To see the other types of publications on this topic, follow the link: Vertical and horizontal surfaces.
Journal articles on the topic 'Vertical and horizontal surfaces'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Vertical and horizontal surfaces.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Pierce, Byron J., Ian P. Howard, and Catina Feresin. "Depth Interactions between Inclined and Slanted Surfaces in Vertical and Horizontal Orientations." Perception 27, no. 1 (January 1998): 87–103. http://dx.doi.org/10.1068/p270087.
Full textAbstract:
Depth interactions between a frontal test surface and an adjacent induction surface were measured as a function of the type of disparity in the induction surface and of the vertical/horizontal orientation of the boundary between the surfaces. The types of disparity were 4° horizontal-shear disparity, 4° vertical-shear disparity, and 4° rotation disparity; 4% horizontal-size disparity, 4% vertical-size disparity, and 4% overall-size disparity. Depth contrast in a frontal surface was produced by surfaces containing horizontal-size disparity but not by those containing horizontal-shear disparity. Vertical-shear and vertical-size disparities produced induced effects in both the induction and the test surface, which is here explained in terms of deformation-disparity processing. Effects of rotation disparity on the test surface can be accounted for in terms of cyclovergence, deformation disparity, and perhaps also depth contrast. The fact that horizontal-size disparity produced more depth contrast than horizontal-shear disparity is due to an anisotropy of disparity processing rather than the relative orientation of the surfaces. Ground surfaces appeared more slanted than ceiling surfaces. Surfaces containing horizontal disparities produced a sharp boundary with the test surface because horizontal disparities are processed locally. Surfaces with vertical disparities produced a gradual boundary with the test surface because vertical disparities are processed over a wider area.
2
Isik, Hakan. "Vertical and horizontal inversions by curved surfaces." Physics Teacher 51, no. 2 (February 2013): 117. http://dx.doi.org/10.1119/1.4775537.
Full text
3
Parton, A. D., M. F. Bradshaw, B. J. Rogers, and I. R. L. Davies. "The Effect of Surface Orientation on the Perception of Stereoscopic Corrugations." Perception 25, no. 1_suppl (August 1996): 117. http://dx.doi.org/10.1068/v96p0210.
Full textAbstract:
For most observers there is a pronounced orientational anisotropy in the perception of three-dimensional corrugated surfaces (Rogers and Graham, 1983 Science221 1409 – 1411; Bradshaw and Rogers, 1993 Perception22 Supplement, 117). Low-frequency corrugations which are oriented vertically have been found to have higher disparity modulation thresholds, the amount of perceived depth at suprathreshold levels is smaller, and typically they take longer to see than horizontally oriented corrugations. In the present experiments, the orientation of the corrugations was manipulated (from horizontal to vertical in 22.5 deg increments) to investigate the effect of surface orientation on both (i) a threshold detection task and (ii) a suprathreshold depth-matching task. The stimuli were 10 deg in diameter and were presented on two 12 inch monochrome monitors arranged to form a Wheatstone stereoscope. The surfaces were modulated in depth at four different corrugation frequencies (from 0.1 to 0.8 cycle deg−1 in octave steps). Thresholds were found to increase monotonically with increasing surface orientation from the horizontal: ∼2.5 arc s for horizontal corrugations to ∼10 arc s for vertical corrugations. The increase in thresholds was less marked for surfaces with higher corrugation frequencies. The rate of increase of threshold was greatest for surface orientations beyond 45°. A different pattern of results was found in the suprathreshold depth-matching task. Although the perceived depth in vertically oriented corrugations was significantly smaller (>50%) than for horizontally oriented corrugations, the largest amount of perceived depth was found for corrugated surfaces oriented at 45°. These results suggest that the disparity information used to process stereoscopic corrugations at threshold may be different from that used to process suprathreshold surfaces.
4
Liu, Yuansong, Yunxiao Gao, Zhiming Yu, and Yang Zhang. "The Action Difference of Lasiodiplodia theobromae on Infecting and Dyeing Poplar Wood in Spatial Growth." Coatings 11, no. 8 (August 19, 2021): 985. http://dx.doi.org/10.3390/coatings11080985.
Full textAbstract:
Many factors affect the driving force of fungal growth and secretion. To compare the differences of Lasiodiplodia theobromae infected poplar wood, the changes of physical and chemical properties of vertically and horizontally infected poplar wood before and after dyeing were analyzed, and the infection characteristics were studied in this paper. The horizontal infection was more effective than the vertical infection in terms of infection depth, color depth, and microscopic hyphal invasion. The mycelium first intruded into the earlywood tissue and began to secrete a large amount of pigment after twenty days. The crystallinity of mycelium decreased slightly, and the difference in weight loss rate was negligible. The initial contact angle of the dyed specimen on the horizontal infection increased drastically in distilled water, but there was almost no difference between varnish and natural coating. The horizontal infection was more efficient than the vertical infection and had a higher color depth and a better induction effect, which is crucial in future microbial dyeing.
5
Rogers, B. J., and T. Ledgeway. "Scaling of Frontoparallel Surfaces by Vertical Disparities: Effects of Field Size, Location, and Eccentricity." Perception 26, no. 1_suppl (August 1997): 325. http://dx.doi.org/10.1068/v970045.
Full textAbstract:
Since the pattern of horizontal disparities created by a frontal surface depends on the distance of the surface from the observer, additional information about distance is needed in order to judge whether a surface lies in a frontal plane. Rogers and Bradshaw (1995 Perception24 155 – 179) showed that both vertical disparities and vergence angle can be used to scale the curvature of surfaces in a horizontal direction. In the present experiments, we measured the extent of frontal plane scaling as a function of the location and eccentricity of the vertical disparity information. Observers were presented with a series of random-textured stereoscopic surfaces with vertical disparity information appropriate for surfaces located at distances between 28 cm and infinity. The observer's task was to vary the pattern of horizontal disparities until the surface appeared to lie in a frontal plane. The stereoscopic images were masked to reveal either a circular, or an annular, or a rectangular patch with dimensions between 10 deg and 70 deg. Maximum scaling was found for the 70 deg diameter circular patch; it decreased by 50% when the patch was masked down to 20 deg in diameter. Scaling remained at over 80% when the central 60,deg of the display were masked. Scaling was reduced more when the horizontal width of the rectangle was made smaller than when the vertical height was made smaller. Vertical disparities are most effective for frontal plane scaling when they are present in more eccentric regions of the visual field, especially in a horizontal direction.
6
Knott, N. A., A. J. Underwood, M. G. Chapman, and T. M. Glasby. "Growth of the encrusting sponge Tedania anhelans (Lieberkuhn) on vertical and on horizontal surfaces of temperate subtidal reefs." Marine and Freshwater Research 57, no. 1 (2006): 95. http://dx.doi.org/10.1071/mf05092.
Full textAbstract:
On subtidal reefs around Sydney (Australia), Tedania anhelans (Lieberkuhn, 1859)is a common encrusting sponge that occurs as frequently on vertical as on horizontal surfaces on most reefs, but covers more than twice the area on vertical surfaces of reefs. Faster growth, leading to the greater cover of the sponge on vertical surfaces, is a possible explanation for this difference. This was examined by experimental transplants to test the hypothesis that T. anhelans transplanted from vertical to horizontal surfaces grow more slowly than those on vertical surfaces. Over three months, T. anhelans transplanted to horizontal surfaces shrank, by 18 ± 18% and 17 ± 16% (mean ± s.e.) at two sites. Conversely, sponges on vertical surfaces grew rapidly, increasing by 40 ± 18% and 78 ± 19% at two sites. Potential artefacts owing to the experimental procedure of moving sponges between places were tested, but none was detected. These results indicated that orientation had a strong effect on the growth of T. anhelans and that growth has an important role in creating the pattern of its greater cover on vertical than on horizontal surfaces of temperate subtidal reefs.
7
Marchal, Olivier. "Extratropical Rossby Waves in the Presence of Buoyancy Mixing." Journal of Physical Oceanography 39, no. 11 (November 1, 2009): 2910–25. http://dx.doi.org/10.1175/2009jpo4139.1.
Full textAbstract:
Abstract The propagation of Rossby waves on a midlatitude β plane is investigated in the presence of density diffusion with the aid of linear hydrostatic theory. The search for wave solutions in a vertically bounded medium subject to horizontal (vertical) diffusion leads to an eigenvalue problem of second (fourth) order. Exact solutions of the problem are obtained for uniform background stratification (N), and approximate solutions are constructed for variable N using the Wentzel–Kramers–Brillouin method. Roots of the eigenvalue relations for free waves are found and discussed. The barotropic wave of adiabatic theory is also a solution of the eigenvalue problem as this is augmented with density diffusion in the horizontal or vertical direction. The barotropic wave is undamped as fluid parcels in the wave move only horizontally and are therefore insensitive to the vortex stretching induced by mixing. On the other hand, density diffusion modifies the properties of baroclinic waves of adiabatic theory. In the presence of horizontal diffusion the baroclinic modes are damped but their vertical structure remains unaltered. The ability of horizontal diffusion to damp baroclinic waves stems from its tendency to counteract the deformation of isopycnal surfaces caused by the passage of these waves. The damping rate increases (i) linearly with horizontal diffusivity and (ii) nonlinearly with horizontal wavenumber and mode number. In the presence of vertical diffusion the baroclinic waves suffer both damping and a change in vertical structure. In the long-wave limit the damping is critical (wave decay rate numerically equal to wave frequency) and increases as the square roots of vertical diffusivity and zonal wavenumber. Density diffusion in the horizontal or vertical direction reduces the amplitude of the phase speed of westward-propagating waves. Observational estimates of eddy diffusivities suggest that horizontal and vertical mixing strongly attenuates baroclinic waves in the ocean but that vertical mixing is too weak to notably modify the vertical structure of the gravest modes.
8
Fan, Xiao Yi, Yao Xun Zeng, and Xiao Dong Duan. "Underlying Surface Influenced on the Landslide Runout." Advanced Materials Research 671-674 (March 2013): 161–66. http://dx.doi.org/10.4028/www.scientific.net/amr.671-674.161.
Full textAbstract:
The landslide runouts not only were controlled by the volumes and vertical movement distances, but also the underlying surface played an important role. The concave, fold line, ladder and bedded types of the landslide underlying surfaces were studied. It aimed at analysis the underlying surfaces influenced on the runouts of the catastrophic landslides. There was significant correlation between the horizontal distances and the volumes, vertical distances in the seismic and rainfall landslides without river blocking. But the relationships showed different power laws in the seismic and rainfall landslides. The relative errors between actual and forecast values of seismic and rainfall landslides reflected that the underlying surface types influenced on the landslide horizontal movement distances. The results showed that the maximum horizontal distances of seismic and rainfall landslides could be predicted based on the landslides volumes, vertical distances and underlying surfaces.
9
Knott, N. A., A. J. Underwood, M. G. Chapman, and T. M. Glasby. "Epibiota on vertical and on horizontal surfaces on natural reefs and on artificial structures." Journal of the Marine Biological Association of the United Kingdom 84, no. 6 (November 23, 2004): 1117–30. http://dx.doi.org/10.1017/s0025315404010550h.
Full textAbstract:
Subtidal assemblages of epibiota on vertical and on horizontal surfaces of two natural reefs and two concrete breakwalls were sampled photographically during autumn and winter of 1998. Differences in the assemblages on the two types of substrata (natural reefs and concrete breakwalls) were detected between assemblages on horizontal surfaces, but not on vertical surfaces. The covers of several individual taxa (e.g. Herdmania momus, serpulid polychaetes, coralline encrusting algae) and number of sponge taxa showed clear differences between the two types of substrata. There were great differences between the assemblages on vertical and horizontal surfaces on each natural reef and artificial structure. Invertebrates consistently covered a larger area on vertical than on horizontal surfaces with sponges (as a group) and the ascidian Herdmania momus, the dominant invertebrates on these reefs, clearly showing this pattern. Nevertheless, this pattern was complex for sponges because several species covered a larger area on horizontal than on vertical surfaces and there was no difference in the number of taxa of sponges between the two orientations on natural reefs. Algae, contrary to the results of previous studies, did not show any consistent differences in their covers on vertical or on horizontal surfaces. The results of this study indicated that orientation may be of greater influence on the biological diversity of epibiota on subtidal reefs than whether reefs are natural or artificial.
10
Danner, Tobias, and Mette Rica Geiker. "Long-term Influence of Concrete Surface and Crack Orientation on Self-healing and Ingress in Cracks – Field Observations." Nordic Concrete Research 58, no. 1 (June 1, 2018): 1–16. http://dx.doi.org/10.2478/ncr-2018-0001.
Full textAbstract:
Abstract This paper presents results from investigations on the long-term influence of concrete surface and crack orientation on ingress in cracks. Five reinforced concrete structures from Norway exposed to either de-icing salts or seawater have been investigated. Concrete cores were taken with and without cracks from surfaces with vertical and horizontal orientation. Carbonation in cracks was found on all de-iced structures, and a crack on a completely horizontal surface appeared to facilitate chloride ingress. Ingress of substances from seawater was found in all cracks from marine exposure. However, the impact of cracks on chloride ingress was unclear. Horizontal cracks on vertical surfaces appeared to facilitate self-healing.
11
Tulloch, Ross, and K. Shafer Smith. "A Note on the Numerical Representation of Surface Dynamics in Quasigeostrophic Turbulence: Application to the Nonlinear Eady Model." Journal of the Atmospheric Sciences 66, no. 4 (April 1, 2009): 1063–68. http://dx.doi.org/10.1175/2008jas2921.1.
Full textAbstract:
Abstract The quasigeostrophic equations consist of the advection of linearized potential vorticity coupled with advection of temperature at the bounding upper and lower surfaces. Numerical models of quasigeostrophic flow often employ greater (scaled) resolution in the horizontal than in the vertical (the two-layer model is an extreme example). In the interior, this has the effect of suppressing interactions between layers at horizontal scales that are small compared to Nδz/f (where δz is the vertical resolution, N the buoyancy frequency, and f the Coriolis parameter). The nature of the turbulent cascade in the interior is, however, not fundamentally altered because the downscale cascade of potential enstrophy in quasigeostrophic turbulence and the downscale cascade of enstrophy in two-dimensional turbulence (occurring layerwise) both yield energy spectra with slopes of −3. It is shown here that a similar restriction on the vertical resolution applies to the representation of horizontal motions at the surfaces, but the penalty for underresolving in the vertical is complete suppression of the surface temperature cascade at small scales and a corresponding artificial steepening of the surface energy spectrum. This effect is demonstrated in the nonlinear Eady model, using a finite-difference representation in comparison with a model that explicitly advects temperature at the upper and lower surfaces. Theoretical predictions for the spectrum of turbulence in the nonlinear Eady model are reviewed and compared to the simulated flows, showing that the latter model yields an accurate representation of the cascade dynamics. To accurately represent dynamics at horizontal wavenumber K in the vertically finite-differenced model, it is found that the vertical grid spacing must satisfy δz ≲ 0.3f/(NK); at wavenumbers K > 0.3f/(Nδz), the spectrum of temperature variance rolls off rapidly.
12
Domenici, P., D. González-Calderón, and R. S. Ferrari. "Locomotor performance in the sea urchin Paracentrotus lividus." Journal of the Marine Biological Association of the United Kingdom 83, no. 2 (March 20, 2003): 285–92. http://dx.doi.org/10.1017/s0025315403007094h.
Full textAbstract:
The locomotor performance of the Mediterranean sea urchin Paracentrotus lividus was investigated under laboratory conditions. Individuals were placed singly in the centre of a glass surface positioned either horizontally or vertically in tanks with seawater, and their locomotor activity was recorded. For locomotion on a horizontal surface, speed increased with both sea urchin diameter and their straightness of path. Speeds on a vertical surface were size-independent and not related to the straightness of path, although they were affected by vertical path orientation, with the highest speeds occurring for downward movements and the slowest speeds for the upward movements. Taken together, these results suggest that the scaling of sea urchin locomotion may follow similar laws to those of legged animals, for which locomotor performance increases with size on horizontal surface, while their relative cost of locomotion increases with body size on inclined surfaces. It is suggested that differences in horizontal vs vertical locomotion may also be related to differences in the underlying locomotor mechanisms, i.e. using adhesive appendices (tube feet) or levers (spines). In a second experiment, the sea urchin speed obtained during a negative phototactic response to a direct light stimulus was recorded. The results show that speed during light stimulation is higher than that during spontaneous locomotion in sea urchins of intermediate size (2·5–4 cm), suggesting that, in addition to the direction of locomotion as shown by previous studies, light can also have an effect on speed.
13
Ryan, Colin, and Barbara Gillam. "Cue Conflict and Stereoscopic Surface Slant about Horizontal and Vertical Axes." Perception 23, no. 6 (June 1994): 645–58. http://dx.doi.org/10.1068/p230645.
Full textAbstract:
The way in which a planar surface is defined or configured may affect its apparent slant about a given axis, and the magnitude of slant-axis anisotropies. The authors have previously suggested that (i) these within-axis and between-axis configuration effects may be attributable, in part at least, to the perspective—disparity conflict generated when geometrically frontoparallel configured surfaces are slanted stereoscopically; and (ii) that implicit contours, defined by line endings or conjunctions, may have effects analogous to those seen with explicit contours. These possibilities were directly examined in two experiments. In experiment 1, slant-axis anisotropy was progressively induced by adding horizontal lines to a vertical-line (zero anisotropy) grid under conditions of cue conflict; slants about the vertical (but not the horizontal) were attenuated—demonstrating a clear and systematic nexus between surface configuration and slant-axis anisotropy. The presence of regular implicit horizontals similarly and selectively attenuated the slant perceived about the vertical. In experiment 2, cue conflict was seen to exacerbate slant-axis anisotropy, but clearly could not fully account for it. There was an axis asymmetry in the effect of degrading implicit contours: degradation had a marked impact on perceived slant about the horizontal but not the vertical axis.
14
Li, DHW, and JC Lam. "Predicting vertical luminous efficacy using horizontal solar data." Lighting Research & Technology 33, no. 1 (March 2001): 25–42. http://dx.doi.org/10.1177/136578280103300107.
Full textAbstract:
Daylighting is recognized as an important and useful strategy in the design of energy-efficient buildings. Daylight illuminance, particularly on vertical surfaces, plays a major role in determining and evaluating the daylighting performance of a building. Luminous efficacy approach is considered as a versatile and easily applied way to calculate outdoor illuminance. This paper presents an approach to estimate the vertical outdoor illuminance from computed vertical luminous efficacy based on the measured horizontal solar irradiance and illuminance data. Hourly data recorded from January 1996 to December 1998 in Hong Kong were used for the model development. The performance of the proposed model and two well-known anisotropic inclined surface models (Muneer and Perez) was evaluated against data measured in 1999. Statistical analysis indicated that the proposed model gives reasonably good agreement with measured data for all vertical planes. The proposed model can provide an alternative to building designers in estimating the vertical solar illuminance and irradiance where only the horizontal measurements are available.
15
Potvin, Brianna, Colin Swindells, Melanie Tory, and Margaret-Anne Storey. "Comparing Horizontal and Vertical Surfaces for a Collaborative Design Task." Advances in Human-Computer Interaction 2012 (2012): 1–10. http://dx.doi.org/10.1155/2012/137686.
Full textAbstract:
We investigate the use of different surface orientations for collaborative design tasks. Specifically, we compare horizontal and vertical surface orientations used by dyads performing a collaborative design task while standing. We investigate how the display orientation influences group participation including face-to-face contact, total discussion, and equality of physical and verbal participation among participants. Our results suggest that vertical displays better support face-to-face contact whereas side-by-side arrangements encourage more discussion. However, display orientation has little impact on equality of verbal and physical participation, and users do not consistently prefer one orientation over the other. Based on our findings, we suggest that further investigation into the differences between horizontal and vertical orientations is warranted.
16
Walker, Alexander William, and Aleksandar Subic. "Horizontal and vertical reaction force testing for synthetic sports surfaces." Sports Technology 3, no. 1 (February 2010): 34–42. http://dx.doi.org/10.1080/19346190.2010.504277.
Full text
17
GOSHAYESHI, H. R., and F. AMPOFO. "Heat Transfer by Natural Convection from a Vertical and Horizontal Surfaces Using Vertical Fins." Energy and Power Engineering 01, no. 02 (2009): 85–89. http://dx.doi.org/10.4236/epe.2009.12013.
Full text
18
Obianyo, Jude Iloabuchi, and J. C. Agunwamba. "Efficiencies of Horizontal and Vertical Baffle Mixers." Emerging Science Journal 3, no. 3 (June 3, 2019): 130–45. http://dx.doi.org/10.28991/esj-2019-01176.
Full textAbstract:
Efficiencies of sedimentation tanks with horizontal and vertical baffle mixers were studied, compared, and also to determine the optima values of factors of clarification in the sedimentation tanks. These are the discharge, basin baffle spacing and dosing factors, thereby comprises three factors at five levels for a 5k factorial design model. 2.0 mg/l of clay solution was introduced into the basin at discharge rates of 48.75 ml/s, 55.07 ml/s, 60.34 ml/s, 62.45 ml/s and 63.27 ml/s respectively. Alum solution was introduced as coagulant at the inlet of the basin, samples were collected both from the basin and the outlet and concentrations of flocs were measured. Plots of variation of total outlet and average outlet floc with dosing rates for horizontal and vertical mixers show that vertical mixers are better only at discharge of 48.75 ml/s, but horizontal mixers are better at 55.05 ml/s, 60.34 ml/s, 62.45 ml/s and 63.27 ml/s. Variation of grand total floc with dosing rates is also in favour of horizontal mixers. Plots of outlet floc against dosing rates at 48.75 ml/s discharge show that horizontal mixer spaced at 100 mm is better with maximum sediment/floc of 333 10-4 g at a dosing rate of 0.55 ml/s, at 55.07 ml/s discharge vertical mixer is better with 250 mm spacing giving maximum sediment of 985 10-4 g at a dosing rate of 0.95 ml/s. For 60.34 ml/s discharge, horizontal mixer is better at 250 mm spacing with maximum sediment of 307 10-4 g at 0.75 ml/s dosing rate. In the case of 62.45 ml/s discharge, horizontal mixer at a spacing of 300 mm is better with a maximum deposit of 335 10-4 g at a dosing rate of 0.95 ml/s, and for discharge of 63.27 ml/s, horizontal mixer is better at 150 mm spacing having a maximum sediment of 715 10-4 g for a dosing rate of 0.35 ml/s. Response surface methodology (RSM) presented by Montgomery, 2008 was further used for the analysis of data in this study for more reliable inference because it optimized the responses of these three variables. It was observed that for the vertically placed baffles, the stationary points of response surface for discharge rate, baffle spacing and dosing rate are 80.56762847 ml/s, 100.00000 mm and 0.04965779 ml/s, while for horizontally placed baffles, it was 70.636018 ml/s, 332.864704 mm and 1.402526 ml/s, however, these results indicate that horizontally placed baffle mixers are better than vertically placed baffle mixers.
19
Theys, Tom, Siddharth Srivastava, Johannes van Loon, Jan Goffin, and Peter Janssen. "Selectivity for three-dimensional contours and surfaces in the anterior intraparietal area." Journal of Neurophysiology 107, no. 3 (February 2012): 995–1008. http://dx.doi.org/10.1152/jn.00248.2011.
Full textAbstract:
The macaque anterior intraparietal area (AIP) is crucial for visually guided grasping. AIP neurons respond during the visual presentation of real-world objects and encode the depth profile of disparity-defined curved surfaces. We investigated the neural representation of curved surfaces in AIP using a stimulus-reduction approach. The stimuli consisted of three-dimensional (3-D) shapes curved along the horizontal axis, the vertical axis, or both the horizontal and the vertical axes of the shape. The depth profile was defined solely by binocular disparity that varied along either the boundary or the surface of the shape or along both the boundary and the surface of the shape. The majority of AIP neurons were selective for curved boundaries along the horizontal or the vertical axis, and neural selectivity emerged at short latencies. Stimuli in which disparity varied only along the surface of the shape (with zero disparity on the boundaries) evoked selectivity in a smaller proportion of AIP neurons and at considerably longer latencies. AIP neurons were not selective for 3-D surfaces composed of anticorrelated disparities. Thus the neural selectivity for object depth profile in AIP is present when only the boundary is curved in depth, but not for disparity in anticorrelated stereograms.
20
Goulden, T., C. Hopkinson, and M. N. Demuth. "Sensitivity of alpine glacial change detection and mass balance to sampling and datum inconsistencies." Cryosphere Discussions 7, no. 1 (January 2, 2013): 55–101. http://dx.doi.org/10.5194/tcd-7-55-2013.
Full textAbstract:
Abstract. Glacial mass balance estimated through the geodetic method requires glacial surface coordinate observations from historical and contemporary sources. Contemporary observations and historical topographic maps are typically referenced to separate horizontal and vertical datums and observed with different sampling intervals. This research demonstrates the sensitivity of glacial change detection to the datum considerations and sampling schemes through case studies of Andrei, Bridge and Peyto glaciers in Western Canada. To simulate the procedure of observing the glacial surfaces, profile lines were sampled from Digital Elevation Model (DEMs) on contour intervals for historical data and horizontal intervals for contemporary data. Profile lines from the following scenarios were compared: (1) different horizontal and vertical sampling schemes; (2) the horizontal datum was correctly reconciled but the vertical datum was not; (3) the vertical datum was correctly reconciled but the horizontal datum was not; (4) both the horizontal and vertical datums were correctly reconciled; and (5) both the horizontal and vertical datums were incorrectly reconciled. Vertical errors of up to 6.9 m, 6.0 m and 5.0 m were observed due to sampling effects and vertical errors of 22.2 m, 9.9 m and 55.0 m were observed due to datum inconsistencies on Bridge, Andrei and Peyto glacier respectively. Horizontal datum inconsistencies manifested as erratic levels of growth or downwasting along the glacial surface profile and vertical datum errors manifested as a consistent vertical offset. Datum inconsistencies were identified to contribute errors of up to 257.2 × 106 m3 (or 87%) and 54.6 × 106 m3 (or 580%) of estimated volume change below and above the equilibrium line respectively on Peyto Glacier. The results of this study provide an estimate of typical errors due to sampling constraints or datum inconsistencies as well as guidance for identifying where these error sources have contaminated mass balance results.
21
Juang, Hann-Ming Henry, Ching-Teng Lee, Yongxin Zhang, Yucheng Song, Ming-Chin Wu, Yi-Leng Chen, Kevin Kodama, and Shyh-Chin Chen. "Applying Horizontal Diffusion on Pressure Surface to Mesoscale Models on Terrain-Following Coordinates." Monthly Weather Review 133, no. 5 (May 1, 2005): 1384–402. http://dx.doi.org/10.1175/mwr2925.1.
Full textAbstract:
Abstract The National Centers for Environmental Prediction regional spectral model and mesoscale spectral model (NCEP RSM/MSM) use a spectral computation on perturbation. The perturbation is defined as a deviation between RSM/MSM forecast value and their outer model or analysis value on model sigma-coordinate surfaces. The horizontal diffusion used in the models applies perturbation diffusion in spectral space on model sigma-coordinate surfaces. However, because of the large difference between RSM/MSM and their outer model or analysis terrains, the perturbation on sigma surfaces could be large over steep mountain areas as horizontal resolution increases. This large perturbation could introduce systematical error due to artificial vertical mixing from horizontal diffusion on sigma surface for variables with strong vertical stratification, such as temperature and humidity. This nonnegligible error would eventually ruin the forecast and simulation results over mountain areas in high-resolution modeling. To avoid the erroneous vertical mixing on the systematic perturbation, a coordinate transformation is applied in deriving a horizontal diffusion on pressure surface from the variables provided on terrain-following sigma coordinates. Three cases are selected to illustrate the impact of the horizontal diffusion on pressure surfaces, which reduces or eliminates numerical errors of mesoscale modeling over mountain areas. These cases address concerns from all aspects, including unstable and stable synoptic conditions, moist and dry atmospheric settings, weather and climate integrations, hydrostatic and nonhydrostatic modeling, and island and continental orography. After implementing the horizontal diffusion on pressure surfaces for temperature and humidity, the results show better rainfall and flow pattern simulations when compared to observations. Horizontal diffusion corrects the warming, moistening, excessive rainfall, and convergent flow patterns around high mountains under unstable and moist synoptic conditions and corrects the cooling, drying, and divergent flow patterns under stable and dry synoptic settings.
22
Zou, Jinfeng, and Songqing Zuo. "Similarity Solution for the Synchronous Grouting of Shield Tunnel Under the Vertical Non-Axisymmetric Displacement Boundary Condition." Advances in Applied Mathematics and Mechanics 9, no. 1 (October 11, 2016): 205–32. http://dx.doi.org/10.4208/aamm.2016.m1479.
Full textAbstract:
AbstractSimilarity solution is investigated for the synchronous grouting of shield tunnel under the vertical non-axisymmetric displacement boundary condition in the paper. The synchronous grouting process of shield tunnel was simplified as the cylindrical expansion problem, which was based on the mechanism between the slurry and stratum of the synchronous grouting. The stress harmonic function on the horizontal and vertical ground surfaces is improved. Based on the virtual image technique, stress function solutions and Boussinesq's solution, elastic solution under the vertical non-axisymmetric displacement boundary condition on the vertical surface was proposed for synchronous grouting problems of shield tunnel. In addition, the maximum grouting pressure was also obtained to control the vertical displacement of horizontal ground surface. The validity of the proposed approach was proved by the numerical method. It can be known from the parameter analysis that larger vertical displacement of the horizontal ground surface was induced by smaller tunnel depth, smaller tunnel excavation radius, shorter limb distance, larger expansion pressure and smaller elastic modulus of soils.
23
Popa, Simona, and Sorina Boran. "Glass packing materials used for intensification of heat transfer at boiling on tubular surfaces." Thermal Science 21, no. 5 (2017): 2031–37. http://dx.doi.org/10.2298/tsci150728203p.
Full textAbstract:
The paper presents the results obtained in determining the partial heat transfer coefficient at boiling on vertical and horizontal tubular surfaces surrounded by different types of glass packing material. In both cases, an intensification of heat transfer can be noticed as compared to the boiling on the same installation performed without glass packing materials. During the experiments pseudo-critical values of thermal flux appear on the vertical and horizontal heating tube with glass packing materials, and the boiling heat transfer coefficient, ?, has lower critical values than that on nucleate ordinary boiling. This denotes a differential heating mechanism, determined by the presence of the glass package around the heating tube. The heat transfer intensification is greater with the horizontal tube than with the vertical one.
24
Stackman, Robert W., Matthew L. Tullman, and Jeffrey S. Taube. "Maintenance of Rat Head Direction Cell Firing During Locomotion in the Vertical Plane." Journal of Neurophysiology 83, no. 1 (January 1, 2000): 393–405. http://dx.doi.org/10.1152/jn.2000.83.1.393.
Full textAbstract:
Previous studies have identified a subset of neurons in the rat anterodorsal thalamus (ADN) that encode head direction (HD) in absolute space and may be involved in navigation. These HD cells discharge selectively when the rat points its head in a specific direction (the preferred firing direction) in the horizontal plane. HD cells are typically recorded during free movement about a single horizontal surface. The current experiment examined how HD cell firing was influenced by 1) locomotion in the vertical plane and 2) locomotion on two different horizontal surfaces separated in height. Rats were trained in a cylindrical enclosure containing a single polarizing cue card attached to the cylinder wall, covering ∼100° of arc. The enclosure contained two horizontal surfaces: the cylinder floor and an annulus around the cylinder top 76 cm above the floor. A 90° vertical mesh ladder that could be affixed at any angular position on the cylinder wall allowed the rats to locomote back and forth between the two horizontal surfaces. Rats were trained to retrieve food pellets on the cylinder floor as well as climb the mesh ladder to retrieve food pellets on the annulus. HD cell activity was monitored as the rat traversed the horizontal and vertical surfaces of the apparatus. When the angular position of the mesh corresponded to the cell's preferred firing direction, the HD cells maintained their peak discharge rate as the rat climbed up the mesh, but did not fire when the rat climbed down the mesh. In contrast, when the mesh was positioned 180° opposite the preferred firing direction, HD cells did not fire when the rat climbed up the mesh, but exhibited maximal firing when the rat climbed down the mesh. When the mesh was placed 90 or 270° from the preferred firing direction, HD cells exhibited background firing rates during climbing up or down the mesh. While preferred firing directions were maintained between the two horizontal surfaces, peak firing rate increased significantly (∼30%) on the annulus as compared with the cylinder floor. These data demonstrate that HD cells continue to discharge in the vertical plane if the vertical locomotion began with the rat's orientation corresponding to the preferred firing direction. One model consistent with these data are that HD cells define the horizontal reference frame as the animal's plane of locomotion. Further, we propose that HD cell firing, as viewed within a three-dimensional coordinate system, can be characterized as the surface of a hemitorus.
25
Pradhan, Kaustav, and Abhijit Guha. "CFD solutions for magnetohydrodynamic natural convection over horizontal and vertical surfaces." Journal of Molecular Liquids 236 (June 2017): 465–76. http://dx.doi.org/10.1016/j.molliq.2017.03.110.
Full text
26
Zaki, Magdy, Inderjit Nirdosh, and Gomma Sedahmed. "Natural Convective Mass-Transfer Behavior of Horizontal and Vertical Perforated Surfaces." Industrial & Engineering Chemistry Research 41, no. 13 (June 2002): 3307–11. http://dx.doi.org/10.1021/ie0109556.
Full text
27
Yang, Wenhao, and Wenzeng Zhang. "A Worm-Inspired Robot Flexibly Steering on Horizontal and Vertical Surfaces." Applied Sciences 9, no. 10 (May 27, 2019): 2168. http://dx.doi.org/10.3390/app9102168.
Full textAbstract:
Based on the motion principle of bionic earthworms, we designed and fabricated a novel crawling robot driven by pneumatic power. Its structure is divided into four segments, and its motion process is periodic with high stability. Due to the pneumatic suction cups mounted on its feet, it is able to crawl on smooth horizontal, inclined, or vertical walls. On this basis, we designed a novel underactuated steering mechanism. Through the tendons on both sides and the springs installed on the side of the robot, we accurately controlled the steering motion of the robot. We analyzed the steering process in detail, calculated the influence of external parameters on the steering process of the robot, and simulated the trajectory of the robot in the steering process. The experimental results validated our analysis. In addition, we calculate the maximum thrust that each segment of the robot can provide, and determine the maximum load that the robot can bear during climbing motions.
28
Oteiza, Pilar, and Ana Pérez-Burgos. "Diffuse illuminance availability on horizontal and vertical surfaces at Madrid, Spain." Energy Conversion and Management 64 (December 2012): 313–19. http://dx.doi.org/10.1016/j.enconman.2012.05.022.
Full text
29
Somwanshi, Praveen M., K. Muralidhar, and Sameer Khandekar. "Dropwise condensation patterns of bismuth formed on horizontal and vertical surfaces." International Journal of Heat and Mass Transfer 122 (July 2018): 1024–39. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2018.02.052.
Full text
30
Yoon, Dong Hyun, Yoshito Nozaki, Daiki Tanaka, Tetsushi Sekiguchi, and Shuichi Shoji. "Integration of Horizontal and Vertical Microfluidic Modules for Core-Shell Droplet Generation and Chemical Application." Micromachines 10, no. 9 (September 15, 2019): 613. http://dx.doi.org/10.3390/mi10090613.
Full textAbstract:
This paper presents a method for utilizing three-dimensional microfluidic channels fully to realize multiple functions in a single device. The final device structure was achieved by combining three independent modules that consisted of horizontal and vertical channels. The device allowed for the one-step generation of water-in-oil-in-water droplets without the need for partial treatment of the polydimethylsiloxane channel surface using separate modules for generating water-in-oil droplets on the horizontal plane and oil-in-water droplets on the vertical plane. The second vertically structured module provided an efficient flow for the generation of highly wettable liquid droplets, and tuning of the first horizontally structured module enabled different modes of inner-core encapsulation within the oil shell. The successful integration of the vertical and horizontal channels for core-shell droplet generation and the chemical synthesis of a metal complex within the droplets were evaluated. The proposed approach of integrating independent modules will expand and enhance the functions of microfluidic platforms.
31
Kumar, Jyant. "Seismic horizontal pullout capacity of vertical anchors in sands." Canadian Geotechnical Journal 39, no. 4 (August 1, 2002): 982–91. http://dx.doi.org/10.1139/t02-021.
Full textAbstract:
The problem of finding the horizontal pullout capacity of vertical anchors embedded in sands with the inclusion of pseudostatic horizontal earthquake body forces, was tackled in this note. The analysis was carried out using an upper bound limit analysis, with the consideration of two different collapse mechanisms: bilinear and composite logarithmic spiral rupture surfaces. The results are presented in nondimensional form to find the pullout resistance with changes in earthquake acceleration for different combinations of embedment ratio of the anchor (λ), friction angle of the soil (φ;), and the anchor-soil interface wall friction angle (δ). The pullout resistance decreases quite substantially with increases in the magnitude of the earthquake acceleration. For values of δ up to about 0.250.5φ, the bilinear and composite logarithmic spiral rupture surfaces gave almost identical answers, whereas for higher values of δ, the choice of the logarithmic spiral provides significantly smaller pullout resistance. The results compare favorably with the existing theoretical data.Key words: anchors, earthquakes, failure, limit analysis, sands.
32
Ji, Shunying, Xiaodong Chen, and Anliang Wang. "Influence of the loading direction on the uniaxial compressive strength of sea ice based on field measurements." Annals of Glaciology 61, no. 82 (April 15, 2020): 86–96. http://dx.doi.org/10.1017/aog.2020.14.
Full textAbstract:
AbstractSea ice is composed of columnar-shaped grains. To investigate the influence of the loading direction on the uniaxial compressive strength and failure processes of sea ice, field experiments were performed with first-year level ice. Loads were applied both horizontally (parallel to the grain columns) and vertically (across the grain columns) with various nominal strain rates. Two failure modes have been observed: a ductile failure mode at low nominal strain rates, and a brittle failure mode at high nominal strain rates. However, the failure pattern of sea ice was clearly dependent on the loading direction. At low nominal strain rates (ductile failure mode), the sea-ice samples yielded due to the development of wing cracks under horizontal loading and due to splaying out at one end under vertical loading. When sea ice fails in the ductile mode, the deformation is driven by grain boundary sliding under horizontal loading and by grain decohesion and crystal deflection under vertical loading. At high nominal strain rates (brittle failure mode), the sea-ice samples failed in shear faulting under horizontal loading and in cross-column buckling under vertical loading. The nominal strain rate at the brittle–ductile transition zone is about ten times higher under vertical loading.
33
Pecunioso, Alessandra, and Christian Agrillo. "Is the Horizontal-Vertical Illusion Mainly a By-Product of Petter’s Rule?" Symmetry 12, no. 1 (December 18, 2019): 6. http://dx.doi.org/10.3390/sym12010006.
Full textAbstract:
The horizontal-vertical (HV) illusion is a classical example of an asymmetrical perception of size in the vertical and horizontal axes, also known as ‘anisotropy of the perceived space’. Several authors argued that the horizontally-oriented ellipse of the binocular visual field might play an important role in the emergence of this illusion. Alternatively, a length bisection bias and size-constancy mechanisms have been advocated to account for the asymmetrical perception in the two dimensions. To investigate this phenomenon, participants are commonly required to estimate the length of two separate lines, one vertical and one horizontal, often arranged in an inverted-T pattern. Here we suggest that this type of stimulus may introduce physical and subjective biases that prevent a fine investigation. In particular, we believe that Petter’s rule, that applies to two-dimensional patterns formed by two overlapping surfaces, may play a critical role that will not support an interpretation based on the shape of the binocular visual field nor a length bisection bias.
34
Ruotoistenmäki, Tapio. "The gravity anomaly of two‐dimensional sources with continuous density distribution and bounded by continuous surfaces." GEOPHYSICS 57, no. 4 (April 1992): 623–28. http://dx.doi.org/10.1190/1.1443274.
Full textAbstract:
The gravity anomaly of a complicated two‐dimensional (2-D) source having arbitrary surfaces and density varying in either horizontal or vertical direction is calculated using a combination of closed form solutions and numerical integration. The surfaces and density can be defined by continuous or piecewise continuous two‐dimensional functions in the integration interval. For example, the anomalies for intrusions or folded sedimentary units, having an arbitrary density in the horizontal direction and a polynomial density distribution in the vertical direction, can be calculated using surfaces represented by functions of the horizontal dimension. When modeling dipping layered intrusions or sedimentary beds the surfaces are represented by functions of the vertical dimension in which case the density can be an arbitrary function of depth and a polynome function of horizontal coordinate. The accuracy of the method is defined by the user. The method gives simple and general equations to calculate anomalies of complicated sources which have no closed form solution, thus reducing the number of algorithms needed in interpretation programs.
35
AU, THOMAS KWOK-KEUNG, and TOM YAU-HENG WAN. "PRESCRIBED HORIZONTAL AND VERTICAL TREES PROBLEM OF QUADRATIC DIFFERENTIALS." Communications in Contemporary Mathematics 08, no. 03 (June 2006): 381–99. http://dx.doi.org/10.1142/s0219199706002155.
Full textAbstract:
A sufficient condition for the existence of holomorphic quadratic differential on a non-compact simply-connected Riemann surface with prescribed horizontal and vertical trees is obtained. In particular, for any pair of complete ℝ-trees of finite vertices with (n + 2) infinite edges, there exists a polynomial quadratic differential on ℂ of degree n such that the associated vertical and horizontal trees are isometric to the given pair.
36
Backus, B. T., R. van Ee, and M. S. Banks. "Horizontal Disparity Pooling." Perception 25, no. 1_suppl (August 1996): 6. http://dx.doi.org/10.1068/v96p0209.
Full textAbstract:
Vertical magnification in one eye causes a frontoparallel surface to appear slanted about a vertical axis. Stenton, Frisby, and Mayhew [1984 Nature (London)309 622 – 623] showed using a dot display that, for mixtures of dots drawn from two populations of vertical magnification, the amount of horizontal magnification needed to null the perceive slant varies monotonically and nearly linearly with the mixture. We find a similar, but weaker, relationship for mixtures of horizontal magnification. In one experiment, a horizontal row of dots (containing no vertical disparity) was used to measure the local horizontal magnification needed to null the slant-biasing effect of a background which consisted of a pair of transparent planes made up of dots from two populations of horizontal magnification. The nulling magnification for the dot row was generally a monotonic function of the ratio of the number of dots from the two populations. In a second experiment, observers added horizontal disparity to the biplanar display itself until one plane appeared frontoparallel. The nulling horizontal magnification was again a monotonic function of the ratio of the number of dots from the two populations. We conclude that stereoscopic slant perception is influenced by pooling both of vertical and of horizontal magnifications within a stereoscopic image.
37
Pierce, Byron J., and Ian P. Howard. "Types of Size Disparity and the Perception of Surface Slant." Perception 26, no. 12 (December 1997): 1503–17. http://dx.doi.org/10.1068/p261503.
Full textAbstract:
We examined (i) perceived slant of a textured surface about a vertical axis as a function of disparity magnitude for horizontal-size disparity, vertical-size disparity, and overall-size disparity; and (ii) interactions between patterns with various types and magnitudes of size disparity and superimposed or adjacent zero-disparity stimuli. Horizontal-size disparity produced slant which increased with increasing disparity, was enhanced by superimposed zero-disparity stimuli, and induced contrasting slant in superimposed or adjacent zero-disparity stimuli. Vertical-size disparity produced opposite slant (induced effect) which was reduced to near zero by a superimposed zero-disparity pattern and both patterns appeared as one surface. Adjacent vertical-size-disparity and zero-disparity patterns appeared as separate surfaces with a wide curved boundary. Overall-size disparity produced slant which was enhanced by a superimposed zero-disparity pattern and less so by a zero-disparity line, and induced more slant in a zero-disparity line than in a zero-disparity pattern. The results are discussed in terms of depth underestimation of isolated surfaces, depth enhancement, depth contrast, and the processing of deformation disparity.
38
Tang, Hua, Zhenjun Wu, Ailan Che, Conghua Yuan, and Qin Deng. "Failure Mechanism of Rock Slopes under Different Seismic Excitation." Advances in Materials Science and Engineering 2021 (February 20, 2021): 1–16. http://dx.doi.org/10.1155/2021/8866119.
Full textAbstract:
In earthquake-prone areas, special attention should be paid to the study of the seismic stability of rock slope. Particularly, it becomes much more complicated for the rock slopes with weak structural surfaces. In this study, numerical simulation and the shaking table test are carried out to analyze the influence of seismic excitation and structural surface in different directions on dynamic response of rock slope. Huaping slope with bedding structural surfaces and Lijiang slope with discontinuous structural surfaces besides Jinsha River in Yunnan Province are taken as research objects. The results of numerical simulation and the model test both show that discontinuous structure surface has influence on the propagation characteristics of seismic wavefield. For Huaping slope, the seismic wavefield responses repeatedly between the bedding structural surface and slope surface lead to the increase of the amplification effect. The maximum value of seismic acceleration appears on the empty surface where terrain changes. Horizontal motion plays a leading role in slope failure, and the amplification coefficient of horizontal seismic acceleration is about twice that of vertical seismic acceleration. The failure mode is integral sliding along the bedding structural surface. For Lijiang slope, seismic acceleration field affected by complex structural surface is superimposed repeatedly in local area. The maximum value of seismic acceleration appears in the local area near slope surface. And the dynamic response of slope is controlled by vertical and horizontal motion together. Under the seismic excitation with an intense of 0.336 g in X direction and Z direction, the amplification coefficients of seismic acceleration of Lijiang slope are 3.23 and 3.18, respectively. The vertical motion leads to the cracking of the weak structural surface. Then, Lijiang slope shows the toppling failure mode under the action of horizontal motion.
39
Park, Young-San, and Kyaw Tha Paw U. "Numerical Estimations of Horizontal Advection inside Canopies." Journal of Applied Meteorology 43, no. 10 (October 1, 2004): 1530–38. http://dx.doi.org/10.1175/jam2152.1.
Full textAbstract:
Abstract Local advection of scalar quantities such as heat, moisture, or carbon dioxide occurs not only above inhomogeneous surfaces but also within roughness elements on these surfaces. A two-dimensional advection–diffusion equation is applied to examine the fractionation of scalar exchange into horizontal advection within a canopy and vertical turbulent eddy transport at the canopy top. Simulations were executed with combinations of various wind speeds, eddy diffusivities, canopy heights, and source strengths. The results show that the vertical turbulent fluxes at the canopy top increase along the fetch and approach a limit at some downstream distance. The horizontal advection in the canopy is maximum at the edge of canopy and decreases exponentially along the fetch. All cases have the same features, except the absolute quantities depend on the environmental conditions. When the horizontal axis is normalized by using the dimensionless variable xK/uh2, horizontal diffusion is negligible, and the upwind concentration profile is constant, the curves of horizontal advection and vertical flux collapse into single, unique lines, respectively (x is the horizontal distance from the canopy edge, K is the eddy diffusivity, u is the wind speed, and h is the canopy height). The ratios of horizontal advection to the vertical turbulent flux also collapse into one universal curve when plotted against the dimensionless variable xK/uh2, irrespective of source strength. The ratio R shows a power-law relation to the dimensionless distance [R = a(xK/uh2)−b, where a and b are constant].
40
Jeffary, A. V., O. H. Ahmed, R. K. J. Heng, and L. N. L. K. Choo. "Horizontal and vertical emissions of methane from peat soils." Journal of the Bangladesh Agricultural University 17, no. 3 (September 30, 2019): 359–62. http://dx.doi.org/10.3329/jbau.v17i3.43212.
Full textAbstract:
Methane emission depends on the rates of methane production, consumption and ability of soil and plants to transport the gas to the soil surface and also within soil particles. The objective of this study was to determine CH4 fluxes horizontally and vertically from the floor and wall of the pit of a tropical peat soil. The horizontal emissions in the dry and wet seasons were 2.96 t CH4 ha-1yr-1 and 4.27 t CH4 ha-1yr-1, respectively and the vertical emissions were 0.36 t CH4 ha-1yr-1 and 0.51 t CH4 ha-1yr-1, respectively. The total amount of the horizontal and vertical emissions in the dry and wet seasons were 3.32 t CH4 ha-1yr-1 and 4.78 t CH4 ha-1yr-1, respectively. Horizontal emission was higher in the wet season due to an increase in the water table which resulted in an increase of CH4 emission. Thus, there is a need for direct CH4 measurement from cultivated peat soils to ensure that CH4 emission is neither underestimated nor overestimated.
J Bangladesh Agril Univ 17(3): 359–362, 2019
41
Pérez-Burgos, Ana, Argimiro de Miguel, and Julia Bilbao. "Daylight illuminance on horizontal and vertical surfaces for clear skies. Case study of shaded surfaces." Solar Energy 84, no. 1 (January 2010): 137–43. http://dx.doi.org/10.1016/j.solener.2009.10.019.
Full text
42
Lu, Zechen, Bao Zhang, Zhenjun Li, and Chunyu Zhao. "A Method of On-Site Describing the Positional Relation between Two Horizontal Parallel Surfaces and Two Vertical Parallel Surfaces." Applied Sciences 10, no. 6 (March 21, 2020): 2152. http://dx.doi.org/10.3390/app10062152.
Full textAbstract:
The position error of two parallel surfaces is generally constrained by parallelism. However, as a range of change, it cannot represent the positional relation between two parallel surfaces. Large-scale equipment such as machine tools are complex and difficult to move. It is also an engineering problem to perform field measurements on it. To this end, a method of describing the positional relation between two horizontal parallel surfaces and two vertical parallel surfaces on-site is proposed in this paper, which is a novel kind of position error, enriching the form of parallel surface position error, and solves the inconvenience problem of large equipment position error measurement. The measurement mechanisms are designed, and the measurement principle is given. Firstly, the combined projection waveform of the measured surface can be obtained by the geometric relationship between the measurement mechanism and the measured surface. Secondly, an algorithm is studied to process the obtained waveform, and the combined projection curve of the measured surface is acquired. Then, under the condition of considering the shape contours of the two surfaces, an algorithm is developed to acquire the calculated shape contour of the measured surface. According to the difference between the calculated surface shape contour and the known shape contour of the measured surface, the positional relation of the two surfaces can be determined. Meanwhile, the mathematical models of algorithms are established, and the measurement experiments are carried out, and the algorithms are verified by the mutual measurement method of the two surfaces. The results show that this method can accurately obtain the positional relation of two horizontal parallel surfaces and two vertical parallel surfaces.
43
Chen, Tao, Amrita Pal, Jie Gao, Yun Han, Hui Chen, Svetlana Sukhishvili, Henry Du, and Simon G. Podkolzin. "Identification of Vertical and Horizontal Configurations for BPE Adsorption on Silver Surfaces." Journal of Physical Chemistry C 119, no. 43 (October 14, 2015): 24475–88. http://dx.doi.org/10.1021/acs.jpcc.5b07831.
Full text
44
Qi, Wenliang, Junhui Li, and Patricia B. Weisensee. "Evaporation of Sessile Water Droplets on Horizontal and Vertical Biphobic Patterned Surfaces." Langmuir 35, no. 52 (December 6, 2019): 17185–92. http://dx.doi.org/10.1021/acs.langmuir.9b02853.
Full text
45
YUKAWA, Harutoshi, Ryo AZUMA, Syozo KAWAMURA, Hirofumi MINAMOTO, and Kazutoshi KOBAYASHI. "212 Comparison between vertical and horizontal shock attenuation properties in sports surfaces." Proceedings of the Symposium on sports and human dynamics 2012 (2012): 236–41. http://dx.doi.org/10.1299/jsmeshd.2012.236.
Full text
46
Li, HongKai, ZhenDong Dai, AiJu Shi, Hao Zhang, and JiuRong Sun. "Angular observation of joints of geckos moving on horizontal and vertical surfaces." Chinese Science Bulletin 54, no. 4 (February 2009): 592–98. http://dx.doi.org/10.1007/s11434-009-0077-7.
Full text
47
Lambotte, S., L. Rivera, and J. Hinderer. "Vertical and horizontal seismometric observations of tides." Journal of Geodynamics 41, no. 1-3 (January 2006): 39–58. http://dx.doi.org/10.1016/j.jog.2005.08.021.
Full text
48
Yoshimoto, S., H. Sekine, and M. Miyatake. "A non-contact chuck using ultrasonic vibration: Analysis of the primary cause of the holding force acting on a floating object." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 224, no. 2 (February 1, 2010): 305–13. http://dx.doi.org/10.1243/09544062jmes1557.
Full textAbstract:
It is experimentally known that when a flat surface vibrates vertically at ultrasonic frequencies, both vertical and horizontal forces act on an object placed on the vibrating surface, enabling the vibrating surface to support an object vertically and horizontally without any contact. However, the cause of the horizontal force (called ‘the holding force’ in this article) has not been clarified yet. This article investigates experimentally and numerically the cause of the holding force generated by a vibrating surface. In numerical calculations, computational fluid dynamics was used to obtain the pressure distribution of air surrounding the floating object and the vibrating surface. It was consequently found that the holding force acting on the floating object is due to a negative average pressure generated at the edge of the object floating on the vibrating flat surface.
49
Sujatha, K. S., and M. F. Webster. "Modeling Free-Surface Flow in Part-Filled Rotating Vessels: Vertical and Horizontal Orientations." Journal of Fluids Engineering 125, no. 6 (November 1, 2003): 1022–32. http://dx.doi.org/10.1115/1.1625685.
Full textAbstract:
This paper reports on the numerical simulation of rotating flows with free surfaces, typically that arise in dough-kneading situations found within the food processing industry. Free-surface flow in a rotating cylinder is investigated when a fluid is stirred in a cylindrical-shaped vessel with a stirrer attached to its lid. The problem is posed in a three-dimensional cylindrical polar frame of reference. Numerical predictions are based on a Taylor-Galerkin/pressure-correction finite element formulation, with particle tracking to accommodate free-surface movement. Peeling and wetting conditions are incorporated to predict fluid-surface movement in contact with solid boundaries. Free-surface profiles are presented for different speeds of rotation and predictions compare closely to equivalent experimental results. The algorithmic implementation is validated against Newtonian analytical solutions. Typical results are presented to demonstrate the difference between Newtonian and inelastic model fluids.
50
Banks, M. S., and B. T. Backus. "Conflicts with Extraretinal and Monocular Cues Cause the Small Range of the Induced Effect." Perception 26, no. 1_suppl (August 1997): 79. http://dx.doi.org/10.1068/v970170.
Full textAbstract:
A vertical magnifier before one eye causes the induced effect: an apparent rotation of frontal surfaces toward that eye. The rotation required to restore apparent frontoparallelism grows linearly up to ∼4% magnification, but plateaus at 8%. We examined the cause of the plateau. Horizontal disparities (quantified by horizontal size ratios, HSRs) are ambiguous indicators of surface slant. Various retinal and nonretinal signals can allow veridical slant estimation from HSR, sensed eye position, vertical disparities (vertical size ratios, VSRs), and monocular cues. Vertical or horizontal magnification of one eye's image alters the natural relationships among HSR, VSR, eye position, and monocular cues. We argue that the induced-effect plateau is caused by conflicts between these means of estimating slant. A plateau is not observed in the geometric effect because some of the conflicts do not occur with horizontal magnification. Two experiments were designed to test this hypothesis. When strong monocular cues were present, plateaux occurred at ∼8% magnification in the induced, but not the geometric effect. When monocular slant cues were made useless, induced-effect plateaux were abolished. Even with strong monocular cues present, plateaux in the induced effect were eliminated when eye position was consistent with the vertical magnification in the retinal images. The smaller range of the induced effect can only be understood from consideration of all the signals involved in slant estimation.