fiber drilling a preliminary experiment has been conducted, which essential parameters and issues have been described with respective data Tables and numerous images. The holes surface quality and edges dimensional accuracy have been compared for samples obtained using a blade and a diamond tool; established is the instrument blade material impact on the edges’ precision parameters. Confirmed are the typical and revealed some new types of imperfections and their occurrence conditions. The problem of rapid clogging and related diamond tool clogging problem are identified. Some promising ways of processing of carbon fiber are offered.

  5. Fiber loop ringdown humidity sensor.

    Science.gov (United States)

    Alali, Haifa; Wang, Chuji

    2016-11-01

    An optical fiber relative humidity (RH) sensor based on the evanescent field-fiber loop ringdown (EF-FLRD) technique is demonstrated. The sensor was placed inside a chamber that provides a humidity reference and is monitored by a humidity meter. The presence of moisture in the chamber changes the refractive index of the medium; thus the ringdown time changes due to a change in the EF scattering loss induced in the sensor head. The sensor demonstrated a fast response (∼1  s), high sensitivity, and excellent reproducibility and reversibly. The EF-FLRD sensor can measure RH in a wide dynamic range of 4% to 100% at a constant temperature of 20±1°C.

  6. Fundamentals of fiber bonding in thermally point-bonded nonwovens

    Science.gov (United States)

    Chidambaram, Aparna

    Thermal point bonding (TPB) uses heat and pressure to bond a web of fibers at discrete points imparting strength to the manufactured fabric. This process significantly reduces the strength and elongation of the bridging fibers between bond points while strengthening the web. Single fiber experiments were performed with four structurally different polypropylene fibers to analyze the inter-relationships between fiber structure, fiber properties and bonding process. Two fiber types had a low birefringence sheath or surface layer while the remaining had uniform birefringence profiles through their thickness. Bonds were formed between isolated pairs of fibers by subjecting the fibers to a calendering process and simulating TPB process conditions. The dependence of bond strength on bonding temperature and on the type of fiber used was evaluated. Fiber strengths before and after bonding were measured and compared to understand the effect of bonding on fiber strength. Additionally, bonded fiber strength was compared to the strength of single fibers which had experienced the same process conditions as the bonded pairs. This comparison estimated the effect of mechanical damage from pressing fibers together with steel rolls while creating bonds in TPB. Interfiber bond strength increased with bonding temperature for all fiber types. Fiber strength decreased with increasing bonding temperature for all fiber types except for one type of low birefringent sheath fibers. Fiber strength degradation was unavoidable at temperatures required for successful bonding. Mechanical damage from compression of fibers between rolls was an insignificant factor in this strength loss. Thermal damage during bonding was the sole significant contributor to fiber strength degradation. Fibers with low birefringence skins formed strong bonds with minimal fiber strength loss and were superior to fibers without such surface layers in TPB performance. A simple model to predict the behavior of a two

  7. Piezoelectric fibers for conformal acoustics.

    Science.gov (United States)

    Chocat, Noémie; Lestoquoy, Guillaume; Wang, Zheng; Rodgers, Daniel M; Joannopoulos, John D; Fink, Yoel

    2012-10-09

    Ultrasound transducers have many important applications in medical, industrial, and environmental settings. Large-active-area piezoelectric fibers are presented here, which can be woven into extended and flexible ultrasound transducing fabrics. This work opens significant opportunities for large-area, flexible and adjustable acoustic emission and sensing for a variety of emerging applications. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. An Optical Fiber Infrasound Sensor

    Science.gov (United States)

    2006-06-01

    DESTRUCTION NOTICE FOR CLASSIFIED documents, follow the procedures in DoD 5550.22-M, National Industrial Security Program Operating Manual, Chapter 5...accordance with DoD 5220.22M1 Industrial Security manual. PLEASE NOTIFY THE DEFENSE THREAT REDUCTION AGENCY, ATTN: IMMI, 8725 JOHN J. KINGMAN ROAD, MS...directional array element. We have assembled a prototype optical fiber infrasound sensor, have performed laboratory evaluations, and have run

  9. Heavily Tm3+-Doped Silicate Fiber for High-Gain Fiber Amplifiers

    OpenAIRE

    Yin-Wen Lee; Han-Wei Chien; Che-Hung Cho; Ju-Zhe Chen; Juin-Shin Chang; Shibin Jiang

    2013-01-01

    We report on investigation the potential of a 7 wt% (8.35 × 1020 Tm3+/cm3) doped silicate fibers for high-gain fiber amplifiers. Such a high ion concentration significantly reduces the required fiber length of high-power 2 μm fiber laser systems and allows the high-repetition rate operation in 2 μm mode-locked fiber lasers. To evaluate the feasibility of extracting high gain-per-unit-length from this gain medium, we measure several key material properties of the silicate fiber, including the ...

  10. High-resolution wavefront shaping with a photonic crystal fiber for multimode fiber imaging.

    Science.gov (United States)

    Amitonova, Lyubov V; Descloux, Adrien; Petschulat, Joerg; Frosz, Michael H; Ahmed, Goran; Babic, Fehim; Jiang, Xin; Mosk, Allard P; Russell, Philip St J; Pinkse, Pepijn W H

    2016-02-01

    We demonstrate that a high-numerical-aperture photonic crystal fiber allows lensless focusing at an unparalleled resolution by complex wavefront shaping. This paves the way toward high-resolution imaging exceeding the capabilities of imaging with multi-core single-mode optical fibers. We analyze the beam waist and power in the focal spot on the fiber output using different types of fibers and different wavefront shaping approaches. We show that the complex wavefront shaping technique, together with a properly designed multimode photonic crystal fiber, enables us to create a tightly focused spot on the desired position on the fiber output facet with a subwavelength beam waist.

  11. Effective light coupling in reflective fiber optic distance sensors using a double-clad fiber

    Science.gov (United States)

    Werzinger, Stefan; Härteis, Lisa; Köhler, Aaron; Engelbrecht, Rainer; Schmauss, Bernhard

    2017-04-01

    Many fiber optic distance sensors use a reflective configuration, where a light beam is launched from an optical fiber, reflected from a target and coupled back into the fiber. While singlemode fibers (SMF) provide low-loss, high-performance components and a well-defined output beam, the coupling of the reflected light into the SMF is very sensitive to mechanical misalignments and scattering at the reflecting target. In this paper we use a double-clad fiber (DCF) and a DCF coupler to obtain an enhanced multimodal coupling of reflected light into the fiber. Increased power levels and robustness are achieved compared to a pure SMF configuration.

  12. Femtosecond-pulse inscription of fiber Bragg gratings in multimode graded index fiber

    Science.gov (United States)

    Dostovalov, Alexandr V.; Wolf, Alexey A.; Zlobina, Ekaterina A.; Kablukov, Sergey I.; Babin, Sergey A.

    2017-02-01

    Femtosecond-pulse modification of the refractive index in transparent materials enables the inscription of fiber Bragg gratings with new features and extended capabilities. In this study we present the results of fiber Bragg gratings inscription in Corning 62.5/125 multimode graded index fiber with IR femtosecond laser pulses. The specifics of point-by-point inscription including single and multiple Bragg grating inscription in limited fiber segment as well as different transverse modes excitation/suppression is discussed. Multimode fiber Bragg gratings inscribed with femtosecond radiation are investigated for the first time directly in the Raman fiber laser cavity.

  13. Simulation of propagation in a bundle of skeletal muscle fibers: Modulation effects of passive fibers

    DEFF Research Database (Denmark)

    Henneberg, Kaj-åge; F.A., Roberge

    1997-01-01

    Computer simulations are used to study passive fiber modulation of propagation in a tightly packed bundle of frog skeletal muscle fibers (uniform fiber radius of 50 mu m). With T = 20 degrees C and a uniform nominal interstitial cleft width (d) over bar = 0.35 mu m, about 92% of the active fiber...... source current (I-ma) enters the passive tissue as a radial load current (I-ep) while the rest flows longitudinally in the cleft between the active and adjacent passive fibers. The conduction velocity of 1.32 m/s was about 30% lower than on an isolated fiber in a Ringer bath, in close agreement...

  14. Optimization of fiber shapes in biocomposites

    Science.gov (United States)

    Zhou, Yan

    Fibers can be used to improve the mechanical properties of acrylic bone cement. However, debonding of the fibers from the matrix due to the poor fiber/matrix interface is a major failure mechanism for such reinforcements. Optimization of the fiber shape can improve load transfer between the fibers and the matrix, thereby providing improved overall mechanical performance. The goals of this study include: (1) Develop an analytical model to evaluate the effects of fiber end geometry on the pullout load and stress distribution; (2) Determine the optimal fiber morphology for maximum stress transfer in composites using optimization and finite element modeling; (3) Fabricate the fibers with optimal morphology determined by the previous step; (4) Manufacture composites reinforced with the optimized fibers and demonstrate improved mechanical properties experimentally. Analytical solutions were derived to predict the effects of the enlarged end shape on the pullout load and stress distribution. It is shown that the shape of the enlarged end has a significant influence on the stress distribution of the short fiber. A procedure for structural shape optimization of short fibers was developed. The effects of the interfacial bond and fiber orientation were investigated to obtain the optimal fiber shape. The general optimal fiber shape is a variable diameter fiber (VDF). Due to the mechanical interlock, the VDF can both bridge matrix cracks effectively and improve the composite mechanical properties. Ceramic VDFs were successfully fabricated. Static and fatigue tests were carried out on the VDF reinforced composites. Conventional straight fiber (CSF) reinforced bone cement was also tested for comparison purposes. Results demonstrated that both the stiffness and the fatigue life of VDF reinforced bone cement are significantly improved compared with the unreinforced cement. Also, the fatigue life of VDF reinforced bone cement was significantly longer than that of CSF reinforced

  15. Development of a Publicly Available, Comprehensive Database of Fiber and Health Outcomes: Rationale and Methods.

    Directory of Open Access Journals (Sweden)

    Kara A Livingston

    Full Text Available Dietary fiber is a broad category of compounds historically defined as partially or completely indigestible plant-based carbohydrates and lignin with, more recently, the additional criteria that fibers incorporated into foods as additives should demonstrate functional human health outcomes to receive a fiber classification. Thousands of research studies have been published examining fibers and health outcomes.(1 Develop a database listing studies testing fiber and physiological health outcomes identified by experts at the Ninth Vahouny Conference; (2 Use evidence mapping methodology to summarize this body of literature. This paper summarizes the rationale, methodology, and resulting database. The database will help both scientists and policy-makers to evaluate evidence linking specific fibers with physiological health outcomes, and identify missing information.To build this database, we conducted a systematic literature search for human intervention studies published in English from 1946 to May 2015. Our search strategy included a broad definition of fiber search terms, as well as search terms for nine physiological health outcomes identified at the Ninth Vahouny Fiber Symposium. Abstracts were screened using a priori defined eligibility criteria and a low threshold for inclusion to minimize the likelihood of rejecting articles of interest. Publications then were reviewed in full text, applying additional a priori defined exclusion criteria. The database was built and published on the Systematic Review Data Repository (SRDR™, a web-based, publicly available application.A fiber database was created. This resource will reduce the unnecessary replication of effort in conducting systematic reviews by serving as both a central database archiving PICO (population, intervention, comparator, outcome data on published studies and as a searchable tool through which this data can be extracted and updated.

  16. Dietary Fiber Intake and Risk of Chronic Obstructive Pulmonary Disease: A Prospective Cohort Study of Men.

    Science.gov (United States)

    Kaluza, Joanna; Harris, Holly; Wallin, Alice; Linden, Anders; Wolk, Alicja

    2017-09-07

    The limited literature suggests that dietary fiber intake from whole grains, fruits, and vegetables is negatively associated with chronic obstructive pulmonary disease (COPD) via fiber's anti-inflammatory properties. Therefore, we investigated the association between total fiber and fiber sources and risk of COPD in the population-based prospective Cohort of Swedish Men (45,058 men, aged 45-79 years) with no history of COPD at baseline. Dietary fiber intake was assessed with a self-administered questionnaire in 1997 and was energy-adjusted using the residual method. Cox proportional hazard regression models were used to estimate hazard ratios (HRs) with 95% confidence intervals (95% CIs) adjusted for potential confounders. During a mean follow-up of 13.1 years (1998-2012), 1,982 incident cases of COPD were ascertained via linkage to the Swedish health registers. A strong inverse association between total fiber intake (≥36.8 vs. fiber, HRs for highest vs. lowest quintile were 0.62 (95%CI=0.51-0.77,P-trendfiber the HR was 0.65 (95%CI=0.52-0.81,P-trendvegetable fiber it was 0.71 (95%CI=0.57-0.88,P-trend=0.003) in current smokers and 0.92 (95%CI=0.71-1.19,P-trend=0.48) in ex-smokers. Our findings indicate that high fiber intake was inversely associated with COPD incidence in men who are current or ex-smokers.

  17. Carbon nanotube fiber terahertz polarizer

    Science.gov (United States)

    Zubair, Ahmed; Tsentalovich, Dmitri E.; Young, Colin C.; Heimbeck, Martin S.; Everitt, Henry O.; Pasquali, Matteo; Kono, Junichiro

    2016-04-01

    Conventional, commercially available terahertz (THz) polarizers are made of uniformly and precisely spaced metallic wires. They are fragile and expensive, with performance characteristics highly reliant on wire diameters and spacings. Here, we report a simple and highly error-tolerant method for fabricating a freestanding THz polarizer with nearly ideal performance, reliant on the intrinsically one-dimensional character of conduction electrons in well-aligned carbon nanotubes (CNTs). The polarizer was constructed on a mechanical frame over which we manually wound acid-doped CNT fibers with ultrahigh electrical conductivity. We demonstrated that the polarizer has an extinction ratio of ˜-30 dB with a low insertion loss (fiber polarizer and found comparable attenuation to a commercial metallic wire-grid polarizer. Furthermore, based on the classical theory of light transmission through an array of metallic wires, we demonstrated the most striking difference between the CNT-fiber and metallic wire-grid polarizers: the latter fails to work in the zero-spacing limit, where it acts as a simple mirror, while the former continues to work as an excellent polarizer even in that limit due to the one-dimensional conductivity of individual CNTs.

  18. Carbon nanotube fiber terahertz polarizer

    Energy Technology Data Exchange (ETDEWEB)

    Zubair, Ahmed [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Tsentalovich, Dmitri E.; Young, Colin C. [Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005 (United States); Heimbeck, Martin S. [Charles M. Bowden Laboratory, Aviation & Missile Research, Development, and Engineering Center (AMRDEC), Redstone Arsenal, Alabama 35898 (United States); Everitt, Henry O. [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Charles M. Bowden Laboratory, Aviation & Missile Research, Development, and Engineering Center (AMRDEC), Redstone Arsenal, Alabama 35898 (United States); Pasquali, Matteo [Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005 (United States); Department of Chemistry, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Kono, Junichiro, E-mail: kono@rice.edu [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States)

    2016-04-04

    Conventional, commercially available terahertz (THz) polarizers are made of uniformly and precisely spaced metallic wires. They are fragile and expensive, with performance characteristics highly reliant on wire diameters and spacings. Here, we report a simple and highly error-tolerant method for fabricating a freestanding THz polarizer with nearly ideal performance, reliant on the intrinsically one-dimensional character of conduction electrons in well-aligned carbon nanotubes (CNTs). The polarizer was constructed on a mechanical frame over which we manually wound acid-doped CNT fibers with ultrahigh electrical conductivity. We demonstrated that the polarizer has an extinction ratio of ∼−30 dB with a low insertion loss (<0.5 dB) throughout a frequency range of 0.2–1.1 THz. In addition, we used a THz ellipsometer to measure the Müller matrix of the CNT-fiber polarizer and found comparable attenuation to a commercial metallic wire-grid polarizer. Furthermore, based on the classical theory of light transmission through an array of metallic wires, we demonstrated the most striking difference between the CNT-fiber and metallic wire-grid polarizers: the latter fails to work in the zero-spacing limit, where it acts as a simple mirror, while the former continues to work as an excellent polarizer even in that limit due to the one-dimensional conductivity of individual CNTs.

  19. Industrial fiber lidar: some applications

    Science.gov (United States)

    Belanger, Brigitte; Fougeres, Andre; Talbot, Mario; Roy, Gilles

    2000-12-01

    In recent years, INO has developed an eye-safe, transportable industrial fiber lidar (IFL) for industrial applications of pollution control during handling of loose materials'2. However, it can also be used for other applications like urban particulates monitoring, cloud mapping, and unattended surveillance. The IPL is a compact and direct scanning lidar. It is based on 1140's diode pumped Erbium doped fiber laser, which delivers an energy of 1 .5microJoules in l2ns pulses with a high repetition rate of 10kHz at an eye-safe wavelength of 1.5microns. 1140's lidar system is composed of a lidar head containing the transmitter-receiver optics in a biaxial configuration mounted on a scanning platform. The lidar head is connected to the laser source and detector via optical fibers. A computer controls the scanning platform via an optical RS- 232 communication link. This allows remote operation since sensitive equipment like the laser and the computer can be located away from the surveillance site in an environmentally controlled room. The TEL characteristics and results obtained from monitoring in an urban area and field trials on surveillance of hard targets and transmission through obscurants will be detailed.

  20. Fiber-Optic Ammonia Sensors

    Science.gov (United States)

    Carter, Michael T.

    2003-01-01

    Reversible, colorimetric fiber-optic sensors are undergoing development for use in measuring concentrations of ammonia in air at levels relevant to human health [0 to 50 parts per million (ppm)]. A sensor of this type includes an optical fiber that has been modified by replacing a portion of its cladding with a polymer coat that contains a dye that reacts reversibly with ammonia and changes color when it does so. The change in color is measured as a change in the amount of light transmitted from one end of the fiber to the other. Responses are reversible and proportional to the concentration of ammonia over the range from 9 to 175 ppm and in some cases the range of reversibility extends up to 270 ppm. The characteristic time for the response of a sensor to rise from 10 to 90 percent of full scale is about 25 seconds. These sensors are fully operational in pure carbon dioxide and are not adversely affected by humidity. This work was done by Michael T. Carter