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Sample records for microscope phase plate

  1. Ponderomotive phase plate for transmission electron microscopes

    DOEpatents

    Reed, Bryan W.

    2012-07-10

    A ponderomotive phase plate system and method for controllably producing highly tunable phase contrast transfer functions in a transmission electron microscope (TEM) for high resolution and biological phase contrast imaging. The system and method includes a laser source and a beam transport system to produce a focused laser crossover as a phase plate, so that a ponderomotive potential of the focused laser crossover produces a scattering-angle-dependent phase shift in the electrons of the post-sample electron beam corresponding to a desired phase contrast transfer function.

  2. Fabrication of optical multilayer for two-color phase plate in super-resolution microscope

    NASA Astrophysics Data System (ADS)

    Iketaki, Yoshinori; Kitagawa, Katsuichi; Hidaka, Kohjiro; Kato, Naoki; Hirabayashi, Akira; Bokor, Nandor

    2014-07-01

    In super-resolution microscopy based on fluorescence depletion, the two-color phase plate (TPP) is an indispensable optical element, which can independently control the phase shifts for two beams of different color, i.e., the pump and erase beams. By controlling a phase shift of the erase beam through the TPP, the erase beam can be modulated into a doughnut shape, while the pump beam maintains the initial Gaussian shape. To obtain a reliable optical multiplayer (ML) for the TPP, we designed a ML with only two optical layers by performing numerical optimization. The measured phase shifts generated by the fabricated ML using interferometry correspond to the design values. The beam profiles in the focal plane are also consistent with theoretical results. Although the fabricated ML consists of only two optical layers, the ML can provide a suitable phase modulation function for the TPP in a practical super-resolution microscope.

  3. Fabrication of optical multilayer for two-color phase plate in super-resolution microscope

    SciTech Connect

    Iketaki, Yoshinori; Kitagawa, Katsuichi; Hidaka, Kohjiro; Kato, Naoki; Hirabayashi, Akira; Bokor, Nandor

    2014-07-15

    In super-resolution microscopy based on fluorescence depletion, the two-color phase plate (TPP) is an indispensable optical element, which can independently control the phase shifts for two beams of different color, i.e., the pump and erase beams. By controlling a phase shift of the erase beam through the TPP, the erase beam can be modulated into a doughnut shape, while the pump beam maintains the initial Gaussian shape. To obtain a reliable optical multiplayer (ML) for the TPP, we designed a ML with only two optical layers by performing numerical optimization. The measured phase shifts generated by the fabricated ML using interferometry correspond to the design values. The beam profiles in the focal plane are also consistent with theoretical results. Although the fabricated ML consists of only two optical layers, the ML can provide a suitable phase modulation function for the TPP in a practical super-resolution microscope.

  4. Design of an electron microscope phase plate using a focused continuous-wave laser

    SciTech Connect

    Spence, J.; Muller, H; Jin, Jian; Danev, R; Padmore, H; Glaeser, R.M

    2010-07-01

    We propose a Zernike phase contrast electron microscope that uses an intense laser focus to convert a phase image into a visible image. We present the relativistic quantum theory of the phase shift caused by the laser–electron interaction, study resonant cavities for enhancing the laser intensity and discuss applications in biology, soft-materials science and atomic and molecular physics.

  5. Design of an electron microscope phase plate using a focused continuous-wave laser

    PubMed Central

    Müller, H; Jin, Jian; Danev, R; Spence, J; Padmore, H; Glaeser, R M

    2010-01-01

    We propose a Zernike phase contrast electron microscope that uses an intense laser focus to convert a phase image into a visible image. We present the relativistic quantum theory of the phase shift caused by the laser–electron interaction, study resonant cavities for enhancing the laser intensity and discuss applications in biology, soft-materials science and atomic and molecular physics. PMID:20808709

  6. Electron microscope phase enhancement

    DOEpatents

    Jin, Jian; Glaeser, Robert M.

    2010-06-15

    A microfabricated electron phase shift element is used for modifying the phase characteristics of an electron beam passing though its center aperture, while not affecting the more divergent portion of an incident beam to selectively provide a ninety-degree phase shift to the unscattered beam in the back focal plan of the objective lens, in order to realize Zernike-type, in-focus phase contrast in an electron microscope. One application of the element is to increase the contrast of an electron microscope for viewing weakly scattering samples while in focus. Typical weakly scattering samples include biological samples such as macromolecules, or perhaps cells. Preliminary experimental images demonstrate that these devices do apply a ninety degree phase shift as expected. Electrostatic calculations have been used to determine that fringing fields in the region of the scattered electron beams will cause a negligible phase shift as long as the ratio of electrode length to the transverse feature-size aperture is about 5:1. Calculations are underway to determine the feasibility of aspect smaller aspect ratios of about 3:1 and about 2:1.

  7. Phase microscope imaging in phase space

    NASA Astrophysics Data System (ADS)

    Sheppard, Colin J. R.; Mehta, Shalin B.

    2016-03-01

    Imaging in a bright field or phase contrast microscope is partially coherent. We have found that the image can be conveniently considered and modeled in terms of the Wigner distribution function (WDF) of the object transmission. The WDF of the object has a simple physical interpretation for the case of a slowly varying object. Basically, the image intensity is the spatial marginal of the spatial convolution of the object WDF with the phase space imager kernel (PSIkernel), a rotated version of the transmission cross-coefficient. The PSI-kernel can be regarded as a partially-coherent generalization of the point spread function. This approach can be extended to consider the partial coherence of the image itself. In particular, we can consider the mutual intensity, WDF or ambiguity function of the image. It is important to note that the spatial convolution of the object WDF with the PSI-kernel is not a WDF, and not the WDF of the image. The phase space representations of the image have relevance to phase reconstruction methods such as phase space tomography, or the transport of intensity equation approach, and to the three-dimensional image properties.

  8. Soft x-ray microscope with zone plates at UVSOR

    NASA Astrophysics Data System (ADS)

    Watanabe, Norio; Shimanuki, Yoshio; Taniguchi, Mieko; Kihara, Hiroshi

    1993-01-01

    A soft x-ray microscope with zone plates was set up at UVSOR (Okazaki, Japan). A 0.41 micrometers line and space pattern was clearly distinguished using an objective zone plate with the outermost zone width of 0.41 micrometers . Modulation transfer functions were measured at wavelengths of 3.1 nm and 5.4 nm, and compared with theoretical calculations. Considering the resolution of a microchannel plate used as a detector, the agreement is fairly good. With this microscope, some biological specimens such as diatoms, spicule of trepang, crab and rabbit muscles, human blood cells, human chromosomes, and magnetotactic bacterium were observed at 3.1 nm and 5.4 nm. With an environmental chamber (wet cell) using polypropylene foils as windows, wet specimens were observed at a wavelength of 4.6 nm. Images of spicule of trepang, human blood cell, and cultured protoplast of plant cell stained by methyl mercury were observed with good contrast.

  9. Microscopic Description of Nuclear Quantum Phase Transitions

    SciTech Connect

    Niksic, T.; Vretenar, D.; Lalazissis, G. A.; Ring, P.

    2007-08-31

    The relativistic mean-field framework, extended to include correlations related to restoration of broken symmetries and to fluctuations of the quadrupole deformation, is applied to a study of shape transitions in Nd isotopes. It is demonstrated that the microscopic self-consistent approach, based on global effective interactions, can describe not only general features of transitions between spherical and deformed nuclei, but also the singular properties of excitation spectra and transition rates at the critical point of quantum shape phase transition.

  10. Quantitative phase-contrast confocal microscope

    PubMed Central

    Liu, Changgeng; Marchesini, Stefano; Kim, Myung K.

    2014-01-01

    We present a quantitative phase-contrast confocal microscope (QPCCM) by combining a line-scanning confocal system with digital holography (DH). This combination can merge the merits of these two different imaging modalities. High-contrast intensity images with low coherent noise, and the optical sectioning capability are made available due to the confocality. Phase profiles of the samples become accessible thanks to DH. QPCCM is able to quantitatively measure the phase variations of optical sections of the opaque samples and has the potential to take high-quality intensity and phase images of non-opaque samples such as many biological samples. Because each line scan is recorded by a hologram that may contain the optical aberrations of the system, it opens avenues for a variety of numerical aberration compensation methods and development of full digital adaptive optics confocal system to emulate current hardware-based adaptive optics system for biomedical imaging, especially ophthalmic imaging. Preliminary experiments with a microscope objective of NA 0.65 and 40 × on opaque samples are presented to demonstrate this idea. The measured lateral and axial resolutions of the intensity images from the current system are ~0.64μm and ~2.70μm respectively. The noise level of the phase profile by QPCCM is ~2.4nm which is better than the result by DH. PMID:25089404

  11. White Light Photorefractive Phase Zone Plates

    NASA Astrophysics Data System (ADS)

    Gao, Yuan-Mei; Liu, Si-Min

    2008-02-01

    Incoherent white light from an incandescent source is employed to fabricate volume phase zone plates in LiNbO3: Fe, for the first time to our knowledge, which can guide and modulate the input white light or laser light. The diffractive efficiency of the white light volume phase zone plates fabricated can reach as high as 12%. In addition, we test the volume phase zone plates by a probe beam and find that the volume phase zone plate is present in the direction perpendicular to the c-axis and absent in the direction parallel to the c-axis. This directly proves the existence of photovoltaic photorefractive anisotropy of white light.

  12. Observation of a Soft Tissue by a Zernike Phase Contrast Hard X-ray Microscope

    SciTech Connect

    Aoki, Sadao; Namikawa, Tadahiro; Hoshino, Masato; Watanabe, Norio

    2007-01-19

    A Zernike-type phase contrast hard X-ray microscope was constructed at the Photon Factory BL3C2 (KEK). A white beam from a bending magnet was monochromatized by a silicon double crystal monochromator. Monochromatic parallel X-ray beam illuminated a sample, and transmitted and diffracted X-ray beams were imaged by a Fresnel zone plate (FZP) which had the outer zone width of 100 nm. A phase plate made of a thin aluminum foil with a pinhole was set at the back focal plane of the FZP. The phase plate modulated the diffraction beam from the FZP, whereas a direct beam passed through the pinhole. The resolution of the microscope was measured by observing a tantalum test pattern at an X-ray energy of 9 keV. A 100nm line-and-space pattern could be resolved. X-ray montage pictures of growing eggs of artemia (plankton) were obtained.

  13. Observation of a Soft Tissue by a Zernike Phase Contrast Hard X-ray Microscope

    NASA Astrophysics Data System (ADS)

    Aoki, Sadao; Namikawa, Tadahiro; Hoshino, Masato; Watanabe, Norio

    2007-01-01

    A Zernike-type phase contrast hard X-ray microscope was constructed at the Photon Factory BL3C2 (KEK). A white beam from a bending magnet was monochromatized by a silicon double crystal monochromator. Monochromatic parallel X-ray beam illuminated a sample, and transmitted and diffracted X-ray beams were imaged by a Fresnel zone plate (FZP) which had the outer zone width of 100 nm. A phase plate made of a thin aluminum foil with a pinhole was set at the back focal plane of the FZP. The phase plate modulated the diffraction beam from the FZP, whereas a direct beam passed through the pinhole. The resolution of the microscope was measured by observing a tantalum test pattern at an X-ray energy of 9 keV. A 100nm line-and-space pattern could be resolved. X-ray montage pictures of growing eggs of artemia (plankton) were obtained.

  14. Volta potential phase plate for in-focus phase contrast transmission electron microscopy

    PubMed Central

    Danev, Radostin; Buijsse, Bart; Khoshouei, Maryam; Plitzko, Jürgen M.; Baumeister, Wolfgang

    2014-01-01

    We describe a phase plate for transmission electron microscopy taking advantage of a hitherto-unknown phenomenon, namely a beam-induced Volta potential on the surface of a continuous thin film. The Volta potential is negative, indicating that it is not caused by beam-induced electrostatic charging. The film must be heated to ∼200 °C to prevent contamination and enable the Volta potential effect. The phase shift is created “on the fly” by the central diffraction beam eliminating the need for precise phase plate alignment. Images acquired with the Volta phase plate (VPP) show higher contrast and unlike Zernike phase plate images no fringing artifacts. Following installation into the microscope, the VPP has an initial settling time of about a week after which the phase shift behavior becomes stable. The VPP has a long service life and has been used for more than 6 mo without noticeable degradation in performance. The mechanism underlying the VPP is the same as the one responsible for the degradation over time of the performance of thin-film Zernike phase plates, but in the VPP it is used in a constructive way. The exact physics and/or chemistry behind the process causing the Volta potential are not fully understood, but experimental evidence suggests that radiation-induced surface modification combined with a chemical equilibrium between the surface and residual gases in the vacuum play an important role. PMID:25331897

  15. Phase-Scrambler Plate Spreads Point Image

    NASA Technical Reports Server (NTRS)

    Edwards, Oliver J.; Arild, Tor

    1992-01-01

    Array of small prisms retrofit to imaging lens. Phase-scrambler plate essentially planar array of small prisms partitioning aperture of lens into many subapertures, and prism at each subaperture designed to divert relatively large diffraction spot formed by that subaperture to different, specific point on focal plane.

  16. Method of forming aperture plate for electron microscope

    NASA Technical Reports Server (NTRS)

    Heinemann, K. (Inventor)

    1974-01-01

    An electron microscope is described with an electron source a condenser lens having either a circular aperture for focusing a solid cone of electrons onto a specimen or an annular aperture for focusing a hollow cone of electrons onto the specimen. It also has objective lens with an annular objective aperture, for focusing electrons passing through the specimen onto an image plane. A method of making the annular objective aperture using electron imaging, electrolytic deposition and ion etching techniques is included.

  17. Phase contrast without phase plates and phase rings--optical solutions for improved imaging of phase structures.

    PubMed

    Piper, Timm; Piper, Jörg

    2013-10-01

    Using the optical methods described, phase specimens can be observed with a modified light microscope in enhanced clarity, purified from typical artifacts which are apparent in standard phase contrast illumination. In particular, haloing and shade-off are absent, lateral and vertical resolution are maximized and the image quality remains constant even in problematic preparations which cannot be well examined in normal phase contrast, such as specimens beyond a critical thickness or covered by obliquely situated cover slips. The background brightness and thus the range of contrast can be continuously modulated and specimens can be illuminated in concentric-peripheral, axial or paraxial light. Additional contrast effects can be achieved by spectral color separation. Normal glass or mirror lenses can be used; they do not need to be fitted with a phase plate or a phase ring. The methods described should be of general interest for all disciplines using phase microscopy. PMID:23913620

  18. Interference Confocal Microscope Integrated with Spatial Phase Shifter.

    PubMed

    Wang, Weibo; Gu, Kang; You, Xiaoyu; Tan, Jiubin; Liu, Jian

    2016-01-01

    We present an interference confocal microscope (ICM) with a new single-body four-step simultaneous phase-shifter device designed to obtain high immunity to vibration. The proposed ICM combines the respective advantages of simultaneous phase shifting interferometry and bipolar differential confocal microscopy to obtain high axis resolution, large dynamic range, and reduce the sensitivity to vibration and reflectance disturbance seamlessly. A compact single body spatial phase shifter is added to capture four phase-shifted interference signals simultaneously without time delay and construct a stable and space-saving simplified interference confocal microscope system. The test result can be obtained by combining the interference phase response and the bipolar property of differential confocal microscopy without phase unwrapping. Experiments prove that the proposed microscope is capable of providing stable measurements with 1 nm of axial depth resolution for either low- or high-numerical aperture objective lenses. PMID:27563909

  19. Observation of Phase Objects by Using an X-ray Microscope with a Foucault Knife-Edge

    SciTech Connect

    Watanabe, N.; Sasaya, T.; Imai, Y.; Iwata, S.; Zama, K.; Aoki, S.

    2011-09-09

    An x-ray microscope with a zone plate was assembled at the synchrotron radiation source of BL3C, Photon Factory. A Foucault knife-edge was set at the back focal plate of the objective zone plate and phase retrieval was tested by scanning the knife-edge. A preliminary result shows that scanning the knife-edge during exposure was effective for phase retrieval. Phase-contrast tomography was investigated using differential projection images calculated from two Schlieren images with the oppositely oriented knife-edges. Fairly good reconstruction images of polystyrene beads and spores could be obtained.

  20. Observation of Phase Objects by Using an X-ray Microscope with a Foucault Knife-Edge

    NASA Astrophysics Data System (ADS)

    Watanabe, N.; Sasaya, T.; Imai, Y.; Iwata, S.; Zama, K.; Aoki, S.

    2011-09-01

    An x-ray microscope with a zone plate was assembled at the synchrotron radiation source of BL3C, Photon Factory. A Foucault knife-edge was set at the back focal plate of the objective zone plate and phase retrieval was tested by scanning the knife-edge. A preliminary result shows that scanning the knife-edge during exposure was effective for phase retrieval. Phase-contrast tomography was investigated using differential projection images calculated from two Schlieren images with the oppositely oriented knife-edges. Fairly good reconstruction images of polystyrene beads and spores could be obtained.

  1. Intracellular dynamics with the phase microscope Airyscan

    NASA Astrophysics Data System (ADS)

    Tychinsky, Vladimir P.; Perevedentseva, Elena V.; Vyshenskaia, Tatiana V.; Kufal, Georgy E.

    1997-12-01

    Investigation of intracellular dynamics of Allium cepa inner epidermal cells are described. The applicability of the method for quantitative estimation of spatio-temporal phase fluctuations and the effect due to external factors is discussed. The analysis of time-sampled series allows one to detect the regions of various motility in cytoplasm. The intense Fourier-spectra harmonics in 0.2 - 8 Hz interval were observed inside a cell wall and cytoplasm. Regularly spaced 2- to 4-s long batches of 100-ms pulses at cell-wall sites are recorded. The phase-fluctuation intensity decreased and the frequencies of certain harmonics were shifted with lowering temperature. The advantages and specific features of the method are discussed.

  2. Imaging by Zernike phase plates in the TEM.

    PubMed

    Edgcombe, C J

    2016-08-01

    The images produced from simple phase objects, lenses and Zernike phase plates when all have rotational symmetry can be calculated by 1D Fourier-Bessel transforms. For a simple disc object producing a uniform phase shift over its diameter, the resulting image can be defined for any size of object phase change. The monotonic range of intensity variation with object phase is found to depend strongly on the phase change introduced by the phase plate; this property of the system is not well predicted by the weak phase approximation. The effect of spreading the phase transition at the plate over a range of radius is beneficial if the plate phase change is sufficiently small. Weak-phase calculations for a phase distribution more typical of a spherical object are also shown. PMID:27183505

  3. Observation of Wet Biological Specimen by Soft X-Ray Microscope with Zone Plates at UVSOR

    NASA Astrophysics Data System (ADS)

    Watanabe, Norio; Taniguchi, Mieko; Shimanuki, Yoshio; Sugiyama, Masaru; Ohba, Akira; Kihara, Hiroshi

    1992-11-01

    With an environmental chamber (wet cell) using polypropylene foils as windows, wet specimens were observed at a wavelength of 4.6 nm with a zone plate imaging X-ray microscope installed at the beamline 8 A of UVSOR (synchrotron radiation facility at Institute for Molecular Science, Okazaki, Japan). Images of spicule of trepang, human blood cells and cultured protoplast of plant cell stained by methyl mercury were observed with good contrast.

  4. Diffractive efficiency of terahertz zone plates with continuous phase

    NASA Astrophysics Data System (ADS)

    Li, Dehua; Zhao, Yang; Sun, Qingzhen; Zhao, Xiangdong; Zhou, Wei; Liu, Liqiang; Jin, Tao

    2010-10-01

    We presented a design of the zone plate with continuous phase with Polytetrafluoroethylene (PTFE) based on scalar diffraction theory. Diffraction fields of the zone plate with continuous phase and the phase-correcting Fresnel zone plate with incidence of uniform plane wave were analyzed and compared. The effects of the focal length and diameter of the zone plate with continuous phase on the diffraction field were discussed. The simulations of intensity distribution on the focal plane and the optic axis based on Rayleigh-Sommerfeld diffraction formula were completed using Matlab. The results indicate that the zone plate with continuous phase performs better than the phase-correcting Fresnel zone plate. The intensity on the focus of the zone plate with continuous phase is 1.17, 1.35, 2.62 times stronger than that on 8-level, 4-level, 2-level phase-correcting Fresnel zone plate's respectively. The fabrication process might give rise to a phase error, such as groove depth error, surface roughness. The effects of the phase errors on the performance of the zone plate were discussed.

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

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

  6. Differential phase acoustic microscope for micro-NDE

    NASA Technical Reports Server (NTRS)

    Waters, David D.; Pusateri, T. L.; Huang, S. R.

    1992-01-01

    A differential phase scanning acoustic microscope (DP-SAM) was developed, fabricated, and tested in this project. This includes the acoustic lens and transducers, driving and receiving electronics, scanning stage, scanning software, and display software. This DP-SAM can produce mechanically raster-scanned acoustic microscopic images of differential phase, differential amplitude, or amplitude of the time gated returned echoes of the samples. The differential phase and differential amplitude images provide better image contrast over the conventional amplitude images. A specially designed miniature dual beam lens was used to form two foci to obtain the differential phase and amplitude information of the echoes. High image resolution (1 micron) was achieved by applying high frequency (around 1 GHz) acoustic signals to the samples and placing two foci close to each other (1 micron). Tone burst was used in this system to obtain a good estimation of the phase differences between echoes from the two adjacent foci. The system can also be used to extract the V(z) acoustic signature. Since two acoustic beams and four receiving modes are available, there are 12 possible combinations to produce an image or a V(z) scan. This provides a unique feature of this system that none of the existing acoustic microscopic systems can provide for the micro-nondestructive evaluation applications. The entire system, including the lens, electronics, and scanning control software, has made a competitive industrial product for nondestructive material inspection and evaluation and has attracted interest from existing acoustic microscope manufacturers.

  7. Comparative study viruses with computer-aided phase microscope AIRYSCAN

    NASA Astrophysics Data System (ADS)

    Tychinsky, Vladimir P.; Koufal, Georgy E.; Perevedentseva, Elena V.; Vyshenskaia, Tatiana V.

    1996-12-01

    Traditionally viruses are studied with scanning electron microscopy (SEM) after complicated procedure of sample preparation without the possibility to study it under natural conditions. We obtained images of viruses (Vaccinia virus, Rotavirus) and rickettsias (Rickettsia provazekii, Coxiella burnetti) in native state with computer-aided phase microscope airyscan -- the interference microscope of Linnik layout with phase modulation of the reference wave with dissector image tube as coordinate-sensitive photodetector and computer processing of phase image. A light source was the He-Ne laser. The main result is coincidence of dimensions and shape of phase images with available information concerning their morphology obtained with SEM and other methods. The fine structure of surface and nuclei is observed. This method may be applied for virus recognition and express identification, investigation of virus structure and the analysis of cell-virus interaction.

  8. Ray transfer matrix for a spiral phase plate.

    PubMed

    Eggleston, M; Godat, T; Munro, E; Alonso, M A; Shi, H; Bhattacharya, M

    2013-12-01

    We present a ray transfer matrix for a spiral phase plate. Using this matrix we determine the stability of an optical resonator made of two spiral phase plates and trace stable ray orbits in the resonator. Our results should be relevant to laser physics, optical micromanipulation, quantum information, and optomechanics. PMID:24323013

  9. Quantitative phase imaging by wide field lensless digital holographic microscope

    NASA Astrophysics Data System (ADS)

    Adinda-Ougba, A.; Koukourakis, N.; Essaidi, A.; Ger­hardt, N. C.; Hofmann, M. R.

    2015-05-01

    Wide field, lensless microscopes have been developed for telemedicine and for resource limited setting [1]. They are based on in-line digital holography which is capable to provide amplitude and phase information resulting from numerical reconstruction. The phase information enables achieving axial resolution in the nanometer range. Hence, such microscopes provide a powerful tool to determine three-dimensional topologies of microstructures. In this contribution, a compact, low-cost, wide field, lensless microscope is presented, which is capable of providing topological profiles of microstructures in transparent material. Our setup consist only of two main components: a CMOSsensor chip and a laser diode without any need of a pinhole. We use this very simple setup to record holograms of microobjects. A wide field of view of ~24 mm², and a lateral resolution of ~2 μm are achieved. Moreover, amplitude and phase information are obtained from the numerical reconstruction of the holograms using a phase retrieval algorithm together with the angular spectrum propagation method. Topographic information of highly transparent micro-objects is obtained from the phase data. We evaluate our system by recording holograms of lines with different depths written by a focused laser beam. A reliable characterization of laser written microstructures is crucial for their functionality. Our results show that this system is valuable for determination of topological profiles of microstructures in transparent material.

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

    PubMed Central

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

    2013-01-01

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

  11. Real-time microscopic phase-shifting profilometry.

    PubMed

    Van der Jeught, Sam; Soons, Joris A M; Dirckx, Joris J J

    2015-05-20

    A real-time microscopic profilometry system based on digital fringe projection and parallel programming has been developed and experimentally tested. Structured light patterns are projected onto an object through one pathway of a stereoscopic operation microscope. The patterns are deformed by the shape of the object and are then recorded with a high-speed CCD camera placed in the other pathway of the microscope. As the optical pathways of both arms are separated and reach the same object point at a relative angle, the recorded patterns allow the full-field object height variations to be calculated and the three-dimensional shape to be reconstructed by employing standard triangulation techniques. Applying proper hardware triggering, the projector-camera system is synchronized to capture up to 120 unique deformed line patterns per second. Using standard four-step phase-shifting profilometry techniques and applying graphics processing unit programming for fast phase wrapping, scaling, and visualization, we demonstrate the capability of the proposed system to generate 30 microscopic height maps per second. This allows the qualitative depth perception of the stereomicroscope operator to be enhanced by live quantitative height measurements with depth resolutions in the micrometer range. PMID:26192534

  12. The North American Astronomical Photographic Plate Center: Phase I.

    NASA Astrophysics Data System (ADS)

    Cline, J. D.; Castelaz, M. W.; Crowley, T.; Griffin, E.; Osborn, W.

    2004-05-01

    Astronomical photographic plates constitute an important and, for the large part, unrepeatable resource for research. International pressure is mounting to preserve and catalog scientifically valuable plate collections and capture their information through digitization. At the same time, many institutions holding plates now lack the space, funds and expertise to adequately preserve this important material. In response, the Pisgah Astronomical Research Institute has established the North American Photographic Plate Center (NAPPC). NAPPC is intended as a long-term repository for direct and objective prism plate collections currently stored in North America. PARI is a natural location for such a center. It offers physically secure and abundant environmentally controlled space for plate storage as well as Internet 2 infrastructure and instrument space necessary for the eventual digitization and Internet distribution of images. Phase I of this initiative is to collect unwanted plate collections, store them in an appropriate manner, prepare catalogues of their relevant information and establish a laboratory for on-site examination or measurement of the plates. This is currently underway. Phase II will be the eventual digitization and development of a public web accessible database of images. We will describe the procedures for placing plate collections in NAPPC, the infrastructure in place for plate storage and measurement, and our preliminary plans for making the plate archive a public image library with Internet access.

  13. Resolution enhancement in a double-helix phase engineered scanning microscope (RESCH microscope) (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Jesacher, Alexander; Ritsch-Marte, Monika; Piestun, Rafael

    2015-08-01

    Recently we introduced RESCH microscopy [1] - a scanning microscope that allows slightly refocusing the sample after the acquisition has been performed, solely by performing appropriate data post-processing. The microscope features a double-helix phase-engineered emission point spread function in combination with camera-based detection. Based on the principle of transverse resolution enhancement in Image Scanning Microscopy [2,3], we demonstrate similar resolution improvement in RESCH. Furthermore, we outline a pathway for how the collected 3D sample information can be used to construct sharper optical sections. [1] A. Jesacher, M. Ritsch-Marte and R. Piestun, accepted for Optica. [2] C.J.R. Sheppard, "Super-resolution in Confocal imaging," Optik, 80, 53-54 (1988). [3] C.B. Müller and J. Enderlein "Image Scanning Microscopy," Phys. Rev. Lett. 104, 198101 (2010).

  14. Phases and phase transitions in the algebraic microscopic shell model

    NASA Astrophysics Data System (ADS)

    Georgieva, A. I.; Drumev, K. P.

    2016-01-01

    We explore the dynamical symmetries of the shell model number conserving algebra, which define three types of pairing and quadrupole phases, with the aim to obtain the prevailing phase or phase transition for the real nuclear systems in a single shell. This is achieved by establishing a correspondence between each of the pairing bases with the Elliott's SU(3) basis that describes collective rotation of nuclear systems. This allows for a complete classification of the basis states of different number of particles in all the limiting cases. The probability distribution of the SU(3) basis states within theirs corresponding pairing states is also obtained. The relative strengths of dynamically symmetric quadrupole-quadrupole interaction in respect to the isoscalar, isovector and total pairing interactions define a control parameter, which estimates the importance of each term of the Hamiltonian in the correct reproduction of the experimental data for the considered nuclei.

  15. Evidence of Microscopic Phase Segregation in CMR thin films

    NASA Astrophysics Data System (ADS)

    Imtiaz, Atif; Anlage, Steven

    2003-03-01

    We have used a Near Field Scanning Microwave Microscope (NFMM) to study local sheet resistance (Rx) contrast in 100nm thick La_0.67Ca_0.33MnO3 thin films. These films show a transition from charge-ordered insulating or paramagnetic insulating to a ferro-magnetic metallic state at a transition temperature Tc ( 250K for the film we studied). No Magnetic Field is applied when performing the experiment. We used our NFMM to study this sample above and below the Tc. Probe/sample distance control is achieved by employing a Scanning Tunneling Microscope feedback. Scanning is done in constant tunnel current mode, and microwave data is collected simultaneously. Several models (transmission line model and lumped element model) of microwave microscope are used to extract the Rx from the data of frequency shift and Quality factor versus position. The Rx images show evidence of the phase transition: we find that the sheet resistance distribution is broader for the data below Tc. Upon closer examination, we see evidence of inhomogeneous conductivity on the scale of 2.5nm below Tc. Discussion of these results and their modeling will be presented. [1] Atif Imtiaz and Steven M. Anlage, "A novel STM-assisted microwave microscope with capacitance and loss imaging capability", Ultramicroscopy (in press); cond-mat/0203540.

  16. Using the gradient histogram to analyze the continuous phase plate

    NASA Astrophysics Data System (ADS)

    Yang, Chunlin

    2015-01-01

    The geometrical optical method has been used to discuss the far-field distribution characteristics of a continuous phase plate. The gradient histogram of the plate’s surface has been calculated. It has been proved that the gradient histogram can be used to show the angular spectrum of a phase plate. The gradient histogram can simplify the analysis process of the angular spectrum and describe the focal spot morphology more intuitively.

  17. On the role of inelastic scattering in phase-plate transmission electron microscopy.

    PubMed

    Hettler, Simon; Wagner, Jochen; Dries, Manuel; Oster, Marco; Wacker, Christian; Schröder, Rasmus R; Gerthsen, Dagmar

    2015-08-01

    The phase contrast of Au nanoparticles on amorphous-carbon films with different thicknesses is analyzed using an electrostatic Zach phase plate in a Zeiss 912 Ω transmission electron microscope with in-column energy filter. Specifically, unfiltered and plasmon-filtered phase-plate transmission electron microscopy (PP TEM) images are compared to gain insight in the role of coherence after inelastic scattering processes. A considerable phase-contrast contribution resulting from a combined elastic-inelastic scattering process is found in plasmon-filtered PP TEM images. The contrast reduction compared to unfiltered images mainly originates from zero-order beam broadening caused by the inelastic scattering process. The effect of the sequence of the elastic and inelastic scattering processes is studied by varying the position of the nanoparticles, which can be either located on top or at the bottom of the amorphous-carbon film with respect to the incident electron beam direction. PMID:25879156

  18. Testing and Calibration of Phase Plates for JWST Optical Simulator

    NASA Technical Reports Server (NTRS)

    Gong, Qian; Chu, Jenny; Tournois, Severine; Eichhorn, William; Kubalak, David

    2011-01-01

    Three phase plates were designed to simulate the JWST segmented primary mirror wavefront at three on-orbit alignment stages: coarse phasing, intermediate phasing, and fine phasing. The purpose is to verify JWST's on-orbit wavefront sensing capability. Amongst the three stages, coarse alignment is defined to have piston error between adjacent segments being 30 m to 300 m, intermediate being 0.4 m to 10 m, and fine is below 0.4 m. The phase plates were made of fused silica, and were assembled in JWST Optical Simulator (OSIM). The piston difference was realized by the thickness difference of two adjacent segments. The two important parameters to phase plates are piston and wavefront errors. Dispersed Fringe Sensor (DFS) method was used for initial coarse piston evaluation, which is the emphasis of this paper. Point Diffraction Interferometer (PDI) is used for fine piston and wavefront error. In order to remove piston's 2 pi uncertainty with PDI, three laser wavelengths, 640nm, 660nm, and 780nm, are used for the measurement. The DHS test setup, analysis algorithm and results are presented. The phase plate design concept and its application (i.e. verifying the JWST on-orbit alignment algorithm) are described. The layout of JWST OSIM and the function of phase plates in OSIM are also addressed briefly.

  19. Testing and calibration of phase plates for JWST optical simulator

    NASA Astrophysics Data System (ADS)

    Gong, Qian; Chu, Jenny; Tournois, Severine; Eichhorn, William; Kubalak, David

    2011-10-01

    Three phase plates were designed to simulate the JWST segmented primary mirror wavefront at three on-orbit alignment stages: coarse phasing, intermediate phasing, and fine phasing. The purpose is to verify JWST's on-orbit wavefront sensing capability. Amongst the three stages, coarse alignment is defined to have piston error between adjacent segments being 30 μm to 300 μm, intermediate being 0.4 μm to 10 μm, and fine being below 0.4 μm. The phase plates were made of fused silica, and were assembled in JWST Optical Simulator (OSIM). The piston difference was realized by the thickness difference of two adjacent segments. The two important parameters to phase plates are piston and wavefront errors. Dispersed Fringe Sensor (DFS) method was used for initial coarse piston evaluation, which is the emphasis of this paper. Point Diffraction Interferometer (PDI) is used for fine piston and wavefront error. In order to remove piston's 2π uncertainty with PDI, three laser wavelengths, 640nm, 660nm, and 780nm, are used for the measurement. The DHS test setup, analysis algorithm and results are presented. The phase plate design concept and its application (i.e. verifying the JWST on-orbit alignment algorithm) are described. The layout of JWST OSIM and the function of phase plates in OSIM are also addressed briefly.

  20. Multi-pore carbon phase plate for phase-contrast transmission electron microscopy.

    PubMed

    Sannomiya, Takumi; Junesch, Juliane; Hosokawa, Fumio; Nagayama, Kuniaki; Arai, Yoshihiro; Kayama, Yoko

    2014-11-01

    A new fabrication method of carbon based phase plates for phase-contrast transmission electron microscopy is presented. This method utilizes colloidal masks to produce pores as well as disks on thin carbon membranes for phase modulation. Since no serial process is involved, carbon phase plate membranes containing hundreds of pores can be mass-produced on a large scale, which allows "disposal" of contaminated or degraded phase modulating objects after use. Due to the spherical shape of the mask colloid particles, the produced pores are perfectly circular. The pore size and distribution can be easily tuned by the mask colloid size and deposition condition. By using the stencil method, disk type phase plates can also be fabricated on a pore type phase plate. Both pore and disk type phase plates were tested by measuring amorphous samples and confirmed to convert the sinus phase contrast transfer function to the cosine shape. PMID:25129640

  1. Microscopic study of a ligand induced electroless plating process onto polymers.

    PubMed

    Garcia, Alexandre; Berthelot, Thomas; Viel, Pascal; Polesel-Maris, Jérôme; Palacin, Serge

    2010-11-01

    The ligand induced electroless plating (LIEP) process was recently developed and thoroughly demonstrated with one of the most used polymers for plating processes: acrylonitrile-butadiene-styrene (ABS). This generic process is based, thanks to the use of diazonium salts as precursors, on the covalent grafting of a thin layer of poly(acrylic acid) (PAA) acting as ligand for metallic salts onto pristine polymer surfaces. This strategy takes advantage of the PAA ion exchange properties. Indeed, carboxylate groups contained in PAA allow one to complex copper ions which are eventually reduced and used as catalysts of the metallic deposition. Essentially based on ABS, ABS-PC (ABS-polycarbonate) and PA (polyamide) substrates, the present paper focuses on the role of the polymer substrate and the relationships between the macroscopic properties and microscopic characterizations such as infrared (IR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The adhesion strength of the metallic layer deposited via that LIEP process with the bulk polymer substrates was successfully compared with the adhesion of similar copper films deposited by the usual process based on chromic acid etching and palladium-based seed layer, by measuring the T-peel adhesion strength, and by carrying out the common industrial scotch tape test. Lastly, the electrical properties of the deposited layer were studied thanks to a four-point probe and scanning tunneling microscopy (STM) measurements. PMID:21053943

  2. Guided wave phased array beamforming and imaging in composite plates.

    PubMed

    Yu, Lingyu; Tian, Zhenhua

    2016-05-01

    This paper describes phased array beamforming using guided waves in anisotropic composite plates. A generic phased array algorithm is presented, in which direction dependent guided wave parameters and the energy skew effect are considered. This beamforming at an angular direction is achieved based on the classic delay-and-sum principle by applying phase delays to signals received at array elements and adding up the delayed signals. The phase delays are determined with the goal to maximize the array output at the desired direction and minimize it otherwise. For array characterization, the beam pattern of rectangular grid arrays in composite plates is derived. In addition to the beam pattern, the beamforming factor in terms of wavenumber distribution is defined to provide intrinsic explanations for phased array beamforming. The beamforming and damage detection in a composite plate are demonstrated using rectangular grid arrays made by a non-contact scanning laser Doppler vibrometer. Detection images of the composite plate with multiple surface defects at various directions are obtained. The results show that the guided wave phased array method is a potential effective method for rapid inspection of large composite structures. PMID:26907891

  3. Conformal dome correction with counterrotating phase plates

    NASA Astrophysics Data System (ADS)

    Sparrold, Scott W.; Mills, James P.; Knapp, David J.; Ellis, Kenneth S.; Mitchell, Thomas A.; Manhart, Paul K.

    2000-07-01

    Windows and domes that are shaped to aerodynamic requirements can increase range and speed for the host platform. This class of optical systems is referred to as conformal optics. The solution discussed here is intended for conformal missile systems having gimbals that point the optical line of sight through different parts of the dome. A conformal dome induces large amounts of varying aberration, tens to hundreds of waves across gimbal angle, and therefore requires dynamic correction. Space is very constricted in missile sensors, and it is therefore highly desirable to limit the number of motors used for aberration correction. This paper describes the performance of a new class of optical systems that employ counterrotating phase prisms to correct conformal dome aberrations while gimbaling the optical system. The phase surfaces on the prisms are described by Zernike circular polynomials. Since the shear across the phase surfaces is rotational, the only aberrations that are generated are those without rotational symmetry, such as tilt, coma, or astigmatism. Using this approach, CODE VTM was used to analyze and design a compact, high-performance conformal optical system.

  4. Methods for testing Zernike phase plates and a report on silicon-based phase plates with reduced charging and improved ageing characteristics

    PubMed Central

    Marko, Michael; Meng, Xing; Hsieh, Chyongere; Roussie, James; Striemer, Christopher

    2013-01-01

    Imaging with Zernike phase plates is increasingly being used in cryo-TEM tomography and cryo-EM single-particle applications. However, rapid ageing of the phase plates, together with the cost and effort in producing them, present serious obstacles to widespread adoption. We are experimenting with phase plates based on silicon chips that have thin windows; such phase plates could be mass-produced and made available at moderate cost. The windows are coated with conductive layers to reduce charging, and this considerably extends the useful life of the phase plates compared to traditional pure-carbon phase plates. However, a compromise must be reached between robustness and transmission through the phase-plate film. Details are given on testing phase-plate performance by means of imaging an amorphous thin film and evaluating the power spectra of the images. PMID:23994351

  5. Zone plate tilt study in transmission x-ray microscope system at 8-11 keV

    NASA Astrophysics Data System (ADS)

    Chao, Fu-Han; Yin, Gung-Chian; Liang, Keng S.; Lai, Yin-Chieh

    2009-08-01

    Zone plate [1] has been used as a focal lens in transmission X-ray microscope (TXM) optical system in recent decades [2, 3]. In TXM of NSRRC[4,5], the thickness of zone plate is about 900nm and the width of its out most zones is 50nm, which has a high aspect ratio 18. When zone plate is tilted, the image quality will be affected by aberration. Since the aspect ratio of zone plate is large, for incident beam, the shape of zone plate's transmission function will look different when zone plate is tilted. The both experimental and simulation result will be shown in this present. A five axes stage is designed and manufactured for the zone plate holder for three dimensional movement, tip and tilt. According to Fourier theory, we can calculate the wave distribution on image plane, if we know the original wave function, the distances between each element, and the transparencies of the sample and zone plate. A parallel simulation process code in MATLAB is developed in workstation cluster with up to 128Gbytes memory. The effects of aberration generated by tilt effect are compared from the experimental data and simulation result. A maximum tilt angle within the acceptable image quality is calculated by simulation and will be verified by experiment.

  6. Brewster Angle Microscope Investigations of Two Dimensional Phase Transitions

    NASA Astrophysics Data System (ADS)

    Schuman, Adam William

    The liquid-liquid interface is investigated by microscopic and thermodynamic means to image and measure interfacial properties when the system undergoes a two-dimensional (2D) phase transition of a Gibbs monolayer by varying the sample temperature. An in-house Brewster angle microscope (BAM) is constructed to visualize the interface during this transition while a quasi-elastic light scattering technique is used to determine the interfacial tension. These results complement x-ray investigations of the same systems. Evidence of interfacial micro-separated structure, microphases, comes from observations across a hexane-water interface with the inclusion of a long-chain fluorinated alcohol surfactant into the bulk hexane. Microphases take the form of spatially modulated structure to the density of the surfactant as it spans laterally across the interface. The surfactant monolayer exhibits microphase morphology over a range of a couple degrees as the temperature of the system is scanned through the 2D gas-solid phase transition. Microphase structure was observed for heating and cooling the hexane-water system and structural comparisons are given when the temperature step and quench depth of the cooling process is varied. A complete sequence of morphological structure was observed from 2D gas to cluster to labyrinthine stripe to a 2D solid mosaic pattern. Two characteristic length scales emerge giving rise to speculation of an elastic contribution to the standard repulsive and attractive competitive forces stabilizing the microphase. The benefit of BAM to laterally image very thin films across the surface of an interface on the micrometer length scale nicely complements x-ray reflectivity methods that average structural data transverse to the liquid interface on a molecular scale. To properly analyze x-ray reflectivity data, the interface is required to be laterally homogeneous. BAM can sufficiently characterize the interface for this purpose as is done for a Langmuir

  7. Phase plate technology for laser marking of magnetic discs

    DOEpatents

    Neuman, B.; Honig, J.; Hackel, L.; Dane, C.B.; Dixit, S.

    1998-10-27

    An advanced design for a phase plate enables the distribution of spots in arbitrarily shaped patterns with very high uniformity and with a continuously or near-continuously varying phase pattern. A continuous phase pattern eliminates large phase jumps typically expected in a grating that provides arbitrary shapes. Large phase jumps increase scattered light outside of the desired pattern, reduce efficiency and can make the grating difficult to manufacture. When manufacturing capabilities preclude producing a fully continuous grating, the present design can be easily adapted to minimize manufacturing errors and maintain high efficiencies. This continuous grating is significantly more efficient than previously described Dammann gratings, offers much more flexibility in generating spot patterns and is easier to manufacture and replicate than a multi-level phase grating. 3 figs.

  8. Phase plate technology for laser marking of magnetic discs

    DOEpatents

    Neuman, Bill; Honig, John; Hackel, Lloyd; Dane, C. Brent; Dixit, Shamasundar

    1998-01-01

    An advanced design for a phase plate enables the distribution of spots in arbitrarily shaped patterns with very high uniformity and with a continuously or near-continuously varying phase pattern. A continuous phase pattern eliminates large phase jumps typically expected in a grating that provides arbitrary shapes. Large phase jumps increase scattered light outside of the desired pattern, reduce efficiency and can make the grating difficult to manufacture. When manufacturing capabilities preclude producing a fully continuous grating, the present design can be easily adapted to minimize manufacturing errors and maintain high efficiencies. This continuous grating is significantly more efficient than previously described Dammann gratings, offers much more flexibility in generating spot patterns and is easier to manufacture and replicate than a multi-level phase grating.

  9. Development of a two-phase cold plate

    NASA Astrophysics Data System (ADS)

    Miyazaki, Y.; Furukawa, M.; Ishii, Y.; Shigehara, M.; Komori, M.; Mimura, K.; Oshima, S.

    1990-03-01

    A two-phase cold plate using evaporators of grooved double-pipe type was tested in order to examine its heat transfer and hydrodynamic characteristics under practical operating conditions. Under a uniform heat load, excellent temperature uniformity of the cold plate was obtained. Under an uneven heat load, however, the temperature distributions were not uniform; they were high in active areas and low in inactive areas. It seems to be due to ineffective liquid flow through inactive pipes, which causes liquid shortage in active tubes and over-cooling by sub-cooled liquid in inactive tubes. Parallel operations with two cold plates were performed successfully, demonstrating that both temperatures were kept at the same level even under different heat loads. In a certain operating condition, the individual flow rate of the two cold plates was observed to oscillate symmetrically to each other, while total flow rate was kept constant and no anomalous behavior on heat transfer was induced. Through the tests, a design approach for the cold plate from the viewpoint of a loop control technology was obtained.

  10. Development of a phase-controlled constant-distance scanning electrochemical microscope.

    PubMed

    Cougnon, Charles; Bauer-Espindola, Klaus; Fabre, Dimitri S; Mauzeroll, Janine

    2009-05-01

    The present shear-force constant-distance scanning electrochemical microscope regulates tip-to-substrate distance using a phase-controlled feedback mechanism that is more sensitive than the amplitude-controlled constant-distance scanning electrochemical microscopes. Phase control responds faster to frequency perturbation and presents enhance sensitivity during distance curves under constant-distance mode. PMID:19326905

  11. Achromatic phase shifts utilizing dielectric plates for nulling interferometery

    NASA Astrophysics Data System (ADS)

    Morgan, R. M.; Burge, J. M.

    1998-12-01

    Schemes for detecting planets around other stars using interferometery have been developed which rely on a half wave phase delay to shift the central constructive fringe of an interferometer to a deep, destructive null fringe. To achieve the sensitivity and spectroscopy desired for exo-planets observations, such a null must be achromatic over a broad spectral region. One method for creating such a half wave phase delay achromatically involves the use of pairs of dielectric, plane parallel plates, analogous to the use of two types of glass in an achromatic lens. An analysis of the technique is presented with solutions using single plates to achieve null fringes to a cancellation of 10 exp -4 in the visible, near infrared, and mid infrared for null. Solutions using two matched materials show that nulls to a depth of 10 exp -6 are achievable in 2 um bands in the 7-17 um regime, or to a depth of 10 exp -5 over the entire 7-17 um band. Experimental results using a single plate of BK7 in the visible spectrum verify the technique.

  12. The electron microscope appearance of the subchondral bone plate in the human femoral head in osteoarthritis and osteoporosis

    PubMed Central

    LI, BAOHUA; MARSHALL, DEBORAH; ROE, MARTIN; ASPDEN, RICHARD M.

    1999-01-01

    The subchondral bone plate supports the articular cartilage in diarthrodial joints. It has a significant mechanical function in transmitting loads from the cartilage into the underlying cancellous bone and has been implicated in the destruction of cartilage in osteoarthritis (OA) and its sparing in osteoporosis (OP), but little is known of its composition, structure or material properties. This study investigated the microscopic appearance and mineral composition of the subchondral bone plate in femoral heads from patients with OA or OP to determine how these correspond to changes in composition and stiffness found in other studies. Freeze-fractured full-depth samples of the subchondral bone plate from the femoral heads of patients with osteoarthritis, osteoporosis or a matched control group were examined using back scattered and secondary emission scanning electron microscopy. Other samples were embedded and polished and examined using back-scattered electron microscopy and electron probe microanalysis. The appearances of the samples from the normal and osteoporotic patients were very similar, with the subchondral bone plate overlayed by a layer of calcified cartilage. Osteoporotic samples presented a more uniform fracture surface and the relative thicknesses of the layers appeared to be different. In contrast, the OA bone plate appeared to be porous and have a much more textured surface. There were occasional sites of microtrabecular bone formation between the trabeculae of the underlying cancellous bone, which were not seen in the other groups, and more numerous osteoclast resorption pits. The calcified cartilage layer was almost absent and the bone plate was apparently thickened. The appearance of the osteoarthritic subchondral bone plate was, therefore, considerably different from both the normal and the osteoporotic, strongly indicative of abnormal cellular activity. PMID:10473297

  13. Coherent x-ray diffraction imaging of paint pigment particles by scanning a phase plate modulator

    NASA Astrophysics Data System (ADS)

    Chen, Bo; Zhang, Fucai; Berenguer, Felisa; Bean, Richard J.; Kewish, Cameron M.; Vila-Comamala, Joan; Chu, Yong S.; Rodenburg, John M.; Robinson, Ian K.

    2011-10-01

    We have implemented a coherent x-ray diffraction imaging technique that scans a phase plate to modulate wave-fronts of the x-ray beam transmitted by samples. The method was applied to measure a decorative alkyd paint containing iron oxide red pigment particles. By employing an iterative algorithm for wave-front modulation phase retrieval, we obtained an image of the paint sample that shows the distribution of the pigment particles and is consistent with the result obtained from a transmission x-ray microscope. The technique has been experimentally proven to be a feasible coherent x-ray imaging method with about 120 nm spatial resolution and was shown to work well with industrially relevant specimens.

  14. Coherent x-ray diffraction imaging of paint pigmentparticles by scanning a phase plate modulator

    SciTech Connect

    Chu Y. S.; Chen B.; Zhang F.; Berenguer F.; Bean R.; Kewish C.; Vila-Comamala J.; Rodenburg J.; Robinson I.

    2011-10-19

    We have implemented a coherent x-ray diffraction imaging technique that scans a phase plate to modulate wave-fronts of the x-ray beam transmitted by samples. The method was applied to measure a decorative alkyd paint containing iron oxide red pigment particles. By employing an iterative algorithm for wave-front modulation phase retrieval, we obtained an image of the paint sample that shows the distribution of the pigment particles and is consistent with the result obtained from a transmission x-ray microscope. The technique has been experimentally proven to be a feasible coherent x-ray imaging method with about 120 nm spatial resolution and was shown to work well with industrially relevant specimens.

  15. Colorful holographic imaging reconstruction based on one thin phase plate

    NASA Astrophysics Data System (ADS)

    Zhu, Jing; Song, Qiang; Wang, Jian; Yue, Weirui; Zhang, Fang; Huang, Huijie

    2014-11-01

    One method of realizing color holographic imaging using one thin diffractive optical element (DOE) is proposed. This method can reconstruct a two-dimensional color image with one phase plate at user defined distance from DOE. For improving the resolution ratio of reproduced color images, the DOE is optimized by combining Gerchberg-Saxton algorithm and compensation algorithm. To accelerate the computational process, the Graphic Processing Unit (GPU) is used. In the end, the simulation result was analyzed to verify the validity of this method.

  16. Antiferromagnetic metal phases in double perovskites having microscopic phase segregation due to strong antisite defect concentration

    NASA Astrophysics Data System (ADS)

    Sanyal, Prabuddha

    2015-11-01

    Recently an antiferromagnetic metal phase has been proposed in double perovskites materials like Sr2FeMoO6 (SFMO), when electron doped. This material has been found to change from half-metallic ferromagnet to a novel antiferromagnetic metal (AFM) upon La-overdoping. The original proposition of such an AFM phase was made for ordered samples, but the experimental realization of La-overdoped SFMO has been found to contain a substantial fraction of antisite defects. A microscopic chemical phase segregation into alternate Fe and Mo rich regions was observed. In this paper we propose a possible scenario in which an antiferromagnetic metal phase can still be stabilized even in presence of such strong antisite defect concentration and phase segregation, by a novel kinetic energy-driven mechanism. Our results thus provide a plausible explanation to the experimental observations in the La-overdoped regime. Antisite regions can thus give rise to antiferromagnetic metallic phases, although the metal is low-dimensional.

  17. Performance characterization of a broadband vector Apodizing Phase Plate coronagraph.

    PubMed

    Otten, Gilles P P L; Snik, Frans; Kenworthy, Matthew A; Miskiewicz, Matthew N; Escuti, Michael J

    2014-12-01

    One of the main challenges for the direct imaging of planets around nearby stars is the suppression of the diffracted halo from the primary star. Coronagraphs are angular filters that suppress this diffracted halo. The Apodizing Phase Plate coronagraph modifies the pupil-plane phase with an anti-symmetric pattern to suppress diffraction over a 180 degree region from 2 to 7 λ/D and achieves a mean raw contrast of 10(-4) in this area, independent of the tip-tilt stability of the system. Current APP coronagraphs implemented using classical phase techniques are limited in bandwidth and suppression region geometry (i.e. only on one side of the star). In this paper, we introduce the vector-APP (vAPP) whose phase pattern is implemented through the vector phase imposed by the orientation of patterned liquid crystals. Beam-splitting according to circular polarization states produces two, complementary PSFs with dark holes on either side. We have developed a prototype vAPP that consists of a stack of three twisting liquid crystal layers to yield a bandwidth of 500 to 900 nm. We characterize the properties of this device using reconstructions of the pupil-plane pattern, and of the ensuing PSF structures. By imaging the pupil between crossed and parallel polarizers we reconstruct the fast axis pattern, transmission, and retardance of the vAPP, and use this as input for a PSF model. This model includes aberrations of the laboratory set-up, and matches the measured PSF, which shows a raw contrast of 10(-3.8) between 2 and 7 λ/D in a 135 degree wedge. The vAPP coronagraph is relatively easy to manufacture and can be implemented together with a broadband quarter-wave plate and Wollaston prism in a pupil wheel in high-contrast imaging instruments. The liquid crystal patterning technique permits the application of extreme phase patterns with deeper contrasts inside the dark holes, and the multilayer liquid crystal achromatization technique enables unprecedented spectral bandwidths

  18. Quantitative phase tomography by using x-ray microscope with Foucault knife-edge scanning filter

    NASA Astrophysics Data System (ADS)

    Watanabe, Norio; Tsuburaya, Yuji; Shimada, Akihiro; Aoki, Sadao

    2016-01-01

    Quantitative phase tomography was evaluated by using a differential phase microscope with a Foucault knife-edge scanning filter. A 3D x-ray phase image of polystyrene beads was obtained at 5.4 keV. The reconstructed refractive index was fairly good agreement with the Henke's tabulated data.

  19. Tomographic imaging of transparent biological samples using the pyramid phase microscope

    PubMed Central

    Iglesias, Ignacio

    2016-01-01

    We show how a pyramid phase microscope can be used to obtain tomographic information of the spatial variation of refractive index in biological samples using the Radon transform. A method that uses the information provided by the phase microscope for axial and lateral repositioning of the sample when it rotates is also described. Its application to the reconstruction of mouse embryos in the blastocyst stage is demonstrated. PMID:27570696

  20. Tomographic imaging of transparent biological samples using the pyramid phase microscope.

    PubMed

    Iglesias, Ignacio

    2016-08-01

    We show how a pyramid phase microscope can be used to obtain tomographic information of the spatial variation of refractive index in biological samples using the Radon transform. A method that uses the information provided by the phase microscope for axial and lateral repositioning of the sample when it rotates is also described. Its application to the reconstruction of mouse embryos in the blastocyst stage is demonstrated. PMID:27570696

  1. Histomorphometric and electron microscopic analyses of tibial epiphyseal plates from Cosmos 1887 rats

    NASA Technical Reports Server (NTRS)

    Duke, P. J.; Durnova, G.; Montufar-Solis, D.

    1990-01-01

    Previous studies have shown that the changes seen in the bones of growing rats exposed to microgravity are due in part to changes that occur in the growth plate during spaceflight. In this study, growth plates of rats flown aboard Cosmos 1887 (12.5-day flight plus 53.5-h recovery at 1 g) were analyzed using light and electron microscopy and computerized planimetry. The proliferative zone of flight animals was found to be significantly (P less than or equal to 0.01) larger than that of controls, while the reserve and hypertrophic/calcification zones were significantly reduced. Flight animals also had more cells per column in the proliferative zone than did controls and less in the hypertrophic/calcification region. The total number of cells, however, was significantly greater in flight animals. No difference was found in perimeter or in shape factor, but area was significantly less in flight animals. Electron microscopy showed that collagen fibrils in flight animals were wider than in controls. Since the time required for a cell to cycle through the growth plate is 2-3 days at 1 g, the results reported here represent both the effects of exposure to microgravity and the initial stages of recovery from that exposure.

  2. Remote laboratory for phase-aided 3D microscopic imaging and metrology

    NASA Astrophysics Data System (ADS)

    Wang, Meng; Yin, Yongkai; Liu, Zeyi; He, Wenqi; Li, Boqun; Peng, Xiang

    2014-05-01

    In this paper, the establishment of a remote laboratory for phase-aided 3D microscopic imaging and metrology is presented. Proposed remote laboratory consists of three major components, including the network-based infrastructure for remote control and data management, the identity verification scheme for user authentication and management, and the local experimental system for phase-aided 3D microscopic imaging and metrology. The virtual network computer (VNC) is introduced to remotely control the 3D microscopic imaging system. Data storage and management are handled through the open source project eSciDoc. Considering the security of remote laboratory, the fingerprint is used for authentication with an optical joint transform correlation (JTC) system. The phase-aided fringe projection 3D microscope (FP-3DM), which can be remotely controlled, is employed to achieve the 3D imaging and metrology of micro objects.

  3. Design of an advanced two-phase capillary cold plate

    NASA Technical Reports Server (NTRS)

    Chalmers, D. R.; Kroliczek, E. J.; Ku, J.

    1986-01-01

    The functional principles and implementation of capillary pumped loop (CPL) two phase heat transport system for various elements of the Space Station program are described. Circulation of the working fluid by the surface-tension forces in a fine-pore capillary wick is the core principle of CPL systems. The liquid, usually NH3 at the moment, is changed into a vapor by heat absorption at one end of the loop, and the vapor is carrried back along the wick by the surface tension within the wick. NASA specifications and the results of mechanical and thermal tests for prototype cold plate and the capillary pump designs are outlined. The CPL is targeted for installation on free-flying platforms, attached payloads, and power subsystem thermal control systems.

  4. Production of distributed phase plates using an energetic ion process

    NASA Astrophysics Data System (ADS)

    Smith, Douglas J.; Warner, Joy A.; LeBarron, Nelson E.; LaDelia, Salvatore

    1999-04-01

    Laser-driven implosion experiments require optical phase conversion to create a uniformly irradiated target. Distributed phase plates provide a quasi-random phase front that aids in beam smoothing on the target; however, the DPP must survive the high fluences of the tripled OMEGA beam at 351 nm. The continuous DPP produces higher efficiency and less risk of damage to opposing optics than the previous binary design. DPPs are created by exposing a gray scale pattern in photoresist and then etching the pattern in to silica. Several problems were solved during the development stage of ion etching DPPs. The etch uniformity was limited to less than 6 percent across a 28-cm clear aperture by modeling the 16-cm ion source and erosion characteristics of the photoresist and silica. Surface texturing was linked to overheating of the photoresist by the ion source and was solved by radiant cooling. Near-field defects capable of focusing damage in levels of fluence on downstream optics were created in the photoresist exposure process and were removed after etching. The damage thresholds of the silica surface generally increase after etching is fare is taken to avoid re-sputtering of tooling onto the optics surface. Sixty ion-etched DPPs were installed in December 1997 and, currently, damage has not been observed on the optics.

  5. Electron cryotomography of vitrified cells with a Volta phase plate.

    PubMed

    Fukuda, Yoshiyuki; Laugks, Ulrike; Lučić, Vladan; Baumeister, Wolfgang; Danev, Radostin

    2015-05-01

    Electron cryotomography provides a means of studying the three dimensional structure of pleomorphic objects, such as organelles or cells, with a resolution of 1-3nm. A limitation in the study of radiation sensitive biological samples is the low signal-to-noise ratio of the tomograms which may obscure fine details. To overcome this limitation, the recently developed Volta phase plate (VPP) was applied in electron cryotomographic studies of a wide range of cellular structures, from magnetotactic bacteria to primary cultured neurons. The results show that the VPP improves contrast significantly and consequently the signal-to-noise ratio of the tomograms, moreover it avoids disturbing fringing artifacts typical for Zernike phase plates. The contrast improvement provided by the VPP was also confirmed in projection images of relatively thick (∼400nm) samples. In order to investigate the respective contributions of the VPP and the energy filter, images acquired with different combinations of the two were compared. Zero-loss energy filtering reduced the background noise in thicker areas of the sample and improved the contrast of features such as poly-β-hydroxybutyrate granules in magnetotactic bacteria, whereas the VPP provided an overall contrast improvement for all sample areas. After 3D reconstruction, tomograms acquired with the combination of a VPP and an energy filter showed structural features in neuronal processes with outstanding clarity. We also show that the VPP can be combined with focused ion beam milling to examine structures embedded deeply inside cells. Thus, we expect that VPP will become a standard element of the electron cryotomography workflow. PMID:25770733

  6. Differential phase microscope and micro-tomography with a Foucault knife-edge scanning filter

    NASA Astrophysics Data System (ADS)

    Watanabe, N.; Hashizume, J.; Goto, M.; Yamaguchi, M.; Tsujimura, T.; Aoki, S.

    2013-10-01

    An x-ray differential phase microscope with a Foucault knife-edge scanning filter was set up at the bending magnet source BL3C, Photon Factory. A reconstructed phase profile from the differential phase image of an aluminium wire at 5.36 keV was fairly good agreement with the numerical simulation. Phase tomography of a biological specimen, such as an Artemia cyst, could be successfully demonstrated.

  7. Statistical and Microscopic Approach to Gas Phase Chemical Kinetics.

    ERIC Educational Resources Information Center

    Perez, J. M.; Quereda, R.

    1983-01-01

    Describes advanced undergraduate laboratory exercise examining the dependence of the rate constants and the instantaneous concentrations with the nature and energy content in a gas-phase complex reaction. Computer program (with instructions and computation flow charts) used with the exercise is available from the author. (Author/JN)

  8. Imaging microscopy by phase-contrast engine: retardation-modulated differential interference contrast microscope

    NASA Astrophysics Data System (ADS)

    Ishiwata, Hiroshi; Itoh, Masahide

    2014-11-01

    In the field of biology and medicine, observation object of the microscope has been changing from the thin specimen to the thick living tissue. Furthermore, observation of the internal structure of a living tissue is also desired by low invasion. However, the real structure of a phase object with three-dimensional distribution such as a living tissue is difficult to observe, because of the influence of the phase distribution before and behind of observation position. We enabled observation of the internal structure of living tissue without stain, by adding a new function to reduce the influence of phase distribution to our Retardation-Modulated differential interference contrast (RM-DIC) microscope system.

  9. Retrofit implementation of Zernike phase plate imaging for cryo-TEM

    PubMed Central

    Marko, Michael; Leith, ArDean; Hsieh, Chyongere; Danev, Radostin

    2011-01-01

    In-focus phase-plate imaging is particularly beneficial for cryo-TEM because it offers a substantial overall increase in image contrast, without an electron dose penalty, and it simplifies image interpretation. We show how phase-plate cryo-TEM can be implemented with an appropriate existing TEM, and provide a basic practical introduction to use of thin-film (carbon) phase plates. We point out potential pitfalls of phase-plate operation, and discuss solutions. We provide information on evaluating a particular TEM for its suitability. PMID:21272647

  10. Effects of low-spatial-frequency response of phase plates on TEM imaging

    NASA Astrophysics Data System (ADS)

    Edgcombe, C. J.

    2015-10-01

    Images of simple objects produced by a perfect lens and a phase plate have been calculated by use of Abbe theory for Foucault, Hilbert and Zernike phase plates. The results show that with a Zernike plate, white outlines and ringing like those observed previously can be caused by the beam hole, which limits the low-spatial-frequency response of the system even when the lens behaves perfectly. When the change of phase added by the phase plate is distributed over a range of radius rather than a simple step, the unwanted effects are substantially reduced.

  11. Phase-shift interference microscope for the investigation of dipole-orientation distributions

    NASA Astrophysics Data System (ADS)

    Brinker, W.; Yilmaz, S.; Wirges, W.; Bauer, S.; Gerhard-Multhaupt, R.

    1995-04-01

    A compact experimental setup for an electro-optical microscope is introduced. The microscope is based on phase-shift interferometry (a well-known tool for surface profilometry) that is modified for measuring electro-optic responses. Its feasibility is demonstrated with a two-dimensional map of the electro-optic activity of a periodically poled nonlinear-optical side-chain polymer.

  12. Calculation of confocal microscope images of cholesteric blue phases

    NASA Astrophysics Data System (ADS)

    Fukuda, Jun-ichi; Okumura, Yasushi; Kikuchi, Hirotsugu

    2016-03-01

    Real-space images of bulk cholesteric blue phases (BPs) have been successfully obtained by confocal microscopy observations using structural color without doping fluorescent dye. However, theoretical interpretation of these images (for example, the understanding of the relation between intensity distribution and the ordering of BPs) remains challenging because typical lattice spacing of BPs is of the order of the wavelength of visible light, and therefore geometrical optics is entirely useless. In this work, we present a numerical approach to calculate the confocal images of BPs by solving the Maxwell equations. Calculated confocal images are consistent with experimental observations in terms of in-plane symmetry.

  13. High-frequency Pn,Sn phases recorded by ocean bottom seismometers on the Cocos plate

    SciTech Connect

    McCreery, C.S.

    1981-05-01

    Data from ocean bottom seismometers located on the Cocos plate indicate that high-frequency Pn,Sn phases are generated by earthquakes along the subducting margin of that plate and are propagated across the plate. The Sn phase appears to be severely attenuated as it approaches the ridge crest. Estimates of Pn velocity are lower than previous extimates for western Pacific paths, which may indicate a relationship between Pn,Sn velocity and lithospheric age. High frequencies found in these phases suggest that Q for Pn,Sn propagation across the Cocos plate is similar to that for the western Pacific.

  14. Direct Imaging Searches with the Apodizing Phase Plate Coronagraph

    NASA Astrophysics Data System (ADS)

    Kenworthy, M.; Meshkat, T.; Otten, , G.; Codona, J.

    2014-03-01

    The sensitivity of direct imaging searches for extrasolar planets is limited by the presence of diffraction rings from the primary star. Coronagraphs are angular filters that minimise these diffraction structures whilst allowing light from faint companions to shine through. The Apodizing Phase Plate (APP; Kenworthy 2007) coronagraph is a simple pupil plane optic that suppresses diffraction over a 180 degree region around each star simultaneously, providing easy beam switching observations and requiring no time consuming optical alignment at the telescope. We will present our results on using the APP at the Very Large Telescope in surveys for extrasolar planets around A/F and debris disk hosting stars in the L' band (3.8 microns) in the Southern Hemisphere, where we reach a contrast of 12 magnitudes at 0.5 arcseconds (Meshkat 2013). In Leiden, we are also developing the next generation of broadband achromatic coronagraphs that can simultaneously image both sides of the star using Vector APPs (Snik 2012, Otten 2012). Recent laboratory results showing the potential of this technology for future ELTs will also be presented.

  15. Wave transfer matrix for a spiral phase plate.

    PubMed

    Rumala, Yisa S

    2015-05-10

    The wave transfer matrix (WTM) is applied to calculating various characteristics of a spiral phase plate (SPP) for the first time to our knowledge. This approach provides a more convenient and systematic approach to calculating properties of a multilayered SPP device. In particular, it predicts the optical wave characteristics on the input and output plane of the device when the SPP is fabricated on a substrate of the same refractive index as the SPP as well as on a substrate of a different refractive index compared to the SPP. The dependence of the parameters on the input laser frequency is studied in detail for a low finesse SPP etalon device for both cases. The equations derived from the WTM are used to show that a variation in input laser frequency causes the optical intensity pattern on the output plane to rotate, while preserving the topology of the optical vortex, i.e., the variation in laser frequency has a minimal effect on the parameters describing the azimuthal intensity modulation and orbital angular momentum content of the beam. In addition, the equations predict the presence of longitudinal modes in the SPP device. PMID:25967494

  16. Polynomial phase masks for extending the depth of field of a microscope.

    PubMed

    Caron, Nicolas; Sheng, Yunlong

    2008-08-01

    A polynomial phase mask is designed and fabricated for enhancing the depth of field of a microscope by more than tenfold. A generic polynomial of degree 31 that consists of 16 odd power terms is optimized by simulated annealing with a realistic average modulation transfer function (MTF) iteratively set as the target MTF. Optical experimental results are shown. PMID:18670540

  17. A meniscus where three phases coexist at equilibrium: Microscopic derivation of the Herring relations

    SciTech Connect

    De Coninck, J.; de Gottal, P.; Menu, F. )

    1989-07-01

    The geometrical characteristics of a meniscus between 2 phases are studied. In particular, the behavior of the contact angles as a function of the temperature is derived for SOS-type models. A microscopic derivation of the Herring relations is given within a continuous Gaussian model.

  18. Identification of malaria infected red blood samples by digital holographic quantitative phase microscope

    NASA Astrophysics Data System (ADS)

    Patel, Nimit R.; Chhaniwal, Vani K.; Javidi, Bahram; Anand, Arun

    2015-07-01

    Development of devices for automatic identification of diseases is desired especially in developing countries. In the case of malaria, even today the gold standard is the inspection of chemically treated blood smears through a microscope. This requires a trained technician/microscopist to identify the cells in the field of view, with which the labeling chemicals gets attached. Bright field microscopes provide only low contrast 2D images of red blood cells and cell thickness distribution cannot be obtained. Quantitative phase contrast microscopes can provide both intensity and phase profiles of the cells under study. The phase information can be used to determine thickness profile of the cell. Since cell morphology is available, many parameters pertaining to the 3D shape of the cell can be computed. These parameters in turn could be used to decide about the state of health of the cell leading to disease diagnosis. Here the investigations done on digital holographic microscope, which provides quantitative phase images, for comparison of parameters obtained from the 3D shape profile of objects leading to identification of diseased samples is described.

  19. At wavelength observation of phase defect embedded in EUV mask using microscope technique

    NASA Astrophysics Data System (ADS)

    Terasawa, Tsuneo; Amano, Tsuyoshi; Yamane, Takeshi; Watanabe, Hidehiro; Toyoda, Mitsunori; Harada, Tetsuo; Watanabe, Takeo; Kinoshita, Hiroo

    2014-04-01

    The effect of phase defect on extreme ultraviolet (EUV) lithography was examined using an EUV microscope. A test mask containing periodic absorber line patterns and programmed pit phase defects embedded in a multilayer-coated mask blank was prepared, and the mask patterns were observed by the EUV microscope developed by Tohoku University and constructed at the site of a beam line of the New SUBARU of the University of Hyogo. The half pitches of the absorber patterns were 64 nm and 44 nm at mask which corresponded to 16 nm and 11 nm device generations. The programmed defects included not only square-shape defects but also rectangular-shape defects with different orientations. When a phase defect was located between two adjacent absorber patterns, then the observation image intensity of the absorber lines and spaces (L/S) patterns varied, and the impact of a phase defect was predicted as an intensity variation of bright space image. Phase defect location dependency and defect shape dependency of the observation image intensity were examined. The effectiveness of the EUV microscope to predict the phase defect impacts was confirmed.

  20. Phase imaging of moving DNA molecules and DNA molecules replicated in the atomic force microscope.

    PubMed Central

    Argaman, M; Golan, R; Thomson, N H; Hansma, H G

    1997-01-01

    Phase imaging with a tapping mode atomic force microscope (AFM) has many advantages for imaging moving DNA and DNA-enzyme complexes in aqueous buffers at molecular resolution. In phase images molecules can be resolved at higher scan rates and lower forces than in height images from the AFM. Higher scan rates make it possible to image faster processes. At lower forces the molecules are imaged more gently. Moving DNA molecules are also resolved more clearly in phase images than in height images. Phase images in tapping mode AFM show the phase difference between oscillation of the piezoelectric crystal that drives the cantilever and oscillation of the cantilever as it interacts with the sample surface. Phase images presented here show moving DNA molecules that have been replicated with Sequenase in the AFM and DNA molecules tethered in complexes with Escherichia coli RNA polymerase. PMID:9336471

  1. Light-Weight, Single-Phase, Liquid-Cooled Cold Plate (Presentation)

    SciTech Connect

    Narumanchi, S.

    2013-07-01

    This presentation, 'Light-Weight, Low-Cost, Single-Phase Liquid-Cooled Cold Plate,' directly addresses program goals of increased power density, specific power, and lower cost of power electronics components through improved thermal management.

  2. Light-Weight, Low-Cost, Single-Phase, Liquid-Cooled Cold Plate (Presentation)

    SciTech Connect

    Narumanchi, S.

    2013-07-01

    This presentation, 'Light-Weight, Low-Cost, Single-Phase Liquid-Cooled Cold Plate,' directly addresses program goals of increased power density, specific power, and lower cost of power electronics components through improved thermal management.

  3. Cryo-EM single particle analysis with the Volta phase plate

    PubMed Central

    Danev, Radostin; Baumeister, Wolfgang

    2016-01-01

    We present a method for in-focus data acquisition with a phase plate that enables near-atomic resolution single particle reconstructions. Accurate focusing is the determining factor for obtaining high quality data. A double-area focusing strategy was implemented in order to achieve the required precision. With this approach we obtained a 3.2 Å resolution reconstruction of the Thermoplasma acidophilum 20S proteasome. The phase plate matches or slightly exceeds the performance of the conventional defocus approach. Spherical aberration becomes a limiting factor for achieving resolutions below 3 Å with in-focus phase plate images. The phase plate could enable single particle analysis of challenging samples in terms of small size, heterogeneity and flexibility that are difficult to solve by the conventional defocus approach. DOI: http://dx.doi.org/10.7554/eLife.13046.001 PMID:26949259

  4. Cryo-EM single particle analysis with the Volta phase plate.

    PubMed

    Danev, Radostin; Baumeister, Wolfgang

    2016-01-01

    We present a method for in-focus data acquisition with a phase plate that enables near-atomic resolution single particle reconstructions. Accurate focusing is the determining factor for obtaining high quality data. A double-area focusing strategy was implemented in order to achieve the required precision. With this approach we obtained a 3.2 Å resolution reconstruction of the Thermoplasma acidophilum 20S proteasome. The phase plate matches or slightly exceeds the performance of the conventional defocus approach. Spherical aberration becomes a limiting factor for achieving resolutions below 3 Å with in-focus phase plate images. The phase plate could enable single particle analysis of challenging samples in terms of small size, heterogeneity and flexibility that are difficult to solve by the conventional defocus approach. PMID:26949259

  5. Anisotropic pure-phase plates for quality improvement of partially coherent, partially polarized beams.

    PubMed

    Martínez-Herrero, Rosario; Mejías, Pedro M; Piquero, Gemma

    2003-03-01

    From a theoretical point of view, the use of anisotropic pure-phase plates (APP) is considered in order to improve the quality parameter of certain partially coherent, partially polarized beams. It is shown that, to optimize the beam-quality parameter, the phases of the two Cartesian components of the field at the output of the APP plate should be identical and should exhibit a quadratic dependence on the radial polar coordinate. PMID:12630845

  6. Anisotropic pure-phase plates for quality improvement of partially coherent, partially polarized beams

    NASA Astrophysics Data System (ADS)

    MartíNez-Herrero, Rosario; MejíAs, Pedro M.; Piquero, Gemma

    2003-03-01

    From a theoretical point of view, the use of anisotropic pure-phase plates (APP) is considered in order to improve the quality parameter of certain partially coherent, partially polarized beams. It is shown that, to optimize the beam-quality parameter, the phases of the two Cartesian components of the field at the output of the APP plate should be identical and should exhibit a quadratic dependence on the radial polar coordinate.

  7. Change dynamics of RBC morphology after injection glucose for diabetes by diffraction phase microscope

    NASA Astrophysics Data System (ADS)

    Talaykova, N. A.; Kalyanov, A. L.; Lychagov, V. V.; Ryabukho, V. P.; Malinova, L. I.

    2013-11-01

    Experimental setup of diffraction phase microscope (DPM) with double low-coherence lighting system is presented in the paper. Algorithm of interference picture processing and optical thickness, height, volume and mean cells volume (MCV) of RBC calculating is shown. We demonstrate results of experiments with blood smears and ability of the method to calculate 3D model of the biological cells shape. Investigation change dynamics of RBC morphology after injection glucose for diabetes by DPM is shown in the paper.

  8. Characterisation of ferromagnetic rings for Zernike phase plates using the Aharonov-Bohm effect.

    PubMed

    Edgcombe, C J; Ionescu, A; Loudon, J C; Blackburn, A M; Kurebayashi, H; Barnes, C H W

    2012-09-01

    Holographic measurements on magnetised thin-film cobalt rings have demonstrated both onion and vortex states of magnetisation. For a ring in the vortex state, the difference between phases of electron paths that pass through the ring and those that travel outside it was found to agree very well with Aharonov-Bohm theory within measurement error. Thus the magnetic flux in thin-film rings of ferromagnetic material can provide the phase shift required for phase plates in transmission electron microscopy. When a ring of this type is used as a phase plate, scattered electrons will be intercepted over a radial range similar to the ring width. A cobalt ring of thickness 20 nm can produce a phase difference of π/2 from a width of just under 30 nm, suggesting that the range of radial interception for this type of phase plate can be correspondingly small. PMID:22842114

  9. Chromatic characterization of ion-exchanged glass binary phase plates for mode-division multiplexing.

    PubMed

    Prieto-Blanco, Xesús; Montero-Orille, Carlos; Moreno, Vicente; Mateo, Eduardo F; Liñares, Jesús

    2015-04-10

    Mode-division multiplexing (MDM) in few-mode fibers is regarded as a promising candidate to increase optical network capacity. A fundamental element for MDM is a modal transformer to LP modes which can be implemented in a free-space basis by using multiregion phase plates, that is, LP plates. Likewise, several wavelengths have to be used due to wavelength multiplexing purposes, optical amplification tasks, and so on. In this work we show that efficient monolithic binary phase plates for different wavelengths can be fabricated by ion-exchange in glass and used for MDM tasks. We introduce an optical characterization method of the chromatic properties of such phase plates which combines the inverse Wentzel-Kramers-Brillouin (IWKB) together with Mach-Zehnder and Michelson-based interferometric techniques. The interferometric method provides a measurement of the phase step for several wavelengths, which characterizes the chromatic properties of the phase plate. Consequently, it is shown that the IWKB method allows us to design and characterize the phase plates in an easy and fast way. PMID:25967318

  10. The extended depth of field microscope imaging system with the phase pupil mask

    NASA Astrophysics Data System (ADS)

    Lyu, Qinghua; Zhai, Zhongsheng; Sharp, Martin; French, Paul

    2015-11-01

    A `0/π' phase pupil mask was developed to extend the depth of field of a circularly symmetric optical microscope imaging system. The modulation transfer function curves, the normalized point spread function figures and the spot diagrams of the imaging system with the optimal mask were analyzed and simulated. The results show that the large depth of field imaging system with the `0/π' phase pupil mask has a high resolution in a long frequency band and can obtain clear images without any post-processing. The experimental results also demonstrate that the depth of field of the imaging system is extended successfully.

  11. Selective scanning tunneling microscope light emission from rutile phase of VO2.

    PubMed

    Sakai, Joe; Kuwahara, Masashi; Hotsuki, Masaki; Katano, Satoshi; Uehara, Yoichi

    2016-09-28

    We observed scanning tunneling microscope light emission (STM-LE) induced by a tunneling current at the gap between an Ag tip and a VO2 thin film, in parallel to scanning tunneling spectroscopy (STS) profiles. The 34 nm thick VO2 film grown on a rutile TiO2 (0 0 1) substrate consisted of both rutile (R)- and monoclinic (M)-structure phases of a few 10 nm-sized domains at room temperature. We found that STM-LE with a certain photon energy of 2.0 eV occurs selectively from R-phase domains of VO2, while no STM-LE was observed from M-phase. The mechanism of STM-LE from R-phase VO2 was determined to be an interband transition process rather than inverse photoemission or inelastic tunneling processes. PMID:27460183

  12. Selective scanning tunneling microscope light emission from rutile phase of VO2

    NASA Astrophysics Data System (ADS)

    Sakai, Joe; Kuwahara, Masashi; Hotsuki, Masaki; Katano, Satoshi; Uehara, Yoichi

    2016-09-01

    We observed scanning tunneling microscope light emission (STM-LE) induced by a tunneling current at the gap between an Ag tip and a VO2 thin film, in parallel to scanning tunneling spectroscopy (STS) profiles. The 34 nm thick VO2 film grown on a rutile TiO2 (0 0 1) substrate consisted of both rutile (R)- and monoclinic (M)-structure phases of a few 10 nm-sized domains at room temperature. We found that STM-LE with a certain photon energy of 2.0 eV occurs selectively from R-phase domains of VO2, while no STM-LE was observed from M-phase. The mechanism of STM-LE from R-phase VO2 was determined to be an interband transition process rather than inverse photoemission or inelastic tunneling processes.

  13. Phase Tomography Reconstructed by 3D TIE in Hard X-ray Microscope

    SciTech Connect

    Yin, G.-C.; Chen, F.-R.; Pyun, Ahram; Je, Jung Ho; Hwu, Yeukuang; Liang, Keng S.

    2007-01-19

    X-ray phase tomography and phase imaging are promising ways of investigation on low Z material. A polymer blend of PE/PS sample was used to test the 3D phase retrieval method in the parallel beam illuminated microscope. Because the polymer sample is thick, the phase retardation is quite mixed and the image can not be distinguished when the 2D transport intensity equation (TIE) is applied. In this study, we have provided a different approach for solving the phase in three dimensions for thick sample. Our method involves integration of 3D TIE/Fourier slice theorem for solving thick phase sample. In our experiment, eight sets of de-focal series image data sets were recorded covering the angular range of 0 to 180 degree. Only three set of image cubes were used in 3D TIE equation for solving the phase tomography. The phase contrast of the polymer blend in 3D is obviously enhanced, and the two different groups of polymer blend can be distinguished in the phase tomography.

  14. Three-Phase Coexistence in Colloidal Rod-Plate Mixtures.

    PubMed

    Woolston, Phillip; van Duijneveldt, Jeroen S

    2015-09-01

    Aqueous suspensions of clay particles, such as montmorillonite (MMT) platelets and sepiolite (Sep) rods, tend to form gels at concentrations around 1 vol %. For Sep rods, adsorbing sodium polyacrylate to the surface allows for an isotropic-nematic phase separation to be seen instead. Here, MMT is added to such Sep suspensions, resulting in a complex phase behavior. Across a range of clay concentrations, separation into three phases is observed: a lower, nematic phase dominated by Sep rods, a MMT-rich middle layer, which is weakly birefringent and probably a gel, and a dilute top phase. Analysis of phase volumes suggests that the middle layer may contain as much as 6 vol % MMT. PMID:26262770

  15. Two-phase gas-liquid flow characteristics inside a plate heat exchanger

    SciTech Connect

    Nilpueng, Kitti; Wongwises, Somchai

    2010-11-15

    In the present study, the air-water two-phase flow characteristics including flow pattern and pressure drop inside a plate heat exchanger are experimentally investigated. A plate heat exchanger with single pass under the condition of counter flow is operated for the experiment. Three stainless steel commercial plates with a corrugated sinusoidal shape of unsymmetrical chevron angles of 55 and 10 are utilized for the pressure drop measurement. A transparent plate having the same configuration as the stainless steel plates is cast and used as a cover plate in order to observe the flow pattern inside the plate heat exchanger. The air-water mixture flow which is used as a cold stream is tested in vertical downward and upward flow. The results from the present experiment show that the annular-liquid bridge flow pattern appeared in both upward and downward flows. However, the bubbly flow pattern and the slug flow pattern are only found in upward flow and downward flow, respectively. The variation of the water and air velocity has a significant effect on the two-phase pressure drop. Based on the present data, a two-phase multiplier correlation is proposed for practical application. (author)

  16. Amplitude and phase images of cellular structures with a scanning surface plasmon microscope.

    PubMed

    Berguiga, L; Roland, T; Monier, K; Elezgaray, J; Argoul, F

    2011-03-28

    Imaging cellular internal structure at nanometer scale axial resolution with non invasive microscopy techniques has been a major technical challenge since the nineties. We propose here a complement to fluorescence based microscopies with no need of staining the biological samples, based on a Scanning Surface Plasmon Microscope (SSPM). We describe the advantages of this microscope, namely the possibility of both amplitude and phase imaging and, due to evanescent field enhancement by the surface plasmon resonance, a very high resolution in Z scanning (Z being the axis normal to the sample). We show for fibroblast cells (IMR90) that SSPM offers an enhanced detection of index gradient regions, and we conclude it is very well suited to discriminate regions of variable density in biological media such as cell compartments, nucleus, nucleoli and membranes. PMID:21451685

  17. Programmable phase plate for tool modification in laser machining applications

    DOEpatents

    Thompson Jr., Charles A.; Kartz, Michael W.; Brase, James M.; Pennington, Deanna; Perry, Michael D.

    2004-04-06

    A system for laser machining includes a laser source for propagating a laser beam toward a target location, and a spatial light modulator having individual controllable elements capable of modifying a phase profile of the laser beam to produce a corresponding irradiance pattern on the target location. The system also includes a controller operably connected to the spatial light modulator for controlling the individual controllable elements. By controlling the individual controllable elements, the phase profile of the laser beam may be modified into a desired phase profile so as to produce a corresponding desired irradiance pattern on the target location capable of performing a machining operation on the target location.

  18. Simultaneous microscopic measurements of thermal and spectroscopic fields of a phase change material

    NASA Astrophysics Data System (ADS)

    Romano, M.; Ryu, M.; Morikawa, J.; Batsale, J. C.; Pradere, C.

    2016-05-01

    In this paper, simultaneous microscopic measurements of thermal and spectroscopic fields of a paraffin wax n-alkane phase change material are reported. Measurements collected using an original set-up are presented and discussed with emphasis on the ability to perform simultaneous characterization of the system when the proposed imaging process is used. Finally, this work reveals that the infrared wavelength contains two sets of important information. Furthermore, this versatile and flexible technique is well adapted to characterize many systems in which the mass and heat transfers effects are coupled.

  19. Fabrication of large aperture kinoform phase plates in fused silica for smoothing focal plane intensity profiles

    SciTech Connect

    Rushford, M.; Dixit, S.; Thomas, I.; Perry, M.

    1996-04-26

    We have fabricated large aperture (40-cm) kinoform phase plates for producing super-Gaussian focal plane intensity profiles. The continuous phase screen, designed using a new iterative procedure, was fabricated in fused silica as a 16-level, one-wave deep rewrapped phase profile using a lithographic process and wet etching in buffered hydrofluoric acid. The observed far-field contains 94% of the incident energy inside the desired spot.

  20. Vapour phase details in the oscillatory combustion of propellants A porous plate analogue

    NASA Technical Reports Server (NTRS)

    Ramohalli, K.; Magiawala, K. R.

    1979-01-01

    A perforated porous plate burner is designed to scale up the vapor phase details in composite propellant combustion. A fuel vapor is passed through the pores and an oxidizer vapor is passed through the discrete perforations drilled in the plate. Discussion of the scale modeling of the vapor phase details in oscillatory combustion of composite propellants leads to the following conclusions: (1) the concept of a perforated porous plate analog for the composite propellant vapor phase combustion appears to be valid during oscillatory combustion as well; (2) the flame standoff distance can be conveniently determined with motion picture photography; (3) the flame standoff distance varies with the flow velocity during oscillatory combustion much the same way as during time-independent combustion; and (4) the overall structure of the combustion zone (flame) does not appear to vary too much from its time-independent structure during oscillatory combustion

  1. Measurement of displacement using phase shifted wedge plate lateral shearing interferometry

    NASA Astrophysics Data System (ADS)

    Disawal, Reena; Prakash, Shashi

    2016-03-01

    In present communication, a simple technique for measurement of displacement using phase shifted wedge plate lateral shearing interferometry is described. The light beam from laser is expanded and illuminates a wedge plate of relatively large angle. Light transmitted through the wedge plate is converged onto a reflecting specimen using a focusing lens. Back-reflected wavefront from the specimen is incident on the wedge plate. Because of the tilt and shear of the wavefront reflected from the wedge plate, typical straight line fringes appear. These fringes are superimposed onto a sinusoidal grating forming a moiré pattern. The orientation of the moiré fringes is a function of specimen displacement. Four step phase shifting test procedure has been incorporated by translating the grating in phase steps of π/2. Necessary mathematical formulation to establish correlation between the 'difference phase' and the displacement of the specimen surface is undertaken. The technique is automatic and provides resolution and expanded uncertainty of 1 μm and 0.246 μm, respectively. Detailed uncertainty analysis is also reported.

  2. Fabrication of a new substrate for atomic force microscopic observation of DNA molecules from an ultrasmooth sapphire plate.

    PubMed Central

    Yoshida, K; Yoshimoto, M; Sasaki, K; Ohnishi, T; Ushiki, T; Hitomi, J; Yamamoto, S; Sigeno, M

    1998-01-01

    A new stable substrate applicable to the observation of DNA molecules by atomic force microscopy (AFM) was fabricated from a ultrasmooth sapphire (alpha-Al2O3 single crystal) plate. The atomically ultrasmooth sapphire as obtained by high-temperature annealing has hydrophobic surfaces and could not be used for the AFM observation of DNA. However, sapphire treated with Na3PO4 aqueous solution exhibited a hydrophilic character while maintaining a smooth surface structure. The surface of the wet-treated sapphire was found by x-ray photoelectron spectroscopy and AFM to be approximately 0.3 nm. The hydrophilic surface character of the ultrasmooth sapphire plate made it easy for DNA molecules to adhere to the plate. Circular molecules of the plasmid DNA could be imaged by AFM on the hydrophilic ultrasmooth sapphire plate. PMID:9545030

  3. Volta phase plate cryo-EM of the small protein complex Prx3.

    PubMed

    Khoshouei, Maryam; Radjainia, Mazdak; Phillips, Amy J; Gerrard, Juliet A; Mitra, Alok K; Plitzko, Jürgen M; Baumeister, Wolfgang; Danev, Radostin

    2016-01-01

    Cryo-EM of large, macromolecular assemblies has seen a significant increase in the numbers of high-resolution structures since the arrival of direct electron detectors. However, sub-nanometre resolution cryo-EM structures are rare compared with crystal structure depositions, particularly for relatively small particles (<400 kDa). Here we demonstrate the benefits of Volta phase plates for single-particle analysis by time-efficient cryo-EM structure determination of 257 kDa human peroxiredoxin-3 dodecamers at 4.4 Å resolution. The Volta phase plate improves the applicability of cryo-EM for small molecules and accelerates structure determination. PMID:26817416

  4. Volta phase plate cryo-EM of the small protein complex Prx3

    NASA Astrophysics Data System (ADS)

    Khoshouei, Maryam; Radjainia, Mazdak; Phillips, Amy J.; Gerrard, Juliet A.; Mitra, Alok K.; Plitzko, Jürgen M.; Baumeister, Wolfgang; Danev, Radostin

    2016-01-01

    Cryo-EM of large, macromolecular assemblies has seen a significant increase in the numbers of high-resolution structures since the arrival of direct electron detectors. However, sub-nanometre resolution cryo-EM structures are rare compared with crystal structure depositions, particularly for relatively small particles (<400 kDa). Here we demonstrate the benefits of Volta phase plates for single-particle analysis by time-efficient cryo-EM structure determination of 257 kDa human peroxiredoxin-3 dodecamers at 4.4 Å resolution. The Volta phase plate improves the applicability of cryo-EM for small molecules and accelerates structure determination.

  5. Phase Velocity Method for Guided Wave Measurements in Composite Plates

    NASA Astrophysics Data System (ADS)

    Moreno, E.; Galarza, N.; Rubio, B.; Otero, J. A.

    Carbon Fiber Reinforced Polymer is a well-recognized material for aeronautic applications. Its plane structure has been widely used where anisotropic characteristics should be evaluated with flaw detection. A phase velocity method of ultrasonic guided waves based on a pitch-catch configuration is presented for this purpose. Both shear vertical (SV) and shear horizontal (SH) have been studied. For SV (Lamb waves) the measurements were done at different frequencies in order to evaluate the geometrical dispersion and elastic constants. The results for SV are discussed with an orthotropic elastic model. Finally experiments with lamination flaws are presented.

  6. Practical factors affecting the performance of a thin-film phase plate for transmission electron microscopy

    PubMed Central

    Danev, Radostin; Glaeser, Robert M.; Nagayama, Kuniaki

    2011-01-01

    A number of practical issues must be addressed when using thin carbon films as quarter-wave plates for Zernike phase-contrast electron microscopy. We describe, for example, how we meet the more stringent requirements that must be satisfied for beam alignment in this imaging mode. In addition we address the concern that one might have regarding the loss of some of the scattered electrons as they pass through such a phase plate. We show that two easily measured parameters, (1) the low-resolution image contrast produced in cryo-EM images of tobacco mosaic virus particles and (2) the fall-off of the envelope function at high resolution, can be used to quantitatively compare the data quality for Zernike phase-contrast images and for defocused bright-field images. We describe how we prepare carbon-film phase plates that are initially free of charging or other effects that degrade image quality. We emphasize, however, that even though the buildup of hydrocarbon contamination can be avoided by heating the phase plates during use, their performance nevertheless deteriorates over the time scale of days to weeks, thus requiring their frequent replacement in order to maintain optimal performance. PMID:19157711

  7. Selective mode multiplexer based on phase plates and Mach-Zehnder interferometer with image inversion function.

    PubMed

    Igarashi, Koji; Souma, Daiki; Takeshima, Koki; Tsuritani, Takehiro

    2015-01-12

    We propose a novel mode multiplexer based on phase plates followed by a Mach-Zehnder interferometer (MZI) with image inversion. After the higher-order modes are selectively converted from fundamental linear-polarized (LP) modes by the phase plates, the converted modes are coupled without fundamental loss using MZI with image inversion, in which the original spatial pattern and inverted pattern of the optical signal are interfered. Our scheme is also applicable to the coupling of degenerated LP modes such as LP(11a) and LP(11b). First, we numerically and experimentally evaluate the performance of the mode converter based on phase plates. The mode converter is suitable as long as the five LP modes such as LP(01), LP(11ab) and LP(21ab) are sustained in a few-mode fiber (FMF), although the crosstalk due to excitation of undesirable modes is unavoidable when the higher-order modes over LP(02) are sustained in FMF. Next, we develop and characterize the proposed mode multiplexers based on phase plates and MZIs with image inversion. The insertion loss is suppressed to around 3 dB for mode multiplexing of LP(11a) and LP(11b). Using a fabricated mode multiplexer for LP(31a) and LP(31b), we measure the bit-error rate performance of single-polarization mode-multiplexed quadrature-phase shift keying optical signals. PMID:25835665

  8. Damage localization in aluminum plate with compact rectangular phased piezoelectric transducer array

    NASA Astrophysics Data System (ADS)

    Liu, Zenghua; Sun, Kunming; Song, Guorong; He, Cunfu; Wu, Bin

    2016-03-01

    In this work, a detection method for the damage in plate-like structure with a compact rectangular phased piezoelectric transducer array of 16 piezoelectric elements was presented. This compact array can not only detect and locate a single defect (through hole) in plate, but also identify multi-defects (through holes and surface defect simulated by an iron pillar glued to the plate). The experiments proved that the compact rectangular phased transducer array could detect the full range of plate structures and implement multiple-defect detection simultaneously. The processing algorithm proposed in this paper contains two parts: signal filtering and damage imaging. The former part was used to remove noise from signals. Continuous wavelet transform was applicable to signal filtering. Continuous wavelet transform can provide a plot of wavelet coefficients and the signal with narrow frequency band can be easily extracted from the plot. The latter part of processing algorithm was to implement damage detection and localization. In order to accurately locate defects and improve the imaging quality, two images were obtained from amplitude and phase information. One image was obtained with the Total Focusing Method (TFM) and another phase image was obtained with the Sign Coherence Factor (SCF). Furthermore, an image compounding technique for compact rectangular phased piezoelectric transducer array was proposed in this paper. With the proposed technique, the compounded image can be obtained by combining TFM image with SCF image, thus greatly improving the resolution and contrast of image.

  9. Effect of metachronal phasing on the pumping efficiency of oscillating plate arrays

    NASA Astrophysics Data System (ADS)

    Larson, Mary; Kiger, Ken T.; Abdelaziz, Khaled; Balaras, Elias

    2014-05-01

    A programmable oscillating plate array was constructed in order to study the detailed hydrodynamics of external pumping by a series of oscillating plates at Reynolds numbers on the order of 10. The array was modeled after the geometry and kinematics found in the nymphal mayfly (Ephemeroptera) Centroptilum triangulifer, and consisted of five plates, each of which could be actuated independently for stroke and pitch. Scaled tests were performed at a Reynolds number, Re = fL {g/2}/ ν = 18, with a single stroke kinematic pattern modeled after the living animal. In mayflies, and in many other oscillating plate systems, an antiplectic metachronal wave is used with a phase delay of approximately 90°, which corresponds to a travelling wave that moves from posterior to anterior with a wavelength of approximately four plates. In order to better understand possible reasons for why the animal system might favor the observed phase lag, ensemble-correlation stereo PIV measurements were made to reconstruct the unsteady three-dimensional phase averaged flow field at a resolution that allowed a uniform and converged estimate of the net pumped flux and the total energy dissipation within and around the vicinity of the gill array. The results indicate that the baseline case offered an optimal spot in the mass flux of fluid pumped through the array per unit energy expended, while also providing a great deal of flexibility in modifying the stroke amplitude without interference effects from adjacent gills.

  10. Individual-based modelling of bacterial cultures to study the microscopic causes of the lag phase.

    PubMed

    Prats, Clara; López, Daniel; Giró, Antoni; Ferrer, Jordi; Valls, Joaquim

    2006-08-21

    The lag phase has been widely studied for years in an effort to contribute to the improvement of food safety. Many analytical models have been built and tested by several authors. The use of Individual-based Modelling (IbM) allows us to probe deeper into the behaviour of individual cells; it is a bridge between theories and experiments when needed. INDividual DIScrete SIMulation (INDISIM) has been developed and coded by our group as an IbM simulator and used to study bacterial growth, including the microscopic causes of the lag phase. First of all, the evolution of cellular masses, specifically the mean mass and biomass distribution, is shown to be a determining factor in the beginning of the exponential phase. Secondly, whenever there is a need for an enzyme synthesis, its rate has a direct effect on the lag duration. The variability of the lag phase with different factors is also studied. The known decrease of the lag phase with an increase in the temperature is also observed in the simulations. An initial study of the relationship between individual and collective lag phases is presented, as a complement to the studies already published. One important result is the variability of the individual lag times and generation times. It has also been found that the mean of the individual lags is greater than the population lag. This is the first in a series of studies of the lag phase that we are carrying out. Therefore, the present work addresses a generic system by making a simple set of assumptions. PMID:16524598

  11. New concepts for chip-supported multi-well-plates: realization of a 24-well-plate with integrated impedance-sensors for functional cellular screening applications and automated microscope aided cell-based assays.

    PubMed

    Ressler, J; Grothe, H; Motrescu, E; Wolf, B

    2004-01-01

    Based on the experience with multiparametric bioelectronic sensor chips for the monitoring of living cells, we have combined the established multi-well-format with the advantages of microelectronic sensors. The result is a 24-well-plate where the bottom of the wells is replaced by glass-based chips with integrated IDES (interdigital electrode structure). By using IDES it is possible to detect adhesion and morphological changes of adherent growing cell cultures. Up to now these measurements were inaccessible in conjunction with multi-well-plates, especially in high throughput applications. If microscopic monitoring of the cell culture is required, the IDES can be fabricated using transparent conductor materials like ITO (indium tin oxide). Both the transparent material for the sensors and the sensor-carrier make the multi-well-plate also applicable for all kinds of fluorescence and luminescence biological tests. In addition to the impedance-sensors optical read-out sensor layers for pH and pO2 can be integrated. For this reason there are many possible fields of application in biological and biomedical areas such as drug screening, chemosensitive testing and environmental toxicology as well as in biosensing for biological and chemical warfare. Especially the possibility of using this multi-well-plate together with automated imaging-systems has the great advantage of combining optical and sensory monitoring accessible to high-throughput-applications. PMID:17272129

  12. High-speed line-field confocal holographic microscope for quantitative phase imaging.

    PubMed

    Liu, Changgeng; Knitter, Sebastian; Cong, Zhilong; Sencan, Ikbal; Cao, Hui; Choma, Michael A

    2016-05-01

    We present a high-speed and phase-sensitive reflectance line-scanning confocal holographic microscope (LCHM). We achieved rapid confocal imaging using a fast line-scan CCD camera and quantitative phase imaging using off-axis digital holography (DH) on a 1D, line-by-line basis in our prototype experiment. Using a 20 kHz line scan rate, we achieved a frame rate of 20 Hz for 512x512 pixels en-face confocal images. We realized coherent holographic detection two different ways. We first present a LCHM using off-axis configuration. By using a microscope objective of a NA 0.65, we achieved axial and lateral resolution of ~3.5 micrometers and ~0.8 micrometers, respectively. We demonstrated surface profile measurement of a phase target at nanometer precision and the digital refocusing of a defocused confocal en-face image. Ultrahigh temporal resolution M mode is demonstrated by measuring the vibration of a PZT-actuated mirror driven by a sine wave at 1 kHz. We then report our experimental work on a LCHM using an in-line configuration. In this in-line LCHM, the coherent detection is enabled by moving the reference arm at a constant speed, thereby introducing a Doppler frequency shift that leads to spatial interference fringes along the scanning direction. Lastly, we present a unified formulation that treats off-axis and in-line LCHM in a unified joint spatiotemporal modulation framework and provide a connection between LCHM and the traditional off-axis DH. The presented high-speed LCHM may find applications in optical metrology and biomedical imaging. PMID:27137541

  13. Microcanonical thermostatistics as foundation of thermodynamics: The microscopic origin of condensation and phase separations

    NASA Astrophysics Data System (ADS)

    Gross, D. H. E.

    2005-10-01

    Conventional thermo-statistics address infinite homogeneous systems within the canonical ensemble. However, some 150 years ago the original motivation of thermodynamics was the description of steam engines, i.e., boiling water. Its essential physics is the separation of the gas phase from the liquid. Of course, boiling water is inhomogeneous and as such cannot be treated by canonical thermo-statistics. Then it is not astonishing that a phase transition of first order is signaled canonically by a Yang Lee singularity. Thus it is only treated correctly by microcanonical Boltzmann Planck statistics. This is elaborated in the present article. It turns out that the Boltzmann Planck statistics is much richer and gives fundamental insight into statistical mechanics and especially into entropy. This can even be done to some extend rigorously and analytically. The microcanonical entropy has a very simple physical meaning: It measures the microscopic uncertainty that we have about the system, i.e., the number of points in 6N-dim phase, which are consistent with our information about the system. It can rigorously be split into an ideal-gas part and a configuration part which contains all the physics and especially is responsible for all phase transitions. The deep and essential difference between “extensive” and “intensive” control parameters, i.e., microcanonical and canonical statistics, is exemplified by rotating, self-gravitating systems.

  14. Joint research effort on vibrations of twisted plates, phase 1: Final results

    NASA Technical Reports Server (NTRS)

    Kielb, R. E.; Leissa, A. W.; Macbain, J. C.; Carney, K. S.

    1985-01-01

    The complete theoretical and experimental results of the first phase of a joint government/industry/university research study on the vibration characteristics of twisted cantilever plates are given. The study is conducted to generate an experimental data base and to compare many different theoretical methods with each other and with the experimental results. Plates with aspect ratios, thickness ratios, and twist angles representative of current gas turbine engine blading are investigated. The theoretical results are generated by numerous finite element, shell, and beam analysis methods. The experimental results are obtained by precision matching a set of twisted plates and testing them at two laboratories. The second and final phase of the study will concern the effects of rotation.

  15. Germanium x-ray phase plates for the production of circularly polarized x-rays

    SciTech Connect

    Yahnke, C.J.; Srajer, G.; Haeffner, D.R.; Mills, D.M.; Assoufid, L.

    1993-10-01

    The authors have constructed an x-ray phase plate to produce both linearly and circularly polarized x-rays at discrete energies between 20 keV and 88 keV. The plate is a monolithic two-crystal design, constructed from germanium, which increases the resultant degree of circular polarization of the output beam. They have measured the degree of circular polarization at 65 keV to be 90% {+-} 4%, significantly better than that produced by silicon phase plates. This radiation was used to measure the magnetic Compton profile for Fe, which was found to be in good agreement with theory and previous work. The underlying x-ray optics and the characterization of the device between 62 keV and 93 keV at the Cornell High Energy Synchrotron Source are presented.

  16. Biaxial nematic phase stability and demixing behaviour in monolayers of rod-plate mixtures.

    PubMed

    Martínez-Ratón, Yuri; González-Pinto, Miguel; Velasco, Enrique

    2016-09-21

    We theoretically study the phase behaviour of monolayers of hard rod-plate mixtures using a fundamental-measure density functional in the restricted-orientation (Zwanzig) approximation. Particles can rotate in 3D but their centres of mass are constrained to be on a flat surface. In addition, we consider both species to be subject to an attractive potential proportional to the particle contact area on the surface and with adsorption strengths that depend on the species type. Particles have board-like shape, with sizes chosen using a symmetry criterion: same volume and same aspect ratio κ. Phase diagrams were calculated for κ = 10, 20 and 40 and different values of adsorption strengths. For small adsorption strengths the mixtures exhibit a second-order uniaxial nematic-biaxial nematic transition for molar fraction of rods 0 ≤x≲ 0.9. In the uniaxial nematic phase the particle axes of rods and plates are aligned perpendicular and parallel to the monolayer, respectively. At the transition, the orientational symmetry of the plate axes is broken, and they orient parallel to a director lying on the surface. For large and equal adsorption strengths the mixture demixes at low pressures into a uniaxial nematic phase, rich in plates, and a biaxial nematic phase, rich in rods. The demixing transition is located between two tricritical points. Also, at higher pressures and in the plate-rich part of the phase diagram, the system exhibits a strong first-order uniaxial nematic-biaxial nematic phase transition with a large density coexistence gap. When rod adsorption is considerably large while that of plates is small, the transition to the biaxial nematic phase is always of second order, and its region of stability in the phase diagram considerably widens. At very high pressures the mixture can effectively be identified as a two-dimensional mixture of squares and rectangles which again demixes above a certain critical point. We also studied the relative stability of uniform

  17. Planar gas chromatography column on aluminum plate with multi-walled carbon nanotubes as stationary phase

    NASA Astrophysics Data System (ADS)

    Platonov, I. A.; Platonov, V. I.; Pavelyev, V. S.

    2016-04-01

    The high selectivity of the adsorption layer for low-boiling alkanes is shown, the separation factor (α) couple iso-butane / butane is 1.9 at a column temperature of 50 °C.The paper presents sorption and selective properties of planar gas chromatography column on aluminum plate with multi-walled carbon nanotubes as the stationary phase.

  18. A line scanned light-sheet microscope with phase shaped self-reconstructing beams.

    PubMed

    Fahrbach, Florian O; Rohrbach, Alexander

    2010-11-01

    We recently demonstrated that Microscopy with Self-Reconstructing Beams (MISERB) increases both image quality and penetration depth of illumination beams in strongly scattering media. Based on the concept of line scanned light-sheet microscopy, we present an add-on module to a standard inverted microscope using a scanned beam that is shaped in phase and amplitude by a spatial light modulator. We explain technical details of the setup as well as of the holograms for the creation, positioning and scaling of static light-sheets, Gaussian beams and Bessel beams. The comparison of images from identical sample areas illuminated by different beams allows a precise assessment of the interconnection between beam shape and image quality. The superior propagation ability of Bessel beams through inhomogeneous media is demonstrated by measurements on various scattering media. PMID:21164769

  19. Massively parallel haplotyping on microscopic beads for the high-throughput phase analysis of single molecules.

    PubMed

    Boulanger, Jérôme; Muresan, Leila; Tiemann-Boege, Irene

    2012-01-01

    In spite of the many advances in haplotyping methods, it is still very difficult to characterize rare haplotypes in tissues and different environmental samples or to accurately assess the haplotype diversity in large mixtures. This would require a haplotyping method capable of analyzing the phase of single molecules with an unprecedented throughput. Here we describe such a haplotyping method capable of analyzing in parallel hundreds of thousands single molecules in one experiment. In this method, multiple PCR reactions amplify different polymorphic regions of a single DNA molecule on a magnetic bead compartmentalized in an emulsion drop. The allelic states of the amplified polymorphisms are identified with fluorescently labeled probes that are then decoded from images taken of the arrayed beads by a microscope. This method can evaluate the phase of up to 3 polymorphisms separated by up to 5 kilobases in hundreds of thousands single molecules. We tested the sensitivity of the method by measuring the number of mutant haplotypes synthesized by four different commercially available enzymes: Phusion, Platinum Taq, Titanium Taq, and Phire. The digital nature of the method makes it highly sensitive to detecting haplotype ratios of less than 1:10,000. We also accurately quantified chimera formation during the exponential phase of PCR by different DNA polymerases. PMID:22558329

  20. Quantum coherent optical phase modulation in an ultrafast transmission electron microscope

    NASA Astrophysics Data System (ADS)

    Feist, Armin; Echternkamp, Katharina E.; Schauss, Jakob; Yalunin, Sergey V.; Schäfer, Sascha; Ropers, Claus

    2015-05-01

    Coherent manipulation of quantum systems with light is expected to be a cornerstone of future information and communication technology, including quantum computation and cryptography. The transfer of an optical phase onto a quantum wavefunction is a defining aspect of coherent interactions and forms the basis of quantum state preparation, synchronization and metrology. Light-phase-modulated electron states near atoms and molecules are essential for the techniques of attosecond science, including the generation of extreme-ultraviolet pulses and orbital tomography. In contrast, the quantum-coherent phase-modulation of energetic free-electron beams has not been demonstrated, although it promises direct access to ultrafast imaging and spectroscopy with tailored electron pulses on the attosecond scale. Here we demonstrate the coherent quantum state manipulation of free-electron populations in an electron microscope beam. We employ the interaction of ultrashort electron pulses with optical near-fields to induce Rabi oscillations in the populations of electron momentum states, observed as a function of the optical driving field. Excellent agreement with the scaling of an equal-Rabi multilevel quantum ladder is obtained, representing the observation of a light-driven `quantum walk' coherently reshaping electron density in momentum space. We note that, after the interaction, the optically generated superposition of momentum states evolves into a train of attosecond electron pulses. Our results reveal the potential of quantum control for the precision structuring of electron densities, with possible applications ranging from ultrafast electron spectroscopy and microscopy to accelerator science and free-electron lasers.

  1. Method for preparing surfaces of metal composites having a brittle phase for plating. [Patent application

    DOEpatents

    Coates, C.W.; Wilson, T.J.

    1982-05-19

    The present invention is directed to a method for preparing surfaces of two-phase metal composites having relatively brittle and malleable components for plating with corrosion-resistant material. In practice of the present invention, the surfaces of the composite are etched to remove a major portion or fraction of the brittle component. The etched surface is then peened with particulates for breaking the brittle component from the surfaces and for spreading or smearing the malleable component over the surfaces. The peened surface is then chemically cleaned of residual traces of the brittle component to which the corrosion-resistant material may be plated thereon in an adherent manner.

  2. Orientation based segmentation for phase-contrast microscopic image of confluent cell.

    PubMed

    Sasaki, K; Yuasa, T; Sasaki, H; Kato, R

    2013-01-01

    In this research, we propose a novel segmentation method for image of cultured cell at a confluent state, obtained by phase-contrast microscope, based on the orientation. First, we assign to each pixel in the image the direction of an eigenvector corresponding to a smaller eigenvalue of the 2 by 2 Hessian matrix with respect to brightness. Next, we define the orientation at a certain pixel as the histograms of the direction at pixels in the surrounding regions. Then, we evaluate deviation of histograms in the individual regions by entropy, and regard the series of entropy as a multi-dimensional vector, the dimension of which corresponds with the number of regions. We suppose that the vector is assigned to the pixel of interest. Finally, we segment the image based on the multi-dimensional vector using K-means method. We investigate the efficacy of the proposed method using an actual human confluent fibroblast image acquired by phase-contrast microscopy. PMID:24110439

  3. Switchable Ultrathin Quarter-wave Plate in Terahertz Using Active Phase-change Metasurface

    PubMed Central

    Wang, Dacheng; Zhang, Lingchao; Gu, Yinghong; Mehmood, M. Q.; Gong, Yandong; Srivastava, Amar; Jian, Linke; Venkatesan, T.; Qiu, Cheng-Wei; Hong, Minghui

    2015-01-01

    Metamaterials open up various exotic means to control electromagnetic waves and among them polarization manipulations with metamaterials have attracted intense attention. As of today, static responses of resonators in metamaterials lead to a narrow-band and single-function operation. Extension of the working frequency relies on multilayer metamaterials or different unit cells, which hinder the development of ultra-compact optical systems. In this work, we demonstrate a switchable ultrathin terahertz quarter-wave plate by hybridizing a phase change material, vanadium dioxide (VO2), with a metasurface. Before the phase transition, VO2 behaves as a semiconductor and the metasurface operates as a quarter-wave plate at 0.468 THz. After the transition to metal phase, the quarter-wave plate operates at 0.502 THz. At the corresponding operating frequencies, the metasurface converts a linearly polarized light into a circularly polarized light. This work reveals the feasibility to realize tunable/active and extremely low-profile polarization manipulation devices in the terahertz regime through the incorporation of such phase-change metasurfaces, enabling novel applications of ultrathin terahertz meta-devices. PMID:26442614

  4. Switchable Ultrathin Quarter-wave Plate in Terahertz Using Active Phase-change Metasurface

    NASA Astrophysics Data System (ADS)

    Wang, Dacheng; Zhang, Lingchao; Gu, Yinghong; Mehmood, M. Q.; Gong, Yandong; Srivastava, Amar; Jian, Linke; Venkatesan, T.; Qiu, Cheng-Wei; Hong, Minghui

    2015-10-01

    Metamaterials open up various exotic means to control electromagnetic waves and among them polarization manipulations with metamaterials have attracted intense attention. As of today, static responses of resonators in metamaterials lead to a narrow-band and single-function operation. Extension of the working frequency relies on multilayer metamaterials or different unit cells, which hinder the development of ultra-compact optical systems. In this work, we demonstrate a switchable ultrathin terahertz quarter-wave plate by hybridizing a phase change material, vanadium dioxide (VO2), with a metasurface. Before the phase transition, VO2 behaves as a semiconductor and the metasurface operates as a quarter-wave plate at 0.468 THz. After the transition to metal phase, the quarter-wave plate operates at 0.502 THz. At the corresponding operating frequencies, the metasurface converts a linearly polarized light into a circularly polarized light. This work reveals the feasibility to realize tunable/active and extremely low-profile polarization manipulation devices in the terahertz regime through the incorporation of such phase-change metasurfaces, enabling novel applications of ultrathin terahertz meta-devices.

  5. Switchable Ultrathin Quarter-wave Plate in Terahertz Using Active Phase-change Metasurface.

    PubMed

    Wang, Dacheng; Zhang, Lingchao; Gu, Yinghong; Mehmood, M Q; Gong, Yandong; Srivastava, Amar; Jian, Linke; Venkatesan, T; Qiu, Cheng-Wei; Hong, Minghui

    2015-01-01

    Metamaterials open up various exotic means to control electromagnetic waves and among them polarization manipulations with metamaterials have attracted intense attention. As of today, static responses of resonators in metamaterials lead to a narrow-band and single-function operation. Extension of the working frequency relies on multilayer metamaterials or different unit cells, which hinder the development of ultra-compact optical systems. In this work, we demonstrate a switchable ultrathin terahertz quarter-wave plate by hybridizing a phase change material, vanadium dioxide (VO2), with a metasurface. Before the phase transition, VO2 behaves as a semiconductor and the metasurface operates as a quarter-wave plate at 0.468 THz. After the transition to metal phase, the quarter-wave plate operates at 0.502 THz. At the corresponding operating frequencies, the metasurface converts a linearly polarized light into a circularly polarized light. This work reveals the feasibility to realize tunable/active and extremely low-profile polarization manipulation devices in the terahertz regime through the incorporation of such phase-change metasurfaces, enabling novel applications of ultrathin terahertz meta-devices. PMID:26442614

  6. Tracking three-phase coexistences in binary mixtures of hard plates and spheres

    NASA Astrophysics Data System (ADS)

    Aliabadi, Roohollah; Moradi, Mahmood; Varga, Szabolcs

    2016-02-01

    The stability of demixing phase transition in binary mixtures of hard plates (with thickness L and diameter D) and hard spheres (with diameter σ) is studied by means of Parsons-Lee theory. The isotropic-isotropic demixing, which is found in mixtures of large spheres and small plates, is very likely to be pre-empted by crystallization. In contrast, the nematic-nematic demixing, which is obtained in mixtures of large plates and small spheres, can be stabilized at low diameter ratios (σ/D) and aspect ratios (L/D). At intermediate values of σ/D, where the sizes of the components are similar, neither the isotropic-isotropic nor the nematic-nematic demixing can be stabilized, but a very strong fractionation takes place between a plate rich nematic and a sphere rich isotropic phases. Our results show that the excluded volume interactions are capable alone to explain the experimental observation of the nematic-nematic demixing, but they fail in the description of isotropic-isotropic one [M. Chen et al., Soft Matter 11, 5775 (2015)].

  7. Quantum coherent optical phase modulation in an ultrafast transmission electron microscope.

    PubMed

    Feist, Armin; Echternkamp, Katharina E; Schauss, Jakob; Yalunin, Sergey V; Schäfer, Sascha; Ropers, Claus

    2015-05-14

    Coherent manipulation of quantum systems with light is expected to be a cornerstone of future information and communication technology, including quantum computation and cryptography. The transfer of an optical phase onto a quantum wavefunction is a defining aspect of coherent interactions and forms the basis of quantum state preparation, synchronization and metrology. Light-phase-modulated electron states near atoms and molecules are essential for the techniques of attosecond science, including the generation of extreme-ultraviolet pulses and orbital tomography. In contrast, the quantum-coherent phase-modulation of energetic free-electron beams has not been demonstrated, although it promises direct access to ultrafast imaging and spectroscopy with tailored electron pulses on the attosecond scale. Here we demonstrate the coherent quantum state manipulation of free-electron populations in an electron microscope beam. We employ the interaction of ultrashort electron pulses with optical near-fields to induce Rabi oscillations in the populations of electron momentum states, observed as a function of the optical driving field. Excellent agreement with the scaling of an equal-Rabi multilevel quantum ladder is obtained, representing the observation of a light-driven 'quantum walk' coherently reshaping electron density in momentum space. We note that, after the interaction, the optically generated superposition of momentum states evolves into a train of attosecond electron pulses. Our results reveal the potential of quantum control for the precision structuring of electron densities, with possible applications ranging from ultrafast electron spectroscopy and microscopy to accelerator science and free-electron lasers. PMID:25971512

  8. Phase behaviour of liquid-crystal monolayers of rod-like and plate-like particles.

    PubMed

    Martínez-Ratón, Yuri; Varga, Szabolcs; Velasco, Enrique

    2014-05-28

    Orientational and positional ordering properties of liquid crystal monolayers are examined by means of Fundamental-Measure Density Functional Theory. Particles forming the monolayer are modeled as hard parallelepipeds of square section of size σ and length L. Their shapes are controlled by the aspect ratio κ = L/σ (>1 for prolate and <1 for oblate shapes). The particle centers of mass are restricted to a flat surface and three possible and mutually perpendicular orientations (in-plane and along the layer normal) of their uniaxial axes are allowed. We find that the structure of the monolayer depends strongly on particle shape and density. In the case of rod-like shapes, particles align along the layer normal in order to achieve the lowest possible occupied area per particle. This phase is a uniaxial nematic even at very low densities. In contrast, for plate-like particles, the lowest occupied area can be achieved by random in-plane ordering in the monolayer, i.e., planar nematic ordering takes place even at vanishing densities. It is found that the random in-plane ordering is not favorable at higher densities and the system undergoes an in-plane ordering transition forming a biaxial nematic phase or crystallizes. For certain values of the aspect ratio, the uniaxial-biaxial nematic phase transition is observed for both rod-like and plate-like shapes. The stability region of the biaxial nematic phase enhances with decreasing aspect ratios for plate-like particles, while the rod-like particles exhibit a reentrant phenomenon, i.e., a sequence of uniaxial-biaxial-uniaxial nematic ordering with increasing density if the aspect ratio is larger than 21.34. In addition to this, packing fraction inversion is observed with increasing surface pressure due to the alignment along the layers normal. At very high densities the nematic phase destabilizes to a nonuniform phases (columnar, smectic, or crystalline phases) for both shapes. PMID:24880324

  9. Axisymmetric deformation of plates and shells with phase trasformations under thermal cycling

    NASA Astrophysics Data System (ADS)

    Shkutin, L. I.

    2008-03-01

    A mathematical formulation is given of nonlinear axisymmetric buckling problems for plates and shells in the two-phase zones of austenite-to-martensite transformation. Numerical solutions of the direct-and inverse-transformation problems are used to construct hysteresis loops for thermomechanically cycled, pressure-loaded circular plates and shallow spherical domes of titanium nickelide (NiTi) alloy. It is shown that dynamic instability of the dome deformation process can occur during transformation under loads notably lower than the upper critical values for the isothermal states of the material outside the transformation zone. A theoretical analysis gives external loads below which the dome remains stable in the thermally cycled material with phase transformations.

  10. Volta phase plate cryo-EM of the small protein complex Prx3

    PubMed Central

    Khoshouei, Maryam; Radjainia, Mazdak; Phillips, Amy J.; Gerrard, Juliet A.; Mitra, Alok K.; Plitzko, Jürgen M.; Baumeister, Wolfgang; Danev, Radostin

    2016-01-01

    Cryo-EM of large, macromolecular assemblies has seen a significant increase in the numbers of high-resolution structures since the arrival of direct electron detectors. However, sub-nanometre resolution cryo-EM structures are rare compared with crystal structure depositions, particularly for relatively small particles (<400 kDa). Here we demonstrate the benefits of Volta phase plates for single-particle analysis by time-efficient cryo-EM structure determination of 257 kDa human peroxiredoxin-3 dodecamers at 4.4 Å resolution. The Volta phase plate improves the applicability of cryo-EM for small molecules and accelerates structure determination. PMID:26817416

  11. Beam quality changes of radially and azimuthally polarized fields propagating through quartic phase plates

    NASA Astrophysics Data System (ADS)

    Martínez-Herrero, R.; Piquero, G.; Mejías, P. M.

    2008-02-01

    In terms of the so-called irradiance moments of a light field, the beam quality change, Δ Q, of radially and azimuthally polarized beams caused by propagation through a quartic phase plate (as occurs, for example, in strongly pumped laser rods used in high-power solid-state lasers) is studied. Analytical expressions for Δ Q are given, and a comparison between the scalar and vectorial regimes is also shown. The results are applied to several cases of interest.

  12. Surface modes in "photonic cholesteric liquid crystal-phase plate-metal" structure.

    PubMed

    Vetrov, S Ya; Pyatnov, M V; Timofeev, I V

    2014-05-01

    The light transmission spectrum has been calculated for a "cholesteric liquid crystal-phase plate-metal" structure. It is shown that the system can have an isolated waveguide surface mode with characteristics efficiently controllable by external fields acting on the cholesteric. The degree of localization of surface modes and the transmission coefficients have been found to differ considerably for the light of different polarizations. PMID:24784092

  13. Toward structural/chemical cotailoring of phase-change Ge-Sb-Te in a transmission electron microscope.

    PubMed

    Zhang, W; Kim, J-G; Zheng, W T; Cui, X Q; Kim, Y-J; Song, S A

    2015-03-01

    Ge2Sb2Te5, as the prototype material for phase-change memory, can be transformed from amorphous phase into nanoscale rocksalt-type GeTe provided with an electron irradiation assisted by heating to 520°C in a 1250 kV transmission electron microscope. This sheds a new light into structural and chemical cotailoring of materials through coupling of thermal and electrical fields. PMID:25623497

  14. Direct-write liquid phase transformations with a scanning transmission electron microscope.

    PubMed

    Unocic, Raymond R; Lupini, Andrew R; Borisevich, Albina Y; Cullen, David A; Kalinin, Sergei V; Jesse, Stephen

    2016-08-25

    The highly energetic electron beam (e-beam) in a scanning transmission electron microscope (STEM) can induce local changes in the state of matter, ranging from knock-on and atomic movement, to amorphization/crystallization, and to localized chemical/electrochemical reactions. To date, fundamental studies of e-beam induced phenomena and practical applications have been limited by conventional STEM e-beam rastering modes that allow only for uniform e-beam exposures. Here, an automated liquid phase nanolithography method has been developed that enables the direct writing of nanometer scaled features within microfabricated liquid cells. An external e-beam control system, connected to the scan coils of an aberration-corrected STEM, is used to precisely control the position, dwell time, and scan rate of a sub-nanometer STEM probe. Site-specific locations in a sealed liquid cell containing an aqueous solution of H2PdCl4 are irradiated to deposit palladium nanocrystals onto silicon nitride membranes in a highly controlled manner. The threshold electron dose required for the radiolytic deposition of metallic palladium has been determined, the influence of electron dose on the nanolithographically patterned feature size and morphology is explored, and a feedback-controlled monitoring method for active control of the nanofabricated structures through STEM detector signal monitoring is proposed. This approach enables fundamental studies of electron beam induced interactions with matter in liquid cells and opens new pathways to fabricate nanostructures with tailored architectures and chemistries via shape-controlled nanolithographic patterning from liquid-phase precursors. PMID:27510435

  15. Upper boundary of the Pacific plate subducting beneath Hokkaido, Japan, estimated from ScSp phase

    NASA Astrophysics Data System (ADS)

    Osada, Kinue; Yoshizawa, Kazunori; Yomogida, Kiyoshi; Suetsugu, Daisuke; Bina, Craig; Inoue, Toru; Wiens, Douglas; Jellinek, Mark

    2010-11-01

    Three-dimensional geometry of the upper boundary of the Pacific plate subducting beneath Hokkaido, Japan, was obtained using the ScSp phase: the phase converted from ScS (S wave reflected at the core•mantle boundary) to P wave at the plate boundary. Taking the advantage of a dense seismic network, "Hi-net", recently deployed across the Japanese islands, we applied several seismic array analyses to the recorded waveform data for a large nearby deep earthquake, in order to enhance very weak ScSp signals in the original records. At first, we set up five blocks for the region in plate dip directions. After aligning the travel times of ScS and stacking seismograms among stations in a given sub-block perpendicular to each dip direction, we searched for the optimal plate model (i.e., two-dimensional geometry of the upper boundary) for each block. The model was parameterized by seven depth grids, and seismograms were stacked based on the travel time of ScSp as a time lag of each sub-block, so that the optimal model would yield the maximum spectral energy of ScSp after stacking. This model parameter search was conducted, using ray tracings of ScSp with a reference velocity model and a non-linear inversion scheme (Neighbourhood Algorithm). The optimal model of each block was combined each other by cubic spline interpolation, in order to construct an overall three-dimensional geometry of the upper boundary of the plate. Next, we performed the frequency•wavenumber (f•k) spectral analysis to refine the above result. Assuming each station as a reference point, we made beam output from records of its adjacent stations as a function of wavenumber vector (kx,ky) and frequency. The peak of its power spectrum was considered to represent the wavenumber vector of ScSp, that is, azimuth of arrival and slowness, so that we can estimate the position and depth of the corresponding ScS•ScSp conversion. In the frequency range from 0.5 to 1.5 Hz, we could estimate the conversion

  16. Evidence of lower-mantle slab penetration phases in plate motions.

    PubMed

    Goes, Saskia; Capitanio, Fabio A; Morra, Gabriele

    2008-02-21

    It is well accepted that subduction of the cold lithosphere is a crucial component of the Earth's plate tectonic style of mantle convection. But whether and how subducting plates penetrate into the lower mantle is the subject of continuing debate, which has substantial implications for the chemical and thermal evolution of the mantle. Here we identify lower-mantle slab penetration events by comparing Cenozoic plate motions at the Earth's main subduction zones with motions predicted by fully dynamic models of the upper-mantle phase of subduction, driven solely by downgoing plate density. Whereas subduction of older, intrinsically denser, lithosphere occurs at rates consistent with the model, younger lithosphere (of ages less than about 60 Myr) often subducts up to two times faster, while trench motions are very low. We conclude that the most likely explanation is that older lithosphere, subducting under significant trench retreat, tends to lie down flat above the transition to the high-viscosity lower mantle, whereas younger lithosphere, which is less able to drive trench retreat and deforms more readily, buckles and thickens. Slab thickening enhances buoyancy (volume times density) and thereby Stokes sinking velocity, thus facilitating fast lower-mantle penetration. Such an interpretation is consistent with seismic images of the distribution of subducted material in upper and lower mantle. Thus we identify a direct expression of time-dependent flow between the upper and lower mantle. PMID:18288192

  17. High-resolution transmission electron microscopy with an electrostatic Zach phase plate

    NASA Astrophysics Data System (ADS)

    Hettler, S.; Dries, M.; Zeelen, J.; Oster, M.; Schröder, R. R.; Gerthsen, D.

    2016-05-01

    A new method to control lattice-fringe contrast in high-resolution transmission electron microscopy (HRTEM) images by the implementation of a physical phase plate (PP) is proposed. PPs are commonly used in analogy to Zernike PPs in light microscopy to enhance the phase contrast of weak-phase objects with nm-sized features, which often occur in life science applications. Such objects otherwise require strong defocusing, which leads to a degradation of the instrumental resolution and impedes intuitive image interpretation. The successful application of an electrostatic Zach PP in HRTEM is demonstrated by the investigation of single crystalline Si and Ge samples. The influence of the Zach PP on the image formation process is assessed by analyzing the amplitudes of (111) reflections in power spectra which show a cosine-type dependence on the induced phase shift under certain conditions as predicted by theory.

  18. The Cell Cycle: An Activity Using Paper Plates to Represent Time Spent in Phases of the Cell Cycle

    ERIC Educational Resources Information Center

    Scherer, Yvette D.

    2014-01-01

    In this activity, students are given the opportunity to combine skills in math and geometry for a biology lesson in the cell cycle. Students utilize the data they collect and analyze from an online onion-root-tip activity to create a paper-plate time clock representing a 24-hour cell cycle. By dividing the paper plate into appropriate phases of…

  19. Method for preparing surfaces of metal composites having a brittle phase for plating

    DOEpatents

    Coates, Cameron W.; Wilson, Thomas J.

    1984-01-01

    The present invention is directed to a method for preparing surfaces of two-phase metal composites having relatively brittle and malleable components for plating with corrosion-resistant material. In practice of the present invention, the surfaces of the composites are etched to remove a major portion or fraction of the brittle component. The etched surface is then peened with particulates for breaking the brittle component from the surfaces and for spreading or smearing the malleable component over the surfaces. The peened surface is then chemically cleaned of residual traces of the brittle component so as to provide a surface of essentially the malleable component to which the corrosion-resistant material may be plated thereon in an adherent manner.

  20. Method and apparatus for acoustic plate mode liquid-solid phase transition detection

    DOEpatents

    Blair, Dianna S.; Freye, Gregory C.; Hughes, Robert C.; Martin, Stephen J.; Ricco, Antonio J.

    1993-01-01

    A method and apparatus for sensing a liquid-solid phase transition event is provided which comprises an acoustic plate mode detecting element placed in contact with a liquid or solid material which generates a high-frequency acoustic wave that is attenuated to an extent based on the physical state of the material is contact with the detecting element. The attenuation caused by the material in contact with the acoustic plate mode detecting element is used to determine the physical state of the material being detected. The method and device are particularly suited for detecting conditions such as the icing and deicing of wings of an aircraft. In another aspect of the present invention, a method is provided wherein the adhesion of a solid material to the detecting element can be measured using the apparatus of the invention.

  1. Detection and quantification of delamination in laminated plates from the phase of appropriate guided wave modes

    NASA Astrophysics Data System (ADS)

    Amjad, Umar; Yadav, Susheel Kumar; Kundu, Tribikram

    2016-01-01

    Applicability of specific Lamb wave modes for delamination detection and quantification in a laminated aluminum plate is investigated. The Lamb modes were generated in the plate using a broadband piezoelectric transducer structured with a rigid electrode. Appropriate excitation frequencies and modes for inspection were selected from theoretical dispersion curves. Sensitivity of antisymmetric and symmetric modes for delamination detection and quantification has been investigated using the Hilbert-Huang transform. The mode conversion phenomenon of Lamb waves during progressive delamination is observed. The antisymmetric mode is found to be more reliable for delamination detection and quantification. In this investigation, the changes in the phase of guided Lamb wave modes are related to the degree of delamination, unlike other studies, where mostly the attenuation of the propagating waves has been related to the extent of the internal damage, such as cracks and corrosions. Appropriate features for delamination detection and quantification are extracted from the experimental data.

  2. Insight into the microscopic structure of an AdS black hole from a thermodynamical phase transition.

    PubMed

    Wei, Shao-Wen; Liu, Yu-Xiao

    2015-09-11

    Comparing with an ordinary thermodynamic system, we investigate the possible microscopic structure of a charged anti-de Sitter black hole completely from the thermodynamic viewpoint. The number density of the black hole molecules is introduced to measure the microscopic degrees of freedom of the black hole. We found that the number density suffers a sudden change accompanied by a latent heat when the black hole system crosses the small-large black hole coexistence curve, while when the system passes the critical point, it encounters a second-order phase transition with a vanishing latent heat due to the continuous change of the number density. Moreover, the thermodynamic scalar curvature suggests that there is a weak attractive interaction between two black hole molecules. These phenomena might cast new insight into the underlying microscopic structure of a charged anti-de Sitter black hole. PMID:26406818

  3. On pressure-shear plate impact for studying the kinetics of stress-induced phase transformations

    NASA Astrophysics Data System (ADS)

    Escobar, Joanne C.; Clifton, Rodney J.

    1992-07-01

    Pressure-shear plate impact experiments are proposed for studying the kinetics of stress-induced phase transformations. The purpose of this paper is to determine loading conditions and specimen orientations which can be expected to activate a single habit plane variant parallel to the impact plane, thereby simplifying the study of the kinetics of the transformation through monitoring the wave profiles associated with the propagating phase boundary. The Wechsler Lieberman-Read phenomenological theory was used to determine habit plane indices and directions of shape deformation for a Cu-Al-Ni shape memory alloy which undergoes a martensitic phase transformation under stress. Elastic waves generated by pressure-shear impact were analyzed for wave propagation in the direction of the normal to a habit plane. A critical resolved shear stress criterion was used to predict variants which are expected to be activated for a range of impact velocities and relative magnitudes of the normal and transverse components of the impact velocity.

  4. Local orbital angular momentum revealed by spiral-phase-plate imaging in transmission-electron microscopy

    NASA Astrophysics Data System (ADS)

    Juchtmans, Roeland; Verbeeck, Jo

    2016-02-01

    The orbital angular momentum (OAM) of light and matter waves is a parameter that has been getting increasingly more attention over the past couple of years. Beams with a well-defined OAM, the so-called vortex beams, are applied already in, e.g., telecommunication, astrophysics, nanomanipulation, and chiral measurements in optics and electron microscopy. Also, the OAM of a wave induced by the interaction with a sample has attracted a lot of interest. In all these experiments it is crucial to measure the exact (local) OAM content of the wave, whether it is an incoming vortex beam or an exit wave after interacting with a sample. In this work we investigate the use of spiral phase plates (SPPs) as an alternative to the programmable phase plates used in optics to measure OAM. We derive analytically how these can be used to study the local OAM components of any wave function. By means of numerical simulations we illustrate how the OAM of a pure vortex beam can be measured. We also look at a sum of misaligned vortex beams and show how, by using SPPs, the position and the OAM of each individual beam can be detected. Finally, we look at the OAM induced by a magnetic dipole on a free-electron wave and show how the SPP can be used to localize the magnetic poles and measure their "magnetic charge." Although our findings can be applied to study the OAM of any wave function, our findings are of particular interest for electron microscopy where versatile programmable phase plates do not yet exist.

  5. Wide spectral range multiple orders and half-wave achromatic phase retarders fabricated from two lithium tantalite single crystal plates

    NASA Astrophysics Data System (ADS)

    Emam-Ismail, M.

    2015-11-01

    In a broad spectral range (300-2500 nm), we report the use of channeled spectra formed from the interference of polarized white light to extract the dispersion of the phase birefringence Δnp(λ) of the x- and y-cuts of lithium tantalite (LiTaO3:LT) plates. A new method named as wavenumber difference method is used to extract the spectral behavior of the phase birefringence of the x- and y- cuts of LT plates. The correctness of the obtained birefringence data is confirmed by using Jones vector method through recalculating the plates thicknesses. The spectral variation of the phase birefringence Δnp(λ) of the x- and y-cuts of LT plates is fitted to Cauchy dispersion function with relative error for both x- and y-cuts of order 2.4×10-4. The group birefringence dispersion Δng (λ) of the x- and y-cuts of LT plates is also calculated and fitted to Ghosh dispersion function with relative error for both x- and y-cuts of order 2.83×10-4. Furthermore, the phase retardation introduced by the x- and y-cuts of LT plates is also calculated. It is found that the amount of phase retardation confirms that the x- and y-cuts of LT plates can act as a multiple order half- and quarter-wave plates working at many different wavelengths through the spectral range 300-2500 nm. For the x- and y-cuts of LT plates, a large difference between group and phase birefringence is observed at a short wavelength (λ=300 nm); while such difference progressively diminished at longer wavelength (λ=2000 nm). In the near infrared region (NIR) region (700-2500 nm), a broad spectral full width at half maximum (FWHM) is observed for either x- or y-cut of LT plate which can act as if it is working as a zero order wave plate. Finally, an achromatic half-wave plate working at 598 nm and covering a wide spectral range (300-900 nm) is demonstrated experimentally by combining both x- and y-cuts of LT plates.

  6. Label-free imaging of intracellular motility by low-coherent quantitative phase microscope in reflection geometry

    NASA Astrophysics Data System (ADS)

    Yamauchi, Toyohiko; Iwai, Hidenao; Yamashita, Yutaka

    2011-11-01

    We demonstrate tomographic imaging of intracellular activity of living cells by a low-coherent quantitative phase microscope. The intracellular organelles, such as the nucleus, nucleolus, and mitochondria, are moving around inside living cells, driven by the cellular physiological activity. In order to visualize the intracellular motility in a label-free manner we have developed a reflection-type quantitative phase microscope which employs the phase shifting interferometric technique with a low-coherent light source. The phase shifting interferometry enables us to quantitatively measure the intensity and phase of the optical field, and the low-coherence interferometry makes it possible to selectively probe a specific sectioning plane in the cell volume. The results quantitatively revealed the depth-resolved fluctuations of intracellular surfaces so that the plasma membrane and the membranes of intracellular organelles were independently measured. The transversal and the vertical spatial resolutions were 0.56 μm and 0.93 μm, respectively, and the mechanical sensitivity of the phase measurement was 1.2 nanometers. The mean-squared displacement was applied as a statistical tool to analyze the temporal fluctuation of the intracellular organelles. To the best of our knowledge, our system visualized depth-resolved intracellular organelles motion for the first time in sub-micrometer resolution without contrast agents.

  7. Inexpensive read-out for coincident electron spectroscopy with a transmission electron microscope at nanometer scale using micro channel plates and multistrip anodes

    NASA Astrophysics Data System (ADS)

    Hollander, R. W.; Bom, V. R.; van Eijk, C. W. E.; Faber, J. S.; Hoevers, H.; Kruit, P.

    1994-09-01

    The elemental composition of a sample at nanometer scale is determined by measurement of the characteristic energy of Auger electrons, emitted in coincidence with incoming primary electrons from a microbeam in a scanning transmission electron microscope (STEM). Single electrons are detected with position sensitive detectors, consisting of MicroChannel Plates (MCP) and MultiStrip Anodes (MSA), one for the energy of the Auger electrons (Auger-detector) and one for the energy loss of primary electrons (EELS-detector). The MSAs are sensed with LeCroy 2735DC preamplifiers. The fast readout is based on LeCroy's PCOS III system. On the detection of a coincidence (Event) energy data of Auger and EELS are combined with timing data to an Event word. Event words are stored in list mode in a VME memory module. Blocks of Event words are scanned by transputers in VME and two-dimensional energy histograms are filled using the timing information to obtain a maximal true/accidental ratio. The resulting histograms are stored on disk of a PC-386, which also controls data taking. The system is designed to handle 10 5 Events per second, 90% of which are accidental. In the histograms the "true" to "accidental" ratio will be 5. The dead time is 15%.

  8. Ultra-thin optical vortex phase plate based on the metasurface and the angular momentum transformation

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Li, Yan; Guo, Zhongyi; Li, Rongzhen; Zhang, Jingran; Zhang, Anjun; Qu, Shiliang

    2015-04-01

    The ultra-thin optical vortex phase plate (VPP) has been designed and investigated based on the metasurface of the metal rectangular split-ring resonators (MRSRRs) array. The circularly polarized incident light can convert into corresponding cross-polarization transmission light, and the phase and the amplitude of cross-polarization transmission light can be simultaneously governed by modulating two arms of the MRSRR. The MRSRR has been arranged in a special order for forming an ultra-thin optical VPP that can covert a plane wave into a vortex beam with a variety of the topological charges, and the transformation between spin angular momentum (SAM) and orbital angular momentum (OAM) has been discussed in detail. The multi-spectral characteristics of the VPP have also been investigated, and the operating bandwidth of the designed VPP is 190 nm (in the range of 710-900 nm), which enable a potential implication for integrated optics and vortex optics.

  9. New long trace profiler based on phase plate diffraction for optical metrology of SSRF

    SciTech Connect

    Zeng Danhua; Xiao Tiqiao; Du Guohao; Wen Li; Luo Hongxin; Xia Shaojian; Xu Hongjie

    2006-09-15

    A long trace profiler LTP-1200, with a novel f-{theta} system based on phase plate diffraction and a scanning range up to 1200 mm, has been developed at Shanghai Synchrotron Radiation Facility. The central dark line in the diffraction pattern generated by a {pi} phase plate is taken as the positioning benchmark. A magnet levitated linear rail with very high accuracy is used. A granite bench is employed to reduce deformation due to self-gravity of the rail. The focused diffraction pattern is recorded with an area charge-coupled device. The generalized regression neural network algorithm is adopted to improve the beam positioning precision. The static stability of LTP-1200 in 5 h is 0.14 {mu}rad, and the repeatability reaches 0.05 {mu}rad in a common laboratory without any special control of temperature, air turbulence, etc. Calibration tests were carried out with a high precision autocollimator and a standard spherical mirror, respectively. Results show the high performance and reliability of the LTP-1200.

  10. Numerical modeling of the subwavelength phase-change recording using an apertureless scanning near-field optical microscope.

    PubMed

    Grosges, Thomas; Petit, Stéphane; Barchiesi, Dominique; Hudlet, Sylvain

    2004-11-29

    The electromagnetic field enhancement (FE) at the end of the probe of an Apertureless Scanning Near-field Optical Microscope (ASNOM) is used to write nanometric dots in a phase-change medium. The FE acts as a heat source that allows the transition from amorphous to crystalline phase in a Ge2Sb2Te5 layer. Through the 2D Finite Element Method (FEM) we predict the size of the dot as a function of both the illumination duration and the incoming power density. Numerical results are found to be in good agreement with preliminary experimental data. PMID:19488240

  11. Phase-Contrast versus Off-Axis Illumination: Is a More Complex Microscope Always More Powerful?

    ERIC Educational Resources Information Center

    Hostounsky, Zdenek; Pelc, Radek

    2007-01-01

    In this article, a practical demonstration suitable for any biology college classroom is presented. With the examples of a complex biological specimen (slug's radula) and a simple reference specimen (electron microscopical grid imprint in gelatin), both of which can be easily prepared, the capabilities of two imaging modes commonly used in optical…

  12. Differential Phase-Contrast Scanning X-Ray Microscope For Observation Of Low-Z element Specimen

    SciTech Connect

    Takeuchi, Akihisa; Uesugi, Kentaro; Suzuki, Yoshio

    2010-07-23

    Differential phase-contrast scanning x-ray microscope/microtomography have been developed. A fast readout charge-coupled device (CCD) camera coupled with a visible-light conversion unit is used as a detector to record the transmitted intensity distribution of far-field image for every pixel in a scan. Simultaneous absorption and phase-contrast images are given from a single scan by image-processing of the CCD frames. The system is constructed at BL20XU of SPring-8, and its feasibility is demonstrated at the photon energy of 8 keV. A tantalum test chart is observed and its finest structure of 140 nm pitch pattern is clearly observed. Measured phase sensitivity is approximately {lambda}/270. Some low-Z element specimens are observed and obtained phase contrast image shows much higher sensitivity than that of absorption contrast.

  13. Continuous distributed phase-plate advances for high-energy laser systems

    NASA Astrophysics Data System (ADS)

    Marozas, J. A.; Collins, T. J. B.; Zuegel, J. D.; McKenty, P. W.; Cao, D.; Fochs, S.; Radha, P. B.

    2016-05-01

    The distributed phase plate (DPP) design code Zhizhoo’ has been used to design full- aperture, continuous near-field transmission optics for a wide variety of high-fidelity focal-spot shapes for high-energy laser systems: OMEGA EP, Dynamic Compression Sector (DCS), and the National Ignition Facility (NIF). The envelope shape, or profile, of the focal spot affects the hydrodynamics of directly driven targets in these laser systems. Controlling the envelope shape to a high degree of fidelity impacts the quality of the ablatively driven implosions. The code Zhizhoo’ not only produces DPP's with great control of the envelope shape, but also spectral and gradient control as well as robustness from near-field phase aberrations. The focal-spot shapes can take on almost any profile from symmetric to irregular patterns and with high fidelity relative to the objective function over many decades of intensity. The control over the near-field phase spectrum and phase gradients offer greater manufacturability of the full- aperture continuous surface-relief pattern. The flexibility and speed of the DPP design code Zhizhoo’ will be demonstrated by showing the wide variety of successful designs that have been made and those that are in progress.

  14. Concrete containment tests: Phase 2, Structural elements with liner plates: Interim report

    SciTech Connect

    Hanson, N.W.; Roller, J.J.; Schultz, D.M.; Julien, J.T.; Weinmann, T.L.

    1987-08-01

    The tests described in this report are part of Phase 2 of the Electric Power Research Institute (EPRI) program. The overall objective of the EPRI program is to provide a test-verified analytical method of estimating capacities of concrete reactor containment buildings under internal overpressurization from postulated degraded core accidents. The Phase 2 testing included seven large-scale specimens representing structural elements from reinforced and prestressed concrete reactor containment buildings. Six of the seven test specimens were square wall elements. Of these six specimens, four were used for biaxial tension tests to determine strength, deformation, and leak-rate characteristics of full-scale wall elements representing prestressed concrete containment design. The remaining two square wall elements were used for thermal buckling tests to determine whether buckling of the steel liner plate would occur between anchorages when subjected to a sudden extreme temperature differential. The last of the seven test specimens for Phase 2 represented the region where the wall and the basemat intersect in a prestressed concrete containment building. A multi-directional loading scheme was used to produce high bending moments and shear in the wall/basemat junction region. The objective of this test was to determine if there is potential for liner plate tearing in the junction region. Results presented include observed behavior and extensive measurements of deformations and strains as a function of applied load. The data are being used to confirm analytical models for predicting strength and deformation of containment structures in a separate parallel analytical investigation sponsored by EPRI.

  15. Fabrication of large-scale multilevel phase-type Fresnel zone plate arrays by femtosecond laser direct writing

    NASA Astrophysics Data System (ADS)

    Yu, Yan-Hao; Tian, Zhen-Nan; Jiang, Tong; Niu, Li-Gang; Gao, Bing-Rong

    2016-03-01

    We report on the fabrication of large-scale eight-level phase-type Fresnel zone plate arrays (FZPAs) by femtosecond-laser direct writing technology. A high-speed galvanometer scanning system was used to fabricate each Fresnel zone plate to realize high fabrication efficiency. To overcome the limited fabrication scale in the case of galvanometer scanning, inter-plate movements were controlled by multi-axis air-bearing precise positioning stages. With the system, FZPAs whose fill-factor was designed to be 100% realized a diffraction efficiency of 89%. The focusing and imaging properties of the FZPAs were also evaluated, and the FZPAs showed high fidelity.

  16. Evaluation of gratings for X-ray and neutron phase imaging techniques by using x-ray projection microscope

    SciTech Connect

    Minami, Katsunori; Yashiro, Wataru; Olbinado, Margie; Momose, Atsushi

    2012-07-31

    In the X-ray and neutron Talbot (-Lau) interferometry, fabrication of phase or amplitude grating with a high-aspect ratio is a key factor to obtain high quality images. To improve the ability of the grating, evaluation of shape and thickness variation and feed-back to the fabrication process are essential. Here, it is shown that X-ray projection microscope with a spatial resolution of sub-micrometer is a powerful tool for the purpose. Three kinds of gratings have been evaluated by using a projection X-ray microscope with X-ray source size of 0.6 micrometer. Uniformity of thickness of the grating has been visualized nondestructively.

  17. Simple technique of Fourier-transform holographic microscope with compensation of phase aberration

    NASA Astrophysics Data System (ADS)

    Grishin, Oleg V.; Fedosov, Ivan V.; Tuchin, Valery V.

    2016-04-01

    In this paper, we present a novel simple technique of Fourier-transform holographic microscopy (FTHM). Simplicity of the scheme, possibility to use a small image sensor and provide compensation of aberration, enable one to construct inexpensive holographic microscopes. We experimentally compare FTHM with in-line holographic microscopy. In this paper, we present experimental scheme of FTHM, description of used algorithms and experimental results for an amplitude test object and biological samples (blood smears).

  18. Defect detection in anisotropic plates based on the instantaneous phase of signals.

    PubMed

    Prado, Vander Teixeira; Granja, Silvio Cesar Garcia; Higuti, Ricardo Tokio; Kitano, Cláudio; Martínez-Graullera, Óscar; Segura, Luis Elvira

    2015-10-01

    Anisotropic materials are widely employed in industry and engineering, and efficient nondestructive testing techniques are important to guarantee the structural integrity of the involved parts. A simple technique is proposed to detect defects in anisotropic plates using ultrasonic guided waves and arrays. The technique is based on the application of an objective threshold to a synthetic aperture image obtained from the instantaneous phase (IP) of the emitter-receiver signal combinations. In a previous work the method was evaluated for isotropic materials, and in this paper it is shown that with some considerations the technique can also be applied to anisotropic plates. These considerations, which should be taken into account in beamforming, are (1) group velocity dependence with propagation direction, and (2) elastic focusing, which results in energy concentration in some propagation directions, with the practical consequence that not all aperture signals effectively contribute to the image. When compared with conventional delay-and-sum image beamforming techniques, the proposed IP technique results in significant improvements relative to defect detection and artifacts/dead zone reduction. PMID:26470050

  19. SEARCHING FOR PLANETS IN HOLEY DEBRIS DISKS WITH THE APODIZING PHASE PLATE

    SciTech Connect

    Meshkat, Tiffany; Kenworthy, Matthew A.; Bailey, Vanessa P.; Su, Kate Y. L.; Hinz, Philip M.; Smith, Paul S.; Mamajek, Eric E.

    2015-02-10

    We present our first results from a high-contrast imaging search for planetary mass companions around stars with gapped debris disks, as inferred from the stars' bright infrared excesses. For the six considered stars, we model the disks' unresolved infrared spectral energy distributions in order to derive the temperature and location of the disk components. With VLT/NaCo Apodizing Phase Plate coronagraphic L'-band imaging, we search for planetary mass companions that may be sculpting the disks. We detect neither disks nor companions in this sample, confirmed by comparing plausible point sources with archival data. In order to calculate our mass sensitivity limit, we revisit the stellar age estimates. One target, HD 17848, at 540 ± 100 Myr old is significantly older than previously estimated. We then discuss our high-contrast imaging results with respect to the disk properties.

  20. A novel silver-coated solid-phase microextraction metal fiber based on electroless plating technique.

    PubMed

    Feng, Juanjuan; Sun, Min; Li, Jubai; Liu, Xia; Jiang, Shengxiang

    2011-09-01

    A novel silver-coated solid-phase microextraction fiber was prepared based on electroless plating technique. Good extraction performance of the fiber for model compounds including phthalate esters (dibutyl phthalate, dioctyl phthalate, dicyclohexyl phthalate and diallyl phthalate) and polycyclic aromatic hydrocarbons (naphthalene, fluorene, phenanthrene, fluoranthene) in aqueous solution was obtained. Under the optimized conditions (extraction temperature, extraction time, ionic strength and desorption temperature), the proposed SPME-GC method showed wide linear ranges with correlation coefficients (R(2)) ranging from 0.9745 to 0.9984. The limits of detection were at the range of 0.02 to 0.1 μg L(-1). Single fiber repeatability and fiber-to-fiber reproducibility as well as stability to acid, alkali and high temperature were studied and the results were all satisfactory. The method was applied successfully to the aqueous extracts of disposable paper cup and instant noodle barrel. Several kinds of analytes were detected and quantified. PMID:21801885

  1. GROWTH PLATE ABNORMALITIES IN PEDIATRIC CANCER PATIENTS UNDERGOING PHASE 1 ANTI-ANGIOGENIC THERAPY: A REPORT FROM THE CHILDREN’S ONCOLOGY GROUP PHASE I CONSORTIUM

    PubMed Central

    Voss, Stephan D.; Glade-Bender, Julia; Spunt, Sheri L.; DuBois, Steven G.; Widemann, Brigitte C.; Park, Julie R.; Leary, Sarah E. S.; Nelson, Marvin D.; Adamson, Peter C.; Blaney, Susan M.; Weigel, Brenda

    2014-01-01

    Purpose Pre-clinical studies suggest that anti-angiogenic agents may be toxic to the developing growth plate. The purpose of this study was to evaluate the incidence of growth plate abnormalities in children with refractory cancer undergoing anti-angiogenic therapy. Materials and methods Targeted radiographic studies from 53 subjects enrolled on six separate Children’s Oncology Group Phase 1 and Pilot Consortium clinical trials evaluating new anti-cancer agents agents interfering with angiogenesis were reviewed. Subjects received tyrosine kinase inhibitors with anti-angiogenic effects (n=35), monoclonal antibodies targeting VEGF (n=13), or angiopoietin (n=5). Radiographs of their distal femur/proximal tibia were obtained at baseline. Follow-up radiographs were obtained after odd-numbered treatment cycles in patients with open growth plates who did not experience disease progression prior to cycle 3. Results Baseline and follow-up growth plate radiographs were acquired in 48/53 (90%) of patients. Five patients (9.4%), all of whom received a specific VEGF/VEGFR blocking agent [sunitinib (n=1) or pazopanib (n=4)], had growth plate abnormalities. Four patients had growth plate widening that was apparent on at least two successive radiographs, but was not confirmed by MRI. The fifth patient had progressive growth plate widening and evidence of physeal cartilage hypertrophy on MRI. Subsequent off treatment radiographs showed that the growth plate changes were reversible. Conclusion Growth plate abnormalities occur in a small, but relevant number of patients undergoing anti-angiogenic therapy. These results support the need for growth plate monitoring in children with open growth plates who are receiving anti-angiogenic therapy, and for improved methods to assess toxicity of anti-angiogenic agents to the developing skeleton. PMID:25257751

  2. Phase Separation and Development of a Scanning Time of Flight Microscope to Study Charge Transport in Structured Organic Semiconductors

    NASA Astrophysics Data System (ADS)

    Paul, Sanjoy; Tripathi, Suvagata; Singh, Gautam; Twieg, Robert; Kumar, Satyendra; Ellman, Brett

    2015-03-01

    A scanning time-of-flight microscope (STOFm) has been developed to study charge transport in liquid crystalline organic semiconductors (LCOSCs). The STOFm combines the well-known pulsed laser time-of-flight technique with simultaneous polarized light transmission measurements, both on length scales of ~ 10 μm. In parallel, we have fabricated devices via photopolymerization and phase separation of a monomer/LCOSC mixture. The resulting structure has the LCOSC confined to small regions separated by an insulating polymer. We will discuss fabrication of these systems, as well as their characterization using the STOFm. Finally, we will show results on position-dependent charge transport in various pure LCOSC samples.

  3. Microscopic nature of crystal phase quantum dots in ultrathin GaAs nanowires by nanoscale luminescence characterization

    NASA Astrophysics Data System (ADS)

    Loitsch, Bernhard; Müller, Marcus; Winnerl, Julia; Veit, Peter; Rudolph, Daniel; Abstreiter, Gerhard; Finley, Jonathan J.; Bertram, Frank; Christen, Jürgen; Koblmüller, Gregor

    2016-06-01

    Crystal phase quantum dots (CPQD) embedded in a nanowire (NW) geometry have recently emerged as efficient single photon emitters. In typical III–V semiconductor NWs such CPQDs are linked to the well-known zincblende (ZB)/wurtzite (WZ) polytypism that occurs mostly randomly along the NW axis, making it difficult to assess the exact position and microscopic nature of a particular emitter. Here, we employ highly spatially-resolved cathodoluminescence (CL) spectroscopy directly in a scanning transmission electron microscope to unambiguously identify type, microscopic nature, position and luminescence characteristics of single polytype defects in ultrathin GaAs–AlGaAs core–shell NWs with nanometer-scale resolution. Importantly, we find that individual twin defects (1 ML-inclusion of WZ in a ZB crystal) are the predominant source for QD emission, where the spectral position depends sensitively on the strength of radial confinement by the ultrathin GaAs NW core. By analyzing the temperature-dependent luminescence properties of a ∼1 ML thick/7 nm wide twin-defect CPQD, we determine a thermal activation energy of ∼7.4 meV for the confined excitons, as well as an evolution in linewidth that reflects phonon-mediated broadening processes, corroborating the QD-like behavior. Our findings also reveal the presence of effective carrier diffusion in-between isolated CPQDs.

  4. End plate assembly having a two-phase fluid-filled bladder and method for compressing a fuel cell stack

    DOEpatents

    Carlstrom, Jr., Charles M.

    2001-01-01

    An end plate assembly is disclosed for use in a fuel cell assembly in which the end plate assembly includes a housing having a cavity, and a bladder receivable in the cavity and engageable with the fuel cell stack. The bladder includes a two-phase fluid having a liquid portion and a vapor portion. Desirably, the two-phase fluid has a vapor pressure between about 100 psi and about 600 psi at a temperature between about 70 degrees C. to about 110 degrees C.

  5. Macroscopic and microscopic investigations on uniaxial ratchetting of two-phase Ti–6Al–4V alloy

    SciTech Connect

    Kang, Guozheng; Dong, Yawei; Liu, Yujie; Jiang, Han

    2014-06-01

    The uniaxial ratchetting of Ti–6Al–4V alloy with two phases (i.e., primary hexagonal close packed (HCP) α and secondary body-centered cubic (BCC) β phases) was investigated by macroscopic and microscopic experiments at room temperature. Firstly, the effects of cyclic softening/hardening feature, applied mean stress and stress amplitude on the uniaxial ratchetting of the alloy were discussed. The macroscopic investigation of Ti–6Al–4V alloy presents obvious strain-amplitude-dependent cyclic softening, as well as a three-staged evolution curve with regard to the ratchetting strain rate. The ratchetting depends greatly on the applied mean stress and stress amplitude while the ratchetting strain increases with the increasing applied mean stress and stress amplitude. Then, the evolution of dislocation patterns and deformation twinning during the uniaxial ratchetting of two-phase Ti–6Al–4V alloy were observed using transmission electron microscopy (TEM). The microscopic observation shows that deformation twinning occurs in the primary α phase and its amount increases gradually during the uniaxial ratchetting. Simultaneously, the planar dislocation evolves from discrete lines to some dislocation nets and parallel lines with the increasing number of cycles. The deformation twinning in the primary α phase is one of main contributions to the uniaxial ratchetting of Ti–6Al–4V alloy, and should be considered in the construction of corresponding constitutive model. - Highlights: • A three-staged ratchetting occurs in the stress-controlled cyclic tests of Ti–6Al–4V alloy. • Dislocation patterns change from discrete lines to nets and parallel lines. • Deformation twinning occurs during the uniaxial ratchetting. • Both dislocation slipping and twinning are the causes of ratchetting.

  6. Phased annular array transducers for omnidirectional guided wave mode control in isotropic plate like structures

    NASA Astrophysics Data System (ADS)

    Koduru, Jaya P.; Momeni, Sepandarmaz; Rose, Joseph L.

    2013-12-01

    Ultrasonic guided waves are fast emerging as a reliable tool for continuous structural health monitoring. Their multi-modal nature along with their long range propagation characteristics offer several possibilities for interrogating structures. Transducers commonly used to generate guided waves in structures excite multiple modes at any frequency; their complex scattering and reflection from defects and boundaries often complicates the extraction of useful information. Often it is desirable to control the guided wave modes propagating in a structure to take advantage of their unique properties for different applications. Earlier attempts at guided wave mode control involved developing fixed wavelength linear and annular array transducers. Their only disadvantage is that the transducer is limited to a particular wavelength and a change in wavelength necessitates a change in the transducer. In this paper, we propose the development of an annular array transducer that can generate mode controlled omnidirectional guided waves by independently controlling the amplitude and phase of the array elements. A simplified actuator model that approximates the transducer loading on the structure to a constant pressure load under the array elements is assumed and an optimization problem is set up to compute the excitation voltage and phase of the elements. A five element annular array transducer is designed utilizing 1-3 type piezocomposite materials. The theoretical computations are experimentally verified on an aluminum plate like structure by exciting A0 and S0 guided wave modes.

  7. Neutron Diffraction Residual Strain Tensor Measurements Within The Phase IA Weld Mock-up Plate P-5

    SciTech Connect

    Hubbard, Camden R

    2011-09-01

    Oak Ridge National Laboratory (ORNL) has worked with NRC and EPRI to apply neutron and X-ray diffraction methods to characterize the residual stresses in a number of dissimilar metal weld mockups and samples. The design of the Phase IA specimens aimed to enable stress measurements by several methods and computational modeling of the weld residual stresses. The partial groove in the 304L stainless steel plate was filled with weld beads of Alloy 82. A summary of the weld conditions for each plate is provided in Table 1. The plates were constrained along the long edges during and after welding by bolts with spring-loaded washers attached to the 1-inch thick Al backing plate. The purpose was to avoid stress relief due to bending of the welded stainless steel plate. The neutron diffraction method was one of the methods selected by EPRI for non-destructive through thickness strain and stress measurement. Four different plates (P-3 to P-6) were studied by neutron diffraction strain mapping, representing four different welding conditions. Through thickness neutron diffraction strain mappings at NRSF2 for the four plates and associated strain-free d-zero specimens involved measurement along seven lines across the weld and at six to seven depths. The mountings of each plate for neutron diffraction measurements were such that the diffraction vector was parallel to each of the three primary orthogonal directions of the plate: two in-plane directions, longitudinal and transverse, and the direction normal to the plate (shown in left figure within Table 1). From the three orthogonal strains for each location, the residual stresses along the three plate directions were calculated. The principal axes of the strain and stress tensors, however, need not necessarily align with the plate coordinate system. To explore this, plate P-5 was selected for examination of the possibility that the principal axes of strain are not along the sample coordinate system axes. If adequate data could

  8. MicroRaman, PXRD, EDS and microscopic investigation of magnesium calcite biomineral phases. The case of sea urchin biominerals

    NASA Astrophysics Data System (ADS)

    Borzęcka-Prokop, B.; Wesełucha-Birczyńska, A.; Koszowska, E.

    2007-02-01

    This study concerns Mg-calcite characterization (and in particular molecular structure and microstructural studies of mineral phases) of a sea urchin mineralised test and spines. Sea urchins are spiny sea animals (kingdom Animalia, phylum Echinodermata, class Echinoidea). Microscopic observations, SEM, EDS, PXRD and spectroscopic microRaman methods have been applied to characterize the biomineral parts of the sea urchin. The latter technique is very useful in research of biological systems and especially suitable for monitoring differences within biomineral phases exhibiting varieties of morphological forms. Crystalline magnesium calcium carbonate, Mg xCa 1- xCO 3 (magnesian calcite; space group R-3 cH; a = 4.9594(8) Å, c = 16.886(6) Å), has been identified as the predominant biomineral component.

  9. Nonanalytic microscopic phase transitions and temperature oscillations in the microcanonical ensemble: An exactly solvable one-dimensional model for evaporation

    NASA Astrophysics Data System (ADS)

    Hilbert, Stefan; Dunkel, Jörn

    2006-07-01

    We calculate exactly both the microcanonical and canonical thermodynamic functions (TDFs) for a one-dimensional model system with piecewise constant Lennard-Jones type pair interactions. In the case of an isolated N -particle system, the microcanonical TDFs exhibit (N-1) singular (nonanalytic) microscopic phase transitions of the formal order N/2 , separating N energetically different evaporation (dissociation) states. In a suitably designed evaporation experiment, these types of phase transitions should manifest themselves in the form of pressure and temperature oscillations, indicating cooling by evaporation. In the presence of a heat bath (thermostat), such oscillations are absent, but the canonical heat capacity shows a characteristic peak, indicating the temperature-induced dissociation of the one-dimensional chain. The distribution of complex zeros of the canonical partition may be used to identify different degrees of dissociation in the canonical ensemble.

  10. Piezoelectric phased array acousto-ultrasonic interrogation of damage in thin plates

    NASA Astrophysics Data System (ADS)

    Purekar, Ashish S.

    Structural Health Monitoring (SHM) and Condition Based Maintenance (CBM) systems can provide substantial benefits for aging aerospace systems as well as newer systems still in the design process. In aging aerospace systems, a retrofitted SHM system would alert users of incipient damage preventing catastrophic failure. For newer systems, incorporating a SHM approach and using CBM techniques can reduce life-cycle costs. Central to such SHM and CBM systems is the ability to detect damage in a structure. Traditional approaches to damage detection in structures involve one of two methods. In the modal dynamics approach, the natural frequencies and modeshapes of a structure shift when damage occurs. The location, type, and amount of damage is determined by the shifts in the modal properties due to damage. Alternately, in an Ultrasonics approach, the structure is scanned with a specialized transducer which induces high frequency vibrations in the structure. Damage in the structure is inferred when these vibrations are altered. In the same vein as Ultrasonics, Acoustic Emission based methods listen for energy release in the structure upon defect growth. All of these techniques have limitations which hinder their usage in a practical system. This thesis attempts to develop a methodology with the benefits of the modal approach as well as the Ultrasonics/Acoustic Emission approach. The methodology is commonly referred to as an Acousto-Ultrasonic technique for damage detection. The structural dynamics of plate structures is described as wavelike in nature where the plate is a medium for wave propagation. For thin plates, bulk wave propagation is described using Lamb wave modes. The two fundamental modes of wave propagation are the in-plane acoustic mode and the transverse bending mode. The interaction of these waves with a discontinuity or damaged region changes the way the waves propagate. Part of the incident wavefront is reflected back while the rest is transmitted through

  11. Coherence-controlled holographic microscopy principle embodiment into Q-PHASE microscope: story of a successful technology transfer

    NASA Astrophysics Data System (ADS)

    Lostak, M.; Chmelik, R.

    2016-03-01

    Curiously, the coherence-controlled holographic microscopy (CCHM) was brought into the world owing to the endeavor of Chmelik's team at Brno University of Technology (BUT) to avoid scanning in confocal microscopy. As coherence gating seemed to be the way, the Leith & Upatnieks proposal of incoherent holography had been considered attractive. Their method made interference system free from strict dependence on both spatial and temporal coherence. Off axis holographic system proposed on such basis has been proved capable of coherence based depth discrimination in single wide-field shot in reflected-light arrangement. Consequently, extremely low-coherence holographic imaging had been found highly contributive also to the image quality depriving it from coherence artefacts and improving its transversal resolution. This is why CCHM promised high precision of quantitative phase imaging (QPI) in transmitted light set up that was realized for cell biology. However the cost of necessarily complicated optical design and need of very precise mechanics forced the team of prof Chmelik at BUT to search for a company capable of mastering the instrument. It was TESCAN ORSAY the highly successful scanning electron microscopes producer that finally took charge of the commercial design. Long-term collaboration of the company with BUT made possible both the CCHM technology successful transfer up to Q-PHASE microscope production as well as the company Light microscopy division reinforcement. This contribution merges views of CCHM technology author and the TESCAN development team.

  12. Magnetization process in a two-phase exchange-coupled system: A microscopic study

    SciTech Connect

    Ryan, D.H.; Feutrill, E.H.; Ding, J.

    1997-04-01

    The magnetization process in an exchange-coupled {alpha}-Fe+Nd{sub 2}Fe{sub 14}B nanocomposite has been studied by M{umlt o}ssbauer spectroscopy. Measurements in fields of up to 2 T confirm that the magnetization of the soft phase is strongly coupled to that of the hard phase. Analysis of magnetization curves and magic-angle spectra of saturated samples shows that the remanence is dominated by the hard phase. {copyright} {ital 1997 American Institute of Physics.}

  13. Phase retrieval of microscope objects using the Wavelet-Gabor transform method from holographic filters

    NASA Astrophysics Data System (ADS)

    Hernández-Romo, Martín.; Padilla-Vivanco, Alfonso; Kim, Myung K.; Toxqui-Quitl, Carina

    2014-09-01

    An analysis of an optical-digital system based on the architecture of the Mach-Zehnder interferometer for recording holographic filters is presented. The holographic recording system makes use of one microscope objective in each interferometer arm. Moreover, the Gabor Wavelet Transform is implemented for the holographic reconstruction stage. The samples studied of this research are selected in order to test the retrieval algorithm and to characterize the resolution of the holographic recording system. In this last step, some sections of an USAF1951 resolution chart are used. These samples allow us to study the features of lighting in the recorded system. Additionally, some organic samples are used to proven the capabilities of the method because biological samples have much complex morphological composition than others. With this in mind, we can verify the frequencies recovered with each of the settings set in the retrieval method. Experimental results are presented.

  14. Macroscopic rates, microscopic observations, and molecular models of the dissolution of carbonate phases.

    SciTech Connect

    Duckworth, Owen W.; Cygan, Randall Timothy; Martin, Scot T.

    2004-05-01

    Bulk and surface energies are calculated for endmembers of the isostructural rhombohedral carbonate mineral family, including Ca, Cd, Co, Fe, Mg, Mn, Ni, and Zn compositions. The calculations for the bulk agree with the densities, bond distances, bond angles, and lattice enthalpies reported in the literature. The calculated energies also correlate with measured dissolution rates: the lattice energies show a log-linear relationship to the macroscopic dissolution rates at circumneutral pH. Moreover, the energies of ion pairs translated along surface steps are calculated and found to predict experimentally observed microscopic step retreat velocities. Finally, pit formation excess energies decrease with increasing pit size, which is consistent with the nonlinear dissolution kinetics hypothesized for the initial stages of pit formation.

  15. Surface wave phase velocities from 2-D surface wave tomography studies in the Anatolian plate

    NASA Astrophysics Data System (ADS)

    Arif Kutlu, Yusuf; Erduran, Murat; Çakır, Özcan; Vinnik, Lev; Kosarev, Grigoriy; Oreshin, Sergey

    2014-05-01

    We study the Rayleigh and Love surface wave fundamental mode propagation beneath the Anatolian plate. To examine the inter-station phase velocities a two-station method is used along with the Multiple Filter Technique (MFT) in the Computer Programs in Seismology (Herrmann and Ammon, 2004). The near-station waveform is deconvolved from the far-station waveform removing the propagation effects between the source and the station. This method requires that the near and far stations are aligned with the epicentre on a great circle path. The azimuthal difference of the earthquake to the two-stations and the azimuthal difference between the earthquake and the station are restricted to be smaller than 5o. We selected 3378 teleseismic events (Mw >= 5.7) recorded by 394 broadband local stations with high signal-to-noise ratio within the years 1999-2013. Corrected for the instrument response suitable seismogram pairs are analyzed with the two-station method yielding a collection of phase velocity curves in various period ranges (mainly in the range 25-185 sec). Diffraction from lateral heterogeneities, multipathing, interference of Rayleigh and Love waves can alter the dispersion measurements. In order to obtain quality measurements, we select only smooth portions of the phase velocity curves, remove outliers and average over many measurements. We discard these average phase velocity curves suspected of suffering from phase wrapping errors by comparing them with a reference Earth model (IASP91 by Kennett and Engdahl, 1991). The outlined analysis procedure yields 3035 Rayleigh and 1637 Love individual phase velocity curves. To obtain Rayleigh and Love wave travel times for a given region we performed 2-D tomographic inversion for which the Fast Marching Surface Tomography (FMST) code developed by N. Rawlinson at the Australian National University was utilized. This software package is based on the multistage fast marching method by Rawlinson and Sambridge (2004a, 2004b). The

  16. Microscopic observation and in-situ Raman scattering studies on high-pressure phase transformations of Kr hydrate.

    PubMed

    Sasaki, Shigeo; Hori, Shinsuke; Kume, Tetsuji; Shimizu, Hiroyasu

    2006-05-25

    Direct observations through a microscope and in-situ Raman scattering measurements of synthesized single-crystalline Kr hydrate have been performed at pressures up to 5.2 GPa and 296 K. We have observed that the initial cubic structure II (sII) of Kr hydrate successively transforms to a cubic structure I (sI), a hexagonal structure, and an orthorhombic structure (sO) called "filled ice" at 0.45, 0.75, and 1.8 GPa, respectively. The sO phase exists at least up to 5.2 GPa. In addition to these transformations, we have also found the new phase behavior at 1.0 GPa, which is most likely caused by the change of cage occupancy of host water cages by guest Kr atoms without structural change. Raman scattering measurements for observed phases have shown that the lattice vibrational peak at around 130 cm(-1) disappears in the pressure region of sI, which enables us to distinguish the sI phase from sII and sH phases. PMID:16706436

  17. Spiral phase plates with radial discontinuities for the generation of multiring orbital angular momentum beams: fabrication, characterization, and application

    NASA Astrophysics Data System (ADS)

    Ruffato, Gianluca; Massari, Michele; Carli, Marta; Romanato, Filippo

    2015-11-01

    A design of spiral phase plates for the generation of multiring beams carrying orbital angular momentum (OAM) is presented. Besides the usual helical profile, these phase plates present radial π-discontinuities in correspondence of the zeros of the associated Laguerre polynomials. Samples were fabricated by electron beam lithography over glass substrates coated with a polymethylmethacrylate resist layer. The optical response was analyzed and the purity of the generated beams was investigated in terms of Laguerre-Gaussian modes contributions. The far-field intensity pattern was compared with theoretical models and numerical simulations, while the expected phase features were confirmed by interferometric analysis with a Mach-Zehnder setup. The high quality of the output beams confirms the applicability of these phase plates for the generation of high-order OAM beams with nonzero radial index. An application consisting of the design of computer-generated holograms encoding information for light beams carrying phase singularities is presented and described. A numerical code based on an iterative Fourier transform algorithm has been developed for the computation of phase-only diffractive optical element for illumination under OAM beams. Numerical analysis and preliminary experimental results confirm the applicability of these devices as high-security optical elements for anticounterfeiting applications.

  18. Probing the Microscopic Structure of the Stripe Phase at Filling Factor 5/2

    NASA Astrophysics Data System (ADS)

    Friess, Benedikt; Umansky, Vladimir; Tiemann, Lars; von Klitzing, Klaus; Smet, Jurgen H.

    2014-08-01

    A prominent manifestation of the competition between repulsive and attractive interactions acting on different length scales is the self-organized ordering of electrons in a stripelike fashion in material systems such as high-Tc superconductors. Such stripe phases are also believed to occur in two-dimensional electron systems exposed to a perpendicular magnetic field, where they cause a strong anisotropy in transport. The addition of an in-plane field even enables us to expel fractional quantum Hall states, to the benefit of such anisotropic phases. An important example represents the disappearance of the 5/2 fractional state. Here, we report the use of nuclear magnetic resonance spectroscopy to probe the electron density distribution of this emergent anisotropic phase. A surprisingly strong spatial density modulation was found. The observed behavior suggests a stripe pattern with a period of 2.6±0.6 magnetic lengths and an amplitude as large as 20% relative to the total density.

  19. Phase and TV Based Convex Sets for Blind Deconvolution of Microscopic Images

    NASA Astrophysics Data System (ADS)

    Tofighi, Mohammad; Yorulmaz, Onur; Kose, Kivanc; Yildirim, Deniz Cansen; Cetin-Atalay, Rengul; Cetin, A. Enis

    2016-02-01

    In this article, two closed and convex sets for blind deconvolution problem are proposed. Most blurring functions in microscopy are symmetric with respect to the origin. Therefore, they do not modify the phase of the Fourier transform (FT) of the original image. As a result blurred image and the original image have the same FT phase. Therefore, the set of images with a prescribed FT phase can be used as a constraint set in blind deconvolution problems. Another convex set that can be used during the image reconstruction process is the epigraph set of Total Variation (TV) function. This set does not need a prescribed upper bound on the total variation of the image. The upper bound is automatically adjusted according to the current image of the restoration process. Both of these two closed and convex sets can be used as a part of any blind deconvolution algorithm. Simulation examples are presented.

  20. Imaging performance of attenuated phase-shift mask using coherent scattering microscope

    NASA Astrophysics Data System (ADS)

    Lee, Jae Uk; Jeong, SeeJun; Hong, Seong Chul; Lee, Seung Min; Ahn, Jinho

    2014-03-01

    The half-tone phase shift mask (PSM) has been suggested for better imaging performances like image contrast, NILS and H-V bias compared to the binary mask (BIM) in EUV lithography. In this paper, we measured imaging performance of a fabricated half-tone attenuated PSM with Coherent Scattering Microscopy (CSM) and the results were compared with simulation data obtained by EM-suite tool. We prepared a half-tone attenuated PSM which has 12.7% reflectivity and 180° phase shift with absorber stack of 16.5mn-thick TaN absorber and 24nm-thick Mo phase shifter. With CSM, an actinic inspection tool, we measured the imaging properties of PSM. The diffraction efficiencies of BIM were measured as 31%, 36%, and 44% for 88 nm, 100 nm, and 128 nm mask CD, respectively, while those of PSM were measured as 45%, 62%, and 81%. Also the aerial image at wafer level obtained by CSM with high volume manufacturing tool's (HVM) illumination condition (NA=0.33, σ=0.9) showed higher image contrast and NILS with phase shift effect. And the measured data were consistent with the simulation data.

  1. Generation of plate tectonics with two-phase grain-damage and pinning: Source-sink model and toroidal flow

    NASA Astrophysics Data System (ADS)

    Bercovici, David; Ricard, Yanick

    2013-03-01

    The grain-damage and pinning mechanism of Bercovici and Ricard (2012) for lithospheric shear-localization is employed in two-dimensional flow calculations to test its ability to generate toroidal (strike-slip) motion and influence plate evolution. This mechanism posits that damage to the interface between phases in a polycrystalline material like peridotite (composed primarily of olivine and pyroxene) increases the number of small Zener pinning surfaces, which then constrain mineral grains to ever smaller sizes, regardless of creep mechanism. This effect allows a self-softening feedback in which damage and grain-reduction can co-exist with a grain-size dependent diffusion creep rheology; moreover, grain growth and weak-zone healing are greatly impeded by Zener pinning thereby leading to long-lived relic weak zones. The fluid dynamical calculations employ source-sink driven flow as a proxy for convective poloidal flow (upwelling/downwelling and divergent/convergent motion), and the coupling of this flow with non-linear rheological mechanisms excites toroidal or strike-slip motion. The numerical experiments show that pure dislocation-creep rheology, and grain-damage without Zener pinning (as occurs in a single-phase assemblages) permit only weak localization and toroidal flow; however, the full grain-damage with pinning readily allows focussed localization and intense, plate-like toroidal motion and strike-slip deformation. Rapid plate motion changes are also tested with abrupt rotations of the source-sink field after a plate-like configuration is developed; the post-rotation flow and material property fields retain memory of the original configuration for extensive periods, leading to suboptimally aligned plate boundaries (e.g., strike-slip margins non-parallel to plate motion), oblique subduction, and highly localized, weak and long lived acute plate-boundary junctions such as at what is observed at the Aleutian-Kurile intersection. The grain-damage and pinning

  2. Computer simulations of laser hot spots and implosion symmetry kiniform phase plate experiments on Nova

    SciTech Connect

    Peterson, R. R.; Lindman, E. L.; Delamater, N. D.; Magelssen, G. R.

    2000-05-01

    LASNEX computer code simulations have been performed for radiation symmetry experiments on the Nova laser with vacuum and gas-filled hohlraum targets [R. L. Kauffman et al., Phys. Plasmas 5, 1927 (1998)]. In previous experiments with unsmoothed laser beams, the symmetry was substantially shifted by deflection of the laser beams. In these experiments, laser beams have been smoothed with Kiniform Phase Plates in an attempt to remove deflection of the beams. The experiments have shown that this smoothing significantly improves the agreement with LASNEX calculations of implosion symmetry. The images of laser produced hot spots on the inside of the hohlraum case have been found to differ from LASNEX calculations, suggesting that some beam deflection or self-focusing may still be present or that emission from interpenetrating plasmas is an important component of the images. The measured neutron yields are in good agreement with simulations for vacuum hohlraums but are far different for gas-filled hohlraums. (c) 2000 American Institute of Physics.

  3. Searching for Planets in Holey Debris Disks with the Apodizing Phase Plate

    NASA Astrophysics Data System (ADS)

    Meshkat, Tiffany; Bailey, Vanessa P.; Su, Kate Y. L.; Kenworthy, Matthew A.; Mamajek, Eric E.; Hinz, Philip M.; Smith, Paul S.

    2015-02-01

    We present our first results from a high-contrast imaging search for planetary mass companions around stars with gapped debris disks, as inferred from the stars' bright infrared excesses. For the six considered stars, we model the disks' unresolved infrared spectral energy distributions in order to derive the temperature and location of the disk components. With VLT/NaCo Apodizing Phase Plate coronagraphic L'-band imaging, we search for planetary mass companions that may be sculpting the disks. We detect neither disks nor companions in this sample, confirmed by comparing plausible point sources with archival data. In order to calculate our mass sensitivity limit, we revisit the stellar age estimates. One target, HD 17848, at 540 ± 100 Myr old is significantly older than previously estimated. We then discuss our high-contrast imaging results with respect to the disk properties. Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere, Chile, ESO under program numbers 090.C-0148(A) and 091.C-0457(A)

  4. Simple method for the analysis of food dyes on reversed-phase thin-layer plates.

    PubMed

    Oka, H; Ikai, Y; Kawamura, N; Yamada, M; Inoue, H; Ohno, T; Inagaki, K; Kuno, A; Yamamoto, N

    1987-12-18

    A technique for the determination of food dyes using reversed-phase thin-layer chromatography on octadecyl-modified silica is described. A solvent system containing 5.0% aqueous sodium sulphate solution enables good separation of the food dyes. Their separation is dependent on the pH of the solvent system, good separation among all dyes being obtained between pH 6.0 and 7.0. The determination of thirteen dyes can be achieved by a combination of methanol-acetonitrile-5.0% aqueous sodium sulphate solution (3:3:10) (solvent system A) and methanol-methyl ethyl ketone-5.0% aqueous sodium sulphate solution (1:1:1) (solvent system B). Solvent system A was used for the determination of Tartrazine, Amaranth, Indigo Carmine, New Coccine, Sunset Yellow FCF, Allura Red AC, Fast Green FCF and Brilliant Blue FCF and for the screening of Acid Red (R-106), Eosin (R-103), Erythrosin (R-3), Rose Bengale (R-105) and Phloxine (R-104). When the spots of R-3, R-103, R-104, R-105 and R-106 appear on the plate, their determination can be achieved by using solvent system B. Each calibration graph was linear between 0.2 and 1.0 micrograms. PMID:3443633

  5. Characteristics of Plate-Fin Heat Exchanger with Phase Change Material

    NASA Astrophysics Data System (ADS)

    Okada, Masashi

    In the present paper, a plate-fin heat exchanger with a phase change material (PCM) was studied. The heat exchanger was a singlepass cross-flow type, where both fluids (air) were unmixed. N-octadecane, of which the fusion temperature is 28.0°C, was used as the PCM. Three kinds of experiments were carried out and the inlet and outlet temperatures and the temperatures in the PCM were measured. In the first experiments, the effectiveness and the overall heat-transfer coefficient were obtained at steady states. By the calculations of steady three-dimensional heat conduction, the effects of the parameters, ---, dimensions, thermal properties, and heat transfer coefficients of air ---, on the overall heat-transfer coefficients were obtaiend clearly. In the second experiments, after the higher-temperature air-flow was stopped, the outlet temperatures of the lower-temperature air were maintained at the constant temperatures for 90-150 minutes. In the third experiments, the higher temperature air was flowed intermittently with an equal interval. The fluctuation of the outlet temperature of the lower-temperature air was within ±2.5°C. The above transient and periodical experiments showed that the present heat exchanger with PCM had useful characters of latent heat storage.

  6. Decoding the pair correlations and properties of equilibrium microscopic cluster phases

    NASA Astrophysics Data System (ADS)

    Bollinger, Jonathan; Jadrich, Ryan; Truskett, Thomas

    Due to competing interactions acting between particles, dispersed colloidal suspensions can reversibly transition to phases comprising aggregate clusters. Cluster phases have been reported for both 'model' colloidal particles and complex monomers (e.g., proteins); however, many questions remain regarding how to detect and characterize cluster phases given only pair structural correlations (the information most accessible across diverse systems) and how to relate clustering susceptibility and behavior to underlying monomer-monomer interactions. Using molecular simulations and liquid-state theory across a wide survey of conditions, we decode the widely-observed intermediate range order pre-peak in the structure factor by: (1) validating a physically-intuitive rule for detecting clustering based on the pre-peak thermal correlation length; and (2) relating pre-peak position to cluster size and bulk monomer density. We further demonstrate how clustering transitions and resultant properties relate to monomer interactions along coordinates tunable in experiments. These trends are suitable for comparing against clustering systems that can be directly visualized (via, e.g., confocal microscopy), which should aid in assessing the realism of commonly-adopted monomer interaction potentials.

  7. Laves phase in alloy 718 fusion zone — microscopic and calorimetric studies

    SciTech Connect

    Manikandan, S.G.K.; Sivakumar, D.; Prasad Rao, K.; Kamaraj, M.

    2015-02-15

    Microstructural characterization of alloy 718 fusion zone welded with both solid solution and age hardenable filler metal has been done. The microsegregation and the aging response were studied by employing three levels of weld cooling rate. Gas Tungsten Arc welding process was used. The fusion zone of solid solution filler metal has been responding to the aging treatment due to the weld process conditions and weld metal chemistry. However the weld metal composition was modified due to the higher molybdenum (Mo) content in solid solution filler metal. The effect of this modification on the phase reaction temperatures was studied and the same was compared with the conventional filler metal. - Graphical abstract: Display Omitted - Highlights: • Interdendritic segregation has been controlled by weld cooling rate. • Laves phase formation has been studied with cooling rate and weld metal chemistry. • Aging response with solid solution filler metal has been demonstrated. • Reduction in Laves phase and alloying element segregation has been confirmed. • Reaction temperatures were found modified because of Mo addition.

  8. Real-time monitoring of the cell physiological and pathological processes using computer-aided phase microscope

    NASA Astrophysics Data System (ADS)

    Vasilenko, Irina A.; Shabalin, Vladimir; Tychinsky, Vladimir P.; Kufal, Georgy E.; Konradov, A.; Slinchenko, O. I.

    1996-01-01

    Living cells investigation and cell response to external factors are of great interest for practical medicine and biology. The main advantages of computer aided phase microscope (CPM) Cytoscan which permits us to observe the cell surface and internal structure consists in superresolution and the possibility of the dynamic processes registering. We attempt to characterize some aspects of the morphofunctional status of human lymphocytes determining the dynamics of the selected points in normal or pathological cells. To evaluate the lymphocyte homeostasis donors and persons of autoimmune diseases were analyzed and the changes of optical and geometrical cell parameters registered by CPM Cytoscan. The dynamic process registration allowed us to perform the real-time quantitative analysis of the living lymphocyte activity in norm and pathology.

  9. In situ electron microscope study of the phase transformation, structure and growth of thin Te1-xSex films

    NASA Astrophysics Data System (ADS)

    Vermaak, J. S.; Raubenheimer, D.

    1988-01-01

    An in-situ electron microscope technique was utilized to observe directly the amorphous-to-crystalline phase transformation, the isothermal growth rates, as well as the orientation and structure of the recrystallized films for the Te1-xSex alloy system for x=0.2, 0.3 and 0.4. Activation energies of E=0.91, 0.93 and 0.96 eV and crystallization temperatures of Tc=-14, 81.5 and 85°C for the three alloys, respectively, were found. In all three cases the crystallization process originated from single crystalline nuclei with a hexagonal structure and with the c-axis in general parallel to the substrate surface.

  10. Testing Single Phase IGBT H-Bridge Switch Plates for the High Voltage Converter Modulator at the Spallation Neutron Source

    SciTech Connect

    Peplov, Vladimir V; Anderson, David E; Solley, Dennis J

    2014-01-01

    Three IGBT H-bridge switching networks are used in each High Voltage Converter Modulator (HVCM) system at the Spallation Neutron Source (SNS) to generate drive currents to three boost transformer primaries switching between positive and negative bus voltages at 20 kHz. Every switch plate assembly is tested before installing it into an operational HVCM. A Single Phase Test Stand has been built for this purpose, and it is used for adjustment, measurement and testing of different configurations of switch plates. This paper will present a description of the Test Stand configuration and discuss the results of testing switch plates with two different types of IGBT gate drivers currently in use on the HVCM systems. Comparison of timing characteristics of the original and new drivers and the resulting performance reinforces the necessity to replace the original H-bridge network drivers with the upgraded units.

  11. Electron microscopic evidence for a tribologically induced phase transformation as the origin of wear in diamond

    SciTech Connect

    Zhang, Xinyi; Schneider, Reinhard; Müller, Erich; Gerthsen, Dagmar; Mee, Manuel; Meier, Sven; Gumbsch, Peter

    2014-02-14

    Tribological testing of a coarse-grained diamond layer, deposited by plasma-enhanced chemical vapor deposition, was performed on a ring-on-ring tribometer with a diamond counterpart. The origin of the wear of diamond and of the low friction coefficient of 0.15 was studied by analyzing the microstructure of worn and unworn regions by transmission and scanning electron microscopy. In the worn regions, the formation of an amorphous carbon layer with a thickness below 100 nm is observed. Electron energy loss spectroscopy of the C-K ionization edge reveals the transition from sp{sup 3}-hybridized C-atoms in crystalline diamond to a high fraction of sp{sup 2}-hybridized C-atoms in the tribo-induced amorphous C-layer within a transition region of less than 5 nm thickness. The mechanically induced phase transformation from diamond to the amorphous phase is found to be highly anisotropic which is clearly seen at a grain boundary, where the thickness of the amorphous layer above the two differently oriented grains abruptly changes.

  12. Kinetics of phase transition in protein solutions on microscopic and mesoscopic length scales

    NASA Astrophysics Data System (ADS)

    Filobelo, Luis F.

    2005-11-01

    Phase transformations in solutions of macromolecules are fundamental for all living things, and of great importance in science and industry. For instance, insulin is biosynthesized in the beta cells of the pancreas and stored in crystalline form, which protects it form cleavage, until it is needed. Certain diseases such as Alzheimer, sickle cell anemia, and eye cataract are produced by the polymerization of protein molecules, which loose their functionality after the phase transition. Additionally, separation operations in manufacturing of pharmaceuticals can be eliminated if the crystals produced have a narrow size distribution. The nucleation and growth of crystals can be adequately controlled only if the mechanisms that govern these processes are well understood. Here we have investigated several facets of the kinetics controlling the behavior of phase transition in protein solutions. We performed experiments to determine the homogenous nucleation rate for lysozyme and insulin crystals and the contribution of heterogeneously nucleated crystals. In the first segment of this work we discuss the existence of a solution-to-crystal spinodal boundary derived from these determinations, and showed that the formation of crystalline nuclei from solution occur in two steps for lysozyme: the formation of quasi-droplets of a disordered intermediate, followed by the nucleation of ordered crystalline embryos within these droplets in which the rate of each step depends on a respective free energy barrier and on the growth rate of its near-critical clusters. We addressed experimentally the relative significance of the free-energy barriers and the kinetic factors for the nucleation of crystals from solution. Using dynamic and static light scattering along with differential refractometry, we also characterized the appearance of dense liquid droplets and the magnitude of the second osmotic virial coefficient B2 for insulin in both aqueous solution and in solution containing 15% (v

  13. Spiral phase plates for the generation of high-order Laguerre-Gaussian beams with non-zero radial index

    NASA Astrophysics Data System (ADS)

    Ruffato, G.; Carli, M.; Massari, M.; Romanato, F.

    2015-03-01

    The work of design, fabrication and characterization of spiral phase plates for the generation of Laguerre-Gaussian (LG) beams with non-null radial index is presented. Samples were fabricated by electron beam lithography on polymethylmethacrylate layers over glass substrates. The optical response of these phase optical elements was measured and the purity of the experimental beams was investigated in terms of Laguerre-Gaussian modes contributions. The farfield intensity pattern was compared with theoretical models and numerical simulations, while the expected phase features were confirmed by interferometric analyses. The high quality of the output beams confirms the applicability of these phase plates for the generation of high-order Laguerre-Gaussian beams. A novel application consisting in the design of computer-generated holograms encoding information for light beams carrying phase singularities is shown. A numerical code based on iterative Fourier transform algorithm has been developed for the computation of the phase pattern of phase-only diffractive optical element for illumination under LG beams. Numerical analysis and preliminary experimental results confirm the applicability of these devices as high-security optical elements.

  14. Microscopic analysis of nuclear quantum phase transitions in the N{approx_equal}90 region

    SciTech Connect

    Li, Z. P.; Niksic, T.; Vretenar, D.; Meng, J.; Lalazissis, G. A.; Ring, P.

    2009-05-15

    The analysis of shape transitions in Nd isotopes, based on the framework of relativistic energy-density functionals and restricted to axially symmetric shapes in T. Niksic, D. Vretenar, G. A. Lalazissis, and P. Ring [Phys. Rev. Lett. 99, 092502 (2007)], is extended to the region Z=60,62,64 with N{approx_equal}90 and includes both {beta} and {gamma} deformations. Collective excitation spectra and transition probabilities are calculated starting from a five-dimensional Hamiltonian for quadrupole vibrational and rotational degrees of freedom, with parameters determined by constrained self-consistent relativistic mean-field calculations for triaxial shapes. The results reproduce available data and show that there is an abrupt change of structure at N=90 that can be approximately characterized by the X(5) analytic solution at the critical point of the first-order quantum phase transition between spherical and axially deformed shapes.

  15. A simple and cost-effective solid-phase protein nano-assay using polyacrylamide-coated glass plates.

    PubMed

    Krajewski, Wladyslaw A

    2015-02-01

    A new solid-phase protein nano-assay is suggested for simple and sensitive estimation of protein content in sample buffers (a 1-μl sample is sufficient for analysis). The assay is different from conventional "on-filter" assays in that it uses inexpensive fully transparent polyacrylamide gel (PAAG)-coated glass plates as solid support and, thus, combines the convenience of "on-membrane" staining with the sensitivity and ease of documentation of "in-gel" staining (and, therefore, is especially suited for standard lab gel documentation systems). The PAAG plates assay is compatible with all dyes for in-gel protein staining. Depending on the sensitivity of the staining protocol, the assay can be used in macro-, micro-, and nano-assay formats. We also describe a low-cost two-component colloidal Coomassie brilliant blue G-250 (CBB G-250) staining protocol for fast quantitative visualization of proteins spotted on a PAAG plate (the detection limit is up to 2 ng of proteins even when using a Nikon CoolPix digital camera and white light transilluminator instead of a gel scanner). The suggested colloidal CBB G-250 protocol could also be used for visualizing nano-amounts of proteins in polyacrylamide gels. The PAAG plate assay could be useful for proteomic applications and, in general, for all cases where a fast, sensitive, and easily documentable cost-effective solid-phase protein assay is required. PMID:25449300

  16. High-throughput 3D tracking of bacteria on a standard phase contrast microscope

    NASA Astrophysics Data System (ADS)

    Taute, K. M.; Gude, S.; Tans, S. J.; Shimizu, T. S.

    2015-11-01

    Bacteria employ diverse motility patterns in traversing complex three-dimensional (3D) natural habitats. 2D microscopy misses crucial features of 3D behaviour, but the applicability of existing 3D tracking techniques is constrained by their performance or ease of use. Here we present a simple, broadly applicable, high-throughput 3D bacterial tracking method for use in standard phase contrast microscopy. Bacteria are localized at micron-scale resolution over a range of 350 × 300 × 200 μm by maximizing image cross-correlations between their observed diffraction patterns and a reference library. We demonstrate the applicability of our technique to a range of bacterial species and exploit its high throughput to expose hidden contributions of bacterial individuality to population-level variability in motile behaviour. The simplicity of this powerful new tool for bacterial motility research renders 3D tracking accessible to a wider community and paves the way for investigations of bacterial motility in complex 3D environments.

  17. Influence of Two-Phase Thermocapillary Flow on Cryogenic Liquid Retention in Microscopic Pores

    NASA Technical Reports Server (NTRS)

    Schmidt, G. R.; Nadarajah, A.; Chung, T. J.; Karr, G. R.

    1994-01-01

    Previous experiments indicate that the bubble point pressure of spacecraft liquid hydrogen acquisition devices is reduced substantially when the ullage is pressurized with heated hydrogen vapor. The objective is to determine whether the two-phase thermocapillary convection arising from thermodynamic non-equilibrium along the porous surfaces of such devices could lead to this observed degradation in retention performance. We also examine why retention capability appears to be unaffected by pressurization with heated helium or direct heating through the porous structure. Computational assessments based on coupled solution of the flowfield and liquid free surface indicate that for highly wetting fluids in small pores, dynamic pressure and vapor recoil dictate surface morphology and drive meniscus deformation. With superheating, the two terms exert the same influence on curvature and promote mechanical equilibrium, but with subcooling, the pressure distribution produces a suction about the pore center-line that degrades retention. This result points to thermocapillary-induced deformation arising from condensation as the cause for retention loss. It also indicates that increasing the level of non-equilibrium by reducing accommodation coefficient restricts deformation and explains why retention failure does not occur with direct screen heating or helium pressurization.

  18. High-throughput 3D tracking of bacteria on a standard phase contrast microscope

    PubMed Central

    Taute, K.M.; Gude, S.; Tans, S.J.; Shimizu, T.S.

    2015-01-01

    Bacteria employ diverse motility patterns in traversing complex three-dimensional (3D) natural habitats. 2D microscopy misses crucial features of 3D behaviour, but the applicability of existing 3D tracking techniques is constrained by their performance or ease of use. Here we present a simple, broadly applicable, high-throughput 3D bacterial tracking method for use in standard phase contrast microscopy. Bacteria are localized at micron-scale resolution over a range of 350 × 300 × 200 μm by maximizing image cross-correlations between their observed diffraction patterns and a reference library. We demonstrate the applicability of our technique to a range of bacterial species and exploit its high throughput to expose hidden contributions of bacterial individuality to population-level variability in motile behaviour. The simplicity of this powerful new tool for bacterial motility research renders 3D tracking accessible to a wider community and paves the way for investigations of bacterial motility in complex 3D environments. PMID:26522289

  19. Fluid-structure interaction study of the splitter plate in a TBCC exhaust system during mode transition phase

    NASA Astrophysics Data System (ADS)

    Guo, Shuai; Xu, Jinglei; Mo, Jianwei; Gu, Rui; Pang, Lina

    2015-07-01

    Splitter plate plays an important role in a turbine-based combined-cycle (TBCC) exhaust system during the mode transition phase when turbojet engine and ramjet engine operate simultaneously. Dissimilar pressure distribution on both sides of the plate has a potential origin in the aeroelastic coupling, which is an interesting topic while few research works have devoted to that aspect. To better understand the aeroelastic behavior of the plate and the corresponding dynamic flow features, an integrated fluid-structure interaction simulation is conducted under one particular operation condition during mode transition phase in the TBCC exhaust system. A finite-volume-based CFD solver FLUENT is adopted to solve the unsteady Reynolds average Navier-Stokes equations. ABAQUS, a finite-element-method-based CSD solver, is employed to compute the plate elastic deformation. A two-way interaction between the fluid and the structure is accomplished by the mesh-based parallel-code coupling interface (MpCCI) in a loosely-coupled manner. The accuracy of the coupling procedure is validated for the flutter of a flat plate in supersonic flow. Then, features of steady flow field of the TBCC exhaust system are discussed, followed by the investigation of the aeroelastic phenomenon of the splitter plate and the evolution process of the flow field pattern. Finally, performances variation of the exhaust system is obtained and discussed. The results show that the plate vibrates with decaying amplitude and reaches a dynamic stable state eventually. The thrust, lift and pitch moment of the TBCC exhaust system are increased by 0.68%, 2.82% and 5.86%, respectively, compared with the corresponding values in steady state which does not take into account the fluid-structure interaction effects. The analysis reveals the importance of considering the fluid-structure interaction effects in designing the splitter plate in the TBCC exhaust system and demonstrates the availability of the present coupled

  20. Selective higher order fiber mode excitation using a monolithic setup of a phase plate at a fiber facet

    NASA Astrophysics Data System (ADS)

    Wilde, Johannes; Schulze, Christian; Brüning, Robert; Duparré, Michael; Schröter, Siegmund

    2015-03-01

    Controlling the modal content coupled into an optical fiber can be desirable in many situations, e.g. for adjusting the sensitivity of the guided field distribution to external perturbations1. For this purpose we used a monolithic setup of a phase plate at a fiber input facet to excite selectively higher order modes, which theoretically can provide a mode purity of more than 99%. We investigated the capabilities of this approach by complete modal decomposition of the fiber output signals, considering the achievable mode purity with respect to several possible imperfections of the setup. The experiments are compared with detailed numerical simulations and show a high agreement. Additionally a comparison with a well known setup with free space phase plates2-4 was undertaken. This showed the monolithic setup to be energetically twice as efficient.

  1. Nonequilibrium segregation and phase instability in alloy films during elevated-temperature irradiation in a high-voltage electron microscope

    SciTech Connect

    Lam, N.Q.; Okamoto, P.R.

    1984-05-01

    The effects of defect-production rate gradients, caused by the radial nonuniformity in the electron flux distribution, on solute segregation and phase stability in alloy films undergoing high-voltage electron-microscope (HVEM) irradiation at high temperatures are assessed. Two-dimensional (axially symmetric) compositional redistributions were calculated, taking into account both axial and transverse radial defect fluxes. It was found that when highly focused beams were employed radiation-induced segregation consisted of two stages: dominant axial segregation at the film surfaces at short irradiation times and competitive radial segregation at longer times. The average alloy composition within the irradiated region could differ greatly from that irradiated with a uniform beam, because of the additional atom transport from or to the region surrounding the irradiated zone under the influence of radial fluxes. As a result, damage-rate gradient effects must be taken into account when interpreting in-situ HVEM observations of segregation-induced phase instabilities. The theoretical predictions are compared with experimental observations of the temporal and spatial dependence of segregation-induced precipitation in thin films of Ni-Al, Ni-Ge and Ni-Si solid solutions.

  2. Triggering of leukocytes by phase contrast in imaging cytometry with scanning fluorescence microscope (SFM)

    NASA Astrophysics Data System (ADS)

    Bocsi, József; Pierzchalski, Arkadiusz; Marecka, Monika; Malkusch, Wolf; Tárnok, Attila

    2009-02-01

    Slide-based cytometry (SBC) leads to breakthrough in cytometry of cells in tissues, culture and suspension. Carl Zeiss Imaging Solutions' new automated SFM combines imaging with cytometry. A critical step in image analysis is selection of appropriate triggering signal to detect all objects. Without correct target cell definition analysis is hampered. DNA-staining is among the most common triggering signals. However, the majority of DNA-dyes yield massive spillover into other fluorescence channels limiting their application. By microscopy objects of >5μm diameter can be easily detected by phase-contrast signal (PCS) without any staining. Aim was to establish PCS - triggering for cell identification. Axio Imager.Z1 motorized SFM was used (high-resolution digital camera, AxioCam MRm; AxioVision software: automatic multi-channel scanning, analysis). Leukocytes were stained with FITC (CD4, CD8) and APC (CD3) labelled antibodies in combinations using whole blood method. Samples were scanned in three channels (PCS/FITC/APC). Exposition-times for PCS were set as low as possible; the detection efficiency was verified by fluorescence. CD45-stained leukocytes were counted and compared to the number of PCS detected events. Leukocyte subtyping was compared with other cytometers. In focus the PCS of cells showed ring-form that was not optimal for cell definition. Out of focus PCS allows more effective qualitative and quantitative cell analyses. PCS was an accurate triggering signal for leukocytes enabling cell counting and discrimination of leukocytes from platelets. Leukocyte subpopulation frequencies were comparable to those obtained by other cytometers. In conclusion PCS is a suitable trigger-signal not interfering with fluorescence detection.

  3. Distribution of plates' sizes tell the thermal history in a simulated martensitic-like phase transition

    NASA Astrophysics Data System (ADS)

    Ţolea, F.; Ţolea, M.; Sofronie, M.; Văleanu, M.

    2015-07-01

    A phenomenological 2D model, simulating the martensitic transformation, is built upon existing experimental observations that the size of the formed plates - in direct transformation - decreases as the temperature is lowered; then they transform back in reversed order. As such, if a reverse transformation is incomplete (arrested), the subsequent direct one will show anomalously a large number of big size plates - old plus newly formed - but consequentially a depletion of intermediate sizes, due to geometrical constraints, phenomenon that generates thermal memory.

  4. Direct observation of the topological charge of a terahertz vortex beam generated by a Tsurupica spiral phase plate

    SciTech Connect

    Miyamoto, K.; Suizu, K.; Akiba, T.; Omatsu, T.

    2014-06-30

    A terahertz (THz) spiral phase plate with high transmission (>90% after Fresnel correction) and low dispersion has been developed based on the Tsurupica olefin polymer. Direct observations of the topological charge (both magnitude and sign) of a THz vortex beam are performed by using a THz camera with tilted lens focusing and radial defect introduction. The vortex outputs with a topological charge of ±1 (or ±2) are obtained at a frequency of 2 (or 4) THz.

  5. Effect of fringe-artifact correction on sub-tomogram averaging from Zernike phase-plate cryo-TEM.

    PubMed

    Kishchenko, Gregory P; Danev, Radostin; Fisher, Rebecca; He, Jie; Hsieh, Chyongere; Marko, Michael; Sui, Haixin

    2015-09-01

    Zernike phase-plate (ZPP) imaging greatly increases contrast in cryo-electron microscopy, however fringe artifacts appear in the images. A computational de-fringing method has been proposed, but it has not been widely employed, perhaps because the importance of de-fringing has not been clearly demonstrated. For testing purposes, we employed Zernike phase-plate imaging in a cryo-electron tomographic study of radial-spoke complexes attached to microtubule doublets. We found that the contrast enhancement by ZPP imaging made nonlinear denoising insensitive to the filtering parameters, such that simple low-frequency band-pass filtering made the same improvement in map quality. We employed sub-tomogram averaging, which compensates for the effect of the "missing wedge" and considerably improves map quality. We found that fringes (caused by the abrupt cut-on of the central hole in the phase plate) can lead to incorrect representation of a structure that is well-known from the literature. The expected structure was restored by amplitude scaling, as proposed in the literature. Our results show that de-fringing is an important part of image-processing for cryo-electron tomography of macromolecular complexes with ZPP imaging. PMID:26210582

  6. 3D microscope

    NASA Astrophysics Data System (ADS)

    Iizuka, Keigo

    2008-02-01

    In order to circumvent the fact that only one observer can view the image from a stereoscopic microscope, an attachment was devised for displaying the 3D microscopic image on a large LCD monitor for viewing by multiple observers in real time. The principle of operation, design, fabrication, and performance are presented, along with tolerance measurements relating to the properties of the cellophane half-wave plate used in the design.

  7. 3D tracking and phase-contrast imaging by twin-beams digital holographic microscope in microfluidics

    NASA Astrophysics Data System (ADS)

    Miccio, L.; Memmolo, P.; Finizio, A.; Paturzo, M.; Merola, F.; Grilli, S.; Ferraro, P.

    2012-06-01

    A compact twin-beam interferometer that can be adopted as a flexible diagnostic tool in microfluidic platforms is presented. The devise has two functionalities, as explained in the follow, and can be easily integrated in microfluidic chip. The configuration allows 3D tracking of micro-particles and, at same time, furnishes Quantitative Phase-Contrast maps of tracked micro-objects by interference microscopy. Experimental demonstration of its effectiveness and compatibility with biological field is given on for in vitro cells in microfluidic environment. Nowadays, several microfluidic configuration exist and many of them are commercially available, their development is due to the possibility for manipulating droplets, handling micro and nano-objects, visualize and quantify processes occurring in small volumes and, clearly, for direct applications on lab-on-a chip devices. In microfluidic research field, optical/photonics approaches are the more suitable ones because they have various advantages as to be non-contact, full-field, non-invasive and can be packaged thanks to the development of integrable optics. Moreover, phase contrast approaches, adapted to a lab-on-a-chip configurations, give the possibility to get quantitative information with remarkable lateral and vertical resolution directly in situ without the need to dye and/or kill cells. Furthermore, numerical techniques for tracking of micro-objects needs to be developed for measuring velocity fields, trajectories patterns, motility of cancer cell and so on. Here, we present a compact holographic microscope that can ensure, by the same configuration and simultaneously, accurate 3D tracking and quantitative phase-contrast analysis. The system, simple and solid, is based on twin laser beams coming from a single laser source. Through a easy conceptual design, we show how these two different functionalities can be accomplished by the same optical setup. The working principle, the optical setup and the mathematical

  8. Microscopic identification of Chinese medicinal materials based on X-ray phase contrast imaging: from qualitative to quantitative

    NASA Astrophysics Data System (ADS)

    Xue, Y.; Liang, Z.; Tan, H.; Ni, L.; Zhao, Z.; Xiao, T.; Xu, H.

    2016-07-01

    Although a variety of methods, ranging from simple morphological examination to physical and chemical analysis, and DNA molecular biology, exist for authenticating Chinese medicinal materials(CMMs), no methods can achieve both the source species identification and quality evaluation of CMMs simultaneously. Furthermore, the methods that are currently available for the identification of CMMs, including both optical and electronic microscopy, usually entail strict requirements for sample preparation or testing environment, such as the slicing of super-thin sections, or processing with specific chemical reagents. These treatments not only damage the CMMs but may also cause some of the original microstructures to be missed. Additionally, they may even yield false results. Owing to the unique penetrating character of X-rays, X-ray phase contrast imaging(XPCI) can be used to realize the inner microstructures of CMMs through nondestructive imaging. With the higher flux and luminance of the third generation of synchrotron radiation facility, XPCI can provides clearer and finer microstructures of CMMs, which are mainly composed of C, H, O, and N elements, with better spatial and density resolutions. For more than ten years, the X-ray imaging group at the Shanghai Institute of Applied Physics has investigated the microstructures of CMMs by XPCI and they have established and developed a quantitative X-ray phase contrast micro-CT for investigating the characteristic microstructures of CMMs. During this period, a variety of typical CMMs have been investigated, from two-dimensional (2D) radiography to three-dimensional (3D) micro-CT, from qualitative to quantitative. Taken together, these results verify that quantitative X-ray phase contrast micro-CT is a practical tool for the microscopic investigation of CMMs. Additionally, further efforts are being made to find the relationship between the microstructures' quantitative factors and active chemical components. At present

  9. Large aperture kinoform phase plates in fused silica for spatial beam smoothing on Nova and the Beamlet Lasers

    SciTech Connect

    Rushford, M.C.; Dixit, S.N.; Thomas, I.M.; Martin, A.M.; Perry, M.D.

    1997-03-01

    It is now widely recognized that spatial beam smoothing (homogenization) is essential in coupling the laser energy to the inertial confinement fusion (ICF) targets. For the indirect drive approach to ICF, it is desirable to distribute the laser energy into a uniformly speckled profile that has a flat-top super-Gaussian envelope (8th power or higher) and contains greater than 95% of the energy inside the super-Gaussian profile. Spatial smoothing is easily achieved by introducing a binary random phase plate (RPP) in the beam. This produces a homogenized far-field pattern which consists of an overall envelope function determined by the RPP element superimposed with a fine scale speckle pattern arising due to the interference among the various RPP elements. Although easy to fabricate and currently in routine use in many fusion laboratories, the binary RPPs do not meet the ICF requirements stated above since the far-field intensity profile is restricted to essentially an Airy function containing only 84% (an upper limit) of the energy inside the central spot. Approaches using lenslet arrays (refractive or diffractive) have limited use since they operate in the quasi-far-field and have a short depth of focus. The limitations of the RPPs can be overcome by relaxing the binary phase constraint. We have recently presented 5 continuously varying phase screens for tailoring the focal plane irradiance profiles. Called kinoform phase plates (KPPs), these phase screens offer complete flexibility in tailoring the focal plane envelope and, at the same time, increasing the energy efficiency inside the focal spot. In this paper we discuss the design and fabrication of such kinoform phase plates in fused silica for spatial beam smoothing on the Nova and the Beamlet lasers. Since the phase plates are used at the end of the laser chain, KPPs on Nova and Beamlet have to be fabricated on large aperture optics (65-cm diameter and 40-cm square substrates respectively). The following

  10. Photopolymerized microscopic vortex beam generators: Precise delivery of optical orbital angular momentum

    NASA Astrophysics Data System (ADS)

    Brasselet, Etienne; Malinauskas, Mangirdas; Žukauskas, Albertas; Juodkazis, Saulius

    2010-11-01

    Direct femtosecond laser photopolymerization is used to fabricate high resolution microscopic spiral phase plates. The total phase change all around their center is prepared to be a integer multiple of 2π for the operating wavelength in the visible domain. The optical performances of the spiral plates are measured and we propose a simple single beam interferometric technique to characterize the phase singularity of the generated vortex beams. The experimental results are compared to simulations and a satisfying agreement is obtained. Potential of large scale fabrication, templating, and smart spiral plate architectures are also illustrated.

  11. The Natural History of Uterine Leiomyomas: Light and Electron Microscopic Studies of Fibroid Phases, Interstitial Ischemia, Inanosis, and Reclamation

    PubMed Central

    Flake, Gordon P.; Moore, Alicia B.; Sutton, Deloris; Kissling, Grace E.; Horton, John; Wicker, Benita; Walmer, David; Robboy, Stanley J.; Dixon, Darlene

    2013-01-01

    We propose, and offer evidence to support, the concept that many uterine leiomyomas pursue a self-limited life cycle. This cycle can be arbitrarily divided on the basis of morphologic assessment of the collagen content into 4 phases: (1) proliferation, (2) proliferation and synthesis of collagen, (3) proliferation, synthesis of collagen, and early senescence, and (4) involution. Involution occurs as a result of both vascular and interstitial ischemia. Interstitial ischemia is the consequence of the excessive elaboration of collagen, resulting in reduced microvascular density, increased distance between myocytes and capillaries, nutritional deprivation, and myocyte atrophy. The end stage of this process is an involuted tumor with a predominance of collagen, little to no proliferative activity, myocyte atrophy, and myocyte cell death. Since many of the dying cells exhibit light microscopic and ultrastructural features that appear distinct from either necrosis or apoptosis, we refer to this process as inanosis, because it appears that nutritional deprivation, or inanition, is the underlying cause of cell death. The disposal of myocytes dying by inanosis also differs in that there is no phagocytic reaction, but rather an apparent dissolution of the cell, which might be viewed as a process of reclamation as the molecular contents are reclaimed and recycled. PMID:24348569

  12. Presence of Citrullinated Histone H3-Positive Neutrophils in Microscopic Polyangiitis from the Early Phase: An Autopsy Proven Case.

    PubMed

    Matsuda, Yoko; Hamayasu, Hideki; Seki, Atsuko; Nonaka, Keisuke; Wang, Tan; Matsumoto, Takumi; Hamano, Yoshitomo; Sumikura, Hiroyuki; Kumasaka, Toshio; Murayama, Shigeo; Ishizu, Akihiko; Shimizu, Akira; Sugihara, Takahiko; Arai, Tomio

    2016-08-01

    A 76-year-old man was admitted with general fatigue, weight loss, fever, headache, renal failure, and a high serum level of myeloperoxidase-antineutrophil cytoplasmic antibody. Biopsy revealed citrullinated histone H3 (citH3)-positive neutrophils adherent to the temporal artery endothelium. Three days after completing pulse steroid therapy, he suffered from a sudden disturbance of consciousness and died. On autopsy, the kidneys showed the most severe vasculitis with dense infiltration of citH3-positive neutrophils. The lungs showed intra-alveolar hemorrhage due to capillaritis. Severe brain hemorrhage was found in the left frontal lobe and putamen with uncal herniation. No vasculitis or thrombi was observed in the brain. The right dura mater was thickened due to fibrosis and inflammation. In conclusion, autopsy revealed systemic vasculitis with infiltration of abundant citH3-positive neutrophils, suggesting that the neutrophil extracellular trap formation and citH3 might play important roles in the early phases and development of microscopic polyangiitis. PMID:27427341

  13. Skeletal growth phases of the cold-water coral Lophelia pertusa shown by scanning electron microscope and electron backscatter diffraction

    NASA Astrophysics Data System (ADS)

    Mouchi, Vincent; Vonlanthen, Pierre; Verrecchia, Eric P.; Crowley, Quentin G.

    2016-04-01

    Lophelia pertusa is a cold-water coral, which may form reefs by the association of multiple coralites within which a polyp lives. Each individual polyp builds an aragonite skeleton by an initial phase of early mineralization (traditionally referred to as centres of calcification) from which aragonite fibres grow in thickening deposits. The skeleton wall features successive optically opaque and translucent bands previously attributed to different regimes of growth as either uniform in crystal orientation (translucent bands) or with a chaotic organization (opaque bands). The processes involved in any organizational changes are still unknown. Microlayers in the coral wall, which represent separate periods of skeletal growth, have been recently identified and described. These growth patterns are readily visible under scanning electron microscope (SEM) after etching in dilute formic acid, but they do not necessarily form continuously visible structures. Here we present high quality SEM images and electron backscatter diffraction (EBSD) maps to study aragonite fibre orientation across the wall of L. pertusa. Both microlayers and opaque and translucent bands are compared to the crystallographic orientation of the aragonite fibres. EBSD maps and SEM images indicate that aragonite fibres do not exhibit a chaotic orientation, even in opaque bands. The absence of continuity of microlayers is partially explained by an association of multiple crystallographic preferred orientations of aragonite fibres. In the case of L. pertusa, careful textural characterisation is necessary prior to elemental or isotope analysis in order to select a skeletal transect representing a linear and continuous time period.

  14. Characterization of livestock odors using steel plates, solid-phase microextraction, and multidimensional gas chromatography-mass spectrometry-olfactometry.

    PubMed

    Bulliner, Edward A; Koziel, Jacek A; Cai, Lingshuang; Wright, Donald

    2006-10-01

    Livestock operations are associated with emissions of odor, gases, and particulate matter (PM). Livestock odor characterization is one of the most challenging analytical tasks. This is because odor-causing gases are often present at very low concentrations in a complex matrix of less important or irrelevant gases. The objective of this project was to develop a set of characteristic reference odors from a swine barn in Iowa and, in the process, identify compounds causing characteristic swine odor. Odor samples were collected using a novel sampling methodology consisting of clean steel plates exposed inside and around the swine barn for < or =1 week. Steel plates were then transported to the laboratory and stored in clean jars. Headspace solid-phase microextraction was used to extract characteristic odorants collected on the plates. All of the analyses were conducted on a gas chromatography-mass spectrometry-olfactometry system where the human nose is used as a detector simultaneously with chemical analysis via mass spectrometry. Multidimensional chromatography was used to isolate and identify chemicals with high-characteristic swine odor. The effects of sampling time, distance from a source, and the presence of PM on the abundance of specific gases, odor intensity, and odor character were tested. Steel plates were effectively able to collect key volatile compounds and odorants. The abundance of specific gases and odor was amplified when plates collected PM. The results of this research indicate that PM is major carrier of odor and several key swine odorants. Three odor panelists were consistent in identifying p-cresol as closely resembling characteristic swine odor, as well as attributing to p-cresol the largest odor response out of the samples. Further research is warranted to determine how the control of PM emissions from swine housing could affect odor emissions. PMID:17063862

  15. Planar gas chromatography column on glass plate with nanodispersed silica as the stationary phase

    NASA Astrophysics Data System (ADS)

    Platonov, I. A.; Platonov, V. I.; Pavelyev, V. S.; Agafonov, A. N.

    2016-04-01

    The paper presents the GC column in the plane of the glass plate with the adsorption layer nanodispersed silica. Created gas chromatographic column allows to separate a mixture of five alkanes from pentane to nonane in isothermal (90 ° C) mode less than one minute.

  16. Rayleigh phase velocities in the upper mantle of the Pacific-North American plate boundary in southern California

    NASA Astrophysics Data System (ADS)

    Escobar, L.; Weeraratne, D. S.; Kohler, M. D.

    2013-05-01

    The Pacific-North America plate boundary, located in Southern California, presents an opportunity to study a unique tectonic process that has been shaping the plate tectonic setting of the western North American and Mexican Pacific margin since the Miocene. This is one of the few locations where the interaction between a migrating oceanic spreading center and a subduction zone can be studied. The rapid subduction of the Farallon plate outpaced the spreading rate of the East Pacific Rise rift system causing it to be subducted beneath southern California and northern Mexico 30 Ma years ago. The details of microplate capture, reorganization, and lithospheric deformation on both the Pacific and North American side of this boundary is not well understood, but may have important implications for fault activity, stresses, and earthquake hazard analysis both onshore and offshore. We use Rayleigh waves recorded by an array of 34 ocean bottom seismometers deployed offshore southern California for a 12 month duration from August 2010 to 2011. Our array recorded teleseismic earthquakes at distances ranging from 30° to 120° with good signal-to-noise ratios for magnitudes Mw ≥ 5.9. The events exhibit good azimuthal distribution and enable us to solve simultaneously for Rayleigh wave phase velocities and azimuthal anisotropy. Fewer events occur at NE back-azimuths due to the lack of seismicity in central North America. We consider seismic periods between 18 - 90 seconds. The inversion technique considers non-great circle path propagation by representing the arriving wave field as two interfering plane waves. This takes advantage of statistical averaging of a large number of paths that travel offshore southern California and northern Mexico allowing for improved resolution and parameterization of lateral seismic velocity variations at lithospheric and sublithospheric depths. We present phase velocity results for periods sampling mantle structure down to 150 km depth along the

  17. Feedback Structure-Borne Sound Control of a Flexible Plate with AN Electromagnetic Actuator: the Phase Lag Problem

    NASA Astrophysics Data System (ADS)

    Ren, M. Z.; Seto, K.; Doi, F.

    1997-08-01

    In this paper an experimental study is presented on active control of a clamped plate at audio frequencies by using feedback controller and electromagnetic actuator. The controller is designed with modern control theory on a lumped parameter model of the plate, and is then implemented in experiments to control the real structure. In practice, the optimal control force cannot be generated exactly as desired due to the non-ideal characteristics of the control system. Several factors such as A/D and D/A convertors, velocity estimation through approximate differentiation, and the electromagnetic actuator are examined in respect to their frequency features. An analytical model is developed to predict the phase lag of the actual control force to the designed control force. It is shown that if the phase lag is over 90 degrees, the control system will become unstable. Two techniques are discussed for improving the system performance that is mainly affected by the electromagnetic actuator when the high speed sampling and processing device is used as the controller. The simple and practical method is to employ a phase-lead compensation network in the control circuit. Another one that is more fundamental is to incorporate the characteristics of the actuator into the system by feeding back the current passing through the actuator into the controller. Various experiments are carried out to verify the analysis and the proposed methods, and the potentials of the electromagnetic actuator in controlling the high frequency vibration and noise are therefore demonstrated.

  18. Continuous contour phase plates for tailoring the focal plane irradiance profile

    SciTech Connect

    Dixit, S.N.; Rushford, M.C.; Thomas, I.M.; Perry, M.D.

    1995-08-09

    We present fully continuous phase screens for producing super-Gaussian focal-plane irradiance profiles. Such phase screens are constructed with the assumption of either circular symmetric near-field and far-field profiles or a separable phase screen in Cartesian co-ordinates. In each case, the phase screen is only a few waves deep. Under illumination by coherent light, such phase screens produce high order super-Gaussian profiles in the focal plane with high energy content effects of beam aberrations on the focal profiles and their energy content are also discussed.

  19. Three-dimensional phase-contrast X-ray microtomography with scanning–imaging X-ray microscope optics

    PubMed Central

    Takeuchi, Akihisa; Uesugi, Kentaro; Suzuki, Yoshio

    2013-01-01

    A three-dimensional (3D) X-ray tomographic micro-imaging system has been developed. The optical system is based on a scanning–imaging X-ray microscope (SIXM) optics, which is a hybrid system consisting of a scanning microscope optics with a one-dimensional (1D) focusing (line-focusing) device and an imaging microscope optics with a 1D objective. In the SIXM system, each 1D dataset of a two-dimensional (2D) image is recorded independently. An object is illuminated with a line-focused beam. Positional information of the region illuminated by the line-focused beam is recorded with the 1D imaging microscope optics as line-profile data. By scanning the object with the line focus, 2D image data are obtained. In the same manner as for a scanning microscope optics with a multi-pixel detector, imaging modes such as phase contrast and absorption contrast can be arbitrarily configured after the image data acquisition. By combining a tomographic scan method and the SIXM system, quantitative 3D imaging is performed. Results of a feasibility study of the SIXM for 3D imaging are shown. PMID:23955044

  20. Relationship between phase difference and coefficient of restitution during low velocity foreign object transverse damage of composite plates

    NASA Technical Reports Server (NTRS)

    Lal, K. M.

    1984-01-01

    This work discusses a model to correlate the coefficient of restitution of low velocity transverse impacts of graphite-epoxy laminates with the residual deformation or central deflection at the end of the impact event. It is assumed that the energy absorbed by the target can be calibrated in terms of residual deflection, and thereby in terms of phase difference between the occurrence of impact force and central deflection to their maximas. Analysis was modeled on the basis of the experience from impact tests. Predictions are compared with the test results of impacted circular and flat plates. Experimentally measured values of coefficient of restitution and phase difference agreed well with the predicted relationship between them.

  1. Thermochemical Analysis of Phases Formed at the Interface of a Mg alloy-Ni-plated Steel Joint during Laser Brazing

    NASA Astrophysics Data System (ADS)

    Nasiri, Ali M.; Chartrand, Patrice; Weckman, David C.; Zhou, Norman Y.

    2013-04-01

    The thermodynamic stability of precipitated phases at the steel-Ni-Mg alloy interface during laser brazing of Ni-plated steel to AZ31B magnesium sheet using AZ92 magnesium alloy filler wire has been evaluated using FactSage thermochemical software. Assuming local chemical equilibrium at the interface, the chemical activity-temperature-composition relationships of intermetallic compounds that might form in the steel-Ni interlayer-AZ92 magnesium alloy system in the temperature range of 873 K to 1373 K (600 °C to 1100 °C) were estimated using the Equilib module of FactSage. The results provided better understanding of the phases that might form at the interface of the dissimilar metal joints during the laser brazing process. The addition of a Ni interlayer between the steel and the Mg brazing alloy was predicted to result in the formation of the AlNi, Mg2Ni, and Al3Ni2 intermetallic compounds at the interface, depending on the local maximum temperature. This was confirmed experimentally by laser brazing of Ni electro-plated steel to AZ31B-H24 magnesium alloy using AZ92 magnesium alloy filler wire. As predicted, the formation of just AlNi and Mg2Ni from a monotectic and eutectic reaction, respectively, was observed near the interface.

  2. Oxidation of ammonium sulfite by a multi-needle-to-plate gas phase pulsed corona discharge reactor

    NASA Astrophysics Data System (ADS)

    Ren, Hua; Lu, Na; Shang, Kefeng; Li, Jie; Wu, Yan

    2013-03-01

    The oxidation of ammonium sulfite in the ammonia-based flue gas desulfurization (FGD) process was investigated in a multi-needle-to-plate gas phase pulsed corona discharge reactor in this paper. The effect of several parameters, including capacitance and peak pulse voltage of discharge system, electrode gap and bubbling gas flow rate on the oxidation rate of ammonium sulfite was reviewed. The oxidation rate of ammonium sulfite could reach 47.2% at the capacitance, the peak pulse voltage, electrode gap and bubbling gas flow rate equal to 2 nF, -24.6 k V, 35 mm and 4 L min-1 within treatment time of 40 min The experimental results indicate that the gas phase pulsed discharge system with a multi-needle-to-plate electrode can oxide the ammonium sulfite. The oxidation rate increased with the applied capacitance and peak pulse voltage and decreased with the electrode gap. As the bubbling gas flow rate increased, the oxidation rate increased first and then tended to reach a stationary value. These results would be important for the process optimization of the (NH4)2SO3 to (NH4)2SO4 oxidation.

  3. Determination of retardation parameters of multiple-order wave plate using a phase-sensitive heterodyne ellipsometer.

    PubMed

    Hsieh, Cheng-Hung; Tsai, Chien-Chung; Wei, Hsiang-Chun; Yu, Li-Ping; Wu, Jheng-Syong; Chou, Chien

    2007-08-10

    To characterize the linear birefringence of a multiple-order wave plate (MWP), an oblique incidence is one of the methods available. Multiple reflections in the MWP are produced, and oscillations in the phase retardation measurement versus the oblique incident angle are then measured. Therefore, an antireflection coated MWP is required to avoid oscillation of the phase retardation measurement. In this study, we set up a phase-sensitive heterodyne ellipsometer to measure the phase retardations of an uncoated MWP versus the oblique incident angle, which was scanned in the x-z plane and y-z plane independently. Thus, the effect on multiple reflections by the MWP is reduced by means of subtracting the two measured phase retardations from each other. As a result, a highly sensitive and accurate measurement of retardation parameters (RPs), which includes the refractive indices of the extraordinary ray n(e) and ordinary ray n(o), is obtained by this method. On measurement, a sensitivity (n(e),n(o)) of 10(-6) was achieved by this experiment setup. At the same time, the spatial shifting of the P and S waves emerging from the MWP introduced a deviation between experimental results and the theoretical calculation. PMID:17694147

  4. Analytical Round Robin for Elastic-Plastic Analysis of Surface Cracked Plates: Phase I Results

    NASA Technical Reports Server (NTRS)

    Wells, D. N.; Allen, P. A.

    2012-01-01

    An analytical round robin for the elastic-plastic analysis of surface cracks in flat plates was conducted with 15 participants. Experimental results from a surface crack tension test in 2219-T8 aluminum plate provided the basis for the inter-laboratory study (ILS). The study proceeded in a blind fashion given that the analysis methodology was not specified to the participants, and key experimental results were withheld. This approach allowed the ILS to serve as a current measure of the state of the art for elastic-plastic fracture mechanics analysis. The analytical results and the associated methodologies were collected for comparison, and sources of variability were studied and isolated. The results of the study revealed that the J-integral analysis methodology using the domain integral method is robust, providing reliable J-integral values without being overly sensitive to modeling details. General modeling choices such as analysis code, model size (mesh density), crack tip meshing, or boundary conditions, were not found to be sources of significant variability. For analyses controlled only by far-field boundary conditions, the greatest source of variability in the J-integral assessment is introduced through the constitutive model. This variability can be substantially reduced by using crack mouth opening displacements to anchor the assessment. Conclusions provide recommendations for analysis standardization.

  5. Wind loads on flat plate photovoltaic array fields. Phase III, final report

    SciTech Connect

    Miller, R.D.; Zimmerman, D.K.

    1981-04-01

    The results of an experimental analysis (boundary layer wind tunnel test) of the aerodynamic forces resulting from winds acting on flat plate photovoltaic arrays are presented. Local pressure coefficient distributions and normal force coefficients on the arrays are shown and compared to theoretical results. Parameters that were varied when determining the aerodynamic forces included tilt angle, array separation, ground clearance, protective wind barriers, and the effect of the wind velocity profile. Recommended design wind forces and pressures are presented, which envelop the test results for winds perpendicular to the array's longitudinal axis. This wind direction produces the maximum wind loads on the arrays except at the array edge where oblique winds produce larger edge pressure loads.

  6. Analysis of thermoelastic dissipation in circular micro-plate resonators using the generalized thermoelasticity theory of dual-phase-lagging model

    NASA Astrophysics Data System (ADS)

    Guo, F. L.; Song, J.; Wang, G. Q.; Zhou, Y. F.

    2014-05-01

    This study investigates the thermoelastic dissipation of micro-plate resonators by using the generalized thermoelasticity theory of dual-phase-lagging model. Explicit formulae of thermoelastic damping and frequency shift are derived. Influences of the plate thickness and vibration frequency on the thermoelastic damping are examined. Phenomena distinct from those of classical theory are observed in the numerical results of thermoelastic damping in micro-plate resonators. These results may bring new insights into the study of thermoelastic damping at submicrometer or nanometer scale.

  7. Tissue microscopic changes and artifacts in multi-phase post-mortem computed tomography angiography in a hospital setting: a fatal case of systemic vasculitis.

    PubMed

    Capuani, Caroline; Guilbeau-Frugier, Céline; Mokrane, Fatima-Zohra; Delisle, Marie-Bernadette; Marcheix, Bertrand; Rousseau, Hervé; Telmon, Norbert; Rougé, Daniel; Dedouit, Fabrice

    2014-09-01

    A 27-year-old man suddenly died in hospital of acute respiratory distress syndrome secondary to severe systemic vasculitis. Multi-phase post-mortem computed tomography angiography followed by scientific autopsy of the thoracic and abdominal cavity and histology was performed, illustrating the advantages and drawbacks of such techniques. Imaging enabled us to examine the cranium, as the family refused cerebral dissection. MPMCTA revealed absence of opacification of the left middle cerebral artery. But parenchymal findings of thoracic and abdominal organs were still difficult to interpret after both imaging and macroscopic examination during the autopsy. Microscopic examination provided the definitive diagnosis of cause of death. Analysis revealed systemic vasculitis of the lung complicated by diffuse alveolar, mediastinal, splenic and retroperitoneal lesions. We were unable to determine the type of vasculitis, whether polyarteritis nodosa or microscopic polyangiitis, because of artifactual glomerular collapse. We observed some structural changes in tissue secondary to contrast agent injection, affecting the vascular system and renal parenchyma in particular. Such artifacts must be known in order to avoid misinterpreting them as pathological findings. MPMCTA and conventional autopsy are two complementary techniques showing both their specific advantages and limits which have to be known in order to choose the appropriate technique. One limit of both techniques is the detection of microscopic findings which can only be obtained by additional histological examination. This case report underlines this fact and demonstrates that caution is required in some cases if microscopic analyses are carried out after contrast agent injection. PMID:25085763

  8. Phase transformations during the Ag-In plating and bonding of vertical diode elements of multijunction solar cells

    SciTech Connect

    Klochko, N. P. Khrypunov, G. S.; Volkova, N. D.; Kopach, V. R.; Lyubov, V. N.; Kirichenko, M. V.; Momotenko, A. V.; Kharchenko, N. M.; Nikitin, V. A.

    2013-06-15

    The conditions of the bonding of silicon multijunction solar cells with vertical p-n junctions using Ag-In solder are studied. The compositions of electrodeposited indium films on silicon wafers silver plated by screen printing and silver and indium films fabricated by layer-by-layer electrochemical deposition onto the surface of silicon vertical diode cells silver plated in vacuum are studied. Studying the electrochemical-deposition conditions, structure, and surface morphology of the grown layers showed that guaranteed bonding is provided by 8-min heat treatment at 400 Degree-Sign C under the pressure of a stack of metallized silicon wafers; however, the ratio of the indium and silver layer thicknesses should not exceed 1: 3. As this condition is satisfied, the solder after wafer bonding has the InAg{sub 3} structure (or InAg{sub 3} with an Ag phase admixture), due to which the junction melting point exceeds 700 Degree-Sign C, which guarantees the functioning of such solar cells under concentrated illumination.

  9. Morphological Evolution of Electrochemically Plated/Stripped Lithium Microstructures Investigated by Synchrotron X-ray Phase Contrast Tomography.

    PubMed

    Sun, Fu; Zielke, Lukas; Markötter, Henning; Hilger, André; Zhou, Dong; Moroni, Riko; Zengerle, Roland; Thiele, Simon; Banhart, John; Manke, Ingo

    2016-08-23

    Due to its low redox potential and high theoretical specific capacity, Li metal has drawn worldwide research attention because of its potential use in next-generation battery technologies such as Li-S and Li-O2. Unfortunately, uncontrollable growth of Li microstructures (LmSs, e.g., dendrites, fibers) during electrochemical Li stripping/plating has prevented their practical commercialization. Despite various strategies proposed to mitigate LmS nucleation and/or block its growth, a fundamental understanding of the underlying evolution mechanisms remains elusive. Herein, synchrotron in-line phase contrast X-ray tomography was employed to investigate the morphological evolution of electrochemically deposited/dissolved LmSs nondestructively. We present a 3D characterization of electrochemically stripped Li electrodes with regard to electrochemically plated LmSs. We clarify fundamentally the origin of the porous lithium interface growing into Li electrodes. Moreover, cleavage of the separator caused by growing LmS was experimentally observed and visualized in 3D. Our systematic investigation provides fundamental insights into LmS evolution and enables us to understand the evolution mechanisms in Li electrodes more profoundly. PMID:27463258

  10. CMS Resistive Plate Chamber overview, from the present system to the upgrade phase I

    NASA Astrophysics Data System (ADS)

    Paolucci, P.; Hadjiiska, R.; Litov, L.; Pavlov, B.; Petkov, P.; Dimitrov, A.; Beernaert, K.; Cimmino, A.; Costantini, S.; Guillaume, G.; Lellouch, J.; Marinov, A.; Ocampo, A.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Verwilligen, P.; Yazgan, E.; Zaganidis, N.; Aleksandrov, A.; Genchev, V.; Iaydjiev, P.; Rodozov, M.; Shopova, M.; Sultanov, G.; Ban, Y.; Cai, J.; Xue, Z.; Ge, Y.; Li, Q.; Qian, S.; Avila, C.; Chaparro, L. F.; Gomez, J. P.; Gomez Moreno, B.; Osorio Oliveros, A. F.; Sanabria, J. C.; Assran, Y.; Sharma, A.; Abbrescia, M.; Colaleo, A.; Pugliese, G.; Loddo, F.; Calabria, C.; Maggi, M.; Benussi, L.; Bianco, S.; Colafranceschi, S.; Piccolo, D.; Carrillo, C.; Iorio, O.; Buontempo, S.; Vitulo, P.; Berzano, U.; Gabusi, M.; Kang, M.; Lee, K. S.; Park, S. K.; Shin, S.; Kim, M. S.; Seo, H. K.; Goh, J.; Choi, Y.-I.

    2013-04-01

    Resistive Plate Chambers have been chosen as dedicated trigger muon detector for the Compact Muon Solenoid experiment [1] at the Large Hadron Collider [2] at CERN. The system consists of about 3000 m2 of double gap RPC chambers placed in both the barrel and endcap muon regions. About 5.6 fb-1 (2010-2011) of proton-proton collision data have been used to study the performance of the RPC detector and trigger. A full high voltage scan of all the RPC chambers has been done at beginning of 2011 data taking to evaluate the working point chamber by chamber and to eventually spot aging effects. The excellent behaviour of the RPC detector can be summarized with an average detector efficiency of about 97%, an average cluster size of 1.8 and an intrinsic noise rate of 0.1 Hz/cm2. This is a clear fulfilment of all the requirements decided 18 years ago in the CMS TDR document [3].

  11. Microscopic colitis.

    PubMed

    Pardi, Darrell S

    2014-02-01

    Microscopic colitis is a frequent cause of chronic watery diarrhea, especially in older persons. Common associated symptoms include abdominal pain, arthralgias, and weight loss. The incidence of microscopic colitis had been increasing, although more recent studies have shown a stabilization of incidence rates. The diagnosis is based on characteristic histologic findings in a patient with diarrhea. Microscopic colitis can occur at any age, including in children, but it is primarily seen in the elderly. Several treatment options exist to treat the symptoms of microscopic colitis, although only budesonide has been well studied in randomized clinical trials. PMID:24267602

  12. Relocating Seismicity on the Arctic Plate Boundary Using Teleseismic and Regional Phases and a Bayesian Multiple Event Locator

    NASA Astrophysics Data System (ADS)

    Gibbons, Steven J.; Dahl-Jensen, Trine; Kværna, Tormod; Larsen, Tine B.; Paulsen, Berit; Voss, Peter

    2016-04-01

    The tectonophysics of plate boundaries are illuminated by the pattern of seismicity - and the ability to locate seismic events accurately depends upon the number and quality of observations, the distribution of recording stations, and how well the traveltimes of seismic phases are modelled. The boundary between the Eurasian and North American plates between 70 and 84 degrees North hosts large seismic events which are well recorded teleseismically and many more events at far lower magnitudes that are well recorded only at regional distances. Existing seismic bulletins have considerable spread and bias resulting from limited station coverage and deficiencies in the velocity models applied; this is particularly acute for the lower magnitude events which may only be constrained by a small number of Pn and Sn arrivals. Over the past 15 years, there has been a significant improvement in the seismic network in the Arctic - a difficult region to instrument due to the harsh climate, a sparsity of quiet and accessible sites, and the expense and difficult logistics of deploying and maintaining stations. New deployments and upgrades to stations on Greenland, Svalbard, and the islands Jan Mayen, Hopen, and Bjørnøya have resulted in a sparse but stable regional seismic network which results in events down to magnitudes below 3 generating high quality Pn and Sn signals on multiple stations. A catalog of over 1000 events in the region since 1998 has been generated using many new phase readings on stations on both sides of the spreading ridge in addition to teleseismic P phases. The Bayesloc program, a Bayesian hierarchical multiple event location algorithm, has been used to relocate the full set of events iteratively and this has resulted in a significant reduction in the spread in hypocenter estimates for both large and small events. Whereas single event location algorithms minimize the vector of time residuals on an event-by-event basis, Bayesloc favours the hypocenters which

  13. Scanned optical fiber confocal microscope

    NASA Astrophysics Data System (ADS)

    Dickensheets, David L.; Kino, Gordon S.

    1994-04-01

    The size and weight of conventional optical microscopes often makes them inconvenient for use on the human body or for in-situ examination during materials processing. We describe a new fiber-optic scanning confocal optical microscope which could have a total outside diameter as small as 1 mm, and should lend itself to applications in endoscopy or to optical in vivo histology. The first experimental device utilizes a single-mode optical fiber for illumination and detection. The scanning element is a mechanically resonant fused silica cantilever 1.5 cm long and 0.8 mm across, with a micromachined two-phase zone plate objective mounted at one end. The cantilever is electrostatically scanned near resonance in two dimensions, generating a Lissajous pattern which is scan converted to conventional video for real time display or digitization. The objective lens has N.A. equals 0.25 at (lambda) equals 0.6328 micrometers , with a measured spot size of 1.8 micrometers FWHM.

  14. Microscopic Polyangiitis

    MedlinePlus

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

  15. Application of the solid polymer electrolyte method to organic electrochemistry; 17: Indirect electrochemical debromination using viologens as microscopic phase-transfer mediators

    SciTech Connect

    Inaba, Minoru; Ogumi, Zempachi; Takehara, Zenichiro . Division of Energy and Hydrocarbon Chemistry)

    1994-10-01

    Solid polymer electrolyte composite electrodes have been extensively studied for use in water electrolyzers, brine electrolyzers, and fuel cells. Solid polymer electrolyte (SPE[reg sign]) composite electrodes using a perfluorinated ion-exchange membrane (Nafion[reg sign]), which is known to be microscopically separated into hydrophilic and hydrophobic domains, were prepared. Various N,N[prime]-dialkyl-4-4[prime]-bipyridinium salts (viologens) were incorporated in the SPE composite electrodes as phase transfer mediators. Electrochemical debromination of meso-1,2-dibromo-1,2-diphenylethane was carried out on the SPE composite electrodes. The results were compared with those obtained in an emulsion system consisting of water and dichloromethane. Of the viologen compounds tested, propyl viologen was the most effective mediator for the SPE composite electrode, while octyl viologen dibromide was the most effective mediator in the emulsion system. The active species for the debromination in the emulsion system was shown to be a doubly reduced neutral form of viologen that was generated by the disproportionation of cation radicals. The disproportionation constant, K[sub d], of octyl viologen cation radical in a two-phase system consisting of water and dichloromethane was estimated to be 809. The reaction mechanism on the SPE composite electrode was discussed, and it was considered that the active species was generated by disproportionation at the microscopically heterogeneous interface between the hydrophilic and hydrophobic domains of the Nafion.

  16. Near Fault Observatories (NFO) services and integration plan for European Plate Observing System (EPOS) Implementation Phase

    NASA Astrophysics Data System (ADS)

    Chiaraluce, Lauro

    2016-04-01

    the services provided by other Thematic Core Services for the standard data (e.g. seismic and geodetic) and on the direct access to the e-infrastructures of individual NFOs via the Integrated Core Services web services for access and distribution of non standard data (e.g. strain- and tilt-meters, geochemical and electro- magneto-telluric data). We will collaborate with the other groups possessing the same data on data harmonization in terms of both format and metadata description to optimise and facilitate the integration and interoperability processes. The services will include a Virtual Laboratory, novel visualization tools for data and products describing the anatomy of active faults and the physical processes governing earthquake generation. VL is an online engagement and knowledge sharing initiative for communicating to the other scientists, stockholders and the public the state of scientific knowledge concerning earthquake source and tectonic processes generating catastrophic events. The availability of real-time data provides the unique opportunity of observing all phases of the earthquake rupture. It is thus of crucial importance developing methodologies to follow in real-time the evolution of the event (e.g. Earthquake Early Warning systems). NFOs are ideal infrastructures for hosting testing centers where a variety of scientific algorithms for real-time monitoring can be independently evaluated. Besides the interest for fundamental science, such developments have a societal impact and can attract new stakeholders such as industry partners who are interested in adopting in such (e.g. EEW) technologies.

  17. The microcanonical thermodynamics of finite systems: the microscopic origin of condensation and phase separations, and the conditions for heat flow from lower to higher temperatures.

    PubMed

    Gross, D H E; Kenney, J F

    2005-06-01

    Microcanonical thermodynamics [D. H. E. Gross, Microcanonical Thermodynamics, Phase Transitions in "Small" Systems (World Scientific, Singapore, 2001)] allows the application of statistical mechanics both to finite and even small systems and also to the largest, self-gravitating ones. However, one must reconsider the fundamental principles of statistical mechanics especially its key quantity, entropy. Whereas in conventional thermostatistics, the homogeneity and extensivity of the system and the concavity of its entropy are central conditions, these fail for the systems considered here. For example, at phase separation, the entropy S(E) is necessarily convex to make e(S(E)-E/T) bimodal in E. Particularly, as inhomogeneities and surface effects cannot be scaled away, one must be careful with the standard arguments of splitting a system into two subsystems, or bringing two systems into thermal contact with energy or particle exchange. Not only the volume part of the entropy must be considered; the addition of any other external constraint [A. Wehrl, Rev. Mod. Phys. 50, 221 (1978)], such as a dividing surface, or the enforcement of gradients of the energy or particle profile, reduce the entropy. As will be shown here, when removing such constraints in regions of a negative heat capacity, the system may even relax under a flow of heat (energy) against a temperature slope. Thus the Clausius formulation of the second law: "Heat always flows from hot to cold," can be violated. Temperature is not a necessary or fundamental control parameter of thermostatistics. However, the second law is still satisfied and the total Boltzmann entropy increases. In the final sections of this paper, the general microscopic mechanism leading to condensation and to the convexity of the microcanonical entropy at phase separation is sketched. Also the microscopic conditions for the existence (or nonexistence) of a critical end point of the phase separation are discussed. This is explained for

  18. Relative permeability and the microscopic distribution of wetting and nonwetting phases in the pore space of Berea sandstone

    SciTech Connect

    Schlueter, E.M.; Cook, N.G.W. |; Witherspoon, P.A.; Myer, L.R.

    1994-04-01

    Experiments to study relative permeabilities of a partially saturated rock have been carried out in Berea sandstone using fluids that can be solidified in place. The effective permeability of the spaces not occupied by the wetting fluid (paraffin wax) or the nonwetting fluid (Wood`s metal), have been measured at various saturations after solidifying each of the phases. The tests were conducted on Berea sandstone samples that had an absolute permeability of about 600 md. The shape of the laboratory-derived relative permeability vs. saturation curves measured with the other phase solidified conforms well with typical curves obtained using conventional experimental methods. The corresponding wetting and nonwetting fluid distributions at different saturations are presented and analyzed in light of the role of the pore structure in the invasion process, and their impact on relative permeability and capillary pressure. Irreducible wetting and nonwetting phase fluid distributions are studied. The effect of clay minerals on permeability is also assessed.

  19. Microscopic origin of resistance drift in the amorphous state of the phase-change compound GeTe

    NASA Astrophysics Data System (ADS)

    Gabardi, S.; Caravati, S.; Sosso, G. C.; Behler, J.; Bernasconi, M.

    2015-08-01

    Aging is a common feature of the glassy state. In the case of phase-change chalcogenide alloys the aging of the amorphous state is responsible for an increase of the electrical resistance with time. This phenomenon called drift is detrimental in the application of these materials in phase-change nonvolatile memories, which are emerging as promising candidates for storage class memories. By means of combined molecular dynamics and electronic structure calculations based on density functional theory, we have unraveled the atomistic origin of the resistance drift in the prototypical phase-change compound GeTe. The drift results from a widening of the band gap and a reduction of Urbach tails due to structural relaxations leading to the removal of chains of Ge-Ge homopolar bonds. The same structural features are actually responsible for the high mobility above the glass transition which boosts the crystallization speed exploited in the device.

  20. X-ray diffraction and electron microscope study of phase separation in rod outer segment photoreceptor membrane multilayers

    SciTech Connect

    Gruner, S.M.; Rothschild, K.J.; Clark, N.A.

    1982-09-01

    Phase separation in artificially stacked multilayers of isolated bovine retinal rod outer segment (ROS) membranes has been examined via x-ray diffraction and electron microscopy. Specimens were prepared by isopotential spin drying followed with partial hydration by equilibration against moist gas streams. Upon dehydration, the multilamellar membrane phase assumes a binary phase composition consisting of concentrated protein-containing lamellae interspersed with microdomains of hexagonally packed tubes of lipid in a H/sub II/ configuration. The H/sub II/ lattice is geometrically coupled to the lamellar phase with one set of hexagonal crystal planes co-planar to the local membrane lamellae. The hexagonal microdomains bear a striking resemblance to the ''paracrystalline inclusions'' observed in fast-frozen, intact frog ROS (Corless and Costello, 1981. Exp. Eye Res. 32:217). The lamellar lattice is characterized by an unusually small degree of disorder. Sharp lamellar diffraction with a 120 angstrom unit cell is observed (at near total dehydration) to a resolution of 6 angstrom. A model consistent with the data is that a multilamellar array of ROS disks is stable as long as the external disk surfaces are kept sufficiently far apart. If the distance between the membranes is allowed to shrink below a certain critical value, the disk lipids, spontaneously convert to a nonbilayer phase. This suggests that the structure of the ROS is stabilized by an internal framework that acts to keep the disks apart from one another and from the plasmalemma. Thus, necessity of avoiding phase separations may provide a rationale for the peculiar morphology of the ROS.

  1. Molecular orientation behavior of chiral nematic liquid crystals based on the presence of blue phases using polarized microscopic FT-IR spectroscopy

    NASA Astrophysics Data System (ADS)

    Matsumura, Masanori; Katayama, Norihisa

    2016-07-01

    Study on molecular orientation behavior of highly twisted chiral nematic liquid crystals (N∗LCs) expressing blue phases (BPs) is important for developing new devices. This study examines the change of molecular orientation of N∗LCs due to the presence of BPs. Polarized microscopic FT-IR spectroscopy was used to study the in- and out-of-plane molecular orientations of N∗LCs that undergo a phase transition involving BPs. The band intensity ratio of CN to CH2 stretching modes (CN/CH2) in the IR spectra was used to determine the orientation of N∗LC molecules. The measured spectra indicated that the helical axis of N∗LC molecules was perpendicular to the substrate before heating and inclined on the substrate after cooling the sample which has phase transition from BP I to chiral nematic (N∗). The N∗LC molecule in the cell of rubbed orientation film exhibited the in-plane anisotropy after a heating-cooling ramp only in samples that passed through BP I. These results indicate that the changes of molecular orientation of N∗LC by phase transition are affected by BP I.

  2. Microscopic Polyangiitis

    PubMed Central

    Chung, Sharon A.; Seo, Philip

    2010-01-01

    Synopsis In 1923, Friedrich Wohlwill described two patients with a “microscopic form of periarteritis nodosa”, which was distinct from classical polyarteritis nodosa. This disease, now known as microscopic polyangiitis (MPA), is a primary systemic vasculitis characterized by inflammation of the small-caliber blood vessels and the presence of circulating antineutrophil cytoplasmic antibodies (ANCA). Typically, microscopic polyangiitis presents with glomerulonephritis and pulmonary capillaritis, although involvement of the skin, nerves, and gastrointestinal tract is not uncommon. Treatment of MPA generally requires use of a cytotoxic agent (such as cyclophosphamide) in addition to high-dose glucocorticoids. Recent research has focused on identifying alternate treatment strategies that minimize or eliminate exposure to cytotoxic agents. This article will review the history, pathogenesis, clinical manifestations, and treatment of MPA. PMID:20688249

  3. Martian Microscope

    NASA Technical Reports Server (NTRS)

    2004-01-01

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

  4. Diffuse cone behavior and microscopic structure of the de Vries smectic-A and smectic-C phases

    NASA Astrophysics Data System (ADS)

    Yoon, HyunGuen; Agra-Kooijman, Dena M.; Ayub, Khurshid; Lemieux, Robert P.; Kumar, Satyendra

    2011-10-01

    Direct synchrotron x-ray scattering measurements of the orientational order parameter, S, corresponding to the siloxane and hydrocarbon parts of the molecule, smectic layer spacing, and director tilt angle with respect to the smectic-C (SmC) layer normal in the de Vries smectics-A (SmA) and SmC phases of two organosiloxane mesogens are reported. The results reveal that (i) the SmC (tilt) order parameter exponent β = 0.26 +/- 0.01 for 2nd order SmA-SmC transition in excellent agreement with the tricritical behavior, (ii) the siloxane and hydrocarbon parts of the molecules are segregated and oriented parallel to the director with different degree of orientational order, and (iii) thermal evolution of the effective molecular length is different in the two phases contrary to the conventional wisdom.

  5. Scanning electron microscope for in situ study of crystallization of Ge2Sb2Te5 in phase-change memory.

    PubMed

    Yin, You; Niida, Daisuke; Ota, Kazuhiro; Sone, Hayato; Hosaka, Sumio

    2007-12-01

    By introducing electrical connections into the chamber of a scanning electron microscope (SEM) via its holder assembly, it has become feasible to in situ observe and electrically characterize electronic devices. The in situ SEM was applied to investigate electric-pulse-induced behavior of Ge(2)Sb(2)Te(5) in a lateral phase-change memory cell. Randomly distributed nuclei with sizes from 20 to 80 nm were initiated at a low voltage pulse. Initially, grain growth depended strongly on pulse amplitude at around 60.3 nm/V and then a weak pulse amplitude dependence was observed at around 13.5 nm/V. Device resistance during crystallization dropped by two to three orders of magnitude with two falling steps, which probably resulted from amorphous to face-centered-cubic and subsequently to hexagonal transitions, respectively. PMID:18163750

  6. In situ electron microscope study of the phase transformation, structure and growth of thin Te 1- xSe x films

    NASA Astrophysics Data System (ADS)

    Vermaak, J. S.; Raubenheimer, D.

    1990-01-01

    An in-situ electron microscope technique was utilized to observe directly the amorphous-to-crystalline phase transformation, the isothermal growth rates, as well as the orientation and structure of the recrystallized films for the Te 1-xSe x alloy system for x=0.2, 0.3 and 0.4. Activation energies of E=0.91, 0.93 and 0.96 eV and crystallization temperatures of Tc=-14, 81.5 and 85°C for the three alloys, respectively, were found. In all three cases the crystallization process originated from single crystalline nuclei with a hexagonal structure and with the c-axis in general parallel to the substrate surface.

  7. Scanning and transmission electron microscope observations of magnetite and other iron phases in Ordovician carbonates from east Tennessee

    NASA Astrophysics Data System (ADS)

    Suk, Dongwoo; van der Voo, Rob; Peacor, Donald R.

    1990-08-01

    Previous paleomagnetic observations for the carbonates of the Lower Ordovician Knox Group have indicated that ancient magnetizations in these rocks are of the same age as the late Paleozoic Alleghenian Orogeny. Rock magnetic properties strongly suggest magnetite as the carrier of the magnetization, but the textural and crystalline characteristics, sizes, morphologies, and mineral associations of these magnetites are poorly known. We have examined magnetic extracts and iron oxides in thin sections with scanning (SEM) and scanning/transmission (STEM) electron microscope techniques to determine whether the observed iron-oxide grain textures match the rock magnetic properties and paleomagnetic inferences about the mode of formation of the magnetic carriers. Several different forms of magnetite in limestones and dolomites, which in places are host to Mississippi-Valley type deposits, are documented by imaging and energy-dispersive analysis using SEM and STEM, by X ray diffraction and electron diffraction patterns using STEM. The magnetite is either spherical with a dimpled surface or nonspherical in the form of void-filling single grains or grain aggregates. Most of the iron oxides have the composition of pure end-member magnetite, but occasional titanomagnetite and hematite, including rare zincian hematite, have been observed (only in limestone). Wherever found in thin section, nonspherical magnetites occur in association with secondary dolomite, potassium-feldspar, illite, and quartz. Some iron oxides have, in fact, inclusions of K-feldspar and quartz. Some of the magnetite (spherical and nonspherical) is polycrystalline; this implies that the larger observed grains may consist of single domains or pseudo-single domains. This provides an explanation of the observed rock magnetic properties that apparently reflect the presence of single-domain (but interacting?) subgrains, on the basis of remanent coercivities and blocking temperatures. We interpret the pure end

  8. Measurement of optical absorption in polycrystalline CVD diamond plates by the phase photothermal method at a wavelength of 10.6 {mu}m

    SciTech Connect

    Luk'yanov, A Yu; Serdtsev, E V; Volkov, P V; Ral'chenko, Viktor G; Savel'ev, A V; Konov, Vitalii I; Khomich, A V

    2008-12-31

    A highly-efficient phase photothermal method is developed for quantitative measurements of the small optical absorption coefficient in thin plates made of highly transparent materials in which bulk losses significantly exceed surface losses. The bulk absorption coefficient at 10.6 {mu}m is estimated in polycrystalline diamond plates grown from the vapour phase (a CVD diamond). The results are compared with those for natural and synthetic diamond single crystals and with the concentrations of nitrogen and hydrogen impurities. The absorption coefficient of the best samples of the CVD diamond did not exceed 0.06 cm{sup -1}, which, taking into account the high thermal conductivity of the CVD diamond (1800-2200 W mK{sup -1} at room temperature), makes this material attractive for fabricating output windows of high-power CO{sub 2} lasers, especially for manufacturing large-size optics. (laser applications and other topics in quantum electronics)

  9. Phase Fluctuation of pr and ca Doped YBa2Cu3O7-δ Compounds in a Microscopic Area

    NASA Astrophysics Data System (ADS)

    Poon, T. C.; Gao, J.

    Experimental investigations have been made on the compound Y1-xPrxBa2Cu3O7-δ with increasing praseodymium concentration x. 'Internal temperature gradient' in a muffle furnace would suffice to induce a small-scale melt texture growth to proceed, resulting in a single crystal block with (relatively) regular shape. The ingredients of the materials in the such crystal block, though randomly oriented and sometimes irregular in shape, can be investigated in a systematic way by using techniques such as energy dispersive X-ray analysis. The phase amounts along the crystal layers have been correlated with atomic percentages based on simple, plausible assumptions. This provides us sensible and useful clues to understand the compositions of various samples. Besides, the physical nature of this material has been studied and discussed. Various theoretical models, including the magnetic pair-breaking mechanism and the hole-filling mechanism, were compared with the obtained results.

  10. Search for microscopic and macroscopic biaxiality in the cybotactic nematic phase of new oxadiazole bent-core mesogens

    NASA Astrophysics Data System (ADS)

    Kim, Young-Ki; Cukrov, Greta; Vita, Francesco; Scharrer, Eric; Samulski, Edward T.; Francescangeli, Oriano; Lavrentovich, Oleg D.

    2016-06-01

    The possibility of biaxial orientational order in nematic liquid crystals is a subject of intense current interest. We explore the tendencies toward local and global biaxial ordering in the recently synthesized trimethylated oxadiazole-based bent-core mesogens with a pronounced asymmetric (bow-type) shape of molecules. The combination of x-ray diffraction and optical studies suggests that the biaxial order is expressed differently at the short- and long-range scales. Locally, at the scale of a few molecules, x-ray-diffraction data demonstrate biaxial packing. However, above the mesoscopic scale, the global orientational order in all three compounds is uniaxial, as evidenced by uniform homeotropic alignment of the nematic phase which is optically tested over the entire temperature range and by the observations of topological defects induced by individual and aggregated colloidal spheres in the nematic bulk.

  11. Search for microscopic and macroscopic biaxiality in the cybotactic nematic phase of new oxadiazole bent-core mesogens.

    PubMed

    Kim, Young-Ki; Cukrov, Greta; Vita, Francesco; Scharrer, Eric; Samulski, Edward T; Francescangeli, Oriano; Lavrentovich, Oleg D

    2016-06-01

    The possibility of biaxial orientational order in nematic liquid crystals is a subject of intense current interest. We explore the tendencies toward local and global biaxial ordering in the recently synthesized trimethylated oxadiazole-based bent-core mesogens with a pronounced asymmetric (bow-type) shape of molecules. The combination of x-ray diffraction and optical studies suggests that the biaxial order is expressed differently at the short- and long-range scales. Locally, at the scale of a few molecules, x-ray-diffraction data demonstrate biaxial packing. However, above the mesoscopic scale, the global orientational order in all three compounds is uniaxial, as evidenced by uniform homeotropic alignment of the nematic phase which is optically tested over the entire temperature range and by the observations of topological defects induced by individual and aggregated colloidal spheres in the nematic bulk. PMID:27415328

  12. Atomic Force Microscope Mediated Chromatography

    NASA Technical Reports Server (NTRS)

    Anderson, Mark S.

    2013-01-01

    The atomic force microscope (AFM) is used to inject a sample, provide shear-driven liquid flow over a functionalized substrate, and detect separated components. This is demonstrated using lipophilic dyes and normal phase chromatography. A significant reduction in both size and separation time scales is achieved with a 25-micron-length column scale, and one-second separation times. The approach has general applications to trace chemical and microfluidic analysis. The AFM is now a common tool for ultra-microscopy and nanotechnology. It has also been demonstrated to provide a number of microfluidic functions necessary for miniaturized chromatography. These include injection of sub-femtoliter samples, fluidic switching, and sheardriven pumping. The AFM probe tip can be used to selectively remove surface layers for subsequent microchemical analysis using infrared and tip-enhanced Raman spectroscopy. With its ability to image individual atoms, the AFM is a remarkably sensitive detector that can be used to detect separated components. These diverse functional components of microfluidic manipulation have been combined in this work to demonstrate AFM mediated chromatography. AFM mediated chromatography uses channel-less, shear-driven pumping. This is demonstrated with a thin, aluminum oxide substrate and a non-polar solvent system to separate a mixture of lipophilic dyes. In conventional chromatographic terms, this is analogous to thin-layer chromatography using normal phase alumina substrate with sheardriven pumping provided by the AFM tip-cantilever mechanism. The AFM detection of separated components is accomplished by exploiting the variation in the localized friction of the separated components. The AFM tip-cantilever provides the mechanism for producing shear-induced flows and rapid pumping. Shear-driven chromatography (SDC) is a relatively new concept that overcomes the speed and miniaturization limitations of conventional liquid chromatography. SDC is based on a

  13. Acoustic imaging microscope

    DOEpatents

    Deason, Vance A.; Telschow, Kenneth L.

    2006-10-17

    An imaging system includes: an object wavefront source and an optical microscope objective all positioned to direct an object wavefront onto an area of a vibrating subject surface encompassed by a field of view of the microscope objective, and to direct a modulated object wavefront reflected from the encompassed surface area through a photorefractive material; and a reference wavefront source and at least one phase modulator all positioned to direct a reference wavefront through the phase modulator and to direct a modulated reference wavefront from the phase modulator through the photorefractive material to interfere with the modulated object wavefront. The photorefractive material has a composition and a position such that interference of the modulated object wavefront and modulated reference wavefront occurs within the photorefractive material, providing a full-field, real-time image signal of the encompassed surface area.

  14. Plate-mantle interaction through time explains two-phase uplift history of the eastern Australian passive margin

    NASA Astrophysics Data System (ADS)

    Dietmar Müller, R.; Flament, Nicolas; Matthews, Kara J.; Williams, Simon E.; Gurnis, Michael

    2015-04-01

    The origin of passive margin mountains is a hotly debated topic in geodynamics. The Eastern Highlands of Australia are a type example whose uplift history has been investigated for several decades, with suggested mechanisms ranging from flexural rift shoulder uplift, volcanism and underplating to mantle-convection driven dynamic topography. Most of the highlands have experienced a distinct two-phase uplift history, with the first phase being Late Cretaceous in age, followed by a mid-late Cenozoic renewal in uplift, but the timing and magnitude of uplift differs along strike. We investigate the origin of the Eastern Highlands with a coupled plate-mantle model, using a thorough parameter space analysis, including two alternative subduction boundary evolution models. The first model includes a large (~1000 km width at its maximum extent) Early Cretaceous (140-120 Ma) back-arc basin east of the Lord Howe Rise, representing the now subducted South Loyalty Basin which may have formed due to eastward rollback of the long-lived west-dipping eastern Gondwanaland subduction zone; the alternative scenario is based on the premise that west-dipping subduction is continuous to the East of the Lord Howe Rise between 140-85 Ma, without a large back-arc basin, and the South Loyalty Basin opening as a back arc basin from 85-55 Ma, which is subsequently consumed by subduction. We further investigate the influence of a low-viscosity asthenosphere and of the viscosity profile of the lower mantle on dynamic topography, as well as the effect of changing the buoyancy of the basal dense layer (LLSVP) that contributes to the long-wavelength Pacific superswell. Our best-fit model produces a total uplift up to ~400 m in the interval between 120 and 90-70 Ma, well-matched with recent published estimates from river profile inversion for the Snowy Mountains, New England and the Central Highlands. The driving mechanism is rebound from the eastwards motion of Australia over a sinking slab, first

  15. Volumetric retinal fluorescence microscopic imaging with extended depth of field

    NASA Astrophysics Data System (ADS)

    Li, Zengzhuo; Fischer, Andrew; Li, Wei; Li, Guoqiang

    2016-03-01

    Wavefront-engineered microscope with greatly extended depth of field (EDoF) is designed and demonstrated for volumetric imaging with near-diffraction limited optical performance. A bright field infinity-corrected transmissive/reflective light microscope is built with Kohler illumination. A home-made phase mask is placed in between the objective lens and the tube lens for ease of use. General polynomial function is adopted in the design of the phase plate for robustness and custom merit function is used in Zemax for optimization. The resulting EDoF system achieves an engineered point spread function (PSF) that is much less sensitive to object depth variation than conventional systems and therefore 3D volumetric information can be acquired in a single frame with expanded tolerance of defocus. In Zemax simulation for a setup using 32X objective (NA = 0.6), the EDoF is 20μm whereas a conventional one has a DoF of 1.5μm, indicating a 13 times increase. In experiment, a 20X objective lens with NA = 0.4 was used and the corresponding phase plate was designed and fabricated. Retinal fluorescence images of the EDoF microscope using passive adaptive optical phase element illustrate a DoF around 100μm and it is able to recover the volumetric fluorescence images that are almost identical to in-focus images after post processing. The image obtained from the EDoF microscope is also better in resolution and contrast, and the retinal structure is better defined. Hence, due to its high tolerance of defocus and fine restored image quality, EDoF optical systems have promising potential in consumer portable medical imaging devices where user's ability to achieve focus is not optimal, and other medical imaging equipment where achieving best focus is not a necessary.

  16. Real-time monitoring of the functional status of platelets treated by Infukoll using a computer-aided laser phase microscope

    NASA Astrophysics Data System (ADS)

    Vasilenko, Irina A.; Babakova, Svetlana; Kiseleva, Elena; Dyugeev, Adyan; Konradov, Alexander A.; Shabalin, Vladimir

    1999-02-01

    Combined analysis of optic-geometrical characteristics makes it possible to comprehensively evaluate the morphological and functional state of the cytological object, which can not be done during visual observation. The technique is discussed for real-time monitoring of the functional status of platelets using computer-aided phase microscope (CPM) 'Cytoscan'. High accuracy and sensitivity of CPM with respect to determination of local temporal phase make it possible to register the dynamic processes in the voluntarily chosen points and sections of micro-objects, to obtain the Fourier's spectra and other characteristics suitable for statistical analysis. Human platelets were prepared from venous blood of healthy donors and pregnant women by standard methods, suspended in culture medium 199 and treated by different doses of 6% Infukoll HES. Nonfixating and nonstaining cells were studied with CPM: height accuracy 0.5 nm, magnification 1000, acquisition time 4 - 30 s. In our experiments we used time resolution about 0.03 s and 30 x lens with numerical aperture 0.65. During investigations of temporal processes a certain section was chosen in the topogram of cell image and local values for the phase of scattered wave in each of the points of the chosen cell's profile were measured. On the basis of the results of automated phase image analysis of optic-geometrical characteristics of living cells, the new quantitative express-method for evaluating of the functional status of human platelets was developed and tested. The structural changes of cells were visualized in alteration of 3-D images, phase profiles, in the decrease of mean cell phase diameters, heights, volumes, in disturbance of histograms of phase heights distribution by cell image points. New data on the behavior of platelets treated by Infukoll in vitro and in vivo were obtained. Analysis of intracellular dynamics was allowed to characterize the cell's regions of maximal activity, but the intensity of processes

  17. Pancharatnam-Berry phase optical elements for generation and control of complex light: generalized superelliptical q-plates

    NASA Astrophysics Data System (ADS)

    Piccirillo, Bruno; Kumar, Vijay; Marrucci, Lorenzo; Santamato, E.

    2015-03-01

    We present newly conceived liquid-crystal-based retardation waveplates in which the optic axis distribution has a "superelliptically" symmetric azimuthal structure with a topological charge q superimposed. Such devices, named superelliptical q-plates, act as polarization-to-spatial modes converters that can be used to produce optical beams having peculiar spiral spectra. These spectra reflect the topological charge of the optic axis distribution as well as the symmetry properties of the underlying superellipse. The peculiar capability of q-plates of producing optical modes entangled with respect to spin and orbital angular momentum is here extended to superelliptical q-plates in order to create more complex optical modes structurally inseparable with respect to polarization and spatial degrees of freedom. Such superelliptical modes can play a crucial role in studying polarization singularities or to develop polarization metrology.

  18. Preparation and magnetic properties of Ni-P-La coating by electroless plating on silicon substrate

    NASA Astrophysics Data System (ADS)

    Gao, Yun; Wang, Jihui; Yuan, Jing; Li, Haiqin

    2016-02-01

    Ni-P-La coatings were prepared on Si substrate by electroless plating method under different La content, pH value, plating temperature and plating time. The surface morphology, chemical composition, structure and magnetic properties of coatings were observed and determined by scanning electron microscope (SEM), energy dispersive X-ray spectrometry (EDS), X-ray diffractometer (XRD) and vibrating sample magnetometer (VSM). The results showed that Ni-P-La coating is smooth and uniform with a cellular morphology grown in columnar manner. With the increase of La content, pH value and plating time, the thickness and saturation magnetization of coating are increased continuously, but the stability of plating bath is decreased greatly with La content and pH value. Under higher plating temperature, the thickness and saturation magnetization of coatings are obviously enhanced. But too high plating temperature is harmful to the plating bath and coating. The optimum plating conditions for Ni-P-La coating is La2O3 addition of 10 mg L-1, pH value of 5.0, plating temperature of 75 °C and plating time of 45 min. The role of La element is to benefit the deposition of Ni element, promote the formation of Ni phase during the annealing process, and thus improve the magnetic properties of Ni-P-La coating.

  19. Highly frustrated spin-lattice models of magnetism and their quantum phase transitions: A microscopic treatment via the coupled cluster method

    SciTech Connect

    Bishop, R. F.; Li, P. H. Y.; Campbell, C. E.

    2014-10-15

    We outline how the coupled cluster method of microscopic quantum many-body theory can be utilized in practice to give highly accurate results for the ground-state properties of a wide variety of highly frustrated and strongly correlated spin-lattice models of interest in quantum magnetism, including their quantum phase transitions. The method itself is described, and it is shown how it may be implemented in practice to high orders in a systematically improvable hierarchy of (so-called LSUBm) approximations, by the use of computer-algebraic techniques. The method works from the outset in the thermodynamic limit of an infinite lattice at all levels of approximation, and it is shown both how the 'raw' LSUBm results are themselves generally excellent in the sense that they converge rapidly, and how they may accurately be extrapolated to the exact limit, m → ∞, of the truncation index m, which denotes the only approximation made. All of this is illustrated via a specific application to a two-dimensional, frustrated, spin-half J{sub 1}{sup XXZ}−J{sub 2}{sup XXZ} model on a honeycomb lattice with nearest-neighbor and next-nearest-neighbor interactions with exchange couplings J{sub 1} > 0 and J{sub 2} ≡ κJ{sub 1} > 0, respectively, where both interactions are of the same anisotropic XXZ type. We show how the method can be used to determine the entire zero-temperature ground-state phase diagram of the model in the range 0 ≤ κ ≤ 1 of the frustration parameter and 0 ≤ Δ ≤ 1 of the spin-space anisotropy parameter. In particular, we identify a candidate quantum spin-liquid region in the phase space.

  20. In situ microscopic studies on the structures and phase behaviors of SF/PEG films using solid-state NMR and Raman imaging.

    PubMed

    Chen, Congheng; Yao, Ting; Tu, Sidong; Xu, Weijie; Han, Yi; Zhou, Ping

    2016-06-28

    In order to overcome the drawbacks of silk fibroin (SF)-based materials, SF has been blended with some polymers. Before using the blend material, understanding of the structures and phase behaviors of the blend is thought to be essential. In this study, solid-state (13)C CP-MAS NMR and Raman imaging techniques were used to study the structures and phase behaviors of blends of SF with polyethylene glycol (PEG) at a molecular weight that varied from 2 to 20 kDa and a blend ratio of SF/PEG from 95/5 to 70/30 (w/w%) at the molecular and microscopic levels. It is found that the conformational transition of SF to the β-sheet increased as the PEG content increased, while the amount of the formed β-sheet conformers was decreased as the PEG molecular weight increased for a given content. It is also observed that SF was incompatible with PEG to some extent. The phase separation into "sea" and "island" domains took place in the SF/PEG blend films. SF was dominantly present in the "sea" domain, while PEG in the "island" domains. The conformation of SF in the interface between SF and PEG was changed to the β-sheet, while that in the protein-rich domain remained in the random coil and/or helix conformation. These observations suggest that the specifically expected materials, for example, the silk-based microspheres or scaffold materials can be manufactured by controlling the molecular weight and content of PEG in the blend system. PMID:27255417

  1. Formation of III–V ternary solid solutions on GaAs and GaSb plates via solid-phase substitution reactions

    SciTech Connect

    Vasil’ev, V. I.; Gagis, G. S. Kuchinskii, V. I.; Danil’chenko, V. G.

    2015-07-15

    Processes are considered in which ultrathin layers of III–V ternary solid solutions are formed via the delivery of Group-V element vapors to GaAs and GaSb semiconductor plates, with solid-phase substitution reactions occurring in the surface layers of these plates. This method can form defect-free GaAs{sup 1–x}P{sup x}, GaAs{sup x}Sb{sup 1–x}, and GaP{sup x}Sb{sup 1–x} layers with thicknesses of 10–20 nm and a content x of the embedded components of up to 0.04.

  2. Deformation characteristics of {delta} phase in the delta-processed Inconel 718 alloy

    SciTech Connect

    Zhang, H.Y.; Zhang, S.H.; Cheng, M.; Li, Z.X.

    2010-01-15

    The hot working characteristics of {delta} phase in the delta-processed Inconel 718 alloy during isothermal compression deformation at temperature of 950 deg. C and strain rate of 0.005 s{sup -1}, were studied by using optical microscope, scanning electron microscope and quantitative X-ray diffraction technique. The results showed that the dissolution of plate-like {delta} phase and the precipitation of spherical {delta} phase particles coexisted during the deformation, and the content of {delta} phase decreased from 7.05 wt.% to 5.14 wt.%. As a result of deformation breakage and dissolution breakage, the plate-like {delta} phase was spheroidized and transferred to spherical {delta} phase particles. In the center with largest strain, the plate-like {delta} phase disappeared and spherical {delta} phase appeared in the interior of grains and grain boundaries.

  3. Plate motion

    SciTech Connect

    Gordon, R.G. )

    1991-01-01

    The motion of tectonic plates on the earth is characterized in a critical review of U.S. research from the period 1987-1990. Topics addressed include the NUVEL-1 global model of current plate motions, diffuse plate boundaries and the oceanic lithosphere, the relation between plate motions and distributed deformations, accelerations and the steadiness of plate motions, the distribution of current Pacific-North America motion across western North America and its margin, plate reconstructions and their uncertainties, hotspots, and plate dynamics. A comprehensive bibliography is provided. 126 refs.

  4. Microscopic analysis of the superconducting quantum critical point: Finite-temperature crossovers in transport near a pair-breaking quantum phase transition

    NASA Astrophysics Data System (ADS)

    Shah, Nayana; Lopatin, Andrei

    2007-09-01

    A microscopic analysis of the superconducting quantum critical point realized via a pair-breaking quantum phase transition is presented. Finite-temperature crossovers are derived for the electrical conductivity, which is a key probe of superconducting fluctuations. By using the diagrammatic formalism for disordered systems, we are able to incorporate the interplay between fluctuating Cooper pairs and electrons, that is outside the scope of a time-dependent Ginzburg-Landau or effective bosonic action formalism. It is essential to go beyond the standard approximation in order to capture the zero-temperature correction which results purely from the (dynamic) quantum fluctuations and dictates the behavior of the conductivity in an entire low-temperature quantum regime. All dynamic contributions are of the same order and conspire to add up to a negative total, thereby inhibiting the conductivity as a result of superconducting fluctuations. On the contrary, the classical and the intermediate regimes are dominated by the positive bosonic channel. Our theory is applicable in one, two, and three dimensions and is relevant for experiments on superconducting nanowires, doubly connected cylinders, thin films, and bulk in the presence of magnetic impurities, magnetic field, or other pair breakers. A window of nonmonotonic behavior is predicted to exist as either the temperature or the pair-breaking parameter is swept.

  5. Continuous-wave laser annealing of Si-rich oxide: A microscopic picture of macroscopic Si-SiO{sub 2} phase separation

    SciTech Connect

    Khriachtchev, Leonid; Nikitin, Timur; Raesaenen, Markku; Domanskaya, Alexandra; Boninelli, Simona; Iacona, Fabio; Engdahl, Anders; Juhanoja, Jyrki; Novikov, Sergei

    2010-12-15

    We report on the first observation of the macroscopic (long-range) Si-SiO{sub 2} phase separation in Si-rich oxide SiO{sub x}(x<2) obtained by continuous-wave laser annealing of free-standing SiO{sub x} films. The effect is analyzed by a unique combination of microscopic methods (Raman, transmission, photoluminescence, and infrared spectroscopy, transmission electron microscopy, electron energy loss spectroscopy, and x-ray photoelectron spectroscopy). Three regions can be distinguished on a SiO{sub x} free-standing film after 488 nm laser annealing at intensities above {approx}10{sup 4} W cm{sup -2}: central spot, ring around the central spot, and pristine film outside the irradiated area. In the pristine SiO{sub x} material, small Si nanocrystals (Si-nc) (diameters of a few nanometer) are surrounded by SiO{sub 2} with an addition of residual suboxides, the Si-nc being produced by annealing at 1100 deg. C in a furnace. The central spot of the laser-annealed area (up to {approx}30 {mu}m wide in these experiments) is practically free of Si excess and mainly consists of amorphous SiO{sub 2}. The ring around the central spot contains large spherical Si-nc (diameters up to {approx}100 nm) embedded in amorphous SiO{sub 2} without the presence of suboxides. Laser-induced temperatures in the structurally modified regions presumably exceed the Si melting temperature. The macroscopic Si-SiO{sub 2} phase separation is connected with extensive diffusion in temperature gradient leading to the Si concentration gradient. The present work demonstrates the advantages of high spatial resolution for analysis in materials research.

  6. Activation of carbon dioxide by a terminal uranium-nitrogen bond in the gas-phase: a demonstration of the principle of microscopic reversibility.

    PubMed

    Dau, Phuong D; Armentrout, P B; Michelini, Maria C; Gibson, John K

    2016-03-14

    Activation of CO2 is demonstrated by its spontaneous dissociative reaction with the gas-phase anion complex NUOCl2(-), which can be considered as NUO(+) coordinated by two chloride anion ligands. This reaction was previously predicted by density functional theory to occur exothermically, without barriers above the reactant energy. The present results demonstrate the validity of the prediction of microscopic reversibility, and provide a rare case of spontaneous dissociative addition of CO2 to a gas-phase complex. The activation of CO2 by NUOCl2(-) proceeds by conversion of a U[triple bond, length as m-dash]N bond to a U[double bond, length as m-dash]O bond and creation of an isocyanate ligand to yield the complex UO2(NCO)Cl2(-), in which uranyl, UO2(2+), is coordinated by one isocyanate and two chloride anion ligands. This activation of CO2 by a uranium(vi) nitride complex is distinctive from previous reports of oxidative insertion of CO2 into lower oxidation state U(iii) or U(iv) solid complexes, during which both C-O bonds remain intact. This unusual observation of spontaneous addition and activation of CO2 by NUOCl2(-) is a result of the high oxophilicity of uranium. If the computed Gibbs free energy of the reaction pathway, rather than the energy, is considered, there are barriers above the reactant asymptotes such that the observed reaction should not proceed under thermal conditions. This result provides a demonstration that energy rather than Gibbs free energy determines reactivity under low-pressure bimolecular conditions. PMID:26898535

  7. Novel solid-phase refolding method for preparation of scFv-immobilized polystyrene plates with high-antigen-binding activity.

    PubMed

    Kumada, Yoichi; Shiritani, Yuki; Hamasaki, Kyoko; Nakagawa, Aya; Sasaki, Eiju; Kishimoto, Michimasa

    2010-10-01

    In the present study, we demonstrated site-specific immobilization and solid-phase refolding of single-chain Fv antibodies on hydrophilic polystyrene (phi-PS) plates that was mediated by novel polystyrene binding peptides (PS-tags: RIIIRRIRR), which were originally isolated and optimized in previous studies. Three PS-tag-fused scFvs, namely scFv-PS, scFv-(PS), and scFv-PSII, which were over-expressed in the insoluble fraction of Escherichia coli cells were denatured and site-specifically immobilized onto hydrophilic PS plates in the presence of 0.5-4 M urea and 0.1% Tween 20. The antigen-binding activity of the scFvs was efficiently recovered by washing the surface of the plate with PBS that contained 0.1% Tween 20 (PBST). The solid-phase refolding mediated by PS-tag was successfully applied to several scFvs such as mouse anti-CRP antibodies and an anti-RNase antibody, although further investigation of the versatility of scFv-PSII is needed. The maximal density of PS-tag-fused scFvs was increased more than 15-fold compared with a whole monoclonal antibody (mAb) immobilized on Maxisorp and, consequently, the sensitivity of PS-tag-fused scFvs for CRP in a sandwich ELISA was increased 25-fold. Thus, the novel, solid-phase, refolding method mediated by a PS-tag will be very useful for preparation of solid supports coated with recombinant antibody fragments, which can be used in immunoassays and immuno-separation. PMID:20661728

  8. Fabrication of Alternating-Phase Fed Single-Layer Slotted Waveguide Arrays Using Plastic Materials with Metal-Plating

    NASA Astrophysics Data System (ADS)

    Zhang, Miao; Hirokawa, Jiro; Ando, Makoto

    Lightweight single-layer slotted waveguide array antennas are fabricated using plastic materials with metal-plating. A plastic material that has good heat-radiation properties is investigated. Three types of antennas are fabricated by milling, using ABS resin, heat-radiating plastic, and aluminum alloy. In measurements, all three types of antennas are confirmed to have almost the same VSWR and gain in the 25GHz frequency band.

  9. Effect of combined particle-phase diffusivity and viscosity on the compressible boundary layer of a particulate suspension over a flat plate

    SciTech Connect

    Chamkha, A.J.

    1999-05-01

    Boundary layer flow and heat transfer of pure and contaminated fluids have been an attractive research area for many investigators for many years due to its direct application in the aerospace, automotive, petroleum, geothermal, and many other industries. Here, a mathematical dilute fluid-particle suspension model governing steady, laminar, compressible, boundary layer flow and heat transfer over a semi-infinite flat plate based on the Eulerian or continuum approach is developed. The model accounts for both particulate viscous and diffusive effects. Both the fluid and the particle phases are assumed to have general power-law viscosity-temperature relations. For the case of finite particle-phase viscosity, a general boundary condition borrowed from rarefied gas dynamics is used for the particle phase at the surface. Uniform and nonuniform particle-phase slip coefficients are investigated. Numerical solution of the governing equations is obtained by an implicit, iterative, tridiagonal finite difference method. Graphical results for the displacement thicknesses and skin-friction coefficients of both phases as well as the wall heat transfer are presented for various parametric conditions.

  10. On thermodynamic and microscopic reversibility

    SciTech Connect

    Crooks, Gavin E.

    2011-07-12

    The word 'reversible' has two (apparently) distinct applications in statistical thermodynamics. A thermodynamically reversible process indicates an experimental protocol for which the entropy change is zero, whereas the principle of microscopic reversibility asserts that the probability of any trajectory of a system through phase space equals that of the time reversed trajectory. However, these two terms are actually synonymous: a thermodynamically reversible process is microscopically reversible, and vice versa.

  11. Quantitative phase retrieval with arbitrary pupil and illumination

    DOE PAGESBeta

    Claus, Rene A.; Naulleau, Patrick P.; Neureuther, Andrew R.; Waller, Laura

    2015-10-02

    We present a general algorithm for combining measurements taken under various illumination and imaging conditions to quantitatively extract the amplitude and phase of an object wave. The algorithm uses the weak object transfer function, which incorporates arbitrary pupil functions and partially coherent illumination. The approach is extended beyond the weak object regime using an iterative algorithm. Finally, we demonstrate the method on measurements of Extreme Ultraviolet Lithography (EUV) multilayer mask defects taken in an EUV zone plate microscope with both a standard zone plate lens and a zone plate implementing Zernike phase contrast.

  12. Thermal Lens Microscope

    NASA Astrophysics Data System (ADS)

    Uchiyama, Kenji; Hibara, Akihide; Kimura, Hiroko; Sawada, Tsuguo; Kitamori, Takehiko

    2000-09-01

    We developed a novel laser microscope based on the thermal lens effect induced by a coaxial beam comprised of excitation and probe beams. The signal generation mechanism was confirmed to be an authentic thermal lens effect from the measurement of signal and phase dependences on optical configurations between the sample and the probe beam focus, and therefore, the thermal lens effect theory could be applied. Two-point spatial resolution was determined by the spot size of the excitation beam, not by the thermal diffusion length. Sensitivity was quite high, and the detection ability, evaluated using a submicron microparticle containing dye molecules, was 0.8 zmol/μm2, hence a distribution image of trace chemical species could be obtained quantitatively. In addition, analytes are not restricted to fluorescent species, therefore, the thermal lens microscope is a promising analytical microscope. A two-dimensional image of a histamine molecule distribution, which was produced in mast cells at the femtomole level in a human nasal mucous polyp, was obtained.

  13. The Göttingen X-ray microscopes

    NASA Astrophysics Data System (ADS)

    Niemann, B.; Rudolph, D.; Schmahl, G.

    1983-04-01

    An X-ray microscope (XM) is described. This microscope contains a zone plate linear monochromator as a condenser system and high resolution micro zone plate. With this microscope X-ray microscopy experiments have been performed using synchroton radiation at the electron storage ring ACO in Orsay/Paris. Images with 50 nm resolution have been made. Additionally, a scanning X-ray microscope (SXM) is described. This system is under construction and is projected for a resolution of 10-50 nm.

  14. ⁵⁷Fe polarization-dependent synchrotron Mössbauer spectroscopy using a diamond phase plate and an iron borate nuclear Bragg monochromator.

    PubMed

    Mitsui, Takaya; Imai, Yasuhiko; Masuda, Ryo; Seto, Makoto; Mibu, Ko

    2015-03-01

    Energy-domain (57)Fe polarization-dependent synchrotron radiation Mössbauer spectroscopy was developed by using a diamond X-ray phase plate and an iron borate nuclear Bragg monochromator. The former controls the polarization of the incident synchrotron radiation X-rays and the latter filters the (57)Fe-Mössbauer radiation with a narrow bandwidth of ∼3.4 Γ0 (Γ0 ≃ 4.7 neV: natural linewidth of the (57)Fe nucleus) from the broadband synchrotron radiation. The developed nuclear diffraction optics allowed (57)Fe-Mössbauer studies to be performed with various polarization states, i.e. linear polarization, circular polarization and non-polarization. In this paper, the spectrometer system, beam characterization, performance-test experiments and a grazing-incidence Mössbauer measurement of an isotope-enriched ((57)Fe: 95%) iron thin film are described. PMID:25723944

  15. A large granite stage and measuring microscope.

    NASA Technical Reports Server (NTRS)

    Alston-Garnjost, M.; Davis, J. W.; Dauber, P. M.; Smits, R. G.

    1971-01-01

    A stage and measuring microscope servocontrolled by a computer have been constructed. The travel of the stage is 0.5 x 0.5 m and the travel of the microscope objective is 7.5 cm. The measuring accuracy is 1 micron in the x-y plane and 5 microns along the z axis. The mechanical and optical construction of the stage and microscope, as well as the way in which the control electronics are organized, permit great flexibility of operation. Possible applications include the scanning and measuring of astronomical plates, the laying out of patterns of semiconductor devices of very large sizes, and the measurement of precision grids.

  16. A Full-Field KB-FZP Microscope for Hard X-Ray Imaging with Sub 100 nm Resolution

    SciTech Connect

    Rau, C.; Crecea, V.; Peterson, K.M.; Jemian, P.R.; Richter, C.-P.; Neuhausler, U.; Schmeider, G.; Yu, X.; Braun, P.V.; Robinson, I.K.

    2007-06-28

    A full-field hard X-ray microscope has been built at the UNICAT/APS beamline 34ID-C. A Kirkpatrick-Baez mirror is used for the condenser and a micro-Fresnel Zone Plate (FZP) as the objective lens. The zone plates available give access to 50-85 nm spatial resolution operating the microscope between 6-12keV photon energy. The first tomography experiments have been performed with this device. A KB-FZP microscope has been built for sub-100 nm imaging and tomography. Features of 50 nm have been visualized at 9 keV photon energy. A 40 x 20 microns field of view of can be imaged in a minute. The first tomography experiments have been performed with this device. Further, it is planned to apply phase contrast techniques, such as the Zernike method. Both the efficiency and the resolution of the instrument can be further improved. A more efficient zone plate and an improved detector will reduce the exposure times and the use of the 50x100 times more intense so called 'pink-beam' is possible. To improve the resolution, the zone plates deliver in their third order a resolution of 15 nm. A KB-FZP microscope has been built for sub-100 nm imaging and tomography. Features of 50 nm have been visualized at 9 keV photon energy. A 40 x 20 microns field of view of can be imaged in seconds. Tomography experiments have been performed with this device. Phase objects have been visualized taking image series. Phase contrast techniques, such as the Zernike method will be tested in the future. Both the efficiency and the resolution of the instrument can be further improved. Together with the instrument for In-line phase contrast imaging the nano- and micrometer lenghtscale is covered.

  17. Stepped conical zone plate antenna

    NASA Astrophysics Data System (ADS)

    Wiltse, James C.

    2001-07-01

    The Fresnel zone plate lens was invented and developed for optical frequencies. However, fabrication difficulties at the short optical wavelengths have prevented obtain good efficiencies. At longer microwave or millimeter-wavelengths fabrication is easier and phase correcting zone plate antennas have been used to obtain good efficiencies. This paper describes a new type of phase correcting zone plate having even better efficiency, namely a diffraction efficiency of 99 percent compared to a true lens, and an overall efficiency much better than a true lens. For the usual zone plate antenna employed at microwave or millimeter wavelengths, path length adjustment is accomplished by cutting different depths in a dielectric plate or by using two or more dielectrics having different dielectric constants. The new design uses a tilted cut in a dielectric plate, which more accurately matches the shape of a true lens and produces much lower phase error. The construction is still near and can be made for example, by a milling machine with a tilted bit. For a circular zone plate, the lens is a stepped conical or tapered shape. Because the phase steps are small, the far-field antenna pattern is excellent and sidelobe-levels are very low. Analysis of typical configurations will be given, showing that phase errors are small, lower than those for an eighth-wave corrected phase zone plate.

  18. Microscopic Morphology and Microstructure of Ti-N and Ti-Ni Phase Between the Dilution Zone and the Clad Zone in Laser Remelting NiCrBSi/TiN Layer on Ti-6Al-4V Alloy Surface

    NASA Astrophysics Data System (ADS)

    Liu, Rongxiang; Guo, Lixin; Lei, Tingquan

    The microscopic morphology and microstructure of Ti-N and Ti-Ni phase between the dilution zone and the clad zone in laser remelting NiCrBSi/TiN layer on a Ti-6Al-4V alloy were characterized using TEM and SEM. The experimental results showed that during laser irradiation heating, TiN particles were partially dissolved into the melted Ni-base alloy, and the dissolved Ti and N atoms were precipitated in the form of TiN, TiN0.3. Ti exhibits height activity, it combines with Ni forming Ti2Ni, TiNi matrix intermetallic during laser remelting, faults exist in the Ti2Ni and TiNi phase, and crystal lattice of TiNi phase is superlattice. Lastly, the cause of the formation of the Ti-N and Ti-Ni phase is discussed.

  19. Phase separation in a binary mixture confined between symmetric parallel plates: Capillary condensation transition near the bulk critical point

    NASA Astrophysics Data System (ADS)

    Yabunaka, Shunsuke; Okamoto, Ryuichi; Onuki, Akira

    2013-03-01

    We investigate phase separation of near-critical binary mixtures between parallel symmetric walls in the strong adsorption regime. We take into account the renormalization effect due to the critical fluctuations using the recent local functional theory [Okamoto and Onuki, J. Chem. Phys.0021-960610.1063/1.3693331 136, 114704 (2012)]. In statics, a van der Waals loop is obtained in the relation between the average order parameter <ψ> in the film and the chemical potential when the temperature T is lower than the film critical temperature Tcca (in the case of an upper critical solution temperature). In dynamics, we lower T below the capillary condensation line from above Tcca. We calculate the subsequent time development assuming no mass exchange between the film and the reservoir. In the early stage, the order parameter ψ changes only in the direction perpendicular to the walls. For sufficiently deep quenching, such one-dimensional profiles become unstable with respect to the fluctuations varying in the lateral directions. The late-stage coarsening is then accelerated by the hydrodynamic interaction. A pancake domain of the phase disfavored by the walls finally appears in the middle of the film.

  20. Scanning Microscopes Using X Rays and Microchannels

    NASA Technical Reports Server (NTRS)

    Wang, Yu

    2003-01-01

    Scanning microscopes that would be based on microchannel filters and advanced electronic image sensors and that utilize x-ray illumination have been proposed. Because the finest resolution attainable in a microscope is determined by the wavelength of the illumination, the xray illumination in the proposed microscopes would make it possible, in principle, to achieve resolutions of the order of nanometers about a thousand times as fine as the resolution of a visible-light microscope. Heretofore, it has been necessary to use scanning electron microscopes to obtain such fine resolution. In comparison with scanning electron microscopes, the proposed microscopes would likely be smaller, less massive, and less expensive. Moreover, unlike in scanning electron microscopes, it would not be necessary to place specimens under vacuum. The proposed microscopes are closely related to the ones described in several prior NASA Tech Briefs articles; namely, Miniature Microscope Without Lenses (NPO-20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43; and Reflective Variants of Miniature Microscope Without Lenses (NPO-20610), NASA Tech Briefs, Vol. 26, No. 9 (September 2002) page 6a. In all of these microscopes, the basic principle of design and operation is the same: The focusing optics of a conventional visible-light microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. A microchannel plate containing parallel, microscopic-cross-section holes much longer than they are wide is placed between a specimen and an image sensor, which is typically the CCD. The microchannel plate must be made of a material that absorbs the illuminating radiation reflected or scattered from the specimen. The microchannels must be positioned and dimensioned so that each one is registered with a pixel on the image sensor. Because most of the radiation incident on the microchannel walls becomes absorbed, the radiation that reaches the

  1. Plasma-Enhanced Atomic Layer Deposition of Ruthenium-Titanium Nitride Mixed-Phase Layers for Direct-Plate Liner and Copper Diffusion Barrier Applications

    NASA Astrophysics Data System (ADS)

    Gildea, Adam James

    Current interconnect networks in semiconductor processing utilize a sputtered TaN diffusion barrier, Ta liner, and Cu seed to improve the adhesion, microstructure, and electromigration resistance of electrochemically deposited copper that fills interconnect wires and vias. However, as wire/via widths shrink due to device scaling, it becomes increasingly difficult to have the volume of a wire/via be occupied with ECD Cu which increases line resistance and increases the delay in signal propagation in IC chips. A single layer that could serve the purpose of a Cu diffusion barrier and ECD Cu adhesion promoter could allow ECD Cu to occupy a larger volume of a wire/via, leading to a decrease in line resistance and decrease in signal delay. Previous work has shown RuTaN, RuWCN, and RuCo films can act as Cu diffusion barriers and be directly platable to thickness of 2-3nm. However, other material selections may prove as effective or possibly better. Mixed-phase films of ruthenium titanium nitride grown by atomic layer deposition (ALD) were investigated for their performance as a Cu diffusion barrier and as a surface for the direct plating of ECD Cu. All Ru was deposited by plasma-enhanced atomic layer deposition (PEALD) while TiN was deposited by either thermal ALD or PEALD. RuTiN, films with thermal ALD TiN and a Ru:Ti of 20:1 showed barrier performance comparable to PVD TaN at 3-4 nm thickness and 15 nm planar films were directly platable. Follow up work is certainly needed for this material set, yet initial results indicate RuTiN could serve as an effective direct plate liner for Cu interconnects.

  2. Robot-assisted microscope for neurosurgery.

    PubMed

    Giorgi, C; Eisenberg, H; Costi, G; Gallo, E; Garibotto, G; Casolino, D S

    1995-01-01

    We describe the implementation of a robotic arm connected to a neurosurgical operative microscope. A force feedback sensor drives the motors of the arm in response to the positioning of the microscope by the surgeon. Computer graphic techniques allow tracking of the current position of the microscope within the volumetric reconstruction of the brain. The integration of the prototype into the neurosurgical operating room is currently being evaluated. Preliminary comments on this experimental phase are offered. PMID:9079441

  3. Microscopic Rayleigh Droplet Beams

    NASA Astrophysics Data System (ADS)

    Doak, R. B.

    2005-11-01

    A periodically triggered Rayleigh Droplet Beam (RDB) delivers a perfectly linear and periodic stream of identical, monoenergetic droplets that are phase-locked to the trigger signal. The droplet diameter and spacing are easily adjusted of choice of nozzle diameter and trigger frequency. Any liquid of low viscosity may be emloyed as the beam fluid. Although the field of nanofluidics is expanding rapidly, little effort has yet been devoted to ``external flows'' such as RDB's. At ASU we have generated RDB's of water and methanol down to 2 microns in droplet diameter. Nozzle clogging is the sole impediment to smaller droplets. Microscopic Rayleigh droplet beams offer tremendous potential for fundamental physical measurements, fluid dynamics research, and nanofabrication. This talk will describe the apparatus and techniques used at ASU to generate RDB's (surprisingly simple and inexpensive), discuss the triboelectric phenomena that play a role (surprisingly significant), present some initial experimental fluid dynamics measurements, and briefly survey RDB applications. Our particular interest in RDB's is as microscopic transport systems to deliver hydrated, undenatured proteins into vacuum for structure determination via serial diffraction of x-rays or electrons. This may offer the first general method for structure determination of non-crystallizable proteins.

  4. Peen plating

    NASA Technical Reports Server (NTRS)

    Babecki, A. J. (Inventor); Haehner, C. L.

    1973-01-01

    A process for metal plating which comprises spraying a mixture of metallic powder and small peening particles at high velocity against a surface is described. The velocity must be sufficient to impact and bond metallic powder onto the surface. In the case of metal surfaces, the process has as one of its advantages providing mechanical working (hardening) of the surface simultaneously with the metal plating.

  5. Soft x-ray laser microscope

    SciTech Connect

    Suckewer, P.I.

    1990-10-01

    The program consisted of two phases (Phase I and Phase II). The goal of the Phase I (first year program) was to design and construct the Soft X-ray Laser Contact Microscope. Such microscope was constructed and adapted to PPL's 18.2nm soft X-ray Laser (SXL), which in turn was modified and prepared for microscopy experiments. Investigation of the photoresist response to 18.2nm laser radiation and transmissivity of 0.1m thick silicion-nitride (Si[sub 3]N[sub 4]) windows were important initial works. The goal of the first year of Phase II was to construct X-ray contact microscope in combination with existing optical phase microscope, already used by biologists. In the second year of Phase II study of dehydrated Horeseshoe Crab and Hela cancer cells were performed with COXRALM. Also during Phase II, the Imaging X-Ray Laser Microscope (IXRALM) was designed and constructed. This paper describes the development of each of the microscopes and their application for research.

  6. Development of a scanning time of flight microscope and its application to the study of charge transport in phase separated structured organic semiconductors

    NASA Astrophysics Data System (ADS)

    Paul, Sanjoy; Ellman, Brett; Tripathi, Suvagata; Singh, Gautam; Twieg, Robert J.

    2016-04-01

    We describe a tool for studying the two-dimensional spatial variation in electronic properties of organic semiconductors: the scanning time-of-flight microscope (STOFm). The STOFm simultaneously measures the transmittance of polarized light and time-of-flight current transients with a pixel size <30 μm, making it especially valuable for studies of the correlations of structure with charge generation and transport in liquid crystalline organic semiconductors (LC OSCs). Adapting a previously developed photopolymerization technique, we characterize the instrument using patterned samples of a LC OSC bounded by a non-semiconducting polymer matrix.

  7. Microscope and method of use

    DOEpatents

    Bongianni, Wayne L.

    1984-01-01

    A method and apparatus for electronically focusing and electronically scanning microscopic specimens are given. In the invention, visual images of even moving, living, opaque specimens can be acoustically obtained and viewed with virtually no time needed for processing (i.e., real time processing is used). And planar samples are not required. The specimens (if planar) need not be moved during scanning, although it will be desirable and possible to move or rotate nonplanar specimens (e.g., laser fusion targets) against the lens of the apparatus. No coupling fluid is needed, so specimens need not be wetted. A phase acoustic microscope is also made from the basic microscope components together with electronic mixers.

  8. Microscope and method of use

    DOEpatents

    Bongianni, W.L.

    1984-04-17

    A method and apparatus for electronically focusing and electronically scanning microscopic specimens are given. In the invention, visual images of even moving, living, opaque specimens can be acoustically obtained and viewed with virtually no time needed for processing (i.e., real time processing is used). And planar samples are not required. The specimens (if planar) need not be moved during scanning, although it will be desirable and possible to move or rotate nonplanar specimens (e.g., laser fusion targets) against the lens of the apparatus. No coupling fluid is needed, so specimens need not be wetted. A phase acoustic microscope is also made from the basic microscope components together with electronic mixers. 7 figs.

  9. FIRST RESULTS FROM VERY LARGE TELESCOPE NACO APODIZING PHASE PLATE: 4 {mu}m IMAGES OF THE EXOPLANET {beta} PICTORIS b

    SciTech Connect

    Quanz, Sascha P.; Meyer, Michael R.; Kenworthy, Matthew A.; Girard, Julien H. V.; Kasper, Markus; Lagrange, Anne-Marie; Bonnefoy, Mickael; Chauvin, Gael; Apai, Daniel; Boccaletti, Anthony; Hinz, Philip M.; Lenzen, Rainer

    2010-10-10

    Direct imaging of exoplanets requires both high contrast and high spatial resolution. Here, we present the first scientific results obtained with the newly commissioned apodizing phase plate coronagraph (APP) on VLT/NACO. We detected the exoplanet {beta} Pictoris b in the narrowband filter centered at 4.05 {mu}m (NB4.05). The position angle (209.{sup 0}13 {+-} 2.{sup 0}12) and the projected separation to its host star (0.''354 {+-} 0.''012, i.e., 6.8 {+-} 0.2 AU at a distance of 19.3 pc) are in good agreement with the recently presented data from Lagrange et al. Comparing the observed NB4.05 magnitude of 11.20 {+-} 0.23 mag to theoretical atmospheric models, we find a best fit with a 7-10 M {sub Jupiter} object for an age of 12 Myr, again in agreement with previous estimates. Combining our results with published L' photometry, we can compare the planet's [L' - NB4.05] color to that of cool field dwarfs of higher surface gravity suggesting an effective temperature of {approx}1700 K. The best-fit theoretical model predicts an effective temperature of {approx}1470 K, but this difference is not significant given our photometric uncertainties. Our results demonstrate the potential of NACO/APP for future planet searches and provide independent confirmation as well as complementary data for {beta} Pic b.

  10. Experimental and numerical analyses on a plate heat exchanger with phase change for waste heat recovery at off-design conditions

    NASA Astrophysics Data System (ADS)

    Cipollone, Roberto; Bianchi, Giuseppe; Di Battista, Davide; Fatigati, Fabio

    2015-11-01

    This paper analyzes the performances of an evaporator for small scale waste heat recovery applications based on bottoming Organic Rankine Cycles with net output power in the range 2-5 kW. The heat recovery steam generator is a plate heat exchanger with oil as hot stream and an organic fluid on the cold side. An experimental characterization of the heat exchanger was carried out at different operating points measuring temperatures, pressures and flow rates on both sides. The measurement data further allowed to validate a numerical model of the evaporator whereas heat transfer coefficients were evaluated comparing several literature correlations, especially for the phase-change of the organic fluid. With reference to a waste heat recovery application in industrial compressed air systems, multiple off-design conditions were simulated considering the effects of oil mass flow rate and temperature on the superheating of the organic fluid, a key parameter to ensure a proper operation of the expansion machine, thus of the energy recovery process.

  11. MRF Applications: On the Road to Making Large-Aperture Ultraviolet Laser Resistant Continuous Phase Plates for High-Power Lasers

    SciTech Connect

    Menapace, J A; Davis, P J; Steele, W A; Hachkowski, M R; Nelson, A; Xin, K

    2006-10-26

    Over the past two years we have developed MRF tools and procedures to manufacture large-aperture (430 X 430 mm) continuous phase plates (CPPs) that are capable of operating in the infrared portion (1053 nm) of high-power laser systems. This is accomplished by polishing prescribed patterns of continuously varying topographical features onto finished plano optics using MRF imprinting techniques. We have been successful in making, testing, and using large-aperture CPPs whose topography possesses spatial periods as low as 4 mm and surface peak-to-valleys as high as 8.6 {micro}m. Combining this application of MRF technology with advanced MRF finishing techniques that focus on ultraviolet laser damage resistance makes it potentially feasible to manufacture large-aperture CPPs that can operate in the ultraviolet (351 nm) without sustaining laser-induced damage. In this paper, we will discuss the CPP manufacturing process and the results of 351-nm/3-nsec equivalent laser performance experiments conducted on large-aperture CPPs manufactured using advanced MRF protocols.

  12. Diffraction of a finite-radius plane wave and a Gaussian beam by a helical axicon and a spiral phase plate

    NASA Astrophysics Data System (ADS)

    Kotlyar, Victor V.; Kovalev, Alexey A.; Skidanov, Roman V.; Moiseev, Oleg Yu.; Soifer, Victor A.

    2007-07-01

    We derive what we believe to be new analytical relations to describe the Fraunhofer diffraction of the finite-radius plane wave by a helical axicon (HA) and a spiral phase plate (SPP). The solutions are deduced in the form of a series of the Bessel functions for the HA and a finite sum of the Bessel functions for the SPP. The solution for the HA changes to that for the SPP if the axicon parameter is set equal to zero. We also derive what we believe to be new analytical relations to describe the Fresnel and Fraunhofer diffraction of the Gaussian beam by a HA are derived. The solutions are deduced in the form of a series of the hypergeometric functions. We have fabricated by photolithography a binary diffractive optical element (a HA with number n=10) able to produce in the focal plane of a spherical lens an optical vortex, which was then used to perform rotation of several polystyrene beads of diameter 5 μm.

  13. Plate tectonics conserves angular momentum

    NASA Astrophysics Data System (ADS)

    Bowin, C.

    2009-03-01

    A new combined understanding of plate tectonics, Earth internal structure, and the role of impulse in deformation of the Earth's crust is presented. Plate accelerations and decelerations have been revealed by iterative filtering of the quaternion history for the Euler poles that define absolute plate motion history for the past 68 million years, and provide an unprecedented precision for plate angular rotation variations with time at 2-million year intervals. Stage poles represent the angular rotation of a plate's motion between adjacent Euler poles, and from which the maximum velocity vector for a plate can be determined. The consistent maximum velocity variations, in turn, yield consistent estimates of plate accelerations and decelerations. The fact that the Pacific plate was shown to accelerate and decelerate, implied that conservation of plate tectonic angular momentum must be globally conserved, and that is confirmed by the results shown here (total angular momentum ~1.4 E+27 kgm2s-1). Accordingly, if a plate decelerates, other plates must increase their angular momentums to compensate. In addition, the azimuth of the maximum velocity vectors yields clues as to why the "bend" in the Emperor-Hawaiian seamount trend occurred near 46 Myr. This report summarizes processing results for 12 of the 14 major tectonic plates of the Earth (except for the Juan de Fuca and Philippine plates). Plate accelerations support the contention that plate tectonics is a product of torques that most likely are sustained by the sinking of positive density anomalies due to phase changes in subducted gabbroic lithosphere at depth in the upper lower mantle (above 1200 km depth). The tectonic plates are pulled along by the sinking of these positive mass anomalies, rather than moving at near constant velocity on the crests of convection cells driven by rising heat. These results imply that spreading centers are primarily passive reactive features, and fracture zones (and wedge-shaped sites

  14. The Scanning Optical Microscope.

    ERIC Educational Resources Information Center

    Sheppard, C. J. R.

    1978-01-01

    Describes the principle of the scanning optical microscope and explains its advantages over the conventional microscope in the improvement of resolution and contrast, as well as the possibility of producing a picture from optical harmonies generated within the specimen.

  15. Mantle convection with plates and mobile, faulted plate margins.

    PubMed

    Zhong, S; Gurnis, M

    1995-02-10

    A finite-element formulation of faults has been incorporated into time-dependent models of mantle convection with realistic rheology, continents, and phase changes. Realistic tectonic plates naturally form with self-consistent coupling between plate and mantle dynamics. After the initiation of subduction, trenches rapidly roll back with subducted slabs temporarily laid out along the base of the transition zone. After the slabs have penetrated into the lower mantle, the velocity of trench migration decreases markedly. The inhibition of slab penetration into the lower mantle by the 670-kilometer phase change is greatly reduced in these models as compared to models without tectonic plates. PMID:17813909

  16. Chemically twinned phases in the Ag 2S-PbS-Bi 2S 3 system.Part I. Electron microscope study

    NASA Astrophysics Data System (ADS)

    Skowron, A.; Tilley, R. J. D.

    1990-04-01

    Phases in the PbS-rich region of the Ag 2S-PbS-Bi 2S 3 system have been studied by high resolution transmission electron microscopy. In samples quenched from the melt or melted and annealed at 773 or 973 K a number of new chemically twinned phases have been found. Their structures contain galena-like slabs four-, five-, seven-, and eight-octahedra wide, joined along twin planes. Ordered phases predominate in the PbS-rich region of the phase diagram, while both ordered and disordered intergrowths occur in the PbS-poor region. The role of Ag in stabilizing slabs of galena-like material five- and eight-octahedra wide and its function in the formation of these twinned phases is discussed.

  17. TEAM Electron Microscope Animation

    SciTech Connect

    2012-01-01

    The TEAM Electron Microscope, a device that enables atomic-scale imaging in 3-D, has a rotating stage that can hold and position samples inside electron microscopes with unprecedented stability, position-control accuracy, and range of motion.The TEAM Stage makes one of the world's most powerful electron microscopes even better, and enables previously impossible experiments.

  18. A microfabricated scanning confocal optical microscope for in situ imaging

    NASA Astrophysics Data System (ADS)

    Dickensheets, David Lee

    Scanning confocal optical microscopes are well suited for imaging living tissue because of their ability to 'cross section' intact tissue. They are not, however, well suited for imaging tissues in situ. This dissertation describes a new, miniature, mirror scanned, high resolution confocal optical microscope that operates in real time. It is small enough to fit into an endoscope, and may eventually be incorporated into a hypodermic needle. Such a device would provide immediate in-situ tissue assessment at the cellular level and may enable, for example, biopsy without tissue removal. Non-medical applications may include process monitoring and endoscopic inspection. The microfabricated confocal optical scanning microscope, or μCOSM, incorporates single mode optical fiber illumination, silicon torsional scan mirrors, and an off- axis micro diffractive lens. The prototype device is monochromatic, at 633 nm, with a 1.1 mm working distance and 0.25 NA. It achieves a line response of 0.98 μm FWHM, and an axial response of 11.1 μm FWHM. The first part of the dissertation describes the opto- mechanical design of the microscope, which was chosen to be compatible with the microfabrication technologies used for its construction. Then the imaging properties of the off-axis diffractive objective lens are developed, including the aberrations of second and third order which constrain its use. The lens is a surface relief phase grating, and a rigorous electromagnetic analysis is employed to specify the pupil function of the microscope. Then the image forming properties of the μCOSM are derived and compared to experimental results. The second part of the dissertation describes the fabrication of the individual elements of the μCOSM, and their assembly into an imaging instrument. The lens is constructed using electron beam lithography and reactive ion etching of a fused silica substrate. The scanning mirrors for the microscope, which comprise a single crystal silicon plate

  19. Subtraction threshold for an isotropic fluorescence emission difference microscope

    NASA Astrophysics Data System (ADS)

    Wang, Nan; Kobayashi, Takayoshi

    2015-12-01

    Isotropic fluorescence emission difference microscopy proposed recently provides a simple method to enhance the spatial resolution in three-dimensions (3D) for fluorescence imaging. However, the subtraction threshold to achieve the condition for appropriately resolving the sample in 3D have not been studied. Then the subtraction factors used in this type of microscopes are still experientially chosen. Based on vector diffraction theory and a 3D numerical model developed here, the subtraction threshold is numerically investigated for the isotropic fluorescence subtraction microscopy. The subtraction factors and peak intensities at the threshold are obtained and comparied both in lateral and axial planes for achieving most appropriate subtraction and inspecting the isotropic characteristic. The effects of radius ratios of implemented 0-π annular phase plate for generating three dimensional donut spot on the subtracted resolution, peak intensity and negative sidebands are also discussed.

  20. Electron microscopic studies of the antiferroelectric phase in Sr 0.60Ca 0.40TiO 3 ceramic

    NASA Astrophysics Data System (ADS)

    Anwar, Shahid; Lalla, N. P.

    2008-05-01

    The structural variants and their coexistence across the antiferroelectric phase transition in Sr 0.60Ca 0.40TiO 3 ceramic has been studied through transmission electron microscopy (TEM) at room temperature and ˜100 °C. A clear evidence of the presence of superlattice reflections, corresponding to the cell doubling along the c-axis of Pbnm (or b-axis along Pnma), occurring during paraelectric to antiferroelectric transition, has been obtained through selected area electron diffraction, convergent beam electron diffraction and lattice-resolution imaging. Coexistence of the Pbnm and Pbcm phases at room temperature has been observed and attributed to the strain/disorder-induced broadening of the first-order antiferroelectric phase transition. Drastic changes in the domain structure during Pbnm to Pbcm transformation have been observed. This clearly indicates that the antiferrodistortive transition responsible for the occurrence of the antiferroelectric phase is of completely different origin and it is not just an additional follow-up of the already-existing ordering due to a-a-c+ tilt schemes in the Pbnm domain. Thermal cycling studies on microstructural changes indicate some kind of memory mechanism, which retains the memory of the original a-a-c+ tilt schemes in the Pbnm phase. This has been attributed to the symmetry conforming short-range order (SC-SRO) of the point defects.

  1. Phase measurements of EUV mask defects

    DOE PAGESBeta

    Claus, Rene A.; Wang, Yow-Gwo; Wojdyla, Antoine; Benk, Markus P.; Goldberg, Kenneth A.; Neureuther, Andrew R.; Naulleau, Patrick P.; Waller, Laura

    2015-02-22

    Extreme Ultraviolet (EUV) Lithography mask defects were examined on the actinic mask imaging system, SHARP, at Lawrence Berkeley National Laboratory. Also, a quantitative phase retrieval algorithm based on the Weak Object Transfer Function was applied to the measured through-focus aerial images to examine the amplitude and phase of the defects. The accuracy of the algorithm was demonstrated by comparing the results of measurements using a phase contrast zone plate and a standard zone plate. Using partially coherent illumination to measure frequencies that would otherwise fall outside the numerical aperture (NA), it was shown that some defects are smaller than themore » conventional resolution of the microscope. We found that the programmed defects of various sizes were measured and shown to have both an amplitude and a phase component that the algorithm is able to recover.« less

  2. Phase measurements of EUV mask defects

    SciTech Connect

    Claus, Rene A.; Wang, Yow-Gwo; Wojdyla, Antoine; Benk, Markus P.; Goldberg, Kenneth A.; Neureuther, Andrew R.; Naulleau, Patrick P.; Waller, Laura

    2015-02-22

    Extreme Ultraviolet (EUV) Lithography mask defects were examined on the actinic mask imaging system, SHARP, at Lawrence Berkeley National Laboratory. Also, a quantitative phase retrieval algorithm based on the Weak Object Transfer Function was applied to the measured through-focus aerial images to examine the amplitude and phase of the defects. The accuracy of the algorithm was demonstrated by comparing the results of measurements using a phase contrast zone plate and a standard zone plate. Using partially coherent illumination to measure frequencies that would otherwise fall outside the numerical aperture (NA), it was shown that some defects are smaller than the conventional resolution of the microscope. We found that the programmed defects of various sizes were measured and shown to have both an amplitude and a phase component that the algorithm is able to recover.

  3. Cryogenic immersion microscope

    DOEpatents

    Le Gros, Mark; Larabell, Carolyn A.

    2010-12-14

    A cryogenic immersion microscope whose objective lens is at least partially in contact with a liquid reservoir of a cryogenic liquid, in which reservoir a sample of interest is immersed is disclosed. When the cryogenic liquid has an index of refraction that reduces refraction at interfaces between the lens and the sample, overall resolution and image quality are improved. A combination of an immersion microscope and x-ray microscope, suitable for imaging at cryogenic temperatures is also disclosed.

  4. Development of x-ray laminography under an x-ray microscopic condition.

    PubMed

    Hoshino, Masato; Uesugi, Kentaro; Takeuchi, Akihisa; Suzuki, Yoshio; Yagi, Naoto

    2011-07-01

    An x-ray laminography system under an x-ray microscopic condition was developed to obtain a three-dimensional structure of laterally-extended planar objects which were difficult to observe by x-ray tomography. An x-ray laminography technique was introduced to an x-ray transmission microscope with zone plate optics. Three prototype sample holders were evaluated for x-ray imaging laminography. Layered copper grid sheets were imaged as a laminated sample. Diatomite powder on a silicon nitride membrane was measured to confirm the applicability of this method to non-planar micro-specimens placed on the membrane. The three-dimensional information of diatom shells on the membrane was obtained at a spatial resolution of sub-micron. Images of biological cells on the membrane were also obtained by using a Zernike phase contrast technique. PMID:21806188

  5. Development of x-ray laminography under an x-ray microscopic condition

    SciTech Connect

    Hoshino, Masato; Uesugi, Kentaro; Takeuchi, Akihisa; Suzuki, Yoshio; Yagi, Naoto

    2011-07-15

    An x-ray laminography system under an x-ray microscopic condition was developed to obtain a three-dimensional structure of laterally-extended planar objects which were difficult to observe by x-ray tomography. An x-ray laminography technique was introduced to an x-ray transmission microscope with zone plate optics. Three prototype sample holders were evaluated for x-ray imaging laminography. Layered copper grid sheets were imaged as a laminated sample. Diatomite powder on a silicon nitride membrane was measured to confirm the applicability of this method to non-planar micro-specimens placed on the membrane. The three-dimensional information of diatom shells on the membrane was obtained at a spatial resolution of sub-micron. Images of biological cells on the membrane were also obtained by using a Zernike phase contrast technique.

  6. Development of x-ray laminography under an x-ray microscopic condition

    NASA Astrophysics Data System (ADS)

    Hoshino, Masato; Uesugi, Kentaro; Takeuchi, Akihisa; Suzuki, Yoshio; Yagi, Naoto

    2011-07-01

    An x-ray laminography system under an x-ray microscopic condition was developed to obtain a three-dimensional structure of laterally-extended planar objects which were difficult to observe by x-ray tomography. An x-ray laminography technique was introduced to an x-ray transmission microscope with zone plate optics. Three prototype sample holders were evaluated for x-ray imaging laminography. Layered copper grid sheets were imaged as a laminated sample. Diatomite powder on a silicon nitride membrane was measured to confirm the applicability of this method to non-planar micro-specimens placed on the membrane. The three-dimensional information of diatom shells on the membrane was obtained at a spatial resolution of sub-micron. Images of biological cells on the membrane were also obtained by using a Zernike phase contrast technique.

  7. This-layer chromatography/electrospray ionization triple-quadrupole linear ion trap mass spectrometry system: analysis of rhodamine dyes separated on reversed-phase C8 plates

    SciTech Connect

    Ford, Michael J; Kertesz, Vilmos; Van Berkel, Gary J

    2005-01-01

    The direct analysis of separated rhodamine dyes on reversed-phase C{sub 8} thin-layer chromatography plates using a surface sampling/electrospray emitter probe coupled with a triple-quadrupole linear ion trap mass spectrometer is presented. This report represents continuing work to advance the performance metrics and utility of this basic surface sampling electrospray mass spectrometry system for the analysis of thin-layer chromatography plates. Experimental results examining the role of sampling probe spray end configuration on liquid aspiration rate and gas-phase ion signal generated are discussed. The detection figures-of-merit afforded by full-scan, automated product ion and selected reaction monitoring modes of operation were examined. The effect of different eluting solvents on mass spectrum signal levels with the reversed-phase C{sub 8} plate was investigated. The combined effect of eluting solvent flow-rate and development lane surface scan rate on preservation of chromatographic resolution was also studied. Analysis of chromatographically separated red pen ink extracts from eight different pens using selected reaction monitoring demonstrated the potential of this surface sampling electrospray mass spectrometry system for targeted compound analysis with real samples.

  8. Thermal-Wave Microscope

    NASA Technical Reports Server (NTRS)

    Jones, Robert E.; Kramarchuk, Ihor; Williams, Wallace D.; Pouch, John J.; Gilbert, Percy

    1989-01-01

    Computer-controlled thermal-wave microscope developed to investigate III-V compound semiconductor devices and materials. Is nondestructive technique providing information on subsurface thermal features of solid samples. Furthermore, because this is subsurface technique, three-dimensional imaging also possible. Microscope uses intensity-modulated electron beam of modified scanning electron microscope to generate thermal waves in sample. Acoustic waves generated by thermal waves received by transducer and processed in computer to form images displayed on video display of microscope or recorded on magnetic disk.

  9. Recurrence tracking microscope

    SciTech Connect

    Saif, Farhan

    2006-03-15

    In order to probe nanostructures on a surface we present a microscope based on the quantum recurrence phenomena. A cloud of atoms bounces off an atomic mirror connected to a cantilever and exhibits quantum recurrences. The times at which the recurrences occur depend on the initial height of the bouncing atoms above the atomic mirror, and vary following the structures on the surface under investigation. The microscope has inherent advantages over existing techniques of scanning tunneling microscope and atomic force microscope. Presently available experimental technology makes it possible to develop the device in the laboratory.

  10. Upgrade of a Scanning Confocal Microscope to a Single-Beam Path STED Microscope

    PubMed Central

    Klauss, André; König, Marcelle; Hille, Carsten

    2015-01-01

    By overcoming the diffraction limit in light microscopy, super-resolution techniques, such as stimulated emission depletion (STED) microscopy, are experiencing an increasing impact on life sciences. High costs and technically demanding setups, however, may still hinder a wider distribution of this innovation in biomedical research laboratories. As far-field microscopy is the most widely employed microscopy modality in the life sciences, upgrading already existing systems seems to be an attractive option for achieving diffraction-unlimited fluorescence microscopy in a cost-effective manner. Here, we demonstrate the successful upgrade of a commercial time-resolved confocal fluorescence microscope to an easy-to-align STED microscope in the single-beam path layout, previously proposed as “easy-STED”, achieving lateral resolution < λ/10 corresponding to a five-fold improvement over a confocal modality. For this purpose, both the excitation and depletion laser beams pass through a commercially available segmented phase plate that creates the STED-doughnut light distribution in the focal plane, while leaving the excitation beam unaltered when implemented into the joint beam path. Diffraction-unlimited imaging of 20 nm-sized fluorescent beads as reference were achieved with the wavelength combination of 635 nm excitation and 766 nm depletion. To evaluate the STED performance in biological systems, we compared the popular phalloidin-coupled fluorescent dyes Atto647N and Abberior STAR635 by labeling F-actin filaments in vitro as well as through immunofluorescence recordings of microtubules in a complex epithelial tissue. Here, we applied a recently proposed deconvolution approach and showed that images obtained from time-gated pulsed STED microscopy may benefit concerning the signal-to-background ratio, from the joint deconvolution of sub-images with different spatial information which were extracted from offline time gating. PMID:26091552

  11. VSL#3 induces and maintains short-term clinical response in patients with active microscopic colitis: a two-phase randomised clinical trial

    PubMed Central

    Rohatgi, Sarika; Ahuja, Vineet; Makharia, Govind K; Rai, Tarun; Das, Prasenjit; Dattagupta, Siddharth; Mishra, Veena; Garg, Sushil Kumar

    2015-01-01

    Background The probiotic mixture VSL#3 has proven efficacious in inflammatory bowel diseases and irritable bowel syndrome; however, its efficacy in microscopic colitis (MC) is being investigated. Objective To evaluate the safety and efficacy of a multistrain probiotic, VSL#3, in inducing clinical remission and achieving clinical response, as compared with mesalamine, in patients with active MC. Methods A randomised, open labelled study comparing the efficacy of 900 billion colony-forming units/day of VSL#3 (group (Gp) A) or 1.6 g of mesalamine/day (Gp B) for 8 weeks in 30 patients with MC was conducted. After a washout period of 2 weeks, Gp B received 8 weeks of VSL#3 and Gp A was off medication for the next 8 weeks. The primary end points were clinical remission and clinical response at 8 weeks. Results Of 30 patients, 15 were randomised in each arm. 11 patients in Gp A and 13 patients in Gp B completed 8 weeks of treatment. 5 (46%) of 11 patients in Gp A and 1 (8%) of 13 patients in Gp B attained clinical remission (p=0.022). Clinical response was seen in Gp A, as evidenced by a lower stool weight (377.6±104.5 g) as compared with Gp B (507±168.2 g; p=0.03). VSL#3 was effective in maintaining clinical response up to 10 weeks, even after discontinuation of therapy. Secondary end points like stool parameters, histology and well-being improved in both treatment groups. Conclusions The probiotic VSL#3 was found to offer the benefit of inducing as well as maintaining short-term clinical response in patients with active MC. Trial registration number The clinical trial is registered with CLINICAL TRIAL REGISTRY INDIA; http://ctri.nic.in, CTRI No. “CTRI/2008/091/000086” (registered on: 23/06/2008). PMID:26462271

  12. Mailing microscope slides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many insects feed agriculturally important crops, trees, and ornamental plants and cause millions of dollars of damage annually. Identification for some of these require the preparation of a microscope slide for examination. There are times when a microscope slide may need to be sent away to a speci...

  13. The Light Microscope.

    ERIC Educational Resources Information Center

    Baker, W. L.

    1995-01-01

    Describes the function of the various parts of the microscope and their integration in the formation of an optical image. Presents a procedure for setting up a microscope to obtain maximum resolution and contrast for each objective lens at all magnifications. (JRH)

  14. Photography through the Microscope.

    ERIC Educational Resources Information Center

    McNeil, D. W.

    1992-01-01

    Describes how to illuminate and optically stain slides for microscope use and how to interface a 35mm camera with a microscope using an adaptor. Provides equipment descriptions and sources, details about illumination, image formation, darkfield adaptors, centerable filter adaptors, darkfield stops, rheinburg filters, and choosing specimens to…

  15. The Homemade Microscope.

    ERIC Educational Resources Information Center

    Baker, Roger C., Jr.

    1991-01-01

    Directions for the building of a pocket microscope that will make visible the details of insect structure and living bacteria are described. Background information on the history of microscopes and lenses is provided. The procedures for producing various types of lenses are included. (KR)

  16. Surface imaging microscope

    NASA Astrophysics Data System (ADS)

    Rogala, Eric W.; Bankman, Isaac N.

    2008-04-01

    The three-dimensional shapes of microscopic objects are becoming increasingly important for battlespace CBRNE sensing. Potential applications of microscopic 3D shape observations include characterization of biological weapon particles and manufacturing of micromechanical components. Aerosol signatures of stand-off lidar systems, using elastic backscatter or polarization, are dictated by the aerosol particle shapes and sizes that must be well characterized in the lab. A low-cost, fast instrument for 3D surface shape microscopy will be a valuable point sensor for biological particle sensing applications. Both the cost and imaging durations of traditional techniques such as confocal microscopes, atomic force microscopes, and electron scanning microscopes are too high. We investigated the feasibility of a low-cost, fast interferometric technique for imaging the 3D surface shape of microscopic objects at frame rates limited only by the camera in the system. The system operates at two laser wavelengths producing two fringe images collected simultaneously by a digital camera, and a specialized algorithm we developed reconstructs the surface map of the microscopic object. The current implementation assembled to test the concept and develop the new 3D reconstruction algorithm has 0.25 micron resolution in the x and y directions, and about 0.1 micron accuracy in the z direction, as tested on a microscopic glass test object manufactured with etching techniques. We describe the interferometric instrument, present the reconstruction algorithm, and discuss further development.

  17. Optical Analysis of Microscope Images

    NASA Astrophysics Data System (ADS)

    Biles, Jonathan R.

    Microscope images were analyzed with coherent and incoherent light using analog optical techniques. These techniques were found to be useful for analyzing large numbers of nonsymbolic, statistical microscope images. In the first part phase coherent transparencies having 20-100 human multiple myeloma nuclei were simultaneously photographed at 100 power magnification using high resolution holographic film developed to high contrast. An optical transform was obtained by focussing the laser onto each nuclear image and allowing the diffracted light to propagate onto a one dimensional photosensor array. This method reduced the data to the position of the first two intensity minima and the intensity of successive maxima. These values were utilized to estimate the four most important cancer detection clues of nuclear size, shape, darkness, and chromatin texture. In the second part, the geometric and holographic methods of phase incoherent optical processing were investigated for pattern recognition of real-time, diffuse microscope images. The theory and implementation of these processors was discussed in view of their mutual problems of dimness, image bias, and detector resolution. The dimness problem was solved by either using a holographic correlator or a speckle free laser microscope. The latter was built using a spinning tilted mirror which caused the speckle to change so quickly that it averaged out during the exposure. To solve the bias problem low image bias templates were generated by four techniques: microphotography of samples, creation of typical shapes by computer graphics editor, transmission holography of photoplates of samples, and by spatially coherent color image bias removal. The first of these templates was used to perform correlations with bacteria images. The aperture bias was successfully removed from the correlation with a video frame subtractor. To overcome the limited detector resolution it is necessary to discover some analog nonlinear intensity

  18. Population dynamics of the modified theta model: macroscopic phase reduction and bifurcation analysis link microscopic neuronal interactions to macroscopic gamma oscillation.

    PubMed

    Kotani, Kiyoshi; Yamaguchi, Ikuhiro; Yoshida, Lui; Jimbo, Yasuhiko; Ermentrout, G Bard

    2014-06-01

    Gamma oscillations of the local field potential are organized by collective dynamics of numerous neurons and have many functional roles in cognition and/or attention. To mathematically and physiologically analyse relationships between individual inhibitory neurons and macroscopic oscillations, we derive a modification of the theta model, which possesses voltage-dependent dynamics with appropriate synaptic interactions. Bifurcation analysis of the corresponding Fokker-Planck equation (FPE) enables us to consider how synaptic interactions organize collective oscillations. We also develop the adjoint method (infinitesimal phase resetting curve) for simultaneous equations consisting of ordinary differential equations representing synaptic dynamics and a partial differential equation for determining the probability distribution of the membrane potential. This method provides a macroscopic phase response function (PRF), which gives insights into how it is modulated by external perturbation or internal changes of parameters. We investigate the effects of synaptic time constants and shunting inhibition on these gamma oscillations. The sensitivity of rising and decaying time constants is analysed in the oscillatory parameter regions; we find that these sensitivities are not largely dependent on rate of synaptic coupling but, rather, on current and noise intensity. Analyses of shunting inhibition reveal that it can affect both promotion and elimination of gamma oscillations. When the macroscopic oscillation is far from the bifurcation, shunting promotes the gamma oscillations and the PRF becomes flatter as the reversal potential of the synapse increases, indicating the insensitivity of gamma oscillations to perturbations. By contrast, when the macroscopic oscillation is near the bifurcation, shunting eliminates gamma oscillations and a stable firing state appears. More interestingly, under appropriate balance of parameters, two branches of bifurcation are found in our

  19. Stereoscopic Video Microscope

    NASA Astrophysics Data System (ADS)

    Butterfield, James F.

    1980-11-01

    The new electronic technology of three-dimensional video combined with the established. science of microscopy has created. a new instrument. the Stereoscopic Video Microscope. The specimen is illuminated so the stereoscopic objective lens focuses the stereo-pair of images side-by-side on the video camera's pick-up, tube. The resulting electronic signal can be enhanced, digitized, colorized, quantified, its polarity reverse., and its gray scale expanJed non-linearally. The signal can be transmitted over distances and can be stored on video. tape for later playback. The electronic signal is converted to a stereo-pair of visual images on the video monitor's cathode-ray-tube. A stereo-hood is used to fuse the two images for three-dimensional viewing. The conventional optical microscope has definite limitations, many of which can be eliminated by converting the optical image to an electronic signal in the video microscope. The principal aHvantages of the Stereoscopic Video Microscope compared to the conventional optical microscope are: great ease of viewing; group viewing; ability to easily recohd; and, the capability of processing the electronic signal for video. enhancement. The applications cover nearly all fields of microscopy. These include: microelectronics assembly, inspection, and research; biological, metallurgical, and che.illical research; and other industrial and medical uses. The Stereo-scopic Video Microscope is particularly useful for instructional and recordkeeping purposes. The video microscope can be monoscopic or three dimensional.

  20. [Comparative electron-microscopic study of 8 representatives of the genus Corynebacterium grown on solid nutrient medium during the stationary phase of development].

    PubMed

    Vysotskiĭ, V V; Mazurova, I K; Shmeleva, E A

    1976-09-01

    After 18 hours of growth on selective serum-agar medium C diphtheriae cultures with different toxicogenic activity, and also diphtheroid and Hoffmann's baccillus cultures were removed, washed of the remnants of the nutrient medium and fixed under cold conditions by two combined methods (with glutaric aldehyde-osmic acid--uranyl acetate, and potassium permeanganate--uranyl acetate). The preparations were studied in ultrathin sections. It appeared that corynebacteria had during the stationary phase of development a general structural plan characteristic of Gram positive microorganisms and for all the corynebacterium genus. Cells of diphtheria toxicognic strains had signs of the accelerated (in comparison with other strains) rate of development; the principal mass of toxicogenic cells after 18 hours of growth had morphological signs of the stage of rest. The majority of cells whose toxicogenicity was inconstant had an extensive microcapsule which was also a characteristic element of the diphtheroid and Hoffmann's bacillus ultrastructure. The total thickness of the walls in the cells of toxicogenic strains and of the strains whose toxicogenicity was inconstant constituted 190-200 A; in nontoxicogenic strains, diphtheroid and Hoffmann's bacillus it was from 230 to 320 A. Surface structures of corynebacteria were differentiated better in the cells with toxicogenic activity. In the majority of cells of nontoxicogenic strains and also diphtheroid and Hoffmann's bacillus individual wall layers were differentiated with difficulty. PMID:827882

  1. Determination of nanostructures and mechanical properties on the surface of molybdenum dithiocarbamate and zinc dialkyl-dithiophosphate tribochemical reacted films using atomic force microscope phase imaging technique

    NASA Astrophysics Data System (ADS)

    Ye, Jiping; Kano, Makoto; Yasuda, Yoshiteru

    2003-05-01

    Nanostructures and mechanical properties on the surface of two kinds of tribofilm formed from zinc dialkyl-dithiophosphate (ZDDP) and molybdenum dithiocarbamate (MoDTC) additives, which exhibited obviously different friction coefficients in a pin-on-disc test, were determined by using an atomic force microscopy (AFM) phase imaging technique. The level of interactive force between the tip and sample was modulated for distinguishing well-defined structures and mechanical properties of individual components not only on the uppermost surface but also in the underlying area near the surface in the AFM tapping mode. It was found that the MoDTC/ZDDP tribofilm possessed a lower surface modulus than the ZDDP film in the elastic deformation range. Most importantly, nanostrips oriented in the sliding direction were found in the MoDTC/ZDDP tribofilm at a depth of around 10 nm from the surface. These nanostrips possessed lower shearing stress than the surface matrix and formed the inner skin layer, which exhibited lower friction behavior than that of the ZDDP tribofilm. These results agreed with our recent nanoindentation and nanoscratch measurements for estimating the mechanical and frictional properties of MoDTC/ZDDP and ZDDP tribofilms. These findings and previous surface analytical results suggest that the nanostrips act as a type of solid lubricant, such as MoS2 single sheets, to lower the boundary friction coefficient.

  2. Phase contrast in high resolution electron microscopy

    DOEpatents

    Rose, H.H.

    1975-09-23

    This patent relates to a device for developing a phase contrast signal for a scanning transmission electron microscope. The lens system of the microscope is operated in a condition of defocus so that predictable alternate concentric regions of high and low electron density exist in the cone of illumination. Two phase detectors are placed beneath the object inside the cone of illumination, with the first detector having the form of a zone plate, each of its rings covering alternate regions of either higher or lower electron density. The second detector is so configured that it covers the regions of electron density not covered by the first detector. Each detector measures the number of electrons incident thereon and the signal developed by the first detector is subtracted from the signal developed by the record detector to provide a phase contrast signal. (auth)

  3. Plate tectonics conserves angular momentum

    NASA Astrophysics Data System (ADS)

    Bowin, C.

    2010-03-01

    A new combined understanding of plate tectonics, Earth internal structure, and the role of impulse in deformation of the Earth's crust is presented. Plate accelerations and decelerations have been revealed by iterative filtering of the quaternion history for the Euler poles that define absolute plate motion history for the past 68 million years, and provide an unprecedented precision for plate angular rotation variations with time at 2-million year intervals. Stage poles represent the angular rotation of a plate's motion between adjacent Euler poles, and from which the maximum velocity vector for a plate can be determined. The consistent maximum velocity variations, in turn, yield consistent estimates of plate accelerations and decelerations. The fact that the Pacific plate was shown to accelerate and decelerate, implied that conservation of plate tectonic angular momentum must be globally conserved, and that is confirmed by the results shown here (total angular momentum ~1.4+27 kg m2 s-1). Accordingly, if a plate decelerates, other plates must increase their angular momentums to compensate. In addition, the azimuth of the maximum velocity vectors yields clues as to why the "bend" in the Emperor-Hawaiian seamount trend occurred near 46 Myr. This report summarizes processing results for 12 of the 14 major tectonic plates of the Earth (except for the Juan de Fuca and Philippine plates). Plate accelerations support the contention that plate tectonics is a product of torques that most likely are sustained by the sinking of positive density anomalies revealed by geoid anomalies of the degree 4-10 packet of the Earth's spherical harmonic coefficients. These linear positive geoid anomalies underlie plate subduction zones and are presumed due to phase changes in subducted gabbroic lithosphere at depth in the upper lower mantle (above 1200 km depth). The tectonic plates are pulled along by the sinking of these positive mass anomalies, rather than moving at near constant

  4. [Microscopic colitis: update 2014].

    PubMed

    Burgmann, Konstantin; Fraga, Montserrat; Schoepfer, Alain M; Yun, Pu

    2014-09-01

    Microscopic colitis, which includes lymphocytic colitis and collagenous colitis, represents a frequent cause of chronic watery diarrhea especially in the elderly population. Several medications, such as nonsteroidal antiinflammatory drugs, proton pump inhibitors or antidepressants, as well as cigarette smoking have been recognized as risk factors for microscopic colitis. The diagnosis of microscopic colitis is based on a macroscopically normal ileo-colonoscopy and several biopsies from the entire colon, which demonstrate the pathognomonic histopathologic findings. Therapy is mainly based on the use of budesonide. Other medications, such as mesalazine, cholestyramine and bismuth, have been evaluated as well but the evidence is less solid. PMID:25276996

  5. Mars Life? - Microscopic Structures

    NASA Technical Reports Server (NTRS)

    1996-01-01

    In the center of this electron microscope image of a small chip from a meteorite are several tiny structures that are possible microscopic fossils of primitive, bacteria-like organisms that may have lived on Mars more than 3.6 billion years ago. A two-year investigation by a NASA research team found organic molecules, mineral features characteristic of biological activity and possible microscopic fossils such as these inside of an ancient Martian rock that fell to Earth as a meteorite. The largest possible fossils are less than 1/100th the diameter of a human hair in size while most are ten times smaller.

  6. Revealing the architecture of the upper boundary of the Philippine Sea Plate beneath the northern tip of the Izu-Tanzawa Collision Zone, Central Japan, using later-phase of P waves

    NASA Astrophysics Data System (ADS)

    Shuri, Y.; Tsumura, N.

    2010-12-01

    In Izu-Tanzawa Collision Zone (ITCZ), Izu arc collides with Japan arc due to subduction of the Philippine Sea plate (PHP). Recent studies by Kikuchi (2008) and Arai et al. (2009) have revealed that the upper boundary of PHP has a complex geometry in this area. High seismicity near the top boundary of PHP is reported in the front (northern) edge of the ITCZ, which is the transition zone from collision to subduction of PHP, whereas an aseismic zone is located on the western part of the high seismicity region. This spatial variation of seismicity is probably related to the shape of PHP caused by the difference between collisional vs. subductive movements. To better correlate the spatial distribution of seismicity and the plate configuration, we attempt to find a discontinuous surface near the upper boundary of PHP using later phases of P waves. We used seismic-waveform data from the website of Hi-net seismic network. In the high seismicity region, clear later phases of P waves (X phases) are observed in vertical component seismograms recorded at the stations above the high seismicity region. The X phases arrive 0.5s to 2.0s after P arrivals. Time difference between P and X arrivals (X-P times) increases with distances between the plate boundary and the hypocenters. Similarly, X-P times increase as the distances from the northwestern edge of the high seismicity region to the hypocenters increase. These observations suggest two possibilities for the origin of the X phases: (1) a converted wave at the upper boundary of PHP or (2) a reflected wave from the edge of the high seismicity region. First we searched a suitable plane for which calculated X-P times can match the observed X-P times, by assuming the X phases are converted waves. We found that two converted planes located at different depths would best explain all observed X-P times simultaneously; the depth of the estimated plane in the western side of the high seismicity zone is deeper than that of the eastern side

  7. Microscopic tubes in igneous rocks

    NASA Technical Reports Server (NTRS)

    Richter, D.; Simmons, G.

    1977-01-01

    Microscopic tubes have been observed in several igneous rocks and may be quite common. They occur in single crystals and have either elliptical or circular cross-sections 1 to 5 microns in diameter and are ten to hundreds of microns long. Microtubes may be hollow or partially or completely filled with another phase, but are distinct from acicular crystals of accessory minerals such as rutile. Microtubes can form by at least three processes: (1) the partial annealing of microcracks, (2) the natural etching of dislocations, or (3) the primary inclusion of fluid material during crystal growth.

  8. Hyperspectral confocal microscope

    NASA Astrophysics Data System (ADS)

    Sinclair, Michael B.; Haaland, David M.; Timlin, Jerilyn A.; Jones, Howland D. T.

    2006-08-01

    We have developed a new, high performance, hyperspectral microscope for biological and other applications. For each voxel within a three-dimensional specimen, the microscope simultaneously records the emission spectrum from 500 nm to 800 nm, with better than 3 nm spectral resolution. The microscope features a fully confocal design to ensure high spatial resolution and high quality optical sectioning. Optical throughput and detection efficiency are maximized through the use of a custom prism spectrometer and a backside thinned electron multiplying charge coupled device (EMCCD) array. A custom readout mode and synchronization scheme enable 512-point spectra to be recorded at a rate of 8300 spectra per second. In addition, the EMCCD readout mode eliminates curvature and keystone artifacts that often plague spectral imaging systems. The architecture of the new microscope is described in detail, and hyperspectral images from several specimens are presented.

  9. Hyperspectral confocal microscope.

    PubMed

    Sinclair, Michael B; Haaland, David M; Timlin, Jerilyn A; Jones, Howland D T

    2006-08-20

    We have developed a new, high performance, hyperspectral microscope for biological and other applications. For each voxel within a three-dimensional specimen, the microscope simultaneously records the emission spectrum from 500 nm to 800 nm, with better than 3 nm spectral resolution. The microscope features a fully confocal design to ensure high spatial resolution and high quality optical sectioning. Optical throughput and detection efficiency are maximized through the use of a custom prism spectrometer and a backside thinned electron multiplying charge coupled device (EMCCD) array. A custom readout mode and synchronization scheme enable 512-point spectra to be recorded at a rate of 8300 spectra per second. In addition, the EMCCD readout mode eliminates curvature and keystone artifacts that often plague spectral imaging systems. The architecture of the new microscope is described in detail, and hyperspectral images from several specimens are presented. PMID:16892134

  10. Assessment of Petrological Microscopes.

    ERIC Educational Resources Information Center

    Mathison, Charter Innes

    1990-01-01

    Presented is a set of procedures designed to check the design, ergonomics, illumination, function, optics, accessory equipment, and image quality of a microscope being considered for purchase. Functions for use in a petrology or mineralogy laboratory are stressed. (CW)

  11. Computerized Measuring Microscope

    NASA Astrophysics Data System (ADS)

    Schoonmaker, Thomas D.

    1980-05-01

    In the manufacturing of printed circuit boards, microscopic analysis is an essential process control activity. An inspector microscopically analyzes board samples to deter-mine board lot quality and process conditions. Prior to computerizing, this sustained measurement-taking involved the tedious process of recording raw data, converting microscope filar readings, calculating averages, logging information in a job notebook, and completing detailed final lab reports. It is evident from this brief task description that this time-consuming repetitious data recording routine was an added burden to the already fatiguing visual inspection method and therefore was a prime candidate for automatic data capture and printout. Secondly, the creation of a permanent and easily accessible data base would improve process feedback and provide for a system with quick identification of any suspect boards if further assembly/testing exhibited board-related failures. This paper describes the evolution and implementation of a computer-aided microscopic inspection operation.

  12. Microscope collision protection apparatus

    DOEpatents

    DeNure, Charles R.

    2001-10-23

    A microscope collision protection apparatus for a remote control microscope which protects the optical and associated components from damage in the event of an uncontrolled collision with a specimen, regardless of the specimen size or shape. In a preferred embodiment, the apparatus includes a counterbalanced slide for mounting the microscope's optical components. This slide replaces the rigid mounts on conventional upright microscopes with a precision ball bearing slide. As the specimen contacts an optical component, the contacting force will move the slide and the optical components mounted thereon. This movement will protect the optical and associated components from damage as the movement causes a limit switch to be actuated, thereby stopping all motors responsible for the collision.

  13. Infrared microscope inspection apparatus

    DOEpatents

    Forman, Steven E.; Caunt, James W.

    1985-02-26

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

  14. Infrared microscope inspection apparatus

    DOEpatents

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

    1985-02-26

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

  15. Hypoxia in Microscopic Tumors

    PubMed Central

    Li, Xiao-Feng; O’Donoghue, Joseph A

    2008-01-01

    Tumor hypoxia has been commonly observed in a broad spectrum of primary solid malignancies. Hypoxia is associated with tumor progression, increased aggressiveness, enhanced metastatic potential and poor prognosis. Hypoxic tumor cells are resistant to radiotherapy and some forms of chemotherapy. Using an animal model, we recently showed that microscopic tumors less than 1 mm diameter were severely hypoxic. In this review, models and techniques for the study of hypoxia in microscopic tumors are discussed. PMID:18384940

  16. Microscopic treatment of solute trapping and drag

    NASA Astrophysics Data System (ADS)

    Humadi, Harith; Hoyt, J. J.; Provatas, Nikolas

    2016-01-01

    The long wavelength limit of a recent microscopic phase-field crystal (PFC) theory of a binary alloy mixture is used to derive an analytical approximation for the segregation coefficient as a function of the interface velocity, and relate it to the two-point correlation function of the liquid and the thermodynamic properties of solid and liquid phases. Our results offer the first analytical derivation of solute segregation from a microscopic model, and support recent molecular dynamics and numerical PFC simulations. Our results also provide an independent framework, motivated from classical density functional theory, from which to elucidate the fundamental nature of solute drag, which is still highly contested in the literature.

  17. Integrated elastic microscope device

    NASA Astrophysics Data System (ADS)

    Lee, W. M.; Wright, D.; Watkins, R.; Cen, Zi

    2015-03-01

    The growing power of imaging and computing power of smartphones is creating the possibility of converting your smartphone into a high power pocket microscopy system. High quality miniature microscopy lenses attached to smartphone are typically made with glass or plastics that can only be produce at low cost with high volume. To revise the paradigm of microscope lenses, we devised a simple droplet lens fabrication technique that which produces low cost and high performance lens. Each lens is integrated into thin 3-D printed holder with complimentary light emitted diode (LEDs) that clips onto majority of smartphones. The integrated device converts a smartphone into a high power optical microscope/dermatoscope at around $2. This low cost device has wide application in a multitude of practical uses such as material inspection, dermascope and educational microscope.

  18. Wobble plate engine

    SciTech Connect

    Derderian, H.; Pronovost, J.

    1980-07-01

    A description is given of a conventional Stirling cycle engine of the type characterized by an elongated cylinder having a closed end and an open end, means for applying heat to the exterior of the cylinder to heat gas in the interior of the cylinder at the closed end thereof, a displacer piston mounted for a reciprocation within the closed end of the cylinder and a power piston axially aligned with the displacer piston and mounted for coaxial reciprocation between the displacer piston and the open end of the cylinder, the reciprocation of the displacer piston leading the corresponding stroke of the power piston by a predetermined phase angle, the improved means for properly phasing the reciprocation of the two pistons and for converting the reciprocation of the power piston into rotation of an output shaft which is parallel to the axis of reciprocation comprising: a supporting frame; an output shaft mounted on said frame for rotation about a first axis which is parallel to the axis of reciprocation of the two pistons, said shaft having an inclined cylindrical bearing surface the axis of which intersects said first axis at an acute angle; gimbal means pivotally mounted on said supporting frame for oscillation about a second axis perpendicular to and intersecting first axis; a wobble plate pivotally mounted on a third axis within said gimbal means for oscillation with said gimbal means and for further oscillation about said third axis which is mutually perpendicular to and intersecting said first and second axes, said wobble plate being rotatably mounted on said inclined cylindrical bearing surface in a plane which is perpendicular to said axis of said bearing surface whereby said output shaft can rotate about said first axis as said wobble plate oscillates about said second and third axes.

  19. Zernike Phase Contrast Electron Cryo-Tomography Applied to Marine Cyanobacteria Infected with Cyanophages

    PubMed Central

    Dai, Wei; Fu, Caroline; Khant, Htet A.; Ludtke, Steven J.; Schmid, Michael F.; Chiu, Wah

    2015-01-01

    Advances in electron cryo-tomography have provided a new opportunity to visualize the internal 3D structures of a bacterium. An electron microscope equipped with Zernike phase contrast optics produces images with dramatically increased contrast compared to images obtained by conventional electron microscopy. Here we describe a protocol to apply Zernike phase plate technology for acquiring electron tomographic tilt series of cyanophage-infected cyanobacterial cells embedded in ice, without staining or chemical fixation. We detail the procedures for aligning and assessing phase plates for data collection, and methods to obtain 3D structures of cyanophage assembly intermediates in the host, by subtomogram alignment, classification and averaging. Acquiring three to four tomographic tilt series takes approximately 12 h on a JEM2200FS electron microscope. We expect this time requirement to decrease substantially as the technique matures. Time required for annotation and subtomogram averaging varies widely depending on the project goals and data volume. PMID:25321408

  20. Electron microscope studies

    SciTech Connect

    Crewe, A.V.; Kapp, O.H.

    1992-07-01

    This is a report covering the research performed in the Crewe laboratory between 1964 and 1992. Because of limitations of space we have provided relatively brief summaries of the major research directions of the facility during these years. A complete bibliography has been included and we have referenced groups of pertinent publications at the beginning of each section. This report summarizes our efforts to develop better electron microscopes and chronicles many of the experimental programs, in materials science and biology, that acted both as a stimulus to better microscope design and also as a testing ground for many instrumental innovations.

  1. In-phase dynamics of the exhalation sequence in Popocatépetl volcano and slow-slip events in Cocos-North American plate boundary

    NASA Astrophysics Data System (ADS)

    Alvarez-Ramirez, Jose; Sosa, Eliceo; Hernandez-Martinez, Eliseo

    2011-02-01

    It has long been considered that the Trans-Mexican Volcanic Belt (TMVB) is related to subduction along the Middle America trench. Within this view, it is expected that the tectonic dynamics of the Cocos plate can be reflected, to some extent, in the Popocatépetl's volcanic activity This work uses detrended fluctuation analysis, a method borrowed from statistical mechanics, to quantify the fractality and autocorrelations in the exhalation sequence of the Popocatepetl. It is found that the autocorrelations exhibit cyclic, non-periodic, dynamics with dominant periods of the order of 0.85 to 1.25 years. Interestingly, it is shown that the occurrence of slow-slip events in Southern (Guerrero and Oaxaca) Mexico coincides with peaks of the autocorrelation cycle of the exhalation sequence. The result suggests the use of the volcano exhalation sequence as a proxy of aseismic events in the Cocos-North American plate boundary. That is, by monitoring the autocorrelation dynamics of the exhalation sequence in the Popocatepetl, one could be able to suspect the occurrence of a slow-slip event in Southern Mexico.

  2. Making Art with Microscopes

    ERIC Educational Resources Information Center

    Benedis-Grab, Gregory

    2011-01-01

    Interdisciplinary teaching is a great way to focus on overarching concepts and help students make connections across disciplines. Historically, art and science have been connected disciplines. The botanical prints of the 18th and 19th centuries and early work with microscopes are two examples of a need for strong artistic skills in the science…

  3. Microscopic plasma Hamiltonian

    NASA Technical Reports Server (NTRS)

    Peng, Y.-K. M.

    1974-01-01

    A Hamiltonian for the microscopic plasma model is derived from the Low Lagrangian after the dual roles of the generalized variables are taken into account. The resulting Hamilton equations are shown to agree with the Euler-Lagrange equations of the Low Lagrangian.

  4. Microscope on Mars

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image taken at Meridiani Planum, Mars by the panoramic camera on the Mars Exploration Rover Opportunity shows the rover's microscopic imager (circular device in center), located on its instrument deployment device, or 'arm.' The image was acquired on the ninth martian day or sol of the rover's mission.

  5. IMIS: An intelligence microscope imaging system

    NASA Technical Reports Server (NTRS)

    Caputo, Michael; Hunter, Norwood; Taylor, Gerald

    1994-01-01

    Until recently microscope users in space relied on traditional microscopy techniques that required manual operation of the microscope and recording of observations in the form of written notes, drawings, or photographs. This method was time consuming and required the return of film and drawings from space for analysis. No real-time data analysis was possible. Advances in digital and video technologies along with recent developments in article intelligence will allow future space microscopists to have a choice of three additional modes of microscopy: remote coaching, remote control, and automation. Remote coaching requires manual operations of the microscope with instructions given by two-way audio/video transmission during critical phases of the experiment. When using the remote mode of microscopy, the Principal Investigator controls the microscope from the ground. The automated mode employs artificial intelligence to control microscope functions and is the only mode that can be operated in the other three modes as well. The purpose of this presentation is to discuss the advantages and disadvantages of the four modes of of microscopy and how the IMIS, a proposed intelligent microscope imaging system, can be used as a model for developing and testing concepts, operating procedures, and equipment design of specifications required to provide a comprehensive microscopy/imaging capability onboard Space Station Freedom.

  6. X-ray laser microscope apparatus

    DOEpatents

    Suckewer, Szymon; DiCicco, Darrell S.; Hirschberg, Joseph G.; Meixler, Lewis D.; Sathre, Robert; Skinner, Charles H.

    1990-01-01

    A microscope consisting of an x-ray contact microscope and an optical microscope. The optical, phase contrast, microscope is used to align a target with respect to a source of soft x-rays. The source of soft x-rays preferably comprises an x-ray laser but could comprise a synchrotron or other pulse source of x-rays. Transparent resist material is used to support the target. The optical microscope is located on the opposite side of the transparent resist material from the target and is employed to align the target with respect to the anticipated soft x-ray laser beam. After alignment with the use of the optical microscope, the target is exposed to the soft x-ray laser beam. The x-ray sensitive transparent resist material whose chemical bonds are altered by the x-ray beam passing through the target mater GOVERNMENT LICENSE RIGHTS This invention was made with government support under Contract No. De-FG02-86ER13609 awarded by the Department of Energy. The Government has certain rights in this invention.

  7. Stop motion microphotography of laser driven plates

    SciTech Connect

    Frank, A.M.; Trott, W.M.

    1994-09-01

    Laser driven plates have been used for several years for high velocity shock wave and impact studies. Recent questions about the integrity and ablation rates of these plates coupled with an improved capability for microscopic stop motion photography led to this study. For these experiments, the plates were aluminum, coated on the ends of optical fibers. A high power laser pulse in the fiber ionizes the aluminum at the fiber/coating interface. The plasma thus created accelerates the remaining aluminum to high velocities, several kilometers per second. We defined {open_quotes}thick{close_quotes} or {open_quotes}thin{close_quotes} coatings as those where a flying plate (flyer) was launched vs. the material being completely ionized. Here we were specifically interested in the thick/thin boundary to develop data for the numerical models attempting to predict flyer behavior.

  8. Writing 40 nm marks by using a beaked metallic plate near-field optical probe.

    PubMed

    Matsumoto, T; Anzai, Y; Shintani, T; Nakamura, K; Nishida, T

    2006-01-15

    We have developed a near-field optical probe that uses a triangular metallic plate with a three-dimensionally tapered apex as a light source for thermally assisted magnetic recording. Numerical analysis using a finite-element method shows that the size of the optical spot generated at the apex is 15 nm x 20 nm, and the efficiency (defined as the ratio between the power of the optical near field at the surface of the recording medium and that of the incident light) is 15% when the incident light is focused by a lens with a numerical aperture of 0.8. The metallic plate was fabricated on the surface of a quartz slider and used for writing marks on a phase change recording medium. The marks were observed with a scanning electron microscope, and we confirmed that marks with a diameter of 40 nm were successfully written on the medium. PMID:16441049

  9. Microscopic features of moving traffic jams

    NASA Astrophysics Data System (ADS)

    Kerner, Boris S.; Klenov, Sergey L.; Hiller, Andreas; Rehborn, Hubert

    2006-04-01

    Empirical and numerical microscopic features of moving traffic jams are presented. Based on a single vehicle data analysis, it is found that within wide moving jams, i.e., between the upstream and downstream jam fronts there is a complex microscopic spatiotemporal structure. This jam structure consists of alternations of regions in which traffic flow is interrupted and flow states of low speeds associated with “moving blanks” within the jam. Moving blanks within a wide moving jam resemble electron holes in the valence band of semiconductors: As the moving blanks that propagate upstream appear due to downstream vehicle motion within the jam, so appearance of electron holes moving with the electric field results from electron motion against the electric field in the valence band of semiconductors. Empirical features of moving blanks are found. Based on microscopic models in the context of the Kerner’s three-phase traffic theory, physical reasons for moving blanks emergence within wide moving jams are disclosed. Microscopic nonlinear effects of moving jam emergence, propagation, and dissolution as well as a diverse variety of hysteresis effects in freeway traffic associated with phase transitions and congested traffic propagation are numerically investigated. Microscopic structure of moving jam fronts is numerically studied and compared with empirical results.

  10. Self-referencing digital holographic microscope for dynamic imaging of living cells

    NASA Astrophysics Data System (ADS)

    Anand, Arun; Chhaniwal, Vani; Mahajan, Swapnil; Trivedi, Vismay; Singh, Amardeep; Leitgeb, Rainer; Javidi, Bahram

    2014-06-01

    Digital holographic microscope is an ideal tool for quantitative phase contrast imaging of living cells. It yields the thickness distribution of the object under investigation from a single hologram. From a series of holograms the dynamics of the cell under investigation can be obtained. But two-beam digital holographic microscopes has low temporal stability due to uncorrelated phase changes occurring in the reference and object arms. One way to overcome is to use common path techniques, in which, the reference beam is derived from the object beam itself. Both the beams travel along the same path, increasing the temporal stability of the setup. In self-referencing techniques a portion of the object beam is converted into reference beam. It could be achieved by example, using a glass plate to create two laterally sheared versions of the object beam at the sensor, which interfere to produce the holograms/interferograms. This created a common path setup, leading to high temporal stability (~0.6nm). This technique could be used to map cell membrane fluctuations with high temporal stability. Here we provide an overview of our work on the development of temporally stable quantitative phase contrast techniques for dynamic imaging of micro-objects and biological specimen including red blood cells.

  11. Sputtering and ion plating

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The proceedings of a conference on sputtering and ion plating are presented. Subjects discussed are: (1) concepts and applications of ion plating, (2) sputtering for deposition of solid film lubricants, (3) commercial ion plating equipment, (4) industrial potential for ion plating and sputtering, and (5) fundamentals of RF and DC sputtering.

  12. Soft x-ray laser microscope. Final report

    SciTech Connect

    Suckewer, P.I.

    1990-10-01

    The program consisted of two phases (Phase I and Phase II). The goal of the Phase I (first year program) was to design and construct the Soft X-ray Laser Contact Microscope. Such microscope was constructed and adapted to PPL`s 18.2nm soft X-ray Laser (SXL), which in turn was modified and prepared for microscopy experiments. Investigation of the photoresist response to 18.2nm laser radiation and transmissivity of 0.1m thick silicion-nitride (Si{sub 3}N{sub 4}) windows were important initial works. The goal of the first year of Phase II was to construct X-ray contact microscope in combination with existing optical phase microscope, already used by biologists. In the second year of Phase II study of dehydrated Horeseshoe Crab and Hela cancer cells were performed with COXRALM. Also during Phase II, the Imaging X-Ray Laser Microscope (IXRALM) was designed and constructed. This paper describes the development of each of the microscopes and their application for research.

  13. Battery plate containing filler with conductive coating

    NASA Technical Reports Server (NTRS)

    Rowlette, John J. (Inventor)

    1986-01-01

    The plate (10) comprises a matrix or binder resin phase (12) in which is dispersed particulate, conductive tin oxide such as tin oxide coated glass fibers (14). A monopolar plate (11) is prepared by coating a layer (18) of electrolytically active material onto a surface of the plate (10). Tin oxide is prevented from reduction by coating a surface of the plate (10) with a conductive, impervious layer resistant to reduction such as a thin film (22) of lead adhered to the plate with a layer (21) of conductive adhesive. The plate (10) can be formed by casting a molten dispersion from mixer (36) onto a sheet (30) of lead foil or by passing an assembly of a sheet (41) of resin, a sheet (43) of fiberglass and a sheet (45) of lead between the nip of heated rollers (48, 50).

  14. Battery plate containing filler with conductive coating

    NASA Technical Reports Server (NTRS)

    Rowlette, John J. (Inventor)

    1985-01-01

    The plate (10) comprises a matrix or binder resin phase (12) in which is dispersed particulate, conductive tin oxide such as tin oxide coated glass fibers (14). A monopolar plate (11) is prepared by coating a layer (18) of electrolytically active material onto a surface of the plate (10). Tin oxide is prevented from reduction by coating a surface of the plate (10) with a conductive, impervious layer resistant to reduction such as a thin film (22) of lead adhered to the plate with a layer (21) of conductive adhesive. The plate (10) can be formed by casting a molten dispersion from mixer (36) onto a sheet (30) of lead foil or by passing an assembly of a sheet (41) of resin, a sheet (43) of fiberglass and a sheet (45) of lead between the nip of heated rollers (48, 50).

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

    SciTech Connect

    Lehman, S K

    2005-10-27

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

  16. Femtosecond scanning tunneling microscope

    SciTech Connect

    Taylor, A.J.; Donati, G.P.; Rodriguez, G.; Gosnell, T.R.; Trugman, S.A.; Some, D.I.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). By combining scanning tunneling microscopy with ultrafast optical techniques we have developed a novel tool to probe phenomena on atomic time and length scales. We have built and characterized an ultrafast scanning tunneling microscope in terms of temporal resolution, sensitivity and dynamic range. Using a novel photoconductive low-temperature-grown GaAs tip, we have achieved a temporal resolution of 1.5 picoseconds and a spatial resolution of 10 nanometers. This scanning tunneling microscope has both cryogenic and ultra-high vacuum capabilities, enabling the study of a wide range of important scientific problems.

  17. Ion photon emission microscope

    DOEpatents

    Doyle, Barney L.

    2003-04-22

    An ion beam analysis system that creates microscopic multidimensional image maps of the effects of high energy ions from an unfocussed source upon a sample by correlating the exact entry point of an ion into a sample by projection imaging of the ion-induced photons emitted at that point with a signal from a detector that measures the interaction of that ion within the sample. The emitted photons are collected in the lens system of a conventional optical microscope, and projected on the image plane of a high resolution single photon position sensitive detector. Position signals from this photon detector are then correlated in time with electrical effects, including the malfunction of digital circuits, detected within the sample that were caused by the individual ion that created these photons initially.

  18. Ultra high frequency imaging acoustic microscope

    DOEpatents

    Deason, Vance A.; Telschow, Kenneth L.

    2006-05-23

    An imaging system includes: an object wavefront source and an optical microscope objective all positioned to direct an object wavefront onto an area of a vibrating subject surface encompassed by a field of view of the microscope objective, and to direct a modulated object wavefront reflected from the encompassed surface area through a photorefractive material; and a reference wavefront source and at least one phase modulator all positioned to direct a reference wavefront through the phase modulator and to direct a modulated reference wavefront from the phase modulator through the photorefractive material to interfere with the modulated object wavefront. The photorefractive material has a composition and a position such that interference of the modulated object wavefront and modulated reference wavefront occurs within the photorefractive material, providing a full-field, real-time image signal of the encompassed surface area.

  19. Plate mode velocities in graphite/epoxy plates

    NASA Technical Reports Server (NTRS)

    Prosser, W. H.; Gorman, M. R.

    1994-01-01

    Measurements of the velocities of the extensional and flexural plate modes were made along three directions of propagation in four graphite/epoxy composite plates. The acoustic signals were generated by simulated acoustic emission events (pencil lead breaks or Hsu-Neilson sources) and detected by by broadband ultrasonic transducers. The first arrival of the extensional plate mode, which is nondispersive at low frequencies, was measured at a number of different distances from the source along the propagation direction of interest. The velocity was determined by plotting the distance versus arrival time and computing its slope. Because of the large dispersion of the flexural mode, a Fourier phase velocity technique was used to characterize this mode. The velocity was measured up to a frequency of 160 kHz. Theoretical predictions of the velocities of these modes were also made and compared with experimental observations. Classical plate theory yields good agreement with the measured extensional velocities. For predictions of the dispersion of the flexural mode, Mindlin plates theory, which includes the effects of shear deformation and rotatory inertia was shown to give better agreement with the experimental measurements.

  20. Microscopic enteritis: Bucharest consensus.

    PubMed

    Rostami, Kamran; Aldulaimi, David; Holmes, Geoffrey; Johnson, Matt W; Robert, Marie; Srivastava, Amitabh; Fléjou, Jean-François; Sanders, David S; Volta, Umberto; Derakhshan, Mohammad H; Going, James J; Becheanu, Gabriel; Catassi, Carlo; Danciu, Mihai; Materacki, Luke; Ghafarzadegan, Kamran; Ishaq, Sauid; Rostami-Nejad, Mohammad; Peña, A Salvador; Bassotti, Gabrio; Marsh, Michael N; Villanacci, Vincenzo

    2015-03-01

    Microscopic enteritis (ME) is an inflammatory condition of the small bowel that leads to gastrointestinal symptoms, nutrient and micronutrient deficiency. It is characterised by microscopic or sub-microscopic abnormalities such as microvillus changes and enterocytic alterations in the absence of definite macroscopic changes using standard modern endoscopy. This work recognises a need to characterize disorders with microscopic and submicroscopic features, currently regarded as functional or non-specific entities, to obtain further understanding of their clinical relevance. The consensus working party reviewed statements about the aetiology, diagnosis and symptoms associated with ME and proposes an algorithm for its investigation and treatment. Following the 5(th) International Course in Digestive Pathology in Bucharest in November 2012, an international group of 21 interested pathologists and gastroenterologists formed a working party with a view to formulating a consensus statement on ME. A five-step agreement scale (from strong agreement to strong disagreement) was used to score 21 statements, independently. There was strong agreement on all statements about ME histology (95%-100%). Statements concerning diagnosis achieved 85% to 100% agreement. A statement on the management of ME elicited agreement from the lowest rate (60%) up to 100%. The remaining two categories showed general agreement between experts on clinical presentation (75%-95%) and pathogenesis (80%-90%) of ME. There was strong agreement on the histological definition of ME. Weaker agreement on management indicates a need for further investigations, better definitions and clinical trials to produce quality guidelines for management. This ME consensus is a step toward greater recognition of a significant entity affecting symptomatic patients previously labelled as non-specific or functional enteropathy. PMID:25759526

  1. Focusing the surgical microscope.

    PubMed

    Socea, Sergiu D; Barak, Yoreh; Blumenthal, Eytan Z

    2015-01-01

    A well-focused operating microscope addresses several needs that are all secondary to the surgeon's need to see clearly at all times. These needs include: the assistant; the sharpness of the video and monitor; as well as field of view, asthenopia, and focusing issues related to zoom, accommodation, and presbyopia. We provide a practical approach to achieve optimal focus that we call the sloping paper calibration method. PMID:25891029

  2. Microscopic and macroscopic dynamics

    SciTech Connect

    Hoover, W.G.; Hoover, C.G.; De Groot, A.J.; Pierce, T.G. |

    1993-06-01

    Atomistic Molecular Dynamics and Lagrangian Continuum Mechanics can be very similarly adapted to massively-parallel computers. Millions of degrees of freedom can be treated. The two complementary approaches, microscopic and macroscopic, are being applied to increasingly realistic flows of fluids and solids. The two approaches can also be combined in a hybrid simulation scheme. Hybrids combine the fundamental constitutive advantage of atoms with the size advantage of the continuum picture.

  3. Microscopic enteritis: Bucharest consensus

    PubMed Central

    Rostami, Kamran; Aldulaimi, David; Holmes, Geoffrey; Johnson, Matt W; Robert, Marie; Srivastava, Amitabh; Fléjou, Jean-François; Sanders, David S; Volta, Umberto; Derakhshan, Mohammad H; Going, James J; Becheanu, Gabriel; Catassi, Carlo; Danciu, Mihai; Materacki, Luke; Ghafarzadegan, Kamran; Ishaq, Sauid; Rostami-Nejad, Mohammad; Peña, A Salvador; Bassotti, Gabrio; Marsh, Michael N; Villanacci, Vincenzo

    2015-01-01

    Microscopic enteritis (ME) is an inflammatory condition of the small bowel that leads to gastrointestinal symptoms, nutrient and micronutrient deficiency. It is characterised by microscopic or sub-microscopic abnormalities such as microvillus changes and enterocytic alterations in the absence of definite macroscopic changes using standard modern endoscopy. This work recognises a need to characterize disorders with microscopic and submicroscopic features, currently regarded as functional or non-specific entities, to obtain further understanding of their clinical relevance. The consensus working party reviewed statements about the aetiology, diagnosis and symptoms associated with ME and proposes an algorithm for its investigation and treatment. Following the 5th International Course in Digestive Pathology in Bucharest in November 2012, an international group of 21 interested pathologists and gastroenterologists formed a working party with a view to formulating a consensus statement on ME. A five-step agreement scale (from strong agreement to strong disagreement) was used to score 21 statements, independently. There was strong agreement on all statements about ME histology (95%-100%). Statements concerning diagnosis achieved 85% to 100% agreement. A statement on the management of ME elicited agreement from the lowest rate (60%) up to 100%. The remaining two categories showed general agreement between experts on clinical presentation (75%-95%) and pathogenesis (80%-90%) of ME. There was strong agreement on the histological definition of ME. Weaker agreement on management indicates a need for further investigations, better definitions and clinical trials to produce quality guidelines for management. This ME consensus is a step toward greater recognition of a significant entity affecting symptomatic patients previously labelled as non-specific or functional enteropathy. PMID:25759526

  4. Virtual pinhole confocal microscope

    SciTech Connect

    George, J.S.; Rector, D.M.; Ranken, D.M.; Peterson, B.; Kesteron, J.

    1999-06-01

    Scanned confocal microscopes enhance imaging capabilities, providing improved contrast and image resolution in 3-D, but existing systems have significant technical shortcomings and are expensive. Researchers at Los Alamos National Laboratory have developed a novel approach--virtual pinhole confocal microscopy--that uses state of the art illumination, detection, and data processing technologies to produce an imager with a number of advantages: reduced cost, faster imaging, improved efficiency and sensitivity, improved reliability and much greater flexibility. Work at Los Alamos demonstrated proof of principle; prototype hardware and software have been used to demonstrate technical feasibility of several implementation strategies. The system uses high performance illumination, patterned in time and space. The authors have built functional confocal imagers using video display technologies (LCD or DLP) and novel scanner based on a micro-lens array. They have developed a prototype system for high performance data acquisition and processing, designed to support realtime confocal imaging. They have developed algorithms to reconstruct confocal images from a time series of spatially sub-sampled images; software development remains an area of active development. These advances allow the collection of high quality confocal images (in fluorescence, reflectance and transmission modes) with equipment that can inexpensively retrofit to existing microscopes. Planned future extensions to these technologies will significantly enhance capabilities for microscopic imaging in a variety of applications, including confocal endoscopy, and confocal spectral imaging.

  5. Cryo X-ray microscope with flat sample geometry for correlative fluorescence and nanoscale tomographic imaging.

    PubMed

    Schneider, Gerd; Guttmann, Peter; Rehbein, Stefan; Werner, Stephan; Follath, Rolf

    2012-02-01

    X-ray imaging offers a new 3-D view into cells. With its ability to penetrate whole hydrated cells it is ideally suited for pairing fluorescence light microscopy and nanoscale X-ray tomography. In this paper, we describe the X-ray optical set-up and the design of the cryo full-field transmission X-ray microscope (TXM) at the electron storage ring BESSY II. Compared to previous TXM set-ups with zone plate condenser monochromator, the new X-ray optical layout employs an undulator source, a spherical grating monochromator and an elliptically shaped glass capillary mirror as condenser. This set-up improves the spectral resolution by an order of magnitude. Furthermore, the partially coherent object illumination improves the contrast transfer of the microscope compared to incoherent conditions. With the new TXM, cells grown on flat support grids can be tilted perpendicular to the optical axis without any geometrical restrictions by the previously required pinhole for the zone plate monochromator close to the sample plane. We also developed an incorporated fluorescence light microscope which permits to record fluorescence, bright field and DIC images of cryogenic cells inside the TXM. For TXM tomography, imaging with multi-keV X-rays is a straightforward approach to increase the depth of focus. Under these conditions phase contrast imaging is necessary. For soft X-rays with shrinking depth of focus towards 10nm spatial resolution, thin optical sections through a thick specimen might be obtained by deconvolution X-ray microscopy. As alternative 3-D X-ray imaging techniques, the confocal cryo-STXM and the dual beam cryo-FIB/STXM with photoelectron detection are proposed. PMID:22273540

  6. Microscopic dynamics of synchronization in driven colloids

    PubMed Central

    Juniper, Michael P.N.; Straube, Arthur V.; Besseling, Rut; Aarts, Dirk G.A.L.; Dullens, Roel P.A.

    2015-01-01

    Synchronization of coupled oscillators has been scrutinized for over three centuries, from Huygens' pendulum clocks to physiological rhythms. One such synchronization phenomenon, dynamic mode locking, occurs when naturally oscillating processes are driven by an externally imposed modulation. Typically only averaged or integrated properties are accessible, leaving underlying mechanisms unseen. Here, we visualize the microscopic dynamics underlying mode locking in a colloidal model system, by using particle trajectories to produce phase portraits. Furthermore, we use this approach to examine the enhancement of mode locking in a flexible chain of magnetically coupled particles, which we ascribe to breathing modes caused by mode-locked density waves. Finally, we demonstrate that an emergent density wave in a static colloidal chain mode locks as a quasi-particle, with microscopic dynamics analogous to those seen for a single particle. Our results indicate that understanding the intricate link between emergent behaviour and microscopic dynamics is key to controlling synchronization. PMID:25994921

  7. Microscopic dynamics of synchronization in driven colloids.

    PubMed

    Juniper, Michael P N; Straube, Arthur V; Besseling, Rut; Aarts, Dirk G A L; Dullens, Roel P A

    2015-01-01

    Synchronization of coupled oscillators has been scrutinized for over three centuries, from Huygens' pendulum clocks to physiological rhythms. One such synchronization phenomenon, dynamic mode locking, occurs when naturally oscillating processes are driven by an externally imposed modulation. Typically only averaged or integrated properties are accessible, leaving underlying mechanisms unseen. Here, we visualize the microscopic dynamics underlying mode locking in a colloidal model system, by using particle trajectories to produce phase portraits. Furthermore, we use this approach to examine the enhancement of mode locking in a flexible chain of magnetically coupled particles, which we ascribe to breathing modes caused by mode-locked density waves. Finally, we demonstrate that an emergent density wave in a static colloidal chain mode locks as a quasi-particle, with microscopic dynamics analogous to those seen for a single particle. Our results indicate that understanding the intricate link between emergent behaviour and microscopic dynamics is key to controlling synchronization. PMID:25994921

  8. Constructing a multi-scan synchrotron X-ray microscope to study the function of osteocyte canaliculi in mouse bone

    SciTech Connect

    Nango, Nobuhito; Kubota, Shogo; Yashiro, Wataru; Momose, Atsushi; Takada, Yasunari; Matsuo, Koichi

    2012-07-31

    Formulating a multi-scan method applied to an X-ray microscope CT with synchrotron radiation, we attempted to analyze the 3D functional structure of osteocyte canaliculi inside the cortical bone of a mouse tibia. We employed a two-method combination to scan the same position of the specimen. To extract the internal bone canalicular structure, we first combined a Talbot interferometer with an X-ray microscope, and applied a differential phase imaging method to measure the absolute value of bone mineral around the canaliculi. Next, we used the X-ray microscope without the Talbot interferometer under a defocus condition, moving the specimen toward the zone plate by 6 mm. This defocus contrast method visualizes the canaliculi by emphasizing the edges of the bone. We performed CT scans by the two configurations and precisely aligned resultant 3D images so that the same position in the specimen is compared. We could extract the osteocyte canaliculi and evaluate the mineral density of their surroundings. The degree of mineralization varied for each osteocyte lacuna and canaliculus. The multi-scan microscopic X-ray CT is a powerful tool for analyzing bone mineralization.

  9. Super-resolution imaging of ciliary microdomains in isolated olfactory sensory neurons using a custom STED microscope

    NASA Astrophysics Data System (ADS)

    Meyer, Stephanie A.; Ozbay, Baris; Restrepo, Diego; Gibson, Emily A.

    2014-03-01

    We performed super-resolution imaging of isolated olfactory sensory neurons (OSNs) using a custom-built Stimulated Emission Depletion (STED) microscope. The design for the STED microscope is based on the system developed in the laboratory of Dr. Stefan Hell1. Our system is capable of imaging with sub-diffraction limited resolution simultaneously in two color channels (at Atto 590/Atto 647N wavelengths). A single, pulsed laser source (ALP; Fianium, Inc.) generates all four laser beams, two excitation and two STED. The two STED beams are coupled into one polarization maintaining (PM) fiber and the two excitation beams into another. They are then collimated and both STED beams pass through a vortex phase plate (RPC Photonics) to allow shaping into a donut at the focus of the objective lens. The beams are then combined and sent into an inverted research microscope (IX-71; Olympus Inc.) allowing widefield epifluorescence, brightfield and DIC imaging on the same field of view as STED imaging. A fast piezo stage scans the sample during STED and confocal imaging. The fluorescent signals from the two color channels are detected with two avalanche photodiodes (APD) after appropriate spectral filtering. The resolution of the system was characterized by imaging 40 nm fluorescent beads as ~60 nm (Atto 590) and ~50 nm (Atto 647N). We performed STED imaging on immunolabeled isolated OSNs tagged at the CNGA2 and ANO2 proteins. The STED microscope allows us to resolve ciliary CNGA2 microdomains of ~54 nm that were blurred in confocal.

  10. Q: How do Microscopes Work?

    ERIC Educational Resources Information Center

    Zimov, Sarah

    2004-01-01

    Microscopes allow scientists to examine everyday objects in extraordinary ways. They provide high-resolution images that show objects in fine detail. This brief article describes the many types of microscopes and how they are used in different scientific venues.

  11. Microscopic fungi as significant sesquiterpene emission sources

    NASA Astrophysics Data System (ADS)

    HorváTh, Eszter; Hoffer, AndráS.; SebőK, Flóra; Dobolyi, Csaba; Szoboszlay, SáNdor; Kriszt, BaláZs; GelencséR, AndráS.

    2011-08-01

    Among the volatile organic compounds emitted by vegetation, isoprene, monoterpenes, sesquiterpenes, and their derivatives are thought to contribute to secondary organic aerosol formation. Although it is well known that microscopic fungi globally turn over vast amount of carbon by decomposing the organic matter in the soil, vegetation is considered as the exclusive source of biogenic secondary organic aerosol precursors in various atmospheric models. Secondary fungal metabolites including sesquiterpenes have been recognized as characteristic volatile organic compounds emitted by fungi. In the present study, we investigated the rates of sesquiterpene emission of microscopic fungi to establish their potential significance compared to those from vegetation. To sample the headspace of the pure culture of some common fungi, we used an aseptic flow-through apparatus designed for solid phase microextraction in our laboratory. The identified sesquiterpenes in the headspace extracts were quantified for eight strains of microscopic fungi belonging to four different genera. Our results showed that microscopic fungi emit a considerable amount of sesquiterpenes. Based on our first estimations microscopic fungi may be considered as potentially significant sesquiterpene emission sources whose contribution to secondary organic aerosol formation may be comparable to that of vegetation.

  12. Nanoscale X-ray microscopic imaging of mammalian mineralized tissue.

    PubMed

    Andrews, Joy C; Almeida, Eduardo; van der Meulen, Marjolein C H; Alwood, Joshua S; Lee, Chialing; Liu, Yijin; Chen, Jie; Meirer, Florian; Feser, Michael; Gelb, Jeff; Rudati, Juana; Tkachuk, Andrei; Yun, Wenbing; Pianetta, Piero

    2010-06-01

    A novel hard transmission X-ray microscope (TXM) at the Stanford Synchrotron Radiation Lightsource operating from 5 to 15 keV X-ray energy with 14 to 30 microm2 field of view has been used for high-resolution (30-40 nm) imaging and density quantification of mineralized tissue. TXM is uniquely suited for imaging of internal cellular structures and networks in mammalian mineralized tissues using relatively thick (50 microm), untreated samples that preserve tissue micro- and nanostructure. To test this method we performed Zernike phase contrast and absorption contrast imaging of mouse cancellous bone prepared under different conditions of in vivo loading, fixation, and contrast agents. In addition, the three-dimensional structure was examined using tomography. Individual osteocytic lacunae were observed embedded within trabeculae in cancellous bone. Extensive canalicular networks were evident and included processes with diameters near the 30-40 nm instrument resolution that have not been reported previously. Trabecular density was quantified relative to rod-like crystalline apatite, and rod-like trabecular struts were found to have 51-54% of pure crystal density and plate-like areas had 44-53% of crystal density. The nanometer resolution of TXM enables future studies for visualization and quantification of ultrastructural changes in bone tissue resulting from osteoporosis, dental disease, and other pathologies. PMID:20374681

  13. Nanoscale X-Ray Microscopic Imaging of Mammalian Mineralized Tissue

    PubMed Central

    Andrews, Joy C.; Almeida, Eduardo; van der Meulen, Marjolein C.H.; Alwood, Joshua S.; Lee, Chialing; Liu, Yijin; Chen, Jie; Meirer, Florian; Feser, Michael; Gelb, Jeff; Rudati, Juana; Tkachuk, Andrei; Yun, Wenbing; Pianetta, Piero

    2010-01-01

    A novel hard transmission X-ray microscope (TXM) at the Stanford Synchrotron Radiation Light-source operating from 5 to 15 keV X-ray energy with 14 to 30 µm2 field of view has been used for high-resolution (30–40 nm) imaging and density quantification of mineralized tissue. TXM is uniquely suited for imaging of internal cellular structures and networks in mammalian mineralized tissues using relatively thick (50 µm), untreated samples that preserve tissue micro- and nanostructure. To test this method we performed Zernike phase contrast and absorption contrast imaging of mouse cancellous bone prepared under different conditions of in vivo loading, fixation, and contrast agents. In addition, the three-dimensional structure was examined using tomography. Individual osteocytic lacunae were observed embedded within trabeculae in cancellous bone. Extensive canalicular networks were evident and included processes with diameters near the 30–40 nm instrument resolution that have not been reported previously. Trabecular density was quantified relative to rod-like crystalline apatite, and rod-like trabecular struts were found to have 51–54% of pure crystal density and plate-like areas had 44–53% of crystal density. The nanometer resolution of TXM enables future studies for visualization and quantification of ultrastructural changes in bone tissue resulting from osteoporosis, dental disease, and other pathologies. PMID:20374681

  14. A microscopic field theoretical approach for active systems

    NASA Astrophysics Data System (ADS)

    Alaimo, F.; Praetorius, S.; Voigt, A.

    2016-08-01

    We consider a microscopic modeling approach for active systems. The approach extends the phase field crystal (PFC) model and allows us to describe generic properties of active systems within a continuum model. The approach is validated by reproducing results obtained with corresponding agent-based and microscopic phase field models. We consider binary collisions, collective motion and vortex formation. For larger numbers of particles we analyze the coarsening process in active crystals and identify giant number fluctuation in a cluster formation process.

  15. The turbulent wake behind side-by-side plates

    NASA Astrophysics Data System (ADS)

    Hoseini Dadmarzi, Fatemeh; Narasimhamurthy, Vagesh D.; Andersson, Helge I.; Pettersen, Bjørnar

    2011-12-01

    The wake behind two flat plates placed side by side normal to the inflow has been investigated by direct numerical simulation. The spacing between the two plates is one plate width d and the Reynolds number based on the plate width and inflow velocity is 1000. Flow pattern study indicates an anti-phase vortex shedding behind flat plates in the near wake which merges to one large wake downstream. Such a vortex structure has not been observed behind the flat plates for this gap ratio.

  16. Adirondack Under the Microscope

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image was taken by the Mars Exploration Rover Spirit front hazard-identification camera after the rover's first post-egress drive on Mars Sunday, Jan. 15, 2004. Engineers drove the rover approximately 3 meters (10 feet) from the Columbia Memorial Station toward the first rock target, seen in the foreground. The football-sized rock was dubbed Adirondack because of its mountain-shaped appearance. Scientists have begun using the microscopic imager instrument at the end of the rover's robotic arm to examine the rock and understand how it formed.

  17. Low frequency acoustic microscope

    DOEpatents

    Khuri-Yakub, Butrus T.

    1986-11-04

    A scanning acoustic microscope is disclosed for the detection and location of near surface flaws, inclusions or voids in a solid sample material. A focused beam of acoustic energy is directed at the sample with its focal plane at the subsurface flaw, inclusion or void location. The sample is scanned with the beam. Detected acoustic energy specularly reflected and mode converted at the surface of the sample and acoustic energy reflected by subsurface flaws, inclusions or voids at the focal plane are used for generating an interference signal which is processed and forms a signal indicative of the subsurface flaws, inclusions or voids.

  18. Atomic Force Microscope

    SciTech Connect

    Day, R.D.; Russell, P.E.

    1988-12-01

    The Atomic Force Microscope (AFM) is a recently developed instrument that has achieved atomic resolution imaging of both conducting and non- conducting surfaces. Because the AFM is in the early stages of development, and because of the difficulty of building the instrument, it is currently in use in fewer than ten laboratories worldwide. It promises to be a valuable tool for obtaining information about engineering surfaces and aiding the .study of precision fabrication processes. This paper gives an overview of AFM technology and presents plans to build an instrument designed to look at engineering surfaces.

  19. Photography with a Microscope

    NASA Astrophysics Data System (ADS)

    Rost, Fred; Oldfield, Ron

    2000-03-01

    This beautifully illustrated book describes the methods used to record images viewed through a microscope. The text describes the principles and practices of photomicrography, and is written for all who take photomicrographs, beginners and/or experienced practitioners. The authors describe techniques that may be applied to many disciplines for teaching, research, archives, or pleasure. The book includes chapters on standard photography, modern digital techniques, methods for improving contrast, and a short chapter on drawing. In addition to its value as a work of reference, the authors' clear, didactic style makes this book suitable as a textbook for courses in photomicrography and/or elementary light microscopy.

  20. Solid state optical microscope

    DOEpatents

    Young, Ian T.

    1983-01-01

    A solid state optical microscope wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. A galvanometer scanning mirror, for scanning in one of two orthogonal directions is provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal.

  1. Solid state optical microscope

    DOEpatents

    Young, I.T.

    1983-08-09

    A solid state optical microscope wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. A galvanometer scanning mirror, for scanning in one of two orthogonal directions is provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal. 2 figs.

  2. Earth's Decelerating Tectonic Plates

    SciTech Connect

    Forte, A M; Moucha, R; Rowley, D B; Quere, S; Mitrovica, J X; Simmons, N A; Grand, S P

    2008-08-22

    Space geodetic and oceanic magnetic anomaly constraints on tectonic plate motions are employed to determine a new global map of present-day rates of change of plate velocities. This map shows that Earth's largest plate, the Pacific, is presently decelerating along with several other plates in the Pacific and Indo-Atlantic hemispheres. These plate decelerations contribute to an overall, globally averaged slowdown in tectonic plate speeds. The map of plate decelerations provides new and unique constraints on the dynamics of time-dependent convection in Earth's mantle. We employ a recently developed convection model constrained by seismic, geodynamic and mineral physics data to show that time-dependent changes in mantle buoyancy forces can explain the deceleration of the major plates in the Pacific and Indo-Atlantic hemispheres.

  3. Microscopic Tribotactic Walkers

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    The translational motion of a rotating object near a surface is strongly dependent on the friction between the object and the surface. The process of friction is inherently directional and the friction coefficient can be anisotropic even in the absence of a net friction coefficient gradient. This is macroscopically observed in the ordering motif of some animal hair or scales and a microscopic analog can be imagined where the friction coefficient is determined by the strength and density of reversible bonds between a rotating object and the substrate. For high friction coefficients most of the rotational motion is converted into translational motion; conversely for low friction coefficients the object primarily rotates in place. We exploited this property to design and test a new class of motile system that displays tribotaxis, which is the process by which an object detects differences in the local friction coefficient and moves accordingly either to regions of higher or lower friction. These synthetic tribotactic microscopic walkers, composed of a pair of functionalized superparamagnetic beads, detect gradients in the spatial friction coefficient and migrate towards high friction areas when actuated in a random fashion. The effective friction between the walkers and the substrate is controlled by the local density of active receptors in the substrate. The tribotactic walkers also displayed trapping in high friction areas where the density of free receptors is higher.

  4. Forensic Scanning Electron Microscope

    NASA Astrophysics Data System (ADS)

    Keeley, R. H.

    1983-03-01

    The scanning electron microscope equipped with an x-ray spectrometer is a versatile instrument which has many uses in the investigation of crime and preparation of scientific evidence for the courts. Major applications include microscopy and analysis of very small fragments of paint, glass and other materials which may link an individual with a scene of crime, identification of firearms residues and examination of questioned documents. Although simultaneous observation and chemical analysis of the sample is the most important feature of the instrument, other modes of operation such as cathodoluminescence spectrometry, backscattered electron imaging and direct x-ray excitation are also exploited. Marks on two bullets or cartridge cases can be compared directly by sequential scanning with a single beam or electronic linkage of two instruments. Particles of primer residue deposited on the skin and clothing when a gun is fired can be collected on adhesive tape and identified by their morphology and elemental composition. It is also possible to differentiate between the primer residues of different types of ammunition. Bullets may be identified from the small fragments left behind as they pass through the body tissues. In the examination of questioned documents the scanning electron microscope is used to establish the order in which two intersecting ink lines were written and to detect traces of chemical markers added to the security inks on official documents.

  5. ASSEMBLY OF PARALLEL PLATES

    DOEpatents

    Groh, E.F.; Lennox, D.H.

    1963-04-23

    This invention is concerned with a rigid assembly of parallel plates in which keyways are stamped out along the edges of the plates and a self-retaining key is inserted into aligned keyways. Spacers having similar keyways are included between adjacent plates. The entire assembly is locked into a rigid structure by fastening only the outermost plates to the ends of the keys. (AEC)

  6. Accelerated plate tectonics.

    PubMed

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence. PMID:17799689

  7. Plating Tank Control Software

    Energy Science and Technology Software Center (ESTSC)

    1998-03-01

    The Plating Tank Control Software is a graphical user interface that controls and records plating process conditions for plating in high aspect ratio channels that require use of low current and long times. The software is written for a Pentium II PC with an 8 channel data acquisition card, and the necessary shunt resistors for measuring currents in the millampere range.

  8. Rotatable shear plate interferometer

    DOEpatents

    Duffus, Richard C.

    1988-01-01

    A rotatable shear plate interferometer comprises a transparent shear plate mounted obliquely in a tubular supporting member at 45.degree. with respect to its horizontal center axis. This tubular supporting member is supported rotatably around its center axis and a collimated laser beam is made incident on the shear plate along this center axis such that defocus in different directions can be easily measured.

  9. Microscopic treatment of solute trapping and drag.

    PubMed

    Humadi, Harith; Hoyt, J J; Provatas, Nikolas

    2016-01-01

    The long wavelength limit of a recent microscopic phase-field crystal (PFC) theory of a binary alloy mixture is used to derive an analytical approximation for the segregation coefficient as a function of the interface velocity, and relate it to the two-point correlation function of the liquid and the thermodynamic properties of solid and liquid phases. Our results offer the first analytical derivation of solute segregation from a microscopic model, and support recent molecular dynamics and numerical PFC simulations. Our results also provide an independent framework, motivated from classical density functional theory, from which to elucidate the fundamental nature of solute drag, which is still highly contested in the literature. PMID:26871012

  10. The Nature of the Distinctive Microscopic Features in R5(SixGe1-x)4 Magnetic Refrigeration Materials

    SciTech Connect

    Ozan Ugurlu

    2006-05-01

    Magnetic refrigeration is a promising technology that offers a potential for high energy efficiency. The giant magnetocaloric effect of the R{sub 5}(Si{sub x}, Ge{sub 1-x}){sub 4} alloys (where R=rare-earth and O {le} x {le} 1), which was discovered in 1997, make them perfect candidates for magnetic refrigeration applications. In this study the microstructures of Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4} alloys have been characterized using electron microscopy techniques, with the focus being on distinctive linear features first examined in 1999. These linear features have been observed in R{sub 5}(Si{sub x}, Ge{sub 1-x}){sub 4} alloys prepared from different rare-earths (Gd, Tb, Dy and Er) with different crystal structures (Gd{sub 5}Si{sub 4}-type orthorhombic, monoclinic and Gd{sub 5}Ge{sub 4}-type orthorhombic). Systematic scanning electron microscope studies revealed that these linear features are actually thin-plates, which grow along specific directions in the matrix material. The crystal structure of the thin-plates has been determined as hexagonal with lattice parameters a=b=8.53 {angstrom} and c=6.40 {angstrom} using selected area diffraction (SAD). Energy dispersive spectroscopy analysis, carried out in both scanning and transmission electron microscopes, showed that the features have a composition approximating to R{sub 5}(Si{sub x},Ge{sub 1-x}){sub 3}.phase. Orientation relationship between the matrix and the thin-plates has been calculated as [- 1010](1-211){sub p}//[010](10-2){sub m}. The growth direction of the thin plates are calculated as (22 0 19) and (-22 0 19) by applying the Ag approach of Zhang and Purdy to the SAD patterns of this system. High Resolution TEM images of the Gd{sub 5}Ge{sub 4} were used to study the crystallographic relationship. A terrace-ledge structure was observed at the interface and a 7{sup o} rotation of the reciprocal lattices with respect to each other, consistent with the determined orientation relationship, was noted

  11. Abrupt plate accelerations shape rifted continental margins.

    PubMed

    Brune, Sascha; Williams, Simon E; Butterworth, Nathaniel P; Müller, R Dietmar

    2016-08-11

    Rifted margins are formed by persistent stretching of continental lithosphere until breakup is achieved. It is well known that strain-rate-dependent processes control rift evolution, yet quantified extension histories of Earth's major passive margins have become available only recently. Here we investigate rift kinematics globally by applying a new geotectonic analysis technique to revised global plate reconstructions. We find that rifted margins feature an initial, slow rift phase (less than ten millimetres per year, full rate) and that an abrupt increase of plate divergence introduces a fast rift phase. Plate acceleration takes place before continental rupture and considerable margin area is created during each phase. We reproduce the rapid transition from slow to fast extension using analytical and numerical modelling with constant force boundary conditions. The extension models suggest that the two-phase velocity behaviour is caused by a rift-intrinsic strength--velocity feedback, which can be robustly inferred for diverse lithosphere configurations and rheologies. Our results explain differences between proximal and distal margin areas and demonstrate that abrupt plate acceleration during continental rifting is controlled by the nonlinear decay of the resistive rift strength force. This mechanism provides an explanation for several previously unexplained rapid absolute plate motion changes, offering new insights into the balance of plate driving forces through time. PMID:27437571

  12. THz wave emission microscope

    NASA Astrophysics Data System (ADS)

    Yuan, Tao

    Sensing and imaging using Terahertz (THz) radiation has attracted more and more interest in the last two decades thanks to the abundant material 'finger prints' in the THz frequency range. The low photon energy also makes THz radiation an attractive tool for nondestructive evaluation of materials and devices, biomedical applications, security checks and explosive screening. Due to the long wavelength, the far-field THz wave optical systems have relatively low spatial resolution. This physical limitation confines THz wave sensing and imaging to mostly macro-size samples. To investigate local material properties or micro-size structures and devices, near-field technology has to be employed. In this dissertation, the Electro-Optical THz wave emission microscope is investigated. The basic principle is to focus the femtosecond laser to a tight spot on a thin THz emitter layer to produce a THz wave source with a similar size as the focus spot. The apparatus provides a method for placing a THz source with sub-wavelength dimension in the near-field range of the investigated sample. Spatial resolution to the order of one tenth of the THz wavelength is demonstrated by this method. The properties of some widely used THz wave emission materials under tight focused pump light are studied. As an important branch of THz time domain spectroscopy (THz-TDS), THz wave emission spectroscopy has been widely used as a tool to investigate the material physics, such as energy band structure, carrier dynamics, material nonlinear properties and dynamics. As the main work of this dissertation, we propose to combine the THz wave emission spectroscopy with scanning probe microscopy (SPM) to build a tip-assisted THz wave emission microscope (TATEM), which is a valuable extension to current SPM science and technology. Illuminated by a femtosecond laser, the biased SPM tip forms a THz wave source inside the sample beneath the tip. The source size is proportional to the apex size of the tip so

  13. Holographic NDT of thin titanium plate described

    NASA Astrophysics Data System (ADS)

    Yang, R.

    1986-01-01

    Holography is a technique for recording the amplitude and phase changes of an object on a photographic plate in the form of interference fringes. Because the holographic interference method can examine a component in the noncontact mode and is not bothered by complicated part shape or surface roughness, it has been widely used in nondestructive testing. In the rapidly developing aerospace industry, titanium and titanium alloy thin plates are used more and more but local delamination has been found in the production process of bonded titanium plates. Using ultrasonic methods, such defects are difficult to detect and large area delaminations with tightly closed edges can easily be missed. Other testing methods are also unsuccessful. A holographic method was developed for detecting defects in thin titanium plates and several high temperature alloy plates were tested. The testing equipment, methods and results are discussed.

  14. An improved plating process

    NASA Technical Reports Server (NTRS)

    Askew, John C.

    1994-01-01

    An alternative to the immersion process for the electrodeposition of chromium from aqueous solutions on the inside diameter (ID) of long tubes is described. The Vessel Plating Process eliminates the need for deep processing tanks, large volumes of solutions, and associated safety and environmental concerns. Vessel Plating allows the process to be monitored and controlled by computer thus increasing reliability, flexibility and quality. Elimination of the trivalent chromium accumulation normally associated with ID plating is intrinsic to the Vessel Plating Process. The construction and operation of a prototype Vessel Plating Facility with emphasis on materials of construction, engineered and operational safety and a unique system for rinse water recovery are described.

  15. Imaging arrangement and microscope

    DOEpatents

    Pertsinidis, Alexandros; Chu, Steven

    2015-12-15

    An embodiment of the present invention is an imaging arrangement that includes imaging optics, a fiducial light source, and a control system. In operation, the imaging optics separate light into first and second tight by wavelength and project the first and second light onto first and second areas within first and second detector regions, respectively. The imaging optics separate fiducial light from the fiducial light source into first and second fiducial light and project the first and second fiducial light onto third and fourth areas within the first and second detector regions, respectively. The control system adjusts alignment of the imaging optics so that the first and second fiducial light projected onto the first and second detector regions maintain relatively constant positions within the first and second detector regions, respectively. Another embodiment of the present invention is a microscope that includes the imaging arrangement.

  16. Embryos, microscopes, and society.

    PubMed

    Maienschein, Jane

    2016-06-01

    Embryos have different meanings for different people and in different contexts. Seen under the microscope, the biological embryo starts out as one cell and then becomes a bunch of cells. Gradually these divide and differentiate to make up the embryo, which in humans becomes a fetus at eight weeks, and then eventually a baby. At least, that happens in those cases that carry through normally and successfully. Yet a popular public perception imagines the embryo as already a little person in the very earliest stages of development, as if it were predictably to become an adult. In actuality, cells can combine, pull apart, and recombine in a variety of ways and still produce embryos, whereas most embryos never develop into adults at all. Biological embryos and popular imaginations of embryos diverge. This paper looks at some of the historical reasons for and social implications of that divergence. PMID:26996410

  17. Mars Under the Microscope

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This magnified look at the martian soil near the Mars Exploration Rover Opportunity's landing site, Meridiani Planum, shows coarse grains sprinkled over a fine layer of sand. The image was captured by the rover's microscopic imager on the 10th day, or sol, of its mission. Scientists are intrigued by the spherical rocks, which can be formed by a variety of geologic processes, including cooling of molten lava droplets and accretion of concentric layers of material around a particle or 'seed.'

    The examined patch of soil is 3 centimeters (1.2 inches) across. The circular grain in the lower left corner is approximately 3 millimeters (.12 inches) across, or about the size of a sunflower seed.

  18. Atomic Force Microscope Operation

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation (large file)

    This animation is a scientific illustration of the operation of NASA's Phoenix Mars Lander's Atomic Force Microscope, or AFM. The AFM is part of Phoenix's Microscopy, Electrochemistry, and Conductivity Analyzer, or MECA.

    The AFM is used to image the smallest Martian particles using a very sharp tip at the end of one of eight beams.

    The beam of the AFM is set into vibration and brought up to the surface of a micromachined silicon substrate. The substrate has etched in it a series of pits, 5 micrometers deep, designed to hold the Martian dust particles.

    The microscope then maps the shape of particles in three dimensions by scanning them with the tip.

    At the end of the animation is a 3D representation of the AFM image of a particle that was part of a sample informally called 'Sorceress.' The sample was delivered to the AFM on the 38th Martian day, or sol, of the mission (July 2, 2008).

    The image shows four round pits, only 5 microns in depth, that were micromachined into the silicon substrate.

    A Martian particle only one micrometer, or one millionth of a meter, across is held in the upper left pit.

    The rounded particle shown at the highest magnification ever seen from another world is a particle of the dust that cloaks Mars. Such dust particles color the Martian sky pink, feed storms that regularly envelop the planet and produce Mars' distinctive red soil.

    The AFM was developed by a Swiss-led consortium, with Imperial College London producing the silicon substrate that holds sampled particles.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  19. Paper microzone plates.

    PubMed

    Carrilho, Emanuel; Phillips, Scott T; Vella, Sarah J; Martinez, Andres W; Whitesides, George M

    2009-08-01

    This paper describes 96- and 384-microzone plates fabricated in paper as alternatives to conventional multiwell plates fabricated in molded polymers. Paper-based plates are functionally related to plastic well plates, but they offer new capabilities. For example, paper-microzone plates are thin (approximately 180 microm), require small volumes of sample (5 microL per zone), and can be manufactured from inexpensive materials ($0.05 per plate). The paper-based plates are fabricated by patterning sheets of paper, using photolithography, into hydrophilic zones surrounded by hydrophobic polymeric barriers. This photolithography used an inexpensive formulation photoresist that allows rapid (approximately 15 min) prototyping of paper-based plates. These plates are compatible with conventional microplate readers for quantitative absorbance and fluorescence measurements. The limit of detection per zone loaded for fluorescence was 125 fmol for fluorescein isothiocyanate-labeled bovine serum albumin, and this level corresponds to 0.02 the quantity of analyte per well used to achieve comparable signal-to-noise in a 96-well plastic plate (using a solution of 25 nM labeled protein). The limits of detection for absorbance on paper was approximately 50 pmol per zone for both Coomassie Brilliant Blue and Amaranth dyes; these values were 0.4 that required for the plastic plate. Demonstration of quantitative colorimetric correlations using a scanner or camera to image the zones and to measure the intensity of color, makes it possible to conduct assays without a microplate reader. PMID:19572563

  20. Multicolor printing plate joining

    NASA Technical Reports Server (NTRS)

    Waters, W. J. (Inventor)

    1984-01-01

    An upper plate having ink flow channels and a lower plate having a multicolored pattern are joined. The joining is accomplished without clogging any ink flow paths. A pattern having different colored parts and apertures is formed in a lower plate. Ink flow channels each having respective ink input ports are formed in an upper plate. The ink flow channels are coated with solder mask and the bottom of the upper plate is then coated with solder. The upper and lower plates are pressed together at from 2 to 5 psi and heated to a temperature of from 295 F to 750 F or enough to melt the solder. After the plates have cooled and the pressure is released, the solder mask is removed from the interior passageways by means of a liquid solvent.

  1. Acoustic microscope surface inspection system and method

    DOEpatents

    Khuri-Yakub, Butrus T.; Parent, Philippe; Reinholdtsen, Paul A.

    1991-01-01

    An acoustic microscope surface inspection system and method in which pulses of high frequency electrical energy are applied to a transducer which forms and focuses acoustic energy onto a selected location on the surface of an object and receives energy from the location and generates electrical pulses. The phase of the high frequency electrical signal pulses are stepped with respected to the phase of a reference signal at said location. An output signal is generated which is indicative of the surface of said selected location. The object is scanned to provide output signals representative of the surface at a plurality of surface locations.

  2. Acoustic microscope surface inspection system and method

    DOEpatents

    Khuri-Yakub, B.T.; Parent, P.; Reinholdtsen, P.A.

    1991-02-26

    An acoustic microscope surface inspection system and method are described in which pulses of high frequency electrical energy are applied to a transducer which forms and focuses acoustic energy onto a selected location on the surface of an object and receives energy from the location and generates electrical pulses. The phase of the high frequency electrical signal pulses are stepped with respect to the phase of a reference signal at said location. An output signal is generated which is indicative of the surface of said selected location. The object is scanned to provide output signals representative of the surface at a plurality of surface locations. 7 figures.

  3. Femtosecond photoelectron point projection microscope

    SciTech Connect

    Quinonez, Erik; Handali, Jonathan; Barwick, Brett

    2013-10-15

    By utilizing a nanometer ultrafast electron source in a point projection microscope we demonstrate that images of nanoparticles with spatial resolutions of the order of 100 nanometers can be obtained. The duration of the emission process of the photoemitted electrons used to make images is shown to be of the order of 100 fs using an autocorrelation technique. The compact geometry of this photoelectron point projection microscope does not preclude its use as a simple ultrafast electron microscope, and we use simple analytic models to estimate temporal resolutions that can be expected when using it as a pump-probe ultrafast electron microscope. These models show a significant increase in temporal resolution when comparing to ultrafast electron microscopes based on conventional designs. We also model the microscopes spectroscopic abilities to capture ultrafast phenomena such as the photon induced near field effect.

  4. Proper alignment of the microscope.

    PubMed

    Rottenfusser, Rudi

    2013-01-01

    The light microscope is merely the first element of an imaging system in a research facility. Such a system may include high-speed and/or high-resolution image acquisition capabilities, confocal technologies, and super-resolution methods of various types. Yet more than ever, the proverb "garbage in-garbage out" remains a fact. Image manipulations may be used to conceal a suboptimal microscope setup, but an artifact-free image can only be obtained when the microscope is optimally aligned, both mechanically and optically. Something else is often overlooked in the quest to get the best image out of the microscope: Proper sample preparation! The microscope optics can only do its job when its design criteria are matched to the specimen or vice versa. The specimen itself, the mounting medium, the cover slip, and the type of immersion medium (if applicable) are all part of the total optical makeup. To get the best results out of a microscope, understanding the functions of all of its variable components is important. Only then one knows how to optimize these components for the intended application. Different approaches might be chosen to discuss all of the microscope's components. We decided to follow the light path which starts with the light source and ends at the camera or the eyepieces. To add more transparency to this sequence, the section up to the microscope stage was called the "Illuminating Section", to be followed by the "Imaging Section" which starts with the microscope objective. After understanding the various components, we can start "working with the microscope." To get the best resolution and contrast from the microscope, the practice of "Koehler Illumination" should be understood and followed by every serious microscopist. Step-by-step instructions as well as illustrations of the beam path in an upright and inverted microscope are included in this chapter. A few practical considerations are listed in Section 3. PMID:23931502

  5. Transmission electron microscope CCD camera

    DOEpatents

    Downing, Kenneth H.

    1999-01-01

    In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.

  6. Athena microscopic Imager investigation

    USGS Publications Warehouse

    Herkenhoff, K. E.; Squyres, S. W.; Bell, J.F., III; Maki, J.N.; Arneson, H.M.; Bertelsen, P.; Brown, D.I.; Collins, S.A.; Dingizian, A.; Elliott, S.T.; Goetz, W.; Hagerott, E.C.; Hayes, A.G.; Johnson, M.J.; Kirk, R.L.; McLennan, S.; Morris, R.V.; Scherr, L.M.; Schwochert, M.A.; Shiraishi, L.R.; Smith, G.H.; Soderblom, L.A.; Sohl-Dickstein, J. N.; Wadsworth, M.V.

    2003-01-01

    The Athena science payload on the Mars Exploration Rovers (MER) includes the Microscopic Imager (MI). The MI is a fixed-focus camera mounted on the end of an extendable instrument arm, the Instrument Deployment Device (IDD). The MI was designed to acquire images at a spatial resolution of 30 microns/pixel over a broad spectral range (400-700 nm). The MI uses the same electronics design as the other MER cameras but has optics that yield a field of view of 31 ?? 31 mm across a 1024 ?? 1024 pixel CCD image. The MI acquires images using only solar or skylight illumination of the target surface. A contact sensor is used to place the MI slightly closer to the target surface than its best focus distance (about 66 mm), allowing concave surfaces to be imaged in good focus. Coarse focusing (???2 mm precision) is achieved by moving the IDD away from a rock target after the contact sensor has been activated. The MI optics are protected from the Martian environment by a retractable dust cover. The dust cover includes a Kapton window that is tinted orange to restrict the spectral bandpass to 500-700 nm, allowing color information to be obtained by taking images with the dust cover open and closed. MI data will be used to place other MER instrument data in context and to aid in petrologic and geologic interpretations of rocks and soils on Mars. Copyright 2003 by the American Geophysical Union.

  7. Microscopic Chondritic Chemical Reactors

    NASA Astrophysics Data System (ADS)

    Maurette, Michel

    Maurette (1998a and 1998b) gives a more detailed discussion of previous works supporting the role of unmelted micrometeorites in prebiotic chemistry. Krueger and Kissel (1987) quoted thermodynamic computations suggesting that the μm-size C-rich grains that they discovered in the tail of Halley’s comet with their time-of-flight mass spectrometer on board the Vega spacecraft, when added to a prebiotic soup of organics, could trigger the formation of nucleic acids. Anders (1989) relied on the characteristics of the tiny stratospheric micrometeorites with sizes of about 5 15 μm, which amount to less than about 1% of the micrometeorite mass flux, to argue that micrometeorites played a major role in the delivery of organics to the Earth. As first quoted by Ponchelet (1989), we proposed in 1989 that much larger micrometeorites, similar to Antarctic micrometeorites, might have been functioning as individual microscopic chemical reactors on the early Earth during their interactions with gases and waters (Maurette et al., 1990, 1991b, 1998a, 1998b). Subsequently, Chyba and Sagan (1992) ceased fully supporting the role of the direct impact of comets in the delivery of such organics, and started to refer that of micrometeorites.

  8. The microscope mission

    NASA Astrophysics Data System (ADS)

    Touboul, Pierre; Foulon, Bernard; Lafargue, Laurent; Metris, Gilles

    2002-04-01

    The MICROSCOPE mission had been selected at the end of 1999 by the French space agency Cnes for a launch scheduled in 2004. The scientific objective of the mission is the test of the Equivalence Principle (EP) up to an accuracy of 10 -15 with its well-known manifestation, the universality of free fall. This principle, at the origin of general relativity, is only consolidated by experimental results and presently with an accuracy of several 10 -13. The micro-satellite developed by Cnes weighs less than 120 kg and is compatible with a low-cost launch like ASAP ARIANE V. The instrument is composed of two differential electrostatic accelerometers operating at finely stabilised room temperature. Each accelerometer includes two cylindrical and concentric test masses, made of platinum or titanium alloys. The experiment consists in controlling the two masses in the same orbital motion. Because of the drag compensation system of the satellite including field effect electrical thrusters, this motion is quite purely gravitational. The electrostatic control forces used in the differential accelerometers are finely measured. The principle of the experiment is presented, the configuration of the instrument and of the satellite is detailed with regard to the present development status. The specifications for the major parameters of the experiment are detailed.

  9. Hypervelocity plate acceleration

    SciTech Connect

    Marsh, S.P.; Tan, T.H.

    1991-01-01

    Shock tubes have been used to accelerate 1.5-mm-thick stainless steel plates to high velocity while retaining their integrity. The fast shock tubes are 5.1-cm-diameter, 15.2-cm-long cylinders of PBX-9501 explosive containing a 1.1-cm-diameter cylindrical core of low-density polystyrene foam. The plates have been placed directly in contact with one face of the explosive system. Plane-wave detonation was initiated on the opposite face. A Mach disk was formed in the imploding styrofoam core, which provided the impulse required to accelerate the metal plate to high velocity. Parametric studies were made on this system to find the effect of varying plate metal, plate thickness, foam properties, and addition of a barrel. A maximum plate velocity of 9.0 km/s has been observed. 6 refs., 17 figs.

  10. WFPDB: European Plate Archives

    NASA Astrophysics Data System (ADS)

    Tsvetkov, Milcho

    2007-08-01

    The Wide-Field Plate Database (WFPDB) gives an inventory of all wide-field (>~ 1 sq. deg) photographic observations archived in astronomical institutions over the world. So it facilitates and stimulates their use and preservation as a valuable source of information for future investigations in astronomy. At present WFPDB manages plate-index information for 25% of all existing plates providing on-line access from Sofia (http://www.skyarchive.org/search) and in CDS, Strasbourg. Here we present the new development of WFPDB as an instrument for searching of long term brightness variations of different sky objects stressing on the European photographic plate collections (from existing 2 million wide-field plates more than 55% are in Europe: Germany, Russia, Ukraine, Italy, Czech Republic, etc.). We comment examples of digitization (with flatbed scanners) of the European plate archives in Sonneberg, Pulkovo, Asiago, Byurakan, Bamberg, etc. and virtual links of WFPDB with European AVO, ADS, IBVS.

  11. GOLD PLATING PROCESS

    DOEpatents

    Seegmiller, R.

    1957-08-01

    An improved bath is reported for plating gold on other metals. The composition of the plating bath is as follows: Gold cyanide from about 15 to about 50 grams, potassium cyanide from about 70 to about 125 grams, and sulfonated castor oil from about 0.1 to about 10 cc. The gold plate produced from this bath is smooth, semi-hard, and nonporous.

  12. Plating methods, a survey

    NASA Technical Reports Server (NTRS)

    Berkowitz, J. B.; Emerson, N. H.

    1972-01-01

    Results are presented of a comprehensive search of the literature available, much of which has been generated by the research centers of NASA and its contractors, on plating and coating methods and techniques. Methods covered included: (1) electroplating from aqueous solutions; (2) electroplating from nonaqueous solutions; (3) electroplating from fused-salt baths; (4) electroforming; (5) electroless plating, immersion plating, and mirroring; (6) electroplating from gaseous plasmas; and (7) anodized films and conversion coatings.

  13. Large-Area Zone Plate Fabrication with Optical Lithography

    SciTech Connect

    Denbeaux, G.

    2011-09-09

    Zone plates as condenser optics for x-ray microscopes offer simple optical designs for both illumination and spectral resolution when used as a linear monochromator. However, due to the long write times for electron beam lithography, both the availability and the size of zone plates for condensers have been limited. Since the resolution provided by the linear monochromator scales almost linearly with the diameter of the zone plate, the full potential for zone plate monochromators as illumination systems for x-ray microscopes has not been achieved. For example, the 10-mm-diameter zone plate has demonstrated a spectral resolution of E/{Delta}E = 700[1], but with a 26-mm-diameter zone plate, the calculated spectral resolution is higher than E/{Delta}E = 3000. These large-area zone plates are possible to fabricate with the leading edge semiconductor lithography tools such as those available at the College of Nanoscale Science and Engineering at the University at Albany. One of the lithography tools available is the ASML TWINSCAN XT: 1950i with 37-nm resolution [2]. A single 300-mm wafer can contain more than 60 fields, each with a large area condenser, and the throughput of the tool can be more than one wafer every minute.

  14. CALUTRON FACE PLATE

    DOEpatents

    Brobeck, W.M.

    1959-08-25

    The construction of a removable cover plate for a calutron tank is described. The plate is fabricated of a rectangular frame member to which is welded a bowed or dished plate of thin steel, reinforced with transverse stiffening ribs. When the tank is placed between the poles of a magnet, the plate may be pivoted away from the tank and magnet and is adapted to support the ion separation mechanism secured to its inner side as well as the vacuum load within the tank.

  15. PLATES WITH OXIDE INSERTS

    DOEpatents

    West, J.M.; Schumar, J.F.

    1958-06-10

    Planar-type fuel assemblies for nuclear reactors are described, particularly those comprising fuel in the oxide form such as thoria and urania. The fuel assembly consists of a plurality of parallel spaced fuel plate mennbers having their longitudinal side edges attached to two parallel supporting side plates, thereby providing coolant flow channels between the opposite faces of adjacent fuel plates. The fuel plates are comprised of a plurality of longitudinally extending tubular sections connected by web portions, the tubular sections being filled with a plurality of pellets of the fuel material and the pellets being thermally bonded to the inside of the tubular section by lead.

  16. The Latest in Handheld Microscopes

    ERIC Educational Resources Information Center

    Wighting, Mervyn J.; Lucking, Robert A.; Christmann, Edwin P.

    2004-01-01

    Around 1590, Zacharias Jansenn of Holland invented the microscope. Jansenn, an eyeglass maker by trade, experimented with lenses and discovered that things appeared closer with combinations of lenses. Over the past 400 years, several refinements to microscopes have occurred, making it possible to magnify objects between 200 and 1,500 times their…

  17. Scientists View Battery Under Microscope

    SciTech Connect

    2015-04-10

    PNNL researchers use a special microscope setup that shows the inside of a battery as it charges and discharges. This battery-watching microscope is located at EMSL, DOE's Environmental Molecular Sciences Laboratory that resides at PNNL. Researchers the world over can visit EMSL and use special instruments like this, many of which are the only one of their kind available to scientists.

  18. Electroless Nickel Phosphorus Plating on AZ31

    NASA Astrophysics Data System (ADS)

    Shartal, Kh. M.; Kipouros, G. J.

    2009-04-01

    One of the major drawbacks to using magnesium parts in automotive applications is poor corrosion resistance, which can be improved with a nickel-boron coating placed on a nickel-phosphorus coating, which, in turn, is placed on a phosphate-permanganate conversion-coating layer produced on the magnesium alloy AZ31. This work reports on the determination of the optimum kinetic parameters for producing a coherent nickel-phosphorus coating using an electroless-procedure phosphate-permanganate conversion-coating layer and for studying the effects of the experimental variables of the electroless plating process on the phosphorus content, surface morphology, and structure of the electroless nickel-phosphorus (EN-P) coatings produced. Measurements of the plating rate as a function of experimental variables such as the compositions of the plating bath constituents, temperature, and pH were implemented using the weight-gain method; the phosphorus content of the EN-P coatings was measured using energy-dispersive spectroscopy (EDS) analysis. The surface morphology of the coating was examined using a scanning electron microscope (SEM); X-ray diffraction (XRD) was used to characterize the structure of each coating. An empirical rate law was determined for EN-P plating on a phosphate-permanganate conversion coating. It is found that the deposition rate of the EN-P coating increases by increasing the deposition temperature, the concentration of free nickel ions, and the concentration of hypophosphite ions in the plating bath. In addition, the deposition rate decreases by increasing both the plating bath pH and the concentration of citric acid in the plating bath.

  19. A Quantum Gas Microscope for Fermionic Potassium

    NASA Astrophysics Data System (ADS)

    Cheuk, Lawrence; Nichols, Matthew; Okan, Melih; Lawrence, Katherine; Zhang, Hao; Zwierlein, Martin

    2016-05-01

    Ultracold atoms in optical lattices have enabled experimental studies of quantum many-body physics in Hubbard-type lattice systems in a clean and well-controlled environment. In particular, the advent of quantum gas microscopes has made available new experimental probes ideally suited for observing magnetic order and spatial correlations. In the past year, several groups, including ours, first realized quantum gas microscopes for fermionic atoms. In this talk, we describe our experimental setup, which combines high-resolution imaging with Raman sideband cooling to achieve single-site-resolved fluorescent imaging of fermionic 40 K atoms. We also report on recent progress towards observing quantum phases of the Fermi-Hubbard model with single-site resolution.

  20. Surface Detection in a STXM Microscope

    SciTech Connect

    Behyan, S.; Haines, B.; Urquhart, S. G.; Karanukaran, C.; Wang, J.; Obst, M.; Tyliszczak, T.

    2011-09-09

    We have modified scanning transmission x-ray microscopes (STXM) at the Canadian Light Source and the Advanced Light Source with total electron yield (TEY) detection (TEY-STXM). This provides improved surface-sensitive detection, simultaneous with existing bulk-sensitive transmission detection in the STXM microscopes. We have explored sample-current and channeltron-based electron yield detection. Both approaches provide improved surface sensitive imaging and spectroscopy, although channeltron-based detection is superior. TEY-STXM provides surface sensitive imaging of ultrathin films such as phase-separated Langmuir-Blodgett monolayer films, as well as differentiation of surface and bulk oxides of patterned metallic thin films. This paper will outline the experimental challenges of this method and the opportunities for correlative surface and bulk measurements of complex samples.

  1. A High Resolution Full Field Transmission X-ray Microscope at SSRL

    SciTech Connect

    Luening, Katharina; Pianetta, Piero; Yun Wenbing; Almeida, Eduardo; Meulen, Marjolein van der

    2007-01-19

    The Stanford Synchrotron Radiation Laboratory (SSRL) in collaboration with Xradia Inc., the NASA Ames Research Center and Cornell University is implementing a commercial hard x-ray full field imaging microscope based on zone plate optics on a wiggler beam line on SPEAR3. This facility will provide unprecedented analytical capabilities for a broad range of scientific areas and will enable research on nanoscale phenomena and structures in biology as well as materials science and environmental science. This instrument will provide high resolution x-ray microscopy, tomography, and spectromicroscopy capabilities in a photon energy range between 5-14 keV. The spatial resolution of the TXM microscope is specified as 20 nm exploiting imaging in third diffraction order. This imaging facility will optimally combine the latest imaging technology developed by Xradia Inc. with the wiggler source characteristics at beam line 6-2 at SSRL. This will result in an instrument capable of high speed and high resolution imaging with spectral tunability for spectromicroscopy, element specific and Zernike phase contrast imaging. Furthermore, a scanning microprobe capability will be integral to the system thus allowing elemental mapping and fluorescence yield XANES to be performed with a spatial resolution of about 1 {mu}m without introducing any changes to the optical configuration of the instrument.

  2. A High Resolution Full Field Transmission X-ray Microscope at SSRL

    NASA Astrophysics Data System (ADS)

    Lüning, Katharina; Pianetta, Piero; Yun, Wenbing; Almeida, Eduardo; van der Meulen, Marjolein

    2007-01-01

    The Stanford Synchrotron Radiation Laboratory (SSRL) in collaboration with Xradia Inc., the NASA Ames Research Center and Cornell University is implementing a commercial hard x-ray full field imaging microscope based on zone plate optics on a wiggler beam line on SPEAR3. This facility will provide unprecedented analytical capabilities for a broad range of scientific areas and will enable research on nanoscale phenomena and structures in biology as well as materials science and environmental science. This instrument will provide high resolution x-ray microscopy, tomography, and spectromicroscopy capabilities in a photon energy range between 5-14 keV. The spatial resolution of the TXM microscope is specified as 20 nm exploiting imaging in third diffraction order. This imaging facility will optimally combine the latest imaging technology developed by Xradia Inc. with the wiggler source characteristics at beam line 6-2 at SSRL. This will result in an instrument capable of high speed and high resolution imaging with spectral tunability for spectromicroscopy, element specific and Zernike phase contrast imaging. Furthermore, a scanning microprobe capability will be integral to the system thus allowing elemental mapping and fluorescence yield XANES to be performed with a spatial resolution of about 1 μm without introducing any changes to the optical configuration of the instrument.

  3. Development of flat-plate solar plate collector: Evaporator

    NASA Astrophysics Data System (ADS)

    Abramzon, B.; Yaron, I.

    1981-11-01

    In the present study the thermal performance of a flat plate solar collector is analyzed theoretically for the case in which the working fluid may undergo a phase change within the tubes of the collector. In addition to the common domestic applications, such a collector - evaporator may be used as a generator of vapors for the production of mechanical or electrical energy, e.g., solar water pumps, solar power stations, etc., as well as for solar - powered absorption refrigeration machines, distillation installations, etc.

  4. Partially Coherent Quantitative Phase Retrieval with Applications to Extreme Ultraviolet Lithography

    NASA Astrophysics Data System (ADS)

    Claus, Rene Andre

    This dissertation presents a new quantitative phase retrieval algorithm that fully models partially coherent imaging in microscopes. Unlike existing algorithms, our algorithm fully considers the pupil function and illumination by using the Weak Object Transfer Function (WOTF). Using an iterative approach, we extend the applicability of the WOTF beyond weakly scattering objects. This allows almost any measurement to be used during phase retrieval. As an example of how this feature can be used to invent practical new measurement schemes, we present the illumination switched pupil. This measurement uses a phase contrast objective and varied illumination to maximize the sensitivity of the microscope to both the phase and amplitude of the sample. Using only two images, the complex field can be recovered with high sensitivity at almost all spatial frequencies. A complete model of imaging in the microscope enables self-calibration of the measurements and improved phase retrieval. Since all important characteristics of the microscope can be incorporated, an optimization over critical parameters, such as the best focus position and image alignment, can be performed after the images have been captured. This allows errors in the calibration to be corrected after the measurements have been performed, improving the accuracy of the recovered field while simplifying the experiments. To verify and apply the algorithm experimentally, we have performed phase retrieval measurements of Extreme Ultraviolet (EUV) photomasks on the zone plate microscope, SHARP, at Lawrence Berkeley National Laboratory (LBNL). Phase retrieval has enabled the quantitative analysis of multilayer roughness and defects. Experiments, comparing the size of defects measured using phase retrieval to measurements performed by AFM, indicate that AFM consistently underestimates the effective height of the buried multilayer defects by 1 nm. Other measurements of defects, comparing the recovered field extracted from

  5. Blue Willow Story Plates

    ERIC Educational Resources Information Center

    Fontes, Kris

    2009-01-01

    In the December 1997 issue of "SchoolArts" is a lesson titled "Blue Willow Story Plates" by Susan Striker. In this article, the author shares how she used this lesson with her middle-school students many times over the years. Here, she describes a Blue Willow plate painting project that her students made.

  6. Earthquakes and plate tectonics

    USGS Publications Warehouse

    Spall, H.

    1977-01-01

    An explanation is to be found in plate tectonics, a concept which has revolutionized thinking in the Earth sciences in the last 10 years. The theory of plate tectonics combines many of the ideas about continental drift (originally proposed in 1912 by Alfred Wegener in Germany) and sea-floor spreading (suggested originally by Harry Hess of Princeton University). 

  7. Characterization of Al-Cu-Mg-Ag Alloy RX226-T8 Plate

    NASA Technical Reports Server (NTRS)

    Lach, Cynthia L.; Domack, Marcia S.

    2003-01-01

    Aluminum-copper-magnesium-silver (Al-Cu-Mg-Ag) alloys that were developed for thermal stability also offer attractive ambient temperature strength-toughness combinations, and therefore, can be considered for a broad range of airframe structural applications. The current study evaluated Al-Cu-Mg-Ag alloy RX226-T8 in plate gages and compared performance with sheet gage alloys of similar composition. Uniaxial tensile properties, plane strain initiation fracture toughness, and plane stress tearing resistance of RX226-T8 were examined at ambient temperature as a function of orientation and thickness location in the plate. Properties were measured near the surface and at the mid-plane of the plate. Tensile strengths were essentially isotropic, with variations in yield and ultimate tensile strengths of less than 2% as a function of orientation and through-thickness location. However, ductility varied by more than 15% with orientation. Fracture toughness was generally higher at the mid-plane and greater for the L-T orientation, although the differences were small near the surface of the plate. Metallurgical analysis indicated that the microstructure was primarily recrystallized with weak texture and was uniform through the plate with the exception of a fine-grained layer near the surface of the plate. Scanning electron microscope analysis revealed Al-Cu-Mg second phase particles which varied in composition and were primarily located on grain boundaries parallel to the rolling direction. Fractography of toughness specimens for both plate locations and orientations revealed that fracture occurred predominantly by transgranular microvoid coalescence. Introduction High-strength, low-density Al-Cu-Mg-Ag alloys were initially developed to replace conventional 2000 (Al-Cu-Mg) and 7000 (Al-Zn-Cu-Mg) series aluminum alloys for aircraft structural applications [1]. During the High Speed Civil Transport (HSCT) program, improvements in thermal stability were demonstrated for candidate

  8. Turbine vane plate assembly

    DOEpatents

    Schiavo Jr., Anthony L.

    2006-01-10

    A turbine vane assembly includes a turbine vane having first and second shrouds with an elongated airfoil extending between. Each end of the airfoil transitions into a shroud at a respective junction. Each of the shrouds has a plurality of cooling passages, and the airfoil has a plurality of cooling passages extending between the first and second shrouds. A substantially flat inner plate and an outer plate are coupled to each of the first and second shrouds so as to form inner and outer plenums. Each inner plenum is defined between at least the junction and the substantially flat inner plate; each outer plenum is defined between at least the substantially flat inner plate and the outer plate. Each inner plenum is in fluid communication with a respective outer plenum through at least one of the cooling passages in the respective shroud.

  9. A modified agar plate method for detection of Strongyloides stercoralis.

    PubMed

    Koga, K; Kasuya, S; Khamboonruang, C; Sukhavat, K; Ieda, M; Takatsuka, N; Kita, K; Ohtomo, H

    1991-10-01

    The agar plate method is a new technique with high detection rates for coprological diagnosis of human strongyloidiasis. This report details modifications of the technique and establishes a standardized procedure. We recommend that all plates should be carefully observed using a microscope because macroscopic observation can lead to false negative results. It is also advisable to pour formalin solution directly into microscopically positive dishes to collect worms by sedimentation. This procedure enables one to observe worms otherwise hidden. Sealing dishes with adhesive tape prevents larvae from crawling out of the dishes, eliminating any possibility in the reduction of detection rates, and greatly improves the safety conditions for the technician performing the procedure. We consider the agar plate method to be superior to the filter paper method in detecting Strongyloides, and we believe that it will eventually become the technique of choice. PMID:1951861

  10. Microscopic dielectric permittivities of graphene nanoribbons and graphene

    NASA Astrophysics Data System (ADS)

    Fang, Jingtian; Vandenberghe, William G.; Fischetti, Massimo V.

    2016-07-01

    We derive a microscopic Poisson equation using the density-density response function. This equation is valid for any realistic potential perturbation and permits the study of dielectric response in nanostructures, especially in one-dimensional nanostructures and quantum dots. We apply this equation to simulate a nanoscale parallel-plate capacitor (nanocapacitor) with graphene as dielectric and two nanocapacitors with a graphene nanoribbon (GNR) as dielectric. The density-density response function is calculated using first-order perturbation theory and empirical pseudopotentials. From the microscopic electric field of the graphene nanocapacitor, we calculate the out-of-plane microscopic dielectric constant of graphene and from the electric field of GNR nanocapacitors, we calculate the full microscopic dielectric tensor of several GNRs with different widths. We find that the out-of-plane microscopic dielectric constants of GNRs and graphene do not depend on their energy band gap. We also study the effect of a surrounding dielectric on the dielectric permittivity of graphene and we conclude that the surrounding dielectric barely affects the dielectric permittivity of graphene.

  11. A portable laser photostimulation and imaging microscope

    PubMed Central

    Nikolenko, Volodymyr; Peterka, Darcy S.; Yuste, Rafael

    2013-01-01

    We describe a compact microscope that uses a Spatial Light Modulator (SLM) to control the excitation laser light. The flexibility of SLMs, which can mimic virtually any optical transfer function, enables the experimenter to create, in software, arbitrary spatio-temporal light patterns, including focusing and beam scanning, simply by calculating the appropriate phase mask. Our prototype, a scan-less device with no moving parts, can be used for laser imaging or photostimulation, supplanting the need for an elaborate optical setup. As a proof of principle, we generate complex excitation patterns on fluorescent samples and also perform functional imaging of neuronal activity in living brain slices. PMID:20644244

  12. Earthquakes and plate tectonics.

    USGS Publications Warehouse

    Spall, H.

    1982-01-01

    Earthquakes occur at the following three kinds of plate boundary: ocean ridges where the plates are pulled apart, margins where the plates scrape past one another, and margins where one plate is thrust under the other. Thus, we can predict the general regions on the earth's surface where we can expect large earthquakes in the future. We know that each year about 140 earthquakes of magnitude 6 or greater will occur within this area which is 10% of the earth's surface. But on a worldwide basis we cannot say with much accuracy when these events will occur. The reason is that the processes in plate tectonics have been going on for millions of years. Averaged over this interval, plate motions amount to several mm per year. But at any instant in geologic time, for example the year 1982, we do not know, exactly where we are in the worldwide cycle of strain build-up and strain release. Only by monitoring the stress and strain in small areas, for instance, the San Andreas fault, in great detail can we hope to predict when renewed activity in that part of the plate tectonics arena is likely to take place. -from Author

  13. Lohse's historic plate archive

    NASA Astrophysics Data System (ADS)

    Tsvetkov, M.; Tsvetkova, K.; Richter, G.; Scholz, G.; Böhm, P.

    The description and the analysis of Oswald Lohse's astrophotographic plates, collected at the Astrophysical Observatory Potsdam in the period 1879 - 1889, are presented. 67 plates of the archive, taken with the greatest instrument of the observatory at that time - the refractor (D = 0.30 m, F = 5.40 m, scale = 38''/mm) and with the second heliographic objective (D = 0.13 m, F = 1.36 m, scale = 152''/mm) - - survived two world wars in relative good condition. The plate emulsions are from different manufacturers in the beginning of astrophotography (Gädicke, Schleussner, Beernaert, etc.). The sizes of the plates are usually 9x12 cm2, which corresponds to fields of 1.2deg and 5deg respectively for each instrument mentioned above. The average limiting magnitude is 13.0(pg). Besides of the plates received for technical experiments (work on photographic processes, testing of new instruments and methods of observations), the scientific observations follow programs for studies of planet surfaces, bright stars, some double stars, stellar clusters and nebulous objects. Lohse's archive is included into the Wide Field Plate Database (http://www.skyarchive.org) as the oldest systematic one, covering the fields of Orion (M42/43), Pleiades, h & chi Persei, M37, M3, M11, M13, M92, M31, etc. With the PDS 2020 GM+ microdensitometer of Münster University 10 archive plates were digitized.

  14. (Center of excellence: Microlaser microscope)

    SciTech Connect

    Webb, R.H.

    1992-01-01

    This Center-of-Excellence grant has two components: development of an imaging system based on microlaser arrays forms a central project among a group of laser diagnostic and therapeutic efforts primarily funded outside the grant. In these first 8 months we have set up the Microlaser Microscope using small microlaser arrays. We have emphasized the basics of microlaser handling and electronic addressing and the optics of the microscope. Details of electronics and optics given here will be used in the larger arrays which should be available soon. After a description of the central Microlaser Microscope project, we touch briefly on the other projects of the Center, which have been outstandingly fruitful this year. Publications are necessarily concerned with the smaller projects, since the Microlaser Microscope is in its early stages.

  15. Center of excellence: Microlaser microscope

    NASA Astrophysics Data System (ADS)

    Webb, R. H.

    This Center-of-Excellence grant has two components: development of an imaging system based on microlaser arrays forms a central project among a group of laser diagnostic and therapeutic efforts primarily funded outside the grant. In these first 8 months we have set up the Microlaser Microscope using small microlaser arrays. We have emphasized the basics of microlaser handling and electronic addressing and the optics of the microscope. Details of electronics and optics given here will be used in the larger arrays which should be available soon. After a description of the central Microlaser Microscope project, we touch briefly on the other projects of the Center, which have been outstandingly fruitful this year. Publications are necessarily concerned with the smaller projects, since the Microlaser Microscope is in its early stages.

  16. Mars Life? - Microscopic Tubular Structures

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This electron microscope image shows extremely tiny tubular structures that are possible microscopic fossils of bacteria-like organisms that may have lived on Mars more than 3.6 billion years ago. A two-year investigation by a NASA research team found organic molecules, mineral features characteristic of biological activity and possible microscopic fossils such as these inside of an ancient Martian rock that fell to Earth as a meteorite. The largest possible fossils are less than 1/100th the diameter of a human hair in size while most are ten times smaller. The fossil-like structures were found in carbonate minerals formed along pre-existing fractures in the meteorite in a fashion similar to the way fossils occur in limestone on Earth, although on a microscopic scale.

  17. Microscopic Procedures for Plant Meiosis.

    ERIC Educational Resources Information Center

    Braselton, James P.

    1997-01-01

    Describes laboratory techniques designed to familiarize students with meiosis and how microscopic preparations of meiosis are made. These techniques require the use of fresh or fixed flowers. Contains 18 references. (DDR)

  18. Adirondack Under the Microscope-2

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This overhead look at the martian rock dubbed Adirondack was captured by the Mars Exploration Rover Spirit's panoramic camera. It shows the approximate region where the rover's microscopic imager began its first close-up inspection.

  19. Microscopic derivation of discrete hydrodynamics.

    PubMed

    Español, Pep; Anero, Jesús G; Zúñiga, Ignacio

    2009-12-28

    By using the standard theory of coarse graining based on Zwanzig's projection operator, we derive the dynamic equations for discrete hydrodynamic variables. These hydrodynamic variables are defined in terms of the Delaunay triangulation. The resulting microscopically derived equations can be understood, a posteriori, as a discretization on an arbitrary irregular grid of the Navier-Stokes equations. The microscopic derivation provides a set of discrete equations that exactly conserves mass, momentum, and energy and the dissipative part of the dynamics produces strict entropy increase. In addition, the microscopic derivation provides a practical implementation of thermal fluctuations in a way that the fluctuation-dissipation theorem is satisfied exactly. This paper points toward a close connection between coarse-graining procedures from microscopic dynamics and discretization schemes for partial differential equations. PMID:20059064

  20. Analysis of Multi-step Forming of Metallic Bipolar Plate for MCFC Using Various Shapes of Preforms

    NASA Astrophysics Data System (ADS)

    Lee, Chang-Hwan; Ryu, Seung-Min; Yang, Dong-Yol; Kang, Dong-Woo; Chang, In-Gab; Lee, Tae-Won

    2010-06-01

    The metallic bipolar plates of a molten carbonate fuel cell (MCFC) consist of a shielded slot plate and a center plate. Among these, the shielded slot plate (the current collector) supports the Membrane Electrode Assembly (MEA) mechanically. The anode gases and the cathode gases pass through a space between individual slot patterns. The catalysts are located in the upper part of the shielded slot plate. Therefore, triple phase boundaries can be generated, and carbonate ions can act as the mobile charge carrier for the MCFC. Due to these properties, the shielded slot plate should have a sheared corrugated pattern. In order to form a sheared corrugated pattern, a slitting process is required during the first stage of the forming process. However, it is not possible to obtain a high aspect ratio in a sheared corrugated trapezoidal pattern due to the plastic strain concentration on the upper round region of the pattern. Therefore additional forming processes are required to form a high aspect-ratio pattern. For example, the two additional processes such as a "stretching process using a preform" and a "final forming process" can be done subsequent to the first slitting process. Before the final forming process, a stretching process, which forms an intermediate shape (perform), can make the strain distribution more uniform. Hence, various examples of performs were evaluated by using FEM simulation employing simplified boundary conditions. Finally, experiments involving microscopic and macroscopic observations using the proposed shape of a preform were conducted to characterize the formability of the sheared corrugated pattern. It was found that the numerical simulations are in good agreement with the experimental results.

  1. Dynamic Evolution of Microscopic Hybrid Events

    NASA Astrophysics Data System (ADS)

    Ghaffari, H.; Benson, P. M.

    2014-12-01

    The interactions of water with microscopic defects in porous rock continues to be a long standing challenge in the studying of corresponding emitted acoustic signals. Although different physical aspects of these microscopic events, driven or influenced by water, have been extensively discussed in atomic scale calculations, they have yet to be matched by calibrations or testing on laboratory scale experimentation. For the first time we present new data and analysis of the emitted signals generated during dynamic rock deformation experiments on samples with a well characterised defects. We find that the onset of secondary instability - known as hybrid events -occurs in during a fast healing phase of micro cracking. This leads to a localised and rapid increase of pore water pressure in the damage/process zone, inducing a secondary instability, which is then followed by a fast-locking regime of the microscopic faults (i.e., pulse-like rupture). Furthermore, we show that wet-crackling noise could reveal symmetric to right-handed asymmetry signatures; a distinguished feature from dry-micro defects. Our findings elucidate of the role of water in enhancing the ability of fracture and rupture formation by weakening atomic bonds prior to the main weakening regime, and consequently how ruptures then spread throughout the micro-fault before the fast detachment front (i.e., main fast-slip regime).

  2. HIGH TEMPERATURE MICROSCOPE AND FURNACE

    DOEpatents

    Olson, D.M.

    1961-01-31

    A high-temperature microscope is offered. It has a reflecting optic situated above a molten specimen in a furnace and reflecting the image of the same downward through an inert optic member in the floor of the furnace, a plurality of spaced reflecting plane mirrors defining a reflecting path around the furnace, a standard microscope supported in the path of and forming the end terminus of the light path.

  3. Hydrothermal synthesis of hydroxyapatite plates prepared using low molecular weight heparin (LMWH).

    PubMed

    Rajeswari, A; Kumar, V Ganesh; Karthick, V; Dhas, T Stalin; Potluri, Sri Lakshmi

    2013-11-01

    Materials with enhanced physical and biological properties have been used for biomedical applications and can be developed by functionalizing them using various components. Hydroxyapatite (HAP), among other available synthetic material, serves as one of the best tools in orthopaedics and ceramic coatings. The porous structure of HAP helps in bone cell regeneration, chemical integration of bone and also favours the interaction between bone and tissues. Herein, we have demonstrated a simple procedure for the synthesis of HAP using low molecular weight heparin (LMWH), a structural analogue of bone heparan sulphate proteoglycan. The presence of small sized HAP plates with well-defined structures was revealed using electron microscopic analysis. The phase purity of the synthesized HAP was evaluated using X-ray diffraction pattern obtained before and after immersion in simulated body fluid (SBF). PMID:23871522

  4. A swirl flow evaporative cold plate

    NASA Technical Reports Server (NTRS)

    Niggemann, R. E.; Greenlee, W. J.; Hill, D. G.; Ellis, W.; Marshall, P.

    1985-01-01

    A forced flow evaporative cold plate is under development for future application to the thermal bus concept being pursued by NASA for Space Station Thermal Control. The vaporizer is a swirl-flow device employing a spiral tube coil geometry sandwiched between conductive metal plates upon which electric components could be mounted. This concept is based on the inherent phase separation that occurs in a two phase stream in curvilinear flow. This is a zero 'g' design with one 'g' all-attitude capability and is capable of high heat transfer coefficients, good isothermality, and the ability to function at heat fluxes approaching 5w/sq cm on the cold plates (10w/sq cm on the tube wall) with Freon 114. The advantages of this design over other two phase evaporator approaches are high heat flux capability, simplified control requirements, insensitivity to micro-gravity oscillations, and inexpensive manufacturability. The program included design, fabrication, and test of such a cold plate utilizing an existing test stand developed for two-phase thermal management system (TPTMS) testing. Test results analysis and conclusions are included.

  5. Scanning Miniature Microscopes without Lenses

    NASA Technical Reports Server (NTRS)

    Wang, Yu

    2009-01-01

    The figure schematically depicts some alternative designs of proposed compact, lightweight optoelectronic microscopes that would contain no lenses and would generate magnified video images of specimens. Microscopes of this type were described previously in Miniature Microscope Without Lenses (NPO - 20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43 and Reflective Variants of Miniature Microscope Without Lenses (NPO 20610), NASA Tech Briefs, Vol. 26, No. 9 (September 1999), page 6a. To recapitulate: In the design and construction of a microscope of this type, the focusing optics of a conventional microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. Elimination of focusing optics reduces the size and weight of the instrument and eliminates the need for the time-consuming focusing operation. The microscopes described in the cited prior articles contained two-dimensional CCDs registered with two-dimensional arrays of microchannels and, as such, were designed to produce full two-dimensional images, without need for scanning. The microscopes of the present proposal would contain one-dimensional (line image) CCDs registered with linear arrays of microchannels. In the operation of such a microscope, one would scan a specimen along a line perpendicular to the array axis (in other words, one would scan in pushbroom fashion). One could then synthesize a full two-dimensional image of the specimen from the line-image data acquired at one-pixel increments of position along the scan. In one of the proposed microscopes, a beam of unpolarized light for illuminating the specimen would enter from the side. This light would be reflected down onto the specimen by a nonpolarizing beam splitter attached to the microchannels at their lower ends. A portion of the light incident on the specimen would be reflected upward, through the beam splitter and along the microchannels, to form an image on the CCD. If the

  6. Tectonic Plate Movement.

    ERIC Educational Resources Information Center

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  7. Flat plate solar oven

    SciTech Connect

    Parikh, M.

    1981-01-01

    The construction of an Indian Rs. 186 (US $20.33) flat-plate solar oven is described. Detailed drawings are provided and relevant information on cooking times and temperature for different foods is given.

  8. Plate tectonics: Metamorphic myth

    NASA Astrophysics Data System (ADS)

    Korenaga, Jun

    2016-01-01

    Clear evidence for subduction-induced metamorphism, and thus the operation of plate tectonics on the ancient Earth has been lacking. Theoretical calculations indicate that we may have been looking for something that cannot exist.

  9. Violin plate modes.

    PubMed

    Gough, Colin

    2015-01-01

    As the first step toward developing a generic model for the acoustically radiating vibrational modes of the violin and related instruments, the modes of both freely supported and edge-constrained top and back plates have been investigated as functions of shape, arching height, elastic anisotropy, the f-holes and associated island area, thickness graduations, and the additional boundary constraints of the ribs, soundpost, and bass-bar present in the assembled instrument. Comsol shell structure finite element software has been used as a quasi-experimental tool, with physical and geometric properties varied smoothly, often over several orders of magnitude, allowing the development of the plate modes to be followed continuously from those of an initially square plate to those of doubly-arched, guitar-shaped, orthotropic plates and their dependence on all the above factors. PMID:25618046

  10. Positive battery plate

    NASA Technical Reports Server (NTRS)

    Rowlette, John R. (Inventor)

    1985-01-01

    The power characteristics of a lead acid battery are improved by incorporating a dispersion of 1 to 10% by weight of a thermodynamically stable conductivity additive, such as conductive tin oxide coated glass fibers (34) of filamentary glass wool (42) in the positive active layer (32) carried on the grid (30) of the positive plate (16). Positive plate potential must be kept high enough to prevent reduction of the tin oxide to tin by utilizing an oversized, precharged positive paste.

  11. Fractal multifiber microchannel plates

    NASA Technical Reports Server (NTRS)

    Cook, Lee M.; Feller, W. B.; Kenter, Almus T.; Chappell, Jon H.

    1992-01-01

    The construction and performance of microchannel plates (MCPs) made using fractal tiling mehtods are reviewed. MCPs with 40 mm active areas having near-perfect channel ordering were produced. These plates demonstrated electrical performance characteristics equivalent to conventionally constructed MCPs. These apparently are the first MCPs which have a sufficiently high degree of order to permit single channel addressability. Potential applications for these devices and the prospects for further development are discussed.

  12. Phononic plate waves.

    PubMed

    Wu, Tsung-Tsong; Hsu, Jin-Chen; Sun, Jia-Hong

    2011-10-01

    In the past two decades, phononic crystals (PCs) which consist of periodically arranged media have attracted considerable interest because of the existence of complete frequency band gaps and maneuverable band structures. Recently, Lamb waves in thin plates with PC structures have started to receive increasing attention for their potential applications in filters, resonators, and waveguides. This paper presents a review of recent works related to phononic plate waves which have recently been published by the authors and coworkers. Theoretical and experimental studies of Lamb waves in 2-D PC plate structures are covered. On the theoretical side, analyses of Lamb waves in 2-D PC plates using the plane wave expansion (PWE) method, finite-difference time-domain (FDTD) method, and finite-element (FE) method are addressed. These methods were applied to study the complete band gaps of Lamb waves, characteristics of the propagating and localized wave modes, and behavior of anomalous refraction, called negative refraction, in the PC plates. The theoretical analyses demonstrated the effects of PC-based negative refraction, lens, waveguides, and resonant cavities. We also discuss the influences of geometrical parameters on the guiding and resonance efficiency and on the frequencies of waveguide and cavity modes. On the experimental side, the design and fabrication of a silicon-based Lamb wave resonator which utilizes PC plates as reflective gratings to form the resonant cavity are discussed. The measured results showed significant improvement of the insertion losses and quality factors of the resonators when the PCs were applied. PMID:21989878

  13. The planar jet-plate oscillator

    NASA Astrophysics Data System (ADS)

    Arthurs, David; Ziada, Samir

    2011-01-01

    The aeroacoustic noise generated by a high speed, planar gas jet impinging on a flat plate is investigated experimentally. The jet used in this study is typical of those commonly found in industrial applications such as in various coating control and heat transfer processes. Normal jet impingement on the plate is found to generate strong acoustic tones over a wide range of impingement distances and jet velocities. The characteristics of these tones, as a function of the jet velocity and impingement distance, are quantified. Phase and amplitude measurements of the pressure fluctuations on the impingement plate indicate that the acoustic tones are generated by an antisymmetric instability mode of the jet oscillation. The effect of plate inclination in both the transverse and span-wise directions, with respect to the incident jet, is also studied. The jet-plate tone is found to be much more sensitive to changes in the span-wise plate inclination than to changes in the transverse inclination, but in both cases, a complete suppression of the tone is found to be possible.

  14. Caribbean plate interactions

    SciTech Connect

    Ball, M. )

    1993-02-01

    Vector analysis of plate motions, derived from studies of Atlantic magnetic lineations and fracture zone trends, indicates the following relative movements between the Caribbean, North American, and South American Plates. (1) During Early Jurassic to Early Cretaceous, the North American Plate moved 1900 km westward and 900 km northward relative to the South American Plate. A broad zone including the Caribbean region, i.e., the zone between the North and South America Plates, was a site of left-lateral shear and north-south extension. (2) During Early Cretaceous to Late Cretaceous, the North American Mate moved an additional 1200 km westward relative to South America across this zone. (3) During Late Cretaceous to the end of the Eocene, the North American Plate moved 200 km westward and 400 km northward relative to the South American Plate. (4) From the end of the Eocene to near the end of the Miocene, North America converged on South America some 200 km and moved 100 km eastward relative to it. Through the Mesozoic and earliest Tertiary history of the Caribbean, the region was a shear zone within which left-lateral displacement exceeded 3000 km and north-south extension exceeded 1300 km. In regard to time, 80% of the history of the Caribbean region is one of north-south extension and left-lateral shear. In terms of space, 97% of the shear is left-lateral and the ratio of divergence versus convergence is 7 to 1. Thus, characterizing the Caribbean region, and the Atlantic to its east, as a zone of north-south extension and left-lateral shear, is a fair generalization.

  15. Macroscopic-microscopic mass models

    SciTech Connect

    Nix, J.R.; Moller, P.

    1995-07-01

    We discuss recent developments in macroscopic-microscopic mass models, including the 1992 finite-range droplet model, the 1992 extended- Thomas-Fermi Strutinsky-integral model, and the 1994 Thomas-Fermi model, with particular emphasis on how well they extrapolate to new regions of nuclei. We also address what recent developments in macroscopic-microscopic mass models are teaching us about such physically relevant issues as the nuclear curvature energy, a new congruence energy arising from a greater-than-average overlap of neutron and proton wave functions, the nuclear incompressibility coefficient, and the coulomb redistribution energy arising from a central density depression. We conclude with a brief discussion of the recently discovered rock of metastable superheavy nuclei near {sup 272}110 that had been correctly predicted by macroscopic-microscopic models, along with a possible new tack for reaching an island near {sup 290}110 beyond our present horizon.

  16. High Resolution Neutral Atom Microscope

    NASA Astrophysics Data System (ADS)

    Bucay, Igal; Castillo-Garza, Rodrigo; Stratis, Georgios; Raizen, Mark

    2015-03-01

    We are developing a high resolution neutral atom microscope based on metastable atom electron spectroscopy (MAES). When a metastable atom of a noble gas is near a solid, a surface electron will tunnel to an empty energy level of the metastable atom, thereby ejecting the excited electron from the atom. The emitted electrons carry information regarding the local topography and electronic, magnetic, and chemical structures of most hard materials. Furthermore, using a chromatic aberration corrected magnetic hexapole lens we expect to attain a spatial resolution below 10 nm. We will use this microscope to investigate how local phenomena can give rise to macroscopic effects in materials that cannot be probed using a scanning tunneling microscope, namely insulating transition metal oxides.

  17. Mosaic of Commemorative Microscope Substrate

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Written by electron beam lithography in the Microdevices Laboratory of NASA's Jet Propulsion Laboratory, this Optical Microscope substrate helps the Phoenix Mars Mission science team learn how to assemble individual microscope images into a mosaic by aligning rows of text.

    Each line is about 0.1 millimeter tall, the average thickness of a human hair. Except for the Mogensen twins, the names are of babies born and team members lost during the original development of MECA (the Microscopy, Electrochemistry and Conductivity Analyzer) for the canceled 2001 Mars lander mission. The plaque also acknowledges the MECA 2001 principal investigator, now retired.

    This image was taken by the MECA Optical Microscope on Sol 111, or the 111th day of the Phoenix mission (Sept. 16, 2008).

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by JPL, Pasadena, Calif. Spacecraft development was by Lockheed Martin Space Systems, Denver.

  18. Using Plate Mapping to Examine Portion Size and Plate Composition for Large and Small Divided Plates

    PubMed Central

    Sharp, David E.; Sobal, Jeffery; Wansink, Brian

    2015-01-01

    Does the size of a plate influence the serving of all items equally, or does it influence the serving of some foods – such as meat versus starch versus vegetables – very differently? To examine this, we utilize a promising new plate mapping method where people drew a meal on a paper plate to examine sensitivity to small versus large three-compartment divided plates in portion size and meal composition in a sample of 109 university students. The total drawn meal area was 37% bigger on large plates than small plates, that is, the portion of plate coverage did not differ by plate size. Men and women drew bigger vegetable portions and men drew bigger meat portions on large plates when compared to small plates. These results suggest that men and women are differentially sensitive to plate size for overall meal size and for meal composition. Implications for decreasing portion size and improving meal balance are discussed. PMID:25280373

  19. Spirit Says Goodbye to 'Home Plate'

    NASA Technical Reports Server (NTRS)

    2006-01-01

    For the past several weeks, Spirit has been examining spectacular layered rocks exposed at 'Home Plate.' The rover has been driving around the northern and eastern edges of Home Plate, on the way to 'McCool Hill.' Before departing, Spirit took this image showing some of the most complex layering patterns seen so far at this location.

    The layered nature of these rocks presents new questions for the rover team. In addition to their chemical properties, which scientists can study using Spirit's spectrometers, these rocks record a detailed history of the physical properties that formed them. In the center of this image, one group of layers slopes downward to the right. The layers above and below this group are more nearly horizontal. Where layers of different orientations intersect, other layers are truncated. This indicates that there were complex patterns of alternating erosion and deposition occurring when these layers were being deposited. Similar patterns can be found in some sedimentary rocks on Earth. Physical relationships among the various layers exposed at Home Plate are crucial evidence in understanding how these Martian rocks formed. Scientists suspect that the rocks at Home Plate were formed in the aftermath of a volcanic explosion or impact event, and they are investigating the possibility that wind may also have played a role in redistributing materials after such an event.

    Images like this one from panoramic camera (Pancam), which shows larger-scale layering, as well as those from the microscopic imager, which reveal the individual sand-sized grains that make up these rocks, are essential to understanding the geologic history of Home Plate.

    This view is an approximately true-color rendering that combines separate images taken through the Pancam's 753-nanometer, 535-namometer, and 432-nanometer filters during Spirit's 774th Martian day (March 8, 2006).

  20. Developing a Quantum Electron Microscope

    NASA Astrophysics Data System (ADS)

    Kohstall, Christoph; Klopfer, Brannon; Francis, Josh; Skulason, Gunnar; Juffmann, Thomas; Kasevich, Mark; QEM Team

    2014-03-01

    We develop a new electron microscope based on the interaction-free measurement principle. Such a Quantum Electron Microscope (QEM) may enable imaging of biological samples with radiation doses so small that they are non-lethal. The realization of the QEM will require precise control over the quantum motion of free electrons. On this poster, we discuss our approach to build a QEM including the realization of an electron resonator and an electron amplitude beam-splitter. On top of the QEM application, these developments will advance the electron analogue to photon quantum optics. Funded by the Gordon and Betty Moore Foundation.

  1. Advanced Microscopic Integrated Thermocouple Arrays

    NASA Technical Reports Server (NTRS)

    Pettigrew, Penny J.

    1999-01-01

    The purpose of this research is to develop and refine a technique for making microscopic thermocouple arrays for use in measuring the temperature gradient across a solid-liquid interface during the solidification process. Current thermocouple technology does not allow for real-time measurements across the interface due to the prohibitive size of available thermocouples. Microscopic thermocouple arrays will offer a much greater accuracy and resolution of temperature measurements across the solid-liquid interface which will lead to a better characterization of the solidification process and interface reaction which affect the properties of the resulting material.

  2. Long working distance interference microscope

    DOEpatents

    Sinclair, Michael B.; DeBoer, Maarten P.; Smith, Norman F.

    2004-04-13

    Disclosed is a long working distance interference microscope suitable for three-dimensional imaging and metrology of MEMS devices and test structures on a standard microelectronics probe station. The long working distance of 10-30 mm allows standard probes or probe cards to be used. This enables nanometer-scale 3-D height profiles of MEMS test structures to be acquired across an entire wafer. A well-matched pair of reference/sample objectives is not required, significantly reducing the cost of this microscope, as compared to a Linnik microinterferometer.

  3. Microscopic Materials on a Magnet

    NASA Technical Reports Server (NTRS)

    2008-01-01

    These images show a comparison of the weak magnet OM7 from the Optical Microscope on NASA's Phoenix Mars Lander before (left) and after (right) soil deposition.

    The microscope took the left image during Phoenix's Sol 15 (June 10, 2008) and the right image during Sol 21 (Jun 16, 2008).

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  4. Cadmium plating replacements

    SciTech Connect

    Nelson, M.J.; Groshart, E.C.

    1995-03-01

    The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

  5. Cadmium plating replacements

    NASA Technical Reports Server (NTRS)

    Nelson, Mary J.; Groshart, Earl C.

    1995-01-01

    The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

  6. Recent Opportunity Microscopic Imager Results

    NASA Astrophysics Data System (ADS)

    Herkenhoff, K. E.; Arvidson, R. E.; Jolliff, B. L.; Yingst, R.; Team, A.

    2013-12-01

    Opportunity arrived at exposures of Endeavour crater rim rocks in August 2011, on a hill dubbed 'Cape York.' These rocks have been the goal of exploration by Opportunity for the past few years because spectral evidence for phyllosilicates was observed at this location in orbital remote sensing data. As Opportunity circum¬navigated Cape York, the Microscopic Imager (MI) was used to examine the fine-scale textures of various soils and rocky outcrops. As reported previously, Opportunity discovered multiple bright linear features along the western periphery of Cape York that have been interpreted as veins of Ca sulfate deposited in fractures within the bedrock of Cape York. Opportunity then explored the northern and eastern sides of Cape York, including the area around 'Matijevic Hill' that shows evidence for phyllosilicates in CRISM data acquired from the Mars Reconnaissance Orbiter. One of the first outcrops examined near Matijevic Hill, dubbed 'Kirkwood,' is dominated by millimeter-size spherules. Unlike the hematite-rich concretions observed by Opportunity on Meridiani Planum, the aggregated 'newberries' in the Kirkwood exposure display internal structure and resistant rims. Compositionally, the spherule-rich rock is very similar to a nearby spherule-poor outcrop dubbed 'Whitewater Lake.' Thus these spherules have a more basalt-like composition compared to the hematite-rich concretions of the Burns Formation. The origin of the Kirkwood outcrop is uncertain, but the setting on the rim of the 22-km diameter Endeavour crater suggests that perhaps impact melting was involved in lapilli formation, possibly followed by mobilization and sorting in the ejecta blanket. Alternatively, the newberries may be diagenetic iron oxide concretions that are less well cemented than the 'blueberries' of the younger sulfate-rich Burns Formation. The Whitewater Lake outcrops contain the phyllosilicate phases observed from orbit, and are the oldest materials yet investigated by

  7. The transmission X-ray microscope at BESSY II

    NASA Astrophysics Data System (ADS)

    Guttmann, P.; Niemann, B.; Rehbein, S.; Knöchel, C.; Rudolph, D.; Schmahl, G.

    2003-03-01

    The new transmission X-ray microscope (TXM) at BESSY II is the first one using soft X-rays in the water window region at an undulator beamline. For this, the condenser monochromator has been adapted to the highly collimated X-ray beam of the undulator U41. This is done by using a rotating condenser (RK) which can match the numerical aperture of any micro objective zone plate [1]. The actual setup of the TXM is given in this report. Several beam diagnostic instruments have been incorporated into the beamline and the microscope to adjust the optical elements and to study the behaviour of the complete system. The results of the characterization done so far will be presented as well as first images of applications will be shown.

  8. Advanced methods of microscope control using μManager software

    PubMed Central

    Edelstein, Arthur D.; Tsuchida, Mark A.; Amodaj, Nenad; Pinkard, Henry; Vale, Ronald D.; Stuurman, Nico

    2014-01-01

    μManager is an open-source, cross-platform desktop application, to control a wide variety of motorized microscopes, scientific cameras, stages, illuminators, and other microscope accessories. Since its inception in 2005, μManager has grown to support a wide range of microscopy hardware and is now used by thousands of researchers around the world. The application provides a mature graphical user interface and offers open programming interfaces to facilitate plugins and scripts. Here, we present a guide to using some of the recently added advanced μManager features, including hardware synchronization, simultaneous use of multiple cameras, projection of patterned light onto a specimen, live slide mapping, imaging with multi-well plates, particle localization and tracking, and high-speed imaging. PMID:25606571

  9. Acoustic Plate Mode sensing in liquids based on free and electrically shorted plate surfaces.

    PubMed

    Anisimkin, V I; Caliendo, C; Verona, E

    2016-05-01

    The sensing behavior to liquids for Acoustic Plate Modes (APMs) propagating along 64°Y, 90°X LiNbO3 plate was investigated vs. two electric boundary conditions. The changes in the APMs phase velocity and attenuation were measured upon exposure to different liquids wetting one of the surfaces of the plate, either free or electrically shorted by a thin conductive Al layer. The experimental data confirm that the presence of a metallic layer covering one of the plate surfaces affects the viscosity and temperature sensitivity of the device. The differences between the sensor response for various liquids, with free or metalized faces, are interpreted in terms of the APM polarization. PMID:26901669

  10. Bipolar battery plate

    NASA Technical Reports Server (NTRS)

    Rowlette, John J. (Inventor)

    1987-01-01

    A liquid-impermeable plate (10) having through-plate conductivity with essentially zero resistance comprises an insulator sheet (12) having a series of spaced perforations (14) each of which contains a metal element (16) sealingly received into the perforation (14). A low-cost plate can readily be manufactured by punching a thermoplastic sheet (40) such as polypropylene with a punching tool (52), filling the apertures with led spheres (63) having a diameter smaller than the holes (50) but larger than the thickness of the sheet, sweeping excess spheres (62) off the sheet with a doctor blade (60) and then pressing a heated platen (74) onto the sheet to swage the spheres into a cylindrical shape and melt the surrounding resin to form a liquid-impermeable collar (4) sealing the metal into the sheet.

  11. The Effect of Systemic Delivery of Aminoguanidine versus Doxycycline on the Resorptive Phase of Alveolar Bone Following modified Widman Flap in Diabetic Rats: A Histopathological and Scanning Electron Microscope (SEM) study

    PubMed Central

    Tella, E; Aldahlawi, S; Eldeeb, A; El Gazaerly, H

    2014-01-01

    Objectives Aminoguanidine (guanylhydrazinehydrochloride) is a drug that prevents many of the classical systemic complications of diabetes including diabetic osteopenia through its inhibitory activity on the accumulation of advanced glycation end –products (AGEs). The aim of the present study was to evaluate the effectiveness of aminoguanidine versus doxycycline in reducing alveolar bone resorption following mucoperiosteal flap in diabetic rats, using the conventional histopathology and scanning electron microscope (SEM). Methods Twenty-seven male albino rats were used in this study. Periodontal defects were induced experimentally on lower anterior teeth. All rats were subjected to induction of diabetes, by IV injection of the pancreatic B-cells toxin alloxan monohydrate. After eight weeks following the establishment of periodontal defects in all rats, the ligation was removed and 3 rats were scarified as negative control (group 1). The remaining animals were divided into three group based on treatment applied following mucoperiosteal flap surgery. Group 2 received saline treatment only, group 3 received doxycycline periostat (1.5 mg/kg/day) for 3 weeks, and group 4 received aminoguanidine (7.3 mmol/kg) for 3 weeks. The fasting glucose level was measured weekly post operatively. After 21 days all rats were sacrificed. Three anterior parts of the mandible of each group was prepared for histopathological examination and two parts were prepared for SEM. Results Aminoguanidine treated group (group 4) showed statistically significant increased new bone formation, higher number of osteoblasts and decrease osteoclasts number, resorptive lacunae and existing inflammatory cell infiltration as compared to positive control group (group 2) (P<0.05). Doxycycline was also effective in reducing bone loss as documental by histopathological study. Conclusion The present study showed that aminoguanidine was significantly effective in reducing alveolar bone loss and can modify the

  12. Nitrided Metallic Bipolar Plates

    SciTech Connect

    Brady, Michael P; Tortorelli, Peter F; Pihl, Josh A; Toops, Todd J; More, Karren Leslie; Meyer III, Harry M; Vitek, John Michael; Wang, Heli; Turner, John; Wilson, Mahlon; Garzon, Fernando; Rockward, Tommy; Connors, Dan; Rakowski, Jim; Gervasio, Don

    2008-01-01

    The objectives are: (1) Develop and optimize stainless steel alloys amenable to formation of a protective Cr-nitride surface by gas nitridation, at a sufficiently low cost to meet DOE targets and with sufficient ductility to permit manufacture by stamping. (2) Demonstrate capability of nitridation to yield high-quality stainless steel bipolar plates from thin stamped alloy foils (no significant stamped foil warping or embrittlement). (3) Demonstrate single-cell fuel cell performance of stamped and nitrided alloy foils equivalent to that of machined graphite plates of the same flow-field design ({approx}750-1,000 h, cyclic conditions, to include quantification of metal ion contamination of the membrane electrode assembly [MEA] and contact resistance increase attributable to the bipolar plates). (4) Demonstrate potential for adoption in automotive fuel cell stacks. Thin stamped metallic bipolar plates offer the potential for (1) significantly lower cost than currently-used machined graphite bipolar plates, (2) reduced weight/volume, and (3) better performance and amenability to high volume manufacture than developmental polymer/carbon fiber and graphite composite bipolar plates. However, most metals exhibit inadequate corrosion resistance in proton exchange membrane fuel cell (PEMFC) environments. This behavior leads to high electrical resistance due to the formation of surface oxides and/or contamination of the MEA by metallic ions, both of which can significantly degrade fuel cell performance. Metal nitrides offer electrical conductivities up to an order of magnitude greater than that of graphite and are highly corrosion resistant. Unfortunately, most conventional coating methods (for metal nitrides) are too expensive for PEMFC stack commercialization or tend to leave pinhole defects, which result in accelerated local corrosion and unacceptable performance.

  13. Damping in micro-scale generalized thermoelastic circular plate resonators.

    PubMed

    Sharma, J N; Sharma, R

    2011-04-01

    The out-of-plane vibrations of a generalized thermoelastic circular plate are studied under different environmental temperature, plate dimensions and boundary conditions. The analytical expressions for thermoelastic damping of vibration and phase velocity of circumferential surface wave modes are obtained. It is noticed that the damping of vibrations and phase velocities of circumferential surface wave modes significantly depend on thermal relaxation time in addition to thermoelastic coupling in circular plates under resonance conditions. The surface conditions also impose significant effects on the vibrations of such resonators. The expressions for displacement and temperature fields in the plate resonator are also derived and obtained. Some numerical results have also been presented for illustration purpose in case of silicon material plate. PMID:21168892

  14. Plate-mantle coupling from post-Pangea plate kinematics

    NASA Astrophysics Data System (ADS)

    Zahirovic, Sabin; Dietmar Müller, R.; Seton, Maria; Flament, Nicolas

    2015-04-01

    Convection in the Earth's mantle that involves plates at the surfaces gives rise to plate velocities that vary through time and depend on the balance of plate boundary forces, with the present-day providing a snapshot of this ongoing process. However, present-day plate velocities do not capture plate behaviour over geologically representative timeframes and thus cannot be used to evaluate factors limiting plate velocities. Previous studies investigated the effects of continental keels on plate speeds by either using the present-day snapshot or a limited number of reconstructed plate configurations, often leading to conflicting results. For example, an early assumption was that continental keels (especially cratons) were unlikely to impede fast plate motions because India's velocity approached ~20 cm/yr in the Eocene prior to the collision with Eurasia. We employ a modern plate reconstruction approach with evolving global topological plate boundaries for the post-Pangea timeframe (since 200 Ma) to evaluate factors controlling plate velocities. Plate boundary configurations and plate velocities are extracted from the open-source and cross-platform plate reconstruction package GPlates (www.gplates.org) at 1 Myr intervals. For each plate, at each timestep, the area of continental and cratonic lithosphere is calculated to evaluate the effect on plate velocities. Our results support that oceanic plates tend to be 2-3 times faster than plates with large portion of continental plate area, consistent with predictions of numerical models of mantle convection. The fastest plates (~8.5 cm/yr RMS) are dominated by oceanic plate area and high subducting portion of plate perimeter, while the slowest plates (~2.6-2.8 cm/yr RMS) are dominated by continental plate area and bounded by transforms and mid-oceanic ridge segments. Importantly, increasing cratonic fractions (both Proterozoic and Archean lithosphere) significantly impede plate velocities, suggesting that deep continental

  15. Reduced Plating Ignitron

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A (Inventor); Pearson, J Boise (Inventor)

    2014-01-01

    An ignitron apparatus has an airtight tubular housing having a first sealed end and a second sealed end. An anode is connected at the first sealed end, projecting into the housing, and a recess at the second sealed and forms a well which contains a quantity of liquid gallium or gallium alloy making up the cathode. An ignitor projects through the liquid metal and into the housing. The inner surface of the housing includes at least one plating-reduction structure to prevent electrical shorting of the apparatus caused by plating of the liquid metal.

  16. NICKEL PLATING PROCESS

    DOEpatents

    Hoover, T.B.; Zava, T.E.

    1959-05-12

    A simplified process is presented for plating nickel by the vapor decomposition of nickel carbonyl. In a preferred form of the invention a solid surface is nickel plated by subjecting the surface to contact with a mixture containing by volume approximately 20% nickel carbonyl vapor, 2% hydrogen sulfide and .l% water vapor or 1% oxygen and the remainder carbon dioxide at room temperature until the desired thickness of nickel is obtained. The advantage of this composition over others is that the normally explosive nickel carbonyl is greatly stabilized.

  17. Light-Fueled Microscopic Walkers.

    PubMed

    Zeng, Hao; Wasylczyk, Piotr; Parmeggiani, Camilla; Martella, Daniele; Burresi, Matteo; Wiersma, Diederik Sybolt

    2015-07-01

    The first microscopic artificial walker equipped with liquid-crystalline elastomer muscle is reported. The walker is fabricated by direct laser writing, is smaller than any known living terrestrial creatures, and is capable of several autonomous locomotions on different surfaces. PMID:26033690

  18. Switch on Micro*scope!

    ERIC Educational Resources Information Center

    Roland, Sarah; Bahr, Michele; Olendzenski, Lorraine; Patterson, David J.

    2005-01-01

    Scientists at the Marine Biological Laboratory in Woods Hole, Massachusetts, have created micro*scope, a free, searchable knowledge environment for exploring the microbial world. Microbiology can easily be incorporated into the curriculum, because microbial communities are easy to access. Organisms grow quickly, making certain arrays of…

  19. Toolmaker's Microscope With Video Monitor

    NASA Technical Reports Server (NTRS)

    Ahmed, Arif S.

    1988-01-01

    Display accessories increase resolution and flexibility of use. Toolmaker's microscope equipped with video monitor, auxiliary lighting, and high-resolution readout devices enables noncontacting measurements of tiny slots, indentations, and similar features on parts. Measures places difficult or impossible to reach by mechanical means.

  20. Scanning tunneling microscope nanoetching method

    DOEpatents

    Li, Yun-Zhong; Reifenberger, Ronald G.; Andres, Ronald P.

    1990-01-01

    A method is described for forming uniform nanometer sized depressions on the surface of a conducting substrate. A tunneling tip is used to apply tunneling current density sufficient to vaporize a localized area of the substrate surface. The resulting depressions or craters in the substrate surface can be formed in information encoding patterns readable with a scanning tunneling microscope.

  1. Chasing Meteors With a Microscope.

    ERIC Educational Resources Information Center

    Jones, Richard C.

    1993-01-01

    Describes types of meteors and micrometeorites that enter the Earth's atmosphere. Presents an activity where students collect micrometeorites with a strip of tape in an undisturbed outdoor area. After 24 hours, they examine the tape by sandwiching it between 2 glass slides and view through a microscope at 100X. (PR)

  2. Nature Study with the Microscope.

    ERIC Educational Resources Information Center

    Sollberger, Dwight E.

    1991-01-01

    Identifies specific instruction difficulties, potential problems, solutions, and activities for successful use of microscopes in the classroom. Procedures are outlined for guiding students in creating their own slides with monocotyledon and dicotyledon stems, fern spores, stomata, lichens, and red onions. (MCO)

  3. The microscope in the hatchery

    USGS Publications Warehouse

    Fish, F.F.

    1935-01-01

    Without the aid of the microscope, it is safe to assume that fish Culture would now stand exactly where it did seventy-five years ago when methods of artificial fertilization were first applied. It is also safe to assume that the results from fish culture would be as unsatisfactory as they were at that time when the fishery resources were steadily declining in spite of the increased liberation of advanced fry from the hatcheries. During the past few years the microscope has saved millions of fish in our hatcheries which otherwise would have been sacrificed to disease. Moreover, the microscope has permitted all of the recent work in selective breeding, nutritional requirements, and disease control. This work marks most of the progress fish culture has made during the past twenty-five years. This progress forms the first definite step away from the old system of hatching and distributing fish, a system which was founded by the ancient Chinese. The microscope has been the key which enabled the fish culturist to solve the riddle of success which has stood, unanswered, for 2,500 years.

  4. Curriculum Guidelines for Microscopic Anatomy.

    ERIC Educational Resources Information Center

    Journal of Dental Education, 1993

    1993-01-01

    The American Association of Dental Schools' guidelines for curricula in microscopic anatomy offer an overview of the histology curriculum, note primary educational goals, outline specific content for general and oral histology, suggest prerequisites, and make recommendations for sequencing. Appropriate faculty and facilities are also suggested.…

  5. The Biggest Microscopic Image Ever

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This is a mosaic of four individual frames taken by the microscopic imager that have been very carefully stitched together to reveal the entire 5-centimeter-diameter (almost 2-inch) hole left on the rock dubbed 'Humphrey.' The holes were created by the Mars Exploration Rover Spirit's rock abrasion tool. The mosaic, created on March 7, 2004, is the first of its kind of an abraded surface on Mars, and gave scientists their first ever microscopic imager view of the entire drilled area. While it is easy for the panoramic camera and the navigation cameras to fit an area this size into their field of view, the microscopic imager can only capture a portion of the ground area with each image.

    Scientists are interested in many of the small features on 'Humphrey' uncovered by the rock abrasion tool and made visible by the microscopic imager. The sinuous veins within the rock could be evidence that water was trickling through the material while it was deep underground, whereas the dark 'age spots' in the center of the hole may be crystals of the mineral olivine.

  6. Long working-distance, incoherent light interference microscope

    SciTech Connect

    Sinclair, Michael B.; de Boer, Maarten Pieter; Corwin, Alex David

    2005-06-01

    We describe the design and operation of a long-working-distance, incoherent light interference microscope that has been developed to address the growing demand for new microsystem characterization tools. The design of the new microscope is similar to that of a Linnik interference microscope and thus preserves the full working distance of the long-working-distance objectives utilized. However, in contrast to a traditional Linnik microscope, the new microscope does not rely on the use of matched objectives in the sample and the reference arms of the interferometer. An adjustable optical configuration has been devised that allows the total optical path length, wavefront curvature, and dispersion of the reference arm to be matched to the sample arm of the interferometer. The reference arm configuration can be adjusted to provide matching for 5x, 10x, and 20x long-working-distance objectives in the sample arm. In addition to retaining the full working distance of the sample arm objectives, the new design allows interference images to be acquired in situations in which intervening windows are necessary, such as occur with packaged microsystems, microfluidic devices, and cryogenic, vacuum, or environmental chamber studies of microsystem performance. The interference microscope is compatible with phase-shifting interferometry, vertical scanning interferometry, and stroboscopic measurement of dynamic processes.

  7. Long-working-distance incoherent-light interference microscope

    NASA Astrophysics Data System (ADS)

    Sinclair, Michael B.; de Boer, Maarten P.; Corwin, Alex D.

    2005-12-01

    We describe the design and operation of a long-working-distance, incoherent light interference microscope that has been developed to address the growing demand for new microsystem characterization tools. The design of the new microscope is similar to that of a Linnik interference microscope and thus preserves the full working distance of the long-working-distance objectives utilized. However, in contrast to a traditional Linnik microscope, the new microscope does not rely on the use of matched objectives in the sample and the reference arms of the interferometer. An adjustable optical configuration has been devised that allows the total optical path length, wavefront curvature, and dispersion of the reference arm to be matched to the sample arm of the interferometer. The reference arm configuration can be adjusted to provide matching for 5×, 10×, and 20× long-working-distance objectives in the sample arm. In addition to retaining the full working distance of the sample arm objectives, the new design allows interference images to be acquired in situations in which intervening windows are necessary, such as occur with packaged microsystems, microfluidic devices, and cryogenic, vacuum, or environmental chamber studies of microsystem performance. The interference microscope is compatible with phase-shifting interferometry, vertical scanning interferometry, and stroboscopic measurement of dynamic processes.

  8. On the dip angle of subducting plates

    NASA Technical Reports Server (NTRS)

    Hsui, Albert T.; Tang, Xiao-Ming; Toksoz, M. Nafi

    1990-01-01

    A new approximate analytic model is developed for the thermal structure of a subducting plate with a finite length. This model provides the capability of easily examining the thermal and mechanical structure of a subducting plate with different lengths and at different angles. Also, the torque balance of a descending plate can be examined, and effects such as the leading edge effect, the adiabatic compression effect, and the phase change effect can be incorporated. A comparison with observed data indicates that short slabs are likely under torque equilibrium at present, while long slabs are probably dominated by their gravitational torques such that their dip angles are transient, moving toward a steeper dip angle similar to that of the Mariana slab.

  9. Study of deposition patterns of plating layers in SiC/Cu composites by electro-brush plating

    NASA Astrophysics Data System (ADS)

    Li, Xiangliang; Wang, Xibao; Gao, Rui; Sun, Li

    2011-09-01

    SiC reinforced copper composite coatings were prepared by electro-brush plating with micron-size silicon carbide (SiC) ranging from 1 to 5 μm on pure copper sheet in this paper. The micro-structural characterizations of SiC/Cu composite coatings were performed by optical microscope and Scanning Electron Microscope (SEM) coupled with spectrometer, to study co-deposition mechanism of SiC/Cu. It was found that there were three different patterns of SiC deposition in plating layers during electro-brush plating process, i.e. the particles could deposit inside copper grains, in grain boundaries, or in holes of the surface. To investigate deposition mechanism of each pattern, size of SiC and copper grains was compared. By comparison of size of copper grains and hard particles, SiC were either wrapped in copper grains or deposited in grain boundaries. Moreover, electro-brush plating layers at different brush velocities and current densities were obtained respectively, to analyze the microstructure evolution of the composite coatings. The hardness of plating layers was measured. The results indicated at the current density of 3 A/dm2, the SiC/Cu coating was compact with SiC content at a high level and the hardness reached a maximum.

  10. Heterodyne Interferometry with a Scanning Optical Microscope.

    NASA Astrophysics Data System (ADS)

    Hobbs, Philip Charles Danby

    The design and implementation of a confocal optical microscope which functions as an electronically scanned heterodyne interferometer are described. Theoretical models based on Fourier optics for general samples and on exact series solution of the scalar Helmholtz equation for a class of trench structures are developed and compared with experimental data. Good agreement is obtained. The associated data acquisition system, also described, enables the system to measure both the amplitude (to 12 bits) and the phase (to 0.1^circ) of a returned optical beam, at a continuous rate of 30,000 points per second. The microscope system uses a wide-band tellurium dioxide acousto-optic cell for electronic scanning, frequency shifting, and beam splitting/combining. It uses a stationary reference beam on the sample for vibration cancellation, which results in a system of great vibration immunity. It can measure relief ranging from a few tenths of a micron down to a few Angstroms, and line widths down to well below 0.4 micron, using light of 0.5 micron wavelength. Angstrom resolution can be achieved in a single full-speed scan, without special vibration isolation equipment, providing that folding mirrors are avoided. A signal processing algorithm based on Fourier deconvolution is presented; it takes advantage of the extra bandwidth of a confocal system and the availability of both amplitude and phase, to improve the lateral resolution by approximately a factor of two. Experimental results are shown, which demonstrate phase edge resolution (10%-90%) of 0.45 lambda (raw data), and 0.18 lambda (after filtering), in excellent agreement with the Fourier optics prediction. The exact scalar theory calculates the response of the microscope as it scans over an infinitely long rectangular trench in a plane boundary on which Dirichlet boundary conditions apply. An expansion in cavity modes inside the trench is used to match the field and its derivatives across the mouth of the trench to get

  11. Nuclear reactor alignment plate configuration

    DOEpatents

    Altman, David A; Forsyth, David R; Smith, Richard E; Singleton, Norman R

    2014-01-28

    An alignment plate that is attached to a core barrel of a pressurized water reactor and fits within slots within a top plate of a lower core shroud and upper core plate to maintain lateral alignment of the reactor internals. The alignment plate is connected to the core barrel through two vertically-spaced dowel pins that extend from the outside surface of the core barrel through a reinforcement pad and into corresponding holes in the alignment plate. Additionally, threaded fasteners are inserted around the perimeter of the reinforcement pad and into the alignment plate to further secure the alignment plate to the core barrel. A fillet weld also is deposited around the perimeter of the reinforcement pad. To accomodate thermal growth between the alignment plate and the core barrel, a gap is left above, below and at both sides of one of the dowel pins in the alignment plate holes through with the dowel pins pass.

  12. Light microscopic and electron microscopic histopathology of an iris microhaemangioma.

    PubMed Central

    Meades, K V; Francis, I C; Kappagoda, M B; Filipic, M

    1986-01-01

    A patient who had been observed to have an iris microhaemangioma (capillary haemangioma), confirmed on fluorescein iris angiography, came to cataract surgery. The lesion was excised at the time of surgery and submitted to light and electron microscopic study. It had the features of a hamartoma of the capillary haemangioma type, with its characteristics being specific for vessels seen in iris tissue. Images PMID:3964627

  13. Growth Plate Injuries

    MedlinePlus

    ... or crushed, the growth plate may close prematurely, forming a bony bridge or “bar.” The risk of ... this publication: James S. Panagis, M.D., M.P.H., NIAMS/NIH; R. Tracy Ballock, M.D., Case ...

  14. The Plate Tectonics Project

    ERIC Educational Resources Information Center

    Hein, Annamae J.

    2011-01-01

    The Plate Tectonics Project is a multiday, inquiry-based unit that facilitates students as self-motivated learners. Reliable Web sites are offered to assist with lessons, and a summative rubric is used to facilitate the holistic nature of the project. After each topic (parts of the Earth, continental drift, etc.) is covered, the students will…

  15. INL HIP Plate Fabrication

    SciTech Connect

    B. H. Park; C. R. Clark; J. F. Jue

    2010-02-01

    This document outlines the process used to bond monolithic fuel plates by Hot Isostatic Pressing (HIP). This method was developed at Idaho National Laboratory (INL) for the Reduced Enrichment for Research and Test Reactors (RERTR) program. These foils have been used in a number of irradiation experiments in support of the United States Global Threat Reduction Initiative (GTRI) program.

  16. Unitary plate electrode

    NASA Technical Reports Server (NTRS)

    Rowlette, John J. (Inventor); Clough, Thomas J. (Inventor); Josefowicz, Jack Y. (Inventor); Sibert, John W. (Inventor)

    1985-01-01

    The unitary electrode (10) comprises a porous sheet (12) of fiberglass the strands (14) of which contain a coating (16) of conductive tin oxide. The lower portion of the sheet contains a layer (18) of resin and the upper layer (20) contains lead dioxide forming a positive active electrode on an electrolyte-impervious layer. The strands (14) form a continuous conduction path through both layers (16, 18). Tin oxide is prevented from reduction by coating the surface of the plate facing the negative electrode with a conductive, impervious layer resistant to reduction such as a thin film (130) of lead or graphite filled resin adhered to the plate with a layer (31) of conductive adhesive. The plate (10) can be formed by casting a molten resin from kettle (60) onto a sheet of glass wool (56) overlying a sheet of lead foil and then applying positive active paste from hopper (64) into the upper layer (68). The plate can also be formed by passing an assembly of a sheet ( 80) of resin, a sheet (86) of sintered glass and a sheet (90) of lead between the nip (92) of heated rollers (93, 95) and then filling lead oxide into the pores (116) of the upper layer (118).

  17. The Scanning TMR Microscope for Biosensor Applications.

    PubMed

    Vyas, Kunal N; Love, David M; Ionescu, Adrian; Llandro, Justin; Kollu, Pratap; Mitrelias, Thanos; Holmes, Stuart; Barnes, Crispin H W

    2015-06-01

    We present a novel tunnel magnetoresistance (TMR) scanning microscope set-up capable of quantitatively imaging the magnetic stray field patterns of micron-sized elements in 3D. By incorporating an Anderson loop measurement circuit for impedance matching, we are able to detect magnetoresistance changes of as little as 0.006%/Oe. By 3D rastering a mounted TMR sensor over our magnetic barcodes, we are able to characterize the complex domain structures by displaying the real component, the amplitude and the phase of the sensor's impedance. The modular design, incorporating a TMR sensor with an optical microscope, renders this set-up a versatile platform for studying and imaging immobilised magnetic carriers and barcodes currently employed in biosensor platforms, magnetotactic bacteria and other complex magnetic domain structures of micron-sized entities. The quantitative nature of the instrument and its ability to produce vector maps of magnetic stray fields has the potential to provide significant advantages over other commonly used scanning magnetometry techniques. PMID:25849347

  18. The Scanning TMR Microscope for Biosensor Applications

    PubMed Central

    Vyas, Kunal N.; Love, David M.; Ionescu, Adrian; Llandro, Justin; Kollu, Pratap; Mitrelias, Thanos; Holmes, Stuart; Barnes, Crispin H. W.

    2015-01-01

    We present a novel tunnel magnetoresistance (TMR) scanning microscope set-up capable of quantitatively imaging the magnetic stray field patterns of micron-sized elements in 3D. By incorporating an Anderson loop measurement circuit for impedance matching, we are able to detect magnetoresistance changes of as little as 0.006%/Oe. By 3D rastering a mounted TMR sensor over our magnetic barcodes, we are able to characterise the complex domain structures by displaying the real component, the amplitude and the phase of the sensor’s impedance. The modular design, incorporating a TMR sensor with an optical microscope, renders this set-up a versatile platform for studying and imaging immobilised magnetic carriers and barcodes currently employed in biosensor platforms, magnetotactic bacteria and other complex magnetic domain structures of micron-sized entities. The quantitative nature of the instrument and its ability to produce vector maps of magnetic stray fields has the potential to provide significant advantages over other commonly used scanning magnetometry techniques. PMID:25849347

  19. Nanocarpets for Trapping Microscopic Particles

    NASA Technical Reports Server (NTRS)

    Noca, Flavio; Chen, Fei; Hunt, Brian; Bronikowski, Michael; Hoenk, Michael; Kowalczyk, Robert; Choi, Daniel

    2004-01-01

    Nanocarpets that is, carpets of carbon nanotubes are undergoing development as means of trapping microscopic particles for scientific analysis. Examples of such particles include inorganic particles, pollen, bacteria, and spores. Nanocarpets can be characterized as scaled-down versions of ordinary macroscopic floor carpets, which trap dust and other particulate matter, albeit not purposefully. Nanocarpets can also be characterized as mimicking both the structure and the particle-trapping behavior of ciliated lung epithelia, the carbon nanotubes being analogous to cilia. Carbon nanotubes can easily be chemically functionalized for selective trapping of specific particles of interest. One could, alternatively, use such other three-dimensionally-structured materials as aerogels and activated carbon for the purposeful trapping of microscopic particles. However, nanocarpets offer important advantages over these alternative materials: (1) Nanocarpets are amenable to nonintrusive probing by optical means; and (2) Nanocarpets offer greater surface-to-volume ratios.

  20. Shear Brillouin light scattering microscope.

    PubMed

    Kim, Moonseok; Besner, Sebastien; Ramier, Antoine; Kwok, Sheldon J J; An, Jeesoo; Scarcelli, Giuliano; Yun, Seok Hyun

    2016-01-11

    Brillouin spectroscopy has been used to characterize shear acoustic phonons in materials. However, conventional instruments had slow acquisition times over 10 min per 1 mW of input optical power, and they required two objective lenses to form a 90° scattering geometry necessary for polarization coupling by shear phonons. Here, we demonstrate a confocal Brillouin microscope capable of detecting both shear and longitudinal phonons with improved speeds and with a single objective lens. Brillouin scattering spectra were measured from polycarbonate, fused quartz, and borosilicate in 1-10 s at an optical power level of 10 mW. The elastic constants, phonon mean free path and the ratio of the Pockels coefficients were determined at microscopic resolution. PMID:26832263