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Sample records for vertical cup-to-disc ratio

  1. Vertical cup-to-disc ratio measurement for diagnosis of glaucoma on fundus images

    NASA Astrophysics Data System (ADS)

    Hatanaka, Yuji; Noudo, Atsushi; Muramatsu, Chisako; Sawada, Akira; Hara, Takeshi; Yamamoto, Tetsuya; Fujita, Hiroshi

    2010-03-01

    Glaucoma is a leading cause of permanent blindness. Retinal fundus image examination is useful for early detection of glaucoma. In order to evaluate the presence of glaucoma, the ophthalmologists determine the cup and disc areas and they diagnose glaucoma using a vertical cup-to-disc ratio. However, determination of the cup area is very difficult, thus we propose a method to measure the cup-to-disc ratio using a vertical profile on the optic disc. First, the blood vessels were erased from the image and then the edge of optic disc was then detected by use of a canny edge detection filter. Twenty profiles were then obtained around the center of the optic disc in the vertical direction on blue channel of the color image, and the profile was smoothed by averaging these profiles. After that, the edge of the cup area on the vertical profile was determined by thresholding technique. Lastly, the vertical cup-to-disc ratio was calculated. Using seventy nine images, including twenty five glaucoma images, the sensitivity of 80% and a specificity of 85% were achieved with this method. These results indicated that this method can be useful for the analysis of the optic disc in glaucoma examinations.

  2. Genetic Variants Associated with Optic Nerve Vertical Cup-to-Disc Ratio Are Risk Factors for Primary Open Angle Glaucoma in a US Caucasian Population

    PubMed Central

    Fan, Bao Jian; Wang, Dan Yi; Pasquale, Louis R.; Haines, Jonathan L.

    2011-01-01

    Purpose. Genetically complex disorders, such as primary open angle glaucoma (POAG), may include highly heritable quantitative traits as part of the overall phenotype, and mapping genes influencing the related quantitative traits may effectively identify genetic risk factors predisposing to the complex disease. Recent studies have identified SNPs associated with optic nerve area and vertical cup-to-disc ratio (VCDR). The purpose of this study was to evaluate the association between these SNPs and POAG in a US Caucasian case-control sample. Methods. Five SNPs previously associated with optic disc area, or VCDR, were genotyped in 539 POAG cases and 336 controls. Genotype data were analyzed for single SNP associations and SNP interactions with VCDR and POAG. Results. SNPs associated with VCDR rs1063192 (CDKN2B) and rs10483727 (SIX1/SIX6) were also associated with POAG (P = 0.0006 and P = 0.0043 for rs1063192 and rs10483727, respectively). rs1063192, associated with smaller VCDR, had a protective effect (odds ratio [OR] = 0.73; 95% confidence interval [CI], 0.58–0.90), whereas rs10483727, associated with larger VCDR, increased POAG risk (OR = 1.33; 95% CI, 1.08–1.65). POAG risk associated with increased VCDR was significantly influenced by the C allele of rs1900004 (ATOH7), associated with increased optic nerve area (P-interaction = 0.025; OR = 1.89; 95% CI, 1.22–2.94). Conclusions. Genetic variants influencing VCDR are associated with POAG in a US Caucasian population. Variants associated with optic nerve area are not independently associated with disease but can influence the effects of VCDR variants suggesting that increased optic disc area can significantly contribute to POAG risk when coupled with risk factors controlling VCDR. PMID:21398277

  3. ARGALI: an automatic cup-to-disc ratio measurement system for glaucoma detection and AnaLysIs framework

    NASA Astrophysics Data System (ADS)

    Liu, J.; Wong, D. W. K.; Lim, J. H.; Li, H.; Tan, N. M.; Wong, T. Y.

    2009-02-01

    Glaucoma is an irreversible ocular disease leading to permanent blindness. However, early detection can be effective in slowing or halting the progression of the disease. Physiologically, glaucoma progression is quantified by increased excavation of the optic cup. This progression can be quantified in retinal fundus images via the optic cup to disc ratio (CDR), since in increased glaucomatous neuropathy, the relative size of the optic cup to the optic disc is increased. The ARGALI framework constitutes of various segmentation approaches employing level set, color intensity thresholds and ellipse fitting for the extraction of the optic cup and disc from retinal images as preliminary steps. Following this, different combinations of the obtained results are then utilized to calculate the corresponding CDR values. The individual results are subsequently fused using a neural network. The learning function of the neural network is trained with a set of 100 retinal images For testing, a separate set 40 images is then used to compare the obtained CDR against a clinically graded CDR, and it is shown that the neural network-based result performs better than the individual components, with 96% of the results within intra-observer variability. The results indicate good promise for the further development of ARGALI as a tool for the early detection of glaucoma.

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

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

    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.

  5. 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)

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

    2009-02-01

    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.

  6. Automated segmentation of optic disc in SD-OCT images and cup-to-disc ratios quantification by patch searching-based neural canal opening detection.

    PubMed

    Wu, Menglin; Leng, Theodore; de Sisternes, Luis; Rubin, Daniel L; Chen, Qiang

    2015-11-30

    Glaucoma is one of the most common causes of blindness worldwide. Early detection of glaucoma is traditionally based on assessment of the cup-to-disc (C/D) ratio, an important indicator of structural changes to the optic nerve head. Here, we present an automated optic disc segmentation algorithm in 3-D spectral domain optical coherence tomography (SD-OCT) volumes to quantify this ratio. The proposed algorithm utilizes a two-stage strategy. First, it detects the neural canal opening (NCO) by finding the points with maximum curvature on the retinal pigment epithelium (RPE) boundary with a spatial correlation smoothness constraint on consecutive B-scans, and it approximately locates the coarse disc margin in the projection image using convex hull fitting. Then, a patch searching procedure using a probabilistic support vector machine (SVM) classifier finds the most likely patch with the NCO in its center in order to refine the segmentation result. Thus, a reference plane can be determined to calculate the C/D radio. Experimental results on 42 SD-OCT volumes from 17 glaucoma patients demonstrate that the proposed algorithm can achieve high segmentation accuracy and a low C/D ratio evaluation error. The unsigned border error for optic disc segmentation and the evaluation error for C/D ratio comparing with manual segmentation are 2.216 ± 1.406 pixels (0.067 ± 0.042 mm) and 0.045 ± 0.033, respectively.

  7. A distinct X-linked syndrome involving joint contractures, keloids, large optic cup-to-disc ratio, and renal stones results from a filamin A (FLNA) mutation.

    PubMed

    Lah, Melissa; Niranjan, Tejasvi; Srikanth, Sujata; Holloway, Lynda; Schwartz, Charles E; Wang, Tao; Weaver, David D

    2016-04-01

    We further evaluated a previously reported family with an apparently undescribed X-linked syndrome involving joint contractures, keloids, an increased optic cup-to-disc ratio, and renal stones to elucidate the genetic cause. To do this, we obtained medical histories and performed physical examination on 14 individuals in the family, five of whom are affected males and three are obligate carrier females. Linkage analysis was performed on all but one individual and chromosome X-exome sequencing was done on two affected males. The analysis localized the putative gene to Xq27-qter and chromosome X-exome sequencing revealed a mutation in exon 28 (c.4726G>A) of the filamin A (FLNA) gene, predicting that a conserved glycine had been replaced by arginine at amino acid 1576 (p.G1576R). Segregation analysis demonstrated that all known carrier females tested were heterozygous (G/A), all affected males were hemizygous for the mutation (A allele) and all normal males were hemizygous for the normal G allele. The data and the bioinformatic analysis indicate that the G1576R mutation in the FLNA gene is very likely pathogenic in this family. The syndrome affecting the family shares phenotypic overlap with other syndromes caused by FLNA mutations, but appears to be a distinct phenotype, likely representing a unique genetic syndrome.

  8. Aspect ratio of undulation in a vertically vibrated granular layer

    NASA Astrophysics Data System (ADS)

    Dose, Yoshihito; Sano, Osamu

    2016-03-01

    The aspect ratio of the height δ to the wavelength λ of the undulation generated by a vertical vibration of the granular layer was investigated experimentally, and its dependence on the frequency f and amplitude a is disclosed. We found that δ / λ is well described by an almost linear function of fa rather than by that of Γ ≡(2 πf) 2 a / g, irrespective of the horizontal size of the container, where g is the acceleration of gravity. Appearance of sub-arches to maintain the main eigenmode and the transitions between eigenmodes of undulation are also elucidated.

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

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

    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 μm 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.

  10. The effect of tip speed ratio on a vertical axis wind turbine at high Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Parker, Colin M.; Leftwich, Megan C.

    2016-05-01

    This work visualizes the flow surrounding a scaled model vertical axis wind turbine at realistic operating conditions. The model closely matches geometric and dynamic properties—tip speed ratio and Reynolds number—of a full-size turbine. The flow is visualized using particle imaging velocimetry (PIV) in the midplane upstream, around, and after (up to 4 turbine diameters downstream) the turbine, as well as a vertical plane behind the turbine. Time-averaged results show an asymmetric wake behind the turbine, regardless of tip speed ratio, with a larger velocity deficit for a higher tip speed ratio. For the higher tip speed ratio, an area of averaged flow reversal is present with a maximum reverse flow of -0.04U_∞. Phase-averaged vorticity fields—achieved by syncing the PIV system with the rotation of the turbine—show distinct structures form from each turbine blade. There were distinct differences in results by tip speed ratios of 0.9, 1.3, and 2.2 of when in the cycle structures are shed into the wake—switching from two pairs to a single pair of vortices being shed—and how they convect into the wake—the middle tip speed ratio vortices convect downstream inside the wake, while the high tip speed ratio pair is shed into the shear layer of the wake. Finally, results show that the wake structure is much more sensitive to changes in tip speed ratio than to changes in Reynolds number.

  11. Nitrogen removal in intermittently aerated vertical flow constructed wetlands: impact of influent COD/N ratios.

    PubMed

    Fan, Jinlin; Wang, Wengang; Zhang, Bo; Guo, Yeye; Ngo, Huu Hao; Guo, Wenshan; Zhang, Jian; Wu, Haiming

    2013-09-01

    The performance response of eight vertical flow constructed wetlands (VFCWs) to different influent COD/N ratios and intermittent aeration in domestic wastewater treatment was investigated. Almost complete nitrification was obtained by intermittent aeration, which well developed alternate anaerobic and aerobic conditions for nitrification and denitrification. Sufficient carbon source supply resulted from influent COD/N ratio of 10 simultaneously obtained high removals of COD (96%), ammonia nitrogen (99%) and total nitrogen (90%) in intermittently aerated VFCWs. In all non-aerated VFCWs, poor nitrification was observed due to oxygen deficiency whilst high COD/N ratios further led to lower COD and nitrogen removal efficiency. The results suggest that intermittent aeration combined with high influent COD/N ratios could achieve high nitrogen removal in VFCWs.

  12. Diffusion of dilute gas in arrays of randomly distributed, vertically aligned, high-aspect-ratio cylinders.

    PubMed

    Szmyt, Wojciech; Guerra, Carlos; Utke, Ivo

    2017-01-01

    In this work we modelled the diffusive transport of a dilute gas along arrays of randomly distributed, vertically aligned nanocylinders (nanotubes or nanowires) as opposed to gas diffusion in long pores, which is described by the well-known Knudsen theory. Analytical expressions for (i) the gas diffusion coefficient inside such arrays, (ii) the time between collisions of molecules with the nanocylinder walls (mean time of flight), (iii) the surface impingement rate, and (iv) the Knudsen number of such a system were rigidly derived based on a random-walk model of a molecule that undergoes memoryless, diffusive reflections from nanocylinder walls assuming the molecular regime of gas transport. It can be specifically shown that the gas diffusion coefficient inside such arrays is inversely proportional to the areal density of cylinders and their mean diameter. An example calculation of a diffusion coefficient is delivered for a system of titanium isopropoxide molecules diffusing between vertically aligned carbon nanotubes. Our findings are important for the correct modelling and optimisation of gas-based deposition techniques, such as atomic layer deposition or chemical vapour deposition, frequently used for surface functionalisation of high-aspect-ratio nanocylinder arrays in solar cells and energy storage applications. Furthermore, gas sensing devices with high-aspect-ratio nanocylinder arrays and the growth of vertically aligned carbon nanotubes need the fundamental understanding and precise modelling of gas transport to optimise such processes.

  13. Diffusion of dilute gas in arrays of randomly distributed, vertically aligned, high-aspect-ratio cylinders

    PubMed Central

    Guerra, Carlos

    2017-01-01

    In this work we modelled the diffusive transport of a dilute gas along arrays of randomly distributed, vertically aligned nanocylinders (nanotubes or nanowires) as opposed to gas diffusion in long pores, which is described by the well-known Knudsen theory. Analytical expressions for (i) the gas diffusion coefficient inside such arrays, (ii) the time between collisions of molecules with the nanocylinder walls (mean time of flight), (iii) the surface impingement rate, and (iv) the Knudsen number of such a system were rigidly derived based on a random-walk model of a molecule that undergoes memoryless, diffusive reflections from nanocylinder walls assuming the molecular regime of gas transport. It can be specifically shown that the gas diffusion coefficient inside such arrays is inversely proportional to the areal density of cylinders and their mean diameter. An example calculation of a diffusion coefficient is delivered for a system of titanium isopropoxide molecules diffusing between vertically aligned carbon nanotubes. Our findings are important for the correct modelling and optimisation of gas-based deposition techniques, such as atomic layer deposition or chemical vapour deposition, frequently used for surface functionalisation of high-aspect-ratio nanocylinder arrays in solar cells and energy storage applications. Furthermore, gas sensing devices with high-aspect-ratio nanocylinder arrays and the growth of vertically aligned carbon nanotubes need the fundamental understanding and precise modelling of gas transport to optimise such processes. PMID:28144565

  14. Vertical split-ring resonator based anomalous beam steering with high extinction ratio

    PubMed Central

    Hsu, Wei-Lun; Wu, Pin Chieh; Chen, Jia-Wern; Chen, Ting-Yu; Cheng, Bo Han; Chen, Wei Ting; Huang, Yao-Wei; Liao, Chun Yen; Sun, Greg; Tsai, Din Ping

    2015-01-01

    Metasurfaces created artificially with metal nanostructures that are patterned on surfaces of different media have shown to possess “unusual” abilities to manipulate light. Limited by nanofabrication difficulties, so far most reported works have been based on 2D metal structures. We have recently developed an advanced e-beam process that allowed for the deposition of 3D nanostructures, namely vertical split-ring resonators (VSRRs), which opens up another degree of freedom in the metasurface design. Here we explore the functionality of beam steering with phase modulation by tuning only the vertical dimension of the VSRRs and show that anomalous steering reflection of a wide range of angles can be accomplished with high extinction ratio using the finite-difference-time-domain simulation. We also demonstrate that metasurfaces made of 3D VSRRs can be made with roughly half of the footprint compared to that of 2D nano-rods, enabling high density integration of metal nanostructures. PMID:26054048

  15. Vertical split-ring resonator based anomalous beam steering with high extinction ratio.

    PubMed

    Hsu, Wei-Lun; Wu, Pin Chieh; Chen, Jia-Wern; Chen, Ting-Yu; Cheng, Bo Han; Chen, Wei Ting; Huang, Yao-Wei; Liao, Chun Yen; Sun, Greg; Tsai, Din Ping

    2015-06-08

    Metasurfaces created artificially with metal nanostructures that are patterned on surfaces of different media have shown to possess "unusual" abilities to manipulate light. Limited by nanofabrication difficulties, so far most reported works have been based on 2D metal structures. We have recently developed an advanced e-beam process that allowed for the deposition of 3D nanostructures, namely vertical split-ring resonators (VSRRs), which opens up another degree of freedom in the metasurface design. Here we explore the functionality of beam steering with phase modulation by tuning only the vertical dimension of the VSRRs and show that anomalous steering reflection of a wide range of angles can be accomplished with high extinction ratio using the finite-difference-time-domain simulation. We also demonstrate that metasurfaces made of 3D VSRRs can be made with roughly half of the footprint compared to that of 2D nano-rods, enabling high density integration of metal nanostructures.

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

    SciTech Connect

    Lu, Qing; Qiu, Suizheng; Su, Guanghui; Tian, Wenxi; Ye, Zhonghao

    2010-01-15

    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)

  17. A Genome-Wide Association Study of Vertical Cup-Disc Ratio in a Latino Population

    PubMed Central

    Nannini, Drew R.; Torres, Mina; Chen, Yii-Der I.; Taylor, Kent D.; Rotter, Jerome I.; Varma, Rohit; Gao, Xiaoyi

    2017-01-01

    Purpose Vertical cup-disc ratio (VCDR) is used as a clinical assessment measure to identify and monitor glaucomatous damage to the optic nerve. Previous genetic studies conducted in European and Asian populations have identified many loci associated with VCDR. The genetic factors in other ethnic populations, such as Latino, influencing VCDR remain to be determined. Here, we describe the first genome-wide association study (GWAS) on VCDR in Latino individuals. Methods We conducted this GWAS on VCDR using 4537 Latino individuals who were genotyped by using either the Illumina OmniExpress BeadChip (∼730K markers) or the Illumina Hispanic/SOL BeadChip (∼2.5 million markers). Study subjects were 40 years of age and older. Linear regression, adjusting for age, sex, and principal components of genetic ancestry, was conducted to assess the associations between single nucleotide polymorphisms (SNPs) and VCDR. We imputed SNPs from the 1000 Genomes Project to integrate additional SNPs not directly genotyped. Results We replicated two previously reported SNPs that reached GWAS significance, rs1900005 and rs7916697, in the ATOH7-PBLD region, as well as identified two suggestive associations in the CDC7-TGFBR3 region on chromosome 1p22.1 and in the ZNF770-DPH6 region on chromosome 15q14. We discovered a novel SNP, rs56238729 (P = 1.22 × 10−13), in the ATOH7-PBLD region that is significantly associated with VCDR in Latino individuals. We replicated eight previously reported regions, including COL8A1, CDKN2B-CDKN2BAS, BMP2, and CHEK2 (P < 2.17 × 10−3). Conclusions Our results discovered a novel SNP that is significantly associated with VCDR in Latino individuals and confirmed previously reported loci, providing further insight into the genetic architecture of VCDR. PMID:28061514

  18. High Rayleigh number convection in rectangular enclosures with differentially heated vertical walls and aspect ratios between zero and unity

    NASA Technical Reports Server (NTRS)

    Kassemi, Siavash A.

    1988-01-01

    High Rayleigh number convection in a rectangular cavity with insulated horizontal surfaces and differentially heated vertical walls was analyzed for an arbitrary aspect ratio smaller than or equal to unity. Unlike previous analytical studies, a systematic method of solution based on linearization technique and analytical iteration procedure was developed to obtain approximate closed-form solutions for a wide range of aspect ratios. The predicted velocity and temperature fields are shown to be in excellent agreement with available experimental and numerical data.

  19. High Rayleigh number convection in rectangular enclosures with differentially heated vertical walls and aspect ratios between zero and unity

    SciTech Connect

    Kassemi, S.A.

    1988-04-01

    High Rayleigh number convection in a rectangular cavity with insulated horizontal surfaces and differentially heated vertical walls was analyzed for an arbitrary aspect ratio smaller than or equal to unity. Unlike previous analytical studies, a systematic method of solution based on linearization technique and analytical iteration procedure was developed to obtain approximate closed-form solutions for a wide range of aspect ratios. The predicted velocity and temperature fields are shown to be in excellent agreement with available experimental and numerical data.

  20. Design and optimization of vertical surrounding gate MOSFETs for enhanced transconductance-to-current ratio ( gm/ Ids)

    NASA Astrophysics Data System (ADS)

    Kranti, A.; Rashmi; Haldar, S.; Gupta, R. S.

    2003-01-01

    The present analysis proposes a new technique to optimize the device parameters for improving the transconductance-to-current ratio of vertical surrounding gate (VSG) and double gate (DG) MOSFETs. Advantages of VSG MOSFETs over DG MOSFETs in terms of transconductance-to-current ratio ( gm/ Ids) are examined in detail. Model shows new opportunities for realizing future ULSI circuits with VSG MOSFETs. Close proximity with published results confirms the validity of the present model.

  1. Magnetic field alignment of randomly oriented, high aspect ratio silicon microwires into vertically oriented arrays.

    PubMed

    Beardslee, Joseph A; Sadtler, Bryce; Lewis, Nathan S

    2012-11-27

    External magnetic fields have been used to vertically align ensembles of silicon microwires coated with ferromagnetic nickel films. X-ray diffraction and image analysis techniques were used to quantify the degree of vertical orientation of the microwires. The degree of vertical alignment and the minimum field strength required for alignment were evaluated as a function of the wire length, coating thickness, magnetic history, and substrate surface properties. Nearly 100% of 100 μm long, 2 μm diameter, Si microwires that had been coated with 300 nm of Ni could be vertically aligned by a 300 G magnetic field. For wires ranging from 40 to 60 μm in length, as the length of the wire increased, a higher degree of alignment was observed at lower field strengths, consistent with an increase in the available magnetic torque. Microwires that had been exposed to a magnetic sweep up to 300 G remained magnetized and, therefore, aligned more readily during subsequent magnetic field alignment sweeps. Alignment of the Ni-coated Si microwires occurred at lower field strengths on hydrophilic Si substrates than on hydrophobic Si substrates. The magnetic field alignment approach provides a pathway for the directed assembly of solution-grown semiconductor wires into vertical arrays, with potential applications in solar cells as well as in other electronic devices that utilize nano- and microscale components as active elements.

  2. Uniform vertical trench etching on silicon with high aspect ratio by metal-assisted chemical etching using nanoporous catalysts.

    PubMed

    Li, Liyi; Liu, Yan; Zhao, Xueying; Lin, Ziyin; Wong, Ching-Ping

    2014-01-08

    Recently, metal-assisted chemical etching (MaCE) has been proposed as a promising wet-etching method for the fabrication of micro- and nanostructures on silicon with low cost. However, uniform vertical trench etching with high aspect ratio is still of great challenge for traditional MaCE. Here we report an innovated MaCE method, which combined the use of a nanoporous gold thin film as the catalyst and a hydrofluoric acid (HF)-hydrogen peroxide (H2O2) mixture solution with a low HF-to-H2O2 concentration ratio (ρ) as the etchant. The reported method successfully fabricated vertical trenches on silicon with a width down to 2 μm and an aspect ratio of 16. The geometry of the trenches was highly uniform throughout the 3D space. The vertical etching direction was favored on both (100)- and (111)-oriented silicon substrates. The reported method was also capable of producing multiple trenches on the same substrate with individually-tunable lateral geometry. An etching mechanism including a through-catalyst mass-transport process and an electropolishing-favored charge-transport process was identified by a comparative study. The novel method fundamentally solves the problems of distortion and random movement of isolated catalysts in MaCE. The results mark a breakthrough in high-quality silicon trench-etching technology with a cost of more than 2 orders of magnitude lower than that of the currently available methods.

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

    SciTech Connect

    Schmelling, M.; Hashim, N.O.; Grupen, C.; Luitz, S.; Maciuc, F.; Mailov, A.; Muller, A.-S.; Sander, H.-G.; Schmeling, S.; Tcaciuc, R.; Wachsmuth, H.; Zuber, K.; /Dresden, Tech. U.

    2012-09-14

    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.

  4. Difference of Horizontal-to-Vertical (H/V) Spectral Ratios of Microtremors and Earthquake Motions: Theory and Observation

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    Horizontal-to-vertical spectral ratios (HVRs) of microtremors have been traditionally interpreted theoretically as representing the Rayleigh wave ellipticity or just utilized a convenient tool to extract predominant periods of ground. However, based on the diffuse field theory (Sánchez-Sesma et al., 2011) the microtremor H/V spectral ratios (MHVRs) correspond to the square root of the ratio of the imaginary part of horizontal displacement for a horizontally applied unit harmonic load and the imaginary part of vertical displacement for a vertically applied unit load. The same diffuse field concept leads us to derive a simple formula for earthquake HVRs (EHVRs), that is, the ratio of the horizontal motion on the surface for a vertical incidence of S wave divided by the vertical motion on the surface for a vertical incidence of P wave with a fixed coefficient (Kawase et al., 2011). The difference for EHVRs comes from the fact that primary contribution of earthquake motions would be of plane body waves. Traditionally EHVRs are interpreted as the responses of inclined SV wave incidence only for their S wave portions. Without these compact theoretical solutions, EHVRs and MHVRs are either considered to be very similar/equivalent, or totally different in the previous studies. With these theoretical solutions we need to re-focus our attention on the difference of HVRs. Thus we have compared here HVRs at several dozens of strong motion stations in Japan. When we compared observed HVRs we found that EHVRs tend to be higher in general than the MHVRs, especially around their peaks. As previously reported, their general shapes share the common features. Especially their fundamental peak and trough frequencies show quite a good match to each other. However, peaks in EHVRs in the higher frequency range would not show up in MHVRs. When we calculated theoretical HVRs separately at these target sites, their basic characteristics correspond to these observed differences. At this

  5. A new method to measure Bowen ratios using high-resolution vertical dry and wet bulb temperature profiles

    NASA Astrophysics Data System (ADS)

    Euser, T.; Luxemburg, W. M. J.; Everson, C. S.; Mengistu, M. G.; Clulow, A. D.; Bastiaanssen, W. G. M.

    2014-06-01

    The Bowen ratio surface energy balance method is a relatively simple method to determine the latent heat flux and the actual land surface evaporation. The Bowen ratio method is based on the measurement of air temperature and vapour pressure gradients. If these measurements are performed at only two heights, correctness of data becomes critical. In this paper we present the concept of a new measurement method to estimate the Bowen ratio based on vertical dry and wet bulb temperature profiles with high spatial resolution. A short field experiment with distributed temperature sensing (DTS) in a fibre optic cable with 13 measurement points in the vertical was undertaken. A dry and a wetted section of a fibre optic cable were suspended on a 6 m high tower installed over a sugar beet trial plot near Pietermaritzburg (South Africa). Using the DTS cable as a psychrometer, a near continuous observation of vapour pressure and air temperature at 0.20 m intervals was established. These data allowed the computation of the Bowen ratio with a high spatial and temporal precision. The daytime latent and sensible heat fluxes were estimated by combining the Bowen ratio values from the DTS-based system with independent measurements of net radiation and soil heat flux. The sensible heat flux, which is the relevant term to evaluate, derived from the DTS-based Bowen ratio (BR-DTS) was compared with that derived from co-located eddy covariance (R2 = 0.91), surface layer scintillometer (R2 = 0.81) and surface renewal (R2 = 0.86) systems. By using multiple measurement points instead of two, more confidence in the derived Bowen ratio values is obtained.

  6. Self-organized vertically aligned single-crystal silicon nanostructures with controlled shape and aspect ratio by reactive plasma etching

    NASA Astrophysics Data System (ADS)

    Xu, S.; Levchenko, I.; Huang, S. Y.; Ostrikov, K.

    2009-09-01

    The formation of vertically aligned single-crystalline silicon nanostructures via "self-organized" maskless etching in Ar+H2 plasmas is studied. The shape and aspect ratio can be effectively controlled by the reactive plasma composition. In the optimum parameter space, single-crystalline pyramid-like nanostructures are produced; otherwise, nanocones and nanodots are formed. This generic nanostructure formation approach does not involve any external material deposition. It is based on a concurrent sputtering, etching, hydrogen termination, and atom/radical redeposition and can be applied to other nanomaterials.

  7. Vertical cup/disc ratio in relation to optic disc size: its value in the assessment of the glaucoma suspect

    PubMed Central

    Garway-Heath, D.; Ruben, S.; Viswanathan, A.; Hitchings, R.

    1998-01-01

    AIMS—The vertical cup/disc ratio (CDR) has long been used in the assessment of the glaucoma suspect, though the wide range of CDR values in the normal population limits its use. Cup size is related physiologically to disc size and pathologically to glaucomatous damage. Disc size can be measured at the slit lamp as the vertical disc diameter (DD). The ability of the CDR, in relation to DD, to identify glaucomatous optic discs was investigated.
METHODS—88 normal, 53 early glaucoma, and 59 ocular hypertensive subjects underwent stereoscopic optic disc photography and clinical biometry. Photographs were analysed in a masked fashion by computer assisted planimetry. The relation between vertical cup diameter and DD was explored by linear regression, and expressed in terms of CDR. The upper limit of normal was defined by the 95% prediction intervals of this regression (method 1) and by the upper 97.5 percentile for CDR (method 2). The sensitivity and specificity of CDR to identify an optic disc as glaucomatous was tested with these disc size dependent and disc size independent cut offs in small, medium, and large discs.
RESULTS—The CDR was related to DD by the equation CDR = (−1.31 + (1.194 × DD))/DD. The sensitivity in small, medium, and large discs was 80%, 60%, and 38% respectively for method 1 and 33%, 67%, and 63% respectively for method 2. Specificity was 98.9% (method 1) and 97.7% (method 2).
CONCLUSIONS—The CDR, relative to disc size, is useful clinically, especially to assist in identifying small glaucomatous discs.

 Keywords: cup/disc ratio; glaucoma; imaging PMID:9924296

  8. A new method to measure bowen ratios using high resolution vertical dry and wet bulb temperature profiles

    NASA Astrophysics Data System (ADS)

    Euser, T.; Luxemburg, W.; Everson, C.; Mengistu, M.; Clulow, A.; Bastiaanssen, W.

    2013-06-01

    The Bowen ratio surface energy balance method is a relatively simple method to determine the latent heat flux and the actual land surface evaporation. Despite its simplicity, the Bowen ratio method is generally considered to be unreliable due to the use of two-level sensors that are installed by default in operational Bowen ratio systems. In this paper we present the concept of a new measurement methodology to estimate the Bowen ratio from high resolution vertical dry and wet bulb temperature profiles. A short field experiment with Distributed Temperature Sensing (DTS) in a fibre optic cable having 13 levels was undertaken. A dry and a wetted section of a fibre optic cable were suspended on a 6 m high tower installed over a sugar beet trial near Pietermaritzburg (South Africa). Using the DTS cable as a psychrometer, a near continuous observation of vapour pressure and temperature at 0.20 m intervals was established. These data allows the computation of the Bowen ratio with a high precision. By linking the Bowen ratio to net radiation and soil heat flux, the daytime latent heat flux was estimated. The latent heat flux derived from DTS-based Bowen ratio (BR-DTS) showed consistent agreement (correlation coefficients between 0.97 and 0.98) with results derived from eddy covariance, surface layer scintillometer and surface renewal techniques. The latent heat from BR-DTS overestimated the latent heat derived with the eddy covariance by 4% and the latent heat derived with the surface layer scintillometer by 8%. Through this research, a new window is opened to engage on simplified, inexpensive and easy to interpret in situ measurement techniques for measuring evaporation.

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

    NASA Astrophysics Data System (ADS)

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

    2002-02-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2003-02-01

    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.

  11. Inventory and vertical migration of 90Sr fallout and 137Cs/90Sr ratio in Spanish mainland soils.

    PubMed

    Herranz, M; Romero, L M; Idoeta, R; Olondo, C; Valiño, F; Legarda, F

    2011-11-01

    In this paper the inventory of (90)Sr in 34 points distributed along the Spanish peninsular territory is presented. Obtained values range between 173 Bq/m(2) and 2047 Bq/m(2). From these data set and those (137)Cs data obtained in a previous work the (137)Cs/(90)Sr activity ratio has been established, laying this value between 0.9 and 3.6. Also the migration depth of both radionuclides has been analysed obtaining for (137)Cs an average value 57% lower than that obtained for (90)Sr. Additionally, this paper presents the results obtained in 11 sampling points in which the activity vertical profile has been measured. These profiles have been analysed to state the behaviour of strontium in soils and after, by using a convective-diffusive model, the parameters of the model which governs the vertical migration of (90)Sr in the soil, v (apparent convection velocity) and D (apparent diffusion coefficient) have been evaluated. Mean values obtained are 0.20 cm/year and 3.67 cm(2)/year, respectively.

  12. Electrochemical growth of vertically-oriented high aspect ratio titania nanotubes by rabid anodization in fluoride-free media.

    PubMed

    Fahim, Narges Fathy; Sekino, Tohru; Morks, Magdi Farouk; Kusunose, Takafumi

    2009-03-01

    Vertically-oriented high aspect ratio titania nanotube bundles have been grown by a potentiostatic anodization of titanium sheet in fluoride-free electrolytes. The anodization conditions like the applied voltage were optimized for the synthesis of titania nanotubes in HClO4 and NaCl electrolyte. The resulting nanotubes have a length of about 30 microm, outer diameter about 40 nm, inner pore size of about 10 nm and the aspect ratio was 750:1 by anodization in 0.1 M perchloric acid of pH approximaately 1 at applied voltage of 20 V. While for nanotubes prepared in 0.3 M NaCl of pH 4.3, the length was above 50 microm with the aspect ratio of 1250:1. A method to increase the uniformity of nanotube was demonstrated by pretreatment the titanium sheet by (4 wt% HF + 5 M HNO3) solution prior to anodization. Titania nanotubes were prepared, for the first time, by anodization in aqueous H2SO4 electrolyte alone with tube length above 500 nm. Annealing studies were performed, on high aspect ratio Titania nanotube layers produced in HClO4 electrolyte, in the temperature interval of 300 to 550 degrees C. The XRD patterns and TEM data confirmed the formation of single anatase phase after annealing at 450 degrees C with perfect nanoubular structure. While the rutile titania phase starts to emerege after annealing at about 500 degrees C and the evidence for the appearance of rutile phase due to the oxidation of the underlying Ti metal at the interface between nanotube/Ti-metal was given. On the other hand, the nanotubular structure starts to destroy upon annealing temperature of approximate 550 degrees C by tube flattening and losing of roll-up characteristics as indicated in SEM images. The superior morphology of these high aspect ratio nanotubes and their rapid growth rate foreshadow a bright future in wide applications like dye-sensitized solar cells, water photolysis and nanobiomedical.

  13. Design and Analysis of Novel Micromachined Thermocouples with Vertical Free-Standing High-Aspect-Ratio Geometry

    NASA Astrophysics Data System (ADS)

    Wick, M.; Hedler, H.; Seidel, H.

    2015-06-01

    This paper describes the design and analysis of free-standing three-dimensional (3D) thermocouples (TCs) for uncooled high-resolution infrared imaging. In contrast to the conventional horizontal thermocouple design, our 3D TCs consist of vertically oriented coaxial thermoelectric legs covered by an infrared absorber plate. The high aspect ratio of the 3D TCs of up to 100:1 leads to increased thermal resistance and, thus, higher electrical responsivity. Furthermore, reduced lateral dimensions of the device are achieved by coaxial mounting. This allows a closely packed arrangement of 3D TCs, which results in a high-resolution microarray sensor setup. These features represent the 3D TC's innovative uniqueness and open up new possibilities for further minimized uncooled thermal sensors and low-cost high-resolution imagers. We developed a fabrication process for 3D TCs with doped polysilicon as thermoelectric legs and a geometry with diameter of m and length of m. Performance analysis has been carried out using the lumped-heat-capacity method, resulting in an electrical responsivity and specific detectivity of a 3D TC of 383 V/W and cm /W, respectively.

  14. Ratio

    NASA Astrophysics Data System (ADS)

    Webster, Nathan A. S.; Pownceby, Mark I.; Madsen, Ian C.; Studer, Andrew J.; Manuel, James R.; Kimpton, Justin A.

    2014-12-01

    Effects of basicity, B (CaO:SiO2 ratio) on the thermal range, concentration, and formation mechanisms of silico-ferrite of calcium and aluminum (SFCA) and SFCA-I iron ore sinter bonding phases have been investigated using an in situ synchrotron X-ray diffraction-based methodology with subsequent Rietveld refinement-based quantitative phase analysis. SFCA and SFCA-I phases are the key bonding materials in iron ore sinter, and improved understanding of the effects of processing parameters such as basicity on their formation and decomposition may assist in improving efficiency of industrial iron ore sintering operations. Increasing basicity significantly increased the thermal range of SFCA-I, from 1363 K to 1533 K (1090 °C to 1260 °C) for a mixture with B = 2.48, to ~1339 K to 1535 K (1066 °C to 1262 °C) for a mixture with B = 3.96, and to ~1323 K to 1593 K (1050 °C to 1320 °C) at B = 4.94. Increasing basicity also increased the amount of SFCA-I formed, from 18 wt pct for the mixture with B = 2.48 to 25 wt pct for the B = 4.94 mixture. Higher basicity of the starting sinter mixture will, therefore, increase the amount of SFCA-I, considered to be more desirable of the two phases. Basicity did not appear to significantly influence the formation mechanism of SFCA-I. It did, however, affect the formation mechanism of SFCA, with the decomposition of SFCA-I coinciding with the formation of a significant amount of additional SFCA in the B = 2.48 and 3.96 mixtures but only a minor amount in the highest basicity mixture. In situ neutron diffraction enabled characterization of the behavior of magnetite after melting of SFCA produced a magnetite plus melt phase assemblage.

  15. Specific behaviour of thermosolutal convection induced in a vertical porous medium in the case of a separation coefficient identical to the ratio of buoyancy forces

    NASA Astrophysics Data System (ADS)

    Er-Raki, Mohammed; Hasnaoui, Mohammed; Amahmid, Abdelkhalk; El Ganaoui, Mohammed

    2008-03-01

    Thermosolutal natural convection induced in a vertical porous layer heated and salted with uniform fluxes is studied analytically and numerically. The study is focused on a specific case where the separation coefficient is identical to the ratio of buoyancy forces. Analytical results, describing both pseudo-conductive and boundary layer regimes, are discussed. Specific behaviour, corresponding to this particular situation, is presented. To cite this article: M. Er-Raki et al., C. R. Mecanique 336 (2008).

  16. Increasing the signal-to-noise ratio by using vertically stacked phased array coils for low-field magnetic resonance imaging.

    PubMed

    Liang, Dandan; Hui, Hon Tat; Yeo, Tat Soon

    2012-11-01

    A new method is introduced to increase the signal-to-noise ratio (SNR) in low-field magnetic resonance imaging (MRI) systems by using a vertically stacked phased coil array. It is shown theoretically that the SNR is increased with the square root of the number of coils in the array if the array signals are properly combined to remove the mutual coupling effect. Based on this, a number of vertically stacked phased coil arrays have been designed and characterized by a numerical simulation method. The performance of these arrays confirms the significant increase of SNR by increasing the number of coils in the arrays. This provides a simple and efficient method to improve the SNR for low-field MRI systems.

  17. Statistical comparison of methods for estimating sediment thickness from Horizontal-to-Vertical Spectral Ratio (HVSR) seismic methods: An example from Tylerville, Connecticut, USA

    USGS Publications Warehouse

    Johnson, Carole D.; Lane, John

    2016-01-01

    Determining sediment thickness and delineating bedrock topography are important for assessing groundwater availability and characterizing contamination sites. In recent years, the horizontal-to-vertical spectral ratio (HVSR) seismic method has emerged as a non-invasive, cost-effective approach for estimating the thickness of unconsolidated sediments above bedrock. Using a three-component seismometer, this method uses the ratio of the average horizontal- and vertical-component amplitude spectrums to produce a spectral ratio curve with a peak at the fundamental resonance frequency. The HVSR method produces clear and repeatable resonance frequency peaks when there is a sharp contrast (>2:1) in acoustic impedance at the sediment/bedrock boundary. Given the resonant frequency, sediment thickness can be determined either by (1) using an estimate of average local sediment shear-wave velocity or by (2) application of a power-law regression equation developed from resonance frequency observations at sites with a range of known depths to bedrock. Two frequently asked questions about the HVSR method are (1) how accurate are the sediment thickness estimates? and (2) how much do sediment thickness/bedrock depth estimates change when using different published regression equations? This paper compares and contrasts different approaches for generating HVSR depth estimates, through analysis of HVSR data acquired in the vicinity of Tylerville, Connecticut, USA.

  18. Depth-dependent Vertical-to-Horizontal (V/H) Ratios of Free-Field Ground Motion Response Spectra for Deeply Embedded Nuclear Structures

    SciTech Connect

    Wei, X.; Braverman, J.; Miranda, M.; Rosario, M. E.; Costantino, C. J.

    2015-02-01

    This report documents the results of a study to determine the depth-dependent V/H ratios of ground motion response spectra in the free field. The V/H ratios reported herein were developed from a worldwide database of surface and downhole acceleration recordings obtained from 45 vertical array stations. This database was specifically compiled for this project, and includes information from a diversity of active tectonic regions (California, Alaska, Taiwan, Japan), site conditions (rock to soft soil), ground motion intensity levels (PGAs between 0.01 g and 0.50 g), magnitudes (between ML 2.78 and JMA 8.1), epicentral distances (between 3.2 km and 812 km), and source depths (between 1.2 km and 112 km), as well as sensors at surface and at a wide range of depths relevant to the project. To study the significance of the depth effect, V/H ratios from all the records were sorted into a number of depth bins relevant to the project, and statistics (average, standard deviation, coefficient of variation, 16th, 50th, and 84th percentiles) of the V/H ratios within each bin were computed. Similar analyses were repeated, controlling for different site conditions, ground motion intensity levels, array locations, and source depths, to study their relative effect on the V/H ratios. Our findings confirm the importance of the depth effect on the V/H ratios. The research findings in this report can be used to provide guidance on the significance of the depth effect, and the extent to which this effect should be considered in the seismic design of deeply embedded SMR structures and NPP structures in general.

  19. Analysis of the La:P ratio in lake sediments - Vertical and spatial distribution assessed by a multiple-core survey.

    PubMed

    Yasseri, Said; Epe, Tim S

    2016-06-15

    In recent years, lanthanum modified bentonite has been increasingly applied to eutrophic lakes with the aim of converting potentially bio-available forms of phosphorus in sediments into biologically unavailable forms. In many of these applications, however, no attempts have been made to assess the efficiency and efficacy of the measure in terms of its effect on the sediment. In this study, we collected sediment cores from a heavily eutrophied lake that has previously been treated with lanthanum modified clay. This restoration method is based on the strong ionic bond formed between lanthanum and phosphate which results in the formation of LaPO4 (Rhabdophane) in the sediment. In order to determine the changes that had occurred in the sediments as a result of the addition of the clay, we measured the vertical distribution of lanthanum in the collected cores, calculated La:P ratios of the different sediment layers and used the ratios to determine whether or not the applied dosage was sufficient. By means of the geostatistical method of kriging these values were transferred into maps of different depth intervals to visualize the results. The results indicate that the La:P ratio may be a useful tool which allows lake managers to measure the vertical distribution of lanthanum in sediments following treatments and determine whether or not dosages are sufficient to permanently render sediment phosphorus biologically unavailable. The method may also provide a basis on which to decide whether or not smaller reapplications are needed and can be used to control the dispersion of the material.

  20. Engineered high aspect ratio vertical nanotubes as a model system for the investigation of catalytic methanol synthesis over Cu/ZnO.

    PubMed

    Güder, Firat; Frei, Elias; Kücükbayrak, Umut M; Menzel, Andreas; Thomann, Ralf; Luptak, Roman; Hollaender, Bernd; Krossing, Ingo; Zacharias, Margit

    2014-02-12

    Catalytically synthesized methanol from H2 and CO2 using porous Cu/ZnO aggregates is a promising, carbon neutral, and renewable alternative to replace fossil fuel based transport fuels. However, the absence of surface-engineered model systems to understand and improve the industrial Cu/ZnO catalyst poses a big technological gap in efforts to increase industrial methanol conversion efficiency. In this work, we report a novel process for the fabrication of patterned, vertically aligned high aspect ratio 1D nanostructures on Si that can be used as an engineered model catalyst. The proposed strategy employs near-field phase shift lithography (NF-PSL), deep reactive ion etching (DRIE), and atomic layer deposition (ALD) to pattern, etch, and coat Si wafers to produce high aspect ratio 1D nanostructures. Using this method, we produced a model system consisting of high aspect ratio Cu-decorated ZnO nanotubes (NTs) to investigate the morphological effects of ZnO catalyst support in comparison to the planar Cu/ZnO catalyst in terms of the catalytic reactions. The engineered catalysts performed 70 times better in activating CO2 than the industrial catalyst. In light of the obtained results, several important points are highlighted, and recommendations are made to achieve higher catalytic performance.

  1. Vertical organic light-emitting transistor showing a high current on/off ratio through dielectric encapsulation for the effective charge pathway

    NASA Astrophysics Data System (ADS)

    Lee, Gyujeong; Lee, In-Ho; Park, Hea-Lim; Lee, Sin-Hyung; Han, Jongseok; Lee, Changhee; Keum, Chang-Min; Lee, Sin-Doo

    2017-01-01

    We demonstrate a vertical organic light emitting transistor (VOLET) showing a high current on/off ratio through dielectric encapsulation of a finger-like source electrode, which is placed between the bottom gate electrode and the top drain electrode. In such a VOLET configuration, the charge transport occurs largely from the source electrode to an underlying organic semiconductor (OSC) layer through the interface between the OSC and the gate insulator. Accordingly, the current leakage is greatly reduced and the transistor-type switching behavior with a high on/off current ratio is achieved. The on/off current ratio of our VOLET is about 100 times higher than that of an existing VOLET with no dielectric encapsulation. Numerical simulations of the spatial distributions of the charge densities and the charge pathways performed in the two different VOLET configurations are in good agreement with the experimental results. Our dielectric encapsulation approach will provide a versatile method for developing a new class of high-performance OLET displays.

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

    USGS Publications Warehouse

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

    2013-01-01

    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.

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

    PubMed

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

    2012-11-01

    The results of γ 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 γ 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 γ 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.

  4. Evaluation of the horizontal-to-vertical spectral ratio (HVSR) seismic method to determine sediment thickness in the vicinity of the south well field, Franklin county, OH

    USGS Publications Warehouse

    Haefner, R.J.; Sheets, R.A.; Andrews, R.E.

    2010-01-01

    The horizontal-to-vertical spectral ratio (HVSR) seismic method involves analyzing measurements of ambient seismic noise in three dimensions to determine the fundamental site resonance frequency. Resonance is excited by the interaction of surface waves (Rayleigh and Love) and body waves (vertically incident shear) with the high-contrast acoustic impedance boundary at the bedrock-sediment interface. Measurements were made to determine the method's utility for estimating thickness of unconsolidated glacial sediments at 18 locations at the South Well Field, Franklin County, OH, and at six locations in Pickaway County where sediment thickness was already known. Measurements also were made near a high-capacity production well (with pumping on and off ) and near a highway and a limestone quarry to examine changes in resonance frequencies over a 20-hour period. Although the regression relation for resonance frequency and sediment thickness had a relatively low r 2(0.322), estimates of sediment thickness were, on average, within 14 percent of known thicknesses. Resonance frequencies for pumping on and pumping off were identical, although the amplitude of the peak was nearly double under pumping conditions. Resonance frequency for the 20-hour period did not change, but the amplitude of the peak changed considerably, with a maximum amplitude in the early afternoon and minimum in the very early morning hours. Clay layers within unconsolidated sediments may influence resonance frequency and the resulting regression equation, resulting in underestimation of sediment thickness; however, despite this and other complicating factors, hydrogeologists should consider this method when thickness data are needed for unconsolidated sediments. ?? 2011 by The Ohio Academy of Science. All Rights Reserved.

  5. Evaluation of the horizontal-to-vertical spectral ratio (HVSR) seismic method to determine sediment thickness in the vicinity of the South Well Field, Franklin County, OH

    USGS Publications Warehouse

    Haefner, Ralph J.; Sheets, Rodney A.; Andrews, Robert E.

    2011-01-01

    The horizontal-to-vertical spectral ratio (HVSR) seismic method involves analyzing measurements of ambient seismic noise in three dimensions to determine the fundamental site resonance frequency. Resonance is excited by the interaction of surface waves (Rayleigh and Love) and body waves (vertically incident shear) with the high-contrast aconstic impedance boundary at the bedrock-sediment interface. Measurements were made to determine the method's utility for estimating thickness of unconsolidated glacial sediments at 18 locations at the South Well Field, Franklin County, OH, and at six locations in Pickaway County where sediment thickness was already known. Measurements also were made near a high-capacity production well (with pumping on and off) and near a highway and a limestone quarry to examine changes in resonance frequencies over a 20-hour period. Although the regression relation for resonance frequency and sediment thickness had a relatively low [r.sup.2] (0.322), estimates of sediment thickness were, on average, within 14 percent of known thicknesses. Resonance frequencies for pumping on and pumping off were identical, although the amplitude of the peak was nearly double under pumping conditions. Resonance frequency for the 20-hour period did not change, but the amplitude of the peak changed considerably, with a maximum amplitude in the early afternoon and minimum in the very early morning hours. Clay layers within unconsolidated sediments may influence resonance frequency and the resulting regression equation, resulting in underestimation of sediment thickness; however, despite this and other complicating factors, hydrogeologists should consider this method when thickness data are needed for unconsolidated sediments.

  6. 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)

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

    2008-12-01

    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.

  7. A new significance on the vertical component ratio of the power spectra between two sites in the application of array methods.

    PubMed

    Zhang, Xinrui; Morikawa, Hitoshi

    2016-01-01

    Array methods like spatial auto-correlation (SPAC) method and the centerless circular array (CCA) method have provided a convenient means of inferring the phase velocity of surface waves. However, these methods are under the assumption of horizontally layered medium (lateral homogeneity) while the ground structure is actually likely to be inclined. Hence, it is expected to obtain more detailed information of ground structure such as inclination by making better use of the records. In recent years, the seismic interferometry theory has also been widely used to estimate ground structure. According to seismic interferometry theory, the cross correlation of motion between two sites is proportional to the imaginary part of the Green's function (IOG) between the two sites in diffuse wavefield. In this study, we can obtain the ratio of IOG between two sites by taking the ratio of power spectra between the same two sites. We propose this ratio as an indicator of the lateral heterogeneity between two sites. Through numerical simulation and a field test, we demonstrate that the significance of ratio of power spectra can be interpreted from the sight of ratio of IOG successfully.

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

    PubMed

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

    2010-03-01

    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.

  9. A new significance on the vertical component ratio of the power spectra between two sites in the application of array methods

    NASA Astrophysics Data System (ADS)

    Zhang, Xinrui; Morikawa, Hitoshi

    2016-01-01

    Array methods like spatial auto-correlation (SPAC) method and the centerless circular array (CCA) method have provided a convenient means of inferring the phase velocity of surface waves. However, these methods are under the assumption of horizontally layered medium (lateral homogeneity) while the ground structure is actually likely to be inclined. Hence, it is expected to obtain more detailed information of ground structure such as inclination by making better use of the records. In recent years, the seismic interferometry theory has also been widely used to estimate ground structure. According to seismic interferometry theory, the cross correlation of motion between two sites is proportional to the imaginary part of the Green's function (IOG) between the two sites in diffuse wavefield. In this study, we can obtain the ratio of IOG between two sites by taking the ratio of power spectra between the same two sites. We propose this ratio as an indicator of the lateral heterogeneity between two sites. Through numerical simulation and a field test, we demonstrate that the significance of ratio of power spectra can be interpreted from the sight of ratio of IOG successfully.

  10. Effects of influent C/N ratios on wastewater nutrient removal and simultaneous greenhouse gas emission from the combinations of vertical subsurface flow constructed wetlands and earthworm eco-filters for treating synthetic wastewater.

    PubMed

    Zhao, Yongjun; Zhang, Yuejin; Ge, Zhigang; Hu, Changwei; Zhang, Hui

    2014-03-01

    This research focused on the nutrient removal and the simultaneous CO2, CH4, and N2O emission rates of various combinations of vertical subsurface flow constructed wetlands (VSFCWs) and earthworm eco-filters (EEs) under different influent C/N ratios in synthetic wastewater. The optimal parameters for nutrient removal were influent C/N ratios of 5 : 1 and 10 : 1 as well as the combination VSFCW-EE. Relatively low values of greenhouse gas (GHG) emission rates measured in situ were obtained at a C/N ratio of 5 : 1. The emission rates of CH4 and N2O were considerably lower than that of CO2. The VSFCW-EE and EE-VSFCW combinations showed similar GHG emission results. The C/N ratio of 5 : 1 and the VSFCW-EE combination exhibited the highest nutrient removal efficiency with the lowest GHG emission rate. Wastewater nutrient removal and GHG emission were both high during summer (June to August) and low during winter (December to February).

  11. Increased x-ray conversion efficiency from ultra high contrast, relativistic laser pulse irradiation of large aspect ratio, vertically aligned nanowires

    NASA Astrophysics Data System (ADS)

    Hollinger, R. C.; Bargsten, C.; Shlyaptsev, V. N.; Kaymak, V.; Pukhov, A.; Capeluto, M. G.; Wang, Y.; Wang, S.; Rockwood, A.; Curtis, A.; Rocca, J. J.

    2016-10-01

    Recent experiments at Colorado State University have shown that the effective trapping of clean, Joule-level fs laser pulses of relativistic intensity in arrays of high aspect ratio aligned nanowire creates multi-kev, near solid density, large scale (>4um deep) plasmas. The drastically decreased radiative life time and increased hydrodynamic cooling time from these plasmas increases the x-ray conversion efficiency. We measured a record conversion efficiency of 10% into hv>1KeV photons (2pi steradians), and of 0.3% for hv>6KeV. The experiments used Au and Ni nanowires of 55nm, 80nm and 100nm in diameter with 12% of solid density irradiated by high contrast (>1012) pulses of 60fs FWHM duration from a frequency doubled Ti:Sa laser at intensities of I =5x1019Wcm-2. We also present preliminary results on x-ray emission from Rhodium nanowires in the 19-22KeV range and demonstrate the potential of this picosecond X-ray source in flash radiography. This work was supported by the Fusion Energy Program, Office of Science of the U.S Department of Energy, and by the Defense Threat Reduction Agency Grant HDTRA-1-10-1-0079.

  12. Assessment of nonlinear site response at ocean bottom seismograph sites based on S-wave horizontal-to-vertical spectral ratios: a study at the Sagami Bay area K-NET sites in Japan

    NASA Astrophysics Data System (ADS)

    Dhakal, Yadab P.; Aoi, Shin; Kunugi, Takashi; Suzuki, Wataru; Kimura, Takeshi

    2017-02-01

    We analyzed S-wave horizontal-to-vertical (S-H/V) spectral ratios at six ocean bottom seismograph (OBS) sites of K-NET located in the Sagami Bay area of Japan for nonlinear site responses. The degree of nonlinearity was computed by comparing the S-H/V spectral ratios for strong motions (PGA ≥ 20 cm/s2) with those for weak motions (PGA < 20 cm/s2). Our analyses, which showed that the weak-motion S-H/V spectral ratios differ from site to site, indicate that the underlying site geology is not uniform at the OBS sites. It was found that the threshold PGA causing a nonlinear site response is generally different from site to site. Recordings having horizontal PGAs greater than about 50-150 cm/s2 display clear signatures of nonlinear site effects, i.e., the shift of predominant frequencies to lower ones and/or the decrease in high-frequency spectral ratios. We also found that the degree of nonlinearity is generally larger at the OBS sites due to the smaller threshold motions that cause a nonlinear site response compared with the available data at land sites. The above findings suggest the possibility of a widespread nonlinear site response at the OBS sites for offshore earthquakes with a large magnitude. However, frequencies lower than about 2 Hz are not affected by the nonlinear site response in the analyzed data ranges (PGA < 467 cm/s2). These results indicate the need for careful utilization of recorded strong motions at OBS sites for applications such as real-time ground motion predictions as front detections.

  13. THE VERTICAL

    NASA Technical Reports Server (NTRS)

    Albert, Stephen L.; Spencer, Jeffrey B.

    1994-01-01

    'THE VERTICAL' computer keyboard is designed to address critical factors which contribute to Repetitive Motion Injuries (RMI) (including Carpal Tunnel Syndrome) in association with computer keyboard usage. This keyboard splits the standard QWERTY design into two halves and positions each half 90 degrees from the desk. In order to access a computer correctly. 'THE VERTICAL' requires users to position their bodies in optimal alignment with the keyboard. The orthopaedically neutral forearm position (with hands palms-in and thumbs-up) reduces nerve compression in the forearm. The vertically arranged keypad halves ameliorate onset occurrence of keyboard-associated RMI. By utilizing visually-reference mirrored mylar surfaces adjustable to the user's eye, the user is able to readily reference any key indicia (reversed) just as they would on a conventional keyboard. Transverse adjustability substantially reduces cumulative musculoskeletal discomfort in the shoulders. 'THE VERTICAL' eliminates the need for an exterior mouse by offering a convenient finger-accessible curser control while the hands remain in the vertically neutral position. The potential commercial application for 'THE VERTICAL' is enormous since the product can effect every person who uses a computer anywhere in the world. Employers and their insurance carriers are spending hundreds of millions of dollars per year as a result of RMI. This keyboard will reduce the risk.

  14. Bedrock topography of western Cape Cod, Massachusetts, based on bedrock altitudes from geologic borings and analysis of ambient seismic noise by the horizontal-to-vertical spectral-ratio method

    USGS Publications Warehouse

    Fairchild, Gillian M.; Lane, Jr., John W.; Voytek, Emily B.; LeBlanc, Denis R.

    2013-01-01

    This report presents a topographic map of the bedrock surface beneath western Cape Cod, Massachusetts, that was prepared for use in groundwater-flow models of the Sagamore lens of the Cape Cod aquifer. The bedrock surface of western Cape Cod had been characterized previously through seismic refraction surveys and borings drilled to bedrock. The borings were mostly on and near the Massachusetts Military Reservation (MMR). The bedrock surface was first mapped by Oldale (1969), and mapping was updated in 2006 by the Air Force Center for Environmental Excellence (AFCEE, 2006). This report updates the bedrock-surface map with new data points collected by using a passive seismic technique based on the horizontal-to-vertical spectral ratio (HVSR) of ambient seismic noise (Lane and others, 2008) and from borings drilled to bedrock since the 2006 map was prepared. The HVSR method is based on a relationship between the resonance frequency of ambient seismic noise as measured at land surface and the thickness of the unconsolidated sediments that overlie consolidated bedrock. The HVSR method was shown by Lane and others (2008) to be an effective method for determining sediment thickness on Cape Cod owing to the distinct difference in the acoustic impedance between the sediments and the underlying bedrock. The HVSR data for 164 sites were combined with data from 559 borings to bedrock in the study area to create a spatially distributed dataset that was manually contoured to prepare a topographic map of the bedrock surface. The interpreted bedrock surface generally slopes downward to the southeast as was shown on the earlier maps by Oldale (1969) and AFCEE (2006). The surface also has complex small-scale topography characteristic of a glacially eroded surface. More information about the methods used to prepare the map is given in the pamphlet that accompanies this plate.

  15. A common variant near TGFBR3 is associated with primary open angle glaucoma.

    PubMed

    Li, Zheng; Allingham, R Rand; Nakano, Masakazu; Jia, Liyun; Chen, Yuhong; Ikeda, Yoko; Mani, Baskaran; Chen, Li-Jia; Kee, Changwon; Garway-Heath, David F; Sripriya, Sarangapani; Fuse, Nobuo; Abu-Amero, Khaled K; Huang, Chukai; Namburi, Prasanthi; Burdon, Kathryn; Perera, Shamira A; Gharahkhani, Puya; Lin, Ying; Ueno, Morio; Ozaki, Mineo; Mizoguchi, Takanori; Krishnadas, Subbiah Ramasamy; Osman, Essam A; Lee, Mei Chin; Chan, Anita S Y; Tajudin, Liza-Sharmini A; Do, Tan; Goncalves, Aurelien; Reynier, Pascal; Zhang, Hong; Bourne, Rupert; Goh, David; Broadway, David; Husain, Rahat; Negi, Anil K; Su, Daniel H; Ho, Ching-Lin; Blanco, Augusto Azuara; Leung, Christopher K S; Wong, Tina T; Yakub, Azhany; Liu, Yutao; Nongpiur, Monisha E; Han, Jong Chul; Hon, Do Nhu; Shantha, Balekudaru; Zhao, Bowen; Sang, Jinghong; Zhang, NiHong; Sato, Ryuichi; Yoshii, Kengo; Panda-Jonas, Songhomita; Ashley Koch, Allison E; Herndon, Leon W; Moroi, Sayoko E; Challa, Pratap; Foo, Jia Nee; Bei, Jin-Xin; Zeng, Yi-Xin; Simmons, Cameron P; Bich Chau, Tran Nguyen; Sharmila, Philomenadin Ferdinamarie; Chew, Merwyn; Lim, Blanche; Tam, Pansy O S; Chua, Elaine; Ng, Xiao Yu; Yong, Victor H K; Chong, Yaan Fun; Meah, Wee Yang; Vijayan, Saravanan; Seongsoo, Sohn; Xu, Wang; Teo, Yik Ying; Cooke Bailey, Jessica N; Kang, Jae H; Haines, Jonathan L; Cheng, Ching Yu; Saw, Seang-Mei; Tai, E-Shyong; Richards, Julia E; Ritch, Robert; Gaasterland, Douglas E; Pasquale, Louis R; Liu, Jianjun; Jonas, Jost B; Milea, Dan; George, Ronnie; Al-Obeidan, Saleh A; Mori, Kazuhiko; Macgregor, Stuart; Hewitt, Alex W; Girkin, Christopher A; Zhang, Mingzhi; Sundaresan, Periasamy; Vijaya, Lingam; Mackey, David A; Wong, Tien Yin; Craig, Jamie E; Sun, Xinghuai; Kinoshita, Shigeru; Wiggs, Janey L; Khor, Chiea-Chuen; Yang, Zhenglin; Pang, Chi Pui; Wang, Ningli; Hauser, Michael A; Tashiro, Kei; Aung, Tin; Vithana, Eranga N

    2015-07-01

    Primary open angle glaucoma (POAG), a major cause of blindness worldwide, is a complex disease with a significant genetic contribution. We performed Exome Array (Illumina) analysis on 3504 POAG cases and 9746 controls with replication of the most significant findings in 9173 POAG cases and 26 780 controls across 18 collections of Asian, African and European descent. Apart from confirming strong evidence of association at CDKN2B-AS1 (rs2157719 [G], odds ratio [OR] = 0.71, P = 2.81 × 10(-33)), we observed one SNP showing significant association to POAG (CDC7-TGFBR3 rs1192415, ORG-allele = 1.13, Pmeta = 1.60 × 10(-8)). This particular SNP has previously been shown to be strongly associated with optic disc area and vertical cup-to-disc ratio, which are regarded as glaucoma-related quantitative traits. Our study now extends this by directly implicating it in POAG disease pathogenesis.

  16. Vertical bounce of two vertically aligned balls

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2007-11-01

    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.

  17. Vertical axis wind turbines

    DOEpatents

    Krivcov, Vladimir [Miass, RU; Krivospitski, Vladimir [Miass, RU; Maksimov, Vasili [Miass, RU; Halstead, Richard [Rohnert Park, CA; Grahov, Jurij [Miass, RU

    2011-03-08

    A vertical axis wind turbine is described. The wind turbine can include a top ring, a middle ring and a lower ring, wherein a plurality of vertical airfoils are disposed between the rings. For example, three vertical airfoils can be attached between the upper ring and the middle ring. In addition, three more vertical airfoils can be attached between the lower ring and the middle ring. When wind contacts the vertically arranged airfoils the rings begin to spin. By connecting the rings to a center pole which spins an alternator, electricity can be generated from wind.

  18. Offset vertical radar profiling

    USGS Publications Warehouse

    Witten, A.; Lane, J.

    2003-01-01

    Diffraction tomography imaging was applied to VRP data acquired by vertically moving a receiving antenna in a number of wells. This procedure simulated a vertical downhole receiver array. Similarly, a transmitting antenna was sequentially moved along a series of radial lines extending outward from the receiver wells. This provided a sequence of multistatic data sets and, from each data set, a two-dimensional vertical cross-sectional image of spatial variations in wave speed was reconstructed.

  19. Vertical Axis Wind Turbine

    SciTech Connect

    Homicz, Greg

    2002-04-01

    Blade fatigue life is an important element in determining the economic viability of the Vertical-Axis Wind Turbine (VAWT). VAWT-SAL Vertical Axis Wind Turbine- Stochastic Aerodynamic Loads Ver 3.2 numerically simulates the stochastic (random0 aerodynamic loads of the Vertical-Axis Wind Turbine (VAWT) created by the atomspheric turbulence. The program takes into account the rotor geometry, operating conditions, and assumed turbulence properties.

  20. Vertical constituent transport in the mesosphere

    NASA Technical Reports Server (NTRS)

    Strobel, Darrell F.; Summers, Michael E.; Bevilacqua, Richard M.; Deland, Matthew T.; Allen, Mark

    1987-01-01

    Ground-based microwave spectroscopy measurements of mesospheric CO and H2O vertical mixing ratio profiles are used to infer vertical mixing rates in the upper mesosphere. The CO and H2O data consistently imply vertical eddy diffusion coefficients in the 70- to 85-km region of 100,000-200,000 sq cm/s during spring through summer at midlatidues. Although chemical acceleration of vertical transport is substantial for O and O3, below the mesopause, the divergences of their associated fluxes are modest, with at most a factor of 2 effect on the concentrations of O and O3 for measured variability in gravity wave activity. Comparison of Solar Mesosphere Explorer (SME) O3 data with model results reinforces the conclusions of slow vertical mixing in the upper mesosphere as a consequence of the reduced HO(x) catalytic loss of odd oxygen. The changes in chemical rate constants recommended by Rusch and Eckman (1985), in conjunction with slow vertical mixing, yield good agreement with SME O3 data. The slow vertical mixing deduced in this study is consistent with upper limits obtained from studies of the mesospheric heat budget and could be construed as evidence for an advectively controlled mesosphere. A comparison of the vertical eddy diffusion coefficients for momentum stresses, constituent transport, and heat transport suggests that the eddy Prandtl number must be of order 10.

  1. Vertical constituent transport in the mesosphere

    NASA Astrophysics Data System (ADS)

    Strobel, Darrell F.; Summers, Michael E.; Bevilacqua, Richard M.; Deland, Matthew T.; Allen, Mark

    1987-06-01

    Ground-based microwave spectroscopy measurements of mesospheric CO and H2O vertical mixing ratio profiles are used to infer vertical mixing rates in the upper mesosphere. The CO and H2O data consistently imply vertical eddy diffusion coefficients in the 70- to 85-km region of 100,000-200,000 sq cm/s during spring through summer at midlatidues. Although chemical acceleration of vertical transport is substantial for O and O3, below the mesopause, the divergences of their associated fluxes are modest, with at most a factor of 2 effect on the concentrations of O and O3 for measured variability in gravity wave activity. Comparison of Solar Mesosphere Explorer (SME) O3 data with model results reinforces the conclusions of slow vertical mixing in the upper mesosphere as a consequence of the reduced HO(x) catalytic loss of odd oxygen. The changes in chemical rate constants recommended by Rusch and Eckman (1985), in conjunction with slow vertical mixing, yield good agreement with SME O3 data. The slow vertical mixing deduced in this study is consistent with upper limits obtained from studies of the mesospheric heat budget and could be construed as evidence for an advectively controlled mesosphere. A comparison of the vertical eddy diffusion coefficients for momentum stresses, constituent transport, and heat transport suggests that the eddy Prandtl number must be of order 10.

  2. Improved automated optic cup segmentation based on detection of blood vessel bends in retinal fundus images.

    PubMed

    Hatanaka, Yuji; Nagahata, Yuuki; Muramatsu, Chisako; Okumura, Susumu; Ogohara, Kazunori; Sawada, Akira; Ishida, Kyoko; Yamamoto, Tetsuya; Fujita, Hiroshi

    2014-01-01

    Glaucoma is a leading cause of permanent blindness. Retinal imaging is useful for early detection of glaucoma. In order to evaluate the presence of glaucoma, ophthalmologists may determine the cup and disc areas and diagnose glaucoma using a vertical optic cup-to-disc (C/D) ratio and a rim-to-disc (R/D) ratio. Previously we proposed a method to determine cup edge by analyzing a vertical profile of pixel values, but this method provided a cup edge smaller than that of an ophthalmologist. This paper describes an improved method using the locations of the blood vessel bends. The blood vessels were detected by a concentration feature determined from the density gradient. The blood vessel bends were detected by tracking the blood vessels from the disc edge to the primary cup edge, which was determined by our previous method. Lastly, the vertical C/D ratio and the R/D ratio were calculated. Using forty-four images, including 32 glaucoma images, the AUCs of both the vertical C/D ratio and R/D ratio by this proposed method were 0.966 and 0.936, respectively.

  3. Vertical axis windmill

    SciTech Connect

    Campbell, J.S.

    1980-04-08

    A vertical axis windmill is described which involves a rotatable central vertical shaft having horizontal arms pivotally supporting three sails that are free to function in the wind like the main sail on a sail boat, and means for disabling the sails to allow the windmill to be stopped in a blowing wind.

  4. Sonic Anemometer Vertical Wind Speed Measurement Errors

    NASA Astrophysics Data System (ADS)

    Kochendorfer, J.; Horst, T. W.; Frank, J. M.; Massman, W. J.; Meyers, T. P.

    2014-12-01

    In eddy covariance studies, errors in the measured vertical wind speed cause errors of a similar magnitude in the vertical fluxes of energy and mass. Several recent studies on the accuracy of sonic anemometer measurements indicate that non-orthogonal sonic anemometers used in eddy covariance studies underestimate the vertical wind speed. It has been suggested that this underestimation is caused by flow distortion from the interference of the structure of the anemometer itself on the flow. When oriented ideally with respect to the horizontal wind direction, orthogonal sonic anemometers that measure the vertical wind speed with a single vertically-oriented acoustic path may measure the vertical wind speed more accurately in typical surface-layer conditions. For non-orthogonal sonic anemometers, Horst et al. (2014) proposed that transducer shadowing may be a dominant factor in sonic flow distortion. As the ratio of sonic transducer diameter to path length and the zenith angle of the three transducer paths decrease, the effects of transducer shadowing on measurements of vertical velocity will decrease. An overview of this research and some of the methods available to correct historical data will be presented.

  5. Oblique patterned etching of vertical silicon sidewalls

    SciTech Connect

    Burckel, D. Bruce; Finnegan, Patrick S.; Henry, M. David; Resnick, Paul J.; Jarecki, Jr., Robert L.

    2016-04-05

    A method for patterning on vertical silicon surfaces in high aspect ratio silicontopography is presented. A Faraday cage is used to direct energetic reactive ions obliquely through a patterned suspended membrane positioned over the topography. The technique is capable of forming high-fidelity pattern (100 nm) features, adding an additional fabrication capability to standard top-down fabrication approaches.

  6. Oblique patterned etching of vertical silicon sidewalls

    NASA Astrophysics Data System (ADS)

    Bruce Burckel, D.; Finnegan, Patrick S.; David Henry, M.; Resnick, Paul J.; Jarecki, Robert L.

    2016-04-01

    A method for patterning on vertical silicon surfaces in high aspect ratio silicon topography is presented. A Faraday cage is used to direct energetic reactive ions obliquely through a patterned suspended membrane positioned over the topography. The technique is capable of forming high-fidelity pattern (100 nm) features, adding an additional fabrication capability to standard top-down fabrication approaches.

  7. Micromachined electrostatic vertical actuator

    DOEpatents

    Lee, Abraham P.; Sommargren, Gary E.; McConaghy, Charles F.; Krulevitch, Peter A.

    1999-10-19

    A micromachined vertical actuator utilizing a levitational force, such as in electrostatic comb drives, provides vertical actuation that is relatively linear in actuation for control, and can be readily combined with parallel plate capacitive position sensing for position control. The micromachined electrostatic vertical actuator provides accurate movement in the sub-micron to micron ranges which is desirable in the phase modulation instrument, such as optical phase shifting. For example, compact, inexpensive, and position controllable micromirrors utilizing an electrostatic vertical actuator can replace the large, expensive, and difficult-to-maintain piezoelectric actuators. A thirty pound piezoelectric actuator with corner cube reflectors, as utilized in a phase shifting diffraction interferometer can be replaced with a micromirror and a lens. For any very precise and small amplitudes of motion` micromachined electrostatic actuation may be used because it is the most compact in size, with low power consumption and has more straightforward sensing and control options.

  8. A vertical cephalometric analysis.

    PubMed

    Alió Sanz, Juan J; Iglesias Conde, Carmen

    2007-01-01

    Correctly assessing open-bite malocclusions has remained problematic because clinicians have not had entirely reliable methods of determining the exact amount of skeletal and dental contributions to the problem. A new cephalometric technique, the vertical cephalometric analysis, offers orthodontists a system that precisely identifies the percentage of skeletal and dentoalveolar components that open-bite patients have. The vertical cephalometric analysis offers a discriminating diagnostic method for evaluating, diagnosing, and treatment planning for patients with open bite. This technique will allow clinicians to classify patients with accuracy, as well as to establish prognoses and select therapies.

  9. Vertical shaft windmill

    NASA Technical Reports Server (NTRS)

    Grana, D. C.; Inge, S. V., Jr. (Inventor)

    1983-01-01

    A vertical shaft has several equally spaced blades mounted. Each blade consists of an inboard section and an outboard section skew hinged to the inboard section. The inboard sections automatically adjust their positions with respect to the fixed inboard sections with changes in velocity of the wind. This windmill design automatically governs the maximum rotational speed of shaft.

  10. Aiding Vertical Guidance Understanding

    NASA Technical Reports Server (NTRS)

    Feary, Michael; McCrobie, Daniel; Alkin, Martin; Sherry, Lance; Polson, Peter; Palmer, Everett; McQuinn, Noreen

    1998-01-01

    A two-part study was conducted to evaluate modern flight deck automation and interfaces. In the first part, a survey was performed to validate the existence of automation surprises with current pilots. Results indicated that pilots were often surprised by the behavior of the automation. There were several surprises that were reported more frequently than others. An experimental study was then performed to evaluate (1) the reduction of automation surprises through training specifically for the vertical guidance logic, and (2) a new display that describes the flight guidance in terms of aircraft behaviors instead of control modes. The study was performed in a simulator that was used to run a complete flight with actual airline pilots. Three groups were used to evaluate the guidance display and training. In the training, condition, participants went through a training program for vertical guidance before flying the simulation. In the display condition, participants ran through the same training program and then flew the experimental scenario with the new Guidance-Flight Mode Annunciator (G-FMA). Results showed improved pilot performance when given training specifically for the vertical guidance logic and greater improvements when given the training and the new G-FMA. Using actual behavior of the avionics to design pilot training and FMA is feasible, and when the automated vertical guidance mode of the Flight Management System is engaged, the display of the guidance mode and targets yields improved pilot performance.

  11. Direct Observation of Ultralow Vertical Emittance using a Vertical Undulator - presentation slides

    SciTech Connect

    Wootton, Kent

    2015-09-17

    Direct emittance measurement based on vertical undulator is discussed. Emittance was evaluated from peak ratios, the smallest measured being 𝜀𝑦 =0.9 ±0.3 pm rad. The angular distribution of undulator radiation departs from Gaussian approximations, a fact of which diffraction-limited light sources should be aware.

  12. Vertical orbital dystopia.

    PubMed

    Tan, S T; Ashworth, G; Czypionka, S; Poole, M D; Briggs, M

    1996-06-01

    Many pathologic processes may lead to vertical orbital dystopia. We reviewed 47 consecutive cases seen over a 13-year period. Twenty-nine patients underwent eye leveling procedures to improve cosmesis, 2 of these by camouflage procedures and 27 by orbital translocation. Ten patients had 16 secondary operations. There was one death, serious complications occurred in 3 patients, and nuisance complications occurred in 20 others. Seven patients developed diplopia postoperatively, and in 6 patients it was troublesome. In these, it resolved fully in 2 patients, improved to be of no consequence in 2, and in the remaining 2 troublesome symptoms persisted requiring inferior oblique muscle recession in 1. Binocular vision was never restored when not present preoperatively, and in 3 patients temporary loss occurred. There was an overall modest but significant improvement in appearance after surgery. It is concluded that vertical orbital translocation is rewarding and worthwhile.

  13. Hilly Surroundings (vertical)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This 360-degree view of the terrain surrounding NASA's Mars Exploration Rover Spirit was taken on the rover's 189th sol on Mars (July 15, 2004). It was assembled from images taken by the rover's navigation camera at a position referred to as Site 72, which is at the base of the 'West Spur' portion of the 'Columbia Hills.'' The view is presented in a vertical projection with geometrical seam correction.

  14. Protective Vertical Shelters.

    DTIC Science & Technology

    1983-06-29

    on Generic MX Structures" by John Betz. 5. (AFCMD/82-013) "Finite Element Dynamic Analysis of th, DCT-2 Models" by Barry Bingham . 61 (AFCMD/82-017) "MX...facility to define the HEST structure for the GOVS tests. A SAMSON dynamic finite-element computer code provided pretest predictions of strdsses and...as piecewise linear, elastic- plastic materials. TEST DESCRIPTION Shel ter Models The generic MX vertical shelter is basically a large, reinforced

  15. Vertical bloch line memory

    NASA Technical Reports Server (NTRS)

    Katti, Romney R. (Inventor); Stadler, Henry L. (Inventor); Wu, Jiin-chuan (Inventor)

    1995-01-01

    A new read gate design for the vertical Bloch line (VBL) memory is disclosed which offers larger operating margin than the existing read gate designs. In the existing read gate designs, a current is applied to all the stripes. The stripes that contain a VBL pair are chopped, while the stripes that do not contain a VBL pair are not chopped. The information is then detected by inspecting the presence or absence of the bubble. The margin of the chopping current amplitude is very small, and sometimes non-existent. A new method of reading Vertical Bloch Line memory is also disclosed. Instead of using the wall chirality to separate the two binary states, the spatial deflection of the stripe head is used. Also disclosed herein is a compact memory which uses vertical Bloch line (VBL) memory technology for providing data storage. A three-dimensional arrangement in the form of stacks of VBL memory layers is used to achieve high volumetric storage density. High data transfer rate is achieved by operating all the layers in parallel. Using Hall effect sensing, and optical sensing via the Faraday effect to access the data from within the three-dimensional packages, an even higher data transfer rate can be achieved due to parallel operation within each layer.

  16. Vertical distribution of acetonitrile in the atmosphere

    NASA Technical Reports Server (NTRS)

    Ingels, J.; Nevejans, D.; Arijs, E.

    1985-01-01

    The presence of acetonitrile in the atmosphere was confirmed by results of surface and stratospheric investigations. Stratospheric measurements give mixing ratios typically decreasing with height from 3 ppt at 25 km to 0.5 ppt at 40 km. Measurements at the Earth's surface are less unanimous, although a ground level background mixing ratio of a few times 10 ppt seems realistic. Measurements are compatible with a small global surface source of acetonitrile and a small tropospheric loss. The vertical distribution of acetonitrile presented in consistent with general knowledge of its atmospheric chemistry.

  17. Assessment of the Optic Disc Morphology Using Spectral-Domain Optical Coherence Tomography and Scanning Laser Ophthalmoscopy

    PubMed Central

    Calvo, Pilar; Ferreras, Antonio; Abadia, Beatriz; Ara, Mirian; Figus, Michele; Pablo, Luis E.; Frezzotti, Paolo

    2014-01-01

    Objective. To compare the equivalent optic nerve head (OHN) parameters obtained with confocal scanning laser ophthalmoscopy (HRT3) and spectral-domain optical coherence tomography (OCT) in healthy and glaucoma patients. Methods. One hundred and eighty-two consecutive healthy subjects and 156 patients with open-angle glaucoma were divided into 2 groups according to intraocular pressure and visual field outcomes. All participants underwent imaging of the ONH with the HRT3 and the Cirrus OCT. The ONH parameters and the receiver operating characteristic (ROC) curves were compared between both groups. Results. Mean age did not differ between the normal and glaucoma groups (59.55 ± 9.7 years and 61.05 ± 9.4 years, resp.; P = 0.15). Rim area, average cup-to-disc (C/D) ratio, vertical C/D ratio, and cup volume were different between both instruments (P < 0.001). All equivalent ONH parameters, except disc area, were different between both groups (P < 0.001). The best areas under the ROC curve were observed for vertical C/D ratio (0.980 for OCT and 0.942 for HRT3; P = 0.11). Sensitivities at 95% fixed-specificities of OCT parameters were higher than those of HRT3. Conclusions. Equivalent ONH parameters of Cirrus OCT and HRT3 are different and cannot be used interchangeably. ONH parameters measured with OCT yielded a slightly better diagnostic performance. PMID:25110668

  18. A World Vertical Network.

    DTIC Science & Technology

    1980-02-01

    and continental levelling nets into a unifiled World Vertical Network. OD ,~ 173 OITON F I OV 5 I OSOLEI tnc las 9if led SECURITY CLASSIP CATION O T...rp,0p,Xp is T(P) = V(P) - U (P) (2.2) The gravity potential of the Earth is W(P) = V(P) + ((P) (2.3) where o ( P) = w rp’ cos 2 Op corresponds to the...is, therefore, A W(P,Q) = U(P) + T(P) + 0 (P) - U(Q) - T(Q) - o (Q) (2.4) With both P and Q on the Earth’s surface, the uncertainties in the calculated

  19. Multicolored Vertical Silicon Nanowires

    SciTech Connect

    Seo, Kwanyong; Wober, Munib; Steinvurzel, P.; Schonbrun, E.; Dan, Yaping; Ellenbogen, T.; Crozier, K. B.

    2011-04-13

    We demonstrate that vertical silicon nanowires take on a surprising variety of colors covering the entire visible spectrum, in marked contrast to the gray color of bulk silicon. This effect is readily observable by bright-field microscopy, or even to the naked eye. The reflection spectra of the nanowires each show a dip whose position depends on the nanowire radii. We compare the experimental data to the results of finite difference time domain simulations to elucidate the physical mechanisms behind the phenomena we observe. The nanowires are fabricated as arrays, but the vivid colors arise not from scattering or diffractive effects of the array, but from the guided mode properties of the individual nanowires. Each nanowire can thus define its own color, allowing for complex spatial patterning. We anticipate that the color filter effect we demonstrate could be employed in nanoscale image sensor devices.

  20. Direct Observation of Ultralow Vertical Emittance using a Vertical Undulator

    SciTech Connect

    Wootton, Kent

    2015-09-17

    In recent work, the first quantitative measurements of electron beam vertical emittance using a vertical undulator were presented, with particular emphasis given to ultralow vertical emittances [K. P. Wootton, et al., Phys. Rev. ST Accel. Beams, 17, 112802 (2014)]. Using this apparatus, a geometric vertical emittance of 0.9 #6;± 0.3 pm rad has been observed. A critical analysis is given of measurement approaches that were attempted, with particular emphasis on systematic and statistical uncertainties. The method used is explained, compared to other techniques and the applicability of these results to other scenarios discussed.

  1. Laser drilling of vertical vias in silicon

    SciTech Connect

    Miller, W.D.; Gassman, R.A.; Keicher, D.M.

    1993-08-01

    Any advance beyond the density of standard 2D Multichip Modules (MCM) will require a vertical interconnect technology that can produce reliable area array interconnection with small feature sizes. Laser drilled vertical vias have been controllably produced in standard silicon (Si) wafers down to 0.035mm (0.0014 inches) in diameter. Several laser systems and their system parameters have been explored to determine the optimum parametric set for repeatable vias in Si. The vias produced have exhibited clean smooth interior surfaces with an aspect ratio of up to 20:1 with little or no taper. All laser systems used, their system parameters, design modifications, theory of operation, and drilling results are discussed.

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

    PubMed Central

    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

    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. PMID:20107173

  3. Energy Balance Bowen Ratio Station (EBBR) Handbook

    SciTech Connect

    Cook, DR

    2011-02-23

    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.

  4. Energy Balance Bowen Ratio (EBBR) Handbook

    SciTech Connect

    Cook, D. R.

    2016-01-01

    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.

  5. Coupled resonator vertical cavity laser

    SciTech Connect

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

    1998-01-01

    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.

  6. ON-LINE TOOLS FOR PROPER VERTICAL POSITIONING OF VERTICAL SAMPLING INTERVALS DURING SITE ASSESSMENT

    EPA Science Inventory

    This presentation presents on-line tools for proper vertical positioning of vertical sampling intervals during site assessment. Proper vertical sample interval selection is critical for generate data on the vertical distribution of contamination. Without vertical delineation, th...

  7. Chen’s Double Eyelid Fold Ratio

    PubMed Central

    Chen, Chen-Chia; Tai, Hao-Chih

    2016-01-01

    Background: Double eyelidplasty can construct palpebral folds and enhance beauty perception for Asians with single eyelids. A new palpebral parameter for the quantitative interpretation of surgical outcomes is proposed on the basis of a photometric study of the altered proportions of Asian eyes after double eyelid operation. Methods: A total of 100 Asian adults with single upper eyelids who were satisfied with the enlarged eyes by operation were included in the study. A retrospective measurement of palpebral parameters in the frontal profile both preoperatively and 6 months postoperatively was performed. The proportions of various parameters in the eyebrow–eye aesthetic unit were calculated and analyzed. Results: Double eyelidplasty can augment the vertical dimension of palpebral fissure by 27.9% increase on average. The vertical ratio of palpebral fissure to the eyebrow–eye unit is augmented by 34.4% increase. The vertical ratio of the subunit below double eyelid fold peak to the unit is augmented by 82.6% increase. Conclusions: Double eyelidplasty can substantially enlarge the vertical dimensions of the eyes of Asians with single eyelids. The eyes are perceived to be larger because of the visually assimilated illusion of the superimposed eyelid fold and the relative proportions of the eyebrow–eye unit. The authors propose using a vertical ratio of the subunit below double eyelid fold peak in the eyebrow–eye unit to measure the visually perceived proportion of the eye in the unit. This ratio can be applied clinically for a quantitative evaluation of the surgical outcome after double eyelidplasty. PMID:27200243

  8. Vertical landing on an asteroid

    NASA Technical Reports Server (NTRS)

    Harel, D.; Geulman, M.

    1992-01-01

    This work is concerned with the final approach phase and vertical landing on an asteroid with a power-limited, electrically propelled spacecraft. With gravitational effects taken into account, a new solution to the fuel optimal vertical landing on an asteroid was obtained. In this solution, the spacecraft commanded acceleration is explicitly expressed as a function of vehicle velocity and time to go. Based on qualitative methods of analysis, the guidance strategy and the resulting trajectories were studied. It is shown that these fuel-optimal trajectories effectively assure a vertical soft landing on the asteroid. Results of numerical simulations for the vertical landing, starting from an elliptical orbit are presented.

  9. 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

  10. Effective solidity in vertical axis wind turbines

    NASA Astrophysics Data System (ADS)

    Parker, Colin M.; Leftwich, Megan C.

    2016-11-01

    The flow surrounding vertical axis wind turbines (VAWTs) is investigated using particle imaging velocimetry (PIV). This is done in a low-speed wind tunnel with a scale model that closely matches geometric and dynamic properties tip-speed ratio and Reynolds number of a full size turbine. Previous results have shown a strong dependance on the tip-speed ratio on the wake structure of the spinning turbine. However, it is not clear whether this is a speed or solidity effect. To determine this, we have measured the wakes of three turbines with different chord-to-diameter ratios, and a solid cylinder. The flow is visualized at the horizontal mid-plane as well as the vertical mid-plane behind the turbine. The results are both ensemble averaged and phase averaged by syncing the PIV system with the rotation of the turbine. By keeping the Reynolds number constant with both chord and diameter, we can determine how each effects the wake structure. As these parameters are varied there are distinct changes in the mean flow of the wake. Additionally, by looking at the vorticity in the phase averaged profiles we can see structural changes to the overall wake pattern.

  11. Vertical 2D Heterostructures

    NASA Astrophysics Data System (ADS)

    Lotsch, Bettina V.

    2015-07-01

    Graphene's legacy has become an integral part of today's condensed matter science and has equipped a whole generation of scientists with an armory of concepts and techniques that open up new perspectives for the postgraphene area. In particular, the judicious combination of 2D building blocks into vertical heterostructures has recently been identified as a promising route to rationally engineer complex multilayer systems and artificial solids with intriguing properties. The present review highlights recent developments in the rapidly emerging field of 2D nanoarchitectonics from a materials chemistry perspective, with a focus on the types of heterostructures available, their assembly strategies, and their emerging properties. This overview is intended to bridge the gap between two major—yet largely disjunct—developments in 2D heterostructures, which are firmly rooted in solid-state chemistry or physics. Although the underlying types of heterostructures differ with respect to their dimensions, layer alignment, and interfacial quality, there is common ground, and future synergies between the various assembly strategies are to be expected.

  12. Vertically reciprocating auger

    NASA Technical Reports Server (NTRS)

    Etheridge, Mark; Morgan, Scott; Fain, Robert; Pearson, Jonathan; Weldi, Kevin; Woodrough, Stephen B., Jr.

    1988-01-01

    The mathematical model and test results developed for the Vertically Reciprocating Auger (VRA) are summarized. The VRA is a device capable of transporting cuttings that result from below surface drilling. It was developed chiefly for the lunar surface, where conventional fluid flushing while drilling would not be practical. The VRA uses only reciprocating motion and transports material through reflections with the surface above. Particles are reflected forward and land ahead of radially placed fences, which prevent the particles from rolling back down the auger. Three input wave forms are considered to drive the auger. A modified sawtooth wave form was chosen for testing, over a modified square wave or sine wave, due to its simplicity and effectiveness. The three-dimensional mathematical model predicted a sand throughput rate of 0.2667 pounds/stroke, while the actual test setup transported 0.075 pounds/stroke. Based on this result, a correction factor of 0.281 is suggested for a modified sawtooth input.

  13. Latitude and longitude vertical disparity

    PubMed Central

    Read, Jenny C. A.; Phillipson, Graeme P.; Glennerster, Andrew

    2010-01-01

    The literature on vertical disparity is complicated by the fact that several different definitions of the term “vertical disparity” are in common use, often without a clear statement about which is intended or a widespread appreciation of the properties of the different definitions. Here, we examine two definitions of retinal vertical disparity: elevation-latitude and elevation-longitude disparity. Near the fixation point, these definitions become equivalent, but in general, they have quite different dependences on object distance and binocular eye posture, which have not previously been spelt out. We present analytical approximations for each type of vertical disparity, valid for more general conditions than previous derivations in the literature: we do not restrict ourselves to objects near the fixation point or near the plane of regard, and we allow for non-zero torsion, cyclovergence and vertical misalignments of the eyes. We use these expressions to derive estimates of the latitude and longitude vertical disparity expected at each point in the visual field, averaged over all natural viewing. Finally, we present analytical expressions showing how binocular eye position – gaze direction, convergence, torsion, cyclovergence, and vertical misalignment – can be derived from the vertical disparity field and its derivatives at the fovea. PMID:20055544

  14. Measuring Growth with Vertical Scales

    ERIC Educational Resources Information Center

    Briggs, Derek C.

    2013-01-01

    A vertical score scale is needed to measure growth across multiple tests in terms of absolute changes in magnitude. Since the warrant for subsequent growth interpretations depends upon the assumption that the scale has interval properties, the validation of a vertical scale would seem to require methods for distinguishing interval scales from…

  15. The School Library Vertical File.

    ERIC Educational Resources Information Center

    Smallwood, Carol

    1990-01-01

    Discusses the maintenance of vertical files in the school library. Topics covered include circulation, weeding, using materials for special displays, acquiring materials, policies on advertising and controversial issues, cross-references, subject headings, introducing students to vertical files, beginning a collection, and preservation. (MES)

  16. Automated segmentation of optic disc region on retinal fundus photographs: Comparison of contour modeling and pixel classification methods.

    PubMed

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

    2011-01-01

    The automatic determination of the optic disc area in retinal fundus images can be useful for calculation of the cup-to-disc (CD) ratio in the glaucoma screening. We compared three different methods that employed active contour model (ACM), fuzzy c-mean (FCM) clustering, and artificial neural network (ANN) for the segmentation of the optic disc regions. The results of these methods were evaluated using new databases that included the images captured by different camera systems. The average measures of overlap between the disc regions determined by an ophthalmologist and by using the ACM (0.88 and 0.87 for two test datasets) and ANN (0.88 and 0.89) methods were slightly higher than that by using FCM (0.86 and 0.86) method. These results on the unknown datasets were comparable with those of the resubstitution test; this indicates the generalizability of these methods. The differences in the vertical diameters, which are often used for CD ratio calculation, determined by the proposed methods and based on the ophthalmologist's outlines were even smaller than those in the case of the measure of overlap. The proposed methods can be useful for automatic determination of CD ratios.

  17. Vertical bloch line memory

    NASA Technical Reports Server (NTRS)

    Katti, R.; Wu, J.; Stadler, H.

    1990-01-01

    Vertical Bloch Line (VBL) memory is a recently conceived, integrated, solid-state, block-access, VLSI memory which offers the potential of 1Gbit/sq cm real storage density, gigabit per second data rates, and sub-millisecond average access times simultaneously at relatively low mass, volume, and power values when compared to alternative technologies. VBL's are micromagnetic structures within magnetic domain walls which can be manipulated using magnetic fields from integrated conductors. The presence or absence of VBL pairs are used to store binary information. At present, efforts are being directed at developing a single-chip memory using 25Mbit/sq cm technology in magnetic garnet material which integrates, at a single operating point, the writing, storage, reading, and amplification functions needed in a memory. This paper describes the current design architecture, functional elements, and supercomputer simulation results which are used to assist the design process. The current design architecture uses three metal layers, two ion implantation steps for modulating the thickness of the magnetic layer, one ion implantation step for assisting propagation in the major line track, one NiFe soft magnetic layer, one CoPt hard magnetic layer, and one reflective Cr layer for facilitating magneto-optic observation of magnetic structure. Data are stored in a series of elongated magnetic domains, called stripes, which serve as storage sites for arrays of VBL pairs. The ends of these stripes are placed near conductors which serve as VBL read/write gates. A major line track is present to provide a source and propagation path for magnetic bubbles. Writing and reading, respectively, are achieved by converting magnetic bubbles to VBL's and vice versa. The output function is effected by stretching a magnetic bubble and detecting it magnetoresistively. Experimental results from the past design cycle created four design goals for the current design cycle. First, the bias field ranges

  18. Equilibrium studies for low-aspect-ratio torsatrons

    SciTech Connect

    Garcia, L.; Carreras, B.A.; Harris, J.H.; Hicks, H.R.; Lynch, V.E.

    1983-10-01

    Three-dimensional MHD equilibrium studies have been done for low aspect ratio torsatrons. These studies cover continuous-coil and modular torsatrons. The equilibrium properties improve with aspect ratio, as is expected. The role played by the vertical field has also been investigated. Outward shifts cause the flux surfaces to deteriorate. Inward shifts improve the flux surfaces at the expense of stability properties.

  19. Vertical Localization of the Malar Prominence

    PubMed Central

    Kaptein, John S.; Markarian, Alexander

    2015-01-01

    Background: During reconstruction or augmentation, it is important to localize the malar complex in a symmetrical and aesthetically pleasing position. Few studies have determined the location of this feature and none related the location to gender, age, or ethnicity. Some of these have attempted to relate the position to the aesthetically pleasing Golden Ratio φ. Methods: We assessed the vertical location of the malar prominence relative to other facial landmarks, determined consistency among individuals, and compared this with values used in artistry. Study population consisted of a convenience sample of 67 patients taken from an otolaryngology practice at a large urban medical center. Coordinates of the malar prominence were referenced to distinct facial landmarks from which the ratio of chin-to-malar prominence to chin-to-eye canthus was determined. Results: Average chin-to-malar prominence distance was 0.793 ± 0.023 (SD) of the chin-to-eye canthus distance. Variability due to the specific image chosen [coefficient of variation (CV) = 1.19%] and combined inter/intrareader variability (CV = 1.71%) validate the methodology. Variability among individuals (CV = 2.84%) indicates population consistency. No difference was found between gender and age groups or between whites and Hispanics. Individuals of other/unknown ethnicities were within the range common to whites and Hispanics. Our population’s value is not different from the value of 0.809 used in artistry, which is based on the Golden Ratio φ. Conclusions: The vertical position of the malar prominence is consistent among individuals, is clinically well-approximated by the value based on the Golden Ratio, and may be useful as a reference for surgical reconstruction or augmentation. PMID:26180712

  20. The Golden Ratio

    ERIC Educational Resources Information Center

    Hyde, Hartley

    2004-01-01

    The Golden Ratio is sometimes called the "Golden Section" or the "Divine Proportion", in which three points: A, B, and C, divide a line in this proportion if AC/AB = AB/BC. "Donald in Mathmagicland" includes a section about the Golden Ratio and the ratios within a five-pointed star or pentagram. This article presents two computing exercises that…

  1. Vertical Beam Polarization at MAMI

    NASA Astrophysics Data System (ADS)

    Schlimme, B. S.; Achenbach, P.; Aulenbacher, K.; Baunack, S.; Bender, D.; Beričič, J.; Bosnar, D.; Correa, L.; Dehn, M.; Distler, M. O.; Esser, A.; Fonvieille, H.; Friščić, I.; Gutheil, B.; Herrmann, P.; Hoek, M.; Kegel, S.; Kohl, Y.; Kolar, T.; Kreidel, H.-J.; Maas, F.; Merkel, H.; Mihovilovič, M.; Müller, J.; Müller, U.; Nillius, F.; Nuck, A.; Pochodzalla, J.; Schoth, M.; Schulz, F.; Sfienti, C.; Širca, S.; Spruck, B.; Štajner, S.; Thiel, M.; Tioukine, V.; Tyukin, A.; Weber, A.

    2017-04-01

    For the first time a vertically polarized electron beam has been used for physics experiments at MAMI in the energy range between 180 and 855 MeV. The beam-normal single-spin asymmetry An, which is a direct probe of higher-order photon exchange beyond the first Born approximation, has been measured in the reaction 12C (e → , e ‧)12C . Vertical polarization orientation was necessary to measure this asymmetry with the existing experimental setup. In this paper we describe the procedure to orient the electron polarization vector vertically, and the concept of determining both its magnitude and orientation with the available setup. A sophisticated method has been developed to overcome the lack of a polarimeter setup sensitive to the vertical polarization component.

  2. Vertical axis wind turbine airfoil

    DOEpatents

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

    2012-12-18

    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.

  3. Vertically scanned laser sheet microscopy.

    PubMed

    Dong, Di; Arranz, Alicia; Zhu, Shouping; Yang, Yujie; Shi, Liangliang; Wang, Jun; Shen, Chen; Tian, Jie; Ripoll, Jorge

    2014-01-01

    Laser sheet microscopy is a widely used imaging technique for imaging the three-dimensional distribution of a fluorescence signal in fixed tissue or small organisms. In laser sheet microscopy, the stripe artifacts caused by high absorption or high scattering structures are very common, greatly affecting image quality. To solve this problem, we report here a two-step procedure which consists of continuously acquiring laser sheet images while vertically displacing the sample, and then using the variational stationary noise remover (VSNR) method to further reduce the remaining stripes. Images from a cleared murine colon acquired with a vertical scan are compared with common stitching procedures demonstrating that vertically scanned light sheet microscopy greatly improves the performance of current light sheet microscopy approaches without the need for complex changes to the imaging setup and allows imaging of elongated samples, extending the field of view in the vertical direction.

  4. A common variant near TGFBR3 is associated with primary open angle glaucoma

    PubMed Central

    Li, Zheng; Allingham, R. Rand; Nakano, Masakazu; Jia, Liyun; Chen, Yuhong; Ikeda, Yoko; Mani, Baskaran; Chen, Li-Jia; Kee, Changwon; Garway-Heath, David F.; Sripriya, Sarangapani; Fuse, Nobuo; Abu-Amero, Khaled K.; Huang, Chukai; Namburi, Prasanthi; Burdon, Kathryn; Perera, Shamira A.; Gharahkhani, Puya; Lin, Ying; Ueno, Morio; Ozaki, Mineo; Mizoguchi, Takanori; Krishnadas, Subbiah Ramasamy; Osman, Essam A.; Lee, Mei Chin; Chan, Anita S.Y.; Tajudin, Liza-Sharmini A.; Do, Tan; Goncalves, Aurelien; Reynier, Pascal; Zhang, Hong; Bourne, Rupert; Goh, David; Broadway, David; Husain, Rahat; Negi, Anil K.; Su, Daniel H; Ho, Ching-Lin; Blanco, Augusto Azuara; Leung, Christopher K.S.; Wong, Tina T.; Yakub, Azhany; Liu, Yutao; Nongpiur, Monisha E.; Han, Jong Chul; Hon, Do Nhu; Shantha, Balekudaru; Zhao, Bowen; Sang, Jinghong; Zhang, NiHong; Sato, Ryuichi; Yoshii, Kengo; Panda-Jonas, Songhomita; Ashley Koch, Allison E.; Herndon, Leon W.; Moroi, Sayoko E.; Challa, Pratap; Foo, Jia Nee; Bei, Jin-Xin; Zeng, Yi-Xin; Simmons, Cameron P.; Bich Chau, Tran Nguyen; Sharmila, Philomenadin Ferdinamarie; Chew, Merwyn; Lim, Blanche; Tam, Pansy O.S.; Chua, Elaine; Ng, Xiao Yu; Yong, Victor H.K.; Chong, Yaan Fun; Meah, Wee Yang; Vijayan, Saravanan; Seongsoo, Sohn; Xu, Wang; Teo, Yik Ying; Cooke Bailey, Jessica N.; Kang, Jae H.; Haines, Jonathan L.; Cheng, Ching Yu; Saw, Seang-Mei; Tai, E-Shyong; Richards, Julia E.; Ritch, Robert; Gaasterland, Douglas E.; Pasquale, Louis R.; Liu, Jianjun; Jonas, Jost B.; Milea, Dan; George, Ronnie; Al-Obeidan, Saleh A.; Mori, Kazuhiko; Macgregor, Stuart; Hewitt, Alex W.; Girkin, Christopher A.; Zhang, Mingzhi; Sundaresan, Periasamy; Vijaya, Lingam; Mackey, David A.; Wong, Tien Yin; Craig, Jamie E.; Sun, Xinghuai; Kinoshita, Shigeru; Wiggs, Janey L.; Khor, Chiea-Chuen; Yang, Zhenglin; Pang, Chi Pui; Wang, Ningli; Hauser, Michael A.; Tashiro, Kei; Aung, Tin; Vithana, Eranga N.

    2015-01-01

    Primary open angle glaucoma (POAG), a major cause of blindness worldwide, is a complex disease with a significant genetic contribution. We performed Exome Array (Illumina) analysis on 3504 POAG cases and 9746 controls with replication of the most significant findings in 9173 POAG cases and 26 780 controls across 18 collections of Asian, African and European descent. Apart from confirming strong evidence of association at CDKN2B-AS1 (rs2157719 [G], odds ratio [OR] = 0.71, P = 2.81 × 10−33), we observed one SNP showing significant association to POAG (CDC7–TGFBR3 rs1192415, ORG-allele = 1.13, Pmeta = 1.60 × 10−8). This particular SNP has previously been shown to be strongly associated with optic disc area and vertical cup-to-disc ratio, which are regarded as glaucoma-related quantitative traits. Our study now extends this by directly implicating it in POAG disease pathogenesis. PMID:25861811

  5. Spectral characteristics of vertical ground motion in the Northridge and other earthquakes

    SciTech Connect

    Bozorgnia, Y.; Niazi, M.; Campbell, K.W.

    1995-12-31

    Spectral characteristics of vertical ground motion recorded during the Northridge earthquake are evaluated and compared to those of other earthquakes. Relationship between vertical and horizontal spectra is examined through development of attenuation of vertical and horizontal response spectra. Vertical-to-horizontal response spectral relationship is then compared to that of 1989 Loma Prieta earthquake, and several other earthquakes recorded over SMART-1 array in Taiwan. This preliminary analysis shows that the main characteristics of vertical-to-horizontal spectral ratio are similar to those of other earthquakes. One main characteristic is that in the near-field region and in short period range, the ratio is much higher than commonly assumed ratio of 2/3.

  6. Vertical vibration and shape oscillation of acoustically levitated water drops

    SciTech Connect

    Geng, D. L.; Xie, W. J.; Yan, N.; Wei, B.

    2014-09-08

    We present the vertical harmonic vibration of levitated water drops within ultrasound field. The restoring force to maintain such a vibration mode is provided by the resultant force of acoustic radiation force and drop gravity. Experiments reveal that the vibration frequency increases with the aspect ratio for drops with the same volume, which agrees with the theoretical prediction for those cases of nearly equiaxed drops. During the vertical vibration, the floating drops undergo the second order shape oscillation. The shape oscillation frequency is determined to be twice the vibration frequency.

  7. Offer/Acceptance Ratio.

    ERIC Educational Resources Information Center

    Collins, Mimi

    1997-01-01

    Explores how human resource professionals, with above average offer/acceptance ratios, streamline their recruitment efforts. Profiles company strategies with internships, internal promotion, cooperative education programs, and how to get candidates to accept offers. Also discusses how to use the offer/acceptance ratio as a measure of program…

  8. CALIPSO lidar ratio retrieval over the ocean.

    PubMed

    Josset, Damien; Rogers, Raymond; Pelon, Jacques; Hu, Yongxiang; Liu, Zhaoyan; Omar, Ali; Zhai, Peng-Wang

    2011-09-12

    We are demonstrating on a few cases the capability of CALIPSO to retrieve the 532 nm lidar ratio over the ocean when CloudSat surface scattering cross section is used as a constraint. We are presenting the algorithm used and comparisons with the column lidar ratio retrieved by the NASA airborne high spectral resolution lidar. For the three cases presented here, the agreement is fairly good. The average CALIPSO 532 nm column lidar ratio bias is 13.7% relative to HSRL, and the relative standard deviation is 13.6%. Considering the natural variability of aerosol microphysical properties, this level of accuracy is significant since the lidar ratio is a good indicator of aerosol types. We are discussing dependencies of the accuracy of retrieved aerosol lidar ratio on atmospheric aerosol homogeneity, lidar signal to noise ratio, and errors in the optical depth retrievals. We are obtaining the best result (bias 7% and standard deviation around 6%) for a nighttime case with a relatively constant lidar ratio (in the vertical) indicative of homogeneous aerosol type.

  9. CALIPSO Lidar Ratio Retrieval Over the Ocean

    NASA Technical Reports Server (NTRS)

    Josset, Damien B.; Rogers, Raymond R.; Pelon, Jacques; Hu, Yongxiang; Liu, Zhaoyan; Omar, Ali H.; Zhai, Peng-Wang

    2011-01-01

    We are demonstrating on a few cases the capability of CALIPSO to retrieve the 532 nm lidar ratio over the ocean when CloudSat surface scattering cross section is used as a constraint. We are presenting the algorithm used and comparisons with the column lidar ratio retrieved by the NASA airborne high spectral resolution lidar. For the three cases presented here, the agreement is fairly good. The average CALIPSO 532 nm column lidar ratio bias is 13.7% relative to HSRL, and the relative standard deviation is 13.6%. Considering the natural variability of aerosol microphysical properties, this level of accuracy is significant since the lidar ratio is a good indicator of aerosol types. We are discussing dependencies of the accuracy of retrieved aerosol lidar ratio on atmospheric aerosol homogeneity, lidar signal to noise ratio, and errors in the optical depth retrievals. We are obtaining the best result (bias 7% and standard deviation around 6%) for a nighttime case with a relatively constant lidar ratio (in the vertical) indicative of homogeneous aerosol type

  10. Vertical motion simulator familiarization guide

    NASA Technical Reports Server (NTRS)

    Danek, George L.

    1993-01-01

    The Vertical Motion Simulator Familiarization Guide provides a synoptic description of the Vertical Motion Simulator (VMS) and descriptions of the various simulation components and systems. The intended audience is the community of scientists and engineers who employ the VMS for research and development. The concept of a research simulator system is introduced and the building block nature of the VMS is emphasized. Individual sections describe all the hardware elements in terms of general properties and capabilities. Also included are an example of a typical VMS simulation which graphically illustrates the composition of the system and shows the signal flow among the elements and a glossary of specialized terms, abbreviations, and acronyms.

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

    SciTech Connect

    Rotondo, M.

    2005-10-12

    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.

  12. Physics and the Vertical Jump

    ERIC Educational Resources Information Center

    Offenbacher, Elmer L.

    1970-01-01

    The physics of vertical jumping is described as an interesting illustration for motivating students in a general physics course to master the kinematics and dynamics of one dimensional motion. The author suggests that mastery of the physical principles of the jump may promote understanding of certain biological phenomena, aspects of physical…

  13. Vertical Instability at IPNS RCS.

    SciTech Connect

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

    2008-01-01

    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.

  14. Vertical reactor coolant pump instabilities

    NASA Technical Reports Server (NTRS)

    Jones, R. M.

    1985-01-01

    The investigation conducted at the Tennessee Valley Authority's Sequoyah Nuclear Power Plant to determine and correct increasing vibrations in the vertical reactor coolant pumps is described. Diagnostic procedures to determine the vibration causes and evaluate the corrective measures taken are also described.

  15. High Aspect Ratio Wrinkles

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Cheng; Crosby, Alfred

    2015-03-01

    Buckling-induced surface undulations are widely found in living creatures, for instance, gut villi and the surface of flower petal cells. These undulations provide unique functionalities with their extremely high aspect ratios. For the synthetic systems, sinusoidal wrinkles that are induced by buckling a thin film attached on a soft substrate have been proposed to many applications. However, the impact of the synthetic wrinkles have been restricted by limited aspect ratios, ranging from 0 to 0.35. Within this range, wrinkle aspect ratio is known to increase with increasing compressive strain until a critical strain is reached, at which point wrinkles transition to localizations, such as folds or period doublings. Inspired by the living creatures, we propose that wrinkles can be stabilized in high aspect ratio by manipulating the strain energy in the substrate. We experimentally demonstrate this idea by forming a secondary crosslinking network in the wrinkled surface and successfully achieve aspect ratio as large as 0.8. This work not only provides insights for the mechanism of high aspect ratio structures seen in living creatures, but also demonstrates significant promise for future wrinkle-based applications.

  16. Vertical Sextants give Good Sights

    NASA Astrophysics Data System (ADS)

    Dixon, Mark

    Many texts stress the need for marine sextants to be held precisely vertical at the instant that the altitude of a heavenly body is measured. Several authors lay particular emphasis on the technique of the instrument in a small arc about the horizontal axis to obtain a good sight. Nobody, to the author's knowledge, however, has attempted to quantify the errors involved, so as to compare them with other errors inherent in determining celestial position lines. This paper sets out to address these issues and to pose the question: what level of accuracy of vertical alignment can reasonably be expected during marine sextant work at sea ?When a heavenly body is brought to tangency with the visible horizon it is particularly important to ensure that the sextant is held in a truly vertical position. To this end the instrument is rocked gently about the horizontal so that the image of the body describes a small arc in the observer's field of vision. As Bruce Bauer points out, tangency with the horizon must be achieved during the process of rocking and not a second or so after rocking has been discontinued. The altitude is recorded for the instant that the body kisses the visible horizon at the lowest point of the rocking arc, as in Fig. 2. The only other visual clue as to whether the sextant is vertical is provided by the right angle made by the vertical edge of the horizon glass mirror with the horizon. There may also be some input from the observer's sense of balance and his hand orientation.

  17. Verticality perception during off-vertical axis rotation.

    PubMed

    Vingerhoets, R A A; Van Gisbergen, J A M; Medendorp, W P

    2007-05-01

    During prolonged rotation about a tilted yaw axis, often referred to as off-vertical axis rotation (OVAR), a percept of being translated along a conical path slowly emerges as the sense of rotation subsides. Recently, we found that these perceptual changes are consistent with a canal-otolith interaction model that attributes the illusory translation percept to improper interpretation of the ambiguous otolith signals. The model further predicts that the illusory translation percept must be accompanied by slowly worsening tilt underestimates. Here, we tested this prediction in six subjects by measuring the time course of the subjective visual vertical (SVV) during OVAR stimulation at three different tilt-rotation speed combinations, in complete darkness. Throughout the 2-min run, at each left-ear-down and right-ear-down position, the subject indicated whether a briefly flashed line deviated clockwise or counterclockwise from vertical to determine the SVV with an adaptive staircase procedure. Typically, SVV errors indicating tilt underestimation were already present at rotation onset and then increased exponentially to an asymptotic value, reached at about 60 s after rotation onset. The initial error in the SVV was highly correlated to the response error in a static tilt control experiment. The subsequent increase in error depended on both rotation speed and OVAR tilt angle, in a manner predicted by the canal-otolith interaction model. We conclude that verticality misjudgments during OVAR reflect a dynamic component linked to canal-otolith interaction, superimposed on a tilt-related component that is also expressed under stationary conditions.

  18. Suppression of vertical instability in elongated current-carrying plasmas by applying stellarator rotational transform

    SciTech Connect

    ArchMiller, M. C.; Cianciosa, M. R.; Ennis, D. A.; Hanson, J. D.; Hartwell, G. J.; Hebert, J. D.; Herfindal, J. L.; Knowlton, S. F.; Ma, X.; Maurer, D. A.; Pandya, M. D.; Traverso, P.

    2014-05-15

    The passive stability of vertically elongated current-carrying toroidal plasmas has been investigated in the Compact Toroidal Hybrid, a stellarator/tokamak hybrid device. In this experiment, the fractional transform f, defined as the ratio of the imposed external rotational transform from stellarator coils to the total rotational transform, was varied from 0.04 to 0.50, and the elongation κ was varied from 1.4 to 2.2. Plasmas that were vertically unstable were evidenced by motion of the plasma in the vertical direction. Vertical drifts are measured with a set of poloidal field pickup coils. A three chord horizontally viewing interferometer and a soft X-ray diode array confirmed the drifts. Plasmas with low fractional transform and high elongation are the most susceptible to vertical instability, consistent with analytic predictions that the vertical mode in elongated plasmas can be stabilized by the poloidal field of a relatively weak stellarator equilibrium.

  19. Ratio imaging instrumentation.

    PubMed

    Dunn, Kenneth; Maxfield, Frederick R

    2003-01-01

    Using ratio imaging to obtain quantitative information from microscope images is a powerful tool that has been used successfully in numerous studies. Although ratio imaging reduces the effects of many parameters that can interfere with accurate measurements, it is not a panacea. In designing a ratio imaging experiment, all of the potential problems discussed in this chapter must be considered. Undoubtedly, other problems that were not discussed can also interfere with accurate and meaningful measurements. Many of the problems discussed here were observed in the authors' laboratories. In our experience there are no standard routines or methods that can foresee every problem before it has been encountered. Good experimental design can minimize problems, but the investigator must continue to be alert. Progress in instrumentation continues to overcome some of the difficulties encountered in ratio imaging. CCD cameras with 12- to 14-bit pixel depth are being used more frequently, and several confocal microscope manufacturers are now also using 12-bit digitization. The dramatic increase in the use of confocal microscopes over the past decade is now causing microscope manufacturers to more critically evaluate the effect of axial chromatic aberration in objectives, and recent designs to minimize this problem are being implemented. Other developments such as the use of AOTFs to attenuate laser lines extend the applicability of ratio imaging. Ratio imaging is clearly applicable to a wide range of cell biological problems beyond its widespread use for measuring ion concentrations. Imaginative but careful use of this technique should continue to provide novel insights into the properties of cells.

  20. Vertically Integrated Circuits at Fermilab

    SciTech Connect

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

    2010-01-01

    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.

  1. Vertically Integrated Circuits at Fermilab

    SciTech Connect

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

    2009-01-01

    The exploration of the 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. The consortium has submitted over 25 different designs for the Fermilab organized MPW run organized for the first time.

  2. Kinematic Fitting of Detached Vertices

    SciTech Connect

    Mattione, Paul

    2007-05-01

    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.

  3. NASA-Ames vertical gun

    NASA Technical Reports Server (NTRS)

    Schultz, P. H.

    1984-01-01

    A national facility, the NASA-Ames vertical gun range (AVGR) has an excellent reputation for revealing fundamental aspects of impact cratering that provide important constraints for planetary processes. The current logistics in accessing the AVGR, some of the past and ongoing experimental programs and their relevance, and the future role of this facility in planetary studies are reviewed. Publications resulting from experiments with the gun (1979 to 1984) are listed as well as the researchers and subjects studied.

  4. Management of paretic vertical deviations.

    PubMed

    Archer, Steven M

    2011-01-01

    Paretic vertical deviations are characterized by complex patterns of incomitance that make them some of the most challenging strabismus problems to treat. Optimum results are obtained by performing surgery on those muscles, selected from among the eight cyclovertical muscles in the two eyes, that minimize the incomitance. In superior oblique paresis the additional factors of torticollis and torsion need to be addressed and aberrant regeneration can alter the surgical plan in third nerve paresis.

  5. Vertical Launch System Loadout Planner

    DTIC Science & Technology

    2015-03-01

    Submarine Rocket (ASROC): Ship -launched rocket used in ASW.  RIM-174 SM6: Advanced version of a ship -launched SM2 missile capable of over-the...Operational planners strive to fmd ways to load missiles on Vertical Latmch System (VLS) ships to meet mission requit·ements in theit· AI·ea of...Responsibility (AOR). Requirements are variable: there are missions requiting specific types of missiles; each ship may have distinct capability or capacity to

  6. Vertical Gun Test Environmental Assessment

    DTIC Science & Technology

    2004-05-18

    phosphate (TBP) as a chemical agent simulant in a maximum of six vertical gun experiments to be conducted at the Energetic Materials Research and... phosphate . Using either of Ka-Bandprocess, with 2 these two substances would not achieve the test objectives of realistically simulating the threat. In...resources, geology and soils , hazardous materials and hazardous waste, health and safety, land use, noise, socioeconomics and environmental justice

  7. Mated vertical ground vibration test

    NASA Technical Reports Server (NTRS)

    Ivey, E. W.

    1980-01-01

    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 prediction and design of loads, pogo controls, and flutter criteria under various payloads and operational missions. The MVGVT boost and launch program evolution, test configurations, and their suspensions are described. Test results are compared with predicted analytical results.

  8. Wind tunnel investigation of a 14 foot vertical axis windmill

    NASA Technical Reports Server (NTRS)

    Muraca, R. J.; Guillotte, R. J.

    1976-01-01

    A full scale wind tunnel investigation was made to determine the performance characteristics of a 14 ft diameter vertical axis windmill. The parameters measured were wind velocity, shaft torque, shaft rotation rate, along with the drag and yawing moment. A velocity survey of the flow field downstream of the windmill was also made. The results of these tests along with some analytically predicted data are presented in the form of generalized data as a function of tip speed ratio.

  9. SWCNT-MoS2 -SWCNT Vertical Point Heterostructures.

    PubMed

    Zhang, Jin; Wei, Yang; Yao, Fengrui; Li, Dongqi; Ma, He; Lei, Peng; Fang, Hehai; Xiao, Xiaoyang; Lu, Zhixing; Yang, Juehan; Li, Jingbo; Jiao, Liying; Hu, Weida; Liu, Kaihui; Liu, Kai; Liu, Peng; Li, Qunqing; Lu, Wei; Fan, Shoushan; Jiang, Kaili

    2017-02-01

    A vertical point heterostructure (VPH) is constructed by sandwiching a two-dimensional (2D) MoS2 flake with two cross-stacked metallic single-walled carbon nanotubes. It can be used as a field-effect transistor with high on/off ratio and a light detector with high spatial resolution. Moreover, the hybrid 1D-2D-1D VPHs open up new possibilities for nanoelectronics and nano-optoelectronics.

  10. Bimanual-vertical hand movements.

    PubMed

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

    2011-07-01

    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.

  11. Digit ratio in birds.

    PubMed

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

    2008-12-01

    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.

  12. Vertical separation of the two beams

    SciTech Connect

    Heifets, S.

    1985-10-01

    The author discusses the problem of design of insertion points on the SSC, and in particular keeping the length necessary for them under control. Here he considers the possibility of having vertically separated beams, without a vertical dispersion suppressor.

  13. [Vertical fractures: apropos of 2 clinical cases].

    PubMed

    Félix Mañes Ferrer, J; Micò Muñoz, P; Sánchez Cortés, J L; Paricio Martín, J J; Miñana Laliga, R

    1991-01-01

    The aim of the study is to present a clinical review of the vertical root fractures. Two clinical cases are presented to demonstrates the criteria for obtaining a correct diagnosis of vertical root fractures.

  14. Interventions for dissociated vertical deviation

    PubMed Central

    Hatt, Sarah R; Wang, Xue; Holmes, Jonathan M

    2015-01-01

    Background The term “strabismus” describes misalignment of the eyes. One or both eyes may deviate inward, outward, upward, or downward. Dissociated vertical deviation (DVD) is a well-recognized type of upward drifting of one or both eyes, which can occur in children or adults. DVD often develops in the context of infantile- or childhood-onset horizontal strabismus, either esotropia (inward-turning) or exotropia (outward-turning). For some individuals, DVD remains controlled and can only be detected during clinical testing. For others, DVD becomes spontaneously “manifest” and the eye drifts up of its own accord. Spontaneously manifest DVD can be difficult to control and often causes psychosocial concerns. Traditionally, DVD has been thought to be asymptomatic, although some individuals have double vision. More recently it has been suggested that individuals with DVD may also suffer from eyestrain. Treatment for DVD may be sought either due to psychosocial concerns or because of these symptoms. The standard treatment for DVD is a surgical procedure; non-surgical treatments are offered less commonly. Although there are many studies evaluating different management options for the correction of DVD, a lack of clarity remains regarding which treatments are most effective. Objectives The objective of this review was to determine the effectiveness and safety of various surgical and non-surgical interventions in randomized controlled trials of participants with DVD. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2015, Issue 8), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to August 2015), EMBASE (January 1980 to August 2015), PubMed (1948 to August 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (1982 to August 2015), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) (last searched 3

  15. A design for vertical crossing insertions

    SciTech Connect

    Garren, A.

    1985-10-01

    A crossing insertion designed for an SSC with vertically separated 1-in-1 beam lines is presented in this note. The author supposes that the beam lines consist of separate magnets in separate cryostats separated by about 70 cm. He then describes the design, where vertical separation is done with four vertical dipoles producing a steplike beam line.

  16. Vertically aligned nanostructure scanning probe microscope tips

    DOEpatents

    Guillorn, Michael A.; Ilic, Bojan; Melechko, Anatoli V.; Merkulov, Vladimir I.; Lowndes, Douglas H.; Simpson, Michael L.

    2006-12-19

    Methods and apparatus are described for cantilever structures that include a vertically aligned nanostructure, especially vertically aligned carbon nanofiber scanning probe microscope tips. An apparatus includes a cantilever structure including a substrate including a cantilever body, that optionally includes a doped layer, and a vertically aligned nanostructure coupled to the cantilever body.

  17. Vertical Lift - Not Just For Terrestrial Flight

    NASA Technical Reports Server (NTRS)

    Young, Larry A

    2000-01-01

    Autonomous vertical lift vehicles hold considerable potential for supporting planetary science and exploration missions. This paper discusses several technical aspects of vertical lift planetary aerial vehicles in general, and specifically addresses technical challenges and work to date examining notional vertical lift vehicles for Mars, Titan, and Venus exploration.

  18. 46 CFR 108.160 - Vertical ladders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Vertical ladders. 108.160 Section 108.160 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Means of Escape § 108.160 Vertical ladders. (a) Each vertical ladder must...

  19. 46 CFR 108.160 - Vertical ladders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Vertical ladders. 108.160 Section 108.160 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Means of Escape § 108.160 Vertical ladders. (a) Each vertical ladder must...

  20. Multi-ratio transmission

    SciTech Connect

    Polak, J.C.

    1987-07-14

    A preselected multi-ratio power transmission is described comprising: input means for transmitting drive forces; output means; first, second and third friction clutch means each selectively engageable with the input means for accepting drive forces. First input gear means drivingly connects with the first friction clutch means; second input gear means drivingly connects with the second friction clutch means; third input gear means drivingly connects with the third clutch means; first output gear means drivingly connects with the first input gear means; second output gear means drivingly connects with the first and second input gear means; third output means drivingly connects between the third input gear means and the output means; and one double-acting synchronizer clutch for selectively engaging the first output gear means with the output means and alternately the second output gear means with the output means. The first friction clutch means and the one double-acting synchronizer clutch cooperates during engagement to establish two forward drive ratios between the input and output means. The second friction clutch means and the one double-acting synchronizer clutch cooperates during engagement to establish two other forward drive ratios between the input and output means. The third friction clutch means is engageable to provide another forward drive ratio between the input means and the output means; and the one double-acting synchronizer clutch is relieved of transmitting drive forces during the engagement of the third friction clutch means and being manipulable for alternate connection with either the first output gear or the second output gear while the third friction clutch means is engaged.

  1. Analysis of vertical interconnection measurements

    NASA Astrophysics Data System (ADS)

    Karner, F. A.

    The paper examines the predominance of the effects that measurement points, geometries, and alignment have on the interpretation of measured values of contact resistance of vertical interconnections in multilayer electronic packages. It is concluded that: (1) four-terminal measurements for contact resistance are misleading; (2) measured values are mostly a function of structural geometry; (3) simulation in two dimensions and subsequent synthesis is a good predictor in three-dimensional simulations; (4) the dual-contact site is a good alignment aid and contact-resistance indicator; and (5) the measured resistance value should only be used as a reference, and not as an indicator of good or bad.

  2. ?Vertical Sextants give Good Sights?

    NASA Astrophysics Data System (ADS)

    Richey, Michael

    Mark Dixon suggests (Forum, Vol. 50, 137) that nobody thus far has attempted to quantify the errors from tilt that arise while observing with the marine sextant. The issue in fact, with the related problem of what exactly is the axis about which the sextant is rotated whilst being (to define the vertical), was the subject of a lively controversy in the first two volumes of this Journal some fifty years ago. Since the consensus of opinion seems to have been that the maximum error does not necessarily occur at 45 degrees, whereas Dixon's table suggests that it does, some reiteration of the arguments may be in order.

  3. Vertical jumping and signaled avoidance

    PubMed Central

    Cándido, Antonio; Maldonado, Antonio; Vila, Jaime

    1988-01-01

    This paper reports an experiment intended to demonstrate that the vertical jumping response can be learned using a signaled-avoidance technique. A photoelectric cell system was used to record the response. Twenty female rats, divided equally into two groups, were exposed to intertrial intervals of either 15 or 40 s. Subjects had to achieve three successive criteria of acquisition: 3, 5, and 10 consecutive avoidance responses. Results showed that both groups learned the avoidance response, requiring increasingly larger numbers of trials as the acquisition criteria increased. No significant effect of intertrial interval was observed. PMID:16812559

  4. Laser tracking for vertical control

    NASA Technical Reports Server (NTRS)

    Dunn, Peter; Torrence, Mark; Pavlis, Erricos; Kolenkiewicz, Ron; Smith, David

    1993-01-01

    The Global Laser Tracking Network has provided LAGEOS ranging data of high accuracy since the first MERIT campaign in late 1983 and we can now resolve centimeter-level three dimensional positions of participating observatories at monthly intervals. In this analysis, the station height estimates have been considered separately from the horizontal components, and can be determined by the strongest stations with a formal standard error of 2 mm using eight years of continuous observations. The rate of change in the vertical can be resolved to a few mm/year, which is at the expected level of several geophysical effects. In comparing the behavior of the stations to that predicted by recent models of post-glacial rebound, we find no correlation in this very small effect. Particular attention must be applied to data and survey quality control when measuring the vertical component, and the survey observations are critical components of the geodynamic results. Seasonal patterns are observed in the heights of most stations, and the possibility of secular motion at the level of several millimeters per year cannot be excluded. Any such motion must be considered in the interpretation of horizontal inter-site measurements, and can help to identify mechanisms which can cause variations which occur linearly with time, seasonally, or abruptly.

  5. On the vertical distribution of carbon monoxide over Bay of Bengal during winter: Role of water vapour and vertical updrafts

    NASA Astrophysics Data System (ADS)

    Girach, I. A.; Nair, Prabha R.

    2014-09-01

    The differences in the spatial pattern of column carbon monoxide (CO) and in-situ measured near-surface CO over Bay of Bengal (BoB) during winter were examined in the light of vertical distribution of CO as retrieved from MOPITT (Measurements Of Pollution In The Troposphere) on board Terra spacecraft. The column CO showed relatively high values over southern-BoB whereas the near-surface CO showed low mixing ratio indicating the existence of significant amount of CO at higher altitudes. The vertical profiles of CO over the BoB region retrieved from MOPITT exhibit a high altitude peak around ~9 km altitude region. The role of water vapour and convective activity/vertical updrafts in establishing the observed vertical profile of CO was investigated. It is found that CO got uplifted to the higher altitude due to updrafts and water vapour caused depletion of CO at lower altitudes which appeared as an apparent high in CO mixing ratio at higher altitude relative to that over lower altitude. The role of water vapour in the destruction of CO was confirmed by box model simulations. Airmass back-trajectory analysis showed that the long range transport from lower troposphere/boundary layer was also partially responsible for higher mixing ratios at higher altitude. In addition, a comparison of in-situ measured near-surface CO and those retrieved from MOPITT using retrieval algorithm Versions 4 and 5 showed that the points of discrepancy have reduced in the Version 5. Biomass burning and anthropogenic activities taking place over the Myanmar landmass was found to be responsible for the hot spots of near-surface-CO over the northeast-BoB.

  6. Peak power ratio generator

    DOEpatents

    Moyer, R.D.

    A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

  7. Peak power ratio generator

    DOEpatents

    Moyer, Robert D.

    1985-01-01

    A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

  8. 5-foot Vertical Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1932-01-01

    The researcher is sitting above the exit cone of the 5-foot Vertical Wind Tunnel and is examining the new 6-component spinning balance. This balance was developed between 1930 and 1933. It was an important advance in the technology of rotating or rolling balances. As M.J. Bamber and C.H. Zimmerman wrote in NACA TR 456: 'Data upon the aerodynamic characteristics of a spinning airplane may be obtained in several ways; namely, flight tests with full-scale airplanes, flight tests with balanced models, strip-method analysis of wind-tunnel force and moment tests, and wind-tunnel tests of rotating models.' Further, they note: 'Rolling-balance data have been of limited value because it has not been possible to measure all six force and moment components or to reproduce a true spinning condition. The spinning balance used in this investigation is a 6-component rotating balance from which it is possible to obtain wind-tunnel data for any of a wide range of possible spinning conditions.' Bamber and Zimmerman described the balance as follows: 'The spinning balance consists of a balance head that supports the model and contains the force-measuring units, a horizontal turntable supported by streamline struts in the center of the jet and, outside the tunnel, a direct-current driving motor, a liquid tachometer, an air compressor, a mercury manometer, a pair of indicating lamps, and the necessary controls. The balance head is mounted on the turntable and it may be set to give any radius of spin between 0 and 8 inches.' In an earlier report, NACA TR 387, Carl Wenzinger and Thomas Harris supply this description of the tunnel: 'The vertical open-throat wind tunnel of the National Advisory Committee for Aeronautics ... was built mainly for studying the spinning characteristics of airplane models, but may be used as well for the usual types of wind-tunnel tests. A special spinning balance is being developed to measure the desired forces and moments with the model simulating the actual

  9. Making Tracks on Mars (vertical)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    NASA's Mars Exploration Rover Spirit has been making tracks on Mars for seven months now, well beyond its original 90-day mission. The rover traveled more than 3 kilometers (2 miles) to reach the 'Columbia Hills' pictured here. In this 360-degree view of the rolling martian terrain, its wheel tracks can be seen approaching from the northwest (right side of image).

    Spirit's navigation camera took the images that make up this mosaic on sols 210 and 213 (Aug. 5 and Aug. 8, 2004). The rover is now conducting scientific studies of the local geology on the 'Clovis' outcrop of the 'West Spur' region of the 'Columbia Hills.' The view is presented in a vertical projection with geometrical seam correction. Scientists plan for Spirit to take a color panoramic image from this location.

  10. A new vertical grid nesting capability in the Weather Research and Forecasting (WRF) Model

    DOE PAGES

    Daniels, Megan H.; Lundquist, Katherine A.; Mirocha, Jeffrey D.; ...

    2016-09-16

    Mesoscale atmospheric models are increasingly used for high-resolution (<3 km) simulations to better resolve smaller-scale flow details. Increased resolution is achieved using mesh refinement via grid nesting, a procedure where multiple computational domains are integrated either concurrently or in series. A constraint in the concurrent nesting framework offered by the Weather Research and Forecasting (WRF) Model is that mesh refinement is restricted to the horizontal dimensions. This limitation prevents control of the grid aspect ratio, leading to numerical errors due to poor grid quality and preventing grid optimization. Here, a procedure permitting vertical nesting for one-way concurrent simulation is developedmore » and validated through idealized cases. The benefits of vertical nesting are demonstrated using both mesoscale and large-eddy simulations (LES). Mesoscale simulations of the Terrain-Induced Rotor Experiment (T-REX) show that vertical grid nesting can alleviate numerical errors due to large aspect ratios on coarse grids, while allowing for higher vertical resolution on fine grids. Furthermore, the coarsening of the parent domain does not result in a significant loss of accuracy on the nested domain. LES of neutral boundary layer flow shows that, by permitting optimal grid aspect ratios on both parent and nested domains, use of vertical nesting yields improved agreement with the theoretical logarithmic velocity profile on both domains. Lastly, vertical grid nesting in WRF opens the path forward for multiscale simulations, allowing more accurate simulations spanning a wider range of scales than previously possible.« less

  11. A new vertical grid nesting capability in the Weather Research and Forecasting (WRF) Model

    SciTech Connect

    Daniels, Megan H.; Lundquist, Katherine A.; Mirocha, Jeffrey D.; Wiersema, David J.; Chow, Fotini K.

    2016-09-16

    Mesoscale atmospheric models are increasingly used for high-resolution (<3 km) simulations to better resolve smaller-scale flow details. Increased resolution is achieved using mesh refinement via grid nesting, a procedure where multiple computational domains are integrated either concurrently or in series. A constraint in the concurrent nesting framework offered by the Weather Research and Forecasting (WRF) Model is that mesh refinement is restricted to the horizontal dimensions. This limitation prevents control of the grid aspect ratio, leading to numerical errors due to poor grid quality and preventing grid optimization. Here, a procedure permitting vertical nesting for one-way concurrent simulation is developed and validated through idealized cases. The benefits of vertical nesting are demonstrated using both mesoscale and large-eddy simulations (LES). Mesoscale simulations of the Terrain-Induced Rotor Experiment (T-REX) show that vertical grid nesting can alleviate numerical errors due to large aspect ratios on coarse grids, while allowing for higher vertical resolution on fine grids. Furthermore, the coarsening of the parent domain does not result in a significant loss of accuracy on the nested domain. LES of neutral boundary layer flow shows that, by permitting optimal grid aspect ratios on both parent and nested domains, use of vertical nesting yields improved agreement with the theoretical logarithmic velocity profile on both domains. Lastly, vertical grid nesting in WRF opens the path forward for multiscale simulations, allowing more accurate simulations spanning a wider range of scales than previously possible.

  12. Cephalometric differentiation between vertical and horizontal malocclusions in 122 Europeans using the Denture Frame Analysis and standard measurements. Differentiation between vertical and horizontal malocclusion.

    PubMed

    Celar, A G; Freudenthaler, J W; Schneider, B

    1999-01-01

    This study evaluated the ability of some cephalometric measurements to differentiate between horizontal and vertical malocclusions and normal occlusion. Based upon the Angle classification and the vertical incisor overbite, 122 randomly selected subjects were assigned to 3 horizontal and 3 vertical groups: neutrocclusion, distocclusion, mesiocclusion as well as open bite, normal overbite, and deep bite. Evaluation of the lateral cephalograms was based on Denture Frame Analysis and cephalometric standard measurements (SNA, SNB, ANB, Wits appraisal, Björk polygon, overbite depth indicator, incisor inclination, incisor protrusion, facial height ratio). The statistical evaluation assessed the ability of the measurements to show significant differences between the individual horizontal and vertical groups. Using Denture Frame Analysis, all vertical groups could be differentiated by the occlusomandibular angle (OP-MP) and all horizontal groups by the angle between the A-B plane and the mandibular plane as well as by the inclination of the upper incisors to the A-B plane with statistical significance (p < 0.05). Among the standard measurements, the Wits appraisal was the only one to show differences between all horizontal groups with statistical significance. None of the standard measurements could fully differentiate the vertical groups. The above measurements from the Denture Frame Analysis distinguished the types of malocclusion in anteroposterior and vertical direction including significant distinction between the neutrocclusion group and the malocclusion groups. Therefore a cephalometric classification was feasible in terms of hyper- and hypodivergence as well as of a mesial or distal dentofacial relationship.

  13. Spin Transport and Giant Electroresistance in Ferromagnetic Graphene Vertical Heterostructures

    NASA Astrophysics Data System (ADS)

    Park, Hee Chul; Myung, Nojoon; Lee, Seung Joo

    We investigate spin transport through ferromagnetic graphene vertical heterostructures where a sandwiched tunneling layer is either a normal or ferroelectric insulator. We show that the spin-polarization of the tunneling current is electrically controlled via gate voltages. We also demonstrate that the tunneling current of Dirac fermions can be prohibited when the spin configuration of ferromagnetic graphene sheets is opposite. Giant electroresistance can thus be developed by using the proposed heterostructure in this study. The effects of temperature on spin transport and the giant electroresistance ratio are also investigated. Our findings discover the prospect of manipulating the spin transport properties in vertical heterostructures through electric fields via gate and bias electrodes. The research leading to these results has received funding from the European Union Seventh Framework Programme under grant agreement No604391 Graphene Flagship, Project Code (IBS-R024-D1), and the NRF grant funded by MSIP(No. 2014-066298).

  14. Turbulent vertical diffusivity in the sub-tropical stratosphere

    NASA Astrophysics Data System (ADS)

    Pisso, I.; Legras, B.

    2008-02-01

    Vertical (cross-isentropic) mixing is produced by small-scale turbulent processes which are still poorly understood and paramaterized in numerical models. In this work we provide estimates of local equivalent diffusion in the lower stratosphere by comparing balloon borne high-resolution measurements of chemical tracers with reconstructed mixing ratio from large ensembles of random Lagrangian backward trajectories using European Centre for Medium-range Weather Forecasts analysed winds and a chemistry-transport model (REPROBUS). We focus on a case study in subtropical latitudes using data from HIBISCUS campaign. An upper bound on the vertical diffusivity is found in this case study to be of the order of 0.5 m2 s-1 in the subtropical region, which is larger than the estimates at higher latitudes. The relation between diffusion and dispersion is studied by estimating Lyapunov exponents and studying their variation according to the presence of active dynamical structures.

  15. Turbulent vertical diffusivity in the sub-tropical stratosphere

    NASA Astrophysics Data System (ADS)

    Pisso, I.; Legras, B.

    2007-05-01

    Vertical (cross-isentropic) mixing is produced by small-scale turbulent processes which are still poorly understood and parametrized in numerical models. In this work we provide estimates of local equivalent diffusion in the lower stratosphere by comparing balloon borne high-resolution measurements of chemical tracers with reconstructed mixing ratio from large ensembles of random Lagrangian backward trajectories using European Center for Medium-range Weather Forecasts analysed winds and a chemistry-transport model (REPROBUS). We have investigated cases in subtropical latitudes using data from HIBISCUS campaign. Upper bound on the vertical diffusivity is found to be of the order of 0.5 m2 s-1 in the subtropical region, which is larger than the estimates at higher latitudes. The relation between diffusion and dispersion is studied by estimating Lyapunov exponents and studying their variation according to the presence of active dynamical structures.

  16. Natural convection between a vertical cylinder and a surrounding array

    SciTech Connect

    McEligot, D.M.; O'Brien, J.E.; Stoots, C.M.; Larson, T.K.; Christenson, W.A.; Mecham, D.C.; Lussie, W.G.

    1992-01-01

    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 cooling tube temperature, ranged from 2.9 x 10{sup 4} to 4.6 x 10{sup 5}. Results indicate that the convective heat transfer data could be approximated as Nu{sub D} (T{sub ts}/T{sub ct}){sup 0.14} = 0.156 Ra{sub D}{sup 1/3} in the apparent turbulent region for Ra{sub L} > 1.2 x 10{sup 11.}

  17. Natural convection between a vertical cylinder and a surrounding array

    SciTech Connect

    McEligot, D.M.; O`Brien, J.E.; Stoots, C.M.; Larson, T.K.; Christenson, W.A.; Mecham, D.C.; Lussie, W.G.

    1992-09-01

    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 cooling tube temperature, ranged from 2.9 x 10{sup 4} to 4.6 x 10{sup 5}. Results indicate that the convective heat transfer data could be approximated as Nu{sub D} (T{sub ts}/T{sub ct}){sup 0.14} = 0.156 Ra{sub D}{sup 1/3} in the apparent turbulent region for Ra{sub L} > 1.2 x 10{sup 11.}

  18. High-Ratio Gear Train

    NASA Technical Reports Server (NTRS)

    Lefever, A. E.

    1982-01-01

    Proposed arrangement of two connected planetary differentials results in gear ratio many times that obtainable in conventional series gear assembly of comparable size. Ratios of several thousand would present no special problems. Selection of many different ratios is available with substantially similar gear diameters. Very high gear ratios would be obtained from small mechanism.

  19. Classification of particle effective shape ratios in cirrus clouds based on the lidar depolarization ratio.

    PubMed

    Noel, Vincent; Chepfer, Helene; Ledanois, Guy; Delaval, Arnaud; Flamant, Pierre H

    2002-07-20

    A shape classification technique for cirrus clouds that could be applied to future spaceborne lidars is presented. A ray-tracing code has been developed to simulate backscattered and depolarized lidar signals from cirrus clouds made of hexagonal-based crystals with various compositions and optical depth, taking into account multiple scattering. This code was used first to study the sensitivity of the linear depolarization rate to cloud optical and microphysical properties, then to classify particle shapes in cirrus clouds based on depolarization ratio measurements. As an example this technique has been applied to lidar measurements from 15 mid-latitude cirrus cloud cases taken in Palaiseau, France. Results show a majority of near-unity shape ratios as well as a strong correlation between shape ratios and temperature: The lowest temperatures lead to high shape ratios. The application of this technique to space-borne measurements would allow a large-scale classification of shape ratios in cirrus clouds, leading to better knowledge of the vertical variability of shapes, their dependence on temperature, and the formation processes of clouds.

  20. Nutrient Provinces in the Sea: Concentration Ratios, Reaction Rate Ratios, and Ideal Covariation

    NASA Astrophysics Data System (ADS)

    Fanning, Kent A.

    1992-04-01

    Global distributions of the ratios of the concentrations of nitrate + nitrite (= [N]) and phosphate (= [P]) are evaluated from Geochemical Ocean Sections Study (GEOSECS) and Transient Tracers in the Ocean (TTO) data sets. If large oceanic regions (or provinces) can be identified on the basis of constant [N]: [P] ratios, then the distribution equation for a reactive variable shows that the ratio of the net reaction rates involving N and P in each one is equal to its concentration ratio. Organisms within the interiors of the provinces would then be in balance with the ratios in which the nutrients are present, producing a non-fractionated or "ideal" nutrient covariation. Such provinces can be observed throughout the ocean. Notable features are as follows: (1) Between the euphotic zone and 500 m in the west central North Atlantic is a large region in which N-P regeneration produces very high [N]:[P] ratios: ˜50 mol mol-1. Potential causes are 18° Water formation, coccolithophorid growth, nitrogen fixation, or atmospheric fixed-nitrogen deposition. (2) Most oligotrophic surface waters seem to have [N]:[P] between 0 and 3 mol mol-1, implying that the net removal ratio of N and P in those waters is 0-3 mol mol-1. (3) Below 600 m, the ocean contains large provinces with N-P regeneration ratios of 12-18 mol mol-1. The dominant ratio is slightly sub-Redfield at 14.5-15 mol mol-1, with the entire Indian Ocean below 3000 m being ideally covariant at 14.7 mol mol-1. The northeastern Pacific has provinces with very low regeneration ratios (<14 mol mol-1). Vertical boundaries between deep provinces in the western Pacific and eastern Atlantic suggest that particles from immediately above control regeneration ratios, whereas the more horizontal boundaries between western Atlantic provinces appear to reflect a greater importance of horizontally transported particles in water masses like Antarctic Intermediate Water. N-P reaction rate ratios along deep isopycnal surfaces are quite

  1. The Ames Vertical Gun Range

    NASA Technical Reports Server (NTRS)

    Karcz, J. S.; Bowling, D.; Cornelison, C.; Parrish, A.; Perez, A.; Raiche, G.; Wiens, J.-P.

    2016-01-01

    The Ames Vertical Gun Range (AVGR) is a national facility for conducting laboratory- scale investigations of high-speed impact processes. It provides a set of light-gas, powder, and compressed gas guns capable of accelerating projectiles to speeds up to 7 km s(exp -1). The AVGR has a unique capability to vary the angle between the projectile-launch and gravity vectors between 0 and 90 deg. The target resides in a large chamber (diameter approximately 2.5 m) that can be held at vacuum or filled with an experiment-specific atmosphere. The chamber provides a number of viewing ports and feed-throughs for data, power, and fluids. Impacts are observed via high-speed digital cameras along with investigation-specific instrumentation, such as spectrometers. Use of the range is available via grant proposals through any Planetary Science Research Program element of the NASA Research Opportunities in Space and Earth Sciences (ROSES) calls. Exploratory experiments (one to two days) are additionally possible in order to develop a new proposal.

  2. Stability of vertical magnetic chains

    PubMed Central

    2017-01-01

    A linear stability analysis is performed for a pair of coaxial vertical chains made from permanently magnetized balls under the influence of gravity. While one chain rises from the ground, the other hangs from above, with the remaining ends separated by a gap of prescribed length. Various boundary conditions are considered, as are situations in which the magnetic dipole moments in the two chains are parallel or antiparallel. The case of a single chain attached to the ground is also discussed. The stability of the system is examined with respect to three quantities: the number of balls in each chain, the length of the gap between the chains, and a single dimensionless parameter which embodies the competition between magnetic and gravitational forces. Asymptotic scaling laws involving these parameters are provided. The Hessian matrix is computed in exact form, allowing the critical parameter values at which the system loses stability and the respective eigenmodes to be determined up to machine precision. A comparison with simple experiments for a single chain attached to the ground shows good agreement. PMID:28293135

  3. HL-20 Vertical Human Factors

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The HL-20 space taxi, Langley's candidate personnel launch system, is one of several designs being considered by NASA as a complement to the Space Shuttle. Human factors studies, using Langley volunteers as subjects, have been ongoing since March 1991 to verify crew seating arrangements, habitability, ingress and egress, equipment layout and maintenance and handling operations, and to determine visibility requirements during docking and landing operations. Langley volunteers, wearing flight suits and helmets, were put through a series of tests with the craft placed both vertically and horizontally to simulate launch and landing attitudes, The HL-20 would be launched into a low orbit by an expendable rocket and then use its own propulsion system to boost itself to the space station. Following exchange of crews or delivery of small payload, the HL-20 would return to Earth like the space shuttle, making a runway landing near the launch site, The full-scale engineering research model of the HL-20 design was constructed by students and faculty at North Carolina State University and North Carolina A&T State University with the Mars Mission Research Center under a grant from NASA Langley.

  4. Vertical combustor for particulate refuse

    NASA Astrophysics Data System (ADS)

    Chung, P. M.; Carlson, L.

    1981-03-01

    A one-dimensional model is constructed of a vertical combustor for refuse particle combustion in order to analyze it for waste energy recovery. The three components of the model, fuel particles, inert solid particles and the gaseous mixture are described by momentum, energy, and mass conservation equations, resulting in three different flow velocities and temperatures for the medium. The gaseous component is further divided into six chemical species that evolve in combustion at temperatures below about 1367 K. A detailed description is given of the fuel particle combustion through heating, devolatilization, and combustion of the volatile gas in the boundary layer, return of the flame sheet to the fuel surface, and char combustion. The solutions show the combustor to be viable for U.S. refuse which consists of combustibles that can be volatilized up to 85 to 95% below 1366 K. Char combustion, however, is found to be too slow to be attempted in the combustor, where the fuel residence time is of the order of 2 s.

  5. Stability of vertical magnetic chains

    NASA Astrophysics Data System (ADS)

    Schönke, Johannes; Fried, Eliot

    2017-02-01

    A linear stability analysis is performed for a pair of coaxial vertical chains made from permanently magnetized balls under the influence of gravity. While one chain rises from the ground, the other hangs from above, with the remaining ends separated by a gap of prescribed length. Various boundary conditions are considered, as are situations in which the magnetic dipole moments in the two chains are parallel or antiparallel. The case of a single chain attached to the ground is also discussed. The stability of the system is examined with respect to three quantities: the number of balls in each chain, the length of the gap between the chains, and a single dimensionless parameter which embodies the competition between magnetic and gravitational forces. Asymptotic scaling laws involving these parameters are provided. The Hessian matrix is computed in exact form, allowing the critical parameter values at which the system loses stability and the respective eigenmodes to be determined up to machine precision. A comparison with simple experiments for a single chain attached to the ground shows good agreement.

  6. Vertical two chamber reaction furnace

    DOEpatents

    Blaugher, R.D.

    1999-03-16

    A vertical two chamber reaction furnace is disclosed. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700 and 800 C) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800 to 950 C to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product. 2 figs.

  7. Vertical two chamber reaction furnace

    DOEpatents

    Blaugher, Richard D.

    1999-03-16

    A vertical two chamber reaction furnace. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700.degree. and 800.degree. C.) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800.degree. to 950.degree. C. to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product.

  8. Rupture of vertical soap films

    NASA Astrophysics Data System (ADS)

    Rio, Emmanuelle

    2014-11-01

    Soap films are ephemeral and fragile objects. They tend to thin under gravity, which gives rise to the fascinating variations of colors at their interfaces but leads systematically to rupture. Even a child can create, manipulate and admire soap films and bubbles. Nevertheless, the reason why it suddenly bursts remains a mystery although the soap chosen to stabilize the film as well as the humidity of the air seem very important. One difficulty to study the rupture of vertical soap films is to control the initial solution. To avoid this problem we choose to study the rupture during the generation of the film at a controlled velocity. We have built an experiment, in which we measure the maximum length of the film together with its lifetime. The generation of the film is due to the presence of a gradient of surface concentration of surfactants at the liquid/air interface. This leads to a Marangoni force directed toward the top of the film. The film is expected to burst only when its weight is not balanced anymore by this force. We will show that this leads to the surprising result that the thicker films have shorter lifetimes than the thinner ones. It is thus the ability of the interface to sustain a surface concentration gradient of surfactants which controls its stability.

  9. 33 CFR 84.19 - Vertical sectors.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... required intensity of electric lights as fitted shall be maintained on the horizontal. (d) In the case of... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.19 Vertical sectors. (a) The vertical sectors of electric lights as fitted, with the exception of lights on sailing vessels underway...

  10. 33 CFR 84.19 - Vertical sectors.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... required intensity of electric lights as fitted shall be maintained on the horizontal. (d) In the case of... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.19 Vertical sectors. (a) The vertical sectors of electric lights as fitted, with the exception of lights on sailing vessels underway...

  11. 33 CFR 84.19 - Vertical sectors.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... required intensity of electric lights as fitted shall be maintained on the horizontal. (d) In the case of... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.19 Vertical sectors. (a) The vertical sectors of electric lights as fitted, with the exception of lights on sailing vessels underway...

  12. 33 CFR 84.19 - Vertical sectors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... required intensity of electric lights as fitted shall be maintained on the horizontal. (d) In the case of... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.19 Vertical sectors. (a) The vertical sectors of electric lights as fitted, with the exception of lights on sailing vessels underway...

  13. 33 CFR 84.19 - Vertical sectors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... required intensity of electric lights as fitted shall be maintained on the horizontal. (d) In the case of... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.19 Vertical sectors. (a) The vertical sectors of electric lights as fitted, with the exception of lights on sailing vessels underway...

  14. Teaching Students the Verticality of Technical Documentation.

    ERIC Educational Resources Information Center

    Hager, Peter J.

    1992-01-01

    Advocates making technical writing courses more vertical in structure by including an extensive study of at least one specific form of technical documentation. Examines how students can gain experience in the vertical process by designing, writing, testing, and producing user manuals for on-campus cooperative education clients. Lists the benefits…

  15. Vertical Files in Midlands Academic Libraries.

    ERIC Educational Resources Information Center

    Lillis, John G.

    1991-01-01

    Reviews survey responses from 127 nonmedical academic libraries in Nebraska, Iowa, and Kansas regarding their vertical files (e.g., acquisitions, weeding, size, nature, collection management, frequency of use, maintenance of statistics, types of users, circulation, and security), reporting that 109 had vertical files, with most emphasizing topics…

  16. Vertical Hegelianism and Beyond: Digital Cinema Editing.

    ERIC Educational Resources Information Center

    Wyatt, Roger B.

    Cinema as an art and communication form is entering its second century of development. Sergei Eisenstein conceived of editing in horizontal and vertical terms. He saw vertical editing patterns primarily as the synchronization of simultaneous image and sound elements, particularly music, no create cinematic meaning by means of the relationship…

  17. Vertical-Cavity Surface-Emitting Lasers

    NASA Astrophysics Data System (ADS)

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

    2002-01-01

    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.

  18. [Vertical zonation of mountain landscape: a review].

    PubMed

    Sun, Ran-Hao; Chen, Li-Ding; Zhang, Bai-Ping; Fu, Bo-Jie

    2009-07-01

    Vertical gradient of mountain landscape is about 1000 times of its horizontal gradient, and hence, only using landscape pattern index is quite difficult to reflect the landscape regularity along vertical gradient. Mountain altitudinal belt is a kind of classic geographic models representing the vertical differentiation of landscape, being of significance in geographic and ecological researches. However, the discrete expression pattern and the inaccuracy of the borderlines of mountain vertical belts limit the roles of mountain vertical belt in accurately describing landscape pattern in regional scale and in explaining ecological processes. This paper reviewed the research progress and existing problems on mountain altitudinal belt, put forward a suggestion of using modern information technology to establish a comprehensive and continuous mountain landscape information chart, and discussed the framework and prospect of the establishment of the chart, which would have reference value for accurately describing mountain landscape pattern and explaining specific ecological processes, and promote the further improvement of the methodology for mountain ecological research.

  19. Buoyant miscible displacement flows in vertical pipe

    NASA Astrophysics Data System (ADS)

    Amiri, A.; Larachi, F.; Taghavi, S. M.

    2016-10-01

    The displacement flow of two miscible Newtonian fluids is investigated experimentally in a vertical pipe of long aspect ratio (δ-1 ≈ 210). The fluids have a small density difference and they have the same viscosity. The heavy displacing fluid is initially placed above the light displaced fluid. The displacement flow is downwards. The experiments cover a wide range of the two dimensionless parameters that largely describe the flow: the modified Reynolds number (0 ≤ Ret⪅800) and the densimetric Froude number (0 ≤ Fr ≤ 24). We report on the stabilizing effect of the imposed flow and uncover the existence of two main flow regimes at long times: a stable displacement flow and an unstable displacement flow. The transition between the two regimes occurs at a critical modified Reynolds number " separators=" R et | Critical , as a function of Fr. We study in depth the stable flow regime: First, a lubrication model combined with a simple initial acceleration formulation delivers a reasonable prediction to the time-dependent penetrating displacing front velocity. Second, we find two sub-regimes for stable displacements, namely, sustained-back-flows and no-sustained-back-flows. The transition between the two sub-regimes is a marginal stationary interface flow state, which is also well predicted by the lubrication model. The unstable regime is associated to instabilities and diffusive features of the flow. In addition, particular patterns such as front detachment phenomenon appear in the unstable flow regime, for which we quantify the regions of existence versus the dimensionless groups.

  20. The human heart: application of the golden ratio and angle.

    PubMed

    Henein, Michael Y; Zhao, Ying; Nicoll, Rachel; Sun, Lin; Khir, Ashraf W; Franklin, Karl; Lindqvist, Per

    2011-08-04

    The golden ratio, or golden mean, of 1.618 is a proportion known since antiquity to be the most aesthetically pleasing and has been used repeatedly in art and architecture. Both the golden ratio and the allied golden angle of 137.5° have been found within the proportions and angles of the human body and plants. In the human heart we found many applications of the golden ratio and angle, in addition to those previously described. In healthy hearts, vertical and transverse dimensions accord with the golden ratio, irrespective of different absolute dimensions due to ethnicity. In mild heart failure, the ratio of 1.618 was maintained but in end-stage heart failure the ratio significantly reduced. Similarly, in healthy ventricles mitral annulus dimensions accorded with the golden ratio, while in dilated cardiomyopathy and mitral regurgitation patients the ratio had significantly reduced. In healthy patients, both the angles between the mid-luminal axes of the pulmonary trunk and the ascending aorta continuation and between the outflow tract axis and continuation of the inflow tract axis of the right ventricle approximate to the golden angle, although in severe pulmonary hypertension, the angle is significantly increased. Hence the overall cardiac and ventricular dimensions in a normal heart are consistent with the golden ratio and angle, representing optimum pump structure and function efficiency, whereas there is significant deviation in the disease state. These findings could have anatomical, functional and prognostic value as markers of early deviation from normality.

  1. Ratio estimation in SIMS analysis

    NASA Astrophysics Data System (ADS)

    Ogliore, R. C.; Huss, G. R.; Nagashima, K.

    2011-09-01

    The determination of an isotope ratio by secondary ion mass spectrometry (SIMS) traditionally involves averaging a number of ratios collected over the course of a measurement. We show that this method leads to an additive positive bias in the expectation value of the estimated ratio that is approximately equal to the true ratio divided by the counts of the denominator isotope of an individual ratio. This bias does not decrease as the number of ratios used in the average increases. By summing all counts in the numerator isotope, then dividing by the sum of counts in the denominator isotope, the estimated ratio is less biased: the bias is approximately equal to the ratio divided by the summed counts of the denominator isotope over the entire measurement. We propose a third ratio estimator (Beale's estimator) that can be used when the bias from the summed counts is unacceptably large for the hypothesis being tested. We derive expressions for the variance of these ratio estimators as well as the conditions under which they are normally distributed. Finally, we investigate a SIMS dataset showing the effects of ratio bias, and discuss proper ratio estimation for SIMS analysis.

  2. Natural convection heat transfer along vertical rectangular ducts

    NASA Astrophysics Data System (ADS)

    Ali, M.

    2009-12-01

    Experimental investigations have been reported on steady state natural convection from the outer surface of vertical rectangular and square ducts in air. Seven ducts have been used; three of them have a rectangular cross section and the rest have square cross section. The ducts are heated using internal constant heat flux heating elements. The temperatures along the vertical surface and the peripheral directions of the duct wall are measured. Axial (perimeter averaged) heat transfer coefficients along the side of each duct are obtained for laminar and transition to turbulent regimes of natural convection heat transfer. Axial (perimeter averaged) Nusselt numbers are evaluated and correlated using the modified Rayleigh numbers for laminar and transition regime using the vertical axial distance as a characteristic length. Critical values of the modified Rayleigh numbers are obtained for transition to turbulent. Furthermore, total overall averaged Nusselt numbers are correlated with the modified Rayleigh numbers and the area ratio for the laminar regimes. The local axial (perimeter averaged) heat transfer coefficients are observed to decrease in the laminar region and increase in the transition region. Laminar regimes are obtained at the lower half of the ducts and its chance to appear decreases as the heat flux increases.

  3. Inequalities and Monotonicity of the Ratio of the Geometric Means of a Positive Arithmetic Sequence with Unit Difference

    ERIC Educational Resources Information Center

    Qi, Feng

    2003-01-01

    For any nonnegative integer "k" and natural numbers "n" and "m," the equations presented in this paper demonstrate the inequalities obtained on the ratio for the geometric means of a positive arithmetic sequence with unit difference, where alpha epsilon [vertical bar]0,1[vertical bar] is a constant. Using the ideas and methods of Chen (2002),…

  4. Cooling Requirements for the Vertical Shear Instability in Protoplanetary Disks

    NASA Astrophysics Data System (ADS)

    Lin, Min-Kai; Youdin, Andrew N.

    2015-09-01

    The vertical shear instability (VSI) offers a potential hydrodynamic mechanism for angular momentum transport in protoplanetary disks (PPDs). The VSI is driven by a weak vertical gradient in the disk’s orbital motion, but must overcome vertical buoyancy, a strongly stabilizing influence in cold disks, where heating is dominated by external irradiation. Rapid radiative cooling reduces the effective buoyancy and allows the VSI to operate. We quantify the cooling timescale tc needed for efficient VSI growth, through a linear analysis of the VSI with cooling in vertically global, radially local disk models. We find the VSI is most vigorous for rapid cooling with {t}{{c}}\\lt {{{Ω }}}{{K}}-1h| q| /(γ -1) in terms of the Keplerian orbital frequency, {{{Ω }}}{{K}}, the disk’s aspect-ratio, h\\ll 1, the radial power-law temperature gradient, q, and the adiabatic index, γ. For longer tc, the VSI is much less effective because growth slows and shifts to smaller length scales, which are more prone to viscous or turbulent decay. We apply our results to PPD models where tc is determined by the opacity of dust grains. We find that the VSI is most effective at intermediate radii, from ∼5 to ∼50 AU with a characteristic growth time of ∼30 local orbital periods. Growth is suppressed by long cooling times both in the opaque inner disk and the optically thin outer disk. Reducing the dust opacity by a factor of 10 increases cooling times enough to quench the VSI at all disk radii. Thus the formation of solid protoplanets, a sink for dust grains, can impede the VSI.

  5. Composite resonator vertical cavity laser diode

    SciTech Connect

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

    1998-05-01

    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.

  6. Effects of vertical rotation on Arabidopsis development

    NASA Technical Reports Server (NTRS)

    Brown, A. H.; Chapman, D. K.; Dahl, A. O.

    1975-01-01

    Various gross morphological end points of Arabidopsis development are examined in an attempt to separate the effects of growth on the horizontal clinostat into a component caused by rotation alone and another component caused by the altered position with respect to the direction of the g-vector. In a series of tests which involved comparisons between vertical stationary plants, vertical rotated plants, and plants rotated on clinostats, certain characters were consistently influenced by vertical rotation alone. The characters for which this effect was statistically significant were petiole length and leaf blade width.

  7. Magnetohydrodynamic stability of natural convection in a vertical porous slab

    NASA Astrophysics Data System (ADS)

    Shankar, B. M.; Kumar, Jai; Shivakumara, I. S.

    2017-01-01

    The stability of the conduction regime of natural convection in an electrically conducting fluid saturated porous vertical slab is investigated in the presence of a uniform external transverse magnetic field. The flow in the porous medium is described by modified Brinkman-extended Darcy equation with fluid viscosity different from effective viscosity. The boundaries of the vertical porous slab are assumed to be rigid-isothermal and electrically non-conducting. The resulting stability equations are solved numerically using Galerkin method. The critical Grashof number Gc, the critical wave number αc and the critical wave speed cc are computed for a wide range of porous parameter σp, the ratio of effective viscosity to the fluid viscosity Λ, the Prandtl number Pr and the Hartmann number M. Based on these parameters, the stability characteristics of the system are discussed in detail. The presence of advective inertia is to instill instability on the flow in a porous medium and found that the magnetic field, porous parameter and ratio of viscosities have a stabilizing effect on both stationary and oscillatory wave instabilities. Besides, the value of Pr at which transition occurs from stationary to oscillatory mode of instability decreases with increasing M ,σp and Λ .

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

    PubMed

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

    1999-03-01

    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.

  9. Modeling of leachate recirculation using vertical wells in bioreactor landfills.

    PubMed

    Feng, Shi-Jin; Cao, Ben-Yi; Zhang, Xu; Xie, Hai-Jian

    2015-06-01

    Leachate recirculation (LR) in municipal solid waste (MSW) landfills operated as bioreactors offers significant economic and environmental benefits. The subsurface application method of vertical wells is one of the most common LR techniques. The objective of this study was to develop a novel two-dimensional model of leachate recirculation using vertical wells. This novel method can describe leachate flow considering the effects of MSW settlement while also accounting separately for leachate flow in saturated and unsaturated zones. In this paper, a settlement model for MSW when considering the effects of compression and biodegradation on the MSW porosity was adopted. A numerical model was proposed using new governing equations for the saturated and unsaturated zones of a landfill. The following design parameters were evaluated by simulating the recirculated leachate volume and the influence zones of waste under steady-state flow conditions: (1) the effect of MSW settlement, (2) the effect of the initial void ratio, (3) the effect of the injected head, (4) the effect of the unit weight, (5) the effect of the biodegradation rate, and (6) the effect of the compression coefficient. The influence zones of LR when considering the effect of MSW settlement are smaller than those when neglecting the effect. The influence zones and LR volume increased with an increase in the injection pressure head and initial void ratio of MSW. The proposed method and the calculation results can provide important insight into the hydrological behavior of bioreactor landfills.

  10. Vertical and horizontal proportions of the face and their correlation to phi among Indians in Moradabad population: A survey

    PubMed Central

    Anand, Shruti; Tripathi, Siddhi; Chopra, Anubhav; Khaneja, Karan; Agarwal, Swatantra

    2015-01-01

    Purpose: The purpose was to examine the existence of divine proportions among the Indian faces in Moradabad population. Materials and Methods: Totally, 100 patients (50 males; 50 females) aged 25-45 years were selected for the study. All facial photographs were analyzed based on the method of Ricketts assessing the divine proportions in vertical and transverse facial planes. Six horizontal and seven vertical ratios were determined, which were then compared with the phi ratio. Results: The horizontal ratio results showed that three male and female ratios were not significantly different from each other (P > 0.05), and interchilion/nose width ratio was highly significant (P < 0.001). The horizontal mean ratios for females as well as males were highly significant from the phi ratio (P < 0.001) except for interchilion/interdacryon ratio, which was significant (P < 0.05) for females and not significant (P > 0.05) for males. The vertical ratio results showed that there was a highly significant difference (P < 0.001) for forehead height/stomion-soft menton ratio and no significant difference for two ratios between the mean ratios of males and females. All the vertical mean ratios for both the groups were highly significant (P < 0.001), except for the intereye-soft menton/intereye-stomion ratio, which was significant (P < 0.05) for female group and not significant (P > 0.05) for the male group. Conclusion: Although, the golden proportion is a prominent and recurring theme in esthetics, it should not be embraced as the only method by which human beauty is measured to the exclusion of others factors. PMID:26929498

  11. Prediction of Vertical Jump Height from Anthropometric Factors in Male and Female Martial Arts Athletes

    PubMed Central

    Abidin, Nahdiya Zainal; Adam, Mohd Bakri

    2013-01-01

    Background: Vertical jump is an index representing leg/kick power. The explosive movement of the kick is the key to scoring in martial arts competitions. It is important to determine factors that influence the vertical jump to help athletes improve their leg power. The objective of the present study is to identify anthropometric factors that influence vertical jump height for male and female martial arts athletes. Methods: Twenty-nine male and 25 female athletes participated in this study. Participants were Malaysian undergraduate students whose ages ranged from 18 to 24 years old. Their heights were measured using a stadiometer. The subjects were weighted using digital scale. Body mass index was calculated by kg/m2. Waist–hip ratio was measured from the ratio of waist to hip circumferences. Body fat % was obtained from the sum of four skinfold thickness using Harpenden callipers. The highest vertical jump from a stationary standing position was recorded. The maximum grip was recorded using a dynamometer. For standing back strength, the maximum pull upwards using a handle bar was recorded. Multiple linear regression was used to obtain the relationship between vertical jump height and explanatory variables with gender effect. Results: Body fat % has a significant negative relationship with vertical jump height (P < 0.001). The effect of gender is significant (P < 0.001): on average, males jumped 26% higher than females did. Conclusion: Vertical jump height of martial arts athletes can be predicted by body fat %. The vertical jump for male is higher than for their female counterparts. Reducing body fat by proper dietary planning will help to improve leg power. PMID:23785254

  12. Vertical Motions of Oceanic Volcanoes

    NASA Astrophysics Data System (ADS)

    Clague, D. A.; Moore, J. G.

    2006-12-01

    lasting a few hundred thousand years as the island migrates over a broad flexural arch related to isostatic compensation of a nearby active volcano. The arch is located about 190±30 km away from the center of volcanic activity and is also related to the rejuvenated volcanic stage on the islands. Reefs on Oahu that are uplifted several tens of m above sea level are the primary evidence for uplift as the islands over-ride the flexural arch. At the other end of the movement spectrum, both in terms of magnitude and length of response, are the rapid uplift and subsidence that occurs as magma is accumulated within or erupted from active submarine volcanoes. These changes are measured in days to years and are of cm to m variation; they are measured using leveling surveys, tiltmeters, EDM and GPS above sea level and pressure gauges and tiltmeters below sea level. Other acoustic techniques to measure such vertical movement are under development. Elsewhere, evidence for subsidence of volcanoes is also widespread, ranging from shallow water carbonates on drowned Cretaceous guyots, to mapped shoreline features, to the presence of subaerially-erupted (degassed) lavas on now submerged volcanoes. Evidence for uplift is more limited, but includes makatea islands with uplifted coral reefs surrounding low volcanic islands. These are formed due to flexural uplift associated with isostatic loading of nearby islands or seamounts. In sum, oceanic volcanoes display a long history of subsidence, rapid at first and then slow, sometimes punctuated by brief periods of uplift due to lithospheric loading by subsequently formed nearby volcanoes.

  13. Lidar ratio and depolarization ratio for cirrus clouds.

    PubMed

    Chen, Wei-Nai; Chiang, Chih-Wei; Nee, Jan-Bai

    2002-10-20

    We report on studies of the lidar and the depolarization ratios for cirrus clouds. The optical depth and effective lidar ratio are derived from the transmission of clouds, which is determined by comparing the backscattering signals at the cloud base and cloud top. The lidar signals were fitted to a background atmospheric density profile outside the cloud region to warrant the linear response of the return signals with the scattering media. An average lidar ratio, 29 +/- 12 sr, has been found for all clouds measured in 1999 and 2000. The height and temperature dependences ofthe lidar ratio, the optical depth, and the depolarization ratio were investigated and compared with results of LITE and PROBE. Cirrus clouds detected near the tropopause are usually optically thin and mostly subvisual. Clouds with the largest optical depths were found near 12 km with a temperature of approximately -55 degrees C. The multiple-scattering effect is considered for clouds with high optical depths, and this effect lowers the lidar ratios compared with a single-scattering condition. Lidar ratios are in the 20-40 range for clouds at heights of 12.5-15 km and are smaller than approximately 30 in height above 15 km. Clouds are usually optically thin for temperatures below approximately -65 degrees C, and in this region the optical depth tends to decrease with height. The depolarization ratio is found to increase with a height at 11-15 km and smaller than 0.3 above 16 km. The variation in the depolarization ratio with the lidar ratio was also reported. The lidar and depolarization ratios were discussed in terms of the types of hexagonal ice crystals.

  14. Differentiating Leber Hereditary Optic Neuropathy from Normal-Tension Glaucoma.

    PubMed

    Souto, Fernanda Maria Silveira; de Vasconcellos, José Paulo Cabral; de Melo, Mônica Barbosa; Sartorato, Edi Lúcia; Moura, Frederico Castelo

    2017-04-01

    Glaucoma is a neurodegenerative disorder characterized by thinning of neuroretinal rim, enlarged cup-to-disc ratio (CDR) and visual field damage. Although raised intraocular pressure is main risk factor for development of glaucoma, it can occur with consistently normal measurements in the intraocular pressure as normal tension glaucoma (NTG). Enlargement of CDR is a classical sign of glaucoma, but it can also result from non-glaucomatous optic neuropathies such as Leber hereditary optic neuropathy (LHON). We describe a case of LHON with increased CDR, discuss its differential diagnosis with NTG and highlight the reasons for misdiagnoses between these two entities.

  15. Vertical axis wind turbine. Final report

    SciTech Connect

    Hollrock, R.H.

    1983-06-01

    The work reported consisted of the fabrication and whirl testing of a vertical axis wind turbine. Problems are reported in blade fabrication and balancing. It is planned to provide speed control with a water agitator. (LEW)

  16. Vertical stratification in arthropod spatial distribution research.

    PubMed

    Marler, Thomas E

    2013-11-01

    Spatial heterogeneity within individual host trees is often overlooked in surveys of phytophagous arthropod abundance and distribution. The armored scale Aulacaspis yasumatsui is controlled by the predator Rhyzobius lophanthae to a greater degree on leaves at 75-cm height than on leaves at ground level within its host tree Cycas micronesica. The direct influence of elevation on the predator indirectly generates vertical heterogeneity of the scale insect. Arthropod sampling schemes that fail to include all strata within the vertical profile of the host tree species may generate misleading outcomes. Results indicate that sub-meter increments can reveal significant differences in vertical distribution of phytophagous insects, and that inclusion of observations on other organisms that interact with the target arthropod may illuminate determinants of vertical heterogeneity.

  17. Vertical Water Vapor Distribution at Phoenix

    NASA Astrophysics Data System (ADS)

    Tamppari, L. K.; Lemmon, M. T.

    2016-09-01

    The Phoenix SSI camera data along with radiative transfer modeling are used to retrieve the vertical water vapor profile. Preliminary results indicate that water vapor is often confined near the surface.

  18. Geometry independence of three-string vertices

    NASA Astrophysics Data System (ADS)

    Maeno, Masahiro

    1989-01-01

    The geometry independence of three-string vertices in both HIKKO's and Witten's string field theories is examined. A careful regularization shows that the anomaly which has been reported by Morris and Mañes vanishes.

  19. Vertical Axis Wind Turbine Foundation parameter study

    SciTech Connect

    Lodde, P.F.

    1980-07-01

    The dynamic failure criterion governing the dimensions of prototype Vertical Axis Wind Turbine Foundations is treated as a variable parameter. The resulting change in foundation dimensions and costs is examined.

  20. Vertically stabilized elongated cross-section tokamak

    DOEpatents

    Sheffield, George V.

    1977-01-01

    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.

  1. Sex Ratio Elasticity Influences the Selection of Sex Ratio Strategy.

    PubMed

    Wang, Yaqiang; Wang, Ruiwu; Li, Yaotang; Sam Ma, Zhanshan

    2016-12-23

    There are three sex ratio strategies (SRS) in nature-male-biased sex ratio, female-biased sex ratio and, equal sex ratio. It was R. A. Fisher who first explained why most species in nature display a sex ratio of ½. Consequent SRS theories such as Hamilton's local mate competition (LMC) and Clark's local resource competition (LRC) separately explained the observed deviations from the seemingly universal 1:1 ratio. However, to the best of our knowledge, there is not yet a unified theory that accounts for the mechanisms of the three SRS. Here, we introduce the price elasticity theory in economics to define sex ratio elasticity (SRE), and present an analytical model that derives three SRSs based on the following assumption: simultaneously existing competitions for both resources A and resources B influence the level of SRE in both sexes differently. Consequently, it is the difference (between two sexes) in the level of their sex ratio elasticity that leads to three different SRS. Our analytical results demonstrate that the elasticity-based model not only reveals a highly plausible mechanism that explains the evolution of SRS in nature, but also offers a novel framework for unifying two major classical theories (i.e., LMC &LRC) in the field of SRS research.

  2. Sex Ratio Elasticity Influences the Selection of Sex Ratio Strategy

    PubMed Central

    Wang, Yaqiang; Wang, Ruiwu; Li, Yaotang; (Sam) Ma, Zhanshan

    2016-01-01

    There are three sex ratio strategies (SRS) in nature—male-biased sex ratio, female-biased sex ratio and, equal sex ratio. It was R. A. Fisher who first explained why most species in nature display a sex ratio of ½. Consequent SRS theories such as Hamilton’s local mate competition (LMC) and Clark’s local resource competition (LRC) separately explained the observed deviations from the seemingly universal 1:1 ratio. However, to the best of our knowledge, there is not yet a unified theory that accounts for the mechanisms of the three SRS. Here, we introduce the price elasticity theory in economics to define sex ratio elasticity (SRE), and present an analytical model that derives three SRSs based on the following assumption: simultaneously existing competitions for both resources A and resources B influence the level of SRE in both sexes differently. Consequently, it is the difference (between two sexes) in the level of their sex ratio elasticity that leads to three different SRS. Our analytical results demonstrate that the elasticity-based model not only reveals a highly plausible mechanism that explains the evolution of SRS in nature, but also offers a novel framework for unifying two major classical theories (i.e., LMC & LRC) in the field of SRS research. PMID:28009000

  3. Sex Ratio Elasticity Influences the Selection of Sex Ratio Strategy

    NASA Astrophysics Data System (ADS)

    Wang, Yaqiang; Wang, Ruiwu; Li, Yaotang; (Sam) Ma, Zhanshan

    2016-12-01

    There are three sex ratio strategies (SRS) in nature—male-biased sex ratio, female-biased sex ratio and, equal sex ratio. It was R. A. Fisher who first explained why most species in nature display a sex ratio of ½. Consequent SRS theories such as Hamilton’s local mate competition (LMC) and Clark’s local resource competition (LRC) separately explained the observed deviations from the seemingly universal 1:1 ratio. However, to the best of our knowledge, there is not yet a unified theory that accounts for the mechanisms of the three SRS. Here, we introduce the price elasticity theory in economics to define sex ratio elasticity (SRE), and present an analytical model that derives three SRSs based on the following assumption: simultaneously existing competitions for both resources A and resources B influence the level of SRE in both sexes differently. Consequently, it is the difference (between two sexes) in the level of their sex ratio elasticity that leads to three different SRS. Our analytical results demonstrate that the elasticity-based model not only reveals a highly plausible mechanism that explains the evolution of SRS in nature, but also offers a novel framework for unifying two major classical theories (i.e., LMC & LRC) in the field of SRS research.

  4. Software For Computing Image Ratios

    NASA Technical Reports Server (NTRS)

    Yates, Gigi L.

    1993-01-01

    RATIO_TOOL is interactive computer program for viewing and analyzing large sets of multispectral image data created by imaging spectrometer. Uses ratios between intensities in different spectral bands in order to spot significant areas of interest within multispectral image. Each image band viewed iteratively, or selected image band of set of data requested and displayed. When image ratios computed, result displayed as grayscale image. Written in C Language.

  5. Vertical Vergence Calibration for Augmented Reality Displays

    DTIC Science & Technology

    2006-03-01

    2006 2. REPORT TYPE 3. DATES COVERED 00-00-2006 to 00-00-2006 4. TITLE AND SUBTITLE Vertical Vergence Calibration for Augmented Reality Displays...8-98) Prescribed by ANSI Std Z39-18 Vertical Vergence Calibration for Augmented Reality Displays Mark A. Livingston∗ Adam Lederer Virtual Reality...dimensional Graphics and Realism—Virtual Reality Keywords: augmented reality , head-mounted display, vergence 1 INTRODUCTION Many augmented reality (AR

  6. Prevalence odds ratio versus prevalence ratio: choice comes with consequences.

    PubMed

    Tamhane, Ashutosh R; Westfall, Andrew O; Burkholder, Greer A; Cutter, Gary R

    2016-12-30

    Odds ratio, risk ratio, and prevalence ratio are some of the measures of association which are often reported in research studies quantifying the relationship between an independent variable and the outcome of interest. There has been much debate on the issue of which measure is appropriate to report depending on the study design. However, the literature on selecting a particular category of the outcome to be modeled and/or change in reference group for categorical independent variables and the effect on statistical significance, although known, is scantly discussed nor published with examples. In this article, we provide an example of a cross-sectional study wherein prevalence ratio was chosen over (Prevalence) odds ratio and demonstrate the analytic implications of the choice of category to be modeled and choice of reference level for independent variables. Copyright © 2016 John Wiley & Sons, Ltd.

  7. Air/fuel ratio controller

    SciTech Connect

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

    1980-12-23

    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.

  8. Effect of vertical motion on current meters

    USGS Publications Warehouse

    Kallio, Nicholas A.

    1966-01-01

    The effect of vertical motion on the performance of current meters at various stream velocities was evaluated to determine whether accurate discharge measurements can be made from a bobbing boat. Three types of current meters--Ott, Price, and vane types--were tested under conditions simulating a bobbing boat. A known frequency and amplitude of vertical motion were imparted to the current meter, and the related effect on the measured stream velocity was determined. One test of the Price meter was made under actual conditions, using a boat and standard measuring gear. The results of the test under actual conditions verified those obtained by simulating the vertical movements of a boat. The tests show that for stream velocities below 2.5 feet per second the accuracy of all three meters is significantly affected when the meters are subjected to certain conditions of vertical motion that can occur during actual field operations. Both the rate of vertical motion and the frequency of vertical oscillation affect the registration of the meter. The results of these tests, presented in the form of graphs and tables, can be used as a guide to determine whether wind and stream flow are within an acceptable range for a reliable discharge measurement from a boat.

  9. Optic nerve head parameters of high-definition optical coherence tomography and Heidelberg retina tomogram in perimetric and preperimetric glaucoma

    PubMed Central

    Begum, Viquar Unnisa; Addepalli, Uday Kumar; Senthil, Sirisha; Garudadri, Chandra Sekhar; Rao, Harsha Laxmana

    2016-01-01

    Background: Heidelberg retina tomogram (HRT) and optical coherence tomography (OCT) are two widely used imaging modalities to evaluate the optic nerve head (ONH) in glaucoma. Purpose: To compare the ONH parameters of HRT3 and high-definition OCT (HD-OCT) and evaluate their diagnostic abilities in perimetric and preperimetric glaucoma. Design: Cross-sectional analysis. Methods: 35 control eyes (24 subjects), 21 preperimetric glaucoma eyes (15 patients), and 64 perimetric glaucoma eyes (44 patients) from the Longitudinal Glaucoma Evaluation Study underwent HRT3 and HD-OCT examinations. Statistical Analysis: Agreement between the ONH parameters of HRT and HD-OCT were assessed using Bland-Altman plots. Diagnostic abilities of ONH parameters were evaluated using area under the receiver operating characteristic curves (AUCs), sensitivity at fixed specificity, and likelihood ratios (LR). Results: Optic disc area, vertical cup to disc ratio, and cup volume with HD-OCT were larger than with HRT, while the rim area was smaller with HD-OCT (P < 0.001 for all comparisons). AUCs of all HD-OCT ONH parameters (0.90-0.97 in perimetric and 0.62-0.71 in preperimetric glaucoma) were comparable (P > 0.10) to the corresponding HRT ONH parameters (0.81-0.95 in perimetric and 0.55-0.72 in preperimetric glaucoma). LRs associated with diagnostic categorization of ONH parameters of both HD-OCT and HRT were associated with larger effects on posttest probability of perimetric compared to preperimetric glaucoma. Conclusions: ONH measurements of HD-OCT and HRT3 cannot be used interchangeably. Though the diagnostic abilities of ONH parameters of HD-OCT and HRT in glaucoma were comparable, the same were significantly lower in preperimetric compared to perimetric glaucoma. PMID:27221679

  10. 49 CFR 179.14 - Coupler vertical restraint system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... coupler (or simulated coupler) having only frictional vertical force resistance at the mating interface... section; (2) The testing apparatus shall simulate the vertical coupler performance at the mating...

  11. 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

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

    PubMed Central

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

    2014-01-01

    The layered materials such as graphene have attracted considerable interest for future electronics. Here we report the vertical integration of multi-heterostructures of layered materials to enable high current density vertical field-effect transistors (VFETs). An n-channel VFET is created by sandwiching few-layer molybdenum disulfide (MoS2) as the semiconducting channel between a monolayer graphene and a metal thin film. The VFETs exhibit a room temperature on-off ratio >103, while at same time deliver a high current density up to 5,000 A/cm2, sufficient for high performance logic applications. This study offers a general strategy for the vertical integration of various layered materials to obtain both p- and n-channel transistors for complementary logic functions. A complementary inverter with larger than unit voltage gain is demonstrated by vertically stacking the layered materials of graphene, Bi2Sr2Co2O8 (p-channel), graphene, MoS2 (n-channel), and metal thin film in sequence. The ability to simultaneously achieve high on-off ratio, high current density, and logic integration in the vertically stacked multi-heterostructures can open up a new dimension for future electronics to enable three-dimensional integration. PMID:23241535

  13. Effects of volume averaging on the line spectra of vertical velocity from multiple-Doppler radar observations

    NASA Technical Reports Server (NTRS)

    Gal-Chen, T.; Wyngaard, J. C.

    1982-01-01

    Calculations of the ratio of the true one-dimensional spectrum of vertical velocity and that measured with multiple-Doppler radar beams are presented. It was assumed that the effects of pulse volume averaging and objective analysis routines is replacement of a point measurement with a volume integral. A u and v estimate was assumed to be feasible when orthogonal radars are not available. Also, the target fluid was configured as having an infinite vertical dimension, zero vertical velocity at the top and bottom, and having homogeneous and isotropic turbulence with a Kolmogorov energy spectrum. The ratio obtained indicated that equal resolutions among radars yields a monotonically decreasing, wavenumber-dependent response function. A gain of 0.95 was demonstrated in an experimental situation with 40 levels. Possible errors introduced when using unequal resolution radars were discussed. Finally, it was found that, for some flows, the extent of attenuation depends on the number of vertical levels resolvable by the radars.

  14. Vertical transport of ozone and CO during super cyclones in the Bay of Bengal as detected by Tropospheric Emission Spectrometer.

    PubMed

    Fadnavis, S; Beig, G; Buchunde, P; Ghude, Sachin D; Krishnamurti, T N

    2011-02-01

    Vertical profiles of carbon monoxide (CO) and ozone retrieved from Tropospheric Emission Spectrometer have been analyzed during two super cyclone systems Mala and Sidr. Super cyclones Mala and Sidr traversed the Bay of Bengal (BOB) region on April 24-29, 2006 and November 12-16, 2007 respectively. The CO and ozone plume is observed as a strong enhancement of these pollutants in the upper troposphere over the BOB, indicating deep convective transport. Longitude-height cross-section of these pollutants shows vertical transport to the upper troposphere. CO mixing ratio ~90 ppb is observed near the 146-mb level during the cyclone Mala and near 316 mb during the cyclone Sidr. Ozone mixing ratio ~60-100 ppb is observed near the 316-mb level during both the cyclones. Analysis of National Centers for Environmental Prediction (NCEP) reanalysis vertical winds (omega) confirms vertical transport in the BOB.

  15. An adaptive, Courant-number-dependent implicit scheme for vertical advection in oceanic modeling

    NASA Astrophysics Data System (ADS)

    Shchepetkin, Alexander F.

    2015-07-01

    An oceanic model with an Eulerian vertical coordinate and an explicit vertical advection scheme is subject to the Courant-Friedrichs-Lewy (CFL) limitation. Depending on the horizontal grid spacing, the horizontal-to-vertical grid resolution ratio and the flow pattern this limitation may easily become the most restrictive factor in choosing model time step, with the general tendency to become more severe as horizontal resolution becomes finer. Using terrain-following coordinate makes local vertical grid spacing depend on topography, ultimately resulting in very fine resolution in shallow areas in comparison with other models, z-coordinate, and isopycnic, which adds another factor in restricting time step. At the same time, terrain-following models are models of choice for the fine-resolution coastal modeling, often including tides interacting with topography resulting in large amplitude baroclinic vertical motions. In this article we examine the possibility of mitigating vertical CFL restriction, while at the same time avoiding numerical inaccuracies associated with standard implicit advection schemes. In doing so we design a combined algorithm which acts like a high-order explicit scheme when Courant numbers are small enough to allow explicit method (which is usually the case throughout the entire modeling domain except just few "hot spots"), while at the same time has the ability to adjust itself toward implicit scheme should it became necessary to avoid stability limitations. This is done in a seamless manner by continuously adjusting weighting between explicit and implicit components.

  16. Method and apparatus for determining vertical heat flux of geothermal field

    DOEpatents

    Poppendiek, Heinz F.

    1982-01-01

    A method and apparatus for determining vertical heat flux of a geothermal field, and mapping the entire field, is based upon an elongated heat-flux transducer (10) comprised of a length of tubing (12) of relatively low thermal conductivity with a thermopile (20) inside for measuring the thermal gradient between the ends of the transducer after it has been positioned in a borehole for a period sufficient for the tube to reach thermal equilibrium. The transducer is thermally coupled to the surrounding earth by a fluid annulus, preferably water or mud. A second transducer comprised of a length of tubing of relatively high thermal conductivity is used for a second thermal gradient measurement. The ratio of the first measurement to the second is then used to determine the earth's thermal conductivity, k.sub..infin., from a precalculated graph, and using the value of thermal conductivity thus determined, then determining the vertical earth temperature gradient, b, from predetermined steady state heat balance equations which relate the undisturbed vertical earth temperature distributions at some distance from the borehole and earth thermal conductivity to the temperature gradients in the transducers and their thermal conductivity. The product of the earth's thermal conductivity, k.sub..infin., and the earth's undisturbed vertical temperature gradient, b, then determines the earth's vertical heat flux. The process can be repeated many times for boreholes of a geothermal field to map vertical heat flux.

  17. Comparison of Aerosol Classification From Airborne High Spectral Resolution Lidar and the CALIPSO Vertical Feature Mask

    NASA Technical Reports Server (NTRS)

    Burton, Sharon P.; Ferrare, Rich A.; Omar, Ali H.; Vaughan, Mark A.; Rogers, Raymond R.; Hostetler, Chris a.; Hair, Johnathan W.; Obland, Michael D.; Butler, Carolyn F.; Cook, Anthony L.; Harper, David B.

    2012-01-01

    Knowledge of aerosol composition and vertical distribution is crucial for assessing the impact of aerosols on climate. In addition, aerosol classification is a key input to CALIOP aerosol retrievals, since CALIOP requires an inference of the lidar ratio in order to estimate the effects of aerosol extinction and backscattering. In contrast, the NASA airborne HSRL-1 directly measures both aerosol extinction and backscatter, and therefore the lidar ratio (extinction-to-backscatter ratio). Four aerosol intensive properties from HSRL-1 are combined to infer aerosol type. Aerosol classification results from HSRL-1 are used here to validate the CALIOP aerosol type inferences.

  18. Observed changes in the vertical profile of stratopheric nitrous oxide at Thule, Greenland, February - March 1992

    NASA Technical Reports Server (NTRS)

    Emmons, Louisa K.; Reeves, John M.; Shindell, Drew T.; Dezafra, Robert L.

    1994-01-01

    Using a ground-based mm-wave spectrometer, we have observed stratospheric N2O over Thule, Greenland (76.3 N, 68.4 W) during late February and March, 1992. Vertical profiles of mixing ratio ranging from 16 to 50 km were recovered from molecular emission spectra. The profiles of early March show an abrupt increase in the lower-stratosphere N2O mixing ratio similar to the spring-to-summer change associated with the break up of the Antarctic polar vortex. This increase is correlated with changes in potential vorticity, air temperature, and ozone mixing ratio.

  19. Vertical orbital dystopia--surgical correction.

    PubMed

    Edgerton, M T; Jane, J A

    1981-02-01

    The surgical correction of vertical malpositions of the human eye has been made relatively safe and reliable by recent surgical techniques. The authors define this condition as vertical orbital dystopia and review the etiology of this deformity in 38 recent consecutive cases that were surgically treated at the Craniofacial Anomalies Center of The University of Virginia. Some new and useful tests are described that are of value to the plastic surgeon in analysis of the facial deformity and in planning the appropriate surgical procedure to correct the vertical dystopia of one or both eyes. Several cases are illustrated that describe the principal surgical methods of moving the eye up or down without loss of vision. The vertical eye shifts in this series have been in the range of 2 to 3 mm to over 22 mm. No loss of vision was produced by these corrections. The most common difficulties and complications of orbital dystopia corrections are described. The implications of this type of surgery in terms of visual physiology are suggested. The authors conclude that surgical correction of vertical orbital dystopias is possible, safe, and rewarding to the patients. However, they advise that the correction is best performed in young children and by a specially trained team of plastic surgeons, neurosurgeons, and ophthalmologists.

  20. Thermal Impacts of Vertical Greenery Systems

    NASA Astrophysics Data System (ADS)

    Safikhani, Tabassom; Abdullah, Aminatuzuhariah Megat; Ossen, Dilshan Remaz; Baharvand, Mohammad

    2014-12-01

    - Using vertical greenery systems to reduce heat transmission is becoming more common in modern architecture. Vertical greenery systems are divided into two main categories; green facades and living walls. This study aims to examine the thermal performance of vertical greenery systems in hot and humid climates. An experimental procedure was used to measure indoor temperature and humidity. These parameters were also measured for the gap between the vertical greenery systems and wall surfaces. Three boxes were used as small-scale rooms. Two boxes were provided with either a living wall or a green facade and one box did not have any greenery (benchmark). Blue Trumpet Vine was used in the vertical greenery systems. The data were recorded over the course of three sunny days in April 2013. An analyses of the results showed that the living wall and green facade reduced indoor temperature up to 4.0 °C and 3.0 °C, respectively. The living wall and green facade also reduced cavity temperatures by 8.0 °C and 6.5 °C, respectively.

  1. High ratio recirculating gas compressor

    DOEpatents

    Weinbrecht, John F.

    1989-01-01

    A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor.

  2. High ratio recirculating gas compressor

    DOEpatents

    Weinbrecht, J.F.

    1989-08-22

    A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor. 10 figs.

  3. First Observation Of ELM Pacing With Vertical Jogs In A Spherical Torus

    SciTech Connect

    Gerhardt, S P; Canik, J M; Maingi, R; Bell, R; Gates, d; Goldston, R; Hawryluk, R; Le Blanc, B P; Menard, J; Sontag, A C; Sabbagh, S

    2010-07-15

    Experiments in a number of conventional aspect ratio tokamaks have been successful in pacing edge localized modes (ELMs) by rapid vertical jogging of the plasma. This paper demonstrates the first pacing of ELMs in a spherical torus plasma. Applied 30 Hz vertical jogs synchronized the ELMs with the upward motion of the plasma. 45 Hz jogs also lead to an increase in the ELM frequency, though the synchronization of the ELMs and jogs was unclear. A reduction in the ELM energy was observed at the higher driven ELM frequencies. __________________________________________________

  4. Measurements of the vertical profile of water vapor abundance in the Martian atmosphere from Mars Observer

    NASA Technical Reports Server (NTRS)

    Schofield, J. T.; Mccleese, Daniel J.

    1988-01-01

    An analysis is presented of the Pressure Modulator Infrared Radiometer (PMIRR) capabilities along with how the vertical profiles of water vapor will be obtained. The PMIRR will employ filter and pressure modulation radiometry using nine spectral channels, in both limb scanning and nadir sounding modes, to obtain daily, global maps of temperature, dust extinction, condensate extinction, and water vapor mixing ratio profiles as a function of pressure to half scale height or 5 km vertical resolution. Surface thermal properties will also be mapped, and the polar radiactive balance will be monitored.

  5. A nanoradio utilizing the mechanical resonance of a vertically aligned nanopillar array.

    PubMed

    Lee, Chang Hwa; Lee, Seok Woo; Lee, Seung S

    2014-02-21

    A nanoradio based on the mechanical resonance of a nanomaterial has promising applications in terms of size reduction of an antenna and integrity of all components of a radio except a speaker. In this letter, a nanopillar array radio utilizing the mechanical resonance of a vertically aligned nanopillar array is realized by a reliable top-down method. By exploiting the field emission phenomenon, it was found that the nanopillar array functions as a radio with a demodulator without any electrical circuitry. The array of vertically aligned nanopillars increases the demodulated current and signal to noise ratio, and this fabrication method makes manipulation and positioning of nanostructures possible intrinsically for industrial applications.

  6. Vertical distribution of (241)Pu in the southern Baltic Sea sediments.

    PubMed

    Strumińska-Parulska, Dagmara I

    2014-12-15

    The vertical distribution of plutonium (241)Pu in marine sediments can assist in determining the deposition history and sedimentation process of analyzed regions. In addition, (241)Pu/(239+240)Pu activity ratio could be used as a sensitive fingerprint for radioactive source identification. The present preliminary studies on vertical distribution of (241)Pu in sediments from four regions of the southern Baltic Sea are presented. The distribution of (241)Pu was not uniform and depended on sediment geomorphology and depth as well as location. The highest concentrations of plutonium were found in the surface layers of all analyzed sediments and originated from the Chernobyl accident.

  7. Reconstructing the vertical profile of humidity on the basis of the vertical profile of temperature

    NASA Technical Reports Server (NTRS)

    Bazlova, T. I.

    1974-01-01

    The vertical profile of humidity in the atmosphere is developed on the basis of the vertical profile of temperature using an empirical formula linking changes in humidity with changes in temperature and altitude. The atmosphere is divided into three layers by altitude, since the condition for the formation of humidity varies with altitude.

  8. Hydraulic induced instability on a vertical service

    NASA Technical Reports Server (NTRS)

    Bosmans, R. F.

    1985-01-01

    The case history contained provides insight toward the mechanical and hydraulic behavior of a vertical pump. It clearly demonstrates the need for measurements on the rotor at or near the impeller area. The results are reported of an analysis on a service water pump. This pump is typical of the water pumps used throughout the power generation industry. Although little is known of the mechanical behavior of vertical pumps because of difficulty in modeling the rotor system, recent developments in the application of submersible proximity transducers have made possible the measurement of pump dynamics under operating conditions. The purpose of this study was to determine the proper selection and installation of vibration-monitoring transducers as well as to measure the effects of imbalance, misalignment, and hydraulics on the performance and reliability of vertical pumps. In addition, the cause of shaft failures on this pump was to be determined.

  9. Kinematics of horizontal and vertical caterpillar crawling.

    PubMed

    van Griethuijsen, Linnea I; Trimmer, Barry A

    2009-05-01

    Unlike horizontal crawling, vertical crawling involves two counteracting forces: torque rotating the body around its center of mass and gravity resisting forward movement. The influence of these forces on kinematics has been examined in the soft-bodied larval stage of Manduca sexta. We found that crawling and climbing are accomplished using the same movements, with both segment timing and proleg lift indistinguishable in horizontal and vertical locomotion. Minor differences were detected in stride length and in the delay between crawls, which led to a lower crawling speed in the vertical orientation. Although these differences were statistically significant, they were much smaller than the variation in kinematic parameters between animals. The ability of Manduca to crawl and climb using the same movements is best explained by Manduca's relatively small size, slow speed and strong, controlled, passive grip made possible by its proleg/crochets.

  10. Purification process for vertically aligned carbon nanofibers

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

    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.

  11. Turbulence in vertical axis wind turbine canopies

    NASA Astrophysics Data System (ADS)

    Kinzel, Matthias; Araya, Daniel B.; Dabiri, John O.

    2015-11-01

    Experimental results from three different full scale arrays of vertical-axis wind turbines (VAWTs) under natural wind conditions are presented. The wind velocities throughout the turbine arrays are measured using a portable meteorological tower with seven, vertically staggered, three-component ultrasonic anemometers. The power output of each turbine is recorded simultaneously. The comparison between the horizontal and vertical energy transport for the different turbine array sizes shows the importance of vertical transport for large array configurations. Quadrant-hole analysis is employed to gain a better understanding of the vertical energy transport at the top of the VAWT arrays. The results show a striking similarity between the flows in the VAWT arrays and the adjustment region of canopies. Namely, an increase in ejections and sweeps and decrease in inward and outward interactions occur inside the turbine array. Ejections are the strongest contributor, which is in agreement with the literature on evolving and sparse canopy flows. The influence of the turbine array size on the power output of the downstream turbines is examined by comparing a streamwise row of four single turbines with square arrays of nine turbine pairs. The results suggest that a new boundary layer forms on top of the larger turbine arrays as the flow adjusts to the new roughness length. This increases the turbulent energy transport over the whole planform area of the turbine array. By contrast, for the four single turbines, the vertical energy transport due to turbulent fluctuations is only increased in the near wake of the turbines. These findings add to the knowledge of energy transport in turbine arrays and therefore the optimization of the turbine spacing in wind farms.

  12. European Vertical Reference System Influence in Latvia

    NASA Astrophysics Data System (ADS)

    Celms, A.; Reķe, I.; Ratkevičs, A.

    2015-11-01

    Till 1 December, 2014, in Latvia the heights were determined in Baltic Normal Height System 1977. The national height system is determined by the Cabinet of Ministers and internal laws. Now for the change of the national height system to reconcile it with the European Vertical Reference System, amendments to the laws and regulations have been developed, but so far only the amendment to the Geospatial Information Law is in force, the amendment to the regulation of the Cabinet of Ministers is still not approved. This amendment declares the Latvia Height System based on the European Vertical Reference System in Latvia as the national height system. For height transformation, there is a transformation formula for each European country. After calculations it is seen that height difference between Baltic Normal Height System 1977 and European Vertical Reference System depends on point location in the territory (coordinates). This unequal height difference between both height systems will cause unequal height values on border connection points between Baltic countries. The aim of the research is to evaluate the European Vertical Reference System in Latvia. To reach the aim the following tasks are set: 1) to evaluate the components of transformation formulas; 2) using the transformation formulas to calculate height differences between Baltic Normal Height System 1977 and the European Vertical Reference System realization EVRF2007 for the territory of Latvia and also between Baltic Normal Height System 1977 and the Latvia Normal Height System; 3) to get height differences in the European Vertical Reference System on the borderlines of Latvia - Estonia and Latvia - Lithuania.

  13. Pressure Ratio to Thermal Environments

    NASA Technical Reports Server (NTRS)

    Lopez, Pedro; Wang, Winston

    2012-01-01

    A pressure ratio to thermal environments (PRatTlE.pl) program is a Perl language code that estimates heating at requested body point locations by scaling the heating at a reference location times a pressure ratio factor. The pressure ratio factor is the ratio of the local pressure at the reference point and the requested point from CFD (computational fluid dynamics) solutions. This innovation provides pressure ratio-based thermal environments in an automated and traceable method. Previously, the pressure ratio methodology was implemented via a Microsoft Excel spreadsheet and macro scripts. PRatTlE is able to calculate heating environments for 150 body points in less than two minutes. PRatTlE is coded in Perl programming language, is command-line-driven, and has been successfully executed on both the HP and Linux platforms. It supports multiple concurrent runs. PRatTlE contains error trapping and input file format verification, which allows clear visibility into the input data structure and intermediate calculations.

  14. Continually variable transmission having fixed ratio and variable ratio mechanisms

    SciTech Connect

    Moan, R.D

    1989-06-06

    This patent describes a transmission for producing a stepless, continually variable range of ratios of the speed of its output to its input comprising: a fluid coupling having an impeller adapted for connection to a power source and a turbine hydrodynamically connected to the impeller; as planetary gearset having a ring gear, a sun gear, a first set of planet pinions meshing with the sun gear, a second set of planet pinions meshing with the first set of pinions and with the ring gear, and a pinion carrier on which the first and second sets of pinions are rotatably supported; first drive means drivable connecting the turbine and the sun gear for producing a variable speed ratio therebetween having a range between an underdrive ratio and an overdrive ratio; second drive means drivably connecting the impeller and the ring gear for producing a fixed speed ratio therebetween; a first clutch means for drivably connecting and disconnecting the ring gear and the second drive means; and a second clutch means for drivably connecting and disconnecting the first drive means and the pinion carrier.

  15. Radial-vertical profiles of tropical cyclone derived from dropsondes

    NASA Astrophysics Data System (ADS)

    Ren, Yifang

    The scopes of this thesis research are two folds: the first one is to the construct the intensity-based composite radial-vertical profiles of tropical cyclones (TC) using GPS-based dropsonde observations and the second one is to identify the major deficiencies of Mathur vortices against the dropsonde composites of TCs. The intensity-based dropsonde composites of TCs advances our understanding of the dynamic and thermal structure of TCs of different intensity along the radial direction in and above the boundary layer where lies the devastating high wind that causes property damages and storm surges. The identification of the major deficiencies of Mathur vortices in representing the radial-vertical profiles of TC of different intensity helps to improve numerical predictions of TCs since most operational TC forecast models need to utilize bogus vortices, such as Mathur vortices, to initialize TC forecasts and simulations. We first screen all available GPS dropsonde data within and round 35 named TCs over the tropical Atlantic basin from 1996 to 2010 and pair them with TC parameters derived from the best-track data provided by the National Hurricane Center (NHC) and select 1149 dropsondes that have continuous coverage in the lower troposphere. The composite radial-vertical profiles of tangential wind speed, temperature, mixing ratio and humidity are based for each TC category ranging from "Tropical Storm" (TS) to "Hurricane Category 1" (H1) through "Hurricane Category 5" (H5). The key findings of the dropsonde composites are: (i) all TCs have the maximum tangential wind within 1 km above the ground and a distance of 1-2 times of the radius of maximum wind (RMW) at the surface; (ii) all TCs have a cold ring surrounding the warm core near the boundary layer at a distance of 1-3 times of the RMW and the cold ring structure gradually diminishes at a higher elevation where the warm core structure prevails along the radial direction; (iii) the existence of such shallow cold

  16. Sediment Vertical Flux in Unsteady Sheet Flows

    NASA Astrophysics Data System (ADS)

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

    2002-12-01

    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

  17. Photochemistry and vertical mixing. [in Uranus atmosphere

    NASA Technical Reports Server (NTRS)

    Atreya, S. K.; Sandel, B. R.; Romani, P. N.

    1991-01-01

    Earth-based observations relevant to the question of photochemistry and vertical mixing are discussed. Phytolysis of methane, the only known photochemically active volatile in the Uranian atmosphere, produces heavier hydrocarbons, the most abundant of which are ethane, acetylene, and the polyacetylenes. Unlike Jupiter and Saturn, these hydrocarbon products condense at the low temperatures prevalent in the middle atmosphere. Contrary to the pre-Voyager notion that the atmosphere of Uranus is remarkable clear, it is found that the aerosols are widely and extensively distributed. Despite its photodestruction, methane remains stable in the Uranian atmosphere. The vertical mixing on Uranus is found to be the least efficient of any of the planetary atmospheres.

  18. CIRSS vertical data integration, San Bernardino study

    NASA Technical Reports Server (NTRS)

    Hodson, W.; Christenson, J.; Michel, R. (Principal Investigator)

    1982-01-01

    The creation and use of a vertically integrated data base, including LANDSAT data, for local planning purposes in a portion of San Bernardino County, California are described. The project illustrates that a vertically integrated approach can benefit local users, can be used to identify and rectify discrepancies in various data sources, and that the LANDSAT component can be effectively used to identify change, perform initial capability/suitability modeling, update existing data, and refine existing data in a geographic information system. Local analyses were developed which produced data of value to planners in the San Bernardino County Planning Department and the San Bernardino National Forest staff.

  19. Vertical hydrodynamic focusing in glass microchannels.

    PubMed

    Lin, Tony A; Hosoi, A E; Ehrlich, Daniel J

    2009-01-08

    Vertical hydrodynamic focusing in microfluidic devices is investigated through simulation and through direct experimental verification using a confocal microscope and a novel form of stroboscopic imaging. Optimization for microfluidic cytometry of biological cells is examined. By combining multiple crossing junctions, it is possible to confine cells to a single analytic layer of interest. Subtractive flows are investigated as a means to move the analysis layer vertically in the channel and to correct the flatness of this layer. The simulation software (ADINA and Coventor) is shown to accurately capture the complex dependencies of the layer interfaces, which vary strongly with channel geometry and relative flow rates.

  20. Concepts for generating optimum vertical flight profiles

    NASA Technical Reports Server (NTRS)

    Sorensen, J. A.

    1979-01-01

    Algorithms for generating optimum vertical profiles are derived and examined. These algorithms form the basis for the design of onboard flight management concepts. The variations in the optimum vertical profiles (resulting from these concepts) due to variations in wind, takeoff weight, and range-to-destination are presented. Further considerations for mechanizing two different onboard methods of computing near-optimum flight profiles are then outlined. Finally, the results are summarized, and recommendations are made for further work. Technical details of optimum trajectory design, steering requirements for following these trajectories, and off-line computer programs for testing the concepts are included.

  1. Vertical high-precision Michelson wavemeter

    NASA Astrophysics Data System (ADS)

    Morales, A.; de Urquijo, J.; Mendoza, A.

    1993-01-01

    We have designed and tested a traveling, Michelson-type vertical wavemeter for the wavelength measurement of tunable continuous-wave lasers in the visible part of the spectrum. The interferometer has two movable corner cubes, suspending vertically from a driving setup resembling Atwood's machine. To reduce the fraction-of-fringe error, a vernier-type coincidence circuit was used. Although simple, this wavemeter has a relative precision of 3.2 parts in 109 for an overall fringe count of about 7×106.

  2. Integrated asymmetric vertical coupler pressure sensors

    NASA Astrophysics Data System (ADS)

    Kiyat, Isa; Kocabas, Askin; Akcag, Imran; Aydinli, Atilla

    2004-08-01

    Design and analysis of a novel pressure sensor based on a silicon-on-insulator asymmetric integrated vertical coupler is presented. The coupler is composed of a single mode low index waveguide and a thin silicon slab. Wavelength selective optical modulation of asymmetric vertical coupler is examined in detail. Its potential for sensing applications is highlighted as an integrated optical pressure sensor which can be realized by standard silicon micro-fabrication. Sensitivity of transmission of such couplers on refractive index change of silicon slab ensures that they are good candidates for applications requiring high sensitivities.

  3. Vertical Vergence Adaptation Produces an Objective Vertical Deviation That Changes With Head Tilt

    PubMed Central

    Irsch, Kristina; Guyton, David L.; Ramey, Nicholas A.; Adyanthaya, Rohit S.; Ying, Howard S.

    2013-01-01

    Purpose. To document the cyclovertical ocular motor mechanism used for vertical fusion in healthy subjects, and to explore whether vertical vergence training in healthy individuals can produce objectively confirmed vertical deviations that change with head tilt, revealing a basic mechanism that can produce a pattern of misalignment in an otherwise normal ocular motor system that is similar to superior oblique muscle paresis (SOP). Methods. Seven subjects with normal orthoptic examinations were adapted to vertical image disparities using our tilting haploscopic eye-tracking apparatus presenting concentric circle targets without torsional cues. Static eye positions were recorded with head straight and when tilted 45 degrees to the left and right, during both binocular and monocular viewing. Results. Vertical fusional vergence was accompanied by a cycloversion, with the downward-moving eye intorting and the upward-moving eye extorting, implicating primary involvement of the oblique extraocular muscles. After adaptation to the slowly increasing vertical target separation, all subjects developed a temporary vertical deviation in the straight ahead position that increased with head tilt to one side and decreased with head tilt to the other side. Conclusions. These results not only show that head-tilt–dependent changes in vertical deviation are not necessarily pathognomonic for SOP, but also, and more importantly, suggest mechanisms that can mimic SOP and suggest a possible role for vertical vergence training in reducing deviations and thus the amount of head tilt required for fusion. Ultimately, vertical vergence training may provide an adjunct or alternative to extraocular muscle surgery in selected cases. PMID:23572100

  4. Vertical Microcavity Organic Light-emitting Field-effect Transistors

    PubMed Central

    Hu, Yongsheng; Lin, Jie; Song, Li; Lu, Qipeng; Zhu, Wanbin; Liu, Xingyuan

    2016-01-01

    Organic light-emitting field-effect transistors (OLEFETs) are regarded as a novel kind of device architecture for fulfilling electrical-pumped organic lasers. However, the realization of OLEFETs with high external quantum efficiency (EQE) and high brightness simultaneously is still a tough task. Moreover, the design of the resonator structure in LED is far from satisfactory. Here, OLEFETs with EQE of 1.5% at the brightness of 2600 cdm−2, and the corresponding ON/OFF ratio and current efficiency reaches above 104 and 3.1 cdA−1, respectively, were achieved by introducing 1,4,5,8,9,12-hexaazatriphenylene-hexacarbonitrile (HAT-CN) as a charge generation layer. Moreover, a vertical microcavity based on distributed Bragg reflector (DBR) and Ag source/drain electrodes is successfully introduced into the high performance OLEFETs, which results in electroluminescent spectrum linewidth narrowing from 96 nm to 6.9 nm. The results manifest the superiority of the vertical microcavity as an optical resonator in OLEFETs, which sheds some light on achieving the electrically pumped organic lasers. PMID:26986944

  5. Numerical study on small scale vertical axis wind turbine

    NASA Astrophysics Data System (ADS)

    Parra-Santos, Teresa; Gallegos, Armando; Uzarraga, Cristóbal N.; Rodriguez, Miguel A.

    2016-03-01

    The performance of a Vertical Axis Wind Turbine (VAWT) is numerically analyzed. The set-up is Hdarrieus with three straight blades airfoils NACA attached to a rotating vertical shaft. The wind turbine has solidity equals to the unity operating with wind velocity of 7 m/s. Influence of pitch angle is tested to get design tendencies. 2D, transient, Navier Stokes equations are solved using the code Ansys-Fluent. Conservation equations were solved with a Third-Order MUSCL scheme using SIMPLE to couple pressure and velocity. More than six revolutions must be simulated to get the periodic behavior. Two models of turbulence have been contrasted Realizable k-epsilon and Transition SST concluding the last one show more realistic flow features. Pitch angles of 0º, -6º and -10º have been tested with Tip Speed Ratios ranging from 0.7 and 1.6. The no null pitch angles improve the performance of the wind turbine. Instantaneous and averaged power coefficients as well as detailed flow field around the airfoils are showed.

  6. Vertical Distribution of Rotylenchulus reniformis in Cotton Fields

    PubMed Central

    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.

    2005-01-01

    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

  7. Cephalometric appraisal of posttreatment vertical changes in adult orthodontic patients.

    PubMed

    Ahn, J G; Schneider, B J

    2000-10-01

    The purpose of this study was to evaluate vertical facial changes in adult orthodontic patients and to evaluate the stability of these changes. Thirty-three patients (8 males and 25 females) were examined. The patients had been treated with full fixed edgewise appliance mechanics and exhibited at least 1.0 degrees of clockwise rotation of the mandible during treatment. Mandibular rotation was determined by the angular change in the Y-axis to the Frankfort plane. Twelve angular and 14 linear skeletal and dental measurements and 3 skeletal ratios were derived from pretreatment (T1), posttreatment (T2), and postretention (T3) cephalometric radiographs. Paired t tests were used to compare vertical changes that occurred as a result of orthodontic treatment and their stability or relapse tendency during the retention and postretention periods. Twenty-five percent (P <.001) of the opening rotation of the mandible recovered during the posttreatment period, resulting in a significant overall rotation that was maintained. Both treatment and posttreatment changes in the Y-axis angle showed a high correlation with the horizontal position of pogonion (r = -0.797 and -0.889, respectively). Only overjet showed a low correlation between treatment changes and posttreatment changes in the Y-axis angle. Stepwise regression analysis of pretreatment variables and treatment changes failed to predict the behavior of the Y-axis angle change.

  8. 33 CFR 118.85 - Lights on vertical lift bridges.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Lights on vertical lift bridges... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span lights. The vertical lift span of every vertical lift bridge shall be lighted so that the center of...

  9. 33 CFR 118.85 - Lights on vertical lift bridges.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span lights. The vertical lift span of every vertical lift bridge shall be lighted so that the center of the navigable channel under the span will be marked by a range of two green lights when the vertical lift...

  10. Comparison of digital and film stereo photography of the optic nerve in the evaluation of patients with glaucoma.

    PubMed

    Khouri, Albert S; Szirth, Bernard; Realini, Tony; Fechtner, Robert D

    2006-12-01

    The aim of this study was to validate a digital simultaneous stereo photography system against film in the assessment of optic nerve head features in patients with glaucoma. Fifteen digital and 15 corresponding film simultaneous stereo photographs (SSP) of the optic nerve from patients with glaucoma were graded by two glaucoma specialists. Assessed parameters included the vertical and horizontal cup-to-disc ratios (VCD and HCD, respectively), and the image quality score (1 = worse, 5 = best) for each image. Digital and film SSP were presented in random order, two times to each grader. A total of 60 evaluations (30 digital and 30 film) per grader were collected. A Nidek 3-Dx simultaneous stereo disc camera (Gamagori, Japan) was used with both a standard 35-mm-film camera back, and with a 6.1 mega pixel camera (Nikon D1x, Tokyo, Japan) for capture of digital images. All digital images were stored on a computer and reviewed using the Navis Screener software (proprietary software from Nidek). Digital image pairs were evaluated directly on an ADVAN 27-inch Liquid Crystal Display computer monitor (Taipei, Taiwan) with resolution comparable to that of the digital camera, using the screen-vu stereo viewer held at a fixed angle to the monitor. Film image pairs were evaluated using a Pentax stereo slide viewer (Asahi Optical Co., Tokyo, Japan) illuminated by a light box over a neutral density filter to match the luminance between the computer screen and the light box. The mean difference between digital and film was near zero for all three evaluated outcomes (VCD, HCD, and quality score), and there was no significant grader effect for any of the outcomes. Digital images correlated well with film for SSP of the optic nerve in glaucoma.

  11. Ophthalmic examination of the captive western lowland gorilla (Gorilla gorilla gorilla).

    PubMed

    Liang, David; Alvarado, Thomas P; Oral, Deniz; Vargas, Jose M; Denena, Melissa M; McCulley, James P

    2005-09-01

    This study examined the captive western lowland gorilla (Gorilla gorilla gorilla) eye as compared and contrasted with the human eye. Bilateral ophthalmic examinations of western lowland gorillas (n = 5) while under general anesthesia were performed opportunistically, including slit-lamp biomicroscopy, dilated fundus examination, cycloplegic retinoscopy, Schiotz tonometry, corneal diameter and thickness measurements, A-scan and B-scan ultrasonography, keratometry, and cultures of the eyelid margins and bulbar conjunctiva. Mean spherical equivalent refractive error by cycloplegic retinoscopy was +1.20 +/- 0.59 diopters. Mean intraocular pressure by Schiotz tonometry was 12.0 +/- 4.3 mm Hg. Mean optic nerve head cup to disc ratio was 0.42 +/- 0.11. Mean horizontal corneal diameter was 13.4 +/- 0.8 mm, and mean vertical cornea diameter was 12.7 +/- 0.8 mm. Mean central corneal thickness by ultrasound pachymetry was 489 +/- 52 microm. Mean axial length of the eye by A-scan was 22.75 +/- 0.71 mm. Mean lens thickness by A-scan was 4.23 +/- 0.34 mm. Mean anterior chamber depth by A-scan was 4.00 +/- 0.26 mm. Mean keratometry reading was 44.38 +/- 1.64 diopters. Eyelid margin and bulbar conjunctival cultures isolated Candida sp. (n = 5), Staphylococcus aureus (n = 4), Staphylococcus epidermidis (n = 3), Staphylococcus saccharolyticus (n = 3), and Micrococcus sp. (n = 3). This study suggests important similarities between western lowland gorilla and human eyes. These similarities may allow diagnostics, techniques, and equipment for human eye surgery, such as those used for cataract extraction and intraocular lens implantation, to be successfully utilized for gorillas.

  12. Performance Characteristics of a Vertical Axis Hydrokinetic Turbine

    NASA Astrophysics Data System (ADS)

    Bailin, Benjamin; Flack, Karen; Lust, Ethan

    2016-11-01

    Performance characteristics are presented for a vertical axis hydrokinetic turbine designed for use in a riverine environment. The test turbine is a 1:6 scale model of a three-bladed device (9.5 m span, 6.5 m diameter) that has been proposed by the Department of Energy. Experiments are conducted in the large towing tank (116 m long, 7.9 m wide, 5 m deep) at the United States Naval Academy. The large scale facility allows for scale independent results. The turbine is towed beneath a moving carriage at a constant speed in combination with a shaft brake to achieve the desired tip speed ratio (TSR) range. The measured quantities of turbine thrust, torque and RPM result in power and thrust coefficients for a range of TSR. Results will be presented for cases with quiescent flow and flow with mild surface waves, representative of riverine environments.

  13. Field-Effect Tunneling Transistor Based on Vertical Graphene Heterostructures

    NASA Astrophysics Data System (ADS)

    Britnell, L.; Gorbachev, R. V.; Jalil, R.; Belle, B. D.; Schedin, F.; Mishchenko, A.; Georgiou, T.; Katsnelson, M. I.; Eaves, L.; Morozov, S. V.; Peres, N. M. R.; Leist, J.; Geim, A. K.; Novoselov, K. S.; Ponomarenko, L. A.

    2012-02-01

    An obstacle to the use of graphene as an alternative to silicon electronics has been the absence of an energy gap between its conduction and valence bands, which makes it difficult to achieve low power dissipation in the OFF state. We report a bipolar field-effect transistor that exploits the low density of states in graphene and its one-atomic-layer thickness. Our prototype devices are graphene heterostructures with atomically thin boron nitride or molybdenum disulfide acting as a vertical transport barrier. They exhibit room-temperature switching ratios of ≈50 and ≈10,000, respectively. Such devices have potential for high-frequency operation and large-scale integration.

  14. Vertically aligned carbon nanofiber electrode arrays for nucleic acid detection

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

    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.

  15. Field-effect tunneling transistor based on vertical graphene heterostructures.

    PubMed

    Britnell, L; Gorbachev, R V; Jalil, R; Belle, B D; Schedin, F; Mishchenko, A; Georgiou, T; Katsnelson, M I; Eaves, L; Morozov, S V; Peres, N M R; Leist, J; Geim, A K; Novoselov, K S; Ponomarenko, L A

    2012-02-24

    An obstacle to the use of graphene as an alternative to silicon electronics has been the absence of an energy gap between its conduction and valence bands, which makes it difficult to achieve low power dissipation in the OFF state. We report a bipolar field-effect transistor that exploits the low density of states in graphene and its one-atomic-layer thickness. Our prototype devices are graphene heterostructures with atomically thin boron nitride or molybdenum disulfide acting as a vertical transport barrier. They exhibit room-temperature switching ratios of ≈50 and ≈10,000, respectively. Such devices have potential for high-frequency operation and large-scale integration.

  16. Vertically aligned carbon nanotube probes for monitoring blood cholesterol

    NASA Astrophysics Data System (ADS)

    Roy, Somenath; Vedala, Harindra; Choi, Wonbong

    2006-02-01

    Detection of blood cholesterol is of great clinical significance. The amperometric detection technique was used for the enzymatic assay of total cholesterol. Multiwall carbon nanotubes (MWNTs), vertically aligned on a silicon platform, promote heterogeneous electron transfer between the enzyme and the working electrode. Surface modification of the MWNT with a biocompatible polymer, polyvinyl alcohol (PVA), converted the hydrophobic nanotube surface into a highly hydrophilic one, which facilitates efficient attachment of biomolecules. The fabricated working electrodes showed a linear relationship between cholesterol concentration and the output signal. The efficacy of the multiwall carbon nanotubes in promoting heterogeneous electron transfer was evident by distinct electrochemical peaks and higher signal-to-noise ratio as compared to the Au electrode with identical enzyme immobilization protocol. The selectivity of the cholesterol sensor in the presence of common interferents present in human blood, e.g. uric acid, ascorbic acid and glucose, is also reported.

  17. Theoretical calculations of the pressure, forces, and moments at supersonic speeds due to various lateral motions acting on thin isolated vertical tails

    NASA Technical Reports Server (NTRS)

    Margolis, Kenneth; Bobbitt, Percy J

    1956-01-01

    Velocity potentials, pressure, distributions, and stability derivatives are derived by use of supersonic linearized theory for families of thin isolated vertical tails performing steady rolling, steady yawing, and constant-lateral-acceleration motions. Vertical-tail families (half-delta and rectangular plan forms) are considered for a broad Mach number range. Also considered are the vertical tail with arbitrary sweepback and taper ratio at Mach numbers for which both the leading edge and trailing edge of the tail are supersonic and the triangular vertical tail with a subsonic leading edge and a supersonic trailing edge. Expressions for potentials, pressures, and stability derivatives are tabulated.

  18. Rayleigh-Bénard convection with uniform vertical magnetic field.

    PubMed

    Basak, Arnab; Raveendran, Rohit; Kumar, Krishna

    2014-09-01

    We present the results of direct numerical simulations of Rayleigh-Bénard convection in the presence of a uniform vertical magnetic field near instability onset. We have done simulations in boxes with square as well as rectangular cross sections in the horizontal plane. We have considered the horizontal aspect ratio η=L(y)/L(x)=1 and 2. The onset of the primary and secondary instabilities are strongly suppressed in the presence of the vertical magnetic field for η=1. The Nusselt number Nu scales with the Rayleigh number Ra close to the primary instability as [{Ra-Ra(c)(Q)}/Ra(c)(Q)](0.91), where Ra(c)(Q) is the threshold for onset of stationary convection at a given value of the Chandrasekhar number Q. Nu also scales with Ra/Q as (Ra/Q)(μ). The exponent μ varies in the range 0.39≤μ≤0.57 for Ra/Q≥25. The primary instability is stationary as predicted by Chandrasekhar. The secondary instability is temporally periodic for Pr=0.1 but quasiperiodic for Pr=0.025 for moderate values of Q. Convective patterns for higher values of Ra consist of periodic, quasiperiodic, and chaotic wavy rolls above the onset of the secondary instability for η=1. In addition, stationary as well as time-dependent cross rolls are observed, as Ra is further raised. The ratio r(o)/Pr is independent of Q for smaller values of Q. The delay in the onset of the oscillatory instability is significantly reduced in a simulation box with η=2. We also observe inclined stationary rolls for smaller values of Q for η=2.

  19. Vertical Structure of Magnetized Accretion Disks around Young Stars

    NASA Astrophysics Data System (ADS)

    Lizano, S.; Tapia, C.; Boehler, Y.; D'Alessio, P.

    2016-01-01

    We model the vertical structure of the magnetized accretion disks that are subject to viscous and resistive heating and irradiation by the central star. We apply our formalism to the radial structure of the magnetized accretion disks that are threaded by the poloidal magnetic field dragged during the process of star formation, which was developed by Shu and coworkers. We consider disks around low-mass protostars, T Tauri, and FU Orionis stars, as well as two levels of disk magnetization: {λ }{sys}=4 (strongly magnetized disks) and {λ }{sys}=12 (weakly magnetized disks). The rotation rates of strongly magnetized disks have large deviations from Keplerian rotation. In these models, resistive heating dominates the thermal structure for the FU Ori disk, and the T Tauri disk is very thin and cold because it is strongly compressed by magnetic pressure; it may be too thin compared with observations. Instead, in the weakly magnetized disks, rotation velocities are close to Keplerian, and resistive heating is always less than 7% of the viscous heating. In these models, the T Tauri disk has a larger aspect ratio, which is consistent with that inferred from observations. All the disks have spatially extended hot atmospheres where the irradiation flux is absorbed, although most of the mass (˜90%-95%) is in the disk midplane. With the advent of ALMA one expects direct measurements of magnetic fields and their morphology at disk scales. It will then be possible to determine the mass-to-flux ratio of magnetized accretion disks around young stars, an essential parameter for their structure and evolution. Our models contribute to the understanding of the vertical structure and emission of these disks.

  20. A Simple Vertical Slab Gel Electrophoresis Apparatus.

    ERIC Educational Resources Information Center

    Carter, J. B.; And Others

    1983-01-01

    Describes an inexpensive, easily constructed, and safe vertical slab gel kit used routinely for sodium dodecyl sulphate-polyacrylamide gel electrophoresis research and student experiments. Five kits are run from a single transformer. Because toxic solutions are used, students are given plastic gloves and closely supervised during laboratory…

  1. Vertical boring mill capacity is increased

    NASA Technical Reports Server (NTRS)

    Young, R. J.

    1968-01-01

    Commercially available vertical boring mill with a nominal capacity to 27 feet in diameter of workpiece has been modified in-shop to handle work up to 36 feet in diameter. Capacity was increased by adding extension saddles to the mill support columns on each side.

  2. Sexual and vertical transmission of visceral leishmaniasis.

    PubMed

    Turchetti, Andreia P; Souza, Tayse D; Paixão, Tatiane A; Santos, Renato L

    2014-04-15

    Visceral leishmaniasis (VL) is an important zoonosis caused by Leishmania infantum, which has in the domestic dog its principal vertebrate host. VL is usually transmitted by phlebotomine sand flies, however atypical routes of transmission have been described. In this review we discuss the the role of sexual and vertical transmissions, and their role in the maintenance of VL in canine populations.

  3. Vertical motions in the equatorial middle atmosphere

    NASA Technical Reports Server (NTRS)

    Weisman, M. L.

    1979-01-01

    A single station vertical velocity equation which considers ageostrophic and diabatic effects derived from the first law of thermodynamics and a generalized thermal wind relation is presented. An analysis and verification procedure which accounts for measurement and calculation errors as well as time and space continuity arguments and theoretical predictions are described. Vertical velocities are calculated at every kilometer between 25 and 60 km and for approximately every three hours for the above diurnal period at Kourou (French Guiana), Fort Sherman (Panama Canal Zone), Ascension Island, Antigua (British West Indies) and Natal (Brazil). The results, plotted as time series cross sections, suggest vertical motions ranging in magnitude from 1 or 2 cm/sec at 30 km to as much as 15 cm/sec at 60 km. Many of the general features of the results agree well with atmospheric tidal predictions but many particular features suggest that both smaller time scale gravity waves (periods less than 6 hours) and synoptic type waves (periods greater than 1 day) may be interacting significantly with the tidal fields. The results suggest that vertical motions can be calculated for the equatorial middle atmosphere and must be considered a significant part of the motion for time scales from 8 to 24 hours.

  4. Modeling vertical coral connectivity and mesophotic refugia

    NASA Astrophysics Data System (ADS)

    Holstein, Daniel M.; Paris, Claire B.; Vaz, Ana C.; Smith, Tyler B.

    2016-03-01

    Whether mesophotic reefs will behave as refugia for corals threatened by global climate change and coastal development depends on vertical exchange of larvae between diverse habitats. Here we use a biophysical model of larval dispersal to estimate vertical connectivity of a broadcasting ( Orbicella faveolata) and a brooding ( Porites astreoides) species of coral in the US Virgin Islands. Modeling predicts subsidy to shallow areas by mesophotic larvae of both species based on local hydrology, adult reproductive characteristics, larval traits, and a wide range of scenarios developed to test depth-sensitive factors, such as fertilization rates and post-settlement survivorship. In extreme model scenarios of reduced fertilization and post-settlement survivorship of mesophotic larvae, 1-10 % local mesophotic subsidy to shallow recruitment is predicted for both species, which are demographically significant. Although direct vertical connectivity is higher for the broadcaster, the brooder demonstrates higher local multigenerational vertical connectivity, which suggests that local P. astreoides populations are more resilient than those of O. faveolata, and corroborates field studies. As shallow habitat degrades, mesophotic-shallow subsidy is predicted to increase for both species. This study is the first of its kind to simulate larval dispersal and settlement between habitats of different depths, and these findings have local, regional, and global implications for predicting and managing coral reef persistence in a changing climate.

  5. Vertical Alveolar Ridge Augmentation by Distraction Osteogenesis

    PubMed Central

    Kumar, N. Nanda; Ravindran, C.

    2015-01-01

    Introduction Compromised alveolar ridge in vertical and horizontal dimension is a common finding in patients visiting practitioners for dental prosthesis. Various treatment modalities are available for correction of deficient ridges among which alveolar distraction osteogenesis is one. Aim To study the efficacy of alveolar distraction osteogenesis in augmentation of alveolar ridges deficient in vertical dimension. Materials and Methods Ten patients aged 16 to 46 years with deficient alveolar ridge underwent ridge augmentation in 11 alveolar segments using the distraction osteogenesis method. For each patient a custom made distraction device was fabricated. The device was indigenously manufactured with SS-316 (ISO 3506). Results The vertical bone gain reached more than 10mm without the use of bone transplantation. Certain complications like incorrect vector of distraction, paresthesia, pain and loss of transport segment were encountered during the course of the study. Conclusion Alveolar vertical distraction osteogenesis is a reliable and predictable technique for both hard and soft tissue genesis. Implant placement is feasible with primary stability in neogenerated bone at the level of the distracted areas. PMID:26816991

  6. Viewing Vertical Objects with an Overhead Projector.

    ERIC Educational Resources Information Center

    Wild, R. L.

    1988-01-01

    Discusses the use of an overhead projector for the deflection of a vertical image to a screen. Describes three demonstrations: magnetizing of a steel ball bearing and paper clip; convection currents of a hot liquid within a cold liquid; and oscillation of concentrated salt solution into fresh water. (YP)

  7. Electrostatic comb drive for vertical actuation

    SciTech Connect

    Lee, A. P., LLNL

    1997-07-10

    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.

  8. Vertical pump with free floating check valve

    DOEpatents

    Lindsay, Malcolm

    1980-01-01

    A vertical pump with a bottom discharge having a free floating check valve isposed in the outlet plenum thereof. The free floating check valve comprises a spherical member with a hemispherical cage-like member attached thereto which is capable of allowing forward or reverse flow under appropriate conditions while preventing reverse flow under inappropriate conditions.

  9. Vertically aligned biaxially textured molybdenum thin films

    SciTech Connect

    Krishnan, Rahul; Riley, Michael; Lee, Sabrina; Lu, Toh-Ming

    2011-09-15

    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.

  10. Vertical nontransovarial transmission of Bartonella in fleas.

    PubMed

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

    2013-09-01

    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.

  11. A Vertical Approach to Math Instruction

    ERIC Educational Resources Information Center

    Gojak, Linda

    2012-01-01

    In the current era of mathematics standards, whether they are Common Core State Standards or other state standards, effective vertical mathematics teams offer an opportunity for teachers to grow professionally through shared experiences, for leadership to grow among the faculty, and for the school to change its perspective on the teaching and…

  12. Neurofibromatosis type II presenting as vertical diplopia.

    PubMed

    Sokwala, Ahmed; Knapp, Christopher; Gottlob, Irene

    2004-09-01

    Neurofibromatosis type II (NF II) is rare and most commonly presents with hearing loss, tinnitus and/or vestibular disturbance in the third decade of life. The authors describe a rare case presenting with NF II with vertical diplopia due to IV(th) nerve palsy. The patient was otherwise asymptomatic despite multiple extensive lesions on MRI.

  13. The Vertical Limit of State Sovereignty

    DTIC Science & Technology

    2005-06-01

    ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time...comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE 00 JUN 2005 2. REPORT TYPE N/A... 1 - Chapter I: Territorial Sovereignty - - - - - - - - - - - - 5 -- Vertical Sovereignty

  14. Vertical Acoustic Arrays in the Deep Ocean

    NASA Astrophysics Data System (ADS)

    Fisher, F.

    2002-12-01

    The R/P FLIP has made possible the deployments of vertical arrays to study sound propagation and ambient noise in the deep ocean in ways never before possible from existing research vessels. Long vertical arrays can be deployed without the flow noise contamination from platform motion, long a bane for making such studies. The vertical stability of FLIP combined with the deep mooring capability developed by Earl D. Bronson made it possible to deploy multi-element arrays beginning with a versatile 20 element array with variable spacing developed by Bill Whitney in Fred Spiess's group. The 20 element array consisted of bungee mounted hydrophones in metal cages at either uniform spacing or variable spacing to meet directivity or other requirements. It was assembled on station in the vertical and deployed to the desired depths for the elements. Gerald Morris at MPL conducted ambient noise studies using variable spacing of the elements to below the critical depth as well as in the water column above. Vic Anderson used it for his DIMUS processing system for detecting low level signals masked by ambient noise. As a 500 meter array, I used it for a series of CONTRACK (Continuous Tracking of signals at long range) experiments to resolve multipaths so they wouldn't interfere with one another. The VEKA vertical array developed by Rick Swenson of NORDA was deployed in very deep (below 3300 m) water by Dan Ramsdale of NORDA using the winch and double lay armored cable on FLIP, the same cable system for the MPL 20 element array. In my group Bruce Williams designed a rapidly deployable array to study vertical anisotropy of ambient noise as a function of range from near shore shipping via downslope conversion in a series of 48 hours FLIP stations 350, 1000 and 1500 miles from the Pacific coast. A short 120 element array, 1000 meters long, was built by John Hildebrands's group for a test of matched field processing and the SLICE experiment in acoustic tomography research of Peter

  15. Coupling Correction and Beam Dynamics at Ultralow Vertical Emittance in the ALS

    SciTech Connect

    Steier, Christoph; Robin, D.; Wolski, A.; Portmann, G.; Safranek, J.; /LBL, Berkeley /SLAC

    2008-03-17

    For synchrotron light sources and for damping rings of linear colliders it is important to be able to minimize the vertical emittance and to correct the spurious vertical dispersion. This allows one to maximize the brightness and/or the luminosity. A commonly used tool to measure the skew error distribution is the analysis of orbit response matrices using codes like LOCO. Using the new Matlab version of LOCO and 18 newly installed power supplies for individual skew quadrupoles at the ALS the emittance ratio could be reduced below 0.1% at 1.9 GeV yielding a vertical emittance of about 5 pm. At those very low emittances, additional effects like intra beam scattering become more important, potentially limiting the minimum emittance for machine like the damping rings of linear colliders.

  16. Glaucoma detection using novel optic disc localization, hybrid feature set and classification techniques.

    PubMed

    Akram, M Usman; Tariq, Anam; Khalid, Shehzad; Javed, M Younus; Abbas, Sarmad; Yasin, Ubaid Ullah

    2015-12-01

    Glaucoma is a chronic and irreversible neuro-degenerative disease in which the neuro-retinal nerve that connects the eye to the brain (optic nerve) is progressively damaged and patients suffer from vision loss and blindness. The timely detection and treatment of glaucoma is very crucial to save patient's vision. Computer aided diagnostic systems are used for automated detection of glaucoma that calculate cup to disc ratio from colored retinal images. In this article, we present a novel method for early and accurate detection of glaucoma. The proposed system consists of preprocessing, optic disc segmentation, extraction of features from optic disc region of interest and classification for detection of glaucoma. The main novelty of the proposed method lies in the formation of a feature vector which consists of spatial and spectral features along with cup to disc ratio, rim to disc ratio and modeling of a novel mediods based classier for accurate detection of glaucoma. The performance of the proposed system is tested using publicly available fundus image databases along with one locally gathered database. Experimental results using a variety of publicly available and local databases demonstrate the superiority of the proposed approach as compared to the competitors.

  17. A Ratio Explanation for Evolution.

    ERIC Educational Resources Information Center

    Riss, Pam Helfers

    1993-01-01

    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)

  18. Overconfidence, Incentives and Digit Ratio

    PubMed Central

    Neyse, Levent; Bosworth, Steven; Ring, Patrick; Schmidt, Ulrich

    2016-01-01

    This paper contributes to a better understanding of the biological underpinnings of overconfidence by analyzing performance predictions in the Cognitive Reflection Test with and without monetary incentives. In line with the existing literature we find that the participants are too optimistic about their performance on average; incentives lead to higher performance; and males score higher than females on this particular task. The novelty of this paper is an analysis of the relation between participants’ performance prediction accuracy and their second to fourth digit ratio. It has been reported that the digit ratio is a negatively correlated bio-marker of prenatal testosterone exposure. In the un-incentivized treatment, we find that males with low digit ratios, on average, are significantly more overconfident about their performance. In the incentivized treatment, however, we observe that males with low digit ratios, on average, are less overconfident about their performance. These effects are not observed in females. We discuss how these findings fit into the literature on testosterone and decision making and how they might help to explain seemingly opposing evidence. PMID:27039893

  19. A thick photoresist process for high aspect ratio MEMS applications

    NASA Astrophysics Data System (ADS)

    Laforge, Elias; Anthony, Ricky; McCloskey, Paul; O'Mathúna, Cian

    2016-10-01

    In recent years, increased demand for high aspect ratio MEMS structures has driven the need for thick photoresist fabrication processes. In this work, the optimization of a thick photoresist process using a negative tone resist (THB-151N) is described. A thickness of 85 μm is obtained with an aspect ratio of 17:1 in a single coating process, with a 5 μm pitch. Conventional UV lithography is used and its parameters are optimized in order to achieve straight and near vertical sidewall profiles. The developed patterns are used as a mold to electroplate high aspect ratio copper windings of micro-inductors and micro-transformers. A high aspect ratio yields a copper track with a large cross sectional area resulting in a lower DC resistance. This enables a further reduction in the footprint area allowing for a more efficient manufacturing process and smaller device size. Unlike other high aspect ratio resist such as SU-8, this resist does not need a post exposure bake and can be readily removed after metal electroplating.

  20. Effect of gravity on vertical eye position.

    PubMed

    Pierrot-Deseilligny, C

    2009-05-01

    There is growing evidence that gravity markedly influences vertical eye position and movements. A new model for the organization of brainstem upgaze pathways is presented in this review. The crossing ventral tegmental tract (CVTT) could be the efferent tract of an "antigravitational" pathway terminating at the elevator muscle motoneurons in the third nerve nuclei and comprising, upstream, the superior vestibular nucleus and y-group, the flocculus, and the otoliths. This pathway functions in parallel to the medial longitudinal fasciculus pathways, which control vertical eye movements made to compensate for all vertical head movements and may also comprise the "gravitational" vestibular pathways, involved in the central reflection of the gravity effect. The CVTT could provide the upgaze system with the supplement of tonic activity required to counteract the gravity effect expressed in the gravitational pathway, being permanently modulated according to the static positions of the head (i.e., the instantaneous gravity vector) between a maximal activity in the upright position and a minimal activity in horizontal positions. Different types of arguments support this new model. The permanent influence of gravity on vertical eye position is strongly suggested by the vertical slow phases and nystagmus observed after rapid changes in hypo- or hypergravity. The chin-beating nystagmus, existing in normal subjects with their head in the upside-down position, suggests that gravity is not compensated for in the downgaze system. Upbeat nystagmus due to brainstem lesions, most likely affecting the CVTT circuitry, is improved when the head is in the horizontal position, suggesting that this circuitry is involved in the counteraction of gravity between the upright and horizontal positions of the head. In downbeat nystagmus due to floccular damage, in which a permanent hyperexcitation of the CVTT could exist, a marked influence of static positions of the head is also observed. Finally

  1. Habitat Demonstration Unit (HDU) Vertical Cylinder Habitat

    NASA Technical Reports Server (NTRS)

    Howe, Alan; Kennedy, Kriss J.; Gill, Tracy R.; Tri, Terry O.; Toups, Larry; Howard, Robert I.; Spexarth, Gary R.; Cavanaugh, Stephen; Langford, William M.; Dorsey, John T.

    2014-01-01

    NASA's Constellation Architecture Team defined an outpost scenario optimized for intensive mobility that uses small, highly mobile pressurized rovers supported by portable habitat modules that can be carried between locations of interest on the lunar surface. A compact vertical cylinder characterizes the habitat concept, where the large diameter maximizes usable flat floor area optimized for a gravity environment and allows for efficient internal layout. The module was sized to fit into payload fairings for the Constellation Ares V launch vehicle, and optimized for surface transport carried by the All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE) mobility system. Launch and other loads are carried through the barrel to a top and bottom truss that interfaces with a structural support unit (SSU). The SSU contains self-leveling feet and docking interfaces for Tri-ATHLETE grasping and heavy lift. A pressurized module needed to be created that was appropriate for the lunar environment, could be easily relocated to new locations, and could be docked together in multiples for expanding pressurized volume in a lunar outpost. It was determined that horizontally oriented pressure vessels did not optimize floor area, which takes advantage of the gravity vector for full use. Hybrid hard-inflatable habitats added an unproven degree of complexity that may eventually be worked out. Other versions of vertically oriented pressure vessels were either too big, bulky, or did not optimize floor area. The purpose of the HDU vertical habitat module is to provide pressurized units that can be docked together in a modular way for lunar outpost pressurized volume expansion, and allow for other vehicles, rovers, and modules to be attached to the outpost to allow for IVA (intra-vehicular activity) transfer between them. The module is a vertically oriented cylinder with a large radius to allow for maximal floor area and use of volume. The modular, 5- m-diameter HDU vertical habitat

  2. 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...

  3. Stability and control characteristics of an airplane model having a 45.1 degree swept-back wing with aspect ratio 2.50 and taper ratio 0.42 and a 42.8 degree swept-back horizontal tail with aspect ratio 3.87 and taper ratio 0.49

    NASA Technical Reports Server (NTRS)

    Schuldenfrei, Marvin; Comisarow, Paul; Goodson, Kenneth W

    1947-01-01

    Tests were made of an airplane model having a 45.1 degree swept-back wing with aspect ratio 2.50 and taper ratio 0.42 and a 42.8 degree swept-back horizontal tail with aspect ratio 3.87 and taper ratio 0.49 to determine its low-speed stability and control characteristics. The test Reynolds number was 2.87 x 10(6) based on a mean aerodynamic chord of 2.47 feet except for some of the aileron tests which were made at a Reynolds number of 2.05 x 10(6). With the horizontal tail located near the fuselage juncture on the vertical tail, model results indicated static longitudinal instability above a lift coefficient that was 0.15 below the lift coefficient at which stall occurred. Static longitudinal stability, however, was manifested throughout the life range with the horizontal tail located near the top of the vertical tail. The use of 10 degrees negative dihedral on the wing had little effect on the static longitudinal stability characteristics. Preliminary tests of the complete model revealed an undesirable flat spot in the yawing-moment curves at low angles of attack, the directional stability being neutral for yaw angles of plus-or-minus 2 degrees. This undesirable characteristic was improved by replacing the thick original vertical tail with a thin vertical tail and by flattening the top of the dorsal fairing.

  4. Developments in the Use of Proximity and Ratio Cues in Velocity Judgments.

    ERIC Educational Resources Information Center

    Shire, Beatrice; Durkin, Kevin

    Young children's responses to a velocity inference task based on static pictorial stimuli giving cues of proximity and ratio were examined. Subjects (N=65) in preschool through second grade viewed pictures of snails moving horizontally or spiders suspended vertically and were asked to estimate which competitor would reach its destination first.…

  5. Enhance the lifetime and bias stress reliability in organic vertical transistor by UV/Ozone treatment

    NASA Astrophysics Data System (ADS)

    Lin, Hung-Cheng; Chang, Ming-Yu; Zan, Hsiao-Wen; Meng, Hsin-Fei; Chao, Yu-Chiang

    In this paper, we use UV/Ozone treatment to improve the lifetime and bias stress reliability of organic transistor with vertical channel. Even if vertical organic transistor exhibits better bias stress reliability than organic field effect transistor (OFET) due to bulk conduction mechanism, poor lifetime performance is still a challenge. Adding octadecyltrichlorosilane (OTS) to treat the vertical channel can reduce the trapping state and hence improve the bias stress ability. However, off-current is much higher after 6 days and lifetime performance is degraded. On the other hand, after 4000-s on-state bias stress, stable output current and on/off current ratio are demonstrated by using UV/Ozone to treat vertical channels. Threshold voltage shift is only -0.02 V which is much smaller than OFET with the same organic semiconductor material. Furthermore, the output current is also an order enhanced. Nevertheless, unlike device with OTS treatment, no obvious degradation is observed for UV/Ozone treated devices even after 170 days. With UV/Ozone treatment, the output current, bias stress reliability and lifetime were all improved. It makes vertical transistor become a promising device for the further application in display technology and flexible electronics.

  6. Design of passive vehicle suspensions for maximal least damping ratio

    NASA Astrophysics Data System (ADS)

    Smith, Malcolm C.; Swift, Stuart J.

    2016-05-01

    This paper studies the use of the least damping ratio among system poles as a performance metric in passive vehicle suspensions. Methods are developed which allow optimal solutions to be computed in terms of non-dimensional quantities in a quarter-car vehicle model. Solutions are provided in graphical form for convenient use across vehicle types. Three suspension arrangements are studied: the standard suspension involving a parallel spring and damper and two further suspension arrangements involving an inerter. The key parameters for the optimal solutions are the ratios of unsprung mass to sprung mass and suspension static stiffness to tyre vertical stiffness. A discussion is provided of performance trends in terms of the key parameters. A comparison is made with the optimisation of ride comfort and tyre grip metrics for various vehicle types.

  7. High aspect ratio channels in glass and porous silicon

    NASA Astrophysics Data System (ADS)

    Liang, H. D.; Dang, Z. Y.; Wu, J. F.; van Kan, J. A.; Qureshi, S.; Ynsa, M. D.; Torres-Costa, V.; Maira, A.; Venkatesan, T. V.; Breese, M. B. H.

    2017-03-01

    We have developed a micromachining process to produce high-aspect-ratio channels and holes in glass and porous silicon. Our process utilizes MeV proton beam irradiation of silicon using direct writing with a focused beam, followed by electrochemical etching. To increase throughput we have also developed another process for large area ion irradiation based on a radiation-resistant gold surface mask, allowing many square inches to be patterned. We present a study of the achievable channel width, depth and period and sidewall verticality for a range of channels which can be over 100 μm deep or 100 nm wide with aspect ratios up to 80. This process overcomes the difficulty of machining glass on a micro- and nanometer scale which has limited many areas of applications in different fields such as microelectronics and microfluidics.

  8. Highly ordered vertical GaAs nanowire arrays with dry etching and their optical properties.

    PubMed

    Dhindsa, Navneet; Chia, Andrew; Boulanger, Jonathan; Khodadad, Iman; LaPierre, Ray; Saini, Simarjeet S

    2014-08-01

    We report fabrication methods, including metal masks and dry etching, and demonstrate highly ordered vertical gallium arsenide nanowire arrays. The etching process created high aspect ratio, vertical nanowires with insignificant undercutting from the mask, allowing us to vary the diameter from 30 nm to 400 nm with a pitch from 250 nm to 1100 nm and length up to 2.2 μm. A diameter to pitch ratio of ∼68% was achieved. We also measured the reflectance from the nanowire arrays and show experimentally diameter-dependent strong absorption peaks resulting from resonant optical mode excitations within these nanowires. The reflectance curves match very well with simulations. The work done here paves the way towards achieving high efficiency solar cells and tunable photodetectors using III-V nanowires.

  9. Chimney effect due to different vertical position of an isothermal horizontal cylinder confined between two adiabatic walls

    SciTech Connect

    Harsini, Iraj; Ashjaee, Mehdi

    2009-04-15

    The variation of natural convection heat transfer from an isothermal horizontal cylinder confined between two adiabatic walls of constant height is investigated by Mach-Zehnder interferometry technique. This paper focuses on the chimney effect due to the vertical position changes of cylinder (Y) located between two walls with a constant distance of W measuring 1.5 cylinder diameter. The cylinder's local and average Nusselt numbers are determined for ratio of vertical position to its diameter ranging from Y/D = (0 to 10), and the Rayleigh number ranging from 3.5 x 10{sup 3} to 1.4 x 10{sup 4}. There is an optimum distance between the walls in which the Nusselt number is maximum. Results are indicated with a single correlation which gives the average Nusselt number as a function of the ratio of vertical position to cylinder diameter and the Rayleigh number. The experimental data shows that there is an optimum vertical position for the cylinder at which the Nusselt number has a maximum value at each Rayleigh number. This optimal vertical position is derived from the correlation and is presented by an equation. The value of the optimum vertical position increases as the Rayleigh number increases. (author)

  10. Vertical profiles of aerosol optical properties and the solar heating rate estimated by combining sky radiometer and lidar measurements

    NASA Astrophysics Data System (ADS)

    Kudo, Rei; Nishizawa, Tomoaki; Aoyagi, Toshinori

    2016-07-01

    The SKYLIDAR algorithm was developed to estimate vertical profiles of aerosol optical properties from sky radiometer (SKYNET) and lidar (AD-Net) measurements. The solar heating rate was also estimated from the SKYLIDAR retrievals. The algorithm consists of two retrieval steps: (1) columnar properties are retrieved from the sky radiometer measurements and the vertically mean depolarization ratio obtained from the lidar measurements and (2) vertical profiles are retrieved from the lidar measurements and the results of the first step. The derived parameters are the vertical profiles of the size distribution, refractive index (real and imaginary parts), extinction coefficient, single-scattering albedo, and asymmetry factor. Sensitivity tests were conducted by applying the SKYLIDAR algorithm to the simulated sky radiometer and lidar data for vertical profiles of three different aerosols, continental average, transported dust, and pollution aerosols. The vertical profiles of the size distribution, extinction coefficient, and asymmetry factor were well estimated in all cases. The vertical profiles of the refractive index and single-scattering albedo of transported dust, but not those of transported pollution aerosol, were well estimated. To demonstrate the performance and validity of the SKYLIDAR algorithm, we applied the SKYLIDAR algorithm to the actual measurements at Tsukuba, Japan. The detailed vertical structures of the aerosol optical properties and solar heating rate of transported dust and smoke were investigated. Examination of the relationship between the solar heating rate and the aerosol optical properties showed that the vertical profile of the asymmetry factor played an important role in creating vertical variation in the solar heating rate. We then compared the columnar optical properties retrieved with the SKYLIDAR algorithm to those produced with the more established scheme SKYRAD.PACK, and the surface solar irradiance calculated from the SKYLIDAR

  11. Vertically Integrated Multiple Nanowire Field Effect Transistor.

    PubMed

    Lee, Byung-Hyun; Kang, Min-Ho; Ahn, Dae-Chul; Park, Jun-Young; Bang, Tewook; Jeon, Seung-Bae; Hur, Jae; Lee, Dongil; Choi, Yang-Kyu

    2015-12-09

    A vertically integrated multiple channel-based field-effect transistor (FET) with the highest number of nanowires reported ever is demonstrated on a bulk silicon substrate without use of wet etching. The driving current is increased by 5-fold due to the inherent vertically stacked five-level nanowires, thus showing good feasibility of three-dimensional integration-based high performance transistor. The developed fabrication process, which is simple and reproducible, is used to create multiple stiction-free and uniformly sized nanowires with the aid of the one-route all-dry etching process (ORADEP). Furthermore, the proposed FET is revamped to create nonvolatile memory with the adoption of a charge trapping layer for enhanced practicality. Thus, this research suggests an ultimate design for the end-of-the-roadmap devices to overcome the limits of scaling.

  12. Lunar vertical-shaft mining system

    NASA Technical Reports Server (NTRS)

    Introne, Steven D. (Editor); Krause, Roy; Williams, Erik; Baskette, Keith; Martich, Frederick; Weaver, Brad; Meve, Jeff; Alexander, Kyle; Dailey, Ron; White, Matt

    1994-01-01

    This report proposes a method that will allow lunar vertical-shaft mining. Lunar mining allows the exploitation of mineral resources imbedded within the surface. The proposed lunar vertical-shaft mining system is comprised of five subsystems: structure, materials handling, drilling, mining, and planning. The structure provides support for the exploration and mining equipment in the lunar environment. The materials handling subsystem moves mined material outside the structure and mining and drilling equipment inside the structure. The drilling process bores into the surface for the purpose of collecting soil samples, inserting transducer probes, or locating ore deposits. Once the ore deposits are discovered and pinpointed, mining operations bring the ore to the surface. The final subsystem is planning, which involves the construction of the mining structure.

  13. Extreme wave runup on a vertical cliff

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

    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.

  14. Vertical Landing Aerodynamics of Reusable Rocket Vehicle

    NASA Astrophysics Data System (ADS)

    Nonaka, Satoshi; Nishida, Hiroyuki; Kato, Hiroyuki; Ogawa, Hiroyuki; Inatani, Yoshifumi

    The aerodynamic characteristics of a vertical landing rocket are affected by its engine plume in the landing phase. The influences of interaction of the engine plume with the freestream around the vehicle on the aerodynamic characteristics are studied experimentally aiming to realize safe landing of the vertical landing rocket. The aerodynamic forces and surface pressure distributions are measured using a scaled model of a reusable rocket vehicle in low-speed wind tunnels. The flow field around the vehicle model is visualized using the particle image velocimetry (PIV) method. Results show that the aerodynamic characteristics, such as the drag force and pitching moment, are strongly affected by the change in the base pressure distributions and reattachment of a separation flow around the vehicle.

  15. Congenital paralytic vertical talus. An anatomical study.

    PubMed

    Specht, E E

    1975-09-01

    Dissections of the feet of a three-month-old infant with paralytic congenital vertical talus secondary to lumbar myelomeningocele were compared with a dissection of a normal foot. The major differences appeared to be absence of the plantar intrinsic muscles and dorsal dislocation of the talonavicular joint. It is postulated that the pathological process begins as a failure of the intrinsic muscles to oppose the unbalanced, active dorsiflexion forces of the anterior crural muscles. This imbalance then allows disruption of the talonavicular joint, mechanically the least stable joint in the mid-part of the foot. All dorsiflexion forces acting on the ankle then become ineffective and plantar flexion forces serve only to pull the calcaneus and talus into equinus, causing a "vertical" talus. Treatment must be directed at reducing the talonavicular dislocation, correcting the equinus deformity of the hind part of the foot, and substituting for the undeveloped plantar intrinsic muscles.

  16. Vertical-Substrate MPCVD Epitaxial Nanodiamond Growth.

    PubMed

    Tzeng, Yan-Kai; Zhang, Jingyuan Linda; Lu, Haiyu; Ishiwata, Hitoshi; Dahl, Jeremy; Carlson, Robert M K; Yan, Hao; Schreiner, Peter R; Vučković, Jelena; Shen, Zhi-Xun; Melosh, Nicholas; Chu, Steven

    2017-03-08

    Color center-containing nanodiamonds have many applications in quantum technologies and biology. Diamondoids, molecular-sized diamonds have been used as seeds in chemical vapor deposition (CVD) growth. However, optimizing growth conditions to produce high crystal quality nanodiamonds with color centers requires varying growth conditions that often leads to ad-hoc and time-consuming, one-at-a-time testing of reaction conditions. In order to rapidly explore parameter space, we developed a microwave plasma CVD technique using a vertical, rather than horizontally oriented stage-substrate geometry. With this configuration, temperature, plasma density, and atomic hydrogen density vary continuously along the vertical axis of the substrate. This variation allowed rapid identification of growth parameters that yield single crystal diamonds down to 10 nm in size and 75 nm diameter optically active center silicon-vacancy (Si-V) nanoparticles. Furthermore, this method may provide a means of incorporating a wide variety of dopants in nanodiamonds without ion irradiation damage.

  17. Vertical trapezius musculocutaneous flap: a retrospective study.

    PubMed

    Papadopoulos, Othon N; Chrisostomidis, Chrisostomos I; Georgiou, Panagis N; Frangoulis, Marios B; Zapantis-Fragos, Menelaos K; Champsas, Grigorios G

    2005-01-01

    From 1986 to 2001, 17 patients (aged 26-77 years) were treated using the vertical trapezius musculocutaneous flap. A two-stage procedure was used in 7 and a single-stage island flap in 10. The donor site was closed directly in all patients. Mean length of hospital stay was 16 days (range 12-25). There was no operative mortality. Complications were one partial flap necrosis and two seromas of the donor site, complicated by infection. With a minimum follow-up of more than two years, our study confirms the usefulness of the vertical trapezius musculocutaneous flap in head and neck reconstructive surgery. It is a reliable, thin flap of uniform thickness, which carries hairless skin. The length and thickness of its pedicle allows excellent mobility. The main disadvantage of the flap is the complete sacrifice of the muscle necessary for total mobilisation of the flap, and the intraoperative repositioning of the patient.

  18. Coupled Resonator Vertical Cavity Laser Diode

    SciTech Connect

    CHOQUETTE, KENT D.; CHOW, WENG W.; FISCHER, ARTHUR J.; GEIB, KENT M.; HOU, HONG Q.

    1999-09-16

    We report the operation of an electrically injected monolithic coupled resonator vertical cavity laser which consists of an active cavity containing In{sub x}Ga{sub 1{minus}x}As quantum wells optically coupled to a passive GaAs cavity. This device demonstrates novel modulation characteristics arising from dynamic changes in the coupling between the active and passive cavities. A composite mode theory is used to model the output modulation of the coupled resonator vertical cavity laser. It is shown that the laser intensity can be modulated by either forward or reverse biasing the passive cavity. Under forward biasing, the modulation is due to carrier induced changes in the refractive index, while for reverse bias operation the modulation is caused by field dependent cavity enhanced absorption.

  19. Velocity Field in a Vertical Foam Film

    NASA Astrophysics Data System (ADS)

    Seiwert, Jacopo; Kervil, Ronan; Nou, Soniraks; Cantat, Isabelle

    2017-01-01

    The drainage of vertical foam films governs their lifetime. For a foam film supported on a rectangular solid frame, when the interface presents a low resistance to shear, the drainage dynamics involves a complex flow pattern at the film scale, leading to a drainage time proportional to the frame width. Using an original velocimetry technique, based on fluorescent foam films and photobleaching, we measure the horizontal and vertical components of the velocity in a draining film, thus providing the first quantitative experimental evidence of this flow pattern. Upward velocities up to 10 cm /s are measured close to the lateral menisci, whereas a slower velocity field is obtained in the center of the film, with comparable downwards and horizontal components. Scaling laws are proposed for all characteristic velocities, coupling gravitational effects, and capillary suction.

  20. Cephalometric estimation of vertical dimension of occlusion.

    PubMed

    Orthlieb, J D; Laurent, M; Laplanche, O

    2000-09-01

    The literature does not establish a single proven method for determining lower facial height, which is called the Vertical Dimension of Occlusion (VDO), and the concept of a vertical comfort range is generally accepted. This study aimed to test the statistical significance of correlations of mandibular shape versus lower facial height in occlusion, using cephalometric measurements. Correlations for 505 consecutive healthy adults were calculated between angles that estimate the lower facial height and angles that estimate the mandibular shape. The mandibular angle (gonial) showed a higher coefficient of correlation (r = 0.691) than the inferior gonial angle. The dispersion remained large, i.e. r2 = 0.478. Cephalometric measurements, despite theirs imperfections, could help the practitioner to understand what the best course of treatment would be in order to obtain a lower facial height in occlusion showing a skeletal harmony with the mandibular shape.

  1. Experimental Studies in Helicopter Vertical Climb Performance

    NASA Technical Reports Server (NTRS)

    McKillip, Robert M., Jr.

    1996-01-01

    Data and analysis from an experimental program to measure vertical climb performance on an eight-foot model rotor are presented. The rotor testing was performed using a unique moving-model facility capable of accurately simulating the flow conditions during axial flight, and was conducted from July 9, 1992 to July 16, 1992 at the Dynamic Model Track, or 'Long Track,' just prior to its demolition in August of 1992. Data collected during this brief test program included force and moment time histories from a sting-mounted strain gauge balance, support carriage velocity, and rotor rpm pulses. In addition, limited video footage (of marginal use) was recorded from smoke flow studies for both simulated vertical climb and descent trajectories. Analytical comparisons with these data include a series of progressively more detailed calculations ranging from simple momentum theory, a prescribed wake method, and a free-wake prediction.

  2. Natural convection from vertical helical coiled tubes in air

    SciTech Connect

    Ali, M.E.

    1999-07-01

    Helically coiled tubes are used in many engineering applications, such as heating, refrigerating and HVAC systems. They are used also in steam generator and condenser design in power plants because of their large surface area per unit volume. In spite of their widespread use, there is very little information available in the literature on natural convection from such coils. Two experimental investigation have been reported on steady state laminar and transition natural convection from the outer surface of vertically oriented helical coiled tubes in air. Four coils at constant heat flux boundary condition have been used with coil diameter to tube diameter ratio of 16.45 and 23.94. Six more coils have been used at variable surface temperature boundary condition with coil diameter to tube diameter ratio 19.923, 15.904, and 12.798. Local average heat transfer coefficients are obtained for laminar and transition natural convection. The data are correlated with Rayleigh number using the tube diameter as a characteristic length. It has been found that the Nusselt number decreases as Rayleigh number increases for constant heat flux. Transition to turbulent natural convection regime has obtained at a critical Rayleigh number of about 5,000 and it characterizes by a waveform like relation between Nusselt number and Rayleigh number.

  3. Vertical shift register using dipolar interaction in magnetic multilayers

    NASA Astrophysics Data System (ADS)

    Chin, Shin-Liang; Fernández-Pacheco, Amalio; Petit, Dorothée C. M. C.; Cowburn, Russell P.

    2015-12-01

    A vertical shift register consisting of multi-layered ferromagnetic bars with in-plane magnetization is investigated numerically using macrospin simulations. These layers are anti-ferromagnetically coupled via dipolar interactions and their in-plane aspect ratio determines their anisotropy. A single data bit is represented by a magnetic kink soliton, which forms at the boundary of two anti-parallel domains with opposite phases. It can be propagated bi-directionally using an externally applied rotating magnetic field. The soliton propagation is dependent on the applied field strength, the magnetic anisotropy of the ferromagnetic layers, and the dipolar coupling energies. For the device investigated here, the largest field range for soliton propagation is found to be from 35 Oe to 235 Oe at a lateral aspect ratio of 1.33. The soliton is also subjected to edge effects where it can be either pinned or reflected rather than being expelled from the stack. It is found that by reducing the thickness of the edge layer, these effects can be reduced substantially. By reducing the thickness of the edge layer by 20%, the field range in which the soliton is expelled increases by more than a factor of two.

  4. Jamming of Monodisperse Cylindrical Grains in Featureless Vertical Channels

    NASA Astrophysics Data System (ADS)

    Friedl, Nicholas; Baxter, G. William

    2014-03-01

    We study jamming of low aspect-ratio cylindrical Delrin grains falling through a featureless vertical channel under the influence of gravity. These grains have an aspect-ratio less than two (H/D < 2) and resemble aspirin tablets, 35mm film canisters, poker chips, or coins. Monodisperse 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. 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. Supported by an Undergraduate Research Grant from Penn State Erie, The Behrend College.

  5. Blade pitch optimization methods for vertical-axis wind turbines

    NASA Astrophysics Data System (ADS)

    Kozak, Peter

    Vertical-axis wind turbines (VAWTs) offer an inherently simpler design than horizontal-axis machines, while their lower blade speed mitigates safety and noise concerns, potentially allowing for installation closer to populated and ecologically sensitive areas. While VAWTs do offer significant operational advantages, development has been hampered by the difficulty of modeling the aerodynamics involved, further complicated by their rotating geometry. This thesis presents results from a simulation of a baseline VAWT computed using Star-CCM+, a commercial finite-volume (FVM) code. VAWT aerodynamics are shown to be dominated at low tip-speed ratios by dynamic stall phenomena and at high tip-speed ratios by wake-blade interactions. Several optimization techniques have been developed for the adjustment of blade pitch based on finite-volume simulations and streamtube models. The effectiveness of the optimization procedure is evaluated and the basic architecture for a feedback control system is proposed. Implementation of variable blade pitch is shown to increase a baseline turbine's power output between 40%-100%, depending on the optimization technique, improving the turbine's competitiveness when compared with a commercially-available horizontal-axis turbine.

  6. Engineering high-performance vertical cavity lasers

    SciTech Connect

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

    1996-12-31

    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.

  7. Spirit 360-Degree View, Sol 388 (vertical)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    NASA's Mars Exploration Rover Spirit used its navigation camera to take the images combined into this 360-degree view of the rover's surroundings on Spirit's 388th martian day, or sol (Feb. 4, 2005). Spirit had driven about 13 meters (43 feet) uphill toward 'Cumberland Ridge' on this sol. This location is catalogued as Spirit's Site 102, Position 513. The view is presented in a vertical projection with geometric and brightness seam correction.

  8. RADIALLY MAGNETIZED PROTOPLANETARY DISK: VERTICAL PROFILE

    SciTech Connect

    Russo, Matthew; Thompson, Christopher

    2015-11-10

    This paper studies the response of a thin accretion disk to an external radial magnetic field. Our focus is on protoplanetary disks (PPDs), which are exposed during their later evolution to an intense, magnetized wind from the central star. A radial magnetic field is mixed into a thin surface layer, wound up by the disk shear, and pushed downward by a combination of turbulent mixing and ambipolar and ohmic drift. The toroidal field reaches much greater strengths than the seed vertical field that is usually invoked in PPD models, even becoming superthermal. Linear stability analysis indicates that the disk experiences the magnetorotational instability (MRI) at a higher magnetization than a vertically magnetized disk when both the effects of ambipolar and Hall drift are taken into account. Steady vertical profiles of density and magnetic field are obtained at several radii between 0.06 and 1 AU in response to a wind magnetic field B{sub r} ∼ (10{sup −4}–10{sup −2})(r/ AU){sup −2} G. Careful attention is given to the radial and vertical ionization structure resulting from irradiation by stellar X-rays. The disk is more strongly magnetized closer to the star, where it can support a higher rate of mass transfer. As a result, the inner ∼1 AU of a PPD is found to evolve toward lower surface density. Mass transfer rates around 10{sup −8} M{sub ⊙} yr{sup −1} are obtained under conservative assumptions about the MRI-generated stress. The evolution of the disk and the implications for planet migration are investigated in the accompanying paper.

  9. Understanding Vertical Jump Potentiation: A Deterministic Model.

    PubMed

    Suchomel, Timothy J; Lamont, Hugh S; Moir, Gavin L

    2016-06-01

    This review article discusses previous postactivation potentiation (PAP) literature and provides a deterministic model for vertical jump (i.e., squat jump, countermovement jump, and drop/depth jump) potentiation. There are a number of factors that must be considered when designing an effective strength-power potentiation complex (SPPC) focused on vertical jump potentiation. Sport scientists and practitioners must consider the characteristics of the subject being tested and the design of the SPPC itself. Subject characteristics that must be considered when designing an SPPC focused on vertical jump potentiation include the individual's relative strength, sex, muscle characteristics, neuromuscular characteristics, current fatigue state, and training background. Aspects of the SPPC that must be considered for vertical jump potentiation include the potentiating exercise, level and rate of muscle activation, volume load completed, the ballistic or non-ballistic nature of the potentiating exercise, and the rest interval(s) used following the potentiating exercise. Sport scientists and practitioners should design and seek SPPCs that are practical in nature regarding the equipment needed and the rest interval required for a potentiated performance. If practitioners would like to incorporate PAP as a training tool, they must take the athlete training time restrictions into account as a number of previous SPPCs have been shown to require long rest periods before potentiation can be realized. Thus, practitioners should seek SPPCs that may be effectively implemented in training and that do not require excessive rest intervals that may take away from valuable training time. Practitioners may decrease the necessary time needed to realize potentiation by improving their subject's relative strength.

  10. Vertical Carbon Nanotube Device in Nanoporous Templates

    NASA Technical Reports Server (NTRS)

    Maschmann, Matthew Ralph (Inventor); Fisher, Timothy Scott (Inventor); Sands, Timothy (Inventor); Bashir, Rashid (Inventor)

    2014-01-01

    A modified porous anodic alumina template (PAA) containing a thin CNT catalyst layer directly embedded into the pore walls. CNT synthesis using the template selectively catalyzes SWNTs and DWNTs from the embedded catalyst layer to the top PAA surface, creating a vertical CNT channel within the pores. Subsequent processing allows for easy contact metallization and adaptable functionalization of the CNTs and template for a myriad of applications.

  11. Vertical flight path steering system for aircraft

    NASA Technical Reports Server (NTRS)

    Lambregts, Antonius A. (Inventor)

    1983-01-01

    Disclosed is a vertical flight path angle steering system for aircraft, utilizing a digital flight control computer which processes pilot control inputs and aircraft response parameters into suitable elevator commands and control information for display to the pilot on a cathode ray tube. The system yields desirable airplane control handling qualities and responses as well as improvements in pilot workload and safety during airplane operation in the terminal area and under windshear conditions.

  12. Vertical Lift - Not Just For Terrestrial Flight

    DTIC Science & Technology

    2000-10-01

    Cassini space mission will reach Saturn’s orbit and release the Huygens probe (descending via parachute) into Titan’s atmosphere. The Huygens ...is outside the official mission scope). This accomplishment will likely come from future missions post- Cassini / Huygens . The use of vertical lift...from HST) With the arrival of the Cassini / Huygens spacecraft to Saturn and Titan in 2004 -- and the anticipated science and outreach bonanza from this

  13. The distinctive vertical heterophoria of dyslexics

    PubMed Central

    Quercia, Patrick; Quercia, Madeleine; Feiss, Léonard J; Allaert, François

    2015-01-01

    In this study, we looked for the presence of vertical heterophoria (VH) in 42 dyslexic children (22 males and 20 females) aged 118.5±12.9 months who were compared with a control group of 22 nondyslexic children (eleven males and eleven females) aged 112±9.8 months. Dyslexics presented a low-level (always <1 prism diopter) VH combined with torsion. This oculomotor feature clearly separates the dyslexic group from the normal readers group. It is independent of the type of dyslexia. The essential feature of this VH is a lability that appears during specific stimulation of sensory receptors involved in postural regulation. This lability is demonstrated using a vertical Maddox test conducted under very specific conditions in which postural sensors are successively stimulated in a predetermined order. A quantitative variation in this VH may be seen during the Bielchowsky Head Tilt Test, which reveals hypertonia of the lower or upper oblique muscles. Vertical orthophoria can be achieved by placing low-power prisms asymmetrically within the direction of action of the superior or inferior oblique muscles. The selection of power and axis is not only guided by elements of the eye examination but also from observation of postural muscle tone. All these elements suggest that the VH could be of postural origin and somehow related to the vertical action of the oblique muscles. VH and torsion are not harmful per se. There is no statistical relationship between their level and the various parameters used to assess the reading skills of dyslexic children. VH and torsion could be a clinical marker of global proprioceptive dysfunction responsible for high-level multisensory disturbances secondary to poor spatial localization of visual and auditory information. This dysfunction might also explain the motor disorders concomitant to dyslexia. PMID:26445526

  14. Inverse scattering problem for quantum graph vertices

    SciTech Connect

    Cheon, Taksu; Turek, Ondrej; Exner, Pavel

    2011-06-15

    We demonstrate how the inverse scattering problem of a quantum star graph can be solved by means of diagonalization of the Hermitian unitary matrix when the vertex coupling is of the scale-invariant (or Fueloep-Tsutsui) form. This enables the construction of quantum graphs with desired properties in a tailor-made fashion. The procedure is illustrated on the example of quantum vertices with equal transmission probabilities.

  15. Electrically floating, near vertical incidence, skywave antenna

    SciTech Connect

    Anderson, Allen A.; Kaser, Timothy G.; Tremblay, Paul A.; Mays, Belva L.

    2014-07-08

    An Electrically Floating, Near Vertical Incidence, Skywave (NVIS) Antenna comprising an antenna element, a floating ground element, and a grounding element. At least part of said floating ground element is positioned between said antenna element and said grounding element. The antenna is separated from the floating ground element and the grounding element by one or more electrical insulators. The floating ground element is separated from said antenna and said grounding element by one or more electrical insulators.

  16. Calculation of vertical and ramp-assisted takeoffs for supersonic cruise fighters

    NASA Technical Reports Server (NTRS)

    Liu, G. C.

    1984-01-01

    A procedure that allows rapid preliminary evaluations of the vertical, short, and normal takeoff performance of supersonic cruise aircraft concepts was developed into a numerical computer program. The program is used to determine the effects on takeoff performance of various parameters, such as thrust-weight ratio, wing loading, thrust vector angle, and flap setting. Ramp-assisted takeoffs for overloaded configurations typical of a ground-attack mission are included. The effects of wind on the takeoff performance are also considered.

  17. Estimating diversity via frequency ratios.

    PubMed

    Willis, Amy; Bunge, John

    2015-12-01

    We wish to estimate the total number of classes in a population based on sample counts, especially in the presence of high latent diversity. Drawing on probability theory that characterizes distributions on the integers by ratios of consecutive probabilities, we construct a nonlinear regression model for the ratios of consecutive frequency counts. This allows us to predict the unobserved count and hence estimate the total diversity. We believe that this is the first approach to depart from the classical mixed Poisson model in this problem. Our method is geometrically intuitive and yields good fits to data with reasonable standard errors. It is especially well-suited to analyzing high diversity datasets derived from next-generation sequencing in microbial ecology. We demonstrate the method's performance in this context and via simulation, and we present a dataset for which our method outperforms all competitors.

  18. Models of ratio schedule performance.

    PubMed

    Bizo, L A; Killeen, P R

    1997-07-01

    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 engendered more responding, affecting primarily the parameter alpha (specific activation). Key pecking was faster than treadle pressing, affecting primarily the parameter delta (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.

  19. Strange Baryon to Meson Ratio

    NASA Astrophysics Data System (ADS)

    Cuautle, Eleazar; Ayala, Alejandro

    2014-05-01

    We present a model to compute baryon and meson transverse momentum distributions, and their ratios, in relativistic heavy-ion collisions. The model allows to compute the probability to form colorless bound states of either two or three quarks as functions of the evolving density during the collision. The qualitative differences of the baryon to meson ratio for different collision energies and for different particle species can be associated to the different density dependent probabilities and to the combinatorial factors which in turn depend on whether the quarks forming the bound states are heavy or light. We compare to experimental data and show that we obtain a good description up to intermediate values of pt.

  20. A Vertically Integrated Junctionless Nanowire Transistor.

    PubMed

    Lee, Byung-Hyun; Hur, Jae; Kang, Min-Ho; Bang, Tewook; Ahn, Dae-Chul; Lee, Dongil; Kim, Kwang-Hee; Choi, Yang-Kyu

    2016-03-09

    A vertically integrated junctionless field-effect transistor (VJ-FET), which is composed of vertically stacked multiple silicon nanowires (SiNWs) with a gate-all-around (GAA) structure, is demonstrated on a bulk silicon wafer for the first time. The proposed VJ-FET mitigates the issues of variability and fabrication complexity that are encountered in the vertically integrated multi-NW FET (VM-FET) based on an identical structure in which the VM-FET, as recently reported, harnesses a source and drain (S/D) junction for its operation and is thus based on the inversion mode. Variability is alleviated by bulk conduction in a junctionless FET (JL-FET), where current flows through the core of the SiNW, whereas it is not mitigated by surface conduction in an inversion mode FET (IM-FET), where current flows via the surface of the SiNW. The fabrication complexity is reduced by the inherent JL structure of the JL-FET because S/D formation is not required. In contrast, it is very difficult to dope the S/D when it is positioned at each floor of a tall SiNW with greater uniformity and with less damage to the crystalline structure of the SiNW in a VM-FET. Moreover, when the proposed VJ-FET is used as nonvolatile flash memory, the endurance and retention characteristics are improved due to the above-mentioned bulk conduction.

  1. Vertical and horizontal seismometric observations of tides

    NASA Astrophysics Data System (ADS)

    Lambotte, S.; Rivera, L.; Hinderer, J.

    2006-01-01

    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 such as topography, geology and cavity effects, which imply a strain-tilt coupling. We use series of data (duration larger than 1 month) from several permanent broadband seismological stations to examine these disturbances. We search a minimal set of observable signals (tilts, horizontal and vertical displacements, strains, gravity) necessary to reconstruct the seismological record. Such analysis gives a set of coefficients (per component for each studied station), which are stable over years and then can be used systematically to correct data from these disturbances without needing heavy numerical computation. A special attention is devoted to ocean loading for stations close to oceans (e.g. Matsushiro station in Japon (MAJO)), and to pressure correction when barometric data are available. Interesting observations are made for vertical seismometric components; in particular, we found a pressure admittance between pressure and data 10 times larger than for gravimeters for periods larger than 1 day, while this admittance reaches the usual value of -3.5 nm/s 2/mbar for periods below 3 h. This observation may be due to instrumental noise, but the exact mechanism is not yet understood.

  2. Vertical vorticity at a free surface

    NASA Astrophysics Data System (ADS)

    Fontana, Paul W.

    2016-11-01

    The concept of surface vorticity is developed as a necessary consequence of the discontinuity of flow at the fluid surface. The construct provides the proper boundary conditions for a vortex-dynamical description of surface waves. It is shown that the perturbed free surface in general possesses vertical vorticity, even when the underlying flow is irrotational and the fluid is ideal. This resolves a paradox pointed out by Umeki, who discovered irrotational surface waves with surface rotation in the horizontal plane. A dynamical equation for vertical vorticity at the free surface is derived and interpreted physically. The traditional idea that vortex lines terminate at fluid boundaries is shown to be unphysical and is amended to include surface vorticity. The extension of vertical surface vorticity into the bulk is connected with particular topological structures, such as plughole vortices, breaking waves, and Klein's Kaffeelöffel. This analysis generalizes boundary-layer vorticity theory to the free surface in the ideal limit. The analogy between surface vorticity on an ideal liquid and sheet currents at the surface of a superconductor is described. Work done as a Visiting Fellow at the Australian National University.

  3. Diffusion weighted vertical gradient and spin echo.

    PubMed

    Engström, Mathias; Bammer, Roland; Skare, Stefan

    2012-12-01

    In this work, diffusion weighting and parallel imaging is combined with a vertical gradient and spin echo data readout. This sequence was implemented and evaluated on healthy volunteers using a 1.5 and a 3 T whole-body MR system. As the vertical gradient and spin echo trajectory enables a higher k-space velocity in the phase-encoding direction than single-shot echo planar imaging, the geometrical distortions are reduced. When combined with parallel imaging such as generalized autocalibrating partially parallel acquisition, the geometric distortions are reduced even further, while also keeping the minimum echo time reasonably low. However, this combination of a diffusion preparation and multiple refocusing pulses during the vertical gradient and spin echo readout, generally violates the Carr-Purcell-Meiboom-Gill condition, which leads to interferences between echo pathways. To suppress the stimulated echo pathway, refocusing pulses with a sharper slice profiles and an odd/even crusher variation scheme were implemented and evaluated. Being a single-shot acquisition technique, the reconstructed images are robust to rigid-body head motion and spatially varying brain motion, both of which are common sources of artifacts in diffusion MRI.

  4. Vertical tectonics at an active continental margin

    NASA Astrophysics Data System (ADS)

    Houlié, N.; Stern, T. A.

    2017-01-01

    Direct observations of vertical movements of the earth's surface are now possible with space-based GPS networks, and have applications to resources, hazards and tectonics. Here we present data on vertical movements of the Earth's surface in New Zealand, computed from the processing of GPS data collected between 2000 and 2015 by 189 permanent GPS stations. We map the geographical variation in vertical rates and show how these variations are explicable within a tectonic framework of subduction, volcanic activity and slow slip earthquakes. Subsidence of >3 mm/yr is observed along southeastern North Island and is interpreted to be due to the locked segment of the Hikurangi subduction zone. Uplift of 1-3 mm/yr further north along the margin of the eastern North Island is interpreted as being due to the plate interface being unlocked and underplating of sediment on the subduction thrust. The Volcanic Plateau of the central North Island is being uplifted at about 1 mm/yr, which can be explained by basaltic melts being injected in the active mantle-wedge at a rate of ∼6 mm/yr. Within the Central Volcanic Region there is a 250 km2 area that subsided between 2005 and 2012 at a rate of up to 14 mm/yr. Time series from the stations located within and near the zone of subsidence show a strong link between subsidence, adjacent uplift and local earthquake swarms.

  5. Sunrise enhancement of equatorial vertical plasma drift

    NASA Astrophysics Data System (ADS)

    Liu, Libo; Zhang, Ruilong; Le, Huijun

    2016-04-01

    Sunrise enhancement in vertical plasma drift over equatorial regions is not discernible in the statistical picture compared with the significant enhancement during dusk hours. In this report, it is the first time to investigate the occurrence of the dawn enhancement in the equatorial ionospheric vertical plasma drift from ROCSAT-1 observations during geomagnetic quiet times. The dawn enhancements occur most frequently in June solstice and least frequently in December solstice. The statistical survey shows that the occurrence depends on the magnetic declination. The enhancement has the strongest amplitude in regions near 320° longitude and peaks during June solstice. The dawn enhancement reaches its peak after the sunrise in conjugated E regions. Furthermore, it is found that the dawn enhancement is closely related to the difference between the sunrise times in the conjugated E regions (sunrise time lag). The dawn enhancement occurs easily in regions with a large sunrise time lag. Moreover, we will report the effects of the sunrise enhancement of vertical plasma drift on the equatorial ionosphere as indicated from the observations and model simulations. We thanks National Central University of Taiwan providing the ROCSAT-1 data. The Ap and F107 indices are obtained from the National Geophysical Data Center (http://spidr.ngdc.noaa.gov/spidr/). This research is supported by National Natural Science Foundation of China (41231065), the Chinese Academy of Sciences project (KZZD-EW-01-3), National Key Basic Research Program of China (2012CB825604) and National Natural Science Foundation of China (41321003).

  6. Vertical variations of coral reef drag forces

    NASA Astrophysics Data System (ADS)

    Asher, Shai; Niewerth, Stephan; Koll, Katinka; Shavit, Uri

    2016-05-01

    Modeling flow in a coral reef requires a closure model that links the local drag force to the local mean velocity. However, the spatial flow variations make it difficult to predict the distribution of the local drag. Here we report on vertical profiles of measured drag and velocity in a laboratory reef that was made of 81 Pocillopora Meandrina colony skeletons, densely arranged along a tilted flume. Two corals were CT-scanned, sliced horizontally, and printed using a 3-D printer. Drag was measured as a function of height above the bottom by connecting the slices to drag sensors. Profiles of velocity were measured in-between the coral branches and above the reef. Measured drag of whole colonies shows an excellent agreement with previous field and laboratory studies; however, these studies never showed how drag varies vertically. The vertical distribution of drag is reported as a function of flow rate and water level. When the water level is the same as the reef height, Reynolds stresses are negligible and the drag force per unit fluid mass is nearly constant. However, when the water depth is larger, Reynolds stress gradients become significant and drag increases with height. An excellent agreement was found between the drag calculated by a momentum budget and the measured drag of the individual printed slices. Finally, we propose a modified formulation of the drag coefficient that includes the normal dispersive stress term and results in reduced variations of the drag coefficient at the cost of introducing an additional coefficient.

  7. Sex ratios in bumble bees

    PubMed Central

    Bourke, A. F. G.

    1997-01-01

    The median proportion of investment in females among 11 populations of seven bumble bee (Bombus) species was 0.32 (range 0.07 to 0.64). By contrast, two species of workerless social parasites in the related genus Psithyrus had female-biased sex allocation, the reasons for which remain unclear. Male-biased sex allocation in Bombus contradicts the predictions of Trivers and Hare's sex ratio model for the social Hymenoptera, which are that the population sex investment ratio should be 0.5 (1:1) under queen control and 0.75 (3:1 females:males) under worker control (assuming single, once-mated, outbred queens and non-reproductive workers). Male bias in Bombus does not appear to be either an artefact, or purely the result of symbiotic sex ratio distorters. According to modifications of the Trivers–Hare model, the level of worker male-production in Bombus is insufficient to account for observed levels of male bias. There is also no evidence that male bias arises from either local resource competition (related females compete for resources) or local mate enhancement (related males cooperate in securing mates). Bulmer presented models predicting sexual selection for protandry (males are produced before females) in annual social Hymenoptera and, as a consequence (given some parameter values), male-biased sex allocation. Bumble bees fit the assumptions of Bulmer's models and are protandrous. These models therefore represent the best current explanation for the bees' male-biased sex investment ratios. This conclusion suggests that the relative timing of the production of the sexes strongly influences sex allocation in the social Hymenoptera.

  8. Segregation Ratios in Alport's Syndrome

    PubMed Central

    MacNeill, Elizabeth; Shaw, Richard F.

    1973-01-01

    Pooled data of 35 pedigrees for Alport's syndrome were analysed. Affected to normal ratios among the offspring of heterozgyous fathers and mothers were tabulated. Offspring of heterozygous mothers were tabulated separately where the mother showed symptoms of the disease and where she was asymptomatic. Three current theories on the inheritance of Alport's syndrome are considered and discussed. Each theory fails to account fully for the known facts. A non-chromosomal agent has not yet been excluded for this intriguing disease. PMID:4697851

  9. Photoimageable Polyimide: A Dielectric Material For High Aspect Ratio Structures

    NASA Astrophysics Data System (ADS)

    Cech, Jay M.; Oprysko, Modest M.; Young, Peter L.; Li, Kin

    1986-07-01

    Polyimide has been identified as a useful material for microelectronic packaging because of its low dielectric constant and high temperature stability. Difficulties involved with reactive ion etching (RIE), a conventional technique for patterning thick polyimide films (thickness greater than 5 microns) with vertical walls, can be overcome by using photimageable polyimide precursors. The processing steps are similar to those used with negative photoresists. EM Chemical's HTR-3 photosensitive polyimide has been spun on up to a thickness of 12 microns. Exposure with a dose of 780 mJcm-2 of ultraviolet light, followed by spin development produces clean patterns as small as 5 microns corresponding to an aspect ratio of 2.4. When the patterned precursor is heated, an imidization reaction occurs converting the patterned film to polyimide. Baking to ca. 400 degrees C results in substantial loss in the thickness and in line width. However, shrinkage occurs reproducibly so useful rules for mask design can be formulated. Near vertical wall structures can be fabricated by taking advantage of the optical and shrinkage properties of the polyimide precursor. After development, an undercut wall profile can be produced since the bottom of the film receives less exposure and is hence more soluble in the developer. During heating, lateral shrinkage pulls the top of the film inward producing a vertical wall since the bottom is fixed to the substrate by adhesion. As a result, fully cured polyimide structures with straight walls and aspect ratios greater than one can be obtained. Dielectric properties of the fully imidized films were investigated with capacitor test structures. A relative dielectric constant of 3.3 and a loss tangent of .002 were measured at 20 kHz. It was also found that the dielectric constant increases as a linear function of relative humidity.

  10. Optic disc boundary segmentation from diffeomorphic demons registration of monocular fundus image sequences versus 3D visualization of stereo fundus image pairs for automated early stage glaucoma assessment

    NASA Astrophysics Data System (ADS)

    Gatti, Vijay; Hill, Jason; Mitra, Sunanda; Nutter, Brian

    2014-03-01

    Despite the current availability in resource-rich regions of advanced technologies in scanning and 3-D imaging in current ophthalmology practice, world-wide screening tests for early detection and progression of glaucoma still consist of a variety of simple tools, including fundus image-based parameters such as CDR (cup to disc diameter ratio) and CAR (cup to disc area ratio), especially in resource -poor regions. Reliable automated computation of the relevant parameters from fundus image sequences requires robust non-rigid registration and segmentation techniques. Recent research work demonstrated that proper non-rigid registration of multi-view monocular fundus image sequences could result in acceptable segmentation of cup boundaries for automated computation of CAR and CDR. This research work introduces a composite diffeomorphic demons registration algorithm for segmentation of cup boundaries from a sequence of monocular images and compares the resulting CAR and CDR values with those computed manually by experts and from 3-D visualization of stereo pairs. Our preliminary results show that the automated computation of CDR and CAR from composite diffeomorphic segmentation of monocular image sequences yield values comparable with those from the other two techniques and thus may provide global healthcare with a cost-effective yet accurate tool for management of glaucoma in its early stage.

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

    PubMed Central

    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

    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. PMID:21770805

  12. Optic Disc and Optic Cup Segmentation Methodologies for Glaucoma Image Detection: A Survey

    PubMed Central

    Almazroa, Ahmed; Burman, Ritambhar; Raahemifar, Kaamran; Lakshminarayanan, Vasudevan

    2015-01-01

    Glaucoma is the second leading cause of loss of vision in the world. Examining the head of optic nerve (cup-to-disc ratio) is very important for diagnosing glaucoma and for patient monitoring after diagnosis. Images of optic disc and optic cup are acquired by fundus camera as well as Optical Coherence Tomography. The optic disc and optic cup segmentation techniques are used to isolate the relevant parts of the retinal image and to calculate the cup-to-disc ratio. The main objective of this paper is to review segmentation methodologies and techniques for the disc and cup boundaries which are utilized to calculate the disc and cup geometrical parameters automatically and accurately to help the professionals in the glaucoma to have a wide view and more details about the optic nerve head structure using retinal fundus images. We provide a brief description of each technique, highlighting its classification and performance metrics. The current and future research directions are summarized and discussed. PMID:26688751

  13. Envera Variable Compression Ratio Engine

    SciTech Connect

    Charles Mendler

    2011-03-15

    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

  14. 19. VERTICAL VIEW, FROM DECK, SHOWING CONNECTION OF CENTER TRUSS ...

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

    19. VERTICAL VIEW, FROM DECK, SHOWING CONNECTION OF CENTER TRUSS TENSION BARS, DIAGONAL TENSION RODS, AND LATTICE-JOINED VERTICAL CHANNELS - Lenox Bridge, Spanning Obion River, Rural Road S8025, Lenox, Dyer County, TN

  15. A Vertical Grid Module for Baroclinic Models of the Atmosphere

    SciTech Connect

    Drake, John B

    2008-04-01

    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 σ, isentropic θ 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.

  16. 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

  17. 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

  18. 24. PIN CONNECTION AT VERTICAL AND BOTTOM CHORD ON CAMELBACK ...

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

    24. PIN CONNECTION AT VERTICAL AND BOTTOM CHORD ON CAMELBACK THROUGH TRUSS. VERTICAL AND BOTTOM CHORD MADE OF HAND-FORGED EYE BARS - New River Bridge, Spanning New River at State Route 623, Pembroke, Giles County, VA

  19. ostglacial rebound from VLBI Geodesy: On Establishing Vertical Reference

    NASA Technical Reports Server (NTRS)

    Argus, Donald .

    1996-01-01

    I propose that a useful reference frame for vertical motions is that found by minimizing differences between vertical motions observed with VLBI [Ma and Ryan, 1995] and predictions from postglacial rebound predictions [Peltier, 1995].

  20. Autocalibrating Tiled Projectors on Piecewise Smooth Vertically Extruded Surfaces.

    PubMed

    Sajadi, Behzad; Majumder, Aditi

    2011-09-01

    In this paper, we present a novel technique to calibrate multiple casually aligned projectors on fiducial-free piecewise smooth vertically extruded surfaces using a single camera. Such surfaces include cylindrical displays and CAVEs, common in immersive virtual reality systems. We impose two priors to the display surface. We assume the surface is a piecewise smooth vertically extruded surface for which the aspect ratio of the rectangle formed by the four corners of the surface is known and the boundary is visible and segmentable. Using these priors, we can estimate the display's 3D geometry and camera extrinsic parameters using a nonlinear optimization technique from a single image without any explicit display to camera correspondences. Using the estimated camera and display properties, the intrinsic and extrinsic parameters of each projector are recovered using a single projected pattern seen by the camera. This in turn is used to register the images on the display from any arbitrary viewpoint making it appropriate for virtual reality systems. The fast convergence and robustness of this method is achieved via a novel dimension reduction technique for camera parameter estimation and a novel deterministic technique for projector property estimation. This simplicity, efficiency, and robustness of our method enable several coveted features for nonplanar projection-based displays. First, it allows fast recalibration in the face of projector, display or camera movements and even change in display shape. Second, this opens up, for the first time, the possibility of allowing multiple projectors to overlap on the corners of the CAVE-a popular immersive VR display system. Finally, this opens up the possibility of easily deploying multiprojector displays on aesthetic novel shapes for edutainment and digital signage applications.

  1. Using Ratio Analysis to Evaluate Financial Performance.

    ERIC Educational Resources Information Center

    Minter, John; And Others

    1982-01-01

    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)

  2. Adsorption to fish sperm of vertically transmitted fish viruses

    USGS Publications Warehouse

    Mulcahy, D.; Pascho, R.J.

    1984-01-01

    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.

  3. Vertical Structure and Vertical Evolution of Halogen Activation Events Observed by Autonomous Buoys

    NASA Astrophysics Data System (ADS)

    Simpson, W. R.; Peterson, P.; Burd, J.

    2015-12-01

    Heterogeneous reactions on saline surfaces release reactive halogen species in the Arctic during late winter / spring (Feb--May). These reactive halogens drastically alter the photooxidative environment, removing ozone and oxidizing mercury and hydrocarbons. Both the snowpack and suspended particles / blowing snow possess surfaces that can sustain this chemistry, leading to variations in reactive halogen vertical profiles and temporal evolution of those profiles. This chemistry also occurs in a typically stable (inverted) atmospheric structure that hinders vertical mixing, limiting the vertical extent of snowpack influence. In this presentation, Multiple-AXis Differential Optical Absorption Spectroscopy (MAXDOAS) of bromine monoxide (BrO) along with optimal estimation inversions are used to measure the vertical structure of BrO. The effective mixing height of the BrO layer varies with atmospheric stability, and an event is shown where a shallow but highly concentrated layer of surface BrO encounters sea-ice-lead-induced convection that vertically mixes the BrO higher, initially diluting the surface concentration. Over time, the surface concentration recovers and the now thicker layer grows to a higher column density of BrO. Understanding of the relationship between BrO event intensity and meteorological situations can help to understand BrO chemistry and remote sensing and assist in prediction of how reactive halogens may respond to a changing Arctic climate.

  4. Low conversion ratio fuel studies.

    SciTech Connect

    Smith, M. A.

    2006-02-28

    Recent studies on TRU disposition in fast reactors indicated viable reactor performance for a sodium cooled low conversion ratio reactor design. Additional studies have been initiated to refine the earlier work and consider the feasibility of alternate fuel forms such as nitride and oxide fuel (rather than metal fuel). These alternate fuel forms may have significant impacts upon the burner design and the safety behavior. The work performed thus far has focused on compiling the necessary fuel form property information and refinement of the physics models. For this limited project, the burner design and performance using nitride fuel will be assessed.

  5. Are all types of vertical information created equal?

    PubMed

    Weisberg, Steven M; Newcombe, Nora S

    2013-10-01

    The vertical component of space occurs in two distinct fashions in natural environments. One kind of verticality is orthogonal-to-horizontal (as in climbing trees, operating in volumetric spaces such as water or air, or taking elevators in multilevel buildings). Another kind of verticality, which might be functionally distinct, comes from navigating on sloped terrain (as in traversing hills or ramps).

  6. Mechanical design of NASA Ames Research Center vertical motion simulator

    NASA Technical Reports Server (NTRS)

    Engelbert, D. F.; Bakke, A. P.; Chargin, M. K.; Vallotton, W. C.

    1976-01-01

    NASA has designed and is constructing a new flight simulator with large vertical travel. Several aspects of the mechanical design of this Vertical Motion Simulator (VMS) are discussed, including the multiple rack and pinion vertical drive, a pneumatic equilibration system, and the friction-damped rigid link catenaries used as cable supports.

  7. Vertically oval corneas in a child with holoprosencephaly.

    PubMed

    Lee, Esther S; Wasserman, Barry N; Saslow, Judy G; Schnur, Rhonda E; Levin, Alex V

    2012-07-17

    Vertically oval-shaped corneas are an uncommon ophthalmic finding. The normal human cornea has an oval shape, but is wider in the horizontal dimension. The etiology of vertically oval corneas is unclear. This report presents a case of bilateral vertical oval corneas in a male infant with semilobar holoprosencephaly.

  8. 49 CFR 179.14 - Coupler vertical restraint system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... section shall be achieved by verification testing of the coupler vertical restraint system in accordance... be equipped with couplers having this vertical restraint capability. (b) Test verification. Except as... section; (2) The testing apparatus shall simulate the vertical coupler performance at the mating...

  9. 49 CFR 179.14 - Coupler vertical restraint system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... section shall be achieved by verification testing of the coupler vertical restraint system in accordance... be equipped with couplers having this vertical restraint capability. (b) Test verification. Except as... section; (2) The testing apparatus shall simulate the vertical coupler performance at the mating...

  10. 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...

  11. Correction of neglected vertical talus deformity in an adult.

    PubMed

    Lui, Tun Hing

    2015-02-18

    Congenital vertical talus is an uncommon foot deformity that is characterised by a fixed dorsal dislocation of the navicular on the talar head and neck. Left untreated, a congenital vertical talus causes significant long-term disability. We present a case of neglected vertical talus in a middle-aged woman who was successfully treated with resection of the talar head and tendon transfers.

  12. Vertical deformation at western part of Sumatra

    SciTech Connect

    Febriyani, Caroline Prijatna, Kosasih Meilano, Irwan

    2015-04-24

    This research tries to make advancement in GPS signal processing to estimate the interseismic vertical deformation field at western part of Sumatra Island. The data derived by Continuous Global Positioning System (CGPS) from Badan Informasi Geospasial (BIG) between 2010 and 2012. GPS Analyze at Massachusetts Institute of Technology (GAMIT) software and Global Kalman Filter (GLOBK) software are used to process the GPS signal to estimate the vertical velocities of the CGPS station. In order to minimize noise due to atmospheric delay, Vienna Mapping Function 1 (VMF1) is used as atmospheric parameter model and include daily IONEX file provided by the Center for Orbit Determination in Europe (CODE) as well. It improves GAMIT daily position accuracy up to 0.8 mm. In a second step of processing, the GLOBK is used in order to estimate site positions and velocities in the ITRF08 reference frame. The result shows that the uncertainties of estimated displacement velocity at all CGPS stations are smaller than 1.5 mm/yr. The subsided deformation patterns are seen at the northern and southern part of west Sumatra. The vertical deformation at northern part of west Sumatra indicates postseismic phase associated with the 2010 and 2012 Northern Sumatra earthquakes and also the long-term postseismic associated with the 2004 and 2005 Northern Sumatra earthquakes. The uplifted deformation patterns are seen from Bukit Tinggi to Seblat which indicate a long-term interseismic phase after the 2007 Bengkulu earthquake and 2010 Mentawai earthquake. GANO station shows a subsidence at rate 12.25 mm/yr, indicating the overriding Indo-Australia Plate which is dragged down by the subducting Southeast Asian Plate.

  13. Enhancement of Condensation on a Vertical Plate

    NASA Astrophysics Data System (ADS)

    Chu, Rencai; Hatanaka, Tsutomu; Nishio, Shigefumi

    In previous study, the characteristic of the condensation heat transfer on the dispersed vertical surface were investigated experimentally for the application of the finned surface to the thermoelectric generator utilizing boiling and condensation as the electrodes of the thermoelectric module. A prediction model for this diapered finned surface was proposed, based on Adamek-Webb model of the condensation on a finned tube. In this study, a condensation heat transfer experiment on a vertical dispersed finned surfaces using FC5312 was carried out, in order to enhance the condensation heat transfer coefficient by optimizing the fin size on a dispersed heat transfer surface. The object of the experiment was limited to the rectangular fin with the height of 3 mm. Experimental parameters were the temperature difference, the fin groove width, the fin thickness and the dispersing size on the vertical direction. As the results, it was found from the experiment that the dependence of the condensation heat transfer coefficient on the dispersed size is controlled by the fin groove width. That is, the condensation heat transfer coefficient will increase for a smaller fin groove width and will decrease for a larger fin groove width, with decreasing of the dispersing size. Moreover, there is an optimum fin thickness at which the condensation heat transfer coefficient becomes the maximum in the case of constant fin groove width for both size of the fin groove width. This effect of the fin thickness is more significant for the smaller fin groove width. Further, the prediction values exhibit a good agreement with the experimental data in the present experiment.

  14. Long wavelength vertical cavity surface emitting laser

    DOEpatents

    Choquette, Kent D.; Klem, John F.

    2005-08-16

    Selectively oxidized vertical cavity lasers emitting near 1300 nm using InGaAsN quantum wells are reported for the first time which operate continuous wave below, at and above room temperature. The lasers employ two n-type Al.sub.0.94 Ga.sub.0.06 As/GaAs distributed Bragg reflectors each with a selectively oxidized current aperture adjacent to the active region, and the top output mirror contains a tunnel junction to inject holes into the active region. Continuous wave single mode lasing is observed up to 55.degree. C.

  15. OH vertical column abundance - Tropical measurements

    NASA Astrophysics Data System (ADS)

    Burnett, Clyde R.; Minschwaner, Kenneth R.; Burnett, Elizabeth B.

    1990-09-01

    Measurements of the vertical column abundance of atmospheric hydroxyl (OH) have been made during the period 1987-1989 at the National Weather Service (NWS) station at Moen, Truk, Federated States of Micronesia (7 deg N, 152 deg E). A total of 384 independent data sets was obtained. Tropical OH abundance levels average about 22 percent above corresponding mid-latitude values, with OH levels during late winter and early spring up to 50 percent above those observed at 40 deg N. Stratospheric wind and temperature data obtained from the daily NWS radiosonde data are examined for correlations with the OH results.

  16. OH vertical column abundance - Tropical measurements

    NASA Technical Reports Server (NTRS)

    Burnett, Clyde R.; Minschwaner, Kenneth R.; Burnett, Elizabeth B.

    1990-01-01

    Measurements of the vertical column abundance of atmospheric hydroxyl (OH) have been made during the period 1987-1989 at the National Weather Service (NWS) station at Moen, Truk, Federated States of Micronesia (7 deg N, 152 deg E). A total of 384 independent data sets was obtained. Tropical OH abundance levels average about 22 percent above corresponding mid-latitude values, with OH levels during late winter and early spring up to 50 percent above those observed at 40 deg N. Stratospheric wind and temperature data obtained from the daily NWS radiosonde data are examined for correlations with the OH results.

  17. Low-Level Flight Simulation: Vertical Cues

    DTIC Science & Technology

    1983-09-01

    The ASPT visual s’ester Soiftware autoematic’ally droips the’m freim the scene- at altitudes above 2000 fe’et AGI.) In an attempt to make the cue’s...8217 vertical (V) field of view. The ASPT has a - 15’ view o er the nose. - 370 over the left side, and - 15’ over the right side. (The aircraft field of...simulation, the ASPT /F-16 provided several instructional features that were used in this study. A video display of the HUD (Figures 1 and 21 and forward

  18. Vertical-Screw-Auger Conveyer Feeder

    NASA Technical Reports Server (NTRS)

    Walton, Otis (Inventor); Vollmer, Hubert J. (Inventor)

    2016-01-01

    A conical feeder is attached to a vertically conveying screw auger. The feeder is equipped with scoops and rotated from the surface to force-feed regolith the auger. Additional scoops are possible by adding a cylindrical section above the conical funnel section. Such then allows the unit to collect material from swaths larger in diameter than the enclosing casing pipe of the screw auger. A third element includes a flexible screw auger. All three can be used in combination in microgravity and zero atmosphere environments to drill and recover a wide area of subsurface regolith and entrained volatiles through a single access point on the surface.

  19. Vertical orbital dystopia: definition, classification and treatment.

    PubMed

    Wolfe, S A; Sassani, R

    1995-01-01

    Correction of vertical orbital dystopia is an important component part of providing facial symmetry in a number of conditions of varied etiology having facial imbalance and asymmetry. The most important step is the initial one of making a proper diagnosis, since some conditions represent globe dystopia rather than true orbital dystopia, and can be treated by extracranial procedures. However, if an intracranial procedure is felt indicated, it adds to the safety rather than the complexity of the procedure, and one should not hesitate advocating this to the patient.

  20. Vertical Isolation for Photodiodes in CMOS Imagers

    NASA Technical Reports Server (NTRS)

    Pain, Bedabrata

    2008-01-01

    In a proposed improvement in complementary metal oxide/semi conduct - or (CMOS) image detectors, two additional implants in each pixel would effect vertical isolation between the metal oxide/semiconductor field-effect transistors (MOSFETs) and the photodiode of the pixel. This improvement is expected to enable separate optimization of the designs of the photodiode and the MOSFETs so as to optimize their performances independently of each other. The purpose to be served by enabling this separate optimization is to eliminate or vastly reduce diffusion cross-talk, thereby increasing sensitivity, effective spatial resolution, and color fidelity while reducing noise.

  1. Oceanography. Vertical mixing in the ocean.

    PubMed

    Webb, D J; Suginohara, N

    2001-01-04

    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.

  2. Vertical Cable Seismic Survey for Hydrothermal Deposit

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    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

  3. Kinematics of Vertical Saccades during the Yaw Vestibulo-ocular Reflex in Humans

    PubMed Central

    Crane, Benjamin T.; Tian, Junru; Demer, Joseph L.

    2007-01-01

    Purpose Listing’s law (LL) constrains the rotational axes of saccades and pursuit eye movements to Listing’s plane (LP). In the velocity domain, LL is ordinarily equivalent to a tilt in the ocular velocity axis equal to half the change in eye position, giving a tilt angle ratio (TAR) of 0.5. This study was undertaken to investigate vertical saccade behavior after the yaw vestibulo-ocular reflex (VOR) had driven eye torsion out of LP, an initial condition causing the position and velocity domain formulations of LL to differ. Methods Binocular eye and head motions were recorded with magnetic search coils in eight humans. With the head immobile, LP was determined for each eye, and mean TAR was 0.50 ± 0.07 (mean ± SD) for horizontal and 0.45 ± 0.11 for vertical saccades. The VOR was evoked by transient, whole-body yaw at 2800 deg/s2 peak acceleration, capable of evoking large, uninterrupted VOR slow phases. Before rotation, subjects viewed a target at eye level, 20° up, or 20° down. In two thirds of the trials, the target moved upward or downward at systematically varying times, triggering a vertical saccade during the horizontal VOR slow phase. Results Because the head rotation axis was generally misaligned with LP, the eye averaged 3.6° out of LP at vertical saccade onset. During the saccade, eye position continued to depart LP by an average 0.8°. The horizontal TAR at saccade onset was 0.29 ± 0.07. At peak saccade velocity 35 ± 3 ms later, the vertical TAR was 0.45 ± 0.07, statistically similar to that of head fixed saccades. Saccades did not return to LP. Conclusions Although they did not observe the position domain formulation of LL, vertical saccades, during the VOR, observed the half-angle velocity domain formulation of LL. PMID:16043853

  4. Vertical variations in wood CO2 efflux for live emergent trees in a Bornean tropical rainforest.

    PubMed

    Katayama, Ayumi; Kume, Tomonori; Komatsu, Hikaru; Ohashi, Mizue; Matsumoto, Kazuho; Ichihashi, Ryuji; Kumagai, Tomo'omi; Otsuki, Kyoichi

    2014-05-01

    Difficult access to 40-m-tall emergent trees in tropical rainforests has resulted in a lack of data related to vertical variations in wood CO2 efflux, even though significant variations in wood CO2 efflux are an important source of errors when estimating whole-tree total wood CO2 efflux. This study aimed to clarify vertical variations in wood CO2 efflux for emergent trees and to document the impact of the variations on the whole-tree estimates of stem and branch CO2 efflux. First, we measured wood CO2 efflux and factors related to tree morphology and environment for seven live emergent trees of two dipterocarp species at four to seven heights of up to ∼ 40 m for each tree using ladders and a crane. No systematic tendencies in vertical variations were observed for all the trees. Wood CO2 efflux was not affected by stem and air temperature, stem diameter, stem height or stem growth. The ratios of wood CO2 efflux at the treetop to that at breast height were larger in emergent trees with relatively smaller diameters at breast height. Second, we compared whole-tree stem CO2 efflux estimates using vertical measurements with those based on solely breast height measurements. We found similar whole-tree stem CO2 efflux estimates regardless of the patterns of vertical variations in CO2 efflux because the surface area in the canopy, where wood CO2 efflux often differed from that at breast height, was very small compared with that at low stem heights, resulting in little effect of the vertical variations on the estimate. Additionally, whole-tree branch CO2 efflux estimates using measured wood CO2 efflux in the canopy were considerably different from those measured using only breast height measurements. Uncertainties in wood CO2 efflux in the canopy did not cause any bias in stem CO2 efflux scaling, but affected branch CO2 efflux.

  5. Vertical datum standardisation: a fundamental step towards a global vertical reference system

    NASA Astrophysics Data System (ADS)

    Sanchez, L.

    2013-05-01

    One of the most important problems of modern geodesy is the definition and realisation of a global vertical reference system, which unifies, with high accuracy (at least 1 cm-level), the existing classical height datums; i.e. all existing physical heights (or geopotential numbers) have to be referred to one and the same equipotential surface, defined and realised in a global frame. The basic approach proposed at present to achieve this so-called vertical datum unification is based on the combination of physical heights (orthometric or normal heights) derived from levelling (reduced by gravity effects) with those computed from gravimetric (quasi-) geoid models and ellipsoidal heights. However, the combination of these heights "as they are" reflects the inconsistencies included in the height determination; for instance: 1) different ellipsoid parameters in gravity and geometry; 2) different tide systems; 3) different hypotheses for the estimation of orthometric heights and gravimetric geoid models; 4) different reference epochs with unknown height changes in time; 5) systematic errors over long distances in levelling; 6) different reductions for Earth-, ocean-, atmospheric tides, ocean and atmospheric loading, post-glacial rebound, etc. These inconsistencies mislead the vertical datum unification and limit the reliability of the global vertical reference system realisation to the m-level. In order to advance in the homogenisation of the input data and procedures for the solution of the vertical datum problem with a high and reliable accuracy, the Working Group "Vertical Datum Standardisation" was established for the term 2011-2015 by the Global Geodetic Observing System (GGOS) of the International Association of Geodesy (IAG), jointly with the IAG Commission 1 (Reference Frames), IAG Commission 2 (Gravity Field), and the International Gravity Field Service (IGFS). This contribution presents objectives, achievements, and coming challenges of this Working Group.

  6. Variable ratio regenerative braking device

    DOEpatents

    Hoppie, Lyle O.

    1981-12-15

    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.

  7. Weather-Corrected Performance Ratio

    SciTech Connect

    Dierauf, T.; Growitz, A.; Kurtz, S.; Cruz, J. L. B.; Riley, E.; Hansen, C.

    2013-04-01

    Photovoltaic (PV) system performance depends on both the quality of the system and the weather. One simple way to communicate the system performance is to use the performance ratio (PR): the ratio of the electricity generated to the electricity that would have been generated if the plant consistently converted sunlight to electricity at the level expected from the DC nameplate rating. The annual system yield for flat-plate PV systems is estimated by the product of the annual insolation in the plane of the array, the nameplate rating of the system, and the PR, which provides an attractive way to estimate expected annual system yield. Unfortunately, the PR is, again, a function of both the PV system efficiency and the weather. If the PR is measured during the winter or during the summer, substantially different values may be obtained, making this metric insufficient to use as the basis for a performance guarantee when precise confidence intervals are required. This technical report defines a way to modify the PR calculation to neutralize biases that may be introduced by variations in the weather, while still reporting a PR that reflects the annual PR at that site given the project design and the project weather file. This resulting weather-corrected PR gives more consistent results throughout the year, enabling its use as a metric for performance guarantees while still retaining the familiarity this metric brings to the industry and the value of its use in predicting actual annual system yield. A testing protocol is also presented to illustrate the use of this new metric with the intent of providing a reference starting point for contractual content.

  8. High vertical resolution crosswell seismic imaging

    DOEpatents

    Lazaratos, Spyridon K.

    1999-12-07

    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.

  9. Vertical Profiling of Air Pollution at RAPCD

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    The interaction between local and regional pollution levels occurs at the interface of the Planetary Boundary Layer and the Free Troposphere. Measuring the vertical distribution of ozone, aerosols, and winds with high temporal and vertical resolution is essential to diagnose the nature of this interchange and ultimately for accurately forecasting ozone and aerosol pollution levels. The Regional Atmospheric Profiling Center for Discovery, RAPCD, was built and instrumented to address this critical issue. The ozone W DIAL lidar, Nd:YAG aerosol lidar, and 2.1 micron Doppler wind lidar, along with balloon- borne ECC ozonesondes form the core of the W C D instrumentation for addressing this problem. Instrumentation in the associated Mobile Integrated Profiling (MIPS) laboratory includes 91 5Mhz profiler, sodar, and ceilometer. The collocated Applied particle Optics and Radiometry (ApOR) laboratory hosts an FTIR along with MOUDI and optical particle counters. With MODELS-3 analysis by colleagues in the National Space Science and Technology Center on the UAH campus and the co- located National Weather Service Forecasting Office in Huntsville, AL we are developing a unique facility for advancing the state of the science of pollution forecasting.

  10. Thunderstorm vertical velocities estimated from satellite data

    NASA Technical Reports Server (NTRS)

    Adler, R. F.; Fenn, D. D.

    1979-01-01

    Infrared geosynchronous satellite data with an interval of 5 min between images are used to estimate thunderstorm top ascent rates on two case study days. A mean vertical velocity of 3.4 m/sec for 23 clouds is calculated at a height of 8.7 km. This upward motion is representative of an area of approximately 10 km on a side. Thunderstorm mass flux of approximately 2 times 10 to the 8th power kg/sec is calculated, which compares favorably with previous estimates. There is a significant difference in the mean calculated vertical velocity between elements associated with severe weather reports (omega = 4.9 m/sec) and those with no such reports (2.4 m/sec). Calculations were made using a velocity profile for an axially symmetric jet to estimate the peak updraft velocity. For the largest observed omega value of 7.8 m/sec the calculation indicates a peak updraft of approximately 50 m/sec.

  11. Control system for a vertical axis windmill

    DOEpatents

    Brulle, Robert V.

    1983-10-18

    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.

  12. Determinants of Arbovirus Vertical Transmission in Mosquitoes

    PubMed Central

    Lequime, Sebastian; Paul, Richard E.; Lambrechts, Louis

    2016-01-01

    Vertical transmission (VT) and horizontal transmission (HT) of pathogens refer to parental and non-parental chains of host-to-host transmission. Combining HT with VT enlarges considerably the range of ecological conditions in which a pathogen can persist, but the factors governing the relative frequency of each transmission mode are poorly understood for pathogens with mixed-mode transmission. Elucidating these factors is particularly important for understanding the epidemiology of arthropod-borne viruses (arboviruses) of public health significance. Arboviruses are primarily maintained by HT between arthropod vectors and vertebrate hosts in nature, but are occasionally transmitted vertically in the vector population from an infected female to her offspring, which is a proposed maintenance mechanism during adverse conditions for HT. Here, we review over a century of published primary literature on natural and experimental VT, which we previously assembled into large databases, to identify biological factors associated with the efficiency of arbovirus VT in mosquito vectors. Using a robust statistical framework, we highlight a suite of environmental, taxonomic, and physiological predictors of arbovirus VT. These novel insights contribute to refine our understanding of strategies employed by arboviruses to persist in the environment and cause substantial public health concern. They also provide hypotheses on the biological processes underlying the relative VT frequency for pathogens with mixed-mode transmission that can be tested empirically. PMID:27171170

  13. Enhancement of Condensation on a Vertical Plate

    NASA Astrophysics Data System (ADS)

    Chu, Rencai; Hatanaka, Tsutomu; Nishio, Shigefumi

    In previous study, the characteristic of the condensation heat transfer on the dispersed vertical surface were investigated experimentally for the application of the finned surface to the thermoelectric generator utilizing boiling and condensation as the electrodes of the thermoelectric module. A prediction model for this diapered finned surface was proposed, based on Adamek-Webb model of the condensation on a finned tube. In this study, a condensation heat transfer experiment on a vertical dispersed finned surfaces using FC5312 was carried out, in order to enhance the condensation heat transfer coefficient by optimizing the fin size on a dispersed heat transfer surface. Experimental parameters were the fin width, thickness, height and the dispersed fin length. As the results, it was found from the experiment there was a dispersed fin length corresponding to the condensation at the maximum and its value was 1.75 mm. As the characteristic, the condensation changed from slowly increasing to rapidly increasing and then decreasing at a steep grade, with decreasing the dispersed fin length. In addition, the fin height did not affect this optimum dispersed fin length and the dispersed fin length affects the dependence of the condensation on different fin thickness. Further, the prediction values have a good agreement with the experimental data except the case of short dispersed fin length.

  14. Diagnosis of vertical motion from VAS retrievals

    NASA Technical Reports Server (NTRS)

    Fuelberg, Henry E.; Funk, Theodore W.

    1987-01-01

    Satellite-derived temperature profiles are used to determine if reliable estimates of synoptic-scale vertical motion can be obtained from the adiabatic, vorticity, and omega equation techniques. The period of study contains a short-wave trough over the Midwest and a convective outbreak over the middle Mississippi River Valley. Satellite soundings are available at 1-3 h intervals at five times. The emphasis is on assessing the strengths and weaknesses of the three vertical motion procedures, and determining the effects of short-interval observations on the calculations. Results show that the quasi-geostrophic omega equation provided patterns and magnitudes most consistent with observed weather events and 12 h radiosonde-derived motions. The vorticity method produced less satisfactory results, while adiabatic motions were unacceptable. The time derivative term dominated adiabatic motions and was a major influence in the vorticity method. Unrealistic temperature tendencies resulted from the retrieval algorithm; i.e., a diurnal temperature bias extended upwards to 500 mb, and there was a compensating effect at higher levels.

  15. Potential versus actual contribution of vertical transmission to pathogen fitness

    PubMed Central

    Kover, P. X.; Dolan, T. E.; Clay, K.

    1997-01-01

    Theory predicts that virulent parasites cannot be maintained at high prevalence if they are only vertically transmitted. However, parasites with high rates of vertical transmission that cause severe reduction in host fitness have been reported. Atkinsonella hypoxylon is a fungal pathogen capable of both vertical and horizontal transmission that drastically reduces its host's fitness. In contrast with theoretical predictions, field and laboratory observations suggested that the primary mechanism of transmission was vertical. Using randomly amplified polymorphic DNA markers, we investigated the effective contribution of vertical and horizontal transmission to the genetic structure of three natural populations of A. hypoxylon. We found high genotypic diversity and low linkage disequilibrium, indicating that most established genotypes are derived from horizontally transmitted, sexual spores. The low contribution of vertical transmission to the parasite's fitness despite its high potential might be due to lower establishment of cleistogamous seeds (through which vertical transmission occurs) or lower vigour of vertically transmitted fungal genotypes. Low establishment of vertically infected hosts might explain the persistence of virulent parasites with high apparent vertical transmission. Our results suggest that caution must be taken when using the potential for vertical transmission to make predictions about the evolution of parasite virulence.

  16. Compartment in vertical flow reactor for ferruginous mine water

    NASA Astrophysics Data System (ADS)

    Hur, Won; Cheong, Young-Wook; Yim, Gil-Jae; Ji, Sang-Woo; Hong, Ji-Hye

    2014-05-01

    Mine effluents contain varying concentrations of ferrous ion along with other metal ions. Fe(II) that quickly oxidizes to form precipitates in the presence of oxygen under net alkaline or neutral conditions. Thus, passive treatment methods are designed for the mine water to reside in an open containment area so as to allow simultaneous oxidation and precipitation of Fe(II), such as in a lagoon or an oxidation pond. A vertical flow reactor (VFR) was also suggested to remediate ferruginous mine drainage passing down through an accreting bed of ochre. However, VFR has a limited operation time until the system begins to overflow. It was also demonstrated that two-compartment VFR has a longer operation time than single compartment VFR of same size. In this study, a mathematical model was developed as a part of efforts to explore the operation of VFR, showing dynamic changes in head differences, ochre depth and Fe(II)/Fe(III) concentration in the effluent flow. The analysis shows that Fe(II) oxidation and ochre formation should be balanced with permeability of ochre bed to maximize VFR operation time and minimize residual Fe(II) in the effluent. The model demonstrates that two compartment VFR can have a longer operation time than a single-compartment VFR and that an optimum compartment ratio exists that maximize VFR operation time. Accelerated Fe(II) oxidation significantly affects the optimum ratio of compartment area and reduced residual Fe(II) in the effluent. VFR operation time can be significantly prolonged by increasing the rate of ochre formation not by accelerated Fe(II) oxidation. Taken together, ochre forms largely in the first compartment while overflowed mine water with reduced iron contents is efficiently filtered in the second compartment. These results provide us a better understanding of VFR operation and optimum design criteria for maximum operation time in a two-compartment VFR. Rapid ochre accretion in the first compartment maintains constant hydraulic

  17. Bottom-up synthesis of vertically oriented two-dimensional materials

    NASA Astrophysics Data System (ADS)

    Vilá, R. A.; Momeni, K.; Wang, Q.; Bersch, B. M.; Lu, N.; Kim, M. J.; Chen, L. Q.; Robinson, J. A.

    2016-12-01

    Understanding nucleation and growth of two-dimensional (2D) and layered materials is a challenging topic due to the complex van der Waals interactions between layers and substrate. The morphology of 2D materials is known vary depending on experimental conditions. For the case of MoS2, the morphology has been shown to vary from rounded (molybdenum rich) domains to equilateral triangular (sulfur rich) domains. These different morphologies can result in drastically different properties, which can be exploited for applications in catalytic reactions, digital electronics, optoelectronics, and energy storage. Powder vaporization (PV) synthesis of molybdenum disulfide (MoS2) can yield vertical domains, however, these domains are often ignored when the morphology evolution of MoS2 is discussed, thereby completely omitting a major part of the impact of the Mo:S ratio to the growth mode of MoS2 during PV. Combining experimental and numerical simulation methods, we reveal a vertical-to-horizontal growth mode transition for MoS2 that occurs in the presence of a molybdenum oxide partial pressure gradient. Transmission electron microscopy reveals that the growth of vertical MoS2 results from initial seeding of single crystalline molybdenum dioxide, followed by sulfurization from the substrate upward to form vertically oriented MoS2 domains.

  18. Importance of light, temperature, zooplankton and fish in predicting the nighttime vertical distribution of Mysis diluviana

    USGS Publications Warehouse

    Boscarino, B.T.; Rusdtam, L.G.; Eillenberger, J.L.; O'Gorman, R.

    2009-01-01

    The opossum shrimp Mysis diluviana (formerly M. relicta) performs large amplitude diel vertical migrations in Lake Ontario and its nighttime distribution is influenced by temperature, light and the distribution of its predators and prey. At one location in southeastern Lake Ontario, we measured the vertical distribution of mysids, mysid predators (i.e. planktivorous fishes) and mysid prey (i.e. zooplankton), in addition to light and temperature, on 8 occasions from May to September, 2004 and 2005. We use these data to test 3 different predictive models of mysid habitat selection, based on: (1) laboratory-derived responses of mysids to different light and temperature gradients in the absence of predator or prey cues; (2) growth rate of mysids, as estimated with a mysid bioenergetics model, given known prey densities and temperatures at different depths in the water column; (3) ratio of growth rates (g) and mortality risk (??) associated with the distribution of predatory fishes. The model based on light and temperature preferences was a better predictor of mysid vertical distribution than the models based on growth rate and g:?? on all 8 occasions. Although mysid temperature and light preferences probably evolved as mechanisms to reduce predation while increasing foraging intake, the response to temperature and light alone predicts mysid vertical distribution across seasons in Lake Ontario. ?? Inter-Research 2009.

  19. Importance of light, temperature, zooplankton, and fish in predicting the nighttime vertical distribution of Mysis diluviana

    USGS Publications Warehouse

    Murphy, Marilyn K.; ,; Boscarino, Brent T.; Rudstam, Lars G.; Eillenberger, June L.

    2009-01-01

    The opossum shrimp Mysis diluviana (formerly M. relicta) performs large amplitude diel vertical migrations in Lake Ontario and its nighttime distribution is influenced by temperature, light and the distribution of its predators and prey. At one location in southeastern Lake Ontario, we measured the vertical distribution of mysids, mysid predators (i.e. planktivorous fishes) and mysid prey (i.e. zooplankton), in addition to light and temperature, on 8 occasions from May to September, 2004 and 2005. We use these data to test 3 different predictive models of mysid habitat selection, based on: (1) laboratoryderived responses of mysids to different light and temperature gradients in the absence of predator or prey cues; (2) growth rate of mysids, as estimated with a mysid bioenergetics model, given known prey densities and temperatures at different depths in the water column; (3) ratio of growth rates (g) and mortality risk (μ) associated with the distribution of predatory fishes. The model based on light and temperature preferences was a better predictor of mysid vertical distribution than the models based on growth rate and g:μon all 8 occasions. Although mysid temperature and light preferences probably evolved as mechanisms to reduce predation while increasing foraging intake, the response to temperature and light alone predicts mysid vertical distribution across seasons in Lake Ontario.

  20. A novel flexure-based vertical nanopositioning stage with large travel range

    NASA Astrophysics Data System (ADS)

    Zhu, Xiaobo; Xu, Xiao; Wen, Zhijie; Ren, Jiaqi; Liu, Pinkuan

    2015-10-01

    This paper presents the design of a novel flexure-based vertical (or Z-axis) nanopositioning stage driven by a piezoelectric actuator (PZT), which is capable of executing large travel range. The proposed stage consists mainly of a hybrid displacement amplification mechanism (DAM), a motion guiding mechanism, and a decoupling mechanism. The hybrid DAM with amplification ratio of 12.1 is developed to transfer the transverse motion of the PZT actuator into the vertical motion. The motion guiding mechanism is introduced to avoid cross coupling at the output end. The decoupling mechanism can significantly reduce the cross coupling at the driving end to protect the PZT. The stiffness and dynamics of the proposed stage are improved by these mechanisms. Analytical modeling and finite element analysis (FEA) are then adopted to optimize dimensions of the stage. Finally, a prototype of the stage is fabricated and tested for verification. The results of static and dynamic tests show that the proposed stage is capable of vertical travel range of 214 μm with resolution of 8 nm, and the first two resonance frequencies are 205 Hz and 1206 Hz, respectively. Cross coupling tests under various lateral loads (0 g-1000 g) show that the maximum variances of the lateral and angular cross couplings are less than 0.78 μm and 95 μrad, respectively, indicating good decoupling capability. In addition, the low-profile structure of the stage is well suited to be used in limited vertical space.

  1. A novel flexure-based vertical nanopositioning stage with large travel range.

    PubMed

    Zhu, Xiaobo; Xu, Xiao; Wen, Zhijie; Ren, Jiaqi; Liu, Pinkuan

    2015-10-01

    This paper presents the design of a novel flexure-based vertical (or Z-axis) nanopositioning stage driven by a piezoelectric actuator (PZT), which is capable of executing large travel range. The proposed stage consists mainly of a hybrid displacement amplification mechanism (DAM), a motion guiding mechanism, and a decoupling mechanism. The hybrid DAM with amplification ratio of 12.1 is developed to transfer the transverse motion of the PZT actuator into the vertical motion. The motion guiding mechanism is introduced to avoid cross coupling at the output end. The decoupling mechanism can significantly reduce the cross coupling at the driving end to protect the PZT. The stiffness and dynamics of the proposed stage are improved by these mechanisms. Analytical modeling and finite element analysis (FEA) are then adopted to optimize dimensions of the stage. Finally, a prototype of the stage is fabricated and tested for verification. The results of static and dynamic tests show that the proposed stage is capable of vertical travel range of 214 μm with resolution of 8 nm, and the first two resonance frequencies are 205 Hz and 1206 Hz, respectively. Cross coupling tests under various lateral loads (0 g-1000 g) show that the maximum variances of the lateral and angular cross couplings are less than 0.78 μm and 95 μrad, respectively, indicating good decoupling capability. In addition, the low-profile structure of the stage is well suited to be used in limited vertical space.

  2. Mass Spectrometry in Jupiter's Atmosphere: Vertical Variation of Volatile Vapors

    NASA Astrophysics Data System (ADS)

    Wong, Michael H.; Atreya, Sushil K.; Mahaffy, Paul R.

    2014-05-01

    The Galileo Probe made the first and only in situ measurements of composition in Jupiter's atmosphere, led by the Galileo Probe Mass Spectrometer, or GPMS [1]. The major contribution from this instrument was the measurement of abundances and isotope ratios of the noble gases, as well as the volatile gases CH4, NH3, H2O, and H2S [2,3]. These initial results were further refined by detailed laboratory calibrations for the noble gases [4] and the volatiles [5]. The probe measurements resulted in the first determination of the heavy element abundances (except carbon that was known previously) and He/H ratio, which provide critical constraints to models of the formation of Jupiter and the origin of its atmosphere [6,7]. The condensable volatiles, or CVs (ammonia, H2S, and water), increased with depth in the probe entry site. This vertical variation was observed at levels much deeper than the modeled cloud bases, as predicted by one-dimensional chemical equilibrium models. The discrepancy is due to the probe's entry into a dry region known as a 5-μm hot spot. The 5-μm hot spots are part of an atmospheric wave system that encircles Jupiter just north of the equator. Despite the anomalous meteorology, the bulk abundances of NH3 and H2S were measured by the probe, and found to be enriched with respect to solar composition (similarly to the non-condensable volatile CH4). The deepest water mixing ratio, however, was observed to be depleted relative to solar composition. We review an updated context for the CV vertical profiles measured by the GPMS, based on the latest results from remote sensing, simulation, and reinterpretation of Galileo Probe measurements. In particular, we find that (1) the bulk abundance of water in Jupiter's atmosphere must be greater than the subsolar abundance derived from the deepest GPMS measurements [8], and that (2) CV mixing ratios are controlled by a range of processes in addition to condensation of the ices NH3, NH4SH, and H2O [5-9]. Both

  3. Isokinetic Hamstrings: Quadriceps Ratios in Intercollegiate Athletes.

    ERIC Educational Resources Information Center

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

    2001-01-01

    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)

  4. Fluid flow through a vertical to horizontal 90 elbow bend III three phase flow

    SciTech Connect

    Spedding, P.L.; Benard, E.; Crawford, N.M.

    2008-01-15

    Three phase water/oil/air flow was studied around a vertical upward to horizontal 90 elbow bend of R/d = 0.654. The results were more complex than corresponding two phase data. The pressure drop recorded for the two tangent legs sometimes showed significant variations to the straight pipe data. In most cases this variation was caused by differences in the flow regimes between the two systems. The elbow bend tended to constrict the flow presented by the vertical inlet tangent leg while sometimes acting as a wave and droplet generator for the horizontal outlet tangent leg. It could be argued that the inclusion of the elbow bend altered the flow regime map transitional boundaries but it also is possible that insufficient settling length was provided in the apparatus design. The elbow bend pressure drop was best presented as l{sub e}/d the equivalent length to diameter ratio using the actual total pressure drop in the vertical inlet tangent leg. Generally l{sub e}/d values rose with gas rate, but exhibited an increasingly complex relation with f{sub o} the oil to liquid volumetric ratio as liquid rate was increased. A significant maximum in l{sub e}/d was in evidence around the inversion from water dominated to oil dominated flows. Several models are presented to predict the data. (author)

  5. Strain-induced vertical self-organization of semiconductor quantum dots: A computational study

    SciTech Connect

    Shtinkov, N.

    2013-12-28

    Atomistic strain simulations based on the valence force field method are employed to study the vertical arrangements of semiconductor quantum dot (QD) multilayers. The effects of the QD shape, dimensions, and materials parameters are systematically investigated, varying independently the following parameters: spacer width H, QD lateral spacing D, base b, and height h, slope of the side facets, elastic properties of the dot and the substrate materials, and lattice mismatch between the dot and the substrate. The transition between vertically aligned and anti-aligned structures is found to be determined mainly by the ratios H/D and b/D, as well as by the strain anisotropy of the substrate and to a lesser extent of the QD. The dependence on the QD height h is significant only for steep side facets and large aspect ratios h/b, and the effects of the lattice mismatch strain and the bulk elastic moduli are found to be negligible. The comparison with experimental data shows an excellent agreement with the results from the simulations, demonstrating that the presented analysis results in precise theoretical predictions for the vertical self-organization regime in a wide range of QD materials systems.

  6. Vertical distribution of (236)U in the North Pacific Ocean.

    PubMed

    Eigl, R; Steier, P; Sakata, K; Sakaguchi, A

    2017-04-01

    The first extensive study on (236)U in the North Pacific Ocean has been conducted. The vertical distribution of (236)U/(238)U isotopic ratios and the (236)U concentrations were analysed on seven depth profiles, and large variations with depth were found. The range of (236)U/(238)U isotopic ratios was from (0.09 ± 0.03) × 10(-10) to (14.1 ± 2.2) × 10(-10), which corresponds to (236)U concentrations of (0.69 ± 0.24) × 10(5) atoms/kg and (119 ± 21) × 10(5) atoms/kg, respectively. The variations in (236)U concentrations could mainly be attributed to the different water masses in the North Pacific Ocean and their formation processes. Uranium-236 inventories on the water column of each sampling station were calculated and varied between (3.89 ± 0.08) × 10(12) atoms/m(2) and (7.03 ± 0.50) × 10(12) atoms/m(2), which is lower than in former studies on comparable latitudes in the North Atlantic Ocean and the Sea of Japan. The low inventories of (236)U found for the North Pacific Ocean in this study can be explained by the lack of additional input sources of artificial radionuclides, apart from global and regional/local fallout. This study expands the use of (236)U as oceanographic circulation tracer to yet another ocean basin and shows that this isotope can be used for tracing circulation patterns of water masses in the Pacific Ocean.

  7. Comparison of Aerosol Classification from Airborne High Spectral Resolution Lidar and the CALIPSO Vertical Feature Mask

    NASA Astrophysics Data System (ADS)

    Burton, S. P.; Ferrare, R. A.; Omar, A. H.; Hostetler, C. A.; Hair, J. W.; Rogers, R.; Obland, M. D.; Butler, C. F.; Cook, A. L.; Harper, D. B.

    2012-12-01

    The NASA Langley Research Center (LaRC) airborne High Spectral Resolution Lidar (HSRL-1) on the NASA B200 aircraft has acquired large datasets of aerosol extinction (532nm), backscatter (532 and 1064nm), and depolarization (532 and 1064nm) profiles during 349 science flights in 19 field missions across North America since 2006. The extinction-to-backscatter ratio ("lidar ratio"), aerosol depolarization ratios, and backscatter color ratio measurements from HSRL-1 are scale-invariant parameters that depend on aerosol type but not concentration. These four aerosol intensive parameters are combined to qualitatively classify HSRL aerosol measurements into eight separate composition types. The classification methodology uses models formed from "training cases" with known aerosol type. The remaining measurements are then compared with these models using the Mahalanobis distance. Aerosol products from the CALIPSO satellite include aerosol type information as well, which is used as input to the CALIPSO aerosol retrieval. CALIPSO aerosol types are inferred using a mix of aerosol loading-dependent parameters, estimated aerosol depolarization, and location, altitude, and surface type information. The HSRL instrument flies beneath the CALIPSO satellite orbit track, presenting the opportunity for comparisons between the HSRL aerosol typing and the CALIPSO Vertical Feature Mask Aerosol Subtype product, giving insight into the performance of the CALIPSO aerosol type algorithm. We find that the aerosol classification from the two instruments frequently agree for marine aerosols and pure dust, and somewhat less frequently for pollution and smoke. In addition, the comparison suggests that the CALIPSO polluted dust type is overly inclusive, encompassing cases of dust combined with marine aerosol as well as cases without much evidence of dust. Qualitative classification of aerosol type combined with quantitative profile measurements of aerosol backscatter and extinction has many useful

  8. Vertical and Interfacial Transport in Wetlands (Invited)

    NASA Astrophysics Data System (ADS)

    Variano, E. A.

    2010-12-01

    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

  9. Vertical land motion of Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Melbourne, T. I.; Montillet, J. P.; Szeliga, W. M.

    2015-12-01

    We use GPS measurements from 400 stations located throughout the Pacific Northwest to estimate steady-state vertical land motion for the purpose of constraining relative sea level rise projections. Vertical motions are typically only a few percent of horizontal rates and the same order of magnitude as current sea level rise rates, so may either ameliorate or exacerbate future climate impacts. We use data from receivers operating from 1994 through 2015, each with at least three years of continuous daily measurements. Furthermore, daily position time series resulting from the processing of two GPS centers, namely the EarthScope Plate Boundary Observatory (PBO) and the Pacific Northwest Geodetic Array (PANGA), are considered throughout this study. The goal is two fold: the dissemination into the scientific community of the difference in processing between these two centers, and the level of agreement between the estimated crustal for future sea-level studies in the Pacific Northwest. We model both target and reference frame receiver trajectories as a superposition of discrete processes comprising steady-state tectonic motion, annual and bi-annual sinusoids exhibiting stationary phase and amplitude that reflect both local hydrology as well as artifacts introduced through satellite clock and orbit corrections, and discrete offsets due to known earthquakes (with Mw > 6) and hardware changes. Qualitatively, Vancouver Island shows long-term uplift of ~2 mm/year, consistent with both interseismic strain accumulation from the Juan de Fuca subduction along the coast and post-glacial rebound inland, and consistent with earlier reports based on few stations and shorter time series. Further south, coastal uplift rates transition to near-zero south of Pacific Beach, and remain low southward to Cape Blanco. Vertical motion is more heterogeneous throughout Puget Sound, but most regions show subsidence of ~0.5 - 1 mm/yr. The predominant subsidence throughout Puget Sound, where the

  10. Predicting vertical jump height from bar velocity.

    PubMed

    García-Ramos, Amador; Štirn, Igor; Padial, Paulino; Argüelles-Cienfuegos, Javier; De la Fuente, Blanca; Strojnik, Vojko; Feriche, Belén

    2015-06-01

    The objective of the study was to assess the use of maximum (Vmax) and final propulsive phase (FPV) bar velocity to predict jump height in the weighted jump squat. FPV was defined as the velocity reached just before bar acceleration was lower than gravity (-9.81 m·s(-2)). Vertical jump height was calculated from the take-off velocity (Vtake-off) provided by a force platform. Thirty swimmers belonging to the National Slovenian swimming team performed a jump squat incremental loading test, lifting 25%, 50%, 75% and 100% of body weight in a Smith machine. Jump performance was simultaneously monitored using an AMTI portable force platform and a linear velocity transducer attached to the barbell. Simple linear regression was used to estimate jump height from the Vmax and FPV recorded by the linear velocity transducer. Vmax (y = 16.577x - 16.384) was able to explain 93% of jump height variance with a standard error of the estimate of 1.47 cm. FPV (y = 12.828x - 6.504) was able to explain 91% of jump height variance with a standard error of the estimate of 1.66 cm. Despite that both variables resulted to be good predictors, heteroscedasticity in the differences between FPV and Vtake-off was observed (r(2) = 0.307), while the differences between Vmax and Vtake-off were homogenously distributed (r(2) = 0.071). These results suggest that Vmax is a valid tool for estimating vertical jump height in a loaded jump squat test performed in a Smith machine. Key pointsVertical jump height in the loaded jump squat can be estimated with acceptable precision from the maximum bar velocity recorded by a linear velocity transducer.The relationship between the point at which bar acceleration is less than -9.81 m·s(-2) and the real take-off is affected by the velocity of movement.Mean propulsive velocity recorded by a linear velocity transducer does not appear to be optimal to monitor ballistic exercise performance.

  11. Predicting Vertical Jump Height from Bar Velocity

    PubMed Central

    García-Ramos, Amador; Štirn, Igor; Padial, Paulino; Argüelles-Cienfuegos, Javier; De la Fuente, Blanca; Strojnik, Vojko; Feriche, Belén

    2015-01-01

    The objective of the study was to assess the use of maximum (Vmax) and final propulsive phase (FPV) bar velocity to predict jump height in the weighted jump squat. FPV was defined as the velocity reached just before bar acceleration was lower than gravity (-9.81 m·s-2). Vertical jump height was calculated from the take-off velocity (Vtake-off) provided by a force platform. Thirty swimmers belonging to the National Slovenian swimming team performed a jump squat incremental loading test, lifting 25%, 50%, 75% and 100% of body weight in a Smith machine. Jump performance was simultaneously monitored using an AMTI portable force platform and a linear velocity transducer attached to the barbell. Simple linear regression was used to estimate jump height from the Vmax and FPV recorded by the linear velocity transducer. Vmax (y = 16.577x - 16.384) was able to explain 93% of jump height variance with a standard error of the estimate of 1.47 cm. FPV (y = 12.828x - 6.504) was able to explain 91% of jump height variance with a standard error of the estimate of 1.66 cm. Despite that both variables resulted to be good predictors, heteroscedasticity in the differences between FPV and Vtake-off was observed (r2 = 0.307), while the differences between Vmax and Vtake-off were homogenously distributed (r2 = 0.071). These results suggest that Vmax is a valid tool for estimating vertical jump height in a loaded jump squat test performed in a Smith machine. Key points Vertical jump height in the loaded jump squat can be estimated with acceptable precision from the maximum bar velocity recorded by a linear velocity transducer. The relationship between the point at which bar acceleration is less than -9.81 m·s-2 and the real take-off is affected by the velocity of movement. Mean propulsive velocity recorded by a linear velocity transducer does not appear to be optimal to monitor ballistic exercise performance. PMID:25983572

  12. Charge-to-mass Ratio of Saltating Particles in Wind-Blown Sand

    PubMed Central

    Bo, Tian-Li; Zhang, Huan; Zheng, Xiao-Jing

    2014-01-01

    The electrification of sand particles plays an important role in aeolian events. In this paper, the charge-to-mass ratio vertical profiles of saltating particles in wind-blown sand were measured by a field experiments. By combining the results of field measurements with our previous wind-tunnel measurements, we discussed the factors affecting the charge-to-mass ratio of saltating particles. It reveals that the magnitude of the charge-to-mass ratio increases exponentially with height above the surface. In addition, the charge polarity of saltating particles depends on the relative size between saltating and creeping particles, and the magnitude of charge-to-mass ratio is determined by wind velocity and the relative size difference ratio between saltating and creeping particles. PMID:24998641

  13. Some Effects of Frequency on the Contribution of a Vertical Tail to the Free Aerodynamic Damping of a Model Oscillating in Yaw

    NASA Technical Reports Server (NTRS)

    Bird, John D; Fisher, Lewis R; Hubbard, Sadie M

    1953-01-01

    The damping in yaw and the directional stability of a model freely oscillating in yaw were measured tail-off and tail-on and compared with the values obtained by theoretical consideration of the unsteady lift associated with an oscillating vertical tail. A range of low frequencies comparable to those of the lateral motions of airplanes was covered. The analysis includes the effects of vertical-tail aspect ratio and the two-dimensional effects of compressibility.

  14. Vertical peak ground force in human infant crawling.

    PubMed

    Yozu, Arito; Haga, Nobuhiko; Tojima, Michio; Zhang, Yasu; Sumitani, Masahiko; Otake, Yuko

    2013-02-01

    Quadrupedalism is a common mode of locomotion in land animals. The load distribution between the forelimbs (FL) and hindlimbs (HL) in quadrupedalism has been of great interest to researchers, and a database of the vertical peak force (Vpk) for FL and HL has been created for various species. However, Vpk in human infant crawling, a natural form of human quadrupedalism, has not been evaluated. We aimed to study Vpk in human infant crawling. Eight healthy infants who used a typical crawling style (i.e., crawling on the hands and knees) were included. The infants were encouraged to crawl over pressure mats placed on the floor, and Vpk of FL and HL were calculated. FL Vpk was 0.631±0.087 (per BW), and HL Vpk was 0.638±0.089 (per BW). No significant difference was observed between FL and HL Vpk. The mean FL/HL Vpk ratio was -0.011 on a natural logarithmic scale. These data could be added to the current database on Vpk for quadrupedalism.

  15. Comparison of aerodynamic models for Vertical Axis Wind Turbines

    NASA Astrophysics Data System (ADS)

    Simão Ferreira, C.; Aagaard Madsen, H.; Barone, M.; Roscher, B.; Deglaire, P.; Arduin, I.

    2014-06-01

    Multi-megawatt Vertical Axis Wind Turbines (VAWTs) are experiencing an increased interest for floating offshore applications. However, VAWT development is hindered by the lack of fast, accurate and validated simulation models. This work compares six different numerical models for VAWTS: a multiple streamtube model, a double-multiple streamtube model, the actuator cylinder model, a 2D potential flow panel model, a 3D unsteady lifting line model, and a 2D conformal mapping unsteady vortex model. The comparison covers rotor configurations with two NACA0015 blades, for several tip speed ratios, rotor solidity and fixed pitch angle, included heavily loaded rotors, in inviscid flow. The results show that the streamtube models are inaccurate, and that correct predictions of rotor power and rotor thrust are an effect of error cancellation which only occurs at specific configurations. The other four models, which explicitly model the wake as a system of vorticity, show mostly differences due to the instantaneous or time averaged formulation of the loading and flow, for which further research is needed.

  16. Jamming of Cylindrical Grains in Featureless Vertical Channels

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

    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. Supported by an Undergraduate Research Grant from Penn State Erie, The Behrend College

  17. Edge technique Doppler lidar wind measurements with high vertical resolution.

    PubMed

    Korb, C L; Gentry, B M; Li, S X

    1997-08-20

    We have developed a Doppler lidar system using the edge technique and have made atmospheric lidar wind measurements. Line-of-sight wind profiles with a vertical resolution of 22 m have a standard deviation of 0.40 m /s for a ten-shot average. Day and night lidar measurements of the vector wind have been made for altitudes from 200 to 2000 m. We validated the lidar measurements by comparing them with independent rawinsonde and pilot balloon measurements of wind speed and direction. Good agreement was obtained. The instrumental noise for these data is 0.11 m /s for a 500-shot average, which is in good agreement with the observed minimum value of the standard deviation for the atmospheric measurements. The average standard deviation over 30 mins varied from 1.16 to 0.25 m /s for day and night, respectively. High spatial and temporal resolution lidar profiles of line-of-sight winds clearly show wind shear and turbulent features at the 1 -2-m /s level with a high signal-to-noise ratio and demonstrate the potential of the edge-technique lidar for studying turbulent processes and atmospheric dynamics.

  18. Motion of spheroidal particles in vertical shear flows

    NASA Astrophysics Data System (ADS)

    Broday, David; Fichman, Mati; Shapiro, Michael; Gutfinger, Chaim

    1998-01-01

    The motion of non-neutrally buoyant prolate spheroidal particles in vertical shear flows is investigated. Using the generalized Faxen law, we calculate the hydrodynamic forces and moments acting on such inertial and inertialess particles, and their trajectories. The calculations are done for (i) freely rotating particles, and (ii) particles with orientations fixed by means of an external torque exerted by a strong orienting field. Inertial particles are found to migrate across the streamlines, and their trajectories differ considerably from those calculated for inertialess particles. Neutrally buoyant spheroids, inertial or not, which either freely rotate or have fixed orientations in shear flows, translate along the streamlines. Non-neutrally buoyant inertialess spheroids freely moving in simple shear flow translate along periodic trajectories with no net lateral drift. In contrast, inertial particles under similar flow conditions drift laterally toward locations characterized by higher local velocities in a direction opposing gravity. The motion of non-neutrally buoyant inertial particles with fixed orientations may be unstable with the drift velocity growing exponentially with time. Conditions for the occurrence of this unstable motion are formulated analytically in terms of particle and flow parameters. In general, the rate of drift depends on particle shape, via its aspect ratio, and its inertia.

  19. Vertical Structure of Magnetized Accretion Disks Around Young Stars

    NASA Astrophysics Data System (ADS)

    Tapia, Carlos; Lizano, Susana

    2016-01-01

    We model the vertical structure of magnetized accretion disks subject to viscous and resistive heating, and irradiation by the central star. We apply our formalism to the radial structure of magnetized accretion disks threaded by a poloidal magnetic field dragged during the process of star formation developed by Shu and coworkers. We consider disks around low mass protostars, T Tauri, and FU Orionis stars. We consider two levels of disk magnetization, λsys = 4 (strongly magnetized disks), and λsys = 12 (weakly magnetized disks). The rotation rates of strongly magnetized disks have large deviations from Keplerian rotation. In these models, resistive heating dominates the thermal structure for the FU Ori disk. The T Tauri disk is very thin and cold because it is strongly compressed by magnetic pressure; it may be too thin compared with observations. Instead, in the weakly magnetized disks, rotation velocities are close to Keplerian, and resistive heating is always less than 7% of the viscous heating. In these models, the T Tauri disk has a larger aspect ratio, consistent with that inferred from observations. All the disks have spatially extended hot atmospheres where the irradiation flux is absorbed, although most of the mass (~ 90 - 95 %) is in the disk midplane.

  20. Individually addressable vertically aligned carbon nanofiber-based electrochemical probes

    NASA Astrophysics Data System (ADS)

    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

    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.

  1. Rate of loading parameters for vertically loaded piles in clay

    SciTech Connect

    Briaud, J.L.; Felio, G.Y.; Garland, E.

    1984-05-01

    The analysis of 152 laboratory tests and 32 pile load tests confirms that for clays, the faster the rate of loading, the higher the undrained shear strength and the higher the pile capacity. The data shows that the gain in undrained shear strength due to increasing rate of loading increases with increasing water content, plasticity index, liquidity index, overconsolidation ratio but with decreasing undrained shear strength. A simple model is proposed to quantify the rate of loading effects on undrained shear strength. The viscous exponent n which is the main parameter of the model can be measured by conventional laboratory tests or possibly by cone penetrometer testing, or as a last resort by the proposed empirical correlations to index properties. This model is used to develop rate dependent t-z curves and a computer program to predict the response of a pile subjected to a certain rate of vertical loading. The model and the program are checked by comparing the predicted and measured behavior of two piles.

  2. Thermal Conduction in Vertically Aligned Copper Nanowire Arrays and Composites.

    PubMed

    Barako, Michael T; Roy-Panzer, Shilpi; English, Timothy S; Kodama, Takashi; Asheghi, Mehdi; Kenny, Thomas W; Goodson, Kenneth E

    2015-09-02

    The ability to efficiently and reliably transfer heat between sources and sinks is often a bottleneck in the thermal management of modern energy conversion technologies ranging from microelectronics to thermoelectric power generation. These interfaces contribute parasitic thermal resistances that reduce device performance and are subjected to thermomechanical stresses that degrade device lifetime. Dense arrays of vertically aligned metal nanowires (NWs) offer the unique combination of thermal conductance from the constituent metal and mechanical compliance from the high aspect ratio geometry to increase interfacial heat transfer and device reliability. In the present work, we synthesize copper NW arrays directly onto substrates via templated electrodeposition and extend this technique through the use of a sacrificial overplating layer to achieve improved uniformity. Furthermore, we infiltrate the array with an organic phase change material and demonstrate the preservation of thermal properties. We use the 3ω method to measure the axial thermal conductivity of freestanding copper NW arrays to be as high as 70 W m(-1) K(-1), which is more than an order of magnitude larger than most commercial interface materials and enhanced-conductivity nanocomposites reported in the literature. These arrays are highly anisotropic, and the lateral thermal conductivity is found to be only 1-2 W m(-1) K(-1). We use these measured properties to elucidate the governing array-scale transport mechanisms, which include the effects of morphology and energy carrier scattering from size effects and grain boundaries.

  3. Opportunity's Surroundings on Sol 1818 (Vertical)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends.

    This view is presented as a vertical projection with geometric seam correction. North is at the top.

    The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view.

    The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

  4. Opportunity's Surroundings on Sol 1687 (Vertical)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 360-degree view of the rover's surroundings on the 1,687th Martian day, or sol, of its surface mission (Oct. 22, 2008).

    Opportunity had driven 133 meters (436 feet) that sol, crossing sand ripples up to about 10 centimeters (4 inches) tall. The tracks visible in the foreground are in the east-northeast direction.

    Opportunity's position on Sol 1687 was about 300 meters southwest of Victoria Crater. The rover was beginning a long trek toward a much larger crater, Endeavour, about 12 kilometers (7 miles) to the southeast.

    This view is presented as a vertical projection with geometric seam correction.

  5. Opportunity's Surroundings on Sol 1798 (Vertical)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top.

    This view is presented as a vertical projection with geometric seam correction.

    The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches).

    The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

  6. Opportunity's Surroundings After Sol 1820 Drive (Vertical)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009).

    This view is presented as a vertical projection with geometric seam correction. North is at the top.

    The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches).

    The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock.

  7. Vertical and rotational motion of mahogany seed

    NASA Astrophysics Data System (ADS)

    Camposano, A. V. C.; Virtudes, N. C.; Otadoy, R. E. S.; Violanda, R.

    2015-06-01

    Starting with a set of basic assumptions and with the application of well-known Newtonian physics, a theoretical model has been established for the flight of the mahogany winged seed. Using a high-speed camera, we successfully confirmed that the mahogany winged seed attains a vertical and rotational terminal velocity. From our model the mahogany seed has a terminal speed of 1.45 m/s. The experimental value of the terminal velocity on the average is 1.47 m/s (only about 1% error). The experimental value of the angular velocity was found to be around 54.33 rad/s, about 14% error compared to the predicted terminal velocity of 47.5 rad/s. The high predictable nature of a mahogany's terminal velocity can facilitate the biologist's study of mahogany mass seed dispersal.

  8. Vertical-Axis Wind Turbine Mesh Generator

    SciTech Connect

    2014-01-24

    VAWTGen is a mesh generator for creating a finite element beam mesh of arbitrary vertical-axis wind turbines (VAWT). The software accepts input files specifying tower and blade structural and aerodynamic descriptions and constructs a VAWT using a minimal set of inputs. VAWTs with an arbitrary number of blades can be constructed with or without a central tower. Strut connections between the tower and blades can be specified in an arbitrary manner. The software also facilitates specifying arbitrary joints between structural components and concentrated structural tenns (mass and stiffness). The output files which describe the VAWT configuration are intended to be used with the Offshore Wind ENergy Simulation (OWENS) Toolkit software for structural dynamics analysis of VAWTs. Furthermore, VAWTGen is useful for visualizing output from the OWENS analysis software.

  9. Vertical integration and optimal reimbursement policy.

    PubMed

    Afendulis, Christopher C; Kessler, Daniel P

    2011-09-01

    Health care providers may vertically integrate not only to facilitate coordination of care, but also for strategic reasons that may not be in patients' best interests. Optimal Medicare reimbursement policy depends upon the extent to which each of these explanations is correct. To investigate, we compare the consequences of the 1997 adoption of prospective payment for skilled nursing facilities (SNF PPS) in geographic areas with high versus low levels of hospital/SNF integration. We find that SNF PPS decreased spending more in high integration areas, with no measurable consequences for patient health outcomes. Our findings suggest that integrated providers should face higher-powered reimbursement incentives, i.e., less cost-sharing. More generally, we conclude that purchasers of health services (and other services subject to agency problems) should consider the organizational form of their suppliers when choosing a reimbursement mechanism.

  10. Multispectral imaging with vertical silicon nanowires

    PubMed Central

    Park, Hyunsung; Crozier, Kenneth B.

    2013-01-01

    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

  11. Stability of vertical and horizontal axis Levitrons

    NASA Astrophysics Data System (ADS)

    Michaelis, M. M.; Taylor, D. B.

    2015-11-01

    The stability of the new horizontal axis Levitron3 is compared with that of the vertical axis device. The rotation frequency ranges are similar because they are determined by the same precessional micro-trap, for which some theory is given. But the macro-trap of the horizontal axis system gives it far greater mechanical stability. Field-line studies allow this to be more easily visualized. The greater stability allows for educational experiments which could only be contemplated with the old Levitron: driven precession and nutation and motion along the field lines. These experiments illustrate some very fundamental space dynamics and several other topics. The enhanced stability may also lead to electro-mechanical applications.

  12. Vertical axis wind turbine control strategy

    SciTech Connect

    McNerney, G.M.

    1981-08-01

    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.

  13. Integrated Vertical Bloch Line (VBL) memory

    NASA Technical Reports Server (NTRS)

    Katti, R. R.; Wu, J. C.; Stadler, H. L.

    1991-01-01

    Vertical Bloch Line (VBL) Memory is a recently conceived, integrated, solid state, block access, VLSI memory which offers the potential of 1 Gbit/sq cm areal storage density, data rates of hundreds of megabits/sec, and submillisecond average access time simultaneously at relatively low mass, volume, and power values when compared to alternative technologies. VBLs are micromagnetic structures within magnetic domain walls which can be manipulated using magnetic fields from integrated conductors. The presence or absence of BVL pairs are used to store binary information. At present, efforts are being directed at developing a single chip memory using 25 Mbit/sq cm technology in magnetic garnet material which integrates, at a single operating point, the writing, storage, reading, and amplification functions needed in a memory. The current design architecture, functional elements, and supercomputer simulation results are described which are used to assist the design process.

  14. Development of Vertical Cable Seismic System (2)

    NASA Astrophysics Data System (ADS)

    Asakawa, E.; Murakami, F.; Tsukahara, H.; Ishikawa, K.

    2012-12-01

    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 carried out two field surveys in 2011. 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, we have confirmed that the

  15. Evidence for vertical ozone redistribution since 1967

    NASA Astrophysics Data System (ADS)

    Furrer, R.; Döhler, W.; Kirsch, H.-J.; Plessing, P.; Görsdorf, U.

    1993-03-01

    Long-term measurements of the ozone concentration in the vicinity of the city of Berlin have been performed with ground based Dobson spectrophotometers and balloon borne systems. The respective experiments cover the past 24 years. All data have been reevaluated and corrected towards uniform calibration standards, leading to the longest European data set of total column density, altitude-dependent ozone partial pressures and the corresponding temperatures. Smoothing algorithms unravel significant long-term trends. The analysis shows an increase of ozone concentration within the middle stratosphere (below 31 km height) as well as in the troposphere over the past 24 years. On the contrary, ongoing ozone depletion in the lower stratosphere has been found. The large scale vertical redistribution of atmospheric ozone in the troposphere and the lower stratosphere seems to be in agreement with model calculations and trend predictions that have their roots in changes of the chemical composition and the ozone photochemistry due to anthropogenically induced trace gas concentrations.

  16. Evidence for vertical ozone redistribution since 1967

    NASA Astrophysics Data System (ADS)

    Furrer, R.; Döhler, W.; Kirsch, H.-J.; Plessing, P.; Görsdorf, U.

    1993-01-01

    Long-term measurements of ozone concentration in the vicinity of the city of Berlin have been performed with ground-based Dobson spectrophotometers and balloon borne systems. The respective experiments cover the past 24 yr. All data have been re-evaluated and corrected towards uniform calibration standards, leading to the longest lasting European data set of total column density, altitude-dependent ozone partial pressures and the corresponding temperatures. Smoothing algorithms reveal significant longterm trends. The analysis shows an increase of ozone concentration within the middle stratosphere (below 31 km height) as well as in the troposphere over the past 24 yr. On the contrary, ongoing ozone depletion in the lower stratosphere became evident. The large scale vertical redistribution of atmospheric ozone in the troposphere and the lower stratosphere seems to be in agreement with model calculations and trend predictions that have their roots in changes of the chemical composition and the ozone photochemistry due to anthropogenically induced tracer gas concentrations.

  17. Vertical transmission of the Ohdo blepharophimosis syndrome.

    PubMed

    Mhanni, A A; Dawson, A J; Chudley, A E

    1998-05-01

    Ohdo blepharophimosis syndrome (OBS) is a multiple congenital anomalies-mental retardation syndrome composed of blepharophimosis, ptosis, dental hypoplasia, partial deafness, and mental retardation. Previously reported cases of OBS have been sporadic except for the report by Ohdo et al. [1986, J Med Genet 23:242-244] that described two affected sisters and a first cousin favoring autosomal recessive inheritance. The original report by Ohdo et al. [1986] may reflect nonpenetrance of an autosomal dominantly inherited disorder or genetic heterogeneity of OBS. We report on a child and the mother who have blepharophimosis, ptosis, dental anomalies, mild hearing loss, and mental retardation. Chromosome analysis in both showed a balanced paracentric inversion of the long arm of chromosome 9, which was also present in two phenotypically normal sibs of the mother. This is the first report of vertical transmission of OBS suggestive of autosomal dominant inheritance. X-linked dominant and mitochondrial inheritance are other possible modes of inheritance.

  18. Analytical model for a vertical buoyant jet

    SciTech Connect

    Lee, D.W.

    1980-10-01

    An analytical model for a round and two-dimensional turbulent buoyant jet which is discharged vertically into a stagnant ambient is developed. The buoyant jet is considered to have three separate zone models which are matched to form a complete solution. The velocity field is determined for the entire jet and plume regions by the use of an eddy viscosity which varies along the axis of the jet. The centerline decay of buoyancy is determined throughout and the results are compared to existing numerical codes. The model is applied to the disposal of carbon dioxide enriched seawater. The results can be used to provide design information for minimizing or maximizing the dilution of a discharge by the receiving environment.

  19. Estimating tropical vertical motion profile shapes from satellite observations

    NASA Astrophysics Data System (ADS)

    Back, L. E.; Handlos, Z.

    2013-12-01

    The vertical structure of tropical deep convection strongly influences interactions with larger scale circulations and climate. This research focuses on investigating this vertical structure and its relationship with mesoscale tropical weather states. We test the hypothesis that vertical motion shape varies in association with weather state type. We estimate mean state vertical motion profile shapes for six tropical weather states defined using cloud top pressure and optical depth properties from the International Satellite Cloud Climatology Project. The relationship between vertical motion and the dry static energy budget are utilized to set up a regression analysis that empirically determines two modes of variability in vertical motion from reanalysis data. We use these empirically determined modes, this relationship and surface convergence to estimate vertical motion profile shape from observations of satellite retrievals of rainfall and surface convergence. We find that vertical motion profile shapes vary systematically between different tropical weather states. The "isolated systems" regime exhibits a more ''bottom-heavy'' profile shape compared to the convective/thick cirrus and vigorous deep convective regimes, with maximum upward vertical motion occurring in the lower troposphere rather than the middle to upper troposphere. The variability we observe with our method does not coincide with that expected based on conventional ideas about how stratiform rain fraction and vertical motion are related.

  20. Vertical structure of recent Arctic warming.

    PubMed

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

    2008-01-03

    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.

  1. Gravity dependence of subjective visual vertical variability.

    PubMed

    Tarnutzer, A A; Bockisch, C; Straumann, D; Olasagasti, I

    2009-09-01

    The brain integrates sensory input from the otolith organs, the semicircular canals, and the somatosensory and visual systems to determine self-orientation relative to gravity. Only the otoliths directly sense the gravito-inertial force vector and therefore provide the major input for perceiving static head-roll relative to gravity, as measured by the subjective visual vertical (SVV). Intraindividual SVV variability increases with head roll, which suggests that the effectiveness of the otolith signal is roll-angle dependent. We asked whether SVV variability reflects the spatial distribution of the otolithic sensors and the otolith-derived acceleration estimate. Subjects were placed in different roll orientations (0-360 degrees, 15 degrees steps) and asked to align an arrow with perceived vertical. Variability was minimal in upright, increased with head-roll peaking around 120-135 degrees, and decreased to intermediate values at 180 degrees. Otolith-dependent variability was modeled by taking into consideration the nonuniform distribution of the otolith afferents and their nonlinear firing rate. The otolith-derived estimate was combined with an internal bias shifting the estimated gravity-vector toward the body-longitudinal. Assuming an efficient otolith estimator at all roll angles, peak variability of the model matched our data; however, modeled variability in upside-down and upright positions was very similar, which is at odds with our findings. By decreasing the effectiveness of the otolith estimator with increasing roll, simulated variability matched our experimental findings better. We suggest that modulations of SVV precision in the roll plane are related to the properties of the otolith sensors and to central computational mechanisms that are not optimally tuned for roll-angles distant from upright.

  2. Monolithically integrated self-rolled-up microtube-based vertical coupler for three-dimensional photonic integration

    NASA Astrophysics Data System (ADS)

    Yu, Xin; Arbabi, Ehsan; Goddard, Lynford L.; Li, Xiuling; Chen, Xiaogang

    2015-07-01

    We demonstrate a self-rolled-up microtube-based vertical photonic coupler monolithically integrated on top of a ridge waveguide to achieve three-dimensional (3D) photonic integration. The fabrication process is fully compatible with standard planar silicon processing technology. Strong light coupling between the vertical coupler and the ridge waveguide was observed experimentally, which may provide an alternative route for 3D heterogeneous photonic integration. The highest extinction ratio observed in the transmission spectrum passing through the ridge waveguide was 23 dB.

  3. Monolithically integrated self-rolled-up microtube-based vertical coupler for three-dimensional photonic integration

    SciTech Connect

    Yu, Xin; Arbabi, Ehsan; Goddard, Lynford L.; Li, Xiuling; Chen, Xiaogang

    2015-07-20

    We demonstrate a self-rolled-up microtube-based vertical photonic coupler monolithically integrated on top of a ridge waveguide to achieve three-dimensional (3D) photonic integration. The fabrication process is fully compatible with standard planar silicon processing technology. Strong light coupling between the vertical coupler and the ridge waveguide was observed experimentally, which may provide an alternative route for 3D heterogeneous photonic integration. The highest extinction ratio observed in the transmission spectrum passing through the ridge waveguide was 23 dB.

  4. Modular low aspect ratio-high beta torsatron

    DOEpatents

    Sheffield, George V.; Furth, Harold P.

    1984-02-07

    A fusion reactor device in which the toroidal magnetic field and at least a portion of the poloidal magnetic field are provided by a single set of modular coils. The coils are arranged on the surface of a low aspect ratio toroid in planes having the cylindrical coordinate relationship .phi.=.phi..sub.i +kz where k is a constant equal to each coil's pitch and .phi..sub.i is the toroidal angle at which the i'th coil intersects the z=o plane. The device may be described as a modular, high beta torsation whose screw symmetry is pointed along the systems major (z) axis. The toroid defined by the modular coils preferably has a racetrack minor cross section. When vertical field coils and preferably a toroidal plasma current are provided for magnetic field surface closure within the toroid, a vacuum magnetic field of racetrack shaped minor cross section with improved stability and beta valves is obtained.

  5. Modular low-aspect-ratio high-beta torsatron

    DOEpatents

    Sheffield, G.V.

    1982-04-01

    A fusion-reactor device is described which the toroidal magnetic field and at least a portion of the poloidal magnetic field are provided by a single set of modular coils. The coils are arranged on the surface of a low-aspect-ratio toroid in planed having the cylindrical coordinate relationship phi = phi/sub i/ + kz, where k is a constant equal to each coil's pitch and phi/sub i/ is the toroidal angle at which the i'th coil intersects the z = o plane. The toroid defined by the modular coils preferably has a race track minor cross section. When vertical field coils and, preferably, a toroidal plasma current are provided for magnetic-field-surface closure within the toroid, a vacuum magnetic field of racetrack-shaped minor cross section with improved stability and beta valves is obtained.

  6. High extinction ratio bandgap of photonic crystals in LNOI wafer

    NASA Astrophysics Data System (ADS)

    Zhang, Shao-Mei; Cai, Lu-Tong; Jiang, Yun-Peng; Jiao, Yang

    2017-02-01

    A high-extinction-ratio bandgap of air-bridge photonic crystal slab, in the near infrared, is reported. These structures were patterned in single-crystalline LiNbO3 film bonded to SiO2/LiNbO3 substrate by focused ion beam. To improve the vertical confinement of light, the SiO2 layer was removed by 3.6% HF acid. Compared with photonic crystals sandwiched between SiO2 and air, the structures suspending in air own a robust photonic bandgap and high transmission efficiency at valence band region. The measured results are in good agreement with numerically computed transmission spectra by finite-difference time-domain method. The air-bridge photonic crystal waveguides were formed by removing one line holes. We reveal experimentally the guiding characteristics and calculate the theoretical results for photonic crystal waveguides in LiNbO3 film.

  7. Strong turbulent mixing induced by internal bores interacting with internal tide-driven vertically sheared flow

    NASA Astrophysics Data System (ADS)

    Masunaga, Eiji; Fringer, Oliver B.; Yamazaki, Hidekatsu; Amakasu, Kazuo

    2016-03-01

    We observed the formation of an internal bore interacting with the vertically sheared flow generated during the previous phase of the internal tide, which resulted in strong turbulent mixing. The rate of turbulent kinetic energy dissipation reached on the order of 10-5 W kg-1 during the event. Numerical simulations reproduced the observed interaction of internal bores with the sheared flow and verified the hypothesized breaking and mixing mechanism. The numerical results indicated that the Iribarren number, or the ratio of the topographic slope to the internal wave slope, plays a major role in the mixing intensity and types of internal bores. It was found that waves with low Iribarren numbers lead to bores that interact with vertically sheared flows induced by the previous phase of the internal tide and are more likely to produce strong wave breaking and mixing.

  8. Deep and vertical silicon bulk micromachining using metal assisted chemical etching

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    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.

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

    PubMed

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

    2013-08-27

    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.

  10. Crystal Ice Formation of Solution and Its Removal Phenomena around Vertical Cooled Cylinder

    NASA Astrophysics Data System (ADS)

    Hirata, Tetsuo; Ishikawa, Masaaki; Akutsu, Nobuaki

    Experimental and analytical studies for freezing phenomena of ethylene glycol solution around a vertical cooled polyvinyl-chloride cylinder have been performed. It is found that the crystal ice formed around the vertical cylinder is removed from the cylinder surface due to buoyancy force acting on the crystal ice. The crystal ice slides along the cylinder surface due to buoyancy force and grows in a shape of tube by joining with the neighbour ice. It is shown that the onset of ice removal condition is related to the heat flux at the cylinder surface when the latent heat of fusion is discharged with freezing, and that the heat flux ratio of 'from the cylinder surface into the cylinder' to 'from the cylinder surface to the solution' is an important parameter for the onset conditions. The ice removal occurs easily for short cylinders than for long ones.

  11. Decoration of vertical graphene with aerosol nanoparticles for gas sensing

    NASA Astrophysics Data System (ADS)

    Cui, Shumao; Guo, Xiaoru; Ren, Ren; Zhou, Guihua; Chen, Junhong

    2015-08-01

    A facile method was demonstrated to decorate aerosol Ag nanoparticles onto vertical graphene surfaces using a mini-arc plasma reactor. The vertical graphene was directly grown on a sensor electrode using a plasma-enhanced chemical vapor deposition (PECVD) method. The aerosol Ag nanoparticles were synthesized by a simple vapor condensation process using a mini-arc plasma source. Then, the nanoparticles were assembled on the surface of vertical graphene through the assistance of an electric field. Based on our observation, nonagglomerated Ag nanoparticles formed in the gas phase and were assembled onto vertical graphene sheets. Nanohybrids of Ag nanoparticle-decorated vertical graphene were characterized for ammonia gas detection at room temperature. The vertical graphene served as the conductance channel, and the conductance change upon exposure to ammonia was used as the sensing signal. The sensing results show that Ag nanoparticles significantly improve the sensitivity, response time, and recovery time of the sensor.

  12. Infants' sensitivity to vertical disparity for depth perception

    NASA Astrophysics Data System (ADS)

    Tsuruhara, Aki; Kaneko, Hirohiko; Kanazawa, So; Otsuka, Yumiko; Shirai, Nobu; Yamaguchi, Masami K.

    2013-05-01

    Both horizontal and vertical binocular disparities produce depth perception in adults. In developmental studies, infants aged around 4 to 6 months were shown to perceive depth from horizontal disparity. However, infants' sensitivity to vertical disparity has not been shown clearly. To examine the sensitivity in infants, this study measured preferential looking behavior of infants aged 20 to 27 weeks. Results showed a significant preference for the stimulus with vertical disparity, providing the first evidence of infants' sensitivity to vertical disparity. The infants in the same age group did not show preference for stimulus with horizontal disparity when the stimulus were comparable to the stimulus with vertical disparity, while their sensitivity to horizontal disparity was confirmed with the stimuli used in a previous study. Our results would suggest that properties in processing horizontal and vertical disparities are different in infancy, and that the sensitivity to horizontal disparity are still premature in 27 weeks after birth.

  13. Evaluation of procalcitonin for diagnosis of neonatal sepsis of vertical transmission

    PubMed Central

    López Sastre, José B; Solís, David Pérez; Serradilla, Vicente Roqués; Colomer, Belén Fernández; Cotallo, Gil D Coto

    2007-01-01

    Background The results of recent studies suggest the usefulness of PCT for early diagnosis of neonatal sepsis, with varying results. The aim of this prospective multicenter study was to determine the behavior of serum PCT concentrations in both uninfected and infected neonates, and to assess the value of this marker for diagnosis of neonatal sepsis of vertical transmission. Methods PCT was measured in 827 blood samples collected prospectively from 317 neonates admitted to 13 acute-care teaching hospitals in Spain over one year. Serum PCT concentrations were determined by a specific immunoluminometric assay. The diagnostic efficacy of PCT at birth and within 12–24 h and 36–48 h of life was evaluated calculating the sensitivity, specificity, and likelihood ratio of positive and negative results. Results 169 asymptomatic newborns and 148 symptomatic newborns (confirmed vertical sepsis: 31, vertical clinical sepsis: 38, non-infectious diseases: 79) were studied. In asymptomatic neonates, PCT values at 12–24 h were significantly higher than at birth and at 36–48 h of life. Resuscitation at birth and chorioamnionitis were independently associated to PCT values. Neonates with confirmed vertical sepsis showed significantly higher PCT values than those with clinical sepsis. PCT thresholds for the diagnosis of sepsis were 0.55 ng/mL at birth (sensitivity 75.4%, specificity 72.3%); 4.7 ng/mL within 12–24 h of life (sensitivity 73.8%, specificity 80.8%); and 1.7 ng/mL within 36–48 h of life (sensitivity 77.6%, specificity 79.2%). Conclusion Serum PCT was moderately useful for the detection of sepsis of vertical transmission, and its reliability as a maker of bacterial infection requires specific cutoff values for each evaluation point over the first 48 h of life. PMID:17324267

  14. FAME-C: Retrieval of cloud top pressure with vertically inhomogeneous cloud profiles

    NASA Astrophysics Data System (ADS)

    Henken, Cintia Carbajal; Lindstrot, Rasmus; Filipitsch, Florian; Walther, Andi; Preusker, Rene; Fischer, Jürgen

    2013-05-01

    A synergistic FAME-C (Freie Universität Berlin AATSR-MERIS Cloud Retrieval) algorithm is developed within the frame of the ESA CCI Cloud project. Within FAME-C the ratio of two MERIS measurements (the Oxygen-A absorption channel and a window channel) is used to retrieve cloud top pressure. In case of high, extended clouds the retrieved cloud top pressure is generally too high. This can be understood as an overestimation of extinction in upper cloud layers due to the assumption of vertical homogeneous clouds in the radiative transfer simulations. To include more realistic cloud vertical profiles, one year of data from the Cloud Profiling Radar (CPR) onboard CloudSat has been used to determine average normalized cloud vertical extinction profiles with a fixed pressure thickness for nine cloud types. The nine cloud types are based on the ISCCP COT-CTP classification table. The retrieved cloud top pressure, now using CloudSat cloud profiles in the forward model, is compared to CPR reflectivities as well as the retrieved cloud top pressure using vertically homogeneous cloud profiles. In the first number of cases under examination the overestimation of cloud top pressure, and therefore the bias, is reduced by a large amount when using CloudSat vertical cloud profiles. Another advantage is that no assumption about the cloud geometrical thickness has to be made in the new retrieval. It should be noted that comparisons between FAME-C products and A-train products can only be made at high latitudes where A-train and ENVISAT have overlapping overflights.

  15. Robotic platform for traveling on vertical piping network

    DOEpatents

    Nance, Thomas A; Vrettos, Nick J; Krementz, Daniel; Marzolf, Athneal D

    2015-02-03

    This invention relates generally to robotic systems and is specifically designed for a robotic system that can navigate vertical pipes within a waste tank or similar environment. The robotic system allows a process for sampling, cleaning, inspecting and removing waste around vertical pipes by supplying a robotic platform that uses the vertical pipes to support and navigate the platform above waste material contained in the tank.

  16. Vertical δ13C and δ15N changes during pedogenesis

    NASA Astrophysics Data System (ADS)

    Brunn, Melanie; Spielvogel, Sandra; Wells, Andrew; Condron, Leo; Oelmann, Yvonne

    2015-04-01

    The natural abundance of soil organic matter (SOM) stable C and N isotope ratios are subjected to vertical changes throughout the soil profile. This vertical distribution is a widely reported phenomenon across varieties of ecosystems and constitutes important insights of soil carbon cycling. In most ecosystems, SOM becomes enriched in heavy isotopes by several per mill in the first few centimeters of the topsoil. The enrichment of 13C in SOM with soil depth is attributed to biological and physical-chemical processes in soil e.g., plant physiological impacts, microbial decomposition, sorption and transport processes. Such vertical trends in 13C and 15N abundance have rarely been related to SOM composition during pedogenesis. The aims of our study were to investigate short and long-term δ13C and δ15N depth changes and their interrelations under progressing pedogenesis and ecosystem development. We sampled soils across the well studied fordune progradation Haast-chronosequence, a dune ridge system under super-humid climate at the West Coast of New Zealand's South Island (43° 53' S, 169° 3' E). Soils from 11 sites with five replicates each covered a time span of around 2870 yr of soil development (from Arenosol to Podzol). Vertical changes of δ13C and δ15N values of SOM were investigated in the organic layers and in 1-cm depth intervals of the upper 10 cm of the mineral soil. With increasing soil depth SOM became enriched in δ13C by 1.9 ± SE 0.1 o and in δ15N by 6.0 ± 0.4 ‰˙Litter δ13C values slightly decreased with increasing soil age (r = -0.61; p = 0.00) likely due to less efficient assimilation linked to nutrient limitations. Fractionation processes during mycorrhizal transfer appeared to affect δ15N values in the litter. We found a strong decrease of δ15N in the early succession stages ≤ 300 yr B.P. (r = -0.95; p = 0.00). Positive relations of vertical 13C and 15N enrichment with soil age might be related to decomposition and appeared to be

  17. Length perception of horizontal and vertical bisected lines.

    PubMed

    Charras, Pom; Lupiáñez, Juan

    2010-03-01

    In an inverted T figure, the vertical line is largely overestimated (Avery and Day in J Exp Psychol 81:376-380, 1969). This vertical overestimation results from the vertical and bisection biases. Line orientation biases length perception in the sense that the vertical line of a L shape is perceived as longer than the horizontal line of the same physical length. In the inverted T figure, the vertical line is overestimated because of its orientation but also because the horizontal line is bisected. In the current study, we used various two-line configurations to investigate the role of bisection a/symmetry in line length perception and its interaction with the vertical bias. Experiment 1 showed that symmetry and asymmetry of bisection have different consequences on line length perception, as previously shown by Wolfe et al. (Percept Psychophys 67:967-979, 2005). Experiments 2 focused on the relation between the vertical and bisection biases by manipulating orthogonally line orientation and bisection a/symmetry. The results provided evidence that bisection can prevent the manifestation of the vertical bias, so that when the two lines are bisected, vertical lines are not anymore overestimated. These results are discussed in the light of recent findings claiming that saccades could play an essential role in length perception.

  18. 7. VIEW NORTHWEST, DETAIL VERTICAL SUPPORT SYSTEM, STRINGER, CONNECTIONS AND ...

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

    7. VIEW NORTHWEST, DETAIL VERTICAL SUPPORT SYSTEM, STRINGER, CONNECTIONS AND TRAFFIC DECK - Hagerstown Road Bridge, Spanning Little Cotoctin Creek at Old Hagerstown Road, Middletown, Frederick County, MD

  19. Cross-sectional study of the retinal nerve fiber layer thickness at 7 years after an acute episode of unilateral primary acute angle closure.

    PubMed

    Lee, Jacky W Y; Woo, Tiffany T Y; Yau, Gordon S K; Yip, Stan; Yick, Doris W F; Wong, Jasper; Wong, Raymond L M; Wong, Ian Y H

    2015-01-01

    The purpose of this article is to investigate the long-term retinal nerve fiber layer (RNFL) status and determinants of RNFL thinning after an episode of unilateral primary acute angle closure (AAC). This cross-sectional study analyzed the medical records of consecutive patients with a single episode of unilateral AAC from 1999 to 2009 in Hong Kong. The peripapillary RNFL thickness was correlated with age, gender, presenting intraocular pressure (IOP), time to laser iridotomy, time to cataract extraction, follow-up duration, as well as the last IOP, vertical cup-to-disc ratio (CDR), and vision. The fellow uninvolved eye was used as a proxy comparison of RNFL loss in the attack eye. In 40 eligible patients, the mean age was 68.3 ± 8.7 years with a male-to-female ratio of 1:7. The mean presenting IOP was 49.2 ± 14.0 mm Hg and the time from presentation to laser iridotomy was 6.7 ± 6.9 days. Forty percent of subjects received a cataract extraction at 3.2 ± 2.9 years after the attack. The last IOP, CDR, and LogMAR vision were 16.0 ± 3.8 mm Hg, 0.6 ± 0.2, and 0.6 ± 0.6 LogMAR units, respectively, at 7.9 ± 2.4 years. The RNFL thickness in the attack eye (69.2 ± 19.1 μm) was 25.2 ± 17.9% thinner than the fellow eye (93.0 ± 17.8 μm) at 7.5 ± 2.9 years post-AAC. Using univariate analysis, the last vertical CDR (odds ratio [OR] = 17.2, P = 0.049) and LogMAR visual acuity (VA) (OR = 6.6, P = 0.03) were the only significant predictors for RNFL thinning whereas none of the other covariates showed significant associations (P > 0.1). At 7.5 years following unilateral AAC, the RNFL thickness was 25% thinner than the fellow eye. CDR enlargement and poor VA were the only significant predictors for RNFL loss.

  20. Reconstruction of the vertical electron density profile based on vertical TEC using the simulated annealing algorithm

    NASA Astrophysics Data System (ADS)

    Jiang, Chunhua; Yang, Guobin; Zhu, Peng; Nishioka, Michi; Yokoyama, Tatsuhiro; Zhou, Chen; Song, Huan; Lan, Ting; Zhao, Zhengyu; Zhang, Yuannong

    2016-05-01

    This paper presents a new method to reconstruct the vertical electron density profile based on vertical Total Electron Content (TEC) using the simulated annealing algorithm. The present technique used the Quasi-parabolic segments (QPS) to model the bottomside ionosphere. The initial parameters of the ionosphere model were determined from both International Reference Ionosphere (IRI) (Bilitza et al., 2014) and vertical TEC (vTEC). Then, the simulated annealing algorithm was used to search the best-fit parameters of the ionosphere model by comparing with the GPS-TEC. The performance and robust of this technique were verified by ionosonde data. The critical frequency (foF2) and peak height (hmF2) of the F2 layer obtained from ionograms recorded at different locations and on different days were compared with those calculated by the proposed method. The analysis of results shows that the present method is inspiring for obtaining foF2 from vTEC. However, the accuracy of hmF2 needs to be improved in the future work.

  1. CALIPSO Observations of Transatlantic Dust: Vertical Stratification and Effect of Clouds

    NASA Technical Reports Server (NTRS)

    Yang, Weidong; Marshak, Alexander; Varnai, Tamas; Kalashnikova, Olga V.; Kostinski, Alexander B.

    2014-01-01

    We use CALIOP nighttime measurements of lidar backscatter, color and depolarization ratios, as well as particulate retrievals during the summer of 2007 to study transatlantic dust properties downwind of Saharan sources, and to examine the influence of nearby clouds on dust. Our analysis suggests that (1) under clear skies, while lidar backscatter and color ratio do not change much with altitude and longitude in the Saharan Air Layer (SAL), depolarization ratio increases with altitude and decreases westward in the SAL (2) the vertical lapse rate of dust depolarization ratio, introduced here, increases within SAL as plumes move westward (3) 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, (4) the odds of CALIOP finding dust below SAL next to clouds are about of those far away from clouds. This feature, together with an apparent increase in depolarization ratio near clouds, indicates that particles in some dust volumes loose asphericity in the humid air near clouds, and cannot be identified by CALIPSO as dust.

  2. CALIPSO Observations of Transatlantic Dust: Vertical Stratification and Effect of Clouds

    NASA Technical Reports Server (NTRS)

    Yang, Weidong; Marshak, Alexander; Varnai, Tamas; Kalashnikova, Olga V.; Kostinski, Alexander B.

    2012-01-01

    CALIOP nighttime measurements of lidar backscatter, color and depolarization ratios during the summer of 2007 are used to study transatlantic dust properties downwind of Saharan sources, and to examine the interaction of clouds and dust. We discuss the following findings: (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 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. 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.

  3. A vertical coarse approach scanning tunneling microscope

    NASA Astrophysics Data System (ADS)

    Drevniok, Benedict

    A Pan-style scanning tunneling microscope (STM), with a vertical coarse approach mechanism, was designed, built and tested. The microscope will be operated in ultra-high vacuum and also at cryogenic temperatures (8 K) inside a continuous flow cryostat. Fundamental differences in operating principle exist between the new microscope and the beetle-type inertial sliders [1] that have been the mainstay of the group for the last eight years. While Pan-style microscopes do already exist [2], they remain challenging to build, and an active area of research [3]. This system represents a bold departure from well-trodden paths, and will greatly expand the range of experiments that our group can perform. The operating principles of inertial piezoelectric motors are detailed. Design guidelines for a piezoelectric motor are given, and used in the design of the vertical coarse approach motor. A simple, inexpensive implementation for creating waveforms with an extremely fast fall time is discussed. Motor performance is tested, and a minimum step size of 20nm is found for frequencies ranging from 0 Hz to 3 kHz. The motor operates with high dynamic range: individual 20nm steps can be taken, as well as being able to move at a velocity of 0.4mm s-1. Little is known about the vibrational properties of Pan-style microscopes. Vibrational testing of the microscope revealed the expected scanner bending mode at 1.6 kHz (above the scanner bending mode of our beetles at 1.2 kHz), and a complicated response signal above this frequency. Custom extension springs for an eddy-current damping system are built and tested. A low resonant frequency of 1.8 Hz is found, which is ideal for the application. Initial testing of the STM in ambient conditions is performed on two different surfaces. A moire supermesh [4] with periodicity 3nm is observed on a highly-oriented pyrolytic graphite (HOPG) surface, and agrees well with previously published results. Using a flame-annealed Gold on mica surface, a low

  4. Development of Vertical Cable Seismic System (3)

    NASA Astrophysics Data System (ADS)

    Asakawa, E.; Murakami, F.; Tsukahara, H.; Mizohata, S.; Ishikawa, K.

    2013-12-01

    The VCS (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. 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. We carried out several VCS surveys combining with surface towed source, deep towed source and ocean bottom source. The water depths of the survey are from 100m up to 2100m. The target of the survey includes not only hydrothermal deposit but oil and gas exploration. Through these experiments, our VCS data acquisition system has been completed. But the data processing techniques are still on the way. One of the most critical issues is the positioning in the water. The uncertainty in the positions of the source and of the hydrophones in water degraded the quality of subsurface image. GPS navigation system are available on sea surface, but in case of deep-towed source or ocean bottom source, the accuracy of shot position with SSBL/USBL is not sufficient for the very high-resolution imaging. We have developed another approach to determine the positions in water using the travel time data from the source to VCS hydrophones. In the data acquisition stage, we estimate the position of VCS location with slant ranging method from the sea surface. The deep-towed source or ocean bottom source is estimated by SSBL/USBL. The water velocity profile is measured by XCTD. After the data acquisition, we pick the first break times of the VCS recorded data. The estimated positions of

  5. Development of Vertical Cable Seismic System

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    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

  6. Vertical Cable Seismic Survey for SMS exploration

    NASA Astrophysics Data System (ADS)

    Asakawa, Eiichi; Murakami, Fumitoshi; Tsukahara, Hotoshi; Mizohata, Shigeharu

    2014-05-01

    The Vertical Cable Seismic (VCS) survey is one of the reflection seismic methods. It uses hydrophone arrays vertically moored from the seafloor to record acoustic waves generated by sea-surface, deep-towed or ocean bottom sources. Analyzing the reflections from the sub-seabed, we could look into the subsurface structure. Because the VCS is an efficient high-resolution 3D seismic survey method for a spatially-bounded area, we proposed it for the SMS survey tool development program that the Ministry of Education, Culture, Sports, Science and Technology (MEXT) started in 2009. We have been developing the VCS survey system, including not only data acquisition hardware but data processing and analysis technique. We carried out several VCS surveys combining with surface towed source, deep towed source and ocean bottom source. The water depths of these surveys are from 100m up to 2100 m. Through these experiments, our VCS data acquisition system has been also completed. But the data processing techniques are still on the way. One of the most critical issues is the positioning in the water. The uncertainty in the positions of the source and of the hydrophones in water degraded the quality of subsurface image. GPS navigation system is available on sea surface, but in case of deep-towed source or ocean bottom source, the accuracy of shot position with SSBL/USBL is not sufficient for the very high-resolution imaging. We have developed a new approach to determine the positions in water using the travel time data from the source to VCS hydrophones. In 2013, we have carried out the second VCS survey using the surface-towed high-voltage sparker and ocean bottom source in the Izena Cauldron, which is one of the most promising SMS areas around Japan. The positions of ocean bottom source estimated by this method are consistent with the VCS field records. The VCS data with the sparker have been processed with 3D PSTM. It gives the very high resolution 3D volume deeper than two

  7. A Librarian's Primer on Financial Ratios.

    ERIC Educational Resources Information Center

    Kerbel, Sandra Sandor

    1982-01-01

    Explains in simple terms the nature and function of a number of basic types of business and industrial financial ratios. An annotated list of five basic sources for ratios is included and a reference list and bibliography are attached. (JL)

  8. Evolutionarily stable sex ratios and mutation load.

    PubMed

    Hough, Josh; Immler, Simone; Barrett, Spencer C H; Otto, Sarah P

    2013-07-01

    Frequency-dependent selection should drive dioecious populations toward a 1:1 sex ratio, but biased sex ratios are widespread, especially among plants with sex chromosomes. Here, we develop population genetic models to investigate the relationships between evolutionarily stable sex ratios, haploid selection, and deleterious mutation load. We confirm that when haploid selection acts only on the relative fitness of X- and Y-bearing pollen and the sex ratio is controlled by the maternal genotype, seed sex ratios evolve toward 1:1. When we also consider haploid selection acting on deleterious mutations, however, we find that biased sex ratios can be stably maintained, reflecting a balance between the advantages of purging deleterious mutations via haploid selection, and the disadvantages of haploid selection on the sex ratio. Our results provide a plausible evolutionary explanation for biased sex ratios in dioecious plants, given the extensive gene expression that occurs across plant genomes at the haploid stage.

  9. Variable mixture ratio performance through nitrogen augmentation

    NASA Technical Reports Server (NTRS)

    Beichel, R.; Obrien, C. J.; Bair, E. K.

    1988-01-01

    High/variable mixture ratio O2/H2 candidate engine cycles are examined for earth-to-orbit vehicle application. Engine performance and power balance information are presented for the candidate cycles relative to chamber pressure, bulk density, and mixture ratio. Included in the cycle screening are concepts where a third fluid (liquid nitrogen) is used to achieve a variable mixture ratio over the trajectory from liftoff to earth orbit. The third fluid cycles offer a very low risk, fully reusable, low operation cost alternative to high/variable mixture ratio bipropellant cycles. Variable mixture ratio engines with extendible nozzle are slightly lower performing than a single mixture ratio engine (MR = 7:1) with extendible nozzle. Dual expander engines (MR = 7:1) have slightly better performance than the single mixture ratio engine. Dual fuel dual expander engines offer a 16 percent improvement over the single mixture ratio engine.

  10. Worldwide Uncertainty Assessments of Ladar and Radar Signal-to-Noise Ratio Performance for Diverse Low Altitude Atmospheric Environments

    DTIC Science & Technology

    2009-05-01

    interrogation. Results are presented in the form of worldwide plots of notional signal to noise ratio. The ladar and 95 GHz system types exhibit similar SNR ...signal to noise ratio. The ladar and 95 GHz system types exhibit similar SNR performance for forward oblique clear air operation. 1.557 µm ladar...good to very good SNR performance for both oblique and vertical paths for both fog and stratus conditions. 1.1 HELEEOS Worldwide Seasonal, Diurnal

  11. Vertical distribution of hydrocarbons in the low troposphere below and above the mixing height: tethered balloon measurements in Milan, Italy.

    PubMed

    Sangiorgi, G; Ferrero, L; Perrone, M G; Bolzacchini, E; Duane, M; Larsen, B R

    2011-12-01

    A novel approach for measuring vertical profiles of HCs and particle number concentrations was described and applied in the low troposphere over Milan (Italy) during typical spring and summer days. Particle profiles yielded nearly homogeneous concentrations below the mixing height, with level-to-ground concentration ratios of 92-97%, while HCs showed a more pronounced decrease (74-95%). Vertical mixing and photochemical loss of HCs were demonstrated to cause these gradients. Much lower concentrations were observed for the profiles above the mixing height, where the HC mixtures showed also a different composition, which was partially explained by the horizontal advection of air with HC sources different to those prevailing at the site. The application of pseudo-first order kinetics for reactions between HCs and the hydroxyl radical allowed for the estimation of the vertical mixing time scale in the order of 100 ± 20 min.

  12. Vertical barriers with increased sorption capacities

    SciTech Connect

    Bradl, H.B.

    1997-12-31

    Vertical barriers are commonly used for the containment of contaminated areas. Due to the very small permeability of the barrier material which is usually in the order of magnitude of 10-10 m/s or less the advective contaminant transport can be more or less neglected. Nevertheless, there will always be a diffusive contaminant transport through the barrier which is caused by the concentration gradient. Investigations have been made to increase the sorption capacity of the barrier material by adding substances such as organoclays, zeolites, inorganic oxides and fly ashes. The contaminants taken into account where heavy metals (Pb) and for organic contaminants Toluole and Phenantrene. The paper presents results of model calculations and experiments. As a result, barrier materials can be designed {open_quotes}tailor-made{close_quotes} depending on the individual contaminant range of each site (e.g. landfills, gasworks etc.). The parameters relevant for construction such as rheological properties, compressive strength and permeability are not affected by the addition of the sorbents.

  13. ATLAS LTCS Vertically Challenged System Lessons Learned

    NASA Technical Reports Server (NTRS)

    Patel, Deepak; Garrison, Matt; Ku, Jentung

    2014-01-01

    Re-planning of LTCS TVAC testing and supporting RTA (Receiver Telescope Assembly) Test Plan and Procedure document preparation. The Laser Thermal Control System (LTCS) is designed to maintain the lasers onboard Advanced Topographic Laser Altimeter System (ATLAS) at their operational temperatures. In order to verify the functionality of the LTCS, a thermal balance test of the thermal hardware was performed. During the first cold start of the LTCS, the Loop Heat Pipe (LHP) was unable to control the laser mass simulators temperature. The control heaters were fully on and the loop temperature remained well below the desired setpoint. Thermal analysis of the loop did not show these results. This unpredicted behavior of the LTCS was brought up to a panel of LHP experts. Based on the testing and a review of all the data, there were multiple diagnostic performed in order to narrow down the cause. The prevailing theory is that gravity is causing oscillating flow within the loop, which artificially increased the control power needs. This resulted in a replan of the LTCS test flow and the addition of a GSE heater to allow vertical operation.

  14. Functionalization of vertically aligned carbon nanotubes

    PubMed Central

    Snyders, Rony; Colomer, Jean-François

    2013-01-01

    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. PMID:23504581

  15. Morpheus Vertical Test Bed Flight Testing

    NASA Technical Reports Server (NTRS)

    Hart, Jeremy; Devolites, Jennifer

    2014-01-01

    NASA's Morpheus Project has developed and tested a prototype planetary lander capable of vertical takeoff and landing, that is designed to serve as a testbed for advanced spacecraft technologies. The lander vehicle, propelled by a LOX/Methane engine and sized to carry a 500kg payload to the lunar surface, provides a platform for bringing technologies from the laboratory into an integrated flight system at relatively low cost. Morpheus onboard software is autonomous from ignition all the way through landing, and is designed to be capable of executing a variety of flight trajectories, with onboard fault checks and automatic contingency responses. The Morpheus 1.5A vehicle performed 26 integrated vehicle test flights including hot-fire tests, tethered tests, and two attempted freeflights between April 2011 and August 2012. The final flight of Morpheus 1.5A resulted in a loss of the vehicle. In September 2012, development began on the Morpheus 1.5B vehicle, which subsequently followed a similar test campaign culminating in free-flights at a simulated planetary landscape built at Kennedy Space Center's Shuttle Landing Facility. This paper describes the integrated test campaign, including successes and setbacks, and how the system design for handling faults and failures evolved over the course of the project.

  16. Drop motion induced by vertical vibrations

    NASA Astrophysics Data System (ADS)

    Sartori, Paolo; Quagliati, Damiano; Varagnolo, Silvia; Pierno, Matteo; Mistura, Giampaolo; Magaletti, Francesco; Massimo Casciola, Carlo

    2015-11-01

    We have studied the motion of liquid drops on an inclined plate subject to vertical vibrations. The liquids comprised distilled water and different aqueous solutions of glycerol, ethanol and isopropanol spanning the range 1-39 mm2 s-1 in kinematic viscosities and 40-72 mN m-1 in surface tension. At sufficiently low oscillating amplitudes, the drops are always pinned to the surface. Vibrating the plate above a certain amplitude yields sliding of the drop. Further increasing the oscillating amplitude drives the drop upward against gravity. In the case of the most hydrophilic aqueous solutions, this motion is not observed and the drop only slides downward. Images taken with a fast camera show that the drop profile evolves in a different way during sliding and climbing. In particular, the climbing drop experiences a much bigger variation in its profile during an oscillating period. Complementary numerical simulations of 2D drops based on a diffuse interface approach confirm the experimental findings. The overall qualitative behavior is reproduced suggesting that the contact line pinning due to contact angle hysteresis is not necessary to explain the drop climbing.

  17. Thermal convection in vertically suspended soap films

    NASA Astrophysics Data System (ADS)

    Zhang, Jie

    In normal fluids, a temperature difference can create a density difference. In the presence of the gravitational field, denser fluid will fall and lighter fluid will rise, causing fluid motion known as thermal convection. This type of convection can occur on different scales, from a single growing crystal to mantle movement inside the earth. Although many experiments have been conducted in unstably stratified fluids, there have been few laboratory experiments studying convective turbulence in stably stratified fluids, which is more common in nature. Here I present a two-dimensional (2D) convection in a stably stratified vertical soap film. It was found that the interaction between the gravitational potential energy, due to the 2D density fluctuation, and the kinetic energy is important. This interplay between the two energy sources manifests itself in the statistical properties of velocity and 2D density fluctuations in the system. Our experimental findings shed new lights to a turbulent system that strongly couples to a non-passive field.

  18. Engineering design of vertical test stand cryostat

    SciTech Connect

    Suhane, S.K.; Sharma, N.K.; Raghavendra, S.; Joshi, S.C.; Das, S.; Kush, P.K.; Sahni, V.C.; Gupta, P.D.; Sylvester, C.; Rabehl, R.; Ozelis, J.; /Fermilab

    2011-03-01

    Under Indian Institutions and Fermilab collaboration, Raja Ramanna Centre for Advanced Technology and Fermi National Accelerator Laboratory are jointly developing 2K Vertical Test Stand (VTS) cryostats for testing SCRF cavities at 2K. The VTS cryostat has been designed for a large testing aperture of 86.36 cm for testing of 325 MHz Spoke resonators, 650 MHz and 1.3 GHz multi-cell SCRF cavities for Fermilab's Project-X. Units will be installed at Fermilab and RRCAT and used to test cavities for Project-X. A VTS cryostat comprises of liquid helium (LHe) vessel with internal magnetic shield, top insert plate equipped with cavity support stand and radiation shield, liquid nitrogen (LN{sub 2}) shield and vacuum vessel with external magnetic shield. The engineering design and analysis of VTS cryostat has been carried out using ASME B&PV Code and Finite Element Analysis. Design of internal and external magnetic shields was performed to limit the magnetic field inside LHe vessel at the cavity surface <1 {micro}T. Thermal analysis for LN{sub 2} shield has been performed to check the effectiveness of LN{sub 2} cooling and for compliance with ASME piping code allowable stresses.

  19. A theoretical analysis of vertical flow equilibrium

    SciTech Connect

    Yortsos, Y.C.

    1992-01-01

    The assumption of Vertical Flow Equilibrium (VFE) and of parallel flow conditions, in general, is often applied to the modeling of flow and displacement in natural porous media. However, the methodology for the development of the various models is rather intuitive, and no rigorous method is currently available. In this paper, we develop an asymptotic theory using as parameter the variable R{sub L} = (L/H){radical}(k{sub V})/(k{sub H}). It is rigorously shown that present models represent the leading order term of an asymptotic expansion with respect to 1/R{sub L}{sup 2}. Although this was numerically suspected, it is the first time that is is theoretically proved. Based on the general formulation, a series of models are subsequently obtained. In the absence of strong gravity effects, they generalize previous works by Zapata and Lake (1981), Yokoyama and Lake (1981) and Lake and Hirasaki (1981), on immiscible and miscible displacements. In the limit of gravity-segregated flow, we prove conditions for the fluids to be segregated and derive the Dupuit and Dietz (1953) approximations. Finally, we also discuss effects of capillarity and transverse dispersion.

  20. Investigation of dust vertical dispersion relations

    NASA Astrophysics Data System (ADS)

    Kong, Jie; Qiao, Ke; Hyde, Truell

    2007-11-01

    The dust acoustic wave (DAW) was first theoretically predicted in 1990 by Rao et al. [Ref] and later observed experimentally by Barkan, et al. [Ref. 2], Pieper and Goree [Ref. 3] and others. The charge on the dust, Debye length and various other fundamental complex plasma parameters can be obtained experimentally through measurement of the DAW. Since under normal laboratory conditions, ordered structures formed within a complex plasma are generally two dimensional in nature, the majority of experiments to date examining such a system's dispersion relationships have been conducted on the horizontal plane. We will present an experimental method providing for a vertical dispersion relationship measurement, and present corresponding data. References [1]. N. N. Rao, P. K. Shukla, and M. Y. Yu, ``Dust-acoustic waves in dusty plasmas,'' Planet. Space Sci. 38, 543-546 (1990). [2]. A. Barkan, R. L. Merlino, and N. D'Angelo, ``Laboratory observation of the dust-acoustic wave mode,'' Phys. Plasmas, 2, 3563-3565, 1995. [3]. J. B. Pieper, J. Goree, ``Dispersion of Plasma Dust Acoustic Waves in the Strong-Coupling Regime,'' Phys. Rev. Lett., 77, 3137-3140, 1996.

  1. Premixed flame propagation in vertical tubes

    NASA Astrophysics Data System (ADS)

    Kazakov, Kirill A.

    2016-04-01

    Analytical treatment of the premixed flame propagation in vertical tubes with smooth walls is given. Using the on-shell flame description, equations for a quasi-steady flame with a small but finite front thickness are obtained and solved numerically. It is found that near the limits of inflammability, solutions describing upward flame propagation come in pairs having close propagation speeds and that the effect of gravity is to reverse the burnt gas velocity profile generated by the flame. On the basis of these results, a theory of partial flame propagation driven by a strong gravitational field is developed. A complete explanation is given of the intricate observed behavior of limit flames, including dependence of the inflammability range on the size of the combustion domain, the large distances of partial flame propagation, and the progression of flame extinction. The role of the finite front-thickness effects is discussed in detail. Also, various mechanisms governing flame acceleration in smooth tubes are identified. Acceleration of methane-air flames in open tubes is shown to be a combined effect of the hydrostatic pressure difference produced by the ambient cold air and the difference of dynamic gas pressure at the tube ends. On the other hand, a strong spontaneous acceleration of the fast methane-oxygen flames at the initial stage of their evolution in open-closed tubes is conditioned by metastability of the quasi-steady propagation regimes. An extensive comparison of the obtained results with the experimental data is made.

  2. Vertical Distribution of Water at Phoenix

    NASA Technical Reports Server (NTRS)

    Tamppari, L. K.; Lemmon, M. T.

    2011-01-01

    Phoenix results, combined with coordinated observations from the Mars Reconnaissance Orbiter of the Phoenix lander site, indicate that the water vapor is nonuniform (i.e., not well mixed) up to a calculated cloud condensation level. It is important to understand the mixing profile of water vapor because (a) the assumption of a well-mixed atmosphere up to a cloud condensation level is common in retrievals of column water abundances which are in turn used to understand the seasonal and interannual behavior of water, (b) there is a long history of observations and modeling that conclude both that water vapor is and is not well-mixed, and some studies indicate that the water vapor vertical mixing profile may, in fact, change with season and location, (c) the water vapor in the lowest part of the atmosphere is the reservoir that can exchange with the regolith and higher amounts may have an impact on the surface chemistry, and (d) greater water vapor abundances close to the surface may enhance surface exchange thereby reducing regional transport, which in turn has implications to the net transport of water vapor over seasonal and annual timescales.

  3. Absolute Position Encoders With Vertical Image Binning

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B.

    2005-01-01

    Improved optoelectronic patternrecognition encoders that measure rotary and linear 1-dimensional positions at conversion rates (numbers of readings per unit time) exceeding 20 kHz have been invented. Heretofore, optoelectronic pattern-recognition absoluteposition encoders have been limited to conversion rates <15 Hz -- too low for emerging industrial applications in which conversion rates ranging from 1 kHz to as much as 100 kHz are required. The high conversion rates of the improved encoders are made possible, in part, by use of vertically compressible or binnable (as described below) scale patterns in combination with modified readout sequences of the image sensors [charge-coupled devices (CCDs)] used to read the scale patterns. The modified readout sequences and the processing of the images thus read out are amenable to implementation by use of modern, high-speed, ultra-compact microprocessors and digital signal processors or field-programmable gate arrays. This combination of improvements makes it possible to greatly increase conversion rates through substantial reductions in all three components of conversion time: exposure time, image-readout time, and image-processing time.

  4. Evidence for vertical ozone redistribution since 1967

    NASA Astrophysics Data System (ADS)

    Furrer, R.; Doehler, W.; Kirsch, H.-J.; Plessing, P.; Goersdorf, U.

    1992-12-01

    Long-term measurements of ozone concentration in the vicinity of the city of Berlin have been performed with ground-based Dobson spectrophotometers and balloon borne systems. The respective experiments cover the past 24 yr. All data have been re-evaluated and corrected towards uniform calibration standards, leading to the longest lasting European data set of total column density, altitude-dependent ozone partial pressures and the corresponding temperatures. Smoothing algorithms reveal significant long-term trends. The analysis shows an increase of ozone concentration within the middle stratosphere (below 31 km height) as well as in the troposphere over the past 24 yr. On the contrary, ongoing ozone depletion in the lower stratosphere became evident. The large scale vertical redistribution of atmospheric ozone in the troposphere and the lower stratosphere seems to be in agreement with model calculations and trend predictions that have their roots in changes of the chemical composition and the ozone photochemistry due to anthropogenically induced tracer gas concentrations.

  5. The vertical oscillations of coupled magnets

    NASA Astrophysics Data System (ADS)

    Kewei, Li; Jiahuang, Lin; Yang, Kang Zi; Liang, Samuel Yee Wei; Wong Say Juan, Jeremias

    2011-07-01

    The International Young Physicists' Tournament (IYPT) is a worldwide, annual competition for high school students. This paper is adapted from the winning solution to Problem 14, Magnetic Spring, as presented in the final round of the 23rd IYPT in Vienna, Austria. Two magnets were arranged on top of each other on a common axis. One was fixed, while the other could move vertically. Various parameters of interest were investigated, including the effective gravitational acceleration, the strength, size, mass and geometry of the magnets, and damping of the oscillations. Despite its simplicity, this setup yielded a number of interesting and unexpected relations. The first stage of the investigation was concerned only with the undamped oscillations of small amplitudes, and the period of small amplitude oscillations was found to be dependent only on the eighth root of important magnet properties such as its strength and mass. The second stage sought to investigate more general oscillations. A numerical model which took into account magnet size, magnet geometry and damping effects was developed to model the general oscillations. Air resistance and friction were found to be significant sources of damping, while eddy currents were negligible.

  6. Vertical landscraping, a big regionalism for Dubai.

    PubMed

    Wilson, Matthew

    2010-01-01

    Dubai's ecologic and economic complications are exacerbated by six years of accelerated expansion, a fixed top-down approach to urbanism and the construction of iconic single-phase mega-projects. With recent construction delays, project cancellations and growing landscape issues, Dubai's tower typologies have been unresponsive to changing environmental, socio-cultural and economic patterns (BBC, 2009; Gillet, 2009; Lewis, 2009). In this essay, a theory of "Big Regionalism" guides an argument for an economically and ecologically linked tower typology called the Condenser. This phased "box-to-tower" typology is part of a greater Landscape Urbanist strategy called Vertical Landscraping. Within this strategy, the Condenser's role is to densify the city, facilitating the creation of ecologic voids that order the urban region. Delineating "Big Regional" principles, the Condenser provides a time-based, global-local urban growth approach that weaves Bigness into a series of urban-regional, economic and ecological relationships, builds upon the environmental performance of the city's regional architecture and planning, promotes a continuity of Dubai's urban history, and responds to its landscape issues while condensing development. These speculations permit consideration of the overlooked opportunities embedded within Dubai's mega-projects and their long-term impact on the urban morphology.

  7. Free convective condensation in a vertical enclosure

    SciTech Connect

    Fox, R.J.; Peterson, P.F.; Corradini, M.L.; Pernsteiner, A.P.

    1995-09-01

    Free convective condensation in a vertical enclosure was studied numerically and the results were compared with experiments. In both the numerical and experimental investigations, mist formation was observed to occur near the cooling wall, with significant droplet concentrations in the bulk. Large recirculation cells near the end of the condensing section were generated as the heavy noncondensing gas collecting near the cooling wall was accelerated downward. Near the top of the enclosure the recirculation cells became weaker and smaller than those below, ultimately disappearing near the top of the condenser. In the experiment the mist density was seen to be highest near the wall and at the bottom of the condensing section, whereas the numerical model predicted a much more uniform distribution. The model used to describe the formation of mist was based on a Modified Critical Saturation Model (MCSM), which allows mist to be generated once the vapor pressure exceeds a critical value. Equilibrium, nonequilibrium, and MCSM calculations were preformed, showing the experimental results to lie somewhere in between the equilibrium and nonequilibrium predictions of the numerical model. A single adjustable constant (indicating the degree to which equilibrium is achieved) is used in the model in order to match the experimental results.

  8. Mudflow rheology in a vertically rotating flume

    USGS Publications Warehouse

    Holmes, Jr., Robert R.; Westphal, Jerome A.; Jobson, Harvey E.; ,

    1990-01-01

    Joint research by the U.S. Geological Survey and the University of Missouri-Rolla currently (1990) is being conducted on a 3.05 meters in diameter vertically rotating flume used to simulate mudflows under steady-state conditions. Observed mudflow simulations indicate flow patterns in the flume are similar to those occurring in natural mudflows. Variables such as mean and surface velocity, depth, and average boundary shear stress can be measured in this flume more easily than in the field or in a traditional tilting flume. Sensitive variables such as sediment concentration, grain-size distribution, and Atterberg limits also can be precisely and easily controlled. A known Newtonian fluid, SAE 30 motor oil, was tested in the flume and the computed value for viscosity was within 12.5 percent of the stated viscosity. This provided support that the data from the flume can be used to determine the rheological properties of fluids such as mud. Measurements on mud slurries indicate that flows with sediment concentrations ranging from 81 to 87 percent sediment by weight can be approximated as Bingham plastic for strain rates greater than 1 per second. In this approximation, the yield stress and Bingham viscosity were extremely sensitive to sediment concentration. Generally, the magnitude of the yield stress was large relative to the change in shear stress with increasing mudflow velocity.

  9. Vertical Distribution of Vibrationally Excited Hydroxyl

    NASA Astrophysics Data System (ADS)

    Grygalashvyly, Mykhaylo; Becker, Erich; Sonnemann, Gerd

    2016-04-01

    Knowledge about the vertical distribution of the vibrationally excited states of hydroxyl (OH*) is important for the interpretation of airglow measurements with respect to dynamical processes in the mesopause region. We derive an approximate analytical expression for the distribution of OH* that highlights the dependence on atomic oxygen and temperature. In addition, we use an advanced numerical model for the formation and relaxation of OH* and investigate the distributions of the different vibrationally exited states of OH*. For the production of OH*, the model includes the reaction of atomic hydrogen with ozone, as well as the reaction of atomic oxygen with hydroperoxy radicals. As loss processes we include 1) deactivation by atomic oxygen, molecular oxygen, and molecular nitrogen, 2) spontaneous emission, and 3) loss due to chemical reaction with atomic oxygen. All these processes take the dependence on the vibrational number into account. The quenching by molecular and atomic oxygen is parameterized by a multi-quantum relaxation scheme. This diagnostic model for OH* has been implemented as part of a chemistry-transport model that is driven by the dynamics simulated with the KMCM (Kühlungsborn Mechanistic general Circulation Model). Numerical results confirm that emission from excited states with higher vibrational number is weaker and emanates from higher altitudes. In addition we find that the OH*-peak altitudes depend significantly on season and latitude. This behavior is mainly controlled by the corresponding variations of atomic oxygen and temperature, as is also confirmed by the aforementioned approximate theory.

  10. Microfluidic dielectrophoretic sorter using gel vertical electrodes

    PubMed Central

    Luo, Jason; Nelson, Edward L.; Li, G. P.; Bachman, Mark

    2014-01-01

    We report the development and results of a two-step method for sorting cells and small particles in a microfluidic device. This approach uses a single microfluidic channel that has (1) a microfabricated sieve which efficiently focuses particles into a thin stream, followed by (2) a dielectrophoresis (DEP) section consisting of electrodes along the channel walls for efficient continuous sorting based on dielectric properties of the particles. For our demonstration, the device was constructed of polydimethylsiloxane, bonded to a glass surface, and conductive agarose gel electrodes. Gold traces were used to make electrical connections to the conductive gel. The device had several novel features that aided performance of the sorting. These included a sieving structure that performed continuous displacement of particles into a single stream within the microfluidic channel (improving the performance of downstream DEP, and avoiding the need for additional focusing flow inlets), and DEP electrodes that were the full height of the microfluidic walls (“vertical electrodes”), allowing for improved formation and control of electric field gradients in the microfluidic device. The device was used to sort polymer particles and HeLa cells, demonstrating that this unique combination provides improved capability for continuous DEP sorting of particles in a microfluidic device. PMID:24926390

  11. Spray Gun With Constant Mixing Ratio

    NASA Technical Reports Server (NTRS)

    Simpson, William G.

    1987-01-01

    Conceptual mechanism mounted in handle of spray gun maintains constant ratio between volumetric flow rates in two channels leading to spray head. With mechanism, possible to keep flow ratio near 1:1 (or another desired ratio) over range of temperatures, orifice or channel sizes, or clogging conditions.

  12. Management Ratios 1. For Colleges & Universities.

    ERIC Educational Resources Information Center

    Minter, John, Ed.

    Ratios that enable colleges and universities to select other institutions for comparison are presented. The ratios and underlying data also enable colleges to rank order institutions and to calculate means, quartiles, and ranges for these groups. The data are based on FY 1983 U.S. Department of Education Statistics. The ratios summarize the…

  13. 7 CFR 400.162 - Qualification ratios.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Qualification ratios. 400.162 Section 400.162...; Regulations for the 1997 and Subsequent Reinsurance Years § 400.162 Qualification ratios. The sixteen qualification ratios include: (a) Eleven National Association of Insurance Commissioner's (NAIC's)...

  14. 12 CFR 567.8 - Leverage ratio.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 6 2012-01-01 2012-01-01 false Leverage ratio. 567.8 Section 567.8 Banks and... § 567.8 Leverage ratio. (a) The minimum leverage capital requirement for a savings association assigned a composite rating of 1, as defined in § 516.3 of this chapter, shall consist of a ratio of...

  15. 12 CFR 167.8 - Leverage ratio.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Leverage ratio. 167.8 Section 167.8 Banks and... § 167.8 Leverage ratio. (a) The minimum leverage capital requirement for a Federal savings association assigned a composite rating of 1, as defined in § 116.3 of this chapter, shall consist of a ratio of...

  16. 7 CFR 400.162 - Qualification ratios.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Qualification ratios. 400.162 Section 400.162...; Regulations for the 1997 and Subsequent Reinsurance Years § 400.162 Qualification ratios. The sixteen qualification ratios include: (a) Eleven National Association of Insurance Commissioner's (NAIC's)...

  17. 12 CFR 390.467 - Leverage ratio.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 5 2014-01-01 2014-01-01 false Leverage ratio. 390.467 Section 390.467 Banks... REGULATIONS TRANSFERRED FROM THE OFFICE OF THRIFT SUPERVISION Capital § 390.467 Leverage ratio. (a) The... defined in this subpart, shall consist of a ratio of core capital to adjusted total assets of 3...

  18. 7 CFR 400.162 - Qualification ratios.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Qualification ratios. 400.162 Section 400.162...; Regulations for the 1997 and Subsequent Reinsurance Years § 400.162 Qualification ratios. The sixteen qualification ratios include: (a) Eleven National Association of Insurance Commissioner's (NAIC's)...

  19. 12 CFR 390.467 - Leverage ratio.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Leverage ratio. 390.467 Section 390.467 Banks... REGULATIONS TRANSFERRED FROM THE OFFICE OF THRIFT SUPERVISION Capital § 390.467 Leverage ratio. (a) The... defined in this subpart, shall consist of a ratio of core capital to adjusted total assets of 3...

  20. 7 CFR 400.162 - Qualification ratios.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Qualification ratios. 400.162 Section 400.162...; Regulations for the 1997 and Subsequent Reinsurance Years § 400.162 Qualification ratios. The sixteen qualification ratios include: (a) Eleven National Association of Insurance Commissioner's (NAIC's)...

  1. 12 CFR 567.8 - Leverage ratio.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Leverage ratio. 567.8 Section 567.8 Banks and... § 567.8 Leverage ratio. (a) The minimum leverage capital requirement for a savings association assigned a composite rating of 1, as defined in § 516.3 of this chapter, shall consist of a ratio of...

  2. 12 CFR 390.467 - Leverage ratio.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Leverage ratio. 390.467 Section 390.467 Banks... REGULATIONS TRANSFERRED FROM THE OFFICE OF THRIFT SUPERVISION Capital § 390.467 Leverage ratio. (a) The... defined in this subpart, shall consist of a ratio of core capital to adjusted total assets of 3...

  3. 12 CFR 567.8 - Leverage ratio.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Leverage ratio. 567.8 Section 567.8 Banks and... § 567.8 Leverage ratio. (a) The minimum leverage capital requirement for a savings association assigned a composite rating of 1, as defined in § 516.3 of this chapter, shall consist of a ratio of...

  4. 12 CFR 167.8 - Leverage ratio.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Leverage ratio. 167.8 Section 167.8 Banks and... § 167.8 Leverage ratio. (a) The minimum leverage capital requirement for a Federal savings association assigned a composite rating of 1, as defined in § 116.3 of this chapter, shall consist of a ratio of...

  5. 12 CFR 167.8 - Leverage ratio.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 1 2012-01-01 2012-01-01 false Leverage ratio. 167.8 Section 167.8 Banks and... § 167.8 Leverage ratio. (a) The minimum leverage capital requirement for a Federal savings association assigned a composite rating of 1, as defined in § 116.3 of this chapter, shall consist of a ratio of...

  6. 12 CFR 567.8 - Leverage ratio.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 6 2013-01-01 2012-01-01 true Leverage ratio. 567.8 Section 567.8 Banks and... § 567.8 Leverage ratio. (a) The minimum leverage capital requirement for a savings association assigned a composite rating of 1, as defined in § 516.3 of this chapter, shall consist of a ratio of...

  7. 12 CFR 567.8 - Leverage ratio.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 6 2014-01-01 2012-01-01 true Leverage ratio. 567.8 Section 567.8 Banks and... § 567.8 Leverage ratio. (a) The minimum leverage capital requirement for a savings association assigned a composite rating of 1, as defined in § 516.3 of this chapter, shall consist of a ratio of...

  8. Experimental Study of a Reference Model Vertical-Axis Cross-Flow Turbine

    PubMed Central

    Wosnik, Martin; Gunawan, Budi; Neary, Vincent S.

    2016-01-01

    The mechanical power, total rotor drag, and near-wake velocity of a 1:6 scale model (1.075 m diameter) of the US Department of Energy’s Reference Model vertical-axis cross-flow turbine were measured experimentally in a towing tank, to provide a comprehensive open dataset for validating numerical models. Performance was measured for a range of tip speed ratios and at multiple Reynolds numbers by varying the rotor’s angular velocity and tow carriage speed, respectively. A peak power coefficient CP = 0.37 and rotor drag coefficient CD = 0.84 were observed at a tip speed ratio λ0 = 3.1. A regime of weak linear Re-dependence of the power coefficient was observed above a turbine diameter Reynolds number ReD ≈ 106. The effects of support strut drag on turbine performance were investigated by covering the rotor’s NACA 0021 struts with cylinders. As expected, this modification drastically reduced the rotor power coefficient. Strut drag losses were also measured for the NACA 0021 and cylindrical configurations with the rotor blades removed. For λ = λ0, wake velocity was measured at 1 m (x/D = 0.93) downstream. Mean velocity, turbulence kinetic energy, and mean kinetic energy transport were compared with results from a high solidity turbine acquired with the same test apparatus. Like the high solidity case, mean vertical advection was calculated to be the largest contributor to near-wake recovery. However, overall, lower levels of streamwise wake recovery were calculated for the RM2 case—a consequence of both the relatively low solidity and tapered blades reducing blade tip vortex shedding—responsible for mean vertical advection—and lower levels of turbulence caused by higher operating tip speed ratio and therefore reduced dynamic stall. Datasets, code for processing and visualization, and a CAD model of the turbine have been made publicly available. PMID:27684076

  9. Experimental Study of a Reference Model Vertical-Axis Cross-Flow Turbine.

    PubMed

    Bachant, Peter; Wosnik, Martin; Gunawan, Budi; Neary, Vincent S

    The mechanical power, total rotor drag, and near-wake velocity of a 1:6 scale model (1.075 m diameter) of the US Department of Energy's Reference Model vertical-axis cross-flow turbine were measured experimentally in a towing tank, to provide a comprehensive open dataset for validating numerical models. Performance was measured for a range of tip speed ratios and at multiple Reynolds numbers by varying the rotor's angular velocity and tow carriage speed, respectively. A peak power coefficient CP = 0.37 and rotor drag coefficient CD = 0.84 were observed at a tip speed ratio λ0 = 3.1. A regime of weak linear Re-dependence of the power coefficient was observed above a turbine diameter Reynolds number ReD ≈ 106. The effects of support strut drag on turbine performance were investigated by covering the rotor's NACA 0021 struts with cylinders. As expected, this modification drastically reduced the rotor power coefficient. Strut drag losses were also measured for the NACA 0021 and cylindrical configurations with the rotor blades removed. For λ = λ0, wake velocity was measured at 1 m (x/D = 0.93) downstream. Mean velocity, turbulence kinetic energy, and mean kinetic energy transport were compared with results from a high solidity turbine acquired with the same test apparatus. Like the high solidity case, mean vertical advection was calculated to be the largest contributor to near-wake recovery. However, overall, lower levels of streamwise wake recovery were calculated for the RM2 case-a consequence of both the relatively low solidity and tapered blades reducing blade tip vortex shedding-responsible for mean vertical advection-and lower levels of turbulence caused by higher operating tip speed ratio and therefore reduced dynamic stall. Datasets, code for processing and visualization, and a CAD model of the turbine have been made publicly available.

  10. Three-dimensional Numerical Analysis on Blade Response of Vertical Axis Tidal Current Turbine Under Operational Condition

    SciTech Connect

    Li, Ye; Karri, Naveen K.; Wang, Qi

    2014-04-30

    Tidal power as a large-scale renewable source of energy has been receiving significant attention recently because of its advantages over the wind and other renewal energy sources. The technology used to harvest energy from tidal current is called a tidal current turbine. Though some of the principles of wind turbine design are applicable to tidal current turbines, the design of latter ones need additional considerations like cavitation damage, corrosion etc. for the long-term reliability of such turbines. Depending up on the orientation of axis, tidal current turbines can be classified as vertical axis turbines or horizontal axis turbines. Existing studies on the vertical axis tidal current turbine focus more on the hydrodynamic aspects of the turbine rather than the structural aspects. This paper summarizes our recent efforts to study the integrated hydrodynamic and structural aspects of the vertical axis tidal current turbines. After reviewing existing methods in modeling tidal current turbines, we developed a hybrid approach that combines discrete vortex method -finite element method that can simulate the integrated hydrodynamic and structural response of a vertical axis turbine. This hybrid method was initially employed to analyze a typical three-blade vertical axis turbine. The power coefficient was used to evaluate the hydrodynamic performance, and critical deflection was considered to evaluate the structural reliability. A sensitivity analysis was also conducted with various turbine height-to-radius ratios. The results indicate that both the power output and failure probability increase with the turbine height, suggesting a necessity for optimal design. An attempt to optimize a 3-blade vertical axis turbine design with hybrid method yielded a ratio of turbine height to radius (H/R) about 3.0 for reliable maximum power output.

  11. Where have all the females gone? Male biased sex-ratio in Arctodiaptomus alpinus (Imhof, 1885) in alpine lakes

    NASA Astrophysics Data System (ADS)

    Žibrat, U.; Brancelj, A.

    2009-04-01

    In populations with both males and females sex-ratio is one of the driving forces of population dynamics. It influences fecundity, inbreeding and social interactions. Sex-ratio is affected by several biotic and abiotic factors, either by selective killing of one sex or by inducing migrations. In alpine lakes of Triglav National Park, Slovenia, an extremely male biased sex-ratio in Arctodiaptomus alpinus (Imhof, 1885) was regularly observed since 1992. We analysed population dynamics and sex-ratio of A. alpinus in three alpine lakes (Jezero v Ledvicah, Rjavo jezero and Zgornje Kriško jezero) from Triglav National Park in Slovenia. In addition to seasonal dynamics we also researched long-term changes in sex-ratio (in a period of 11 years from autumn samples) as a result of increased air-temperature, and zooplankton diurnal vertical migrations. Adults of both sexes were found to appear at the same time in the water collumn with males prevailing throughout the season. A similar trend was found in copepodites CV. The percent of adult females began increasing in late summer, when there were no more copepodites and recrutation from copepodites CV to adults stopped, while male mortality increased. All cohorts of A. alpinus were found to perform diurnal vertical migrations. Both adult and CV females remained close to the bottom during the day and migrated vertically during the night. Results of the long-term study show no changes in sex-ratio in autumn.

  12. Vapor detection performance of vertically aligned, ordered arrays of silicon nanowires with a porous electrode.

    PubMed

    Field, Christopher R; In, Hyun Jin; Begue, Nathan J; Pehrsson, Pehr E

    2011-06-15

    Vertically aligned, ordered arrays of silicon nanowires capped with a porous top electrode are used to detect gas phase ammonia and nitrogen dioxide in humidified air. The sensors had very fast response times and large signal-to-noise ratios. Calibration curves were created using both an initial slope method and a fixed-time point method. The initial-slope method had a power law dependence that correlates well with concentration, demonstrating a viable alternative for eventual quantitative vapor detection and enabling shorter sampling and regeneration times.

  13. Measurements of Aerosol Vertical Profiles and Optical Properties during INDOEX 1999 Using Micro-Pulse Lidars

    NASA Technical Reports Server (NTRS)

    Welton, Ellsworth J.; Voss, Kenneth J.; Quinn, Patricia K.; Flatau, Piotr J.; Markowicz, Krzysztof; Campbell, James R.; Spinhirne, James D.; Gordon, Howard R.; Johnson, James E.; Starr, David OC. (Technical Monitor)

    2001-01-01

    Micro-pulse lidar systems (MPL) were used to measure aerosol properties during the Indian Ocean Experiment (INDOEX) 1999 field phase. Measurements were made from two platforms: the NOAA ship RN Ronald H. Brown, and the Kaashidhoo Climate Observatory (KCO) in the Maldives. Sunphotometers were used to provide aerosol optical depths (AOD) needed to calibrate the MPL. This study focuses on the height distribution and optical properties (at 523 nm) of aerosols observed during the campaign. The height of the highest aerosols (top height) was calculated and found to be below 4 km for most of the cruise. The marine boundary layer (MBL) top was calculated and found to be less than 1 km. MPL results were combined with air mass trajectories, radiosonde profiles of temperature and humidity, and aerosol concentration and optical measurements. Humidity varied from approximately 80% near the surface to 50% near the top height during the entire cruise. The average value and standard deviation of aerosol optical parameters were determined for characteristic air mass regimes. Marine aerosols in the absence of any continental influence were found to have an AOD of 0.05 +/- 0.03, an extinction-to-backscatter ratio (S-ratio) of 33 +/- 6 sr, and peak extinction values around 0.05/km (near the MBL top). The marine results are shown to be in agreement with previously measured and expected values. Polluted marine areas over the Indian Ocean, influenced by continental aerosols, had AOD values in excess of 0.2, S-ratios well above 40 sr, and peak extinction values approximately 0.20/km (near the MBL top). The polluted marine results are shown to be similar to previously published values for continental aerosols. Comparisons between MPL derived extinction near the ship (75 m) and extinction calculated at ship-level using scattering measured by a nephelometer and absorption using a PSAP were conducted. The comparisons indicated that the MPL algorithm (using a constant S-ratio throughout the

  14. Matrix replacement route to vertically aligned nickel nanowire array/polydimethylsiloxane nanocomposite film

    NASA Astrophysics Data System (ADS)

    Meng, Xin; Zhou, Liang-Tian; Zhu, Ji-Xiang; Song, Jie; Wang, Xuan-Rui; Qiao, Zheng-Ping

    2008-12-01

    Vertically aligned magnetic anisotropic nickel (Ni) nanowire (NW) array/polydimethylsiloxane (PDMS) film was prepared from (Ni NW array)/anodic aluminum oxide by a simple matrix replacement route. The main challenge is to preserve the parallelly aligned Ni NW during replacement. The diameter and thickness of the as-prepared Ni NW and the Ni NW array/PDMS film are 8 mm and 60 μm, respectively. The magnetic property measurement shows that the film has remarkably enhanced coercivity and remanence ratio compared to that of bulk nickel and exhibits perpendicular magnetic anisotropy.

  15. Lorentz resonances and the vertical structure of dusty rings - Analytical and numerical results

    NASA Astrophysics Data System (ADS)

    Schaffer, Les; Burns, Joseph A.

    1992-03-01

    The Schaffer and Burns (1987) linear theory of Lorentz resonances (LRs) in planetary rings is extended in order to accurately compute LR locations and to elucidate the nature of grain trajectories within the LR zones. Using the perturbation theory and energy arguments, it is shown that an increase in the inclination or eccentricity of a grain must be accompanied by a shift in the mean orbital radius of the particle. This shift alters the epicyclic frequencies in such a way that the infinite response of the linear resonance theory is suppressed. Chaotic motion is found for the range of charge-to-mass ratios that cause the vertical and horizontal LRs to overlap.

  16. Vertical profiling of ozone and meteorological parameters in the lower atmosphere using kite and balloon platforms

    NASA Astrophysics Data System (ADS)

    Knapp, Karl Glenn

    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

  17. Competency-Based Route to Vertical Curriculum Articulation.

    ERIC Educational Resources Information Center

    Burger, Laura; And Others

    What competency-based instruction is and how it can help improve vertical articulation between the curriculum of secondary and postsecondary vocational-technical education programs in Minnesota is the focus of this booklet. Explanation consists of responses to the following questions: (1) What is vertical curriculum articulation? (2) What is…

  18. 15. Detail showing lower chord pinconnected to vertical member, showing ...

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

    15. Detail showing lower chord pin-connected to vertical member, showing floor beam riveted to extension of vertical member below pin-connection, and showing brackets supporting cantilevered sidewalk. View to southwest. - Selby Avenue Bridge, Spanning Short Line Railways track at Selby Avenue between Hamline & Snelling Avenues, Saint Paul, Ramsey County, MN

  19. Proposed technique for vertical alignment of a crane's cable

    NASA Technical Reports Server (NTRS)

    Gera, J., Jr.

    1969-01-01

    Proposed vertical alignment technique senses the attitude of a cranes cable and displays any deviation from the vertical. The system consists of a detector assembly fixed to the boom and a display scope located in the cabin. It has potential application with either fixed-boom cranes or gantries.

  20. 33 CFR 118.85 - Lights on vertical lift bridges.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... below the outermost edge of the bridge span structure so as to be visible from an approaching vessel... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Lights on vertical lift bridges... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span...