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1

Cup to disc ratio by optical coherence tomography is abnormal in Multiple Sclerosis  

PubMed Central

Objective To identify and characterize cup to disc ratio (CDR) and related optic nerve head abnormalities in multiple sclerosis (MS) using spectral domain optical coherence tomography (OCT). Background While CDR is routinely assessed by ophthalmologists in the evaluation of glaucoma, CDR and related optic nerve head metrics remain largely unexplored in MS. Design/Methods Cirrus-HD (high density) OCT was used to evaluate average CDR, vertical CDR, optic disc area, optic cup volume and neuro-retinal rim area in 105 MS patients and 88 age-matched healthy individuals. High-contrast (100%) visual acuity, 2.5% low-contrast letter acuity and 1.25% low-contrast letter acuity were assessed in 77 MS patients. Two-sample t-tests were used in the analysis of OCT-derived optic nerve head measures between healthy controls and MS patients. Multivariate regression (accounting for age and gender) was used to assess relationships between optic nerve head measures and visual function. Results Average CDR (p=0.007) and vertical CDR (p=0.005) was greater in MS patients compared to healthy controls, while neuro-retinal rim area was decreased in MS patients (p=0.001). CDR increased with retinal nerve fiber layer (RNFL) thinning (r=?0.29, p=0.001). 2.5% low-contrast (p=0.005) and 1.25% low-contrast letter acuity (p=0.03) were lower in MS patients with higher vertical CDR. Conclusions/Relevance CDR (as determined by spectral domain OCT), is abnormal in MS and correlates with visual function. OCT derived CDR and related optic nerve head metrics may represent an objective measure by which to monitor disease progression, and potentially neuroprotection, in therapeutic MS trials.

Syc, S.B.; Warner, C.V.; Saidha, S.; Farrell, S.K.; Conger, A.; Bisker, E.R.; Wilson, J.; Frohman, E.M.; Balcer, L.J.; Calabresi, P.A.

2010-01-01

2

Optic cup and disk extraction from retinal fundus images for determination of cup-to-disc ratio  

Microsoft Academic Search

The ratio of the optic cup to disc (CDR) in retinal fundus images is one of the principal physiological characteristics in the diagnosis of glaucoma. Currently the CDR is manually determined which can be subjective and limits its use in mass screening. To automatically extract the disc, a variational level set method is proposed in this paper. For the cup,

J. Liu; D. W. K. Wong; J. H. Lim; X. Jia; F. Yin; H. Li; W. Xiong; T. Y. Wong

2008-01-01

3

Automated determination of cup-to-disc ratio for classification of glaucomatous and normal eyes on stereo retinal fundus images  

NASA Astrophysics Data System (ADS)

Early diagnosis of glaucoma, which is the second leading cause of blindness in the world, can halt or slow the progression of the disease. We propose an automated method for analyzing the optic disc and measuring the cup-to-disc ratio (CDR) on stereo retinal fundus images to improve ophthalmologists' diagnostic efficiency and potentially reduce the variation on the CDR measurement. The method was developed using 80 retinal fundus image pairs, including 25 glaucomatous, and 55 nonglaucomatous eyes, obtained at our institution. A disc region was segmented using the active contour method with the brightness and edge information. The segmentation of a cup region was performed using a depth map of the optic disc, which was reconstructed on the basis of the stereo disparity. The CDRs were measured and compared with those determined using the manual segmentation results by an expert ophthalmologist. The method was applied to a new database which consisted of 98 stereo image pairs including 60 and 30 pairs with and without signs of glaucoma, respectively. Using the CDRs, an area under the receiver operating characteristic curve of 0.90 was obtained for classification of the glaucomatous and nonglaucomatous eyes. The result indicates potential usefulness of the automated determination of CDRs for the diagnosis of glaucoma.

Muramatsu, Chisako; Nakagawa, Toshiaki; Sawada, Akira; Hatanaka, Yuji; Yamamoto, Tetsuya; Fujita, Hiroshi

2011-09-01

4

Determination of cup-to-disc ratio of optical nerve head for diagnosis of glaucoma on stereo retinal fundus image pairs  

NASA Astrophysics Data System (ADS)

A large cup-to-disc (C/D) ratio, which is the ratio of the diameter of the depression (cup) to that of the optical nerve head (ONH, disc), can be one of the important signs for diagnosis of glaucoma. Eighty eyes, including 25 eyes with the signs of glaucoma, were imaged by a stereo retinal fundus camera. An ophthalmologist provided the outlines of cup and disc on a regular monitor and on the stereo display. The depth image of the ONH was created by determining the corresponding pixels in a pair of images based on the correlation coefficient in localized regions. The areas of the disc and cup were determined by use of the red component in one of the color images and by use of the depth image, respectively. The C/D ratio was determined based on the largest vertical lengths in the cup and disc areas, which was then compared with that by the ophthalmologist. The disc areas determined by the computerized method agreed relatively well with those determined by the ophthalmologist, whereas the agreement for the cup areas was somewhat lower. When C/D ratios were employed for distinction between the glaucomatous and non-glaucomatous eyes, the area under the receiver operating characteristic curve (AUC) was 0.83. The computerized analysis of ONH can be useful for diagnosis of glaucoma.

Muramatsu, Chisako; Nakagawa, Toshiaki; Sawada, Akira; Hatanaka, Yuji; Hara, Takeshi; Yamamoto, Tetsuya; Fujita, Hiroshi

2009-02-01

5

The path to open-angle glaucoma gene discovery: endophenotypic status of intraocular pressure, cup-to-disc ratio, and central corneal thickness.  

PubMed

PURPOSE. Primary open-angle glaucoma (POAG) is a complex disease with a genetic architecture that can be simplified through the investigation of individual traits underlying disease risk. It has been well studied in twin models, and this study was undertaken to investigate the heritability of some of these key endophenotypes in extended pedigrees. METHODS. These data are derived from a large, multicenter study of extended, Caucasian POAG families from Australia and the United States. The study included 1181 people from 22 extended pedigrees. Variance components modeling was used to determine the heritabilities of maximum intraocular pressure (IOP), maximum vertical cup-to-disc ratio (VCDR), and mean central corneal thickness (CCT). Bivariate quantitative genetic analysis between these eye-related phenotypes and POAG itself was performed to determine whether any of these traits represent true endophenotypes. RESULTS. Heritability estimates for IOP, VCDR, and CCT (0.42, 0.66, and 0.72, respectively) were significant and show strong concordance with data in previous studies. Bivariate analysis revealed that both IOP (RhoG = 0.80; P = 9.6 x 10(-6)) and VCDR (RhoG = 0.76; P = 4.8 x 10(-10)) showed strong evidence of genetic correlation with POAG susceptibility. These two traits also correlated genetically with each other (RhoG = 0.45; P = 0.0012). Alternatively, CCT did not correlate genetically with risk of POAG. CONCLUSIONS. All the proposed POAG-related traits have genetic components. However, the significant genetic correlations observed between IOP, VCDR, and POAG itself suggest that they most likely represent true endophenotypes that could aid in the identification of genes underlying POAG susceptibility. CCT did not correlate genetically with disease and is unlikely to be a useful surrogate endophenotype for POAG. PMID:20237253

Charlesworth, Jac; Kramer, Patricia L; Dyer, Tom; Diego, Victor; Samples, John R; Craig, Jamie E; Mackey, David A; Hewitt, Alex W; Blangero, John; Wirtz, Mary K

2010-03-17

6

LETTER: Relation of vertical stability and aspect ratio in tokamaks  

NASA Astrophysics Data System (ADS)

It is evaluated how the upper limit to plasma elongation kappa , caused by vertical stability, varies with the ratio A=R/a of the tokamak. Equilibria were generated with EFITD and the vertical stability was assessed by GATO. For a 'generic' tokamak with a superconducting wall conformal to the plasma shape and a distance 0.5 a away from the plasma edge and a constant current profile (q0=1.0, li simeq 1.0, q95 = 3.2) it is found that the maximum stable kappa decreased only slowly from 2.65 at A = 2.0 to 2.4 at A=6.0. To first order, a reasonable assumption in tradeoff studies of new machine designs is no dependence of ?max on A

Stambaugh, R. D.; Lao, L. L.; Lazarus, E. A.

1992-09-01

7

Variability in digital analysis of optic disc topography  

Microsoft Academic Search

We determined the magnitude of variability in optic disc topographical parameters on digital analysis of the optic disc using the IS 2000. The variability introduced by the system, the observer, the observer and patient, and by clinically different types of discs was assessed in the measurement of the vertical cup-to-disc ratio, horizontal cup-to-disc ratio, cup area-to-disc area, cup volume, neuroretinal

Rohit Varma; William C. Steinmann; George L. Spaeth; Richard P. Wilson

1988-01-01

8

Facile Route to Vertically Aligned High-Aspect Ratio Block Copolymer Films via Dynamic Zone Annealing  

NASA Astrophysics Data System (ADS)

Directed assembly of block copolymers (BCP) can be used to fabricate a diversity of nanostructures useful for nanotech applications. The ability to vertically orient etchable high aspect ratio (˜30) ordered BCP domains on flexible substrates via continuous processing methods are particularly attractive for nanomanufacturing. We apply sharp dynamic cold zone annealing (CZA-S) to create etchable, and predominantly vertically oriented 30nm cylindrical domains in 1 ?m thick poly(styrene-b-methylmethacrylate) films on low thermal conductivity rigid (quartz) and flexible (PDMS & Kapton) substrates. Under similar static conditions, temporally stable vertical cylinders form within a narrow zone above a critical temperature gradient. Primary ordering mechanism of CZA-S involves sweeping this vertically orienting zone created at maximum thermal gradient. An optimal speed is needed since the process competes with preferential surface wetting dynamics that favors parallel orientation. GISAXS of etched BCP films confirms internal morphology.

Singh, Gurpreet; Kulkarni, Manish; Yager, Kevin; Smilgies, Detlef; Bucknall, David; Karim, Alamgir

2012-02-01

9

Widespread vertical transmission and associated host sex-ratio distortion within the eukaryotic phylum Microspora  

Microsoft Academic Search

Vertical transmission (VT) and associated manipulation of host reproduction are widely reported among prokaryotic endosymbionts. Here, we present evidence for widespread use of VT and associated sex-ratio distortion in a eukaryotic phylum. The Microspora are an unusual and diverse group of eukaryotic parasites that infect all animal phyla. Following our initial description of a microsporidian that feminizes its crus- tacean

Rebecca S. Terry; Judith E. Smith; Rosie G. Sharpe; Thierry Rigaud; D. T. J. Littlewood; J. E. Ironside; D. Rollinson; D. Bouchon; C. MacNeil; J. T. A. Dick; A. M. Dunn

2004-01-01

10

Methane flux, vertical gradient and mixing ratio measurements in a tropical forest  

NASA Astrophysics Data System (ADS)

Measurements of CH4 mixing ratio, vertical gradients and turbulent fluxes were carried out in a tropical forest (Reserva Biológica Cuieiras), about 60 km north of Manaus, Brazil. The methane mixing ratio and flux measurements were performed at a height of 53 m (canopy height 35 m). In addition, vertical CH4 gradients were measured within the canopy using custom made air samplers at levels of 2, 16 and 36 m above ground. The methane gradients within the canopy reveal that there is a continuous methane source at the surface. No clear evidence for aerobic methane emission from the canopy was found. The methane fluxes above the canopy are small but consistently show an upward flux with a maximum early in the morning, and the measured fluxes are in agreement with what is expected from the positive CH4 gradient in the canopy. In the morning hours, a strong canopy venting peak is observed for both CH4 and CO2, but for CO2 this peak is then superimposed by photosynthetic uptake, whereas the peak lasts longer for CH4. Monthly averaged diurnal cycles of the CH4 mixing ratio show a decrease during daytime and increase during nighttime. The magnitude of the difference in CH4 mixing ratio between day and night gradually increases throughout the wet season. The fluxes required to explain the nighttime increase are in agreement with the nighttime fluxes measured above the canopy, which implies that the CH4 increase in the nighttime boundary layer originates from local sources.

Querino, C. A. S.; Smeets, C. J. P. P.; Vigano, I.; Holzinger, R.; Moura, V.; Gatti, L. V.; Martinewski, A.; Manzi, A. O.; de Araújo, A. C.; Röckmann, T.

2011-02-01

11

Methane flux, vertical gradient and mixing ratio measurements in a tropical forest  

NASA Astrophysics Data System (ADS)

Measurements of CH4 mixing ratio, vertical gradients and turbulent fluxes were carried out in a tropical forest (Reserva Biológica Cuieiras), about 60 km north of Manaus, Brazil. The methane mixing ratio and flux measurements were performed at a height of 53 m (canopy height 35 m). In addition, vertical CH4 gradients were measured within the canopy using custom made air samplers at levels of 2, 16 and 36 m above ground. The methane gradients within the canopy reveal that there is a continuous methane source at the surface. No clear evidence for aerobic methane emission from the canopy was found. The methane fluxes above the canopy are small but consistently upwards with a maximum early in the morning. The measured fluxes are in agreement with the observed CH4 gradient in the canopy. In the morning hours, a strong canopy venting peak is observed for both CH4 and CO2, but for CO2 this peak is then superimposed by photosynthetic uptake, whereas the peak lasts longer for CH4. Monthly averaged diurnal cycles of the CH4 mixing ratio show a decrease during daytime and increase during nighttime. The magnitude of the difference in CH4 mixing ratio between day and night gradually increases throughout the wet season. The fluxes required to explain the nighttime increase are in agreement with the nighttime fluxes measured above the canopy, which implies that the CH4 increase in the nighttime boundary layer originates from local sources.

Querino, C. A. S.; Smeets, C. J. P. P.; Vigano, I.; Holzinger, R.; Moura, V.; Gatti, L. V.; Martinewski, A.; Manzi, A. O.; de Araújo, A. C.; Röckmann, T.

2011-08-01

12

Experimental research on heat transfer of natural convection in vertical rectangular channels with large aspect ratio  

SciTech Connect

This work presents the experimental research on the steady laminar natural convection heat transfer of air in three vertical thin rectangular channels with different gap clearance. The much higher ratio of width to gap clearance (60-24) and the ratio of length to gap clearance (800-320) make the rectangular channels similar with the coolant flow passage in plate type fuel reactors. The vertical rectangular channels were composed of two stainless steal plates and were heated by electrical heating rods. The wall temperatures were detected with the K-type thermocouples which were inserted into the blind holes drilled in the steal plates. Also the air temperatures at the inlet and outlet of the channel were detected. The wall heat fluxes added to the air flow were calculated by the Fourier heat conduction law. The heat transfer characteristics were analyzed, and the average Nusselt numbers in all the three channels could be well correlated with the Rayleigh number or the modified Rayleigh number in a uniform correlation. Furthermore, the maximum wall temperatures were investigated, which is a key parameter for the fuel's integrity during some accidents. It was found that even the wall heat flux was up to 1500 W/m{sup 2}, the maximum wall temperature was lower than 350 C. All this work is valuable for the plate type reactor's design and safety analysis. (author)

Lu, Qing; Qiu, Suizheng; Su, Guanghui [State Key Laboratory of Multi Phase Flow in Power Engineering, Xi'an JIaotong University, Xi'an, Shaanxi 710049 (China); School of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China); Tian, Wenxi; Ye, Zhonghao [School of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)

2010-01-15

13

Development and characterisation of a high aspect ratio vertical FET sensor for motion detection  

Microsoft Academic Search

In this paper the development, the fabrication and the experimental characterisation of a novel vertical field effect transistor (vertical FET) is presented. The vertical FET can be used for signal conversion from the mechanical to the electrical domain. This low impedance sensing technique was realized by introducing a source and drain region in opposite of a movable mass which acts

S. Buschnakowski; A. Bertz; W. Brauer; S. Heinz; R. Schuberth; G. Ebest; T. Gessner

2003-01-01

14

Twin study on cup/disc ratio of the optic nerve head.  

PubMed Central

Seventeen healthy twin pairs (10 monozygotic and seven dizygotic) from the Finnish Twin Cohort Study were examined to study the impact of heredity v environment in the determination of cup-to-disc area ratio. These twins were free from any known eye disease. The cup/disc ratio was determined using stereo photography and a computer assisted analysis technique. The zygosity of all twin pairs was confirmed with the DNA 'fingerprint' technique. The intrapair correlations were high among monozygotic pairs compared with those among dizygotic twin pairs. The difference of cup/disc area ratios between the right eyes of members of monozygotic twin pairs was statistically significantly smaller than that of dizygotic twin pairs (p < 0.001). The same was true for left eyes (p < 0.01). This result confirms a genetic determination in cup/disc area ratio in normal eyes. Images

Teikari, J. M.; Airaksinen, J. P.

1992-01-01

15

Vertical Profile Control in Ultrahigh-Aspect-Ratio Contact Hole Etching with 0.05-µm-Diameter Range  

Microsoft Academic Search

Vertical processing of 0.05-µm-class SiO2 holes with an aspect ratio around 20 was realized using a dipole-ring-type magnetron reactive-ion-etching system in a mixture of C4F8\\/O2\\/Ar gas. Secondary ion mass spectrometric study of the F and C concentration profiles of the polymer deposited inside the holes in the depth direction revealed that a very small amount of polymer deposition occurred in

Naokatsu Ikegami; Atsushi Yabata; Guo Lin Liu; Hidetsugu Uchida; Norio Hirashita; Jun Kanamori

1998-01-01

16

Length-Dependent Charge Generation from Vertical Arrays of High-Aspect-Ratio ZnO Nanowires.  

PubMed

Aqueous chemical growth of zinc oxide nanowires is a flexible and effective approach to obtain dense arrays of vertically oriented nanostructures with high aspect ratio. Herein we present a systematic study of the different synthesis parameters that influence the ZnO seed layer and thus the resulting morphological features of the free-standing vertically oriented ZnO nanowires. We obtained a homogeneous coverage of transparent conductive substrates with high-aspect-ratio nanowire arrays (length/diameter ratio of up to 52). Such nanostructured vertical arrays were examined to assess their electric and piezoelectric properties, and showed an electric charge generation upon mechanical compressive stress. The principle of energy harvesting with these nanostructured ZnO arrays was demonstrated by connecting them to an electronic charge amplifier and storing the generated charge in a series of capacitors. We found that the generated charge and the electrical behavior of the ZnO nanowires are strictly dependent on the nanowire length. We have shown the importance of controlling the morphological properties of such ZnO nanostructures for optimizing a nanogenerator device. PMID:24027171

Rivera, Vivian Farías; Auras, Florian; Motto, Paolo; Stassi, Stefano; Canavese, Giancarlo; Celasco, Edvige; Bein, Thomas; Onida, Barbara; Cauda, Valentina

2013-09-11

17

Spectrum and Charge Ratio of Vertical Cosmic Ray Muons up to Momenta of 2.5 TeV/c  

SciTech Connect

The ALEPH detector at LEP has been used to measure the momentum spectrum and charge ratio of vertical cosmic ray muons underground. The sea-level cosmic ray muon spectrum for momenta up to 2.5 TeV/c has been obtained by correcting for the overburden of 320 meter water equivalent (mwe). The results are compared with Monte Carlo models for air shower development in the atmosphere. From the analysis of the spectrum the total flux and the spectral index of the cosmic ray primaries is inferred. The charge ratio suggests a dominantly light composition of cosmic ray primaries with energies up to 10{sup 15} eV.

Schmelling, M.; /Heidelberg, Max Planck Inst.; Hashim, N.O.; /Kenyatta U. Coll.; Grupen, C.; /Siegen U.; Luitz, S.; /SLAC; Maciuc, F.; /Heidelberg, Max Planck Inst.; Mailov, A.; /Siegen U.; Muller, A.-S.; /Karlsruhe, Inst. Technol.; Sander, H.-G.; /Mainz U., Inst. Phys.; Schmeling, S.; /CERN; Tcaciuc, R.; /Siegen U.; Wachsmuth, H.; /CERN; Zuber, K.; /Dresden, Tech. U.

2012-09-14

18

Ratios  

NSDL National Science Digital Library

This "homework help" lesson introduces students to ratios, ratio language, equivalent ratios, and allows students to practice with a set of problems at the end. The lesson is divided into four parts: First Glance, In Depth, Examples, and Workout.

2005-01-01

19

Spectrum and charge ratio of vertical cosmic ray muons up to momenta of 2.5 TeV/c  

NASA Astrophysics Data System (ADS)

The ALEPH detector at LEP has been used to measure the momentum spectrum and charge ratio of vertical cosmic ray muons underground. The sea-level cosmic ray muon spectrum for momenta up to 2.5 TeV/c has been obtained by correcting for the overburden of 320 m water equivalent (mwe). The results are compared with Monte Carlo models for air shower development in the atmosphere. From the analysis of the spectrum the total flux and the spectral index of the cosmic ray primaries is inferred. The charge ratio suggests a dominantly light composition of cosmic ray primaries with energies in the energy range between 103 and 105 GeV.

Schmelling, M.; Hashim, N. O.; Grupen, C.; Luitz, S.; Maciuc, F.; Mailov, A.; Müller, A.-S.; Sander, H.-G.; Schmeling, S.; Tcaciuc, R.; Wachsmuth, H.; Ziegler, T.; Zuber, K.

2013-09-01

20

Male-biased sex-ratio distortion caused by Octosporea bayeri, a vertically and horizontally-transmitted parasite of Daphnia magna  

Microsoft Academic Search

Female-biased sex-ratio distortion is often observed in hosts infected with vertically-transmitted microsporidian parasites. This bias is assumed to benefit the spread of the parasite, because male offspring usually do not transmit the parasite further. The present study reports on sex-ratio distortion in a host–parasite system with both horizontal and vertical parasite transmission: the microsporidium Octosporea bayeri and its host, the

Olivia Roth; Dieter Ebert; Dita B. Vizoso; Annette Bieger; Sandra Lass

2008-01-01

21

Energy dependence of the ratio of isovector effective interaction strengths Vertical BarJ/sub sigmatau//J/sub tau/Vertical Bar from 0/sup 0/ (p,n) cross sections  

SciTech Connect

Information concerning the ratio of the isovector effective interaction strengths Vertical BarJ/sub sigmatau//J/sub tau/Vertical Bar may be obtained from the ratio of (p,n) Gamow-Teller and isobaric analog state 0/sup 0/ differential cross sections. We have examined 0/sup 0/ (p,n) data for the energy range 5--200 MeV and find that for energies larger than 50 MeV and for targets with A = 7--42 the product of the interaction-strength and distortion-factor ratios Vertical BarJ/sub sigmatau//J/sub tau/Vertical Bar(N/sub sigmatau//N/sub tau/)/sup 1/2/ appears to be mass independent and linear as a function of bombarding energy.

Taddeucci, T.N.; Rapaport, J.; Bainum, D.E.; Goodman, C.D.; Foster, C.C.; Gaarde, C.; Larsen, J.; Goulding, C.A.; Horen, D.J.; Masterson, T.; Sugarbaker, E.

1982-02-01

22

Ratios  

NSDL National Science Digital Library

This set of instructional materials and problems helps students understand ratios and proportions, starting with a simple review and progressing into the more advanced territory of similar triangles. The first three pages introduce ratios, proportions, and checking proportionality and the last four pages present mathematical and real-world problems for students to solve given their understanding of ratios and proportions.

Stapel, Elizabeth

2000-01-01

23

Effects of C\\/Si ratio in fast epitaxial growth of 4H–SiC(0 0 0 1) by vertical hot-wall chemical vapor deposition  

Microsoft Academic Search

The C\\/Si ratio dependence of growth rate, surface morphology, micropipe closing ratio, doping concentration and deep-level concentration have been investigated in fast epitaxial growth of 4H–SiC (0001) epilayers by chemical vapor deposition in a vertical hot-wall reactor. The doping, Z1\\/2 and EH6\\/7 centers concentrations of thick epilayers decrease with increasing C\\/Si ratio of source gases. By adjusting the C\\/Si ratio

H. Fujiwara; K. Danno; T. Kimoto; T. Tojo; H. Matsunami

2005-01-01

24

Vertical and meridional distributions of the atmospheric CO2 mixing ratio between northern midlatitudes and southern subtropics  

NASA Astrophysics Data System (ADS)

The atmospheric CO2 mixing ratio was measured using a continuous measurement system onboard a Gulfstream-II aircraft between the northern midlatitudes and the southern subtropics during the Biomass Burning and Lightning Experiment Phase A (BIBLE A) campaign in September-October 1998. The vertical distribution of CO2 over tropical regions was almost constant from the surface to an altitude of 13 km. CO2 enhancements from biomass burning and oceanic release were observed in the tropical boundary layer. Measurements in the upper troposphere indicate interhemispheric exchange was effectively suppressed between 2°N-7°N. Interhemispheric transport of air in the upper troposphere was suppressed effectively in this region. The CO2 mixing ratios in the Northern and Southern Hemispheres were almost constant, with an average value of about 365 parts per million (ppm) and 366 ppm, respectively. The correlation between the CO2 and NOy mixing ratios observed north of 7°N was apparently different from that obtained south of 2°N. This fact strongly supports the result that the north-south boundary in the upper troposphere during BIBLE A was located around 2°N-7°N as the boundary is not necessary a permanent feature.

Machida, T.; Kita, K.; Kondo, Y.; Blake, D.; Kawakami, S.; Inoue, G.; Ogawa, T.

2002-02-01

25

Vertical and meridional distributions of the atmospheric CO2 mixing ratio between northern midlatitudes and southern subtropics  

NASA Astrophysics Data System (ADS)

The atmospheric CO2 mixing ratio was measured using a continuous measurement system onboard a Gulfstream-II aircraft between the northern midlatitudes and the southern subtropics during the Biomass Burning and Lightning Experiment Phase A (BIBLE A) campaign in September-October 1998. The vertical distribution of CO2 over tropical regions was almost constant from the surface to an altitude of 13 km. CO2 enhancements from biomass burning and oceanic release were observed in the tropical boundary layer. Measurements in the upper troposphere indicate interhemispheric exchange was effectively suppressed between 2°N-7°N. Interhemispheric transport of air in the upper troposphere was suppressed effectively in this region. The CO2 mixing ratios in the Northern and Southern Hemispheres were almost constant, with an average value of about 365 parts per million (ppm) and 366 ppm, respectively. The correlation between the CO2 and NOy mixing ratios observed north of 7°N was apparently different from that obtained south of 2°N. This fact strongly supports the result that the north-south boundary in the upper troposphere during BIBLE A was located around 2°N-7°N as the boundary is not necessary a permanent feature.

Machida, T.; Kita, K.; Kondo, Y.; Blake, D.; Kawakami, S.; Inoue, G.; Ogawa, T.

2003-02-01

26

The BELST II process for a silicon high-aspect-ratio micromaching vertical comb actuator and its applications  

NASA Astrophysics Data System (ADS)

The BELST process has been proposed and it has demonstrated the capability to overcome anchoring and depth controlling issues in many high-aspect-ratio micromaching (HARM) processes. However, the actuation mechanisms are still restricted to in-plane motion only. In this study, a novel fabrication process called BELST II has successfully been developed. Moreover, the BELST II process was employed to fabricate a novel electrostatic vertical comb actuator (VCA). Three advantages for this VCA can be observed. First, through some exquisite designs the fabrication process has no critical alignment and bonding problems. Secondly, the relative vertical position between the moving and the stationary fingers can be adjusted freely to optimize the performance of the VCA. Thirdly, both a large mirror structure and trimmed torsional spring are available through this process. Thus, improved performance regarding enlarged traveling distance with reduced driving voltage can be obtained. In the application of the BELST II process, various HARM devices were realized, such as an optical scanner mirror and variable optical attenuator driven by the VCA.

Tsai, Julius Ming-Lin; Chu, Huai-Yuan; Hsieh, Jerwei; Fang, Weileun

2004-02-01

27

Comparison of Optic Nerve Head Assessment with a Digital Stereoscopic Camera (Discam), Scanning Laser Ophthalmoscopy, and Stereophotography  

PubMed Central

Purpose To compare computer-assisted planimetry using the Discam system (Marcher Enterprises Ltd., Hereford, UK), confocal scanning laser ophthalmoscopy (CSLO), and stereoscopic disc photography with respect to optic nerve head (ONH) measurements and glaucoma status. Design Comparative, observational case series and interobserver variability study. Methods Three hundred eighty-six eyes of 233 consecutive subjects were imaged with the Discam, and a subset underwent ONH evaluation with CSLO (n = 297), stereoscopic photography (n = 233), or both. Subjects were classified into normal, glaucoma suspect, and glaucoma groups based on clinical findings of slit-lamp disc examination and visual field testing. Agreement of cup-to-disc ratio measurements among the three technologies was assessed by the intraclass correlation coefficient (ICC) and areas under the receiver operator characteristic (AROC) curves. Main Outcome Measures Cup-to-disc ratio as measured by Discam, CSLO, and stereography. Results Intraclass correlation coefficients calculated using the two-way random effects model for comparing Discam, CSLO, and stereography among cup-to-disc area ratio, vertical cup-to-disc ratio, and horizontal cup-to-disc ratio were 0.46 to 0.53. The ICC was higher for eyes with larger optic discs (0.51) than those with smaller ones (0.32). The ICC calculated using the fixed effects model for the Discam and CSLO comparison was 0.72. Areas under the receiver operator characteristic curves were 0.67 to 0.80 among the three technologies comparing normal with glaucomatous eyes. In general, there was no statistically significant difference between techniques with respect to sensitivity and specificity of glaucoma detection. Conclusions There is good agreement between ONH measurements obtained by Discam, CSLO, and stereography; however, the results are not interchangeable. Similar AROC curve values among all three techniques imply that the Discam, CSLO, and stereography perform equally for the determination of glaucoma status.

Correnti, Anthony J.; Wollstein, Gadi; Price, Lori Lyn; Schuman, Joel S.

2007-01-01

28

Epitaxial growth of a nanoscale, vertically faceted, one-dimensional, high-aspect ratio grating in III-V materials for integrated photonics  

SciTech Connect

Homoepitaxial selective growth of a GaAs nanoscale, high-aspect ratio, one-dimensional (1D) grating with vertical facets is reported. For a pattern direction along [110], the kinetics of faceting in selective molecular-beam epitaxy (MBE) induce (110)-type facets vertical to a GaAs(001) substrate near the boundary between an SiO{sub 2} mask and an open substrate area. On a 1.25-{mu}m period, 1D stripe, SiO{sub 2}-patterned GaAs(001) substrate with an opening width of {approx}300 nm, vertical faceting results in a grating structure consisting of 2.8-{mu}m-high, 820-nm-wide features. Kinetics of faceting in selective MBE is explained as a result of the minimization of total surface energy.

Lee, S.C.; Dawson, L.R.; Brueck, S.R.J. [Center for High Technology Materials and Department of Electrical and Computer Engineering, University of New Mexico, 1313 Goddard, SE, Albuquerque, New Mexico 87106 (United States)

2005-08-15

29

Improvement in the on\\/off ratio of a vertical-type metal-base organic transistor by heat treatment in air  

Microsoft Academic Search

The on\\/off ratio of a vertical-type metal-base organic transistor was significantly improved by subjecting it to heat treatment in air. The heat treatment of the collector layer and the base electrode reduced the off current that is mainly due to leakage current between the base and the collector, resulting in a considerable decrease in the off current. As a result,

Ken-ichi Nakayama; Shin-ya Fujimoto; Masaaki Yokoyama

2009-01-01

30

Effects of C/Si ratio in fast epitaxial growth of 4H SiC(0 0 0 1) by vertical hot-wall chemical vapor deposition  

NASA Astrophysics Data System (ADS)

The C/Si ratio dependence of growth rate, surface morphology, micropipe closing ratio, doping concentration and deep-level concentration have been investigated in fast epitaxial growth of 4H SiC (0 0 0 1) epilayers by chemical vapor deposition in a vertical hot-wall reactor. The doping, Z1/2 and EH6/7 centers concentrations of thick epilayers decrease with increasing C/Si ratio of source gases. By adjusting the C/Si ratio at 0.7, specular surface morphology with a low doping concentration of 1×1013 cm-3 has been obtained at a growth rate of 33 ?m/h, and the concentrations of Z1/2 and EH6/7 centers have been kept low, 8×1012 and 4×1012 cm-3, respectively.

Fujiwara, H.; Danno, K.; Kimoto, T.; Tojo, T.; Matsunami, H.

2005-08-01

31

Analysis of Cassini/CIRS limb spectra of Titan acquired during the nominal mission. I. Hydrocarbons, nitriles and CO2 vertical mixing ratio profiles  

NASA Astrophysics Data System (ADS)

Observations of the Composite InfraRed Spectrometer (CIRS) during the entire nominal Cassini mission (2004-2008) provide us with an accurate global view of composition and temperature in the middle atmosphere of Titan (between 100 and 500 km). We investigated limb spectra acquired at 0.5cm-1 resolution at nine different latitudes between 56°S and 80°N, with a better sampling in the northern hemisphere where molecular abundances and temperature present strong latitudinal variations. From this limb data acquired between February 2005 and May 2008, we retrieved the vertical mixing ratio profiles of C2H2, C2H4, C2H6, C3H8, CH3C2H, C4H2, C6H6, HCN, HC3N and CO2. We present here for the first time, the latitudinal variations of the C2H6, C3H8, CO2, C2H4 and C6H6 vertical mixing ratios profiles. Some molecules, such as C2H6 or C3H8 present little variations above their condensation level. The other molecules (except CO2) show a significant enhancement of their mixing ratios poleward of 50°N. C2H4 is the only molecule whose mixing ratio decreases with height at latitudes below 46°N. Regions depleted in C2H2, HCN and C4H2 are observed around 400 km (0.01 mbar) and 55°N. We also inferred a region enriched in CO2 located between 30 and 40°N in the 2-0.7 mbar pressure range. At 80°N, almost all molecules studied here present a local minimum of their mixing ratio profiles near 300 km (˜0.07 mbar), which is in contradiction with Global Circulation Models that predict constant-with-height vertical profiles due to subsidence at the north pole.

Vinatier, Sandrine; Bézard, Bruno; Nixon, Conor A.; Mamoutkine, Andrei; Carlson, Ronald C.; Jennings, Donald E.; Guandique, Ever A.; Teanby, Nick A.; Bjoraker, Gordon L.; Michael Flasar, F.; Kunde, Virgil G.

2010-02-01

32

Three-terminal Si-based negative differential resistance circuit element with adjustable peak-to-valley current ratios using a monolithic vertical integration  

NASA Astrophysics Data System (ADS)

Si-based resonant bipolar transistors are demonstrated by the monolithic vertical integration of Si-based resonant interband tunnel diodes atop the emitter of Si/SiGe heterojunction bipolar transistors (HBTs) on a silicon substrate. In the common emitter configuration, IC versus VCE shows negative differential resistance characteristics. The resulting characteristics are adjustable peak-to-valley current ratios, including infinite and negative values, and tailorable peak current densities by the control of the HBT base current under room temperature operation. With the integrated RITD-HBT combination, latching properties which are the key operating principle for high-speed mixed-signal, memory, and logic circuitry, are experimentally demonstrated.

Chung, Sung-Yong; Jin, Niu; Berger, Paul R.; Yu, Ronghua; Thompson, Phillip E.; Lake, Roger; Rommel, Sean L.; Kurinec, Santosh K.

2004-04-01

33

Mapping bedrock surface contours using the horizontal-to-vertical spectral ratio (HVSR) method near the middle quarter srea, Woodbury, Connecticut  

USGS Publications Warehouse

The bedrock surface contours in Woodbury, Connecticut, were determined downgradient of a commercial zone known as the Middle Quarter area (MQA) using the novel, noninvasive horizontal-to-vertical (H/V) spectral ratio (HVSR) passive seismic geophysical method. Boreholes and monitoring wells had been drilled in this area to characterize the shallow subsurface to within 20 feet (ft) of the land surface, but little was known about the deep subsurface, including sediment thicknesses and depths to bedrock (Starn and Brown, 2007; Brown and others, 2009). Improved information on the altitude of the bedrock surface and its spatial variation was needed for assessment and remediation of chlorinated solvents that have contaminated the overlying glacial aquifer that supplies water to wells in the area.

Brown, Craig J.; Voytek, Emily B.; Lane, John W., Jr.; Stone, Janet R.

2013-01-01

34

Isotopic ratio and vertical distribution of radionuclides in soil affected by the accident of Fukushima Dai-ichi nuclear power plants.  

PubMed

The results of ? analyses of soil samples obtained from 50 locations in Fukushima prefecture on April 20, 2011, revealed the presence of a spectrum of radionuclides resulted from the accident of the Fukushima Dai-ichi nuclear power plant (FDNPP). The sum ? radioactivity concentration ranged in more than 3 orders of magnitude, depending on the sampling locations. The contamination of soils in the northwest of the FDNPP was considerable. The (131)I/(137)Cs activity ratios of the soil samples plotted as a function of the distance from the F1 NPPs exhibited three distinctive patterns. Such patterns would reflect not only the different deposition behaviors of these radionuclides, but also on the conditions of associated release events such as temperature and compositions and physicochemical forms of released radionuclides. The (136)Cs/(137)Cs activity ratio, on the other hand, was considered to only reflect the difference in isotopic compositions of source materials. Two locations close to the NPP in the northwest direction were found to be depleted in short-lived (136)Cs. This likely suggested the presence of distinct sources with different (136)Cs/(137)Cs isotopic ratios, although their details were unknown at present. Vertical ? activity profiles of (131)I and (137)Cs were also investigated, using 20-30 cm soil cores in several locations. About 70% or more of the radionuclides were present in the uppermost 2-cm regions. It was found that the profiles of (131)I/(137)Cs activity ratios showed maxima in the 2-4 cm regions, suggesting slightly larger migration of the former nuclide. PMID:22634028

Fujiwara, Takeshi; Saito, Takumi; Muroya, Yusa; Sawahata, Hiroyuki; Yamashita, Yuji; Nagasaki, Shinya; Okamoto, Koji; Takahashi, Hiroyuki; Uesaka, Mitsuru; Katsumura, Yosuke; Tanaka, Satoru

2012-05-23

35

Averaging Horizontal-to-Vertical (H/V) Spectral Ratios of Earthquake Motions for Velocity Inversions Based on Diffuse Field Theory for Plane Waves  

NASA Astrophysics Data System (ADS)

In this work we explore the application of diffuse field concepts to analyze strong motion records at a site in which site effects can be described using a one dimensional (1D) model. For this case we derived a corollary of Claerbout (1968) result for 1D layered medium. We found that the imaginary part of Green function at the free surface is proportional to the square of the absolute value of the corresponding transfer function for a plane, vertically incident wave with unit amplitude. Average strong ground motion in a "sufficiently" flat layered site will be statistically equivalent. We may conceive the illumination as produced by incident plane waves. They represent the most important part of earthquake ground motions. Their associated motions, being multiple scattered, are formed of waves that sample significant portions of the considered area. This is a distinctive feature of earthquake motions, for which the excited domain is large, basically from the source to the receiver. For a set of incoming plane waves (of P, SV, and SH types) with varying azimuths and incidence angles we assume that the ground motion will be spatially homogeneous in a statistical sense. In other words, the average of normalized ground motion spectral densities will depend only on depth. Therefore, we can apply a 1D description of wave propagation for a diffuse (average) field of ground motions. To prove the above hypothesis for H/V ratios of earthquake ground motions, we first show a comparison of averaged synthetics of 1D underground structures with a corresponding simple theoretical prediction from 1D transfer functions. After summing up a few hundreds of synthetics with different angles of incidences, azimuths, and polarizations, we can obtain identical H/V ratios that the simple theory of diffuse field predicts. Then we show several examples of H/V ratios for actual seismic motions observed in Japan. We found that the earthquake H/V ratios are quite stable (and converging rapidly) no matter what part of the waveform is used to analyze, except for the P-wave part. We also found that their basic spectral characteristics can be well reproduced by the extracted velocity structures from the simple theory of diffuse field. Yet the matching between theory and observation is not perfect in the high frequency range, which in turn implies that the inversion of an underground 1D structure from the bedrock to the surface could be accomplished using the proposed theory for earthquake H/V ratios.

Matsushima, S.; Sanchez-Sesma, F. J.; Kawase, H.

2010-12-01

36

A comparative study of vertical flow and free-water surface constructed wetlands for low C/N ratio domestic wastewater treatment and its greenhouse gases emission  

NASA Astrophysics Data System (ADS)

Constructed wetland (CW) systems are reliable, flexible in design, and can be built, operated, and maintained at lower costs compared to conventional methods of chemical treatment. Therefore, CW systems are widely used for controlling water-body eutrophication as an ease-operation and cost-effective ecological technology in developing countries. However, growing attention has been directed to its greenhouse side-effect and global-warming potential in recent years. In this study, two typical constructed wetlands: Vertical flow (VF) and Free-water surface (FWS) constructed wetlands were used not only to compare the nutrients removal performance for treatment of low C/N ratio loading domestic wastewater, but also to investigate and compare their CH4 and N2O greenhouse gases emission characteristics. The results indicated that the VF CW showed a comparatively good performance for nitrogen and phosphorus removal than FWS constructed wetland, which was 98.5, 95.9, 93.2 and 90.7 percent for BOD5, SS, NH4-N and TP under 6 days HRT, respectively. It was found that the FWS CW had the higher tendency to emit CH4 than the VF CW during four seasons of one year.

Xu, K.; Liu, C.; Ebie, Y.; Inamori, Y.

2008-12-01

37

Initial results from spatially averaged coherency, frequency-wavenumber, and horizontal to vertical spectrum ratio microtremor survey methods for site hazard study at Launceston, Tasmania  

NASA Astrophysics Data System (ADS)

The Tamar rift valley runs through the City of Launceston, Tasmania. Damage has occurred to city buildings due to earthquake activity in Bass Strait. The presence of the ancient valley, the Tamar valley, in-filled with soft sediments that vary rapidly in thickness from 0 to 250m over a few hundreds metres, is thought to induce a 2D resonance pattern, amplifying the surface motions over the valley and in Launceston. Spatially averaged coherency (SPAC), frequency-wavenumber (FK) and horizontal to vertical spectrum ratio (HVSR) microtremor survey methods are combined to identify and characterise site effects over the Tamar valley. Passive seismic array measurements acquired at seven selected sites were analysed with SPAC to estimate shear wave velocity (slowness) depth profiles. SPAC was then combined with HVSR to improve the resolution of these profiles in the sediments to an approximate depth of 125m. Results show that sediments thicknesses vary significantly throughout Launceston. The top layer is composed of as much as 20m of very soft Quaternary alluvial sediments with a velocity from 50m/s to 125m/s. Shear-wave velocities in the deeper Tertiary sediment fill of the Tamar valley, with thicknesses from 0 to 250m vary from 400m/s to 750m/s. Results obtained using SPAC are presented at two selected sites (GUN and KPK) that agree well with dispersion curves interpreted with FK analysis. FK interpretation is, however, limited to a narrower range of frequencies than SPAC and seems to overestimate the shear wave velocity at lower frequencies. Observed HVSR are also compared with the results obtained by SPAC, assuming a layered earth model, and provide additional constraints on the shear wave slowness profiles at these sites. The combined SPAC and HVSR analysis confirms the hypothesis of a layered geology at the GUN site and indicates the presence of a 2D resonance pattern across the Tamar valley at the KPK site.

Claprood, Maxime; Asten, Michael W.

2009-02-01

38

Performance of pilot-scale vertical-flow constructed wetlands in responding to variation in influent C/N ratios of simulated urban sewage.  

PubMed

The performance response of planted and the unplanted wetlands to simulated wastewater with different ratios of carbon to nitrogen (C/N) was studied during a 9-month period in greenhouse conditions. With different C/N ratios for influent water (C/N ratios 2.5:1, 5:1 and 10:1), average removal efficiencies for the unplanted and the planted wetlands were as follows: COD (41-52% and 59-68%), TN (24-48% and 25-62%), TP (35-64% and 59-71%) and TOC (22-37% and 16-33%). At C/N 5:1, both systems performed most efficiently for removal of COD and TP. However, high N removal efficiency only occurred when C/N ratio ranged 2.5-5. Both wetlands exhibited good capabilities of total organic carbon removal at C/N 10:1. Maybe, appropriate control of the carbon or nitrogen source concentration and C/N ratio in the influent can achieve the optimal effect of nutrients removal. PMID:19854043

Zhao, Yong Jun; Liu, Bo; Zhang, Wen Guang; Ouyang, Yan; An, Shu Qing

2009-10-23

39

Vertical Separation  

Microsoft Academic Search

A simple duopoly model is used to show the advantage to a manufacturer of se lling his product through an independent retailer (vertical separatio n) rather than directly to consumers (vertical integration). Vertical separation is profitable insofar as it induces more friendly behavio r from the rival manufacturer. The authors consider the case where fr anchise fees can be used

Giacomo Bonanno; John Vickers

1988-01-01

40

Observation of picometer vertical emittance with a vertical undulator.  

PubMed

Using a vertical undulator, picometer vertical electron beam emittances have been observed at the Australian Synchrotron storage ring. An APPLE-II type undulator was phased to produce a horizontal magnetic field, which creates a synchrotron radiation field that is very sensitive to the vertical electron beam emittance. The measured ratios of undulator spectral peak heights are evaluated by fitting to simulations of the apparatus. With this apparatus immediately available at most existing electron and positron storage rings, we find this to be an appropriate and novel vertical emittance diagnostic. PMID:23215388

Wootton, K P; Boland, M J; Dowd, R; Tan, Y-R E; Cowie, B C C; Papaphilippou, Y; Taylor, G N; Rassool, R P

2012-11-08

41

Observation of Picometer Vertical Emittance with a Vertical Undulator  

NASA Astrophysics Data System (ADS)

Using a vertical undulator, picometer vertical electron beam emittances have been observed at the Australian Synchrotron storage ring. An APPLE-II type undulator was phased to produce a horizontal magnetic field, which creates a synchrotron radiation field that is very sensitive to the vertical electron beam emittance. The measured ratios of undulator spectral peak heights are evaluated by fitting to simulations of the apparatus. With this apparatus immediately available at most existing electron and positron storage rings, we find this to be an appropriate and novel vertical emittance diagnostic.

Wootton, K. P.; Boland, M. J.; Dowd, R.; Tan, Y.-R. E.; Cowie, B. C. C.; Papaphilippou, Y.; Taylor, G. N.; Rassool, R. P.

2012-11-01

42

Optic disc and visual test findings in patients with migraine.  

PubMed

This study was conducted to determine whether the optic disc appearance and the visual field parameters of patients with migraine vary from those of age-matched controls. Twenty-two patients with migraine and 20 control participants were enrolled in the study. The automated visual field tests by Humphrey Field Analyzer® and optic disc images by Topcon® fundus camera were obtained from each participant. Horizontal and vertical cup-to-disc ratios were calculated by a manual, planimetric technique performed by two independent observers. The visual field indices including mean deviation (MD) and pattern standard deviations (PSD) were documented. No difference was found in the average cup-to-disc ratio between patients with migraine and control participants. However, MD and PSD of the groups were different. The average MD in the migraine group was -0.86+1.21, and in the control group was 0.10+1.03 (p=0.009). The average PSD in the migraine group was 2.11+0.68 and in the control group was 1.68+0.44 (p=0.024). In conclusion, this study demonstrated that patients with migraine had decreased sensitivity in their visual fields compared to the control participants. PMID:23014074

Dersu, Inci I; Thostenson, Jeff; Durcan, F Jane; Hamilton, Sarah M; Digre, Kathleen B

2012-09-24

43

RetCam image analysis of the optic disc in premature infants.  

PubMed

PurposeTo evaluate the correlation between optic disc parameters and birth weight or gestational age in premature infants.MethodsRetCam fundal images were taken of 97 premature infants who needed screening for retinopathy of prematurity and who had no ischemic brain injury. The images were taken at a postmenstrual age of 36 weeks and analyzed. The optic disc cup to disc ratio, optic disc area, rim area, and cup to disc area ratio were calculated using image analysis. We evaluated the relationship between these optic disc parameters and gestational age or birth weight.ResultsThe optic cup to disc ratio was less than 0.15 in 139 eyes (71.6%) and 0.5 or more in six eyes (3.1%). The optic cup disc area ratio was less than 0.05 in 146 eyes (75.3%) and 0.3 or more in four eyes (2.1%). On evaluating the association between optic disc parameters and gestational age or birth weight, optic disc cup to disc ratio, optic disc area, rim area, and cup to disc area ratio did not show significant relationships.ConclusionThe optic disc parameters of premature infants had no correlation with birth weight and gestational age. PMID:23846380

Park, J W; Park, S W; Heo, H

2013-07-12

44

Vertical mammaplasty.  

PubMed

Current criticisms regarding vertical mammaplasty include problems with poor immediate postoperative appearance, nipple-areola complex malposition, and excessive lower pole length. These problems can be avoided by proper patient selection, by utilizing correct concepts of skin design, and by observing correct glandular resection and closure concepts. Vertical mammaplasty also can result in other problems, such as hypertrophic circumareolar scars and lower pole deformities, including notching, boxy shape, infra-areolar depression, and flatness. These problems are also largely avoidable by using correct technique. Several basic concepts described previously have not proven necessary to achieve good results. Abandoning some of these principles has contributed to the ability to establish an aesthetically ideal breast shape intraoperatively as well as to a decrease in morbidity. This includes eliminating liposuction as a major integral component of the procedure, eliminating suturing the gland to the pectoralis muscle, not undermining the lower pole skin, and avoiding overly wide skin resection and tight wound closure that produces significant lower pole distortion in the early postoperative period. An important concept that has proven reliable is to use a "closed" design that does not predetermine the areolar opening whenever circumstances permit. When this is not possible, a modification that utilizes the smallest possible circumference as an open design is better than a large "mosque." These alternatives allow greater flexibility in determining final nipple position and also reduce the risk of hypertrophic circumareolar scars. Important glandular resection concepts include creating pillars that are attached to both the skin and the chest wall; making them of adequate dimension to avoid postoperative lower pole shape problems, such as flattening; resecting closer to the skin lateral to the pillars to avoid a boxy breast shape; and using a drain both to assist in accurately determining the endpoint of resection and to avoid postoperative seromas. Key closure concepts include approximation of the superior surfaces of the pillars at their base to maintain vertical height and thereby prevent lower pole flattening; approximation of the inferior surfaces of the pillars to the base of the breast to prevent notching; and proper management of the vertical incision by restricting the purse-string suture effect to only the inferior portion of the incision, where there may be skin excess present. Inclusion of these concepts leads to predictable and improved aesthetic results in vertical mammaplasty. This allows full realization of the purported advantages of vertical mammaplasty and allows this method to be utilized with a level of confidence similar to that seen with inverted-T techniques. PMID:15793463

Hidalgo, David A

2005-04-01

45

Jamming in Vertical Channels  

NASA Astrophysics Data System (ADS)

We study jamming of low aspect-ratio cylindrical Delrin grains in a vertical channel. Grain heights are less than their diameter so the grains resemble antacid tablets, coins, or poker chips. These grains are allowed to fall through a vertical channel with a square cross section where the channel width is greater than the diameter of a grain and constant throughout the length of the channel with no obstructions or constrictions. Grains are sometimes observed to form jams, stable structures supported by the channel walls with no support beneath them. The probability of jam occurrence and the strength or robustness of a jam is effected by grain and channel sizes. We will present experimental measurements of the jamming probability and jam strength in this system and discuss the relationship of these results to other experiments and theories.

Baxter, G. William; Steel, Fiona

2011-03-01

46

Jamming in Vertical Channels  

NASA Astrophysics Data System (ADS)

We experimentally study jamming of cylindrical grains in a vertical channel. The grains have a low aspect-ratio (height/diameter < 1) so their shape is like antacid tablets or poker chips. They are allowed to fall through a vertical channel with a square cross section. The channel width is greater than the diameter of a grain and constant throughout the length of the channel with no obstructions or constrictions. It is observed that grains sometimes jam in this apparatus. In a jam, grains form a stable structure from one side of the channel to the other with nothing beneath them. Jams may be strong enough to support additional grains above. The probability of a jam occurring is a function of the grain height and diameter. We will present experimental measurements of the jamming probability in this system and discuss the relationship of these results to other experiments and theories.

Baxter, G. William; McCausland, Jeffrey; Steel, Fiona

2010-03-01

47

Dynamic Young's Moduli, Poisson's Ratios and Damping Ratios of Antrim Oil Shale.  

National Technical Information Service (NTIS)

Dynamic Young's Modulus, Poisson's Ratio and Damping Ratio in the horizontal and vertical directions have been measured on approximately 30 samples recovered from Well No. 201 and three samples from Well No. 107. Young's Moduli and Damping Ratios were det...

F. Somogyi

1980-01-01

48

Natural convection between a vertical cylinder and a surrounding array.  

National Technical Information Service (NTIS)

The generic situation considered is natural convection between a single heated, vertical cylinder and a surrounding array of cooler vertical cylinders in a triangular pattern. The ratio of the test section temperature to the cooling tube temperature was v...

D. M. McEligot J. E. O'Brien C. M. Stoots T. K. Larson W. A. Christenson

1992-01-01

49

Vertical structure of debris discs  

NASA Astrophysics Data System (ADS)

Context: The vertical thickness of debris discs is often used as a measure of these systems' dynamical excitation, and as clues to the presence of hidden massive perturbers such as planetary embryos. However, this argument might be flawed because the observed dust should be naturally placed on inclined orbits by the combined effect of radiation pressure and mutual collisions. Aims: We critically reinvestigate this issue and numerically estimate the “natural” vertical thickness of a collisionally evolving disc, in the absence of any additional perturbing body. Methods: We use a deterministic collisional code, to follow the dynamical evolution of a population of indestructible test grains suffering mutual inelastic impacts. Grain differential sizes as well as the effect of radiation pressure are taken into account. Results: We find that, under the coupled effect of radiation pressure and collisions, grains naturally acquire inclinations of a few degrees. The disc is stratified with respect to grain sizes, the smallest grains having the largest vertical dispersion and the largest being clustered closer to the midplane. Conclusions: Debris discs should have a minimum “natural” observed aspect ratio hmin ~ 0.04±0.02 from visible to mid-IR wavelengths, where the flux is dominated by the smallest bound grains. These values are comparable to the estimated thicknesses of several vertically resolved debris discs, as illustrated by the specific example of AU Mic. For all systems with h ~ hmin, the presence (or absence) of embedded perturbing bodies cannot be inferred from the vertical dispersion of the disc.

Thébault, P.

2009-10-01

50

Advanced Vertical Array Beamformer.  

National Technical Information Service (NTIS)

The advanced vertical array beamformer signal processor accomplishes acoustic beamforming of an underwater vertical array used in shallow water utilizing matched beam processing to suppress generated noise and/or ship radiated noise thereby increasing the...

T. C. Yang J. A. Mobbs

1998-01-01

51

Vertical Map Storage.  

ERIC Educational Resources Information Center

Discusses the superiority of vertical filing of maps in compressor-style vertical units over horizontal filing in drawers, emphasizing such factors as physical protection of the collection, ease of filing and retrieval, and efficient use of space. Disadvantages of vertical filing are also reviewed. (Author/JL)

Perry, Joanne M.

1982-01-01

52

Vertical bounce of two vertically aligned balls  

NASA Astrophysics Data System (ADS)

When a tennis ball rests on top of a basketball and both drop to the floor together, the tennis ball is projected vertically at high speed. A mass-spring model of the impact, as well as air track data, suggest that the tennis ball should be projected at relatively low speed. Measurements of the forces on each ball and the bounce of vertically aligned superballs are used to resolve the discrepancy.

Cross, Rod

2007-11-01

53

Hunger enhances vertical vection.  

PubMed

Hunger was found to facilitate visually induced illusory upward and downward self-motions (vertical vection), but not illusory self-motion in depth (vection in depth). We propose that the origin of this hunger effect lies in the possibility that vertical self-motions (both real and illusory) are more likely to induce changes in visceral state. PMID:23362680

Seno, Takeharu; Ito, Hiroyuki; Sunaga, Shoji; Palmisano, Stephen

2012-01-01

54

Aiding vertical guidance understanding  

Microsoft Academic Search

A study was conducted to evaluate training and displays for the vertical guidance system of a modern glass cockpit airliner. The experiment consisted of a complete flight performed in a fixed-base simulator with airline pilots. Three groups were used to evaluate a new flight mode annunciator display and vertical navigation training. Results showed improved pilot performance with training and significant

Everett Palmer; Martin Alkin; Peter Polson; Daniel McCrobie; Lance Sherry

1999-01-01

55

Wave forces on a vertical cylinder defenced by a perforated vertical and inclined barriers  

Microsoft Academic Search

Wave forces on a vertical cylinder defensed by a perforated vertical and inclined barriers with 45° angle of inclina- tion were experimentally investigated. The relative wave height, (Hi\\/d) varied from 0.114 to 0.429 and the porosity was kept constant with 12%. The force ratios were found reducing with increase of Hi\\/d. It is estimated that on an average, the reduction

S. Neelamani; M. G. Muni Reddy

2002-01-01

56

Population Dynamics under Parasitic Sex Ratio Distortion  

Microsoft Academic Search

We analyse the population dynamic effects of sex ratio distortion by vertically transmitted, feminizing parasites. We show that, for diploid hosts, sex ratio distortion may lead to extinction as males become too rare to maintain the host population through reproduction. Feminizers can magnify Allee effects, broadening the range of conditions leading to extinction of small populations. Depending on male mating

Melanie J. Hatcher; Dale E. Taneyhill; Alison M. Dunn; Chris Tofts

1999-01-01

57

Vertical Line Test  

NSDL National Science Digital Library

In this activity, students try to connect given points on a graph in a way that they will pass the vertical line test. If the points can't be made to pass the vertical line test, the student must adjust the points so they will pass the test. This activity allows students to explore the vertical line test for functions. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet.

2010-01-01

58

Natural convection between a vertical cylinder and a surrounding array  

Microsoft Academic Search

The generic situation considered is natural convection between a single heated, vertical cylinder and a surrounding array of cooler vertical cylinders in a triangular pattern. The ratio of the test section temperature to the cooling tube temperature was varied up to 2.6 by adjusting the electrical power. The Rayleigh number, based on test section diameter and air properties evaluated at

D. M. McEligot; J. E. Obrien; C. M. Stoots; T. K. Larson; W. A. Christenson; D. C. Mecham; W. G. Lussie

1992-01-01

59

Spatial Distribution of Vertical Shear.  

National Technical Information Service (NTIS)

Spatial variations in small scale vertical shear in the upper ocean are described, relationships between small scale vertical shear and density stratification are investigated, and the potential for predicting mean vertical shear from measurements of the ...

S. L. Patterson F. C. Newman D. M. Rubenstein R. B. Lambert

1981-01-01

60

Vertical Multijunction Solar Cells.  

National Technical Information Service (NTIS)

A theoretical analysis of the vertical multijunction (VMJ) solar cell was performed which indicated that using silicon certain configurations could be fabricated to satisfy the program objectives. Results indicate that initial AMO efficiencies of 15% can ...

P. M. Stella

1973-01-01

61

Validation of vertical velocities using in situ measurements  

NASA Astrophysics Data System (ADS)

We use a conceptional backward trajectory approach to reconstruct water vapor and ozone mixing ratios in various diabatic or kinematic vertical velocity scenarios to validate vertical velocities in the upper TTL. Therefore, backward trajectories are initialized along the flight tracks of the tropical SCOUT-O3 campaign in Northern Australia/2005 and are calculated in either a diabatic or a kinematic vertical velocity scenario. Here, diabatic denotes a scenario with vertical coordinate potential temperature and vertical cross-isentropic motion deduced from diabatic heating rates (radiative or total). Kinematic denotes a scenario with vertical coordinate pressure and pressure tendency as vertical velocity. First, we find a large sensitivity of certain transport characteristics, like timescales, dispersion and subsidence in the upper TTL, to the choice of vertical velocities. The kinematic trajectories show much higher dispersion and frequent regions of subsidence, compared to the diabatic trajectories. The different fractions of subsiding versus ascending trajectories above the maritime continent in the kinematic and diabatic scenario cause differences in the reconstructed water vapor and ozone mixing ratios. Finally, by comparing to high-resolution in situ measurements from SCOUT-O3 we validate the vertical velocities, quantify their impact on tracer reconstructions and try to answer the question, whether a diabatic or a kinematic scenario represents the real atmosphere best.

Ploeger, Felix; Konopka, Paul; Schiller, Cornelius; Günther, Gebhard; Grooss, Jens-Uwe; Müller, Rolf

2010-05-01

62

Vertical Bargraph Display.  

National Technical Information Service (NTIS)

The program involves the generation of an advance approach to electronic aircraft instrumentation. The display media is a twisted nematic liquid crystal display (TN LCD). The instrument was designed as a one-for-one replacement for the existing vertical b...

S. Aftergut G. M. Gozeba C. R. Stein R. L. Skovholt W. W. Thurlow

1975-01-01

63

Vertical Differentiation among Occupations.  

ERIC Educational Resources Information Center

|It is reported that research on the socioeconomic achievement process has begun to generate anomalous findings, many of which involve occupational status as conventionally measured. The author proposes a theory of vertical occupational differentiation based on the role activities of occupational incumbents. (Author/RLV)|

Spaeth, Joe L.

1979-01-01

64

Flow boiling in vertical down-flow  

SciTech Connect

An experimental program has been conducted to investigate the onset of Ledinegg instability in vertical down-flow. For three size uniformly heated test sections with L/D ratios from 100 to 150, the pressure drop under subcooled boiling conditions has been obtained for a wide range of operating parameters. The results are presented in non-dimensional forms which correlate the important variables and provide techniques for predicting the onset of flow instability. 3 refs.

Dougherty, T.; Fighetti, C.; Reddy, G.; Yang, B.; Jafri, T. (Columbia Univ., New York, NY (United States)); McAssey, E. (Villanova Univ., PA (United States)); Qureshi, Z. (Westinghouse Savannah River Co., Aiken, SC (United States))

1989-01-01

65

Flow boiling in vertical down-flow  

SciTech Connect

An experimental program has been conducted to investigate the onset of Ledinegg instability in vertical down-flow. For three size uniformly heated test sections with L/D ratios from 100 to 150, the pressure drop under subcooled boiling conditions has been obtained for a wide range of operating parameters. The results are presented in non-dimensional forms which correlate the important variables and provide techniques for predicting the onset of flow instability. 3 refs.

Dougherty, T.; Fighetti, C.; Reddy, G.; Yang, B.; Jafri, T. [Columbia Univ., New York, NY (United States); McAssey, E. [Villanova Univ., PA (United States); Qureshi, Z. [Westinghouse Savannah River Co., Aiken, SC (United States)

1989-12-31

66

Platinum ratio search versus golden ratio search  

Microsoft Academic Search

In this simulation study, we examine the traditional golden ratio search in view of cost minimization and search risk, and propose an alternative search plan with what we call “platinum ratio”. The golden ratio search has been thought the best for unimodal optimization. However, our study shows that the golden ratio search is the best only in the sense of

Xia Pan

2008-01-01

67

Vertical axis wind turbine  

Microsoft Academic Search

A vertical axis wind turbine is provided based on the co-pending application ser. No. 890,998, filed Mar. 28, 1978, now U.S. Pat. No. 4,204,805. In this improved system the centrifugal forces of rotation produce no bending moments in the air foil spars. Also, the center of mass, the center of useful aerodynamic pressure and the center of main bearing supported

Bolie

1981-01-01

68

Optimum phase ratio in the triple jump  

Microsoft Academic Search

The purpose of this study was to develop and validate a method to determine the optimum phase ratio that yields the longest actual distance for a given triple jumper. Two hypotheses were tested: (a) for any given triple jumper, the greater the gain in the vertical velocity the greater the loss in the horizontal velocity; and (b) there is no

Bing Yu; James G. Hay

1996-01-01

69

Stress Ratio Determination from the Core-Disking Phenomenon.  

National Technical Information Service (NTIS)

The ability to predict in situ stress conditions from standard core samples offers planning and site-selection advantages for most underground facilities. This paper presents an empirical relation for estimating the horizontal to vertical stress ratio in ...

T. F. Lehnhoff B. Stefansson K. Thirumalai

1982-01-01

70

Vertical distribution of natural radionuclides in soils  

NASA Astrophysics Data System (ADS)

Low-level alpha spectrometry techniques using semiconductor detectors (PIPS) and liquid scintillation counters (LKB Quantulus 1220™) were used in order to determine the activity concentration of 238U, 232Th, 234U, 230Th, 226Ra, and 210Pb in soil samples. The soils were collected from an old disused uranium mine located in southwest Spain. The soils were selected with different levels of influence from the installation, in such a way that they had different levels of radioactive contamination. The vertical profiles in the soils (down to 40 cm depth) were studied in order to evaluate the vertical distribution of the natural radionuclides. The possible contamination of subsurface waters depends strongly on vertical migration, and the transfer to plants (herbs, shrubs, and trees) also will depend on the distribution of the radionuclides in the root zone. The study of the activity ratios between radionuclides belonging to the same series allowed us to assess the differing behaviour of the radionuclides involved. The vertical profiles for these radionuclides were different at each sampling point, showing the local impact of the installation. However, the profiles per point were similar for the long-lived radionuclides of the 238TJ series (238U, 234U, 230Th, and 226Ra). Also, a major disequilibrium was observed between 210Pb and 226Ra in the surface layer, due to 222Rn emanation and subsequent surface deposition of 210Pb.

Blanco Rodríguez, P.; Tomé, F. Vera; Lozano, J. C.

2012-04-01

71

Vertically moored platform anchoring  

SciTech Connect

An improved system is disclosed for anchoring a floating vessel which is anchored only by parallel and essentially vertical conduits. The anchoring load is carried by units of concentric pipes including an outer riser pipe and inner strings of casing. Drilling wells and/or production of oil and gas or like operations are conducted through these casings. The tension of the inner casing string is transmitted to the floating vessel through the upper end of the outer riser pipe. The system prevents excessive buildup of stresses in the upper end of the inner casing due to the bending caused by excursions caused by the waves, the wind and the current.

Blenkarn, K.A.; Beynet, P.A.

1984-02-14

72

Torsional nystagmus during vertical pursuit.  

PubMed

We examined three patients with cavernous angioma within the middle cerebellar peduncle. Each patient had an unusual ocular motor finding: the appearance of a strong torsional nystagmus during vertical pursuit. The uncalled-for torsion changed direction when vertical pursuit changed direction. In one patient, we recorded eye movements with the magnetic field technique using a combined direction and torsion eye coil. The slow-phase velocity of the inappropriate torsional nystagmus was linearly related to the slow-phase velocity of vertical smooth pursuit, and changed direction when vertical pursuit changed direction. This torsional nystagmus also appeared during fixation suppression of the vertical vestibulo-ocular reflex (VOR), but was minimal during vertical head rotation when fixing a stationary target in the light. We suggest that inappropriately directed eye movements during pursuit might be another ocular motor sign of cerebellar dysfunction. Furthermore, we speculate that the signals used for vertical smooth pursuit are, at some stage, encoded in a semicircular canal VOR coordinate framework. To illustrate, for the vertical semicircular canals, vertical and torsional motion are combined on the same cells, with the anterior semicircular canals mediating upward movements and the posterior semicircular canals mediating downward movements. For the right labyrinth, however, both vertical semicircular canals produce clockwise slow phases (ipsilateral eye intorts, contralateral eye extorts). The opposite is true for the vertical semicircular canals in the left labyrinth; counterclockwise slow phases are produced. Hence, to generate a pure vertical VOR, the anterior or posterior semicircular canals on both sides of the head must be excited so that opposite-directed torsional components cancel. Thus, if pursuit were organized in a way similar to the VOR, pure vertical pursuit would require that oppositely-directed torsional components cancel in normals. If this did not happen, a residual torsional nystagmus could appear during attempted vertical pursuit. PMID:8797162

FitzGibbon, E J; Calvert, P C; Dieterich, M; Brandt, T; Zee, D S

1996-06-01

73

Association of POAG Risk Factors and the Thr377Met MYOC Mutation in an Isolated Greek Population  

PubMed Central

Purpose. To characterize the MYOC genotype correlation with phenotypes in an isolated Greek population with a high incidence of glaucoma. Methods. Five hundred thirty-one villagers were enrolled in the study. Participants underwent a comprehensive ophthalmic examination. All three exons of myocilin were bidirectionally sequenced. Power calculations and measured genotype analysis was conducted using the genetic variance analysis program, SOLAR version 4.2, to account for the relatedness between individuals. Results. The participants, 376 of whom were linked in a single 11-generation pedigree, ranged in age from 10 to 95 years with a mean age of 49. Sixty-five individuals had POAG, and 27 of those carried the Thr377Met MYOC mutation. Both peak intraocular pressure and vertical cup-to dis- ratio were significantly associated with the MYOC Thr377Met variant (P = 9 × 10?14 and P = 9 × 10?8, respectively), whereas central corneal thickness showed no significant association (P < 0.7). Conclusions. This village had a high frequency of glaucoma, with 12% of the participants aged 10 to 95 years having the disease. In this cohort, the Thr377Met MYOC mutation was significantly associated with both high intraocular pressures and high vertical cup-to-disc ratios. No association was found with central corneal thickness.

Samples, John R.; Toumanidou, Victoria; Charlesworth, Jac; Mikropoulos, Dimitrios G.; Kaltsos, Konstantinos; Economou, Athanasios; Dimopoulos, Antonios; Georgiadou, Irene N.; Moumtzis, Georgios; Papanastasiou, Athanasios; Kramer, Patricia L.; Dyer, Tom; Blangero, John; Konstas, Anastasios G. P.

2010-01-01

74

Energy Balance Bowen Ratio Station (EBBR) Handbook  

SciTech Connect

The energy balance Bowen ratio (EBBR) system produces 30-minute estimates of the vertical fluxes of sensible and latent heat at the local surface. Flux estimates are calculated from observations of net radiation, soil surface heat flux, and the vertical gradients of temperature and relative humidity (RH). Meteorological data collected by the EBBR are used to calculate bulk aerodynamic fluxes, which are used in the Bulk Aerodynamic Technique (BA) EBBR value-added product (VAP) to replace sunrise and sunset spikes in the flux data. A unique aspect of the system is the automatic exchange mechanism (AEM), which helps to reduce errors from instrument offset drift.

Cook, DR

2011-02-23

75

Jamming of Cylindrical Grains in Vertical Channels  

NASA Astrophysics Data System (ADS)

We study jamming of low aspect-ratio cylindrical Delrin grains in a vertical channel. These cylindrical grains resemble antacid tablets, poker chips, or coins since their height is less than their diameter. Grains are allowed to fall through a vertical channel with a square cross section where the channel width is greater than the diameter of a grain and constant throughout the length of the channel with no obstructions or constrictions. Within this channel, grains are sometimes observed to form jams, stable structures supported by the channel walls with no support beneath them. The probability of jam occurrence and the strength or robustness of a jam is effected by the grain dimensions and channel size. We will present experimental measurements of the jamming probability and jam strength in this system and discuss the relationship of these results to other experiments and theories.

Baxter, G. William; Spier, Gregory; Barr, Nicholas; Steel, Fiona

2012-02-01

76

The Golden Ratio  

NSDL National Science Digital Library

Students learn about ratios, including the “Golden Ratio”, a ratio of length to width that can be found in art, architecture, and nature. Students examine different ratios to determine whether the Golden Ratio can be found in the human body.

Mathematics, Illuminations N.

2009-02-18

77

Dynamics of geckos running vertically  

Microsoft Academic Search

Geckos with adhesive toe pads rapidly climb even smooth vertical surfaces. We challenged geckos (Hemidactylus garnotii) to climb up a smooth vertical track that contained a force platform. Geckos climbed vertically at up to 77·cm·s -1 with a stride frequency of 15·Hz using a trotting gait. During each step, whole body fore-aft, lateral and normal forces all decreased to zero

K. Autumn; S. T. Hsieh; D. M. Dudek; J. Chen; C. Chitaphan; R. J. Full

2006-01-01

78

Coupled resonator vertical cavity laser  

SciTech Connect

The monolithic integration of coupled resonators within a vertical cavity laser opens up new possibilities due to the unique ability to tailor the interaction between the cavities. The authors report the first electrically injected coupled resonator vertical-cavity laser diode and demonstrate novel characteristics arising from the cavity coupling, including methods for external modulation of the laser. A coupled mode theory is used model the output modulation of the coupled resonator vertical cavity laser.

Choquette, K.D.; Chow, W.W.; Hou, H.Q.; Geib, K.M.; Hammons, B.E.

1998-01-01

79

30.VERTIGO AND VERTICALITY IN  

Microsoft Academic Search

The vertical dimension is crucial to Super Monkey Ball on all levels1, and invites us to meditate on vertigo and verticality, falling and failing in the construc- tion of space and game-play in this game and in comput- er-games as such. In Super Monkey Ball, the vertical dimension should be mastered (landing on tiny islands with the ball glider), avoided

Troels Degn Johansson

80

Association of eNOS and HSP70 gene polymorphisms with glaucoma in Pakistani cohorts  

Microsoft Academic Search

PURPOSE: To investigate the involvement of stress-regulating genes, endothelial nitric oxide synthase (eNOS) and heat shock protein 70 (HSP70) with primary open angle glaucoma (POAG) and primary closed angle glaucoma (PCAG). METHODS: POAG and PCAG patients recruited from different areas of Pakistan were diagnosed on the basis of clinical history, raised intraocular pressure (IOP), cup-to-disc ratio (CDR) and visual field

Humaira Ayub; Muhammad Imran Khan; Shazia Micheal; Farah Akhtar; Muhammad Ajmal; Sobia Shafique; Syeda Hafiza Benish Ali; Anneke I. den Hollander; Asifa Ahmed; Raheel Qamar

2010-01-01

81

4. VIEW OF VERTICAL BORING MACHINE. (Bullard) Vertical turning lathe ...  

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

4. VIEW OF VERTICAL BORING MACHINE. (Bullard) Vertical turning lathe (VTL). Machining the fixture for GE Turboshroud. G.S. O'Brien, operator. - Juniata Shops, Machine Shop No. 1, East of Fourth Avenue at Third Street, Altoona, Blair County, PA

82

Functions and Vertical Line Test  

NSDL National Science Digital Library

This lesson is designed to introduce students to the vertical line test for functions as well as practice plotting points and drawing simple functions. The lesson provides links to discussions and activities related to the vertical line test and functions as well as suggested ways to integrate them into the lesson.

2010-01-01

83

The anterior vertical SMAS lift  

Microsoft Academic Search

With minimal skin and SMAS undermining, as well as a rotation point that is closest to the nasolabial folds and jowls, the “anterior vertical SMAS lift” reduces the risk of hematoma while optimizing direct pull on those surface features that require improvement. The vertical rotation enhances the malar region and decreases preauricular skin excision. Further, the author has found this

Robert W. Bernard

2003-01-01

84

Fast vertical mining using diffsets  

Microsoft Academic Search

A number of vertical mining algorithms have been proposed recently for association mining, which have shown to be very effective and usually outperform horizontal approaches. The main advantage of the vertical format is support for fast frequency counting via intersection operations on transaction ids (tids) and automatic pruning of irrelevant data. The main problem with these approaches is when intermediate

Mohammed Javeed Zaki; Karam Gouda

2003-01-01

85

Emotional sounds influence vertical vection.  

PubMed

While viewing a large vertically moving sinusoidal luminance grating, the perception of upward self-motion (vection) was modulated by positive sounds (e.g., a baby's laughter). This may be because positive emotion and the spatial metaphor of vertical directions were unified in the mind. PMID:23155739

Sasaki, Kyoshiro; Seno, Takeharu; Yamada, Yuki; Miura, Kayo

2012-01-01

86

Liquefied strength ratio from liquefaction flow failure case histories  

Microsoft Academic Search

The shear strength of liquefied soil, su(LIQ), mobilized during a liquefaction flow failure is normalized with re- spect to the vertical effective stress ( ? vo ' ) prior to failure to evaluate the liquefied strength ratio, su(LIQ)\\/? vo ' . Liquefied strength ratios mobilized during 33 cases of liquefaction flow failure are estimated using a procedure developed to directly

Scott M. Olson; Timothy D. Stark

2002-01-01

87

Mass Distribution and Frequencies of a Vertical Spring  

Microsoft Academic Search

A vertical spring in a gravitational field has a density increase from top to bottom. The density variation, which is often not noticeable, depends on the ratio of the spring weight to the quantity kz0, the spring constant k times the unstretched length z0. Two springs prepared by prestretch-ing 78 and 23 turn portions of a ``Slinky'' showed density increases

T. W. Edwards; R. A. Hultsch

1972-01-01

88

Natural convection within a vertical finite-length channel in free space  

SciTech Connect

Natural convection within a vertical finite length channel in free space is studied in this article to remove assumptions that need to be made on velocity and temperature profiles at the channel entrance. For small channel aspect ratios and low Rayleigh numbers, significant deviations of the Nusselt number and temperature distributions exist due to the effects of vertical thermal diffusion and free space stratification in the channel. A new correlation was proposed on induced Reynolds number for vertical finite length channel. 8 refs.

Lin, S.C.; Chang, K.P.; Hung, Y.H. (National Tsing Hua Univ., Hsinchu (Taiwan, Province of China))

1994-04-01

89

Evaluating Objective and Subjective Quantitative Parameters at the Initial Visit to Predict Future Glaucomatous Visual Field Progression  

PubMed Central

BACKGROUND AND OBJECTIVE To evaluate the ability of structural assessment to predict glaucomatous visual field progression. PATIENTS AND METHODS A total of 119 healthy eyes with suspected glaucoma and glaucomatous eyes with 5 or more optic nerve stereophotographs, optical coherence tomography (OCT), and confocal scanning laser ophthalmoscopy (CSLO) all acquired within 6 months of each other were enrolled. Odds ratios to predict progression were determined by generalized estimating equation models. RESULTS Median follow-up was 4.0 years (range: 1.5 to 5.7 years). Fifteen eyes progressed by glaucoma progression analysis, 20 by visual field index, and 10 by both. Baseline parameters from stereophotographs (vertical cup-to-disc ratio and Disc Damage Likelihood Scale), OCT (global, superior quadrant, and inferior quadrant retinal nerve fiber layer thickness), and CSLO (cup shape measure and mean cup depth) were significant predictors of progression. Comparing the single best parameter from all models, only the OCT superior quadrant RNFL predicted progression. CONCLUSION Baseline stereophotographs, OCT, and CSLO measurements may be clinically useful to predict glaucomatous visual field progression.

Ungar, Allison K.; Wollstein, Gadi; Ishikawa, Hiroshi; Folio, Lindsey S.; Ling, Yun; Bilonick, Richard A.; Noecker, Robert J.; Xu, Juan; Kagemann, Larry; Mattox, Cynthia; Schuman, Joel S.

2012-01-01

90

Finite Element Surface Model for Flow around Vertical Wall Abutments  

NASA Astrophysics Data System (ADS)

A two-dimensional finite element surface model is developed to determine velocities, depths, and turning angles around vertical wall abutments. The model solves the Reynolds-averaged turbulent flow equations along a horizontal plane passing through the average water surface. This approach is an improvement over the depth-averaged flow models where dispersion terms reflecting vertical effects are neglected. In the model, vertical gradient effects are accounted for through the use of power law for the vertical distribution of the longitudinal velocity; a similar treatment is applied to lateral turbulent shear stresses. The model is capable of computing the dynamic pressure distribution, which in turn is converted to water elevation values. The model, being two dimensional, is computationally efficient and practical to use. The numerical model was successfully verified using experimental data from vertical wall abutments and groins with protrusion ratios (ratio of protrusion length perpendicular to direction of flow to total channel width) of 0.1, 0.2 and 0.3. The results show the occurrence of a high intensity velocity zone close to the upstream abutment nose similar to those observed experimentally. The effects of roughness, depth, and energy slope on the intensity of flow field is investigated and an analytical expression is developed. Numerical experiments indicate that grain roughness affects flow field around the abutment nose by controlling the magnitude of the lateral velocity component and by controlling the lateral extent of the affected zone. Velocity amplification at the abutment nose is found to be mainly related to the protrusion ratio and to the friction factor, and can be up to 1.75 times the approach velocities for protrusion ratios of 0.3. For a protrusion ratio of 0.3, for a typical range of roughness values the increase in nose velocities due to friction factor alone was found to be up to 20 percent.

Molinas, A.; Hafez, Y. I.

2000-07-01

91

Backward Vertical Linkages of Foreign Manufacturing Affiliates: Evidence from Japanese Multinationals  

Microsoft Academic Search

We examine the determinants of backward vertical linkages established by multinational firms in host economies through an analysis of the local content ratio of 272 Japanese electronics manufacturing affiliates in 24 countries. Host country factors promoting vertical linkages are the quality of infrastructure and the size of the local components supply industry, while restrictive trade policies have a detrimental effect.

Kyoji Fukao; Giovanni Capannelli

2001-01-01

92

A numerical study of laminar free convection heat transfer between inner sphere and outer vertical cylinder  

Microsoft Academic Search

The effects of height and radius ratio with a Newtonian fluid have been investigated numerically to determine heat transfer by natural convection between the sphere and vertical cylinder with isothermal boundary conditions. The inner sphere and outer vertical cylinder were heated and cooled in a steady change of temperature. Calculations were carried out systematically for a range of the Rayleigh

Wen Ruey Chen

2007-01-01

93

Experimental Study of Natural Convection from Electrically Heated Vertical Cylinders Immersed in Air  

Microsoft Academic Search

An experimental study of laminar steady-state natural convection heat transfer from electrically heated vertical cylinders immersed in air has been undertaken. Three stainless steel (316 SS) test sections of different slenderness ratios were employed. Surface temperature profiles along the vertical cylinders were obtained using miniature thermocouples when the cylinders were heated with different power levels resulting in different total wall

Sad Jarall; Antonio Campo

2005-01-01

94

Vertical axis wind turbine airfoil  

SciTech Connect

A vertical axis wind turbine airfoil is described. The wind turbine airfoil can include a leading edge, a trailing edge, an upper curved surface, a lower curved surface, and a centerline running between the upper surface and the lower surface and from the leading edge to the trailing edge. The airfoil can be configured so that the distance between the centerline and the upper surface is the same as the distance between the centerline and the lower surface at all points along the length of the airfoil. A plurality of such airfoils can be included in a vertical axis wind turbine. These airfoils can be vertically disposed and can rotate about a vertical axis.

Krivcov, Vladimir; Krivospitski, Vladimir; Maksimov, Vasili; Halstead, Richard; Grahov, Jurij Vasiljevich

2012-12-18

95

Mated Vertical Ground Vibration Test.  

National Technical Information Service (NTIS)

The Mated Vertical Ground Vibration Test (MVGVT) was considered to provide an experimental base in the form of structural dynamic characteristics for the shuttle vehicle. This data base was used in developing high confidence analytical models for the pred...

E. W. Ivey

1980-01-01

96

Horizontal Inequity and Vertical Redistribution  

Microsoft Academic Search

Inequality of post-tax income among pre-tax equals is evaluated andaggregated to form a global index of horizontal inequity in the income tax.The vertical action of the tax is captured by its inequality effect on averagebetween groups of pre-tax equals. Putting the two together, horizontalinequity measures loss of vertical performance. The identification problem,which has previously been thought insuperable, is addressed by

Peter J. Lambert; Xavier Ramos

1997-01-01

97

Maximum ratio transmission  

Microsoft Academic Search

This paper presents the concept, principles, and analysis of maximum ratio transmission for wireless communications, where multiple antennas are used for both transmission and reception. The principles and analysis are applicable to general cases, including maximum-ratio combining. Simulation results agree with the analysis. The analysis shows that the average overall signal-to-mise ratio (SNR) is proportional to the cross correlation between

Titus K. Y. Lo

1999-01-01

98

Vertical coupling between gap plasmon waveguides.  

PubMed

This work examines vertical coupling between gap plasmon waveguides for use in high confinement power transfer and power splitting applications at 1.55 microm free space wavelength. The supermode interference method is used to obtain key coupler performance parameters such as coupling length, extinction ratio, net coupled output power, radiated power, and reflected power as a function of waveguide center-to-center spacing, core refractive index, and gap width. The initial power distribution among the two coupler supermodes is obtained via the mode matching method for a single input waveguide feed. Excellent agreement with three-dimensional finite difference time domain simulations is observed for the case of square 50 nm gaps with core refractive indices of 2.50 and a center-to-center spacing of 112 nm. Local maxima in the net coupled output power are found to coincide with local minima in the coupling length. An increase in the core refractive index from 1.00 to 2.5 increases the local maximum net coupled output power from 6.4% to 49% but decreases the extinction ratio from 12.7 to 6.94. A sweep of the width of the core from 25 to 100 nm increases the net coupled output power from 43.7% to 52.0%, but increases the coupling length from 1.58 to 3.19 ???m and decreases the extinction ratio from 7.39 to 6.57. PMID:18711506

Hoffman, Galen B; Reano, Ronald M

2008-08-18

99

Graphene p-n vertical tunneling diodes.  

PubMed

Formation and characterization of graphene p-n junctions are of particular interest because the p-n junctions are used in a wide variety of electronic/photonic systems as building blocks. Graphene p-n junctions have been previously formed by using several techniques, but most of the studies are based on lateral-type p-n junctions, showing no rectification behaviors. Here, we report a new type of graphene p-n junction. We first fabricate and characterize vertical-type graphene p-n junctions with two terminals. One of the most important characteristics of the vertical junctions is the asymmetric rectifying behavior showing an on/off ratio of ~10(3) under bias voltages below ±10 V without gating at higher n doping concentrations, which may be useful for practical device applications. In contrast, at lower n doping concentrations, the p-n junctions are ohmic, consistent with the Klein-tunneling effect. The observed rectification results possibly from the formation of strongly corrugated insulating or semiconducting interlayers between the metallic p- and n-graphene sheets at higher n doping concentrations, which is actually a structure like a metal-insulator-metal or metal-semiconductor-metal tunneling diode. The properties of the diodes are almost invariant even 6 months after fabrication. PMID:23692508

Kim, Sung; Shin, Dong Hee; Kim, Chang Oh; Kang, Soo Seok; Kim, Jong Min; Jang, Chan Wook; Joo, Soong Sin; Lee, Jae Sung; Kim, Ju Hwan; Choi, Suk-Ho; Hwang, Euyheon

2013-05-24

100

RHIC VERTICAL AC DIPOLE COMMISSIONING.  

SciTech Connect

The RHIC vertical ac dipole was installed in the summer of 2001. The magnet is located in the interaction region between sector 3 and sector 4 common to both beams. The resonant frequency of the ac dipole was first configured to be around half of the beam revolution frequency to act as a spin flipper. At the end of the RHIC 2002 run, the ac dipole frequency was reconfigured for linear optics studies. A 0.35 mm driven betatron oscillation was excited with the vertical ac dipole and the vertical betatron functions and phase advances at each beam position monitor (BPM) around the RHIC yellow ring were measured using the excited coherence. We also recorded horizontal turn-by-turn beam positions at each BPM location to investigate coupling effects. Analysis algorithms and measurement results are presented.

BAI,M.; DELONG,J.; HOFF,L.; PAI,C.; PEGGS,S.; PIACENTINO,J.; OERTER,B.; ODDO,P.; ROSER,T.; SATOGATA,T.; TRBOJEVIC,D.; ZALTSMAN,A.

2002-06-02

101

Marine Respiration Ratios  

Microsoft Academic Search

Considerable confusion exists regarding the choice of numerical values for the so-called Redfield ratios. Most often quoted are those determined by Redfield himself O2 : C : N : P = 138 : 106 : 16 : 1. He determined these ratios based on the bulk chemical composition of plankton as well as changes in the chemical compositions observed in

W. S. Broecker; T. Takahashi

2003-01-01

102

Measurements of vertical bar Vcb vertical bar and vertical bar Vub vertical bar at BaBar  

SciTech Connect

We report results from the BABAR Collaboration on the semileptonic B decays, highlighting the measurements of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix elements Vub and Vcb. We describe the techniques used to obtain the matrix element |Vcb| using the measurement of the inclusive B {yields} Xclv process and a large sample of exclusive B {yields} D*lv decays. The vertical bar Vub vertical bar matrix elements has been measured studying different kinematic variables of the B {yields} Xulv process, and also with the exclusive reconstruction of B {yields} {pi}({rho})lv decays.

Rotondo, M. [Dipartimento di Fisica Galileo Galilei, Via Marzolo 8, Padova 35131 (Italy)

2005-10-12

103

Observed impacts of vertical velocity on cloud microphysics and implications for aerosol indirect effects  

NASA Astrophysics Data System (ADS)

The simultaneous measurements of vertical velocity and cloud droplet size distributions in cumuli collected during the RACORO field campaign over the Atmospheric Radiation Measurement Program's Southern Great Plains site near Lamont, Oklahoma, US, are analyzed to determine the effects of vertical velocity on droplet number concentration, relative dispersion (the ratio of standard deviation to mean radius), and their relationship. The results show that with increasing vertical velocity the droplet number concentration increases while the relative dispersion decreases. The data also exhibit a negative correlation between relative dispersion and droplet number concentration. These empirical relationships can be fitted well with power law functions. This observational study confirms the theoretical and numerical expectations of the effects of vertical velocity on cloud microphysics by analyzing the data of vertical velocity directly. The effects of vertical velocity on relative dispersion and its relationship with droplet number concentration are opposite to that associated with aerosol loading, posing a confounding challenge for separating aerosol indirect effects from dynamical effects.

Lu, Chunsong; Liu, Yangang; Niu, Shengjie; Vogelmann, Andrew M.

2012-11-01

104

Aerosol Properties Computed from Aircraft-Based Observations During the ACE-Asia Campaign: 2. A Case Study of Lidar Ratio Closure  

Microsoft Academic Search

For a vertical profile with three distinct layers (marine boundary, pollution, and dust layers), observed during the ACE-Asia campaign, we carried out a comparison between the modeled lidar ratio vertical profile and that obtained from co-located airborne NASA AATS-14 sunphotometer and shipborne Micro-Pulse Lidar (MPL) measurements. The vertically resolved lidar ratio was calculated from two size distribution vertical profiles—one obtained

M. Kuzmanoski; M. A. Box; B. Schmid; G. P. Box; J. Wang; P. B. Russell; D. Bates; H. H. Jonsson; E. J. Welton; J. H. Seinfeld

2007-01-01

105

Vertical Integration: Networks, and Markets  

Microsoft Academic Search

The organization of supply relations varies across industries. This paper builds a theoretical framework to compare three alternative supply structures: vertical integration, networks, and markets. The analysis considers the relationship between uncertainty in demand for specific inputs, investment costs, and industrial structure. It shows that network structures are more likely when productive assets are expensive and firms experience large idiosyncratic

Rachel E. Kranton; Deborah F. Minehart

1999-01-01

106

Freezing in a vertical tube  

Microsoft Academic Search

Fundamental heat transfer experiments were performed for freezing of an initially superheated or nonsuperheated liquid in a cooled vertical tube. Measurements were made which yielded information about the freezing front and the frozen mass, about the various energy components extracted from the tube, and about the decay of the initial liquid superheat. Four component energies were identified and evaluated from

E. M. Sparrow; J. A. Broadbent

1983-01-01

107

Vertical tube liquid pollutant separators  

Microsoft Academic Search

A plurality of elongated hollow, circular, foraminous substantially vertical tubes contiguously stacked transversely to the direction flowing liquid such as waste water containing foreign matter, I.E., settable solids and free oil, in a coalescer-separator apparatus provide a filter body providing for significant surface area contact by the liquid on both inside and outside surfaces of the tubes to entrap the

1982-01-01

108

Vertical integration in group learning  

Microsoft Academic Search

This paper is mainly concerned with the teaching of Computer Science to first year (freshman) students. The method outlined is an attempt to change their generally 'convergent' attitudes into a more 'divergent' way of tackling problems. One of the most wasteful features of modern education is the vertical separation of students, so that the collective wisdom acquired by one generation

R. D. Parslow

1980-01-01

109

Control of vertically polarized glare.  

PubMed

Reflected glare often interferes with vision. Since such glare is usually polarized it can be controlled with polarizers. The use of polarized filters to eliminate vertically polarized glare from blackboards and glossy printed material is presented. Practical means for the construction of such filters are discussed. PMID:6863803

Peli, E

1983-05-01

110

Vertical Instability at IPNS RCS.  

SciTech Connect

The rapid cycling synchrotron (RCS) of the intense pulsed neutron source (IPNS) at ANL accelerates > 3.0 times 10{sup 12} protons from 50 MeV to 450 MeV with 30-Hz repetition frequency. During the acceleration cycle, the rf frequency varies from 2.21 MHz to 5.14 MHz. Presently, the beam current is limited by a vertical instability. By analyzing turn-by-turn beam position monitor (BPM) data, large- amplitude mode 0 and mode 1 vertical beam centroid oscillations were observed in the later part of the acceleration cycle. The oscillations start in the tail of the bunch, build up, and remain localized in the tail half of the bunch. This vertical instability was compared with a head-tail instability that was intentionally induced in the RCS by adjusting the trim sextupoles. It appears that our vertical instability is not a classical head-tail instability [1]. More data analysis and experiments were performed to characterize the instability.

Wang, S.; Brumwell, F. R.; Dooling, J. C.; Harkay, K. C.; Kustom, R.; McMichael, G. E.; Middendorf, M. E.; Nassiri, A.; Accelerator Systems Division (APS)

2008-01-01

111

Quantum well vertical cavity laser  

SciTech Connect

This patent describes an apparatus which comprises: quantum well laser vertical cavity structure for lasing in a direction non-parallel to the major dimensions of a quantum well, such laser consisting essentially of an active element containing one or two quantum wells and a cavity dependent upon reflectance as between two distributed feedback mirrors.

Huang, R.F.; Jewell, J.L.; McCall, S.L. Jr.; Tai, K.

1991-03-12

112

A search for thermospheric composition perturbations due to vertical winds  

NASA Astrophysics Data System (ADS)

The thermosphere is generally in hydrostatic equilibrium, with winds blowing horizontally along stratified constant-pressure surfaces, driven by the dayside-to-nightside pressure gradient. A marked change in this paradigm resulted after Spencer et al. [1976] reported vertical wind measurements of 80 m·s-1 from analyses of AE-C satellite data. It is now established that the thermosphere routinely supports large-magnitude (˜30-150 m·s-1) vertical winds at auroral latitudes. These vertical winds represent significant departure from hydrostatic and diffusive equilibrium, altering locally---and potentially globally---the thermosphere's and ionosphere's composition, chemistry, thermodynamics and energy budget. Because of their localized nature, large-magnitude vertical wind effects are not entirely known. This thesis presents ground-based Fabry-Perot Spectrometer OI(630.0)-nm observations of upper-thermospheric vertical winds obtained at Inuvik, NT, Canada and Poker Flat, AK. The wind measurements are compared with vertical displacement estimates at ˜104 km2 horizontal spatial scales determined from a new modification to the electron transport code of Lummerzheim and Lilensten [1994] as applied to FUV-wavelength observations by POLAR spacecraft's Ultraviolet Imager [Torr et al. , 1995]. The modification, referred to as the column shift, simulates vertical wind effects such as neutral transport and disruption of diffusive equilibrium by vertically displacing the Hedin [1991] MSIS-90 [O2]/[N2] and [O]/([N2]+[O2]) mixing ratios and subsequently redistributing the O, O2, and N 2 densities used in the transport code. Column shift estimates are inferred from comparisons of UVI OI(135.6)-nm auroral observations to their corresponding modeled emission. The modeled OI(135.6)-nm brightness is determined from the modeled thermospheric response to electron precipitation and estimations of the energy flux and characteristic energy of the precipitation, which are inferred from UVI-observed Lyman-Birge-Hopfield N2 emissions in two wavelength ranges. Two-dimensional column shift maps identify the spatial morphology of thermospheric composition perturbations associated with auroral forms relative to the model thermosphere. Case-study examples and statistical analyses of the column shift data sets indicate that column shifts can be attributed to vertical winds. Unanticipated limitations associated with modeling of the OI(135.6)-nm auroral emission make absolute column shift estimates indeterminate. Insufficient knowledge of thermospheric air-parcel time histories hinders interpretations of point-to-point time series comparisons between column shifts and vertical winds.

Krynicki, Matthew P.

113

Fixed-ratio punishment.  

PubMed

Responses were maintained by a variable-interval schedule of food reinforcement. At the same time, punishment was delivered following every nth response (fixed-ratio punishment). The introduction of fixed-ratio punishment produced an initial phase during which the emission of responses was positively accelerated between punishments. Eventually, the degree of positive acceleration was reduced and a uniform but reduced rate of responding emerged. Large changes in the over-all level of responding were produced by the intensity of punishment, the value of the punishment ratio, and the level of food deprivation. The uniformity of response rate between punishments was invariant in spite of these changes in over-all rate and contrary to some plausible a priori theoretical considerations. Fixed-ratio punishment also produced phenomena previously observed under continuous punishment: warm-up effect and a compensatory increase. This type of intermittent punishment produced less rapid and less complete suppression than did continuous punishment. PMID:13965779

AZRIN, N H; HOLZ, W C; HAKE, D F

1963-04-01

114

New "Golden" Ratios for Facial Beauty  

PubMed Central

In four experiments, we tested the existence of an ideal facial feature arrangement that could optimize the attractiveness of any face given its facial features. Participants made paired comparisons of attractiveness between faces with identical facial features but different eye-mouth distances and different interocular distances. We found that although different faces have varying attractiveness, individual attractiveness is optimized when the face’s vertical distance between the eyes and the mouth is approximately 36% of its length, and the horizontal distance between the eyes is approximately 46% of the face’s width. These “new” golden ratios match those of an average face.

Pallett, Pamela M.; Link, Stephen; Lee, Kang

2009-01-01

115

MEASUREMENT OF VERTICAL TRACK MODULUS FROM A MOVING RAILCAR  

Microsoft Academic Search

Track performance and maintenance requirements are strongly related to track modulus - the ratio between the rail deflection and the vertical contact pressure between the rail base and track foundation. This work seeks to develop an on-board, real-time, non-contact track modulus measurement system that functions at track speed. Measuring track modulus from a moving rail car is nontrivial because there

Richard Arnold; Sheng Lu; Cory Hogan; Shane Farritor; Mahmood Fateh; Magdy El-Sibaie

116

Combined natural and forced convection in vertical ducts  

Microsoft Academic Search

Numerical solutions to the boundary-layer equations, expressed in transformed and physical coordinates, are presented for the vertical flow in a duct where thermal wall-boundary conditions lead to aided or opposed natural and forced convection. Results are presented for values of the ratio of (Gr\\/R-squared) of 0.001 to 1.0 and for Prandtl numbers of 0.1, 0.72, and 10 and include distributions

T. Cebeci; A. A. Khattab; R. Lamont

1982-01-01

117

Stress ratio determination from the core-disking phenomenon  

Microsoft Academic Search

The ability to predict in situ stress conditions from standard core samples offers planning and site-selection advantages for most underground facilities. This paper presents an empirical relation for estimating the horizontal to vertical stress ratio in basalt. The resulting estimates can then be used to help assess the extent to which measurement of in situ stress is required. The core

T. F. Lehnhoff; B. Stefansson; K. Thirumalai

1982-01-01

118

Kinematic Fitting of Detached Vertices  

SciTech Connect

The eg3 experiment at the Jefferson Lab CLAS detector aims to determine the existence of the $\\Xi_{5}$ pentaquarks and investigate the excited $\\Xi$ states. Specifically, the exotic $\\Xi_{5}^{--}$ pentaquark will be sought by first reconstructing the $\\Xi^{-}$ particle through its weak decays, $\\Xi^{-}\\to\\pi^{-}\\Lambda$ and $\\Lambda\\to\\pi^{-}$. A kinematic fitting routine was developed to reconstruct the detached vertices of these decays, where confidence level cuts on the fits are used to remove background events. Prior to fitting these decays, the exclusive reaction $\\gamma D\\rightarrow pp\\pi^{-}$ was studied in order to correct the track measurements and covariance matrices of the charged particles. The $\\Lambda\\rightarrow p\\pi^{-}$ and $\\Xi^{-}\\to\\pi^{-}\\Lambda$ decays were then investigated to demonstrate that the kinematic fitting routine reconstructs the decaying particles and their detached vertices correctly.

Paul Mattione

2007-05-01

119

Vertically Integrated Circuits at Fermilab  

SciTech Connect

The exploration of vertically integrated circuits, also commonly known as 3D-IC technology, for applications in radiation detection started at Fermilab in 2006. This paper examines the opportunities that vertical integration offers by looking at various 3D designs that have been completed by Fermilab. The emphasis is on opportunities that are presented by through silicon vias (TSV), wafer and circuit thinning, and finally fusion bonding techniques to replace conventional bump bonding. Early work by Fermilab has led to an international consortium for the development of 3D-IC circuits for High Energy Physics. For the first time, Fermilab has organized a 3D MPW run, to which more than 25 different designs have been submitted by the consortium.

Deptuch, Grzegorz; Demarteau, Marcel; Hoff, James; Lipton, Ronald; Shenai, Alpana; Trimpl, Marcel; Yarema, Raymond; Zimmerman, Tom; /Fermilab

2010-01-01

120

Next generation vertical electrode cells  

NASA Astrophysics Data System (ADS)

The concept of the vertical electrode cell (VEC) for aluminum electrowinning is presented with reference to current research. Low-temperature electrolysis allows nonconsumable metal-alloy anodes to show ongoing promise in laboratory tests. The economic and environmental advantages of the VEC are surveyed. The unique challenges of bringing VEC technology into practice are discussed. The current status of laboratory research is summarized. New results presented show that commercial purity aluminum can be produced with promisingly high current efficiency.

Brown, Craig

2001-05-01

121

Bimanual-Vertical Hand Movements  

PubMed Central

Patients often demonstrate attentional and action-intentional biases in both the transverse and coronal planes. In addition, when making forelimb movements in the transverse plane, normal participants also have spatial and magnitude asymmetries, but forelimb spatial asymmetries have not been studied in coronal space. Thus, to learn if when normal people make vertical movements they have right–left spatial and magnitude biases, seventeen healthy, blindfolded volunteers had their hands (holding pens) placed vertically in their midsagittal plane, 10 inches apart, on pieces of paper positioned above, below, and at eye-level. Participants were asked to move their hands together vertically and meet in the middle. Participants demonstrated less angular deviation in the below-eye condition than in the other spatial conditions, when moving down than up, and with their right than left hand. Movements toward eye level from upper or lower space were also more accurate than movements in the other directions. Independent of hand, lines were longer with downward than upward movements and the right hand moved more distance than the left. These attentional-intentional asymmetries may be related to gravitational force, hand-hemispheric dominance, and spatial “where” asymmetries; however, the mechanisms accounting for these asymmetries must be ascertained by future research.

Kwon, Jay C.; Cohen, Matthew L.; Williamson, John; Burtis, Brandon; Heilman, Kenneth M.

2012-01-01

122

The Golden Ratio  

NSDL National Science Digital Library

This Web site provides a "basic introduction to one of the most amazing discoveries in mathematics: the Golden Ratio." Created by David L. Narain, this site offers a particularly engaging way to bring together math and the natural sciences in the classroom. Seven straightforward activities have students construct a golden rectangle and spiral, and also explore the Golden Ratio in nature and in other contexts. The site also includes a quiz; answers are not provided, though. The activities are designed for 9th and 10th graders, but would also be appropriate for middle school students.

Narain, David L.

2001-01-01

123

The TIROS-N Operational Vertical Sounder.  

National Technical Information Service (NTIS)

TIROS-N is the first of a new series of operational polar-orbiting meteorological satellites. Aboard each spacecraft is a third-generation complement of vertical sounding instruments capable of providing complete global coverage of vertical temperature da...

W. L. Smith H. M. Woolf C. M. Hayden D. W. Wark L. M. McMillin

1979-01-01

124

Area Ratios of Quadrilaterals.  

ERIC Educational Resources Information Center

Shows that the ratio of the area of the quadrilateral formed by joining the kth points to the area of the original quadrilateral is constant whether it is convex or concave quadrilateral. Presents many geoboard or dot paper diagrams and geometrical expresssions. (YP)

Anderson, David R.; Arcidiacono, Michael J.

1989-01-01

125

Fuel efficiency ratio  

Microsoft Academic Search

Example of calculations are shown to illustrate how fuel costs and solid waste yardage are related. A commercial front loader is used for the examples, but any vehicle can be substituted using the same mathematical concept. Three new ratios, engine efficiency, fuel efficiency, and per yard fuel cost, that may enter the refuse industry in the 1980s are discussed. (MCW)

1980-01-01

126

The Likelihood Ratio Test  

NSDL National Science Digital Library

This module, created by Don Johnson of Rice University, provides an explanation and an example of the likelihood ratio test. Topics include: decision regions, Bayes' decision criterion, Bayes' cost, and likelihood function. The site is enhanced by Johnson's use of graphic and numerical demonstrations to better explain his points. Additionally, a PDF attachment providing an in-depth explanation is also featured.

Johnson, Don

2009-01-08

127

Project Plan for Vertical Lift Machine  

Microsoft Academic Search

This document describes the Project Plan for the development and manufacture of a Vertical Lift Machine. It is assumed by this project plan that the Vertical Lift Machine will be developed, designed, manufactured, and tested by a qualified vendor. LLNL will retain review and approval authority for each step given in this project plan. The Vertical Lift Machine is a

Ellsworth

2002-01-01

128

Modernizing Vertical Datums in the United States  

Microsoft Academic Search

The National Geodetic Survey (NGS) defines and maintains the National Spatial Reference System (NSRS). Additionally, NGS has a definitive role in providing direct access to the NSRS. An important aspect of the NSRS is the vertical datum, to which geodetic control of elevations is referred. The current official vertical datum for the United States is the North American Vertical Datum

D. B. Zilkoski; D. A. Smith

2006-01-01

129

Digit ratio in birds.  

PubMed

The Homeobox (Hox) genes direct the development of tetrapod digits. The expression of Hox genes may be influenced by endogenous sex steroids during development. Manning (Digit ratio. New Brunswick, NJ: Rutgers University Press, 2002) predicted that the ratio between the lengths of digits 2 (2D) and 4 (4D) should be sexually dimorphic because prenatal exposure to estrogens and androgens positively influence the lengths of 2D and 4D, respectively. We measured digits and other morphological traits of birds from three orders (Passeriformes, house sparrow, Passer domesticus; tree swallow, Tachycineta bicolor; Pscittaciformes, budgerigar, Melopsittacus undulates; Galliformes, chicken, Gallus domesticus) to test this prediction. None were sexually dimorphic for 2D:4D and there were no associations between 2D:4D and other sexually dimorphic traits. When we pooled data from all four species after we averaged right and left side digits from each individual and z-transformed the resulting digit ratios, we found that males had significantly larger 2D:4D than did females. Tetrapods appear to be sexually dimorphic for 2D:4D with 2D:4D larger in males as in some birds and reptiles and 2D:4D smaller in males as in some mammals. The differences between the reptile and mammal lineages in the directionality of 2D:4D may be related to the differences between them in chromosomal sex determination. We suggest that (a) natural selection for a perching foot in the first birds may have overridden the effects of hormones on the development of digit ratio in this group of vertebrates and (b) caution be used in making inferences about prenatal exposure to hormones and digit ratio in birds. PMID:18833568

Lombardo, Michael P; Thorpe, Patrick A; Brown, Barbara M; Sian, Katie

2008-12-01

130

The choice of organizational form: Vertical financial ownership versus other methods of vertical integration  

Microsoft Academic Search

Vertical integration is a fundamental corporate strategy of interest to the fields of strategic management and organizational economics. This paper synthesizes theoretical arguments and empirical findings from this literature to identify the underlying advantages and disadvantages of choosing vertical financial ownership relative to vertical contracts. It then suggests that in the absence of agency and transaction costs, vertical financial ownership

Joseph T. Mahoney

1992-01-01

131

Three-dimensional numerical study of natural convection in vertical cylinders partially heated from the side  

Microsoft Academic Search

Three-dimensional steady and oscillatory flows are simulated in a vertical cylinder partially heated from the side. The vertical wall is heated in a zone at midheight and is insulated above and below this middle zone, while both ends of the cylinder are cooled. The cylinder aspect ratio (A=height?radius) ranges from 2 to 8, whereas a fixed Prandtl number, Pr=0.021, is

D. J. Ma; D. Henry; H. Ben Hadid

2005-01-01

132

Three-dimensional numerical study of natural convection in vertical cylinders partially heated from the side  

Microsoft Academic Search

Three-dimensional steady and oscillatory flows are simulated in a vertical cylinder partially heated from the side. The vertical wall is heated in a zone at midheight and is insulated above and below this middle zone, while both ends of the cylinder are cooled. The cylinder aspect ratio (A=height\\/radius) ranges from 2 to 8, whereas a fixed Prandtl number, Pr=0.021, is

D. J. Ma; D. Henry; H. Ben Hadid

2005-01-01

133

What's My Ratio?  

NSDL National Science Digital Library

In this activity, students use linear measurement and calculators to investigate proportionality and determine the constant ratio between similar figures. In it, students draw a figure on centimeter graph paper, increase or decrease the size, and predict the dimensions. Then students compare the ratio of two pictures by measuring, recording their data, and discussing their findings to draw conclusions. Suggested guidelines for instruction and classroom discussion are included, as well as data collection worksheets for students, and centimeter graph paper to print. The lesson may be introduced by reading appropriate sections from "GoosebumpsâMonster Blood III" (Chapters 15 and 16) by R.L. Stine, or "The Shrinking of Treehorn" by F. Heide.

2003-01-01

134

The Golden Ratio Encoder  

Microsoft Academic Search

This paper proposes a novel Nyquist-rate analog-to-digital (A\\/D) conversion algorithm which achieves exponential accuracy in the bit-rate despite using imperfe ct components. The proposed algorithm is based on a robust implementation of a beta-encoder with ? = ? = (1 + ? 5)\\/2, the golden ratio. It was previously shown that beta-encoders can be implemented in such a way that

Ingrid Daubechies; C. Sinan Güntürk; Yang Wang; Özgür Yilmaz

2008-01-01

135

Thinking Blocks: Ratios  

NSDL National Science Digital Library

This set of six interactive Flash activities gives students an opportunity to visually model and calculate the unknown quantity from ratios and other information, all in the context of solving word problems. A video demonstration introduces each method, and then students work on modeling and solving five problems. Students can check their modeling of the problem at intermediate stages. Teachers can track a student's progress throughout the problem set.

2012-01-01

136

PROPORTIONS and RATIOS  

NSDL National Science Digital Library

Using what you already know and the text, can you solve these problems? Just by looking at the titles below, describe in your journal what you think each activity is going to be about and how it relates to proportions and ratios. Which tastes juicier? Statue of Liberty : is the Statue of Liberty's nose too long? Describe in your journal how your favorite question above was answered. Also, include any fun facts you learned along the way. What ...

Squire, Mrs.

2009-04-13

137

Vertical dynamics of marine risers  

SciTech Connect

A study of the vertical dynamics of marine riser-load systems has been performed to determine the amplitude of dynamic forces and displacements caused by heave action. The analysis predicts circumstances under which slackening or compression, and subsequent failure of a riser can occur. Results show that a suitably designed heave compensator can reduce the dynamic stress amplitude to acceptable values under all operating modes including hangoff, by increasing compliance at the riser vessel interface. Finally, recommendations for the design of heave compensation equipment intended to limit the dynamic force amplitude on riser-load systems hanging in deeper waters and harsher environments are presented.

Apiazu, W.R.; Nguyen, V.N.

1984-05-01

138

Crystalline beams: The vertical zigzag  

SciTech Connect

This note is the continuation of our comprehensive investigation of Crystalline Beams. After having determined the equations of motion and the conditions for the formation of the simplest configuration, i.e. the string, we study the possibility of storing an intense beam of charged particles in a storage ring where they form a vertical zigzag. We define the equilibrium configuration, and examine the confinement conditions. Subsequently, we derive the transfer matrix for motion through various elements of the storage ring. Finally we investigate the stability conditions for such a beam.

Haffmans, A.F.; Maletic, D.; Ruggiero, A.G.

1994-05-04

139

Handy Measuring Ratio  

NSDL National Science Digital Library

In this activity, learners use their hands as tools for indirect measurement. Learners explore how to use ratios to calculate the approximate height of something that can't be measured directly by first measuring something that can be directly measured. This activity can also be used to explain how scientists use indirect measurement to determine distances between things in the universe that are too far away, too large or too small to measure directly (i.e. diameter of the moon or number of bacteria in a volume of liquid).

Exploratorium

2010-01-01

140

Controls on vertical mixing of sediment in gravel bed rivers  

NASA Astrophysics Data System (ADS)

Understanding controls on vertical mixing of sediment in gravel bed rivers is important in areas of managing aquatic and riparian habitat, sediment bedload and yield, sediment storage and channel stability, water quality and hydraulic engineering. Sediment tracers disperse in rivers longitudinally downstream and vertically within the channel bed. Few sediment tracer studies focus on vertical mixing of sediment; fewer still focus on its modeling. A deterministic modeling approach to sediment mixing is difficult due to complex physics and limitations in direct measurement. Here we use a simple probability modeling approach to determine primary physical controls on vertical mixing of sediment tracers in three gravel bed rivers: East Creek in British Columbia, and the Allt Dubhaig and Monachyle Burn rivers in Scotland. Burial of sediment tracers is modeled as a binary response with mass, axis dimensions, axis measurement ratios, stone shape and angularity as particle characteristic covariates. Other potential model covariates are particle travel distance and endpoint morphology of tracers. Simple generalized linear models are developed using logistic methods to explore main effects on burial. Primary controls from simple models found to be common across all channels and tracer surveys are then used to develop multivariate logistic models to determine how simultaneous controls and their interactions affect sediment burial. Significant primary controls on vertical mixing were particle size, travel distance and endpoint morphology. Most multivariate models had either one of two significant outcomes with respect to simultaneous control on burial: (1) burial probability given particle size and endpoint morphology (Figure 1), or (2) burial probability given particle size and particle travel distance (not shown).

Voepel, H.; Schumer, R.; Hassan, M. A.

2011-12-01

141

Interactions between Short-Term Vertical Phoria Adaptation and Nonconjugate Adaptation of Vertical Pursuits. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

We have demonstrated that short-term vertical position-specific phoria adaptation contributes to nonconjugate adaptation of vertical pursuits, but not to nonconjugate adaptation of vertical saccades. Binocular adaptation to multiple stationary vertical di...

C. M. Schor G. Gleason R. Lunn

1993-01-01

142

Vertical structuring of gigantic jets  

NASA Astrophysics Data System (ADS)

Gigantic Jets (GJs) are initiated deep inside the thundercloud as intracloud discharges whose upward-directed leaders manage to escape through the thundercloud top and propagate up to the ionosphere. The speed at which leaders propagate is limited by the air heating of every newly formed leader section, rate of which is slower at upper altitudes in the Earth's atmosphere. Despite the expected deceleration of an upward-directed leader, GJs are observed to accelerate as they approach the ionosphere. In this letter, we discuss the dependence of the leader speed on current density in the leader stem, and we propose a simple time-dynamic model for GJ propagation that includes the effects of the expansion of the streamer zone adjacent to the leader head. We propose that the GJ acceleration is a consequence of its vertical structuring and, therefore, can be used to trace the transition altitude between the leader and streamer zone sections of GJs.

Silva, Caitano L.; Pasko, Victor P.

2013-06-01

143

[Occlusal vertical dimension in removable complete dentures].  

PubMed

In removable complete dentures, the occlusal vertical dimension is an important factor for patients' satisfaction with aesthetics. An excessively reduced occlusal vertical dimension is especially likely to lead to complaints about aesthetics, whereas an increased occlusal vertical dimension may lead to discomfort and a decision not to wear the complete dentures. There are various methods for determining the occlusal vertical dimension in complete dentures, based on the vertical dimension in the rest position of the mandible or on phonetics. However, none of the methods have proven to be clearly superior, in terms of reliability, than the others. The assessment of the occlusal vertical dimension will become more reliable if several methods are used simultaneously. Moreover, knowledge of the characteristics of the ageing face is essential. PMID:22292357

den Haan, R; Witter, D J

2011-12-01

144

Micromachined widely tunable vertical cavity laser diodes  

Microsoft Academic Search

Wavelength tunable vertical-cavity surface-emitting lasers (VCSELs) are potentially useful for future optical communications. Traditionally, the emission wavelength of a vertical cavity laser was tuned by modulating the active region temperature. However, thermal tuning is slow, and the realized tuning range is quite limited. Micromachined tunable VCSELs (Mi-T-VCSELs) combine the traditional vertical cavity laser structure with a monolithically micromachined deformable membrane,

Fredy Sugihwo; Michael C. Larson; James S. Harris

1998-01-01

145

Horizontal Distributions of Thermospheric Vertical Winds in the Polar Region  

NASA Astrophysics Data System (ADS)

Thermospheric vertical winds can play a significant role in the thermospheric dynamics, energy balance between thermosphere and ionosphere, and displacement of the altitude profiles of mixing ratio for each atmospheric species. Optical measurements with Fabry-Perot Interferometers are powerful method to observe vertical winds, but the observing area is restricted in small portion of the sky just above the instruments. Several attempts have been executed to extend the observable region. Innis and Conde [2002a,b] shows thermospheric vertical winds obtainedfrom DE2 satellite data (WATS, NACS). In the recent studies, a rocket experimentwith TMA trail measured horizontal distribution of vertical winds in HEX (Horizontal E-region eXperiments) campaign on March 2003. In this campaign, multi-site observation with Fabry-Perot Interferometers was conducted for another approach. In this study, we will show several results of detailed analysis obtained with two Fabry-Perot Interferometers at Poker Flat Research Range (PFRR) and Eagle (EGL). These two sites are separated about 300 km along a typical auroral arc and we can expect to deduce vertical wind distribution on the vicinity of auroral arc from these results. The present results show that the vertical winds estimated from OI557.7nm at the two sites has high correlation (the correlation coefficients are higher than 0.6 in six of 13 nights). In many of low correlated cases, one observatory (EGL in most cases) was displaced from auroral arc. This results mean that the neutral wind system is uniform along the auroral arc. Innis, J. L., and M. Conde, High-latitude thermospheric vertical wind activity from Dynamics Explorer 2 Wind and Temperature Spectrometer Observations: Indications of a source region for polar cap gravity waves, J. Geophys. Res., 107, A8, 10.1029/2001JA009130, 2002a. Innis J. L., and M. Conde, Characterization of acoustic-gravity waves in the upper thermosphere using Dynamics Explorer 2 Wind and Temperature Spectrometer (WATS) and Nuetral Atmosphere Composition Spectrometer (NACS) data, J. Geophys. Res., 107, A12, 10.1029/2002JA009370, 2002b.

Ishii, M.; Kubota, M.; Conde, M.; Smith, R. W.; Krynicki, M.

2003-12-01

146

Microplasma illumination enhancement of vertically aligned conducting ultrananocrystalline diamond nanorods  

NASA Astrophysics Data System (ADS)

Vertically aligned conducting ultrananocrystalline diamond (UNCD) nanorods are fabricated using the reactive ion etching method incorporated with nanodiamond particles as mask. High electrical conductivity of 275 ?·cm-1 is obtained for UNCD nanorods. The microplasma cavities using UNCD nanorods as cathode show enhanced plasma illumination characteristics of low threshold field of 0.21 V/?m with plasma current density of 7.06 mA/cm2 at an applied field of 0.35 V/?m. Such superior electrical properties of UNCD nanorods with high aspect ratio potentially make a significant impact on the diamond-based microplasma display technology.

Sankaran, Kamatchi Jothiramalingam; Kunuku, Srinivasu; Lou, Shiu-Cheng; Kurian, Joji; Chen, Huang-Chin; Lee, Chi-Young; Tai, Nyan-Hwa; Leou, Keh-Chyang; Chen, Chulung; Lin, I.-Nan

2012-09-01

147

Microplasma illumination enhancement of vertically aligned conducting ultrananocrystalline diamond nanorods.  

PubMed

Vertically aligned conducting ultrananocrystalline diamond (UNCD) nanorods are fabricated using the reactive ion etching method incorporated with nanodiamond particles as mask. High electrical conductivity of 275??·cm-1 is obtained for UNCD nanorods. The microplasma cavities using UNCD nanorods as cathode show enhanced plasma illumination characteristics of low threshold field of 0.21?V/?m with plasma current density of 7.06?mA/cm2 at an applied field of 0.35?V/?m. Such superior electrical properties of UNCD nanorods with high aspect ratio potentially make a significant impact on the diamond-based microplasma display technology. PMID:23009733

Sankaran, Kamatchi Jothiramalingam; Kunuku, Srinivasu; Lou, Shiu-Cheng; Kurian, Joji; Chen, Huang-Chin; Lee, Chi-Young; Tai, Nyan-Hwa; Leou, Keh-Chyang; Chen, Chulung; Lin, I-Nan

2012-09-25

148

Vertical conformance in an alternating water-miscible gas flood  

SciTech Connect

Oil recovery by the injection of water alternately with gas (WAG flooding) is often limited by gravity segregation, which causes the injected gas to rise to the top of the formation and water to migrate to the bottom. This segregation results in a miscible flood in only a thin layer at the top of the formation, whereas the remainder is waterflooded. However, vertical conformance in a WAG flood can be greatly improved by use of injection rates that are high relative to well spacing. The degree of improvement and, hence, the resultant oil recovery is primarily a function of a single dimensionless parameter, depending on the viscosity density ratio.

Stone, H.L.

1982-09-01

149

Vertical conformance in an alternating water-miscible gas flood  

SciTech Connect

Oil recovery by the injection of water alternately with gas (WAG flooding) is often limited by gravity segregation, which causes the injected gas to rise to the top of the formation and water to migrate to the bottom. This segregation results in a miscible flood in only a thin layer at the top of the formation, whereas the remainder is waterflooded. However, vertical conformance in a WAG flood can be improved by use of injection rates that are high relative to well spacing. The degree of improvement and the resultant oil recovery is primarily a function of a single dimensionless parameter, which is one form of the viscous-gravity ratio.

Stone, H.L.

1982-01-01

150

Vertically Moving Visual Stimuli and Vertical Vection: A Tool Against Space Motion Sickness.  

National Technical Information Service (NTIS)

Vertical vection is a motion illusion that can be elicited by vertical optokinetic stimulation with gaze fixation. Overruling the otolithic and all other sensory canals visual information leads to the perception of lift or pitch vection in a stationary su...

C. Mueller G. Wiest L. Deecke

1990-01-01

151

Ultrahigh-Aspect-Ratio Contact Hole Etching  

NASA Astrophysics Data System (ADS)

An ultrasmall, 60nm-diameter, 2um-deep contact hole pattern of BPSG film was successfully fabricated using a poly-Si mask and a magnetically enhanced reactive-ion-etching system. Significantly weaker dependence of etch rate on aspect ratio(AR) was obtained up to AR=30, showing that the energetic ions (and/or neutralized molecules) with a sufficient flux for etching reaction are supplied onto the hole bottom even in such a extremely fine feature. On the other hand, neutral supply of polymer precursors onto the hole bottom (Si substrate) is not sufficient for polymerization in holes with aspect ratios greater than 10, where several energetic particles reach the hole bottoms and contribute to the etching reaction with Si substrates. For features with dimensions below 100nm, processing of vertical profiles is extremely difficult, and problems in the form of bowing at the sidewalls of the holes can occur. The shape of the etched feature and the occurrence of etch stops were shown to be in a trade-off relationship. However, vertical profiles were successfully obtained with diameters greater than 100nm without etch stops. It is possible that ion flux is significantly influenced (reduced) when ions pass through the poly-Si mask, rather than through the BPSG hole. The bowing is associated with bending of the incident ion trajectories, where the first stage of the trajectory change occurs at the mask, and subsequent multiple scattering of ions at the sidewall of the hole can occur. Other factors include sidewall protection by redeposited Si that was sputtered from the poly-Si mask and/or the deposited fluorocarbon polymers, and the effects of ion flux and energy bombarding these deposited materials. In the future, it will be necessary to clarify the details of the mechanisms of these phenomena and to establish technologies to control them. note number.

Ikegami, Naokatsu

1997-10-01

152

THE RELATIONSHIP BETWEEN VERTICAL AND HORIZONTAL MAGNETIC FIELDS IN THE QUIET SUN  

SciTech Connect

Vertical magnetic fields have been known for decades to exist in the internetwork region of the Sun, while the properties of horizontal magnetic fields have only recently been extensively investigated with Hinode. Vertical and horizontal magnetic fields in the internetwork region are considered to be separate entities and have thus far not been investigated in a unified way. We discover a clear positional association between the vertical and horizontal magnetic fields in the internetwork region with Hinode. Essentially, all of the horizontal magnetic patches are associated with the vertical magnetic patches. Alternatively, half of the vertical magnetic patches accommodate the horizontal magnetic patches. These horizontal patches are located around the borders of the vertical patches. The intrinsic magnetic field strength as obtained with the Stokes V line ratio inside the horizontal patches is weak, and is in the subequipartition field regime (B < 700 G), while the field strength outside the horizontal patches ranges from weak to strong (kG) fields. Vertical magnetic patches are known to be concentrated on mesogranular and supergranular boundaries, while the horizontal magnetic patches are found only on mesogranular boundaries. These observations provide us with new information on the origin of the vertical and horizontal internetwork magnetic fields, in a unified way. We conjecture that internetwork magnetic fields are formed by the emergence of small-scale flux tubes with bipolar footpoints, and the vertical magnetic fields of the footpoints are intensified to kG fields due to convective collapse. Resultant strong vertical fields are advected by the supergranular flow, and eventually form the network fields.

Ishikawa, Ryohko [Department of Astronomy, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Tsuneta, Saku, E-mail: ryoko.ishikawa@nao.ac.jp [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

2011-07-10

153

Empirical evaluation of microtremor H\\/V spectral ratio  

Microsoft Academic Search

The objective of this work is to perform a purely empirical assessment of the actual capabilities of the horizontal-to-vertical\\u000a (H\\/V) spectral ratio technique to provide reliable and relevant information concerning site conditions and\\/or site amplification.\\u000a This objective has been tackled through the homogeneous (re)processing of a large volume of earthquakes and ambient noise\\u000a data recorded by different research teams in

E. Haghshenas; P.-Y. Bard; N. Theodulidis

2008-01-01

154

A High Aspect-Ratio Polysilicon Vibrating Ring Gyroscope  

Microsoft Academic Search

Drive and Control This paper presents the fabrication and testing of a high aspect-ratio 80um tall polysilicon ring gyroscope (PRG) fabricated using a new dry-release poly-silicon MEMS technology. This single-wafer technology is capable of producing electrically isolated vertical electrodes as tall as the main body polysilicon structure (50 to 100's urn tall) with various size air-gaps ranging from sub-micron to

Farrokh Ayazi; Hsiao H. Chen; Fatih Kocer; Guohong He; Khalil Najafl

2000-01-01

155

Evaluation of vertical coordinate and vertical mixing algorithms in the HYbrid-Coordinate Ocean Model (HYCOM)  

Microsoft Academic Search

Vertical coordinate and vertical mixing algorithms included in the HYbrid Coordinate Ocean Model (HYCOM) are evaluated in low-resolution climatological simulations of the Atlantic Ocean. The hybrid vertical coordinates are isopycnic in the deep ocean interior, but smoothly transition to level (pressure) coordinates near the ocean surface, to sigma coordinates in shallow water regions, and back again to level coordinates in

George R. Halliwell

2004-01-01

156

Control system for a vertical axis windmill  

Microsoft Academic Search

A vertical axis windmill having a rotating structure is provided with a series of articulated vertical blades whose positions are controlled to maintain a constant RPM for the rotating structure, when wind speed is sufficient. A microprocessor controller is used to process information on wind speed, wind direction and RPM of the rotating structure to develop an electrical signal for

Brulle; Robert V

1983-01-01

157

The vertical concept of power MOSFETs  

Microsoft Academic Search

One major goal in power device research is the reduction of power losses while keeping high breakdown voltages. Commonly used power devices, e.g. DMOS™, use a combination of lateral channel and vertical drift zone. This involves power losses that can be reduced by a device concept with vertical channel and drift zone. We will discuss the classical DMOS™ structure in

C Tolksdorf; C Fink; J Schulze; S Sedlmaier; W Hansch; W Werner; W Kanert; I Eisele

2002-01-01

158

Behavioral mechanisms controlling vertical migration in Daphnia  

Microsoft Academic Search

We used infrared video monitoring to study cladoceran vertical migration in laboratory tanks exposed to natural and simulated daylight cycles. There are changes in the behavior patterns at different times of the year, with both Daphnia magna and Daphnia longispina showing increased vertical migration and greater average depth later in the year. This change in behavior pattern is due to

STEPHEN YOUNG; PENELOPE WATT

1993-01-01

159

Vertical profiles of aeolian sand mass flux  

Microsoft Academic Search

Vertical profiles of the horizontal mass flux of blown sand are investigated experimentally using a passive vertical array in a wind tunnel. Considering lower sampling efficiency of the sand trap in the near-bed region, this investigation is complemented by the measurements of the longitudinal profiles of mass flux made using a horizontal sand trap. The experiments were conducted with two

J. R Ni; Z. S Li; C Mendoza

2003-01-01

160

Vertically supported two-directional comb drive  

Microsoft Academic Search

A vertically supported comb drive with the feasibility of actuation in two perpendicular directions utilizing electrostatic force from interdigitated comb-shape electrodes has been demonstrated. The prototype microstructures are made of 2 µm thick polysilicon by a standard surface micromachining process. They are vertically lifted after the final sacrificial layer releasing process and are fixed on the substrate with the assistance

Ki Bang Lee; Liwei Lin

2005-01-01

161

Vertical Economies of Scope in Dairy Farming  

Microsoft Academic Search

With the exception of Azzam and Skinner (2007), the economic literature on farm structure has largely neglected issues of vertical organization of the farm. In this article we estimate a multi-stage, multi-output cost function in order to measure vertical economies of scope in organic and conventional dairy farms. In particular, we model the integration of production of grains and forages

Carlos D. Mayen; Joseph V. Balagtas; Corinne E. Alexander

2009-01-01

162

VERTICAL INTEGRATION IN AGRICULTURE AND CONTRACT FARMING  

Microsoft Academic Search

It has been widely argued recently that agriculture is undergoing a process of vertical integration with allied industries. One of the worldwide ways of vertical integration in agriculture is contract farming. Contract farming is a continually evolving process. Worldwide applications of contract farming have shown that the terms of contracts are shaped by their own conditions and varied from product

Erkan Rehber

1998-01-01

163

An inexpensive vertical-displacement indentation tester  

Microsoft Academic Search

A displacement transducer is used to follow the vertical movements of an indenter tip, which is forced into the material specimen under a selected dead weight load. Measurement of indentation depth under load and vertical recovery following load removal allows both plastic and elastic characteristics of the material to be evaluated. The equipment gives consistent results, is readily portable, and

P. J. P. White; M. E. Aulton

1980-01-01

164

Vertical Integration, Monopoly, and the First Amendment.  

ERIC Educational Resources Information Center

|This paper addresses the relationship between the First Amendment, monopoly of transmission media, and vertical integration of transmission and content provision. A survey of some of the incentives a profit-maximizing transmission monopolist may have with respect to content is followed by a discussion of how vertical integration affects those…

Brennan, Timothy J.

165

Arthropod vertical stratification in temperate deciduous forests ...  

Treesearch

Description: Studies on the vertical distribution patterns of arthropods in ... age, season, time of day); (2) forest structure (height, vertical foliage complexity, plant ... (7) logistics (dispersal abilities, proximity to emergence sites, open flight zones) . ... of canopy arthropod taxa associated with standing or suspended dead wood,  ...

166

Wave impact pressures on vertical cylinders  

Microsoft Academic Search

Laboratory measurements of the pressure distributions on surface-piercing vertical cylinders due to breaking waves are presented. Breaking waves are generated in a repeatable fashion under program control, and both vertical and azimuthal distributions of pressures were measured over many repeats of the experiments. Despite the repeatability of the controllable experimental conditions, it is found that the highest impact pressures are

D. Zhou; E. S. Chan; W. K. Melville

1991-01-01

167

Validity of vertical jump measurement devices  

Microsoft Academic Search

Vertical jump height is thought to provide a valuable index of muscular power, which is an important factor in sports performance and for assessing the mobility and functional capacity of injured or aged individuals. The purpose of the present study was to investigate the criterion validity of four popular devices for measuring vertical jump height. A belt mat, contact mat,

Matthew Buckthorpe; John Morris; Jonathan P. Folland

2011-01-01

168

Validity of vertical jump measurement devices  

Microsoft Academic Search

Vertical jump height is thought to provide a valuable index of muscular power, which is an important factor in sports performance and for assessing the mobility and functional capacity of injured or aged individuals. The purpose of the present study was to investigate the criterion validity of four popular devices for measuring vertical jump height. A belt mat, contact mat,

Matthew Buckthorpe; John Morris; Jonathan P. Folland

2012-01-01

169

Remote sensing reflectance measured with and without a vertical polarizer  

NASA Astrophysics Data System (ADS)

Remote-sensing reflectance (Rrs ratio of the water- leaving radiance to the downwelling irradiance above the surface) with and without a vertical polarizer in front of the sensor were derived for measurements made at 90 degrees to the solar plane and in a direction 30 degrees to nadir. These measurements were carried out to see if a vertical polarizer mounted in front of a sensor would improve the Rrs results. For 28 pairs of measurements with chlorophyll- a concentrations ranging from 0.07 to 38 mg/m3, solar zenith angles from 18 degrees to 66 degrees, clear to cloudy skies, and for optically shallow and deep waters, there was no significant variation between the polarized and unpolarized Rrs values. Statistical comparisons of polarized to unpolarized results provided R2 values of 0.987, 0.987, 0.994, and 0.999 with slopes 1.007, 1.005, 0.983 and 0.998 for wavelengths at 410, 440, 550 and 630 nm, respectively. These results suggest that although the underwater light field is partially polarized, a vertical polarizer in front of a sensor will provide close results to unpolarized sensor, if the measurements were made in a direction 90 degrees to the solar plane and 30 degrees to the nadir.

Lee, Zhongping; Carder, Kendall L.; Peacock, Thomas G.; Steward, Robert G.

1997-02-01

170

Vertical-Cavity Surface-Emitting Lasers  

NASA Astrophysics Data System (ADS)

1. Introduction to VCSELs L. A. Coldren, C. W. Wilmsen and H. Temkin; 2. Fundamental issues in VCSEL design L. A. Coldren and Eric R. Hegblom; 3. Enhancement of spontaneous emission in microcavities E. F. Schubert and N. E. J. Hunt; 4. Epitaxy of vertical-cavity lasers R. P. Schneider Jr and Y. H. Young; 5. Fabrication and performance of vertical-cavity surface-emitting lasers Kent D. Choquette and Kent Geib; 6. Polarization related properties of vertical cavity lasers Dmitri Kuksenkov and Henryk Temkin; 7. Visible light emitting vertical cavity lasers Robert L. Thornton; 8. Long-wavelength vertical-cavity lasers Dubrakovo I. Babic, Joachim Piprek and John E. Bowers; 9. Overview of VCSEL applications Richard C. Williamson; 10. Optical interconnection applications and required characteristics Kenichi Kasahara; 11. VCSEL-based fiber-optic data communications Kenneth Hahn and Kirk Giboney; 12. VCSEL-based smart pixels for free space optoelectronic processing C. W. Wilmsen.

Wilmsen, Carl W.; Temkin, Henryk; Coldren, Larry A.

2002-01-01

171

A vertical axis cyclogiro type wind-turbine with freely-hinged blades  

NASA Astrophysics Data System (ADS)

A description is given of the design, construction and testing of a prototype vertical axis cycloturbine. The machine has straight vertical blades of symmetrical cross-section. Each blade is hinged, on a vertical axis, near its upper and lower extremities to the ends of radial arms projecting from a central, rotating, tower structure. What is believed to be a unique method is used for the control of blade articulation. The cyclic motion of each blade is derived solely from a combination of the centrifuging action of a mass attached to the blade and the aerodynamic load acting on the blade. Results of open-air tests of the small two-bladed prototype unit resulted in the achievement of a maximum power coefficient of 0.37 at a velocity ratio of 3.6 with a runaway velocity ratio of 5.2. The machine was found to self-start easily.

Bayly, D. A.; Kentfield, J. A. C.

172

Multiple Byoyancy-Driven Flows in a Vertical Cylinder Heated from below  

Microsoft Academic Search

The structure of axisymmetric buoyancy-driven convection in a vertical cylinder heated from below is probed by finite-element solution of the Boussinesq equations coupled with computer-implemented perturbation techniques for detecting and tracking multiple flows and for determining flow stability. Results are reported for fluids with a Prandtl number of one and for cylinders with aspect ratio Lambda (defined as the ratio

Y. Yamaguchi; C. J. Chang; R. A. Brown

1984-01-01

173

Experimental and numerical study on natural convection from vertical plates with horizontal rectangular grooves  

Microsoft Academic Search

Natural convection from two-dimensional vertical plates with horizontal rectangular grooves was studied experimentally and numerically. A Mach-Zehnder interferometer was used in the experiment and the local Nusselt numbers at each groove surface (outer, bottom, inner, and top surfaces) were measured quantitatively from the interferograms. In some cases (grooves of some aspect ratios with low Rayleigh number), the total heat transfer

C. E. Kwak; T. H. Song

1998-01-01

174

A vertical beamforming design approach for increased area coverage rate for synthetic aperture sonar  

Microsoft Academic Search

The authors present a design approach for increasing the area coverage rate for a bottom mapping synthetic aperture sonar (SAS). The approach uses dual acoustic data channels which are established by vertical beamforming from a single phase-shifted transducer array. An SAR (synthetic aperture radar) image quality criterion known as the ambiguity ratio, which affects image contrasts, is applied to the

James C. Nelander; Arthur Craig Kenton; James A. Wright

1989-01-01

175

Optimal Design and Reduced Threshold in Vertically Emitting Circular Bragg Disk Resonator Lasers  

Microsoft Academic Search

We derive a comprehensive coupled-mode theory, including resonant vertical emission effects, for the analysis of nonperiodic circular Bragg lasers. We derive the governing characteristic equation for such lasers, yielding the threshold gain level and the resonance frequency. By reducing the threshold gain and maximizing the ratio of \\

Xiankai Sun; Jacob Scheuer; Amnon Yariv

2007-01-01

176

Viability of Cross-Flow Fan for Vertical Take-Off and Landing Aircraft.  

National Technical Information Service (NTIS)

The present study is focused on determining a housing design that, when paired with an off-the-shelf cross-flow fan rotor, will generate a trust- to-weight ratio significant enough to allow for vertical take-off. The commercial computational fluid dynamic...

C. T. Delagrange

2012-01-01

177

Natural convection in a vertical annulus containing water near the density maximum  

Microsoft Academic Search

Steady natural convection of water near the density extremum in a vertical annulus is studied numerically. Results for flow in annuli with aspect ratio 1 ⤠A ⤠8 and varying degrees of curvature are given for 10³ ⤠Ra ⤠10⁵. It is shown that both the density distribution parameter R and the annulus curvature K have a strong

D. S. Lin; M. W. Nansteel

1987-01-01

178

Multiple buoyancy driven flows in a vertical cylinder heated from below  

Microsoft Academic Search

The structure of axisymmetric buoyancy-driven convection in a vertical cylinder heated from below is probed by finite element solution of the Boussinesq equations coupled with computed-implemented perturbation techniques for detecting and tracking multiple flows and for determining flow stability. Results are reported for fluids with Prandtl number of one and for cylinders with aspect ratio (Lambda) (defined as the height

Y. Yamaguchi; C. J. Chang; R. A. Brown

1983-01-01

179

Climatic significance of isotope ratios  

Microsoft Academic Search

The hydrogen and oxygen isotope ratios of water, which can be measured by Isotope Ratio Mass Spectrometry (IRMS), exhibit climatic dependencies and are commonly exploited in hydrogeology. More generally, the overall carbon or hydrogen isotope ratios of plant organic matter, and in particular of tree-ring cellulose, have been frequently used for climatic reconstruction. However, since many physicochemical and biochemical fractionation

Gérard J. Martin; Maryvonne L. Martin

2003-01-01

180

Horizontal and vertical disparity, eye position, and stereoscopic slant perception.  

PubMed

The slant of a stereoscopically defined surface cannot be determined solely from horizontal disparities or from derived quantities such as horizontal size ratio (HSR). There are four other signals that, in combination with horizontal disparity, could in principle allow an unambiguous estimate of slant: the vergence and version of the eyes, the vertical size ratio (VSR), and the horizontal gradient of VSR. Another useful signal is provided by perspective slant cues. The determination of perceived slant can be modeled as a weighted combination of three estimates based on those signals: a perspective estimate, a stereoscopic estimate based on HSR and VSR, and a stereoscopic estimate based on HSR and sensed eye position. In a series of experiments, we examined human observers' use of the two stereoscopic means of estimation. Perspective cues were rendered uninformative. We found that VSR and sensed eye position are both used to interpret the measured horizontal disparities. When the two are placed in conflict, the visual system usually gives more weight to VSR. However, when VSR is made difficult to measure by using short stimuli or stimuli composed of vertical lines, the visual system relies on sensed eye position. A model in which the observer's slant estimate is a weighted average of the slant estimate based on HSR and VSR and the one based on HSR and eye position accounted well for the data. The weights varied across viewing conditions because the informativeness of the signals they employ vary from one situation to another. PMID:10343832

Backus, B T; Banks, M S; van Ee, R; Crowell, J A

1999-03-01

181

Emission Ratios from SCIAMACHY simultaneous measurements  

NASA Astrophysics Data System (ADS)

The spectra of reflected and backscattered solar radiation as measured by SCIAMACHY in nadir observation mode in the UV/visible/near-infrared/short-wave-infrared spectral region contain information on the vertical columns of numerous air pollutants and therefore provide a large-scale perspective on spacious and uncertain pollution sources like biomass burnings. It will be shown that under a number of reasonable assumptions we can obtain a quantitative charac-teristics of biomass burning emissions in terms of emission ratios (ER) using only the averages of the atmospheric gas columns retrieved from the space-based simultaneous measurements. Considering for example the SCIAMACHY carbon monoxide (CO), taken as a reference car-bon component, together with the SCIAMACHY formaldehyde (HCHO) and nitrogen dioxide (NO2) columns in the scope of a well established emission quantification method we calcu-late the emission ratios, CO/HCHO and CO/NO2, over large biomass burning events in 2004 (established with the help of the AATSR fire counts product). We show that the calculated ER values are in reasonable agreement with the values obtained locally over similar biomass burning events reported in the literature. In addition, we discuss the relatively large values over the boreal forest fires in Alaska and Siberia, where ER values from local measurements were not yet reported.

Khlystova, Iryna; Richter, Andreas; Wittrock, Folkard; Burrows, John P.; Buchwitz, Michael; Bovensmann, Heinrich

182

Composite resonator vertical cavity laser diode  

SciTech Connect

The use of two coupled laser cavities has been employed in edge emitting semiconductor lasers for mode suppression and frequency stabilization. The incorporation of coupled resonators within a vertical cavity laser opens up new possibilities due to the unique ability to tailor the interaction between the cavities. Composite resonators can be utilized to control spectral and temporal properties within the laser; previous studies of coupled cavity vertical cavity lasers have employed photopumped structures. The authors report the first composite resonator vertical cavity laser diode consisting of two optical cavities and three monolithic distributed Bragg reflectors. Cavity coupling effects and two techniques for external modulation of the laser are described.

Choquette, K.D.; Hou, H.Q.; Chow, W.W.; Geib, K.M.; Hammons, B.E.

1998-05-01

183

CRISTA-NF measurements with unprecedented vertical resolution made during the RECONCILE aircraft campaign  

NASA Astrophysics Data System (ADS)

The Cryogenic Infrared Spectrometers and Telescope for the Atmosphere - New Frontiers (CRISTA-NF), an airborne infrared limb-sounder, was operated aboard the high-flying Russian research aircraft M55-Geophysica during the Arctic RECONCILE campaign from January to March 2011. This poster describes the calibration process of the instrument and the employed retrieval algorithm and then proceeds to present retrieved trace gas mixing ratio cross-sections for one specific flight of this campaign. We are able to resolve the uppermost troposphere / lower stratosphere for several trace gas species for several kilometres below the flight altitude (16 to 19km) with an unprecedented vertical resolution of 400 to 500m for the limb-sounding technique. The observations are also characterised by a rather high horizontal sampling along the flight track that provides a full vertical profile every ?15km. Assembling the vertical trace gas profiles derived from CRISTA-NF measurements to cross-sections depicts filaments of vortex and extra-vortex air masses in the vicinity of the polar vortex. By using horizontal regularisation, the vertical resolution of the retrieved volume mixing ratios could be improved even further, especially for trace gases with a low signal-to-noise ratio. During this campaign, the M55-Geophysica carried further instruments, which allows for a validation of trace gas mixing ratios derived from CRISTA-NF against measurements by the in situ instruments HAGAR and FOZAN and observations by MIPAS-STR. This validation sug- gests that the retrieved trace gas mixing ratios are both qualitatively and quantitatively reliable. The derived dataset allows the observation of several filaments of air with a very small vertical extent in the order of 500m to 1km in the lower stratosphere. These filaments stem from different sources and can be exploited to examine mixing processes in the lower stratosphere.

Ungermann, J.; Guggenmoser, T.; Kalicinsky, C.; Riese, M.

2012-04-01

184

The Vertical Distribution of Dust in the Martian Atmosphere: The Haze in the Clear Season and the Haze After the Storm  

Microsoft Academic Search

Observations by the Mars Climate Sounder (MCS) over the last two martian years have permitted the creation of pressure-pegged retrievals of temperature, dust opacity, and water ice opacity at a vertical resolution of approximately 5 km. These retrievals provide information about the vertical distribution of dust and water ice over a wide dynamic range of mass mixing ratio and\\/or aerosol

N. G. Heavens; M. I. Richardson; A. Kleinboehl; D. Kass; D. J. McCleese

2010-01-01

185

Terrestrial refraction and vertical temperature gradient  

NASA Astrophysics Data System (ADS)

An assessment of the techniques and accuracy of current observations of coefficient of terrestrial refraction, including its diurnal and seasonal variations, is presented. One methodology has employed 1924 measurements of vertical angles between two geodetic stations with either one-way or line refraction techniques. The stations were 15 km apart and at heights of 177 and 361 m. Additional data has been gathered from adjustments of trigonometric leveling traverses with vertical angle capability, using stations 4 km apart. Another network featured lines of 4-23 km, with measurements repeated 12-60 hours sequentially. Mention is also given to measuring light attenuation and evaluation of the vertical refraction angle from the variance of the angle of arrival fluctuations. Formulas for modeling the vertical temperature gradient are discussed.

Mavridis, L. N.

186

Development of a Vertical Flash Evaporator.  

National Technical Information Service (NTIS)

Various process cycles for the conventional horizontal flash evaporator are discussed along with the flow characteristics of vertical risers. Other topics discussed include the experimental determination of the process properties of a flash-down stage, ma...

D. G. Klaren

1975-01-01

187

Vertical Profiles of Horizontal Ocean Currents.  

National Technical Information Service (NTIS)

Data collected from moored current meters at a single site (Site D) in the western North Atlantic are used to define vertical profiles of steady and time-dependent horizontal ocean currents. The mean velocity profile shows currents systematically flowing ...

F. Webster

1968-01-01

188

Calculation of the Radar Vertical Coverage Diagram.  

National Technical Information Service (NTIS)

Algorithms are described for the calculation and plotting of radar vertical coverage diagrams. Two contour VCD algorithms are presented, with a brief discussion on the problem of numerical stability, and the effects of ship motion and frequency agility. (...

M. R. Battaglia

1984-01-01

189

Engineering high-performance vertical cavity lasers.  

National Technical Information Service (NTIS)

The cw and high-speed performance of vertical cavity surface emitting laser diodes (VCSELs) are affected by both electrical and optical issues arising from the geometry and fabrication of these devices. Structures with low resistance semiconductor mirrors...

K. L. Lear H. Q. Hou V. M. Hietala K. D. Choquette R. P. Schneider

1996-01-01

190

Foundation Precompression with Vertical Sand Drains.  

National Technical Information Service (NTIS)

The precompression technique combined with vertical sand drains is often applicable where structure loads are reasonably uniform and do not include heavy concentrated loadings and where earth fills for highways do not exceed 40 to 50 ft, although this lim...

S. J. Johnson

1969-01-01

191

Handicapped and Elderly Vertical Movement Assessment Study.  

National Technical Information Service (NTIS)

The report discusses the selection and assessment of seven (7) types of vertical movement devices for potential use in older types of fixed rail urban mass transit facilities. The potential utilization of these devices is directed towards an increased usa...

R. Kangas R. Mann D. Glater C. Cofield J. Bottari

1976-01-01

192

Vertically stabilized elongated cross-section tokamak  

DOEpatents

This invention provides a vertically stabilized, non-circular (minor) cross-section, toroidal plasma column characterized by an external separatrix. To this end, a specific poloidal coil means is added outside a toroidal plasma column containing an endless plasma current in a tokamak to produce a rectangular cross-section plasma column along the equilibrium axis of the plasma column. By elongating the spacing between the poloidal coil means the plasma cross-section is vertically elongated, while maintaining vertical stability, efficiently to increase the poloidal flux in linear proportion to the plasma cross-section height to achieve a much greater plasma volume than could be achieved with the heretofore known round cross-section plasma columns. Also, vertical stability is enhanced over an elliptical cross-section plasma column, and poloidal magnetic divertors are achieved.

Sheffield, George V. (Hopewell, NJ)

1977-01-01

193

Evaluation of vertical permeability anisotropy in fractured reservoirs  

SciTech Connect

In fractured reservoir flow simulations, the vertical permeability anisotropy ratio (Kv/Kh) is one of the most poorly defined input parameters. In the best cases, this ratio is obtained from well-test interpretation with partial penetration models. More generally, it is considered as a parameter that can be varied to allow matching of actual data in flow simulations. However it is obtained, extrapolation of the anisotropy ratio away from the well is difficult due to the lack of geological basis in its estimation. A more rigorous association with the fracture descriptions and structural controls is clearly required. This study presents a new approach based on stochastic fracture generation (Boolean technique) combined with upscaling techniques to calculate permeability tensors at different scales. Several geological cases are tested ([open quotes]homogeneous[close quotes] or layered reservoir) as well as the influence of many parameters: fracture form index, fracture width, and matrix permeability. For each case, the influence of fracture density is evaluated; typical curves, anisotropy ratios vs. density of fractures, are obtained, whose general form is the same, thereby allowing comparisons to be made.

Massonnat, G.J. (Elf Aquitaine, Pau (France)); Manisse, E. (Institut Physique du Globe, Strasbourg (France))

1994-07-01

194

Long vertical shaft bioreactor of simplified design  

SciTech Connect

An improved long vertical shaft bioreactor for the treatment of degradable waste is provided wherein the head tank or basin surmounting the vertical downcomer and riser chambers is surrounded by a foam oxidation vessel. Conduits are provided between the head tank and the foam vessel through which (A) foam accumulated in the head tank is passed to the foam vessel and (B) through which excess fluid in the head tank may be vented.

Pollock, D.C.

1981-06-09

195

Vertical paxos and primary-backup replication  

Microsoft Academic Search

We introduce a class of Paxos algorithms called Vertical Paxos, in which reconguration can occur in the middle of reaching agreement on an individual state-machine command. Vertical Paxos algorithms use an auxiliary conguration master that facilitates agreement on recong- uration. A special case of these algorithms leads to traditional primary-backup protocols. We show how primary-backup systems in current use can

Leslie Lamport; Dahlia Malkhi; Lidong Zhou

2009-01-01

196

Consumer Responses to Vertical Service Line Extensions  

Microsoft Academic Search

Vertical line extensions extend an established brand to products at different price\\/quality points. In this study, we examine consumer evaluations of vertical service line extensions and the feedback effects of these extensions on the parent brand. Findings of two empirical studies in the hotel industry indicate that consumers perceive higher risks in step-up extensions than in step-down extensions, which consequently

Jing Lei; Ko de Ruyter; Martin Wetzels

2008-01-01

197

Burning Behavior of Vertical Matchstick Arrays  

Microsoft Academic Search

Vertical arrays of horizontally protruding wood matchsticks, 0.25 cm in diameter and 1.91 cm long, arranged from one to five matches across were used to investigate the influence of the spacing of discrete fuel elements on rates of upward flame spread. Vertical spacing's between the matchsticks in the array (0.0, 0.6, 0.8, 1.0, 1.2, and 1.4 cm) were used to reveal the influence

Michael J. Gollner; Yanxuan Xie; Minkyu Lee; Yuji Nakamura; Ali S. Rangwala

2012-01-01

198

Soybean–chickpea rotation on Vertic Inceptisols  

Microsoft Academic Search

Vertic Inceptisols are prone to land degradation because of excessive run-off and soil erosion during the rainy season. Productivity of soybean-based systems on these soils needs to be improved and sustained by better management of natural resources, particularly soil and water. During 1995–1997 a field study was conducted in Peninsular India on a Vertic Inceptisol watershed to study the effect

Piara Singh; G. Alagarswamy; P. Pathak; S. P. Wani; G. Hoogenboom; S. M. Virmani

1999-01-01

199

Tropical cyclone energy dispersion under vertical shears  

Microsoft Academic Search

Tropical cyclone Rossby wave energy dispersion under easterly and westerly vertical shears is investigated in a baroclinic model. In a resting environment, the model simulates a Rossby wave train that has a baroclinic structure with alternating cyclonic-anticyclonic-cyclonic (anticyclonic-cyclonic-anticyclonic) circulations in the lower (upper) troposphere. A significant asymmetry appears in the wave train development under easterly and westerly vertical shears, that

Xuyang Ge; Tim Li; Xiaqiong Zhou

2007-01-01

200

Vertical sounding balloons for long duration flights  

NASA Astrophysics Data System (ADS)

Vertical soundings in the lower stratosphere are possible on command with an Infrared Montgolfiere, between 16 km and 28 km. Results of simulations are presented. The first test flight of a 7800 cu m Montgolfiere with a relief valve, has been conducted in Arctic area (Spitzbergen, July 1992). The flight of an Infrared Montgolfiere, with full vertical sounding capabilities, is planned for the end of 1993, from Ecuador (South AMERICA).

Malaterre, P.

1994-02-01

201

Vertical sounding balloons for long duration flights  

NASA Astrophysics Data System (ADS)

Vertical soundings in the lower stratosphere are possible on command with an Infrared Montgolfiere, between 16 km and 28 km. Results of simulations are presented. The first test flight of a 7800 m3 Montgolfiere with a relief valve, has been conducted in Arctic area (Spitzbergen, July 1992). The flight of an Infrared Montgolfiere, with full vertical sounding capabilities, is planned for the end of 1993, from Ecuador (South AMERICA).

Malaterre, P.

1994-02-01

202

Vertical transfer coefficient in natural streams  

Microsoft Academic Search

Turbulent vertical transfer in natural open and under-ice channel flows is considered. Methods for the assessment of turbulent\\u000a viscosity in the core and shift layers of under-ice flow are proposed and checked. A method is developed for the calculation\\u000a of the vertical distribution of turbulent exchange coefficient in an underice flow given the mean flow characteristics.

E. N. Dolgopolova

2008-01-01

203

Vertical Integration in the Japanese Movie Industry  

Microsoft Academic Search

This study examines vertical integration in the Japanese movie industry. I estimate an admission price equation, and a moviegoing\\u000a demand equation derived from a discrete choice model of product differentiation. In order to overcome identification problems,\\u000a this study exploits a panel structure dataset. My results show that the price of vertically integrated theaters tends to be\\u000a higher than nonintegrated theaters,

Mitsuru Sunada

2010-01-01

204

Vertically stacked multi-heterostructures of layered materials for logic transistors and complementary inverters.  

PubMed

Graphene has attracted considerable interest for future electronics, but the absence of a bandgap limits its direct applicability in transistors and logic devices. Recently, other layered materials such as molybdenum disulphide (MoS(2)) have been investigated to address this challenge. Here, we report the vertical integration of multi-heterostructures of layered materials for the fabrication of a new generation of vertical field-effect transistors (VFETs) with a room temperature on-off ratio > 10(3) and a high current density of up to 5,000 A cm(-2). An n-channel VFET is created by sandwiching few-layer MoS(2) as the semiconducting channel between a monolayer graphene sheet and a metal thin film. This approach offers a general strategy for the vertical integration of p- and n-channel transistors for high-performance logic applications. As an example, we demonstrate a complementary inverter with a larger-than-unity voltage gain by vertically stacking graphene, Bi(2)Sr(2)Co(2)O(8) (p-channel), graphene, MoS(2) (n-channel) and a metal thin film in sequence. The ability to simultaneously achieve a high on-off ratio, a high current density and a logic function in such vertically stacked multi-heterostructures can open up possibilities for three-dimensional integration in future electronics. PMID:23241535

Yu, Woo Jong; Li, Zheng; Zhou, Hailong; Chen, Yu; Wang, Yang; Huang, Yu; Duan, Xiangfeng

2012-12-16

205

Selective Growth of Vertically Aligned Single, Double, and Triple-Walled Carbon Nanotubes by Radiation-Heated Chemical Vapor Deposition  

Microsoft Academic Search

The synthesis of vertically aligned single-walled carbon nanotube (SWCNT), double-walled carbon nanotube (DWCNT), and triple-walled carbon nanotube (TWCNT) films has been achieved by a combination of radiation-heated chemical vapor deposition (RHCVD) and long-throw sputtering. The proportions of specific walled CNTs\\/as-grown CNTs are as follows: SWCNT\\/CNT ratio of 87%, DWCNT\\/CNT ratio of 83%, and TWCNT\\/CNT ratio of 62%. When the population

Yusuke Taki; Makiko Kikuchi; Kiyoaki Shinohara; Akira Tanaka

2008-01-01

206

Analysis of a vertical compliance prosthetic foot.  

PubMed

Mechanical testing of the Re-Flex VSP Foot was conducted on the pylon alone and on the pylon and forefoot system. Values for spring and damping correspond well to values reported in the literature for spring and damping of physiological limbs. Pylon stiffness was 49.4 kN/m for a 600 N subject and 91.4 kN/m for an 800 N subject. The vertical stiffness of the pylon and forefoot together was 31.9 kN/m and 37.8 kN/m, respectively. Gait parameters of two persons with transtibial amputation who used vertically compliant feet for walking, jogging in place, and curb descent were investigated. Ground reaction forces, vertical trunk movement, event timing, and pylon compression were observed. The spring-loaded telescoping pylon was immobilized for half the trials. The trials were repeated the following week with the vertical compliance feature mobilized. Significant differences in vertical trunk motion and timing were found between the prosthetic limb and normal limb, as might be expected. Vertical compliance appeared to cause little change in gait parameters during normal walking. The largest differences appeared during the higher impact events such as fast walking and jogging in place. PMID:9021625

Miller, L A; Childress, D S

1997-01-01

207

Horizontal Cross Bracing Detail, Vertical Cross Bracing Detail, Horizontal Cross ...  

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

Horizontal Cross Bracing Detail, Vertical Cross Bracing Detail, Horizontal Cross Bracing Detail, Vertical Cross Bracing-End Detail - Cumberland Covered Bridge, Spanning Mississinewa River, Matthews, Grant County, IN

208

Vertical resolution study on the GOES-R Hyperspectral Environmental Suite (HES)  

NASA Astrophysics Data System (ADS)

High spectral resolution infrared radiances from the Hyperspectral Environmental Suite (HES) on Geostationary Operational Environmental Satellite (GOES-R and beyond) will allow for monitoring the evolution of atmospheric temperature and moisture vertical distributions. HES, together with the Advanced Baseline Imager (ABI), will operationally provide enhanced spatial, temporal and vertical information for radiances and atmospheric soundings that are desired by numerical weather forecast models. An algorithm has been developed to analyze the retrieval error and the vertical resolution of soundings from HES radiances. Trade-off studies have been done to balance the spectral coverage, spectral resolution, and signal-to-noise ratio in order to achieve the GOES users' requirement of 1 K accuracy with 1km vertical resolution for temperature and 10% accuracy with 2km vertical resolution for relative humidity. The vertical resolution capability of HES is also compared with that of the current GOES Sounder which has 18 infrared spectral channels and the Advanced Microwave Sounding Unit (AMSU) on the NOAA polar orbiting satellites that has good temperature sensitivity in the lower stratosphere and upper troposphere. The advantage of combination of GOES sounder and AMSU is also investigated.

Li, Jun; Wang, Fang; Schmit, Timothy J.; Menzel, W. Paul; Gurka, James J.

2005-01-01

209

Determination of the operation range of a vertical two-phase closed thermosyphon  

NASA Astrophysics Data System (ADS)

A comprehensive model, proposed for a vertical two-phase closed thermosyphon (TPCT) by the present authors, is further developed by utilizing the criteria for dryout, flooding and boiling limits to investigate the effects of filling ratio on them together, while the available models can just consider one or two limits of them. A new concept named dryout ratio is proposed, which can be used for predicting dryout limit. The empirical correlation and the empirical value, provided by other researchers, are used for predicting flooding and boiling limit, respectively. The experiments with nitrogen as working fluid are performed, and compared with the calculations. The maximum filling ratio is introduced, beyond which the liquid could be carried to condenser and the heat transfer performance can be deteriorated. And then the closed operation range of a vertical TPCT is finally determined, which has not been reported before. The effects of operating pressure and geometries on the range are also analyzed.

Jiao, B.; Qiu, L. M.; Gan, Z. H.; Zhang, X. B.

2012-06-01

210

[Dynamics model analysis of pollutants removal in aerated vertical-flow wetland].  

PubMed

Based on the dynamic model building of pollutants removal in aerated vertical-flow constructed wetland, data of the wetland under different aeration conditions were analysed. Different aeration conditions' k values were calculated, which represented the pollutants removal kinetic constants. The results demonstrate that the efficiency of pollutants removal is higher with the increasing gas-water ratio. The most favorable designing gas-water ratio of the aerated vertical-flow constructed wetland was chosen as 2 : 1 through analysis of curve fits by regression with kinetic constants values and gas-water ratio values. The corresponding k values of BOD5 and NH4(+) -N are 3.8 d(-1) and 4.1 d(-1) respectively. PMID:21250444

Pan, Ji-Zheng; Ke, Fan; Li, Wen-Chao

2010-11-01

211

Air/fuel ratio controller  

SciTech Connect

An internal combustion engine has a fuel injection pump and an air/fuel ratio controller. The controller has a lever that is connected to the pump lever. An aneroid moves the controller lever as a function of changes in intake manifold vacuum to maintain a constant air/fuel ratio to the mixture charge. A fuel enrichment linkage is provided that modifies the movement of the fuel flow control lever by the aneroid in response to changes in manifold gas temperature levels and exhaust gas recirculation to maintain the constant air/fuel ratio. A manual override is provided to obtain a richer air/fuel ratio for maximum acceleration.

Schechter, M.M.; Simko, A.O.

1980-12-23

212

Unsteady mixed convective flow and heat transfer in a vertical corrugated channel with composite porous media  

NASA Astrophysics Data System (ADS)

An unsteady mixed convective flow and heat transfer in a vertical corrugated channel containing porous and fluid layers are considered. The equations of momentum and energy are solved under appropriate boundary and interface conditions with the assumption that the solution consists of a mean part and a perturbed one. The exact solutions are obtained in the long-wave approximation. Separate solutions are matched at the interface with the use of suitable matching conditions. The effects of pertinent parameters, such as the Grashof number, viscosity ratio, width ratio, conductivity ratio, frequency, and the wave parameter on the flow field and heat transfer characteristics are studied.

Umavathi, J. C.; Shekar, M.

2013-07-01

213

Effects of Geographic Variation in Vertical Mode Structure on the Sea Surface Topography, Energy, and Wind Forcing of Baroclinic Rossby Waves  

Microsoft Academic Search

Interpretation of sea surface height anomaly (SSHA) and wind forcing of first baroclinic mode Rossby waves is considered using linear inviscid long-wave dynamics for both the standard and surface-intensified vertical mode in a continuously stratified rest-state ocean. The ratio between SSHA variance and vertically integrated energy of waves is proportional to 1) a dimensionless ratio characterizing the surface intensification of

Daniel L. Codiga; Peter Cornillon

2003-01-01

214

LETTER TO THE EDITOR: Ultrahigh-density silicon nanobridges formed between two vertical silicon surfaces  

NASA Astrophysics Data System (ADS)

We report simultaneous lateral growth of a high density of highly oriented, metal-catalyzed silicon nanowires on a patterned silicon substrate and bridging of nanowires between two vertical silicon sidewalls, which can be developed into electrodes of an electronic device. After angled deposition of catalytic metal nanoparticles on one of two opposing vertical silicon surfaces, we used a metal-catalyzed chemical vapour deposition process to grow nanowires and eventually form mechanically robust 'nanobridges'. The growth and bridging of these nanowire arrays can be integrated with existing silicon processes. This method of connecting multiple nanowires between two electrodes offers the high surface-to-volume ratio needed for nanosensor applications.

Saif Islam, M.; Sharma, S.; Kamins, T. I.; Williams, R. Stanley

2004-05-01

215

Progressive Ratio Schedules of Reinforcement  

PubMed Central

Pigeons’ pecks produced grain under progressive ratio (PR) schedules, whose response requirements increased systematically within sessions. Experiment 1 compared arithmetic (AP) and geometric (GP) progressions. Response rates increased as a function of the component ratio requirement, then decreased linearly (AP) or asymptotically (GP). Experiment 2 found the linear decrease in AP rates to be relatively independent of step size. Experiment 3 showed pausing to be controlled by the prior component length, which predicted the differences between PR and regressive ratio schedules found in Experiment 4. When the longest component ratios were signaled by different key colors, rates at moderate ratios increased, demonstrating control by forthcoming context. Models for response rate and pause duration described performance on AP schedules; GP schedules required an additional parameter representing the contextual reinforcement.

Killeen, Peter R.; Posadas-Sanchez, Diana; Johansen, Espen Borga; Thrailkill, Eric A.

2009-01-01

216

Some vertical lineaments of lip position.  

PubMed

This study was performed to elucidate quantitatively upper lip-tooth-jaw relativity in the vertical dimension. Values for five linear dentolabial measurements were generated from male (n = 42) and female (n = 46) reference samples. In addition, three vertical skeletofacial dimensions and two vertical dental dimensions were recorded. A significant sexual dimorphism was found in the vertical lip-tooth-jaw relationship: the upper lip of the female subjects was positioned on average 1.5 mm more superiorly at maximum smile than the upper lip of the male subjects (p less than 0.01). High smile lines appeared to be a female lineament, and low smile lines appeared to be a male lineament. There was a significant sex difference in upper lip length: the male subjects exhibited a longer upper lip than the female subjects (p less than 0.001). The mean difference was 2.2 mm. A similarly significant male-female difference was seen in the skeletal maxillary height measurement: the male sample showed a 2.2 mm mean vertical maxillary increase over the female sample (p less than 0.001). Furthermore, a significant difference was found between the clinical crown height of the maxillary central incisors in the male and female subjects of comparable ages: the male group had longer central incisor crowns (p less than 0.01). PMID:1598892

Peck, S; Peck, L; Kataja, M

1992-06-01

217

Motion sickness induced by off-vertical axis rotation (OVAR)  

PubMed Central

We tested the hypothesis that motion sickness is produced by an integration of the disparity between eye velocity and the yaw-axis orientation vector of velocity storage. Disparity was defined as the magnitude of the cross product between these two vectors. OVAR, which is known to produce motion sickness, generates horizontal eye velocity with a bias level related to velocity storage, as well as cyclic modulations due to re-orientation of the head re gravity. On average, the orientation vector is close to the spatial vertical. Thus, disparity can be related to the bias and tilt angle. Motion sickness sensitivity was defined as a ratio of maximum motion sickness score to the number of revolutions, allowing disparity and motion sickness sensitivity to be correlated. Nine subjects were rotated around axes tilted 10°–30° from the spatial vertical at 30°/s–120°/s. Motion sickness sensitivity increased monotonically with increases in the disparity due to changes in rotational velocity and tilt angle. Maximal motion sickness sensitivity and bias (6.8°/s) occurred when rotating at 60°/s about an axis tilted 30° Modulations in eye velocity during OVAR were unrelated to motion sickness sensitivity. The data were predicted by a model incorporating an estimate of head velocity from otolith activation, which activated velocity storage, followed by an orientation disparity comparator that activated a motion sickness integrator. These results suggest that the sensory-motor conflict that produces motion sickness involves coding of the spatial vertical by the otolith organs and body tilt receptors and processing of eye velocity through velocity storage.

Sofroniou, Sofronis; Kunin, Mikhail; Raphan, Theodore; Cohen, Bernard

2011-01-01

218

PRICE AND VERTICAL CONTROL POLICIES FOR A VERTICALLY INTEGRATED UPSTREAM MONOPOLIST WHEN SABOTAGE IS COSTLY  

Microsoft Academic Search

This paper studies welfare-optimal input pricing and vertical control policies for industries character- ized by an upstream monopolist selling to a downstream oligopoly in which the monopolist has a retail affiliate. Of particular concern is the possibility that the monopolist might favor its affiliate via nonprice discrimination. The degree of vertical control is formally introduced as a policy tool, and

David M. Mandy

219

Vertical stability, high elongation, and the consequences of loss of vertical control on DIII-D  

SciTech Connect

Recent modifications to the vertical control system for DIII-D has enabled operation of discharges with vertical elongation {kappa}, up to 2.5. When vertical stability is lost, a disruption follows and a large vertical force on the vacuum vessel is observed. The loss of plasma energy begins when the edge safety factor q is 2 but the current decay does not begin until q {approximately}1.3. Current flow on the open field lines in the plasma scrapeoff layer has been measured and the magnitude and distribution of these currents can explain the observed force on the vessel. Equilibrium calculations and simulation of this vertical displacement episode are presented. 7 refs., 4 figs.

Kellman, A.G.; Ferron, J.R.; Jensen, T.H.; Lao, L.L.; Luxon, J.L.; Skinner, D.G.; Strait, E.J.; Reis, E.; Taylor, T.S.; Turnbull, A.D. (General Atomics, San Diego, CA (USA)); Lazarus, E.A. (Oak Ridge National Lab., TN (USA)); Lister, J.B. (Centre de Recherches en Physique des Plasmas, Lausanne (Switzerland))

1990-09-01

220

Waferbonded active/passive vertically coupled microring lasers  

NASA Astrophysics Data System (ADS)

We summarize the results of a European Project entitled WAPITI (Waferbonding and Active Passive Integration Technology and Implementation) dealing with the fabrication and investigation of active/passive vertically coupled ring resonators, wafer bonded on GaAs, and based on full wafer technology. The concept allows for the integration of an active ring laser vertically coupled to a transparent bus waveguide. All necessary layers are grown in a single epitaxial run so that the critical coupling gap can be precisely controlled with the high degree of accuracy of epitaxial growth. One key challenge of the project was to establish a reliable wafer bonding technique using BCB as an intermediate layer. In intensive tests we investigated and quantified the effect of unavoidable shrinkage of the BCB on the overall device performance. Results on cw-operation, low threshold currents of about 8 mA, high side-mode suppression ratios in the range of 40 dB and large signal modulation bandwidths of up to 5 GHz for a radius of 40 ?m shows the viability of the integration process.

Hamacher, M.; Heidrich, H.; Troppenz, U.; Syvridis, D.; Alexandropoulos, D.; Mikroulis, S.; Kapsalis, A.; Tee, C. W.; Williams, K.; Dragoi, V.; Alexe, M.; Cristea, D.; Kusko, M.

2008-03-01

221

Vertical Distribution of Rotylenchulus reniformis in Cotton Fields.  

PubMed

The possible impact of Rotylenchulus reniformis below plow depth was evaluated by measuring the vertical distribution of R. reniformis and soil texture in 20 symptomatic fields on 17 farms across six states. The mean nematode population density per field, 0 to 122 cm deep, ranged from 0.4 to 63 nematodes/g soil, and in 15 fields more than half of the R. reniformis present were below 30.5 cm, which is the greatest depth usually plowed by farmers or sampled by consultants. In 11 fields measured, root density was greatest in the top 15 cm of soil; however, roots consistently penetrated 92 to 122 cm deep by midseason, and in five fields in Texas and Louisiana the ratio of nematodes to root-length density within soil increased with depth. Repeated sampling during the year in Texas indicated that up to 20% of the nematodes in soil below 60 cm in the fall survived the winter. Differences between Baermann funnel and sugar flotation extraction methods were not important when compared with field-to-field differences in nematode populations and field-specific vertical distribution patterns. The results support the interpretation that R. reniformis below plow depth can significantly impact diagnosis and treatment of cotton fields infested with R. reniformis. PMID:19262871

Robinson, A F; Akridge, R; Bradford, J M; Cook, C G; Gazaway, W S; Kirkpatrick, T L; Lawrence, G W; Lee, G; McGawley, E C; Overstreet, C; Padgett, B; Rodríguez-Kábana, R; Westphal, A; Young, L D

2005-09-01

222

Lubrication system for a vertical shaft engine  

SciTech Connect

A lubrication system is described for a vertical shaft engine comprising a crank case having an upper and a lower wall, a vertical crank shaft, a vertical balancing shaft, upper and lower bosses formed in the upper and lower walls for rotatably supporting the shafts, an oil pump housed in the lower wall, and an oil feeding passage for feeding lubricating oil from the pump to any part desired to be lubricated in the engine. The improvement comprises: the pump having a drive shaft housed under the balancing shaft, the lower end of the balancing shaft housed in one of the lower losses, the balancing shaft being rotatably supported by an antifriction bearing; and the antifriction bearing being held in an upper part of the one lower boss.

Hashigaki, Y.; Umeda, T.

1987-05-12

223

Liquid storage tanks under vertical excitation  

SciTech Connect

Until recently, the hydrodynamic effects on liquid storage tanks induced by an earthquake excitation were basically treated for the horizontal component of the earthquake. Recent studies, however, showed that the hydrodynamic effects due to the vertical component of an earthquake may be significant. In these studies the tank is assumed to be fixed at the bottom. This paper is concerned with the hydrodynamic behavior of liquid storage tanks induced by vertical earthquake input excitation. First, the fluid-tank system is treated as a fixed-base system and a simple formula is obtained for the coupled fluid-structure natural frequency. Second, additional interaction effects due to the foundation flexibility on the fluid-tank system are investigated. It is concluded that the foundation flexibility may have a significant effect on the hydrodynamic behavior of the liquid storage tanks under a vertical ground shaking.

Philippacopoulos, A.J.

1985-01-01

224

Vertical cable surveys deliver additional seismic data  

SciTech Connect

Texaco and a Norwegian seismic firm have patented a new system for deploying hydrophones on vertical cables for offshore surveys. The system was used in Texaco North Sea UK Ltd.`s Strathspey field during the summer. The new technique was introduced in the article, ``Peaceful use for war technology,`` published in Texaco UK`s Agenda monthly news magazine, October 1995. That article is summarized here. Using technology developed by the US Navy for antisubmarine warfare, the vertical-cable survey relies on hydrophones attached at regular intervals vertically along cables secured to the ocean floor and held taut by a buoy. The shooting vessel fires the airguns in a pattern over a large area on the surface, over and around the cables. The cables are then moved to a new location and the process is repeated, up to six times in the Strathspey application described here.

NONE

1995-12-01

225

Purification process for vertically aligned carbon nanofibers.  

PubMed

Individual, free-standing, vertically aligned multiwall carbon nanotubes or nanofibers are ideal for sensor and electrode applications. Our plasma-enhanced chemical vapor deposition techniques for producing free-standing and vertically aligned carbon nanofibers use catalyst particles at the tip of the fiber. Here we present a simple purification process for the removal of iron catalyst particles at the tip of vertically aligned carbon nanofibers derived by plasma-enhanced chemical vapor deposition. The first step involves thermal oxidation in air, at temperatures of 200-400 degrees C, resulting in the physical swelling of the iron particles from the formation of iron oxide. Subsequently, the complete removal of the iron oxide particles is achieved with diluted acid (12% HCl). The purification process appears to be very efficient at removing all of the iron catalyst particles. Electron microscopy images and Raman spectroscopy data indicate that the purification process does not damage the graphitic structure of the nanotubes. PMID:12908239

Nguyen, Cattien V; Delziet, Lance; Matthews, Kristopher; Chen, Bin; Meyyappan, M

226

Vertical wind turbine power generating tower  

SciTech Connect

The tower comprises a base supported on a framework which mounts a wind powered turbine having a vertical axis of rotation. Air is channeled to the turbine rotor to cause counterclockwise rotation thereof by upper and lower wind deflectors. The wind deflectors include channels which cause the oncoming air to swirl in a counterclockwise motion into the rotor transmitting energy thereto. The vertical struts of the framework are also configured so as to deflect the oncoming air into the rotor in a counterclockwise direction. The rotor itself comprises columns of vertically spaced, radially extending scoops and radially extending curved blades to ensure highly efficient energy conversion. The rotor is formed with no center shaft to allow free flow of air therethrough.

Retz, P.

1982-12-28

227

Vertical vibration analysis for elevator compensating sheave  

NASA Astrophysics Data System (ADS)

Most elevators applied to tall buildings include compensating ropes to satisfy the balanced rope tension between the car and the counter weight. The compensating ropes receive tension by the compensating sheave, which is installed at the bottom space of the elevator shaft. The compensating sheave is only suspended by the compensating ropes, therefore, the sheave can move vertically while the car is traveling. This paper shows the elevator dynamic model to evaluate the vertical motion of the compensating sheave. Especially, behavior in emergency cases, such as brake activation and buffer strike, was investigated to evaluate the maximum upward motion of the sheave. The simulation results were validated by experiments and the most influenced factor for the sheave vertical motion was clarified.

Watanabe, Seiji; Okawa, Takeya; Nakazawa, Daisuke; Fukui, Daiki

2013-07-01

228

Vertical profiles of nitrous acid in the nocturnal urban atmosphere of Houston, TX  

NASA Astrophysics Data System (ADS)

Nitrous acid (HONO) often plays an important role in tropospheric photochemistry as a major precursor of the hydroxyl radical (OH) in early morning hours and potentially during the day. However, the processes leading to formation of HONO and its vertical distribution at night, which can have a considerable impact on daytime ozone formation, are currently poorly characterized by observations and models. Long-path differential optical absorption spectroscopy (LP-DOAS) measurements of HONO during the 2006 TexAQS II Radical and Aerosol Measurement Project (TRAMP), near downtown Houston, TX, show nocturnal vertical profiles of HONO, with mixing ratios of up to 2.2 ppb near the surface and below 100 ppt aloft. Three nighttime periods of HONO, NO2 and O3 observations during TRAMP were used to perform model simulations of vertical mixing ratio profiles. By adjusting vertical mixing and NOx emissions the modeled NO2 and O3 mixing ratios showed very good agreement with the observations. Using a simple conversion of NO2 to HONO on the ground, direct HONO emissions, as well as HONO loss at the ground and on aerosol, the observed HONO profiles were reproduced well by the model. The unobserved increase of HONO to NO2 ratio (HONO/NO2) with altitude that was simulated by the initial model runs was found to be due to HONO uptake being too small on aerosol and too large on the ground. Refined model runs, with adjusted HONO uptake coefficients, showed much better agreement of HONO and HONO/NO2 for two typical nights, except during morning rush hour, when other HONO formation pathways are most likely active. One of the nights analyzed showed increase of HONO mixing ratios together with decreasing NO2 mixing ratios that the model was unable to reproduce, most likely due to the impact of weak precipitation during this night. HONO formation and removal rates averaged over the lowest 300 m of the atmosphere showed that NO2 to HONO conversion on the ground was the dominant source of HONO, followed by traffic emission. Aerosol did not play an important role in HONO formation. Although ground deposition was also a major removal pathway of HONO, net HONO production at the ground was the main source of HONO in our model studies. Sensitivity studies showed that in the stable NBL, net HONO production at the ground tends to increase with faster vertical mixing and stronger emission. Vertical transport was found to be the dominant source of HONO aloft.

Wong, K. W.; Oh, H.-J.; Lefer, B.; Rappenglück, B.; Stutz, J.

2010-12-01

229

Vertical profiles of nitrous acid in the nocturnal urban atmosphere of Houston, TX  

NASA Astrophysics Data System (ADS)

Nitrous acid (HONO) often plays an important role in tropospheric photochemistry as a major precursor of the hydroxyl radical (OH) in early morning hours and potentially during the day. However, the processes leading to formation of HONO and its vertical distribution at night, which can have a considerable impact on daytime ozone formation, are currently poorly characterized by observations and models. Long-path differential optical absorption spectroscopy (LP-DOAS) measurements of HONO during the 2006 TexAQS II Radical and Aerosol Measurement Project (TRAMP), near downtown Houston, TX, show nocturnal vertical profiles of HONO, with mixing ratios of up to 2.2 ppb near the surface and below 100 ppt aloft. Three nighttime periods of HONO, NO2 and O3 observations during TRAMP were used to perform model simulations of vertical mixing ratio profiles. By adjusting vertical mixing and NOx emissions the modeled NO2 and O3 mixing ratios showed very good agreement with the observations. Using a simple conversion of NO2 to HONO on the ground, direct HONO emissions, as well as HONO loss at the ground and on aerosol, the observed HONO profiles were reproduced by the model for 1-2 and 7-8 September in the nocturnal boundary layer (NBL). The unobserved increase of HONO to NO2 ratio (HONO/NO2) with altitude that was simulated by the initial model runs was found to be due to HONO uptake being too small on aerosol and too large on the ground. Refined model runs, with adjusted HONO uptake coefficients, showed much better agreement of HONO and HONO/NO2 for two typical nights, except during morning rush hour, when other HONO formation pathways are most likely active. One of the nights analyzed showed an increase of HONO mixing ratios together with decreasing NO2 mixing ratios that the model was unable to reproduce, most likely due to the impact of weak precipitation during this night. HONO formation and removal rates averaged over the lowest 300 m of the atmosphere showed that NO2 to HONO conversion on the ground was the dominant source of HONO, followed by traffic emission. Aerosol did not play an important role in HONO formation. Although ground deposition was also a major removal pathway of HONO, net HONO production at the ground was the main source of HONO in our model studies. Sensitivity studies showed that in the stable NBL, net HONO production at the ground tends to increase with faster vertical mixing and stronger NOx emission. Vertical transport was found to be the dominant source of HONO aloft.

Wong, K. W.; Oh, H.-J.; Lefer, B. L.; Rappenglück, B.; Stutz, J.

2011-04-01

230

Vortex Formation in Vertically Stratified Protoplanetary Disks  

NASA Astrophysics Data System (ADS)

A central problem of planet formation is how to form large planetesimals in a turbulent protoplanetary disk. Recent work suggests that MRI turbulence would excite such large velocities that the planetesimals would collisionally fragment rather than grow. The structure of chondritic meteorites indicates a gentle nebular environment where chondrules are sorted by size and cemented together rapidly. Although it is well established that anticyclones can concentrate particles that are weakly coupled to the gas in protoplanetary disks, the conditions required for the formation and long-time stability of anticyclones in a vertically stratified disk are still highly uncertain. Fully three dimensional fluid dynamic simulations of protoplanetary disks are computationally expensive when one requires a computational domain that is large compared to the vertical scale height of the disk. An alternative simulation approach is to use potential temperature as the vertical coordinate so that the equations of motion resemble the shallow water equations (Dowling et al. 1998). We have therefore modified a multilayer shallow water simulation code to model the formation of vortices in a vertically stratified protoplanetary disk with a radial entropy gradient. Vertical stratification of the disk is modeled by using multiple layers, where each layer has a different constant value of the entropy. By forcing a slope in the interfaces between the layers, we impose a radial entropy gradient in the disk. Radiative heating and cooling causes vertical mass exchange between adjacent constant entropy layers according to a Newton cooling formula. We find that the formation of anticyclones is robust, and that these vortices actively excite density waves, which in turn, transport angular momentum through the disk. Our simulations therefore yield new insights on how the dusty dead zones of protoplanetary disks can transport angular momentum through the disk by purely hydrodynamic processes. Support from NASA’s Origins of Solar Systems program is gratefully acknowledged.

Stewart, Glen R.

2013-10-01

231

The fluid mechanics of a high aspect ratio slot with an impressed pressure gradient and secondary injection  

Microsoft Academic Search

A high aspect ratio slot flow (which emulates the gas leakage path in a gas turbine engine outer turbine air seal) is studied by use of a high aspect ratio slot using water as the working fluid. The cross section of the geometry is similar to a 'T', the slot being the vertical stroke and the main flow being the

John Bertram Sobanik

1993-01-01

232

Transport of magnetic flux and the vertical structure of accretion discs - II. Vertical profile of the diffusion coefficients  

NASA Astrophysics Data System (ADS)

We investigate the radial transport of magnetic flux in a thin accretion disc, the turbulence being modelled by effective diffusion coefficients (viscosity and resistivity). Both turbulent diffusion and advection by the accretion flow contribute to flux transport, and they are likely to act in opposition. We study the consequences of the vertical variation of the diffusion coefficients, due to a varying strength of the turbulence. For this purpose, we consider three different vertical profiles of these coefficients. The first one is aimed at mimicking the turbulent stress profile observed in numerical simulations of magnetohydrodynamic turbulence in stratified discs. This enables us to confirm the robustness of the main result of Paper I obtained for uniform diffusion coefficients that, for weak magnetic fields, the contribution of the accretion flow to the transport velocity of magnetic flux is much larger than the transport velocity of mass. We then consider the presence of a dead zone around the equatorial plane where the physical resistivity is high while the turbulent viscosity is low. We find that it amplifies the previous effect: weak magnetic fields can be advected orders of magnitude faster than mass, for dead zones with a large vertical extension. The ratio of advection to diffusion, determining the maximum inclination of the field at the surface of the disc, is however not much affected. Finally, we study the effect of a non-turbulent layer at the surface of the disc, which has been suggested as a way to reduce the diffusion of the magnetic flux. We find that the reduction of the diffusion requires the conducting layer to extend below the height at which the magnetic pressure equals the thermal pressure. As a consequence, if the absence of turbulence is caused by the large-scale magnetic field, the highly conducting layer is inefficient at reducing the diffusion.

Guilet, Jérôme; Ogilvie, Gordon I.

2013-04-01

233

Vertically aligned carbon nanofiber electrode arrays for nucleic acid detection  

NASA Astrophysics Data System (ADS)

We present electrochemical detection of DNA targets that corresponds to Escherichia coli O157:H7 16S rRNA gene using a nanoelectrode array consisting of vertically aligned carbon nanofiber (VACNF) electrodes. Parylene C is used as gap filling 'matrix' material to avoid high temperature processing in electrode construction. This easy to deposit film of several micron heights provides a conformal coating between the high aspect ratio VACNFs with negligible pin-holes. The low background currents show the potential of this approach for ultra-sensitive detection. Consistent and reproducible electrochemical-signals are achieved using a simple electrode preparation. This simple, reliable and low-cost approach is a forward step in developing practical sensors for applications like pathogen detection, early cancer diagnosis and environmental monitoring.

Arumugam, Prabhu U.; Yu, Edmond; Riviere, Roger; Meyyappan, M.

2010-10-01

234

Jamming of Cylindrical Grains in Featureless Vertical Channels  

NASA Astrophysics Data System (ADS)

We study jamming of low aspect-ratio cylindrical Delrin grains falling through a featureless vertical channel. With a grain height less than the grain diameter, these grains resemble aspirin tablets, poker chips, or coins. Unidisperse grains are allowed to fall under the influence of gravity through a uniform channel of square cross-section where the channel width is greater than the grain size and constant along the length of the channel. Channel widths are chosen so that no combination of grain heights and diameters is equal to the channel width. Collections of grains sometimes form jams, stable structures in which the grains are supported by the channel walls and not by grains or walls beneath them. The probability of a jam occurring and the jam's strength are influenced by the grain dimensions and channel width. We will present experimental measurements of the jamming probability and jam strength and discuss the relationship of these results to other experiments and theories.

Baxter, G. William; Barr, Nicholas; Weible, Seth; Friedl, Nicholas

2013-03-01

235

Single transverse mode selectively oxidized vertical cavity lasers  

SciTech Connect

Vertical cavity surface emitting lasers (VCSELs) which operate in multiple transverse optical modes have been rapidly adopted into present data communication applications which rely on multi-mode optical fiber. However, operation only in the fundamental mode is required for free space interconnects and numerous other emerging VCSEL applications. Two device design strategies for obtaining single mode lasing in VCSELs based on mode selective loss or mode selective gain are reviewed and compared. Mode discrimination is attained with the use of a thick tapered oxide aperture positioned at a longitudinal field null. Mode selective gain is achieved by defining a gain aperture within the VCSEL active region to preferentially support the fundamental mode. VCSELs which exhibit greater than 3 mW of single mode output power at 850 nm with mode suppression ratio greater than 30 dB are reported.

CHOQUETTE,KENT D.; GEIB,KENT M.; BRIGGS,RONALD D.; ALLERMAN,ANDREW A.; HINDI,JANA JO

2000-04-26

236

Control of dynamic stall phenomenon for vertical axis wind turbine  

NASA Astrophysics Data System (ADS)

In the last years the wind turbine with vertical axis (VAWT) began to be more attractive due benefits in exploitation, the power range covering usually the domain 2 kW-20 kW. But, VAWTs suffer from many complicated aerodynamically problems, of which dynamic stall is an inherent phenomenon when they are operating at low values of tip speed ratio (TSR < 4), and this has a significant impact on vibration, noise, and power output of the VAWTs. For this reason, in the present work we perform a computational investigation of a two-dimensional dynamic stall phenomenon around a NACA0012 airfoil in oscillating motion at relative low Reynolds number (~105). The unsteady flow is investigated numerically using RANS approach with two turbulence models (k-? SST and transition SST). The same analysis was performed to evaluate three flow control methods: two passive and one active.

Frunzulic?, Florin; Dumitrescu, Horia; Dumitrache, Alexandru; Suatean, Bogdan

2013-10-01

237

Fundamental and effective Yang-Mills vertices  

SciTech Connect

Calorons and plane waves within and in between them collectively give rise to a thermal ground state. The latter provides a homgeneous energy density and a negative pressure, and it induces quasiparticle masses to part of the propagating spectrum of deconfining SU(2) Yang-Mills thermodynamics (dynamical gauge-symmetry breaking). In the present talk we discuss the role of a single caloron in inducing effective local vertices, characterized by powers of h, mediating the interaction of plane waves which propagate over large distances. The constraints on momentum transfers through effective 4-vertices are revisited.

Hofmann, Ralf [ITP, Universitaet Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany)

2012-09-26

238

Sediment Vertical Flux in Unsteady Sheet Flows  

NASA Astrophysics Data System (ADS)

In models for sediment suspension, two different boundary conditions have been employed at the sediment bed. Either the sediment concentration is given or the vertical flux of sediment is specified. The specification of the latter is usually called the pick-up function. Recently, several developments towards a better understanding of the sediment bed boundary condition have been reported. Nielson et al (Coastal Engineering 2002, 45, p61-68) have indicated a better performance using the sediment vertical flux as the bed boundary condition in comparisons with experimental data. Also, Drake and Calantoni (Journal of Geophysical Research 2001, 106, C9, p19859-19868) have suggested that in the nearshore environment with its various unsteady flow conditions, the appropriate sediment boundary conditions of a large-scale morphology model must consider both the magnitude the free stream velocity and the acceleration of the flow. In this research, a small-scale sheet flow model based on the two-phase theory is implemented to further study these issues. Averaged two-phase continuum equations are presented for concentrated flows of sediment that are driven by strong, fully developed, unsteady turbulent shear flows over a mobile bed. The particle inter-granular stress is modeled using collisional granular flow theory and a two-equation closure for the fluid turbulence is adopted. In the context of the two-phase theory, sediment is transported through the sediment vertical velocity. Using the fully developed sediment phase continuity equation, it can be shown that the vertical velocity of the sediment must vanish when the flow reaches a steady state. In other words, in fully developed conditions, it is the unsteadiness of the flow that induces the vertical motion of the sediment and that changes the sediment concentration profile. Therefore, implementing a boundary condition based on sediment vertical flux is consistent with both the two-phase theory and with the observation that the flow acceleration is an important parameter. In this paper, the vertical flux of sediment is studied under various combinations of free stream velocity, acceleration, and sediment material properties using the two-phase sheet flow model. Some interesting features of sediment dynamics within the sheet, such as time history of sediment vertical velocity, collisional and turbulent suspension mechanisms are presented.

Hsu, T.; Jenkins, J. T.; Liu, P. L.

2002-12-01

239

Vertical Component of Satellite Navigation Systems  

NASA Astrophysics Data System (ADS)

The altitude is one of four coordinates of the user's position obtained from Satellite Navigation System (SNS) measurements. The distributions (in per cent) of VDOP coefficient value for different constellations of three SNS - GPS, GLONASS and Galileo - for different masking elevation angles for different user's latitudes are presented in the paper. The results of the measurements of GPS position and vertical accuracy in mode "3D" and position accuracy in mode "2D" for different GPS receivers and different receiver's antenna heights are demonstrated also. Additionally the use of vertical component of SNS in maritime navigation like the determination highly accurate sea-floor depths is presented.

Januszewski, Jacek

2010-01-01

240

Vertical cloud structure of Jupiter's equatorial plumes  

NASA Astrophysics Data System (ADS)

A model for the vertical cloud structure of Jupiter's Equatorial Plumes is deduced based on an analysis of Voyager images of the equatorial region in the 6190-Å methane band and the 6000-Å continuum, and ground-based 8900-Å methane band images of Jupiter. A computer code that represents scattering and absorption from aerosol and gas layers was applied to a hierarchy of increasingly complex model aerosol structures to match the observations in the three wavelengths. The observations are consistent with a model for the vertical cloud structure of the equatorial region that consists of four aerosol layers.

Stoker, C. R.; Hord, C.

1985-12-01

241

Poisson'S Ratio in Orthotropic Materials.  

National Technical Information Service (NTIS)

Poisson's ratio is frequently measured in uniaxial testing of orthotropic materials, and values in excess of unity are common for composites. In isotropic materials it is known that values larger than one half are thermodynamically inadmissible, for such ...

B. M. Lempriere

1968-01-01

242

Ardennes Fractional Exchange Ratio Research.  

National Technical Information Service (NTIS)

The US Army Concepts Analysis Agency (CAA) requires guidelines on use and computation of the combat measure of effectiveness (MOE) denote as the fractional exchange ratio (FER). The Ardennes Campaign Simulation Data Base (ACSDB) derived from historical ar...

W. Bauman

1997-01-01

243

Fixed-ratio punishment1  

PubMed Central

Responses were maintained by a variable-interval schedule of food reinforcement. At the same time, punishment was delivered following every nth response (fixed-ratio punishment). The introduction of fixed-ratio punishment produced an initial phase during which the emission of responses was positively accelerated between punishments. Eventually, the degree of positive acceleration was reduced and a uniform but reduced rate of responding emerged. Large changes in the over-all level of responding were produced by the intensity of punishment, the value of the punishment ratio, and the level of food deprivation. The uniformity of response rate between punishments was invariant in spite of these changes in over-all rate and contrary to some plausible a priori theoretical considerations. Fixed-ratio punishment also produced phenomena previously observed under continuous punishment: warm-up effect and a compensatory increase. This type of intermittent punishment produced less rapid and less complete suppression than did continuous punishment.

Azrin, N. H.; Holz, W. C.; Hake, D. F.

1963-01-01

244

Results of a combined adjustable recession and posterior fixation suture of the same vertical rectus muscle for incomitant vertical strabismus  

Microsoft Academic Search

Purpose: The posterior fixation suture (fadenoperation) is an effective treatment for complicated incomitant vertical strabismus. Traditional operative methods do not permit the simultaneous use of an adjustable recession of the same muscle. Methods: Seven patients with incomitant vertical strabismus and diplopia were treated with a combined adjustable recession and posterior fixation suture of the same vertical rectus muscle. Preoperative vertical

Darren L. Hoover

1998-01-01

245

A new estimate of the CaCO3 to organic carbon export ratio  

Microsoft Academic Search

We use an ocean biogeochemical-transport box model of the top 100 m of the water column to estimate the CaCO3 to organic carbon export ratio from observations of the vertical gradients of potential alkalinity and nitrate. We find a global average molar export ratio of 0.06 0.03. This is substantially smaller than earlier estimates of 0.25 on which a majority

J. L. Sarmiento; J. Dunne; A. Gnanadesikan; R. M. Key; K. Matsumoto; R. Slater

2002-01-01

246

Optimal Design of Gear Ratios and Offset for Energy Conservation of an Articulated Manipulator  

Microsoft Academic Search

It is important to minimize the energy dissipated by the reduction gears and motors in a three-jointed vertically articulated manipulator. This paper proposes an optimal design method for simultaneously determining eight design variables, which are three motor masses, three reduction gear ratios, a counterbalancer mass for the third link and an offset between the first and the second links. Using

Teruyuki Izumi; Hai Zhou; Zuowei Li

2009-01-01

247

MEASUREMENT OF BI-DIRECTIONAL AMMONIA FLUXES OVER SOYBEAN USING MODIFIED BOWEN-RATIO TECHNIQUE  

EPA Science Inventory

Measurements of bi-directional ammonia exchange over a fertilized soybean canopy are presented for an 8-week period during the summer of 2002. The modified Bowne-ratio approach was used to determine fluxes from vertical NH3 and temperature gradients in combination with eddy covar...

248

Vertical and horizontal seismometric observations of tides  

Microsoft Academic Search

Tidal signals have been largely studied with gravimeters, strainmeters and tiltmeters, but can also be retrieved from digital records of the output of long-period seismometers, such as STS-1, particularly if they are properly isolated. Horizontal components are often noisier than the vertical ones, due to sensitivity to tilt at long periods. Hence, horizontal components are often disturbed by local effects

S. Lambotte; L. Rivera; J. Hinderer

2006-01-01

249

Trade, Vertical Production Chain, and Competition Policy  

Microsoft Academic Search

The authors build a trade model that renders tractable the process in which imperfect competition in a country's downstream sector affects the rest of the world through international trade. For this purpose, internationally traded goods are viewed as middle products in the vertical chain of production, in which middle products are produced upstream and transformed into final consumption goods downstream.

Makoto Yano; Fumio Dei

2003-01-01

250

Vertical technology transfer via international outsourcing  

Microsoft Academic Search

To analyze the effect of vertical technology transfer on industrial development in lesser developed countries (LDCs), we develop a model in which the technology transferred to an LDC supplier by a developed country (DC) importer can diffuse to other LDC firms. Surprisingly, even if such diffusion in the LDC market leads to entry into the DC market, it can benefit

Howard Pack; Kamal Saggi

2001-01-01

251

Optimum design of vertical rectangular fin arrays  

Microsoft Academic Search

The goal of this analysis has been the search for the optimal configuration for a finned plate (with rectangular and vertical fins) to be cooled in natural convection. Utilizing a simplified relation of the fins heat exchange some simple expressions for the determination of the optimum value of the fins spacing have been developed as a function of the parameters

Andrea de Lieto Vollaro; Stefano Grignaffini; Franco Gugliermetti

1999-01-01

252

Surging verticality: an experience of balance  

Microsoft Academic Search

In our approach to body-focused interactive art, the tangible material with which we craft interactional aesthetic experiences is body experience. Touch and proprioception become primary materials for exploration and embedding in technology-mediated interactional situations. We applied the Feldenkrais Method of somatic bodywork in the development of a prototype interactive artwork, Surging Verticality, to pursue our understanding of how to craft

Lian Loke; George Poonkhin Khut

2011-01-01

253

[From vertical to horizontal. Writing in adolescence].  

PubMed

Writing at adolescence has a non negligible part in identity's construction. Vertical writing as tags, graphs and graffiti refer to a narcissism deficiency and express a pulsional necessity, whereas, horizontal writing as private diaries, letters and novels express object's search and are made in dreaming attitude. PMID:7618823

Catheline-Antipoff, N

1995-04-01

254

V-22 Osprey Joint Advanced Vertical Aircraft.  

National Technical Information Service (NTIS)

The V-22 Osprey Joint Advanced Vertical Aircraft (V-22) is a tilt- rotor, short-take-off-and-landing aircraft, which was developed to fulfill multi-Service operational requirements. The V-22 operates as a helicopter for takeoffs and landings and, once air...

T. F. Gimble M. L. Ugone C. M. Santoni R. L. Shaffer J. A. Hoyt

2000-01-01

255

Electrostatic comb drive for vertical actuation  

SciTech Connect

The electrostatic comb finger drive has become an integral design for microsensor and microactuator applications. This paper reports on utilizing the levitation effect of comb fingers to design vertical-to-the-substrate actuation for interferometric applications. For typical polysilicon comb drives with 2 {micro}m gaps between the stationary and moving fingers, as well as between the microstructures and the substrate, the equilibrium position is nominally 1-2 {micro}m above the stationary comb fingers. This distance is ideal for many phase shifting interferometric applications. Theoretical calculations of the vertical actuation characteristics are compared with the experimental results, and a general design guideline is derived from these results. The suspension flexure stiffnesses, gravity forces, squeeze film damping, and comb finger thicknesses are parameters investigated which affect the displacement curve of the vertical microactuator. By designing a parallel plate capacitor between the suspended mass and the substrate, in situ position sensing can be used to control the vertical movement, providing a total feedback-controlled system. Fundamentals of various capacitive position sensing techniques are discussed. Experimental verification is carried out by a Zygo distance measurement interferometer.

Lee, A. P., LLNL

1997-07-10

256

Vertical nontransovarial transmission of Bartonella in fleas.  

PubMed

Pathogens use diverse pathways to infect host populations by vertical and/or horizontal routes. Horizontal transmission of bacteria belonging to the Bartonella genus via haematophagous vectors is well known. Vertical transmission of Bartonella species was also suggested to occur but its routes remain to be unveiled. In a previous study, we showed the absence of transovarial transmission of Bartonella species OE 1-1 in Xenopsylla ramesis fleas, and that fleas feeding on Bartonella-positive jirds produced Bartonella-positive gut voids. This current study aimed to investigate whether vertical nontransovarial transmission of Bartonella occurs in fleas. For this aim, the X. ramesis-Bartonella sp. OE 1-1 model was used. Four groups of fleas including Bartonella-positive and Bartonella-negative female fleas and larval offspring had access to either Bartonella-negative or Bartonella-positive gut voids and faeces. Sixteen per cent of flea offspring that had access to Bartonella-positive faeces and gut voids became Bartonella positive. Our findings demonstrate that Bartonella-positive flea faeces and gut voids are proper infection sources for flea larvae and indicate that vertical nontransovarial transmission of bartonellae occurs in fleas. This information broadens our understanding of Bartonella transmission routes in flea vectors and enlightens pathways of bartonellae transmission and maintenance in flea populations in nature. PMID:23875817

Morick, Danny; Krasnov, Boris R; Khokhlova, Irina S; Gutiérrez, Ricardo; Gottlieb, Yuval; Harrus, Shimon

2013-07-23

257

Vertical Arc for ILC Low Emittance Transport  

SciTech Connect

The design and parameters of a vertical arc for the ILC Low Emittance Transport (LET) are reviewed. A 1 TeV CM ILC which relies upon 30 MV/m accelerating cavities with a packing fraction of 65% will require almost 48 km of main linac, which suggests that the total site length including BDS and bunch compressors will be on the order of 53 km. If built in a laser-straight tunnel with the low-energy ends near the surface, and assuming a perfectly spherical ''cue ball'' planetary surface with radius 6370 km, the collider halls will necessarily be 55 meters below grade, as shown in the top plot of Figure 1. Such depths would demand extensive use of deep tunneling, which would potentially drive up the cost and difficulty of ILC construction. An alternate solution is to use discrete vertical arcs at a few locations to allow a ''piecewise straight'' construction in which the depth of the tunnel below grade does not vary by more than a few meters. This approach is shown schematically in the bottom plot of Figure 1. In this Note we consider the issues for a design with one such vertical arc at the 250 GeV/c point (ie, midway down the linac for 1 TeV CM), and a second arc at the entrance to the BDS (ie, the entire BDS lies in one plane, with vertical arcs at each end).

Tenenbaum, P.; Woodley, M.; /SLAC

2005-06-07

258

Convective Instabilities in Vertical Fractures and Faults  

Microsoft Academic Search

Natural convection of water contained in a vertical fracture or fault in which the temperature increases with depth is strongly influenced by the heat transport processes not only within the water itself but also by the heat transferred to and from the surrounding rock mass. The results of a linear stability analysis indicate that the critical Rayleigh number R* is

Hugh D. Murphy; Geosciences Division

1979-01-01

259

Higher Education Vertical Infrastructure Maintenance Planning.  

ERIC Educational Resources Information Center

To assist higher education facility officers in documenting their financial needs for renewing and renovating existing physical facilities, this study examined the accuracy against observed conditions of the tools used to identify vertical infrastructure maintenance needs in a large public university. Data developed for U.S. Army facilities is…

Weidner, Theodore J.

260

A dynamic single actuator vertical climbing robot  

Microsoft Academic Search

A climbing robot mechanism is introduced, which uses dynamic movements to climb between two parallel vertical walls. This robot relies on its own internal dynamic motions to gain height, unlike previous mechanisms which are quasi- static. One benefit of dynamics is that it allows climbing with only a single actuated degree of freedom. We show with analysis, simulations and experiments

Amir Degani; Amir Shapiro; Howie Choset; Matthew T. Mason

2007-01-01

261

Vertical Diffusion in Clouds: Some Simple Parameterizations.  

National Technical Information Service (NTIS)

In this paper, some simple parameterizations to account for the different stratification inside clouds are presented. These parameterization are used to modify the so-called Louis scheme, which is a first-order, local-vertical diffusion scheme. The basic ...

K. I. Ivarsson

1997-01-01

262

Abdominal incisions--vertical or transverse?  

Microsoft Academic Search

Two-hundred and nine patients were entered into a prospective, randomized trial in order to determine whether a vertical or transverse abdominal incision is the more satisfactory in producing sound wounds. Ninety-six patients were randomized between paramedian and transverse incisions, and followed up for at least 1 year. No significant difference in the incidence of wound failure could be shown between

H. Ellis; P. D. Coleridge-Smith; A. D. Joyce

1984-01-01

263

Vertical pellet injection in FTU discharges  

Microsoft Academic Search

Central fuelling and pellet enhanced performance modes have been obtained with pellets injected vertically from the high field side on the FTU tokamak. Four phases have been recognized: ablation of the pellets, drifting plasmoids, MHD modes which take the density to the centre of the discharge and finally an anomalous drift which further increases the density peaking. Pellet ablation data

E. Giovannozzi; S. V. Annibaldi; P. Buratti; B. Esposito; D. Frigione; L. Garzotti; S. Martini; M. Marinucci; D. Marocco; C. Mazzotta; G. Monari; M. Romanelli; P. Smeulders; D. Terranova; O. Tudisco

2005-01-01

264

Modifications in vertical scar breast reduction  

Microsoft Academic Search

The use of vertical-scar breast reduction techniques is only slowly increasing, even though they have been advocated by Lassus and Lejour and are requested by patients. Possible reasons why surgeons are reluctant to use these techniques are that they are said to be more difficult to learn, they require considerable experience and intuition, and their applicability is confined to small

G. M. Beer; W. Morgenthaler; I. Spicher; V. E. Meyer

2001-01-01

265

Tailored airfoils for Vertical Axis Wind Turbines*  

SciTech Connect

The evolution of a family of airfoil sections designed to be used as blade elements of a vertical axis wind turbine (VAWT) is described. This evolution consists of extensive computer simulation, wind tunnel testing and field testing. The process reveals that significant reductions in system cost-ofenergy and increases in fatigue lifetime may be expected for VAWT systems using these blade elements.

Klimas, P.C.

1984-08-01

266

Tailored airfoils for vertical axis wind turbines  

SciTech Connect

The evolution of a family of airfoil sections designed to be used as blade elements of a vertical axis wind turbine (VAWT) is described. This evolution consists of extensive computer simulation, wind tunnel testing and field testing. The process reveals that significant reductions in system costs-of-energy and increases in fatigue lifetime may be expected for VAWT systems using these blade elements.

Klimas, P.C.

1984-01-01

267

Tailored airfoils for vertical axis wind turbines  

SciTech Connect

The evolution of a family of airfoil sections designed to be used as blade elements of a vertical axis wind turbine (VAWT) is described. This evolution consists of extensive computer simulation, wind tunnel testing and field testing. The process reveals that significant reductions in system costs-of-energy and increases in fatigue lifetime may be expected for VAWT systems using these blade elements.

Klimas, P.C.

1984-11-01

268

Vertical tail buffeting of fighter aircraft  

Microsoft Academic Search

Vertical tail buffeting at high angles of attack is a phenomenon associated with the impact of vortical flows generated by the aircraft on the fins. This poses a serious problem for both single- and twin-tail fighter aircraft from the point of view of combat maneuverability and structural integrity. The research activities to understand the flow physics with an aim to

B. H. K. Lee

2000-01-01

269

Creating a vertical stop for interocclusal records  

Microsoft Academic Search

This article describes a method of making an accurate interocclusal record when the most distal tooth is an abutment of a fixed partial denture. The method uses conical stops, prepared in the enamel of the abutment or made of composite or a metal core covered with composite, to maintain the vertical dimension of occlusion and to act as a third

Yuuji Sato; Ryuji Hosokawa; Kazuhiro Tsuga; Takayasu Kubo

2000-01-01

270

Vertical File Subject Headings KWIK List.  

ERIC Educational Resources Information Center

|A subject heading keyword-in-context (KWIK) list for the vertical files at the University of California, Davis, is presented. It is noted that the KWIK list was prepared to assist library users in locating more subject headings for available materials in the various pamphlet collections and that the list is computerized to enable frequent…

Knowles, Em Claire; And Others

271

Natural Convection between Concentric Vertical Cylinders  

Microsoft Academic Search

The motion of a fluid in the closed annular cavity formed by two concentric vertical cylinders and two horizontal planes has been analyzed by a numerical solution of the equations of motion and energy using a high-speed digital computer. The motion is generated by a radial density gradient caused by the thermal boundary conditions which are, typically: inner cylinder at

G. de Vahl Davis; R. W. Thomas

1969-01-01

272

The capillary interaction between two vertical cylinders  

Microsoft Academic Search

Particles floating at the surface of a liquid generally deform the liquid surface. Minimizing the energetic cost of these deformations results in an inter-particle force which is usually attractive and causes floating particles to aggregate and form surface clusters. Here we present a numerical method for determining the three-dimensional meniscus around a pair of vertical circular cylinders. This involves the

Himantha Cooray; Pietro Cicuta; Dominic Vella

2012-01-01

273

Energy conservation practices - vertical tube foam evaporation  

Microsoft Academic Search

This paper describes the vertical tube foam evaporation (VTFE) of aqueous liquids which reduces energy requirements by enhancing the evaporation coefficient, which permits the use of a lower temperature difference, to drive the evaporation process. The VTFE method relies on imposing a foamy mode of flow of the evaporating liquid over the heat transfer surface or tube-side wall. This mode

Sephton

1981-01-01

274

Higher Mode Vertical Vibration of Giant Tanker.  

National Technical Information Service (NTIS)

The preliminary analysis was made on the hull vertical vibration of tankers in which the ship hull is simulated by the model of two parallel beams elastically connected. Each beam represents the side shell and the longitudinal bulkhead respectively, and t...

K. Ohtaka K. Kagawa T. Yamamoto

1969-01-01

275

Vertical transmission of Babesia microti, United States.  

PubMed

Babesiosis is usually acquired from a tick bite or through a blood transfusion. We report a case of babesiosis in an infant for whom vertical transmission was suggested by evidence of Babesia spp. antibodies in the heel-stick blood sample and confirmed by detection of Babesia spp. DNA in placenta tissue. PMID:22840424

Joseph, Julie T; Purtill, Kerry; Wong, Susan J; Munoz, Jose; Teal, Allen; Madison-Antenucci, Susan; Horowitz, Harold W; Aguero-Rosenfeld, Maria E; Moore, Julie M; Abramowsky, Carlos; Wormser, Gary P

2012-08-01

276

Vertical Transmission of Babesia microti, United States  

PubMed Central

Babesiosis is usually acquired from a tick bite or through a blood transfusion. We report a case of babesiosis in an infant for whom vertical transmission was suggested by evidence of Babesia spp. antibodies in the heel-stick blood sample and confirmed by detection of Babesia spp. DNA in placenta tissue.

Purtill, Kerry; Wong, Susan J.; Munoz, Jose; Teal, Allen; Madison-Antenucci, Susan; Horowitz, Harold W.; Aguero-Rosenfeld, Maria E.; Moore, Julie M.; Abramowsky, Carlos; Wormser, Gary P.

2012-01-01

277

Vertical distribution of Titan's atmospheric neutral constituents  

Microsoft Academic Search

The vertical distribution of Titan's neutral atmosphere compounds is calculated from a new photochemical model extending from 40 to 1432 km. This model makes use of many updated reaction rates, and of the new scheme for methane photolysis proposed by Mordaunt et al. [1993]. The model also includes a realistic treatment of the dissociation of N2, of the deposition of

L. M. Lara; E. Lellouch; J. J. López-Moreno; R. Rodrigo

1996-01-01

278

On the Design of Vertical Hydraulic Fractures  

Microsoft Academic Search

Some of the assumptions involved in designing vertical hydraulic fractures should be critically examined as to their validity. This is done on the basis of a new width equation and a numerical design procedure. It is found that some of the assumptions related to the fluid mechanics of the problem greatly affect the computed results and therefore deserve special attention.

Abbas Daneshy

1973-01-01

279

Vertically aligned biaxially textured molybdenum thin films  

SciTech Connect

Vertically aligned, biaxially textured molybdenum nanorods were deposited using dc magnetron sputtering with glancing flux incidence (alpha = 85 degrees with respect to the substrate normal) and a two-step substrate-rotation mode. These nanorods were identified with a body-centered cubic crystal structure. The formation of a vertically aligned biaxial texture with a [110] out-of-plane orientation was combined with a [-110] in-plane orientation. The kinetics of the growth process was found to be highly sensitive to an optimum rest time of 35 seconds for the two-step substrate rotation mode. At all other rest times, the nanorods possessed two separate biaxial textures each tilted toward one flux direction. While the in-plane texture for the vertical nanorods maintains maximum flux capture area, inclined Mo nanorods deposited at alpha = 85 degrees without substrate rotation display a [-1-1-4] in-plane texture that does not comply with the maximum flux capture area argument. Finally, an in situ capping film was deposited with normal flux incidence over the biaxially textured vertical nanorods resulting in a thin film over the porous nanorods. This capping film possessed the same biaxial texture as the nanorods and could serve as an effective substrate for the epitaxial growth of other functional materials.

Krishnan, Rahul [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Riley, Michael [Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Lee, Sabrina [US Army Armament Research, Development and Engineering Center, Benet Labs, Watervliet, New York 12189 (United States); Lu, Toh-Ming [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

2011-09-15

280

Distribution of propping agents in vertical fractures  

Microsoft Academic Search

An experimental study has been made of the distribution of propping agents in vertical fractures. The results indicate that propping agent distribution may be described by 2 parameters: equilibrium velocity, which represents the velocity necessary to maintain the propping agents suspended in the fracturing fluid, and the bank build-up constant, which describes the rate of propping agent deposition when the

R. E. Babcock; C. L. Prokop; R. O. Kehle

1967-01-01

281

A Laboratory Study of Vertical Migration  

Microsoft Academic Search

In a tank filled with a suspension of indian ink in tap water, a population of Daphnia magna will undergo a complete cycle of vertical migration when an overhead light source is cyclically varied in intensity. A 'dawn rise' to the surface at low intensity is followed by the descent of the animals to a characteristic maximum depth. The animals

J. E. Harris; Ursula K. Wolfe

1955-01-01

282

A Distributed Concept Lattices Vertical Union Method  

Microsoft Academic Search

Concept lattice, the core data structure of formal context, has high time complexity when it is constructed. This problem has disturbed the further application of concept lattice in data mining. A union method is developed in this paper, which first vertically divide the formal context into distributed stations, construct concept sub-lattices independently, then union them together. The validity and completeness

Feng Ma; Jiankun Yu; Zhiyong Zeng; Ye Tao; Tao Feng

2010-01-01

283

Method and apparatus for seismic survey including using vertical gradient estimation to separate downgoing seismic wavefield  

US Patent & Trademark Office Database

A vertical gradient estimation technique is used to separate downgoing seismic ghost wavefields. The upgoing reflected seismic wavefield, allows the ghost wavefield to be attenuated to improve signal-to-noise ratio. The vertical gradient estimation technique is applicable to both marine seismic surveying using towed hydrophones, and to land seismic surveying using buried geophones. The technique allows the vertical signal gradient to be estimated from seismic signals measured at a single depth, and is based on a relationship between the measured seismic signals, and the source signature and the Green's function for the survey media. The technique involves determning (20) the source signature for the seismic source, and determining (21) the Green's function for the survey media. Seismic signals are then measured (22). These data are then processed to estimate (24) the vertical signal gradient as a function of source signature, Green's function and the measured seismic signals. Once the vertical signal gradient is estimated, it can be used in processing the measured seismic signals to separate and attenuate (26) the downgoing ghost component of the measured seismic signals.

Corrigan; Dennis (Plano, TX); Weglein; Arthur B. (Grapevine, TX); Thompson; David D. (Plano, TX)

1991-09-24

284

A methodology for evaluation of vertical dispersion and dry deposition of atmospheric aerosols  

NASA Astrophysics Data System (ADS)

A new approach to treatment of vertical dispersion and dry deposition of atmospheric aerosols is suggested for primary application in mesoscale to global atmospheric transport models. The vertical exchange scheme extends the resistance analogy formulated earlier for gaseous species and fine aerosols. The approach is based on the exact solution of the steady-state equation for aerosol flux within a finite layer. The flux is expressed as a linear function of concentrations at the layer boundaries and accounts for the vertical inhomogeneity of the diffusion coefficient and the regular vertical velocity. The new dry deposition scheme accounts for physical properties of the air flow, surface and depositing particles. The flow is given by the vertical profile of exchange coefficient and characteristic velocity at the surface. The deposition rate to smooth surfaces is obtained via solution of the budget equation for particle mass. The transition from smooth to rough flow regime is considered. Rough surfaces are characterized by two length scales: the aerodynamic roughness and the "collection scale", introduced in this paper. The collection scale incorporates the effective size of collectors and a ratio of the airflow velocity at the top of the roughness elements to the friction velocity. The particles are described by their physical size, relaxation time and Brownian diffusivity. The scheme was developed basing exclusively on wind-tunnel and numerical experiments available from the literature, and reproduces them well. The data of outdoor experiments have noticeably larger uncertainties, which allowed only general evaluation of their agreement with the predictions.

Kouznetsov, Rostislav; Sofiev, Mikhail

2012-01-01

285

Asymmetries in vertical vorticity and vertical velocity arising during nonlinear homogeneous spindown  

NASA Astrophysics Data System (ADS)

During the spindown of a unidirectional, geostrophic current in a homogeneous fluid, asymmetry arises in the vertical velocity and vertical relative vorticity fields. A closed-form, time-dependent solution valid to order Rossby number is derived to explore these asymmetries. Momentum advection in the interior and the Ekman layer leads to competing tendencies in the vertical vorticity's evolution. In the interior, momentum advection hastens spindown in cyclonic regions. In the Ekman layer, momentum advection weakens Ekman pumping over Ekman suction and thus tends to slow the spindown of cyclonic vorticity. It is shown that the former effect dominates, and hence cyclonic vorticity decays faster than anticyclonic vorticity.

Benthuysen, J. A.; Thomas, L. N.

2012-07-01

286

Isotopic ratios in planetary atmospheres.  

PubMed

Recent progress on measurements of isotopic ratios in planetary or satellite atmospheres include measurements of the D/H ratio in the methane of Uranus, Neptune and Titan and in the water of Mars and Venus. Implications of these measurements on our understanding of the formation and evolution of the planets and satellite are discussed. Our current knowledge of the carbon, nitrogen and oxygen isotopic ratios in the atmospheres of these planets, as well as on Jupiter and Saturn, is also reviewed. We finally show what progress can be expected in the very near future due to some new ground-based instrumentation particularly well suited to such studies, and to forthcoming space missions. PMID:11539257

de Bergh, C

1995-03-01

287

High-definition vertically aligned liquid crystal microdisplays using a circularly polarized light  

NASA Astrophysics Data System (ADS)

A high-definition vertically aligned liquid crystal (LC) microdisplay exhibits a excellent contrast ratio, but its fringing field effect splits the bright state unevenly and leads to a very slow response time. By utilizing a circularly polarized light instead of conventional linearly polarized light, we have overcome the long-standing problems of poor sharpness, low brightness, and slow response time. Confirming computer simulations agree with the experimental results well. This approach can be applied to both reflective and transmissive LC microdisplays.

Fan-Chiang, Kuan-Hsu; Chen, Shu-Hsia; Wu, Shin-Tson

2005-07-01

288

Bulk crystal growth of Mg 2Si by the vertical Bridgman method  

Microsoft Academic Search

Mg2Si were grown by the vertical Bridgman (VB) method in crucibles made of chemical vapor deposition (CVD) pyrolytic graphite (PG) in order to minimize the reaction and sticking of molten Mg–Si during growth. Congruent crystallization was derived from a stoichiometric melt of Mg2Si, and incongruent crystallization was derived from nonstoichiometric melts having Mg\\/Si ratios of 85:15, 70:30 and 60:40. Grown

M. Yoshinaga; T Iida; M Noda; T Endo; Y Takanashi

2004-01-01

289

The dependence of clouds and their radiative impacts on the large-scale vertical velocity  

Microsoft Academic Search

Middle-tropospheric vertical velocity(o500) is used to isolate the effect of large-scale dynamics on the observed radiation budget and cloud properties in the Tropics. The ratio of shortwave to longwave cloud forcing (N=-SWCF\\/LWCF) is approximately 1.2 and independent of the magnitude of w5oo when it is upward over the warmer water. Increasingly negative net cloud forcing (NetCRF) with increasing upward motion

Jian Yuan

2007-01-01

290

Effect of vertical heat transfer on thermocapillary convection in an open shallow rectangular cavity  

Microsoft Academic Search

In order to understand the effect of the vertical heat transfer on thermocapillary convection characteristics in a differentially\\u000a heated open shallow rectangular cavity, a series of two- and three-dimensional numerical simulations were carried out by means\\u000a of the finite volume method. The cavity was filled with the 1cSt silicone oil (Prandtl number Pr = 13.9) and the aspect ratio ranged from 12

You-Rong Li; Hong-Ru Zhang; Chun-Mei Wu; Jin-Liang Xu

291

Growth process conditions of vertically aligned carbon nanotubes using plasma enhanced chemical vapor deposition  

Microsoft Academic Search

The growth of vertically aligned carbon nanotubes using a direct current plasma enhanced chemical vapor deposition system is reported. The growth properties are studied as a function of the Ni catalyst layer thickness, bias voltage, deposition temperature, C2H2:NH3 ratio, and pressure. It was found that the diameter, growth rate, and areal density of the nanotubes are controlled by the initial

M. Chhowalla; K. B. K. Teo; C. Ducati; N. L. Rupesinghe; G. A. J. Amaratunga; A. C. Ferrari; D. Roy; J. Robertson; W. I. Milne

2001-01-01

292

Outward melting from a vertical cylinder with natural convection effects. [N-eicosane  

Microsoft Academic Search

Experiments were performed to investigate melting around an isothermal cylinder embedded vertically in a phase-change material at its fusion temperature. The ratio height-to-diameter of the cylinder was chosen to be five, to allow comparisons with available results. Research grade (99% pure) n-eicosane paraffin was used in the experiments, which investigated the phase-change phenomenon for Rayleigh number values ranging from 7

A. C. Pinho Brasil; P. R. Souza Mendes

1985-01-01

293

Local scour at vertical-wall abutments under clear-water flow conditions  

Microsoft Academic Search

New clear-water tests on abutment scour are presented. Thirty-one tests with sand bed and nine tests with lightweight pumice bed were carried out in a 28-m-long, 4-m-wide flume. Tests typically lasted for 1 week or more. Vertical-wall abutments with length-to-depth L\\/d ratios from 9 up to 36 were used. Other test campaigns in the literature are added to the data,

Cristina Maria Sena Fael; Gonzalo Simarro-Grande; Juan-Pedro Martín-Vide; António Heleno Cardoso

2006-01-01

294

Vertical distribution of chlorofluoromethanes in the upper troposphere and lower stratosphere  

Microsoft Academic Search

Vertical profiles of CCl4, CFCl3, and CF2Cl2 mixing ratios in the upper troposphere and lower stratosphere have been measured on four flights with chartered aircraft, type HS 125. The flights were carried out in November and December 1976 over Europe at latitudes between 50 and 60°N. At least eight air samples were taken during each ascent and descent of the

W. Seiler; F. Müller; H. Oeser

1978-01-01

295

Surface to Volume Ratio Activity  

NSDL National Science Digital Library

By the National Nanotechnology Infrastructure Network, this two-part laboratory activity was designed to complement any chemistry unit on catalysts to "help students understand how nanoparticles may be more effective catalysts by investigating how the surface area-to-volume ratio of a substance is affected as its shape changes." On this site, educators can find both the teacher and student instructions for preparing and presenting the laboratory with objectives, time periods, materials, procedures, example answers, and much more. It is a ready-to-use lesson to help students understand catalysts and surface to volume ratio at molecular and atomic levels.

2009-01-14

296

Soudage Vertical Sous Laitier Avec Guide Fil Fusible (Vertical Welding under Flux Using Melting Wire Guide).  

National Technical Information Service (NTIS)

An automatic welding procedure for vertical weldings is described. The method allows high welding velocity and can be used by small shops. Recommendations on flux utilization, manufacturing of melting wire guides, welding parameters, welding procedures an...

D. Eliot

1985-01-01

297

Nation's tallest VAWT (Vertical Axis Wind Turbine) turning out the watts. [Vertical Axis Wind Turbine  

SciTech Connect

This article describes the development of the tallest and most powerful windmill of its kind in the U.S. Known as a Vertical Axis Wind Turbine (VAWT), the machine is meant for testing new concepts in vertical axis turbine design. As part of its overall testing program, the turbine will supply electricity to automated water pumps used in irrigation research at the Research Laboratory in Bushland, Texas. Excess power will go to the Southwestern Public Service Company for the area power system.

Miller, S.

1988-05-01

298

Conditional generation of path-entangled optical vertical bar N,0>+ vertical bar 0,N> states  

SciTech Connect

We propose a measurement protocol to generate path-entangled vertical bar N,0>+ vertical bar 0,N> states conditionally from two pulsed type II optical parametric oscillators. We calculate the fidelity of the produced states and the success probability of the protocol. The trigger detectors are assumed to have finite dead time, and for short pulse trigger fields they are modeled as on-off detectors with finite efficiency. Continuous-wave operation of the parametric oscillators is also considered.

Nielsen, Anne E. B.; Moelmer, Klaus [Lundbeck Foundation Theoretical Center for Quantum System Research, Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark)

2007-06-15

299

CRISTA-NF measurements with unprecedented vertical resolution during the RECONCILE aircraft campaign  

NASA Astrophysics Data System (ADS)

The Cryogenic Infrared Spectrometers and Telescope for the Atmosphere - New Frontiers (CRISTA-NF), an airborne infrared limb-sounder, was operated aboard the high-flying Russian research aircraft M55-Geophysica during the Arctic RECONCILE campaign from January to March 2010. This paper describes the calibration process of the instrument and the retrieval algorithm employed and then proceeds to present retrieved trace gas volume mixing ratio cross-sections for one specific flight in this campaign. We are able to resolve the uppermost troposphere/lower stratosphere for several trace gas species for several kilometres below the flight altitude (16 to 19 km) with an unprecedented vertical resolution of 400 to 500 m for the limb-sounding technique. The instrument points sideways with respect to the flight direction. Therefore, the observations are also characterised by a rather high horizontal sampling along the flight track, which provides a full vertical profile every ?15 km. Assembling the vertical trace gas profiles derived from CRISTA-NF measurements to cross-sections shows filaments of vortex and extra-vortex air masses in the vicinity of the polar vortex. During this campaign, the M55-Geophysica carried further instruments enabling trace gas volume mixing ratios derived from CRISTA-NF to be validated by comparing them with measurements by the in situ instruments HAGAR and FOZAN and observations by MIPAS-STR. This validation suggests that the retrieved trace gas volume mixing ratios are both qualitatively and quantitatively reliable.

Ungermann, J.; Kalicinsky, C.; Olschewski, F.; Knieling, P.; Hoffmann, L.; Blank, J.; Woiwode, W.; Oelhaf, H.; Hösen, E.; Volk, C. M.; Ulanovsky, A.; Ravegnani, F.; Weigel, K.; Stroh, F.; Riese, M.

2012-05-01

300

Air/fuel ratio detector  

SciTech Connect

This patent describes a method for detecting the air/fuel ratio of exhaust gas with a detector comprising an electrochemical cell sensor element and an oxygen pump element. Each element is in the form of an oxygen-ion-conductive solid electrolyte having a porous electrode formed on both sides thereof. The electrochemical cell sensor element being disposed to face the pump element with a small gap therebetween, exposed to the exhaust gas and an air compartment which is open to the atmosphere being formed on that side of the pump element which is opposite to the small gap. An electric current is caused to flow through the oxygen pump element so that oxygen is pumped into the small gap from the air compartment or in the opposite direction, thereby producing an electromotive force in the sensor element. The electromotive force and the current flowing through the pump element is used as a basis for detecting the air/fuel ratio of the exhaust gas. The improvement described here is wherein a sufficient amount of current to pump oxygen from the air compartment into the small gap is caused to flow through the oxygen pump element so as to produce an abrupt change in the electromotive force of the sensor element at a stoichiometric air/fuel ratio. The electromotive force of the sensor element is used to determine whether a present air/fuel ratio is in the fuel-rich or fuel-lean region.

Yamada, T.; Hirate, S.

1986-10-07

301

Declustering Using Golden Ratio Sequences  

Microsoft Academic Search

In this paper we propose a new data declustering scheme for range queries. Our schemeis based on Golden Ratio Sequences (GRS), which have found applications in broadcast disks,hashing, packet routing, etc. We show by analysis and simulation that GRS is nearly the bestpossible scheme for 2-dimensional range queries. Specifically, it is the best possible scheme whenthe number of disks (M

Randeep Bhatia; Rakesh K. Sinha; Chung-min Chen

2000-01-01

302

Surface Area to Volume Ratio  

NSDL National Science Digital Library

This page contains two documents explaining surface area to volume ratio. The topic is covered at an advanced level in relation to nanotechnology and requires background knowledge in geometry, algebra, and linear and non-linear unit conversions. A powerpoint with illustrations and instructor guide (available as both a Microsoft Word Document and PDF) containing activities are included to aid in teaching this subject.

2012-10-16

303

Empirical Likelihood Ratio Confidence Regions  

Microsoft Academic Search

An empirical likelihood ratio function is defined and used to obtain confidence regions for vector valued statistical functionals. The result is a nonparametric version of Wilks' theorem and a multivariate generalization of work by Owen. Cornish-Fisher expansions show that the empirical likelihood intervals for a one dimensional mean are less adversely affected by skewness than are those based on Student's

Art Owen

1990-01-01

304

A Ratio Explanation for Evolution.  

ERIC Educational Resources Information Center

|Describes hands-on physical anthropology activities for teaching students about evolution. Using evidence found in hominid skulls, students conduct investigations that involve calculating ratios. Eight full-page photographs of skulls from the program Stones and Bones are included. (PR)|

Riss, Pam Helfers

1993-01-01

305

Predictions and experiments of the VAWT viscous flow field. [Vertical Axis Wind Turbine  

SciTech Connect

The first objective of the work was to compare the aerodynamic loads and performance predicted by the double-multiple-streamtube model with the viscous-flow-field analysis of a vertical-axis wind turbine. Second, to check the validity of the two performance/load models, their predictions were compared with available experimental data. When the dynamic effects at low tip-speed ratios (dynamic stall) and added mass and circulatory effects at high tip-speed ratios were included, significant improvement was obtained in the prediction of the aerodynamic characteristics of the turbine, such as induced velocities and instantaneous blade forces. 11 references.

Paraschivoiu, I.; Rajagopalan, R.G.; Masson, C.

1987-06-01

306

Air/fuel ratio regulator  

SciTech Connect

A description is given of an air/fuel ratio regulator for use with the fuel injection control system of an internal combustion engine of the spark ignition type having an air and exhaust gas (gas) induction passage open at one end to air at ambient pressure level and connected at its other end to the engine combustion chamber to be subject to manifold vacuum changes therein, a throttle valve rotatably mounted for movement across the passage to control the gas flow therethrough, exhaust gas recirculation (egr) passage means connecting engine exhaust gases to the induction passage above the closed position of the throttle valve, an egr flow control valve mounted in the egr passage means for movement between open and closed postions to control the volume of egr gas flow, an engine speed responsive positive displacement type fuel injection pump having a fuel flow output to the engine that varies in direct proportion to changes in engines speed to match fuel flow and mass airflow through the induction system of the engine over the entire speed and load range of the engine to maintain the intake mixture ratio of air to fuel constant, the pump having a fuel flow control lever movable to vary the fuel rate of flow, the regulator being characterized by engine manifold vacuum responsive first servo means operably connected to the fuel control lever for maintaining a constant air/fuel (A/F) ratio by changing fuel output as a function of changing manifold vacuum and air flow upon opening of the throttle valve, a fuel enrichment control lever operably connected to the pump control lever and movable to modify the position of the pump lever dictated by the first servo means to change the A/F ratio, and further means responsive to engine operating conditions for moving the fuel enrichment control lever to provide the changed A/F ratio.

Simko, A.

1980-07-22

307

Morphologic assessment for glaucoma in the Multicenter Uveitis Steroid Treatment (MUST) Trial  

PubMed Central

Purpose To compare Reading Center (RC) cup-to-disc ratio (CDR) assessment from stereoscopic photographs with clinician estimation in a uveitis clinical trial. Methods Clinical estimation of CDR was performed by ophthalmologists via dilated biomicroscopy. Photographic evaluation was performed at an independent RC by masked, certified evaluators. Quality control was performed by repeat grading of 77 randomly selected images. Results Among 481 eyes with uveitis, 353 eyes had clinical and photographic grades for CDR. Agreement between clinical and RC grading was fair, with exact agreement in 29%. Agreement within 0.1 and 0.2 CDR were 70% and 93%, respectively (wkappa=0.34). Inter-grader reproducibility at the RC was better (wkappa=0.59, ICC 0.74). Conclusion Morphologic assessment of cup to disc ratio is an important outcome and safety measure for determining glaucomatous damage in clinical trials. Masked RC measurements are more likely to be accurate than biomicroscopic grading in identifying meaningful anatomical change associated with glaucoma.

Gangaputra, Sapna; Altaweel, Michael M.; Peng, Qian; Friedman, David S.; Rao, P. Kumar; Foster, C. Stephen; Kim, Rosa Y.; Reed, Susan B.; Srivastava, Sunil K.; Wong, Ira G.; Kempen, John H.

2013-01-01

308

The optic disc is minimal in children with idiopathic intracranial hypertension.  

PubMed

This study sought to characterize the optic disc morphology, particularly the cup-to-disc ratio of the optic nerve head in children with idiopathic intracranial hypertension. The medical charts and digital optic disc photos of children with confirmed diagnosis of idiopathic intracranial hypertension were reviewed retrospectively. The optic disc area, cup area, and cup-to-disc ratio were measured digitally using VISUPAC software, and the mean values of those parameters were compared to the published norms. Of children with idiopathic intracranial hypertension, 83% had absence of the physiological cup of the optic disc, compared to 10% of children in the general population of the same age. The median disc area was 2.2 mm(2), and median cup area was 0.0mm(2), compared to the published norms of 2.69 mm(2) and 0.44 mm(2), respectively. There is very significantly high prevalence of small optic disc cups in children with idiopathic intracranial hypertension, with the cup being absent on majority of cases in our patient cohort. This may signal an underlying systemic predisposition to the development of intracranial hypertension. PMID:23034982

Dai, Shuan; Trimboli, Carmelina; Buncic, J Raymond

2012-10-03

309

Coupled Resonator Vertical Cavity Laser Diodes  

SciTech Connect

For many applications, the device performance of edge emitting semiconductor lasers can be significantly improved through the use of multiple section devices. For example, cleaved coupled cavity (C3) lasers have been shown to provide single mode operation, wavelength tuning, high speed switching, as well as the generation of short pulses via mode-locking and Q-switching [1]. Using composite resonators within a vertical cavity laser opens up new possibilities due to the unique ability to tailor the coupling between the monolithic cavities, incorporate passive or active resonators which are spectrally degenerate or detuned, and to fabricate these devices in 2-dimensional arrays. Composite resonator vertical cavity lasers (CRVCL) have been examined using optical pumping and electrical injection [2-5]. We report on CRVCL diodes and show that efficient modulation of the laser emission can be achieved by either forward or reverse biasing the passive cavity within a CRVCL.

Choquette, K.D.; Chow, W.W.; Fischer, A.J.; Allerman, A.A.; Hou, H.Q.; Geib, K.M.

1999-07-22

310

Vertical circulations in jet flows and frontogenesis  

NASA Astrophysics Data System (ADS)

The paper presents a theoretical analysis of the relationship between the direction of vertical circulation in a jet flow and the nature of evolution of the high-altitude frontal zone. It is shown that with the accentuation of the frontal zone, vertical circulation in this zone and in the jet flow is thermally 'forward', but during frontolysis it is thermally 'reverse'; these motions appear to be compensating in a quasigeostrophic approximation. Expressions are derived indicating that the descending branch of circulation in the accentuating frontal zone occupies the region of maximum frontogenesis resulting from ageostrophic effects. The subsidence of stratospheric air which occurs in this region appears as a branch of a thermally reverse circulation, acting as a regulator of the sharpness of frontal interfaces

Shakina, N. P.

1980-04-01

311

Extreme wave runup on a vertical cliff  

NASA Astrophysics Data System (ADS)

Wave impact and runup onto vertical obstacles are among the most important phenomena which must be taken into account in the design of coastal structures. From linear wave theory, we know that the wave amplitude on a vertical wall is twice the incident wave amplitude with weakly nonlinear theories bringing small corrections to this result. In this present study, however, we show that certain simple wave groups may produce much higher runups than previously predicted, with particular incident wave frequencies resulting in runup heights exceeding the initial wave amplitude by a factor of 5, suggesting that the notion of the design wave used in coastal structure design may need to be revisited. The results presented in this study can be considered as a note of caution for practitioners, on one side, and as a challenging novel material for theoreticians who work in the field of extreme wave-coastal structure interaction.

Carbone, Francesco; Dutykh, Denys; Dudley, John M.; Dias, FréDéRic

2013-06-01

312

Matching a Permanent Magnet Synchronous Generator to a Fixed Pitch Vertical Axis Turbine for Marine Current Energy Conversion  

Microsoft Academic Search

Extracting energy from a free-flow marine current using a vertical axis fixed pitch turbine requires a generator that can handle varying speeds and loads, since such a turbine gives maximum power capture for a fixed tip speed ratio. A prototype of such a generator has been designed and constructed. In this paper, its variable speed and load operation is evaluated,

Katarina Yuen; Karin Thomas; MÅrten Grabbe; Paul Deglaire; Mathias Bouquerel; David Osterberg; Mats Leijon

2009-01-01

313

The conjugate conduction–natural convection heat transfer along a thin vertical plate with non-uniform internal heat generation  

Microsoft Academic Search

The steady state heat transfer characteristics of a thin vertical strip with internal heat generation is studied in this work. The nondimensional temperature distribution in the strip is obtained as a function of the following parameters: (a) the intensity and distribution of the internal heat sources, (b) the aspect ratio of the strip, (c) the longitudinal heat conductance of the

F Méndez; C Treviño

2000-01-01

314

Investigation on effectiveness of a prefabricated vertical drain during cyclic loading  

NASA Astrophysics Data System (ADS)

The effectiveness of prefabricated vertical drains (PVDs) in enhancing the stability of soft soils during cyclic loading was investigated using triaxial cyclic loading tests. Both undrained and with PVD tests were employed to study the associated excess pore pressure and accumulated strain under the repeated loading condition. The loading frequency and cyclic stress ratio have been chosen to be the variables which influence the performance of soft clays. The experimental results illustrate that with PVDs, the excess pore water pressure generation during cyclic loading decreases significantly. It is found that the excess pore water pressure build up depends on both loading frequency and cyclic stress ratio. The excess pore water pressure will increase when each of them is increased. Furthermore, when the loading frequency is 0.1 Hz, the ratio of coefficient of consolidation under cyclic loading to that under static loading is almost one. With the increasing loading frequency, this ratio increases accordingly.

Indraratna, B.; Ni, J.; Rujikiatkamjorn, C.

2010-06-01

315

Smooth Vertical Surface Climbing With Directional Adhesion  

Microsoft Academic Search

Stickybot is a bio-inspired robot that climbs smooth vertical surfaces such as glass, plastic and ceramic tile at 4 cm\\/s. The robot employs several design principles adapted from the gecko including a hierarchy of compliant structures, directional adhesion, and control of tangential contact forces to achieve control of adhesion. We describe the design and fabrication methods used to created under-actuated,

Sangbae Kim; Matthew Spenko; Salomon Trujillo; Barrett Heyneman; Daniel Santos; Mark R. Cutkosky

2008-01-01

316

Vertical graphene spin valve with Ohmic contacts.  

PubMed

Evident spin valve signals are observed in Co/graphene/Co sandwich structures with both monolayer and two-layer graphene stacks at temperatures from 1.5 K to 300 K. All the devices demonstrate linear current-voltage curves, indicating that an Ohmic property is dominating rather than a tunneling effect. The vertical graphene spin valves have potential applications in high-density non-volatile memories. PMID:23907712

Meng, Jie; Chen, Jing-Jing; Yan, Yuan; Yu, Da-Peng; Liao, Zhi-Min

2013-08-01

317

Engineering high-performance vertical cavity lasers  

SciTech Connect

The cw and high-speed performance of vertical cavity surface emitting laser diodes (VCSELs) are affected by both electrical and optical issues arising from the geometry and fabrication of these devices. Structures with low resistance semiconductor mirrors and Al-oxide confinement layers address these issues and have produced record performance including 50% power conversion efficiency and modulation bandwidths up to 20 GHz at small bias currents.

Lear, K.L.; Hou, H.Q.; Hietala, V.M.; Choquette, K.D.; Schneider, R.P. Jr.

1996-12-31

318

Vertical Handover Efficient Transport for Mobile IPTV  

Microsoft Academic Search

\\u000a The success of IPTV suggests that an expansion to mobile devices is likely. A key difference between IPTV delivery to mobile\\u000a devices and broadband access is the possibility of vertical handovers, which can cause disruption to real-time video streaming.\\u000a This paper proposes a lightweight form of IPTV transport based on negative acknowledgments. The performance of the scheme\\u000a is analyzed in

Salah S. Al-Majeed; Martin Fleury

319

Vertical tubular reactor for microalgae cultivation  

Microsoft Academic Search

Summary Vertical glass tubular reactors, 5 cm in diameter and 2.35 m high, were used to grow several species of cyanobacteria, green algae, and diatoms. The reactors were gassed with an air\\/CO2 mixture, to supply CO2, remove O2, and provide mixing. Most of the 10 strains tested had productivities similar to those observed with mechanically mixed reactors. The advantages of

K. Miyamoto; O. Wable; J. R. Benemann

1988-01-01

320

Global and local horizontal-vertical decoupling  

SciTech Connect

In this paper the author investigated systematically the global and local effects of horizontal-vertical couplings on the beam and the measurement and control of these couplings. Piecemeal studies have been made on these subjects by different authors. For completeness, their results are integrated here wherever appropriate. This brings the understanding and execution of the coupling correction to the same degree of completeness as that of the closed orbit correction.

Teng, L.C. [Argonne National Lab., IL (United States). Advanced Photon Source

1997-06-01

321

Advanced Planning in Vertically Integrated Supply Chains  

Microsoft Academic Search

\\u000a During the last few years most production-based businesses have been under enormous pressure to improve their top-line growth\\u000a and bottom-line savings. As a result, many companies are turning to systems and technologies that can help optimise their\\u000a supply chain activities and improving short- and long-term demand forecasting. Given the inherent complexities of planning\\u000a and scheduling in vertically integrated supply chains,

Maksud Ibrahimov; Arvind Mohais; Sven Schellenberg; Zbigniew Michalewicz

322

Vertical Structure of Dissipation in the Nearshore  

Microsoft Academic Search

The vertical structure of the dissipation of turbulence kinetic energy was observed in the nearshore region (3.2-m mean water depth) with a tripod of three acoustic Doppler current meters off a sandy ocean beach. Surface and bottom boundary layer dissipation scaling concepts overlap in this region. No depth-limited wave breaking occurred at the tripod, but wind-induced whitecapping wave breaking did

Falk Feddersen; J. H. Trowbridge; A. J. Williams

2007-01-01

323

Boston University Physics Applets: Vertical Circular Motion  

NSDL National Science Digital Library

This web page is an interactive physics simulation relating to circular motion. An object on a vertical circular pathway is shown, accompanied by an animated free-body diagram. Users may view the motion in steps to observe the net force as the object changes speed due to gravitation. This item is part of a collection of similar simulation-based activities developed for students of introductory physics.

Duffy, Andrew

2008-08-01

324

Laparoscopic Vertical Banded Gastroplasty: The Milwaukee Experience  

Microsoft Academic Search

Background: laparoscopic techniques are being developed for bariatric surgery. Methods: eleven morbidly obese patients underwent\\u000a laparoscopic vertical banded gastroplasty in 1993-1994. Results: average length of hospital stay was 3.9 days, mean operating\\u000a time was 202 min, and the average hospital charges were $12 800. These numbers were compared to the most recent open gastric\\u000a bypass patients, where average length of

Thomas Y. Chua; Rolando M. Mendiola

1995-01-01

325

Vertical reser storage offered by new semi  

SciTech Connect

A semisubmersible drilling rig concept is described. The rig utilizes a large buoyant center caisson and specially shaped lower hulls to improve the vessel's motion characteristics. The center caisson serves as vertical storage for riser joints and one of the units blowout preventer stacks. By use of this buoyant storage area, the vessel's center of gravity is lowered and the upper deck is cleared for extra working space.

Not Available

1985-01-01

326

Asymmetries in processing horizontal and vertical dimensions  

Microsoft Academic Search

The aim of this study was to determine whether the referential term on the horizontal dimension corresponds to the dominant\\u000a hand and whether the referential term on the vertical dimension is independent of handedness. In order to verify the hypothesis,\\u000a right-handers, left-handers, and ambidextrous subjects were required to verify and falsify statements including the words\\u000a ABOVE and BELOW and the

Elisabetta Làdavas

1988-01-01

327

Order in vertically aligned carbon nanotube arrays  

SciTech Connect

We report the direct measurements on the bulk morphology of vertically aligned multiwalled carbon nanotube (CNT) arrays using small angle neutron scattering (SANS). SANS measurements at different heights of CNT arrays corresponding to different stages of the growth reveal increasing alignment order along the thickness and two distinctly different CNT morphologies. The observations suggest that the evolution of the macroscopic CNT morphologies be driven by competing collective growth and spatial constraints.

Wang, Hsin [ORNL; Xu, Z [Michigan State University, East Lansing; Eres, Gyula [ORNL

2006-01-01

328

Shutting off water in vertical fractures  

Microsoft Academic Search

This is a method of vertical fracturing of oil and gas wells to increase oil production without proportionally increasing the water production. The method consists of passing into the fracture a mixture of a carrier fluid and a particle-form propping agent, followed by a particulate sealing material composed of a material different from the particle-form propping agent. The particle-form propping

L. R. Kern; R. E. Wyant; T. K. Perkins

1966-01-01

329

Vertical graphene spin valve with Ohmic contacts  

NASA Astrophysics Data System (ADS)

Evident spin valve signals are observed in Co/graphene/Co sandwich structures with both monolayer and two-layer graphene stacks at temperatures from 1.5 K to 300 K. All the devices demonstrate linear current-voltage curves, indicating that an Ohmic property is dominating rather than a tunneling effect. The vertical graphene spin valves have potential applications in high-density non-volatile memories.

Meng, Jie; Chen, Jing-Jing; Yan, Yuan; Yu, Da-Peng; Liao, Zhi-Min

2013-09-01

330

Micronutrients and vertical transmission of HIV-1.  

PubMed

ABSTRACT Vertical transmission of HIV from mother to infant can occur during pregnancy, at the time of delivery, or post-natally through breast-feeding and is a major factor in the continuing spread of HIV infection. Inadequate nutritional status may increase the risk of vertical HIV transmission by influencing mater-nal and child factors for transmission. The potential effects on these factors include impaired systemic immune function in pregnant women, fetuses, and children; an increased rate of clinical, immunologic, and virologic disease progression; impaired epithelial integrity of the placenta and genital tract; increased viral shedding in breast milk from inflammation of breast tissue; increased risk of low birth weight and preterm birth; and impaired gastrointestinal immune function and integrity in fetuses and children. Micronutrient deficiencies are prevalent in many HIV-infected populations, and numerous studies have reported that these deficiencies impair immune responses, weaken epithelial integrity, and are associated with accelerated HIV disease progression. Although low serum vitamin A concentrations were shown to be associated with an increased risk of vertical HIV transmission in prospective cohort studies, randomized, placebo-controlled trials have reported that vitamin A and other vitamin supplements do not appear to have an effect on HIV transmission during pregnancy or the intrapartum period. However, the ability of prenatal and postpartum micronutrient supplements to reduce transmission during the breast-feeding period is still unknown. PMID:12036800

Dreyfuss, Michele L; Fawzi, Wafaie W

2002-06-01

331

Vertical nanopillars for highly localized fluorescence imaging  

PubMed Central

Observing individual molecules in a complex environment by fluorescence microscopy is becoming increasingly important in biological and medical research, for which critical reduction of observation volume is required. Here, we demonstrate the use of vertically aligned silicon dioxide nanopillars to achieve below-the-diffraction-limit observation volume in vitro and inside live cells. With a diameter much smaller than the wavelength of visible light, a transparent silicon dioxide nanopillar embedded in a nontransparent substrate restricts the propagation of light and affords evanescence wave excitation along its vertical surface. This effect creates highly confined illumination volume that selectively excites fluorescence molecules in the vicinity of the nanopillar. We show that this nanopillar illumination can be used for in vitro single-molecule detection at high fluorophore concentrations. In addition, we demonstrate that vertical nanopillars interface tightly with live cells and function as highly localized light sources inside the cell. Furthermore, specific chemical modification of the nanopillar surface makes it possible to locally recruit proteins of interest and simultaneously observe their behavior within the complex, crowded environment of the cell.

Xie, Chong; Hanson, Lindsey; Cui, Yi; Cui, Bianxiao

2011-01-01

332

Modification of vertical hemispherotomy for refractory epilepsy.  

PubMed

Delalande's vertical hemispherotomy is an innovative evolution of hemispherectomy in minimizing brain resection. We report our modification for this surgical procedure. We modified the original procedure in two aspects for the purpose of less brain resection and confirmation of the complete disconnection. Firstly, all procedures were done via an interhemispheric route instead of a transcortical route. Secondly, we set the anterior disconnection plane as the one that connects the anterior end of the choroidal fissure to the anterior end of the foramen of Monro, instead of the former to the subcallosal area. We applied this modified vertical hemispherotomy to 7 cases. Four cases were children with hemimegalencephaly and other 3 were adults with ulegyric hemisphere. Surgical procedure was completed without complication in all cases. There was no case that required CSF shunting. Seizure outcome was Engel's class I in 6 and class IV in 1. Postoperative MRI revealed complete disconnection of the affected hemisphere in all patients. We reported our modification of vertical hemispherotomy. Although these are minor modifications, they further minimized brain resection and may serve for less invasiveness of procedure and improvement in completeness of disconnection and its confirmation during surgery. PMID:23422258

Kawai, Kensuke; Morino, Michiharu; Iwasaki, Masaki

2013-02-17

333

22. Top Lateral Bracing & Top Chord, Vertical Tension Member ...  

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

22. Top Lateral Bracing & Top Chord, Vertical Tension Member 6, end Vertical Compression Members 5 & 4; South Swing Span; looking N. - Pacific Shortline Bridge, U.S. Route 20,spanning Missouri River, Sioux City, Woodbury County, IA

334

Going Up? The Pros and Cons of Vertical Expansion.  

ERIC Educational Resources Information Center

|Describes the advantages and disadvantages of the vertical expansion of school buildings. Considers such factors as fire protection, compliance with the Americans with Disabilities Act, and cost. Discusses alternatives to vertical expansion. (PKP)|

Myler, Patricia A.; Boggs, Richard C.

2002-01-01

335

Horizontal Cross Bracing Detail, Vertical Cross Bracing Detail, Horizontal Cross ...  

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

Horizontal Cross Bracing Detail, Vertical Cross Bracing Detail, Horizontal Cross Bracing Joint, Vertical Cross Bracing End Detail - Ceylon Covered Bridge, Limberlost Park, spanning Wabash River at County Road 900 South, Geneva, Adams County, IN

336

A Vertical Grid Module for Baroclinic Models of the Atmosphere  

SciTech Connect

The vertical grid of an atmospheric model assigns dynamic and thermo- dynamic variables to grid locations. The vertical coordinate is typically not height but one of a class of meteorological variables that vary with atmo- spheric conditions. The grid system is chosen to further numerical approx- imations of the boundary conditions so that the system is terrain following at the surface. Lagrangian vertical coordinates are useful in reducing the numerical errors from advection processes. That the choices will effect the numercial properties and accuracy is explored in this report. A MATLAB class for Lorentz vertical grids is described and applied to the vertical struc- ture equation and baroclinic atmospheric circulation. A generalized meteo- rolgoical coordinate system is developed which can support ?, isentropic ? vertical coordinate, or Lagrangian vertical coordinates. The vertical atmo- spheric column is a MATLAB class that includes the kinematic and ther- modynamic variables along with methods for computing geopoentials and terms relevant to a 3D baroclinc atmospheric model.

Drake, John B [ORNL

2008-04-01

337

Why the Operation I Prefer is Silastic™ Ring Vertical Gastroplasty  

Microsoft Academic Search

The author prefers Silastic™ ring vertical gastroplasty because it is a rapid and safe method for vertical gastroplasty, with\\u000a minimal complications and a success rate comparable to the other operations.

Otto L. Willbanks

1991-01-01

338

12. Connections at lower chord: diagonal to vertical, arch ring ...  

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

12. Connections at lower chord: diagonal to vertical, arch ring and lower chord and floor beams and verticals to lower chord. - Leatherwood Station Covered Bridge, Spanning Leatherwood Creek (moved to Billie Creek Village), Montezuma, Parke County, IN

339

Nearly Vertical Incidence Skywave (NVIS) HF Frequency Assignment Factors.  

National Technical Information Service (NTIS)

The propagation conditions for Nearly Vertical Incidence Skywave (NVIS) High Frequency (HF) communication that can be used without penetrating existing ionospheric layers are comparable to those under which ionospheric vertical incidence HF frequency meas...

S. Perlman

1973-01-01

340

6. DETAIL OF VERTICAL LIFT SPAN AND FIXED SPAN IMMEDIATELY ...  

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

6. DETAIL OF VERTICAL LIFT SPAN AND FIXED SPAN IMMEDIATELY NORTH OF VERTICAL LIFT SPAN, LOOKING SOUTHEAST. - Shippingsport Bridge, Spanning Illinois River at State Route 51, La Salle, La Salle County, IL

341

Adsorption to Fish Sperm of Vertically Transmitted Fish Viruses  

NASA Astrophysics Data System (ADS)

More than 99 percent of a vertically transmitted fish rhabdovirus, infectious hematopoietic necrosis virus, was removed from suspension in less than 1 minute by adsorption to the surface membrane of sperm from two genera of salmonid fishes. The vertically transmitted, infectious pancreatic necrosis virus adsorbed to a lesser degree, but no adsorption occurred with a second fish rhabdovirus that is not vertically transmitted. Such adsorption may be involved in vertical transmission of these viruses.

Mulcahy, Dan; Pascho, Ronald J.

1984-07-01

342

Disconjugate vertical memory-guided saccades to disparate targets  

Microsoft Academic Search

We studied the binocular coordination of normal memory-guided saccades and the possibility of inducing memory-based disconjugate\\u000a learning. First, we report that normal vertical memory-guided saccades to non-disparate targets are yoked vertically in the\\u000a two eyes as well as visually guided vertical saccades. To induce disconjugate vertical learning, at each trial we flashed\\u000a a target that was disparate (i.e. 8% more

M. P. Bucci; Z. Kapoula

2000-01-01

343

Models of Ratio Schedule Performance  

PubMed Central

Predictions of P. R. Killeen's (1994) mathematical principles of reinforcement were tested for responding on ratio reinforcement schedules. The type of response key, the number of sessions per condition, and first vs. second half of a session had negligible effects on responding. Longer reinforcer durations and larger grain types engeridered more responding, affecting primarily the parameter a (specific activation). Key pecking was faster than treadle pressing, affecting primarily the parameter ? (response time). Longer intertrial intervals led to higher overall response rates and shorter postreinforcement pauses and higher running rates, and ruled out some competing explanations. The treadle data required a distinction between the energetic requirements and rate-limiting properties of extended responses. The theory was extended to predict pause durations and run rates on ratio schedules.

Bizo, Lewis A.; Killeen, Peter R.

2008-01-01

344

ARM Energy Balance Bowen Ratio (EBBR) station: surf. heat flux and related data, 30-min  

SciTech Connect

The Energy Balance Bowen Ratio (EBBR) system produces 30-min estimates of the vertical fluxes of sensible and latent heat at the local surface. Flux estimates are calculated from observations of net radiation, soil surface heat flux, and the vertical gradients of temperature and relative humidity. Meteorological data collected by the EBBR are used to calculate bulk aerodynamic fluxes, which are used in the Bulk Aerodynamic Technique (BA) EBBR value-added product (VAP) to replace sunrise and sunset spikes in the flux data. A unique aspect of the system is the automatic exchange mechanism (AEM), which helps to reduce errors from instrument offset drift.

Cook, David

1993-07-04

345

Heat transfer in vertically aligned phase change energy storage systems  

SciTech Connect

Convection effects on heat transfer are analyzed in low temperature and vertically aligned phase change energy storage systems. This is performed by detailed temperature measurements in the phase change material (PCM) in eighteen locations forming a grid of six radial and three axial positions. The system constitutes a double pipe configuration, where commercial grade paraffin wax is stored in the annular space between the two pipes and water flows inside the inner pipe. Vertical alignment of the system allowed for reverse of the flow direction of the heat transfer fluid (HTF), which is water. Therefore, the PCM is heated from the bottom for HTF flow from bottom to top and from the top as the HTF flow direction is reversed. For the former case, natural convection affects the melting process. Collected data are used to study variations in the transient temperature distribution at axial and radial positions as well as for the two-dimensional temperature field. The data are used to calculate the PCM heat transfer coefficient and to develop correlations for the melting Fourier number. Results indicate that the PCM heat transfer coefficient is higher for the case of PCM heating from bottom to top. Nusselt number correlations are developed as a function of Rayleigh, Stefan, and Fourier numbers for the HTF flow from bottom to top and as a function of Stefan and Fourier numbers for HTF flow from top to bottom. The enhancement ratio for heat transfer caused by natural convection increases and then levels off as the inlet temperature of the HTF is increased.

El-Dessouky, H.T.; Bouhamra, W.S.; Ettouney, H.M.; Akbar, M. [Kuwait Univ., Safat (Kuwait). Dept. of Chemical Engineering

1999-05-01

346

Aerosol particle vertical distributions and optical properties over Singapore  

NASA Astrophysics Data System (ADS)

As part of the Seven Southeast Asian Studies (7SEAS) program, an Aerosol Robotic Network (AERONET) sun photometer and a Micro-Pulse Lidar Network (MPLNET) instrument have been deployed at Singapore to study the regional aerosol environment of the Maritime Continent (MC). Using coincident AERONET Level 2.0 and MPLNET Level 2.0a data from 24 September 2009 to 31 March 2011, the seasonal variability of aerosol particle vertical distributions and optical properties is examined. On average, the bulk (˜65%) of aerosol extinction is found below 1.5 km with substantial aerosol loading (˜35%) above. Possibly due to the transition from El Niño to La Niña conditions and subsequent reduction in fire events, the MPLNET mean integrated aerosol extinction is observed to be the lowest for July-September 2010, which coincides with the typical MC biomass burning season. On the other hand, the highest mean integrated extinctions are derived for January-March 2010 and 2011, which can be attributed to off-season MC biomass burning smoke and anthropogenic pollution. The seasonal lidar ratios also show higher occurrences ?60 sr, which are indicative of biomass burning smoke, for October 2009-June 2010, but such occurrences decrease from July 2010 to March 2011 when La Niña conditions prevail. In addition, principal component analysis (PCA) identifies five primary aerosol vertical profile types over Singapore, i.e. strongly-capped/deep near-surface layer (SCD; 0-1.35 km), enhanced mid-level layer (EML; 1.35-2.4 km), enhanced upper-level layer (EUL; 2.4-3.525 km), deep contiguous layer (DCL; 3.525-4.95 km) and deep multi-layer (DML; >4.95 km). PCA also identifies an off-season MC biomass burning smoke event from 22 February to 8 March 2010, which is subsequently examined in detail.

Chew, Boon Ning; Campbell, James R.; Salinas, Santo V.; Chang, Chew Wai; Reid, Jeffrey S.; Welton, Ellsworth J.; Holben, Brent N.; Liew, Soo Chin

2013-11-01

347

Effect of functional fatigue on vertical ground-reaction force in individuals with flat feet.  

PubMed

Context: Flat foot is one of the lower extremity deformities that might change kinetic variables of gait. Fatigue is one of the factors that can alter the vertical ground-reaction force (GRF). The effect of a fatiguing condition on vertical GRF has not been documented in individuals with flat feet. Objective: To examine the fatigue effect on vertical GRF in individuals with flat feet compared with a normal group during barefoot walking. Design: Repeated-measure ANOVA for the effects of fatigue on individuals with flat feet and normal feet. Setting: Biomechanics laboratory. Participants: 17 subjects with flat feet and 17 normal subjects (recruited according to their arch-height ratio). Main Outcome Measures: Three vertical GRF measures (F1, the first peak force; F2, minimum force; and F3, the second peak force) were extracted before and after a functional fatigue protocol. Results: No significant interaction between fatigue and group was observed for the 3 vertical GRF measures. For F2, fatigue and group effects were significant (P = .001 and P = .02, respectively). Furthermore, F2 was higher in the flat-feet group than in the normal group; F2 also increased after fatigue. For F3, only a significant fatigue effect was observed (P = .004). F3 decreased after fatigue in both groups. Conclusions: In the flat-feet group, a decrease in the variation of vertical GRF might be due to more flexible foot joints. After fatigue, muscles might lose their ability to control the foot joints and cause higher F2 in the flat-feet group. PMID:23475401

Boozari, Sahar; Jamshidi, Ali Ashraf; Sanjari, Mohammad Ali; Jafari, Hassan

2013-03-08

348

Effect of functional fatigue on vertical ground-reaction force in individuals with flat feet.  

PubMed

Context: Flat foot is one of the lower extremity deformities that might change kinetic variables of gait. Fatigue is one of the factors that can alter the vertical ground-reaction force (GRF). The effect of a fatiguing condition on vertical GRF has not been documented in individuals with flat feet. Objective: To examine the fatigue effect on vertical GRF in individuals with flat feet compared with a normal group during barefoot walking. Design: Repeated-measure ANOVA for the effects of fatigue on individuals with flat feet and normal feet. Setting: Biomechanics laboratory. Participants: 17 subjects with flat feet and 17 normal subjects (recruited according to their arch-height ratio). Main Outcome Measures: Three vertical GRF measures (F1, the first peak force; F2, minimum force; and F3, the second peak force) were extracted before and after a functional fatigue protocol. Results: No significant interaction between fatigue and group was observed for the 3 vertical GRF measures. For F2, fatigue and group effects were significant (P = .001 and P = .02, respectively). Furthermore, F2 was higher in the flat-feet group than in the normal group; F2 also increased after fatigue. For F3, only a significant fatigue effect was observed (P = .004). F3 decreased after fatigue in both groups. Conclusions: In the flat-feet group, a decrease in the variation of vertical GRF might be due to more flexible foot joints. After fatigue, muscles might lose their ability to control the foot joints and cause higher F2 in the flat-feet group. PMID:23941715

Boozari, Sahar; Jamshidi, Ali Ashraf; Sanjari, Mohammad Ali; Jafari, Hassan

2013-08-01

349

Fluorescence intensity ratio stereoscopic transform.  

PubMed

A novel approach to 3-D information processing of 2-D cell images is presented, called fluorescence intensity ratio stereoscopic transform (FIRST). Here, we describe its basic principle of image processing and show the results for the ratio of total internal reflection fluorescence (TIRF) to fluorescence intensity. A simple, intuitive transform algorithm would help us to easily obtain a clear stereoscopic image from two 2-D cell images with different fluorescence intensity. For this purpose, nonlinear evanescent-field (EF) imaging of cell-membrane surface and its intracellular structures by using on-chip grating coupler is achieved. This method enabled us to obtain cell images with different signal-to-background ratio and resolution under microfluidic environments. Specifically, we manipulated optic pathway to partially illuminate microscale objects within the microfluidic channel. These findings imply this method will enable selectively to detect optical signals of biomolecular interaction within the cell membrane in a controlled manner. Furthermore, we believe this approach will help to develop an optofluidic sensor for individually detecting dynamic behaviors of intracellular molecules in living cells under microfluidic cell culture environments. PMID:22121719

Yun, Hoyoung; Min, Junggi; Bang, Hyunwoo; Han, Dong-Chul; Lee, Soon-Geul; Lee, Won Gu

2011-07-01

350

Luminescence ratio indicators for oxygen  

SciTech Connect

To improve stability of optical sensors with respect to calibration, the authors developed oxygen indicator systems which have two luminescence bands, one of which is quenched by oxygen while the other is relatively unaffected by oxygen. The measured parameter is the relative intensity of the two bands. The following systems have been evaluated: (1) In water in the presence of ..gamma..-cyclodextrin, the ratio of pyrene monomer fluorescence to pyrene dimer fluorescence decreases with increasing oxygen partial pressure. (2) In water in the presence of ..beta..-cyclodextrin, the ratio of bromonaphthalene phosphorescence to fluorescence decreases with increasing oxygen partial pressure. (3) Bromonaphthoyl derivatives extracted into ..gamma..-cyclodextrin bonded to cellulose and dried show intense oxygen-dependent phosphorescence and oxygen-independent fluorescence. Of these, system 3 is most practical because it is more stable and has higher intensities with a larger change in intensity ratio. However, it is limited to measurements in dry samples, because 100% relative humidity is sufficient to quench phosphorescence.

Lee, E.D.; Werner, T.C.; Seitz, W.R.

1987-01-15

351

Failure to improve readability with a vertical typography  

Microsoft Academic Search

3 experiments found conventional horizontal typography to be superior to vertical. 1 experiment presented the stimulus tachistoscopically in a procedure quite similar to the procedure used in an earlier experiment that found vertical typography to be superior to conventional even with unpracticed Ss. 2 of the experiments used Ss who had been given practice reading 8000 words printed in vertical

E. B. Coleman; S. C. Hahn

1966-01-01

352

Vertical emission profiles for Europe based on plume rise calculations  

Microsoft Academic Search

The vertical allocation of emissions has a major impact on results of Chemistry Transport Models. However, in Europe it is still common to use fixed vertical profiles based on rough estimates to determine the emission height of point sources. This publication introduces a set of new vertical profiles for the use in chemistry transport modeling that were created from hourly

J. Bieser; A. Aulinger; V. Matthias; M. Quante; H. A. C. Denier van der Gon

2011-01-01

353

Novos métodos no estudo da estratificação vertical de marsupiais neotropicais  

Microsoft Academic Search

NEW METHODS FOR THE STUDY OF VERTICAL STRATIFICATION OF NEOTROPICAL OPOSSUMS. New methods have been developed for the study of vertical stratification on small neotropical mammals, alternative to traditional methods using live traps. We reviewed three such alternative methods to study vertical stratification of didelphid marsupials in tropical forests: performance tests in an ecomorphological approach, spool-and-line, and artificial nests. The

Ana Cláudia Delciellos; Diogo Loretto; Marcus Vinícius Vieira

2006-01-01

354

Evaluating the impact of vertical integration on health system peformance  

Microsoft Academic Search

Vertical integration is grounded in economic theory as a corporate strategy for reducing cost and enhancing efficiency. There were three purposes for this dissertation. The first was to describe and understand vertical integration theory. The review of the economic theory established vertical integration as a corporate cost reduction strategy in response to environmental, structural and performance dimensions of the market.

Sandra Dismer Murdock

2001-01-01

355

Contemporary Vertical Surface Displacements in Yellowstone National Park  

Microsoft Academic Search

The comparison of repeated geodetic leveling measurements is a well-established technique for the detection of contemporary vertical displacements Of the Earth's surface (see the reviews by Brown and Oliver [1976] and Vanicek et al. [1980]). The basis for contemporary vertical surface displacement studies in Yellowstone National Park was established in 1923 when leveling of second-order precision provided vertical control throughout

J. R. Pelton; R. B. Smith

1982-01-01

356

Vertical angular selectivity and grating degeneracy of volume holographic gratings  

Microsoft Academic Search

The vertical angular selectivity of volume holographic gratings in photorefractive crystals is investigated both theoretically and experimentally. The vertical selective angle and the shape of the grating degeneracy lines are derived by using a simplified geometrical model relating the k-vector sphere to the reference point plane. The study shows that volume gratings have finite selectivity in vertical direction, so that

Quan Yuan; Shiquan Tao; Zuqing Jiang; Xinchang Yang

1996-01-01

357

Diel Vertical Migration Thresholds of Karenia brevis (Dinophyceae).  

EPA Science Inventory

Light and nutrient availability change throughout dinoflagellate diel vertical migration (DVM) and/or with subpopulation location in the water column along the west Florida shelf. Typically, the vertical depth of the shelf is greater than the distance a subpopulation can vertical...

358

Vertical Integration Versus Outsourcing: A Knowledge-Based Reconciliation  

Microsoft Academic Search

In vertical integration literature, controversy remains over how organizational cost changes after vertical integration and how technological uncertainty influences vertical integration decisions. To reach a reconciliation, I draw on knowledge-based view of the firm (Grant, 1996, 1998; Spender, 1996, 1998), and propose a contingency model that examines moderating effects of knowledge absorptive capacity. In the new competitive landscape featured by

Jun Lin

359

SideWall Vertical Electrodes for Lateral Field Microfluidic Applications  

Microsoft Academic Search

This paper describes the design, fabrication, and testing of microfluidic devices enabled by electrodes embedded vertically in the side walls of SU-8 microchannels. With vertical electrodes on the side walls, one can generate higher lateral electrical fields uniform along the vertical direction in the channel (perpendicular to the substrate). By designing the electrode shapes and configurations, uniform and nonuniform electrical

Lisen Wang; Lisa Flanagan; Abraham P. Lee

2007-01-01

360

33 CFR 118.85 - Lights on vertical lift bridges.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Lights on vertical lift bridges. 118.85 Section 118.85 Navigation...AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span lights. The vertical lift span of every...

2009-07-01

361

33 CFR 118.85 - Lights on vertical lift bridges.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Lights on vertical lift bridges. 118.85 Section 118.85 Navigation...AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span lights. The vertical lift span of every...

2010-07-01

362

Development of wafer bonded vertical cavity surface emitting lasers  

Microsoft Academic Search

This thesis describes the development of wafer bonded vertical cavity surface emitting lasers. By employing a reactive low temperature bonding technique, we have successfully demonstrated oxide-defined 850 nm vertical- cavity surface-emitting lasers (VCSELs) on silicon substrates. In this dissertation the design, fabrication, characterization, and applications of wafer bonded vertical cavity surface emitting lasers have been studied. The reactive low temperature

Yanyan Xiong

2001-01-01

363

Using Ratio Analysis to Evaluate Financial Performance.  

ERIC Educational Resources Information Center

|The ways in which ratio analysis can help in long-range planning, budgeting, and asset management to strengthen financial performance and help avoid financial difficulties are explained. Types of ratios considered include balance sheet ratios, net operating ratios, and contribution and demand ratios. (MSE)|

Minter, John; And Others

1982-01-01

364

Envera Variable Compression Ratio Engine  

SciTech Connect

Aggressive engine downsizing, variable compression ratio and use of the Atkinson cycle are being combined to improve fuel economy by up to 40 percent relative to port fuel injected gasoline engines, while maintaining full engine power. Approach Engine downsizing is viewed by US and foreign automobile manufacturers as one of the best options for improving fuel economy. While this strategy has already demonstrated a degree of success, downsizing and fuel economy gains are currently limited. With new variable compression ratio technology however, the degree of engine downsizing and fuel economy improvement can be greatly increased. A small variable compression ratio (VCR) engine has the potential to return significantly higher vehicle fuel economy while also providing high power. Affordability and potential for near term commercialization are key attributes of the Envera VCR engine. VCR Technology To meet torque and power requirements, a smaller engine needs to do more work per stroke. This is typically accomplished by boosting the incoming charge with either a turbo or supercharger so that more energy is present in the cylinder per stroke to do the work. With current production engines the degree of engine boosting (which correlates to downsizing) is limited by detonation (combustion knock) at high boost levels. Additionally, the turbo or supercharger needs to be responsive and efficient while providing the needed boost. VCR technology eliminates the limitation of engine knock at high load levels by reducing compression ratio to {approx}9:1 (or whatever level is appropriate) when high boost pressures are needed. By reducing the compression ratio during high load demand periods there is increased volume in the cylinder at top dead center (TDC) which allows more charge (or energy) to be present in the cylinder without increasing the peak pressure. Cylinder pressure is thus kept below the level at which the engine would begin to knock. When loads on the engine are low the compression ratio can be raised (to as much as 18:1) providing high engine efficiency. It is important to recognize that for a well designed VCR engine cylinder pressure does not need to be higher than found in current production turbocharged engines. As such, there is no need for a stronger crankcase, bearings and other load bearing parts within the VCR engine. The Envera VCR mechanism uses an eccentric carrier approach to adjust engine compression ratio. The crankshaft main bearings are mounted in this eccentric carrier or 'crankshaft cradle' and pivoting the eccentric carrier 30 degrees adjusts compression ratio from 9:1 to 18:1. The eccentric carrier is made up of a casting that provides rigid support for the main bearings, and removable upper bearing caps. Oil feed to the main bearings transits through the bearing cap fastener sockets. The eccentric carrier design was chosen for its low cost and rigid support of the main bearings. A control shaft and connecting links are used to pivot the eccentric carrier. The control shaft mechanism features compression ratio lock-up at minimum and maximum compression ratio settings. The control shaft method of pivoting the eccentric carrier was selected due to its lock-up capability. The control shaft can be rotated by a hydraulic actuator or an electric motor. The engine shown in Figures 3 and 4 has a hydraulic actuator that was developed under the current program. In-line 4-cylinder engines are significantly less expensive than V engines because an entire cylinder head can be eliminated. The cost savings from eliminating cylinders and an entire cylinder head will notably offset the added cost of the VCR and supercharging. Replacing V6 and V8 engines with in-line VCR 4-cylinder engines will provide high fuel economy at low cost. Numerous enabling technologies exist which have the potential to increase engine efficiency. The greatest efficiency gains are realized when the right combination of advanced and new technologies are packaged together to provide the greatest gains at the least cost. Aggressive engine downsiz

Charles Mendler

2011-03-15

365

Fabrication of a vertical sidewall using double-sided anisotropic etching of <1?0?0> oriented silicon  

NASA Astrophysics Data System (ADS)

A double-sided wet etch process has been proposed to fabricate vertical structures in <1?0?0> oriented silicon substrate. Both sides of a {1?0?0} silicon wafer have been patterned identically along the <1?1?0> direction, and etched using potassium hydroxide (KOH) solution. By precisly controlling the etch time, using etch-timer structure and additive control, structures with smooth and vertical {1?1?0} sidewalls have been fabricated at the edges of a rectangular opening without undercut. Rectangular through-holes, bridges and cantilevers have been constructed using the proposed process. The measured average surface roughness of the vertical sidewall was 481 nm, which has been further reduced to 217 nm and 218 nm by postetching using a KOH-IPA and TMAH-Triton mixture, respectively. Slanted {4?1?1} planes exposed at the concave corners during the vertical etch process have been successfully removed or diminished by the postetching process. A bridge structure with a high aspect ratio of 39:1 has been fabricated, and cantilevers without undercutting were successfully constructed by applying the compensation technique. The proposed process can potentially be utilized in place of the deep reactive ion etching process for the fabrication of structures having vertical through-holes, such as through-silicon vias, high aspect ratio springs and filters for microfluidic applications.

Kim, Hyun-Seok; Kim, Jung-Mu; Bang, Yong-Seung; Song, Eun-Seok; Ji, Chang-Hyeon; Kim, Yong-Kweon

2012-09-01

366

Liquid-metal buoyant convection in a vertical cylinder with a strong vertical magnetic field and with a nonaxisymmetric temperature  

Microsoft Academic Search

In this paper the buoyant convection of a liquid metal in a circular cylinder with a vertical axis and with electrically insulating walls is treated. There is an externally applied, uniform, vertical magnetic field. A nonaxisymmetric heat flux at the vertical wall of the cylinder produces a nonaxisymmetric temperature, which drives a nonaxisymmetric liquid motion. The magnetic field is sufficiently

Nancy Ma; John S. Walker

1995-01-01

367

A conventional approach for comparing vertical reference frames  

NASA Astrophysics Data System (ADS)

A conventional transformation model between different realizations of a vertical reference system is an important tool for geodetic studies related to precise vertical positioning and physical height determination. Its fundamental role is the evaluation of the consistency for colocated vertical reference frames that are obtained from different observation techniques, data sources or optimal estimation strategies in terms of an appropriate set of "vertical datum perturbation" parameters. Our scope herein is to discuss a number of key issues related to the formulation of such a transformation model and to present some simple examples from its practical implementation in the comparison of existing vertical frames over Europe.

Kotsakis, C.

2012-12-01

368

Measurement of tau branching ratios  

SciTech Connect

We have measured the branching ratios for several tau decay modes. We use e/sup +/e/sup -/..-->..tau/sup +/tau/sup -/ events accumulated with the TPC/Two-Gamma facility at the SLAC e/sup +/e/sup -/ storage ring PEP. The data correspond to an integrated luminosity of 77 pb/sup -1/ at a center-of-mass energy of 29 GeV. The one- and three-charged-particle inclusive branching ratios of the tau decay are measured to be B/sub 1/ = (84.7 +- 1.0)% and B/sub 3/ = (15.1 +- 1.0)%, where B/sub 1/+B/sub 3/ is constrained to be 99.85%. The branching ratios of the two leptonic decay modes are B(tau/sup -/..-->..e/sup -/ nu-bar/sub e/..nu../sub tau/) = (18.4 +- 1.6)% and B(tau/sup -/..--> mu../sup -/ nu-bar/sub ..mu../..nu../sub tau/) = (17.7 +- 1.4)%. If we then assume lepton universality, we obtain B(tau/sup -/..-->..e/sup -/ nu-bar/sub e/..nu../sub tau/) = (18.3 +- 0.9)% and B(tau/sup -/..--> mu../sup -/ nu-bar/sub ..mu../..nu../sub tau/) = (17.8 +- 0.9)%. We measure the Cabibbo-allowed semihadronic decay mode B(tau/sup -/..--> pi../sup -/+neutral particles) = (47.0 +- 1.5)%, and the Cabibbo-suppressed tau decay mode B(tau/sup -/..-->..K/sup -/+neutral particles) = (1.6 +- 0.4)%. By looking for associated photons, we find B(tau/sup -/..-->..K/sup -/..pi../sup 0/+neutral particles) to be (1.2 +- 0.6)%.

Aihara, H.; Alston-Garnjost, M.; Avery, R.E.; Bakken, J.A.; Barbaro-Galtieri, A.; Barker, A.R.; Barnes, A.V.; Barnett, B.A.; Barnett, B.A.; Bauer, D.A.; and others

1987-03-01

369

Joint horizontal-vertical anisotropic scaling, isobaric and isoheight wind statistics from aircraft data  

NASA Astrophysics Data System (ADS)

Aircraft measurements of the horizontal wind have consistently found transitions from roughly k-5/3 to k-2.4 spectra at scales ?xc ranging from about 100-500 km. Since drop sondes find k-2.4 spectra in the vertical, the simplest explanation is that the aircraft follow gently sloping trajectories (such as isobars) so that at large scales, they estimate vertical rather than horizontal spectra. In order to directly test this hypothesis, we used over 14500 flight segments from GPS and TAMDAR sensor equipped commercial aircraft. We directly estimate the joint horizontal-vertical (?x, ?z) wind structure function finding - for both longitudinal and transverse components - that the ratio of horizontal to vertical scaling exponents is Hz ? 0.57 ± 0.02, close to the theoretical prediction of the 23/9D turbulence model which predicts Hz = 5/9 = 0.555…. This model also predicts that isobars and isoheight statistics will diverge after ?xc; using the observed fractal dimension of the isobars (?1.79 ± 0.02), we find that the isobaric scaling exponents are almost exactly as predicted theoretically and ?xc ? 160, 125 km, (transverse, longitudinal). These results thus give strong direct support to the 23/9D scaling stratification model.

Pinel, J.; Lovejoy, S.; Schertzer, D.; Tuck, A. F.

2012-06-01

370

Suppression of buoyancy-driven vortex flow resulting from a low speed jet impinging onto a heated disk in a vertical cylinder by cylinder top tilting  

Microsoft Academic Search

Buoyancy-driven vortex flow resulting from a low speed round gas jet impinging vertically downwards onto a heated horizontal circular disk confined in an adiabatic vertical cylindrical chamber can be strong and even unstable as the buoyancy-to-inertia ratio exceeds certain critical level. An experiment combining flow visualization and temperature measurement is conducted in the present study to explore the suppression of

J. C. Hsieh; C. W. Cheng; T. F. Lin

2004-01-01

371

Centropages behaviour: Swimming and vertical migration  

NASA Astrophysics Data System (ADS)

The evolutionary success of any species living in a variable environment depends on its capacity to enhance the probability of finding food and mates, and escaping predators. In the case of copepods of the genus Centropages, as in all planktonic copepods, their swimming behaviour is closely tied to these vital aspects, and shows a high degree of plasticity and adaptive capacity. Swimming mechanisms of Centropages change radically during development, mainly in the transition between naupliar stages to the 1st copepodite; nauplii do not produce feeding currents, whereas copepodites do. Adults and late developmental stages of C. typicus, C. hamatus and C. velificatus spend most of the time in slow swimming and resting breaks, with occasional and brief fast swimming (escape reactions) and grooming events. Slow swimming is closely related to the creation of feeding currents, and results from the beating of the cephalic appendages in a “fling and clap” manner. The proportion of time allocated to the different swimming activities depends on sensory cues like type and concentration of food, presence of potential mates, light intensity, hydrodynamic flow, etc. The responses of Centropages to changes in flow velocity fluctuations (small-scale turbulence) are similar to the escape responses (fast swimming) triggered by the presence of potential predators. Centropages generally have standard nocturnal vertical migration patterns involving considerable vertical displacements. This behaviour is closely related to the narrow spectral sensitivity and the low intensity threshold of the genus, and has important consequences for the active vertical transport of matter and energy. The variety of responses of Centropages to environmental changes, and in general all the aspects related to its swimming behaviour seem to be controlled by the trade-off between energetic gains (food intake), losses (swimming energy expenditure), and predation risk. Behavioural plasticity and adaptation appear to be the most relevant characteristics for the success of the genus in a wide range of marine environments.

Alcaraz, Miguel; Saiz, Enric; Calbet, Albert

2007-02-01

372

Vertical Lorentz Force and Cross-Field Currents in the Photospheric Magnetic Fields of Solar Active Regions  

NASA Astrophysics Data System (ADS)

We demonstrate that the vertical Lorentz force and a corresponding lower limit of the cross-field electric current density can be calculated from vector magnetograms of solar active regions obtained at a single height in the solar atmosphere, provided that the vertical gradient of the magnetic field strength is known at this height. We use a predicted vertical magnetic field gradient derived from a previous analysis. By testing various force-free solutions, we find that the numerical accuracy of our method is satisfactory. Applying the method to active region photospheric vector magnetograms, we find vertical Lorentz forces ranging from several hundredths to a few tenths of the typical photospheric gravitational force, and typical cross-field current densities up to several times 10 mA m-2. The typical vertical current density is found to be 2-3 times smaller, on the order of 10-15 mA m-2. These differences are above the associated uncertainties. The values of the cross-field currents decrease in an averaged vector magnetogram, but the ratio of the cross-field to the vertical current density increases, also above the uncertainties. We conclude that the photospheric active region magnetic fields are not force-free, contrary to the conjectures of some recent studies.

Georgoulis, Manolis K.; LaBonte, Barry J.

2004-11-01

373

Vertical-bandwidth-limited digital holography.  

PubMed

Optical scanning holography (OSH) is a promising technique to acquire a big-size digital hologram. However, the acquisition speed is limited by the mechanical scanner. In this Letter we apply the OSH in conjunction with an anisotropic low-pass filtering pupil to acquire vertical-bandwidth-limited (VBL) holograms. The size and the acquisition time of the VBL hologram can be reduced by one order of magnitude while the horizontal resolution remains the same as the conventional scanning hologram. The VBL hologram can be coded as an off-axis hologram without any postfiltering. Meanwhile, the full horizontal bandwidth of the displaying device can be capitalized. PMID:22743459

Liu, Jung-Ping; Lee, Chieh-Cheng; Lo, Ying-Hau; Luo, Dao-Zheng

2012-07-01

374

Silicon vertical microstructure fabrication by catalytic etching  

NASA Astrophysics Data System (ADS)

This study presents an effective, simple and inexpensive process for forming micro-scale vertical structures on a (1?0?0) silicon wafer. Several modified etchants and micro-patterns including rectangular, snake-like, circular and comb patterns were employed to determine the optimum etching process. We found that an etchant solution consisting of 4.6 M hydrofluoric acid, 0.44 M hydrogen peroxide and isopropyl alcohol produces microstructures at an etching rate of 0.47 µm min-1 and surface roughness of 17.4 nm. All the patterns were transferred faithfully to the silicon substrate.

Huang, Mao-Jung; Yang, Chii-Rong; Chang, Chun-Ming; Chu, Nien-Nan; Shiao, Ming-Hua

2012-08-01

375

Vertical Cable Seismic Survey for Hydrothermal Deposit  

NASA Astrophysics Data System (ADS)

The vertical cable seismic is one of the reflection seismic methods. It uses hydrophone arrays vertically moored from the seafloor to record acoustic waves generated by surface, deep-towed or ocean bottom sources. Analyzing the reflections from the sub-seabed, we could look into the subsurface structure. This type of survey is generally called VCS (Vertical Cable Seismic). Because VCS is an efficient high-resolution 3D seismic survey method for a spatially-bounded area, we proposed the method for the hydrothermal deposit survey tool development program that the Ministry of Education, Culture, Sports, Science and Technology (MEXT) started in 2009. We are now developing a VCS system, including not only data acquisition hardware but data processing and analysis technique. Our first experiment of VCS surveys has been carried out in Lake Biwa, JAPAN in November 2009 for a feasibility study. Prestack depth migration is applied to the 3D VCS data to obtain a high quality 3D depth volume. Based on the results from the feasibility study, we have developed two autonomous recording VCS systems. After we carried out a trial experiment in the actual ocean at a water depth of about 400m and we carried out the second VCS survey at Iheya Knoll with a deep-towed source. In this survey, we could establish the procedures for the deployment/recovery of the system and could examine the locations and the fluctuations of the vertical cables at a water depth of around 1000m. The acquired VCS data clearly shows the reflections from the sub-seafloor. Through the experiment, we could confirm that our VCS system works well even in the severe circumstances around the locations of seafloor hydrothermal deposits. We have, however, also confirmed that the uncertainty in the locations of the source and of the hydrophones could lower the quality of subsurface image. It is, therefore, strongly necessary to develop a total survey system that assures a accurate positioning and a deployment techniques. We have carried out two field surveys in FY2011. One is a 3D survey with a boomer for a high-resolution surface source and the other one for an actual field survey in the Izena Cauldron an active hydrothermal area in the Okinawa Trough. Through these surveys, the VCS will become a practical exploration tool for the exploration of seafloor hydrothermal deposits.

Asakawa, E.; Murakami, F.; Sekino, Y.; Okamoto, T.; Ishikawa, K.; Tsukahara, H.; Shimura, T.

2012-04-01

376

Numerical modeling of vertical cavity semiconductor lasers  

SciTech Connect

A vertical cavity surface emitting laser (VCSEL) is a diode laser whose optical cavity is formed by growing or depositing DBR mirror stacks that sandwich an active gain region. The resulting short cavity supports lasing into a single longitudinal mode normal to the wafer, making these devices ideal for a multitude of applications, ranging from high-speed communication to high-power sources (from 2D arrays). This report describes the development of a numerical VCSEL model, whose goal is to both further their understanding of these complex devices and provide a tool for accurate design and data analysis.

Chow, W.W.; Hadley, G.R.

1996-08-01

377

Vertical Cavities and Micro-Ring Resonators  

NASA Astrophysics Data System (ADS)

The scope of this chapter is to present the concepts of vertical cavities (VCs) and ? -ring resonators (MRs). The chapter commences with the motivation for progressing beyond conventional edge-emitting cavities emphasising on the potential of VC and MRs. The fundamental physics of VC and MRs is then analysed focusing on device design aspects. VCs are studied for optical amplifier applications. Lasing VCs are analysed in terms of polarisation dynamics. MRs in single and multi-ring configurations, like coupled resonator optical waveguides (CROWs) and side-coupled integrated spaced sequence of resonators, (SCISSORs) are discussed. Active MRs for lasers and amplifiers are investigated.

Alexandropoulos, Dimitris; Scheuer, J.; Adams, M. J.

378

So2 vertical profile on Venus  

NASA Astrophysics Data System (ADS)

Introduction The distribution of SO2 below the clouds of Venus is an unsettled matter because various entry probes and earth observed values show big differences for the same altitude levels. A new analysis of the SO2 vertical profile with a 'best of' data set [1] is compared to the Vega 1 and Vega 2 results. For the analysis of the SO2 vertical profile two models have been formulated. While one model considers the fast decrease of SO2 with descending altitude and starts with 0 ppmV at the surface, the other model starts with 25 ppmV, as indicated by Vega 1. Although there is a lack of information on the lowest 10 kms of the atmosphere, an analysis should be done to understand the geological evolution and a possible activity on Venus. Vertical Profiles The two models produce two different vertical profiles and with those it was possible to calculate the mass of SO2 in the whole lower atmosphere. It is important to note that SO2 nearly disappears at 69 km height [1,3] while 99,6% of the whole mass is still contained in the lower atmosphere. The difference in the results is based on the different surface values, which have been used. The first model stands in good agreement with the Vega mission data and the second model can be used as an upper limit of SO2 in the atmosphere. The results yield a good estimation of how much SO2 is existent and give new discussion points about volcanic activity on Venus and a possible still unknown SO2 destroying mechanism. References [1] Bertaux, J. et al. (1996) JGR, 101, 12709-12745. [2] de Bergh, C. et al. (2006) Planetary and Space Sci., 54, 1389-1397. [3] Esposito L.W. et al., (1997) Venus II : Geology, Geophysics, Atmosphere, and Solar Wind Environment. Edited by Stephen W. Bougher, D.M. Hunten, and R.J. Philips. Tucson, AZ : University of Arizona Press, 415-458

Duricic, Alen; Leitner, Johannes; Firneis, Maria G.

2010-05-01

379

Creating a vertical stop for interocclusal records.  

PubMed

This article describes a method of making an accurate interocclusal record when the most distal tooth is an abutment of a fixed partial denture. The method uses conical stops, prepared in the enamel of the abutment or made of composite or a metal core covered with composite, to maintain the vertical dimension of occlusion and to act as a third point of reference for a stable occlusal relationship when occluding the definitive casts. This article also explains how to use the cones and how to make each variety. PMID:10793393

Sato, Y; Hosokawa, R; Tsuga, K; Kubo, T

2000-05-01

380

Lidar measurements of ozone vertical profiles  

NASA Astrophysics Data System (ADS)

Attention is given to the differential absorption lidar technique used in measuring the vertical ozone distribution of the troposphere and stratosphere. The basis of these measurements are UV wavelength range laser sources which encompass Nd:YAG pumped dye lasers and Exciplex lasers. High temporal and spatial resolution, together with measurement continuity, allow the observation of ozone variations at various time and space scales that are important in such areas of current interest as troposphere-stratosphere exchanges, long range transport, the global ozone budget, and correlations between ozone number densities and other atmospheric parameters.

Megie, G. J.; Ancellet, G.; Pelon, J.

1985-11-01

381

Interlayer cooling potential in vertically integrated packages  

Microsoft Academic Search

The heat-removal capability of area-interconnect-compatible interlayer cooling in vertically integrated, high-performance\\u000a chip stacks was characterized with de-ionized water as coolant. Correlation-based predictions and computational fluid dynamic\\u000a modeling of cross-flow heat-removal structures show that the coolant temperature increase due to sensible heat absorption\\u000a limits the cooling performance at hydraulic diameters ?200 ?m. An experimental investigation with uniform and double-side\\u000a heat flux at

T. Brunschwiler; B. Michel; H. Rothuizen; U. Kloter; B. Wunderle; H. Oppermann; H. Reichl

2009-01-01

382

Initial growth of vertically aligned carbon nanofibers  

NASA Astrophysics Data System (ADS)

Samples of vertically aligned carbon nanofibers (VACNFs) were viewed transverse to the growth direction and studied using both scanning and transmission electron microscopy. The VACNFs are composed of graphite layers nearly parallel to the substrate at their bottom end, gradually formed graphite ``cups'' in the main body, and a catalyst particle on the tip. The formation of such structure is due to the corresponding transformation of the shape of the catalyst particle during initial VACNF growth. A model for their initial growth is proposed.

Cui, Hongtao; Yang, Xiaojing; Simpson, Michael L.; Lowndes, Douglas H.; Varela, Maria

2004-05-01

383

Estimation of the vertical velocities associated with large scale dynamics  

NASA Astrophysics Data System (ADS)

Apart from some exceptions (e.g. certain convection movements, small scale turbulence, or surface gravity wave), vertical velocities in the ocean are generally too weak to be measured. In particular, that is the case of the vertical movements associated to the large scale (basin wide) dynamics. This prevents any accurate assessment of the thermohaline circulation return flow and the thermocline vertical ventilation (mass, heat, oxygen and carbon fluxes). A 24 year averaged global run is used to assess the domain of validity of the linear vorticity balance (LVB). In this data set vertical velocities are mainly controlled by the large scale LVB dynamics at subtropical and tropical latitudes. Therefore it should be possible to reconstruct the vertical velocity field by integrating vertically the LVB with an appropriate boundary condition. Various conditions have been tested and it turns out that the condition of no vertical motion at 1000 m is the most promising for applying the same methodology to climatological observations ...

Estrade, P.; Lazar, A.; Ndoye, S.

2012-04-01

384

Laser surface modification with powder feeding for vertical surfaces  

NASA Astrophysics Data System (ADS)

In many applications such as cylinder body, sleeve and mould side wall, vertical surfaces need to be strengthening together with horizontal surfaces. In this paper, a new powder feeding nozzle for laser vertical surface treating was designed and a whole laser surface modification system with powder feeding for vertical surfaces is developed. By using this system, experimental work on laser remelting, laser alloying with powder feeding, laser cladding with powder feeding was performed on vertical surfaces of gray iron substrates. The microstructure, composition and hardness distribution were analyzed. The results indicate that the properties of the vertical surfaces have been greatly improved after these treatments. The powder feeding nozzle and vertical processing can realize various vertical surface modifications with or without powder feeding, which has a promising prospect in industry applications.

He, Jingjiang; Zhong, Minlin; Li, FengSheng; Liu, Wenjin; Zhang, Yu

2005-01-01

385

GaN-based vertical cavity lasers with semiconductor/dielectric and all dielectric reflectors  

NASA Astrophysics Data System (ADS)

GaN-based vertical cavity structures containing bottom AlN/GaN DBRs with top dielectric DBRs on freestanding c-GaN and all dielectric DBRs on GaN on c-sapphire were investigated. Epitaxial lateral overgrowth (ELO) technique allowed the use of both top and bottom all dielectric reflector stacks without substrate removal and the fabrication of the active region containing InGaN multiple quantum wells entirely on the nearly defect-free laterally grown wing regions to avoid nonradiative centers caused by extended and point defects. Compared with the cavity containing hybrid-DBRs on freestanding GaN, the cavity with all dielectric DBRs exhibited quality factors up to 1200 at high optical excitation and an order of magnitude lower stimulated emission threshold density (nearly 5 ?J/cm2). Vertical to lateral growth ratio for ELO could be enhanced up to 5 by increasing the V/III ratio and employment of NH3 modulation, which minimizes the use of dry etching to reduce the cavity thickness and therefore is promising for high quality vertical cavities with all dielectric DBRs.

Zhang, F.; Okur, S.; Hafiz, S.; Avrutin, V.; Özgür, Ü.; Morkoç, H.

2013-03-01

386

Application of a numerical model for the planetary boundary layer to the vertical distribution of radon and its daughter products  

NASA Astrophysics Data System (ADS)

A one-dimensional numerical planetary boundary layer (PBL) model is developed and applied to study the vertical distribution of radon and its daughter products in the atmosphere. The meteorological model contains parameterization for the vertical diffusion coefficient based on turbulent kinetic energy and energy dissipation ( E- ? model). The increased vertical resolution and the realistic concentration of radon and its daughter products based on the time-dependent PBL model is compared with the steady-state model results and field observations. The ratio of radon concentration at higher levels to that at the surface has been studied to see the effects of atmospheric stability. The significant change in the vertical profile of concentration due to decoupling of the upper portion of the boundary layer from the shallow lower stable layer is explained by the PBL model. The disequilibrium ratio of 214Bi/ 214Pb broadly agrees with the observed field values. The sharp decrease in the ratio during transition from unstable to stable atmospheric condition is also reproduced by the model.

Vinod Kumar, A.; Sitaraman, V.; Oza, R. B.; Krishnamoorthy, T. M.

387

Vertical cavity surface emitting lasers emitting near 1.5 {mu}m with Sb-based reflectors  

SciTech Connect

We describe use of AlAsSb/AlGaAsSb lattice matched to InP for distributed Bragg reflectors. These structures are integral to several surface normal devices, in particular vertical cavity surface emitting lasers. The high refractive index ratio of these materials allows formation of a highly reflective mirror with relatively few mirror pairs. As a result, we have been able to show for the first time the 77K CW operation of an optically pumped, monolithic, all-epitaxial vertical cavity laser, emitting at 1.56 {mu}m.

Blum, O.; Klem, J.F.; Vawter, G.A. [and others

1998-04-01

388

The Microtremor H/V Spectral Ratio and Lateral Heterogeneity  

NASA Astrophysics Data System (ADS)

The average cross correlation of the ground motion fluctuations due to microtremors at pairs of given receivers, in the frequency domain, is linked to the imaginary part of Green function for such locations. For a single recording point, the average autocorrelation measures energy density and the Green function side of the equation is proportional to the power injected into the medium by a unit harmonic load at that point. This is the pseudo reflection response of the site. The problem has been dealt with recently for a horizontal stack of layers over a half-space which seems to be appropriate to study cases when ground motion is horizontally isotropic. Horizontal-to-vertical (H/V) spectral ratios of microtremors have been traditionally interpreted as representing either directly the S wave amplification or the Rayleigh wave ellipticity for a horizontal stack of layers. However, based on the diffuse field theory the microtremor H/V spectral ratio corresponds to the square root of the ratio of the imaginary part of horizontal displacement for a horizontally applied unit harmonic load, Imag.[G11], to the imaginary part of vertical displacement for a vertically applied unit load, Imag.[G33]. Both the loads and receivers are at the free surface. Therefore, we can invert the underground structure below a site if we observe microtremors there by using theoretical point source solution. For a sufficiently flat, horizontal stack of layers underneath a site we can easily calculate the theoretical Green function for that 1-D model. On the other hand, for a laterally heterogeneous underground structure, the horizontal reflection responses are different and in order to interpret microtremor H/V spectral ratios a numerical approach is needed. We can use the 3-D Finite Difference Method or the Indirect Boundary Element Method to study a model of a laterally heterogeneous elastic layer over a half-space. As observational evidence of 3-D microtremor H/V spectral ratios, we show that significant directional dependency has been observed at a site in Uji campus, Kyoto University, Japan, where the bedrock depth is varying from east to west from 250m to 420m within 1 km. The observed microtremor NS/UD spectral ratios are quite stable and have only one peak at around 2 seconds. On the other hand, the EW/UD spectral ratios are not as stable and have two peaks for most of the time sections that we observed for a whole day. This directional dependence can be considered to be the result of 3-D surface geology. After preliminary 1-D analysis using a model with a horizontal stack of layers, we perform 3-D point source analysis to see directional dependence in the Green function similar to the observation.

Hirokawa, T.; Matsushima, S.; Kawase, H.; Sanchez-Sesma, F. J.; Pérez Gavilán, J. J.; Suarez, M.; Salinas, V.

2010-12-01

389

The capillary interaction between two vertical cylinders  

NASA Astrophysics Data System (ADS)

Particles floating at the surface of a liquid generally deform the liquid surface. Minimizing the energetic cost of these deformations results in an inter-particle force which is usually attractive and causes floating particles to aggregate and form surface clusters. Here we present a numerical method for determining the three-dimensional meniscus around a pair of vertical circular cylinders. This involves the numerical solution of the fully nonlinear Laplace-Young equation using a mesh-free finite difference method. Inter-particle force-separation curves for pairs of vertical cylinders are then calculated for different radii and contact angles. These results are compared with previously published asymptotic and experimental results. For large inter-particle separations and conditions such that the meniscus slope remains small everywhere, good agreement is found between all three approaches (numerical, asymptotic and experimental). This is as expected since the asymptotic results were derived using the linearized Laplace-Young equation. For steeper menisci and smaller inter-particle separations, however, the numerical simulation resolves discrepancies between existing asymptotic and experimental results, demonstrating that this discrepancy was due to the nonlinearity of the Laplace-Young equation.

Cooray, Himantha; Cicuta, Pietro; Vella, Dominic

2012-07-01

390

Vertical shaft V-type engine  

SciTech Connect

A vertical crankshaft V-type engine is described which consists of a vertical crankshaft having an upper end, a pair of cylinders arranged horizontally forming a V with respect to each other, and each having a cylinder head; a carburetor operatively connected to the cylinders and mounted in the V defined by the cylinders. An air cleaner is operatively connected to the carburetor and mounted upwardly of the carburetor; a flywheel is secured to the upper end of the crankshaft; an air fan is mounted on top of the flywheel; a fan housing covers the cylinders and the air fan, and has a side wall along the crankshaft; and means provide air from the fan to the air cleaner and to the cylinder heads for cooling the latter. The means include an air-intake port leading to the air cleaner and extending substantially normal from the side wall. The means also include an air duct mounted inside the side wall located substantially perpendicular to the port and connected to the air fan in communication therewith for conducting air to the cylinder heads.

Fujikawa, T.; Hirata, M.; Tamba, S.

1987-04-21

391

Vertical profiling of air pollution at RAPCD  

NASA Astrophysics Data System (ADS)

Local and regional pollution interact at the interface between the Planetary Boundary Layer and the Free Troposphere. The vertical distributions of ozone, aerosols, and winds must be measured with high temporal and vertical resolution to characterize this interchange and ultimately to accurately forecast ozone and aerosol pollution. To address this critical issue, the Regional Atmospheric Profiling Center for Discovery (RAPCD) was built and instrumented in the National Space Science and Technology Center on the UAH campus. The UV DIAL ozone lidar, Nd:YAG aerosol lidar, and 2-micron Doppler wind lidar, along with balloon-borne ECC ozonesondes, form the core of the RAPCD instrumentation for studying this problem. Instrumentation in the associated Mobile Integrated Profiling (MIPS) laboratory includes a 915Mhz profiler, sodar, and ceilometer. The collocated Applied Micro-particle Optics and Radiometry (A?OR) laboratory hosts the FTIR, MOUDI, and optical particle counter. Using MODELS-3 analysis by colleagues, and cooperative ventures with the co-located National Weather Service Forecasting Office in Huntsville, AL, we are developing a unique facility for advancing the state-of-the-science in pollution forecasting.

Newchurch, Michael J.; Fuller, Kirk A.; Bowdle, David A.; Johnson, Steven; McNider, Richard T.; Knupp, Kevin; Lapenta, Bill; Gillani, Noor; Biazar, Arastoo; Burris, John

2004-09-01

392

High-Performance Vertical Organic Transistors.  

PubMed

Vertical organic thin-film transistors (VOTFTs) are promising devices to overcome the transconductance and cut-off frequency restrictions of horizontal organic thin-film transistors. The basic physical mechanisms of VOTFT operation, however, are not well understood and VOTFTs often require complex patterning techniques using self-assembly processes which impedes a future large-area production. In this contribution, high-performance vertical organic transistors comprising pentacene for p-type operation and C60 for n-type operation are presented. The static current-voltage behavior as well as the fundamental scaling laws of such transistors are studied, disclosing a remarkable transistor operation with a behavior limited by injection of charge carriers. The transistors are manufactured by photolithography, in contrast to other VOTFT concepts using self-assembled source electrodes. Fluorinated photoresist and solvent compounds allow for photolithographical patterning directly and strongly onto the organic materials, simplifying the fabrication protocol and making VOTFTs a prospective candidate for future high-performance applications of organic transistors. PMID:23637074

Kleemann, Hans; Günther, Alrun A; Leo, Karl; Lüssem, Björn

2013-05-01

393

Vertical Slot Convection: A linear study  

SciTech Connect

The linear stability properties of fluid convection in a vertical slot were studied. We use a Fourier-Chebychev decomposition was used to set up the linear eigenvalue problems for the Vertical Slot Convection and Benard problems. The eigenvalues, neutral stability curves, and critical point values of the Grashof number, G, and the wavenumber were determined. Plots of the real and imaginary parts of the eigenvalues as functions of G and [alpha] are given for a wide range of the Prandtl number, Pr, and special note is made of the complex mode that becomes linearly unstable above Pr [approximately] 12.5. A discussion comparing different special cases facilitates the physical understanding of the VSC equations, especially the interaction of the shear-flow and buoyancy induced physics. Making use of the real and imaginary eigenvalues and the phase properties of the eigenmodes, the eigenmodes were characterized. One finds that the mode structure becomes progressively simpler with increasing Pr, with the greatest complexity in the mid ranges where the terms in the heat equation are of roughly the same size.

McAllister, A. (Tokyo Univ. (Japan)); Steinolfson, R. (Southwest Research Inst., San Antonio, TX (United States)); Tajima, T. (Texas Univ., Austin, TX (United States). Inst. for Fusion Studies)

1992-11-01

394

Vertical Slot Convection: A linear study  

SciTech Connect

The linear stability properties of fluid convection in a vertical slot were studied. We use a Fourier-Chebychev decomposition was used to set up the linear eigenvalue problems for the Vertical Slot Convection and Benard problems. The eigenvalues, neutral stability curves, and critical point values of the Grashof number, G, and the wavenumber were determined. Plots of the real and imaginary parts of the eigenvalues as functions of G and {alpha} are given for a wide range of the Prandtl number, Pr, and special note is made of the complex mode that becomes linearly unstable above Pr {approximately} 12.5. A discussion comparing different special cases facilitates the physical understanding of the VSC equations, especially the interaction of the shear-flow and buoyancy induced physics. Making use of the real and imaginary eigenvalues and the phase properties of the eigenmodes, the eigenmodes were characterized. One finds that the mode structure becomes progressively simpler with increasing Pr, with the greatest complexity in the mid ranges where the terms in the heat equation are of roughly the same size.

McAllister, A. [Tokyo Univ. (Japan); Steinolfson, R. [Southwest Research Inst., San Antonio, TX (United States); Tajima, T. [Texas Univ., Austin, TX (United States). Inst. for Fusion Studies

1992-11-01

395

High vertical resolution crosswell seismic imaging  

DOEpatents

A method for producing high vertical resolution seismic images from crosswell data is disclosed. In accordance with one aspect of the disclosure, a set of vertically spaced, generally horizontally extending continuous layers and associated nodes are defined within a region between two boreholes. The specific number of nodes is selected such that the value of a particular characteristic of the subterranean region at each of the nodes is one which can be determined from the seismic data. Once values are established at the nodes, values of the particular characteristic are assigned to positions between the node points of each layer based on the values at node within that layer and without regard to the values at node points within any other layer. A seismic map is produced using the node values and the assigned values therebetween. In accordance with another aspect of the disclosure, an approximate model of the region is established using direct arrival traveltime data. Thereafter, the approximate model is adjusted using reflected arrival data. In accordance with still another aspect of the disclosure, correction is provided for well deviation. An associated technique which provides improvements in ray tracing is also disclosed.

Lazaratos, Spyridon K. (Houston, TX)

1999-12-07

396

Control system for a vertical axis windmill  

DOEpatents

A vertical axis windmill having a rotating structure is provided with a series of articulated vertical blades whose positions are controlled to maintain a constant RPM for the rotating structure, when wind speed is sufficient. A microprocessor controller is used to process information on wind speed, wind direction and RPM of the rotating structure to develop an electrical signal for establishing blade position. The preferred embodiment of the invention, when connected to a utility grid, is designed to generate 40 kilowatts of power when exposed to a 20 mile per hour wind. The control system for the windmill includes electrical blade actuators that modulate the blades of the rotating structure. Blade modulation controls the blade angle of attack, which in turn controls the RPM of the rotor. In the preferred embodiment, the microprocessor controller provides the operation logic and control functions. A wind speed sensor provides inputs to start or stop the windmill, and a wind direction sensor is used to keep the blade flip region at 90.degree. and 270.degree. to the wind. The control system is designed to maintain constant rotor RPM when wind speed is between 10 and 40 miles per hour.

Brulle, Robert V. (St. Louis County, MO)

1983-10-18

397

Daytime HONO vertical gradients during SHARP 2009 in Houston, TX  

NASA Astrophysics Data System (ADS)

Nitrous Acid (HONO) plays an important role in tropospheric chemistry as a precursor of the hydroxyl radical (OH), the most important oxidizing agent in the atmosphere. Nevertheless, the formation mechanisms of HONO are still not completely understood. Recent field observations found unexpectedly high daytime HONO concentrations in both urban and rural areas, which point to unrecognized, most likely photolytically enhanced HONO sources. Several gas-phase, aerosol, and ground surface chemistry mechanisms have been proposed to explain elevated daytime HONO, but atmospheric evidence to favor one over the others is still weak. New information on whether HONO formation occurs in the gas-phase, on aerosol, or at the ground may be derived from observations of the vertical distribution of HONO and its precursor nitrogen dioxide, NO2, as well as from its dependence on solar irradiance or actinic flux. Here we present field observations of HONO, NO2 and other trace gases in three altitude intervals (30-70 m, 70-130 m and 130-300 m) using UCLA's long path DOAS instrument, as well as in situ measurements of OH, NO, photolysis frequencies and solar irradiance, made in Houston, TX, during the Study of Houston Atmospheric Radical Precursor (SHARP) experiment from 20 April to 30 May 2009. The observed HONO mixing ratios were often ten times larger than the expected photostationary state with OH and NO. Larger HONO mixing ratios observed near the ground than aloft imply, but do not clearly prove, that the daytime source of HONO was located at or near the ground. Using a pseudo steady-state (PSS) approach, we calculated the missing daytime HONO formation rates, Punknown, on four sunny days. The NO2-normalized Punknown, Pnorm, showed a clear symmetrical diurnal variation with a maximum around noontime, which was well correlated with actinic flux (NO2 photolysis frequency) and solar irradiance. This behavior, which was found on all clear days in Houston, is a strong indication of a photolytic HONO source. [HONO]/[NO2] ratios also showed a clear diurnal profile, with maxima of 2-3% around noon. PSS calculations show that this behavior cannot be explained by the proposed gas-phase reaction of photoexcited NO2 (NO2*) or any other gas-phase or aerosol photolytic process occurring at similar or longer wavelengths than that of HONO photolysis. HONO formation by aerosol nitrate photolysis in the UV also seems to be unlikely. Pnorm correlated better with solar irradiance (average R2 = 0.85/0.87 for visible/UV) than with actinic flux (R2 = 0.76) on the four sunny days, clearly pointing to HONO being formed at the ground rather than on the aerosol or in the gas-phase. In addition, the observed [HONO]/[NO2] diurnal variation can be explained if the formation of HONO depends on solar irradiance, but not if it depends on the actinic flux. The vertical mixing ratio profiles, together with the stronger correlation with solar irradiance, support the idea that photolytically enhanced NO2 to HONO conversion on the ground was the dominant source of HONO in Houston.

Wong, K. W.; Tsai, C.; Lefer, B.; Haman, C.; Grossberg, N.; Brune, W. H.; Ren, X.; Luke, W.; Stutz, J.

2012-01-01

398

Daytime HONO Vertical Gradients during SHARP 2009 in Houston, TX  

NASA Astrophysics Data System (ADS)

Nitrous Acid (HONO) plays an important role in tropospheric chemistry as a precursor of the hydroxyl radical (OH), the most important oxidizing agent in the atmosphere. Nevertheless, the formation mechanisms of HONO are still not completely understood. Recent field observations found unexpectedly high daytime HONO concentrations in both urban and rural areas, which point to unrecognized, most likely photolytically enhanced HONO sources. Several gas-phase, aerosol, and ground surface chemistry mechanisms have been proposed to explain elevated daytime HONO, but atmospheric evidence to favor one over the others is still weak. New information on whether the HONO formation occurs in the gas-phase, on aerosol, or at the ground may be derived from observations of the vertical distribution of HONO and its precursor nitrogen dioxide, NO2, as well as its dependence on solar radiation or actinic flux. Here we present field observations of HONO, NO2 and other trace gases in three altitude intervals (30-70 m, 70-130 m and 130-300 m) using UCLA's long path DOAS instrument, as well as in situ measurements of OH, NO, photolysis frequencies and solar irradiance, made in Houston, TX, during the Study of Houston Atmospheric Radical Precursor (SHARP) experiment from 20 April to 30 May 2009. The observed HONO mixing ratios were often ten times larger than the expected photostationary state with OH and NO. Larger HONO mixing ratios observed near the ground than aloft, imply, but do not clearly prove, that the daytime source of HONO was located at or near the ground. Using a pseudo steady-state (PSS) approach, we calculated the missing daytime HONO formation rates, Punknown, on four sunny days. The NO2-normalized Punknown, Pnorm, showed a clear symmetrical diurnal variation with a maximum around noontime, which was well correlated with actinic flux (NO2 photolysis) and solar irradiance. This behavior, which was found on all clear days in Houston, is a strong indication of a photolytic HONO source. [HONO]/[NO2] ratios also showed a clear diurnal profile with maxima of 2-3 % around noon. PSS calculations show that this behavior cannot be explained by the proposed NO2?NO2* photolysis or any other gas-phase or aerosol photolytic process occurring at similar or longer wavelengths than that of HONO photolysis. HONO formation by aerosol nitrate photolysis in the UV also seems to be unlikely. Pnorm correlated better with solar irradiance (average R2 = 0.85/0.87 for visible/UV) than with actinic flux (R2 = 0.76) on the four sunny days, clearly pointing to a HONO formation at the ground rather than the aerosol or the gas-phase. In addition, the observed [HONO]/[NO2] diurnal variation can be explained if the formation of HONO depends on solar irradiance but not if it depends on the actinic flux. The vertical mixing ratio profiles together with the stronger correlation of solar irradiance vs. actinic flux support the idea that photolytically enhanced NO2 to HONO conversion on the ground was the dominant source of HONO in Houston.

Wong, K. W.; Tsai, C.; Lefer, B.; Haman, C.; Grossberg, N.; Brune, W. H.; Ren, X.; Luke, W.; Stutz, J.

2011-08-01

399

Reconstructing bulk isotope ratios from compound-specific isotope ratios.  

PubMed

Carbon isotope analysis by bulk elemental analysis coupled with isotope ratio mass spectrometry has been the mainstay of delta(13)C analyses both at natural abundance and in tracer studies. More recently, compound-specific isotope analysis (CSIA) has become established, whereby organic constituents are separated online by gas or liquid chromatography before oxidation and analysis of CO(2) for constituent delta(13)C. Theoretically, there should be concordance between bulk delta(13)C measurements and carbon-weighted delta(13)C measurements of carbon-containing constituents. To test the concordance between the bulk and CSIA, fish oil was chosen because the majority of carbon in fish oil is in the triacylglycerol form and approximately 95% of this carbon is amenable to CSIA in the form of fatty acids. Bulk isotope analysis was carried out on aliquots of oil extracted from 55 fish samples and delta(13)C values were obtained. Free fatty acids (FFAs) were produced from the oil samples by saponification and derivatised to fatty acid methyl esters (FAMEs) for CSIA by gas chromatography/combustion/isotope ratio mass spectrometry. A known amount of an internal standard (C15:0 FAME) was added to allow analyte quantitation. This internal standard was also isotopically calibrated in both its FFA (delta(13)C = -34.30 per thousand) and FAME (delta(13)C = -34.94 per thousand) form. This allowed reporting of FFA delta(13)C from measured FAME delta(13)C values. The bulk delta(13)C was reconstructed from CSIA data based on each FFA delta(13)C and the relative amount of CO(2) produced by each analyte. The measured bulk mean delta(13)C (SD) was -23.75 per thousand (1.57 per thousand) compared with the reconstructed bulk mean delta(13)C of -23.76 (1.44 per thousand) from CSIA and was not significantly different. Further analysis of the data by the Bland-Altman method did not show particular bias in the data relative to the magnitude of the measurement. Good agreement between the methods was observed with the mean difference between methods (range) of 0.01 per thousand (-1.50 to 1.30). PMID:20499325

Morrison, Douglas J; Cooper, Karen; Preston, Tom

2010-06-30

400

Newborn Brain: Body weight ratios.  

PubMed

Newborn brain:body weight ratios are generally considered to be constant in man. In autopsy studies many factors influence the measured weight of the brain, and therefore the conclusions based on such observations, including the gestational age of the material, the presence or absence of intrauterine growth retardation, and the cause of death. In this study these influences have been eliminated by careful selection of normally grown fullterm newborns not subject to the factors influencing brain weight. Using double logarithmic plots, brain size in fullterm newborns is found to be related to the 0.64 power of birth weight. There is a negative correlation between relative brain size and increasing fullterm birth size in man. PMID:1258985

Jordaan, H V

1976-03-01

401

Variable ratio regenerative braking device  

DOEpatents

Disclosed is a regenerative braking device (10) for an automotive vehicle. The device includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (36) and an output shaft (42), clutches (38, 46) and brakes (40, 48) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. The rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft is clutched to the transmission while the brake on the output shaft is applied, and are torsionally relaxed to deliver energy to the vehicle when the output shaft is clutched to the transmission while the brake on the input shaft is applied. The transmission ratio is varied to control the rate of energy accumulation and delivery for a given rotational speed of the vehicle drivetrain.

Hoppie, Lyle O. (Birmingham, MI)

1981-12-15

402

SILICA SCALING UNDER CONTROLLED HYDRODYNAMIC CONDITIONS: VERTICAL FLAT PLATE AND VERTICAL CYLINDER TESTS  

Microsoft Academic Search

Silica scaling on the surface of a flat plate and a vertical cylinder has been investigated in a water tunnel, where fluid flow and silica colloid size conditions can be controlled. Development of the test rig is described and some preliminary results are presented. Ultimately, the aim of this work is to characterise the lmk between fluid flow characteristics, silica

M. G. Dunstall; K. L. Brown

403

Numerical study of transient conjugated mixed convection in a vertical pipe  

SciTech Connect

This work deals with the problem of transient conjugated mixed convection heat transfer in a vertical pipe maintained at either uniform heat flux (UHF) or uniform wall temperature (UWT). The effects of the ratio of Grashof number to Reynolds number Gr/Re, conductivity ratio K, diffusivity ratio A, and dimensionless wall thickness [Delta] on the interfacial heat flux, velocity, and temperature profiles are discussed in detail. Three conditions of wall effects were examined, i.e., zero wall thickness (case A), effect of heat capacity (case B), and dual effects of heat capacity and wall conduction (case C). The prediction shows that the results of case C give a longer thermal larger than those of case B. Additionally, for the case of UWT, the time for the system to reach the steady state condition is indistinguishable for the system having K and A [>=] 100 or [Delta] [<=] 0.2.

Lee, K.T. (Oriental Inst. of Tech., Taipei (China). Dept. of Mechanical Engineering); Yan, W.M. (Hua Fan Inst. of Tech., Taipei (China). Dept. of Mechanical Engineering)

1994-08-01

404

Large current modulation and spin-dependent tunneling of vertical graphene/MoS2 heterostructures.  

PubMed

Vertical graphene heterostructures have been introduced as an alternative architecture for electronic devices by using quantum tunneling. Here, we present that the current on/off ratio of vertical graphene field-effect transistors is enhanced by using an armchair graphene nanoribbon as an electrode. Moreover, we report spin-dependent tunneling current of the graphene/MoS2 heterostructures. When an atomically thin MoS2 layer sandwiched between graphene electrodes becomes magnetic, Dirac fermions with different spins feel different heights of the tunnel barrier, leading to spin-dependent tunneling. Our finding will develop the present graphene heterostructures for electronic devices by improving the device performance and by adding the possibility of spintronics based on graphene. PMID:23886348

Myoung, Nojoon; Seo, Kyungchul; Lee, Seung Joo; Ihm, G

2013-07-25

405

Deep and vertical silicon bulk micromachining using metal assisted chemical etching  

NASA Astrophysics Data System (ADS)

In this paper, a newfound and simple silicon bulk micromachining process based on metal-assisted chemical etching (MaCE) is proposed which opens a whole new field of research in MEMS technology. This method is anisotropic and by controlling the etching parameters, deep vertical etching, relative to substrate surface, can be achieved in micrometer size for <1?0?0> oriented Si wafer. By utilizing gold as a catalyst and a photoresist layer as the single mask layer for etching, 60 µm deep gyroscope micromachined structures have been fabricated for 2 µm features. The results indicate that MaCE could be the only wet etching method comparable to conventional dry etching recipes in terms of achievable etch rate, aspect ratio, verticality and side wall roughness. It also does not need a vacuum chamber and the other costly instruments associated with dry etching techniques.

Zahedinejad, Mohammad; Delaram Farimani, Saeed; Khaje, Mahdi; Mehrara, Hamed; Erfanian, Alireza; Zeinali, Firooz

2013-05-01

406

A new method to determine depth-dependent carbon export fluxes using vertical 230Th profiles  

NASA Astrophysics Data System (ADS)

Because of their particle-reactive properties, radiogenic thorium isotopes in oceanic waters have been used in studies for the particle removal processes. In particular, 234Th has extensively been utilized to determine the carbon export flux from the euphotic zone. On the other hand, 230Th in seawater has so far mainly provided information on residence times, settling velocities and adsorption-desorption rates of 230Th in the water column. Here we introduce a new model to calculate the carbon export flux from vertical 230Th profiles. According to this model, the carbon export flux is directly related to the POC/230Th ratio in sinking or suspended particulate matter. The carbon export flux can be directly calculated from vertical profiles of POC and particulate 230Th, which should become an effective means to constrain ocean biogeochemical models.

Hirose, Katsumi

2006-03-01

407

A Simple Numerical Method in Modeling Soil Water Dynamics During Vertical Drainage  

NASA Astrophysics Data System (ADS)

The change of soil water content (SWC) during vertical drainage may be divided into two parts. The maximum change of SWC, which results when there is no incoming flow, can be predicted from hydraulic conductivity. The actual change of SWC can be predicted from hydraulic conductivity and the incoming flow. A new model has been developed to simulate soil water dynamics during vertical drainage using this concept. Within this model, the maximum daily change of soil water content (SWC) was calculated using a ratio between initial SWC minus field capacity (FC, defined as SWC after 10 days of drainage) and FC. The actual daily change of SWC was obtained from multiplying the maximum daily change of SWC by a coefficient, F. The coefficient F accounts for the impact of the incoming flow on the change of SWC. The model was tested on more than 300 theoretical soils. The model SWC estimates were comparable to SWC estimates of an analytical model.

Suleiman, A.

2002-12-01

408

Convection regime flow in a vertical slot: continuum of solutions from capped to open ends  

NASA Astrophysics Data System (ADS)

In a recent publication Bühler (Heat Mass Transfer 39:631 638, 2003) reported new results for conduction regime flow between vertical differentially-heated walls that provide a continuum of solutions between capped and open ends. In this paper we extend Bühler’s work to realize a continuum of solutions of convection regime flow using empirical results for the vertical temperature gradient that develops in tall aspect ratio geometries. The mass flux is determined analytically for this three-parameter family of solutions. Identical viscous and thermal boundary layers exist at the opposing walls when the cavity is capped. However, as the flow evolves to one with open ends, there is an intensification (attenuation) of the boundary layers near the hot (cold) walls. In the limit corresponding to an open-ended cavity, the boundary layer at the cold wall vanishes altogether.

Weidman, P. D.

2006-12-01

409

Wet gas flow modeling for a vertically mounted Venturi meter  

NASA Astrophysics Data System (ADS)

Venturi meters are playing an increasingly important role in wet gas metering in natural gas and oil industries. Due to the effect of liquid in a wet gas, the differential pressure over the converging section of a Venturi meter is higher than that when a pure gas flows through with the same flow rate. This phenomenon is referred to as over-reading. Thus, a correction for the over-reading is required. Most of the existing wet gas models are more suitable for higher pressure (>2 MPa) than lower pressure (<1 MPa). Much attention has been paid on higher quality (>0.5) than lower quality (<0.5) in recent years. However, conditions of lower pressure and lower quality also widely exist in the gas and oil industries. By comparing the performances of eight existing wet gas models in low-pressure range of 0.26-0.86 MPa and low-quality range of 0.07-0.36 with a vertically mounted Venturi meter of diameter ratio 0.45, de Leeuw's model was proven to perform best. Derived from de Leeuw's model, a modified model with better performance for the low-pressure and low-quality ranges was obtained. Experimental data showed that the root mean square of the relative errors of the over-reading was 2.30%.

Xu, Lijun; Zhou, Wanlu; Li, Xiaomin

2012-04-01

410

Impacts of mineral dust on the vertical structure of precipitation  

NASA Astrophysics Data System (ADS)

Characteristics of precipitation vertical structure in deep convective cloud systems are compared using measurements from sensors on board multiple satellites over the equatorial Atlantic under dust-laden and dust-free conditions. Both case and statistical studies consistently show that the impacts of mineral dust on tropical cloud and precipitation systems are highly dependent on rain type. For convective rain, the pattern of rainfall profiles above the dust layer is mainly determined by updraft intensity. For similar updraft intensity, the convective rain at and below the dust layer exhibits enhancement of the breakup process of raindrops due to mineral dust and associated warm air with strong wind shear. For stratiform rain, dust-induced microphysical effects are more evident. For similar storm height (or the rain top), precipitation at altitudes above 6 km is enhanced under dust-laden conditions, suggesting an enhancement of ice heterogeneous nucleation. For warm rain with similar storm height, precipitation is systematically weaker under dust-laden conditions. Furthermore, the ratio of precipitation water to the total amount of atmospheric hydrometeors is smaller under dust-laden conditions. Our study suggests that mineral dust exhibits a second aerosol indirect effect on cloud and precipitation systems.

Li, R.; Min, Q.-L.

2010-05-01

411

Individually addressable vertically aligned carbon nanofiber-based electrochemical probes  

NASA Astrophysics Data System (ADS)

In this paper we present the fabrication and initial testing results of high aspect ratio vertically aligned carbon nanofiber (VACNF)-based electrochemical probes. Electron beam lithography was used to define the catalytic growth sites of the VACNFs. Following catalyst deposition, VACNF were grown using a plasma enhanced chemical vapor deposition process. Photolithography was performed to realize interconnect structures. These probes were passivated with a thin layer of SiO2, which was then removed from the tips of the VACNF, rendering them electrochemically active. We have investigated the functionality of completed devices using cyclic voltammetry (CV) of ruthenium hexammine trichloride, a highly reversible, outer sphere redox system. The faradaic current obtained during CV potential sweeps shows clear oxidation and reduction peaks at magnitudes that correspond well with the geometry of these nanoscale electrochemical probes. Due to the size and the site-specific directed synthesis of the VACNFs, these probes are ideally suited for characterizing electrochemical phenomena with an unprecedented degree of spatial resolution.

Guillorn, M. A.; McKnight, T. E.; Melechko, A.; Merkulov, V. I.; Britt, P. F.; Austin, D. W.; Lowndes, D. H.; Simpson, M. L.

2002-03-01

412

Force treadmill for measuring vertical and horizontal ground reaction forces.  

PubMed

We constructed a force treadmill to measure the vertical, horizontal and lateral components of the ground-reaction forces (Fz, Fy, Fx, respectively) and the ground-reaction force moments (Mz, My, Mx), respectively exerted by walking and running humans. The chassis of a custom-built, lightweight (90 kg), mechanically stiff treadmill was supported along its length by a large commercial force platform. The natural frequencies of vibration were >178 Hz for Fz and >87 Hz for Fy, i.e., well above the signal content of these ground-reaction forces. Mechanical tests and comparisons with data obtained from a force platform runway indicated that the force treadmill recorded Fz, Fy, Mx and My ground-reaction forces and moments accurately. Although the lowest natural frequency of vibration was 88 Hz for Fx, the signal-to-noise ratios for Fx and Mz were unacceptable. This device greatly decreases the time and laboratory space required for locomotion experiments and clinical evaluations. The modular design allows for independent use of both treadmill and force platform. PMID:9688758

Kram, R; Griffin, T M; Donelan, J M; Chang, Y H

1998-08-01

413

Ratio cut partitioning for hierarchical designs  

Microsoft Academic Search

Circuit partitioning for hierarchical VLSI design is addressed. A partitioning approach called ratio cut is proposed. It is demonstrated that the ratio cut algorithm can locate the clustering structures in the circuit. Finding the optimal ratio cut is NP-complete. However, in certain cases the ratio cut can be solved by linear programming techniques via the multicommodity flow formulation. Also proposed

Yen-chuen Wei; Chung-kuan Cheng

1991-01-01

414

Isokinetic Hamstrings: Quadriceps Ratios in Intercollegiate Athletes.  

ERIC Educational Resources Information Center

|Compared the differences in the concentric hamstrings to quadriceps (H:Q) ratio among athletes in different sports at three velocities. Measurement of H:Q ratio of both knees among male and female college athletes indicated that the H:Q ratio increased as velocity increased. No differences existed for the H:Q ratio for sport or side of body. (SM)|

Rosene, John M.; Fogarty, Tracey D.; Mahaffey, Brian L.

2001-01-01

415

Velocity structure in upper ocean crust at Hole 504B from vertical seismic profiles  

NASA Astrophysics Data System (ADS)

Hole 504B provides the only opportunity to directly correlate seismic velocity structure to the lithology and physical properties of upper ocean crust, providing a baseline for comparison with seismic measurements elsewhere. We determine P and S velocities from vertical seismic profiles (VSPs) obtained on Ocean Drilling Program (ODP) Legs 111 and 148. Four issues are considered: the location of the seismic layer 2/3 boundary, P to S wave conversion by scattering, transverse isotropy, and Poisson's ratio as an indicator of lithology, porosity, and structure. (1) In the P velocity profile, the change in slope marking the layer 2/3 boundary coincides with the top of the sheeted dike unit. Seismic layer 2 is composed of the extrusives and the lithologic transition zone, the layer in which flows and dikes interfinger. (2) Even in these normal incident VSPs, several second arrivals with velocities indicative of vertically polarized shear energy are observed. P to S wave conversion within the upper 110 m of basement occurs by scattering from surface roughness and volume heterogeneities and does not depend on angle of incidence as predicted by plane boundary transmission coefficient analysis. (3) Vertical velocities determined from the VSP differ by <10% from horizontal velocities obtained from the oblique seismic experiment (OSE) on Deep Sea Drilling Project (DSDP) Leg 92. The P wave velocity structure is determined by small and intermediate (<1 cm) pore structure with no measurable anisotropy. The large-scale, well-oriented vertical fractures, which are formed tectonically, do not have a detectable effect on compressional wave velocities. (4) High Poisson's ratio in the upper 300 m of basement coincides with an extrusive layer composed of pillows and thin flows. Low Poisson's ratio at 850-1150 m below seafloor (mbsf) coincides with the downhole decrease in bulk porosity caused by the transition from extrusives to dikes. Relatively large-aspect ratio cracks are required to produce such low values of Poisson's ratio. The cracks were likely created by hydraulic fracturing when hot dikes encountered low-temperature seawater.

Swift, Stephen A.; Lizarralde, D.; Stephen, Ralph A.; Hoskins, Hartley

1998-07-01

416

Modeling vertical carbon flux from zooplankton respiration  

NASA Astrophysics Data System (ADS)

The transport of carbon from ocean surface waters to the deep sea is a critical factor in calculations of planetary carbon cycling and climate change. This vertical carbon flux is currently thought to support the respiration of all the organisms in the water column below the surface, the respiration of the organisms in the benthos, as well as the carbon lost to deep burial. Accordingly, for conditions where the benthic respiration and the carbon burial are small relative to the respiration in the water column, and where horizontal fluxes are known or negligible, the carbon flux can be calculated by integrating the vertical profile of the water-column plankton respiration rate. Here, this has been done for the zooplankton component of the vertical carbon flux from measurements of zooplankton ETS activity south of the Canary Island Archipelago. From zooplankton ETS activity depth profiles, zooplankton respiration depth profiles were calculated and using the equations for the profiles as models, the epipelagic (3.05 ?mol CO2 m-3 h-1), mesopelagic (112.82 nmol CO2 m-3 h-1), and bathypelagic (27.89 nmol CO2 m-3 h-1) zooplankton respiration for these waters were calculated. Then, by integration of the depth-normalized respiration profiles, zooplankton-associated carbon flux profiles below 150 m were calculated. These had an uncertainty of ±40%. At the station level (local regional variation) the variability was ±114% (n = 16). At 150 m and 500 m the average passive carbon flux associated with the zooplankton was 36 (±114%) and 20 (±113%) ?mol C m-2 h-1. The carbon transfer efficiency (Teff) from the 150 to the 500 m levels averaged 51 ± 21% and a new metric, the nutrient retention efficiency (NRE), averaged 49 ± 21%. This metric is an index of the efficiency with which nutrients are maintained in the epipelagic zone and is directly related to the respiration in the water column. The carbon flux equation describing the pooled data (n = 16) was 131.14Z-0.292. Using this as a model for zooplankton-associated carbon flux south of the Canary Islands one can calculate that carbon flux from epipelagic waters at 200 m is 27.91 ?mol C m-2 h-1, and the carbon flux from mesopelagic waters at 1000 m, is 17.45 ?mol C m-2 h-1.

Packard, Theodore T.; Gómez, May

2013-03-01

417

Vertical and Interfacial Transport in Wetlands (Invited)  

NASA Astrophysics Data System (ADS)

The objective of this work is to understand the fluxes connecting the water column, substrate, and atmosphere in wetland environments. To do this, analytical, numerical, and laboratory models have been used to quantify the hydrodynamic contributions to vertical fluxes. A key question is whether the hydrodynamic transport can be modeled as a diffusivity, and, if so, what the vertical structure of this diffusivity is. This question will be addressed in a number of flow types and for a number of fluxes. The fluxes of interest are heat, sediment, dissolved gases (such as methane and oxygen) and other dissolved solutes (such as nutrients and pollutants). The flows of interest include: unidirectional current, reversing flow (under waves, seiches, and tides), wind-sheared surface flows, and thermal convection. Rain and bioturbation can be important, but are not considered in the modeling work discussed herein. Specifically, we will present results on gas transport at wind-sheared free surface, sediment transport in unidirectional flow, and heat transfer in an oscillating flow cause by a seiche. All three of these will be used to consider the question of appropriate analytical models for vertical transport. The analytic models considered here are all 1D models that assume homogeneity in the horizontal plane. The numerical models use finite element methods and resolve the flow around individual vegetation stems in an idealized geometry. Laboratory models discussed herein also use an idealized geometry. Vegetation is represented by an array of cylinders, whose geometry is modeled after Scirpus spp. wetlands in Northern California. The laboratory model is constructed in a way that allows optical access to the flow, even in dense vegetation and far from boundaries. This is accomplished by using fluoropolymer plastics to construct vegetation models. The optical access allows us to employ particle image velocimetry (PIV) and planar laser induced fluorescence (PLIF) to measure the velocity and scalar fields, respectively. To study sediment transport, an additional step is needed. Idealized sediment grains are manufactured, again using fluoropolymers. This allows the sediment and fluid phase to be resolved simultaneously, and the velocities of each to be determined independently of the other. The use of fluoropolymers means that the laboratory imaging techniques do not suffer from blockage during laser light delivery or during image capture by digital cameras. Cameras are paired and run in stereoscopic mode to allow three-dimensional velocities to be determined. This is important given the 3D nature of flow through vegetation. Current results from ongoing laboratory, field, and modeling efforts will be discussed, as well as the upcoming steps.

Variano, E. A.

2010-12-01

418

[Dynamic rule of organic matter removal in vertical-flow constructed wetland].  

PubMed

Based upon the analysis of the removal rate and form change of the organic pollutants with the different height of the vertical-flow constructed wetland, it comes to the conclusion of the average longitudinal removal rate of variant forms organics and presents the influent concentration and the hydraulic load curve. The results indicated that: Under this experimental condition, the reduction of the organics in the vertical subsurface flow constructed wetland mainly occurred within the 0-10 cm substrate below the pipe distributor. In the meantime, the smaller the hydraulic load of influent, the higher the removal ratio of the organic pollutants in the substrate section. Under the condition that the vertical subsurface flow constructed wetland used the coarse sands as the substrate and kept the influent hydraulic load less than or equal to 0.5 m3/(m2 x d), the effective height of the organics removal was 60 cm. It also showed that the average degradation rate of different kinds of the organic pollutants has a maximum value in the 0-10 cm substrate section below the pipeline. Moreover, the degradation ratio of different kinds of the organics is in significant decreasing tendency with increasing the depth of the longitudinal direction along the pipe. Using sands as the substrate in the vertical subsurface flow constructed wetland, the relationship of the influent concentration and influent hydraulic load can be expressed by formula:(c(in) - c(out)) x q = 1107.02-2.96 c(in) x q. PMID:18839567

Ye, Jian-feng; Xu, Zu-xin; Li, Huai-zheng

2008-08-01

419

Constraints on aerosol processes in climate models from vertically-resolved aircraft observations of black carbon  

NASA Astrophysics Data System (ADS)

Evaluation of the aerosol schemes in current climate models is dependent upon the available observational data. In-situ observations from flight campaigns can provide valuable data about the vertical distribution of aerosol that is difficult to obtain from satellite or ground-based platforms, although they are localised in space and time. Using single-particle soot-photometer (SP2) measurements from the HIAPER Pole-to-Pole Observations (HIPPO) campaign, which consists of many vertical profiles over a large region of the Pacific, we evaluate the meridional and vertical distribution of black carbon (BC) aerosol simulated by the HadGEM3-UKCA and ECHAM5-HAM2 models. Both models show a similar pattern of overestimating the BC column burden compared to that derived from the observations, in many areas by an order of magnitude. However, by sampling the simulated BC mass mixing ratio along the flight track and comparing to the observations, we show that this discrepancy has a rather different vertical structure in the two models. Using this methodology, we conduct sensitivity tests on two specific elements of the models: biomass-burning emissions and scavenging by convective precipitation. We show that, by coupling the convective scavenging more tightly with convective transport, both the column burden and vertical distribution of BC in HadGEM3-UKCA are significantly improved with respect to the observations, demonstrating the importance of a realistic representation of this process. In contrast, updating from GFED2 to GFED3.1 biomass-burning emissions makes a more modest improvement in both models, which is not statistically significant. We also demonstrate the important role that nudged simulations (where the large-scale model dynamics are continuously relaxed towards a reanalysis) can play in this type of evaluation, allowing statistically significant differences between configurations of the aerosol scheme to be seen where the differences between the corresponding free-running simulations would not be significant.

Kipling, Z.; Stier, P.; Schwarz, J. P.; Perring, A. E.; Spackman, J. R.; Mann, G. W.; Johnson, C. E.; Telford, P. J.

2013-01-01

420

White light interferometry for vertical artifact calibration  

NASA Astrophysics Data System (ADS)

In this paper we describe a traceable to the meter standard method to measure the height of an artifact used as a calibrator for observation instruments in nanotechnologies and nanosciences. The artifact is a grating specially manufactured so that its features (height, pitch, width, wall angles) are highly uniform across its area. A Linnik microscope designed for longitudinal (vertical) measurements using the principle of white light interferometry was used to determine the height of the grating. To insure the traceability of the measurements a laser source of known wavelength was used and the measurements obtained using white light were calibrated to it. The experimental data was statistically analyzed and the measurement precision was estimated to be in the range of nanometers. The data were compared with the results obtained using the TIC method with a Carl Zeiss microscope.

Damian, V.; Bojan, Mihaela; Sima, A.; Cristea, Dana; Dinescu, A.; Muller, Raluca

2008-05-01

421

Oceanography. Vertical mixing in the ocean.  

PubMed

The thermohaline circulation of the ocean results primarily from downwelling at sites in the Nordic and Labrador Seas and upwelling throughout the rest of the ocean. The latter is often described as being due to breaking internal waves. Here we reconcile the difference between theoretical and observed estimates of vertical mixing in the deep ocean by presenting a revised view of the thermohaline circulation, which allows for additional upwelling in the Southern Ocean and the separation of the North Atlantic Deep Water cell from the Antarctic Bottom Water cell. The changes also mean that much less wind and tidal energy needs to be dissipated in the deep ocean than was originally thought. PMID:11343103

Webb, D J; Suginohara, N

2001-01-01

422

Multispectral imaging with vertical silicon nanowires.  

PubMed

Multispectral imaging is a powerful tool that extends the capabilities of the human eye. However, multispectral imaging systems generally are expensive and bulky, and multiple exposures are needed. Here, we report the demonstration of a compact multispectral imaging system that uses vertical silicon nanowires to realize a filter array. Multiple filter functions covering visible to near-infrared (NIR) wavelengths are simultaneously defined in a single lithography step using a single material (silicon). Nanowires are then etched and embedded into polydimethylsiloxane (PDMS), thereby realizing a device with eight filter functions. By attaching it to a monochrome silicon image sensor, we successfully realize an all-silicon multispectral imaging system. We demonstrate visible and NIR imaging. We show that the latter is highly sensitive to vegetation and furthermore enables imaging through objects opaque to the eye. PMID:23955156

Park, Hyunsung; Crozier, Kenneth B

2013-08-19

423

Functionalization of vertically aligned carbon nanotubes  

PubMed Central

Summary This review focuses and summarizes recent studies on the functionalization of carbon nanotubes oriented perpendicularly to their substrate, so-called vertically aligned carbon nanotubes (VA-CNTs). The intrinsic properties of individual nanotubes make the VA-CNTs ideal candidates for integration in a wide range of devices, and many potential applications have been envisaged. These applications can benefit from the unidirectional alignment of the nanotubes, the large surface area, the high carbon purity, the outstanding electrical conductivity, and the uniformly long length. However, practical uses of VA-CNTs are limited by their surface characteristics, which must be often modified in order to meet the specificity of each particular application. The proposed approaches are based on the chemical modifications of the surface by functionalization (grafting of functional chemical groups, decoration with metal particles or wrapping of polymers) to bring new properties or to improve the interactions between the VA-CNTs and their environment while maintaining the alignment of CNTs.

Snyders, Rony; Colomer, Jean-Francois

2013-01-01

424

Multichannel Wiener deconvolution of vertical seismic profiles  

SciTech Connect

The authors describe a technique for performing optimal, least-squares deconvolution of vertical seismic profile (VSP) data. The method is a two-step process that involves (1) estimating the source signature and (2) applying a least-squares optimum deconvolution operator that minimizes the noise not coherent with the source signature estimate. The optimum inverse problem, formulated in the frequency domain, gives as a solution an operator that can be interpreted as a simple inverse to the estimated aligned signature multiplied by semblance across the array. An application to a zero-offset VSP acquired with a dynamite source shows the effectiveness of the operator in attaining the two conflicting goals of adaptively spiking the effective source signature and minimizing the noise. Signature design for seismic surveys could benefit from observing that the optimum deconvolution operator gives a flat signal spectrum if and only if the seismic source has the same amplitude spectrum as the noise.

Haldorsen, J.B.U. (Geco Prakla, Hannover (Germany)); Miller, D.E. (Schlumberger-Doll Research, Ridgefield, CT (United States)); Walsh, J.J. (Schlumberger Cambridge Research (United Kingdom))

1994-10-01

425

Tunable ultraviolet vertically-emitting organic laser  

NASA Astrophysics Data System (ADS)

A solid-state organic thin-film laser with intracavity frequency doubling is reported. Tunable ultraviolet emission from 309 to 322 nm is achieved from a vertical external cavity surface-emitting organic laser, with 2% efficiency (1 ?J at 315 nm). The laser comprises a poly(methyl methacrylate) layer doped with Rhodamine 640, spun-cast onto a plane mirror, a remote concave mirror, a nonlinear crystal, and a dichroic separator. The output is spectrally narrow (<0.5 nm full width at half maximum) and tunable through phase-matching selection of the fundamental radiation lasing modes. These results highlight a low-cost and portable alternative to tunable UV laser sources, useful for spectroscopic applications.

Forget, Sébastien; Rabbani-Haghighi, Hadi; Diffalah, Nordine; Siove, Alain; Chénais, Sébastien

2011-03-01

426

[The hyoid bone and vertical dimension].  

PubMed

Located at the center of the neck and the pharyngeal column and, thanks to its attachments, tied to the base of the skull, to the mandible, to the tongue, to the larynx, and to the scapular belt, the hyoid bone is intimately related to an extensive tendino-muscular complex. From this strategic position, the hyoid bone participates in all functional and nutritional activities of the oro-facial complex. Heavily involved in the physiology of the pharyngeal column, it appears to enjoy a remarkable stability in relation to its surrounding structures as it participates in the critical process of vertical ontogenetic development. Deceptively simple in its shape and location it is anything but. While it would be easy to scorn it as a vestigial organ of little importance, the hyoid bone is actually an ancient witness of the evolution of the first human vertebrae and a vestige of the 2nd and 3rd brachial arches. Like a toy buffeted by powerful groups of muscles and tendons, the hyoid bone occupies a crossroads position where it is solicited by many vital functions, the most critical of which is respiration. Its functional behavior seems to have evolved considerably over the course of phylogeny. By piecing together the conceptions of many authors, we can conclude that the similarities--and, later, the differences--existing between the human fetus and those of other primates, and, then between young children and young primates, are related to an essentially different status quo, which modifies the delicate equilibrium of the pharyngeal region. In metamorphosing from a sagittal equilibrium to one that is vertical, this very status quo maintains an open respiratory airway during each time frame, continuously permitting the articulation and modulation of sounds, particularly during the vertical period. The hyoid bone is unpaired, in a mid-line position, symmetrical, and located just below the mandible with which it shares, to an astonishing extent, certain morphological characteristics. Its maturation and its ossification occur slowly and late even though it migrates much more rapidly to a vertical position than does the bulk of the cervical complex. True articulations between the body and the horns of the hyoid bone persist for a very long time; and so the junction between the small horns doesn't fully calcify until about the age of 50; and, in spite of its appearance, the hyoid bone is extremely supple, a quality that allows it to make substantial contributions to functional activity. If the hyoid bone itself scarcely moves during normal respiration, modern research attributes an increasing role to it in the maintenance of the equilibrium of the pharyngeal column. It seems to be called upon to respond to a number of demands that it manages to satisfy as it helps to maintain the permeability of the pharyngeal column and thus make respiration possible. In so doing, the hyoid bone adjusts its positioning, and, perhaps most important, its orientation to the physiological requirements imposed by pharyngeal obstruction and mouth breathing. Intimately connected to the larynx, the hyoid bone plays a part in phonation that has long been recognized. Recent studies now also show that the contribution the hyoid bone makes to respiratory equilibrium is far more important than its small size would suggest. PMID:15301368

Doual, A; Léger, J L; Doual, J M; Hadjiat, F

2003-09-01

427

Vertical integration of thermally activated heat pumps  

SciTech Connect

Many thermally activated heat pump systems are being developed along technology lines, such as, engine-driven and absorption heat pumps. Their thermal performances are temperature dependent. Based on the temperature-dependent behavior of heat pump cycle performance and the energy cascading idea, the concept of vertically integrating various thermally activated heat pump technologies to maximize resources utilization is explored. Based on a preliminary analysis, it is found that integrating a desiccant dehumidification subsystem to an engine-driven heat pump could improve its cooling performance by 36% and integrating an ejector to it could improve its cooling performance by 20%. The added advantage of an ejector-coupled engine-driven heat pump is its system simplicity which should result in equipment cost savings.

Chen, F.C.

1985-01-01

428

Vertical axis wind turbine control strategy  

SciTech Connect

Early expensive in automatic operation of the Sandia 17-m vertical axis research wind turbine (VAWT) has demonstrated the need for a systematic study of control algorithms. To this end, a computer model has been developed that uses actual wind time series and turbine performance data to calculate the power produced by the Sandia 17-m VAWT operating in automatic control. The model has been used to investigate the influence of starting algorithms on annual energy production. The results indicate that, depending on turbine and local wind characteristics, a bad choice of a control algorithm can significantly reduce overall energy production. The model can be used to select control algorithms and threshold parameters that maximize long-term energy production. An attempt has been made to generalize these results from local site and turbine characteristics to obtain general guidelines for control algorithm design.

McNerney, G.M.

1981-08-01

429

Multispectral imaging with vertical silicon nanowires  

PubMed Central

Multispectral imaging is a powerful tool that extends the capabilities of the human eye. However, multispectral imaging systems generally are expensive and bulky, and multiple exposures are needed. Here, we report the demonstration of a compact multispectral imaging system that uses vertical silicon nanowires to realize a filter array. Multiple filter functions covering visible to near-infrared (NIR) wavelengths are simultaneously defined in a single lithography step using a single material (silicon). Nanowires are then etched and embedded into polydimethylsiloxane (PDMS), thereby realizing a device with eight filter functions. By attaching it to a monochrome silicon image sensor, we successfully realize an all-silicon multispectral imaging system. We demonstrate visible and NIR imaging. We show that the latter is highly sensitive to vegetation and furthermore enables imaging through objects opaque to the eye.

Park, Hyunsung; Crozier, Kenneth B.

2013-01-01

430

A prototype for an economical vertical microstomia orthosis.  

PubMed

One of the complications of thermal injury is the development of scars and contractures during the healing process. This scarring can be devastating, especially when it involves the mouth. The purpose of this report is to describe the construction of an alternative vertical mouth stretching orthosis for vertical microstomia. By using thermoplastic splinting material and a long thread screw, a vertical mouth-stretching orthosis can be custom-fit to any patient's mouth. The device can be fabricated for a pediatric or adult patient for the rehabilitation of a circumferential mouth burn, especially targeting the vertical diameter. When using this device, patients gave positive feedback for comfort and ease of use, with increased mouth mobility and range of motion. This vertical orthotic device provides an economical and comfortable alternative for vertical mouth diameter enlargement to the current five devices available in the literature. PMID:16679906

Davis, Shari; Thompson, Jarita G; Clark, Janet; Kowal-Vern, Areta; Latenser, Barbara A

431

Intersexuality in the amphipod Gammarus duebeni results from incomplete feminisation by the vertically transmitted parasitic sex ratio distorter Nosema granulosis  

Microsoft Academic Search

We investigated the effects of parasitism and temperature on the production of intersexes in the amphipod Gammarus duebeni from a field population at Cumbrae, Scotland. There was significant temporal variation in intersex frequency which ranged\\u000a from 0.5 to 5.2% in monthly field collections. Prevalence of Nosema granulosis, a feminising microsporidian parasite, also varied temporally and there was a significant correlation

Andrew Kelly; Melanie J. Hatcher; Alison M. Dunn

2004-01-01

432

Medial Epicanthoplasty Without a Vertical Scar.  

PubMed

BACKGROUND: The epicanthal fold (Mongolian fold) in Asians reduces the aesthetic results of eyelid surgery, and thus, medial epicanthoplasty is commonly performed in combination with a double fold operation or blepharoptosis correction. Epicanthoplasty is one of the most popular cosmetic operations conducted in Asia, but scarring is a common problem. METHODS: From December of 2006 to July of 2011, we treated 60 cases using our epicanthoplasty method, which was designed to reduce scarring. A double fold operation and blepharoptosis correction was performed along with epicanthoplasty in 54 cases and an epicanthoplasty without a double fold operation in the remaining 6 cases. Follow-up periods ranged from 6 months to 4 years and 10 months. Previously, we used an elliptical excision epicanthoplasty method, which was simple and practical. However, the elliptical excision method leaves a vertical scar on the nasal side of the upper and lower eyelids. To avoid this scar, we placed an additional incision parallel with the ciliary margin of the lower and/or upper eyelids. The results of epicanthoplasty were evaluated by asking the patients and the surgeon involved to allocate visual analog scale scores. RESULTS: With the exception of 1 case of hypertrophic scarring and 4 cases of undercorrection, patients were satisfied with their results. Mean patient and surgeon visual analog scale scores were 4.6 and 4.2, respectively. The advantages of the described procedure are its simplicity and the minimal scarring caused in the epicanthal area. CONCLUSIONS: This method could become an effective means of removing the Asian epicanthal fold and minimizing vertical scars. PMID:23636120

Park, Dae Hwan; Park, Sang Uk; Lee, Byung Kwon; Lee, Young Bae; Do, Eon Rok; Han, Dong Gil; Shim, Jeong Su; Lee, Yong Jig

2013-04-30

433

Vertical structure of recent Arctic warming.  

PubMed

Near-surface warming in the Arctic has been almost twice as large as the global average over recent decades-a phenomenon that is known as the 'Arctic amplification'. The underlying causes of this temperature amplification remain uncertain. The reduction in snow and ice cover that has occurred over recent decades may have played a role. Climate model experiments indicate that when global temperature rises, Arctic snow and ice cover retreats, causing excessive polar warming. Reduction of the snow and ice cover causes albedo changes, and increased refreezing of sea ice during the cold season and decreases in sea-ice thickness both increase heat flux from the ocean to the atmosphere. Changes in oceanic and atmospheric circulation, as well as cloud cover, have also been proposed to cause Arctic temperature amplification. Here we examine the vertical structure of temperature change in the Arctic during the late twentieth century using reanalysis data. We find evidence for temperature amplification well above the surface. Snow and ice feedbacks cannot be the main cause of the warming aloft during the greater part of the year, because these feedbacks are expected to primarily affect temperatures in the lowermost part of the atmosphere, resulting in a pattern of warming that we only observe in spring. A significant proportion of the observed temperature amplification must therefore be explained by mechanisms that induce warming above the lowermost part of the atmosphere. We regress the Arctic temperature field on the atmospheric energy transport into the Arctic and find that, in the summer half-year, a significant proportion of the vertical structure of warming can be explained by changes in this variable. We conclude that changes in atmospheric heat transport may be an important cause of the recent Arctic temperature amplification. PMID:18172495

Graversen, Rune G; Mauritsen, Thorsten; Tjernström, Michael; Källén, Erland; Svensson, Gunilla

2008-01-01

434

Isotopic ratios in giant planets  

NASA Astrophysics Data System (ADS)

The accuracy of spectrometric measurements of isotopic ratios in giant planets, and implications on the formation of giant planets are discussed. Derivations of D/H in Jupiter and Saturn form CH3D conflict with derivations from HD. Uncertainties in the interpretation come from the difficulty in estimating the fractionation factor between CH3D and CH4, and from scattering effects in the radiative transfer within HD and H2 absorption lines. However, deuterium abundance in the primordial solar nebula 4.6 billion yr ago can be estimated. Data suggest that D/H is enhanced in Uranus compared to Jupiter and Saturn, in agreement with a scenario of inhomogeneous formation of giant planets. The C12/C13 value in Jupiter from Voyager measurements suggests a value significantly higher than the terrestrial value, but conflicts with the value derived from ground based measurements, which agrees with the terrestrial value. The N14/N15 value is compatible with the terrestrial value.

Gautier, D.

435

Polarization ratio for microwave backscattering from the ocean surface at low to moderate incidence angles  

Microsoft Academic Search

It has become apparent that as the incidence angle increases from nadir, the ratio of the backscattered power for microwave scattering from the ocean surface at horizontal to that at vertical polarization (HH\\/VV) becomes larger than that predicted by standard rough-surface scattering models. Although predictions by models that include the effects of long-wave tilt and hydrodynamic modulation yield some improvement,

Donald R. Thompson; Tanos M. Elfouhaily; Bertrand Chapron

1998-01-01

436

Evaluation of ultra thick photo resist for high aspect ratio bumping applications  

Microsoft Academic Search

This paper presents the evaluation results of two positive, thick resist molds for the electroplating of Copper pillar interconnects. Two different resist molds of 100um and 58um thickness have been fabricated with aspect ratios of 2.5 and 1.3 respectively in a single coat process. Lithography parameters have been optimized using a UV aligner to produce smooth and near vertical sidewall

D. M. Fernandez; Vempati Srinivsa Rao; Soon Wee Ho David; Wai Hong See Toh Justin; Li Yan Siow

2011-01-01

437

3D near-surface soil response from H\\/V ambient-noise ratios  

Microsoft Academic Search

The applicability of the horizontal-to-vertical (H\\/V) ambient-noise spectral ratio for characterizing earthquake site effects caused by near-surface topography and velocity structures was evaluated at sites underlain by thick (i.e. >100m) sediment deposits near the southern-end of the New Madrid seismic zone in the central United States. Three-component ambient-noise and velocity models derived from seismic (shear-wave) refraction\\/reflection surveys showed that a

Edward W. Woolery

2002-01-01

438

A comprehensive study of ion track enabled high aspect ratio microstructures in flexible circuit boards  

Microsoft Academic Search

A process to form deep, vertical and high aspect ratio microstructures of solid as well as porous nature is presented. The process is capable of producing regions with perpendicular sub-micron metal wire connections, with a regulated effective metal density at numerous, arbitrarily specified locations. The structures are created in a two-metallic-layer polyimide laminate, i.e. a flexible printed circuit board. The

M. Lindeberg; K. Hjort

2004-01-01

439

FINITE ELEMENT SURFACE MODEL FOR FLOW AROUND VERTICAL WALL ABUTMENTS  

Microsoft Academic Search

A two-dimensional finite element surface model is developed to determine velocities, depths, and turning angles around vertical wall abutments. The model solves the Reynolds-averaged turbulent flow equations along a horizontal plane passing through the average water surface. This approach is an improvement over the depth-averaged flow models where dispersion terms reflecting vertical effects are neglected. In the model, vertical gradient

A. Molinas; Y. I. Hafez

2000-01-01

440

The dependence of clouds and their radiative impacts on the large-scale vertical velocity  

NASA Astrophysics Data System (ADS)

Middle-tropospheric vertical velocity(o500) is used to isolate the effect of large-scale dynamics on the observed radiation budget and cloud properties in the Tropics. The ratio of shortwave to longwave cloud forcing (N=-SWCF/LWCF) is approximately 1.2 and independent of the magnitude of w5oo when it is upward over the warmer water. Increasingly negative net cloud forcing (NetCRF) with increasing upward motion is mostly related to an increasing abundance of high-thick clouds. Although a consistent dynamical effect on the annual cycle can be identified, the effect of the PDF of o 500 on long-term variations in the tropical mean radiation budget is generally small compared with observed variations. The East Pacific in 1987 and 1998 showed large reductions of N in association with an increase in the fraction of the area with upward motions, and concomitant increases in high clouds. For the West Pacific in 1998 a large increase/decrease in N/NetCRF was caused not by a change in o500, but rather by a shift of the vertical structure of vertical velocity. The structure of tropical large-scale vertical velocity from ERA-40 is compared with satellite measurements. The first two EOFs of the vertical velocity profile represent the traditional deep circulation (PC1) and a middle level divergence (PC2). Together they explain 90% of total variance and can distinguish the "top-heavy" and "bottom-heavy" vertical motions. Cloud and radiation budget quantities have coherent relationships to PC1 and PC2 at all time scales. The relative importance of PC2 is greater on short temporal scales. "Top-heavy" ascent is associated with deep cloud systems. SWCF depends primarily on PC1, while NetCRF depends more on PC2. High-thin clouds are less sensitive to short-term variations of the vertical velocity. Shallow precipitation measured by TRMM-PR is associated with "bottom-heavy" upward motions. During the evolution of intense precipitating systems, upward motion profiles evolve to a more "top-heavy" shape over time, which is consistent with previous radar and sounding measurements. Associated high-thick clouds develop first and extensive anvil clouds later. These results suggest that the elevated latent heating (stratiform type) is responsible for the development of "top-heavy" upward motion profiles in the Tropics.

Yuan, Jian

441

CALIPSO observations of transatlantic dust: vertical stratification and effect of clouds  

NASA Astrophysics Data System (ADS)

We use CALIOP nighttime measurements of lidar backscatter, color and depolarization ratios during the summer of 2007 to study transatlantic dust properties downwind of Saharan sources, and to examine the interaction of clouds and dust. Our analysis suggests that (1) while lidar backscatter doesn't change much with altitude in the Saharan Air Layer (SAL), depolarization and color ratios both increase with altitude in the SAL; (2) lidar backscatter and color ratio increase as dust is transported westward in the SAL; (3) the vertical lapse rate of dust depolarization ratio, introduced here, increases within SAL as plumes move westward; (4) nearby clouds barely affect the backscatter and color ratio of dust volumes within SAL but not so below SAL. Moreover, the presence of nearby clouds tends to decrease the depolarization of dust volumes within SAL. Finally, (5) the odds of CALIOP finding dust below SAL next to clouds are about 2/3 of those far away from clouds. This feature, together with an apparent increase in depolarization ratio near clouds, indicates that particles in some dusty volumes lose asphericity in the humid air near clouds, and cannot be identified by CALIPSO as dust.

Yang, W.; Marshak, A.; Várnai, T.; Kalashnikova, O. V.; Kostinski, A. B.

2012-05-01

442

An Analytical Model for Vertical Profiles in Submarine Channels  

NASA Astrophysics Data System (ADS)

Turbidity currents are the primary agents carrying sediments from the continental shelf to the deep-sea. They are the counterpart of fluvial currents in the deep-sea environment and are responsible for the shaping of submarine channels. Due to the unpredictability of events and to their ability to destroy installed monitoring instruments, only a few attempts to directly measure the properties of turbidity currents in submarine channels has proved to be successful (Xu et al., 2004; Xu, 2010). Consequently the vast majority of the studies concerning the vertical structure of turbidity currents were either laboratory experiments or numerical models. In spite of the relevance of the problem, related to the consequences of flow field on sedimentary deposits, at present an ongoing debate still exist on similarities and differences between submarine and fluvial channels related in particular to the orientation of the helical flow in channel bends. Here we expand on the above ideas and develop an analytical theory for flow and suspended sediment transport in submarine channels able to describe vertical profiles of both flow field and suspendend sediment concentration. The turbulence closure needed to account for density stratification is adapted from the model of Mellor and Yamada (1982). Solutions are found for both straight and constant curvature channels. In the latter case, in order to evaluate the secondary flow induced by curvature, we take advantage of the fact that the ratio of flow depth to radius of curvature is typically small in the field, which leads to a solution of the governing equations through an appropriate asymptotic expansion. Steady fully developed flow conditions in a bend of constant width are considered. Results for longitudinal velocity and concentration profiles in straight channels are then compared with experimental observations of Sequeiros et al. (2010) providing good agreement. We also expect to find under which values of the controlling parameters the orientation of secondary flow in submarine channels can be reversed with respect to the case of fluvial channels hopefully clarifying the ongoing debate. References Mellor, G.L. and Yamada, T. (1982). Development of a Turbulence Closure Model for Geophysical Fluid Problems. Rev. Geophys. Space Phys., 20(4), 851-875. Sequeiros O.E., B. Spinewine, R. T. Beaubouef, T. Sun, M. H. García, and G. Parker, (2010). Characteristics of Velocity and Excess Density Profiles of Saline Underflows and Turbidity Currents Flowing over a Mobile Bed, J. Hydr. Engrg. 136, 412. Xu, J. P., M. A. Noble, and L. K. Rosenfeld (2004), In-situ measurements of velocity structure within turbidity currents, Geophys. Res. Lett., 31, L09311. Xu, J. P., (2010)., Normalized velocity profiles of field-measured turbidity currents, Geology, v. 38; no. 6; p. 563-566.

Bolla Pittaluga, M.; Imran, J.

2011-12-01

443

Probing the Galactic thick disc vertical properties and interfaces  

NASA Astrophysics Data System (ADS)

Aims: This work investigates the properties (metallicity and kinematics) and interfaces of the Galactic thick disc as a function of height above the Galactic plane. The main aim is to study the thick disc in a place where it is the main component of the sample. Methods: We take advantage of former astrometric work in two fields of several square degrees in which accurate proper motions were measured down to V-magnitudes of 18.5 in two directions, one near the north galactic pole and the other at a galactic latitude of 46° and galactic longitude near 0°. Spectroscopic observations have been acquired in these two fields for a total of about 400 stars down to magnitude 18.0, at spectral resolutions of 3.5 to 6.25 Å. The spectra have been analysed with the code ETOILE, comparing the target stellar spectra with a grid of 1400 reference stellar spectra. This comparison allowed us to derive the parameters effective temperature, gravity, [Fe/H] and absolute magnitude for each target star. Results: The Metallicity Distribution Function (MDF) of the thin-thick-disc-halo system is derived for several height intervals between 0 and 5 kpc above the Galactic plane. The MDFs show a decrease of the ratio of the thin to thick disc stars between the first and second kilo-parsec. This is consistent with the classical modelling of the vertical density profile of the disc with 2 populations with different scale heights. A vertical metallicity gradient, ?[Fe/H]/?z = -0.068 ± 0.009 dex kpc-1, is observed in the thick disc. It is discussed in terms of scenarios of formation of the thick disc. Based on observations obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii and at the T193cm telescope, Observatoire de Haute-Provence, France.Full Tables A.1-A.3, B.1-B.3 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/525/A90

Katz, D.; Soubiran, C.; Cayrel, R.; Barbuy, B.; Friel, E.; Bienaymé, O.; Perrin, M.-N.

2011-01-01

444

An experiment on thermosyphon boiling in uniformly heated vertical tube and asymmetrically heated vertical channel  

Microsoft Academic Search

Continuing efforts to achieve increased circuit performance in electronic package have resulted in higher power density at\\u000a chip and module level. As a result, the thermal management of electronic package has been important in maintaining or improving\\u000a the reliability of the component. An experimental investigation of thermosyphonic boiling in vertical tube and channel made\\u000a by two parallel rectangular plates was

Jin-Seok Jeon; Jung Hee Na; Hong Chul Park; Ho-Young Kwak

2001-01-01

445

Association between traditional standing vertical jumps and a soccer-specific vertical jump  

Microsoft Academic Search

The present study aimed to determine the relationships between a soccer-specific vertical jump (ssVJ) test, that included common elements of a soccer VJ (e.g. run-up and intention to head), and three traditional VJ tests using elite soccer players. A secondary purpose of this study was to determine the reliability of the VJs used in the analysis. A randomised order and

Bernardo Requena; Inmaculada Garcia; Francisco Requena; Eadric Bressel; Eduardo Saez-Saez de Villarreal; John Cronin

2012-01-01

446

Estimation of aerosol altitude from reflectance ratio measurements in the O2 A-band  

NASA Astrophysics Data System (ADS)

A methodology is presented to estimate aerosol altitude from reflectance ratio measurements in the O2 absorption A-band. Previous studies have shown the impact of the vertical distribution of scatterers on the reflectance ratio. The reflectance ratio is defined as the ratio of the reflectance in a first spectral band, strongly attenuated by O2 absorption, to the reflectance in a second spectral band, minimally attenuated. First, a sensitivity study is performed to quantify the expected accuracy for various aerosol loadings and models. An accurate, high spectral resolution, radiative transfer model that fully accounts for interactions between scattering and absorption is used in the simulations. Due to their adequate spectral characteristics, POLDER and MERIS instruments are considered for simulations. For a moderately loaded atmosphere (i.e., aerosol optical thickness of 0.3 at 760 nm), the expected error on aerosol altitude is about 0.3 km for MERIS and 0.7 km for POLDER. More accurate estimates are obtained with MERIS, since the spectral reflectance ratio is more sensitive. Second, the methodology is applied to MERIS and POLDER imagery. Estimates of aerosol altitude are compared with lidar profiles of backscattering coefficient acquired during the AOPEX-2004 experiment. Retrievals are consistent with measurements and theory. These comparisons demonstrate the potential of the differential absorption methodology for obtaining information on aerosol vertical distribution.

Dubuisson, P.; Frouin, R.; Dufor"t, L.; Dessailly, D.; Voss, K. J.; Antoine, D.

2006-11-01

447

Vertical gradients of mineral elements in Pinus sylvestris crown in alkalised soil.  

PubMed

Alkalisation of soil has been assumed to be the principal cause of changes in vertical gradients of nutrients in Pinus sylvestris crown. The long-term influence of alkaline dust pollution (pHH2O 12.3-12.6) emitted from a cement plant on the element composition of soil and needles of Scots pine in different canopy layers was studied. In the polluted area, the pH of soils was >7, and high amounts of Ca, K and Mg were measured in the upper layers of soil (0-30 cm), while the mobility and solubility of some contaminants have decreased, nutrition processes have become complicated, and imbalance of mineral composition of trees was revealed. Reduced N and increased K, Ca and Mg concentrations in needles were observed in the heavily polluted area. Vertical gradients of elements and their ratios in canopies varied depending on the alkalisation level of soil. Needles on the upper-crown shoots had higher concentrations of N, C, Ca and Mg and lower concentrations of P and K compared to the lower layer of the crown. In the unpolluted area, higher concentrations of N, P, K and Ca were found in lower-crown needles and of C and Mg in needles at the top of the canopy. The P/N ratio below 0.125 indicated P deficiency in pines. The ratios N/Ca, N/Mg and N/K had significantly decreased, while the ratios Ca/Mg, K/Mg and K/Ca had a tendency to increase in heavily polluted sample plots. Magnitude of changes of element ratios indicates on the disbalances of availability and translocation of nutrients in the crown of trees. PMID:19015943

Mandre, Malle

2008-11-08

448

Cu-Ni composition gradient for the catalytic synthesis of vertically aligned carbon nanofibers  

SciTech Connect

The influence of catalyst alloy composition on the growth of vertically aligned carbon nanofibers was studied using Cu-Ni thin films. Metals were co-sputtered onto a substrate to form a thin film alloy with a wide compositional gradient, as determined by Auger analysis. Carbon nanofibers were then grown from the gradient catalyst film by plasma enhanced chemical vapor deposition. The alloy composition produced substantial differences in the resulting nanofibers, which varied from branched structures at 81%Ni-19%Cu to high aspect ratio nanocones at 80%Cu-20%Ni. Electron microscopy and spectroscopy techniques also revealed segregation of the initial alloy catalyst particles at certain concentrations.

Klein, Kate L [ORNL; Melechko, Anatoli Vasilievich [ORNL; Rack, Philip D [ORNL; Fowlkes, Jason Davidson [ORNL; Meyer III, Harry M [ORNL; Simpson, Michael L [ORNL

2005-01-01

449

Vertical profiling of ozone and meteorological parameters in the lower atmosphere using kite and balloon platforms  

NASA Astrophysics Data System (ADS)

Vertical profiles of ozone mixing ratio, water vapor mixing ratio, temperature and pressure collected as part of the North Atlantic Regional Experiment (NARE) are presented. Two field campaigns to the Maritime Provinces of Canada are described. Thirty-nine profiles collected at Cape Sable Island, Nova Scotia, Canada during the period August 8-28, 1993 illustrate the complex vertical stratification and temporal variability of the lower atmosphere during periods of transport of pollutants to the sampling site. Transport phenomena resulted in pollution events in which ozone at ground level remained in the 20-40 ppbv range while mixing ratios of 90-130 ppbv were observed above ~300 meters. Back trajectories indicate that these highly elevated levels of ozone are attributable to source regions in the eastern United States. Vertical stratification of the lower atmosphere was also present during transport of Canadian air to the sampling site, while marine air did not exhibit layering characteristic of air masses originating from continental source regions. Vertical profiles collected at Ferryland Downs, Newfoundland, Canada during August 3-13, 1995 suggest a potentially important upper atmospheric summertime source of ozone to the Maritime Provinces of Canada. Thirty-four profiles collected during an intensive sampling period, from August 4-7, exhibit layers of ozone reaching 100 ppbv associated with water vapor mixing ratios as low as 0.1 g kg-1. These layers were observed between 2 and 5 km in altitude, with no evidence of dry, ozone-rich layers observed at ground level. Data from free launch balloon soundings during the two weeks prior to the kite/tethered-balloon experiment provide evidence that the dry, ozone-rich air originated at the tropopause. A newly discovered chemiluminescence reaction of nitrogen dioxide with an oxalate ester is described. This reaction is found to be highly solvent specific, and selective to nitrogen dioxide. No chemiluminescence reaction was found to occur with nitric oxide, ozone, nitrate or nitrite. Two signal pathways for nitrogen dioxide initiated peroxyoxalate reaction, one having fast kinetics (secs) and one slow (min), provide evidence that this reaction proceeds via multiple mechanistic channels. The application of this reaction for the detection of atmospheric oxides of nitrogen is proposed.

Knapp, Karl Glenn

450

Etching-dependent reproducible memory switching in vertical SiO2 structures  

NASA Astrophysics Data System (ADS)

Vertical structures of SiO2 sandwiched between a top tungsten electrode and conducting nonmetallic substrate were fabricated by dry and wet etching methods. Both structures exhibit similar voltage-controlled memory behaviors, in which short voltage pulses (1 ?s) can switch the devices between high- and low-impedance states. Through the comparison of current-voltage characteristics in structures made by different methods, filamentary conduction at the etched oxide edges is most consistent with the results, providing insights into similar behaviors in metal/SiO/metal systems. High ON/OFF ratios of over 104 were demonstrated.

Yao, Jun; Zhong, Lin; Natelson, Douglas; Tour, James M.

2008-12-01

451

The effect of canyon aspect ratio on flushing of dense pollutants from an isolated street canyon.  

PubMed

This study presents an experimental investigation of the effect of canyon aspect ratio on the dense pollutant removal from a street canyon by a turbulent overflow. Four series of experiments for different aspect ratios (?=0.45, 0.75, 1, 2) were conducted for a range of Richardson numbers. The qualitative and quantitative results are discussed and compared. Increasing the Richardson number and decreasing the canyon aspect ratio resulted in an increasingly strong stratification within the canyon and longer trapping times for the pollutant. The aspect ratio strongly affects the initial flushing mechanics and subsequent flow regime within the canyon. Narrower street canyons limit the width of large-scale vortices in the canyon and hence reduce vertical mixing. Based on the initial Richardson number, for all geometric configurations, three different flow regimes were observed in the canyon. The Richardson number at which there is a transition between these regimes is a function of the canyon geometry. PMID:23183223

Baratian-Ghorghi, Z; Kaye, Nigel B

2012-11-23

452

Development of Vertical Cable Seismic System  

NASA Astrophysics Data System (ADS)

In 2009, Ministry of Education, Culture, Sports, Science and Technology(MEXT) started the survey system development for Hydrothermal deposit. We proposed the Vertical Cable Seismic (VCS), the reflection seismic survey with vertical cable above seabottom. VCS has the following advantages for hydrothermal deposit survey. (1) VCS is an efficient high-resolution 3D seismic survey in limited area. (2) It achieves high-resolution image because the sensors are closely located to the target. (3) It avoids the coupling problems between sensor and seabottom that cause serious damage of seismic data quality. (4) Because of autonomous recording system on sea floor, various types of marine source are applicable with VCS such as sea-surface source (GI gun etc.) , deep-towed or ocean bottom source. Our first experiment of 2D/3D VCS surveys has been carried out in Lake Biwa, JAPAN, in November 2009. The 2D VCS data processing follows the walk-away VSP, including wave field separation and depth migration. Seismic Interferometry technique is also applied. The results give much clearer image than the conventional surface seismic. Prestack depth migration is applied to 3D data to obtain good quality 3D depth volume. Seismic Interferometry technique is applied to obtain the high resolution image in the very shallow zone. Based on the feasibility study, we have developed the autonomous recording VCS system and carried out the trial experiment in actual ocean at the water depth of about 400m to establish the procedures of deployment/recovery and to examine the VC position or fluctuation at seabottom. The result shows that the VC position is estimated with sufficient accuracy and very little fluctuation is observed. Institute of Industrial Science, the University of Tokyo took the research cruise NT11-02 on JAMSTEC R/V Natsushima in February, 2011. In the cruise NT11-02, JGI carried out the second VCS survey using the autonomous VCS recording system with the deep towed source provided by Institute of Industrial Science, the University of Tokyo. It generates high frequency acoustic waves around 1kHz. The acquired VCS data clearly shows the reflections and currently being processed for imaging the subsurface structure.

Asakawa, E.; Murakami, F.; Sekino, Y.; Okamoto, T.; Ishikawa, K.; Tsukahara, H.; Shimura, T.

2011-12-01

453

Vertically homogeneous stationary tornado-type vortex  

NASA Astrophysics Data System (ADS)

Tornado is regarded as one of the most dangerous atmosphere phenomena. The tornado phenomenon has been intensively studied so far, however, there is still no established and accepted theory of how tornadoes form, an uncertainty still exists concerning extreme winds and pressure drops in tornadoes. It is commonly accepted that it is possible to describe tornado from the set of nonlinear hydrodynamical equations, however, it is still unclear which non-linear processes are responsible for its formation. Nonlinear terms in the system are associated with either centrifugal force, or entropy transport, or transport of humidity. It appears that the amount and spatial distribution of precipitation with the convection are important indicators of the weather phenomena associated with a particular storm. The low-precipitation supercells that produce relatively little precipitation and yet show clear visual signs of rotation. Low-precipitation supercells occur most often near the surface dryline and, owing to the sparse precipitation and relatively dry environments with little cloudiness. Low-precipitation storms are frequently non-tornadic and many are non-severe despite exhibiting persistent rotation. On the other hand, the so-called high-precipitation storms are characterized by substantial precipitation within their mesocyclonic circulations. When high-precipitation storms have a recognizable hook radar echo, reflectivity in the hook is comparable to those in the precipitation core. High-precipitation supercells are probably the most common form of supercell and produce severe weather of all types including tornadoes. Therefore, in this work we consider a hydrodynamic system with only one nonlinear term associated with atmosphere humidity, which yields energy to the system. The tornado vortex is usually to a good approximation cylindrical so we use cylindrical geometry and homogeneity in vertical direction. In this case the problem reduces to a system of ordinary differential equations. Rotation in the vortex is associated with compressibility so we also take into account the compressibility of the gas. Under certain approximations the problem reduces to a single high-order nonlinear equation. Numerical solution of the obtained high-order equation describes all three velocity components and all thermodynamic parameters in the system. The system exhibits high rotation and strong vertical air flow in the middle part of the vortex.

Rutkevich, P. B.; Rutkevych, P. P.

2010-05-01

454

Medical Loss Ratio (MLR) (Affordable Care Act)  

MedlinePLUS

... Letters Regulations and Guidance Stakeholder Engagement Training Resources Medical Loss Ratio Many insurance companies spend a substantial ... services and quality improvement, also known as the Medical Loss Ratio (MLR). It also requires them to ...

455

Poisson`s ratio and crustal seismology  

SciTech Connect

This report discusses the use of Poisson`s ratio to place constraints on continental crustal composition. A summary of Poisson`s ratios for many common rock formations is also included with emphasis on igneous and metamorphic rock properties.

Christensen, N.I. [Purdue Univ., West Lafayette, IN (United States)

1996-02-10

456

Computation of Cold-Start Miss Ratios  

Microsoft Academic Search

Cold-start miss ratios are miss ratios that are measured with an initially empty first-level store. The values obtained depend on C, the first-level storage capacity, and on T, the number of references. These miss ratios, measured for various values of T, are useful in evaluating the effect of task switching on cache miss ratios when the cache capacity is C.

Malcolm C. Easton

1978-01-01

457

Midrapidity Antiproton-to-Proton Ratio in pp Collisons root s=0.9 and 7 TeV Measured by the ALICE Experiment  

Microsoft Academic Search

The ratio of the yields of antiprotons to protons in pp collisions has been measured by the ALICE experiment at root s = 0.9 and 7 TeV during the initial running periods of the Large Hadron Collider. The measurement covers the transverse momentum interval 0.45 < p(t) < 1.05 GeV\\/c and rapidity vertical bar y vertical bar < 0.5. The

K. Aamodt; N. Abel; U. Abeysekara; A. A. Quintana; A. Abramyan; D. Adamova; M. M. Aggarwal; G. A. Rinella; A. G. Agocs; S. A. Salazar; Z. Ahammed; A. Ahmad; N. Ahmad; S. U. Ahn; R. Akimoto; A. Akindinov; D. Aleksandrov; B. Alessandro; R. A. Molina; A. Alici; E. A. Avina; J. Alme; T. Alt; V. Altini; S. Altinpinar; C. Andrei; A. Andronic; G. Anelli; V. Angelov; C. Anson; T. Anticic; F. Antinori; S. Antinori; K. Antipin; D. Antonczyk; P. Antonioli; A. Anzo; L. Aphecetche; S. A. Appelshauser; S. Arcelli; R. Arceo; A. Arend; N. Armesto; R. Arnaldi; T. Aronsson; I. C. Arsene; A. Asryan; A. Augustinus; R. Averbeck; T. C. Awes; J. Aysto; M. D. Azmi; S. Bablok; M. Bach; A. Badala; Y. W. Baek; S. Bagnasco; R. Bailhache; R. Bala; A. Baldisser; A. Baldit; J. Ban; R. Barbera; G. G. Barnafoldi; L. S. Barnby; V. Barret; J. Bartke; F. Barile; M. Basile; V. Basmanov; N. Bastid; B. Bathen; G. Batigne; B. Batyunya; C. Baumann; I. G. Bearden; B. Becker; I. Belikov; R. Bellwied; E. Belmont-Moreno; A. Belogianni; L. Benhabib; S. Beole; I. Berceanu; A. Bercuci; E. Berdermann; Y. Berdnikov; L. Betev; A. Bhasin; A. K. Bhati; L. Bianchi; N. Bianchi; C. Bianchin; J. Bielcik; J. Bielcikova; A. Bilandzic; L. Bimbot; E. Biolcati; A. Blanc; F. Blanco; D. Blau; C. Blume; M. Boccioli; N. Bock; A. Bogdanov; H. Boggild; M. Bogolyubsky; J. Bohm; L. Boldizsar; M. Bombara; C. Bombonati; M. Bondila; H. Borel; A. Borisov; C. Bortolin; S. Bose; L. Bosisio; F. Bossu; M. Botje; S. Bottger; G. Bourdaud; B. Boyer; M. Braun; P. Braun-Munzinger; L. Bravina; M. Bregant; T. Breitner; G. Bruckner; R. Brun; E. Bruna; G. E. Bruno; D. Budnikov; H. Buesching; P. Buncic; O. Busch; Z. Buthelezi; D. Caffarri; X. Cai; H. Caines; E. Calvo; E. Camacho; P. Camerini; M. Campbell; V. C. Roman; G. P. Capitani; G. C. Romeo; F. Carena; W. Carena; F. Carminati; A. C. Diaz; M. Caselle; J. C. Castellanos; J. F. C. Hernandez; V. Catanescu; E. Cattaruzza; C. Cavicchioli; P. Cerello; V. Chambert; B. Chang; S. Chapeland; A. Charpy; J. L. Charvet; S. Chattopadhyay; M. Cherney; C. Cheshkov; B. Cheynis; E. Chiavassa; V. C. Barroso; D. D. Chinellato; P. Chochula; K. Choi; M. Chojnacki; P. Christakoglou; C. H. Christensen; P. Christiansen; T. Chujo; F. Chuman; C. Cicalo; L. Cifarelli; F. Cindolo; J. Cleymans; O. Cobanoglu; J. P. Coffin; S. Coli; A. Colla; G. C. Balbastre; Z. C. del Valle; E. S. Conner; P. Constantin; G. Contin; J. G. Contreras; Y. C. Morales; T. M. Cormier; P. Cortese; I. C. Maldonado; M. R. Cosentino; F. Costa; M. E. Cotallo; E. Crescio; P. Crochet; E. Cuautle; L. Cunqueiro; J. Cussonneau; A. Dainese; H. H. Dalsgaard; A. Danu; I. Das; A. Dash; S. Dash; G. O. V. de Barros; A. de Caro; G. de Cataldo; J. de Cuveland; A. De Falco; M. De Gaspari; J. de Groot; D. De Gruttola; N. De Marco; S. De Pasquale; R. De Remigis; R. de Rooij; G. de Vaux; H. Delagrange; Y. Delgado; G. Dellacasa; A. Deloff; V. Demanov; E. Denes; A. Deppman; G. DErasmo; D. Derkach; A. Devaux; D. Di Bari; C. Di Giglio; S. Di Liberto; A. Di Mauro; P. Di Nezza; M. Dialinas; L. Diaz; R. Diaz; T. Dietel; R. Divia; O. Djuvsland; V. Dobretsov; A. Dobrin; T. Dobrowolski; B. Donigus; I. Dominguez; D. M. M. Don; O. Dordic; A. K. Dubey; J. Dubuisson; L. Ducroux; P. Dupieux; A. K. D. Majumdar; M. R. D. Majumdar; D. Elia; D. Emschermann; A. Enokizono; B. Espagnon; M. Estienne; S. Esumi; D. Evans; S. Evrard; G. Eyyubova; C. W. Fabjan; D. Fabris; J. Faivre; D. Falchieri; A. Fantoni; M. Fasel; O. Fateev; R. Fearick; A. Fedunov; D. Fehlker; V. Fekete; D. Felea; B. Fenton-Olsen; G. Feofilov; A. F. Tellez; E. G. Ferreiro; A. Ferretti; R. Ferretti; M. A. S. Figueredo; S. Filchagin; R. Fini; F. M. Fionda; E. M. Fiore; M. Floris; Z. Fodor; S. Foertsch; P. Foka; S. Fokin; F. Formenti; E. Fragiacomo; M. Fragkiadakis; U. Frankenfeld; A. Frolov; U. Fuchs; F. Furano; C. Furget; M. F. Girard; J. J. Gaardhoje; S. Gadrat; M. Gagliardi; A. Gago; M. Gallio; P. Ganoti; M. S. Ganti; C. Garabatos; C. G. Trapaga; J. Gebelein; R. Gemme; M. Germain; A. Gheata; M. Gheata; B. Ghidini; P. Ghosh; G. Giraudo; P. Giubellino; E. Gladysz-Dziadus; R. Glasow; P. Glassel; A. Glenn; R. G. Jimenez; H. G. Santos; L. H. Gonzalez-Trueba; P. Gonzalez-Zamora; S. Gorbunov; Y. Gorbunov; S. Gotovac; H. Gottschlag; V. Grabski; R. Grajcarek; A. Grelli; A. Grigoras; C. Grigoras; V. Grigoriev; A. Grigoryan; S. Grigoryan; B. Grinyov; N. Grion; P. Gros; J. F. Grosse-Oetringhaus; J. Y. Grossiord; R. Grosso; F. Guber; R. Guernane; C. Guerra; B. Guerzoni; K. Gulbrandsen; H. Gulkanyan; T. Gunji; A. Gupta; R. Gupta; H. A. Gustafsson; H. Gutbrod; O. Haaland; C. Hadjidakis; M. Haiduc; H. Hamagaki; G. Hamar; J. Hamblen; B. H. Han; J. W. Harris; M. Hartig; A. Harutyunyan; D. Hasch; D. Hasegan; D. Hatzifotiadou; A. Hayrapetyan; M. Heide; M. Heinz; H. Helstrup; A. Herghelegiu; C. Hernandez; G. H. Corral; N. Herrmann; K. F. Hetland

2010-01-01

458

TSearch: A Self-learning Vertical Search Spider for Travel  

Microsoft Academic Search

A self-learning vertical search spider for travel is presented. This paper focuses on two machine learning methods SNBC (self-learning naive Bayes classifier) and LQNBC (log quotient naive Bayes classifier) for improving search quality and topic relevance. A framework of designing and implementing a vertical spider TSearch with basic general search spider architecture and functions is also showed. TSearch uses SNBC

Suke Li; CHEN Zhong; Liyong Tang; Zhao Wang

2008-01-01

459

Control system for a vertical-axis windmill  

Microsoft Academic Search

A vertical-axis windmill having a rotating structure is provided with a series of articulated vertical blades whose positions are controlled to maintain a constant RPM for the rotating structure, when wind speed is sufficient. A microprocessor controller is used to process information on wind speed, wind direction and RPM of the rotating structure to develop an electrical signal for establishing

Brulle

1981-01-01

460

Environmental Vertical Wind Shear with Hurricane Bertha (1996)  

Microsoft Academic Search

Hurricane Bertha (1996) was influenced by vertical wind shear with highly variable direction and magnitude. The paper describes a unique method for determining the vertical tilt of a tropical cyclone vortex using satellite and aircraft data. Hurricane Bertha's vortex tracks at three levels are shown during a period of intensification just prior to landfall. During this period, the hurricane vortex

Raymond M. Zehr

2003-01-01

461

Wintertime mesopause region vertical winds from Resolute Bay  

NASA Astrophysics Data System (ADS)

Vertical neutral winds in the upper mesosphere-lower thermosphere, measured by observing the hydroxyl (OH) airglow using a wide-angle Michelson Interferometer from Resolute Bay (74°N), over the course of three Arctic winters, are presented. The measurement of vertical winds, which span 3 to 4 months during the 1995-1996, 1996-1997, and 2000-2001 winters, are unique and allow for a variety of studies on the mechanisms associated with vertical winds in the mesosphere; specifically the influences of both geomagnetic activity and the polar vortex. In this study it is observed that (1) these vertical wind measurements are consistent with other studies of vertical winds from high latitude sites using different instrumentation, (2) the amplitude of vertical winds are not sensitive to Ap index at the measurement location, and (3) the daily variance of vertical winds are moderately correlated to the position of the stratospheric polar vortex as revealed by diagnostics of stratospheric assimilated data at the 10 hPa level. These results should help enhance our understanding of the mechanisms that determine the magnitude and variability of vertical neutral winds at high latitudes.

Bhattacharya, Yajnavalkya; Gerrard, Andrew J.

2010-01-01

462

Does depth perception require vertical-disparity detectors?  

Microsoft Academic Search

Stereo depth perception depends on the fact that objects project to different positions in the two eyes. Because our eyes are offset horizontally, these retinal disparities are mainly horizontal, and horizontal disparity suffices to give an impression of depth. However, depending on eye position, there may also be small vertical disparities. These are significant because, given both vertical and horizontal

Bruce G. Cumming

2006-01-01

463

Recovery of a vertically stratified seabed in shallow water  

Microsoft Academic Search

We describe an algorithm for finding a vertically stratified seabed in shallow water from acoustic data. Numerical reconstructions are given. Introduction: The goal is to find an approximate sound speed profile for a vertically stratified seabed in shallow water. The data is the pressure field measured in the water column where it is assumed that the sound speed is known.

Joyce R. McLaughlin; Shixiao Wang

464

Vertically coupled Si-based athermal double-ring biosensor  

Microsoft Academic Search

A silicon-based athermal double-ring resonator biosensor with a vertically coupled configuration is developed. We present an optimal design of the sensor structure by specifying the radii of the reference and the sensing rings, the vertical coupling offset, d, between the two rings and the bus waveguide, and the lateral offset, l, between the edges of the rings and the bus

Yule Xiong; Winnie N. Ye

2011-01-01

465

Comparison of lower stratospheric tropical mean vertical velocities  

Microsoft Academic Search

We have analyzed 13 years (1993-2005) of tropical stratospheric water vapor data from the Halogen Occultation Experiment and over 3 years of data (October 2004 through November 2007) from the Aura Microwave Limb Sounder. By correlating the phase lag of the water vapor ``tape recorder'' signal between levels we estimate the time mean vertical velocity. Our estimated vertical velocity compares

M. R. Schoeberl; A. R. Douglass; R. S. Stolarski; S. Pawson; S. E. Strahan; W. Read

2008-01-01

466

Comparison of lower stratospheric tropical mean vertical velocities  

Microsoft Academic Search

We have analyzed 13 years (1993–2005) of tropical stratospheric water vapor data from the Halogen Occultation Experiment and over 3 years of data (October 2004 through November 2007) from the Aura Microwave Limb Sounder. By correlating the phase lag of the water vapor “tape recorder” signal between levels we estimate the time mean vertical velocity. Our estimated vertical velocity compares

M. R. Schoeberl; A. R. Douglass; R. S. Stolarski; S. Pawson; S. E. Strahan; W. Read

2008-01-01

467