Science.gov

Sample records for 32-element head array

  1. Evaluation of the JPL X-band 32 element active array. [for deep space communication

    NASA Technical Reports Server (NTRS)

    Boreham, J. F.; Postal, R. B.; Conroy, B. L.

    1979-01-01

    Tests performed on an X-band 32-element active array are described. Antenna pattern characteristics of the array were tested in its standard operating mode as well as several degraded performance modes, including failures of 1, 2, 3, 4, 8, 16, and 31 elements. Additionally, the array was characterized with the addition of a metallic shroud, and also characterized versus rf drive level and at a single off-axis electronic beamsteered position. Characterization was performed on several of the 3/4-watt, three-stage, X-band solid-state power amplifier modules. The characterization included swept amplitude response, amplitude and phase versus temperature from -20 to +60 C, and intermodulation distortion of selected modules. The array is described and conclusions and recommendations based upon the experience and results achieved are included.

  2. Interferometric Imaging with the 32 Element Murchison Wide-Field Array

    NASA Astrophysics Data System (ADS)

    Ord, S. M.; Mitchell, D. A.; Wayth, R. B.; Greenhill, L. J.; Bernardi, G.; Gleadow, S.; Edgar, R. G.; Clark, M. A.; Allen, G.; Arcus, W.; Benkevitch, L.; Bowman, J. D.; Briggs, F. H.; Bunton, J. D.; Burns, S.; Cappallo, R. J.; Coles, W. A.; Corey, B. E.; deSouza, L.; Doeleman, S. S.; Derome, M.; Deshpande, A.; Emrich, D.; Goeke, R.; Gopalakrishna, M. R.; Herne, D.; Hewitt, J. N.; Kamini, P. A.; Kaplan, D. L.; Kasper, J. C.; Kincaid, B. B.; Kocz, J.; Kowald, E.; Kratzenberg, E.; Kumar, D.; Lonsdale, C. J.; Lynch, M. J.; McWhirter, S. R.; Madhavi, S.; Matejek, M.; Morales, M. F.; Morgan, E.; Oberoi, D.; Pathikulangara, J.; Prabu, T.; Rogers, A. E. E.; Roshi, A.; Salah, J. E.; Schinkel, A.; Udaya Shankar, N.; Srivani, K. S.; Stevens, J.; Tingay, S. J.; Vaccarella, A.; Waterson, M.; Webster, R. L.; Whitney, A. R.; Williams, A.; Williams, C.

    2010-11-01

    The Murchison Wide-Field Array (MWA) is a low-frequency radio telescope, currently under construction, intended to search for the spectral signature of the epoch of reionization (EOR) and to probe the structure of the solar corona. Sited in western Australia, the full MWA will comprise 8192 dipoles grouped into 512 tiles and will be capable of imaging the sky south of 40° declination, from 80 MHz to 300 MHz with an instantaneous field of view that is tens of degrees wide and a resolution of a few arcminutes. A 32 station prototype of the MWA has been recently commissioned and a set of observations has been taken that exercise the whole acquisition and processing pipeline. We present Stokes I, Q, and U images from two ~4 hr integrations of a field 20° wide centered on Pictoris A. These images demonstrate the capacity and stability of a real-time calibration and imaging technique employing the weighted addition of warped snapshots to counter extreme wide-field imaging distortions.

  3. Low-frequency Imaging of Fields at High Galactic Latitude with the Murchison Widefield Array 32 Element Prototype

    NASA Astrophysics Data System (ADS)

    Williams, Christopher L.; Hewitt, Jacqueline N.; Levine, Alan M.; de Oliveira-Costa, Angelica; Bowman, Judd D.; Briggs, Frank H.; Gaensler, B. M.; Hernquist, Lars L.; Mitchell, Daniel A.; Morales, Miguel F.; Sethi, Shiv K.; Subrahmanyan, Ravi; Sadler, Elaine M.; Arcus, Wayne; Barnes, David G.; Bernardi, Gianni; Bunton, John D.; Cappallo, Roger C.; Crosse, Brian W.; Corey, Brian E.; Deshpande, Avinash; deSouza, Ludi; Emrich, David; Goeke, Robert F.; Greenhill, Lincoln J.; Hazelton, Bryna J.; Herne, David; Kaplan, David L.; Kasper, Justin C.; Kincaid, Barton B.; Koenig, Ronald; Kratzenberg, Eric; Lonsdale, Colin J.; Lynch, Mervyn J.; McWhirter, S. Russell; Morgan, Edward H.; Oberoi, Divya; Ord, Stephen M.; Pathikulangara, Joseph; Prabu, Thiagaraj; Remillard, Ronald A.; Rogers, Alan E. E.; Anish Roshi, D.; Salah, Joseph E.; Sault, Robert J.; Udaya Shankar, N.; Srivani, K. S.; Stevens, Jamie B.; Tingay, Steven J.; Wayth, Randall B.; Waterson, Mark; Webster, Rachel L.; Whitney, Alan R.; Williams, Andrew J.; Wyithe, J. Stuart B.

    2012-08-01

    The Murchison Widefield Array (MWA) is a new low-frequency, wide-field-of-view radio interferometer under development at the Murchison Radio-astronomy Observatory in Western Australia. We have used a 32 element MWA prototype interferometer (MWA-32T) to observe two 50° diameter fields in the southern sky, covering a total of ~2700 deg2, in order to evaluate the performance of the MWA-32T, to develop techniques for epoch of reionization experiments, and to make measurements of astronomical foregrounds. We developed a calibration and imaging pipeline for the MWA-32T, and used it to produce ~15' angular resolution maps of the two fields in the 110-200 MHz band. We perform a blind source extraction using these confusion-limited images, and detect 655 sources at high significance with an additional 871 lower significance source candidates. We compare these sources with existing low-frequency radio surveys in order to assess the MWA-32T system performance, wide-field analysis algorithms, and catalog quality. Our source catalog is found to agree well with existing low-frequency surveys in these regions of the sky and with statistical distributions of point sources derived from Northern Hemisphere surveys; it represents one of the deepest surveys to date of this sky field in the 110-200 MHz band.

  4. LOW-FREQUENCY IMAGING OF FIELDS AT HIGH GALACTIC LATITUDE WITH THE MURCHISON WIDEFIELD ARRAY 32 ELEMENT PROTOTYPE

    SciTech Connect

    Williams, Christopher L.; Hewitt, Jacqueline N.; Levine, Alan M.; De Oliveira-Costa, Angelica; Hernquist, Lars L.; Bernardi, Gianni; Bowman, Judd D.; Briggs, Frank H.; Gaensler, B. M.; Mitchell, Daniel A.; Subrahmanyan, Ravi; Sadler, Elaine M.; Morales, Miguel F.; Sethi, Shiv K.; Arcus, Wayne; Crosse, Brian W.; Barnes, David G.; Bunton, John D.; Cappallo, Roger C.; Corey, Brian E.; and others

    2012-08-10

    The Murchison Widefield Array (MWA) is a new low-frequency, wide-field-of-view radio interferometer under development at the Murchison Radio-astronomy Observatory in Western Australia. We have used a 32 element MWA prototype interferometer (MWA-32T) to observe two 50 Degree-Sign diameter fields in the southern sky, covering a total of {approx}2700 deg{sup 2}, in order to evaluate the performance of the MWA-32T, to develop techniques for epoch of reionization experiments, and to make measurements of astronomical foregrounds. We developed a calibration and imaging pipeline for the MWA-32T, and used it to produce {approx}15' angular resolution maps of the two fields in the 110-200 MHz band. We perform a blind source extraction using these confusion-limited images, and detect 655 sources at high significance with an additional 871 lower significance source candidates. We compare these sources with existing low-frequency radio surveys in order to assess the MWA-32T system performance, wide-field analysis algorithms, and catalog quality. Our source catalog is found to agree well with existing low-frequency surveys in these regions of the sky and with statistical distributions of point sources derived from Northern Hemisphere surveys; it represents one of the deepest surveys to date of this sky field in the 110-200 MHz band.

  5. A 189 MHz, 2400 deg{sup 2} POLARIZATION SURVEY WITH THE MURCHISON WIDEFIELD ARRAY 32-ELEMENT PROTOTYPE

    SciTech Connect

    Bernardi, G.; Greenhill, L. J.; De Oliveira-Costa, A.; Mitchell, D. A.; Ord, S. M.; Arcus, W.; Arora, B. S.; Hazelton, B. J.; Morales, M. F.; Gaensler, B. M.; Subrahmanyan, R.; Wayth, R. B.; Lenc, E.; Briggs, F. H.; Shankar, N. Udaya; Williams, C. L.; Barnes, D. G.; Bowman, J. D.; Bunton, J. D.; Cappallo, R. J.; and others

    2013-07-10

    We present a Stokes I, Q and U survey at 189 MHz with the Murchison Widefield Array 32 element prototype covering 2400 deg{sup 2}. The survey has a 15.6 arcmin angular resolution and achieves a noise level of 15 mJy beam{sup -1}. We demonstrate a novel interferometric data analysis that involves calibration of drift scan data, integration through the co-addition of warped snapshot images, and deconvolution of the point-spread function through forward modeling. We present a point source catalog down to a flux limit of 4 Jy. We detect polarization from only one of the sources, PMN J0351-2744, at a level of 1.8% {+-} 0.4%, whereas the remaining sources have a polarization fraction below 2%. Compared to a reported average value of 7% at 1.4 GHz, the polarization fraction of compact sources significantly decreases at low frequencies. We find a wealth of diffuse polarized emission across a large area of the survey with a maximum peak of {approx}13 K, primarily with positive rotation measure values smaller than +10 rad m{sup -2}. The small values observed indicate that the emission is likely to have a local origin (closer than a few hundred parsecs). There is a large sky area at {alpha} {>=} 2{sup h}30{sup m} where the diffuse polarized emission rms is fainter than 1 K. Within this area of low Galactic polarization we characterize the foreground properties in a cold sky patch at ({alpha}, {delta}) = (4{sup h}, -27. Degree-Sign 6) in terms of three-dimensional power spectra.

  6. Rapid Volumetric MRI Using Parallel Imaging With Order-of-Magnitude Accelerations and a 32-Element RF Coil Array: Feasibility and Implications1

    PubMed Central

    Sodickson, Daniel K.; Hardy, Christopher J.; Zhu, Yudong; Giaquinto, Randy O.; Gross, Patrick; Kenwood, Gontran; Niendorf, Thoralf; Lejay, Hubert; McKenzie, Charles A.; Ohliger, Michael A.; Grant, Aaron K.; Rofsky, Neil M.

    2007-01-01

    Rationale and Objectives Many clinical applications of Magnetic Resonance Imaging are constrained by basic limits on imaging speed. Parallel MRI relaxes these limits by using the sensitivity patterns of arrays of radiofrequency receiver coils to encode spatial information in a manner complementary to traditional encoding with magnetic field gradients. Until now, parallel MRI has been used to achieve modest improvements in imaging speed; order-of-magnitude improvements have been elusive given fundamental losses in signal-to-noise ratio. The goal of this work was to demonstrate that, with appropriate hardware and careful SNR management, rapid volumetric imaging at high accelerations is in fact feasible. Materials and Methods Contrast-enhanced MRI with an axial 3D spoiled gradient echo imaging sequence was performed in healthy adult subjects using a 32-element RF coil array and a prototype 32-channel MR imaging system. Large imaging volumes were prescribed, in place of traditional limited slabs targeted only to suspect regions. Results As much as 16-fold net accelerations of imaging were achieved repeatably using this approach. The use of large 3D volumes allowed comprehensive anatomical coverage at clinically useful spatial and/or temporal resolution. The need for careful, time-consuming, and subject-specific scan prescription was also eliminated. Conclusion The highly parallel imaging approach presented here allows previously inaccessible volumetric coverage for time-sensitive MRI examinations such as contrast-enhanced MRA, and simultaneously provides a substantially simplified imaging paradigm. The resulting capability for rapid volumetric imaging promises to combine the strengths of MRI with some of the advantages of alternative imaging modalities such as multidetector CT. PMID:15866137

  7. Batch-processed close-track array heads (abstract)

    NASA Astrophysics Data System (ADS)

    Tang, D. D.; Santini, H.; Lee, R. E.; Ju, K.; Krounbi, M.

    1997-04-01

    This article describes novel array heads for close packed track recording. The heads are batch fabricated on wafers in a linear fashion (Fig. 1). These 60-turn thin-film inductive heads are designed with 6 μm pitch helical coils and planar side-by-side P1/G/P2 yoke structures. The linear head array is placed along the upstream-to-downstream direction of the track. By skewing the array slightly off the track direction, each head of the array aligns to an individual track (Fig. 2). In this case, the track pitch is about 5 μm, which is the yoke height. With this head arrangement, even though thermal expansion causes the head-to-head distance to increase along the upstream-downstream direction, it does not cause a thermally induced track misregistration problem. The increased head-to-head distance only affects the timing of signals between tracks, which can be compensated by the channel electronics. Thus, the thermally induced track misregistration problem is eliminated using this design. The guardbands between tracks are not necessary and a close-packed track recording is possible. A state of the art head impedance of the 60-turn head is obtained: 11 Ω and 0.40 μH. The gap-to-gap pitch is 100 μm. The overall head-to-head isolation is greater than 50 dB at 10 MHz. Such a large isolation is realized by suppressing the capacitive coupling between lead wires using a ground plane and grounded wall structures. The tight winding of the helical coils reduces the magnetic coupling between the heads.

  8. Head Mounted Display with a Roof Mirror Array Fold

    NASA Technical Reports Server (NTRS)

    Olczak, Eugene (Inventor)

    2014-01-01

    The present invention includes a head mounted display (HMD) worn by a user. The HMD includes a display projecting an image through an optical lens. The HMD also includes a one-dimensional retro reflective array receiving the image through the optical lens at a first angle with respect to the display and deflecting the image at a second angle different than the first angle with respect to the display. The one-dimensional retro reflective array reflects the image in order to project the image onto an eye of the user.

  9. A micro-SPM head array with exchangeable cantilevers

    NASA Astrophysics Data System (ADS)

    Gao, S.; Wolff, H.; Herrmann, K.; Brand, U.; Hiller, K.; Hahn, S.; Sorger, A.; Mehner, J.

    2012-04-01

    In this paper a MEMS based micro-SPM head array is proposed to enhance the performance of the currently available nano-measuring machines and effectively reduce the measurement time for large specimen. It consists of 1 × N ( N = 7 in our case) micro-SPM heads/units, realized in one chip by MEMS technique. And it can be easily extended to a micro- SPM head matrix. The main part of the micro-SPM head is the MEMS-positioning stage, which is realized on the basis of an electrostatic lateral comb-drive actuator. In order to take the advantage of the high lateral resolution of conventional cantilevers, a flexible cantilever gripper was designed to be integrated into the MEMS-positioning stage within the SPM head. Conventional cantilevers can be mechanically mounted onto the MEMS-positioning stage or dismantled from the MEMS-positioning stage after the tip is worn out. In this way, the well-designed and calibrated MEMS-positioning stage can be repeatedly and efficiently utilized. The structure design and simulation of mechanical and electrical performances of the mico-SPM head will be detailed in this paper. First experimental results proved the feasibility of the cantilever gripper design.

  10. Integrated titer plate-injector head for microdrop array preparation, storage and transfer

    DOEpatents

    Swierkowski, Stefan P.

    2000-01-01

    An integrated titer plate-injector head for preparing and storing two-dimensional (2-D) arrays of microdrops and for ejecting part or all of the microdrops and inserting same precisely into 2-D arrays of deposition sites with micrometer precision. The titer plate-injector head includes integrated precision formed nozzles with appropriate hydrophobic surface features and evaporative constraints. A reusable pressure head with a pressure equalizing feature is added to the titer plate to perform simultaneous precision sample ejection. The titer plate-injector head may be utilized in various applications including capillary electrophoresis, chemical flow injection analysis, microsample array preparation, etc.

  11. A micro-SPM head array for large-scale topography measurement

    NASA Astrophysics Data System (ADS)

    Gao, S.; Li, Z.; Herrmann, K.

    2010-05-01

    Rapid advances in nano-positioning/motion technology have offered metrologists in the field of precision engineering larger and larger potential measurement range. A concept of micro-SPM head array is proposed in this paper to enhance the performance of the currently available nano-measuring machines and effectively reduce the measurement time for large specimen. The proposed micro-SPM head array consists of 1 × N ( N = 7 in our case) micro-SPM heads/units, which are realized in one chip by MEMS technique. The kern of each SPM head is an electrostatic comb-drive actuator, whose main shaft protrudes out of the MEMS chip to sense the surface topography of a specimen under test. To further improve the lateral resolution of the micro-SPM head, an AFM tip can then be mounted onto the end of the actuator's main shaft. To ensure the traceability of the measurement results from micro-SPM head, a fiber-based interferometer array is considered to be integrated within the micro-SPM head array so as to in-situ calibrate the in-plane displacement sensing system of the micro-SPM head. Design and simulation of the mico-SPM head array together with the corresponding micro-interferometer will be detailed in this manuscript.

  12. A 32-Channel Head Coil Array with Circularly Symmetric Geometry for Accelerated Human Brain Imaging.

    PubMed

    Chu, Ying-Hua; Hsu, Yi-Cheng; Keil, Boris; Kuo, Wen-Jui; Lin, Fa-Hsuan

    2016-01-01

    The goal of this study is to optimize a 32-channel head coil array for accelerated 3T human brain proton MRI using either a Cartesian or a radial k-space trajectory. Coils had curved trapezoidal shapes and were arranged in a circular symmetry (CS) geometry. Coils were optimally overlapped to reduce mutual inductance. Low-noise pre-amplifiers were used to further decouple between coils. The SNR and noise amplification in accelerated imaging were compared to results from a head coil array with a soccer-ball (SB) geometry. The maximal SNR in the CS array was about 120% (1070 vs. 892) and 62% (303 vs. 488) of the SB array at the periphery and the center of the FOV on a transverse plane, respectively. In one-dimensional 4-fold acceleration, the CS array has higher averaged SNR than the SB array across the whole FOV. Compared to the SB array, the CS array has a smaller g-factor at head periphery in all accelerated acquisitions. Reconstructed images using a radial k-space trajectory show that the CS array has a smaller error than the SB array in 2- to 5-fold accelerations. PMID:26909652

  13. A 32-Channel Head Coil Array with Circularly Symmetric Geometry for Accelerated Human Brain Imaging

    PubMed Central

    Chu, Ying-Hua; Hsu, Yi-Cheng; Keil, Boris; Kuo, Wen-Jui; Lin, Fa-Hsuan

    2016-01-01

    The goal of this study is to optimize a 32-channel head coil array for accelerated 3T human brain proton MRI using either a Cartesian or a radial k-space trajectory. Coils had curved trapezoidal shapes and were arranged in a circular symmetry (CS) geometry. Coils were optimally overlapped to reduce mutual inductance. Low-noise pre-amplifiers were used to further decouple between coils. The SNR and noise amplification in accelerated imaging were compared to results from a head coil array with a soccer-ball (SB) geometry. The maximal SNR in the CS array was about 120% (1070 vs. 892) and 62% (303 vs. 488) of the SB array at the periphery and the center of the FOV on a transverse plane, respectively. In one-dimensional 4-fold acceleration, the CS array has higher averaged SNR than the SB array across the whole FOV. Compared to the SB array, the CS array has a smaller g-factor at head periphery in all accelerated acquisitions. Reconstructed images using a radial k-space trajectory show that the CS array has a smaller error than the SB array in 2- to 5-fold accelerations. PMID:26909652

  14. Head-up display using an inclined Al2O3 column array.

    PubMed

    Cho, Wen-Hao; Lee, Chao-Te; Kei, Chi-Chung; Liao, Bo-Huei; Chiang, Donyau; Lee, Cheng-Chung

    2014-02-01

    An orderly inclined Al2O3 column array was fabricated by atomic layer deposition and sequential electron beam evaporation using a hollow nanosphere template. The transmittance spectra at various angles of incidence were obtained through the use of a Perkin-Elmer Lambda 900 UV/VIS/NIR spectrometer. The inclined column array could display the image information through a scattering mechanism and was transparent at high viewing angles along the deposition plane. This characteristic of the inclined column array gives it potential for applications in head-up displays in the automotive industry. PMID:24514203

  15. Hybrid monopole/loop coil array for human head MR imaging at 7T

    PubMed Central

    Yan, Xinqiang; Wei, Long; Xue, Rong; Zhang, Xiaoliang

    2015-01-01

    The monopole coil and loop coil have orthogonal radiofrequency (RF) fields and thus are intrinsically decoupled electromagnetically if they are laid out appropriately. In this study, we proposed a hybrid monopole/loop technique which could combine the advantages of both loop arrays and monopole arrays. To investigate this technique, a hybrid RF coil array containing 4 monopole channels and 4 loop channels was developed for human head MR imaging at 7T. In vivo MR imaging and g-factor results using monopole-only channels, loop-only channels and all channels of the hybrid array were acquired and evaluated. Compared with the monopole-only and loop-only channels, the proposed hybrid array has higher SNR and better parallel imaging performance. Sufficient electromagnetic decoupling and diverse RF magnetic field (B1) distributions of monopole channels and loop channels may contribute to this performance improvement. From experimental results, the hybrid monopole/loop array has low g-factor and excellent SNR at both periphery and center of the brain, which is valuable for human head imaging at ultrahigh fields. PMID:26120252

  16. Skew angle effects in shingled magnetic recording system with double/triple reader head array

    NASA Astrophysics Data System (ADS)

    Elidrissi, Moulay Rachid; Sann Chan, Kheong; Greaves, Simon; Kanai, Yasushi; Muraoka, Hiroaki

    2014-05-01

    Shingled Magnetic Recording (SMR) is a scheme used to extend the life of the current perpendicular magnetic recording technology. SMR enables writing narrow tracks with a wide writer. Currently, SMR employs a single reader and will suffer inter-track interference (ITI) as the tracks become comparable in width to the reader. ITI can be mitigated by using narrower readers; however, narrower readers suffer from increased reader noise. Another approach to combat ITI is to process 2D readback and use ITI cancellation schemes to retrieve the data track. Multiple readbacks can be obtained either with a single reader and multiple revolutions or with a reader array. The former suffers from increased readback latency. In this work, we focus on the latter. When using a reader array, the skew angle poses major challenges. During writing, there is increased adjacent track erasure, and during readback the effective reader pitch varies and there is an increase in the 2D intersymbol interference caused by the rotated reader profile. In this work, we run micromagnetic simulations at different skew angles to train the grain flipping probability model, and then evaluate raw bit channel error rate performance at skew. In particular, we investigate the performance degradation caused by skewing of the 2 or 3 read head array for various read-head geometries.

  17. A comparison of headnet electrode arrays for electrical impedance tomography of the human head.

    PubMed

    Tidswell, A T; Bagshaw, A P; Holder, D S; Yerworth, R J; Eadie, L; Murray, S; Morgan, L; Bayford, R H

    2003-05-01

    Three types of commercially available headnet electrode arrays, designed for use in EEG, and conventional EEG Ag/AgCl cup electrodes were tested on human subjects, and a realistic, saline-filled head-shaped tank was prepared with vegetable skin to simulate human skin in order to determine the optimum electrode system for electrical impedance tomography (EIT) of the human head. Impedance changes during EIT acquisition were produced in healthy volunteers during a finger-thumb apposition task and in tanks by the insertion of a Perspex rod. Signal-to-baseline noise, measured from raw EIT data, was 2.3 +/- 0.3 and 2.3 +/- 0.2 for the human and tank data, respectively. In both the human and tank experiments, a commercial hydrogel elasticated electrode headnet produced the least amount of baseline noise, and was the only headnet in the human data with noise levels acceptable for EIT imaging. Image quality measured in the tank was similar for most of the headnets tested, except that the EEG electrodes produced a higher positional error and electrodes in a geodesic elasticated net produced images with worse subjective image quality. Overall, the hydrogel elasticated headnet was judged to be the most suitable for human neuroimaging with EIT. PMID:12812436

  18. Performance evaluation of a novel high performance pinhole array detector module using NEMA NU-4 image quality phantom for four head SPECT Imaging

    NASA Astrophysics Data System (ADS)

    Rahman, Tasneem; Tahtali, Murat; Pickering, Mark R.

    2015-03-01

    Radiolabeled tracer distribution imaging of gamma rays using pinhole collimation is considered promising for small animal imaging. The recent availability of various radiolabeled tracers has enhanced the field of diagnostic study and is simultaneously creating demand for high resolution imaging devices. This paper presents analyses to represent the optimized parameters of a high performance pinhole array detector module using two different characteristics phantoms. Monte Carlo simulations using the Geant4 application for tomographic emission (GATE) were executed to assess the performance of a four head SPECT system incorporated with pinhole array collimators. The system is based on a pixelated array of NaI(Tl) crystals coupled to an array of position sensitive photomultiplier tubes (PSPMTs). The detector module was simulated to have 48 mm by 48 mm active area along with different pinhole apertures on a tungsten plate. The performance of this system has been evaluated using a uniform shape cylindrical water phantom along with NEMA NU-4 image quality (IQ) phantom filled with 99mTc labeled radiotracers. SPECT images were reconstructed where activity distribution is expected to be well visualized. This system offers the combination of an excellent intrinsic spatial resolution, good sensitivity and signal-to-noise ratio along with high detection efficiency over an energy range between 20-160 keV. Increasing number of heads in a stationary system configuration offers increased sensitivity at a spatial resolution similar to that obtained with the current SPECT system design with four heads.

  19. Head-to-Head Comparison of Ultra-High-Performance Liquid Chromatography with Diode Array Detection versus Quantitative Nuclear Magnetic Resonance for the Quantitative Analysis of the Silymarin Complex in Silybum marianum Fruit Extracts.

    PubMed

    Cheilari, Antigoni; Sturm, Sonja; Intelmann, Daniel; Seger, Christoph; Stuppner, Hermann

    2016-02-24

    Quantitative nuclear magnetic resonance (qNMR) spectroscopy is known as an excellent alternative to chromatography-based mixture analysis. NMR spectroscopy is a non-destructive method, needs only limited sample preparation, and can be readily automated. A head-to-head comparison of qNMR to an ultra-high-performance liquid chromatography with diode array detection (uHPLC-DAD)-based quantitative analysis of six flavonolignan congeners (silychristin, silydianin, silybin A, silybin B, isosilybin A, and isosilybin B) of the Silybum marianum silymarin complex is presented. Both assays showed similar performance characteristics (linear range, accuracy, precision, and limits of quantitation) with analysis times below 30 min/sample. The assays were applied to industrial S. marianum extracts (AC samples) and to extracts locally prepared from S. marianum fruits (PL samples). An assay comparison by Bland-Altman plots (relative method bias AC samples, -0.1%; 2SD range, ±5.1%; relative method bias PL samples, -0.3%; 2SD range, ±7.8%) and Passing-Bablok regression analysis (slope and intercept for AC and PL samples not significantly different from 1.00 and 0.00, respectively; Spearman's coefficient of rank correlation, >0.99) did show that qNMR and uHPLC-DAD can be used interchangeably to quantitate flavonolignans in the silymarin complex. PMID:26806429

  20. Exon array analysis of head and neck cancers identifies a hypoxia related splice variant of LAMA3 associated with a poor prognosis.

    PubMed

    Moller-Levet, Carla S; Betts, Guy N J; Harris, Adrian L; Homer, Jarrod J; West, Catharine M L; Miller, Crispin J

    2009-11-01

    The identification of alternatively spliced transcript variants specific to particular biological processes in tumours should increase our understanding of cancer. Hypoxia is an important factor in cancer biology, and associated splice variants may present new markers to help with planning treatment. A method was developed to analyse alternative splicing in exon array data, using probeset multiplicity to identify genes with changes in expression across their loci, and a combination of the splicing index and a new metric based on the variation of reliability weighted fold changes to detect changes in the splicing patterns. The approach was validated on a cancer/normal sample dataset in which alternative splicing events had been confirmed using RT-PCR. We then analysed ten head and neck squamous cell carcinomas using exon arrays and identified differentially expressed splice variants in five samples with high versus five with low levels of hypoxia-associated genes. The analysis identified a splice variant of LAMA3 (Laminin alpha 3), LAMA3-A, known to be involved in tumour cell invasion and progression. The full-length transcript of the gene (LAMA3-B) did not appear to be hypoxia-associated. The results were confirmed using qualitative RT-PCR. In a series of 59 prospectively collected head and neck tumours, expression of LAMA3-A had prognostic significance whereas LAMA3-B did not. This work illustrates the potential for alternatively spliced transcripts to act as biomarkers of disease prognosis with improved specificity for particular tissues or conditions over assays which do not discriminate between splice variants. PMID:19936049

  1. Genomic Alteration in Head and Neck Squamous Cell Carcinoma (HNSCC) Cell Lines Inferred from Karyotyping, Molecular Cytogenetics, and Array Comparative Genomic Hybridization.

    PubMed

    Singchat, Worapong; Hitakomate, Ekarat; Rerkarmnuaychoke, Budsaba; Suntronpong, Aorarat; Fu, Beiyuan; Bodhisuwan, Winai; Peyachoknagul, Surin; Yang, Fengtang; Koontongkaew, Sittichai; Srikulnath, Kornsorn

    2016-01-01

    Genomic alteration in head and neck squamous cell carcinoma (HNSCC) was studied in two cell line pairs (HN30-HN31 and HN4-HN12) using conventional C-banding, multiplex fluorescence in situ hybridization (M-FISH), and array comparative genomic hybridization (array CGH). HN30 and HN4 were derived from primary lesions in the pharynx and base of tongue, respectively, and HN31 and HN12 were derived from lymph-node metastatic lesions belonging to the same patients. Gain of chromosome 1, 7, and 11 were shared in almost all cell lines. Hierarchical clustering revealed that HN31 was closely related to HN4, which shared eight chromosome alteration cases. Large C-positive heterochromatins were found in the centromeric region of chromosome 9 in HN31 and HN4, which suggests complex structural amplification of the repetitive sequence. Array CGH revealed amplification of 7p22.3p11.2, 8q11.23q12.1, and 14q32.33 in all cell lines involved with tumorigenesis and inflammation genes. The amplification of 2p21 (SIX3), 11p15.5 (H19), and 11q21q22.3 (MAML2, PGR, TRPC6, and MMP family) regions, and deletion of 9p23 (PTPRD) and 16q23.1 (WWOX) regions were identified in HN31 and HN12. Interestingly, partial loss of PTPRD (9p23) and WWOX (16q23.1) genes was identified in HN31 and HN12, and the level of gene expression tended to be the down-regulation of PTPRD, with no detectable expression of the WWOX gene. This suggests that the scarcity of PTPRD and WWOX genes might have played an important role in progression of HNSCC, and could be considered as a target for cancer therapy or a biomarker in molecular pathology. PMID:27501229

  2. Genomic Alteration in Head and Neck Squamous Cell Carcinoma (HNSCC) Cell Lines Inferred from Karyotyping, Molecular Cytogenetics, and Array Comparative Genomic Hybridization

    PubMed Central

    Rerkarmnuaychoke, Budsaba; Suntronpong, Aorarat; Fu, Beiyuan; Bodhisuwan, Winai; Peyachoknagul, Surin; Yang, Fengtang; Koontongkaew, Sittichai; Srikulnath, Kornsorn

    2016-01-01

    Genomic alteration in head and neck squamous cell carcinoma (HNSCC) was studied in two cell line pairs (HN30-HN31 and HN4-HN12) using conventional C-banding, multiplex fluorescence in situ hybridization (M-FISH), and array comparative genomic hybridization (array CGH). HN30 and HN4 were derived from primary lesions in the pharynx and base of tongue, respectively, and HN31 and HN12 were derived from lymph-node metastatic lesions belonging to the same patients. Gain of chromosome 1, 7, and 11 were shared in almost all cell lines. Hierarchical clustering revealed that HN31 was closely related to HN4, which shared eight chromosome alteration cases. Large C-positive heterochromatins were found in the centromeric region of chromosome 9 in HN31 and HN4, which suggests complex structural amplification of the repetitive sequence. Array CGH revealed amplification of 7p22.3p11.2, 8q11.23q12.1, and 14q32.33 in all cell lines involved with tumorigenesis and inflammation genes. The amplification of 2p21 (SIX3), 11p15.5 (H19), and 11q21q22.3 (MAML2, PGR, TRPC6, and MMP family) regions, and deletion of 9p23 (PTPRD) and 16q23.1 (WWOX) regions were identified in HN31 and HN12. Interestingly, partial loss of PTPRD (9p23) and WWOX (16q23.1) genes was identified in HN31 and HN12, and the level of gene expression tended to be the down-regulation of PTPRD, with no detectable expression of the WWOX gene. This suggests that the scarcity of PTPRD and WWOX genes might have played an important role in progression of HNSCC, and could be considered as a target for cancer therapy or a biomarker in molecular pathology. PMID:27501229

  3. Limits on the Polarized Power Spectrum at 126 and 164 MHz from PAPER South Africa 32-Element Data

    NASA Astrophysics Data System (ADS)

    Aguirre, James E.; Moore, David; Paper Collaboration

    2015-01-01

    Faraday-rotated, polarized emission represents a potential contaminating foreground for measurements of the highly redshifted 21 cm power spectrum. There are few existing measurements of polarized foreground emission at meter wavelengths (e.g. Bernardi et al 2013, Jelic et al 2014) and its actual effect on the measured Stokes I spectrum from reionization is unclear. We present new limits on the power spectrum of Stokes Q, U, and V emission at 126 and 164 MHz using PAPER South Africa 32-element data, to supplement existing results for Stokes I (Parsons et al 2014, Jacobs et al 2014). We use upper limits on the Q power spectra to place upper limits on the average polarization fraction of point sources.

  4. Quantitative Analysis of the Head Scatter and Jaw Transmission Correction Factor for Commissioning of Enhanced Dynamic Wedge Fields Using a MapCHECK 2 Diode Array

    NASA Astrophysics Data System (ADS)

    Dickerson, Edward C.

    Quality assurance in radiation oncology treatment planning requires independent verification of dose to be delivered to a patient through "second check" calculations for simple plans as well as planar dose fluence measurements for more complex treatments, such as intensity modulated radiation treatments (IMRT). Discrepancies between treatment planning system (TPS) and second check calculations created a need for treatment plan verification using a two dimensional diode array for Enhanced Dynamic Wedge (EDW) fields. While these measurements met clinical standards for treatment, they revealed room for improvement in the EDW model. The purpose of this study is to analyze the head scatter and jaw transmission effects of the moving jaw in EDW fields by measuring dose profiles with a two dimensional diode array in order to minimize differences between the manufacturer provided fluence table (Golden Segmented Treatment Table) and actual machine output. The jaw transmission effect reduces the dose gradient in the wedge direction due to transmission photons adding dose to the heel region of the field. The head scatter effect also reduces the gradient in the dose profile due to decreased accelerator output at increasingly smaller field sizes caused by the moving jaw. The field size continuously decreases with jaw motion, and thus the toe region of the wedge receives less dose than anticipated due to less head scatter contribution for small field sizes. The Golden Segmented Treatment Table (GSTT) does not take these factors into account since they are specific to each individual machine. Thus, these factors need to be accounted for in the TPS to accurately model the gradient of the wedge. The TPS used in this clinic uses one correction factor (transmission factor) to account for both effects since both factors reduce the dose gradient of the wedge. Dose profile measurements were made for 5x5 cm2, 10x10 cm2, and 20x20 cm2 field sizes with open fields and 10°, 15°, 20°, 25

  5. Application of the FD-TD method to the electromagnetic modeling of patch antenna arrays

    SciTech Connect

    Pasik, M.F.; Aguirre, G.; Cangellaris, A.C.

    1996-01-10

    FD-TD method and the Berenger Perfectly Matched Layer (PML) absorbing condition are applied to the modeling of a 32-element patch array. Numerical results for the return loss at the array feed are presented and compared to measured results for the purpose of model validation.

  6. Heads Up

    MedlinePlus

    ... Juvenil HEADS UP to School Sports Online Concussion Training Coaches Parents Athletes Sports Officials HEADS UP to Schools School Nurses Teachers, Counselors, and School Professionals Parents HEADS UP ...

  7. Reverse Phase Protein Array profiling of oropharyngeal cancer and significance of PIK3CA mutations in HPV-associated head and neck cancer

    PubMed Central

    Sewell, Andrew; Brown, Brandee; Biktasova, Asel; Mills, Gordon B.; Lu, Yiling; Tyson, Darren R.; Issaeva, Natalia; Yarbrough, Wendell G.

    2014-01-01

    Purpose HPV-associated (HPV+) oropharyngeal squamous cell carcinomas (OPSCC) have different molecular and biological characteristics and clinical behavior compared to HPV-negative (HPV−) OPSCC. PIK3CA mutations are more common in HPV(+)OPSCC. To define molecular differences and tumor subsets, protein expression and phosphorylation were compared between HPV(+) and HPV(−) OPSCC and between tumors with and without PIK3CA mutations. Experimental design Expression of 137 total and phosphorylated proteins was evaluated by reverse phase protein array(RPPA) in 29 HPV(+) and 13 HPV(−)prospectively collected OPSCCs. 47 OPSCCs were tested for hotspot activating mutations in PIK3CA and AKT. Activation of PIK3CA downstream targets and sensitivity to pathway inhibitors were determined in HPV(+) head and neck cancer cells overexpressing wild-type or mutant PIK3CA. Results Analyses revealed forty-one differentially expressed proteins between HPV(+) and HPV(−) OPSCC categorized into functional groups: DNA repair, cell cycle, apoptosis, PI3K/AKT/mTOR, and receptor kinase pathways. All queried DNA repair proteins were significantly upregulated in HPV(+) samples. 8 of 33 HPV(+) and 0 of 14 HPV(−) tumors contained activating PIK3CA mutations. Despite all activating PIK3CA mutations occurring in HPV(+) samples, HPV(+) tumors had lower mean levels of activated AKT and downstream AKT target phosphorylation. Ectopic expression of mutant PIK3CA in HPV(+) cells increase dmTOR, but not AKT activity. HPV E6/E7 overexpression inhibited AKT phosphorylation in HPV-negative cells. Mutant PIK3CA overexpressing cells were more sensitive to a dual PI3K/mTOR inhibitor compared to an AKT inhibitor. Conclusions Protein expression analyses suggest that HPV(+) and HPV(−) OPSCC differentially activate DNA repair, cell cycle, apoptosis, PI3K/AKT/mTOR, and receptor kinase pathways. PIK3CA mutations are more common in HPV(+) OPSCC and are associated with activation of mTOR, but not AKT. These data

  8. 4 T Actively detuneable double-tuned 1H/31P head volume coil and four-channel 31P phased array for human brain spectroscopy.

    PubMed

    Avdievich, N I; Hetherington, H P

    2007-06-01

    Typically 31P in vivo magnetic resonance spectroscopic studies are limited by SNR considerations. Although phased arrays can improve the SNR; to date 31P phased arrays for high-field systems have not been combined with 31P volume transmit coils. Additionally, to provide anatomical reference for the 31P studies, without removal of the coil or patient from the magnet, double-tuning (31P/1H) of the volume coil is required. In this work we describe a series of methods for active detuning and decoupling enabling use of phased arrays with double-tuned volume coils. To demonstrate these principles we have built and characterized an actively detuneable 31P/1H TEM volume transmit/four-channel 31P phased array for 4 T magnetic resonance spectroscopic imaging (MRSI) of the human brain. The coil can be used either in volume-transmit/array-receive mode or in TEM transmit/receive mode with the array detuned. Threefold SNR improvement was obtained at the periphery of the brain using the phased array as compared to the volume coil. PMID:17379554

  9. Head circumference

    MedlinePlus

    ... a child's head circumference Normal ranges for a child's sex and age (weeks, months), based on values that experts have obtained for normal growth rates of infants' and children's heads Measurement of the head circumference is an ...

  10. Head Lice

    MedlinePlus

    Head lice are parasitic wingless insects. They live on people's heads and feed on their blood. An adult louse ... Children ages 3-11 and their families get head lice most often. Personal hygiene has nothing to ...

  11. Head Injuries

    MedlinePlus

    ... of head injuries include bicycle or motorcycle wrecks, sports injuries, falls from windows (especially among children who live ... to watch for? When can I start playing sports again after a head injury? How can brain damage from a head injury ...

  12. Head Lice

    MedlinePlus

    Head lice are parasitic wingless insects. They live on people's heads and feed on their blood. An adult ... Children ages 3-11 and their families get head lice most often. Personal hygiene has nothing to do ...

  13. Head Injuries

    MedlinePlus

    ... injuries internal head injuries, which may involve the skull, the blood vessels within the skull, or the brain Fortunately, most childhood falls or ... knock the brain into the side of the skull or tear blood vessels. Some internal head injuries ...

  14. Head Lice

    MedlinePlus

    ... or prescription products. Over-the-counter shampoos and lotions containing pyrethrin (one brand name: Rid) or permethrin ( ... commonly used to treat head lice. Shampoos and lotions that kill head lice contain pesticides and other ...

  15. Head MRI

    MedlinePlus

    ... the head; MRI - cranial; NMR - cranial; Cranial MRI; Brain MRI; MRI - brain; MRI - head ... tell your health care provider if you have: Brain aneurysm clips Certain types of artificial heart valves ...

  16. Head lice.

    PubMed

    Devore, Cynthia D; Schutze, Gordon E

    2015-05-01

    Head lice infestation is associated with limited morbidity but causes a high level of anxiety among parents of school-aged children. Since the 2010 clinical report on head lice was published by the American Academy of Pediatrics, newer medications have been approved for the treatment of head lice. This revised clinical report clarifies current diagnosis and treatment protocols and provides guidance for the management of children with head lice in the school setting. PMID:25917986

  17. Head lice.

    PubMed

    Frankowski, Barbara L; Bocchini, Joseph A

    2010-08-01

    Head lice infestation is associated with limited morbidity but causes a high level of anxiety among parents of school-aged children. Since the 2002 clinical report on head lice was published by the American Academy of Pediatrics, patterns of resistance to products available over-the-counter and by prescription have changed, and additional mechanical means of removing head lice have been explored. This revised clinical report clarifies current diagnosis and treatment protocols and provides guidance for the management of children with head lice in the school setting. PMID:20660553

  18. Head injury.

    PubMed

    Hureibi, K A; McLatchie, G R

    2010-05-01

    Head injury is one of the commonest injuries in sport. Most are mild but some can have serious outcomes. Sports medicine doctors should be able to recognise the clinical features and evaluate athletes with head injury. It is necessary during field assessment to recognise signs and symptoms that help in assessing the severity of injury and making a decision to return-to-play. Prevention of primary head injury should be the aim. This includes protective equipment like helmets and possible rule changes. PMID:20533694

  19. Head Injuries

    MedlinePlus

    ... before. Often, the injury is minor because your skull is hard and it protects your brain. But ... injuries can be more severe, such as a skull fracture, concussion, or traumatic brain injury. Head injuries ...

  20. Head Injuries

    MedlinePlus

    ... before. Usually, the injury is minor because your skull is hard and it protects your brain. But ... injuries can be more severe, such as a skull fracture, concussion, or traumatic brain injury. Head injuries ...

  1. Head Noises.

    ERIC Educational Resources Information Center

    Senior, Tom

    2000-01-01

    Explains how a toy called "Sound Bites" can be modified to demonstrate the transmission of sound waves. Students can hear music from the toy when they press it against any bone in their heads or shoulders. (WRM)

  2. Improving the spatial accuracy in functional magnetic resonance imaging (fMRI) based on the blood oxygenation level dependent (BOLD) effect: benefits from parallel imaging and a 32-channel head array coil at 1.5 Tesla.

    PubMed

    Fellner, C; Doenitz, C; Finkenzeller, T; Jung, E M; Rennert, J; Schlaier, J

    2009-01-01

    Geometric distortions and low spatial resolution are current limitations in functional magnetic resonance imaging (fMRI). The aim of this study was to evaluate if application of parallel imaging or significant reduction of voxel size in combination with a new 32-channel head array coil can reduce those drawbacks at 1.5 T for a simple hand motor task. Therefore, maximum t-values (tmax) in different regions of activation, time-dependent signal-to-noise ratios (SNR(t)) as well as distortions within the precentral gyrus were evaluated. Comparing fMRI with and without parallel imaging in 17 healthy subjects revealed significantly reduced geometric distortions in anterior-posterior direction. Using parallel imaging, tmax only showed a mild reduction (7-11%) although SNR(t) was significantly diminished (25%). In 7 healthy subjects high-resolution (2 x 2 x 2 mm3) fMRI was compared with standard fMRI (3 x 3 x 3 mm3) in a 32-channel coil and with high-resolution fMRI in a 12-channel coil. The new coil yielded a clear improvement for tmax (21-32%) and SNR(t) (51%) in comparison with the 12-channel coil. Geometric distortions were smaller due to the smaller voxel size. Therefore, the reduction in tmax (8-16%) and SNR(t) (52%) in the high-resolution experiment seems to be tolerable with this coil. In conclusion, parallel imaging is an alternative to reduce geometric distortions in fMRI at 1.5 T. Using a 32-channel coil, reduction of the voxel size might be the preferable way to improve spatial accuracy. PMID:19713602

  3. A Two-Dimensional, Semiconducting Bolometer Array for HAWC

    NASA Technical Reports Server (NTRS)

    Voellmer, George M.; Allen, Christine A.; Babu, Schidananda R.; Bartels, Arlin E.; Dowell, C. Darren; Dotson, Jessie; Harper, D. Al; Moseley, Harvey; Rennick, Timothy

    2004-01-01

    The Stratospheric Observatory For Infrared Astronomy's (SOFIA's) High resolution Airborne Wideband Camera (HAWC) will use an ion-implanted silicon bolometer array developed at NASA s Goddard Space Flight Center (GSFC). The GSFC Pop-Up Detectors (PUDs) use a unique folding technique to enable a 12 x 32 element closepacked array of bolometers with a filling factor greater than 95%. The HAWC detector uses a resistive metal film on silicon to provide frequency independent, approx. 50% absorption over the 40 - 300 micron band. The silicon bolometers are manufactured in 32-element rows within silicon frames using Micro Electro Mechanical Systems (MEMS) silicon etching techniques. The frames are then cut, "folded", and glued onto a metallized, ceramic, thermal bus "bar". Optical alignment using micrometer jigs ensures their uniformity and correct placement. The rows are then stacked side-by-side to create the final 12 x 32 element array. A kinematic Kevlar suspension system isolates the 200 mK bolometer cold stage from the rest of the 4K detector housing. GSFC - developed silicon bridge chips make electrical connection to the bolometers, while maintaining thermal isolation. The Junction Field Effect Transistor (JFET) preamplifiers for all the signal channels operate at 120 K, yet they are electrically connected and located in close proximity to the bolometers. The JFET module design provides sufficient thermal isolation and heat sinking for these, so that their heat is not detected by the bolometers. Preliminary engineering results from the flight detector dark test run are expected to be available in July 2004. This paper describes the array assembly and mechanical and thermal design of the HAWC detector and the JFET module.

  4. A two-dimensional semiconducting bolometer array for HAWC

    NASA Astrophysics Data System (ADS)

    Voellmer, George M.; Allen, Christine A.; Babu, Sachidananda R.; Bartels, Arlin E.; Dowell, Charles D.; Dotson, Jessie L.; Harper, Doyle A.; Moseley, S. H., Jr.; Rennick, Timothy; Shirron, Peter J.; Smith, W. W.; Wollack, Edward J.

    2004-10-01

    The Stratospheric Observatory For Infrared Astronomy's (SOFIA's) High resolution Airborne Wideband Camera (HAWC) will use an ion-implanted silicon bolometer array developed at NASA's Goddard Space Flight Center (GSFC). The GSFC Pop-Up Detectors (PUDs) use a unique "folding" technique to enable a 12 x 32 element close-packed array of bolometers with a filling factor greater than 95%. The HAWC detector uses a resistive metal film on silicon to provide frequency independent, ~50% absorption over the 40 - 300 micron band. The silicon bolometers are manufactured in 32-element rows within silicon frames using Micro Electro Mechanical Systems (MEMS) silicon etching techniques. The frames are then cut, "folded", and glued onto a metallized, ceramic, thermal bus "bar". Optical alignment using micrometer jigs ensures their uniformity and correct placement. The rows are then stacked side-by-side to create the final 12 x 32 element array. A kinematic Kevlar suspension system isolates the 200 mK bolometer cold stage from the rest of the 4K detector housing. GSFC - developed silicon bridge chips make electrical connection to the bolometers, while maintaining thermal isolation. The Junction Field Effect Transistor (JFET) preamplifiers for all the signal channels operate at 120 K, yet they are electrically connected and located in close proximity to the bolometers. The JFET module design provides sufficient thermal isolation and heat sinking for these, so that their heat is not detected by the bolometers. Preliminary engineering results from the flight detector dark test run are expected to be available in July 2004. This paper describes the array assembly and mechanical and thermal design of the HAWC detector and the JFET module.

  5. General view of Antenna Array and building complex, looking southwest ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of Antenna Array and building complex, looking southwest - Over-the-Horizon Backscatter Radar Network, Tulelake Radar Site Receive Sector Six Antenna Array, Unnamed Road West of Double Head Road, Tulelake, Siskiyou County, CA

  6. General view of Antenna Array and building complex, looking northeast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of Antenna Array and building complex, looking northeast - Over-the-Horizon Backscatter Radar Network, Tulelake Radar Site Receive Sector Six Antenna Array, Unnamed Road West of Double Head Road, Tulelake, Siskiyou County, CA

  7. Cone Heads

    ERIC Educational Resources Information Center

    Coy, Mary

    2005-01-01

    The author, a middle school art teacher, describes a sculpture project lesson involving Cone Heads (sculptures made from cardboard cones). Discussion of caricatures with exaggerated facial features and interesting profiles helped students understand that the more expressive the face, the better. This project took approximately four to five…

  8. Magnetic arrays

    DOEpatents

    Trumper, D.L.; Kim, W.; Williams, M.E.

    1997-05-20

    Electromagnet arrays are disclosed which can provide selected field patterns in either two or three dimensions, and in particular, which can provide single-sided field patterns in two or three dimensions. These features are achieved by providing arrays which have current densities that vary in the windings both parallel to the array and in the direction of array thickness. 12 figs.

  9. Magnetic arrays

    SciTech Connect

    Trumper, David L.; Kim, Won-jong; Williams, Mark E.

    1997-05-20

    Electromagnet arrays which can provide selected field patterns in either two or three dimensions, and in particular, which can provide single-sided field patterns in two or three dimensions. These features are achieved by providing arrays which have current densities that vary in the windings both parallel to the array and in the direction of array thickness.

  10. Kokkos Array

    Energy Science and Technology Software Center (ESTSC)

    2012-09-12

    The Kokkos Array library implements shared-memory array data structures and parallel task dispatch interfaces for data-parallel computational kernels that are performance-portable to multicore-CPU and manycore-accelerator (e.g., GPGPU) devices.

  11. Systolic arrays

    SciTech Connect

    Moore, W.R.; McCabe, A.P.H.; Vrquhart, R.B.

    1987-01-01

    Selected Contents of this book are: Efficient Systolic Arrays for the Solution of Toeplitz Systems, The Derivation and Utilization of Bit Level Systolic Array Architectures, an Efficient Systolic Array for Distance Computation Required in a Video-Codec Based Motion-Detection, On Realizations of Least-Squares Estimation and Kalman Filtering by Systolic Arrays, and Comparison of Systolic and SIMD Architectures for Computer Vision Computations.

  12. Nanocylinder arrays

    DOEpatents

    Tuominen, Mark; Schotter, Joerg; Thurn-Albrecht, Thomas; Russell, Thomas P.

    2007-03-13

    Pathways to rapid and reliable fabrication of nanocylinder arrays are provided. Simple methods are described for the production of well-ordered arrays of nanopores, nanowires, and other materials. This is accomplished by orienting copolymer films and removing a component from the film to produce nanopores, that in turn, can be filled with materials to produce the arrays. The resulting arrays can be used to produce nanoscale media, devices, and systems.

  13. Nanocylinder arrays

    DOEpatents

    Tuominen, Mark; Schotter, Joerg; Thurn-Albrecht, Thomas; Russell, Thomas P.

    2009-08-11

    Pathways to rapid and reliable fabrication of nanocylinder arrays are provided. Simple methods are described for the production of well-ordered arrays of nanopores, nanowires, and other materials. This is accomplished by orienting copolymer films and removing a component from the film to produce nanopores, that in turn, can be filled with materials to produce the arrays. The resulting arrays can be used to produce nanoscale media, devices, and systems.

  14. Design and Fabrication of a Two-Dimensional Superconducting Pop-up Bolometer Array

    NASA Technical Reports Server (NTRS)

    Benford, Dominic J.; Staguhn, Johannes G.; Chervenak, James A.; Allen, Christine A.; Moseley, S. Harvey; Irwin, Kent D.; Stacey, Gordon J.; Page, Lyman A.

    2004-01-01

    We have been developing an architecture for producing large format, two dimensional arrays of close-packed bolometers, which will enable submillimeter cameras and spectrometers to obtain images and spectra orders of magnitude faster than present instruments. The low backgrounds achieved in these instruments require very sensitive detectors with NEPs of order 5 x 10(exp -18) W/square root of Hz. Superconducting transition edge sensor bolometers can be close-packed using the Pop-up Detector (PUD) format, and SQUID multiplexers operating at the detector base temperature can be intimately coupled to them. The array unit cell is 8 x 32 pixels, using 32- element detector and multiplexer components. We have fabricated an engineering model array with this technology which features a very compact, modular approach for large format arrays. We report on the production of the 32-element components for the arrays. Planned instruments using this array architecture include the Submillimeter and Far-InfraRed Experiment (SAFIRE) on the SOFIA airborne observatory, the South Pole Imaging Fabry-Perot Interferometer (SPIFI) for the AST/RO observatory, the Millimeter Bolometer Camera for the Atacama Cosmology Telescope (MBC/ACT), and the Redshift (Z) Early Universe Spectrometer (ZEUS j.

  15. New Fabrication of High-Frequency (100-MHz) Ultrasound PZT Film Kerfless Linear Array

    PubMed Central

    Zhu, Benpeng; Chan, Ngai Yui; Dai, Jiyan; Shung, K. Kirk; Takeuchi, Shinichi; Zhou, Qifa

    2013-01-01

    The paper describes the design, fabrication, and measurements of a high-frequency ultrasound kerfless linear array prepared from hydrothermal lead zirconate titanate (PZT) thick film. The 15-µm hydrothermal PZT thick film with an area of 1 × 1 cm, obtained through a self-separation process from Ti substrate, was used to fabricate a 32-element 100-MHz kerfless linear array with photolithography. The bandwidth at −6 dB without matching layer, insertion loss around center frequency, and crosstalk between adjacent elements were measured to be 39%, −30 dB, and −15 dB, respectively. PMID:23549547

  16. Micro-Machined High-Frequency (80 MHz) PZT Thick Film Linear Arrays

    PubMed Central

    Zhou, Qifa; Wu, Dawei; Liu, Changgeng; Zhu, Benpeng; Djuth, Frank; Shung, K. Kirk

    2010-01-01

    This paper presents the development of a micro-machined high-frequency linear array using PZT piezoelectric thick films. The linear array has 32 elements with an element width of 24 μm and an element length of 4 mm. Array elements were fabricated by deep reactive ion etching of PZT thick films, which were prepared from spin-coating of PZT solgel composite. Detailed fabrication processes, especially PZT thick film etching conditions and a novel transferring-and-etching method, are presented and discussed. Array designs were evaluated by simulation. Experimental measurements show that the array had a center frequency of 80 MHz and a fractional bandwidth (−6 dB) of 60%. An insertion loss of −41 dB and adjacent element crosstalk of −21 dB were found at the center frequency. PMID:20889407

  17. Abnormal Head Position

    MedlinePlus

    ... cause. Can a longstanding head turn lead to any permanent problems? Yes, a significant abnormal head posture could cause permanent ... occipitocervical synostosis and unilateral hearing loss. Are there any ... postures? Yes. Abnormal head postures can usually be improved depending ...

  18. Head and face reconstruction

    MedlinePlus

    Head and face reconstruction is surgery to repair or reshape deformities of the head and face (craniofacial). ... How surgery for head and face deformities (craniofacial reconstruction) ... and the person's condition. Surgical repairs involve the ...

  19. Head circumference (image)

    MedlinePlus

    Head circumference is a measurement of the circumference of the child's head at its largest area (above the eyebrows and ears and around the back of the head). During routine check-ups, the distance is measured ...

  20. Head Injury Prevention Tips

    MedlinePlus

    Head Injury Prevention Tips American Association of Neurological Surgeons 5550 Meadowbrook Drive, Rolling Meadows, IL 60008-3852 ... defined as a blow or jolt to the head or a penetrating head injury that disrupts the ...

  1. Heading and head injuries in soccer.

    PubMed

    Kirkendall, D T; Jordan, S E; Garrett, W E

    2001-01-01

    In the world of sports, soccer is unique because of the purposeful use of the unprotected head for controlling and advancing the ball. This skill obviously places the player at risk of head injury and the game does carry some risk. Head injury can be a result of contact of the head with another head (or other body parts), ground, goal post, other unknown objects or even the ball. Such impacts can lead to contusions, fractures, eye injuries, concussions or even, in rare cases, death. Coaches, players, parents and physicians are rightly concerned about the risk of head injury in soccer. Current research shows that selected soccer players have some degree of cognitive dysfunction. It is important to determine the reasons behind such deficits. Purposeful heading has been blamed, but a closer look at the studies that focus on heading has revealed methodological concerns that question the validity of blaming purposeful heading of the ball. The player's history and age (did they play when the ball was leather and could absorb significant amounts of water), alcohol intake, drug intake, learning disabilities, concussion definition and control group use/composition are all factors that cloud the ability to blame purposeful heading. What does seem clear is that a player's history of concussive episodes is a more likely explanation for cognitive deficits. While it is likely that the subconcussive impact of purposeful heading is a doubtful factor in the noted deficits, it is unknown whether multiple subconcussive impacts might have some lingering effects. In addition, it is unknown whether the noted deficits have any affect on daily life. Proper instruction in the technique is critical because if the ball contacts an unprepared head (as in accidental head-ball contacts), the potential for serious injury is possible. To further our understanding of the relationship of heading, head injury and cognitive deficits, we need to: learn more about the actual impact of a ball on the

  2. Abusive head trauma: past, present, and future.

    PubMed

    Narang, Sandeep; Clarke, Jennifer

    2014-12-01

    Abusive head trauma has a robust and interesting scientific history. Recently, the American Academy of Pediatrics has endorsed a change in terminology to a term that is more general in describing the vast array of abusive mechanisms that can result in pediatric head injury. Simply defined, abusive head trauma is "child physical abuse that results in injury to the head or brain." Abusive head trauma is a relatively common cause of childhood neurotrauma, with an estimated incidence of 16 to 33 cases per 100,000 children per year in the first 2 years of life. Clinical findings are variable; AHT should be considered in all children with neurologic signs and symptoms, especially if no or only mild trauma is described. Subdural and retinal hemorrhages are the most common findings. The current best evidence-based literature has identified some features--apnea and severe retinal hemorrhages--that reliably discriminate abusive from accidental injury. Longitudinal studies of outcomes in abusive head trauma patients demonstrate that approximately one-third of the children are severely disabled, one third of them are moderately disabled, and one third have no or only mild symptoms. Abusive head trauma cases are complex cases that require a rigorous, multidisciplinary team approach. The clinician can establish this diagnosis with confidence if he/she maintains a high index of suspicion for the diagnosis, has knowledge of the signs, symptoms, and risk factors of abusive head trauma, and reasonably excludes other etiologies on the differential diagnosis. PMID:25316728

  3. Interagency arraying

    NASA Astrophysics Data System (ADS)

    Cox, Henry G.

    Activities performed to match ground aperture requirements for the Neptune encounter in August 1989 with the expected capabilities of the JPL Deep Space Network (DSN) are discussed. Ground aperture requirements, DSN capabilities, and the capabilities of other agencies are reviewed. The design and configurations of the receiver subsystem, combiner subsystem, monitor and control subsystem, recording subsystem, and supporting subsystems are described. The implementation of the Very Large Array-Goldstone Telemetry Array is discussed, and the differences involved with the Parkes-Canberra Telemetry Array implementation are highlighted. The operational concept is addressed.

  4. General view of array, looking southwest OvertheHorizon Backscatter Radar ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of array, looking southwest - Over-the-Horizon Backscatter Radar Network, Tulelake Radar Site Receive Sector Four Antenna Array, Unnamed Road West of Double Head Road, Tulelake, Siskiyou County, CA

  5. General view of array, looking northeast OvertheHorizon Backscatter Radar ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of array, looking northeast - Over-the-Horizon Backscatter Radar Network, Tulelake Radar Site Receive Sector Four Antenna Array, Unnamed Road West of Double Head Road, Tulelake, Siskiyou County, CA

  6. Detail of antenna array, looking northnorthwest OvertheHorizon Backscatter Radar ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of antenna array, looking north-northwest - Over-the-Horizon Backscatter Radar Network, Tulelake Radar Site Receive Sector Five Antenna Array, Unnamed Road West of Double Head Road, Tulelake, Siskiyou County, CA

  7. General view of Antenna Array, looking west OvertheHorizon Backscatter ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of Antenna Array, looking west - Over-the-Horizon Backscatter Radar Network, Tulelake Radar Site Receive Sector Six Antenna Array, Unnamed Road West of Double Head Road, Tulelake, Siskiyou County, CA

  8. Enthalpy arrays

    NASA Astrophysics Data System (ADS)

    Torres, Francisco E.; Kuhn, Peter; de Bruyker, Dirk; Bell, Alan G.; Wolkin, Michal V.; Peeters, Eric; Williamson, James R.; Anderson, Gregory B.; Schmitz, Gregory P.; Recht, Michael I.; Schweizer, Sandra; Scott, Lincoln G.; Ho, Jackson H.; Elrod, Scott A.; Schultz, Peter G.; Lerner, Richard A.; Bruce, Richard H.

    2004-06-01

    We report the fabrication of enthalpy arrays and their use to detect molecular interactions, including protein-ligand binding, enzymatic turnover, and mitochondrial respiration. Enthalpy arrays provide a universal assay methodology with no need for specific assay development such as fluorescent labeling or immobilization of reagents, which can adversely affect the interaction. Microscale technology enables the fabrication of 96-detector enthalpy arrays on large substrates. The reduction in scale results in large decreases in both the sample quantity and the measurement time compared with conventional microcalorimetry. We demonstrate the utility of the enthalpy arrays by showing measurements for two protein-ligand binding interactions (RNase A + cytidine 2'-monophosphate and streptavidin + biotin), phosphorylation of glucose by hexokinase, and respiration of mitochondria in the presence of 2,4-dinitrophenol uncoupler.

  9. Array tomography: production of arrays.

    PubMed

    Micheva, Kristina D; O'Rourke, Nancy; Busse, Brad; Smith, Stephen J

    2010-11-01

    Array tomography is a volumetric microscopy method based on physical serial sectioning. Ultrathin sections of a plastic-embedded tissue are cut using an ultramicrotome, bonded in an ordered array to a glass coverslip, stained as desired, and imaged. The resulting two-dimensional image tiles can then be reconstructed computationally into three-dimensional volume images for visualization and quantitative analysis. The minimal thickness of individual sections permits high-quality rapid staining and imaging, whereas the array format allows reliable and convenient section handling, staining, and automated imaging. Also, the physical stability of the arrays permits images to be acquired and registered from repeated cycles of staining, imaging, and stain elution, as well as from imaging using multiple modalities (e.g., fluorescence and electron microscopy). Array tomography makes it possible to visualize and quantify previously inaccessible features of tissue structure and molecular architecture. However, careful preparation of the tissue is essential for successful array tomography; these steps can be time consuming and require some practice to perfect. This protocol describes the sectioning of embedded tissues and the mounting of the serial arrays. The procedures require some familiarity with the techniques used for ultramicrotome sectioning for electron microscopy. PMID:21041397

  10. Array tomography: imaging stained arrays.

    PubMed

    Micheva, Kristina D; O'Rourke, Nancy; Busse, Brad; Smith, Stephen J

    2010-11-01

    Array tomography is a volumetric microscopy method based on physical serial sectioning. Ultrathin sections of a plastic-embedded tissue are cut using an ultramicrotome, bonded in an ordered array to a glass coverslip, stained as desired, and imaged. The resulting two-dimensional image tiles can then be reconstructed computationally into three-dimensional volume images for visualization and quantitative analysis. The minimal thickness of individual sections permits high-quality rapid staining and imaging, whereas the array format allows reliable and convenient section handling, staining, and automated imaging. Also, the physical stability of the arrays permits images to be acquired and registered from repeated cycles of staining, imaging, and stain elution, as well as from imaging using multiple modalities (e.g., fluorescence and electron microscopy). Array tomography makes it possible to visualize and quantify previously inaccessible features of tissue structure and molecular architecture. However, careful preparation of the tissue is essential for successful array tomography; these steps can be time-consuming and require some practice to perfect. In this protocol, tissue arrays are imaged using conventional wide-field fluorescence microscopy. Images can be captured manually or, with the appropriate software and hardware, the process can be automated. PMID:21041399

  11. SU-E-T-87: Comparison Study of Dose Reconstruction From Cylindrical Diode Array Measurements, with TLD Measurements and Treatment Planning System Calculations in Anthropomorphic Head and Neck and Lung Phantoms

    SciTech Connect

    Benhabib, S; Cardan, R; Huang, M; Brezovich, I; Popple, R; Faught, A; Followill, D

    2014-06-01

    Purpose: To assess dose calculated by the 3DVH software (Sun Nuclear Systems, Melbourne, FL) against TLD measurements and treatment planning system calculations in anthropomorphic phantoms. Methods: The IROC Houston (RPC) head and neck (HN) and lung phantoms were scanned and plans were generated using Eclipse (Varian Medical Systems, Milpitas, CA) following IROC Houston procedures. For the H and N phantom, 6 MV VMAT and 9-field dynamic MLC (DMLC) plans were created. For the lung phantom 6 MV VMAT and 15 MV 9-field dynamic MLC (DMLC) plans were created. The plans were delivered to the phantoms and to an ArcCHECK (Sun Nuclear Systems, Melbourne, FL). The head and neck phantom contained 8 TLDs located at PTV1 (4), PTV2 (2), and OAR Cord (2). The lung phantom contained 4 TLDs, 2 in the PTV, 1 in the cord, and 1 in the heart. Daily outputs were recorded before each measurement for correction. 3DVH dose reconstruction software was used to project the calculated dose to patient anatomy. Results: For the HN phantom, the maximum difference between 3DVH and TLDs was -3.4% and between 3DVH and Eclipse was 1.2%. For the lung plan the maximum difference between 3DVH and TLDs was 4.3%, except for the spinal cord for which 3DVH overestimated the TLD dose by 12%. The maximum difference between 3DVH and Eclipse was 0.3%. 3DVH agreed well with Eclipse because the dose reconstruction algorithm uses the diode measurements to perturb the dose calculated by the treatment planning system; therefore, if there is a problem in the modeling or heterogeneity correction, it will be carried through to 3DVH. Conclusion: 3DVH agreed well with Eclipse and TLD measurements. Comparison of 3DVH with film measurements is ongoing. Work supported by PHS grant CA10953 and CA81647 (NCI, DHHS)

  12. Microlens arrays

    NASA Astrophysics Data System (ADS)

    Hutley, Michael C.; Stevens, Richard F.; Daly, Daniel J.

    1992-04-01

    Microlenses have been with us for a long time as indeed the very word lens reminds us. Many early lenses,including those made by Hooke and Leeuwenhoek in the 17th century were small and resembled lentils. Many languages use the same word for both (French tilentillelt and German "Linse") and the connection is only obscure in English because we use the French word for the vegetable and the German for the optic. Many of the applications for arrays of inicrolenses are also well established. Lippmann's work on integral photography at the turn of the century required lens arrays and stimulated an interest that is very much alive today. At one stage, lens arrays played an important part in high speed photography and various schemes have been put forward to take advantage of the compact imaging properties of combinations of lens arrays. The fact that many of these ingenious schemes have not been developed to their full potential has to a large degree been due to the absence of lens arrays of a suitable quality and cost.

  13. Very High Frequency (Beyond 100 MHz) PZT Kerfless Linear Arrays

    PubMed Central

    Wu, Da-Wei; Zhou, Qifa; Geng, Xuecang; Liu, Chang-Geng; Djuth, Frank; Shung, K. Kirk

    2010-01-01

    This paper presents the design, fabrication, and measurements of very high frequency kerfless linear arrays prepared from PZT film and PZT bulk material. A 12-µm PZT thick film fabricated from PZT-5H powder/solution composite and a piece of 15-µm PZT-5H sheet were used to fabricate 32-element kerfless high-frequency linear arrays with photolithography. The PZT thick film was prepared by spin-coating of PZT sol-gel composite solution. The thin PZT-5H sheet sample was prepared by lapping a PZT-5H ceramic with a precision lapping machine. The measured results of the 2 arrays were compared. The PZT film array had a center frequency of 120 MHz, a bandwidth of 60% with a parylene matching layer, and an insertion loss of 41 dB. The PZT ceramic sheet array was found to have a center frequency of 128 MHz with a poorer bandwidth (40% with a parylene matching layer) but a better sensitivity (28 dB insertion loss). PMID:19942516

  14. Head injury. Second edition

    SciTech Connect

    Cooper, P.R.

    1987-01-01

    This book contains 22 chapters. Some of the chapter titles are: Radiographic Evaluation; Epidemiology of Head Injury; Emergency Care and Initial Evaluation; Skull Fracture and Traumatic Cerebrospinal Fluid Fistulas; Mild Head Injury; and Injuries of the Cranial Nerves.

  15. Radial head fracture - aftercare

    MedlinePlus

    Elbow fracture - radial head - aftercare ... the radius bone, just below your elbow. A fracture is a break in your bone. The most common cause of a radial head fracture is falling with an outstretched arm.

  16. Head injury - first aid

    MedlinePlus

    ... medlineplus.gov/ency/article/000028.htm Head injury - first aid To use the sharing features on this page, ... a concussion can range from mild to severe. First Aid Learning to recognize a serious head injury and ...

  17. Increased head circumference

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003305.htm Increased head circumference To use the sharing features on this page, please enable JavaScript. Increased head circumference is when the measured distance around the ...

  18. Head and Neck Cancer

    MedlinePlus

    Head and neck cancer includes cancers of the mouth, nose, sinuses, salivary glands, throat, and lymph nodes in the ... increases your risk. In fact, 85 percent of head and neck cancers are linked to tobacco use, including smoking ...

  19. Head injury - first aid

    MedlinePlus

    ... is shaken, is the most common type of traumatic brain injury. Scalp wounds. Skull fractures. Head injuries may cause ... of people who suffer head injuries are children. Traumatic brain injury (TBI) accounts for over 1 in 6 injury- ...

  20. Head and Neck Cancer

    MedlinePlus

    Head and neck cancer includes cancers of the mouth, nose, sinuses, salivary glands, throat, and lymph nodes in the ... swallowing A change or hoarseness in the voice Head and neck cancers are twice as common in men. Using ...

  1. 290 and 340 nm UV LED arrays for fluorescence detection from single airborne particles

    NASA Astrophysics Data System (ADS)

    Davitt, Kristina; Song, Yoon-Kyu; Patterson, William R., III; Nurmikko, Arto V.; Gherasimova, Maria; Han, Jung; Pan, Yong-Le; Chang, Richard K.

    2005-11-01

    We demonstrate a compact system, incorporating a 32-element linear array of ultraviolet (290 nm and 340 nm) light-emitting diodes (LEDs) and a multi-anode photomultiplier tube, to the in-flight fluorescence detection of aerosolized particles, here containing the biological molecules tryptophan and NADH. This system illustrates substantial advances in the growth and fabrication of new semiconductor UV light emitting devices and an evolution in packaging details for LEDs tailored to the bio-aerosol warning problem. Optical engineering strategies are employed which take advantage of the size and versatility of light-emitting diodes to develop a truly compact fluorescence detector.

  2. 290 and 340 nm UV LED arrays for fluorescence detection from single airborne particles.

    PubMed

    Davitt, Kristina; Song, Yoon-Kyu; Patterson Iii, William; Nurmikko, Arto; Gherasimova, Maria; Han, Jung; Pan, Yong-Le; Chang, Richard

    2005-11-14

    We demonstrate a compact system, incorporating a 32-element linear array of ultraviolet (290 nm and 340 nm) light-emitting diodes (LEDs) and a multi-anode photomultiplier tube, to the in-flight fluorescence detection of aerosolized particles, here containing the biological molecules tryptophan and NADH. This system illustrates substantial advances in the growth and fabrication of new semiconductor UV light emitting devices and an evolution in packaging details for LEDs tailored to the bio-aerosol warning problem. Optical engineering strategies are employed which take advantage of the size and versatility of light-emitting diodes to develop a truly compact fluorescence detector. PMID:19503158

  3. Ultrasonic Air-Coupled Inspection of Textile Materials Using Ferroelectret-Based Phased Arrays

    NASA Astrophysics Data System (ADS)

    Ealo, J.; Camacho, J.; Seco, F.; Fritsch, C.

    2010-02-01

    Most common defects in textile manufacturing processes include weaving errors (such as missing threads), oil spots and material inhomogeneities. In this work, we demonstrate the feasibility of using ferroelectret-based transducers for the inspection of woven material. A linear array of 32 elements was built for this purpose following an easy fabrication procedure recently proposed. Electronic focusing at the textile sample position allowed us to detect weaving errors and oil spots of up to ˜1 mm of width in through transmission mode, at normal incidence and with a good signal-to-noise ratio.

  4. Head Start Facilities Manual.

    ERIC Educational Resources Information Center

    Research Assessment Management, Inc., Silver Spring, MD.

    A quality Head Start facility should provide a physical environment responsive both to the needs of the children and families served and to the needs of staff, volunteers, and community agencies that share space with Head Start. This manual is a tool for Head Start grantees and delegate agencies for assessing existing facilities, making…

  5. The Head Start Debates

    ERIC Educational Resources Information Center

    Zigler, Edward, Ed.; Styfco, Sally J., Ed.

    2004-01-01

    The future of Head Start depends on how well people learn from and apply the lessons from its past. That's why everyone involved in early education needs this timely, forward-thinking book from the leader of Head Start. The first book to capture the Head Start debates in all their complexity and diversity, this landmark volume brings together the…

  6. Pediatric head trauma

    PubMed Central

    Alexiou, George A; Sfakianos, George; Prodromou, Neofytos

    2011-01-01

    Head injury in children accounts for a large number of emergency department visits and hospital admissions. Falls are the most common type of injury, followed by motor-vehicle-related accidents. In the present study, we discuss the evaluation, neuroimaging and management of children with head trauma. Furthermore, we present the specific characteristics of each type of pediatric head injury. PMID:21887034

  7. Speech Enhancement Using Microphone Arrays.

    NASA Astrophysics Data System (ADS)

    Adugna, Eneyew

    Arrays of sensors have been employed effectively in communication systems for the directional transmission and reception of electromagnetic waves. Among the numerous benefits, this helps improve the signal-to-interference ratio (SIR) of the signal at the receiver. Arrays have since been used in related areas that employ propagating waves for the transmission of information. Several investigators have successfully adopted array principles to acoustics, sonar, seismic, and medical imaging. In speech applications the microphone is used as the sensor for acoustic data acquisition. The performance of subsequent speech processing algorithms--such as speech recognition or speaker recognition--relies heavily on the level of interference within the transduced or recorded speech signal. The normal practice is to use a single, hand-held or head-mounted, microphone. Under most environmental conditions, i.e., environments where other acoustic sources are also active, the speech signal from a single microphone is a superposition of acoustic signals present in the environment. Such cases represent a lower SIR value. To alleviate this problem an array of microphones--linear array, planar array, and 3-dimensional arrays--have been suggested and implemented. This work focuses on microphone arrays in room environments where reverberation is the main source of interference. The acoustic wave incident on the array from a point source is sampled and recorded by a linear array of sensors along with reflected waves. Array signal processing algorithms are developed and used to remove reverberations from the signal received by the array. Signals from other positions are considered as interference. Unlike most studies that deal with plane waves, we base our algorithm on spherical waves originating at a source point. This is especially true for room environments. The algorithm consists of two stages--a first stage to locate the source and a second stage to focus on the source. The first part

  8. Global Arrays

    SciTech Connect

    2006-02-23

    The Global Arrays (GA) toolkit provides an efficient and portable “shared-memory” programming interface for distributed-memory computers. Each process in a MIMD parallel program can asynchronously access logical blocks of physically distributed dense multi-dimensional arrays, without need for explicit cooperation by other processes. Unlike other shared-memory environments, the GA model exposes to the programmer the non-uniform memory access (NUMA) characteristics of the high performance computers and acknowledges that access to a remote portion of the shared data is slower than to the local portion. The locality information for the shared data is available, and a direct access to the local portions of shared data is provided. Global Arrays have been designed to complement rather than substitute for the message-passing programming model. The programmer is free to use both the shared-memory and message-passing paradigms in the same program, and to take advantage of existing message-passing software libraries. Global Arrays are compatible with the Message Passing Interface (MPI).

  9. Pacific Array

    NASA Astrophysics Data System (ADS)

    Kawakatsu, H.; Takeo, A.; Isse, T.; Nishida, K.; Shiobara, H.; Suetsugu, D.

    2014-12-01

    Based on our recent results on broadband ocean bottom seismometry, we propose a next generation large-scale array experiment in the ocean. Recent advances in ocean bottom broadband seismometry (e.g., Suetsugu & Shiobara, 2014, Annual Review EPS), together with advances in the seismic analysis methodology, have now enabled us to resolve the regional 1-D structure of the entire lithosphere/asthenosphere system, including seismic anisotropy (both radial and azimuthal), with deployments of ~10-15 broadband ocean bottom seismometers (BBOBSs) (namely "ocean-bottom broadband dispersion survey"; Takeo et al., 2013, JGR; Kawakatsu et al., 2013, AGU; Takeo, 2014, Ph.D. Thesis; Takeo et al., 2014, JpGU). Having ~15 BBOBSs as an array unit for 2-year deployment, and repeating such deployments in a leap-frog way (an array of arrays) for a decade or so would enable us to cover a large portion of the Pacific basin. Such efforts, not only by giving regional constraints on the 1-D structure, but also by sharing waveform data for global scale waveform tomography, would drastically increase our knowledge of how plate tectonics works on this planet, as well as how it worked for the past 150 million years. International collaborations might be sought.

  10. Global Arrays

    Energy Science and Technology Software Center (ESTSC)

    2006-02-23

    The Global Arrays (GA) toolkit provides an efficient and portable “shared-memory” programming interface for distributed-memory computers. Each process in a MIMD parallel program can asynchronously access logical blocks of physically distributed dense multi-dimensional arrays, without need for explicit cooperation by other processes. Unlike other shared-memory environments, the GA model exposes to the programmer the non-uniform memory access (NUMA) characteristics of the high performance computers and acknowledges that access to a remote portion of the sharedmore » data is slower than to the local portion. The locality information for the shared data is available, and a direct access to the local portions of shared data is provided. Global Arrays have been designed to complement rather than substitute for the message-passing programming model. The programmer is free to use both the shared-memory and message-passing paradigms in the same program, and to take advantage of existing message-passing software libraries. Global Arrays are compatible with the Message Passing Interface (MPI).« less

  11. Airborne ultrasonic phased arrays using ferroelectrets: a new fabrication approach.

    PubMed

    Ealo, Joao L; Camacho, Jorge J; Fritsch, Carlos

    2009-04-01

    In this work, a novel procedure that considerably simplifies the fabrication process of ferroelectret-based multielement array transducers is proposed and evaluated. Also, the potential of ferroelectrets being used as active material for air-coupled ultrasonic transducer design is demonstrated. The new construction method of multi-element transducers introduces 2 distinctive improvements. First, active ferroelectret material is not discretized into elements, and second, the need of structuring upper and/or lower electrodes in advance of the permanent polarization of the film is removed. The aperture discretization and the mechanical connection are achieved in one step using a through-thickness conductive tape. To validate the procedure, 2 linear array prototypes of 32 elements, with a pitch of 3.43 mm and a wide usable frequency range from 30 to 300 kHz, were built and evaluated using a commercial phased-array system. A low crosstalk among elements, below -30 dB, was measured by interferometry. Likewise, a homogeneous response of the array elements, with a maximum deviation of +/-1.8 dB, was obtained. Acoustic beam steering measurements were accomplished at different deflection angles using a calibrated microphone. The ultrasonic beam parameters, namely, lateral resolution, side lobe level, grating lobes, and focus depth, were congruent with theory. Acoustic images of a single reflector were obtained using one of the array elements as the receiver. Resulting images are also in accordance with numerical simulation, demonstrating the feasibility of using these arrays in pulse-echo mode. The proposed procedure simplifies the manufacturing of multidimensional arrays with arbitrary shape elements and not uniformly distributed. Furthermore, this concept can be extended to nonflat arrays as long as the transducer substrate conforms to a developable surface. PMID:19406714

  12. Head wave correlations in ambient noise.

    PubMed

    Gebbie, John; Siderius, Martin

    2016-07-01

    Ambient ocean noise is processed with a vertical line array to reveal coherent time-separated arrivals suggesting the presence of head wave multipath propagation. Head waves, which are critically propagating water waves created by seabed waves traveling parallel to the water-sediment interface, can propagate faster than water-only waves. Such eigenrays are much weaker than water-only eigenrays, and are often completely overshadowed by them. Surface-generated noise is different whereby it amplifies the coherence between head waves and critically propagating water-only waves, which is measured by cross-correlating critically steered beams. This phenomenon is demonstrated both experimentally and with a full wave simulation. PMID:27475213

  13. Thermal-independent properties of PIN-PMN-PT single-crystal linear-array ultrasonic transducers.

    PubMed

    Chen, Ruimin; Wu, Jinchuan; Ho Lam, Kwok; Yao, Liheng; Zhou, Qifa; Tian, Jian; Han, Pengdi; Shung, K Kirk

    2012-12-01

    In this paper, low-frequency 32-element linear-array ultrasonic transducers were designed and fabricated using both ternary Pb(In(1/2)Nb(1/2))-Pb(Mg(1/3)Nb(2/3))-PbTiO(3) (PIN-PMN-PT) and binary Pb(Mg(1/3)Nb(2/3))-PbTiO(3) (PMNPT) single crystals. Performance of the array transducers was characterized as a function of temperature ranging from room temperature to 160°C. It was found that the array transducers fabricated using the PIN-PMN-PT single crystal were capable of satisfactory performance at 160°C, having a -6-dB bandwidth of 66% and an insertion loss of 37 dB. The results suggest that the potential of PIN-PMN-PT linear-array ultrasonic transducers for high-temperature ultrasonic transducer applications is promising. PMID:23221227

  14. General view of Sector Four Compound, looking north. Antenna Array ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of Sector Four Compound, looking north. Antenna Array is in background, behind Communications Antennas, Receiver Building, and Water Storage Tank - Over-the-Horizon Backscatter Radar Network, Tulelake Radar Site Receive Sector Four Antenna Array, Unnamed Road West of Double Head Road, Tulelake, Siskiyou County, CA

  15. Treatment of head lice.

    PubMed

    Diamantis, Stephanie A; Morrell, Dean S; Burkhart, Craig N

    2009-01-01

    Pediculosis capitis, or head lice, is a common infestation among children worldwide. Multiple therapies exist for the treatment of this condition, including topical pediculicides and oral medications. When used in combination with environmental decontamination, these drugs can be very effective in eradicating head lice infestation without significant adverse events. The present study discusses the use of available over-the-counter and prescription treatments, including pyrethroids and permethrin, lindane, malathion, ivermectin, and trimethoprim-sulfamethoxazole, in the treatment of head lice. PMID:19580574

  16. Deposition head for laser

    DOEpatents

    Lewis, Gary K.; Less, Richard M.

    1999-01-01

    A deposition head for use as a part of apparatus for forming articles from materials in particulate form in which the materials are melted by a laser beam and deposited at points along a tool path to form an article of the desired shape and dimensions. The deposition head delivers the laser beam and powder to a deposition zone, which is formed at the tip of the deposition head. A controller comprised of a digital computer directs movement of the deposition zone along the tool path and provides control signals to adjust apparatus functions, such as the speed at which the deposition head moves along the tool path.

  17. Bottom head assembly

    DOEpatents

    Fife, A.B.

    1998-09-01

    A bottom head dome assembly is described which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome. The bottom head dome has a plurality of openings extending there through. The liner also has a plurality of openings extending there through, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending there through, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner. In one embodiment, each support shim includes a support stub having a bore there through, and each support stub bore aligns with a respective bottom head dome opening. 2 figs.

  18. Bottom head assembly

    DOEpatents

    Fife, Alex Blair

    1998-01-01

    A bottom head dome assembly which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome is described. The bottom head dome has a plurality of openings extending therethrough. The liner also has a plurality of openings extending therethrough, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending therethrough, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner. In one embodiment, each support shim includes a support stub having a bore therethrough, and each support stub bore aligns with a respective bottom head dome opening.

  19. Design and Fabrication of Two-Dimensional Semiconducting Bolometer Arrays for the High Resolution Airborne Wideband Camera (HAWC) and the Submillimeter High Angular Resolution Camera II (SHARC-II)

    NASA Technical Reports Server (NTRS)

    Voellmer, George M.; Allen, Christine A.; Amato, Michael J.; Babu, Sachidananda R.; Bartels, Arlin E.; Benford, Dominic J.; Derro, Rebecca J.; Dowell, C. Darren; Harper, D. Al; Jhabvala, Murzy D.

    2002-01-01

    The High resolution Airborne Wideband Camera (HAWC) and the Submillimeter High Angular Resolution Camera II (SHARC II) will use almost identical versions of an ion-implanted silicon bolometer array developed at the National Aeronautics and Space Administration's Goddard Space Flight Center (GSFC). The GSFC 'Pop-up' Detectors (PUD's) use a unique folding technique to enable a 12 x 32-element close-packed array of bolometers with a filling factor greater than 95 percent. A kinematic Kevlar(trademark) suspension system isolates the 200 mK bolometers from the helium bath temperature, and GSFC - developed silicon bridge chips make electrical connection to the bolometers, while maintaining thermal isolation. The JFET preamps operate at 120 K. Providing good thermal heat sinking for these, and keeping their conduction and radiation from reaching the nearby bolometers, is one of the principal design challenges encountered. Another interesting challenge is the preparation of the silicon bolometers. They are manufactured in 32-element, planar rows using Micro Electro Mechanical Systems (MEMS) semiconductor etching techniques, and then cut and folded onto a ceramic bar. Optical alignment using specialized jigs ensures their uniformity and correct placement. The rows are then stacked to create the 12 x 32-element array. Engineering results from the first light run of SHARC II at the Caltech Submillimeter Observatory (CSO) are presented.

  20. Design and Fabrication of Two-Dimensional Semiconducting Bolometer Arrays for the High Resolution Airborne Wideband Camera (HAWC) and the Submillimeter High Angular Resolution Camera II (SHARC-II)

    NASA Technical Reports Server (NTRS)

    Voellmer, George M.; Allen, Christine A.; Amato, Michael J.; Babu, Sachidananda R.; Bartels, Arlin E.; Benford, Dominic J.; Derro, Rebecca J.; Dowell, C. Darren; Harper, D. Al; Jhabvala, Murzy D.; Simpson, A. D. (Technical Monitor)

    2002-01-01

    The High resolution Airborne Wideband Camera (HAWC) and the Submillimeter High Angular Resolution Camera II (SHARC 11) will use almost identical versions of an ion-implanted silicon bolometer array developed at the National Aeronautics and Space Administration's Goddard Space Flight Center (GSFC). The GSFC "Pop-Up" Detectors (PUD's) use a unique folding technique to enable a 12 x 32-element close-packed array of bolometers with a filling factor greater than 95 percent. A kinematic Kevlar(Registered Trademark) suspension system isolates the 200 mK bolometers from the helium bath temperature, and GSFC - developed silicon bridge chips make electrical connection to the bolometers, while maintaining thermal isolation. The JFET preamps operate at 120 K. Providing good thermal heat sinking for these, and keeping their conduction and radiation from reaching the nearby bolometers, is one of the principal design challenges encountered. Another interesting challenge is the preparation of the silicon bolometers. They are manufactured in 32-element, planar rows using Micro Electro Mechanical Systems (MEMS) semiconductor etching techniques, and then cut and folded onto a ceramic bar. Optical alignment using specialized jigs ensures their uniformity and correct placement. The rows are then stacked to create the 12 x 32-element array. Engineering results from the first light run of SHARC II at the CalTech Submillimeter Observatory (CSO) are presented.

  1. Head Injuries in Children

    ERIC Educational Resources Information Center

    Pennington, Nicole

    2010-01-01

    School nurses play a crucial role in injury prevention and initial treatment when injuries occur at school. The role of school nurses includes being knowledgeable about the management of head injuries, including assessment and initial treatment. The school nurse must be familiar with the outcomes of a head injury and know when further evaluation…

  2. American Head and Neck Society

    MedlinePlus

    American Head & Neck Society Head and Neck Cancer Research & Education American Head & Neck Society | AHNS Head and Neck Cancer Research & Education About AHNS ... and Announcements Copyright ©2016 · American Head and Neck Society · Privacy and Return Policy Managed by BSC Management, ...

  3. Trunnion-Head Stresses in THA: Are Big Heads Trouble?

    PubMed

    Lavernia, Carlos J; Iacobelli, David A; Villa, Jesus M; Jones, Kinzy; Gonzalez, Jose L; Jones, William Kinzy

    2015-06-01

    The effects of large heads on stresses at the THA trunnion-head junction and their impact on tribocorrosion/metal ion release remain controversial. A 12/14 3D-model of a stem with different head sizes was investigated. Material properties of titanium were assigned to the trunnion and cobalt-chrome/alumina to the heads. A load simulating walking single-leg stand phase was applied to the head. A total contact head-trunnion interface was assumed. The area underneath the junction underwent significant elevations in stresses as head size increased from 28- to 40-mm. Maximum principal stress doubled between 28 and 40-mm heads, regardless of head material. Stress levels had a direct correlation to head diameter. Stress increases observed using increasingly larger heads will probably contribute to head-trunnion tribocorrosion and ion release. PMID:25724112

  4. Solar Science with the Murchison Widefield Array: Commissioning and Beyond

    NASA Astrophysics Data System (ADS)

    Oberoi, D.; Cairns, I. H.; Matthews, L. D.; Benkevitch, L. V.

    2012-12-01

    The Murchison Widefield Array is a low frequency radio interferometer operating in the 80-300 MHz range. Located in radio quiet Western Australia, the MWA has been designated to be a precursor for the Square Kilometre Array, to be built at the same site. The MWA comprises 128 elements distributed in a centrally condensed manner over a region 3 km in diameter. The bulk of the construction phase for the MWA is now over and the commissioning process is currently underway. The MWA collaboration includes US, Australian and Indian institutions. The MWA is the first amongst the new generation of radio arrays to achieve high imaging fidelity, simultaneous with high spectral resolution, high temporal resolution, a good angular resolution and broad spectral coverage. These capabilities of the MWA will enable a wide variety of solar science at low radio frequencies. These range from a robust determination of the solar spectral index and its variation to investigations of coronal scattering, polarimetric imaging of type II radio bursts and associated CME plasma, and imaging of type III solar bursts. Data obtained from the 32 element MWA prototype already offer an order of magnitude improvement in imaging dynamic range (Oberoi et al., ApJ, 728, L27, 2011) and represent the state-of-the art in coronal imaging. Here we present some results from the science commissioning phase of the MWA to illustrate the capabilities of the MWA.

  5. Head Circumference and Neurocognitive Outcomes.

    PubMed

    Millichap, J Gordon

    2015-07-01

    Investigators from Universities of Glasgow and Bristol, UK, determined the value of head circumference (HC) as a screening measure, the incidence of head centile shifting, and the relationship between extremes of head size and later neurodevelopmental problems. PMID:26933592

  6. A Sensor Array for the Detection and Discrimination of Methane and Other Environmental Pollutant Gases.

    PubMed

    Hannon, Ami; Lu, Yijiang; Li, Jing; Meyyappan, M

    2016-01-01

    We address the sensitive detection and discrimination of gases impacting the environment, such as CH₄, NH₃, SO₂, and CO, using a sensor array and aided by principal component analysis (PCA). A 32-element chemiresistive sensor array consisting of nine different sensor materials including seven types of modified single-walled carbon nanotubes and two types of polymers has been constructed. PCA results demonstrate excellent discriminating ability of the chemiresistor sensor chip in the 1-30 ppm concentration range. The accuracy of the sensor was verified against data collected using cavity ring down spectroscopy. The sensor chip has also been integrated with a smartphone and has been shown to reproduce the sensing performance obtained with the laboratory measurement system. PMID:27463716

  7. Maneuvering impact boring head

    DOEpatents

    Zollinger, W.T.; Reutzel, E.W.

    1998-08-18

    An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure. 8 figs.

  8. Maneuvering impact boring head

    DOEpatents

    Zollinger, W. Thor; Reutzel, Edward W.

    1998-01-01

    An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure.

  9. Two-Pass, Diode-Pumped Nd:YAG Slab Laser Head

    NASA Technical Reports Server (NTRS)

    Coyle, D. Barry

    1992-01-01

    Neodymium/yttrium aluminum garnet (Nd:YAG) ring-laser head designed for compactness, simplicity, and increased efficiency for side pumping by diode lasers. Laser head includes two linear arrays of diode lasers, two fused-silica collimating rods, and Nd:YAG slab. Slab mounted on finned copper block, providing good thermal dissipation.

  10. Head and Neck Cancer

    MedlinePlus

    ... head and neck cancer. Poor oral and dental hygiene . Poor care of the mouth and teeth has ... sore throat Foul mouth odor not explained by hygiene Hoarseness or change in voice Nasal obstruction or ...

  11. Head Lice: Treatment

    MedlinePlus

    ... it may be necessary to use a second bottle. Pay special attention to instructions on the label ... or printed on the label. Nit (head lice egg) combs, often found in lice medicine packages, should ...

  12. Overview of Head Injuries

    MedlinePlus

    ... to Baby Health Highlights: Sept. 13, 2016 Smokers' Perceptions May Play Role in Addiction Sugar Companies Shifted ... amount of oxygen given and the rate and depth of breaths given by the ventilator. The head ...

  13. Abnormal Head Position

    MedlinePlus

    ... syndrome, Brown’s syndrome, orbital wall fractures, and restricted eye movement associated with thyroid eye disease. 2) Nystagmus: Some patients with nystagmus (jerky eye movements) will acquire a head turn or tilt if ...

  14. Head CT scan

    MedlinePlus

    Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial ... or other growth (mass) Cerebral atrophy (loss of brain tissue) ... with the hearing nerve Stroke or transient ischemic attack (TIA)

  15. Ultrasound: Head (For Parents)

    MedlinePlus

    ... the head and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  16. Head tilt during driving.

    PubMed

    Zikovitz, D C; Harris, L R

    1999-05-01

    In order to distinguish between the use of visual and gravito-inertial force reference frames, the head tilt of drivers and passengers were measured as they went around corners at various speeds. The visual curvature of the corners were thus dissociated from the magnitude of the centripetal forces (0.30-0.77 g). Drivers' head tilts were highly correlated with the visually-available estimate of the curvature of the road (r2=0.86) but not with the centripetal force (r2<0.1). Passengers' head tilts were inversely correlated with the lateral forces (r2=0.3-0.7) and seem to reflect a passive sway. The strong correlation of the tilt of drivers' heads with a visual aspect of the road ahead, supports the use of a predominantly visual reference frame for the driving task. PMID:10722313

  17. TCGA head Neck

    Cancer.gov

    Investigators with The Cancer Genome Atlas (TCGA) Research Network have discovered genomic differences – with potentially important clinical implications – in head and neck cancers caused by infection with the human papillomavirus (HPV).

  18. Head Injuries in Soccer.

    ERIC Educational Resources Information Center

    Fields, Karl B.

    1989-01-01

    This article reviews the medical literature on head injuries in soccer and concludes that protective headgear to reduce these injuries may not be as effective as rule changes and other measures, such as padding goal posts. (IAH)

  19. Treating Head Lice

    MedlinePlus

    ... and Prevention. Head lice are most common among preschool children attending child care, elementary school children, and ... Emergency Preparedness International Programs News & Events Training & Continuing Education Inspections & Compliance Federal, State & Local Officials Consumers Health ...

  20. PMN-PT single-crystal high-frequency kerfless phased array.

    PubMed

    Chen, Ruimin; Cabrera-Munoz, Nestor E; Lam, Kwok Ho; Hsu, Hsiu-sheng; Zheng, Fan; Zhou, Qifa; Shung, K Kirk

    2014-06-01

    This paper reports the design, fabrication, and characterization of a miniature high-frequency kerfless phased array prepared from a PMN-PT single crystal for forward-looking intravascular or endoscopic imaging applications. After lapping down to around 40 μm, the PMN-PT material was utilized to fabricate 32-element kerfless phased arrays using micromachining techniques. The aperture size of the active area was only 1.0 × 1.0 mm. The measured results showed that the array had a center frequency of 40 MHz, a bandwidth of 34% at -6 dB with a polymer matching layer, and an insertion loss of 20 dB at the center frequency. Phantom images were acquired and compared with simulated images. The results suggest that the feasibility of developing a phased array mounted at the tip of a forward-looking intravascular catheter or endoscope. The fabricated array exhibits much higher sensitivity than PZT ceramic-based arrays and demonstrates that PMN-PT is well suited for this application. PMID:24859667

  1. PMN-PT Single-Crystal High-Frequency Kerfless Phased Array

    PubMed Central

    Chen, Ruimin; Cabrera-Munoz, Nestor E.; Lam, Kwok Ho; Hsu, Hsiu-sheng; Zheng, Fan; Zhou, Qifa; Shung, K. Kirk

    2015-01-01

    This paper reports the design, fabrication, and characterization of a miniature high-frequency kerfless phased array prepared from a PMN-PT single crystal for forward-looking intravascular or endoscopic imaging applications. After lapping down to around 40 μm, the PMN-PT material was utilized to fabricate 32-element kerfless phased arrays using micromachining techniques. The aperture size of the active area was only 1.0 × 1.0 mm. The measured results showed that the array had a center frequency of 40 MHz, a bandwidth of 34% at −6 dB with a polymer matching layer, and an insertion loss of 20 dB at the center frequency. Phantom images were acquired and compared with simulated images. The results suggest that the feasibility of developing a phased array mounted at the tip of a forward-looking intravascular catheter or endoscope. The fabricated array exhibits much higher sensitivity than PZT ceramic-based arrays and demonstrates that PMN-PT is well suited for this application. PMID:24859667

  2. BIOMECHANICS OF HEAD INJURY IN OLYMPIC TAEKWONDO AND BOXING

    PubMed Central

    Fife, G.P.; Pieter, W.

    2013-01-01

    Objective The purpose was to examine differences between taekwondo kicks and boxing punches in resultant linear head acceleration (RLA), head injury criterion (HIC15), peak head velocity, and peak foot and fist velocities. Data from two existing publications on boxing punches and taekwondo kicks were compared. Methods For taekwondo head impacts a Hybrid II Crash Dummy (Hybrid II) head was instrumented with a tri-axial accelerometer mounted inside the Hybrid II head. The Hybrid II was fixed to a height-adjustable frame and fitted with a protective taekwondo helmet. For boxing testing, a Hybrid III Crash Dummy head was instrumented with an array of tri-axial accelerometers mounted at the head centre of gravity. Results Differences in RLA between the roundhouse kick (130.11±51.67 g) and hook punch (71.23±32.19 g, d = 1.39) and in HIC15 (clench axe kick: 162.63±104.10; uppercut: 24.10±12.54, d = 2.29) were observed. Conclusions Taekwondo kicks demonstrated significantly larger magnitudes than boxing punches for both RLA and HIC. PMID:24744497

  3. Spatial sampling of head electrical fields: the geodesic sensor net.

    PubMed

    Tucker, D M

    1993-09-01

    In studying brain electrical activity from scalp sensors (electrodes), the optimal measurement would sample the potential field over the entire surface of the braincase, with a sufficient density to avoid spatial aliasing of the surface electrical fields. The geodesic sensor net organizes an array of sensors, each enclosed in a saline sponge, in a geodesic tension structure comprised of elastic threads. By fixing a sensor pedestal at each geodesic vertex, the geometry of the tension structure insures insures that the sensor array is distributed evenly across the accessible head surface. Furthermore, the tension of the network is translated into compression that is divided equally among the sensor pedestals and directed along head-radial vectors. Various geodesic partitioning frequencies may be selected to provide an even surface distribution of the dense sensor arrays (e.g., 64, 128, or 256) that appear to be necessary to provide adequate spatial sampling of brain electrical events. PMID:7691542

  4. Ka-band MMIC array system for ACTS aeronautical terminal experiment (Aero-X)

    NASA Technical Reports Server (NTRS)

    Raquet, Charles A.; Zakrajsek, Robert J.; Lee, Richard Q.; Andro, Monty; Turtle, John P.

    1995-01-01

    During the summer of 1994, the Advanced Communication Technology Satellite (ACTS) Aeronautical Terminal Experiment (Aero-X) was successfully completed by the NASA Lewis Research Center (LeRC) and the Jet Propulsion Laboratory (JPL). 4.8 and 9.6 Kbps duplex voice links were established between the LeRC Learjet and the ACTS Link Evaluation Terminal (LET) in Cleveland, Ohio, via the ACTS. The antenna system used in this demonstration was developed by LeRC and featured LeRC and US Air Force experimental arrays using GaAs MMIC devices at each radiating element for electronic beam steering and distributed power amplification. The antenna system consisted of three arrays mounted inside the LeRC Learjet, pointing out through the windows. An open loop tracking controller developed by LeRC used information from the aircraft position and attitude sensors to automatically steer the arrays toward ACTS during flight JPL ACTS Mobile Terminal (AMT) system hardware was used as transceivers both on the aircraft and at the LET. The single 32 element MMIC transmit array developed by NASA/LeRC and Texas Instruments has an EIRP of 23.4 dBW at boresight. The two 20 GHz MMIC receive arrays were developed in a cooperative effort with the USAF Rome Laboratory/Electronic System Center, taking advantage of existing USAF array development contracts with Boeing and Martin Marietta. The Boeing array has 23 elements and a G/T of 16/6 db/degK at boresight. The Martin Marietta array has 16 elements and a G/T of 16.1 db/degK at boresight. The three proof-of-concept arrays, the array control system and their integration and operation in the Learjet for Aero-X are described.

  5. On the potential of fixed arrays for hearing aids.

    PubMed

    Stadler, R W; Rabinowitz, W M

    1993-09-01

    Microphone arrays with fixed (time-invariant) weights are directed at enhancing a desired signal from one direction (straight ahead) while attenuating spatially distributed interference and reverberation. Using the theory of sensitivity-constrained optimal beamforming [Cox et al., IEEE Trans. Acoust. Speech Sig. Process. ASSP-34, 393-398 (1986)], free-field arrays of head-sized extents were studied. The key parameters affecting array design and performance are the set of transfer functions from the target direction to each array microphone [H(f)] and the intermicrophone cross-spectral densities for isotropic noise [Szz(f)]. Design variables included the orientation of the array, the number, and [as motivated by Soede, Ph.D. thesis, Delft University of Technology (1990)] the directionality of the microphones within the array, and the complexity and robustness of the required processing. Performance was characterized by the broadband intelligibility-weighted directivity (gain against isotropic noise) and noise sensitivity (reflecting the array's sensitivity to uncorrelated noise, as well as device tolerances). For broadside orientation, a variety of arrays based on cardioid and hypercardioid microphones gave very similar performance. They can provide directivities of 7-8 dB with easily implemented weights (simple scalars). For endfire orientation, as Soede (1990) recognized, similar directivities result with weights based on analog gains and pure time delays. However, with weightings chosen independently for each frequency, directivities up to approximately 11 dB may be obtained, although the increased noise sensitivities of these arrays require practical evaluation. Because of sound diffraction, placement of arrays onto the head potentially impacts both their design and performance. In-situ measurements of H(f) and Szz(f) as well as simplified theoretical models are suggested to explore the optimization of head-mounted arrays. PMID:8408974

  6. Missouri: Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Missouri's Early Head Start/Child Care Partnership Project expands access to Early Head Start (EHS) services for children birth to age 3 by developing partnerships between federal Head Start, EHS contractors, and child care providers. Head Start and EHS contractors that participate in the initiative provide services through community child care…

  7. Head and neck position sense.

    PubMed

    Armstrong, Bridget; McNair, Peter; Taylor, Denise

    2008-01-01

    Traumatic minor cervical strains are common place in high-impact sports (e.g. tackling) and premature degenerative changes have been documented in sports people exposed to recurrent impact trauma (e.g. scrummaging in rugby) or repetitive forces (e.g. Formula 1 racing drivers, jockeys). While proprioceptive exercises have been an integral part of rehabilitation of injuries in the lower limb, they have not featured as prominently in the treatment of cervical injuries. However, head and neck position sense (HNPS) testing and re-training may have relevance in the management of minor sports-related neck injuries, and play a role in reducing the incidence of ongoing pain and problems with function. For efficacious programmes to be developed and tested, fundamental principles associated with proprioception in the cervical spine should be considered. Hence, this article highlights the importance of anatomical structures in the cervical spine responsible for position sense, and how their interaction with the CNS affects our ability to plan and execute effective purposeful movements. This article includes a review of studies examining position sense in subjects with and without pathology and describes the effects of rehabilitation programmes that have sought to improve position sense. In respect to the receptors providing proprioceptive information for the CNS, the high densities and complex arrays of spindles found in cervical muscles suggest that these receptors play a key role. There is some evidence suggesting that ensemble encoding of discharge patterns from muscle spindles is relayed to the CNS and that a pattern recognition system is used to establish joint position and movement. Sensory information from neck proprioceptive receptors is processed in tandem with information from the vestibular system. There are extensive anatomical connections between neck proprioceptive inputs and vestibular inputs. If positional information from the vestibular system is inaccurate or

  8. The EAS-1000 array

    SciTech Connect

    Khristiansen, G.B.; Fomin, IU.A.; Chasnikov, I.IA.; Ivanenko, V.M.; Efimov, N.N. )

    1989-01-01

    The requirements for a newly constructed EAS array are summarized, and the EAS-1000 array now under construction is described. The array is depicted, and its accuracy in finding EAS parameters is shown. The expected statistics in observing EAS of different energies are presented for the most important scientific problems the array is supposed to solve.

  9. Head segmentation in vertebrates

    PubMed Central

    Kuratani, Shigeru; Schilling, Thomas

    2008-01-01

    Classic theories of vertebrate head segmentation clearly exemplify the idealistic nature of comparative embryology prior to the 20th century. Comparative embryology aimed at recognizing the basic, primary structure that is shared by all vertebrates, either as an archetype or an ancestral developmental pattern. Modern evolutionary developmental (Evo-Devo) studies are also based on comparison, and therefore have a tendency to reduce complex embryonic anatomy into overly simplified patterns. Here again, a basic segmental plan for the head has been sought among chordates. We convened a symposium that brought together leading researchers dealing with this problem, in a number of different evolutionary and developmental contexts. Here we give an overview of the outcome and the status of the field in this modern era of Evo-Devo. We emphasize the fact that the head segmentation problem is not fully resolved, and we discuss new directions in the search for hints for a way out of this maze. PMID:20607135

  10. Lubricating the swordfish head.

    PubMed

    Videler, John J; Haydar, Deniz; Snoek, Roelant; Hoving, Henk-Jan T; Szabo, Ben G

    2016-07-01

    The swordfish is reputedly the fastest swimmer on Earth. The concave head and iconic sword are unique characteristics, but how they contribute to its speed is still unknown. Recent computed tomography scans revealed a poorly mineralised area near the base of the rostrum. Here we report, using magnetic resonance imaging and electron microscopy scanning, the discovery of a complex organ consisting of an oil-producing gland connected to capillaries that communicate with oil-excreting pores in the skin of the head. The capillary vessels transport oil to abundant tiny circular pores that are surrounded by denticles. The oil is distributed from the pores over the front part of the head. The oil inside the gland is identical to that found on the skin and is a mixture of methyl esters. We hypothesize that the oil layer, in combination with the denticles, creates a super-hydrophobic layer that reduces streamwise friction drag and increases swimming efficiency. PMID:27385753

  11. Simplified System Efficiency Functions for Linear Phased-Array Transducers

    NASA Astrophysics Data System (ADS)

    Margetan, F. J.; Gray, T. A.; Huang, Ruiju

    2010-02-01

    Computer models are often used to simulate ultrasonic inspections of industrial components. One ingredient of such simulations is a frequency dependent function which describes the efficiency of the inspection system for converting electrical energy to sound and vice versa. For a phased-array transducer there are many such efficiency functions, namely one for each independent pair of piezoelectric elements. In this paper we describe a simplified, approximate approach for specifying these functions. Element-to-element differences are accounted for by two "residual" parameters: (1) a strength factor which describes the relative "hotness" of an element compared to its peers; and (2) a time delay which describes the extent to which an element fires later or earlier than its peers when all elements are instructed to fire in unison. These residuals are used to relate the system efficiency function for any pair of elements to that of an average efficiency which can be readily measured. The use of this approach is demonstrated using front-wall and back-wall responses from a stainless steel block, as acquired using a 5-MHz, 32-element, linear phased-array transducer. Good agreement was found between measured and simulated surface responses.

  12. Solar array drive system

    NASA Technical Reports Server (NTRS)

    Berkopec, F. D.; Sturman, J. C.; Stanhouse, R. W.

    1976-01-01

    A solar array drive system consisting of a solar array drive mechanism and the corresponding solar array drive electronics is being developed. The principal feature of the solar array drive mechanism is its bidirectional capability which enables its use in mechanical redundancy. The solar array drive system is of a widely applicable design. This configuration will be tested to determine its acceptability for generic mission sets. Foremost of the testing to be performed is the testing for extended duration.

  13. Integrated infrared array technology

    NASA Technical Reports Server (NTRS)

    Goebel, J. H.; Mccreight, C. R.

    1986-01-01

    An overview of integrated infrared (IR) array technology is presented. Although the array pixel formats are smaller, and the readout noise of IR arrays is larger, than the corresponding values achieved with optical charge-coupled-device silicon technology, substantial progress is being made in IR technology. Both existing IR arrays and those being developed are described. Examples of astronomical images are given which illustrate the potential of integrated IR arrays for scientific investigations.

  14. Design and Fabrication of Two-Dimensional Superconducting Bolometer Array for SAFIRE

    NASA Technical Reports Server (NTRS)

    Benford, Dominic; Voellmer, George; Chervenak, Jay; Irwin, Kent; Moseley, S. Harvey; Shafer, Rick; Staguhn, Johannes; Oegerle, William (Technical Monitor)

    2002-01-01

    The Submillimeter and Far-InfraRed Experiment (SAFIRE) on the SOFIA airborne observatory will employ a large-format, two-dimensional, close-packed bolometer array. SAFIRE is an imaging Fabry-Perot spectrometer operating at wavelengths between 100 micron and 700 micron. The array format is 16x32 pixels, using a 32-element multiplexer developed in part for this instrument. The low backgrounds achieved in spectroscopy require very sensitive detectors with NEPs (Noise Equivalent Powers) of order 5x10(exp 18)W/square root of Hz. An architecture which permits 512 pixels to be placed adjacent to each other in an area the size of a postage stamp, integrate them with multiplexers, and provide all the necessary wiring interconnections is a complex proposition, but can be achieved. Superconducting detectors can be close-packed using the Pop-Up Detector (PUD) format, and SQUID multiplexers operating at the detector bas temperature can be intimately coupled to them. The result is a compact array, easily scalable to kilopixel arrays. Engineering results from the first such detector arrays will be presented.

  15. Design and Fabrication of a Two-Dimensional Superconducting Bolometer Array

    NASA Technical Reports Server (NTRS)

    Benford, Dominic; Voellmer, George M.; Chervenak, Jay; Irwin, Kent; Moseley, S. Harvey; Shafer, Rick; Stacey, Gordon; Staguhn, J.; Oegerle, William (Technical Monitor)

    2002-01-01

    Large format, two dimensional arrays of close-packed bolometers will enable submillimeter cameras and spectrometers to obtain images and spectra orders of magnitude faster than present instruments. The South Pole Imaging Fabry-Perot Interferometer (SPIFI) for the AST/RO observatory and the Submillimeter and Far-InfraRed Experiment (SAFIRE) on the SOFIA airborne observatory will employ a large-format, two-dimensional, closepacked bolometer arrays. Both these instruments are imaging Fabry-Perot spectrometers operating at wavelengths between 100 micron and 700 micron. The array format is 16x32 pixels, using a 32-element multiplexer developed in part for this purpose. The low backgrounds achieved in spectroscopy require very sensitive detectors with NEPs of order 5x10(exp 18) W/square root of Hz. Superconducting detectors can be close-packed using the Pop-Up Detector (PUD) format, and SQUID multiplexers operating at the detector bas temperature can be intimately coupled to them. We have fabricated an engineering model array with this technology which features a very compact, modular approach for large format arrays.

  16. Reactor pressure vessel vented head

    DOEpatents

    Sawabe, James K.

    1994-01-11

    A head for closing a nuclear reactor pressure vessel shell includes an arcuate dome having an integral head flange which includes a mating surface for sealingly mating with the shell upon assembly therewith. The head flange includes an internal passage extending therethrough with a first port being disposed on the head mating surface. A vent line includes a proximal end disposed in flow communication with the head internal passage, and a distal end disposed in flow communication with the inside of the dome for channeling a fluid therethrough. The vent line is fixedly joined to the dome and is carried therewith when the head is assembled to and disassembled from the shell.

  17. Head Start Curriculum Guide.

    ERIC Educational Resources Information Center

    Smith, Clare Coe; And Others

    One of a series of guides for preschool teachers and aides, the book offers a Head Start curriculum guide to help achieve goals regarding social behavior, general attitudes, academic skills, health, and parent development. Information on curriculum is divided into areas of bloc time outline, classroom arrangement, building concepts (such as…

  18. Sculpting Ceramic Heads.

    ERIC Educational Resources Information Center

    Sapiro, Maurice

    1983-01-01

    Clay sculpture is difficult to produce because of the requirements of kiln firing. The problems can be overcome by modeling the original manikin head and making a plaster mold, pressing molding slabs of clay into the plaster mold to form the hollow clay armature, and sculpting on the armature. (IS)

  19. Imaging of head trauma.

    PubMed

    Rincon, Sandra; Gupta, Rajiv; Ptak, Thomas

    2016-01-01

    Imaging is an indispensable part of the initial assessment and subsequent management of patients with head trauma. Initially, it is important for diagnosing the extent of injury and the prompt recognition of treatable injuries to reduce mortality. Subsequently, imaging is useful in following the sequelae of trauma. In this chapter, we review indications for neuroimaging and typical computed tomography (CT) and magnetic resonance imaging (MRI) protocols used in the evaluation of a patient with head trauma. We review the role of CT), the imaging modality of choice in the acute setting, and the role of MRI in the evaluation of patients with head trauma. We describe an organized and consistent approach to the interpretation of imaging of these patients. Important topics in head trauma, including fundamental concepts related to skull fractures, intracranial hemorrhage, parenchymal injury, penetrating trauma, cerebrovascular injuries, and secondary effects of trauma, are reviewed. The chapter concludes with advanced neuroimaging techniques for the evaluation of traumatic brain injury, including use of diffusion tensor imaging (DTI), functional MRI (fMRI), and MR spectroscopy (MRS), techniques which are still under development. PMID:27432678

  20. MULTIPLE SHAFT TOOL HEAD

    DOEpatents

    Colbert, H.P.

    1962-10-23

    An improved tool head arrangement is designed for the automatic expanding of a plurality of ferruled tubes simultaneously. A plurality of output shafts of a multiple spindle drill head are driven in unison by a hydraulic motor. A plurality of tube expanders are respectively coupled to the shafts through individual power train arrangements. The axial or thrust force required for the rolling operation is provided by a double acting hydraulic cylinder having a hollow through shaft with the shaft cooperating with an internally rotatable splined shaft slidably coupled to a coupling rigidly attached to the respectlve output shaft of the drill head, thereby transmitting rotary motion and axial thrust simultaneously to the tube expander. A hydraulic power unit supplies power to each of the double acting cylinders through respective two-position, four-way valves, under control of respective solenoids for each of the cylinders. The solenoids are in turn selectively controlled by a tool selection control unit which in turn is controlled by signals received from a programmed, coded tape from a tape reader. The number of expanders that are extended in a rolling operation, which may be up to 42 expanders, is determined by a predetermined program of operations depending upon the arrangement of the ferruled tubes to be expanded in the tube bundle. The tape reader also supplies dimensional information to a machine tool servo control unit for imparting selected, horizontal and/or vertical movement to the tool head assembly. (AEC)

  1. Young Stars Emerge from Orion's Head

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This image from NASA's Spitzer Space Telescope shows infant stars 'hatching' in the head of the hunter constellation, Orion. Astronomers suspect that shockwaves from a supernova explosion in Orion's head, nearly three million years ago, may have initiated this newfound birth

    The region featured in this Spitzer image is called Barnard 30. It is located approximately 1,300 light-years away and sits on the right side of Orion's 'head,' just north of the massive star Lambda Orionis.

    Wisps of red in the cloud are organic molecules called polycyclic aromatic hydrocarbons. These molecules are formed anytime carbon-based materials are burned incompletely. On Earth, they can be found in the sooty exhaust from automobile and airplane engines. They also coat the grills where charcoal-broiled meats are cooked.

    This image shows infrared light captured by Spitzer's infrared array camera. Light with wavelengths of 8 and 5.8 microns (red and orange) comes mainly from dust that has been heated by starlight. Light of 4.5 microns (green) shows hot gas and dust; and light of 3.6 microns (blue) is from starlight.

  2. Young Stars Emerge from Orion's Head

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This image from NASA's Spitzer Space Telescope shows infant stars 'hatching' in the head of the hunter constellation, Orion. Astronomers suspect that shockwaves from a supernova explosion in Orion's head, nearly three million years ago, may have initiated this newfound birth

    The region featured in this Spitzer image is called Barnard 30. It is located approximately 1,300 light-years away and sits on the right side of Orion's 'head,' just north of the massive star Lambda Orionis.

    Wisps of green in the cloud are organic molecules called polycyclic aromatic hydrocarbons. These molecules are formed anytime carbon-based materials are burned incompletely. On Earth, they can be found in the sooty exhaust from automobile and airplane engines. They also coat the grills where charcoal-broiled meats are cooked.

    Tints of orange-red in the cloud are dust particles warmed by the newly forming stars. The reddish-pink dots at the top of the cloud are very young stars embedded in a cocoon of cosmic gas and dust. Blue spots throughout the image are background Milky Way along this line of sight.

    This composite includes data from Spitzer's infrared array camera instrument, and multiband imaging photometer instrument. Light at 4.5 microns is shown as blue, 8.0 microns is green, and 24 microns is red.

  3. Head, Neck, and Oral Cancer

    MedlinePlus

    ... Neck and Oral Pathology Head, Neck and Oral Pathology Close to 42,000 Americans will be diagnosed ... Neck and Oral Pathology Head, Neck and Oral Pathology Close to 42,000 Americans will be diagnosed ...

  4. Heads Up to High School Sports

    MedlinePlus

    ... Juvenil HEADS UP to School Sports Online Concussion Training Coaches Parents Athletes Sports Officials HEADS UP to Schools School Nurses Teachers, Counselors, and School Professionals Parents HEADS UP ...

  5. Minnesota: Early Head Start Initiatiive

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Minnesota provides supplemental state funding to existing federal Head Start and Early Head Start (EHS) grantees to increase their capacity to serve additional infants, toddlers, and pregnant women. The initiative was started in 1997 when the state legislature earmarked $1 million of the general state Head Start supplemental funds for children…

  6. Maryland Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Since 2000, Maryland has provided state supplemental funds to Head Start and Early Head Start (EHS) programs to improve access. Local EHS programs may use funds, through child care partnerships, to extend the EHS day or year. Maryland's approach to building on EHS includes: (1) Increase the capacity of existing Head Start and EHS programs to…

  7. Absorbed Power Minimization in Cellular Users with Circular Antenna Arrays

    NASA Astrophysics Data System (ADS)

    Christofilakis, Vasilis; Votis, Constantinos; Tatsis, Giorgos; Raptis, Vasilis; Kostarakis, Panos

    2010-01-01

    Nowadays electromagnetic pollution of non ionizing radiation generated by cellular phones concerns millions of people. In this paper the use of circular antenna array as a means of minimizing the absorbed power by cellular phone users is introduced. In particular, the different characteristics of radiation patterns produced by a helical conventional antenna used in mobile phones operating at 900 MHz and those produced by a circular antenna array, hypothetically used in the same mobile phones, are in detail examined. Furthermore, the percentage of decrement of the power absorbed in the head as a function of direction of arrival is estimated for the circular antenna array.

  8. MAGNETIC RECORDING HEAD

    DOEpatents

    Merrill, L.C.

    1958-06-17

    An electromagetic recording head is described for simultaneous recording of a plurality of signals within a small space on a magnetically semsitized medium. Basically the head structure comprises a non-magnetic centerpiece provided with only first and second groups of spaced cut-out slots respectively on opposite sides of the centerpiece. The two groups of slots are in parallel alignment and the slots of one group are staggered with respect to the slots of the other group so that one slot is not directly opposite another slot. Each slot has a magnet pole piece disposed therein and cooperating with a second pole and coil to provide a magnetic flux gap at the upper end of the slot. As a tape is drawn over the upper end of the centerpiece the individual magnetic circuits are disposed along its width to provide means for simultaneously recording information on separate portions, tracks. of the tape.

  9. Multilaser print head

    NASA Astrophysics Data System (ADS)

    Goodman, Douglas S.; Roblee, Jeffrey W.; Plummer, William T.; Clark, Peter P.

    1998-12-01

    This paper discusses the optical and opto-mechanical design of a new laser head developed at Polaroid for printing Helios binary film for printing high quality medical hard copy images. The head is part of an external drum printer for 14' X 17' film. The pixel size is 84 X 84 micrometer, produced by four lasers, with the smallest printable spot 3 X 6 micrometer, to produce 4096 gray levels. Two pixels side-by-side are simultaneously printed. The head has eight independent 840 nm diode lasers manufactured by Polaroid. Each laser emits up to 1.1 W over an emission length of about 100 micrometer, with a particularly uniform nearfield irradiance. The lasers are microlensed to equalize the divergences in the two principal meridians. Each packaged laser is aligned in a field-replaceable illuminator whose output beam, focused at infinity, is bore-sighted in a mechanical cylinder. The illuminators are arranged roughly radially. Eight lenses image the laser nearfields on a multi-facet mirror produced by diamond machining. The mirror facets truncate the beams to give the desired pixel shapes and separations. A reducing afocal relay images the mirror onto the film. The final element is a molded aspheric lens, mounted in an actuator to maintain focus on the film. The focusing unit also comprises a triangulation-based focus sensor. The alignment procedures and fixtures were devised concurrently with the head for manufacturing simplicity. The main physical structure is a casting, into which reference surfaces are machined. All optical subassemblies are attached to this casting, with a mixture of optical alignment and self-location. Semi-kinematic cylinder-in-V methodology is utilized. The active alignment steps are done in a sequence that tends to reduce errors from previous steps.

  10. [Bilateral caudate head infarcts].

    PubMed

    Kuriyama, N; Yamamoto, Y; Akiguchi, I; Oiwa, K; Nakajima, K

    1997-11-01

    We reported a 67-year-old woman with bilateral caudate head infarcts. She developed sudden mutism followed by abulia. She was admitted to our hospital 2 months after ictus for further examination. She showed prominent abulia and was inactive, slow and apathetic. Spontaneous activity and speech, immediate response to queries, spontaneous word recall and attention and persistence to complex programs were disturbed. Apparent motor disturbance, gait disturbance, motor aphasia, apraxia and remote memory disturbance were not identified. She seemed to be depressed but not sad. Brain CT and MRI revealed bilateral caudate head hemorrhagic infarcts including bilateral anterior internal capsules, in which the left lesion was more extensive than right one and involved the part of the left putamen. These infarct locations were thought to be supplied by the area around the medial striate artery including Heubner's arteries and the A1 perforator. Digital subtraction angiography showed asymptomatic right internal carotid artery occlusion. She bad had hypertension, diabetes mellitus and atrial fibrillation and also had a left atrium with a large diameter. The infarcts were thought to be caused by cardioembolic occlusion to the distal portion of the left internal carotid artery. Although some variations of vasculature at the anterior communicating artery might contribute to bilateral medial striate artery infarcts, we could not demonstrate such abnormalities by angiography. Bilateral caudate head infarcts involving the anterior internal capsule may cause prominent abulia. The patient did not improve by drug and rehabilitation therapy and died suddenly a year after discharge. PMID:9503974

  11. Axiom turkey genotyping array

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Axiom®Turkey Genotyping Array interrogates 643,845 probesets on the array, covering 643,845 SNPs. The array development was led by Dr. Julie Long of the USDA-ARS Beltsville Agricultural Research Center under a public-private partnership with Hendrix Genetics, Aviagen, and Affymetrix. The Turk...

  12. Instrument design and characterization of the Millimeter Bolometer Array Camera on the Atacama Cosmology Telescope

    NASA Astrophysics Data System (ADS)

    Swetz, D. S.; Ade, P. A. R.; Allen, C.; Amiri, M.; Appel, J. W.; Battistelli, E. S.; Burger, B.; Chervenak, J. A.; Dahlen, A. J.; Das, S.; Denny, S.; Devlin, M. J.; Dicker, S. R.; Doriese, W. B.; Dünner, R.; Essinger-Hileman, T.; Fisher, R. P.; Fowler, J. W.; Gao, X.; Hajian, A.; Halpern, M.; Hargrave, P. C.; Hasselfield, M.; Hilton, G. C.; Hincks, A. D.; Irwin, K. D.; Jarosik, N.; Kaul, M.; Klein, J.; Knotek, S.; Lau, J. M.; Limon, M.; Lupton, R. H.; Marriage, T. A.; Martocci, K. L.; Mauskopf, P.; Moseley, S. H.; Netterfield, C. B.; Niemack, M. D.; Nolta, M. R.; Page, L.; Parker, L. P.; Reid, B. A.; Reintsema, C. D.; Sederberg, A. J.; Sehgal, N.; Sievers, J. L.; Spergel, D. N.; Staggs, S. T.; Stryzak, O. R.; Switzer, E. R.; Thornton, R. J.; Tucker, C.; Wollack, E. J.; Zhao, Y.

    2008-07-01

    The Millimeter Bolometer Array Camera (MBAC) was commissioned in the fall of 2007 on the new 6-meter Atacama Cosmology Telescope (ACT). The MBAC on the ACT will map the temperature anisotropies of the Cosmic Microwave Background (CMB) with arc-minute resolution. For this first observing season, the MBAC contained a diffraction-limited, 32 by 32 element, focal plane array of Transition Edge Sensor (TES) bolometers for observations at 145 GHz. This array was coupled to the telescope with a series of cold, refractive, reimaging optics. To meet the performance specifications, the MBAC employs four stages of cooling using closed-cycle 3He/4He sorption fridge systems in combination with pulse tube coolers. In this paper we present the design of the instrument and discuss its performance during the first observing season. Finally, we report on the status of the MBAC for the 2008 observing season, when the instrument will be upgraded to a total of three separate 1024-element arrays at 145 GHz, 220 GHz and 280 GHz.

  13. Thermophotovoltaic Array Optimization

    SciTech Connect

    SBurger; E Brown; K Rahner; L Danielson; J Openlander; J Vell; D Siganporia

    2004-07-29

    A systematic approach to thermophotovoltaic (TPV) array design and fabrication was used to optimize the performance of a 192-cell TPV array. The systematic approach began with cell selection criteria that ranked cells and then matched cell characteristics to maximize power output. Following cell selection, optimization continued with an array packaging design and fabrication techniques that introduced negligible electrical interconnect resistance and minimal parasitic losses while maintaining original cell electrical performance. This paper describes the cell selection and packaging aspects of array optimization as applied to fabrication of a 192-cell array.

  14. Measuring head circumference

    PubMed Central

    Harris, Susan R.

    2015-01-01

    Abstract Objective To provide an evidence-based update emphasizing the importance of measuring head circumference (HC) in infants, with a focus on microcephaly. Quality of evidence PubMed and EMBASE (OvidSP) were searched. Search terms used were head circumference and infants and measurement; microcephaly and infants and measurement; idiopathic microcephaly and infants; and congenital microcephaly and infants. Most of the references for this review were published in 2000 or later. Most evidence is level II. Main message Serial measurement of HC should be incorporated into routine well-child care. Measure the distance around the back of the child’s head with a nonelastic tape measure held above the eyebrows and ears, and plot the measurement on an age- and sex-appropriate growth chart. Microcephaly is HC more than 2 SD below the mean. The most common disability associated with microcephaly is intellectual delay; other common concomitant conditions include epilepsy, cerebral palsy, language delay, strabismus, ophthalmologic disorders, and cardiac, renal, urinary tract, and skeletal anomalies. An interdisciplinary approach to microcephaly is warranted. Although there are no specific interventions to enhance brain growth, dietary or surgical interventions might be helpful in some cases. Infants with microcephaly who show developmental delays might benefit from early intervention programs or developmental physical and occupational therapy. Conclusion Early identification of HC concerns by family physicians can be a critical first step in identifying disorders such as microcephaly, leading to referral to pediatric specialists and, as needed, provision of family-centred early intervention services. PMID:26505062

  15. Active head rotations and eye-head coordination

    NASA Technical Reports Server (NTRS)

    Zangemeister, W. H.; Stark, L.

    1981-01-01

    It is pointed out that head movements play an important role in gaze. The interaction between eye and head movements involves both their shared role in directing gaze and the compensatory vestibular ocular reflex. The dynamics of head trajectories are discussed, taking into account the use of parameterization to obtain the peak velocity, peak accelerations, the times of these extrema, and the duration of the movement. Attention is given to the main sequence, neck muscle EMG and details of the head-movement trajectory, types of head model accelerations, the latency of eye and head movement in coordinated gaze, gaze latency as a function of various factors, and coordinated gaze types. Clinical examples of gaze-plane analysis are considered along with the instantaneous change of compensatory eye movement (CEM) gain, and aspects of variability.

  16. Fabrication and characterization of SiO2/Si heterogeneous nanopillar arrays

    NASA Astrophysics Data System (ADS)

    Wu, Wengang; Mao, Haiyang; Han, Xiang; Xu, Jun; Wang, Weibing

    2016-07-01

    This work presents arrays of heterogeneous nanopillars stacked with Si bodies and SiO2 heads for biomedical applications. Novel crossed and overlapped spacer techniques are proposed to fabricate the nanopillar arrays in controllable dimensions. For the nanopillars in the arrays, the minimum spacing, body diameter and head tip-radius reach 100 nm, 23 nm and 11 nm, respectively. The maximum height is 1.2 μm. In addition, because of hydrophilic/hydrophobic selectivity between the SiO2 heads and Si bodies, localized nanoliter water-droplet condensing, fluorescein solution extraction and protein capturing are observed on the SiO2 pillar heads. These experiments demonstrate the great potential of heterogeneous nanopillars in biomedical applications.

  17. Fabrication and characterization of SiO2/Si heterogeneous nanopillar arrays.

    PubMed

    Wu, Wengang; Mao, Haiyang; Han, Xiang; Xu, Jun; Wang, Weibing

    2016-07-29

    This work presents arrays of heterogeneous nanopillars stacked with Si bodies and SiO2 heads for biomedical applications. Novel crossed and overlapped spacer techniques are proposed to fabricate the nanopillar arrays in controllable dimensions. For the nanopillars in the arrays, the minimum spacing, body diameter and head tip-radius reach 100 nm, 23 nm and 11 nm, respectively. The maximum height is 1.2 μm. In addition, because of hydrophilic/hydrophobic selectivity between the SiO2 heads and Si bodies, localized nanoliter water-droplet condensing, fluorescein solution extraction and protein capturing are observed on the SiO2 pillar heads. These experiments demonstrate the great potential of heterogeneous nanopillars in biomedical applications. PMID:27319739

  18. Reactor vessel head permanent shield

    SciTech Connect

    Hankinson, M.F.; Leduc, R.J.; Richard, J.W.; Malandra, L.J.

    1989-05-09

    A nuclear reactor is described comprising: a nuclear reactor pressure vessel closure head; control rod drive mechanisms (CRDMs) disposed within the closure head so as to project vertically above the closure head; cooling air baffle means surrounding the control rod drive mechanisms for defining cooling air paths relative to the control rod drive mechanisms; means defined within the periphery of the closure head for accommodating fastening means for securing the closure head to its associated pressure vessel; lifting lugs fixedly secured to the closure head for facilitating lifting and lowering movements of the closure head relative to the pressure vessel; lift rods respectively operatively associated with the plurality of lifting lugs for transmitting load forces, developed during the lifting and lowering movements of the closure head, to the lifting lugs; upstanding radiation shield means interposed between the cooling air baffle means and the periphery of the enclosure head of shielding maintenance personnel operatively working upon the closure head fastening means from the effects of radiation which may emanate from the control rod drive mechanisms and the cooling air baffle means; and connecting systems respectively associated with each one of the lifting lugs and each one of the lifting rods for connecting each one of the lifting rods to a respective one of each one of the lifting lugs, and for simultaneously connecting a lower end portion of the upstanding radiation shield means to each one of the respective lifting lugs.

  19. Superconducting Bolometer Array Architectures

    NASA Technical Reports Server (NTRS)

    Benford, Dominic; Chervenak, Jay; Irwin, Kent; Moseley, S. Harvey; Shafer, Rick; Staguhn, Johannes; Wollack, Ed; Oegerle, William (Technical Monitor)

    2002-01-01

    The next generation of far-infrared and submillimeter instruments require large arrays of detectors containing thousands of elements. These arrays will necessarily be multiplexed, and superconducting bolometer arrays are the most promising present prospect for these detectors. We discuss our current research into superconducting bolometer array technologies, which has recently resulted in the first multiplexed detections of submillimeter light and the first multiplexed astronomical observations. Prototype arrays containing 512 pixels are in production using the Pop-Up Detector (PUD) architecture, which can be extended easily to 1000 pixel arrays. Planar arrays of close-packed bolometers are being developed for the GBT (Green Bank Telescope) and for future space missions. For certain applications, such as a slewed far-infrared sky survey, feedhorncoupling of a large sparsely-filled array of bolometers is desirable, and is being developed using photolithographic feedhorn arrays. Individual detectors have achieved a Noise Equivalent Power (NEP) of -10(exp 17) W/square root of Hz at 300mK, but several orders of magnitude improvement are required and can be reached with existing technology. The testing of such ultralow-background detectors will prove difficult, as this requires optical loading of below IfW. Antenna-coupled bolometer designs have advantages for large format array designs at low powers due to their mode selectivity.

  20. Electronic Switch Arrays for Managing Microbattery Arrays

    NASA Technical Reports Server (NTRS)

    Mojarradi, Mohammad; Alahmad, Mahmoud; Sukumar, Vinesh; Zghoul, Fadi; Buck, Kevin; Hess, Herbert; Li, Harry; Cox, David

    2008-01-01

    Integrated circuits have been invented for managing the charging and discharging of such advanced miniature energy-storage devices as planar arrays of microscopic energy-storage elements [typically, microscopic electrochemical cells (microbatteries) or microcapacitors]. The architecture of these circuits enables implementation of the following energy-management options: dynamic configuration of the elements of an array into a series or parallel combination of banks (subarrarys), each array comprising a series of parallel combination of elements; direct addressing of individual banks for charging/or discharging; and, disconnection of defective elements and corresponding reconfiguration of the rest of the array to utilize the remaining functional elements to obtain the desited voltage and current performance. An integrated circuit according to the invention consists partly of a planar array of field-effect transistors that function as switches for routing electric power among the energy-storage elements, the power source, and the load. To connect the energy-storage elements to the power source for charging, a specific subset of switches is closed; to connect the energy-storage elements to the load for discharging, a different specific set of switches is closed. Also included in the integrated circuit is circuitry for monitoring and controlling charging and discharging. The control and monitoring circuitry, the switching transistors, and interconnecting metal lines are laid out on the integrated-circuit chip in a pattern that registers with the array of energy-storage elements. There is a design option to either (1) fabricate the energy-storage elements in the corresponding locations on, and as an integral part of, this integrated circuit; or (2) following a flip-chip approach, fabricate the array of energy-storage elements on a separate integrated-circuit chip and then align and bond the two chips together.

  1. Reactor pressure vessel vented head

    DOEpatents

    Sawabe, J.K.

    1994-01-11

    A head for closing a nuclear reactor pressure vessel shell includes an arcuate dome having an integral head flange which includes a mating surface for sealingly mating with the shell upon assembly therewith. The head flange includes an internal passage extending therethrough with a first port being disposed on the head mating surface. A vent line includes a proximal end disposed in flow communication with the head internal passage, and a distal end disposed in flow communication with the inside of the dome for channeling a fluid therethrough. The vent line is fixedly joined to the dome and is carried therewith when the head is assembled to and disassembled from the shell. 6 figures.

  2. Designing linear systolic arrays

    SciTech Connect

    Kumar, V.K.P.; Tsai, Y.C. . Dept. of Electrical Engineering)

    1989-12-01

    The authors develop a simple mapping technique to design linear systolic arrays. The basic idea of the technique is to map the computations of a certain class of two-dimensional systolic arrays onto one-dimensional arrays. Using this technique, systolic algorithms are derived for problems such as matrix multiplication and transitive closure on linearly connected arrays of PEs with constant I/O bandwidth. Compared to known designs in the literature, the technique leads to modular systolic arrays with constant hardware in each PE, few control lines, lexicographic data input/output, and improved delay time. The unidirectional flow of control and data in this design assures implementation of the linear array in the known fault models of wafer scale integration.

  3. Reconfigurable mosaic annular arrays.

    PubMed

    Thomenius, Kai E; Wodnicki, Robert; Cogan, Scott D; Fisher, Rayette A; Burdick, Bill; Smith, L Scott; Khuri-Yakub, Pierre; Lin, Der-Song; Zhuang, Xuefeng; Bonitz, Barry; Davies, Todd; Thomas, Glen; Woychik, Charles

    2014-07-01

    Mosaic annular arrays (MAA) based on reconfigurable array (RA) transducer electronics assemblies are presented as a potential solution for future highly integrated ultrasonic transducer subsystems. Advantages of MAAs include excellent beam quality and depth of field resulting from superior elevational focus compared with 1-D electronically scanned arrays, as well as potentially reduced cost, size, and power consumption resulting from the use of a limited number of beamforming channels for processing a large number of subelements. Specific design tradeoffs for these highly integrated arrays are discussed in terms of array specifications for center frequency, element pitch, and electronic switch-on resistance. Large-area RAs essentially function as RC delay lines. Efficient architectures which take into account RC delay effects are presented. Architectures for integration of the transducer and electronics layers of large-area array implementations are reviewed. PMID:24960699

  4. Carbon nanotube nanoelectrode arrays

    DOEpatents

    Ren, Zhifeng; Lin, Yuehe; Yantasee, Wassana; Liu, Guodong; Lu, Fang; Tu, Yi

    2008-11-18

    The present invention relates to microelectode arrays (MEAs), and more particularly to carbon nanotube nanoelectrode arrays (CNT-NEAs) for chemical and biological sensing, and methods of use. A nanoelectrode array includes a carbon nanotube material comprising an array of substantially linear carbon nanotubes each having a proximal end and a distal end, the proximal end of the carbon nanotubes are attached to a catalyst substrate material so as to form the array with a pre-determined site density, wherein the carbon nanotubes are aligned with respect to one another within the array; an electrically insulating layer on the surface of the carbon nanotube material, whereby the distal end of the carbon nanotubes extend beyond the electrically insulating layer; a second adhesive electrically insulating layer on the surface of the electrically insulating layer, whereby the distal end of the carbon nanotubes extend beyond the second adhesive electrically insulating layer; and a metal wire attached to the catalyst substrate material.

  5. Solar array automation limitations

    NASA Technical Reports Server (NTRS)

    Trumble, Terry M.

    1990-01-01

    Significant progress in the automation of the spacecraft electrical power systems has been made within the past few years. This is especially important with the development of the space station and the increasing demand on the electrical power systems for future satellites. The key element of the spacecraft power system, the solar arrays which supply the power, will have to grow to supply many tens of kilowatts of power within the next twenty years. This growth will be accompanied by the problems associated with large distributed power systems. The growth of the arrays, the on-array management problems and potential solutions to array degradation or failure are discussed. Multilowatt arrays for unmanned spacecraft with comments on the implications of array degradation for manned spacecraft are discussed.

  6. Firing Properties of Rat Lateral Mammillary Single Units: Head Direction, Head Pitch, and Angular Head Velocity

    PubMed Central

    Stackman, Robert W.; Taube, Jeffrey S.

    2006-01-01

    Many neurons in the rat anterodorsal thalamus (ADN) and postsubiculum (PoS) fire selectively when the rat points its head in a specific direction in the horizontal plane, independent of the animal’s location and ongoing behavior. The lateral mammillary nuclei (LMN) are interconnected with both the ADN and PoS and, therefore, are in a pivotal position to influence ADN/PoS neurophysiology. To further understand how the head direction (HD) cell signal is generated, we recorded single neurons from the LMN of freely moving rats. The majority of cells discharged as a function of one of three types of spatial correlates: (1) directional heading, (2) head pitch, or (3) angular head velocity (AHV). LMN HD cells exhibited higher peak firing rates and greater range of directional firing than that of ADN and PoS HD cells. LMN HD cells were modulated by angular head velocity, turning direction, and anticipated the rat’s future HD by a greater amount of time (~95 msec) than that previously reported for ADN HD cells (~25 msec). Most head pitch cells discharged when the rostrocaudal axis of the rat’s head was orthogonal to the horizontal plane. Head pitch cell firing was independent of the rat’s location, directional heading, and its body orientation (i.e., the cell discharged whenever the rat pointed its head up, whether standing on all four limbs or rearing). AHV cells were categorized as fast or slow AHV cells depending on whether their firing rate increased or decreased in proportion to angular head velocity. These data demonstrate that LMN neurons code direction and angular motion of the head in both horizontal and vertical planes and support the hypothesis that the LMN play an important role in processing both egocentric and allocentric spatial information. PMID:9787007

  7. Pacific Array (Transportable Broadband Ocean Floor Array)

    NASA Astrophysics Data System (ADS)

    Kawakatsu, Hitoshi; Ekstrom, Goran; Evans, Rob; Forsyth, Don; Gaherty, Jim; Kennett, Brian; Montagner, Jean-Paul; Utada, Hisashi

    2016-04-01

    Based on recent developments on broadband ocean bottom seismometry, we propose a next generation large-scale array experiment in the ocean. Recent advances in ocean bottom broadband seismometry1, together with advances in the seismic analysis methodology, have enabled us to resolve the regional 1-D structure of the entire lithosphere/asthenosphere system, including seismic anisotropy (azimuthal, and hopefully radial), with deployments of ~15 broadband ocean bottom seismometers (BBOBSs). Having ~15 BBOBSs as an array unit for a 2-year deployment, and repeating such deployments in a leap-frog way or concurrently (an array of arrays) for a decade or so would enable us to cover a large portion of the Pacific basin. Such efforts, not only by giving regional constraints on the 1-D structure beneath Pacific ocean, but also by sharing waveform data for global scale waveform tomography, would drastically increase our knowledge of how plate tectonics works on this planet, as well as how it worked for the past 150 million years. International collaborations is essential: if three countries/institutions participate this endeavor together, Pacific Array may be accomplished within five-or-so years.

  8. Microstrip monpulse dipole array

    NASA Astrophysics Data System (ADS)

    Miccioli, W.; Toth, J.; Sa, N.; Lewis, M.

    1985-01-01

    The development of a microstrip radiating aperture utilizing multiple microstrip dipole radiators fed by a resonant feed configuration is described. This array combines an efficient capacitively coupled radiator feeding mechanism with a planar power divider configuration to achieve an extremely thin, lightweight antenna aperture. Linear array dipole matching theory and radiator bandwidth improvement techniques are also described. A quadrant based microstrip monopulse antenna was constructed. Experimental data from this array, its subassemblies and individual components are presented and compared to analytical predictions.

  9. Distributed array radar

    NASA Astrophysics Data System (ADS)

    Heimiller, R. C.; Belyea, J. E.; Tomlinson, P. G.

    1983-11-01

    Distributed array radar (DAR) is a concept for efficiently accomplishing surveillance and tracking using coherently internetted mini-radars. They form a long baseline, very thinned array and are capable of very accurate location of targets. This paper describes the DAR concept. Factors involving two-way effective gain patterns for deterministic and random DAR arrays are analyzed and discussed. An analysis of factors affecting signal-to-noise ratio is presented and key technical and performance issues are briefly summarized.

  10. Telescope Array Experiment

    NASA Astrophysics Data System (ADS)

    Kawai, H.; Yoshida, S.; Yoshii, H.; Tanaka, K.; Cohen, F.; Fukushima, M.; Hayashida, N.; Hiyama, K.; Ikeda, D.; Kido, E.; Kondo, Y.; Nonaka, T.; Ohnishi, M.; Ohoka, H.; Ozawa, S.; Sagawa, H.; Sakurai, N.; Shibata, T.; Shimodaira, H.; Takeda, M.; Taketa, A.; Takita, M.; Tokuno, H.; Torii, R.; Udo, S.; Yamakawa, Y.; Fujii, H.; Matsuda, T.; Tanaka, M.; Yamaoka, H.; Hibino, K.; Benno, T.; Doura, K.; Chikawa, M.; Nakamura, T.; Teshima, M.; Kadota, K.; Uchihori, Y.; Hayashi, K.; Hayashi, Y.; Kawakami, S.; Matsuyama, T.; Minamino, M.; Ogio, S.; Ohshima, A.; Okuda, T.; Shimizu, N.; Tanaka, H.; Bergman, D. R.; Hughes, G.; Stratton, S.; Thomson, G. B.; Endo, A.; Inoue, N.; Kawana, S.; Wada, Y.; Kasahara, K.; Azuma, R.; Iguchi, T.; Kakimoto, F.; Machida, S.; Misumi, K.; Murano, Y.; Tameda, Y.; Tsunesada, Y.; Chiba, J.; Miyata, K.; Abu-Zayyad, T.; Belz, J. W.; Cady, R.; Cao, Z.; Huentemeyer, P.; Jui, C. C. H.; Martens, K.; Matthews, J. N.; Mostofa, M.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Thomas, J. R.; Thomas, S. B.; Wiencke, L. R.; Doyle, T.; Taylor, M. J.; Wickwar, V. B.; Wilkerson, T. D.; Hashimoto, K.; Honda, K.; Ikuta, K.; Ishii, T.; Kanbe, T.; Tomida, T.

    2008-01-01

    The TA observatory is a hybrid detector system consisting of both a surface detector array as well as a set of fluorescence detectors. The observatory will measure the energy spectrum, anisotropy and composition of ultra-high energy cosmic rays. The surface detectors are being deployed and the array should be complete by the end of February, 2007. We will soon be collecting hybrid data at the Telecope Array.

  11. Electrically reconfigurable logic array

    NASA Technical Reports Server (NTRS)

    Agarwal, R. K.

    1982-01-01

    To compose the complicated systems using algorithmically specialized logic circuits or processors, one solution is to perform relational computations such as union, division and intersection directly on hardware. These relations can be pipelined efficiently on a network of processors having an array configuration. These processors can be designed and implemented with a few simple cells. In order to determine the state-of-the-art in Electrically Reconfigurable Logic Array (ERLA), a survey of the available programmable logic array (PLA) and the logic circuit elements used in such arrays was conducted. Based on this survey some recommendations are made for ERLA devices.

  12. Integrated avalanche photodiode arrays

    DOEpatents

    Harmon, Eric S.

    2015-07-07

    The present disclosure includes devices for detecting photons, including avalanche photon detectors, arrays of such detectors, and circuits including such arrays. In some aspects, the detectors and arrays include a virtual beveled edge mesa structure surrounded by resistive material damaged by ion implantation and having side wall profiles that taper inwardly towards the top of the mesa structures, or towards the direction from which the ion implantation occurred. Other aspects are directed to masking and multiple implantation and/or annealing steps. Furthermore, methods for fabricating and using such devices, circuits and arrays are disclosed.

  13. Heading Disorientation after Right Posteromedial Infarction

    PubMed Central

    Hashimoto, Ritsuo; Komori, Noriyo; Abe, Masako

    2015-01-01

    We report the case of heading disorientation following ischemic stroke involving the right posteromedial areas. The patient was administered a new test named the Card Placing Test during which a subject was required to recreate an array of three cards, each of which was randomly placed on eight grids around the subject, before and after the subject's rotation. Qualitative analysis of his performance after rotation revealed that over half of the errors comprised transposition and rotational offset. His score on the Card Placing Test was compared with those of normal controls (n = 11). The results showed that his score on Card Placing Test after rotation was significantly lower than those of controls, whereas there was no significant difference between the case and controls in profile of error types. We infer that the heading disorientation observed in the present case was a result of a derangement of a short-term buffer that integrated information on spatial locations of objects with changes in body directions. PMID:26526327

  14. Solar array stepping to minimize array excitation

    NASA Technical Reports Server (NTRS)

    Bhat, Mahabaleshwar K. P. (Inventor); Liu, Tung Y. (Inventor); Plescia, Carl T. (Inventor)

    1989-01-01

    Mechanical oscillations of a mechanism containing a stepper motor, such as a solar-array powered spacecraft, are reduced and minimized by the execution of step movements in pairs of steps, the period between steps being equal to one-half of the period of torsional oscillation of the mechanism. Each pair of steps is repeated at needed intervals to maintain desired continuous movement of the portion of elements to be moved, such as the solar array of a spacecraft. In order to account for uncertainty as well as slow change in the period of torsional oscillation, a command unit may be provided for varying the interval between steps in a pair.

  15. Focal plane array with modular pixel array components for scalability

    SciTech Connect

    Kay, Randolph R; Campbell, David V; Shinde, Subhash L; Rienstra, Jeffrey L; Serkland, Darwin K; Holmes, Michael L

    2014-12-09

    A modular, scalable focal plane array is provided as an array of integrated circuit dice, wherein each die includes a given amount of modular pixel array circuitry. The array of dice effectively multiplies the amount of modular pixel array circuitry to produce a larger pixel array without increasing die size. Desired pixel pitch across the enlarged pixel array is preserved by forming die stacks with each pixel array circuitry die stacked on a separate die that contains the corresponding signal processing circuitry. Techniques for die stack interconnections and die stack placement are implemented to ensure that the desired pixel pitch is preserved across the enlarged pixel array.

  16. Chryse 'Alien Head'

    NASA Technical Reports Server (NTRS)

    2005-01-01

    26 January 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an impact crater in Chryse Planitia, not too far from the Viking 1 lander site, that to seems to resemble a bug-eyed head. The two odd depressions at the north end of the crater (the 'eyes') may have formed by wind or water erosion. This region has been modified by both processes, with water action occurring in the distant past via floods that poured across western Chryse Planitia from Maja Valles, and wind action common occurrence in more recent history. This crater is located near 22.5oN, 47.9oW. The 150 meter scale bar is about 164 yards long. Sunlight illuminates the scene from the left/lower left.

  17. NASA head sworn in

    NASA Astrophysics Data System (ADS)

    James C. Fletcher was sworn in on May 12, 1986, as administrator of the National Aeronautics and Space Administration (NASA). At a news conference after he was sworn in, Fletcher said that NASA would deal with both its technical problems and its procedural problems before the shuttle will fly again. According to press accounts, he stressed that funds should be made available to replace the Challenger orbiter, which was lost in an explosion on January 28.Fletcher, who had also headed the agency from 1971 to 1977, succeeds James M. Beggs, who was indicted in December 1985 for conspiring to defraud the federal government while serving as a senior executive at the General Dynamics Corporation.

  18. Head of Administration

    NASA Astrophysics Data System (ADS)

    2005-03-01

    Purpose and scope of the position: The main task is to provide efficient administrative services and advice to the Director General, Division Leaders and to staff members in the scientific and technical areas in the fields of financial planning and accounting, personnel management, purchasing, legal and contractual matters, information systems and building and site maintenance. As a member of the ESO Management the Head of Administration contributes essentially to the development of the overall policy, strategic planning, relations to the members of the personnel and maintains professional contacts at highest level outside the Organisation. ESO employs in total approximately 650 staff members and the Administration Division comprises the Administration at the Headquarters in Garching near Munich and the Administration in Santiago (Chile). The successful candidate will be supported by some 50 qualified staff members.

  19. Head for high speed spinner having a vacuum chuck. [holding silicon dioxide chips for etching

    NASA Technical Reports Server (NTRS)

    Lombardi, F. (Inventor)

    1981-01-01

    The head for a high-speed spinner is characterized by a substantially cylindrical body adapted to be mounted at the distal end of a vertically oriented drive shaft. A vacuum chuck with an upwardly facing chamber is circumscribed by an annular surface for receiving in supported relation a silicon chip. An ordered array of low-pressure cavities is defined about the periphery of the body and connected in communication with the chamber via radially extended bores in order to translate low pressures to the chamber as the head is angularly displaced. A pressure differential is thereby established across the chip for securing it to the head.

  20. ISS Solar Array Management

    NASA Technical Reports Server (NTRS)

    Williams, James P.; Martin, Keith D.; Thomas, Justin R.; Caro, Samuel

    2010-01-01

    The International Space Station (ISS) Solar Array Management (SAM) software toolset provides the capabilities necessary to operate a spacecraft with complex solar array constraints. It monitors spacecraft telemetry and provides interpretations of solar array constraint data in an intuitive manner. The toolset provides extensive situational awareness to ensure mission success by analyzing power generation needs, array motion constraints, and structural loading situations. The software suite consists of several components including samCS (constraint set selector), samShadyTimers (array shadowing timers), samWin (visualization GUI), samLock (array motion constraint computation), and samJet (attitude control system configuration selector). It provides high availability and uptime for extended and continuous mission support. It is able to support two-degrees-of-freedom (DOF) array positioning and supports up to ten simultaneous constraints with intuitive 1D and 2D decision support visualizations of constraint data. Display synchronization is enabled across a networked control center and multiple methods for constraint data interpolation are supported. Use of this software toolset increases flight safety, reduces mission support effort, optimizes solar array operation for achieving mission goals, and has run for weeks at a time without issues. The SAM toolset is currently used in ISS real-time mission operations.

  1. Array for detecting microbes

    DOEpatents

    Andersen, Gary L.; DeSantis, Todd D.

    2014-07-08

    The present embodiments relate to an array system for detecting and identifying biomolecules and organisms. More specifically, the present embodiments relate to an array system comprising a microarray configured to simultaneously detect a plurality of organisms in a sample at a high confidence level.

  2. Dual-Head Robotic Welder

    NASA Technical Reports Server (NTRS)

    Beard, Gary S.

    1990-01-01

    Robotic welder uses two welding heads simultaneously. Developed for assembly of "hot dog" shell on main injector for Space Shuttle main engine, concept applicable to other, similarly rounded or contoured workpieces. Opposed heads reduce distortion and stress in opposed weld joints and speed up welding operations.

  3. Kansas: Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Kansas Early Head Start (KEHS) provides comprehensive services following federal Head Start Program Performance Standards for pregnant women and eligible families with children from birth to age 4. KEHS was implemented in 1998 using Child Care and Development Block Grant (CCDBG) quality set-aside dollars augmented by a transfer of federal…

  4. Cutting Head for Ultrasonic Lithotripsy

    NASA Technical Reports Server (NTRS)

    Angulo, Earl D. (Inventor); Goodfriend, Roger (Inventor)

    1989-01-01

    A cutting head for attachment to the end of the wire probe of an ultrasonic kidney stone disintegration instrument. The cutting head has a plurality of circumferentially arranged teeth formed at one end thereof to provide a cup-shaped receptacle for kidney stones encountered during the disintegration procedure. An integral reduced diameter collar diminishes stress points in the wire and reduces breakage thereof.

  5. Vision Screening For Head Starters.

    ERIC Educational Resources Information Center

    Foley, Celia

    To determine which children in the Head Start program may have vision problems, Head Start teachers and staff do vision "screening." This booklet demonstrates how to do the screening using the Snellen "E Chart." Trouble signs that the test administrator should be aware of are listed, and vision scores are explained simply. Amblyopia is defined,…

  6. Nebraska: Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Since 1999, Nebraska's Early Head Start Infant/Toddler Quality Initiative has supported Early Head Start (EHS) and community child care partnerships to improve the quality and professionalism of infant and toddler care. EHS programs apply to receive funding to establish partnerships with center-based or home-based child care.The initiative has…

  7. The Acquisition of [Head] Movement.

    ERIC Educational Resources Information Center

    Pye, Clifton

    An analysis of one theory of the acquisition of head movement by children is presented, using longitudinal data from the Mayan language, K'iche'. This theory assumes that children would just require positive evidence of head movement in the input language to instantiate the constructions of their own grammar. The Incorporation Theory addresses the…

  8. Interview with Joe F. Head

    ERIC Educational Resources Information Center

    West, Kim

    2008-01-01

    This article presents an interview with Joe F. Head, Dean of University Admissions and Enrollment Services at Kennesaw State University (KSU) in Georgia, who has more than 35 years of experience in admissions and enrollment services. After completing an M.Ed. in higher education at Georgia Southern University, Head immediately landed a position as…

  9. The Start of Head Start

    ERIC Educational Resources Information Center

    Neugebauer, Roger

    2010-01-01

    The creation of the Head Start program occurred at break-neck speed with many dramatic turns and many colorful players. No one tells the story better than Edward Zigler in "Head Start: The Inside Story of America's Most Successful Educational Experiment"--a detailed and personal, behind the scenes look at the program's inception. From this…

  10. Head Start Impact Study: First Year Findings

    ERIC Educational Resources Information Center

    Puma, Michael; Bell, Stephen; Cook, Ronna; Heid, Camilla; Lopez, Michael

    2005-01-01

    The Congressionally-mandated Head Start Impact Study is being conducted across 84 nationally representative grantee/delegate agencies. Approximately 5,000 newly entering 3- and 4-year-old children applying for Head Start were randomly assigned to either a Head Start group that had access to Head Start program services or to a non-Head Start group…

  11. Micromachined electrode array

    DOEpatents

    Okandan, Murat; Wessendorf, Kurt O.

    2007-12-11

    An electrode array is disclosed which has applications for neural stimulation and sensing. The electrode array, in certain embodiments, can include a plurality of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. In other embodiments of the electrode array, the electrodes can be fixed to the substrate. The electrode array can be formed from a combination of bulk and surface micromachining, and can include electrode tips having an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis.

  12. Microbial sensor cell arrays.

    PubMed

    Melamed, Sahar; Elad, Tal; Belkin, Shimshon

    2012-02-01

    Motivated by the advantages endowed by high-throughput analysis, researchers have succeeded in incorporating multiple reporter cells into a single platform; the technology now allows the simultaneous scrutiny of a large collection of sensor strains. We review current aspects in cell array technology with emphasis on microbial sensor arrays. We consider various techniques for patterning live cells on solid surfaces, describe different array-based applications and devices, and highlight recent efforts for live cell storage. We review mathematical approaches for deciphering the data emanating from bioreporter collections, and discuss the future of single cell arrays. Innovative technologies for cell patterning, preservation and interpretation are continuously being developed; when they all mature, cell arrays may become an efficient analytical tool, in a scope resembling that of DNA microarray biochips. PMID:22176747

  13. Photovoltaic array loss mechanisms

    NASA Technical Reports Server (NTRS)

    Gonzalez, Charles

    1986-01-01

    Loss mechanisms which come into play when solar cell modules are mounted in arrays are identified. Losses can occur either from a reduction in the array electrical performance or with nonoptimal extraction of power from the array. Electrical performance degradation is caused by electrical mismatch, transmission losses from cell surface soiling and steep angle of reflectance, and electrical losses from field wiring resistance and the voltage drop across blocking diodes. The second type of loss, concerned with the operating points of the array, can involve nonoptimal load impedance and limiting the operating envelope of the array to specific ranges of voltage and current. Each of the loss mechanisms are discussed and average energy losses expected from soiling, steep reflectance angles and circuit losses are calculated.

  14. Multibeam Phased Array Antennas

    NASA Technical Reports Server (NTRS)

    Popovic, Zoya; Romisch, Stefania; Rondineau, Sebastien

    2004-01-01

    In this study, a new architecture for Ka-band multi-beam arrays was developed and demonstrated experimentally. The goal of the investigation was to demonstrate a new architecture that has the potential of reducing the cost as compared to standard expensive phased array technology. The goals of this specific part of the project, as stated in the yearly statement of work in the original proposal are: 1. Investigate bounds on performance of multi-beam lens arrays in terms of beamwidths, volume (size), isolation between beams, number of simultaneous beams, etc. 2. Design a small-scale array to demonstrate the principle. The array will be designed for operation around 3OGHz (Ka-band), with two 10-degree beamwidth beams. 3. Investigate most appropriate way to accomplish fine-tuning of the beam pointing within 5 degrees around the main beam pointing angle.

  15. Microfabricated ion trap array

    DOEpatents

    Blain, Matthew G.; Fleming, James G.

    2006-12-26

    A microfabricated ion trap array, comprising a plurality of ion traps having an inner radius of order one micron, can be fabricated using surface micromachining techniques and materials known to the integrated circuits manufacturing and microelectromechanical systems industries. Micromachining methods enable batch fabrication, reduced manufacturing costs, dimensional and positional precision, and monolithic integration of massive arrays of ion traps with microscale ion generation and detection devices. Massive arraying enables the microscale ion traps to retain the resolution, sensitivity, and mass range advantages necessary for high chemical selectivity. The reduced electrode voltage enables integration of the microfabricated ion trap array with on-chip circuit-based rf operation and detection electronics (i.e., cell phone electronics). Therefore, the full performance advantages of the microfabricated ion trap array can be realized in truly field portable, handheld microanalysis systems.

  16. High density pixel array

    NASA Technical Reports Server (NTRS)

    Wiener-Avnear, Eliezer (Inventor); McFall, James Earl (Inventor)

    2004-01-01

    A pixel array device is fabricated by a laser micro-milling method under strict process control conditions. The device has an array of pixels bonded together with an adhesive filling the grooves between adjacent pixels. The array is fabricated by moving a substrate relative to a laser beam of predetermined intensity at a controlled, constant velocity along a predetermined path defining a set of grooves between adjacent pixels so that a predetermined laser flux per unit area is applied to the material, and repeating the movement for a plurality of passes of the laser beam until the grooves are ablated to a desired depth. The substrate is of an ultrasonic transducer material in one example for fabrication of a 2D ultrasonic phase array transducer. A substrate of phosphor material is used to fabricate an X-ray focal plane array detector.

  17. Diode Laser Arrays

    NASA Astrophysics Data System (ADS)

    Botez, Dan; Scifres, Don R.

    1994-08-01

    This book provides a comprehensive overview of the fundamental principles and applications of semiconductor diode laser arrays. All of the major types of arrays are discussed in detail, including coherent, incoherent, edge- and surface-emitting, horizontal- and vertical-cavity, individually addressed, lattice- matched and strained-layer systems. The initial chapters cover such topics as lasers, amplifiers, external-cavity control, theoretical modeling, and operational dynamics. Spatially incoherent arrays are then described in detail, and the uses of vertical-cavity surface emitter and edge-emitting arrays in parallel optical-signal processing and multi-channel optical recording are discussed. Researchers and graduate students in solid state physics and electrical engineering studying the properties and applications of such arrays will find this book invaluable.

  18. Stereotactic Body Radiotherapy for Head and Neck Tumors

    ClinicalTrials.gov

    2016-04-18

    Squamous Cell Carcinoma of the Head and Neck; Nasopharyngeal Carcinoma; Salivary Gland Cancer; Head and Neck Sarcoma; Paraganglioma of Head and Neck; Chordoma of Head and Neck; Chondrosarcoma of Head and Neck; Angiofibroma of Head and Neck

  19. Photoacoustic Imaging of Animals with an Annular Transducer Array

    NASA Astrophysics Data System (ADS)

    Yang, Di-Wu; Zhou, Zhi-Bin; Zeng, Lv-Ming; Zhou, Xin; Chen, Xing-Hui

    2014-07-01

    A photoacoustic system with an annular transducer array is presented for rapid, high-resolution photoacoustic tomography of animals. An eight-channel data acquisition system is applied to capture the photoacoustic signals by using multiplexing and the total time of data acquisition and transferring is within 3 s. A limited-view filtered back projection algorithm is used to reconstruct the photoacoustic images. Experiments are performed on a mouse head and a rabbit head and clear photoacoustic images are obtained. The experimental results demonstrate that this imaging system holds the potential for imaging the human brain.

  20. Turbidity Current Head Mixing

    NASA Astrophysics Data System (ADS)

    Hernandez, David; Sanchez, Miguel Angel; Medina, Pablo

    2010-05-01

    A laboratory experimental set - up for studying the behaviour of sediment in presence of a turbulent field with zero mean flow is compared with the behaviour of turbidity currents [1] . Particular interest is shown on the initiation of sediment motion and in the sediment lift - off. The behaviour of the turbidity current in a flat ground is compared with the zero mean flow oscilating grid generated turbulence as when wave flow lifts off suspended sediments [2,3]. Some examples of the results obtained with this set-up relating the height of the head of the turbidity current to the equilibrium level of stirred lutoclines are shown. A turbulent velocity u' lower than that estimated by the Shield diagram is required to start sediment motion. The minimum u' required to start sediment lift - off, is a function of sediment size, cohesivity and resting time. The lutocline height depends on u', and the vorticity at the lutocline seems constant for a fixed sediment size [1,3]. Combining grid stirring and turbidty current head shapes analyzed by means of advanced image analysis, sediment vertical fluxes and settling speeds can be measured [4,5]. [1] D. Hernandez Turbulent structure of turbidity currents and sediment transport Ms Thesis ETSECCPB, UPC. Barcelona 2009. [2] A. Sánchez-Arcilla; A. Rodríguez; J.C. Santás; J.M. Redondo; V. Gracia; R. K'Osyan; S. Kuznetsov; C. Mösso. Delta'96 Surf-zone and nearshore measurements at the Ebro Delta. A: International Conference on Coastal Research through large Scale Experiments (Coastal Dynamics '97). University of Plymouth, 1997, p. 186-187. [3] P. Medina, M. A. Sánchez and J. M. Redondo. Grid stirred turbulence: applications to the initiation of sediment motion and lift-off studies Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere. 26, Issue 4, 2001, Pages 299-304 [4] M.O. Bezerra, M. Diez, C. Medeiros, A. Rodriguez, E. Bahia., A. Sanchez-Arcilla and J.M. Redondo. Study on the influence of waves on

  1. Magnetization reversal in arrays of Co rings

    NASA Astrophysics Data System (ADS)

    Welp, U.; Vlasko-Vlasov, V. K.; Hiller, J. M.; Zaluzec, N. J.; Metlushko, V.; Ilic, B.

    2003-08-01

    The magnetization behavior of arrays of individual and coupled Co rings has been studied using superconducting quantum interference device magnetometry, magneto-optical imaging, and Lorentz transmission and scanning transmission electron microscopy. The transition from the polarized into the vortex state of isolated rings is shown to occur through the motion and annihilation of head-to-head domain boundaries. The chirality of the vortex state is fixed on subsequent magnetization cycles, indicating that it is predetermined by structural imperfections of the rings. The effect of interactions between the rings has been investigated in arrays of chains of touching rings. For fields applied parallel to the chains rings in extended sections of the chains are found to switch simultaneously. Neighboring rings in these sections can display alternating chirality as well as the same chirality accompanied by a 180° boundary on the nodes. For fields perpendicular to the chain direction the switching occurs pairwise. This coupling introduces a broad distribution of switching fields and correspondingly a magnetization curve that is significantly broader than that for the parallel orientation.

  2. Head and Neck Cancer: Symptoms and Signs

    MedlinePlus

    ... Symptoms and Signs Request Permissions Print to PDF Head and Neck Cancer - Symptoms and Signs Approved by the Cancer. ... Cancer Research and Advocacy Survivorship Blog About Us Head and Neck Cancer Guide Cancer.Net Guide Head and Neck ...

  3. High resolution, MRI-based, segmented, computerized head phantom

    SciTech Connect

    Zubal, I.G.; Harrell, C.R.; Smith, E.O.; Smith, A.L.; Krischlunas, P.

    1999-01-01

    The authors have created a high-resolution software phantom of the human brain which is applicable to voxel-based radiation transport calculations yielding nuclear medicine simulated images and/or internal dose estimates. A software head phantom was created from 124 transverse MRI images of a healthy normal individual. The transverse T2 slices, recorded in a 256x256 matrix from a GE Signa 2 scanner, have isotropic voxel dimensions of 1.5 mm and were manually segmented by the clinical staff. Each voxel of the phantom contains one of 62 index numbers designating anatomical, neurological, and taxonomical structures. The result is stored as a 256x256x128 byte array. Internal volumes compare favorably to those described in the ICRP Reference Man. The computerized array represents a high resolution model of a typical human brain and serves as a voxel-based anthropomorphic head phantom suitable for computer-based modeling and simulation calculations. It offers an improved realism over previous mathematically described software brain phantoms, and creates a reference standard for comparing results of newly emerging voxel-based computations. Such voxel-based computations lead the way to developing diagnostic and dosimetry calculations which can utilize patient-specific diagnostic images. However, such individualized approaches lack fast, automatic segmentation schemes for routine use; therefore, the high resolution, typical head geometry gives the most realistic patient model currently available.

  4. Keeping Your Head On Target

    PubMed Central

    Wong, Aaron L.; Zee, David S.; Jinnah, H. A.

    2013-01-01

    The mechanisms by which the human brain controls eye movements are reasonably well understood, but those for the head less so. Here, we show that the mechanisms for keeping the head aimed at a stationary target follow strategies similar to those for holding the eyes steady on stationary targets. Specifically, we applied the neural integrator hypothesis that originally was developed for holding the eyes still in eccentric gaze positions to describe how the head is held still when turned toward an eccentric target. We found that normal humans make head movements consistent with the neural integrator hypothesis, except that additional sensory feedback is needed, from proprioceptors in the neck, to keep the head on target. We also show that the complicated patterns of head movements in patients with cervical dystonia can be predicted by deficits in a neural integrator for head motor control. These results support ideas originally developed from animal studies that suggest fundamental similarities between oculomotor and cephalomotor control, as well as a conceptual framework for cervical dystonia that departs considerably from current clinical views. PMID:23825431

  5. Ultralightweight solar array technology

    SciTech Connect

    Goldsmith, P.; Kurland, R.

    1982-06-01

    Flat fold array technology is described, and performance for a range of missions and power levels is predicted. The array employs large area flat panel flexible substrates. The solar cells are adhesively bonded to a thin Kapton substrate to form individual panel assemblies. Any number of these panel assemblies may be joined together to make a blanket assembly. A container assembly protects each blanket assembly when stowed, and a tension guide wire assembly controls the flexible blanket shape when fully extended. Blanket extension and retraction are achieved through a motor powered lightweight trilongeron coilable lattice mast assembly. Ground and zero gravity flight tests on prototype array assemblies are successful.

  6. Eye and head motion during head turns in spaceflight

    NASA Technical Reports Server (NTRS)

    Thornton, William E.; Uri, John J.; Moore, Thomas P.; Pool, Sam L.

    1988-01-01

    Eye-head motion was studied pre-, in- and postflight during single voluntary head turns. A transient increase in vestibulo-ocular reflex (VOR) gain occurred early in the flight, but later trended toward normal. This increased gain was produced by a relative increase in eye counterrotation velocity. Asymmetries in gain with right and left turns also occurred, caused by asymmetries in eye counterrotation velocities. These findings were remarkably similar to those from Soviet primate studies using gaze fixation targets, except the human study trended more rapidly toward normal. These findings differ substantially from those measuring VOR gain by head oscillation, in which no significant changes were found inflight. No visual disturbances were noted in either test condition or in normal activities. These head turn studies are the only ones to date documenting any functional change in VOR in weightlessness.

  7. Two-dimensional infrared speckle interferometry with a 32 X 32 InSb charge-injection device (CID) array

    NASA Astrophysics Data System (ADS)

    Sibille, F.; Chelli, A.; Lena, P.; Stefanovitch, D.

    1982-10-01

    The conditions which have to be satisfied to take full advantage of the speckle method are considered. It is found that InSb arrays of infrared detectors with a 32 x 32 format satisfy these conditions with telescopes of the 4 m class and with seeings up to 2 arc seconds at 2 microns, or up to 5 arc seconds at 5 microns. An InSb CID array, type Z 7844, of 32 x 32 elements with 72 x 72 micro sq m pixel pitch and 52 x 52 micro sq m pixel effective collection area providing a filling factor of 70 percent was manufactured by an American company. The first astronomical tests were performed with the array in October 1981. The array was used at the infrared focus of the 2.1 m telescope of the Kitt Peak National Observatory. Two infrared speckled images of the star Beta Peg are shown. The images were obtained at 3.5 and at 5 microns.

  8. Thermal-Independent Properties of PIN-PMN-PT Single-Crystal Linear-Array Ultrasonic Transducers

    PubMed Central

    Chen, Ruimin; Wu, Jinchuan; Lam, Kwok Ho; Yao, Liheng; Zhou, Qifa; Tian, Jian; Han, Pengdi; Shung, K. Kirk

    2013-01-01

    In this paper, low-frequency 32-element linear-array ultrasonic transducers were designed and fabricated using both ternary Pb(In1/2Nb1/2)–Pb(Mg1/3Nb2/3)–PbTiO3 (PIN-PMN-PT) and binary Pb(Mg1/3Nb2/3)–PbTiO3 (PMN-PT) single crystals. Performance of the array transducers was characterized as a function of temperature ranging from room temperature to 160°C. It was found that the array transducers fabricated using the PIN-PMN-PT single crystal were capable of satisfactory performance at 160°C, having a −6-dB bandwidth of 66% and an insertion loss of 37 dB. The results suggest that the potential of PIN-PMN-PT linear-array ultrasonic transducers for high-temperature ultrasonic transducer applications is promising. PMID:23221227

  9. Cutting Head for Ultrasonic Lithotripsy

    NASA Technical Reports Server (NTRS)

    Angulo, E. D.; Goodfriend, R.

    1987-01-01

    Kidney stones lodged in urinary tract disintegrated with increased safety and efficiency by cutting head attached to end of vibrated wire probe. Aligns probe with stone and enables probe to vibrate long enough to disintegrate stone. Design of cutting head reduces risk of metal-fatigue-induced breakage of probe tip leaving metal fragments in urinary tract. Teeth of cutting head both seat and fragment kidney stone, while extension of collar into catheter lessens mechanical strain in probe wire, increasing probe life and lessening danger of in situ probe breakage.

  10. Topiramate Responsive Exploding Head Syndrome

    PubMed Central

    Palikh, Gaurang M.; Vaughn, Bradley V.

    2010-01-01

    Exploding head syndrome is a rare phenomenon but can be a significant disruption to quality of life. We describe a 39-year-old female with symptoms of a loud bang and buzz at sleep onset for 3 years. EEG monitoring confirmed these events occurred in transition from stage 1 sleep. This patient reported improvement in intensity of events with topiramate medication. Based on these results, topiramate may be an alternative method to reduce the intensity of events in exploding head syndrome. Citation: Palikh GM; Vaughn BV. Topiramate responsive exploding head syndrome. J Clin Sleep Med 2010;6(4):382-383. PMID:20726288

  11. Anaphylaxis Due to Head Injury

    PubMed Central

    Bruner, Heather C.; Bruner, David I.

    2015-01-01

    Both anaphylaxis and head injury are often seen in the emergency department, but they are rarely seen in combination. We present a case of a 30-year-old woman who presented with anaphylaxis with urticaria and angioedema following a minor head injury. The patient responded well to intramuscular epinephrine without further complications or airway compromise. Prior case reports have reported angioedema from hereditary angioedema during dental procedures and maxillofacial surgery, but there have not been any cases of first-time angioedema or anaphylaxis due to head injury. PMID:25987924

  12. Head-Up Tilt.

    PubMed

    Xu, Jinyi; Yang, Lihong; Zhang, Qiang; Li, Shuaibing; Qiao, Zihao; Fang, Ying; Zhao, Guihua; Wang, Qingyi; Liu, Guanghui

    2015-01-01

    Autonomic dysfunction has been associated with paroxysmal atrial fibrillation (PAF). The head-up tilt test (HUTT) is an important diagnostic tool for autonomic dysfunction. The aim of this study was to examine atrial fibrillation recurrence after RFCA by performing HUTT. A total of 488 consecutive patients with PAF who underwent RFCA were prospectively enrolled. HUTT was positive in 154 (31.6%) patients after a mean follow-up of 22.7 ± 3.5 months, and 163 (33.4%) had a recurrence. HUTT positive was significantly higher in PAF patients with recurrence compared to those without (68 (41.7%) versus 86 (26.5%), P < 0.001). Multivariate Cox regression analysis revealed that HUTT positive (HR: 1.96; 95% CI: 1.49-2.48, P < 0.001), left atrial diameter (HR: 1.77; 95%CI: 1.15-2.11, P = 0.004), AF duration (HR: 1.27; 95%CI: 0.98-1.83, P = 0.014), and sleep apnea (HR: 1.02; 95%CI: 0.81-1.53, P = 0.032) were independent predictors of clinical recurrence after RFCA. The success rate of ablation was 70.4% in patients in the HUTT negative group compared with 58.4% in patients in the HUTT positive group (log-rank P = 0.006). Patients with a positive headup tilt test were at an increased risk of AF recurrence after catheter ablation. Our results suggest that HUTT was a significant predictor for AF recurrence after catheter ablation for PAF. PMID:26370369

  13. Flexible retinal electrode array

    DOEpatents

    Okandan, Murat; Wessendorf, Kurt O.; Christenson, Todd R.

    2006-10-24

    An electrode array which has applications for neural stimulation and sensing. The electrode array can include a large number of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. The electrode array can be formed from a combination of bulk and surface micromachining, with electrode tips that can include an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis where the electrodes can be tailored to provide a uniform gentle contact pressure with optional sensing of this contact pressure at one or more of the electrodes.

  14. Economical custom LSI arrays

    NASA Technical Reports Server (NTRS)

    Feller, A.; Smith, A.; Ramondetta, P.; Noto, R.; Lombardi, T.

    1976-01-01

    Automatic design technique uses standard circuit cells for producing large-scale integrated arrays. Computerized fabrication process provides individual cells of high density and efficiency, quick turnaround time, low cost, and ease of corrections for changes and errors.

  15. Glory Solar Array Deployment

    NASA Video Gallery

    The Glory spacecraft uses Orbital Sciences Corporation Space Systems Group's LEOStar-1 bus design, with deployable, four-panel solar arrays. This conceptual animation reveals Glory's unique solar a...

  16. Expandable LED array interconnect

    DOEpatents

    Yuan, Thomas Cheng-Hsin; Keller, Bernd

    2011-03-01

    A light emitting device that can function as an array element in an expandable array of such devices. The light emitting device comprises a substrate that has a top surface and a plurality of edges. Input and output terminals are mounted to the top surface of the substrate. Both terminals comprise a plurality of contact pads disposed proximate to the edges of the substrate, allowing for easy access to both terminals from multiple edges of the substrate. A lighting element is mounted to the top surface of the substrate. The lighting element is connected between the input and output terminals. The contact pads provide multiple access points to the terminals which allow for greater flexibility in design when the devices are used as array elements in an expandable array.

  17. Virtual center arraying

    NASA Technical Reports Server (NTRS)

    Deutsch, L. J.; Lipes, R. G.; Miller, R. L.

    1981-01-01

    Methods to increase the amount of data that can be received from outer planet missions are described with emphasis on antenna arraying systems designed to increase the total effective aperture of the receiving system. One such method is virtual center arraying (VCA). In VCA, a combined carrier reference is derived at a point that is, conceptually, the geometric center of the array. This point need not coincide with any of the actual antennas of the array. A noise analysis of the VCA system is given along with formulas for the phase jitter as a function of loop bandwidths and the amount of loop damping. If the ratio of the loop bandwidths of the center loop to the vertex loops is greater than 100, then the jitter is very nearly equal to that expected for ideal combined carrier referencing.

  18. Flexible transceiver array for ultrahigh field human MR imaging.

    PubMed

    Wu, Bing; Zhang, Xiaoliang; Wang, Chunsheng; Li, Ye; Pang, Yong; Lu, Jonathan; Xu, Duan; Majumdar, Sharmila; Nelson, Sarah J; Vigneron, Daniel B

    2012-10-01

    A flexible transceiver array, capable of multiple-purpose imaging applications in vivo at ultrahigh magnetic fields was designed, implemented and tested on a 7 T MR scanner. By alternately placing coil elements with primary and secondary harmonics, improved decoupling among coil elements was accomplished without requiring decoupling circuitry between resonant elements, which is commonly required in high-frequency transceiver arrays to achieve sufficient element-isolation during radiofrequency excitation. This flexible array design is capable of maintaining the required decoupling among resonant elements in different array size and geometry and is scalable in coil size and number of resonant elements (i.e., number of channels), yielding improved filling factors for various body parts with different geometry and size. To investigate design feasibility, flexibility, and array performance, a multichannel, 16-element transceiver array was designed and constructed, and in vivo images of the human head, knee, and hand were acquired using a whole-body 7 T MR system. Seven Tesla parallel imaging with generalized autocalibrating partially parallel acquisitions (GRAPPA) performed using this flexible transceiver array was also presented. PMID:22246803

  19. Random array grid collimator

    DOEpatents

    Fenimore, E.E.

    1980-08-22

    A hexagonally shaped quasi-random no-two-holes touching grid collimator. The quasi-random array grid collimator eliminates contamination from small angle off-axis rays by using a no-two-holes-touching pattern which simultaneously provides for a self-supporting array increasng throughput by elimination of a substrate. The presentation invention also provides maximum throughput using hexagonally shaped holes in a hexagonal lattice pattern for diffraction limited applications. Mosaicking is also disclosed for reducing fabrication effort.

  20. The NMR phased array.

    PubMed

    Roemer, P B; Edelstein, W A; Hayes, C E; Souza, S P; Mueller, O M

    1990-11-01

    We describe methods for simultaneously acquiring and subsequently combining data from a multitude of closely positioned NMR receiving coils. The approach is conceptually similar to phased array radar and ultrasound and hence we call our techniques the "NMR phased array." The NMR phased array offers the signal-to-noise ratio (SNR) and resolution of a small surface coil over fields-of-view (FOV) normally associated with body imaging with no increase in imaging time. The NMR phased array can be applied to both imaging and spectroscopy for all pulse sequences. The problematic interactions among nearby surface coils is eliminated (a) by overlapping adjacent coils to give zero mutual inductance, hence zero interaction, and (b) by attaching low input impedance preamplifiers to all coils, thus eliminating interference among next nearest and more distant neighbors. We derive an algorithm for combining the data from the phased array elements to yield an image with optimum SNR. Other techniques which are easier to implement at the cost of lower SNR are explored. Phased array imaging is demonstrated with high resolution (512 x 512, 48-cm FOV, and 32-cm FOV) spin-echo images of the thoracic and lumbar spine. Data were acquired from four-element linear spine arrays, the first made of 12-cm square coils and the second made of 8-cm square coils. When compared with images from a single 15 x 30-cm rectangular coil and identical imaging parameters, the phased array yields a 2X and 3X higher SNR at the depth of the spine (approximately 7 cm). PMID:2266841

  1. Preventing head injuries in children

    MedlinePlus

    ... strapped in with the safety harness. Store all firearms and bullets in a locked cabinet. ... of Health and Human Services. Centers for Disease Control and Prevention. Heads up. Facts for physicians about ...

  2. Heater head for stirling engine

    DOEpatents

    Corey, John A.

    1985-07-09

    A monolithic heater head assembly which augments cast fins with ceramic inserts which narrow the flow of combustion gas and obtains high thermal effectiveness with the assembly including an improved flange design which gives greater durability and reduced conduction loss.

  3. Carbon nanotube array actuators

    NASA Astrophysics Data System (ADS)

    Geier, S.; Mahrholz, T.; Wierach, P.; Sinapius, M.

    2013-09-01

    Experimental investigations of highly vertically aligned carbon nanotubes (CNTs), also known as CNT-arrays, are the main focus of this paper. The free strain as result of an active material behavior is analyzed via a novel experimental setup. Previous test experiences of papers made of randomly oriented CNTs, also called Bucky-papers, reveal comparably low free strain. The anisotropy of aligned CNTs promises better performance. Via synthesis techniques like chemical vapor deposition (CVD) or plasma enhanced CVD (PECVD), highly aligned arrays of multi-walled carbon nanotubes (MWCNTs) are synthesized. Two different types of CNT-arrays are analyzed, morphologically first, and optically tested for their active characteristics afterwards. One type of the analyzed arrays features tube lengths of 750-2000 μm with a large variety of diameters between 20 and 50 nm and a wave-like CNT-shape. The second type features a maximum, almost uniform, length of 12 μm and a constant diameter of 50 nm. Different CNT-lengths and array types are tested due to their active behavior. As result of the presented tests, it is reported that the quality of orientation is the most decisive property for excellent active behavior. Due to their alignment, CNT-arrays feature the opportunity to clarify the actuation mechanism of architectures made of CNTs.

  4. Tensile Tests of Round-head, Flat-head, and Brazier-head Rivets

    NASA Technical Reports Server (NTRS)

    Schuette, Evan H; Bartone, Leonard M; Mandel, Merven W

    1944-01-01

    An investigation was conducted to determine the tensile strength of round-head (AN43C), flat-head(AN442), and brazier-head (AN4556) aluminum-alloy rivets because of the scarcity of information on the tensile strength of rivets. The results of the investigation are presented as curves that show the variation of the ratio of the tensile strength of the rivet to the tensile strength of the rivet crank with the ratio of the sheet thickness to the rivet diameter for the different types of rivet.

  5. Indications for ulnar head replacement.

    PubMed

    Berger, Richard A

    2008-08-01

    Implanting an endoprosthesis is a clinically proven means of reestablishing mechanical contact between the distal radius and ulna, thus providing the foundation for stability of the entire forearm. The indications for, contraindications to, and outcomes of ulnar head replacement are discussed, together with the underlying mechanics, pathomechanics of ulnar head excision, the theoretical basis for implant arthroplasty, and the designs that have been employed. PMID:18836608

  6. Cutting head for ultrasonic lithotripsy

    NASA Technical Reports Server (NTRS)

    Anguluo, E. D.; Goodfriend, R. (Inventor)

    1985-01-01

    A cutting head for attachment to the end of the wire probe of an ultrasonic kidney stone disintegration instrument is described. The cutting head has a plurality of circumferentially arranged teeth formed at one end thereof to provide a cup shaped receptacle for kidney stones encountered during the disintegration procedure. An integral reduced diameter collar diminishes stress points in the wire and reduce breakage thereof.

  7. 96-Channel Receive-Only Head Coil for 3 Tesla: Design Optimization and Evaluation

    PubMed Central

    Wiggins, Graham C.; Polimeni, Jonathan R.; Potthast, Andreas; Schmitt, Melanie; Alagappan, Vijay; Wald, Lawrence L.

    2010-01-01

    The benefits and challenges of highly parallel array coils for head imaging were investigated through the development of a 3T receive-only phased-array head coil with 96 receive elements constructed on a close-fitting helmet-shaped former. We evaluated several designs for the coil elements and matching circuitry, with particular attention to sources of signal-to-noise ratio (SNR) loss, including various sources of coil loading and coupling between the array elements. The SNR and noise amplification (g-factor) in accelerated imaging were quantitatively evaluated in phantom and human imaging and compared to a 32-channel array built on an identical helmet-shaped former and to a larger commercial 12-channel head coil. The 96-channel coil provided substantial SNR gains in the distal cortex compared to the 12- and 32-channel coils. The central SNR for the 96-channel coil was similar to the 32-channel coil for optimum SNR combination and 20% lower for root-sum-of-squares combination. There was a significant reduction in the maximum g-factor for 96 channels compared to 32; for example, the 96-channel maximum g-factor was 65% of the 32-channel value for acceleration rate 4. The performance of the array is demonstrated in highly accelerated brain images. PMID:19623621

  8. Ghost Head Nebula

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Looking like a colorful holiday card, a new image from NASA's Hubble Space Telescope reveals a vibrant green and red nebula far from Earth.

    The image of NGC 2080, taken by Hubble's Wide Field and Planetary Camera 2, designed and built by NASA's Jet Propulsion Laboratory, Pasadena, Calif., is available online at http://www.jpl.nasa.gov/images/wfpc . Images like this help astronomers investigate star formation in nebulas.

    NGC 2080, nicknamed 'The Ghost Head Nebula,' is one of a chain of star-forming regions lying south of the 30 Doradus nebula in the Large Magellanic Cloud. 30 Doradus is the largest star-forming complex in the local group of galaxies. This 'enhanced color' picture is composed of three narrow-band-filter images obtained by Hubble on March 28, 2000.

    The red and blue light come from regions of hydrogen gas heated by nearby stars. The green light on the left comes from glowing oxygen. The energy to illuminate the green light is supplied by a powerful stellar wind, a stream of high-speed particles coming from a massive star just outside the image. The central white region is a combination of all three emissions and indicates a core of hot, massive stars in this star-formation region. Intense emission from these stars has carved a bowl-shaped cavity in surrounding gas.

    In the white region, the two bright areas (the 'eyes of the ghost') - named A1 (left) and A2 (right) -- are very hot, glowing 'blobs' of hydrogen and oxygen. The bubble in A1 is produced by the hot, intense radiation and powerful stellar wind from one massive star. A2 contains more dust and several hidden, massive stars. The massive stars in A1 and A2 must have formed within the last 10,000 years, since their natal gas shrouds are not yet disrupted by the powerful radiation of the newborn stars.

    The Space Telescope Science Institute is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract with the Goddard Space Flight Center

  9. Sampled Longest Common Prefix Array

    NASA Astrophysics Data System (ADS)

    Sirén, Jouni

    When augmented with the longest common prefix (LCP) array and some other structures, the suffix array can solve many string processing problems in optimal time and space. A compressed representation of the LCP array is also one of the main building blocks in many compressed suffix tree proposals. In this paper, we describe a new compressed LCP representation: the sampled LCP array. We show that when used with a compressed suffix array (CSA), the sampled LCP array often offers better time/space trade-offs than the existing alternatives. We also show how to construct the compressed representations of the LCP array directly from a CSA.

  10. Magnetocardiogram measured by fundamental mode orthogonal fluxgate array

    NASA Astrophysics Data System (ADS)

    Karo, Hikaru; Sasada, Ichiro

    2015-05-01

    Magnetocardiography (MCG) of healthy volunteers has been measured by using a fundamental mode orthogonal fluxgate magnetometer array of 32 channels in a magnetic shielded room (MSR). Sensor heads, which are employed, consist of a 45 mm long U-shaped amorphous wire core and a 1000-turn solenoid pick-up coil of 30 mm in length and 3 mm in outer diameter. The excitation current of 100 kHz with large dc bias current is fed directly into wire cores, which are connected in series, whereas the signal detection circuit is provided to each of the sensor heads. A special technique to avoid mutual interaction between sensor heads is implemented, where all the sensor heads are excited synchronously by using a single ac source. A 2-D array having 32 sensors with 4 cm grid spacing was used to measure MCG signals inside an MSR. Measured data from each channel were first filtered (0.16-100 Hz pass band), then averaged for 2 min synchronously with electrocardiogram's peaks taken from both hands. Noise remaining after the average is about 1.8 pTrms for the band-width of 0.16-100 Hz. The QRS complex and the T-wave are clearly detected.

  11. 29 CFR 1917.93 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Head protection. 1917.93 Section 1917.93 Labor Regulations...) MARINE TERMINALS Personal Protection § 1917.93 Head protection. (a) The employer shall ensure that each... the head from falling objects. (b)(1) The employer must ensure that head protection complies with...

  12. 29 CFR 1917.93 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Head protection. 1917.93 Section 1917.93 Labor Regulations...) MARINE TERMINALS Personal Protection § 1917.93 Head protection. (a) The employer shall ensure that each... the head from falling objects. (b)(1) The employer must ensure that head protection complies with...

  13. 29 CFR 1926.100 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Head protection. 1926.100 Section 1926.100 Labor... § 1926.100 Head protection. (a) Employees working in areas where there is a possible danger of head... Institute, Z89.1-1969, Safety Requirements for Industrial Head Protection. (c) Helmets for the...

  14. 29 CFR 1917.93 - Head protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Head protection. 1917.93 Section 1917.93 Labor Regulations...) MARINE TERMINALS Personal Protection § 1917.93 Head protection. (a) The employer shall ensure that each... the head from falling objects. (b)(1) The employer must ensure that head protection complies with...

  15. 29 CFR 1917.93 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Head protection. 1917.93 Section 1917.93 Labor Regulations...) MARINE TERMINALS Personal Protection § 1917.93 Head protection. (a) The employer shall ensure that each... the head from falling objects. (b)(1) The employer must ensure that head protection complies with...

  16. 29 CFR 1917.93 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Head protection. 1917.93 Section 1917.93 Labor Regulations...) MARINE TERMINALS Personal Protection § 1917.93 Head protection. (a) The employer shall ensure that each... the head from falling objects. (b)(1) The employer must ensure that head protection complies with...

  17. Communicating printed headings to the ear.

    PubMed

    Lorch, Robert F; Chen, Hung-Tao; Jawahir, Aqeel A; Lemarié, Julie

    2016-05-01

    Two experiments compared three methods of translating printed headings into an auditory format. In both experiments, college students listened to a text with instructions to stop the recording whenever they heard a heading and type the hierarchical level and exact wording of the heading. Listeners were poor at identifying headings and their levels if the headings were not distinguished from the rest of the text. However, listeners were very good at identifying headings if any method of signalling was used to distinguish headings and communicate their hierarchical level. The methods included: (1) tones preceding headings, (2) changes of speaker to indicate headings or (3) verbal labels preceding headings. Although all three signalling methods improved identification of a heading's hierarchical level, the labelling method was the most effective means of communicating hierarchical level. Thus, the study identifies a simple method of effectively communicating headings in spoken text. Practitioner Summary: The study attempted to identify effective ways of communicating heading information in spoken text. College students listened to texts in order to detect headings and record their wording and hierarchical level. Performance was excellent when headings were preceded by verbal phrases that signalled the upcoming headings and their levels. PMID:27267653

  18. Flexible and Array Eddy Current Probes for Fast Inspection of Complex Parts

    NASA Astrophysics Data System (ADS)

    Marchand, B.; Decitre, J. M.; Casula, O.

    2010-02-01

    Eddy Current is a powerful mean of detection of detects located in conductive parts. This technique has already proved great performances and brought solutions to different industrial issues in nuclear or aeronautics domains for instance. Probes used in Non Destructive Testing (NDT) are mainly based on winding coils. This technology has shown good efficiency and gave good results in a lot of applications. Nonetheless, it reveals some limits in some cases, when the part has a complex shape for instance or when the defect is deeply buried. Therefore, other technologies have been developed at CEA LIST. An original scheme, optimized using the NDT platform CIVA, led to the development of a 32-elements flexible probe, based on micro-coils. Experimental testing reveals its efficiency in the detection of small surface defects. In other hand, magnetic sensors are very attractive for NDT. Thanks to their small size, a 22-GMRs arrays probe and a 96-AMRs array probes have been achieved. Their high spatial resolution and efficiency in the detection of small defects are demonstrated. The high sensitivity of magnetic sensors at low frequency has been used to design a flexible probe dedicated to the detection of deep defects. Its design and experimental testing are given.

  19. Imaging antenna arrays

    NASA Technical Reports Server (NTRS)

    Rutledge, D. B.; Muha, M. S.

    1982-01-01

    Many millimeter and far-infrared imaging systems are limited in sensitivity and speed because they depend on a single scanned element. Because of recent advances in planar detectors such as Schottky diodes, superconducting tunnel junctions, and microbolometers, an attractive approach to this problem is a planar antenna array with integrated detectors. A planar line antenna array and optical system for imaging has been developed. The significant advances are a 'reverse-microscope' optical configuration and a modified bow-tie antenna design. In the 'reverse-microscope' configuration, a lens is attached to the bottom of the substrate containing the antennas. Imaging is done through the substrate. This configuration eliminates the troublesome effects of substrate surface waves. The substrate lens has only a single refracting surface, making possible a virtually aplanatic system, with little spherical aberration or coma. The array is characterized by an optical transfer function that is easily measured. An array with 19 dB crosstalk levels between adjacent antennas has been tested and it was found that the array captured 50 percent of the available power. This imaging system was diffraction limited.

  20. Striped tertiary storage arrays

    NASA Technical Reports Server (NTRS)

    Drapeau, Ann L.

    1993-01-01

    Data stripping is a technique for increasing the throughput and reducing the response time of large access to a storage system. In striped magnetic or optical disk arrays, a single file is striped or interleaved across several disks; in a striped tape system, files are interleaved across tape cartridges. Because a striped file can be accessed by several disk drives or tape recorders in parallel, the sustained bandwidth to the file is greater than in non-striped systems, where access to the file are restricted to a single device. It is argued that applying striping to tertiary storage systems will provide needed performance and reliability benefits. The performance benefits of striping for applications using large tertiary storage systems is discussed. It will introduce commonly available tape drives and libraries, and discuss their performance limitations, especially focusing on the long latency of tape accesses. This section will also describe an event-driven tertiary storage array simulator that is being used to understand the best ways of configuring these storage arrays. The reliability problems of magnetic tape devices are discussed, and plans for modeling the overall reliability of striped tertiary storage arrays to identify the amount of error correction required are described. Finally, work being done by other members of the Sequoia group to address latency of accesses, optimizing tertiary storage arrays that perform mostly writes, and compression is discussed.

  1. Folding of Nucleosome Arrays

    NASA Astrophysics Data System (ADS)

    Howell, Steven; Jimenez-Useche, Isabel; Andresen, Kurt; Yuan, Chongli; Qiu, Xiangyun

    2014-03-01

    Chromatin conformation and dynamics is central to gene functions including packaging, regulation, and repair. At the molecular level, the basic building block of chromatin is a nucleosome core particle (NCP) made of 147 base pairs (bp) of dsDNA wrapped around an octamer of histone proteins. These NCPs are connected by short 10-90 bps of linker DNA as beads on a string. Key factors determining the packaging of NCP arrays to form chromatin include ionic condition, linker DNA length, and epigenetic modifications, especially of the histone tails. We have investigated how the conformations of model tetra-NCP arrays are modulated by these factors using small angle x-ray scattering (SAXS). Here we present recent studies of the effects of ion (KCl and MgCl2), linker length, and histone modification (tail deletions) on NCP arrays. Our SAXS measurement makes it possible to learn about both the global compaction of NCP arrays and local inter-NCP spatial correlations within the same array.

  2. Solar array flight experiment

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Emerging satellite designs require increasing amounts of electrical power to operate spacecraft instruments and to provide environments suitable for human habitation. In the past, electrical power was generated by covering rigid honeycomb panels with solar cells. This technology results in unacceptable weight and volume penalties when large amounts of power are required. To fill the need for large-area, lightweight solar arrays, a fabrication technique in which solar cells are attached to a copper printed circuit laminated to a plastic sheet was developed. The result is a flexible solar array with one-tenth the stowed volume and one-third the weight of comparably sized rigid arrays. An automated welding process developed to attack the cells to the printed circuit guarantees repeatable welds that are more tolerant of severe environments than conventional soldered connections. To demonstrate the flight readiness of this technology, the Solar Array Flight Experiment (SAFE) was developed and flown on the space shuttle Discovery in September 1984. The tests showed the modes and frequencies of the array to be very close to preflight predictions. Structural damping, however, was higher than anticipated. Electrical performance of the active solar panel was also tested. The flight performance and postflight data evaluation are described.

  3. Si Radial p-i-n Junction Photovoltaic Arrays with Built-In Light Concentrators.

    PubMed

    Yoo, Jinkyoung; Nguyen, Binh-Minh; Campbell, Ian H; Dayeh, Shadi A; Schuele, Paul; Evans, David; Picraux, S Tom

    2015-05-26

    High-performance photovoltaic (PV) devices require strong light absorption, low reflection and efficient photogenerated carrier collection for high quantum efficiency. Previous optical studies of vertical wires arrays have revealed that extremely efficient light absorption in the visible wavelengths is achievable. Photovoltaic studies have further advanced the wire approach by employing radial p-n junction architectures to achieve more efficient carrier collection. While radial p-n junction formation and optimized light absorption have independently been considered, PV efficiencies have further opportunities for enhancement by exploiting the radial p-n junction fabrication procedures to form arrays that simultaneously enhance both light absorption and carrier collection efficiency. Here we report a concept of morphology control to improve PV performance, light absorption and quantum efficiency of silicon radial p-i-n junction arrays. Surface energy minimization during vapor phase epitaxy is exploited to form match-head structures at the tips of the wires. The match-head structure acts as a built-in light concentrator and enhances optical absorptance and external quantum efficiencies by 30 to 40%, and PV efficiency under AM 1.5G illumination by 20% compared to cylindrical structures without match-heads. The design rules for these improvements with match-head arrays are systematically studied. This approach of process-enhanced control of three-dimensional Si morphologies provides a fab-compatible way to enhance the PV performance of Si radial p-n junction wire arrays. PMID:25961330

  4. The perception of heading during eye movements

    NASA Technical Reports Server (NTRS)

    Royden, Constance S.; Banks, Martin S.; Crowell, James A.

    1992-01-01

    Warren and Hannon (1988, 1990), while studying the perception of heading during eye movements, concluded that people do not require extraretinal information to judge heading with eye/head movements present. Here, heading judgments are examined at higher, more typical eye movement velocities than the extremely slow tracking eye movements used by Warren and Hannon. It is found that people require extraretinal information about eye position to perceive heading accurately under many viewing conditions.

  5. Synchronizing large systolic arrays

    SciTech Connect

    Fisher, A.L.; Kung, H.T.

    1982-04-01

    Parallel computing structures consist of many processors operating simultaneously. If a concurrent structure is regular, as in the case of systolic array, it may be convenient to think of all processors as operating in lock step. Totally synchronized systems controlled by central clocks are difficult to implement because of the inevitable problem of clock skews and delays. An alternate means of enforcing necessary synchronization is the use of self-timed, asynchronous schemes, at the cost of increased design complexity and hardware cost. Realizing that different circumstances call for different synchronization methods, this paper provides a spectrum of synchronization models; based on the assumptions made for each model, theoretical lower bounds on clock skew are derived, and appropriate or best-possible synchronization schemes for systolic arrays are proposed. This paper represents a first step towards a systematic study of synchronization problems for large systolic arrays.

  6. Red microchip VECSEL array

    NASA Astrophysics Data System (ADS)

    Hastie, Jennifer E.; Morton, Lynne G.; Calvez, Stephane; Dawson, Martin D.; Leinonen, Tomi; Pessa, Markus; Gibson, Graham; Padgett, Miles J.

    2005-09-01

    We report an InGaP/AlInGaP/GaAs microchip vertical-external-cavity surface emitting laser operating directly at red wavelengths and demonstrate its potential for array-format operation. Optical pumping with up to 3.3W at 532nm produced a maximum output power of 330mW at 675nm, in a single circularly-symmetric beam with M2<2. Simultaneous pumping with three separate input beams, generated using a diffractive optical element, achieved lasing from three discrete areas of the same chip. Output power of ~95mW per beam was obtained from this 3x1 array, each beam having a Gaussian intensity profile with M2<1.2. In a further development, a spatial light modulator allowed computer control over the orientation and separation of the pump beams, and hence dynamic control over the configuration of the VECSEL array.

  7. Red microchip VECSEL array.

    PubMed

    Hastie, Jennifer; Morton, Lynne; Calvez, Stephane; Dawson, Martin; Leinonen, Tomi; Pessa, Markus; Gibson, Graham; Padgett, Miles

    2005-09-01

    We report an InGaP/AlInGaP/GaAs microchip vertical-external-cavity surface emitting laser operating directly at red wavelengths and demonstrate its potential for array-format operation. Optical pumping with up to 3.3W at 532nm produced a maximum output power of 330mW at 675nm, in a single circularly-symmetric beam with M2<2. Simultaneous pumping with three separate input beams, generated using a diffractive optical element, achieved lasing from three discrete areas of the same chip. Output power of ~95mW per beam was obtained from this 3x1 array, each beam having a Gaussian intensity profile with M2<1.2. In a further development, a spatial light modulator allowed computer control over the orientation and separation of the pump beams, and hence dynamic control over the configuration of the VECSEL array. PMID:19498743

  8. FEL phased array configurations

    NASA Astrophysics Data System (ADS)

    Shellan, Jeffrey B.

    1986-01-01

    The advantages and disadvantages of various phased array and shared aperture concepts for FEL configurations are discussed. Consideration is given to the characteristics of intra- and inter-micropulse phasing; intra-macropulse phasing; an internal coupled resonator configuration; and an injection locked oscillator array. The use of a master oscillator power amplifier (MOPA) configuration with multiple or single master oscillators for FELs is examined. The venetian blind, rotating plate, single grating, and grating rhomb shared aperture concepts are analyzed. It is noted that the shared aperture approach using a grating rhomb and the MOPA concept with a single master oscillator and a coupled resonator are useful for FEL phased array configurations; and the MOPA concept is most applicable.

  9. Electrostatically clean solar array

    NASA Technical Reports Server (NTRS)

    Stern, Theodore Garry (Inventor); Krumweide, Duane Eric (Inventor)

    2004-01-01

    Provided are methods of manufacturing an electrostatically clean solar array panel and the products resulting from the practice of these methods. The preferred method uses an array of solar cells, each with a coverglass where the method includes machining apertures into a flat, electrically conductive sheet so that each aperture is aligned with and undersized with respect to its matched coverglass sheet and thereby fashion a front side shield with apertures (FSA). The undersized portion about each aperture of the bottom side of the FSA shield is bonded to the topside portions nearest the edges of each aperture's matched coverglass. Edge clips are attached to the front side aperture shield edges with the edge clips electrically and mechanically connecting the tops of the coverglasses to the solar panel substrate. The FSA shield, edge clips and substrate edges are bonded so as to produce a conductively grounded electrostatically clean solar array panel.

  10. Wireless Josephson Junction Arrays

    NASA Astrophysics Data System (ADS)

    Adams, Laura

    2015-03-01

    We report low temperature, microwave transmission measurements on a wireless two- dimensional network of Josephson junction arrays composed of superconductor-insulator -superconductor tunnel junctions. Unlike their biased counterparts, by removing all electrical contacts to the arrays and superfluous microwave components and interconnects in the transmission line, we observe new collective behavior in the transmission spectra. In particular we will show emergent behavior that systematically responds to changes in microwave power at fixed temperature. Likewise we will show the dynamic and collective response of the arrays while tuning the temperature at fixed microwave power. We discuss these spectra in terms of the Berezinskii-Kosterlitz-Thouless phase transition and Shapiro steps. We gratefully acknowledge the support Prof. Steven Anlage at the University of Maryland and Prof. Allen Goldman at the University of Minnesota. Physics and School of Engineering and Applied Sciences.

  11. Coaxial phased array antenna

    NASA Astrophysics Data System (ADS)

    Ellis, H., Jr.

    1980-08-01

    A coaxial antenna array for communicating circularly polarized electromagnetic radiation is disclosed. A pair of open ended antenna cavities is coaxially constructed and operates by excitation of linear radiation elements arranged within each of the cavities. A pair of crossed dipole radiation devices is centered within the inner cavity and operated by means of a phase shifting network circuit to transmit as well as receive circularly polarized radiation. Four monopole radiation devices are symmetrically arranged to operate in the outer cavity in phase quadrature by means of the phase shifting network circuit to both transmit and receive circularly polarized electromagnetic radiation. Combined operation of the two antenna cavities with a 180 deg phase differential between the fields related to the two antenna cavities provides a broad beam, relatively wide frequency bandwidth communication capability. Particular embodiments disclosed feature a generally square cavity array as well as a circular cavity array.

  12. Coaxial phased array antenna

    NASA Technical Reports Server (NTRS)

    Ellis, H., Jr. (Inventor)

    1980-01-01

    A coaxial antenna array for communicating circularly polarized electromagnetic radiation is disclosed. A pair of open ended antenna cavities is coaxially constructed and operates by excitation of linear radiation elements arranged within each of the cavities. A pair of crossed dipole radiation devices is centered within the inner cavity and operated by means of a phase shifting network circuit to transmit as well as receive circularly polarized radiation. Four monopole radiation devices are symmetrically arranged to operate in the outer cavity in phase quadrature by means of the phase shifting network circuit to both transmit and receive circularly polarized electromagnetic radiation. Combined operation of the two antenna cavities with a 180 deg phase differential between the fields related to the two antenna cavities provides a broad beam, relatively wide frequency bandwidth communication capability. Particular embodiments disclosed feature a generally square cavity array as well as a circular cavity array.

  13. Pyroelectric detector arrays

    NASA Technical Reports Server (NTRS)

    Fripp, A. L.; Robertson, J. B.; Breckenridge, R. (Inventor)

    1982-01-01

    A pyroelectric detector array and the method for using it are described. A series of holes formed through a silicon dioxide layer on the surface of a silicon substrate forms the mounting fixture for the pyroelectric detector array. A series of nontouching strips of indium are formed around the holes to make contact with the backside electrodes and form the output terminals for individual detectors. A pyroelectric detector strip with front and back electrodes, respectively, is mounted over the strips. Biasing resistors are formed on the surface of the silicon dioxide layer and connected to the strips. A metallized pad formed on the surface of layer is connected to each of the biasing resistors and to the film to provide the ground for the pyroelectric detector array.

  14. Pyroelectric detector arrays

    NASA Technical Reports Server (NTRS)

    Fripp, A. L.; Robertson, J. B.; Breckenridge, R. A. (Inventor)

    1982-01-01

    A pryoelectric detector array and the method for making it are described. A series of holes formed through a silicon dioxide layer on the surface of a silicon substrate forms the mounting fixture for the pyroelectric detector array. A series of nontouching strips of indium are formed around the holes to make contact with the backside electrodes and form the output terminals for individual detectors. A pyroelectric detector strip with front and back electrodes, respectively, is mounted over the strip. Biasing resistors are formed on the surface of the silicon dioxide layer and connected to the strips. A metallized pad formed on the surface of the layer is connected to each of the biasing resistors and to the film to provide the ground for the pyroelectric detector array.

  15. Optical logic array processor

    SciTech Connect

    Tanida, J.; Ichioka, Y.

    1983-01-01

    A simple method for optically implementing digital logic gates in parallel has been developed. Parallel logic gates can be achieved by using a lensless shadow-casting system with a light emitting diode array as an incoherent light source. All the sixteen logic functions for two binary variables, which are the fundamental computations of Boolean algebra, can be simply realised in parallel with these gates by changing the switching modes of a led array. Parallel computation structures of the developed optical digital array processor are demonstrated by implementing pattern logics for two binary images with high space-bandwidth product. Applications of the proposed method to parallel shift operation of the image, differentiation, and processing of gray-level image are shown. 9 references.

  16. Efficient Dual Head Nd:YAG 100mJ Oscillator for Remote Sensing

    NASA Technical Reports Server (NTRS)

    Coyle, Donald B.; Stysley, Paul R.; Kay, Richard b.; Poulios, Demetrios

    2007-01-01

    A diode pumped, Nd:YAG laser producing 100 mJ Q-switched pulses and employing a dual-pump head scheme in an unstable resonator configuration is described. Each head contains a side pumped zig-zag slab and four 6-bar QCW 808 nm diodes arrays which are de-rated 23%. Denoting 'z' as the lasing axis, the pump directions were along the x-axis in one head and the y-axis in the other, producing a circularized thermal lens, more typical in laser rod-based cavities. The dual head design's effective thermal lens is now corrected with a proper HR mirror curvature selection. This laser has demonstrated over 100 mJ output with high optical efficiency (24%), good TEM(sub 00) beam quality, and high pointing stability.

  17. Visualization of Head–Head Interactions in the Inhibited State of Smooth Muscle Myosin

    PubMed Central

    Wendt, Thomas; Taylor, Dianne; Messier, Terri; Trybus, Kathleen M.; Taylor, Kenneth A.

    1999-01-01

    The structural basis for the phosphoryla- tion-dependent regulation of smooth muscle myosin ATPase activity was investigated by forming two- dimensional (2-D) crystalline arrays of expressed unphosphorylated and thiophosphorylated smooth muscle heavy meromyosin (HMM) on positively charged lipid monolayers. A comparison of averaged 2-D projections of both forms at 2.3-nm resolution reveals distinct structural differences. In the active, thiophosphorylated form, the two heads of HMM interact intermolecularly with adjacent molecules. In the unphosphorylated or inhibited state, intramolecular interactions position the actin-binding interface of one head onto the converter domain of the second head, thus providing a mechanism whereby the activity of both heads could be inhibited. PMID:10613897

  18. Photovoltaic array performance model.

    SciTech Connect

    Kratochvil, Jay A.; Boyson, William Earl; King, David L.

    2004-08-01

    This document summarizes the equations and applications associated with the photovoltaic array performance model developed at Sandia National Laboratories over the last twelve years. Electrical, thermal, and optical characteristics for photovoltaic modules are included in the model, and the model is designed to use hourly solar resource and meteorological data. The versatility and accuracy of the model has been validated for flat-plate modules (all technologies) and for concentrator modules, as well as for large arrays of modules. Applications include system design and sizing, 'translation' of field performance measurements to standard reporting conditions, system performance optimization, and real-time comparison of measured versus expected system performance.

  19. Array signal processing

    SciTech Connect

    Haykin, S.; Justice, J.H.; Owsley, N.L.; Yen, J.L.; Kak, A.C.

    1985-01-01

    This is the first book to be devoted completely to array signal processing, a subject that has become increasingly important in recent years. The book consists of six chapters. Chapter 1, which is introductory, reviews some basic concepts in wave propagation. The remaining five chapters deal with the theory and applications of array signal processing in (a) exploration seismology, (b) passive sonar, (c) radar, (d) radio astronomy, and (e) tomographic imaging. The various chapters of the book are self-contained. The book is written by a team of five active researchers, who are specialists in the individual fields covered by the pertinent chapters.

  20. Wire Array Photovoltaics

    NASA Astrophysics Data System (ADS)

    Turner-Evans, Dan

    Over the past five years, the cost of solar panels has dropped drastically and, in concert, the number of installed modules has risen exponentially. However, solar electricity is still more than twice as expensive as electricity from a natural gas plant. Fortunately, wire array solar cells have emerged as a promising technology for further lowering the cost of solar. Si wire array solar cells are formed with a unique, low cost growth method and use 100 times less material than conventional Si cells. The wires can be embedded in a transparent, flexible polymer to create a free-standing array that can be rolled up for easy installation in a variety of form factors. Furthermore, by incorporating multijunctions into the wire morphology, higher efficiencies can be achieved while taking advantage of the unique defect relaxation pathways afforded by the 3D wire geometry. The work in this thesis shepherded Si wires from undoped arrays to flexible, functional large area devices and laid the groundwork for multijunction wire array cells. Fabrication techniques were developed to turn intrinsic Si wires into full p-n junctions and the wires were passivated with a-Si:H and a-SiNx:H. Single wire devices yielded open circuit voltages of 600 mV and efficiencies of 9%. The arrays were then embedded in a polymer and contacted with a transparent, flexible, Ni nanoparticle and Ag nanowire top contact. The contact connected >99% of the wires in parallel and yielded flexible, substrate free solar cells featuring hundreds of thousands of wires. Building on the success of the Si wire arrays, GaP was epitaxially grown on the material to create heterostructures for photoelectrochemistry. These cells were limited by low absorption in the GaP due to its indirect bandgap, and poor current collection due to a diffusion length of only 80 nm. However, GaAsP on SiGe offers a superior combination of materials, and wire architectures based on these semiconductors were investigated for multijunction

  1. Automated array assembly

    NASA Technical Reports Server (NTRS)

    Williams, B. F.

    1976-01-01

    Manufacturing techniques are evaluated using expenses based on experience and studying basic cost factors for each step to evaluate expenses from a first-principles point of view. A formal cost accounting procedure is developed which is used throughout the study for cost comparisons. The first test of this procedure is a comparison of its predicted costs for array module manufacturing with costs from a study which is based on experience factors. A manufacturing cost estimate for array modules of $10/W is based on present-day manufacturing techniques, expenses, and materials costs.

  2. Solar array subsystems study

    NASA Technical Reports Server (NTRS)

    Richardson, P. W.; Miller, F. Q.; Badgley, M. B.

    1980-01-01

    The effects on life cycle costs of a number of technology areas are examined for a LEO, 500 kW solar array. A baseline system conceptual design is developed and the life cycle costs estimated in detail. The baseline system requirements and design technologies are then varied and their relationships to life cycle costs quantified. For example, the thermal characteristics of the baseline design are determined by the array materials and masses. The thermal characteristics in turn determine configuration, performance and hence life cycle cost.

  3. Soldered solar arrays

    NASA Astrophysics Data System (ADS)

    Allen, H. C.

    1982-06-01

    The ability of soldered interconnects to withstand a combination of long life and severe environmental conditions was investigated. Improvements in joint life from the use of solder mixes appropriate to low temperature conditons were studied. Solder samples were placed in a 150 C oven for 5 weeks (= 12 yr at 80 C, or 24 at 70 C according to Arrhenius's rule). Conventional and high solder melting point array samples underwent 1000 thermal cycles between -186 and 100 C. Results show that conventional and lead rich soldered arrays can survive 10 yr geostationary orbit missions.

  4. Nanocone array glass

    NASA Astrophysics Data System (ADS)

    D'Urso, Brian; Simpson, John T.; Kalyanaraman, Meenaa

    2007-04-01

    We report a novel method of producing ordered arrays of glass nanocones with precisely controlled height, lattice constant and aspect ratio. As with nanochannel glass, fibre drawing, bundling and redrawing are used to produce structured glass composite material. The surface of the composite is etched to form nanocones through a differential etching process. The lattice constant of the arrays ranges from 40 µm to 1.6 µm, while the aspect ratio of the nanocones is varied from 0.4 to 13 by simple changes in the chemistry of the hydrofluoric acid etching solution.

  5. Pulsar Timing Arrays - towards the SKA and beyond

    NASA Astrophysics Data System (ADS)

    Stappers, Ben

    2015-08-01

    I will discuss the development of pulsar timing arrays as we head towards the Square Kilometre Array and then beyond. This will address where progress needs to be made in terms of sensitivity to gravitational waves including improvements to existing observing approaches and new telescopes such as MeerKAT and FAST and techniques like LEAP. Developments in analytic techniques will also be discussed such as removal of interstellar medium effects, red noise and pulse profile variations. With the likelihood that the SKA will implement some form of Key Science Project approach, some ideas of how will this affect how the International Pulsar Timing Array effort and how it might evolve into a KSP will be presented.

  6. 49 CFR 33.32 - Elements of a rated order.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... CFR Part 33. (2) If the rated order is placed in support of emergency preparedness requirements and... 49 CFR Part 33. ... 49 Transportation 1 2012-10-01 2012-10-01 false Elements of a rated order. 33.32 Section...

  7. 49 CFR 33.32 - Elements of a rated order.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... CFR Part 33. (2) If the rated order is placed in support of emergency preparedness requirements and... 49 CFR Part 33. ... 49 Transportation 1 2014-10-01 2014-10-01 false Elements of a rated order. 33.32 Section...

  8. 10 CFR 217.32 - Elements of a rated order.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Energy Priorities and Allocations System regulation at 10 CFR part 217. (2) If the rated order is placed... imminent hazard, as specified in EPAS Section 217.33(e), 10 CFR 217.33(e). ... 10 Energy 3 2014-01-01 2014-01-01 false Elements of a rated order. 217.32 Section 217.32...

  9. 10 CFR 217.32 - Elements of a rated order.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Energy Priorities and Allocations System regulation at 10 CFR part 217. (2) If the rated order is placed... imminent hazard, as specified in EPAS Section 217.33(e), 10 CFR 217.33(e). ... 10 Energy 3 2013-01-01 2013-01-01 false Elements of a rated order. 217.32 Section 217.32...

  10. 49 CFR 33.32 - Elements of a rated order.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... CFR Part 33. (2) If the rated order is placed in support of emergency preparedness requirements and... 49 CFR Part 33. ... 49 Transportation 1 2013-10-01 2013-10-01 false Elements of a rated order. 33.32 Section...

  11. 10 CFR 217.32 - Elements of a rated order.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Energy Priorities and Allocations System regulation at 10 CFR part 217. (2) If the rated order is placed... imminent hazard, as specified in EPAS Section 217.33(e), 10 CFR 217.33(e). ... 10 Energy 3 2012-01-01 2012-01-01 false Elements of a rated order. 217.32 Section 217.32...

  12. Photovoltaic module kit including connector assembly for non-penetrating array installation

    DOEpatents

    Botkin, Jonathan; Graves, Simon; Danning, Matt; Culligan, Matthew

    2011-11-22

    A PV module kit for non-penetrating rooftop installation, including a plurality of PV modules and a plurality of connectors. Each of the PV modules includes a PV laminate and a frame forming a mounting region assembled thereto. The connectors include a male connector having a male fastener extending from a head, and a female connector having a female fastener assembled within a head. The heads are entirely formed of plastic. The kit provides a mounted array state including a junction at which the mounting region of at least two of the PV modules are aligned and interconnected by engagement of the male connector with the female connector. The so-formed junction is substantially electrically insulated. The plurality of connectors can further include a spacer connector including a head forming a bore sized to slidably receive the male fastener, with all of the connector heads being identical.

  13. Photovoltaic module kit including connector assembly for non-penetrating array installation

    DOEpatents

    Botkin, Jonathan; Graves, Simon; Danning, Matt; Culligan, Matthew

    2013-12-31

    A PV module kit for non-penetrating rooftop installation, including a plurality of PV modules and a plurality of connectors. Each of the PV modules includes a PV laminate and a frame forming a mounting region assembled thereto. The connectors include a male connector having a male fastener extending from a head, and a female connector having a female fastener assempbled within a head. The heads are entirely formed of plastic. The kit provides a mounted array state including a junction at which the mounting regions of at least two of the PV modules are aligned and interconnected by engagement of the male connector with the female connector. The so-formed junction is substantially electrically insulated. The plurality of connectors can further include a spacer connector including a head forming a bore sized slidably receive the male fastener, with all of the connector heads being identical.

  14. Photovoltaic module kit including connector assembly for non-penetrating array installation

    DOEpatents

    Botkin, Jonathan; Graves, Simon; Danning, Matt; Culligan, Matthew

    2012-10-23

    A PV module kit for non-penetrating rooftop installation, including a plurality of PV modules and a plurality of connectors. Each of the PV modules includes a PV laminate and a frame forming a mounting region assembled thereto. The connectors include a male connector having a male fastener extending from a head, and a female connector having a female fastener assembled within a head. The heads are entirely formed of plastic. The kit provides a mounted array state including a junction at which the mounting region of at least two of the PV modules are aligned and interconnected by engagement of the male connector with the female connector. The so-formed junction is substantially electrically insulated. The plurality of connectors can further include a spacer connector including a head forming a bore sized to slidably receive the male fastener, with all of the connector heads being identical.

  15. Development and use of a spherical microphone array for measurement of spatial properties of reverberant sound fields

    NASA Astrophysics Data System (ADS)

    Gover, Bradford Noel

    The problem of hands-free speech pick-up is introduced, and it is identified how details of the spatial properties of the reverberant field may be useful for enhanced design of microphone arrays. From this motivation, a broadly-applicable measurement system has been developed for the analysis of the directional and spatial variations in reverberant sound fields. Two spherical, 32-element arrays of microphones are used to generate narrow beams over two different frequency ranges, together covering 300--3300 Hz. Using an omnidirectional loudspeaker as excitation in a room, the pressure impulse response in each of 60 steering directions is measured. Through analysis of these responses, the variation of arriving energy with direction is studied. The system was first validated in simple sound fields in an anechoic chamber and in a reverberation chamber. The system characterizes these sound fields as expected, both quantitatively through numerical descriptors and qualitatively from plots of the arriving energy versus direction. The system was then used to measure the sound fields in several actual rooms. Through both qualitative and quantitative output, these sound fields were seen to be highly anisotropic, influenced greatly by the direct sound and early-arriving reflections. Furthermore, the rate of sound decay was not independent of direction, sound being absorbed more rapidly in some directions than in others. These results are discussed in the context of the original motivation, and methods for their application to enhanced speech pick-up using microphone arrays are proposed.

  16. [Bobble-head doll syndrome].

    PubMed

    Roubergue, A; Beauvais, P; Richardet, J M

    1985-05-01

    A new case of Bobble-head doll syndrome with aqueductal stenosis is presented in a 14 year-old boy. Ventriculocisternostomy performed 8 years after the onset of the abnormal movement resulted in moderate reduction of the head bobbling. Twenty-two cases were found in a review of the literature. In all cases there was a chronic slowly progressive hydrocephalus with usually a cyst of the third ventricle; aqueductal stenosis was less frequent. When recorded, psychomotor development was impaired. Treatment is neurosurgical. Pathogenesis remains unknown. PMID:4074089

  17. Rotary head type reproducing apparatus

    DOEpatents

    Takayama, Nobutoshi; Edakubo, Hiroo; Kozuki, Susumu; Takei, Masahiro; Nagasawa, Kenichi

    1986-01-01

    In an apparatus of the kind arranged to reproduce, with a plurality of rotary heads, an information signal from a record bearing medium having many recording tracks which are parallel to each other with the information signal recorded therein and with a plurality of different pilot signals of different frequencies also recorded one by one, one in each of the recording tracks, a plurality of different reference signals of different frequencies are simultaneously generated. A tracking error is detected by using the different reference signals together with the pilot signals which are included in signals reproduced from the plurality of rotary heads.

  18. Variation in natural head position and establishing corrected head position.

    PubMed

    Barbera, A L; Sampson, W J; Townsend, G C

    2014-06-01

    Corrected head position (CHP) has been simulated by using the Frankfurt horizontal (FH) for over 100 years but FH varies between individuals. Because CHP is biologically relevant for orthodontic diagnosis and treatment planning, orthognathic surgical planning, and art, this study examined relationships between head position and selected cephalometric planes. Natural head position cephalograms of Aboriginal Australians and two contemporary samples from private orthodontic practices were analysed. Each sample comprised 40 individuals (20 males and 20 females). The Aboriginal Australian sample comprised longitudinal data (T1 early adolescent, T2 late adolescent, and T3 adult), enabling examination of natural head position (NHP) reproducibility over a period of approximately 8 years. Results of reproducibility differences revealed an absolute mean=2.9°, range=-7.9° to 8.2°, and standard deviation=3.6°. Stable basicranial line (SBL), neutral horizontal axis (NHA), FH, palatal plane (P plane), and Krogman-Walker plane (KW plane) demonstrated near parallelism and their mean angulations from the true horizontal (HOR) ranged between -4.6° and 2.4°. While NHP is not consistently reproducible at the individual level, the combined use of multiple planes such as SBL, P plane, and KW plane enables a more consistent CHP to be achieved. PMID:24785580

  19. Head kinematics during shaking associated with abusive head trauma.

    PubMed

    Lintern, T O; Puhulwelle Gamage, N T; Bloomfield, F H; Kelly, P; Finch, M C; Taberner, A J; Nash, M P; Nielsen, P M F

    2015-09-18

    Abusive head trauma (AHT) is a potentially fatal result of child abuse but the mechanisms of injury are controversial. To address the hypothesis that shaking alone is sufficient to elicit the injuries observed, effective computational and experimental models are necessary. This paper investigates the use of a coupled rigid-body computational modelling framework to reproduce in vivo shaking kinematics in AHT. A sagittal plane OpenSim computational model of a lamb was developed and used to interpret biomechanical data from in vivo shaking experiments. The acceleration of the head during shaking was used to provide in vivo validation of the associated computational model. Results of this study demonstrated that peak accelerations occurred when the head impacted the torso and produced acceleration magnitudes exceeding 200ms(-)(2). The computational model demonstrated good agreement with the experimental measurements and was shown to be able to reproduce the high accelerations that occur during impact. The biomechanical results obtained with the computational model demonstrate the utility of using a coupled rigid-body modelling framework to describe infant head kinematics in AHT. PMID:26256822

  20. Array processors in chemistry

    SciTech Connect

    Ostlund, N.S.

    1980-01-01

    The field of attached scientific processors (''array processors'') is surveyed, and an attempt is made to indicate their present and possible future use in computational chemistry. The current commercial products from Floating Point Systems, Inc., Datawest Corporation, and CSP, Inc. are discussed.

  1. Automated array assembly

    NASA Technical Reports Server (NTRS)

    Daiello, R. V.

    1977-01-01

    A general technology assessment and manufacturing cost analysis was presented. A near-term (1982) factory design is described, and the results of an experimental production study for the large-scale production of flat-panel silicon and solar-cell arrays are detailed.

  2. Antenna array research

    NASA Technical Reports Server (NTRS)

    Tai, C.

    1973-01-01

    Antenna array research on electromagnetic field problems in inhomogeneous media is presented along with characteristics of the Eaton lens. Comparisons are given of the radiation pattern and directivity of small Luneburg lens with a homogeneous lens. References and figure captions on radiation patterns are included.

  3. Solar-Array Simulator

    NASA Technical Reports Server (NTRS)

    Wright, M. C.

    1982-01-01

    A convenient solar-array simulator has been built for testing systems powered by solar cells. Built for evaluating power extension package in Space Shuttle, the circuit produces the V/I curves of photocell sources; even duplicating transient behavior under partial illumination associated with morning and evening penumbra.

  4. Semiconductor Laser Phased Array

    NASA Technical Reports Server (NTRS)

    Katz, J.

    1985-01-01

    Oscillations synchronized and modulated individually for beam steering. Phased array of GaAs infrared lasers put out powerful electronically-steerable coherent beam. Fabricated as integrated circuit on GaAs chip, new device particularly suited to optical communications, optical data processing and optical detection and ranging systems.

  5. TRMM Solar Array Panels

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This final report presents conclusions/recommendations concerning the TRMM Solar Array; deliverable list and schedule summary; waivers and deviations; as-shipped performance data, including flight panel verification matrix, panel output detail, shadow test summary, humidity test summary, reverse bias test panel; and finally, quality assurance summary.

  6. The Allen Telescope Array

    NASA Astrophysics Data System (ADS)

    Bower, Geoffrey C.; Allen Telescope Array Team

    2010-01-01

    The ATA is a 42-element centimeter wavelength array located in Hat Creek, California and jointly operated by UC Berkeley Radio Astronomy Laboratory and the SETI Institute. Since the ATA dedication in Fall 2007, activities have been focused on commissioning the array, retrofitting a handful of components including the feed, developing an operations model, creation of pipeline processing for correlator imaging data, early science observations, and launching of the major surveys for which the telescope was built. The retrofit of the feed improves feed mechanical robustness as well as high frequency performance. Science programs launched include imaging radio transient and static sky surveys (ATATS and PiGSS), commensal SETI and transient surveys of the Galactic Center, targeted SETI observations of nearby stars, the Fly's Eye transient survey, broadband spectra of nearby star-forming galaxies, polarimetric observations of bright radio sources, observations of hydrogen in nearby galaxies and galaxy groups, molecular line observations in the Galaxy, and observations of Jupiter and the Moon. The baseline Square Kilometer Array (SKA) design, a large-N-small-diameter (LNSD) array with wide-band single-pixel feeds and an offset Gregorian antenna, bears a strong resemblance to the ATA. Additional ATA contributions to the SKA include configuration studies for LNSD arrays, the use of fiber optics for broadband data transmission, the use of flexible FPGA-based digital electronics, passive cooling of antennas, and implementation of commensal observing modes. The ATA is currently used for exploration of calibration and imaging algorithms necessary for the SKA. I will summarize current technical status and performance, the results from early science and surveys, and ATA contributions to SKA development.

  7. Allen Telescope Array

    NASA Astrophysics Data System (ADS)

    Bower, Geoffrey

    2007-05-01

    The Allen Telescope Array (ATA) is a pioneering centimeter-wavelength radio telescope that will produce science that cannot be done with any other instrument. The ATA is the first radio telescope designed for commensal observing; it will undertake the most comprehensive and sensitive SETI surveys ever done as well as the deepest and largest area continuum and spectroscopic surveys. Science operations will commence this year with a 42-element array. The ATA will ultimately comprise 350 6-meter dishes at Hat Creek in California, and will make possible large, deep radio surveys that were not previously feasible. The telescope incorporates many new design features including hydroformed antenna surfaces, a log-periodic feed covering the entire range of frequencies from 500 MHz to 11.2 GHz, low noise, wide-band amplifiers with a flat response over the entire band. The full array has the sensitivity of the Very Large Array but with a survey capability that is greater by an order of magnitude due to the wide field of view of the 6-meter dishes. Even with 42 elements, the ATA will be one of the most powerful radio survey telescopes. Science goals include the Five GHz sky survey (FiGSS) to match the 1.4-GHz NRAO VLA Sky Survey (NVSS) and the Sloan Digital Sky Survey within the first year of operation with the 42 element array, and a deep all-sky survey of extragalactic hydrogen to investigate galaxy evolution and intergalactic gas accretion. Transient and variable source surveys, pulsar science, spectroscopy of new molecular species in the galaxy, large-scale mapping of galactic magnetic filaments, and wide-field imaging of comets and other solar system objects are among the other key science objectives of the ATA. SETI surveys will reach sufficient sensitivity to detect an Arecibo planetary radar from 1,000,000 stars to distances of 300 pc.

  8. Detail of array structural elements through axis of array, looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of array structural elements through axis of array, looking north-northeast - Over-the-Horizon Backscatter Radar Network, Columbia Falls Radar Site Receive Sector Two Antenna Array, At the end of Shadagee Ridge Road, Columbia Falls, Washington County, ME

  9. The Longest Run of Heads.

    ERIC Educational Resources Information Center

    Schilling, Mark F.

    1990-01-01

    Developed are simple recursion formulas for generating the exact distribution of the longest run of heads, both for a fair coin and for a biased coin. Discusses the applications of runs-related phenomena such as molecular biology, Markov chains, geometric variables, and random variables. (YP)

  10. Graham confirmed as OSTP Head

    NASA Astrophysics Data System (ADS)

    William R. Graham was confirmed by the Senate on October 1, 1986, as the science advisor to President Ronald Reagan and head of the Office of Science and Technology Policy (OSTP). Formerly the deputy administrator of the National Aeronautics and Space Administration (NASA), Graham started his new post on October 6.

  11. HANDBOOK FOR PROJECT HEAD START.

    ERIC Educational Resources Information Center

    GRAHAM, JORY

    THIS BOOKLET WAS DESIGNED TO MEET SOME IMMEDIATE NEEDS FOR THE FIRST SUMMER SESSION OF PROJECT HEAD START. IT CONTAINS SOME OF THE MOST WORKABLE AND PROMISING TEACHING METHODS IN THE ENTIRE FIELD OF COMPENSATORY EDUCATIONS, METHODS THAT HAVE BEEN USED IN PRIVATELY SPONSORED CENTERS AND HAVE PROVED VALUABLE IN COPING WITH PROBLEMS ENCOUNTERED IN…

  12. Femoral head cartilage disarticulation disorder

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Femoral head cartilage disarticulation disorder and necrosis is a major skeletal problem in broiler breeders since they are maintained for a long time in the farm. The etiology of this disease is not well understood. A field study was conducted to understand the basis of this metabolic disease. Six ...

  13. Head Start Planned Variation Program.

    ERIC Educational Resources Information Center

    Klein, Jenny

    There is little agreement concerning which methods of preschool intervention are most effective. In order to evaluate several approaches to early childhood education, Project Head Start, in conjunction with Project Follow Through, has initiated the Planned Variation program. This year only a pilot project is underway with eight schools…

  14. Head Start Dental Health Curriculum.

    ERIC Educational Resources Information Center

    Administration for Children, Youth, and Families (DHHS), Washington, DC. Head Start Bureau.

    This curriculum for Head Start programs provides preschool learning experiences that teach about dental health. The majority of the curriculum guide is devoted to the following lesson plans: (1) "Introduction of 'Smiley the Super Pup'," an optional puppet character which may be used to review the concepts covered in each lesson; (2) "Visiting the…

  15. Neuroelectromagnetic Forward Head Modeling Toolbox

    PubMed Central

    Acar, Zeynep Akalin; Makeig, Scott

    2014-01-01

    This paper introduces a Neuroelectromagnetic Forward Head Modeling Toolbox (NFT) running under MATLAB (The Mathworks, Inc.) for generating realistic head models from available data (MRI and/or electrode locations) and for computing numerical solutions for the forward problem of electromagnetic source imaging. The NFT includes tools for segmenting scalp, skull, cerebrospinal fluid (CSF) and brain tissues from T1-weighted magnetic resonance (MR) images. The Boundary Element Method (BEM) is used for the numerical solution of the forward problem. After extracting segmented tissue volumes, surface BEM meshes can be generated. When a subject MR image is not available, a template head model can be warped to measured electrode locations to obtain an individualized head model. Toolbox functions may be called either from a graphic user interface compatible with EEGLAB (http://sccn.ucsd.edu/eeglab), or from the MATLAB command line. Function help messages and a user tutorial are included. The toolbox is freely available under the GNU Public License for noncommercial use and open source development. PMID:20457183

  16. Model of beam head erosion

    SciTech Connect

    Lee, E.P.

    1980-08-08

    An analytical model of beam head dynamics is presented, leading to an estimate of the erosion rate due to the combined effects of Ohmic dissipation and scattering. Agreement with the results of a computer simulation and detailed one-dimensional computations is good in all respects except for the scaling of the erosion rate with net current.

  17. Head nurse or hotel manager?

    PubMed

    McAlvanah, M

    1989-01-01

    The responsibility of making room assignments for patients can be both a challenging and frustrating experience for a head nurse. Many factors must be considered when making room assignments while consumer dissatisfaction with the process must be handled creatively and with understanding. PMID:2734042

  18. Head banging in young children.

    PubMed

    Vinson, R P; Gelinas-Sorell, D F

    1991-05-01

    Head banging is a rhythmic motor activity that may occur in normal infants and young children, as well as in children with underlying psychiatric or neurologic disease. Once underlying pathology has been excluded, parents should be reassured about the benign nature of the activity. PMID:2021098

  19. Hurricane Rina Headed to Mexico

    NASA Video Gallery

    An animation of NOAA GOES-13 satellite observations from October 23 at 2:45 p.m. EDT through Oct. 25 at 1:30 p.m. EDT shows a strengthening Hurricane Rina in the western Caribbean Sea and headed fo...

  20. Concurrent array-based queue

    SciTech Connect

    Heidelberger, Philip; Steinmacher-Burow, Burkhard

    2015-01-06

    According to one embodiment, a method for implementing an array-based queue in memory of a memory system that includes a controller includes configuring, in the memory, metadata of the array-based queue. The configuring comprises defining, in metadata, an array start location in the memory for the array-based queue, defining, in the metadata, an array size for the array-based queue, defining, in the metadata, a queue top for the array-based queue and defining, in the metadata, a queue bottom for the array-based queue. The method also includes the controller serving a request for an operation on the queue, the request providing the location in the memory of the metadata of the queue.

  1. A 64-channel 3T array coil for accelerated brain MRI

    PubMed Central

    Keil, Boris; Blau, James N.; Biber, Stephan; Hoecht, Philipp; Tountcheva, Veneta; Setsompop, Kawin; Triantafyllou, Christina; Wald, Lawrence L.

    2012-01-01

    A 64-channel brain array coil was developed and compared to a 32-channel array constructed with the same coil former geometry in order to precisely isolate the benefit of the two-fold increase in array coil elements. The constructed coils were developed for a standard clinical 3T MRI scanner and used a contoured head-shape curved former around the occipital pole and tapered in at the neck to both improve sensitivity and patient comfort. Additionally, the design is a compact, split-former design intended for robust daily use. Signal-to-noise ratio (SNR) and noise amplification (G-factor) for parallel imaging were quantitatively evaluated in human imaging and compared to a size and shape-matched 32-channel array coil. For unaccelerated imaging, the 64-channel array provided similar SNR in the brain center to the 32-channel array and 1.3-fold more SNR in the brain cortex. Reduced noise amplification during highly parallel imaging of the 64-channel array provided the ability to accelerate at approximately one unit higher at a given noise amplification compared to the sized-matched 32-channel array. For example, with a 4-fold acceleration rate, the central brain and cortical SNR of the 64-channel array was 1.2 and 1.4-fold higher, respectively, compared to the 32-channel array. The characteristics of the coil are demonstrated in accelerated brain imaging. PMID:22851312

  2. Carbon nanotube array based sensor

    DOEpatents

    Lee, Christopher L.; Noy, Aleksandr; Swierkowski, Stephan P.; Fisher, Karl A.; Woods, Bruce W.

    2005-09-20

    A sensor system comprising a first electrode with an array of carbon nanotubes and a second electrode. The first electrode with an array of carbon nanotubes and the second electrode are positioned to produce an air gap between the first electrode with an array of carbon nanotubes and the second electrode. A measuring device is provided for sensing changes in electrical capacitance between the first electrode with an array of carbon nanotubes and the second electrode.

  3. Waveguide-excited slot arrays for synthetic array radar applications

    NASA Technical Reports Server (NTRS)

    Bostrom, D. E.; Lewis, D. J.; Rupp, F. C.

    1978-01-01

    The basic design considerations for waveguide slottery arrays are reviewed, with emphasis on those design requirements that are most significant to both airborne and spaceborne synthetic array radar (SAR) systems. As an illustration of both design procedures and performance capability of slotted waveguide planar arrays, an L-band planar array was designed, fabricated, and tested. This array has an aperture approximately one meter wide by two meters high and was designed to be a typical submodule of a larger antenna. Measurements of radiation patterns, gain, and VSWR were recorded and are presented, together with the performance characteristics predicted on the basis of theoretical analysis.

  4. Microreactor array device.

    PubMed

    Wiktor, Peter; Brunner, Al; Kahn, Peter; Qiu, Ji; Magee, Mitch; Bian, Xiaofang; Karthikeyan, Kailash; LaBaer, Joshua

    2015-01-01

    We report a device to fill an array of small chemical reaction chambers (microreactors) with reagent and then seal them using pressurized viscous liquid acting through a flexible membrane. The device enables multiple, independent chemical reactions involving free floating intermediate molecules without interference from neighboring reactions or external environments. The device is validated by protein expressed in situ directly from DNA in a microarray of ~10,000 spots with no diffusion during three hours incubation. Using the device to probe for an autoantibody cancer biomarker in blood serum sample gave five times higher signal to background ratio compared to standard protein microarray expressed on a flat microscope slide. Physical design principles to effectively fill the array of microreactors with reagent and experimental results of alternate methods for sealing the microreactors are presented. PMID:25736721

  5. Microreactor Array Device

    PubMed Central

    Wiktor, Peter; Brunner, Al; Kahn, Peter; Qiu, Ji; Magee, Mitch; Bian, Xiaofang; Karthikeyan, Kailash; LaBaer, Joshua

    2015-01-01

    We report a device to fill an array of small chemical reaction chambers (microreactors) with reagent and then seal them using pressurized viscous liquid acting through a flexible membrane. The device enables multiple, independent chemical reactions involving free floating intermediate molecules without interference from neighboring reactions or external environments. The device is validated by protein expressed in situ directly from DNA in a microarray of ~10,000 spots with no diffusion during three hours incubation. Using the device to probe for an autoantibody cancer biomarker in blood serum sample gave five times higher signal to background ratio compared to standard protein microarray expressed on a flat microscope slide. Physical design principles to effectively fill the array of microreactors with reagent and experimental results of alternate methods for sealing the microreactors are presented. PMID:25736721

  6. Detector array design

    SciTech Connect

    Lari, S.

    1996-02-01

    Neutron scattering facility at Oak-Ridge National is used to measure residual stresses in many different materials. Neutron beam from the reactor can be used to penetrate the inner atomic distances of metals which then can be diffracted to a detector to measure the strain. The strain data later can be converted to stresses. The facility currently uses only one detector to carry the measurement. By designing an array of detectors data can be obtained at a much faster rate and or having a much better and improved resolution. The purpose of this report is to show design of such array of detectors and their movements (rotation) for possible maximum data collection at a faster rate.

  7. Microreactor Array Device

    NASA Astrophysics Data System (ADS)

    Wiktor, Peter; Brunner, Al; Kahn, Peter; Qiu, Ji; Magee, Mitch; Bian, Xiaofang; Karthikeyan, Kailash; Labaer, Joshua

    2015-03-01

    We report a device to fill an array of small chemical reaction chambers (microreactors) with reagent and then seal them using pressurized viscous liquid acting through a flexible membrane. The device enables multiple, independent chemical reactions involving free floating intermediate molecules without interference from neighboring reactions or external environments. The device is validated by protein expressed in situ directly from DNA in a microarray of ~10,000 spots with no diffusion during three hours incubation. Using the device to probe for an autoantibody cancer biomarker in blood serum sample gave five times higher signal to background ratio compared to standard protein microarray expressed on a flat microscope slide. Physical design principles to effectively fill the array of microreactors with reagent and experimental results of alternate methods for sealing the microreactors are presented.

  8. Optically interconnected phased arrays

    NASA Technical Reports Server (NTRS)

    Bhasin, Kul B.; Kunath, Richard R.

    1988-01-01

    Phased-array antennas are required for many future NASA missions. They will provide agile electronic beam forming for communications and tracking in the range of 1 to 100 GHz. Such phased arrays are expected to use several hundred GaAs monolithic integrated circuits (MMICs) as transmitting and receiving elements. However, the interconnections of these elements by conventional coaxial cables and waveguides add weight, reduce flexibility, and increase electrical interference. Alternative interconnections based on optical fibers, optical processing, and holography are under evaluation as possible solutions. In this paper, the current status of these techniques is described. Since high-frequency optical components such as photodetectors, lasers, and modulators are key elements in these interconnections, their performance and limitations are discussed.

  9. Photovoltaic cell array

    NASA Technical Reports Server (NTRS)

    Eliason, J. T. (Inventor)

    1976-01-01

    A photovoltaic cell array consisting of parallel columns of silicon filaments is described. Each fiber is doped to produce an inner region of one polarity type and an outer region of an opposite polarity type to thereby form a continuous radial semi conductor junction. Spaced rows of electrical contacts alternately connect to the inner and outer regions to provide a plurality of electrical outputs which may be combined in parallel or in series.

  10. The CHARA optical array

    NASA Technical Reports Server (NTRS)

    Mcalister, Harold A.

    1992-01-01

    The Center for High Angular Resolution Astronomy (CHARA) was established in the College of Arts and Sciences at Georgia State University in 1984 with the goals of designing, constructing, and then operating a facility for very high spatial resolution astronomy. The interest in such a facility grew out of the participants' decade of activity in speckle interferometry. Although speckle interferometry continues to provide important astrophysical measurements of a variety of objects, many pressing problems require resolution far beyond that which can be expected from single aperture telescopes. In early 1986, CHARA received a grant from the National Science Foundation which has permitted a detailed exploration of the feasibility of constructing a facility which will provide a hundred-fold increase in angular resolution over what is possible by speckle interferometry at the largest existing telescopes. The design concept for the CHARA Array was developed initially with the contractural collaboration of United Technologies Optical Systems, Inc., in West Palm Beach, Florida, an arrangement that expired in August 1987. In late November 1987, the Georgia Tech Research Institute joined with CHARA to continue and complete the design concept study. Very high-resolution imaging at optical wavelengths is clearly coming of age in astronomy. The CHARA Array and other related projects will be important and necessary milestones along the way toward the development of a major national facility for high-resolution imaging--a true optical counterpart to the Very Large Array. Ground-based arrays and their scientific output will lead to high resolution facilities in space and, ultimately, on the Moon.

  11. Solar collector array

    SciTech Connect

    Hall, John Champlin; Martins, Guy Lawrence

    2015-09-06

    A method and apparatus for efficient manufacture, assembly and production of solar energy. In one aspect, the apparatus may include a number of modular solar receiver assemblies that may be separately manufactured, assembled and individually inserted into a solar collector array housing shaped to receive a plurality of solar receivers. The housing may include optical elements for focusing light onto the individual receivers, and a circuit for electrically connecting the solar receivers.

  12. Phased array antenna control

    NASA Technical Reports Server (NTRS)

    Doland, G. D. (Inventor)

    1978-01-01

    Several new and useful improvements in steering and control of phased array antennas having a small number of elements, typically on the order of 5 to 17 elements are provided. Among the improvements are increasing the number of beam steering positions, reducing the possibility of phase transients in signals received or transmitted with the antennas, and increasing control and testing capacity with respect to the antennas.

  13. Drugs Approved for Head and Neck Cancer

    MedlinePlus

    ... Professionals Questions to Ask about Your Treatment Research Drugs Approved for Head and Neck Cancer This page ... and neck cancer that are not listed here. Drugs Approved for Head and Neck Cancer Abitrexate (Methotrexate) ...

  14. Adjustment of saccade characteristics during head movements.

    NASA Technical Reports Server (NTRS)

    Morasso, P.; Bizzi, E.; Dichgans, J.

    1973-01-01

    Saccade characteristics have been studied during coordinated eye-head movements in monkeys. Amplitude, duration, and peak velocity of saccades with head turning were compared with saccades executed while the head was artificially restrained. The results indicate that the saccade characteristics are modulated as a function of head movement, hence the gaze movement (eye+head) exactly matches saccades with head fixed. Saccade modulation is achieved by way of negative vestibulo-ocular feedback. The neck proprioceptors, because of their longer latency, are effective only if the head starts moving prior to the onset of saccade. It is concluded that saccades make with head turning are not 'ballistic' movements because their trajectory is not entirely predetermined by a central command.

  15. Mir Cooperative Solar Array

    NASA Technical Reports Server (NTRS)

    Skor, Mike; Hoffman, Dave J.

    1997-01-01

    The Mir Cooperative Solar Array (MCSA), produced jointly by the United States and Russia, was deployed on the Mir Russian space station on May 25, 1996. The MCSA is a photovoltaic electrical power system that can generate up to 6 kW. The power from the MCSA is needed to extend Mir's lifetime and to support experiments conducted there by visiting U.S. astronauts. The MCSA was brought to Mir via the Space Shuttle Atlantis on the STS-74 mission, launched November 12, 1995. This cooperative venture combined the best technology of both countries: the United States provided high-efficiency, lightweight photovoltaic panel modules, whereas Russia provided the array structure and deployment mechanism. Technology developed in the Space Station Freedom Program, and now being used in the International Space Station, was used to develop MCSA's photovoltaic panel. Performance data obtained from MCSA operation on Mir will help engineers better understand the performance of the photovoltaic panel modules in orbit. This information will be used to more accurately predict the performance of the International Space Station solar arrays. Managed by the NASA Lewis Research Center for NASA's International Space Station Program Office in Houston, Texas, the MCSA Project was completed on time and under budget despite a very aggressive schedule.

  16. Solar array construction

    DOEpatents

    Crouthamel, Marvin S.; Coyle, Peter J.

    1982-01-01

    An interconnect tab on each cell of a first set of circular solar cells connects that cell in series with an adjacent cell in the set. This set of cells is arranged in alternate columns and rows of an array and a second set of similar cells is arranged in the remaining alternate columns and rows of the array. Three interconnect tabs on each solar cell of the said second set are employed to connect the cells of the second set to one another, in series and to connect the cells of the second set to those of the first set in parallel. Some tabs (making parallel connections) connect the same surface regions of adjacent cells to one another and others (making series connections) connect a surface region of one cell to the opposite surface region of an adjacent cell; however, the tabs are so positioned that the array may be easily assembled by depositing the cells in a certain sequence and in proper orientation.

  17. DSN Array Simulator

    NASA Technical Reports Server (NTRS)

    Tikidjian, Raffi; Mackey, Ryan

    2008-01-01

    The DSN Array Simulator (wherein 'DSN' signifies NASA's Deep Space Network) is an updated version of software previously denoted the DSN Receive Array Technology Assessment Simulation. This software (see figure) is used for computational modeling of a proposed DSN facility comprising user-defined arrays of antennas and transmitting and receiving equipment for microwave communication with spacecraft on interplanetary missions. The simulation includes variations in spacecraft tracked and communication demand changes for up to several decades of future operation. Such modeling is performed to estimate facility performance, evaluate requirements that govern facility design, and evaluate proposed improvements in hardware and/or software. The updated version of this software affords enhanced capability for characterizing facility performance against user-defined mission sets. The software includes a Monte Carlo simulation component that enables rapid generation of key mission-set metrics (e.g., numbers of links, data rates, and date volumes), and statistical distributions thereof as functions of time. The updated version also offers expanded capability for mixed-asset network modeling--for example, for running scenarios that involve user-definable mixtures of antennas having different diameters (in contradistinction to a fixed number of antennas having the same fixed diameter). The improved version also affords greater simulation fidelity, sufficient for validation by comparison with actual DSN operations and analytically predictable performance metrics.

  18. Spaceborne Processor Array

    NASA Technical Reports Server (NTRS)

    Chow, Edward T.; Schatzel, Donald V.; Whitaker, William D.; Sterling, Thomas

    2008-01-01

    A Spaceborne Processor Array in Multifunctional Structure (SPAMS) can lower the total mass of the electronic and structural overhead of spacecraft, resulting in reduced launch costs, while increasing the science return through dynamic onboard computing. SPAMS integrates the multifunctional structure (MFS) and the Gilgamesh Memory, Intelligence, and Network Device (MIND) multi-core in-memory computer architecture into a single-system super-architecture. This transforms every inch of a spacecraft into a sharable, interconnected, smart computing element to increase computing performance while simultaneously reducing mass. The MIND in-memory architecture provides a foundation for high-performance, low-power, and fault-tolerant computing. The MIND chip has an internal structure that includes memory, processing, and communication functionality. The Gilgamesh is a scalable system comprising multiple MIND chips interconnected to operate as a single, tightly coupled, parallel computer. The array of MIND components shares a global, virtual name space for program variables and tasks that are allocated at run time to the distributed physical memory and processing resources. Individual processor- memory nodes can be activated or powered down at run time to provide active power management and to configure around faults. A SPAMS system is comprised of a distributed Gilgamesh array built into MFS, interfaces into instrument and communication subsystems, a mass storage interface, and a radiation-hardened flight computer.

  19. Array processor architecture

    NASA Technical Reports Server (NTRS)

    Barnes, George H. (Inventor); Lundstrom, Stephen F. (Inventor); Shafer, Philip E. (Inventor)

    1983-01-01

    A high speed parallel array data processing architecture fashioned under a computational envelope approach includes a data base memory for secondary storage of programs and data, and a plurality of memory modules interconnected to a plurality of processing modules by a connection network of the Omega gender. Programs and data are fed from the data base memory to the plurality of memory modules and from hence the programs are fed through the connection network to the array of processors (one copy of each program for each processor). Execution of the programs occur with the processors operating normally quite independently of each other in a multiprocessing fashion. For data dependent operations and other suitable operations, all processors are instructed to finish one given task or program branch before all are instructed to proceed in parallel processing fashion on the next instruction. Even when functioning in the parallel processing mode however, the processors are not locked-step but execute their own copy of the program individually unless or until another overall processor array synchronization instruction is issued.

  20. Solid state neutron detector array

    DOEpatents

    Seidel, J.G.; Ruddy, F.H.; Brandt, C.D.; Dulloo, A.R.; Lott, R.G.; Sirianni, E.; Wilson, R.O.

    1999-08-17

    A neutron detector array is capable of measuring a wide range of neutron fluxes. The array includes multiple semiconductor neutron detectors. Each detector has a semiconductor active region that is resistant to radiation damage. In one embodiment, the array preferably has a relatively small size, making it possible to place the array in confined locations. The ability of the array to detect a wide range of neutron fluxes is highly advantageous for many applications such as detecting neutron flux during start up, ramp up and full power of nuclear reactors. 7 figs.

  1. Solid state neutron detector array

    DOEpatents

    Seidel, John G.; Ruddy, Frank H.; Brandt, Charles D.; Dulloo, Abdul R.; Lott, Randy G.; Sirianni, Ernest; Wilson, Randall O.

    1999-01-01

    A neutron detector array is capable of measuring a wide range of neutron fluxes. The array includes multiple semiconductor neutron detectors. Each detector has a semiconductor active region that is resistant to radiation damage. In one embodiment, the array preferably has a relatively small size, making it possible to place the array in confined locations. The ability of the array to detect a wide range of neutron fluxes is highly advantageous for many applications such as detecting neutron flux during start up, ramp up and full power of nuclear reactors.

  2. Head Start on Science Preliminary Findings.

    ERIC Educational Resources Information Center

    Ritz, William C.; Von Blum, Ruth

    For many Head Start teachers and staff, the word "science" conjures up uncomfortable feelings and memories. The purpose of this project--a collaborative effort of California State University, Long Beach and the Head Start Program of Long Beach Unified School District (LBUSD)--was to prepare Head Start staff to become more capable, comfortable,…

  3. Effects of Headings on Text Processing.

    ERIC Educational Resources Information Center

    Brooks, Larry W.; And Others

    1983-01-01

    Two experiments examined the effects of embedded and intact (outline) headings on the processing of complex text material by college students. Results indicated that embedded headings reliably improved delayed test performance. It was further found that instructions in the use of headings as processing aids facilitated test performance. (Author/PN)

  4. 29 CFR 1910.135 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 5 2011-07-01 2011-07-01 false Head protection. 1910.135 Section 1910.135 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General... in areas where there is a potential for injury to the head from falling objects. (2) The...

  5. 29 CFR 1915.155 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Head protection. 1915.155 Section 1915.155 Labor... (PPE) § 1915.155 Head protection. (a) Use. (1) The employer shall ensure that each affected employee wears a protective helmet when working in areas where there is a potential for injury to the head...

  6. 33 CFR 142.30 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Head protection. 142.30 Section... CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.30 Head... conductors shall wear a head protector meeting the specifications of ANSI Z89.1, for the hazard involved....

  7. 29 CFR 1915.155 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Head protection. 1915.155 Section 1915.155 Labor... (PPE) § 1915.155 Head protection. (a) Use. (1) The employer shall ensure that each affected employee wears a protective helmet when working in areas where there is a potential for injury to the head...

  8. 33 CFR 142.30 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Head protection. 142.30 Section... CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.30 Head... conductors shall wear a head protector meeting the specifications of ANSI Z89.1, for the hazard involved....

  9. 49 CFR 572.16 - Head.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Head. 572.16 Section 572.16 Transportation Other... OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 3-Year-Old Child § 572.16 Head. (a) The head consists of the assembly designated as SA 103C 010 on drawing No. SA 103C 001, and conforms...

  10. 29 CFR 1918.103 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Head protection. 1918.103 Section 1918.103 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Personal Protective Equipment § 1918.103 Head... in areas where there is a potential for injury to the head from falling objects. (b)(1) The...

  11. 29 CFR 1910.135 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 5 2014-07-01 2014-07-01 false Head protection. 1910.135 Section 1910.135 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General... in areas where there is a potential for injury to the head from falling objects. (2) The...

  12. 49 CFR 572.16 - Head.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Head. 572.16 Section 572.16 Transportation Other... OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 3-Year-Old Child § 572.16 Head. (a) The head consists of the assembly designated as SA 103C 010 on drawing No. SA 103C 001, and conforms...

  13. 31 CFR 0.106 - Bureau Heads.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... explanation of the applicable post-employment restrictions contained in 18 U.S.C. 207 and 5 CFR part 2641 and... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Bureau Heads. 0.106 Section 0.106... RULES OF CONDUCT General Provisions Responsibilities § 0.106 Bureau Heads. Bureau heads or designees...

  14. 29 CFR 1910.135 - Head protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 5 2012-07-01 2012-07-01 false Head protection. 1910.135 Section 1910.135 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General... in areas where there is a potential for injury to the head from falling objects. (2) The...

  15. 29 CFR 1918.103 - Head protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Head protection. 1918.103 Section 1918.103 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Personal Protective Equipment § 1918.103 Head... in areas where there is a potential for injury to the head from falling objects. (b)(1) The...

  16. 33 CFR 142.30 - Head protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Head protection. 142.30 Section... CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.30 Head... conductors shall wear a head protector meeting the specifications of ANSI Z89.1, for the hazard involved....

  17. 29 CFR 1915.155 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Head protection. 1915.155 Section 1915.155 Labor... (PPE) § 1915.155 Head protection. (a) Use. (1) The employer shall ensure that each affected employee wears a protective helmet when working in areas where there is a potential for injury to the head...

  18. 29 CFR 1915.155 - Head protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Head protection. 1915.155 Section 1915.155 Labor... (PPE) § 1915.155 Head protection. (a) Use. (1) The employer shall ensure that each affected employee wears a protective helmet when working in areas where there is a potential for injury to the head...

  19. 29 CFR 1918.103 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Head protection. 1918.103 Section 1918.103 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Personal Protective Equipment § 1918.103 Head... in areas where there is a potential for injury to the head from falling objects. (b)(1) The...

  20. 33 CFR 142.30 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Head protection. 142.30 Section... CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.30 Head... conductors shall wear a head protector meeting the specifications of ANSI Z89.1, for the hazard involved....

  1. 29 CFR 1918.103 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Head protection. 1918.103 Section 1918.103 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Personal Protective Equipment § 1918.103 Head... in areas where there is a potential for injury to the head from falling objects. (b)(1) The...

  2. 29 CFR 1910.135 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Head protection. 1910.135 Section 1910.135 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General... in areas where there is a potential for injury to the head from falling objects. (2) The...

  3. 29 CFR 1915.155 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Head protection. 1915.155 Section 1915.155 Labor... (PPE) § 1915.155 Head protection. (a) Use. (1) The employer shall ensure that each affected employee wears a protective helmet when working in areas where there is a potential for injury to the head...

  4. 29 CFR 1910.135 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 5 2013-07-01 2013-07-01 false Head protection. 1910.135 Section 1910.135 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General... in areas where there is a potential for injury to the head from falling objects. (2) The...

  5. 29 CFR 1918.103 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Head protection. 1918.103 Section 1918.103 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Personal Protective Equipment § 1918.103 Head... in areas where there is a potential for injury to the head from falling objects. (b)(1) The...

  6. HISTOLOGY AND PHYSIOLOGY OF FUSARIUM HEAD BLIGHT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight re-emerged as a devastating disease of wheat and barley in the 1990s in the midwestern U.S. Research efforts to control the disease have been hampered by limited knowledge of how the fungal head blight pathogens infect and damage head tissue and what natural defenses the plant h...

  7. Combustor with non-circular head end

    SciTech Connect

    Kim, Won -Wook; McMahan, Kevin Weston

    2015-09-29

    The present application provides a combustor for use with a gas turbine engine. The combustor may include a head end with a non-circular configuration, a number of fuel nozzles positioned about the head end, and a transition piece extending downstream of the head end.

  8. Dimensions of Family Coping with Head Injury.

    ERIC Educational Resources Information Center

    Kosciulek, John F.

    1994-01-01

    Examined dimensions underlying family coping with head injury. Data from 150 families with a member with a head injury identified 3 dimensions of coping: individual-to-family versus family-to-community coping; family-respite versus head-injury-focused coping; and cognitive versus behavioral coping. Findings have implications for family stress and…

  9. The development and evaluation of head probes for optical imaging of the infant head

    NASA Astrophysics Data System (ADS)

    Branco, Gilberto

    The objective of this thesis was to develop and evaluate optical imaging probes for mapping oxygenation and haemodynamic changes in the newborn infant brain. Two imaging approaches are being developed at University College London (UCL): optical topography (surface mapping of the cortex) and optical tomography (volume imaging). Both have the potential to provide information about the function of the normal brain and about a variety of neurophysiologies! abnormalities. Both techniques require an array of optical fibres/fibre bundles to be held in contact with the head, for periods of time from tens of seconds to an hour or more. The design of suitable probes must ensure the comfort and safety of the subject, and provide measurements minimally sensitive to external sources of light and patient motion. A series of prototype adaptable helmets were developed for optical tomography of the premature infant brain using the UCL 32-channel time-resolved system. They were required to attach 32 optical fibre bundles over the infant scalp, and were designed to accommodate infants with a variety of head shapes and sizes, aged between 24-weeks gestational age and term. Continual improvements to the helmet design were introduced following the evaluation of each prototype on infants in the hospital. Data were acquired to generate images revealing the concentration and oxygenation of blood in the brain, and the response of the brain to sensory stimulation. This part of the project also involved designing and testing new methods of acquiring calibration data using reference phantoms. The second focus of the project was the development of probes for use with the UCL frequency-multiplexed near-infrared topography system. This is being used to image functional activation in the infant cortex. A series of probes were developed and experiments were conducted to evaluate their sensitivity to patient motion and to compression of the probe. The probes have been used for a variety of

  10. [The bobble head doll syndrome].

    PubMed

    Notholt-Heerich, B; Körholz, D; Voit, T; Lumenta, C

    1987-01-01

    A 4,1 year old girl with bobble head doll syndrome is described. The child showed the typical 2-3 per second anterior-posterior movements of the head. The girl had a retarded motor development and retarded growth. On CT scan we found a cyst within the third ventricle and a hydrocephalus of the lateral ventricles. To reduce the hydrocephalus we implanted a ventricular-cardial low pressure shunt system. Repeated emptying of the cyst via an Ommaya reservoir had no long-term effect. Implantation of a cysto-peritoneal shunt-system led to a reduction of the cyst (determined by CT scan) and an improvement of the symptoms. PMID:3586562

  11. Low cutter load raise head

    SciTech Connect

    Saxman, W.C.

    1981-03-31

    A raise head having a multiplicity of cutters for enlarging a pilot hole into a larger diameter hole by disintegrating the earth formations that surround the pilot hole is provided that will require lower cutter loads to penetrate the formations being bored by directing the rock fracture planes toward the pilot hole forcing the rock to yield with less input energy. The cutters are positioned on the raise head to provide an earth formation contact profile with a major portion of said earth formation contact profile extending outward and upward from said pilot hole. The included angle between the major portion of the earth formation contact profile and the axis of the pilot hole is less than 90/sup 0/.

  12. Head Resistance Due to Radiators

    NASA Technical Reports Server (NTRS)

    Kleinschmidt, R V; Parsons, S R

    1920-01-01

    Part 1 deals with the head resistance of a number of common types of radiator cores at different speeds in free air, as measured in the wind tunnel at the bureau of standards. This work was undertaken to determine the characteristics of various types of radiator cores, and in particular to develop the best type of radiator for airplanes. Some 25 specimens of core were tested, including practically all the general types now in use, except the flat plate type. Part 2 gives the results of wind tunnel tests of resistance on a model fuselage with a nose radiator. Part 3 presents the results of preliminary tests of head resistance of a radiator enclosed in a streamlined casing. Special attention is given to the value of wing radiator and of the radiator located in the open, especially when it is provided with a properly designed streamlined casing.

  13. Sealed head access area enclosure

    DOEpatents

    Golden, Martin P.; Govi, Aldo R.

    1978-01-01

    A liquid-metal-cooled fast breeder power reactor is provided with a sealed head access area enclosure disposed above the reactor vessel head consisting of a plurality of prefabricated structural panels including a center panel removably sealed into position with inflatable seals, and outer panels sealed into position with semipermanent sealant joints. The sealant joints are located in the joint between the edge of the panels and the reactor containment structure and include from bottom to top an inverted U-shaped strip, a lower layer of a room temperature vulcanizing material, a separator strip defining a test space therewithin, and an upper layer of a room temperature vulcanizing material. The test space is tapped by a normally plugged passage extending to the top of the enclosure for testing the seal or introducing a buffer gas thereinto.

  14. Magnetic nanocap arrays with tilted magnetization

    NASA Astrophysics Data System (ADS)

    Albrecht, Manfred

    2009-03-01

    In modern magnetic recording materials the ``superparamagnetic effect'' has become increasingly important as new magnetic hard disk drive products are designed for higher storage densities. In this regard, patterned media [1], where two-dimensional arrays of nanostructures are used, is one of the concepts that might provide the required areal density in future magnetic recording devices. However, also nanostructure arrays will ultimately need high anisotropy material such as L10-FePt to provid enough thermal stability and thus much higher writing fields than currently obtainable from perpendicular magnetic recording heads. One proposed solution to this problem is the use of tilted magnetic recording media [2]. The basic idea is to tilt the easy axis of the magnetic medium from the perpendicular direction to 45 degree. In this case, the switching field will be reduced by a foctor of two in the Stoner-Wohlfarth limit. Recently, this approach was realized by oblique film deposition onto arrays of self-assembled spherical particles [3-5]. In this presentation, recent results on different film systems including Co/Pt multilayers, FePt and CoPtCr-SiO2 alloys which have been deposited onto SiO2 particle monolayers will be presented. It turned out that by tuning the growth conditions single domain nanocaps with enhanced magnetic coercivity and tilted anisostropy axis can be achieved even for particle sizes below 50 nm. [4pt] [1] B. D. Terris and T. Thomson, J. Phys. D: Appl. Phys. 38 (2005) R199 [0pt] [2] J.-P. Wang, Nat. Mater. 4, 191 (2005). [0pt] [3] M. Albrecht et al., Nat. Mater. 4, 203 (2005). [0pt] [4] T. Ulbrich et al., Phys. Rev. Lett. 96 (2006) 077202. [0pt] [5] D. Makarov et al., Appl. Phys. Lett. 93, 153112 (2008).

  15. Trends in phased array development

    NASA Astrophysics Data System (ADS)

    Schell, A. C.

    1986-03-01

    In the past 15 years, several outstanding phased arrays have been taken into service for functions involving defense applications. It is pointed out, however, that the impact of phased array technology on radar and communications antennas has been minor in comparison to the impact of solid-state technology on the other major subsystem, the signal processor. This situation is mainly related to cost considerations, and the scale of the commercial market involved. Attention is given to details regarding the economics of phased arrays, a possible key to improved solutions to phased array construction and operation, the employment of the techniques of photolithography in the fabrication of a transversely-developed array, the need for manufacturing techniques to incorporate magnetic or electroacoustic control devices into the array, problems of heat generation, small mm-wave arrays, questions of reliability, and integrated antennas.

  16. Family Connections: Helping Early Head Start/Head Start Staff and Parents Address Mental Health Challenges

    ERIC Educational Resources Information Center

    Beardslee, William R.; Avery, Mary Watson; Ayoub, Catherine; Watts, Caroline L.

    2009-01-01

    Early Head Start/Head Start teachers and staff encounter parents who have wrestled with depression and other adversities every day. This article describes an innovative program of trainings for and consultation to Early Head Start/Head Start staff to help them effectively deal with mental heath challenges faced by parents and children. The program…

  17. Hot gas engine heater head

    DOEpatents

    Berntell, John O.

    1983-01-01

    A heater head for a multi-cylinder double acting hot gas engine in which each cylinder is surrounded by an annular regenerator unit, and in which the tops of each cylinder and its surrounding regenerator are interconnected by a multiplicity of heater tubes. A manifold for the heater tubes has a centrally disposed duct connected to the top of the cylinder and surrounded by a wider duct connecting the other ends of the heater tubes with the regenerator unit.

  18. ACR Appropriateness Criteria Head Trauma.

    PubMed

    Shetty, Vilaas S; Reis, Martin N; Aulino, Joseph M; Berger, Kevin L; Broder, Joshua; Choudhri, Asim F; Kendi, A Tuba; Kessler, Marcus M; Kirsch, Claudia F; Luttrull, Michael D; Mechtler, Laszlo L; Prall, J Adair; Raksin, Patricia B; Roth, Christopher J; Sharma, Aseem; West, O Clark; Wintermark, Max; Cornelius, Rebecca S; Bykowski, Julie

    2016-06-01

    Neuroimaging plays an important role in the management of head trauma. Several guidelines have been published for identifying which patients can avoid neuroimaging. Noncontrast head CT is the most appropriate initial examination in patients with minor or mild acute closed head injury who require neuroimaging as well as patients with moderate to severe acute closed head injury. In short-term follow-up neuroimaging of acute traumatic brain injury, CT and MRI may have complementary roles. In subacute to chronic traumatic brain injury, MRI is the most appropriate initial examination, though CT may have a complementary role in select circumstances. Advanced neuroimaging techniques are areas of active research but are not considered routine clinical practice at this time. In suspected intracranial vascular injury, CT angiography or venography or MR angiography or venography is the most appropriate imaging study. In suspected posttraumatic cerebrospinal fluid leak, high-resolution noncontrast skull base CT is the most appropriate initial imaging study to identify the source, with cisternography reserved for problem solving. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. PMID:27262056

  19. Five-Channel Polychromator Head

    NASA Technical Reports Server (NTRS)

    Eskridge, Richard; Dobson, Chris; Lee, Mike; Robertson, Tony

    1995-01-01

    Five-channel polychromator head samples Raman-scattering spectrum simultaneously at five wavelengths. Each channel consists of 1-mm fiber-optic cable that is individually translatable along dispersion axis of spectrometer to provide both flexibility and fine-tuning capability. Laser raman thermometer not thermometer in usual sense of word, but noncontact spectrometer that measures temperature indirectly in terms of relative intensities of selected Raman-scattering spectral lines.

  20. Arthroplasty in Femoral Head Osteonecrosis

    PubMed Central

    Nam, Dong Cheol; Jung, Kwangyoung

    2014-01-01

    Osteonecrosis of the femoral head is a destructive joint disease requiring early hip arthroplasty. The polyethylene-metal design using a 22-mm femoral head component, introduced by Charnley in 1950, has been widely used for over half a century. Since then, different materials with the capacity to minimize friction between bearing surfaces and various cement or cementless insert fixations have been developed. Although the outcome of second and third generation designs using better bearing materials and technologies has been favorable, less favorable results are seen with total hip arthroplasty in young patients with osteonecrosis. Selection of appropriate materials for hip arthroplasty is important for any potential revisions that might become inevitable due to the limited durability of a prosthetic hip joint. Alternative hip arthroplasties, which include hemiresurfacing arthroplasty and bipolar hemiarthroplasty, have not been found to have acceptable outcomes. Metal-on-metal resurfacing has recently been suggested as a feasible option for young patients with extra physical demands; however, concerns about complications such as hypersensitivity reaction or pseudotumor formation on metal bearings have emerged. To ensure successful long-term outcomes in hip arthroplasty, factors such as insert stabilization and surfaces with less friction are essential. Understanding these aspects in arthroplasty is important to selection of proper materials and to making appropriate decisions for patients with osteonecrosis of the femoral head. PMID:27536561

  1. Head Start Oral Health Assessment.

    PubMed

    Reed, Rebecca; York, Jill; Dady, Nadege; Chaviano-Moran, Rosa; Jiang, Shuying; Holtzman, Joseph

    2016-05-01

    Purpose A Head Start program located in Paterson, New Jersey considered establishing a school-based dental clinic to address unmet oral health needs such as access to care and the need for restorative treatment. The purpose of this study was to establish the oral health status of Head Start children, their treatment needs, and parents' interest and willingness to utilize a school-based dental clinic. Description School-based dental care has been used to address access to care issues, particularly among children who live in underserved areas. A 21 item survey was used to correlate the results of an oral exam performed on the Head Start children and the parents' preferences, beliefs and access patterns. Fisher's exact test and Chi squared test were used to study the association among variable with significance levels set at 0.05. Assessment The oral exam revealed a high caries rate amongst all of the children. Parental responses indicated strong support for the establishment of a school-based clinic and identified the need for further parental education. Having a regular source of care was found to be unrelated to treatment needs. Conclusion Further education of the parents regarding the child's oral health is critical to the success and viability of this school-based clinic. PMID:27017227

  2. Animal Models of Head Trauma

    PubMed Central

    Cernak, Ibolja

    2005-01-01

    Summary: Animal models of traumatic brain injury (TBI) are used to elucidate primary and secondary sequelae underlying human head injury in an effort to identify potential neuroprotective therapies for developing and adult brains. The choice of experimental model depends upon both the research goal and underlying objectives. The intrinsic ability to study injury-induced changes in behavior, physiology, metabolism, the blood/tissue interface, the blood brain barrier, and/or inflammatory- and immune-mediated responses, makes in vivo TBI models essential for neurotrauma research. Whereas human TBI is a highly complex multifactorial disorder, animal trauma models tend to replicate only single factors involved in the pathobiology of head injury using genetically well-defined inbred animals of a single sex. Although such an experimental approach is helpful to delineate key injury mechanisms, the simplicity and hence inability of animal models to reflect the complexity of clinical head injury may underlie the discrepancy between preclinical and clinical trials of neuroprotective therapeutics. Thus, a search continues for new animal models, which would more closely mimic the highly heterogeneous nature of human TBI, and address key factors in treatment optimization. PMID:16389305

  3. Porcine Head Response to Blast

    PubMed Central

    Shridharani, Jay K.; Wood, Garrett W.; Panzer, Matthew B.; Capehart, Bruce P.; Nyein, Michelle K.; Radovitzky, Raul A.; Bass, Cameron R. ‘Dale’

    2012-01-01

    Recent studies have shown an increase in the frequency of traumatic brain injuries related to blast exposure. However, the mechanisms that cause blast neurotrauma are unknown. Blast neurotrauma research using computational models has been one method to elucidate that response of the brain in blast, and to identify possible mechanical correlates of injury. However, model validation against experimental data is required to ensure that the model output is representative of in vivo biomechanical response. This study exposes porcine subjects to primary blast overpressures generated using a compressed-gas shock tube. Shock tube blasts were directed to the unprotected head of each animal while the lungs and thorax were protected using ballistic protective vests similar to those employed in theater. The test conditions ranged from 110 to 740 kPa peak incident overpressure with scaled durations from 1.3 to 6.9 ms and correspond approximately with a 50% injury risk for brain bleeding and apnea in a ferret model scaled to porcine exposure. Instrumentation was placed on the porcine head to measure bulk acceleration, pressure at the surface of the head, and pressure inside the cranial cavity. Immediately after the blast, 5 of the 20 animals tested were apneic. Three subjects recovered without intervention within 30 s and the remaining two recovered within 8 min following respiratory assistance and administration of the respiratory stimulant doxapram. Gross examination of the brain revealed no indication of bleeding. Intracranial pressures ranged from 80 to 390 kPa as a result of the blast and were notably lower than the shock tube reflected pressures of 300–2830 kPa, indicating pressure attenuation by the skull up to a factor of 8.4. Peak head accelerations were measured from 385 to 3845 G’s and were well correlated with peak incident overpressure (R2 = 0.90). One SD corridors for the surface pressure, intracranial pressure (ICP), and head acceleration are

  4. Right-left asymmetries in the whisking behavior of rats anticipate head movements.

    PubMed

    Towal, R Blythe; Hartmann, Mitra J

    2006-08-23

    Rats use rhythmic movements of their vibrissae (whiskers) to tactually explore their environment. This "whisking" behavior has generally been reported to be strictly synchronous and symmetric about the snout, and it is thought to be controlled by a brainstem central pattern generator. Because the vibrissae can move independently of the head, however, maintaining a stable perception of the world would seem to require that rats adjust the bilateral symmetry of whisker movements in response to head movements. The present study used high-speed videography to reveal dramatic bilateral asymmetries and asynchronies in free-air whisking during head rotations. Kinematic analysis suggested that these asymmetric movements did not serve to maintain any fixed temporal relationship between right and left arrays, but rather to redirect the whiskers to a different region of space. More specifically, spatial asymmetry was found to be strongly correlated with rotational head velocity, ensuring a "look-ahead" distance of almost exactly one whisk. In contrast, bilateral asynchrony and velocity asymmetry were only weakly dependent on head velocity. Bilateral phase difference was found to be independent of the whisking frequency, suggesting the presence of two distinct left and right central pattern generators, connected as coupled oscillators. We suggest that the spatial asymmetries are analogous to the saccade that occurs during the initial portion of a combined head-eye gaze shift, and we begin to develop the rat vibrissal system as a new model for studying vestibular and proprioceptive contributions to the acquisition of sensory data. PMID:16928873

  5. Diode laser array

    NASA Technical Reports Server (NTRS)

    Carlson, Nils W. (Inventor); Evans, Gary A. (Inventor); Kaiser, Charlie J. (Inventor)

    1990-01-01

    A diode laser array comprises a substrate of a semiconductor material having first and second opposed surfaces. On the first surface is a plurality of spaced gain sections and a separate distributed Bragg reflector passive waveguide at each end of each gain section and optically connecting the gain sections. Each gain section includes a cavity therein wherein charge carriers are generated and recombine to generate light which is confined in the cavity. Also, the cavity, which is preferably a quantum well cavity, provides both a high differential gain and potentially large depth of loss modulation. Each waveguide has a wavelength which is preferably formed by an extension of the cavity of the gain sections and a grating. The grating has a period which provides a selective feedback of light into the gain sections to supporting lasing, which allows some of the light to be emitted from the waveguide normal to the surface of the substrate and which allows optical coupling of the gain sections. Also, the grating period provides an operating wavelength which is on the short wavelength side of the gain period of the gain sections required for laser oscillation. An RF pulse is applied so as to maximize the magnitude of the loss modulation and the differential gain in the gain sections. The array is operated by applying a DC bias to all the gain sections at a level just below the threshold of the gain sections to only one of the gain sections which raises the bias in all of the gain sections to a level that causes all of the gain sections to oscillate. Thus, a small bias can turn the array on and off.

  6. Phased array ghost elimination.

    PubMed

    Kellman, Peter; McVeigh, Elliot R

    2006-05-01

    Parallel imaging may be applied to cancel ghosts caused by a variety of distortion mechanisms, including distortions such as off-resonance or local flow, which are space variant. Phased array combining coefficients may be calculated that null ghost artifacts at known locations based on a constrained optimization, which optimizes SNR subject to the nulling constraint. The resultant phased array ghost elimination (PAGE) technique is similar to the method known as sensitivity encoding (SENSE) used for accelerated imaging; however, in this formulation is applied to full field-of-view (FOV) images. The phased array method for ghost elimination may result in greater flexibility in designing acquisition strategies. For example, in multi-shot EPI applications ghosts are typically mitigated by the use of an interleaved phase encode acquisition order. An alternative strategy is to use a sequential, non-interleaved phase encode order and cancel the resultant ghosts using PAGE parallel imaging. Cancellation of ghosts by means of phased array processing makes sequential, non-interleaved phase encode acquisition order practical, and permits a reduction in repetition time, TR, by eliminating the need for echo-shifting. Sequential, non-interleaved phase encode order has benefits of reduced distortion due to off-resonance, in-plane flow and EPI delay misalignment. Furthermore, the use of EPI with PAGE has inherent fat-water separation and has been used to provide off-resonance correction using a technique referred to as lipid elimination with an echo-shifting N/2-ghost acquisition (LEENA), and may further generalized using the multi-point Dixon method. Other applications of PAGE include cancelling ghosts which arise due to amplitude or phase variation during the approach to steady state. Parallel imaging requires estimates of the complex coil sensitivities. In vivo estimates may be derived by temporally varying the phase encode ordering to obtain a full k-space dataset in a scheme

  7. Stability of dendritic arrays

    NASA Technical Reports Server (NTRS)

    Warren, James A.; Langer, J. S.

    1990-01-01

    An approximate method for studying steady-state properties and linear stability of the dendritic arrays that are formed in directional solidification of alloys is proposed. This analysis is valid at high growth rates where the primary spacing between dendrites is larger than the velocity-dependent solutal diffusion length. A neutral stability boundary is computed and it is found that, in the situations where the results should be valid, the experimental data of Somboonsuk, et al. (1984) lie in the stable region, well away from the boundary.

  8. Noise amplification in parallel whole-head ultra-low-field magnetic resonance imaging using 306 detectors.

    PubMed

    Lin, Fa-Hsuan; Vesanen, Panu T; Nieminen, Jaakko O; Hsu, Yi-Cheng; Zevenhoven, Koos C J; Dabek, Juhani; Parkkonen, Lauri T; Zhdanov, Andrey; Ilmoniemi, Risto J

    2013-08-01

    In ultra-low-field magnetic resonance imaging, arrays of up to hundreds of highly sensitive superconducting quantum interference devices (SQUIDs) can be used to detect the weak magnetic fields emitted by the precessing magnetization. Here, we investigate the noise amplification in sensitivity-encoded ultra-low-field MRI at various acceleration rates using a SQUID array consisting of 102 magnetometers, 102 gradiometers, or 306 magnetometers and gradiometers, to cover the whole head. Our results suggest that SQUID arrays consisting of 102 magnetometers and 102 gradiometers are similar in g-factor distribution. A SQUID array of 306 sensors (102 magnetometers and 204 gradiometers) only marginally improves the g-factor. Corroborating with previous studies, the g-factor in 2D sensitivity-encoded ultra-low-field MRI with 9 to 16-fold 2D accelerations using the SQUID array studied here may be acceptable. PMID:23023497

  9. Noise amplification in parallel whole-head ultra-low-field magnetic resonance imaging using 306 detectors

    PubMed Central

    Lin, Fa-Hsuan; Vesanen, Panu T.; Nieminen, Jaakko O.; Hsu, Yi-Cheng; Koos, C.J.; Ilmoniemi, åJ.

    2012-01-01

    In ultra-low-field (ULF) magnetic resonance imaging (MRI), arrays of up to hundreds of highly sensitive superconducting quantum interference devices (SQUIDs) can be used to detect the weak magnetic fields emitted by the precessing magnetization. Here we investigate the noise amplification in sensitivity encoded (SENSE) ULF MRI at various acceleration rates using a SQUID array consisting of 102 magnetometers, 102 gradiometers, or 306 magnetometers and gradiometers, to cover the whole head. Our results suggest that SQUID arrays consisting of 102 magnetometers and 102 gradiometers are similar in g-factor distribution. A SQUID array of 306 sensors (102 magnetometers and 204 gradiometers) only marginally improves the g-factor. Corroborating with previous studies, the g-factor in 2D SENSE ULF MRI with 9 to 16-fold 2D accelerations using the SQUID array studied here may be acceptable. PMID:23023497

  10. Nonlinear phased array imaging

    NASA Astrophysics Data System (ADS)

    Croxford, Anthony J.; Cheng, Jingwei; Potter, Jack N.

    2016-04-01

    A technique is presented for imaging acoustic nonlinearity within a specimen using ultrasonic phased arrays. Acoustic nonlinearity is measured by evaluating the difference in energy of the transmission bandwidth within the diffuse field produced through different focusing modes. The two different modes being classical beam forming, where delays are applied to different element of a phased array to physically focus the energy at a single location (parallel firing) and focusing in post processing, whereby one element at a time is fired and a focused image produced in post processing (sequential firing). Although these two approaches are linearly equivalent the difference in physical displacement within the specimen leads to differences in nonlinear effects. These differences are localized to the areas where the amplitude is different, essentially confining the differences to the focal point. Direct measurement at the focal point are however difficult to make. In order to measure this the diffuse field is used. It is a statistical property of the diffuse field that it represents the total energy in the system. If the energy in the diffuse field for both the sequential and parallel firing case is measured then the difference between these, within the input signal bandwidth, is largely due to differences at the focal spot. This difference therefore gives a localized measurement of where energy is moving out of the transmission bandwidth due to nonlinear effects. This technique is used to image fatigue cracks and other damage types undetectable with conventional linear ultrasonic measurements.

  11. Effects of vestibular loss on head stabilization in response to head and body perturbations

    NASA Technical Reports Server (NTRS)

    Shupert, C. L.; Horak, F. B.; Peterson, B. W. (Principal Investigator)

    1996-01-01

    Control of head position during postural responses is important to facilitate both the interpretation of vestibular signals and the stabilization of gaze. In these experiments, we compared head stabilization for two different postural tasks: 1) in response to perturbations at the head, and 2) in response to perturbations induced at the support surface, which perturb both body and head position. To determine whether normal vestibular function is necessary for head stabilization in these two tasks, responses to forward and backward mechanical perturbations of the head and body were compared for 13 normal subjects and 4 patients with profound bilateral vestibular loss (two with vestibular loss in adulthood and two in infancy). Normal subjects showed little neck muscle activity for body perturbations, but large, early activations in both neck extensors and flexors for head perturbations. In contrast, vestibular patients showed excessive neck muscle activation for body perturbations and reduced or absent neck muscle activity for head perturbations. Patients with vestibular loss in adulthood also showed increased head acceleration in response to both head and body perturbations, but patients with vestibular loss in infancy showed more normal head accelerations. For body perturbations, the differences in head acceleration between patients and normals were greater for later head acceleration peaks, indicating poor head control during the execution of the postural response. Trunk angle changes were also higher in the patients for forward body perturbations, indicating that poorer control of trunk position could have contributed to their poorer head stabilization. These results indicate that the vestibular system plays an important role in head and trunk stabilization for both head and body perturbations. However, the more normal head accelerations of the patients with infant vestibular loss also indicate that other mechanisms, possibly involving neck reflexes, can at least

  12. Electromagnetically Clean Solar Arrays

    NASA Technical Reports Server (NTRS)

    Stem, Theodore G.; Kenniston, Anthony E.

    2008-01-01

    The term 'electromagnetically clean solar array' ('EMCSA') refers to a panel that contains a planar array of solar photovoltaic cells and that, in comparison with a functionally equivalent solar-array panel of a type heretofore used on spacecraft, (1) exhibits less electromagnetic interferences to and from other nearby electrical and electronic equipment and (2) can be manufactured at lower cost. The reduction of electromagnetic interferences is effected through a combination of (1) electrically conductive, electrically grounded shielding and (2) reduction of areas of current loops (in order to reduce magnetic moments). The reduction of cost is effected by designing the array to be fabricated as a more nearly unitary structure, using fewer components and fewer process steps. Although EMCSAs were conceived primarily for use on spacecraft they are also potentially advantageous for terrestrial applications in which there are requirements to limit electromagnetic interference. In a conventional solar panel of the type meant to be supplanted by an EMCSA panel, the wiring is normally located on the back side, separated from the cells, thereby giving rise to current loops having significant areas and, consequently, significant magnetic moments. Current-loop geometries are chosen in an effort to balance opposing magnetic moments to limit far-0field magnetic interactions, but the relatively large distances separating current loops makes full cancellation of magnetic fields problematic. The panel is assembled from bare photovoltaic cells by means of multiple sensitive process steps that contribute significantly to cost, especially if electomagnetic cleanliness is desired. The steps include applying a cover glass and electrical-interconnect-cell (CIC) sub-assemble, connecting the CIC subassemblies into strings of series-connected cells, laying down and adhesively bonding the strings onto a panel structure that has been made in a separate multi-step process, and mounting the

  13. Electrode array for neural stimulation

    DOEpatents

    Wessendorf, Kurt O.; Okandan, Murat; Stein, David J.; Yang, Pin; Cesarano, III, Joseph; Dellinger, Jennifer

    2011-08-16

    An electrode array for neural stimulation is disclosed which has particular applications for use in a retinal prosthesis. The electrode array can be formed as a hermetically-sealed two-part ceramic package which includes an electronic circuit such as a demultiplexer circuit encapsulated therein. A relatively large number (up to 1000 or more) of individually-addressable electrodes are provided on a curved surface of a ceramic base portion the electrode array, while a much smaller number of electrical connections are provided on a ceramic lid of the electrode array. The base and lid can be attached using a metal-to-metal seal formed by laser brazing. Electrical connections to the electrode array can be provided by a flexible ribbon cable which can also be used to secure the electrode array in place.

  14. An Array Module for Python

    NASA Astrophysics Data System (ADS)

    Greenfield, Perry; Miller, Todd; Hsu, Jin-Chung; White, Richard L.

    Although Python has long had a module for numeric array manipulations, it has had some shortcomings that prevent it from being as useful for astronomy applications as it could be. We have re-implemented the module to handle large arrays in a more memory-efficient manner, and to support direct access of data in tables and non-native data formats. The new module has been implemented mostly in Python although the core computational loops are performed in C for efficiency. The new approach allows arrays to be sub-classed as well as new kinds of array objects, such as record arrays, to be created. This paper discusses the design and implementation issues that were addressed in the development of the new array module for Python and gives examples of its use.

  15. Head position modulates optokinetic nystagmus.

    PubMed

    Pettorossi, V E; Ferraresi, A; Botti, F M; Panichi, R; Barmack, N H

    2011-08-01

    Orientation and movement relies on both visual and vestibular information mapped in separate coordinate systems. Here, we examine how coordinate systems interact to guide eye movements of rabbits. We exposed rabbits to continuous horizontal optokinetic stimulation (HOKS) at 5°/s to evoke horizontal eye movements, while they were statically or dynamically roll-tilted about the longitudinal axis. During monocular or binocular HOKS, when the rabbit was roll-tilted 30° onto the side of the eye stimulated in the posterior → anterior (P → A) direction, slow phase eye velocity (SPEV) increased by 3.5-5°/s. When the rabbit was roll-tilted 30° onto the side of the eye stimulated in the A → P direction, SPEV decreased to ~2.5°/s. We also tested the effect of roll-tilt after prolonged optokinetic stimulation had induced a negative optokinetic afternystagmus (OKAN II). In this condition, the SPEV occurred in the dark, "open loop." Modulation of SPEV of OKAN II depended on the direction of the nystagmus and was consistent with that observed during "closed loop" HOKS. Dynamic roll-tilt influenced SPEV evoked by HOKS in a similar way. The amplitude and the phase of SPEV depended on the frequency of vestibular oscillation and on HOKS velocity. We conclude that the change in the linear acceleration of the gravity vector with respect to the head during roll-tilt modulates the gain of SPEV depending on its direction. This modulation improves gaze stability at different image retinal slip velocities caused by head roll-tilt during centric or eccentric head movement. PMID:21735244

  16. Solid state image sensing arrays

    NASA Technical Reports Server (NTRS)

    Sadasiv, G.

    1972-01-01

    The fabrication of a photodiode transistor image sensor array in silicon, and tests on individual elements of the array are described along with design for a scanning system for an image sensor array. The spectral response of p-n junctions was used as a technique for studying the optical-absorption edge in silicon. Heterojunction structures of Sb2S3- Si were fabricated and a system for measuring C-V curves on MOS structures was built.

  17. Active membrane phased array radar

    NASA Technical Reports Server (NTRS)

    Moussessian, Alina; Del Castillo, Linda; Huang, John; Sadowy, Greg; Hoffman, James; Smith, Phil; Hatake, Toshiro; Derksen, Chuck; Lopez, Bernardo; Caro, Ed

    2005-01-01

    We have developed the first membrane-based active phased array in L-band (1.26GHz). The array uses membrane compatible Transmit/Receive (T/R) modules (membrane T/R) for each antenna element. We use phase shifters within each T/R module for electronic beam steering. We will discuss the T/R module design and integration with the membrane, We will also present transmit and receive beam-steering results for the array.

  18. Aligators for Arrays (Tool Paper)

    NASA Astrophysics Data System (ADS)

    Henzinger, Thomas A.; Hottelier, Thibaud; Kovács, Laura; Rybalchenko, Andrey

    This paper presents Aligators, a tool for the generation of universally quantified array invariants. Aligators leverages recurrence solving and algebraic techniques to carry out inductive reasoning over array content. The Aligators' loop extraction module allows treatment of multi-path loops by exploiting their commutativity and serializability properties. Our experience in applying Aligators on a collection of loops from open source software projects indicates the applicability of recurrence and algebraic solving techniques for reasoning about arrays.

  19. Electrodynamic Arrays Having Nanomaterial Electrodes

    NASA Technical Reports Server (NTRS)

    Trigwell, Steven (Inventor); Biris, Alexandru S. (Inventor); Calle, Carlos I. (Inventor)

    2013-01-01

    An electrodynamic array of conductive nanomaterial electrodes and a method of making such an electrodynamic array. In one embodiment, a liquid solution containing nanomaterials is deposited as an array of conductive electrodes on a substrate, including rigid or flexible substrates such as fabrics, and opaque or transparent substrates. The nanomaterial electrodes may also be grown in situ. The nanomaterials may include carbon nanomaterials, other organic or inorganic nanomaterials or mixtures.

  20. Multi-Channel Microstrip Transceiver Arrays Using Harmonics for High Field MR Imaging in Humans

    PubMed Central

    Wu, Bing; Wang, Chunsheng; Lu, Jonathan; Pang, Yong; Nelson, Sarah J; Vigneron, Daniel B; Zhang, Xiaoliang

    2012-01-01

    RF transceiver array design using primary and higher order harmonics for in-vivo parallel MR imaging and spectroscopic imaging is proposed. The improved electromagnetic decoupling performance, unique magnetic field distributions and high-frequency operation capabilities of higher-order harmonics of resonators would benefit transceiver arrays for parallel MRI, especially for ultrahigh field parallel MRI. To demonstrate this technique, microstrip transceiver arrays using first and second harmonic resonators were developed for human head parallel imaging at 7T. Phantom and human head images were acquired and evaluated using the GRAPPA reconstruction algorithm. The higher-order harmonic transceiver array design technique was also assessed numerically using FDTD simulation. Compared with regular primary-resonance transceiver designs, the proposed higher-order harmonic technique provided an improved g-factor and increased decoupling among resonant elements without using dedicated decoupling circuits, which would potentially lead to a better parallel imaging performance and ultimately faster and higher quality imaging. The proposed technique is particularly suitable for densely spaced transceiver array design where the increased mutual inductance among the elements becomes problematic. In addition, it also provides a simple approach to readily upgrade the channels of a conventional primary resonator microstrip array to a larger number for faster imaging. PMID:21878410

  1. Resonance in a head massager

    NASA Astrophysics Data System (ADS)

    Ribeiro, Jair Lúcio Prados

    2015-04-01

    Mechanical structures such as pendula, bridges, or buildings always exhibit one (or more) natural oscillation frequency.1 If that structure is subjected to oscillatory forces of this same frequency, resonance occurs, with consequent increase of the structure oscillation amplitude. There is no shortage of simple experiments for demonstrating resonance in high school classes using a variety of materials, such as saw blades,2 guitars,3 pendulums,4 wine glasses,5 bottles,6 Ping-Pong balls,7 and pearl strings.8 We present here an experimental demonstration using only an inexpensive head (or scalp) massager, which can be purchased for less than a dollar.

  2. Reactor Pressure Vessel Head Packaging & Disposal

    SciTech Connect

    Wheeler, D. M.; Posivak, E.; Freitag, A.; Geddes, B.

    2003-02-26

    Reactor Pressure Vessel (RPV) Head replacements have come to the forefront due to erosion/corrosion and wastage problems resulting from the susceptibility of the RPV Head alloy steel material to water/boric acid corrosion from reactor coolant leakage through the various RPV Head penetrations. A case in point is the recent Davis-Besse RPV Head project, where detailed inspections in early 2002 revealed significant wastage of head material adjacent to one of the Control Rod Drive Mechanism (CRDM) nozzles. In lieu of making ASME weld repairs to the damaged head, Davis-Besse made the decision to replace the RPV Head. The decision was made on the basis that the required weld repair would be too extensive and almost impractical. This paper presents the packaging, transport, and disposal considerations for the damaged Davis-Besse RPV Head. It addresses the requirements necessary to meet Davis Besse needs, as well as the regulatory criteria, for shipping and burial of the head. It focuses on the radiological characterization, shipping/disposal package design, site preparation and packaging, and the transportation and emergency response plans that were developed for the Davis-Besse RPV Head project.

  3. Multiple intake poppet valve array for a single port

    SciTech Connect

    Bergeron, C.W.

    1990-03-13

    This patent describes a multiple poppet valve array for use with a single intake duct in a four cycle internal combustion engine. It comprises: three or more poppet valves; an engine cylinder; a cylinder head having at least one intake duct in fluid communication with the combustion chamber. The intake duct having three or more apertures opening into the engine cylinder. The apertures including poppet valve seats about their perimeter for seating the three or more poppet valves; and means for opening and closing each of the poppet valves in communication with the poppet valves.

  4. Integrated residential photovoltaic array development

    NASA Technical Reports Server (NTRS)

    Shepard, N. F., Jr.

    1981-01-01

    An advanced, universally-mountable, integrated residential photovoltaic array concept was defined based upon an in-depth formulation and evaluation of three candidate approaches which were synthesized from existing or proposed residential array concepts. The impact of module circuitry and process sequence is considered and technology gaps and performance drivers associated with residential photovoltaic array concepts are identified. The actual learning experience gained from the comparison of the problem areas of the hexagonal shingle design with the rectangular module design led to what is considered an advanced array concept. Building the laboratory mockup provided actual experience and the opportunity to uncover additional technology gaps.

  5. Integrated residential photovoltaic array development

    NASA Astrophysics Data System (ADS)

    Shepard, N. F., Jr.

    1981-12-01

    An advanced, universally-mountable, integrated residential photovoltaic array concept was defined based upon an in-depth formulation and evaluation of three candidate approaches which were synthesized from existing or proposed residential array concepts. The impact of module circuitry and process sequence is considered and technology gaps and performance drivers associated with residential photovoltaic array concepts are identified. The actual learning experience gained from the comparison of the problem areas of the hexagonal shingle design with the rectangular module design led to what is considered an advanced array concept. Building the laboratory mockup provided actual experience and the opportunity to uncover additional technology gaps.

  6. Future directions for NICMOS arrays

    NASA Technical Reports Server (NTRS)

    Thompson, R.; Rieke, Marcia J.; Young, Erick T.; Mccarthy, D.; Rasche, Robert; Blessinger, Michael; Vural, Kadri; Kleinhans, William

    1989-01-01

    The Near Infrared Camera and Multi-Object Spectrometer (NICMOS) for the Hubble Space Telescope (HST) requires focal plane arrays of 256x256 pixels for both its cameras and its spectrometers. The new arrays, developed by the Rockwell Corporation for NICMOS, have 40 microns pixels of HgCdTe bump bonded to a switched MOSFET readout. Expected read noise and dark current for the arrays at 60 K are 30 e and 1 e/sec. respectively. The basis for these numbers is previous experience with 128x128 arrays.

  7. Nanoelectrode array for electrochemical analysis

    DOEpatents

    Yelton, William G.; Siegal, Michael P.

    2009-12-01

    A nanoelectrode array comprises a plurality of nanoelectrodes wherein the geometric dimensions of the electrode controls the electrochemical response, and the current density is independent of time. By combining a massive array of nanoelectrodes in parallel, the current signal can be amplified while still retaining the beneficial geometric advantages of nanoelectrodes. Such nanoelectrode arrays can be used in a sensor system for rapid, non-contaminating field analysis. For example, an array of suitably functionalized nanoelectrodes can be incorporated into a small, integrated sensor system that can identify many species rapidly and simultaneously under field conditions in high-resistivity water, without the need for chemical addition to increase conductivity.

  8. Head movement during walking in the cat.

    PubMed

    Zubair, Humza N; Beloozerova, Irina N; Sun, Hai; Marlinski, Vladimir

    2016-09-22

    Knowledge of how the head moves during locomotion is essential for understanding how locomotion is controlled by sensory systems of the head. We have analyzed head movements of the cat walking along a straight flat pathway in the darkness and light. We found that cats' head left-right translations, and roll and yaw rotations oscillated once per stride, while fore-aft and vertical translations, and pitch rotations oscillated twice. The head reached its highest vertical positions during second half of each forelimb swing, following maxima of the shoulder/trunk by 20-90°. Nose-up rotation followed head upward translation by another 40-90° delay. The peak-to-peak amplitude of vertical translation was ∼1.5cm and amplitude of pitch rotation was ∼3°. Amplitudes of lateral translation and roll rotation were ∼1cm and 1.5-3°, respectively. Overall, cats' heads were neutral in roll and 10-30° nose-down, maintaining horizontal semicircular canals and utriculi within 10° of the earth horizontal. The head longitudinal velocity was 0.5-1m/s, maximal upward and downward linear velocities were ∼0.05 and ∼0.1m/s, respectively, and maximal lateral velocity was ∼0.05m/s. Maximal velocities of head pitch rotation were 20-50°/s. During walking in light, cats stood 0.3-0.5cm taller and held their head 0.5-2cm higher than in darkness. Forward acceleration was 25-100% higher and peak-to-peak amplitude of head pitch oscillations was ∼20°/s larger. We concluded that, during walking, the head of the cat is held actively. Reflexes appear to play only a partial role in determining head movement, and vision might further diminish their role. PMID:27339731

  9. Heading in football. Part 1: Development of biomechanical methods to investigate head response

    PubMed Central

    Shewchenko, N; Withnall, C; Keown, M; Gittens, R; Dvorak, J

    2005-01-01

    Objectives: There has been growing controversy regarding long term effects of repeated low severity head impacts such as when heading a football. However, there are few scientific data substantiating these concerns in terms of the biomechanical head response to impact. The present study aimed to develop a research methodology to investigate the biomechanical response of human subjects during intentional heading and identify strategies for reducing head impact severity. Methods: A controlled laboratory study was carried out with seven active football players, aged 20–23 and of average stature and weight. The subjects were fitted with photographic targets for kinematic analysis and instrumented to measure head linear/angular accelerations and neck muscle activity. Balls were delivered at two speeds (6 m/s and 8 m/s) as the subjects executed several specific forward heading manoeuvres in the standing position. Heading speeds up to 11 m/s were seen when the head closing speed was considered. One subject demonstrating averaged flexion–extension muscle activity phased with head acceleration data and upper torso kinematics was used to validate a biofidelic 50th percentile human model with a detailed head and neck. The model was exercised under ball incoming speeds of 6–7 m/s with parameter variations including torso/head alignment, neck muscle tensing, and follow through. The model output was subsequently compared with additional laboratory tests with football players (n = 3). Additional heading scenarios were investigated including follow through, non-active ball impact, and non-contact events. Subject and model head responses were evaluated with peak linear and rotational accelerations and maximum incremental head impact power. Results: Modelling of neck muscle tensing predicted lower head accelerations and higher neck loads whereas volunteer head acceleration reductions were not consistent. Modelling of head–torso alignment predicted a modest reduction in

  10. Array biosensor: recent developments

    NASA Astrophysics Data System (ADS)

    Golden, Joel P.; Rowe-Taitt, Chris A.; Feldstein, Mark J.; Ligler, Frances S.

    1999-05-01

    A fluorescence-based immunosensor has been developed for simultaneous analyses of multiple samples for 1 to 6 different antigens. A patterned array of recognition antibodies immobilized on the surface of a planar waveguide is used to 'capture' analyte present in samples. Bound analyte is then quantified by means of fluorescent detector molecules. Upon excitation of the fluorescent label by a small diode laser, a CCD camera detects the pattern of fluorescent antigen:antibody complexes on the sensor surface. Image analysis software correlates the position of fluorescent signals with the identity of the analyte. A new design for a fluidics distribution system is shown, as well as results from assays for physiologically relevant concentrations of staphylococcal enterotoxin B (SEB), F1 antigen from Yersinia pestis, and D- dimer, a marker of sepsis and thrombotic disorders.

  11. Solitons in optomechanical arrays.

    PubMed

    Gan, Jing-Hui; Xiong, Hao; Si, Liu-Gang; Lü, Xin-You; Wu, Ying

    2016-06-15

    We show that optical solitons can be obtained with a one-dimensional optomechanical array that consists of a chain of periodically spaced identical optomechanical systems. Unlike conventional optical solitons, which originate from nonlinear polarization, the optical soliton here stems from a new mechanism, namely, phonon-photon interaction. Under proper conditions, the phonon-photon induced nonlinearity that refers to the optomechanical nonlinearity will exactly compensate the dispersion caused by photon hopping of adjacent optomechanical systems. Moreover, the solitons are capable of exhibiting very low group velocity, depending on the photon hopping rate, which may lead to many important applications, including all-optical switches and on-chip optical architecture. This work may extend the range of optomechanics and nonlinear optics and provide a new field to study soliton theory and develop corresponding applications. PMID:27304261

  12. Diagnosable structured logic array

    NASA Technical Reports Server (NTRS)

    Whitaker, Sterling (Inventor); Miles, Lowell (Inventor); Gambles, Jody (Inventor); Maki, Gary K. (Inventor)

    2009-01-01

    A diagnosable structured logic array and associated process is provided. A base cell structure is provided comprising a logic unit comprising a plurality of input nodes, a plurality of selection nodes, and an output node, a plurality of switches coupled to the selection nodes, where the switches comprises a plurality of input lines, a selection line and an output line, a memory cell coupled to the output node, and a test address bus and a program control bus coupled to the plurality of input lines and the selection line of the plurality of switches. A state on each of the plurality of input nodes is verifiably loaded and read from the memory cell. A trusted memory block is provided. The associated process is provided for testing and verifying a plurality of truth table inputs of the logic unit.

  13. TRMM Solar Array

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Basic requirement of 978.59 watts per Panel output @ 58.9 volts B.O.L. was met on an average basis per agreement with NASA. Lower grade Cells were used on the shadowed Panel (Boom shadow) to maximize available power to the Spacecraft. The average output @ 58.9 volts was 991 watts. The outputs of the four t4) Panels ranged from 960 to 1,022 watts. The Panels successfully passed environmental testing at TRW to the contract specification and subsequent testing at NASA which involved output measurements at elevated temperatures. As this type of Array had never previously been built by TRW (aluminum Substrate with 4 cm x 4.4 cm GaAs Cells), the TRMM Program was a development effort combined with a Qual and Flight production effort. The most significant technical problem was Cell cracking during Qual thermal cycling. The cracking problem was determined to be generic within our Solar Array factory in the application of GaAs Cells to our designs. As a result, a TRW funded manufacturing process verification panel (known as the Manufacturing Verification Panel) was built to demonstrate our ability to properly apply GaAs Cells. The original Qual Panel comprised three (3) design variations with respect to Coverglass-to-Cell and Cell-to-Substrate adhesives. The intent was to qualify multiple designs in case one or more failed. When two of the three combinations failed due to excessive Cell breakage during thermal cycling, NASA was reluctant to allow Flight production based on the one remaining good Qual Panel Quadrant. This issue was pivotal for continuing the contract. Facts and recommendations are as follows: (1) The cause of the excessive cracking was never determined. and (2) The areas where the excessive cracking occurred utilized DC93-500 glassing adhesive which was NASA approved, and had been widely used by TRW on a multitude of projects.

  14. Networked Sensor Arrays

    SciTech Connect

    R. J. Tighe

    2002-10-01

    A set of independent radiation sensors, coupled with real-time data telemetry, offers the opportunity to run correlation algorithms for the sensor array as well as to incorporate non-radiological data into the system. This may enhance the overall sensitivity of the sensors and provide an opportunity to project the location of a source within the array. In collaboration with Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories (SNL), we have conducted field experiments to test a prototype system. Combining the outputs of a set of distributed sensors permits the correlation that the independent sensor outputs. Combined with additional information such as traffic patterns and velocities, this can reduce random/false detections and enhance detection capability. The principle components of such a system include: (1) A set of radiation sensors. These may be of varying type and complexity, including gamma and/or neutron detectors, gross count and spectral-capable sensors, and low to high energy-resolution sensors. (2) A set of non-radiation sensors. These may include sensors such as vehicle presence and imaging sensors. (3) A communications architecture for near real-time telemetry. Depending upon existing infrastructure and bandwidth requirements, this may be a radio or hard-wire based system. (4) A central command console to pole the sensors, correlate their output, and display the data in a meaningful form to the system operator. Both sensitivity and selectivity are important considerations when evaluating the performance of a detection system. Depending on the application, the optimization of sensitivity as well as the rejection of ''nuisance'' radioactive sources may or may not be critical.

  15. Anatomy of the infant head

    SciTech Connect

    Bosma, J.F.

    1986-01-01

    This text is mainly an atlas of illustration representing the dissection of the head and upper neck of the infant. It was prepared by the author over a 20-year period. The commentary compares the anatomy of the near-term infant with that of a younger fetus, child, and adult. As the author indicates, the dearth of anatomic information about postnatal anatomic changes represents a considerable handicap to those imaging infants. In part 1 of the book, anatomy is related to physiologic performance involving the pharynx, larynx, and mouth. Sequential topics involve the regional anatomy of the head (excluding the brain), the skeleton of the cranium, the nose, orbit, mouth, larynx, pharynx, and ear. To facilitate use of this text as a reference, the illustrations and text on individual organs are considered separately (i.e., the nose, the orbit, the eye, the mouth, the larynx, the pharynx, and the ear). Each part concerned with a separate organ includes materials from the regional illustrations contained in part 2 and from the skeleton, which is treated in part 3. Also included in a summary of the embryologic and fetal development of the organ.

  16. A Pre-Hispanic Head

    PubMed Central

    Bianucci, Raffaella; Jeziorska, Maria; Lallo, Rudy; Mattutino, Grazia; Massimelli, Massimo; Phillips, Genevieve; Appenzeller, Otto

    2008-01-01

    This report on a male head revealed biologic rhythms, as gleaned from hydrogen isotope ratios in hair, consistent with a South-American origin and Atomic Mass Spectrometry radiocarbon dating (AMS) compatible with the last pre-Hispanic period (1418–1491 AD, 95.4% probability). Biopsies showed exceptionally well-preserved tissues. The hair contained high levels of toxic elements (lead, arsenic and mercury) incompatible with life. There was no evidence for lead deposition in bone consistent with post-mortem accumulation of this toxic element in the hair. We propose that the high content of metals in hair was the result of metabolic activity of bacteria leading to metal complexation in extra cellular polymeric substances (EPS). This is a recognized protective mechanism for bacteria that thrive in toxic environments. This mechanism may account for the tissues preservation and gives a hint at soil composition where the head was presumably buried. Our results have implications for forensic toxicology which has, hitherto, relied on hair analyses as one means to reconstruct pre-mortem metabolism and for detecting toxic elements accumulated during life. Our finding also has implications for other archaeological specimens where similar circumstances may distort the results of toxicological studies. PMID:18446229

  17. Clinical Trials in Head Injury

    PubMed Central

    NARAYAN, RAJ K.; MICHEL, MARY ELLEN; Ansell, Beth; Baethmann, Alex; Biegon, Anat; Bracken, Michael B.; Bullock, M. Ross; Choi, Sung C.; Clifton, Guy L.; Contant, Charles F.; Coplin, William M.; Dietrich, W. Dalton; Ghajar, Jamshid; Grady, Sean M.; Grossman, Robert G.; Hall, Edward D.; Heetderks, William; Hovda, David A.; Jallo, Jack; Katz, Russell L.; Knoller, Nachshon; Kochanek, Patrick M.; Maas, Andrew I.; Majde, Jeannine; Marion, Donald W.; Marmarou, Anthony; Marshall, Lawrence F.; McIntosh, Tracy K.; Miller, Emmy; Mohberg, Noel; Muizelaar, J. Paul; Pitts, Lawrence H.; Quinn, Peter; Riesenfeld, Gad; Robertson, Claudia S.; Strauss, Kenneth I.; Teasdale, Graham; Temkin, Nancy; Tuma, Ronald; Wade, Charles; Walker, Michael D.; Weinrich, Michael; Whyte, John; Wilberger, Jack; Young, A. Byron; Yurkewicz, Lorraine

    2006-01-01

    Traumatic brain injury (TBI) remains a major public health problem globally. In the United States the incidence of closed head injuries admitted to hospitals is conservatively estimated to be 200 per 100,000 population, and the incidence of penetrating head injury is estimated to be 12 per 100,000, the highest of any developed country in the world. This yields an approximate number of 500,000 new cases each year, a sizeable proportion of which demonstrate signficant long-term disabilities. Unfortunately, there is a paucity of proven therapies for this disease. For a variety of reasons, clinical trials for this condition have been difficult to design and perform. Despite promising pre-clinical data, most of the trials that have been performed in recent years have failed to demonstrate any significant improvement in outcomes. The reasons for these failures have not always been apparent and any insights gained were not always shared. It was therefore feared that we were running the risk of repeating our mistakes. Recognizing the importance of TBI, the National Institute of Neurological Disorders and Stroke (NINDS) sponsored a workshop that brought together experts from clinical, research, and pharmaceutical backgrounds. This workshop proved to be very informative and yielded many insights into previous and future TBI trials. This paper is an attempt to summarize the key points made at the workshop. It is hoped that these lessons will enhance the planning and design of future efforts in this important field of research. PMID:12042091

  18. Modeling heading in adult soccer players.

    PubMed

    Ponce, Ernesto; Ponce, Daniel; Andresen, Max

    2014-01-01

    Heading soccer balls can generate mild brain injuries and in the long run can lead to difficulty in solving problems, memory deficits, and language difficulties. Researchers evaluated the effects on the head for both correct and incorrect heading techniques. They based the head's geometry on medical images. They determined the injury's magnitude by comparing the neurological tissue's resistance with predictions of the generated stresses. The evaluation examined fast playing conditions in adult soccer, taking into account the ball's speed and the type of impact. Mathematical simulations using the finite element method indicated that correctly heading balls arriving at moderate speed presents a low risk of brain injury. However, damage can happen around the third cervical vertebra. These results coincide with medical studies. Incorrect heading greatly increases the brain injury risk and can alter the parietal area. PMID:25248195

  19. High-Temperature Gas Sensor Array (Electronic Nose) Demonstrated

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.

    2002-01-01

    The ability to measure emissions from aeronautic engines and in commercial applications such as automotive emission control and chemical process monitoring is a necessary first step if one is going to actively control those emissions. One single sensor will not give all the information necessary to determine the chemical composition of a high-temperature, harsh environment. Rather, an array of gas sensor arrays--in effect, a high-temperature electronic "nose"--is necessary to characterize the chemical constituents of a diverse, high-temperature environment, such as an emissions stream. The signals produced by this nose could be analyzed to determine the constituents of the emission stream. Although commercial electronic noses for near-room temperature applications exist, they often depend significantly on lower temperature materials or only one sensor type. A separate development effort necessary for a high-temperature electronic nose is being undertaken by the NASA Glenn Research Center, Case Western Reserve University, Ohio State University, and Makel Engineering, Inc. The sensors are specially designed for hightemperature environments. A first-generation high-temperature electronic nose has been demonstrated on a modified automotive engine. This nose sensor array was composed of sensors designed for hightemperature environments fabricated using microelectromechanical-systems- (MEMS-) based technology. The array included a tin-oxide-based sensor doped for nitrogen oxide (NOx) sensitivity, a SiC-based hydrocarbon (CxHy) sensor, and an oxygen sensor (O2). These sensors operate on different principles--resistor, diode, and electrochemical cell, respectively--and each sensor has very different responses to the individual gases in the environment. A picture showing the sensor head for the array is shown in the photograph on the left and the sensors installed in the engine are shown in the photograph on the right. Electronics are interfaced with the sensors for

  20. Fusobacterial head and neck infections in children.

    PubMed

    Brook, Itzhak

    2015-07-01

    Fusobacterium species are increasingly recognized as a cause of head and neck infections in children. These infections include acute and chronic otitis, sinusitis, mastoiditis, and tonsillitis; peritonsillar and retropharyngeal abscesses; Lemierre syndrome; post-anginal cervical lymphadenitis; and periodontitis. They can also be involved in brain abscess and bacteremia associated with head and neck infections. This review describes the clinical spectrum of head and neck fusobacterial infection in children and their management. PMID:25980688

  1. Paragangliomas of the Head and Neck.

    PubMed

    Woolen, Sean; Gemmete, Joseph J

    2016-05-01

    Paragangliomas of the head and neck are rare vascular skull-base tumors derived from the paraganglionic system with an estimated incidence of 1:30,000 accounting for 3% of all paragangliomas. The most common paraganglioma locations of the head and neck in descending order are the carotid body, jugular, tympanic, and vagal paragangliomas. This article discusses the clinical characterics, normal anatamy, imaging findings and protocols, pathology, staging, and differential diagnosis for paragangliomas of the head and neck. PMID:27154608

  2. Head-Mounted and Head-Up Display Glossary

    NASA Technical Reports Server (NTRS)

    Newman, Richard L.; Allen, J. Edwin W. (Technical Monitor)

    1997-01-01

    One of the problems in head-up and helmet-mounted display (HMD) literature has been a lack of standardization of words and abbreviations. Several different words have been used for the same concept; for example, flight path angle, flight path marker, velocity vector, and total velocity vector all refer to the same thing. In other cases, the same term has been used with two different meanings, such as binocular field-of-view which means the field-of-view visible to both left and right eyes according to some or the field-of-view visible to either the left or right eye or both according to others. Many of the terms used in HMD studies have not been well-defined. We need to have a common language to ensure that system descriptions are communicated. As an example, the term 'stabilized' has been widely used with two meanings. 'Roll-stabilized' has been used to mean a symbol which rotates to indicate the roll or bank of the aircraft. 'World-stabilized' and 'head-stabilized' have both been used to indicate symbols which move to remain fixed with respect to external objects. HMDs present unique symbology problems not found in HUDs. Foremost among these is the issue of maintaining spatial orientation of the symbols. All previous flight displays, round dial instruments, HDDs, and HUDs have been fixed in the cockpit. With the HMD, the flight display can move through a large angle. The coordinates use in transforming from the real-world to the aircraft to the HMD have not been consistently defined. This glossary contains terms relating to optics and vision, displays, and flight information, weapons and aircraft systems. Some definitions, such as Navigation Display, have been added to clarify the definitions for Primary Flight Display and Primary Flight Reference. A list of HUD/HMD related abbreviations is also included.

  3. High Voltage Space Solar Arrays

    NASA Technical Reports Server (NTRS)

    Ferguson, D. C.; Hillard, G. B.; Vayner, B. V.; Galofaro, J. T.; Lyons, Valerie (Technical Monitor)

    2002-01-01

    Recent tests performed at the NASA Glenn Research Center and elsewhere have shown promise in the design and construction of high voltage (300-1000 V) solar arrays for space applications. Preliminary results and implications for solar array design will be discussed, with application to direct-drive electric propulsion and space solar power.

  4. Array tomography: semiautomated image alignment.

    PubMed

    Micheva, Kristina D; O'Rourke, Nancy; Busse, Brad; Smith, Stephen J

    2010-11-01

    Array tomography is a volumetric microscopy method based on physical serial sectioning. Ultrathin sections of a plastic-embedded tissue are cut using an ultramicrotome, bonded in an ordered array to a glass coverslip, stained as desired, and imaged. The resulting two-dimensional image tiles can then be reconstructed computationally into three-dimensional volume images for visualization and quantitative analysis. The minimal thickness of individual sections permits high-quality rapid staining and imaging, whereas the array format allows reliable and convenient section handling, staining, and automated imaging. Also, the physical stability of the arrays permits images to be acquired and registered from repeated cycles of staining, imaging, and stain elution, as well as from imaging using multiple modalities (e.g., fluorescence and electron microscopy). Array tomography makes it possible to visualize and quantify previously inaccessible features of tissue structure and molecular architecture. However, careful preparation of the tissue is essential for successful array tomography; these steps can be time-consuming and require some practice to perfect. Successful array tomography requires that the captured images be properly stacked and aligned, and the software to achieve these ends is freely available. This protocol describes the construction of volumetric image stacks from images of fluorescently labeled arrays for three-dimensional image visualization, analysis, and archiving. PMID:21041400

  5. Hubble Space Telescope Solar Array

    NASA Technical Reports Server (NTRS)

    1985-01-01

    This is a view of a solar cell blanket deployed on a water table during the Solar Array deployment test. The Hubble Space Telescope (HST) Solar Arrays provide power to the spacecraft. The arrays are mounted on opposite sides of the HST, on the forward shell of the Support Systems Module. Each array stands on a 4-foot mast that supports a retractable wing of solar panels 40-feet (12.1-meters) long and 8.2-feet (2.5-meters) wide, in full extension. The arrays rotate so that the solar cells face the Sun as much as possible to harness the Sun's energy. The Space Telescope Operations Control Center at the Goddard Space Center operates the array, extending the panels and maneuvering the spacecraft to focus maximum sunlight on the arrays. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST Solar Array was designed by the European Space Agency and built by British Aerospace. The Marshall Space Flight Center had overall responsibility for design, development, and construction of the HST.

  6. Phase multiplying electronic scanning array

    NASA Technical Reports Server (NTRS)

    Seaton, A. F.

    1969-01-01

    Scanning array was designed with properties of low RF loss and phase control. The array consists of a series of special waveguides, hybrids made up of two variable reactance branch arms for input signals, an edge slot for the difference port, and a sum arm for the unradiated signal.

  7. Molecular dynamics on transputer arrays

    NASA Astrophysics Data System (ADS)

    Petersen, Henrik Gordon; Perram, John W.

    We extend earlier work on implementing boxing algorithms for simulating very large systems of particles on massively parallel S.I.M.D. arrays to more modest ones. We report details and preliminary results obtained using an OCCAM 2 program running on a linear array of transputers.

  8. Concentrator-Enhanced Solar Array

    NASA Technical Reports Server (NTRS)

    Morse, B. J.

    1984-01-01

    Deployable solar array for satellites uses slanted low-mass planar mirrors as walls of trough to triple light falling on GaAs solar cells forming bottom of trough. Power-to-mass ratio of new design 42 percent higher than planar array of same power output.

  9. Bilateral internuclear ophthalmoplegia following mild head injury.

    PubMed

    Muthukumar, N; Veerarajkumar, N; Madeswaran, K

    2001-05-01

    A 7-year-old child presented with bilateral internuclear ophthalmoplegia (INO) following a trivial head injury. CT was normal. MRI revealed a pontine lesion. Two months after the injury the patient was neurologically normal. INO following head injury is rare. Rarer still is INO following mild head injury. To date, only four cases of INO had been reported following mild head injury; the present case is the fifth and the first in which the lesion was documented using MRI. The relevant literature is reviewed. PMID:11417420

  10. Passive microfluidic array card and reader

    DOEpatents

    Dugan, Lawrence Christopher; Coleman, Matthew A.

    2011-08-09

    A microfluidic array card and reader system for analyzing a sample. The microfluidic array card includes a sample loading section for loading the sample onto the microfluidic array card, a multiplicity of array windows, and a transport section or sections for transporting the sample from the sample loading section to the array windows. The microfluidic array card reader includes a housing, a receiving section for receiving the microfluidic array card, a viewing section, and a light source that directs light to the array window of the microfluidic array card and to the viewing section.

  11. Trial of Postoperative Radiation, Cisplatin, and Panitumumab in Locally Advanced Head and Neck Cancer

    ClinicalTrials.gov

    2016-06-28

    Cancer of Head; Cancer of Head and Neck; Cancer of Neck; Cancer of the Head; Cancer of the Head and Neck; Cancer of the Neck; Head and Neck Cancer; Head Cancer; Head Neoplasms; Head, Neck Neoplasms; Neck Cancer; Neck Neoplasms; Neoplasms, Head; Neoplasms, Head and Neck; Neoplasms, Neck; Neoplasms, Upper Aerodigestive Tract; UADT Neoplasms; Upper Aerodigestive Tract Neoplasms

  12. A systolic array parallelizing compiler

    SciTech Connect

    Tseng, P.S. )

    1990-01-01

    This book presents a completely new approach to the problem of systolic array parallelizing compiler. It describes the AL parallelizing compiler for the Warp systolic array, the first working systolic array parallelizing compiler which can generate efficient parallel code for complete LINPACK routines. This book begins by analyzing the architectural strength of the Warp systolic array. It proposes a model for mapping programs onto the machine and introduces the notion of data relations for optimizing the program mapping. Also presented are successful applications of the AL compiler in matrix computation and image processing. A complete listing of the source program and compiler-generated parallel code are given to clarify the overall picture of the compiler. The book concludes that systolic array parallelizing compiler can produce efficient parallel code, almost identical to what the user would have written by hand.

  13. Massively parallel MRI detector arrays

    NASA Astrophysics Data System (ADS)

    Keil, Boris; Wald, Lawrence L.

    2013-04-01

    Originally proposed as a method to increase sensitivity by extending the locally high-sensitivity of small surface coil elements to larger areas via reception, the term parallel imaging now includes the use of array coils to perform image encoding. This methodology has impacted clinical imaging to the point where many examinations are performed with an array comprising multiple smaller surface coil elements as the detector of the MR signal. This article reviews the theoretical and experimental basis for the trend towards higher channel counts relying on insights gained from modeling and experimental studies as well as the theoretical analysis of the so-called “ultimate” SNR and g-factor. We also review the methods for optimally combining array data and changes in RF methodology needed to construct massively parallel MRI detector arrays and show some examples of state-of-the-art for highly accelerated imaging with the resulting highly parallel arrays.

  14. Massively Parallel MRI Detector Arrays

    PubMed Central

    Keil, Boris; Wald, Lawrence L

    2013-01-01

    Originally proposed as a method to increase sensitivity by extending the locally high-sensitivity of small surface coil elements to larger areas, the term parallel imaging now includes the use of array coils to perform image encoding. This methodology has impacted clinical imaging to the point where many examinations are performed with an array comprising multiple smaller surface coil elements as the detector of the MR signal. This article reviews the theoretical and experimental basis for the trend towards higher channel counts relying on insights gained from modeling and experimental studies as well as the theoretical analysis of the so-called “ultimate” SNR and g-factor. We also review the methods for optimally combining array data and changes in RF methodology needed to construct massively parallel MRI detector arrays and show some examples of state-of-the-art for highly accelerated imaging with the resulting highly parallel arrays. PMID:23453758

  15. Massively parallel MRI detector arrays.

    PubMed

    Keil, Boris; Wald, Lawrence L

    2013-04-01

    Originally proposed as a method to increase sensitivity by extending the locally high-sensitivity of small surface coil elements to larger areas via reception, the term parallel imaging now includes the use of array coils to perform image encoding. This methodology has impacted clinical imaging to the point where many examinations are performed with an array comprising multiple smaller surface coil elements as the detector of the MR signal. This article reviews the theoretical and experimental basis for the trend towards higher channel counts relying on insights gained from modeling and experimental studies as well as the theoretical analysis of the so-called "ultimate" SNR and g-factor. We also review the methods for optimally combining array data and changes in RF methodology needed to construct massively parallel MRI detector arrays and show some examples of state-of-the-art for highly accelerated imaging with the resulting highly parallel arrays. PMID:23453758

  16. Chunking of Large Multidimensional Arrays

    SciTech Connect

    Rotem, Doron; Otoo, Ekow J.; Seshadri, Sridhar

    2007-02-28

    Data intensive scientific computations as well on-lineanalytical processing applications as are done on very large datasetsthat are modeled as k-dimensional arrays. The storage organization ofsuch arrays on disks is done by partitioning the large global array intofixed size hyper-rectangular sub-arrays called chunks or tiles that formthe units of data transfer between disk and memory. Typical queriesinvolve the retrieval of sub-arrays in a manner that accesses all chunksthat overlap the query results. An important metric of the storageefficiency is the expected number of chunks retrieved over all suchqueries. The question that immediately arises is "what shapes of arraychunks give the minimum expected number of chunks over a query workload?"In this paper we develop two probabilistic mathematical models of theproblem and provide exact solutions using steepest descent and geometricprogramming methods. Experimental results, using synthetic workloads onreal life data sets, show that our chunking is much more efficient thanthe existing approximate solutions.

  17. Nanoplasmonics of prime number arrays.

    PubMed

    Forestiere, Carlo; Walsh, Gary F; Miano, Giovanni; Dal Negro, Luca

    2009-12-21

    In this paper, we investigate the plasmonic near-field localization and the far-field scattering properties of non-periodic arrays of Ag nanoparticles generated by prime number sequences in two spatial dimensions. In particular, we demonstrate that the engineering of plasmonic arrays with large spectral flatness and particle density is necessary to achieve a high density of electromagnetic hot spots over a broader frequency range and a larger area compared to strongly coupled periodic and quasi-periodic structures. Finally, we study the far-field scattering properties of prime number arrays illuminated by plane waves and we discuss their angular scattering properties. The study of prime number arrays of metal nanoparticles provides a novel strategy to achieve broadband enhancement and localization of plasmonic fields for the engineering of nanoscale nano-antenna arrays and active plasmonic structures. PMID:20052140

  18. Integrated residential photovoltaic array development

    NASA Technical Reports Server (NTRS)

    Shepard, N. F., Jr.

    1981-01-01

    Three basic module design concepts were analyzed with respect to both production and installation costs. The results of this evaluation were used to synthesize a fourth design which incorporates the best features of these initial concepts to produce a module/array design approach which offers the promise of a substantial reduction in the installed cost of a residential array. A unique waterproofing and mounting scheme was used to reduce the cost of installing an integral array while still maintaining a high probability that the installed array will be watertight for the design lifetime of the system. This recommended concept will also permit the array to be mounted as a direct or stand-off installation with no changes to the module design.

  19. Image data rate converter having a drum with a fixed head and a rotatable head

    NASA Technical Reports Server (NTRS)

    Billingsley, F. C. (Inventor)

    1973-01-01

    A data-rate converter is disclosed comprising a rotatable data-storing drum with at least one fixed read/record head and a rotatable read/record head. The latter is rotatable in a circular path about the drum axis of rotation. The drum is positionable in any one of a plurality of axial positions with respect to the heads, so that at least one drum track is aligned with the fixed head in one drum position and with the rotatable head in another drum position. When a track is aligned with the fixed head, data may be recorded therin or read out therefrom at a rate which is a function of drum rotation, while when aligned with the rotatable head, data may be recorded or read out at a rate which is a function of the rates and directions of rotation of both the drum and the head.

  20. Radial head button holing: a cause of irreducible anterior radial head dislocation.

    PubMed

    Shin, Su-Mi; Chai, Jee Won; You, Ja Yeon; Park, Jina; Bae, Kee Jeong

    2016-10-01

    "Buttonholing" of the radial head through the anterior joint capsule is a known cause of irreducible anterior radial head dislocation associated with Monteggia injuries in pediatric patients. To the best of our knowledge, no report has described an injury consisting of buttonholing of the radial head through the annular ligament and a simultaneous radial head fracture in an adolescent. In the present case, the radiographic findings were a radial head fracture with anterior dislocation and lack of the anterior fat pad sign. Magnetic resonance imaging (MRI) clearly demonstrated anterior dislocation of the fractured radial head through the torn annular ligament. The anterior joint capsule and proximal portion of the annular ligament were interposed between the radial head and capitellum, preventing closed reduction of the radial head. Familiarity with this condition and imaging findings will aid clinicians to make a proper diagnosis and fast decision to perform an open reduction. PMID:27502623

  1. An evaluation of flight path formats head-up and head-down

    NASA Technical Reports Server (NTRS)

    Sexton, George A.; Moody, Laura E.; Evans, Joanne; Williams, Kenneth E.

    1988-01-01

    Flight path primary flight display formats were incorporated on head-up and head-down electronic displays and integrated into an Advanced Concepts Flight Simulator. Objective and subjective data were collected while ten airline pilots evaluated the formats by flying an approach and landing task under various ceiling, visibility and wind conditions. Deviations from referenced/commanded airspeed, horizontal track, vertical track and touchdown point were smaller using the head-up display (HUD) format than the head-down display (HDD) format, but not significantly smaller. Subjectively, the pilots overwhelmingly preferred (1) flight path formats over attitude formats used in current aircraft, and (2) the head-up presentation over the head-down, primarily because it eliminated the head-down to head-up transition during low visibility landing approaches. This report describes the simulator, the flight displays, the format evaluation, and the results of the objective and subjective data.

  2. Array gain for a cylindrical array with baffle scatter effects.

    PubMed

    Bertilone, Derek C; Killeen, Damien S; Bao, Chaoying

    2007-11-01

    Cylindrical arrays used in sonar for passive underwater surveillance often have sensors surrounding a cylindrical metal baffle. In some operational sonars, the phones in each stave (i.e., each line of phones aligned with the cylinder axis) are hardwired together so that the array is equivalent to a baffled circular array of directional elements, where each element corresponds to a line array of omnidirectional phones steered to broadside. In this paper a model is introduced for computing the array gain of such an array at high frequencies, which incorporates baffle scatter using infinite, rigid cylinder scattering theory, and with ambient noise described by an angular spectral density function. In practice the phones are often offset from the baffle surface, and the acoustic field sampled by the staves is distorted at high frequencies due to interference between the incident and scattered fields. Examples are given to illustrate the resulting array gain degradation, using three noise distributions that are frequently used in sonar performance modeling: three-dimensional isotropic, two-dimensional isotropic, and surface dipole noise. PMID:18189560

  3. Nano electrode arrays for in-situ identification and quantification of chemicals in water.

    SciTech Connect

    Gurule, Natalia J.; Kelly, Michael James; Brevnov, Dmitri A.; Ashby, Carol Iris Hill; Pfeifer, Kent Bryant; Yelton, William Graham

    2004-12-01

    The nano electrode arrays for in-situ identification and quantification of chemicals in water progress in four major directions. (1) We developed and engineering three nanoelectrode array designs which operate in a portable field mode or as distributed sensor network for water systems. (2) To replace the fragile glass electrochemical cells using in the lab, we design and engineered field-ready sampling heads that combine the nanoelectrode arrays with a high-speed potentiostat. (3) To utilize these arrays in a portable system we design and engineered a light weight high-speed potentiostat with pulse widths from 2 psec. to 100 msec. or greater. (4) Finally, we developed the parameters for an analytical method in low-conductivity solutions for Pb(II) detection, with initial studies for the analysis of As(III) and As(V) analysis in natural water sources.

  4. The Long Wavelength Array

    NASA Astrophysics Data System (ADS)

    Taylor, G. B.

    2006-08-01

    The Long Wavelength Array (LWA) will be a new, open, user-oriented astronomical instrument operating in the poorly explored window from 20-80 MHz at arcsecond level resolution and mJy level sensitivity. Key science drivers include (1) acceleration, propagation, and turbulence in the ISM, including the space-distribution and spectrum of Galactic cosmic rays, supernova remnants, and pulsars; (2) the high redshift universe, including the most distant radio galaxies and clusters - tools for understanding the earliest black holes and the cosmological evolution of Dark Matter and Dark Energy; (3) planetary, solar, and space science, including space weather prediction and extra-solar planet searches; and (4) the radio transient universe: including the known (e.g., SNe, GRBs) and the unknown. Because the LWA will explore one of the last and least investigated regions of the spectrum, the potential for new discoveries, including new classes of physical phenomena, is high, and there is a strong synergy with exciting new X-ray and Gamma-ray measurements, e.g. for cosmic ray acceleration, transients, and galaxy clusters. Operated by the University of New Mexico on behalf of the South West Consortium (SWC) the LWA will also provide a unique training ground for the next generation of radio astronomers. Students may also put skills learned on the LWA to work in computer science, electrical engineering, and the communications industry, among others. The development of the LWA will follow a phased build, which benefits from lessons learned at each phase. Four university-based Scientific Testing and Evaluation (ST&E) teams with different areas of concentration (1. High resolution imaging and particle acceleration; 2. Wide field imaging and large scale structures; 3. Ionosphere, and 4. RFI suppression and transient detection) will provide the feedback needed to assure that science objectives are met as the build develops. Currently in its first year of construction funding, the LWA

  5. Solar Array Tracking Control

    Energy Science and Technology Software Center (ESTSC)

    1995-06-22

    SolarTrak used in conjunction with various versions of 68HC11-based SolarTrack hardware boards provides control system for one or two axis solar tracking arrays. Sun position is computed from stored position data and time from an on-board clock/calendar chip. Position feedback can be by one or two offset motor turn counter square wave signals per axis, or by a position potentiometer. A limit of 256 counts resolution is imposed by the on-board analog to digital (A/D)more » convertor. Control is provided for one or two motors. Numerous options are provided to customize the controller for specific applications. Some options are imposed at compile time, some are setable during operation. Software and hardware board designs are provided for Control Board and separate User Interface Board that accesses and displays variables from Control Board. Controller can be used with range of sensor options ranging from a single turn count sensor per motor to systems using dual turn-count sensors, limit sensors, and a zero reference sensor. Dual axis trackers oriented azimuth elevation, east west, north south, or polar declination can be controlled. Misalignments from these orientations can also be accommodated. The software performs a coordinate transformation using six parameters to compute sun position in misaligned coordinates of the tracker. Parameters account for tilt of tracker in two directions, rotation about each axis, and gear ration errors in each axis. The software can even measure and compute these prameters during an initial setup period if current from a sun position sensor or output from photovoltaic array is available as an anlog voltage to the control board''s A/D port. Wind or emergency stow to aj present position is available triggered by digital or analog signals. Night stow is also available. Tracking dead band is adjustable from narrow to wide. Numerous features of the hardware and software conserve energy for use with battery powered systems.« less

  6. Electromagnetic Detection of Fatigue Cracks under Protruding Head Ferromagnetic Fasteners

    NASA Technical Reports Server (NTRS)

    Wincheski, Buzz; Namkung, Min

    2004-01-01

    The detection of fatigue cracks under installed fasteners has been a major goal of the aging aircraft NDE community. The Sliding Probe, Magneto-Optic Imager, Rotating Self-Nulling Probe, Low Frequency Eddy Current Array, and Eddyscan systems are among the instruments developed for this inspection. It has been verified that the detection of fatigue cracks under flush head aluminum and titanium fasteners can be accomplished with a high resolution by the above techniques. The detection of fatigue cracks under ferromagnetic and protruding head fasteners, however, has been found to be much more difficult. For the present work, the inspection for fatigue cracks under SAE 4340 Steel Hi-Lok fasteners is explored. Modifications to the Rotating Self-Nulling Eddy Current Probe System are presented which enable the detection of fatigue cracks hidden under the protruding head of the ferromagnetic fastener. Inspection results for samples with varying length EDM notches are shown, as well as a comparison between the signature from an EDM notch and an actual fatigue crack. Finite Element Modeling is used to investigate the effect of the ferromagnetic fastener on the induced eddy current distribution in order to help explain the detection characteristics of the system. This paper will also introduce a modification to the Rotating Probe System designed specifically for the detection of deeply buried flaws in multilayer conductors. The design change incorporates a giant magnetoresistive (GMR) sensor as the pickup device to improve the low frequency performance of the probe. The flaw detection capabilities of the GMR based Self- Nulling Probe are presented along with the status of the GMR based Rotating Probe System for detection of deeply buried flaws under installed fasteners.

  7. Where Is Health Care Headed?

    PubMed

    Bland, Jeffrey

    2016-06-01

    Looking at the trends, developments, and discoveries points us toward the future, but it is only when we consider these in the context of our understanding about the origins of disease that we can truly gain a clearer view of where health care is headed. This is the view that moves us from a focus on the diagnosis and treatment of a disease to an understanding of the origin of the alteration in function in the individual. This change in both perspective and understanding of the origin of disease is what will lead us to a systems approach to health care that delivers personalized and precision care that is based on the inherent rehabilitative power that resides within the genome. PMID:27547161

  8. Natural head position: An overview

    PubMed Central

    Meiyappan, N.; Tamizharasi, S.; Senthilkumar, K. P.; Janardhanan, K.

    2015-01-01

    Cephalometrics has given us a different perspective of interpreting various skeletal problems in the dentofacial complex. Natural head position (NHP) is a reproducible, physiologically determined aspect of function. To determine NHP, a horizontal or vertical reference line outside the crania was used, but preference was given generally to the horizontal. Various intra and extracranial cephalometric horizontal reference planes have been used to formulate diagnosis and plan individualized treatment for an integrated correction of the malocclusion cephalometrics is constantly undergoing refinements in its techniques and analyses to improve the clinical applications. Even though various methods for establishing NHP have been proposed, still it remains a challenge to the clinicians to implement the concept of NHP thoroughly in all the stages of treatment because of practical difficulties in the clinical scenario. PMID:26538891

  9. Lightweight camera head for robotic-based binocular stereo vision: an integrated engineering approach

    NASA Astrophysics Data System (ADS)

    Pretlove, John R. G.; Parker, Graham A.

    1992-03-01

    This paper presents the design and development of a real-time eye-in-hand stereo-vision system to aid robot guidance in a manufacturing environment. The stereo vision head comprises a novel camera arrangement with servo-vergence, focus, and aperture that continuously provides high-quality images to a dedicated image processing system and parallel processing array. The stereo head has four degrees of freedom but it relies on the robot end- effector for all remaining movement. This provides the robot with exploratory sensing abilities allowing it to undertake a wider variety of less constrained tasks. Unlike other stereo vision research heads, the overriding factor in the Surrey head has been a truly integrated engineering approach in an attempt to solve an extremely complex problem. The head is low cost, low weight, employs state-of-the-art motor technology, is highly controllable and occupies a small size envelope. Its intended applications include high-accuracy metrology, 3-D path following, object recognition and tracking, parts manipulation, and component inspection for the manufacturing industry.

  10. Reactor vessel lower head integrity

    SciTech Connect

    Rubin, A.M.

    1997-02-01

    On March 28, 1979, the Three Mile Island Unit 2 (TMI-2) nuclear power plant underwent a prolonged small break loss-of-coolant accident that resulted in severe damage to the reactor core. Post-accident examinations of the TMI-2 reactor core and lower plenum found that approximately 19,000 kg (19 metric tons) of molten material had relocated onto the lower head of the reactor vessel. Results of the OECD TMI-2 Vessel Investigation Project concluded that a localized hot spot of approximately 1 meter diameter had existed on the lower head. The maximum temperature on the inner surface of the reactor pressure vessel (RPV) in this region reached 1100{degrees}C and remained at that temperature for approximately 30 minutes before cooling occurred. Even under the combined loads of high temperature and high primary system pressure, the TMI-2 RPV did not fail. (i.e. The pressure varied from about 8.5 to 15 MPa during the four-hour period following the relocation of melt to the lower plenum.) Analyses of RPV failure under these conditions, using state-of-the-art computer codes, predicted that the RPV should have failed via local or global creep rupture. However, the vessel did not fail; and it has been hypothesized that rapid cooling of the debris and the vessel wall by water that was present in the lower plenum played an important role in maintaining RPV integrity during the accident. Although the exact mechanism(s) of how such cooling occurs is not known, it has been speculated that cooling in a small gap between the RPV wall and the crust, and/or in cracks within the debris itself, could result in sufficient cooling to maintain RPV integrity. Experimental data are needed to provide the basis to better understand these phenomena and improve models of RPV failure in severe accident codes.

  11. The submillimeter array polarimeter

    NASA Astrophysics Data System (ADS)

    Marrone, Daniel P.; Rao, Ramprasad

    2008-07-01

    We describe the Submillimeter Array (SMA) Polarimeter, a polarization converter and feed multiplexer installed on the SMA. The polarimeter uses narrow-band quarter-wave plates to generate circular polarization sensitivity from the linearly-polarized SMA feeds. The wave plates are mounted in rotation stages under computer control so that the polarization handedness of each antenna is rapidly selectable. Positioning of the wave plates is found to be highly repeatable, better than 0.2 degrees. Although only a single polarization is detected at any time, all four cross correlations of left- and right-circular polarization are efficiently sampled on each baseline through coordinated switching of the antenna polarizations in Walsh function patterns. The initial set of anti-reflection coated quartz and sapphire wave plates allows polarimetry near 345 GHz; these plates have been have been used in observations between 325 and 350 GHz. The frequency-dependent cross-polarization of each antenna, largely due to the variation with frequency of the retardation phase of the single-element wave plates, can be measured precisely through observations of bright point sources. Such measurements indicate that the cross-polarization of each antenna is a few percent or smaller and stable, consistent with the expected frequency dependence and very small alignment errors. The polarimeter is now available for general use as a facility instrument of the SMA.

  12. Microheater Array Boiling Experiment

    NASA Technical Reports Server (NTRS)

    Kim, Jungho; McQuillen, John; Balombin, Joe

    2002-01-01

    By conducting pool boiling tests in microgravity, the effect of buoyancy on the overall boiling process and the relative magnitude of other phenomena can be assessed. Data from KC-135 and sounding rocket experiments indicate little effect of gravity on boiling heat transfer at wall superheats below 25 C, despite vast differences in bubble behavior between gravity levels. In microgravity, a large primary bubble, surrounded by smaller satellite bubbles, moved over the surface, occasionally causing nucleation. Once formed, the primary bubble size remained constant for a given superheat, indicating evaporation at the bubble base is balanced with condensation on the bubble cap. The primary bubble's size increased with wall superheat. Most heaters under the primary bubble had low heat transfer rates, suggesting liquid dryout. Strong Marangoni convection developed in microgravity, forming a 'jet' into the bulk liquid that forced the bubble onto the heater. An experiment is being designed for the. Microgravity Science Glovebox. This experiment uses two 96 element microheater arrays, 2.7 and 7.0 mm in size. These heaters are individually controlled to operate at a constant temperature, measuring local heat fluxes as a function of time and space. Most boiling experiments operate at constant wall heat flux with larger heaters, allowing only time and space-averaged measurements. Each heater is about the bubble departure size in normal gravity, but significantly smaller than the bubble departure size in reduced gravity.

  13. VLSI array processor

    NASA Astrophysics Data System (ADS)

    Greenwood, E.

    1982-07-01

    The Arithmetic Processor Unit (APU) data base design check was completed. Minor design rule violations and design improvements were accomplished. The APU mask set has been fabricated and checked. Initial checking of all mask layers revealed a design rule problem in one layer. That layer was corrected, refabricated and checked out. The mask set has been delivered to the chip fabrication area. The fabrication process has been initiated. All work on the Array Processor Demonstration System (APDS) has been suspended at CHI until the additionally requested funding was received. That funding has been authorized and CHI will begin work on the APDS in July. The following activities are planned in the following quarter: 1) Complete fabrication of the first lot of VLSI APU devices. 2) Complete integration and check-out of the APDS simulator. 3) Complete integration and check-out of the APU breadboard. 4) Verify the VLSI APU wafer tests with the APU breadboard. 5) Complete check-out of the APDS using the APU breadboard.

  14. Particle sensor array

    NASA Technical Reports Server (NTRS)

    Buehler, Martin G. (Inventor); Blaes, Brent R. (Inventor); Lieneweg, Udo (Inventor)

    1994-01-01

    A particle sensor array which in a preferred embodiment comprises a static random access memory having a plurality of ion-sensitive memory cells, each such cell comprising at least one pull-down field effect transistor having a sensitive drain surface area (such as by bloating) and at least one pull-up field effect transistor having a source connected to an offset voltage. The sensitive drain surface area and the offset voltage are selected for memory cell upset by incident ions such as alpha-particles. The static random access memory of the present invention provides a means for selectively biasing the memory cells into the same state in which each of the sensitive drain surface areas is reverse biased and then selectively reducing the reversed bias on these sensitive drain surface areas for increasing the upset sensitivity of the cells to ions. The resulting selectively sensitive memory cells can be used in a number of applications. By way of example, the present invention can be used for measuring the linear energy transfer of ion particles, as well as a device for assessing the resistance of CMOS latches to Cosmic Ray induced single event upsets. The sensor of the present invention can also be used to determine the uniformity of an ion beam.

  15. Replica amplification of nucleic acid arrays

    DOEpatents

    Church, George M.; Mitra, Robi D.

    2010-08-31

    Disclosed are improved methods of making and using immobilized arrays of nucleic acids, particularly methods for producing replicas of such arrays. Included are methods for producing high density arrays of nucleic acids and replicas of such arrays, as well as methods for preserving the resolution of arrays through rounds of replication. Also included are methods which take advantage of the availability of replicas of arrays for increased sensitivity in detection of sequences on arrays. Improved methods of sequencing nucleic acids immobilized on arrays utilizing single copies of arrays and methods taking further advantage of the availability of replicas of arrays are disclosed. The improvements lead to higher fidelity and longer read lengths of sequences immobilized on arrays. Methods are also disclosed which improve the efficiency of multiplex PCR using arrays of immobilized nucleic acids.

  16. Offering an Array of Improvements

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Sensors Unlimited, Inc., with SBIR funding from NASA's Langley Research Center, Goddard Space Flight Center, Marshall Space Flight Center, and the Jet Propulsion Laboratory, developed a monolithic focal plane array for near-infrared imaging. The company developed one- (1- D) and two-dimensional (2-D) imaging arrays consisting of a highly reliable InGaAs p-I-n diode as a photodetector for monitoring a variety of applications, including single element device applications in receivers. The InGaAs 1-D and 2-D arrays have many applications. For example, they monitor the performance of dense wavelength division multiplexing (DWDM) systems- the process of packaging many channels into a single fiber-optic cable. Sensors Unlimited commercially offers its LXTM and LYTM Series InGaAs linear arrays for reliable DWDM performance monitoring. The LX and LY arrays enable instrument module designs with no moving parts, which provides for superior uniformity, and fast, linear outputs that remain stable over a wide temperature range. Innovative technologies derived from the monolithic focal plane array have enabled telecommunication companies to optimize existing bandwidth in their fiber-optic networks in order to support a high volume of network traffic. At the same time, the technologies obtained from the array have the potential for reducing costs, while increasing performance from Sensors Unlimited's current product lines.

  17. Radiation therapy for head and neck neoplasms

    SciTech Connect

    Wang, C.C.

    1990-01-01

    This book presents the clinical manifestations of disease, applied anatomy pertaining to the management of head and neck tumors, and results of conventional radiation therapy for uncommon tumors have been explored. It also contains an additional chapter on altered fractionation radiation therapy pertaining to irradiation of major head and neck tumors.

  18. Head Start Impact Study. Final Report

    ERIC Educational Resources Information Center

    Puma, Michael; Bell, Stephen; Cook, Ronna; Heid, Camilla; Shapiro, Gary; Broene, Pam; Jenkins, Frank; Fletcher, Philip; Quinn, Liz; Friedman, Janet; Ciarico, Janet; Rohacek, Monica; Adams, Gina; Spier, Elizabeth

    2010-01-01

    This report addresses the following four questions by reporting on the impacts of Head Start on children and families during the children's preschool, kindergarten, and 1st grade years: (1) What difference does Head Start make to key outcomes of development and learning (and in particular, the multiple domains of school readiness) for low-income…

  19. Head Start Impact Study. Technical Report

    ERIC Educational Resources Information Center

    Puma, Michael; Bell, Stephen; Cook, Ronna; Heid, Camilla; Shapiro, Gary; Broene, Pam; Jenkins, Frank; Fletcher, Philip; Quinn, Liz; Friedman, Janet; Ciarico, Janet; Rohacek, Monica; Adams, Gina; Spier, Elizabeth

    2010-01-01

    This Technical Report is designed to provide technical detail to support the analysis and findings presented in the "Head Start Impact Study Final Report" (U.S. Department of Health and Human Services, January 2010). Chapter 1 provides an overview of the Head Start Impact Study and its findings. Chapter 2 provides technical information on the…

  20. The Texas Head Start Metro Models.

    ERIC Educational Resources Information Center

    Riley, Mary Tom, Ed.; Flores, Alfredo R., Ed.

    The Texas Metro Network (TMN) is an informal group of Head Start Directors and Executive Directors organized for the purposes of improving the delivery of training and technical assistance and for assisting communication between large scale Head Start programs in the metropolitan areas of Texas. In pursuit of these aims, each member unit of the…

  1. The Role of the Primary School Head.

    ERIC Educational Resources Information Center

    Davies, Lester

    1987-01-01

    This study uses Henry Mintzberg's structural observation method to examine British primary school head teachers' work patterns and determine the nature of their role. Head teachers' days were characterized by brevity, variety, and fragmentation similar to those discussed in findings of other empirical managerial studies. Leadership roles stressed…

  2. Using Music with Head Start Children.

    ERIC Educational Resources Information Center

    Griffin, Louise

    This pamphlet describes the function of music in Head Start programs. Suggestions are made to help children sense motion and develop their self-concepts and motor coordination skills through rhythmic songs and activities. The construction and use of rhythm instruments are suggested as a means of involving mothers in Head Start programs. Certain…

  3. High density tape/head interface study

    NASA Technical Reports Server (NTRS)

    Csengery, L. C.

    1983-01-01

    The high energy (H sub c approximately or = to 650 oersteds) tapes and high track density (84 tracks per inch) heads investigated had, as its goal, the definition of optimum combinations of head and tape, including the control required of their interfacial dynamics that would enable the manufacture of high rate (150 Mbps) digital tape recorders for unattended space flight.

  4. 21 CFR 868.1930 - Stethoscope head.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Stethoscope head. 868.1930 Section 868.1930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1930 Stethoscope head. (a) Identification....

  5. 21 CFR 868.1930 - Stethoscope head.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stethoscope head. 868.1930 Section 868.1930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1930 Stethoscope head. (a) Identification....

  6. 21 CFR 868.1930 - Stethoscope head.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Stethoscope head. 868.1930 Section 868.1930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1930 Stethoscope head. (a) Identification....

  7. 21 CFR 868.1930 - Stethoscope head.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Stethoscope head. 868.1930 Section 868.1930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1930 Stethoscope head. (a) Identification....

  8. 21 CFR 868.1930 - Stethoscope head.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Stethoscope head. 868.1930 Section 868.1930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1930 Stethoscope head. (a) Identification....

  9. 49 CFR 572.32 - Head.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Head. 572.32 Section 572.32 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES Hybrid III Test Dummy § 572.32 Head....

  10. "Starfish" Heater Head For Stirling Engine

    NASA Technical Reports Server (NTRS)

    Vitale, N.

    1993-01-01

    Proposed "starfish" heater head for Stirling engine enables safe use of liquid sodium as heat-transfer fluid. Sodium makes direct contact with heater head but does not come in contact with any structural welds. Design concept minimizes number of, and simplifies nonstructural thermal welds and facilitates inspection of such welds.

  11. 49 CFR 572.82 - Head.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Head. 572.82 Section 572.82 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.82 Head. The...

  12. 49 CFR 572.82 - Head.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Head. 572.82 Section 572.82 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.82 Head. The...

  13. 49 CFR 572.82 - Head.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Head. 572.82 Section 572.82 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.82 Head. The...

  14. 49 CFR 572.82 - Head.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Head. 572.82 Section 572.82 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.82 Head. The...

  15. 49 CFR 572.82 - Head.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Head. 572.82 Section 572.82 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.82 Head. The...

  16. 49 CFR 572.112 - Head assembly.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... to its application in a test. (2) Clean the impact surface of the head skin and impact plate surface... degrees with the impact surface and its anterior-posterior axis is horizontal ±1 degree. (4) Drop the head... means that ensures a smooth, clean release into a rigidly supported flat horizontal steel plate,...

  17. 49 CFR 572.112 - Head assembly.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... to its application in a test. (2) Clean the impact surface of the head skin and impact plate surface... degrees with the impact surface and its anterior-posterior axis is horizontal ±1 degree. (4) Drop the head... means that ensures a smooth, clean release into a rigidly supported flat horizontal steel plate,...

  18. Marshall Space Flight Center head development program

    NASA Technical Reports Server (NTRS)

    Harrer, Jim

    1994-01-01

    This report summarizes the results of the candidate head evaluation for the new long-life magnetic head per the SOW of Contract No. NAS8-39407, MSFC Head Development Program. The original program plans were to test a candidate head, fabricate a new head, then qualify the new head. These activities were scheduled to be carried out between March 1993 and March 1994. The program was halted after the evaluation of the candidate head by NAS8-39407 Amendment No. 4. MSFC has provided and authorized the use the MARS-2000 SRB QUAL Recorder PN 10400-0677-801 - Serial Number 200004 (Datatape PN 591000 - Serial Number 1004), Reproduce Amplifier Module (RAM) Datatape PN 533040 - Serial Number 2006, associated cables, and magnetic tape on special SRB/DFI tapered reels to Datatape for this program. All the testing that has been done for the candidate head evaluation was done at Datatape's facility in Pasadena,CA. The testing was performed in a Class 100,000 particle counts clean room at ambient temperature, except for the thermal testing which was conducted in a different area at Datatape. The Performance Verification Test Procedure PVT-11004-4 (PVT) and Acceptance Test Procedure ATP-11004-09 (ATP) procedures were used when tests were conducted on the recorder.

  19. University Department Heads: Agents of Changes.

    ERIC Educational Resources Information Center

    Reyna, Sheila Sullivan

    A theoretical framework for the process of faculty renewal in the 1980s was proposed, based on examination of the role of department heads as in-house agents of change for staff development. Support for the theory was sought using three empirical statements to test the relationship of department heads' manipulative orientation and social insight…

  20. Borrelia recurrentis in Head Lice, Ethiopia

    PubMed Central

    Boutellis, Amina; Mediannikov, Oleg; Bilcha, Kassahun Desalegn; Ali, Jemal; Campelo, Dayana; Barker, Stephen C.

    2013-01-01

    Since the 1800s, the only known vector of Borrelia recurrentis has been the body louse. In 2011, we found B. recurrentis DNA in 23% of head lice from patients with louse-borne relapsing fever in Ethiopia. Whether head lice can transmit these bacteria from one person to another remains to be determined. PMID:23648147

  1. Administration for Children and Families: Head Start

    ERIC Educational Resources Information Center

    US Department of Health and Human Services, 2010

    2010-01-01

    This paper presents an overview of the Head Start program. Under the American Recovery and Reinvestment Act (Recovery Act), $1 billion will be provided to the Office of Head Start to promote the school readiness of low-income children, including children on federally-recognized reservations and children of migratory farm workers, by enhancing…

  2. Head Injury in Partner-Abusive Men.

    ERIC Educational Resources Information Center

    Rosenbaum, Alan; And Others

    1994-01-01

    Fifty-three partner-abusive men, 45 maritally satisfied, and 32 maritally discordant, nonviolent men were evaluated for past history of head injury. Logistic regressions confirmed head injury was significant predictor of being a batterer. Implications of findings for both marital aggression and posthead injury rehabilitation are discussed. (Author)

  3. Head Start. What Works Clearinghouse Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2015

    2015-01-01

    "Head Start" is a national, federally funded program that provides services to promote school readiness for children from birth to age 5 from predominantly low-income families. Based on a review of the research, the WWC found "Head Start" to have potentially positive effects on general reading achievement and no discernible…

  4. Newborns' Head Orientation toward Sounds Within Hemifields.

    ERIC Educational Resources Information Center

    Fenwick, Kimberley; And Others

    This experiment examined the accuracy with which newborn infants orient their heads toward a sound positioned off midline within hemifields. The study also evaluated newborns' ability to update the angle of their head turn to match a change in localization of an ongoing sound. Alert newborns were held in a supine position and presented a sound at…

  5. Systematic Biases in Human Heading Estimation

    PubMed Central

    Cuturi, Luigi F.; MacNeilage, Paul R.

    2013-01-01

    Heading estimation is vital to everyday navigation and locomotion. Despite extensive behavioral and physiological research on both visual and vestibular heading estimation over more than two decades, the accuracy of heading estimation has not yet been systematically evaluated. Therefore human visual and vestibular heading estimation was assessed in the horizontal plane using a motion platform and stereo visual display. Heading angle was overestimated during forward movements and underestimated during backward movements in response to both visual and vestibular stimuli, indicating an overall multimodal bias toward lateral directions. Lateral biases are consistent with the overrepresentation of lateral preferred directions observed in neural populations that carry visual and vestibular heading information, including MSTd and otolith afferent populations. Due to this overrepresentation, population vector decoding yields patterns of bias remarkably similar to those observed behaviorally. Lateral biases are inconsistent with standard Bayesian accounts which predict that estimates should be biased toward the most common straight forward heading direction. Nevertheless, lateral biases may be functionally relevant. They effectively constitute a perceptual scale expansion around straight ahead which could allow for more precise estimation and provide a high gain feedback signal to facilitate maintenance of straight-forward heading during everyday navigation and locomotion. PMID:23457631

  6. Historical Perspectives on Project Head Start.

    ERIC Educational Resources Information Center

    Slaughter, Diana T.

    Historical changes in the emphasis and focus of Project Head Start from 1965 to the present are briefly reviewed in this paper. Head Start was conceived of as primary prevention designed to enable children from lower income families to obtain educational prerequisites to formal schooling. The early years of the project were also characterized by…

  7. Efficient array design for sonotherapy.

    PubMed

    Stephens, Douglas N; Kruse, Dustin E; Ergun, Arif S; Barnes, Stephen; Lu, X Ming; Ferrara, Katherine W

    2008-07-21

    New linear multi-row, multi-frequency arrays have been designed, constructed and tested as fully operational ultrasound probes to produce confocal imaging and therapeutic acoustic intensities with a standard commercial ultrasound imaging system. The triple-array probes and imaging system produce high quality B-mode images with a center row imaging array at 5.3 MHz and sufficient acoustic power with dual therapeutic arrays to produce mild hyperthermia at 1.54 MHz. The therapeutic array pair in the first probe design (termed G3) utilizes a high bandwidth and peak pressure, suitable for mechanical therapies. The second multi-array design (termed G4) has a redesigned therapeutic array pair which is optimized for a high time-averaged power output suitable for mild hyperthermia applications. The 'thermal therapy' design produces more than 4 W of acoustic power from the low-frequency arrays with only a 10.5 degrees C internal rise in temperature after 100 s of continuous use with an unmodified conventional imaging system or substantially longer operation at lower acoustic power. The low-frequency arrays in both probe designs were examined and contrasted for real power transfer efficiency with a KLM model which includes all lossy contributions in the power delivery path from system transmitters to the tissue load. Laboratory verification was successfully performed for the KLM-derived estimates of transducer parallel model acoustic resistance and dissipation resistance, which are the critical design factors for acoustic power output and undesired internal heating, respectively. PMID:18591737

  8. CLAES focal plane array. [Cryogenic Limb Array Etalon Spectrometer

    NASA Technical Reports Server (NTRS)

    Roche, A. E.; Sterritt, L. W.; Kumer, J. B.; Callary, P. C.; Nielsen, R. L.

    1989-01-01

    The Cryogenic Limb Array Etalon Spectrometer for the NASA Upper Atmospheric Research Satellite uses solid-state focal plane arrays to detect emission from the earth's atmosphere over the IR wavelength range 3.5 to 13 microns. This paper discusses the design of the focal plane detector assembly and compares calculated performance with measurements. Measurements were made of focal plane noise and responsivity as functions of frequency (2 to 500 Hz) and temperature (12 to 19 K), pixel-to-pixel and across-array crosstalk, and linearity over a dynamic range of 100,000. The measurements demonstrate that the arrays satisfy the science requirements, and that, in general, there is reasonable agreement between the measurements and the analytical model.

  9. Heading Tuning in Macaque Area V6

    PubMed Central

    Fan, Reuben H.; Liu, Sheng; DeAngelis, Gregory C.

    2015-01-01

    Cortical areas, such as the dorsal subdivision of the medial superior temporal area (MSTd) and the ventral intraparietal area (VIP), have been shown to integrate visual and vestibular self-motion signals. Area V6 is interconnected with areas MSTd and VIP, allowing for the possibility that V6 also integrates visual and vestibular self-motion cues. An alternative hypothesis in the literature is that V6 does not use these sensory signals to compute heading but instead discounts self-motion signals to represent object motion. However, the responses of V6 neurons to visual and vestibular self-motion cues have never been studied, thus leaving the functional roles of V6 unclear. We used a virtual reality system to examine the 3D heading tuning of macaque V6 neurons in response to optic flow and inertial motion stimuli. We found that the majority of V6 neurons are selective for heading defined by optic flow. However, unlike areas MSTd and VIP, V6 neurons are almost universally unresponsive to inertial motion in the absence of optic flow. We also explored the spatial reference frames of heading signals in V6 by measuring heading tuning for different eye positions, and we found that the visual heading tuning of most V6 cells was eye-centered. Similar to areas MSTd and VIP, the population of V6 neurons was best able to discriminate small variations in heading around forward and backward headings. Our findings support the idea that V6 is involved primarily in processing visual motion signals and does not appear to play a role in visual–vestibular integration for self-motion perception. SIGNIFICANCE STATEMENT To understand how we successfully navigate our world, it is important to understand which parts of the brain process cues used to perceive our direction of self-motion (i.e., heading). Cortical area V6 has been implicated in heading computations based on human neuroimaging data, but direct measurements of heading selectivity in individual V6 neurons have been lacking. We

  10. Head Start Impact Study: First Year Findings. Executive Summary

    ERIC Educational Resources Information Center

    Puma, Michael; Bell, Stephen; Cook, Ronna; Heid, Camilla; Lopez, Michael

    2005-01-01

    The Congressionally-mandated Head Start Impact Study is being conducted across 84 nationally representative grantee/delegate agencies. Approximately 5,000 newly entering 3- and 4-year-old children applying for Head Start were randomly assigned to either a Head Start group that had access to Head Start program services or to a non-Head Start group…

  11. A Guide for Providing Social Services in Head Start.

    ERIC Educational Resources Information Center

    Administration for Children, Youth, and Families (DHHS), Washington, DC. Head Start Bureau.

    The social services component of Head Start links family, Head Start, and the community. This document addresses components of Head Start, providing Head Start staff who have social services responsibility with a guide to the provision of services to families. The chapters in the guide are: (1) "Overview of Head Start," including its origins,…

  12. Application specific serial arithmetic arrays

    NASA Technical Reports Server (NTRS)

    Winters, K.; Mathews, D.; Thompson, T.

    1990-01-01

    High performance systolic arrays of serial-parallel multiplier elements may be rapidly constructed for specific applications by applying hardware description language techniques to a library of full-custom CMOS building blocks. Single clock pre-charged circuits have been implemented for these arrays at clock rates in excess of 100 Mhz using economical 2-micron (minimum feature size) CMOS processes, which may be quickly configured for a variety of applications. A number of application-specific arrays are presented, including a 2-D convolver for image processing, an integer polynomial solver, and a finite-field polynomial solver.

  13. Interferometric optical vortex array generator.

    PubMed

    Vyas, Sunil; Senthilkumaran, P

    2007-05-20

    Two new interferometric configurations for optical vortex array generation are presented. These interferometers are different from the conventional interferometers in that they are capable of producing a large number of isolated zeros of intensity, and all of them contain optical vortices. Simulation and theory for optical vortex array generation using three-plane-wave interference is presented. The vortex dipole array produced this way is noninteracting, as there are no attraction or repulsion forces between them, leading to annihilation or creation of vortex pairs. PMID:17514234

  14. Interferometric optical vortex array generator

    SciTech Connect

    Vyas, Sunil; Senthilkumaran, P

    2007-05-20

    Two new interferometric configurations for optical vortex array generation are presented.These interferometers are different from the conventional interferometers in that they are capable of producing a large number of isolated zeros of intensity, and all of them contain optical vortices. Simulation and theory for optical vortex array generation using three-plane-wave interference is presented. The vortex dipole array produced this way is noninteracting, as there are no attraction or repulsion forces between them, leading to annihilation or creation of vortex pairs.

  15. Spatially extended atmospheric plasma arrays

    NASA Astrophysics Data System (ADS)

    Cao, Z.; Nie, Q.; Bayliss, D. L.; Walsh, J. L.; Ren, C. S.; Wang, D. Z.; Kong, M. G.

    2010-04-01

    This paper reports a systematic study of spatially extended atmospheric plasma (SEAP) arrays employing many parallel plasma jets packed densely and arranged in an honeycomb configuration. The work is motivated by the challenge of using inherently small atmospheric plasmas to address many large-scale processing applications including plasma medicine. The first part of the study considers a capillary-ring electrode configuration as the elemental jet with which to construct a 2D SEAP array. It is shown that its plasma dynamics is characterized by strong interaction between two plasmas initially generated near the two electrodes. Its plume length increases considerably when the plasma evolves into a high-current continuous mode from the usual bullet mode. Its electron density is estimated to be at the order of 3.7 × 1012 cm-3. The second part of the study considers 2D SEAP arrays constructed from parallelization of identical capillary-ring plasma jets with very high jet density of 0.47-0.6. Strong jet-jet interactions of a 7-jet 2D array are found to depend on the excitation frequency, and are effectively mitigated with the jet-array structure that acts as an effective ballast. The impact range of the reaction chemistry of the array exceeds considerably the cross-sectional dimension of the array itself, and the physical reach of reactive species generated by any single jet exceeds significantly the jet-jet distance. As a result, the jet array can treat a large sample surface without relative sample-array movement. A 37-channel SEAP array is used to indicate the scalability with an impact range of up to 48.6 mm in diameter, a step change in capability from previously reported SEAP arrays. 2D SEAP arrays represent one of few current options as large-scale low-temperature atmospheric plasma technologies with distinct capability of directed delivery of reactive species and effective control of the jet-jet and jet-sample interactions.

  16. Bobbling head in a young subject

    PubMed Central

    Bhattacharyya, Kalyan B.; Deb, Sumit; Ghosh, S. N.; Mondal, S.

    2014-01-01

    Bobble-head Doll Syndrome is a rare and unique movement disorder found in children. Clinically, it is characterized by a to and fro or side to side movement of the head at the frequency of 2 to 3 Hz. It is mostly associated with cystic lesions around the third ventricle, choroid plexus papilloma, aqueductal stenosis and other rare disorders. An eleven year old child presented in the outpatient department with continuous to and fro movement of the head and declining vision for the last one month. MRI Scan showed a large contrast-enhanced lesion in the region of the third ventricle along with gross hydrocephalus. Ventriculo-peritoneal shunt was inserted and the movements of the head disappeared completely. Bobble-head doll syndrome is a rare condition and therefore this case is presented and the literature reviewed. PMID:25506155

  17. Bobbling head in a young subject.

    PubMed

    Bhattacharyya, Kalyan B; Deb, Sumit; Ghosh, S N; Mondal, S

    2014-10-01

    Bobble-head Doll Syndrome is a rare and unique movement disorder found in children. Clinically, it is characterized by a to and fro or side to side movement of the head at the frequency of 2 to 3 Hz. It is mostly associated with cystic lesions around the third ventricle, choroid plexus papilloma, aqueductal stenosis and other rare disorders. An eleven year old child presented in the outpatient department with continuous to and fro movement of the head and declining vision for the last one month. MRI Scan showed a large contrast-enhanced lesion in the region of the third ventricle along with gross hydrocephalus. Ventriculo-peritoneal shunt was inserted and the movements of the head disappeared completely. Bobble-head doll syndrome is a rare condition and therefore this case is presented and the literature reviewed. PMID:25506155

  18. Intrapartum sonographic imaging of fetal head asynclitism.

    PubMed

    Ghi, T; Youssef, A; Pilu, G; Malvasi, A; Ragusa, A

    2012-02-01

    Anterior asynclitism was suspected on digital examination of a laboring woman with late arrest of dilatation and no evidence of fetal head progression. Clinical examination revealed a fixed non-engaged fetal head (station −1), with a transverse posterior sagittal suture. A static three-dimensional volume was obtained by translabial ultrasound, offline analysis of which confirmed the clinical diagnosis of anterior asynclitism. Owing to the posterior twisting of the head towards the sacrum, the midline echo could only be obtained by cutting the volume with an oblique line, the direction of which was not perpendicular to the pubis as expected in cases of synclitic head. The sonographic appearance of the midline echo approaching the sacrum in a non-engaged transverse fetal head strongly supports the clinical suspicion of anterior asynclitism. PMID:21523842

  19. Management of head injuries in children.

    PubMed

    Conchie, Henry; Palmer, Sarah; Fernando, Katalin; Paul, Siba Prosad

    2016-07-01

    Head injury is the most common cause of injury-related death and permanent disability in children. Minor head trauma is common in childhood and does not require any medical treatment. Although deficits can occur even after mild to moderate head injury, they are markedly greater and become clinically evident following severe head injury. It is important that emergency department clinicians are aware of the signs and symptoms that indicate severe traumatic brain injury and triage for urgent intervention in those children who present with these signs and symptoms. Clinicians also need to know when children can be sent home with reassurance and information, and when they require admission or transfer to a neurosurgical unit. This article examines the literature on head injuries in children, describes assessment, management and treatment, and provides a simple management algorithm. PMID:27384805

  20. Natural convection around the human head.

    PubMed

    Clark, R P; Toy, N

    1975-01-01

    1. Factors determining the convective flow patterns around the human head in 'still' conditions are discussed in relation to body posture. 2. The flow patterns have been visualized using a schlieren optical system which reveals that the head has a thicker 'insulating' layer of convecting air in the erect posture than in the supine position. 3. Local convective and radiative heat transfer measurements from the head have been using surface calorimeters. These results are seen to be closely related to the thickness of the convective boundary layer flows. 4. The total convective and radiative heat loss from the head of a subject in the erect and supine position has been evaluated from the local measurements. For the head of the supine subject the heat loss was found to be 30% more than when the subject was standing. PMID:1142118

  1. Immunotherapy With MK-3475 in Surgically Resectable Head and Neck Squamous Cell Carcinoma

    ClinicalTrials.gov

    2016-07-11

    Cancer of Head and Neck; Head and Neck Cancer; Neoplasms, Head and Neck; Carcinoma, Squamous Cell of Head and Neck; Squamous Cell Carcinoma of the Head and Neck; Squamous Cell Carcinoma, Head and Neck

  2. Areal array jetting device for ball grid arrays

    SciTech Connect

    Frear, D.R.; Yost, F.G.; Schmale, D.T.; Essien, M.

    1997-08-01

    Package designs for microelectronics devices have moved from through-hole to surface mount technology in order to increase the printed wiring board real estate available by utilizing both sides of the board. The traditional geometry for surface mount devices is peripheral arrays where the leads are on the edges of the device. As the technology drives towards high input/output (I/O) count (increasing number of leads) and smaller packages with finer pitch (less distance between peripheral leads), limitations on peripheral surface mount devices arise. A solution to the peripheral surface mount issue is to shift the leads to the area under the device. This scheme is called areal array packaging and is exemplified by the ball grid array (BGA) package. In a BGA package, the leads are on the bottom surface of the package in the form of an array of solder balls. The current practice of joining BGA packages to printed wiring boards involves a hierarchy of solder alloy compositions. A high melting temperature ball is typically used for standoff. A promising alternative to current methods is the use of jetting technology to perform monolithic solder ball attachment. This paper describes an areal array jetter that was designed and built to simultaneously jet arrays of solder balls directly onto BGA substrates.

  3. Elbow dislocation with irreparable fracture radial head

    PubMed Central

    Tanna, Dilip

    2013-01-01

    Background: Treatment of elbow dislocation with irreparable radial head fracture needs replacement of radial head to achieve stability of elbow. An alternate method in cases of elbow dislocation with radial head fracture can be resection of radial head with repair of medial collateral ligament. We report a retrospective analysis of cases of elbow dislocation with irreparable radial head treated by excision head of radius and repair of MCL. Materials and Methods: Nine patients of elbow dislocation with associated irreparable fractures of the head of the radius were included in this analysis (6 F:3 M, Age: 35-47 years). Radial head excision was done through the lateral approach and MCL was sutured using no 3 Ethibond using medial approach. Above elbow plaster was given for 6 weeks and gradual mobilization was done thereafter. All patients were assessed at final followup using Mayo elbow performance score (MEPS). Results: Mean followup was 19.55 ± 7.12 months (range 14-36 months). There was no extension deficit when compared to opposite side with mean range of flexion of 138.8° ± 6.97° (range 130 -145°). Mean pronation was 87.7° ± 4.4° (range 80-90°) and mean supination was 87.7 ± 4.62° (range 80-90°). The mean MEPS was 98.8 ± 3.33 (range 90-100). No patient had pain, sensory complaints, subluxation or redislocation. All were able to carry out their daily activities without disability. Conclusion: Radial head excision with MCL repair is an acceptable option for treatment of patients with elbow dislocation and irreparable radial head fracture. PMID:23798760

  4. Shape controllable synthesis of ZnO nanorod arrays via vapor phase growth

    NASA Astrophysics Data System (ADS)

    Sun, Xiaochen; Zhang, Hongzhou; Xu, Jun; Zhao, Qing; Wang, Rongming; Yu, Dapeng

    2004-03-01

    ZnO nanorod arrays with peculiar morphologies were synthesized on (111)-oriented Si substrate and glass via a vapor phase growth. The morphology of the individual nanorod can be flat-headed bottle-like, and needle-like, which depends on the deposition positions relative to the source materials in the presence of a controlling element Se. In addition, the arrays of all the three morphologies exhibit good alignment and high coverage. This fabrication technique can be also used to direct the controllable growth of other nanomaterials with similar morphologies.

  5. Fracture characterisation using geoelectric null-arrays

    NASA Astrophysics Data System (ADS)

    Falco, Pierik; Negro, François; Szalai, Sándor; Milnes, Ellen

    2013-06-01

    The term "geoelectric null-array" is used for direct current electrode configurations yielding a potential difference of zero above a homogeneous half-space. This paper presents a comparative study of the behaviour of three null-arrays, midpoint null-array (MAN), Wenner-γ null-array and Schlumberger null-array in response to a fracture, both in profiling and in azimuthal mode. The main objective is to determine which array(s) best localise fractures or best identify their orientation. Forward modelling of the three null-arrays revealed that the Wenner-γ and Schlumberger null-arrays localise vertical fractures the most accurately, whilst the midpoint null-array combined with the Schlumberger null-array allows accurate orientation of a fracture. Numerical analysis then served as a basis to interpret the field results. Field test measurements were carried out above a quarry in Les Breuleux (Switzerland) with the three null-arrays and classical arrays. The results were cross-validated with quarry-wall geological mapping. In real field circumstances, the Wenner-γ null-array proved to be the most efficient and accurate in localising fractures. The orientations of the fractures according to the numerical results were most efficiently determined with the midpoint null-array, whilst the Schlumberger null-array adds accuracy to the results. This study shows that geoelectrical null-arrays are more suitable than classical arrays for the characterisation of fracture geometry.

  6. Silicon Heat Pipe Array

    NASA Technical Reports Server (NTRS)

    Yee, Karl Y.; Ganapathi, Gani B.; Sunada, Eric T.; Bae, Youngsam; Miller, Jennifer R.; Beinsford, Daniel F.

    2013-01-01

    Improved methods of heat dissipation are required for modern, high-power density electronic systems. As increased functionality is progressively compacted into decreasing volumes, this need will be exacerbated. High-performance chip power is predicted to increase monotonically and rapidly with time. Systems utilizing these chips are currently reliant upon decades of old cooling technology. Heat pipes offer a solution to this problem. Heat pipes are passive, self-contained, two-phase heat dissipation devices. Heat conducted into the device through a wick structure converts the working fluid into a vapor, which then releases the heat via condensation after being transported away from the heat source. Heat pipes have high thermal conductivities, are inexpensive, and have been utilized in previous space missions. However, the cylindrical geometry of commercial heat pipes is a poor fit to the planar geometries of microelectronic assemblies, the copper that commercial heat pipes are typically constructed of is a poor CTE (coefficient of thermal expansion) match to the semiconductor die utilized in these assemblies, and the functionality and reliability of heat pipes in general is strongly dependent on the orientation of the assembly with respect to the gravity vector. What is needed is a planar, semiconductor-based heat pipe array that can be used for cooling of generic MCM (multichip module) assemblies that can also function in all orientations. Such a structure would not only have applications in the cooling of space electronics, but would have commercial applications as well (e.g. cooling of microprocessors and high-power laser diodes). This technology is an improvement over existing heat pipe designs due to the finer porosity of the wick, which enhances capillary pumping pressure, resulting in greater effective thermal conductivity and performance in any orientation with respect to the gravity vector. In addition, it is constructed of silicon, and thus is better

  7. The Millimeter Array

    NASA Astrophysics Data System (ADS)

    Brown, R. L.

    1996-05-01

    The Millimeter Array (MMA) is the second highest priority among the Bahcall Committee's recommendations for new large ground-based facilities in the decade of the 1990s. It is expected that the NSF will support the recommendation and begin construction of the revolutionary MMA synthesis telescope in the very near future. The MMA consists of forty 8-m antennas designed to operate throughout the millimeter/submillimeter atmospheric windows that are accessible from a high altitude site. Scientifically, the MMA will provide high fidelity images, both spectroscopic and continuum, of thermal objects--planets, stars, interstellar molecular clouds, protostars, galactic disks, and cosmologically distant protogalaxies. The sub-arcsecond angular resolution of the MMA is needed so that the MMA images can complement those of the HST and the next-generation infrared telescopes. The principal technical challenges facing the MMA include the following: Location of a site with low opacity and good atmospheric stability; Design of a high performance antenna; Design of SIS mixers with quantum-limited performance; Design of a wideband, 16 GHz, signal transmission system and correlator; Demonstration of an effective phase calibration technique; Design of antenna configurations for imaging both high brightness compact sources and very low brightness extended emission. The MMA technical design is being carried out as a partnership between the NRAO, OVRO and BIMA called the MMA Development Consortium (MDC). It is anticipated that the MMA will have substantial involvement from international partners; such a collaboration is now being forged that will meld the capabilities of the MMA with those of other projects and serve to enhance the scientific capabilities of all. Extensive information on the MMA can be found on the WWW via http://www.tuc.nrao.edu/mma.html

  8. Sword-Like Trauma to the Shoulder with Open Head-Splitting Fracture of the Head

    PubMed Central

    Pantazis, Konstantinos; Iliopoulos, Ilias; Seferlis, Ioannis; Kokkalis, Zinon

    2016-01-01

    Head-splitting fractures occur as a result of violent compression of the head against the glenoid; the head splits and the tuberosities may remain attached to the fragments or split and separate. Isolated humeral head-splitting fractures are rare injuries. Favorable results with osteosynthesis can be difficult to achieve because of the very proximal location of the head fracture and associated poor vascularity. We present a case of a 67-year-old man who sustained a severe, sword-like trauma to his left shoulder after a road traffic accident with associated isolated open Gustilo-Anderson IIIA humeral head-splitting fracture. Bony union was achieved with minimal internal fixation but the clinical outcome deteriorated due to accompanying axillary nerve apraxia. To our knowledge, this type of sword-like injury with associated humeral head-split fracture has not previously been reported. PMID:27478665

  9. Heading in the right direction? An innovative approach toward proper patient head positioning

    SciTech Connect

    Grush, William H.; Steffen, Gary A

    2002-12-31

    An in-house-manufactured modification of the standard A-F foam rubber head-neck supports (aka. Timo Supports) was designed to eliminate clinical setup problems with head immobilization and instability during treatment, thus providing for a more comfortable head rest for the patient. The custom design of this head holder seeks to eliminate superior-to-inferior shift, and minimize the lateral right-to-left rotational movement of the head when coupled with an AquaPlast casting system. By focusing attention to the seating of the occipital portion of the head and contour of the patient's neck, the aforementioned problems of movement were addressed, while adhering to the interests of patient comfort in this modified head support system.

  10. Sword-Like Trauma to the Shoulder with Open Head-Splitting Fracture of the Head.

    PubMed

    Panagopoulos, Andreas; Pantazis, Konstantinos; Iliopoulos, Ilias; Seferlis, Ioannis; Kokkalis, Zinon

    2016-01-01

    Head-splitting fractures occur as a result of violent compression of the head against the glenoid; the head splits and the tuberosities may remain attached to the fragments or split and separate. Isolated humeral head-splitting fractures are rare injuries. Favorable results with osteosynthesis can be difficult to achieve because of the very proximal location of the head fracture and associated poor vascularity. We present a case of a 67-year-old man who sustained a severe, sword-like trauma to his left shoulder after a road traffic accident with associated isolated open Gustilo-Anderson IIIA humeral head-splitting fracture. Bony union was achieved with minimal internal fixation but the clinical outcome deteriorated due to accompanying axillary nerve apraxia. To our knowledge, this type of sword-like injury with associated humeral head-split fracture has not previously been reported. PMID:27478665

  11. Dynamically Reconfigurable Systolic Array Accelerator

    NASA Technical Reports Server (NTRS)

    Dasu, Aravind; Barnes, Robert

    2012-01-01

    A polymorphic systolic array framework has been developed that works in conjunction with an embedded microprocessor on a field-programmable gate array (FPGA), which allows for dynamic and complimentary scaling of acceleration levels of two algorithms active concurrently on the FPGA. Use is made of systolic arrays and a hardware-software co-design to obtain an efficient multi-application acceleration system. The flexible and simple framework allows hosting of a broader range of algorithms, and is extendable to more complex applications in the area of aerospace embedded systems. FPGA chips can be responsive to realtime demands for changing applications needs, but only if the electronic fabric can respond fast enough. This systolic array framework allows for rapid partial and dynamic reconfiguration of the chip in response to the real-time needs of scalability, and adaptability of executables.

  12. Bolometric Arrays for Millimeter Wavelengths

    NASA Astrophysics Data System (ADS)

    Castillo, E.; Serrano, A.; Torres-Jácome, A.

    2009-11-01

    During last years, semiconductor bolometers using thin films have been developed at INAOE, specifically boron-doped hydrogenated amorphous silicon films. The characteristics shown by these devices made them attractive to be used in astronomical instrumentation, mainly in two-dimentional arrays. These detector arrays used at the Large Millimeter Telescope will make possible to obtain astronomical images in millimeter and sub-millimeter wavelengths. With this in mind, we are developing a method to produce, with enough reliability, bolometer arrays at INAOE. Until now, silicon nitride diaphragm arrays, useful as radiation absorbers, have succesfully been obtained. Sizes going from one to four millimeter by element in a consistent way; however we have not tested thermometers and metallic contact deposition yet. At the same time, we are working on two possible configurations for the readout electronics; one of them using commercial components while the other will be an integrated circuit specifically designed for this application. Both versions will work below 77K.

  13. Ga:Ge array development

    NASA Technical Reports Server (NTRS)

    Young, Erick T.; Rieke, G. H.; Low, Frank J.; Haller, E. E.; Beeman, J. W.

    1989-01-01

    Work at the University of Arizona and at Lawrence Berkeley Laboratory on the development of a far infrared array camera for the Multiband Imaging Photometer on the Space Infrared Telescope Facility (SIRTF) is discussed. The camera design uses stacked linear arrays of Ge:Ga photoconductors to make a full two-dimensional array. Initial results from a 1 x 16 array using a thermally isolated J-FET readout are presented. Dark currents below 300 electrons s(exp -1) and readout noises of 60 electrons were attained. Operation of these types of detectors in an ionizing radiation environment are discussed. Results of radiation testing using both low energy gamma rays and protons are given. Work on advanced C-MOS cascode readouts that promise lower temperature operation and higher levels of performance than the current J-FET based devices is described.

  14. Downsampling Photodetector Array with Windowing

    NASA Technical Reports Server (NTRS)

    Patawaran, Ferze D.; Farr, William H.; Nguyen, Danh H.; Quirk, Kevin J.; Sahasrabudhe, Adit

    2012-01-01

    In a photon counting detector array, each pixel in the array produces an electrical pulse when an incident photon on that pixel is detected. Detection and demodulation of an optical communication signal that modulated the intensity of the optical signal requires counting the number of photon arrivals over a given interval. As the size of photon counting photodetector arrays increases, parallel processing of all the pixels exceeds the resources available in current application-specific integrated circuit (ASIC) and gate array (GA) technology; the desire for a high fill factor in avalanche photodiode (APD) detector arrays also precludes this. Through the use of downsampling and windowing portions of the detector array, the processing is distributed between the ASIC and GA. This allows demodulation of the optical communication signal incident on a large photon counting detector array, as well as providing architecture amenable to algorithmic changes. The detector array readout ASIC functions as a parallel-to-serial converter, serializing the photodetector array output for subsequent processing. Additional downsampling functionality for each pixel is added to this ASIC. Due to the large number of pixels in the array, the readout time of the entire photodetector is greater than the time between photon arrivals; therefore, a downsampling pre-processing step is done in order to increase the time allowed for the readout to occur. Each pixel drives a small counter that is incremented at every detected photon arrival or, equivalently, the charge in a storage capacitor is incremented. At the end of a user-configurable counting period (calculated independently from the ASIC), the counters are sampled and cleared. This downsampled photon count information is then sent one counter word at a time to the GA. For a large array, processing even the downsampled pixel counts exceeds the capabilities of the GA. Windowing of the array, whereby several subsets of pixels are designated

  15. The Applicability of Incoherent Array Processing to IMS Seismic Arrays

    NASA Astrophysics Data System (ADS)

    Gibbons, Steven J.

    2014-03-01

    The seismic arrays of the International Monitoring System (IMS) for the Comprehensive Nuclear-Test-Ban Treaty (CTBT) are highly diverse in size and configuration, with apertures ranging from under 1 km to over 60 km. Large and medium aperture arrays with large inter-site spacings complicate the detection and estimation of high-frequency phases lacking coherence between sensors. Pipeline detection algorithms often miss such phases, since they only consider frequencies low enough to allow coherent array processing, and phases that are detected are often attributed qualitatively incorrect backazimuth and slowness estimates. This can result in missed events, due to either a lack of contributing phases or by corruption of event hypotheses by spurious detections. It has been demonstrated previously that continuous spectral estimation can both detect and estimate phases on the largest aperture arrays, with arrivals identified as local maxima on beams of transformed spectrograms. The estimation procedure in effect measures group velocity rather than phase velocity, as is the case for classical f-k analysis, and the ability to estimate slowness vectors requires sufficiently large inter-sensor distances to resolve time-delays between pulses with a period of the order 4-5 s. Spectrogram beampacking works well on five IMS arrays with apertures over 20 km (NOA, AKASG, YKA, WRA, and KURK) without additional post-processing. Seven arrays with 10-20 km aperture (MJAR, ESDC, ILAR, KSRS, CMAR, ASAR, and EKA) can provide robust parameter estimates subject to a smoothing of the resulting slowness grids, most effectively achieved by convolving the measured slowness grids with the array response function for a 4 or 5 s period signal. Even for medium aperture arrays which can provide high-quality coherent slowness estimates, a complementary spectrogram beampacking procedure could act as a quality control by providing non-aliased estimates when the coherent slowness grids display

  16. Mid-Range Coil Array for Magnetic Resonance Imaging of Small Animals

    NASA Astrophysics Data System (ADS)

    Solis, S. E.; Tomasi, D.; Rodríguez, A. O.

    2008-08-01

    The vast majority of articles on MRI RF coils over the past two decades have focused on large coils, where sample losses dominate, or on micro-coils, where sample and capacitor losses are negligible. Few have addressed the mid-range coils, seen in the majority of small-animal applications, where all the sources of loss are important, for example, mouse brain and body coils from 125 to 750 MHz. We developed a four-saddle coil array for magnetic resonance imaging of small animals. The saddle coil elements in the array were evenly distributed to cover the rat's head. The coil array was tuned to the resonant frequency of 170 MHz. Due to the close proximity of the coil elements, it was necessary to decouple the coil array using nonmagnetic trimmers and, it was operated in the transceiver mode and quadrature-driven. To test the coil array performance at high field, phantom images were acquired with our saddle coil array and standard pulse sequences on a research-dedicated 4 Tesla scanner. Ex vivo brain images of a rat were also acquired, and proved the feasibility of the scaled version of a saddle coil array and, its compatibility with standard pulse sequences when used in a high field magnetic resonance imager.

  17. Effect of towed array stability on instantaneous localization of marine mammals.

    PubMed

    von Benda-Beckmann, A M; Beerens, S P; van Ijsselmuide, S P

    2013-09-01

    Reliable localization of marine mammals using towed arrays is often required for mitigation, population density estimates, and bioacoustics research. The accuracy of the range estimates using towed arrays is often not well quantified. Triangulation methods using multiple hydrophones allow for fast range estimates but are sensitive to the species type, location of the animal with respect to the array, sound propagation conditions, and array stability. A simple model is presented that is used to estimate the range accuracy of towed arrays for different vocalizations and is compared to measured range accuracies of sperm whale clicks recorded with a 15 m baseline towed array. The ranging performance is particularly sensitive to hydrophone position errors which are found to dominate. Hydrophone position errors could be estimated using heading sensors placed in the array and are taken into account in the model. A good agreement is found between the empirical range errors and theoretically predicted ones. Extrapolation of the model to other species suggests that species emitting high frequency clicks and calls can be localized from distances out to a few kilometers with a baseline of 15 m, but baleen whales transmitting low frequency calls require longer baselines to obtain range estimates. PMID:23968038

  18. Mid-Range Coil Array for Magnetic Resonance Imaging of Small Animals

    SciTech Connect

    Solis, S. E.; Tomasi, D.; Rodriguez, A. O.

    2008-08-11

    The vast majority of articles on MRI RF coils over the past two decades have focused on large coils, where sample losses dominate, or on micro-coils, where sample and capacitor losses are negligible. Few have addressed the mid-range coils, seen in the majority of small-animal applications, where all the sources of loss are important, for example, mouse brain and body coils from 125 to 750 MHz. We developed a four-saddle coil array for magnetic resonance imaging of small animals. The saddle coil elements in the array were evenly distributed to cover the rat's head. The coil array was tuned to the resonant frequency of 170 MHz. Due to the close proximity of the coil elements, it was necessary to decouple the coil array using nonmagnetic trimmers and, it was operated in the transceiver mode and quadrature-driven. To test the coil array performance at high field, phantom images were acquired with our saddle coil array and standard pulse sequences on a research-dedicated 4 Tesla scanner. Ex vivo brain images of a rat were also acquired, and proved the feasibility of the scaled version of a saddle coil array and, its compatibility with standard pulse sequences when used in a high field magnetic resonance imager.

  19. Flexible solar-array mechanism

    NASA Technical Reports Server (NTRS)

    Olson, M. C.

    1972-01-01

    One of the key elements of the flexible rolled-up solar array system is a mechanism to deploy, retract, and store the flexible solar-cell arrays. The selection of components, the design of the mechanism assembly, and the tests that were performed are discussed. During 6 months in orbit, all mission objectives were satisfied, and inflight performance has shown good correlation with preflight analyses and tests.

  20. A lightweight inflatable solar array

    SciTech Connect

    Malone, P.K.; Williams, G.T.

    1995-12-31

    L`Garde and Phillips Laboratory have developed a light weight deployable solar array wing in the 200-1000 watt range, on the Inflatable Torus Solar Array Technology Demonstration (ITSAT Demo) Project. The power density of a flight unit could be as high as 93 W/kg for a 200 Watt-class wing, including structure and deployment mechanisms. In Phase 1, a proof of concept torus and array was constructed and deployed in the laboratory. During Phase 2, a revised torus and array were constructed and tested at L`Garde and the Naval Research Lab. The qualification tests included random vibration, deployment in a thermal vacuum chamber, natural frequency determination, and thermal cycling. The flight design uses 2 mil thick crystalline Si cells on an AO protected flexible Kapton film substrate folded accordion style for stowage. The support structure is a rectangular frame comprised of two inflated then rigidized cylinders, the array stowage box and its cover. The cylinders, flattened, folded and stored for launch, are deployed by inflating with N{sub 2} and rigidized by straining the cylinder laminate material controllably beyond the elastic limit. The engineering protoflight array was designed for optimum power density but, due to availability, some of the components came from excess production runs. Because of this, the actual power density of the test article was 59 W/kg, or 36% less than the baseline flight array. However, using components as designed, the projected 93 w/kg can be achieved. Due to simple deployment mechanism, the cost of an ITSAT-type solar array is about one-half that of competing systems.