Science.gov

Sample records for steeps inclines lokomotivfoerderung

  1. An episode of steep geomagnetic inclination 120,000 years ago.

    PubMed

    Verosub, K L

    1983-07-22

    The mean inclinations of three sections of 120,000-year-old fine-grained sediments from northern California range from 62 degrees to 66 degrees . These inclinations are significantly steeper than the inclination of the geocentric axial dipole at this site. Because these sediments have probably recorded an actual episode of steep inclination lasting several thousand years, they provide new insights into the significance of mean inclinations shallower than the geocentric axial dipole. Such inclinations are characteristic of fine-grained sediments younger than 35,000 years. The results raise questions about the time-averaged geomagnetic field and about the determination of plate motions from paleomagnetic data. PMID:17798888

  2. Avian orientation at steep angles of inclination: experiments with migratory white-crowned sparrows at the magnetic North Pole.

    PubMed

    Akesson, S; Morin, J; Muheim, R; Ottosson, U

    2001-09-22

    The Earth's magnetic field and celestial cues provide animals with compass information during migration. Inherited magnetic compass courses are selected based on the angle of inclination, making it difficult to orient in the near vertical fields found at high geomagnetic latitudes. Orientation cage experiments were performed at different sites in high Arctic Canada with adult and young white-crowned sparrows (Zonotrichia leucophrys gambelii) in order to investigate birds' ability to use the Earth's magnetic field and celestial cues for orientation in naturally very steep magnetic fields at and close to the magnetic North Pole. Experiments were performed during the natural period of migration at night in the local geomagnetic field under natural clear skies and under simulated total overcast conditions. The experimental birds failed to select a meaningful magnetic compass course under overcast conditions at the magnetic North Pole, but could do so in geomagnetic fields deviating less than 3 degrees from the vertical. Migratory orientation was successful at all sites when celestial cues were available. PMID:11564346

  3. STEEP32 computer code

    NASA Technical Reports Server (NTRS)

    Goerke, W. S.

    1972-01-01

    A manual is presented as an aid in using the STEEP32 code. The code is the EXEC 8 version of the STEEP code (STEEP is an acronym for shock two-dimensional Eulerian elastic plastic). The major steps in a STEEP32 run are illustrated in a sample problem. There is a detailed discussion of the internal organization of the code, including a description of each subroutine.

  4. The Steep Nekhoroshev's Theorem

    NASA Astrophysics Data System (ADS)

    Guzzo, M.; Chierchia, L.; Benettin, G.

    2016-03-01

    Revising Nekhoroshev's geometry of resonances, we provide a fully constructive and quantitative proof of Nekhoroshev's theorem for steep Hamiltonian systems proving, in particular, that the exponential stability exponent can be taken to be {1/(2nα_1\\cdotsα_{n-2}}) ({α_i}'s being Nekhoroshev's steepness indices and {n ≥ 3} the number of degrees of freedom). On the base of a heuristic argument, we conjecture that the new stability exponent is optimal.

  5. Robot Would Climb Steep Terrain

    NASA Technical Reports Server (NTRS)

    Kennedy, Brett; Ganino, Anthony; Aghazarian, Hrand; Hogg, Robert; McHerny, Michael; Garrett, Michael

    2007-01-01

    This brief describes the steep terrain access robot (STAR) -- a walking robot that has been proposed for exploring steep terrain on remote planets. The STAR would be able to climb up or down on slopes as steep as vertical, and even beyond vertical to overhangs. Its system of walking mechanisms and controls would be to react forces and maintain stability. To enable the STAR to anchor itself in the terrain on steep slopes to maintain stability and react forces, it would be necessary to equip the tips of the walking legs with new ultrasonic/ sonic drill corers (USDCs) and to develop sensors and control algorithms to enable robust utilization of the USDCs.

  6. 2. VIEW SOUTH, INCLINE PLANE CAR, INCLINE PLANE TRACK, UPPER ...

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

    2. VIEW SOUTH, INCLINE PLANE CAR, INCLINE PLANE TRACK, UPPER STATION. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  7. Weatherford Inclined Wellbore Construction

    SciTech Connect

    Schulte, R.

    2002-08-19

    The Rocky Mountain Oilfield Testing Center (RMOTC) has recently completed construction of an inclined wellbore with seven (7) inch, twenty-three (23) pound casing at a total depth of 1296 feet. The inclined wellbore is near vertical to 180 feet with a build angle of approximately 4.5 degrees per hundred feet thereafter. The inclined wellbore was utilized for further proprietary testing after construction and validation. The wellbore is available to other companies requiring a cased hole environment with known deviation out to fifty degrees (50) from vertical. The wellbore may also be used by RMOTC for further deepening into the fractured shales of the Steele and Niobrara formation.

  8. 3. INCLINE PLANE CAR INTERIOR, UPPER COMPARTMENT. Monongahela Incline ...

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

    3. INCLINE PLANE CAR INTERIOR, UPPER COMPARTMENT. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  9. Photoelectric inclination sensor

    NASA Astrophysics Data System (ADS)

    Kato, Hisao; Kojima, Masahiko; Hayashi, Morihiko; Sasaki, Shunji

    1986-06-01

    A new photoelectric inclination sensor consisting of a light emitting diode (LED) spirit level mounted on a photodiode array is introduced. Light from the LED projects a bubble in the level and throws a shadow onto the surface of the array composed of four equivalent square-shaped diodes, isolated from each other by a cross on a wafer. When the transducer is kept horizontal, the area of the shadow in each diode is exactly equivalent. By taking the difference output positioned obliquely in the array, the water level in the two-dimensional plane is detected. This transducer detects the two-dimensional water level accurately, can be compact, and the response is fast.

  10. Motion of an inclined cylinder on an inclined plane

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2015-09-01

    We consider in this paper the motion of an inclined cylinder on an inclined plane. At low inclined plane angles, the cylinder rolls without slipping across the incline, in a direction perpendicular to its long axis. At steeper angles, long cylinders follow a straight line path in a direction that veers away from the low angle path. Short cylinders follow a curved path. These effects are described in terms of a transition from rolling to sliding as the incline angle is increased. The results help to explain why a vehicle normally turns in the direction that the wheels are pointing and why a vehicle can veer away from that direction on a slippery surface.

  11. PERCENT OF CROPLAND ON STEEP SLOPES

    EPA Science Inventory

    Clearing land for agriculture tends to increase soil erosion. The amount of erosion is related to the steepness of the slope, farming methods used and soil type. High amounts of cropland on steep slopes can increase the amount of soil erosion leading to increased sediment in sur...

  12. PERCENT AGRICULTURAL LAND COVER ON STEEP SLOPES

    EPA Science Inventory

    Clearing land for agriculture tends to increase soil erosion. The amount of erosion is related to the steepness of the slope, farming methods used and soil type. High amounts of agriculture on steep slopes can increase the amount of soil erosion leading to increased sediment in ...

  13. How steep are the Alps?

    NASA Astrophysics Data System (ADS)

    Robl, Jörg; Prasicek, Günther; Stüwe, Kurt; Hergarten, Stefan

    2014-05-01

    The topography of the European Alps reflects continental collision, crustal thickening and buoyancy driven surface uplift, overprinted by erosional processes. Topographic gradients generally steepen from the valley floors up to about 1500 m - 2000 m followed by an unexpected decrease in slope up to about 2900 m and a further increase to the highest summits of the range. Several studies have interpreted this pattern and the accompanied maximum in the hypsometric curve in terms of either the critical slope stability angle, the prematurity of the Alps caused by recent tectonic uplift, or the effect of the glacial "buzz saw" related to the Pleistocene glaciation cycles. There is consensus that the lithological inventory represents a first order parameter for the steepness of fluvial channels and the angle of hillslopes in steady state and that the response time of a transient landscape is controlled by lithology. In this study we systematically explore the slope-elevation distributions for several hundred continuous domains of the major structural units of the Alps. For this, we apply a novel numerical code to determine the predominant cause for the observed peculiar topography. We compare adjacent alpine domains with contrasting lithology to explore lithological effects on the limiting slope stability angle. We analyze domains with different lithology in the non-glaciated parts of the orogen to highlight the state of maturity related to a recent uplift event. We evaluate the glacial effects on the landscape by the comparison of areas belonging to the same structural units but affected by a variable amount of glacial imprint. The results show that lithology has a major impact on the morphometric characteristics of the European Alps. Adjacent but different structural units show a significant variability in their slope-elevation distributions although they have experienced the same uplift history and the same amount of glacial imprint. This suggests that the response

  14. Resonance capture at arbitrary inclination

    NASA Astrophysics Data System (ADS)

    Namouni, F.; Morais, M. H. M.

    2015-01-01

    Resonance capture is studied numerically in the three-body problem for arbitrary inclinations. Massless particles are set to drift from outside the 1:5 resonance with a Jupiter-mass planet thereby encountering the web of the planet's diverse mean motion resonances. Randomly constructed samples explore parameter space for inclinations from 0 to 180° with 5° increments totalling nearly 6 × 105 numerical simulations. 30 resonances internal and external to the planet's location are monitored. We find that retrograde resonances are unexpectedly more efficient at capture than prograde resonances and that resonance order is not necessarily a good indicator of capture efficiency at arbitrary inclination. Capture probability drops significantly at moderate sample eccentricity for initial inclinations in the range [10°,110°]. Orbit inversion is possible for initially circular orbits with inclinations in the range [60°,130°]. Capture in the 1:1 co-orbital resonance occurs with great likelihood at large retrograde inclinations. The planet's orbital eccentricity, if larger than 0.1, reduces the capture probabilities through the action of the eccentric Kozai-Lidov mechanism. A capture asymmetry appears between inner and outer resonances as prograde orbits are preferentially trapped in inner resonances. The relative capture efficiency of retrograde resonance suggests that the dynamical lifetimes of Damocloids and Centaurs on retrograde orbits must be significantly larger than those on prograde orbits implying that the recently identified asteroids in retrograde resonance, 2006 BZ8, 2008 SO218, 2009 QY6 and 1999 LE31 may be among the oldest small bodies that wander between the outer giant planets.

  15. The Divergence of Wear Propagation and Stress at Steep Acetabular Cup Positions Using Ceramic Heads and Sequentially Cross-Linked Polyethylene Liners.

    PubMed

    Zietz, Carmen; Fabry, Christian; Baum, Felix; Bader, Rainer; Kluess, Daniel

    2015-08-01

    The aim of the present wear simulator study was to assess the effect of steep acetabular cup positions on the wear propagation of highly cross-linked-PE (HX-PE) liners. Furthermore, a finite element analysis (FEA) was performed in order to calculate the stress within the HX-PE material in case of steep cup positions under physiological loadings. The higher stress in the HX-PE at a steep acetabular cup position did not result in increased wear in the present wear simulator study. The gravimetrical wear rates at normal (45°) and steep cup inclinations (75°) showed wear amounts of 3.15±0.27mg and 2.18±0.31mg per million cycles (p=0.028), respectively. However, FEA revealed clear increase in stress at the HX-PE liners with respect to steep cup positions. PMID:25770865

  16. Parameterization of the sediment transport in steep channels with boulders

    NASA Astrophysics Data System (ADS)

    Ghilardi, Tamara; Franca, Mário J.; Schleiss, Anton

    2015-04-01

    The presence of large relatively immobile boulders in steep mountain rivers is generally not taken into account in the development of equations to predict the bedload, leading to overestimates of the bedload rate by several times when applied to mountain rivers. Sediment transport in steep channels with boulders is herein investigated using 41 laboratory experiments carried out on a steep (longitudinal inclination of 6.7 to 13%), 8 m long (7 m usable) and 0.25 m wide, tilting flume. The experiments were made for varying flume slopes and boulder configurations (combination of boulder dimensionless distance and diameter), and for several sediment supply conditions. 35 experiments are made with boulders and six experiments without boulders. Boulders are herein defined as elements that although not transported by the flow, may move several times their diameter during experiments, mainly due to the scour holes formed around them. Water and poorly sorted sediments are constantly supplied at the flume inlet. Bedload at the channel downstream section, bulk flow velocities and morphological parameters are measured regularly during the experiments. The poorly sorted sediments (d50=9.3 mm, d65=11.9 mm, d30=7.1 mm, d84=16.6 mm, and d90=19.0 mm) are constantly fed into the system by a calibrated sediment feeder situated upstream, and recirculated during the experiments. The experiments show that the sediment transport capacity clearly decreases with the dimensionless boulder distance and is better estimated in terms of critical discharge for incipient motion of mobile sediments than in terms of critical bed shear stress. The channel longitudinal slope shows the strongest impact on the transport capacity, namely in what concerns the critical discharge for beginning of motion. In addition, it is also shown that the sediment transport decreases with boulder density. A sediment transport formula based on excess discharge relative to a critical value, which depends not only on the

  17. An exact solution for ideal dam-break floods on steep slopes

    USGS Publications Warehouse

    Ancey, C.; Iverson, R.M.; Rentschler, M.; Denlinger, R.P.

    2008-01-01

    The shallow-water equations are used to model the flow resulting from the sudden release of a finite volume of frictionless, incompressible fluid down a uniform slope of arbitrary inclination. The hodograph transformation and Riemann's method make it possible to transform the governing equations into a linear system and then deduce an exact analytical solution expressed in terms of readily evaluated integrals. Although the solution treats an idealized case never strictly realized in nature, it is uniquely well-suited for testing the robustness and accuracy of numerical models used to model shallow-water flows on steep slopes. Copyright 2008 by the American Geophysical Union.

  18. INCLINATION MIXING IN THE CLASSICAL KUIPER BELT

    SciTech Connect

    Volk, Kathryn; Malhotra, Renu

    2011-07-20

    We investigate the long-term evolution of the inclinations of the known classical and resonant Kuiper Belt objects (KBOs). This is partially motivated by the observed bimodal inclination distribution and by the putative physical differences between the low- and high-inclination populations. We find that some classical KBOs undergo large changes in inclination over gigayear timescales, which means that a current member of the low-inclination population may have been in the high-inclination population in the past, and vice versa. The dynamical mechanisms responsible for the time variability of inclinations are predominantly distant encounters with Neptune and chaotic diffusion near the boundaries of mean motion resonances. We reassess the correlations between inclination and physical properties including inclination time variability. We find that the size-inclination and color-inclination correlations are less statistically significant than previously reported (mostly due to the increased size of the data set since previous works with some contribution from inclination variability). The time variability of inclinations does not change the previous finding that binary classical KBOs have lower inclinations than non-binary objects. Our study of resonant objects in the classical Kuiper Belt region includes objects in the 3:2, 7:4, 2:1, and eight higher-order mean motion resonances. We find that these objects (some of which were previously classified as non-resonant) undergo larger changes in inclination compared to the non-resonant population, indicating that their current inclinations are not generally representative of their original inclinations. They are also less stable on gigayear timescales.

  19. 46 CFR 28.535 - Inclining test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Inclining test. 28.535 Section 28.535 Shipping COAST... VESSELS Stability § 28.535 Inclining test. (a) Except as provided in paragraphs (b) and (c) of this... order to do the calculations required in this subpart must have an inclining test performed. (b)...

  20. Bedload transport calculations for steep streams

    NASA Astrophysics Data System (ADS)

    Rickenmann, D.; Turowski, J. M.; Nitsche, M.; Badoux, A.; Raymond, M.

    2011-12-01

    Due to large flow resistance, bedload transport calculations for steep streams often result in a clear overestimation of observed bedload. This contribution discusses the importance of introducing a proper partitioning of flow resistance for bedload transport calculations for steep streams. Several approaches to account for additional flow resistance were tested. They were used with the same reference bedload transport equation, and the predictions were then compared with bedload observations for a number of mountain streams. To this end, we measured the streambed parameters required for these calculations for flood events in 7 mountain rivers and torrents and for long-term discharge and bedload data of 6 torrents. The streams have channel slopes from 2 to 19 %, catchment areas from 0.5 to 170 km2, and are all located in the Swiss Alps. Some approaches give better predictions for rougher streams and for the extreme flood events than for less rough streams and for the long-term data from the torrents (Nitsche et al., 2011). An example for this prediction pattern is the approach of Yager et al. (2007) which is the one mostly based on physical principles for flow resistance calculations. This approach requires additional field measurements regarding the key roughness parameters. On the other hand considering all the bedload data, the empirical approach of Rickenmann and Recking (2011) appears to give the best overall predictions. This approach has the advantage to be easy to apply. Further bedload transport calculations were made for steep streams upstream of water intakes in the Swiss Alps where information is available on both discharge and annual sediment yield. If no correction for high flow resistance is made, calculated bedload transport rates with many equations tend to result in elevated bedload concentrations which are expected for debris flood or debris flow conditions. Some observations from the widespread flood events of August 2005 in Switzerland

  1. Dipping longwalls in semi-steep seams

    SciTech Connect

    Dietrich, J.; Delcruzel, J.

    1982-07-01

    Use of high productivity equipment designed for level seams gives encouraging results in the semi-steep seams of the Lorraine Basin. In the Lorraine coal basin, this type of coal seam has been mined by ascending horizontal slices with back filling, using two basic methods: (1) multiple front faces in a stepped pattern using drilling, blasting, and timber support. (2) longwall mining to the rise, which is usable in favorable conditions of seam width and ground stability. This method gives face productivities up to 15 metric tons per manshift. The technical progress that has been made in recent years in the area of support, coal cutting, and coal clearance has allowed the mechanization of steep and semi-steep seams. A new method was started in 1981 at the Simon colliery. A caving longwall mining method is used. The dip of the seam averages 33/sup 0/. A two-entry retreat system was selected. The first longwalls were worked at heights of 3 to 3.5 meters (10 to 11 feet). Most of the equipment is similar to that used for mining flat seams. High performance four-leg, self-advancing chock supports are used. In order to meet certain requirements imposed by the dip, the supports have the following particular features: (1) The shields are positioned close to each other to increase support. Also, to reduce caving dangers, side flaps are mounted on the canopy, the rear shield, and the base. (2) The shields are advanced in a staggered fashion to maintain proper roof support after shearing. (3)Telescopic front shields can be brought down onto the spill plates of the conveyor to isolate the face line from the travel way. This provides extra protection against falling materials while giving access to the face.

  2. Rough and Steep Terrain Lunar Surface Mobility

    NASA Technical Reports Server (NTRS)

    Wilcox, Brian

    2005-01-01

    In the summer of 2004, the NASA Exploration Systems Mission Directorate conducted an open call for projects relevant to human and robotic exploration of the Earth-Moon and Mars systems. A project entitled 'Rough and Steep Terrain Lunar Surface Mobility' was submitted by JPL and accepted by NASA. The principal investigator of this project describes the robotic vehicle being developed for this effort, which includes six 'wheels-on-legs' so that it can roll efficiently on relatively smooth terrain but walk (using locked wheels as footpads) when "the going gets rough".

  3. Electron heat transport down steep temperature gradients

    SciTech Connect

    Matte, J.P.; Virmont, J.

    1982-12-27

    Electron heat transport is studied by numerically solving the Fokker-Planck equation, with a spherical harmonic representation of the distribution function. The first two terms (f/sub 0/, f/sub 1/) suffice, even in steep temperature gradients. Deviations from the Spitzer-Haerm law appear for lambda/L/sub T/ ((mean free path)/(temperature gradient length))> or approx. =0.01, as a result of non-Maxwellian f/sub 0/. For lambda/L/sub T/> or approx. =1, the heat flux is (1/3) of the free-streaming value. In intermediate cases, a harmonic law describes well the hottest part of the plasma.

  4. Functional and evolutionary correlations of steep leaf angles in the mexical shrubland.

    PubMed

    Valiente-Banuet, Alfonso; Verdú, Miguel; Valladares, Fernando; García-Fayos, Patricio

    2010-05-01

    In the evergreen shrubland vegetation of Mexico (mexical), most of the species are sclerophyllous woody plants with steep leaf angles. This architectural pattern has been interpreted as a strategy to cope with water shortages and high radiation. However, the current association between evergreenness and steep leaf angles across mexical plant species could be the result of an adaptive association achieved through correlated evolutionary change between both traits or, alternatively, may be the result of common evolutionary ancestry. In this study, we quantified leaf angle in 28 dominant species under a phylogenetic framework and evaluated the functional implications of the observed range of leaf angles in terms of leaf temperature, water potentials and transpiration by combining manipulative experiments restraining leaves horizontally with microclimatic and stomatal conductance measurements in selected species and energy balance calculations. Horizontally restrained leaves exhibited reduced water potentials and stomatal conductances, and significantly increased temperatures and transpiration rates. Steeply inclined leaves operated near air temperatures and could sustain relatively high stomatal conductances during the dry season since they were associated with low transpiration rates. Phylogenetic analyses showed that steep leaf angles evolved in a correlated fashion in evergreen species. The functional consequences of leaf angle together with the phylogenetic analysis indicate the adaptive nature of this trait which allows the evergreen species to cope with arid conditions and therefore to persist within the mexical community. PMID:19956973

  5. Cooperative Three-Robot System for Traversing Steep Slopes

    NASA Technical Reports Server (NTRS)

    Stroupe, Ashley; Huntsberger, Terrance; Aghazarian, Hrand; Younse, Paulo; Garrett, Michael

    2009-01-01

    Teamed Robots for Exploration and Science in Steep Areas (TRESSA) is a system of three autonomous mobile robots that cooperate with each other to enable scientific exploration of steep terrain (slope angles up to 90 ). Originally intended for use in exploring steep slopes on Mars that are not accessible to lone wheeled robots (Mars Exploration Rovers), TRESSA and systems like TRESSA could also be used on Earth for performing rescues on steep slopes and for exploring steep slopes that are too remote or too dangerous to be explored by humans. TRESSA is modeled on safe human climbing of steep slopes, two key features of which are teamwork and safety tethers. Two of the autonomous robots, denoted Anchorbots, remain at the top of a slope; the third robot, denoted the Cliffbot, traverses the slope. The Cliffbot drives over the cliff edge supported by tethers, which are payed out from the Anchorbots (see figure). The Anchorbots autonomously control the tension in the tethers to counter the gravitational force on the Cliffbot. The tethers are payed out and reeled in as needed, keeping the body of the Cliffbot oriented approximately parallel to the local terrain surface and preventing wheel slip by controlling the speed of descent or ascent, thereby enabling the Cliffbot to drive freely up, down, or across the slope. Due to the interactive nature of the three-robot system, the robots must be very tightly coupled. To provide for this tight coupling, the TRESSA software architecture is built on a combination of (1) the multi-robot layered behavior-coordination architecture reported in "An Architecture for Controlling Multiple Robots" (NPO-30345), NASA Tech Briefs, Vol. 28, No. 10 (October 2004), page 65, and (2) the real-time control architecture reported in "Robot Electronics Architecture" (NPO-41784), NASA Tech Briefs, Vol. 32, No. 1 (January 2008), page 28. The combination architecture makes it possible to keep the three robots synchronized and coordinated, to use data

  6. A comparison of coronal and interplanetary current sheet inclinations

    NASA Technical Reports Server (NTRS)

    Behannon, K. W.; Burlaga, L. F.; Hundhausen, A. J.

    1983-01-01

    The HAO white light K-coronameter observations show that the inclination of the heliospheric current sheet at the base of the corona can be both large (nearly vertical with respect to the solar equator) or small during Cararington rotations 1660 - 1666 and even on a single solar rotation. Voyager 1 and 2 magnetic field observations of crossing of the heliospheric current sheet at distances from the Sun of 1.4 and 2.8 AU. Two cases are considered, one in which the corresponding coronameter data indicate a nearly vertical (north-south) current sheet and another in which a nearly horizontal, near equatorial current sheet is indicated. For the crossings of the vertical current sheet, a variance analysis based on hour averages of the magnetic field data gave a minimum variance direction consistent with a steep inclination. The horizontal current sheet was observed by Voyager as a region of mixed polarity and low speeds lasting several days, consistent with multiple crossings of a horizontal but irregular and fluctuating current sheet at 1.4 AU. However, variance analysis of individual current sheet crossings in this interval using 1.92 see averages did not give minimum variance directions consistent with a horizontal current sheet.

  7. Mechanics and energetics of incline walking with robotic ankle exoskeletons.

    PubMed

    Sawicki, Gregory S; Ferris, Daniel P

    2009-01-01

    We examined healthy human subjects wearing robotic ankle exoskeletons to study the metabolic cost of ankle muscle-tendon work during uphill walking. The exoskeletons were powered by artificial pneumatic muscles and controlled by the user's soleus electromyography. We hypothesized that as the demand for net positive external mechanical work increased with surface gradient, the positive work delivered by ankle exoskeletons would produce greater reductions in users' metabolic cost. Nine human subjects walked at 1.25 m s(-1) on gradients of 0%, 5%, 10% and 15%. We compared rates of O(2) consumption and CO(2) production, exoskeleton mechanics, joint kinematics, and surface electromyography between unpowered and powered exoskeleton conditions. On steeper inclines, ankle exoskeletons delivered more average positive mechanical power (P<0.0001; +0.37+/-0.03 W kg(-1) at 15% grade and +0.23+/-0.02 W kg(-1) at 0% grade) and reduced subjects' net metabolic power by more (P<0.0001; -0.98+/-0.12 W kg(-1) at 15% grade and -0.45+/-0.07 W kg(-1) at 0% grade). Soleus muscle activity was reduced by 16-25% when wearing powered exoskeletons on all surface gradients (P<0.0008). The ;apparent efficiency' of ankle muscle-tendon mechanical work decreased from 0.53 on level ground to 0.38 on 15% grade. This suggests a decreased contribution from previously stored Achilles' tendon elastic energy and an increased contribution from actively shortening ankle plantar flexor muscle fibers to ankle muscle-tendon positive work during walking on steep uphill inclines. Although exoskeletons delivered 61% more mechanical work at the ankle up a 15% grade compared with level walking, relative reductions in net metabolic power were similar across surface gradients (10-13%). These results suggest a shift in the relative distribution of mechanical power output to more proximal (knee and hip) joints during inclined walking. PMID:19088208

  8. Vortex dynamics in jets from inclined nozzles

    NASA Astrophysics Data System (ADS)

    Webster, D. R.; Longmire, E. K.

    1997-03-01

    Experimental tests were performed on round jets exiting inclined nozzles at a Reynolds number of 9000. Both natural jets and jets forced with single frequencies corresponding to StD=0.25, 0.5, 0.75, and 1.0 were examined. In the natural case, the nozzle incline caused a mild increase in the radial spreading in the plane of azimuthal symmetry. The forcing amplified the asymmetric radial spreading by altering the vortex structure. In general, the inclined vortex rings rolled up at an angle slightly smaller than the nozzle incline angle. As the rings moved downstream, they migrated away from the jet centerline and their incline angle increased. Vortex rings generated at StD=0.5 did not pair because that Strouhal number was near the "preferred" mode. For nozzles with slight inclines, forcing at larger Strouhal numbers led to pairing near x/D=2 in order to achieve the "preferred" mode. For nozzles with larger inclines, the vortex cores broke down before pairing could occur. Forcing at a lower Strouhal number (StD=0.25) yielded ring formation at StD=0.5 and subsequent pairing. Increasing the incline angle moved the pairing location closer to the nozzle lip. Also, the pairing process was found to depend on the nozzle incline angle.

  9. On inclination resonances in Artificial Satellite Theory

    NASA Astrophysics Data System (ADS)

    Lara, Martin

    2015-05-01

    The frozen-perigee behavior of elliptic orbits at the critical inclination is usually displayed after an averaging procedure. However, this singularity in Artificial Satellite Theory manifests also in the presence of short-period effects. Indeed, a closed form expression relating orbital inclination and the ratio anomalistic draconitic frequencies is derived for the main problem, which demonstrates that the critical inclination results from commensurability between the periods with which the radial and polar variables evolve in the instantaneous plane of motion. This relation also shows that the critical inclination value is slightly modified by the degree of oblateness of the attracting body, as well as by the orbit's size and shape.

  10. Robotic chair at steep and narrow stairways

    NASA Astrophysics Data System (ADS)

    Imazato, Masahiro; Yamaguchi, Masahiro; Moromugi, Shunji; Ishimatsu, Takakazu

    2007-12-01

    A robotic chair is developed to support mobility of elderly and disabled people living in the house where steep and narrow stairways are installed. In order to deal with such mobility problem the developed robotic chair has a compact original configuration. The robotic chair vertically moves by actuation of electric cylinders and horizontally moves by push-pull operation given by a care-giver. In order to navigate safely every action of the chair is checked by the operator. Up-and-down motions of the robotic chair on the stairway are executed through combinations of motor and cylinder actuations. Performance of the robotic chair was evaluated through two kinds of experiments. The excellent ability of the robotic chair could be confirmed through these experiments.

  11. Slipping and Rolling on an Inclined Plane

    ERIC Educational Resources Information Center

    Aghamohammadi, Cina; Aghamohammadi, Amir

    2011-01-01

    In the first part of the paper, using a direct calculation two-dimensional motion of a particle sliding on an inclined plane is investigated for general values of friction coefficient ([mu]). A parametric equation for the trajectory of the particle is also obtained. In the second part of the paper, the motion of a sphere on the inclined plane is…

  12. IONIZED OUTFLOWS FROM COMPACT STEEP SPECTRUM SOURCES

    SciTech Connect

    Shih, Hsin-Yi; Stockton, Alan; Kewley, Lisa E-mail: stockton@ifa.hawaii.edu

    2013-08-01

    Massive outflows are known to exist, in the form of extended emission-line regions (EELRs), around about one-third of powerful FR II radio sources. We investigate the origin of these EELRs by studying the emission-line regions around compact-steep-spectrum (CSS) radio galaxies that are younger (10{sup 3}-10{sup 5} yr old) versions of the FR II radio galaxies. We have searched for and analyzed the emission-line regions around 11 CSS sources by taking integral field spectra using Gemini Multi-Object Spectrograph on Gemini North. We fit the [O III] {lambda}5007 line and present the velocity maps for each detected emission-line region. We find, in most cases, that the emission-line regions have multi-component velocity structures with different velocity dispersions and/or flux distributions for each component. The velocity gradients of the emission-line gas are mostly well aligned with the radio axis, suggesting a direct causal link between the outflowing gas and the radio jets. The complex velocity structure may be a result of different driving mechanisms related to the onset of the radio jets. We also present the results from the line-ratio diagnostics we used to analyze the ionization mechanism of the extended gas, which supports the scenario where the emission-line regions are ionized by a combination of active galactic nucleus radiation and shock excitation.

  13. Bedform migration in steep channels: from local avalanches to large scale changes

    NASA Astrophysics Data System (ADS)

    Mettra, F.; Heyman, J.; Ancey, C.

    2013-12-01

    Many studies have emphasized the strength of bedload transport fluctuations in steep streams, especially at low and intermediate transport conditions (relative to the threshold of incipient motion). The origins of these fluctuations, which appear on a wide range of time scales, are still not well understood. In this study, we present the data obtained from a 2D idealized laboratory experiment with the objective of simultaneously recording the channel bed evolution and bedload transport rate at a high temporal resolution. A 3-m long by 8-cm wide transparent flume filled with well-sorted natural gravel (d50=6.5 mm) was used. An efficient technique using accelerometers has been developed to record the arrival time of every particle at the outlet of the flume for long experimental durations (up to a few days). In addition, bed elevation was monitored using cameras filming from the side of the channel, allowing the observation of global aggradation/degradation as well as bedform migration. The experimental parameters were the water discharge, the flume inclination (from 2° to 5°) and the constant feeding rate of sediments. Large-scale bed evolution showed successive aggradation and rapid degradation periods. Indeed, the measured global channel slope, i.e. mean slope over the flume length, fluctuated continuously within a range sometimes wider than 1° (experimental parameters were constant over the entire run). The analysis of these fluctuations provides evidence that steep channels behave like metastable systems, similarly to grain piles. The metastable effects increased for steeper channels and lower transport conditions. In this measurement campaign, we mainly observed upstream-migrating antidunes. For each run, various antidune heights and celerities were measured. On average, the mean antidune migration rate increased with decreasing channel slope and increasing sediment feeding rate. Relatively rare tall and fast-moving antidunes appeared more frequently at high

  14. PERCENT AGRICULTURAL LAND COVER ON STEEP SLOPES (FUTURE)

    EPA Science Inventory

    Clearing land for agriculture tends to increase soil erosion. The amount of erosion is related to the steepness of the slope, farming methods used and soil type. High amounts of agriculture on steep slopes can increase the amount of soil erosion leading to increased sediment in ...

  15. The early history of the lunar inclination. [effect of tidal friction

    NASA Technical Reports Server (NTRS)

    Rubincam, D. P.

    1973-01-01

    The effect of tidal friction on the inclination of the lunar orbit to the earth's equator for earth-moon distances of less than 10 earth radii is examined. The results obtained bear on a conclusion drawn by Gerstenkorn and others which has been raised as a fatal objection to the fission hypothesis of lunar origin, namely, that the present nonzero inclination of the moon's orbit to the ecliptic implies a steep inclination of the moon's orbit to the earth's equatorial plane in the early history of the earth-moon system. This conclusion is shown to be valid only for particular rheological models of the earth. The earth is assumed to behave like a highly viscous fluid in response to tides raised in it by the moon. The moon is assumed to be tideless and in a circular orbit about the earth. The equations of tidal friction are integrated numerically to give inclination of the lunar orbit as a function of earth-moon distance.

  16. Modelling Steep Surfaces by Various Configurations of Nadir and Oblique Photogrammetry

    NASA Astrophysics Data System (ADS)

    Casella, V.; Franzini, M.

    2016-06-01

    Among the parts of the territory requiring periodical and careful monitoring, many have steep surfaces: quarries, river basins, land-slides, dangerous mountainsides. Aerial photogrammetry based on lightweight unmanned aircraft systems (UAS) is rapidly becoming the tool of election to survey limited areas of land with a high level of detail. Aerial photogrammetry is traditionally based on vertical images and only recently the use of significantly inclined imagery has been considered. Oblique photogrammetry presents peculiar aspects and offers improved capabilities for steep surface reconstruction. Full comprehension of oblique photogrammetry still requires research efforts and the evaluation of diverse case studies. In the present paper, the focus is on the photogrammetric UAS-based survey of a part of a large sandpit. Various flight configurations are considered: ordinary linear strips, radial strips (as the scarp considered has a semi-circular shape) and curved ones; moreover, nadir looking and oblique image blocks were acquired. Around 300 control points were measured with a topographic total station. The various datasets considered are evaluated in terms of density of the extracted point cloud and in terms of the distance between the reconstructed surface and a number of check points.

  17. 23. INCLINED END POST / VERTICAL / DIAGONAL / PORTAL ...

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

    23. INCLINED END POST / VERTICAL / DIAGONAL / PORTAL BRACING DETAIL. VIEW TO SOUTHEAST. - Abraham Lincoln Memorial Bridge, Spanning Missouri River on Highway 30 between Nebraska & Iowa, Blair, Washington County, NE

  18. Measurements of turbulent inclined plane dual jets

    NASA Astrophysics Data System (ADS)

    Wang, C. S.; Lin, Y. F.; Sheu, M. J.

    1993-11-01

    Measurements of mean velocities, flow direction, velocity fluctuations and Reynolds shear stress were made with a split film probe of hot wire anemometer to investigate the interactions created by two air jets issuing from two identical plane inclined nozzles. The reverse flow was detected by using the split film probe and observed by flow visualization. Experimental results with an inclined angle of 9° are presented in the paper. Some experimental results with an inclined angle of 27° are presented to investigate the effect of inclination on the flow field. Mean velocities approach self-preservation in both the converging region and the combining region. Velocity fluctuations and Reynolds shear stress approach self-preservation in the combining region only. The spreads of jet and the square of the decay of maximum mean velocity increase linearly as the distance from the nozzle exit increases.

  19. The solid angle through the inclined rectangle

    NASA Astrophysics Data System (ADS)

    Schröer, H.

    We want to determine the solid angle through the inclined rectangle. We use the cosine law for sides and the spherical law of sines. The relation to luminous flux(radiant flux or radiant power) is shown.

  20. Dewetting films with inclined contact lines

    NASA Astrophysics Data System (ADS)

    Gao, Peng; Li, Lei; Lu, Xi-Yun

    2015-02-01

    A partially wetting plate withdrawn from a liquid reservoir causes the deposition of a liquid film that is characterized by inclined contact lines. It has been experimentally indicated that the normal component of the contact-line velocity relative to the plate remains constant and is independent of the inclination angles, a fact that has never theoretically been justified. We demonstrate, in the framework of lubrication theory, that the speed-angle independence is only approximate and the normal velocity actually exhibits a weak decrease with the inclination angle of the contact line. This correlation is attributed to the variation of the effective separation of microscopic and macroscopic length scales. In addition, the inclination of the contact line results in a tangential flux of the liquid, which is confined in the vicinity of the contact line. Simple scaling relations are provided for both the normal velocity and the tangential flux.

  1. Stair ascent and descent at different inclinations.

    PubMed

    Riener, Robert; Rabuffetti, Marco; Frigo, Carlo

    2002-02-01

    The aim of this study was to investigate the biomechanics and motor co-ordination in humans during stair climbing at different inclinations. Ten normal subjects ascended and descended a five-step staircase at three different inclinations (24 degrees, 30 degrees, 42 degrees ). Three steps were instrumented with force sensors and provided 6 dof ground reactions. Kinematics was analysed by a camera-based optoelectronic system. An inverse dynamics approach was applied to compute joint moments and powers. The different kinematic and kinetic patterns of stair ascent and descent were analysed and compared to level walking patterns. Temporal gait cycle parameters and ground reactions were not significantly affected by staircase inclination. Joint angles and moments showed a relatively low but significant dependency on the inclination. A large influence was observed in joint powers. This can be related to the varying amount of potential energy that has to be produced (during ascent) or absorbed (during descent) by the muscles. The kinematics and kinetics of staircase walking differ considerably from level walking. Interestingly, no definite signs could be found indicating that there is an adaptation or shift in the motor patterns when moving from level to stair walking. This can be clearly seen in the foot placement: compared to level walking, the forefoot strikes the ground first--independent from climbing direction and inclination. This and further findings suggest that there is a certain inclination angle or angular range where subjects do switch between a level walking and a stair walking gait pattern. PMID:11809579

  2. Potential changes of wave steepness and occurrence of rogue waves

    NASA Astrophysics Data System (ADS)

    Bitner-Gregersen, Elzbieta M.; Toffoli, Alessandro

    2015-04-01

    Wave steepness is an important characteristic of a sea state. It is also well established that wave steepness is one of the parameter responsible for generation of abnormal waves called also freak or rogue waves. The study investigates changes of wave steepness in the past and future wave climate in the North Atlantic. The fifth assessment report IPCC (2013) uses four scenarios for future greenhouse gas concentrations in the atmosphere called Representative Concentration Pathways (RCP). Two of these scenarios RCP 4.5 and RCP 8.5 have been selected to project future wave conditions in the North Atlantic. RCP 4.5 is believed to achieve the political target of a maximum global mean temperature increase of 2° C while RPC 8.5 is close to 'business as usual' and expected to give a temperature increase of 4° C or more. The analysis includes total sea, wind sea and swell. Potential changes of wave steepness for these wave systems are shown and compared with wave steepness derived from historical data. Three historical data sets with different wave model resolutions are used. The investigations show also changes in the mean wind direction as well as in the relative direction between wind sea and swell. Consequences of wave steepness changes for statistics of surface elevation and generation of rogue waves are demonstrated. Uncertainties associated with wave steepness projections are discussed.

  3. Channel erosion in steep gradient, gravel-paved streams

    SciTech Connect

    Lepp, L.R.; Koger, C.J.; Wheeler, J.A.

    1993-12-01

    Discharges were measured in steep gradient (> 5 percent) gravel-paved streams from 1988 to 1991 in order to empirically determine erosional thresholds based on sediment size, related to critical velocity, tractive force, and unit stream power. Results suggest that the empirical relationship between sediment size and unit stream power provides an accurate and simple methodology for determining the minimum erosion threshold discharge for steep gradient streams common in western Washington and other similar mountain terrains.

  4. Moments of inclination error distribution computer program

    NASA Technical Reports Server (NTRS)

    Myler, T. R.

    1981-01-01

    A FORTRAN coded computer program is described which calculates orbital inclination error statistics using a closed-form solution. This solution uses a data base of trajectory errors from actual flights to predict the orbital inclination error statistics. The Scott flight history data base consists of orbit insertion errors in the trajectory parameters - altitude, velocity, flight path angle, flight azimuth, latitude and longitude. The methods used to generate the error statistics are of general interest since they have other applications. Program theory, user instructions, output definitions, subroutine descriptions and detailed FORTRAN coding information are included.

  5. 46 CFR 28.535 - Inclining test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... section, each vessel for which the lightweight displacement and centers of gravity must be determined in... of the vessel which was inclined and the location of the longitudinal center of gravity differs less... characteristics can be made and the precise location of the position of the vessel's vertical center of gravity...

  6. 46 CFR 28.535 - Inclining test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... section, each vessel for which the lightweight displacement and centers of gravity must be determined in... undocumented weight difference between the two vessels is less than 3 percent of the lightweight displacement... test, or the inclining test may be dispensed with, if an accurate estimate of the vessel's...

  7. The Ballistic Cart on an Incline Revisited.

    ERIC Educational Resources Information Center

    Serway, Raymond A.; And Others

    1995-01-01

    Presents the theory behind the mechanics demonstration that involves projecting a ball vertically upward from a ballistic cart moving along an inclined plane. The measured overshoot is believed to be due, in part, to the presence of rolling friction and the inertial properties of the cart wheels. (JRH)

  8. Particle Sliding on a Rough Incline

    ERIC Educational Resources Information Center

    Zurcher, Ulrich

    2007-01-01

    We study a particle sliding on a rough inclined plane as an example of a mechanical problem with nonholonomic constraint. The particle is launched in an arbitrary direction so that its motion has both a horizontal and a "vertical" (i.e., up- and downhill) direction. The friction force acts along the instantaneous velocity, so that the horizontal…

  9. Penning trap with an inclined magnetic field.

    PubMed

    Yaremko, Yurij; Przybylska, Maria; Maciejewski, Andrzej J

    2016-08-01

    A modified Penning trap with a spatially uniform magnetic field B inclined with respect to the axis of rotational symmetry of the electrodes is considered. The inclination angle can be arbitrary. Canonical transformation of phase variables transforming the Hamiltonian of the considered system into a sum of three uncoupled harmonic oscillators is found. We determine the region of stability in space of two parameters controlling the dynamics: the trapping parameter κ and the squared sine of the inclination angle ϑ0. If the angle ϑ0 is smaller than 54°, a charge occupies a finite spatial volume within the processing chamber. A rigid hierarchy of trapping frequencies is broken if B is inclined at the critical angle: the magnetron frequency reaches the modified cyclotron frequency while the axial frequency exceeds them. Apart from this resonance, we reveal the family of resonant curves in the region of stability. In the relativistic regime, the system is not linear. We show that it is not integrable in the Liouville sense. The averaging over the fast variable allows to reduce the system to two degrees of freedom. An analysis of the Poincaré cross-sections of the averaged systems shows the regions of effective stability of the trap. PMID:27586614

  10. Analysis of inclined growth of silicon sheet

    NASA Technical Reports Server (NTRS)

    Brown, R. A.

    1984-01-01

    A general-purpose finite element program was developed for analysis of silicon sheet growth in inclined configurations. This program will be used to study parametric sensitivity of various growth geometries with respect to thermal control and growth rate, dopant segregation, thermal stress and interface morphology and instability.

  11. Correlation equation for the marine drag coefficient and wave steepness

    NASA Astrophysics Data System (ADS)

    Foreman, Richard J.; Emeis, Stefan

    2012-09-01

    This work questions, starting from dimensional considerations, the generality of the belief that the marine drag coefficient levels off with increasing wind speed. Dimensional analysis shows that the drag coefficient scales with the wave steepness as opposed to a wave-age scaling. A correlation equation is employed here that uses wave steepness scaling at low aspect ratios (inverse wave steepnesses) and a constant drag coefficient at high aspect ratios. Invoked in support of the correlation are measurements sourced from the literature and at the FINO1 platform in the North Sea. The correlation equation is then applied to measurements recorded from buoys during the passage of hurricanes Rita, Katrina (2005) and Ike (2008). Results show that the correlation equation anticipates the expected levelling off in deeper water, but a drag coefficient more consistent with a Charnock type relation is also possible in more shallower water. Some suggestions are made for proceeding with a higher-order analysis than that conducted here.

  12. Effects of inclination and vorticity on interfacial flow dynamics in horizontal and inclined pipes

    NASA Astrophysics Data System (ADS)

    Kiara, Areti; Hendrickson, Kelli; Liu, Yuming

    2015-11-01

    The transport of oil and gas in long horizontal pipelines can be significantly affected by the development of violent roll waves and slugs, but the mechanics causing such transitions have not been well understood. To enable the improvement of the prediction of flow transition criteria in long pipelines we perform theoretical analysis and direct numerical simulations of multiphase pipe flows to quantify the roles of inclination and vorticity in the flow dynamics. We find that backflow or flooding may occur even in the absence of disturbances due to inclination effects and obtain criteria on the maximum pipe length for steady flows. We identify and compare the effects of inclination and vorticity on the stability of interfacial wave disturbances. We discuss the mechanisms of non-linear energy transfer between stable and unstable wave disturbances and present results from direct numerical simulations for the predictions of spectrum evolutions for broad-banded interfacial disturbances in inclined pipes.

  13. 10. LOWER STATION, FIRST FLOOR, INCLINE PLANE TRCK LOOKING SOUTH ...

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

    10. LOWER STATION, FIRST FLOOR, INCLINE PLANE TRCK LOOKING SOUTH SOUTHEAST, UPPER STATION. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  14. 1. VIEW WEST SOUTHWEST, UPPER STATION. INCLINE PLANE TRACK AND ...

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

    1. VIEW WEST SOUTHWEST, UPPER STATION. INCLINE PLANE TRACK AND LOWER STATION. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  15. 8. LOWER STATION, FIRST FLOOR, EAST SIDE ACCESS TO INCLINE ...

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

    8. LOWER STATION, FIRST FLOOR, EAST SIDE ACCESS TO INCLINE PLANE CARS, LOOKING NORTH NORTHEAST. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  16. 4. VIEW SOUTHWEST, LOWER STATION FRONT, INCLINE PLANE TRACK, UPPER ...

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

    4. VIEW SOUTHWEST, LOWER STATION FRONT, INCLINE PLANE TRACK, UPPER STATION. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  17. 19. UPPER STATION, FIRST FLOOR, OPERATOR'S CABIN, DOORS TO INCLINE ...

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

    19. UPPER STATION, FIRST FLOOR, OPERATOR'S CABIN, DOORS TO INCLINE PLANE CARS, LOOKING WEST. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  18. 5. VIEW SOUTHWEST, LOWER STATION FRONT, INCLINE PLANE TRACK, UPPER ...

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

    5. VIEW SOUTHWEST, LOWER STATION FRONT, INCLINE PLANE TRACK, UPPER STATION. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  19. 5. VIEW WEST, PERSPECTIVE UP INCLINED PLANE FROM TOP OF ...

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

    5. VIEW WEST, PERSPECTIVE UP INCLINED PLANE FROM TOP OF ABUTMENT, FILL CONFIGURATION - Laurel Hill Quarry, Incline Plane, Both sides of State Route 56, 2.4 miles East of State Route 711, Seward, Westmoreland County, PA

  20. 6. VIEW WEST, PERSPECTIVE UP INCLINED PLANE FROM MIDSLOPE VICINITY, ...

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

    6. VIEW WEST, PERSPECTIVE UP INCLINED PLANE FROM MID-SLOPE VICINITY, CUT CONFIGURATION - Laurel Hill Quarry, Incline Plane, Both sides of State Route 56, 2.4 miles East of State Route 711, Seward, Westmoreland County, PA

  1. 2. VIEW SOUTH, PERSPECTIVE OF ABUTMENT AND INCLINED PLANE ON ...

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

    2. VIEW SOUTH, PERSPECTIVE OF ABUTMENT AND INCLINED PLANE ON WEST SIDE OF PA ROUTE 56 - Laurel Hill Quarry, Incline Plane, Both sides of State Route 56, 2.4 miles East of State Route 711, Seward, Westmoreland County, PA

  2. 3. VIEW NORTHWEST, PERSPECTIVE OF ABUTMENT AND INCLINED PLANE ON ...

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

    3. VIEW NORTHWEST, PERSPECTIVE OF ABUTMENT AND INCLINED PLANE ON WEST SIDE OF PA ROUTE 56 - Laurel Hill Quarry, Incline Plane, Both sides of State Route 56, 2.4 miles East of State Route 711, Seward, Westmoreland County, PA

  3. A new inclination instability in planetary systems

    NASA Astrophysics Data System (ADS)

    Madigan, Ann-Marie

    2015-08-01

    I describe a new instability in Keplerian disks of massive particles on eccentric orbits. Gravitational torques between the orbits align their angles of pericenter and drive exponential growth in orbital inclination. This instability implies specific ratios for Kepler elements of the orbits, similar to what is seen in the inner Oort Cloud of our solar system. I also discuss implications for extra-solar planetary systems and for nuclear star clusters in the centers of galaxies.

  4. 30 CFR 785.15 - Steep slope mining.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Steep slope mining. 785.15 Section 785.15 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR SURFACE COAL MINING AND RECLAMATION OPERATIONS PERMITS AND COAL EXPLORATION SYSTEMS UNDER REGULATORY...

  5. 30 CFR 785.15 - Steep slope mining.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Steep slope mining. 785.15 Section 785.15 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR SURFACE COAL MINING AND RECLAMATION OPERATIONS PERMITS AND COAL EXPLORATION SYSTEMS UNDER REGULATORY...

  6. 30 CFR 785.15 - Steep slope mining.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Steep slope mining. 785.15 Section 785.15 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR SURFACE COAL MINING AND RECLAMATION OPERATIONS PERMITS AND COAL EXPLORATION SYSTEMS UNDER REGULATORY...

  7. 30 CFR 785.15 - Steep slope mining.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Steep slope mining. 785.15 Section 785.15 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR SURFACE COAL MINING AND RECLAMATION OPERATIONS PERMITS AND COAL EXPLORATION SYSTEMS UNDER REGULATORY...

  8. 30 CFR 785.15 - Steep slope mining.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Steep slope mining. 785.15 Section 785.15 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR SURFACE COAL MINING AND RECLAMATION OPERATIONS PERMITS AND COAL EXPLORATION SYSTEMS UNDER REGULATORY...

  9. Improved numerical modelling of morphodynamics of rivers with steep banks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The flow and sediment transport processes near steep streambanks, which are commonly found in meandering, braided, and anastomosing stream systems, exhibit complex patterns. The interactions between bed and bank morphologic adjustment, and their governing processes are still not well understood. Inc...

  10. 30 CFR 816.107 - Backfilling and grading: Steep slopes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Backfilling and grading: Steep slopes. 816.107 Section 816.107 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS-SURFACE...

  11. 30 CFR 817.107 - Backfilling and grading: Steep slopes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Backfilling and grading: Steep slopes. 817.107 Section 817.107 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS-UNDERGROUND...

  12. 166. Big Laurel Mountain Viaduct. View of the steep slope ...

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

    166. Big Laurel Mountain Viaduct. View of the steep slope upon which the steel pier is built. The construction of this viaduct eliminated either a large scar of fill, helping to preserve the mountainside. Facing north. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  13. Measurement of steep edges and undercuts in confocal microscopy.

    PubMed

    Mueller, T; Jordan, M; Schneider, T; Poesch, A; Reithmeier, E

    2016-05-01

    Confocal microscopy is widely used to measure the surface topography of specimen with a precision in the micrometer range. The measurement uncertainty and quality of the acquired data of confocal microscopy depends on various effects, such as optical aberrations, vibrations of the measurement setup and variations in the surface reflectivity. In this article, the influence of steep edges and undercuts on measurement results is examined. Steep edges on the specimen's surface lead to a reduced detector signal which influences the measurement accuracy and undercuts cause surface regions, which cannot be captured in a measurement. The article describes a method to overcome the negative effects of steep edges and undercuts by capturing several measurements of the surface with different angles between the surface and the optical axis of the objective. An algorithm is introduced which stitches different angle measurements together without knowledge of the exact position and orientation of the rotation axis. Thus, the measurement uncertainty due to steep edges and undercuts can be avoided without expensive high-precision rotation stages and time consuming adjustment of the measurement setup. PMID:27011256

  14. A jumping cylinder on an inclined plane

    NASA Astrophysics Data System (ADS)

    Gómez, R. W.; Hernández-Gómez, J. J.; Marquina, V.

    2012-09-01

    The problem of a cylinder of mass m and radius r, with its centre of mass out of the cylinder’s axis, rolling on an inclined plane that makes an angle α with respect to the horizontal, is analysed. The equation of motion is partially solved to obtain the site where the cylinder loses contact with the inclined plane (jumps). Several simplifications are made: the analysed system consists of an homogeneous disc with a one-dimensional straight line mass parallel to the disc axis at a distance y < r of the centre of the cylinder. To compare our results with experimental data, we use a styrofoam cylinder to which a long brass rod is embedded parallel to the disc axis at a distance y < r from it, so the centre of mass lies at a distance d from the centre of the cylinder. Then the disc rolls without slipping on a long wooden ramp inclined at 15°, 30° and 45° with respect to the horizontal. To determine the jumping site, the movements are recorded with a high-speed video camera (Casio EX ZR100) at 240 and 480 frames per second. The experimental results agree well with the theoretical predictions.

  15. A jumping cylinder in an incline

    NASA Astrophysics Data System (ADS)

    Gomez, Raul W.; Hernandez, Jorge; Marquina, Vivianne

    2012-02-01

    The problem of a cylinder of mass m and radius r, with its center of mass out of the cylinder axis, rolling in an incline that makes an angle α respect to the horizontal is analyzed. The equation of motion is solved to obtain the site where the cylinder loses contact with the incline (jumps). Several simplifications are made: the analyzed system consists of an homogeneous disc with a one dimensional straight line of mass parallel to the disc axis at a distance d < r of the center of the cylinder. To compare our results with experimental data, we use a Styrofoam cylinder of radius r = 10.0 ± 0.05 cm, high h = 5.55 ± 0.05 cm and a mass m1 = 24.45 ± 0.05 g, to which a 9.50 ± 0.01 mm diameter and 5.10 ± 0.001 cm long brass road of mass m2 = 30.75 ± 0.05 g was imbibed parallel to the disc axis at a distance of 5.40 ± 0.05 cm from it. Then the disc rolls on a 3.20 m long wooden ramp inclined at 30 and 45 respect to the horizontal. To determine the jumping site, the movements were recorded with a high-speed video camera (Casio EX ZR100) at 400 frames per second. The experimental results agree well with the theoretical predictions.

  16. HIGH-INCLINATION ATENS ARE INDEED RARE

    SciTech Connect

    Greenstreet, S.; Gladman, B.

    2013-04-10

    A recent publication by the Near-Earth Object (NEOWISE) team (Mainzer et al.) using data from the Wide-field Infrared Survey Explorer compared the spacecraft's detected near-Earth asteroid subpopulation orbital element distributions to those expected from the Bottke et al. NEO orbital model. They found a discrepency between the detected and expected Aten inclination distribution. We show that the more recent NEO orbital distribution model by Greenstreet et al., when biased using the NEOWISE detection biases, gives a better match to the NEOWISE detections for the Aten (a < 1.0 AU, Q > 0.983 AU) population in semimajor axis (a), eccentricity (e), and inclination (i) than the Bottke et al. model. A Kolmogorov-Smirnov test gives the probability of drawing the NEOWISE detections from the biased Bottke et al. model as not rejectable (at >99% confidence) for the Aten semimajor axis distribution, but is rejectable at such a high level of confidence for the Aten eccentricity and inclination distributions. For all three orbital element distributions, the biased Greenstreet et al. model provides an acceptable match to the NEOWISE Aten detections. The deficiency in the previous model is likely due to the numerical integration's accuracy having broken down in the high-speed regime for planetary encounters near the Sun, an effect which the newer model does not suffer, and thus likely is the model of preference for perihelia q < 1.0 AU.

  17. Earth Collision with High Inclination Asteroids

    NASA Astrophysics Data System (ADS)

    Solovaya, N. A.; Pittich, E. M.

    2000-01-01

    The orbital evolution of fictitious high inclination main belt asteroids with movement corresponding to the conditions of the Tisserand invariant for C = C(Ll) in the restricted three body problem has been investigated. The obtained results showed that the bodies with inclinations within 40-80 deg and 100-140 deg and eccentricities within 0-0.4 are dynamically stable at least during the 200,000 years investigated period, and periodically change their inclinations, eccentricities and perihelion distances. In some time, they can reach the vicinity of the Sun and during their orbital evolution they cross the Earth orbits many times. The bodies belong to the potential candidates dangerous for the Earth in that they may bring about catastrophic events on its surface. The discoveries of some tents retrograde sungrazers with LASCO coronographs of the SOHO spacecraft and MMC and SOLWIN space equipments lead to the idea that bodies with the studied orbital parameters exist, whereby majority of their revolution around the Sun occur in the space outside the Mars orbit.

  18. Drop impact on inclined superhydrophobic surfaces

    NASA Astrophysics Data System (ADS)

    Choi, Wonjae; Leclear, Sani; Leclear, Johnathon; Abhijeet, .; Park, Kyoo-Chul

    We report an empirical study and dimensional analysis on the impact patterns of water drops on inclined superhydrophobic surfaces. While the classic Weber number determines the spreading and recoiling dynamics of a water drop on a horizontal / smooth surface, for a superhydrophobic surface, the dynamics depends on two distinct Weber numbers, each calculated using the length scale of the drop or of the pores on the surface. Impact on an inclined superhydrophobic surface is even more complicated, as the velocity that determines the Weber number is not necessarily the absolute speed of the drop but the velocity components normal and tangential to the surface. We define six different Weber numbers, using three different velocities (absolute, normal and tangential velocities) and two different length scales (size of the drop and of the texture). We investigate the impact patterns on inclined superhydrophobic surfaces with three different types of surface texture: (i) posts, (ii) ridges aligned with and (iii) ridges perpendicular to the impact direction. Results suggest that all six Weber numbers matter, but affect different parts of the impact dynamics, ranging from the Cassie-Wenzel transition, maximum spreading, to anisotropic deformation. We acknowledge financial support from the Office of Naval Research (ONR) through Contract 3002453812.

  19. Analysis of inclined showers measured with LOPES

    NASA Astrophysics Data System (ADS)

    Lopes Collaboration; Saftoiu, A.; Apel, W. D.; Arteaga, J. C.; Asch, T.; Auffenberg, J.; Badea, F.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Buitink, S.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Falcke, H.; Finger, M.; Fuhrmann, D.; Gemmeke, H.; Ghia, P. L.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Kolotaev, Y.; Krömer, O.; Kuijpers, J.; Lafebre, S.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Nigl, A.; Oehlschläger, J.; Over, S.; Petcu, M.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Schieler, H.; Schmidt, A.; Schröder, F.; Sima, O.; Singh, K.; Stümpert, M.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; Zensus, J. A.; LOPES Collaboration

    2009-06-01

    In the present study, we analyze the radio signal from inclined air showers recorded by LOPES-30 in coincidence with KASCADE-Grande. LOPES-30 consists of 30 East-West oriented digital antennas, which are amplitude calibrated by an external source. Radio emission from air showers is considered a geomagnetic effect. Inclined events provide a larger range of values for geomagnetic angle (angle between shower axis and geomagnetic field direction) than vertical showers and thus more information on the emission processes can be gathered. In order to have the geometry of the air shower we use the reconstruction provided by the KASCADE-Grande particle detectors array. Analyzing events observed by both LOPES and the extended part of the KASCADE array, Grande, gives the possibility to test in particular the capability and efficiency of radio detection of more distant events. The results are compared with a previous analysis of inclined events recorded by the initial 10 antenna set-up, LOPES-10, in coincidence with the Grande array.

  20. Ultraprecision machining of steep aspheric parts with large sagittal height

    NASA Astrophysics Data System (ADS)

    Mu, Lin; Zhao, Rui; Xin, Qiming

    2009-05-01

    Problems occurred during machining steep aspheric parts with large sagittal height on double-spindle diamond turning machine are presented and the main reasons of the problems are described. And methods of solving these problems are also suggested. When we machine steep aspheric parts with large sagittal height on a 2 axis diamond turning machine, we have such problems as difficult control of part edge accuracy, poor roughness and rapid wear of the cutting tool. The main reasons for these problems lie in: 1) Measurement. To make accurate measurements, the measurement range of the profilometer must fall within the sagittal heights of the aspheric parts, and the measurement angle must also meet the requirements, an insufficient measurement angle, for example, will have a big impact on the measurement and fabrication accuracy of such parts; and 2) Machine and tool, firstly, the diamond cutting tool will suffer a very big force when turning the edge section, resulting in bigger micro-vibration in the tool and tool post, thus affecting the part accuracy and surface roughness. Secondly, the machine itself has location errors in axes X and Z during the processing, leading to the severest destruction in the steep section of the aspheric part by their resultant force. Lastly, anisotropy of diamond cutting tool hardness. The indentation hardness of the diamond is maximum in the direction of <1.0.0> of face (100) and the front clearance has the best strength at tool point in the direction of <1.0.0>. When cutting a steep aspheric part with large sagittal height, a bigger included angle of the diamond tool point arc will be used, and there will be a more deviation from the <1.0.0> lattice direction. So the tool hardness is consistently decreased, resulting in a rapid wear of the cutting tool when turning the steep section of the aspheric part, thus the accuracy and roughness in machining an aspheric part become more difficult to control. The paper is concluded with the

  1. 47 CFR 25.280 - Inclined orbit operations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Inclined orbit operations. 25.280 Section 25... COMMUNICATIONS Technical Operations § 25.280 Inclined orbit operations. (a) Satellite operators may commence operation in inclined orbit mode without obtaining prior Commission authorization provided that...

  2. 47 CFR 25.280 - Inclined orbit operations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Inclined orbit operations. 25.280 Section 25... COMMUNICATIONS Technical Operations § 25.280 Inclined orbit operations. (a) Satellite operators may commence operation in inclined orbit mode without obtaining prior Commission authorization provided that...

  3. 47 CFR 25.280 - Inclined orbit operations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Inclined orbit operations. 25.280 Section 25... COMMUNICATIONS Technical Operations § 25.280 Inclined orbit operations. (a) Satellite operators may commence operation in inclined orbit mode without obtaining prior Commission authorization provided that...

  4. 47 CFR 25.280 - Inclined orbit operations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Inclined orbit operations. 25.280 Section 25... COMMUNICATIONS Technical Operations § 25.280 Inclined orbit operations. (a) Satellite operators may commence operation in inclined orbit mode without obtaining prior Commission authorization provided that...

  5. 47 CFR 25.280 - Inclined orbit operations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Inclined orbit operations. 25.280 Section 25... COMMUNICATIONS Technical Operations § 25.280 Inclined orbit operations. (a) Satellite operators may commence operation in inclined orbit mode without obtaining prior Commission authorization provided that...

  6. 4. VIEW EAST, PERSPECTIVE DOWN INCLINED PLANE FROM TOP OF ...

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

    4. VIEW EAST, PERSPECTIVE DOWN INCLINED PLANE FROM TOP OF ABUTMENT TO CONEMAUGH RIVER AND AREA OF LOWER INCLINE - Laurel Hill Quarry, Incline Plane, Both sides of State Route 56, 2.4 miles East of State Route 711, Seward, Westmoreland County, PA

  7. Precession of a Spinning Ball Rolling down an Inclined Plane

    ERIC Educational Resources Information Center

    Cross, Rod

    2015-01-01

    A routine problem in an introductory physics course considers a rectangular block at rest on a plane inclined at angle a to the horizontal. In order for the block not to slide down the incline, the coefficient of sliding friction, µ, must be at least tan a. The situation is similar for the case of a ball rolling down an inclined plane. In order…

  8. PRECISE TULLY-FISHER RELATIONS WITHOUT GALAXY INCLINATIONS

    SciTech Connect

    Obreschkow, D.; Meyer, M.

    2013-11-10

    Power-law relations between tracers of baryonic mass and rotational velocities of disk galaxies, so-called Tully-Fisher relations (TFRs), offer a wealth of applications in galaxy evolution and cosmology. However, measurements of rotational velocities require galaxy inclinations, which are difficult to measure, thus limiting the range of TFR studies. This work introduces a maximum likelihood estimation (MLE) method for recovering the TFR in galaxy samples with limited or no information on inclinations. The robustness and accuracy of this method is demonstrated using virtual and real galaxy samples. Intriguingly, the MLE reliably recovers the TFR of all test samples, even without using any inclination measurements—that is, assuming a random sin i-distribution for galaxy inclinations. Explicitly, this 'inclination-free MLE' recovers the three TFR parameters (zero-point, slope, scatter) with statistical errors only about 1.5 times larger than the best estimates based on perfectly known galaxy inclinations with zero uncertainty. Thus, given realistic uncertainties, the inclination-free MLE is highly competitive. If inclination measurements have mean errors larger than 10°, it is better not to use any inclinations than to consider the inclination measurements to be exact. The inclination-free MLE opens interesting perspectives for future H I surveys by the Square Kilometer Array and its pathfinders.

  9. Electrically assisted drop sliding on inclined planes

    NASA Astrophysics Data System (ADS)

    't Mannetje, D. J. C. M.; Murade, C. U.; van den Ende, D.; Mugele, F.

    2011-01-01

    We demonstrate that electrowetting using alternating current (ac) voltage can be used to overcome pinning of small drops due to omnipresent heterogeneities on solid surfaces. By balancing contact angle hysteresis with gravity on inclined planes, we find that the critical electrowetting number for mobilizing drops is consistent with the voltage-dependent reduction in contact angle hysteresis in ac electrowetting. Moreover, the terminal velocity of sliding drops under ac electrowetting is found to increase linearly with the electrowetting number. Based on this effect, we present a prototype of a wiper-free windscreen.

  10. Eccentricity and inclination of Miranda's orbit

    NASA Technical Reports Server (NTRS)

    Whitaker, E.; Greenberg, R.

    1973-01-01

    Careful re-measurement of all available plates showing Uranus V (Miranda), supplemented by some recently obtained images, shows that this satellite has both a pronounced orbital eccentricity and inclination (to the plane of the other satellites). Observations are sufficient in number and distribution to allow determinations of the precession rates of both pericenter and node, with implications for the dynamical oblateness of Uranus and the gravitational interaction of the satellites. An improved value for the revolution period is a byproduct of the investigation. The success of the study is due to the improved precision of the measures resulting from the adoption of a very simple, direct method of measurement.

  11. Eccentricity and inclination of Miranda's orbit

    NASA Technical Reports Server (NTRS)

    Whitaker, E.; Greenberg, R.

    1973-01-01

    Careful re-measurement of all available plates showing Uranus V (Miranda), supplemented by some recently obtained images, shows that this satellite has both a pronounced orbital eccentricity and inclination (to the plane of the other satellites). Observations are sufficient in number and distribution to allow determinations of the precession rates of both pericenter and node, with implications for the dynamical oblateness of Uranus and the gravitational interaction of the satellites. An improved value for the revolution period is a by-product of the investigation. The success of this study is due to the improved precision of the measures resulting from the adoption of a very simple, direct method of measurement.

  12. Internal Extinction in Spiral Galaxies. Inclination Dependence

    NASA Astrophysics Data System (ADS)

    Magris, G. C.; Bruzual, G. A.

    1987-05-01

    . Kent (1986) finds that the surface brightness profiles (r) of spiral galaxies have a weak dependence, if any, on the inclination e with respect to the line of sight. This author also finds a correlation between the MIL ratio and the inclination of a galaxy. The lack of dependence of (r) in , = cos 8 indicates that the disk of these galaxies is optically thick ( .>l), due to the presence of dust grains. For an optically thick system o(r) a + 2.5 log . The cosecant law : 1.086 (Holmberg, 1975) does not explain the observed behaviour of a(r) with . 8ru'ual, Magris and Calvet (1986) solved the radiative transfer equation for a mixture of stars and dispersive dust grains distributed homogeneously in a plane parallel configuration, taking into account the wavelenght dependence of the albedo and , as well as the redistribution in angle of photons scattered by dust grains. The transfer equation is solved for the dimensionless intensity ?( , ) I( , )/I*, where 1* is the intensity emerging from the dust free configuration. The solution, CA -2.5 log (r..=0, ) , includes the correction to the galaxy magnitude due to the excess number 0+ stellar sources along the line o+ sigth (cc -i) with respect to the =I case (face on galaxy). For optically thick systems, does not depend on . The luminosity of a disk galaxy observed with inclination ,q 1 given in our model by L cc , from which log(M/L) = const + (.4 8.N( )'. with G.N . ) = -2.5 log( ). The constant is determined from the mass- luminosity. ratio of a dust free system. In terms of the correction (3(N) we can explain Kent's observations with values of between .3 and 4. These values are consistent with the observation of . -independent surface brightness profiles mentioned above. From this analysis we conclude that the correction terms of Bruzual, Magris and Calvet (1986), which take into account the dispersive properties of interstellar dust, can explain the behaviour of ar) and MIL with galaxy inclination. These correction

  13. The speed of an inclined ruck

    PubMed Central

    Balmforth, N. J.; Craster, R. V.; Hewitt, I. J.

    2015-01-01

    Steady rucks in an elastic beam can roll at constant speed down an inclined plane. We examine the dynamics of these travelling-wave structures and argue that their speed can be dictated by a combination of the physical conditions arising in the vicinity of the ‘contact points’ where the beam is peeled off the underlying plane and stuck back down. We provide three detailed models for the contact dynamics: viscoelastic fracture, a thermodynamic model for bond formation and detachment and adhesion mediated by a thin liquid film. The results are compared with experiments. PMID:25568622

  14. On the existence of smooth Cauchy steep time functions

    NASA Astrophysics Data System (ADS)

    Minguzzi, E.

    2016-06-01

    A simple proof (based on results in Chruściel et al 2015 Ann. Henri Poincaré arXiv:1301.2909) is given that every globally hyperbolic spacetime admits a smooth Cauchy steep time function. This result is useful in order to show that globally hyperbolic spacetimes can be isometrically embedded in Minkowski spacetimes and that they split as a product. The proof is based on a recent result on the differentiability of Geroch’s volume functions.

  15. Emplacement and composition of steep-sided domes on Venus

    NASA Astrophysics Data System (ADS)

    Stofan, Ellen R.; Anderson, Steven W.; Crown, David A.; Plaut, Jeffrey J.

    2000-11-01

    Steep-sided domes on Venus have surface characteristics that can provide information on their emplacement, including relatively smooth upper surfaces, radial and polygonal fracture patterns, and pits. These characteristics indicate that domes have surface crusts which are relatively unbroken, have mobile interiors after emplacement, and preserve fractures from only late in their history in response to endogenous growth or sagging of the dome surface. We have calculated the time necessary to form a 12-cm-thick crust for basalt and rhyolite under current terrestrial and Venusian ambient conditions. A 12-cm-thick crust will form in all cases in <10 hours. Although Venusian lava flows should develop a brittle carapace during emplacement, only late-stage brittle fractures are preserved at steep-sided domes. We favor an emplacement model where early-formed surface crusts are entrained or continually annealed as they deform to accommodate dome growth. Entrainment and annealing of fractures are not mutually exclusive processes and thus may both be at work during steep-sided dome emplacement. Our results are most consistent with basaltic compositions, as rhyolitic lavas would quickly form thick crusts which would break into large blocks that would be difficult to entrain or anneal. However, if Venus has undergone large temperature excursions in the past (producing ambient conditions of 800-1000 K [e.g., Bullock and Grinspoon, 1996, 1998]), rhyolitic lavas would be unable to form crusts at high surface temperatures and could produce domes with surface characteristics consistent with those of Venusian steep-sided domes.

  16. Sidewall spacer optimization for steep switching junctionless transistors

    NASA Astrophysics Data System (ADS)

    Gupta, Manish; Kranti, Abhinav

    2016-06-01

    In this work, we analyze the impact of a high permittivity (high-κ) sidewall spacer and gate dielectric on the occurrence of sub-60 mV/decade subthreshold swing (S-swing) in symmetrical junctionless (JL) double gate (DG) transistors. It is shown that steep S-swing values (≤10 mV/decade) can be achieved in JL devices with a combination of a high permittivity (high-κ) gate dielectric and a narrow low permittivity (low-κ) sidewall spacer. Implementation of a wider high-κ spacer will diminish the degree of impact ionization by the influence of the fringing component of the gate electric field, and will not be useful for steep off-to-on current transition. A wider spacer with low-κ and a narrow spacer with high-κ permittivity will be useful to limit the latching effect that can occur at lower temperatures (250 K). For high temperature operation, the decrease in the impact ionization rate can be compensated by designing a JL transistor with a thicker silicon film. The work demonstrates opportunities to enhance impact ionization at sub bandgap voltages, and proposes optimal guidelines for selecting a sidewall spacer to facilitate steep switching in JL transistors.

  17. Formation mechanism of steep wave front in magnetized plasmas

    SciTech Connect

    Sasaki, M. Kasuya, N.; Itoh, S.-I.; Kobayashi, T.; Arakawa, H.; Itoh, K.; Fukunaga, K.; Yamada, T.; Yagi, M.

    2015-03-15

    Bifurcation from a streamer to a solitary drift wave is obtained in three dimensional simulation of resistive drift waves in cylindrical plasmas. The solitary drift wave is observed in the regime where the collisional transport is important as well as fluctuation induced transport. The solitary drift wave forms a steep wave front in the azimuthal direction. The phase of higher harmonic modes are locked to that of the fundamental mode, so that the steep wave front is sustained for a long time compared to the typical time scale of the drift wave oscillation. The phase entrainment between the fundamental and second harmonic modes is studied, and the azimuthal structure of the stationary solution is found to be characterized by a parameter which is determined by the deviation of the fluctuations from the Boltzmann relation. There are two solutions of the azimuthal structures, which have steep wave front facing forward and backward in the wave propagation direction, respectively. The selection criterion of these solutions is derived theoretically from the stability of the phase entrainment. The simulation result and experimental observations are found to be consistent with the theoretical prediction.

  18. Acoustic signals generated in inclined granular flows

    NASA Astrophysics Data System (ADS)

    Tan, Danielle S.; Jenkins, James T.; Keast, Stephen C.; Sachse, Wolfgang H.

    2015-10-01

    Spontaneous avalanching in specific deserts produces a low-frequency sound known as "booming." This creates a puzzle, because avalanches down the face of a dune result in collisions between sand grains that occur at much higher frequencies. Reproducing this phenomenon in the laboratory permits a better understanding of the underlying mechanisms for the generation of such lower frequency acoustic emissions, which may also be relevant to other dry granular flows. Here we report measurements of low-frequency acoustical signals, produced by dried "sounding" sand (sand capable of booming in the desert) flowing down an inclined chute. The amplitude of the signal diminishes over time but reappears upon drying of the sand. We show that the presence of this sound in the experiments may provide supporting evidence for a previously published "waveguide" explanation for booming. Also, we propose a model based on kinetic theory for a sheared inclined flow in which the flowing layer exhibits "breathing" modes superimposed on steady shearing. The predicted oscillation frequency is of a similar order of magnitude as the measurements, indicating that small perturbations can sustain oscillations of a low frequency. However, the frequency is underestimated, which indicates that the stiffness has been underestimated. Also, the model predicts a discrete spectrum of frequencies, instead of the broadband spectrum measured experimentally.

  19. Nonlocal modeling of granular flows down inclines.

    PubMed

    Kamrin, Ken; Henann, David L

    2015-01-01

    Flows of granular media down a rough inclined plane demonstrate a number of nonlocal phenomena. We apply the recently proposed nonlocal granular fluidity model to this geometry and find that the model captures many of these effects. Utilizing the model's dynamical form, we obtain a formula for the critical stopping height of a layer of grains on an inclined surface. Using an existing parameter calibration for glass beads, the theoretical result compares quantitatively to existing experimental data for glass beads. This provides a stringent test of the model, whose previous validations focused on driven steady-flow problems. For layers thicker than the stopping height, the theoretical flow profiles display a thickness-dependent shape whose features are in agreement with previous discrete particle simulations. We also address the issue of the Froude number of the flows, which has been shown experimentally to collapse as a function of the ratio of layer thickness to stopping height. While the collapse is not obvious, two explanations emerge leading to a revisiting of the history of inertial rheology, which the nonlocal model references for its homogeneous flow response. PMID:25376561

  20. Legged-locomotion on inclined granular media

    NASA Astrophysics Data System (ADS)

    Rieser, Jennifer; Qian, Feifei; Goldman, Daniel

    Animals traverse a wide variety of complex environments, including situations in which the ground beneath them can yield (e.g. dry granular media in desert dunes). Locomotion strategies that are effective on level granular media can fail when traversing a granular slope. Taking inspiration from successful legged-locomotors in sandy, uneven settings, we explore the ability of a small (15 cm long, 100 g), six-c-shaped legged robot to run uphill in a bed of 1-mm-diameter poppy seeds, using an alternating tripod gait. Our fully automated experiments reveal that locomotor performance can depend sensitively on both environmental parameters such as the inclination angle and volume fraction of the substrate, and robot morphology and control parameters like leg shape, step frequency, and the friction between the feet of the robot and the substrate. We assess performance by measuring the average speed of the robot, and we find that the robot tends to perform better at higher step frequency and lower inclination angles, and that average speed decreases more rapidly with increasing angle for higher step frequency.

  1. Tenebrio beetles use magnetic inclination compass

    NASA Astrophysics Data System (ADS)

    Vácha, Martin; Drštková, Dana; Půžová, Tereza

    2008-08-01

    Animals that guide directions of their locomotion or their migration routes by the lines of the geomagnetic field use either polarity or inclination compasses to determine the field polarity (the north or south direction). Distinguishing the two compass types is a guideline for estimation of the molecular principle of reception and has been achieved for a number of animal groups, with the exception of insects. A standard diagnostic method to distinguish a compass type is based on reversing the vertical component of the geomagnetic field, which leads to the opposite reactions of animals with two different compass types. In the present study, adults of the mealworm beetle Tenebrio molitor were tested by means of a two-step laboratory test of magnetoreception. Beetles that were initially trained to memorize the magnetic position of the light source preferred, during the subsequent test, this same direction, pursuant geomagnetic cues only. In the following step, the vertical component was reversed between the training and the test. The beetles significantly turned their preferred direction by 180°. Our results brought until then unknown original findings that insects, represented here by the T. molitor species, use—in contrast to another previously researched Arthropod, spiny lobster—the inclination compass.

  2. An experimental study on jets issuing from elliptic inclined nozzles

    NASA Astrophysics Data System (ADS)

    New, T. H.

    2009-06-01

    This paper reports on an experimental flow visualisation and digital particle image velocimetry investigation on forced jets exhausting from aspect ratio equal to three elliptic nozzles with exits inclined at 30° and 60°. Flow images show that shear layer instabilities and subsequent vortex roll-ups are formed parallel to the inclined nozzle exits at 30° incline and that rapid re-orientation of the vortex roll-ups occurs at 60° incline. Flow observations also show that strong axis-switching occurs in a non-inclined elliptic nozzle. However, 30° and 60° elliptic inclined nozzles produce significant distortions to and suppression of the axis-switching behaviour, respectively. As a result, flow stresses and turbulent kinetic energy distributions become increasingly asymmetric. Their coherency and magnitudes along the shorter nozzle lengths also vary significantly. This can be attributed to the dissimilar formations of vortex roll-ups and rib structures, as well as unequal mutual interactions between them as the incline-angle increases. Lastly, results also show that unlike circular inclined nozzles, elliptic inclined nozzles do not produce serpentine-shaped jet columns nor lead to significant lateral jet-spread at large incline-angles.

  3. Why arboreal snakes should not be cylindrical: body shape, incline and surface roughness have interactive effects on locomotion.

    PubMed

    Jayne, Bruce C; Newman, Steven J; Zentkovich, Michele M; Berns, H Matthew

    2015-12-01

    Depending on animal size, shape, body plan and behaviour, variation in surface structure can affect the speed and ease of locomotion. The slope of branches and the roughness of bark both vary considerably, but their combined effects on the locomotion of arboreal animals are poorly understood. We used artificial branches with five inclines and five peg heights (≤40 mm) to test for interactive effects on the locomotion of three snake species with different body shapes. Unlike boa constrictors (Boa constrictor), corn snakes (Pantherophis guttatus) and brown tree snakes (Boiga irregularis) can both form ventrolateral keels, which are most pronounced in B. irregularis. Increasing peg height up to 10 mm elicited more of the lateral undulatory behaviour (sliding contact without gripping) rather than the concertina behaviour (periodic static gripping) and increased the speed of lateral undulation. Increased incline: (1) elicited more concertina locomotion, (2) decreased speed and (3) increased the threshold peg height that elicited lateral undulation. Boiga irregularis was the fastest species, and it used lateral undulation on the most surfaces, including a vertical cylinder with pegs only 1 mm high. Overall, B. constrictor was the slowest and used the most concertina locomotion, but this species climbed steep, smooth surfaces faster than P. guttatus. Our results illustrate how morphology and two different aspects of habitat structure can have interactive effects on organismal performance and behaviour. Notably, a sharper keel facilitated exploiting shorter protrusions to prevent slipping and provide propulsion, which became increasingly important as surface steepness increased. PMID:26677261

  4. Unsteady granular flows down an inclined plane.

    PubMed

    Parez, Stanislav; Aharonov, Einat; Toussaint, Renaud

    2016-04-01

    The continuum description of granular flows is still a challenge despite their importance in many geophysical and industrial applications. We extend previous works, which have explored steady flow properties, by focusing on unsteady flows accelerating or decelerating down an inclined plane in the simple shear configuration. We solve the flow kinematics analytically, including predictions of evolving velocity and stress profiles and the duration of the transient stage. The solution shows why and how granular materials reach steady flow on slopes steeper than the angle of repose and how they decelerate on shallower slopes. The model might facilitate development of natural hazard assessment and may be modified in the future to explore unsteady granular flows in different configurations. PMID:27176375

  5. Unsteady granular flows down an inclined plane

    NASA Astrophysics Data System (ADS)

    Parez, Stanislav; Aharonov, Einat; Toussaint, Renaud

    2016-04-01

    The continuum description of granular flows is still a challenge despite their importance in many geophysical and industrial applications. We extend previous works, which have explored steady flow properties, by focusing on unsteady flows accelerating or decelerating down an inclined plane in the simple shear configuration. We solve the flow kinematics analytically, including predictions of evolving velocity and stress profiles and the duration of the transient stage. The solution shows why and how granular materials reach steady flow on slopes steeper than the angle of repose and how they decelerate on shallower slopes. The model might facilitate development of natural hazard assessment and may be modified in the future to explore unsteady granular flows in different configurations.

  6. Transient natural convection in heated inclined tubes

    NASA Astrophysics Data System (ADS)

    McEligot, Donald M.; Denbow, David A.; Murphy, Hugh D.

    1990-05-01

    To simulate natural convection flow patterns in directionally drilled wellbores, experiments and analyses were conducted for a circular tube with length-to-diameter (L/D) ratio of 36 at angles of 0, 20, and 35 degrees from the vertical. The tube was heated at the bottom and cooled at the top, and the insulation was adjusted so that approximately one- to two-thirds of the power dissipated was transferred through the tube wall to the surroundings. An aqueous solution of polyvinyl alcohol was employed as the working fluid in order to obtain low Rayleigh numbers corresponding to conditions in geothermal wellbores. Results were primarily qualitative but were useful in providing insight into the phenomena occurring. Steady-state temperature distributions were measured for the three orientations and for several heating rates to demonstrate the effects of tube angle and Rayleigh number. Transient measurements of the temperature distribution were obtained during cooling from a higher temperature without a heat source to calibrate the heat losses. With the electrical heat source, temporal data were taken during heating to examine the approach to steady state. Quasi-steady flow conditions were approached rapidly, but the overall time constant of the apparatus was of the order of one-third of a day. Predictions with the three-dimensional TEMPEST code were first tested by comparison with simple conduction analyses. Comparison with actual data showed good agreement of the predicted temperature levels for the maximum inclination, 35 degrees, and slightly poorer agreement for the other limit, a vertical tube. Trends of temperature level and Nusselt number with heating rate or Rayleigh number were reasonable, but the predicted variation of the end Nusselt number versus inclination was in the opposite direction from the experiment.

  7. Transient natural convection in heated inclined tubes

    SciTech Connect

    McEligot, D.M. . Oceanic Div.); Denbow, D.A. ); Murphy, H.D. )

    1990-05-01

    To simulate natural convection flow patterns in directionally drilled wellbores, experiments and analyses were conducted for a circular tube with length-to-diameter (L/D) ratio of 36 at angles of 0{degree}, 20{degree}, and 35{degree} from the vertical. The tube was heated at the bottom and cooled at the top, and the insulation was adjusted so that approximately one- to two-thirds of the power dissipated was transferred through the tube wall to the surroundings. An aqueous solution of polyvinyl alcohol was employed as the working fluid in order to obtain low Rayleigh numbers corresponding to conditions in geothermal wellbores. Results were primarily qualitative but were useful in providing insight into the phenomena occurring. Steady-state temperature distributions were measured for the three orientations and for several heating rates to demonstrate the effects of tube angle and Rayleigh number. transient measurements of the temperature distribution were obtained during cooling from a higher temperature without a heat source to calibrate the heat losses. With the electrical heat source, temporal data were taken during heating to examine the approach to steady state. Quasi-steady flow conditions were approached rapidly, but the overall time constant of the apparatus was of the order of one-third of a day. Predictions with the three-dimensional TEMPEST code were first tested by comparison with simple conduction analyses. Comparison with actual data showed good agreement of the predicted temperature levels for the maximum inclination, 35{degree}, and slightly poorer agreement for the other limit, a vertical tube. Trends of temperature level and Nusselt number with heating rate or Rayleigh number were reasonable, but the predicted variation of the end Nusselt number versus inclination was in the opposite direction from the experiment. 75 refs., 20 figs., 8 tabs.

  8. Enhanced photovoltaic performance of an inclined nanowire array solar cell.

    PubMed

    Wu, Yao; Yan, Xin; Zhang, Xia; Ren, Xiaomin

    2015-11-30

    An innovative solar cell based on inclined p-i-n nanowire array is designed and analyzed. The results show that the inclined geometry can sufficiently increase the conversion efficiency of solar cells by enhancing the absorption of light in the active region. By tuning the nanowire array density, nanowire diameter, nanowire length, as well as the proportion of intrinsic region of the inclined nanowire solar cell, a remarkable efficiency in excess of 16% can be obtained in GaAs. Similar results have been obtained in InP and Si nanowire solar cells, demonstrating the universality of the performance enhancement of inclined nanowire arrays. PMID:26698807

  9. Detection of very inclined showers with the Auger Observatory

    SciTech Connect

    Nellen, Lukas; /Mexico U., ICN

    2005-07-01

    The Pierre Auger Observatory can detect air showers with high efficiency at large zenith angles with both the fluorescence and surface detectors. Since half the available solid angle corresponds to zeniths between 60 and 90 degrees, a large number of inclined events can be expected and are indeed observed. In this paper, we characterize the inclined air showers detected by the Observatory and we present the aperture for inclined showers and an outlook of the results that can be obtained in future studies of the inclined data set.

  10. Transient river response, captured by channel steepness and its concavity

    NASA Astrophysics Data System (ADS)

    Vanacker, Veerle; von Blanckenburg, Friedhelm; Govers, Gerard; Molina, Armando; Campforts, Benjamin; Kubik, Peter W.

    2015-01-01

    Mountain rivers draining tropical regions are known to be great conveyor belts carrying efficiently more than half of the global sediment flux to the oceans. Many tropical mountain areas are located in tectonically active belts where the hillslope and stream channel morphology are rapidly evolving in response to changes in base level. Here, we report basin-wide denudation rates for an east-west transect through the tropical Andes. Hillslope and channel morphology vary systematically from east to west, reflecting the transition from high relief, strongly dissected topography in the escarpment zones into relatively low relief topography in the inter-Andean valley. The spatial pattern of differential denudation rates reflects the transient adjustment of the landscape to rapid river incision following tectonic uplift and river diversion. In the inter-Andean valley, upstream of the wave of incision, slopes and river channels display a relatively smooth, concave-up morphology and denudation rates (time scale of 104-105 a) are consistently low (3 to 200 mm/ka). In contrast, slopes and river channels of rejuvenated basins draining the eastern cordillera are steep to very steep; and the studied drainage basins show a wide range of denudation rate values (60 to 400 mm/ka) that increase systematically with increasing basin mean slope gradient, channel steepness, and channel convexity. Drainage basins that are characterised by strong convexities in their river longitudinal profiles systematically have higher denudation rates. As such, this is one of the first studies that provides field-based evidence of a correlation between channel concavity and basin mean denudation rates, consistent with process-based fluvial incision models.

  11. Seismic Monitoring of Bedload Transport in a Steep Mountain Catchment

    NASA Astrophysics Data System (ADS)

    Roth, D. L.; Finnegan, N. J.; Brodsky, E. E.; Turowski, J. M.; Wyss, C. R.; Badoux, A.

    2014-12-01

    Predicting river channel evolution relies on an understanding of when and at what rate coarse sediment moves in a channel. Unfortunately, our predictive abilities are limited by the logistical challenges and potential dangers inherent in current techniques for monitoring sediment transport during flood events, especially in steep, highly active landscapes. However, the use of seismic signals near rivers shows promise as a safe, low-cost method for studying sediment transport in these settings. Seismic signals near rivers are partially generated by both water turbulence and bedload sediment particles impacting the river bed during transport. Here, we attempt to isolate the seismic signatures of discharge and bedload transport in a steep mountain channel by examining high-frequency broadband seismic data from the well-studied Erlenbach stream (local slope of ~10%) in the Swiss Prealps. The extensive monitoring infrastructure and long history of sediment transport data at this field site allow us to independently constrain discharge, precipitation, and bedload transport during flood events over a two month field campaign. We perform a general linear least squares inversion of the seismic data, exploiting times with isolated rain or discharge events, to identify the spectral signals of water turbulence, rain, and bedload sediment transport. We find that the signal generated by rain exhibits a roughly broadband spectrum, while discharge and sediment transport exhibit power primarily in lower frequency bands. Our preliminary results indicate that with only precipitation and discharge data, it is possible to isolate the seismic signal of bedload transport in steep fluvial environments. Seismic studies may therefore have the potential to revolutionize our ability to monitor and understand these environments.

  12. The discovery of diffuse steep spectrum sources in Abell 2256

    NASA Astrophysics Data System (ADS)

    van Weeren, R. J.; Intema, H. T.; Oonk, J. B. R.; Röttgering, H. J. A.; Clarke, T. E.

    2009-12-01

    Context: Hierarchical galaxy formation models indicate that during their lifetime galaxy clusters undergo several mergers. An example of such a merging cluster is Abell 2256. Here we report on the discovery of three diffuse radio sources in the periphery of Abell 2256, using the Giant Metrewave Radio Telescope (GMRT). Aims: The aim of the observations was to search for diffuse ultra-steep spectrum radio sources within the galaxy cluster Abell 2256. Methods: We have carried out GMRT 325 MHz radio continuum observations of Abell 2256. V, R and I band images of the cluster were taken with the 4.2 m William Herschel Telescope (WHT). Results: We have discovered three diffuse elongated radio sources located about 1 Mpc from the cluster center. Two are located to the west of the cluster center, and one to the southeast. The sources have a measured physical extent of 170, 140 and 240 kpc, respectively. The two western sources are also visible in deep low-resolution 115-165 MHz Westerbork Synthesis Radio Telescope (WSRT) images, although they are blended into a single source. For the combined emission of the blended source we find an extreme spectral index (α) of -2.05 ± 0.14 between 140 and 351 MHz. The extremely steep spectral index suggests these two sources are most likely the result of adiabatic compression of fossil radio plasma due to merger shocks. For the source to the southeast, we find that {α < -1.45} between 1369 and 325 MHz. We did not find any clear optical counterparts to the radio sources in the WHT images. Conclusions: The discovery of the steep spectrum sources implies the existence of a population of faint diffuse radio sources in (merging) clusters with such steep spectra that they have gone unnoticed in higher frequency (⪆1 GHz) observations. Simply considering the timescales related to the AGN activity, synchrotron losses, and the presence of shocks, we find that most massive clusters should possess similar sources. An exciting possibility

  13. Check dams effects on sediment transport in steep slope flume

    NASA Astrophysics Data System (ADS)

    Piton, Guillaume; Recking, Alain

    2014-05-01

    Depending on many influences (geology, relief, hydrology, land use, etc.) some mountainous watershed are prone to cause casualties and facilities damages. Large amounts of sediments episodically released by torrents are often the biggest problem in torrent related hazard mitigation. Series of transversal structures as check dams and ground sills are often used in the panel of risk mitigation technics. A large literature exits on check dams and it mainly concerns engineering design, e.g. toe scouring, stability stress diagram, changes in upper and lower reaches equilibrium slopes. Check dams in steep slope rivers constitute fixed points in the bed profile and prevent general bed incision. However their influence on sediment transport once they are filled is not yet clear. Two flume test campaigns, synthetize in Table 1, were performed to investigate this question: Table 1 : experiment plan Run (duration) Ref1 (50h)CD1a (30h)CD1b (30h)Ref2 (92h)CD2 (18h) Solid feeding discharge (g.s^-1) 44 44 44 60 60 Number of check dams none 1 3 none 2 A nearly 5-m-long, 10-cm-wide and 12%-steep flume was used. The water discharge was set to 0,55 l/s in all runs. A mixture of poorly sorted natural sediments with diameters between 0.8 and 40 mm was used. An open solid-discharge-feeding circuit kept the inlet sediment flux constant during all experiments. As both feeding rates did not present variation, changes in outlet solid discharge were assumed to be due to bed variations in the bed storage. We observed strong fluctuations of solid flux and slope in each reaches of all runs between: (i) steep aggradating armoured bed and (ii) less steep and finer bed releasing bedload sheets during erosion events and inducing bedload pulses. All experiments showed consistent results: transported volume associated with erosion event decreased with the length between two subsequent check dams. Solid transversal structures shorten the upstream erosion-propagation and avoid downstream change in the

  14. Field experiments of nonlocal sediment transport on a steep hillslope

    NASA Astrophysics Data System (ADS)

    DiBiase, R.; Booth, A. M.; Ganti, V.; Scheingross, J. S.; Lamb, M. P.

    2014-12-01

    Steep rocky hillslopes dominate the areal extent of rapidly uplifting mountain ranges, and pose a significant hazard to encroaching population centers. Existing models for hillslope sediment transport developed for soil-mantled landscapes are poorly suited to explain the evolution of steep hillslopes characterized by: (1) intermittent or patchy soil cover, (2) slopes that exceed the angle of repose, and (3) transport events that often involve long travel distances. Recently, nonlocal formulations of hillslope sediment transport laws that account for long travel distances have been proposed to overcome the limitations of traditional continuum-based models. However, their application to natural landscapes has been limited owing to few field constraints on key parameters, and computational difficulties expanding the framework to two-dimensions. To address this knowledge gap, we performed a series of field experiments on natural hillslopes to inform a simple particle-based model of hillslope sediment transport. We compiled the distribution of average velocity and transport distance for over 300 stones ranging in diameter from 2-10 cm using a video camera and laser range-finder. To characterize surface roughness, we used a tripod-based laser scanner to generate a 1 cm-resolution digital elevation model of each 30 m long hillslope. We find that hillslope travel distance follows a heavy-tailed distribution that varies systematically with the ratio of particle diameter to roughness height, in general agreement to published laboratory experiments. Mean particle velocity ranges from 1-3 m/s and scales weakly with distance traveled. Our modeling exercise reveals three key effects that should be included in any treatment of steep hillslope evolution: (1) there is a strong grain-size and surface roughness dependence on sediment transport distance, (2) sediment storage on slopes steeper than the angle of repose is possible due to vegetation or topographic roughness, and (3

  15. Jet evolution in Steep Spectrum Radio Quasars: a multiwavelength study

    NASA Astrophysics Data System (ADS)

    Torresi, Eleonora; Grandi, Paola

    2013-12-01

    Thanks to the Fermi γ-ray satellite, it is now confirmed that Misaligned Active Galactic Nuclei (MAGN), i.e. radio galaxies and steep spectrum radio quasars, are a new class of GeV emitters. In this work we present the first γ-ray and multiwavelength study of the two steep spectrum radio quasars, i.e. 3C 207 and 3C 380, belonging to the MAGN sample. From the γ -ray variability study we estimate the physical size of the zone where high-energy photons are dissipated: for both sources this region should be very compact, not larger than 0.05 pc. As a successive step, we build multiwavelength light curves of 3C 207 and 3C 380 to search for possible simultaneous outbursts in different wavebands with the aim of localizing the compact emitting region. This is an important issue with strong impact on theoretical models: indeed, knowing where highenergy photons are dissipated (at sub-pc or pc-scale) provides information on the nature of the seed photons involved in the production of the GeV radiation.

  16. Computing nonhydrostatic shallow-water flow over steep terrain

    USGS Publications Warehouse

    Denlinger, R.P.; O'Connell, D. R. H.

    2008-01-01

    Flood and dambreak hazards are not limited to moderate terrain, yet most shallow-water models assume that flow occurs over gentle slopes. Shallow-water flow over rugged or steep terrain often generates significant nonhydrostatic pressures, violating the assumption of hydrostatic pressure made in most shallow-water codes. In this paper, we adapt a previously published nonhydrostatic granular flow model to simulate shallow-water flow, and we solve conservation equations using a finite volume approach and an Harten, Lax, Van Leer, and Einfeldt approximate Riemann solver that is modified for a sloping bed and transient wetting and drying conditions. To simulate bed friction, we use the law of the wall. We test the model by comparison with an analytical solution and with results of experiments in flumes that have steep (31??) or shallow (0.3??) slopes. The law of the wall provides an accurate prediction of the effect of bed roughness on mean flow velocity over two orders of magnitude of bed roughness. Our nonhydrostatic, law-of-the-wall flow simulation accurately reproduces flume measurements of front propagation speed, flow depth, and bed-shear stress for conditions of large bed roughness. ?? 2008 ASCE.

  17. Steep dose gradients for simultaneous integrated boost IMRT.

    PubMed

    Bratengeier, Klaus; Meyer, Jürgen; Schwab, Franz; Vordermark, Dirk; Flentje, Michael

    2009-01-01

    Steep dose gradients between two planning target volumes (PTVs) as may be required for simultaneous integrated boosts (SIB) should be an option provided by IMRT algorithms. The aim was to analyse the geometry of the SIB problem and to implement the results in an algorithm for IMRT segment generation denoted two-step intensity modulated radiotherapy (2-Step IMRT). It was hypothesized that a gap between segments directed to the inner and the outer PTV would steepen the dose gradient. The mathematical relationships were derived from the individual dose levels and the geometry (diameters) of the PTVs. The results generated by means of 2-Step IMRT segments were equivalent or better than the segment generation using a commercial IMRT planning system. The dose to both the inner and the outer PTV was clearly more homogeneous and the composite objective value was the lowest. The segment numbers were lower or equal--with better sparing of the surrounding tissue. In summary, it was demonstrated that 2-Step IMRT was able to achieve steep dose gradients for SIB constellations. PMID:19678528

  18. The Role of a Steepness Parameter in the Exponential Stability of a Model Problem. Numerical Aspects

    NASA Astrophysics Data System (ADS)

    Todorovic, N.

    2011-06-01

    The Nekhoroshev theorem considers quasi integrable Hamiltonians providing stability of actions in exponentially long times. One of the hypothesis required by the theorem is a mathematical condition called steepness. Nekhoroshev conjectured that different steepness properties should imply numerically observable differences in the stability times. After a recent study on this problem (Guzzo et al. 2011, Todorovic et al. 2011) we show some additional numerical results on the change of resonances and the diffusion laws produced by the increasing effect of steepness. The experiments are performed on a 4-dimensional steep symplectic map designed in a way that a parameter smoothly regulates the steepness properties in the model.

  19. Relationships between Migration to Urban Settings and Children's Creative Inclinations

    ERIC Educational Resources Information Center

    Shi, Baoguo; Lu, Yongli; Dai, David Yun; Lin, Chongde

    2013-01-01

    In this study, 909 5th- and 6th-grade children were recruited as participants, and questionnaires were used to investigate the relationships between migration to urban settings and children's creative inclinations. The study was broken down to 2 parts. Study 1 compared scores on measures of creative inclinations among migrant, rural, and urban…

  20. 46 CFR 111.01-19 - Inclination of the vessel.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Inclination of the vessel. 111.01-19 Section 111.01-19 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS General § 111.01-19 Inclination of the vessel. (a) All electrical equipment must...

  1. 46 CFR 111.01-19 - Inclination of the vessel.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Inclination of the vessel. 111.01-19 Section 111.01-19 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS General § 111.01-19 Inclination of the vessel. (a) All electrical equipment must...

  2. 46 CFR 111.01-19 - Inclination of the vessel.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Inclination of the vessel. 111.01-19 Section 111.01-19 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS General § 111.01-19 Inclination of the vessel. (a) All electrical equipment must...

  3. 46 CFR 111.01-19 - Inclination of the vessel.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Inclination of the vessel. 111.01-19 Section 111.01-19 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS General § 111.01-19 Inclination of the vessel. (a) All electrical equipment must...

  4. 46 CFR 111.01-19 - Inclination of the vessel.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Inclination of the vessel. 111.01-19 Section 111.01-19 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS General § 111.01-19 Inclination of the vessel. (a) All electrical equipment must...

  5. 30 CFR 57.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Inclined conveyors: backstops or brakes. 57.14113 Section 57.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR...: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to...

  6. 30 CFR 56.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Inclined conveyors: backstops or brakes. 56.14113 Section 56.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to prevent...

  7. Generation of highly inclined protoplanetary discs through single stellar flybys

    NASA Astrophysics Data System (ADS)

    Xiang-Gruess, M.

    2016-01-01

    We study the three-dimensional evolution of a viscous protoplanetary disc which is perturbed by a passing star on a parabolic orbit. The aim is to test whether a single stellar flyby is capable to excite significant disc inclinations which would favour the formation of so-called misaligned planets. We use smoothed particle hydrodynamics to study inclination, disc mass and angular momentum changes of the disc for passing stars with different masses. We explore different orbital configurations for the perturber's orbit to find the parameter spaces which allow significant disc inclination generation. Prograde inclined parabolic orbits are most destructive leading to significant disc mass and angular momentum loss. In the remaining disc, the final disc inclination is only below 20°. This is due to the removal of disc particles which have experienced the strongest perturbing effects. Retrograde inclined parabolic orbits are less destructive and can generate disc inclinations up to 60°. The final disc orientation is determined by the precession of the disc angular momentum vector about the perturber's orbital angular momentum vector and by disc orbital inclination changes. We propose a sequence of stellar flybys for the generation of misalignment angles above 60°. The results taken together show that stellar flybys are promising and realistic for the explanation of misaligned Hot Jupiters with misalignment angles up to 60°.

  8. Three-Dimensional Vortex Structure in Jets from Inclined Nozzles

    NASA Astrophysics Data System (ADS)

    Webster, D. R.; Longmire, E. K.

    1996-11-01

    Flow visualization and particle image velocimetry measurements were performed on round jets exiting nozzles with inclines from 0 to 45 deg at a Reynolds number of 9000. Results from natural jets and jets forced with single frequencies corresponding to StD = 0.25 and 0.5 will be presented. In the natural case, the nozzle incline caused a mild increase in the radial spreading in the plane of azimuthal symmetry. The forcing amplified the asymmetric radial spreading by altering the vortex structure. In general, inclined vortex rings rolled up at an angle slightly smaller than the nozzle incline angle. As the rings moved downstream, they migrated away from the jet centerline, and their incline angle increased until breakdown occurred. For StD = 0.5, the rings did not pair, and the maximum incline angle observed was 49 deg. Forcing at StD = 0.25 yielded a pairing where the pairing location moved upstream with increasing nozzle incline angle. The nature of the pairing, which was also dependent on the nozzle incline angle, will be described.

  9. 40. CONSTRUCTION OF GALLERY NO. 3, SHOWING INCLINED PLANE USED ...

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

    40. CONSTRUCTION OF GALLERY NO. 3, SHOWING INCLINED PLANE USED TO TRANSPORT MATERIALS, ALSO SPOIL FROM TUNNEL INTERIOR. POWDER HOUSE AND TOOL SHED VISIBLE TO RIGHT OF BASE INCLINE - Zion-Mount Carmel Highway, Tunnel, Two miles east of Zion Canyon Scenic Drive, Springdale, Washington County, UT

  10. 3. Inclined Plane 10, 1970. Track bed at left. View ...

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

    3. Inclined Plane 10, 1970. Track bed at left. View some what similar to that of NJ-30-2. Stone track bed is visible under cable system of NJ-30-2. - Morris Canal, Inclined Plane 10 West, Phillipsburg, Warren County, NJ

  11. 7. VIEW WEST, PERSPECTIVE VIEW OF TOP OF INCLINED PLANE ...

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

    7. VIEW WEST, PERSPECTIVE VIEW OF TOP OF INCLINED PLANE AND EAST FACE OF CUT STONE TOWER - Laurel Hill Quarry, Incline Plane, Both sides of State Route 56, 2.4 miles East of State Route 711, Seward, Westmoreland County, PA

  12. Gaining Momentum: Re-Creating Galileo's Inclined Plane.

    ERIC Educational Resources Information Center

    Albrecht, Bob; Firedrake, George

    1998-01-01

    Provides an excerpt of Galileo's description of his inclined plane experiment. Describes the replication of Galileo's inclined plane experiment by students at Rice University (Texas) using an Internet site called the Galileo Project; then describes the authors' replication of the Project. (AEF)

  13. A New Dynamics Cart on an Inclined Plane.

    ERIC Educational Resources Information Center

    Theodorsson, Pall

    1995-01-01

    Presents an experiment to study the acceleration of a cart moving up and down an inclined plane. Demonstrates how multitiming and the study of the movement in both directions allows the determination of the component of gravitational force along an inclined plane without any assumptions about friction. (JRH)

  14. Operational Experiences in Planning and Reconstructing Aqua Inclination Maneuvers

    NASA Technical Reports Server (NTRS)

    Rand, David; Reilly, Jacqueline; Schiff, Conrad

    2004-01-01

    As the lead satellite in NASA's growing Earth Observing System (EOS) PM constellation, it is increasingly critical that Aqua maintain its various orbit requirements. The two of interest for this paper are maintaining an orbit inclination that provides for a consistent mean local time and a semi-major Axis (SMA) that allows for ground track repeatability. Maneuvers to adjust the orbit inclination involve several flight dynamics constraints and complexities which make planning such maneuvers challenging. In particular, coupling between the orbital and attitude degrees of freedom lead to changes in SMA when changes in inclination are effected. A long term mission mean local time trend analysis was performed in order to determine the size and placement of the required inclination maneuvers. Following this analysis, detailed modeling of each burn and its Various segments was performed to determine its effects on the immediate orbit state. Data gathered from an inclination slew test of the spacecraft and first inclination maneuver uncovered discrepancies in the modeling method that were investigated and resolved. The new modeling techniques were applied and validated during the second spacecraft inclination maneuver. These improvements should position Aqua to successfully complete a series of inclination maneuvers in the fall of 2004. The following paper presents the events and results related

  15. 46 CFR 58.01-40 - Machinery, angles of inclination.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Machinery, angles of inclination. 58.01-40 Section 58.01... AUXILIARY MACHINERY AND RELATED SYSTEMS General Requirements § 58.01-40 Machinery, angles of inclination. (a) Propulsion machinery and all auxiliary machinery essential to the propulsion and safety of the vessel must...

  16. 30 CFR 56.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Inclined conveyors: backstops or brakes. 56.14113 Section 56.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to prevent...

  17. 30 CFR 56.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Inclined conveyors: backstops or brakes. 56.14113 Section 56.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to prevent...

  18. 30 CFR 56.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Inclined conveyors: backstops or brakes. 56.14113 Section 56.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to prevent...

  19. 30 CFR 57.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Inclined conveyors: backstops or brakes. 57.14113 Section 57.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR...: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to...

  20. 30 CFR 57.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Inclined conveyors: backstops or brakes. 57.14113 Section 57.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR...: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to...

  1. 30 CFR 57.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Inclined conveyors: backstops or brakes. 57.14113 Section 57.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR...: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to...

  2. 30 CFR 56.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Inclined conveyors: backstops or brakes. 56.14113 Section 56.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to prevent...

  3. 30 CFR 57.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Inclined conveyors: backstops or brakes. 57.14113 Section 57.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR...: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to...

  4. Capillary Penetration into Inclined Circular Glass Tubes.

    PubMed

    Trabi, Christophe L; Ouali, F Fouzia; McHale, Glen; Javed, Haadi; Morris, Robert H; Newton, Michael I

    2016-02-01

    The spontaneous penetration of a wetting liquid into a vertical tube against the force of gravity and the imbibition of the same liquid into a horizontal tube (or channel) are both driven by capillary forces and described by the same fundamental equations. However, there have been few experimental studies of the transition from one orientation to the other. We report systematic measurements of capillary penetration of polydimethylsiloxane oils of viscosities 9.6, 19.2, and 48.0 mPa·s into glass capillary tubes. We first report the effect of tube radii R between 140 and 675 μm on the dynamics of spontaneous imbibition. We show that the data can be fitted using the exact numerical solution to the governing equations and that these are similar to fits using the analytical viscogravitational approximation. However, larger diameter tubes show a rate of penetration slower than expected using an equilibrium contact angle and the known value of liquid viscosity. To account for the slowness, an increase in viscosity by a factor (η/ρ)(scaling) is needed. We show full agreement with theory requires the ratio R/κ(-1) ∼ 0.1 or less, where κ(-1) is the capillary length. In addition, we propose an experimental method that enables the determination of the dynamic contact angle during imbibition, which gives values that agree with the literature values. We then report measurements of dynamic penetration into the tubes of R = 190 and 650 μm for a range of inclination angles to the horizontal, φ, from 5 to 90°. We show that capillary penetration can still be fitted using the viscogravitational solution, rather than the Bosanquet solution which describes imbibition without gravity, even for inclination angles as low as 10°. Moreover, at these low angles, the effect of the tube radius is found to diminish and this appears to relate to an effective capillary length, κ(-1)(φ) = (γ(LV)/ρg sin φ)(1/2). PMID:26738739

  5. Use of IQRF technology for detection of construction inclination

    NASA Astrophysics Data System (ADS)

    Martin, Pies; Radovan, Hajovsky

    2016-06-01

    This paper deals with the application of wireless measurement of inclination of objects located at mining dumps. Measurement of inclination uses a set of sensors including a gyroscope, an accelerometer and a magnetometer. Measured data is processed by AHRS algorithm that, once applied, allows getting more precise information on rotation of the object in the area compared to unprocessed data from accelerometer or gyroscope. Measurement chain consists of two parts. The first one is a wireless module reading the data from particular sensors via I2C bus and sends it consequently to a computer that performs evaluation and visualization of inclination. Communication among particular devices is ensured by IQRF technology working within ISM band of 868MHz. Application of this approach for measurement of inclination is a reasonable choice in case of measurement of inclination by inclinometers.

  6. Bioinspired dynamic inclination measurement using inertial sensors.

    PubMed

    Vikas, Vishesh; Crane, Carl

    2015-06-01

    Biologically, the vestibular feedback is critical to the ability of human body to balance in different conditions. This balancing ability inspires analysis of the reference equilibrium position in dynamic environments. The research proposes and experimentally validates the concept of equilibrium for the human body modeled as an inverted pendulum, which is instrumental in explaining why we align the body along the surface normal when standing on a surface but not on an incline, and tend to lean backward or forward on non-static surfaces e.g. accelerating or decelerating bus. This equilibrium position--the dynamic equilibrium axis--is dependent only on the acceleration of surface of contact (e.g. gravity) and acts as the reference to the orientation measurements. The research also draws design inspiration from the two human ears--symmetry and plurality of inertial sensors. The vestibular dynamic inclinometer and planar vestibular dynamic inclinometer consist of multiple (two or four) symmetrically placed accelerometers and a gyroscope. The sensors measure the angular acceleration and absolute orientation, not the change in orientation, from the reference equilibrium position and are successful in separating gravity from motion for objects moving on ground. The measurement algorithm is an analytical solution that is not time-recursive, independent of body dynamics and devoid of integration errors. The experimental results for the two sensor combinations validate the theoretically (kinematics) derived analytical solution of the measurement algorithm. PMID:25879912

  7. UNBIASED INCLINATION DISTRIBUTIONS FOR OBJECTS IN THE KUIPER BELT

    SciTech Connect

    Gulbis, A. A. S.; Elliot, J. L.; Adams, E. R.; Benecchi, S. D.; Buie, M. W.; Trilling, D. E.; Wasserman, L. H. E-mail: jle@mit.ed E-mail: lhw@lowell.ed E-mail: buie@boulder.swri.ed

    2010-08-15

    Using data from the Deep Ecliptic Survey (DES), we investigate the inclination distributions of objects in the Kuiper Belt. We present a derivation for observational bias removal and use this procedure to generate unbiased inclination distributions for Kuiper Belt objects (KBOs) of different DES dynamical classes, with respect to the Kuiper Belt plane. Consistent with previous results, we find that the inclination distribution for all DES KBOs is well fit by the sum of two Gaussians, or a Gaussian plus a generalized Lorentzian, multiplied by sin i. Approximately 80% of KBOs are in the high-inclination grouping. We find that Classical object inclinations are well fit by sin i multiplied by the sum of two Gaussians, with roughly even distribution between Gaussians of widths 2.0{sup +0.6}{sub -0.5}{sup 0} and 8.1{sup +2.6}{sub -2.1}{sup 0}. Objects in different resonances exhibit different inclination distributions. The inclinations of Scattered objects are best matched by sin i multiplied by a single Gaussian that is centered at 19.1{sup +3.9}{sub -3.6}{sup 0} with a width of 6.9{sup +4.1}{sub -2.7}{sup 0}. Centaur inclinations peak just below 20{sup 0}, with one exceptionally high-inclination object near 80{sup 0}. The currently observed inclination distribution of the Centaurs is not dissimilar to that of the Scattered Extended KBOs and Jupiter-family comets, but is significantly different from the Classical and Resonant KBOs. While the sample sizes of some dynamical classes are still small, these results should begin to serve as a critical diagnostic for models of solar system evolution.

  8. Preferential Transport of Coarse Sediment in Steep Channels

    NASA Astrophysics Data System (ADS)

    Moody, J. A.

    2002-12-01

    Wildfires can change a source-limited system to a transport-limited system especially in steep mountainous terrain where the erosion threshold has been lowered by a wildfire. Such a situation occurred in the Buffalo and Spring Creek watersheds after the 1996 Buffalo Creek Fire, when 1 to 3 m of sediment was deposited in two relatively steep main channels (channel slope equal to 0.02 and 0.04 respectively) after an intense rainstorm of about 110 mm/hour. The bed material was a mixture of coarse grain sizes in both channels. The median size class in Buffalo Creek was 2-4 mm and in Spring Creek it was 4-8 mm. Bedload transport samples were collected in the field using a US BLH-84 sampler for discharge ranging from 0.0036 to 5.2 m3/s. The particle-size distributions for the bedload samples were analyzed to investigate sediment mobility. For each size class, a ratio was calculated equal to the percent of sediment transported divided by the percent of sediment available for transport. The percent available for transport was determined by recalculating the particle-size distribution of the bed material by excluding those sizes that did not move. The average ratio for the median-size class was 1.00 (13 samples) for Buffalo Creek and 0.94 (12 samples) for Spring Creek. In the Buffalo Creek channel, the average ratio for sizes larger than the median size (greater than 2-4 mm) was less than 1.00. Whereas in the Spring Creek channel, the data indicate a preferential transport of sizes larger than the median size with the ratio ranging from 0.86 to 2.22 and averaging 1.42 for the 8-16 mm size class and from 0.37 to 3.86 and averaging 1.28 for the 16-32 mm size class. Possible causes for the difference between Buffalo and Spring Creeks are: 1) the smaller value of the relative roughness (particle diameter/flow depth) in Buffalo Creek, 2) the less steep bed slope in Buffalo Creek, and 3) the difference in the sediment-size distribution

  9. Measurement of steep aspheric surfaces using an anamorphic probe

    NASA Astrophysics Data System (ADS)

    Biswas, Amiya; Coupland, Jeremy

    2008-04-01

    Synthetic aperture interferometry has been previously proposed as a possible in-process method to measure aspheric form (R. Tomlinson, Appl. Opt.42, 701, 2003.APOPAI0003-693510.1364/AO.42.000701). Preliminary demonstration utilized a scanning probe consisting of a pair of bare single mode fibers to perform source and receive functions. It was found that this probe did not have sufficient numerical aperture (NA) to measure steep surfaces and that simply increasing the NA decreases the light gathering efficiency substantially. In this paper, we introduce supplementary optics to increase the NA, and the light gathering efficiency has been increased by adopting an anamorphic design. A spherical test optic of known form is measured to demonstrate the capability of the new probe design.

  10. Ducted kinetic Alfven waves in plasma with steep density gradients

    SciTech Connect

    Houshmandyar, Saeid; Scime, Earl E.

    2011-11-15

    Given their high plasma density (n {approx} 10{sup 13} cm{sup -3}), it is theoretically possible to excite Alfven waves in a conventional, moderate length (L {approx} 2 m) helicon plasma source. However, helicon plasmas are decidedly inhomogeneous, having a steep radial density gradient, and typically have a significant background neutral pressure. The inhomogeneity introduces regions of kinetic and inertial Alfven wave propagation. Ion-neutral and electron-neutral collisions alter the Alfven wave dispersion characteristics. Here, we present the measurements of propagating kinetic Alfven waves in helium helicon plasma. The measured wave dispersion is well fit with a kinetic model that includes the effects of ion-neutral damping and that assumes the high density plasma core defines the radial extent of the wave propagation region. The measured wave amplitude versus plasma radius is consistent with the pile up of wave magnetic energy at the boundary between the kinetic and inertial regime regions.

  11. EPA External Research Grants Program Faces Steep Budget Cuts

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2004-03-01

    The Bush administration's proposed budget cuts to the Environmental Protection Agency's research grants program, Science to Achieve Results (STAR), came under criticism at hearing of the Science Subcommittee on Environment, Technology and Standards of U.S. House of Representatives. The hearing was held 11 March. Subcommittee members and several witnesses said that a proposed $36 million cut to the STAR's fiscal year 2005 budget-compared to the FY2004 proposed budget-is too steep. They said the proposed $65 million budget-which would represents a cut of 30% from the previous fiscal year-would harm the program, as well as the agency's ability to receive outside research advice on a range of cutting-edge environmental issues. Funding for STAR graduate fellowships also would be cut by 3.1%, compared to the enacted level for FY2004.

  12. An important erosion process on steep burnt hillslopes

    NASA Astrophysics Data System (ADS)

    Langhans, Christoph; Nyman, Petter; Noske, Philip; Lane, Patrick; Sheridan, Gary

    2016-04-01

    Steep forested hillslopes often display a high degree of armouring where diffusive erosion processes preferentially remove the fine fraction of the surface soil. High infiltration capacities, hydraulic resistance to overland flow and physical anchoring by cover plants and litter mean that even the most extreme rainfall events usually do not erode the armouring substantially. We argue that fire (wild or planned) is essential to the mobilization and transport of the armouring by increasing the rates of overland flow and decreasing trapping opportunities. We present evidence of the types of erosion that lead to the stripping of the surface armouring using post-event surveys and high-rate overland flow experiments. The type of erosion depends on the relative abundance of non-cohesive surface material to overland flow, but we found that a particular type of transport dominates that has no representation in current erosion models: On steep slopes overland flow can lead to incipient motion of individual stones that transfer their momentum to other stones leading to a rapid mobilization of the whole non-cohesive, armoured surface layer. Once in motion, the layer quickly separates out into a granular flow front and liquefied body, akin to debris flows in channels. Depending on the size of the event, these hillslope debris flows (HDF) either get trapped or enter into the channel, stripping the hillslope of most armouring on their way. They provide channels with the material and shear stress needed to erode into the channel bed, increasing the risk of channel debris flows. We present a simple physical model of HDF initiation, movement, and possible re-mobilization on hillslopes that was derived from debris flow theory. Understanding this process, its frequency, and magnitude are important for assessing the role of fire in landscape evolution and risk to humans through debris flow impacts.

  13. Oscillations of relative inclination angles in compact extrasolar planetary systems

    NASA Astrophysics Data System (ADS)

    Becker, Juliette C.; Adams, Fred C.

    2016-01-01

    The Kepler mission has detected dozens of compact planetary systems with more than four transiting planets. This sample provides a collection of close-packed planetary systems with relatively little spread in the inclination angles of the inferred orbits. A large fraction of the observational sample contains limited multiplicity, begging the question whether there is a true diversity of multitransiting systems, or if some systems merely possess high mutual inclinations, allowing them to appear as single-transiting systems in a transit-based survey. This paper begins an exploration of the effectiveness of dynamical mechanisms in exciting orbital inclination within exoplanetary systems of this class. For these tightly packed systems, we determine that the orbital inclination angles are not spread out appreciably through self-excitation. In contrast, the two Kepler multiplanet systems with additional non-transiting planets are susceptible to oscillations of their inclination angles, which means their currently observed configurations could be due to planet-planet interactions alone. We also provide constraints and predictions for the expected transit duration variations for each planet. In these multiplanet compact Kepler systems, oscillations of their inclination angles are remarkably hard to excite; as a result, they tend to remain continually mutually transiting (CMT-stable). We study this issue further by augmenting the planet masses and determining the enhancement factor required for oscillations to move the systems out of transit. The oscillations of inclination found here inform the recently suggested dichotomy in the sample of Solar systems observed by Kepler.

  14. Size Distribution of Main-Belt Asteroids with High Inclination

    NASA Astrophysics Data System (ADS)

    Terai, Tsuyoshi; Itoh, Yoichi

    2011-04-01

    We investigated the size distribution of high-inclination main-belt asteroids (MBAs) so as to explore asteroid collisional evolution under hypervelocity collisions of around 10 km s-1. We performed a wide-field survey for high-inclination sub-km MBAs using the 8.2-m Subaru Telescope with the Subaru Prime Focus Camera (Suprime-Cam). Suprime-Cam archival data were also used. A total of 616 MBA candidates were detected in an area of 9.0 deg² with a limiting magnitude of 24.0 mag in the SDSS r filter. Most of the candidate diameters were estimated to be smaller than 1 km. We found a scarcity of sub-km MBAs with high inclination. Cumulative size distributions (CSDs) were constructed using Subaru data and published asteroid catalogs. The power-law indexes of the CSDs were 2.17±0.02 for low-inclination (<15°) MBAs and 2.02±0.03 for high-inclination (>15°) MBAs in the 0.7-50 km diameter range. The high-inclination MBAs had a shallower CSD. We also found that the CSD of S-like MBAs had a small slope with high inclination, whereas the slope did not vary with the inclination in the C-like group. The most probable cause of the shallow CSD of the high-inclination S-like MBAs is the large power-law index in the diameter-impact strength curve in hypervelocity collisions. The collisional evolution of MBAs may have advanced with oligopolistic survival during the dynamical excitation phase in the final stage of planet formation.

  15. Ground reaction forces on stairs: effects of stair inclination and age.

    PubMed

    Stacoff, Alex; Diezi, Christian; Luder, Gerhard; Stüssi, Edgar; Kramers-de Quervain, Inès A

    2005-01-01

    The goals of the study were to compare data of vertical ground reaction force (GRF) parameters during level walking, stair ascent and descent on three different stair inclinations and three different age groups. Twenty healthy subjects of three age groups (young 33.7 years; middle 63.6 years; old 76.5 years) were tested during the seven test conditions with 8-10 repetitions. Vertical forces were measured during two consecutive steps with force plates embedded in the walkway and the staircase. The results showed that during level walking the vertical GRF curves were very regular and repetitive, the trail-to-trial variability and left-right asymmetry of defined test parameters being around 2-5% and 3-5%. During stair ascent the vertical GRF force pattern was found to change slightly compared to level gait, but considerably compared to stair descent. On the steep stair the average vertical load increased up to 1.6 BW, and variability (5-10%) and asymmetry (5-15%) were increased significantly. The steep stair descent condition was found to be the most demanding test showing the largest variability and asymmetry and thus, the least stable gait pattern. Age was found to be a factor which should be considered, because the young age group walked faster and produced larger vertical GRF maxima during level walking and on stair ascent than the middle and old age group. Differences between the middle and old age group were found to be small. The present investigation is the first to provide normative data of GRF parameters on gait variability and symmetry of two consecutive steps during level gait and stair ambulation. It is the intention that the results of this study may be used as a basis for comparison with patient data. PMID:15536031

  16. 8. DETAIL VIEW OF INCLINED OUTLET GATE WHEEL, LOOKING EAST ...

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

    8. DETAIL VIEW OF INCLINED OUTLET GATE WHEEL, LOOKING EAST - High Mountain Dams in Upalco Unit, Kidney Lake Dam, Ashley National Forest, 4.7 miles North of Miners Gulch Campground, Mountain Home, Duchesne County, UT

  17. 7. VIEW OF INCLINED OUTLET GATE WHEEL AND STEM, LOOKING ...

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

    7. VIEW OF INCLINED OUTLET GATE WHEEL AND STEM, LOOKING NORTH - High Mountain Dams in Upalco Unit, Kidney Lake Dam, Ashley National Forest, 4.7 miles North of Miners Gulch Campground, Mountain Home, Duchesne County, UT

  18. 12. DETAIL VIEW OF NORTHEAST CORNER, SHOWING HIP VERTICAL, INCLINED ...

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

    12. DETAIL VIEW OF NORTHEAST CORNER, SHOWING HIP VERTICAL, INCLINED END POST, AND UPPER CHORD - Kennan-Jump River Bridge, Spanning South fork of Jump River on County Highway "N", Kennan, Price County, WI

  19. 22. INCLINED END POST / DECK / GUARDRAIL DETAIL OF ...

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

    22. INCLINED END POST / DECK / GUARDRAIL DETAIL OF THROUGH TRUSSES. VIEW TO SOUTHEAST. - Abraham Lincoln Memorial Bridge, Spanning Missouri River on Highway 30 between Nebraska & Iowa, Blair, Washington County, NE

  20. 5. DETAIL OF NORTHWEST END OF TRUSS, SHOWING INCLINED POST, ...

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

    5. DETAIL OF NORTHWEST END OF TRUSS, SHOWING INCLINED POST, TOP CHORD AND DIAGONAL BRACING. - North Branch Quantico Creek Bridge, Prince William Forest Park, on NPS Route 406 spanning north branch of Quantico Creek, Dumfries, Prince William County, VA

  1. The orbital inclination of Cygnus XR-1 measured polarimetrically

    SciTech Connect

    Dolan, J.F.; Tapia, S.; Steward Observatory, Tucson, AZ )

    1989-09-01

    The X-ray binary Cyg XR-1/HDE 226868 was observed polarimetrically over one orbit at three different optical wavelengths. The standard theory of Brown, et al. (1978) is used to derive an orbital inclination i = 62 deg (+5 deg, -37 deg), where the error is the 90-percent-confidence interval derived by the method of Simmons, et al. (1980). The value of the orbital inclination is significantly lower than values based on polarimetric observations. The difference is a result of the observational protocols used. A bias toward larger values of the inclination caused by the tidal distortion of the primary is still found in the present result. The inclination derived corresponds to a mass of the compact component of 6.3 solar masses, above the maximum mass of any degenerate configuration consistent with general relativity except a black hole. 37 refs.

  2. 20. VIEW LOOKING SOUTHWEST OF NORTH PONY TRUSS; SHOWING INCLINED ...

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

    20. VIEW LOOKING SOUTHWEST OF NORTH PONY TRUSS; SHOWING INCLINED END POST, HIP VERTICAL, VERTICAL POSTS, DIAGONALS, AND COUNTER BRACING - Boyleston Bridge, Spanning Skunk River, Lowell, Henry County, IA

  3. 26. UPPER STATION, LOWER FLOOR, BULL WHEEL. Monongahela Incline ...

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

    26. UPPER STATION, LOWER FLOOR, BULL WHEEL. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  4. 6. VIEW NORTH, LOWER STATION EAST SIDE. Monongahela Incline ...

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

    6. VIEW NORTH, LOWER STATION EAST SIDE. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  5. Students as Researchers: An Inclined-Plane Activity.

    ERIC Educational Resources Information Center

    Edwards, Thomas G.

    1995-01-01

    Describes an inquiry activity in which students explore the variables that influence the amount of time it takes a ball to roll down an inclined plane. Relates features of the activity to recommendations in the NCTM Standards. (MKR)

  6. Mission analysis data for inclined geosynchronous orbits, part 1

    NASA Technical Reports Server (NTRS)

    Graf, O. F., Jr.; Wang, K. C.

    1980-01-01

    Data needed for preliminary design of inclined geosynchronous missions are provided. The inertial and Earth fixed coordinate systems are described, as well as orbit parameters and elements. The complete family of geosynchronous orbits is discussed. It is shown that circular inclined geosynchronous orbits comprise only one set in this family. The major orbit perturbation and their separate effects on the geosynchronous orbit are discussed. Detailed information on the orbit perturbation of inclined circular geosynchronous orbits is given, with emphasis on time history data of certain orbital elements. Orbit maintenance delta velocity (V) requirements to counteract the major orbit perturbations are determined in order to provide order of magnitude estimates and to show the effects of orbit inclination on delta V. Some of the considerations in mission design for a multisatellite system, such as a halo orbit constellation, are discussed.

  7. 5. VIEW OF INCLINED OUTLET GATE WHEEL, STEM AND STEM ...

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

    5. VIEW OF INCLINED OUTLET GATE WHEEL, STEM AND STEM GUIDE, (12' DIAMETER HARDESTY MODEL 112 CIRCULAR GATE), LOOKING NORTHEAST - High Mountain Dams in Bonneville Unit, Island Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

  8. 4. VIEW OF INCLINED OUTLET GATE WHEEL AND STEM, LOOKING ...

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

    4. VIEW OF INCLINED OUTLET GATE WHEEL AND STEM, LOOKING NORTHWEST - High Mountain Dams in Upalco Unit, Brown Duck Lake Dam, Ashley National Forest, 4.4 miles North of Miners Gulch Campground, Mountain Home, Duchesne County, UT

  9. 7. VIEW OF INCLINED OUTLET GATE WHEEL, STEM AND STEM ...

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

    7. VIEW OF INCLINED OUTLET GATE WHEEL, STEM AND STEM GUIDE (15' HARDESTY MODEL 115 GATE), LOOKING NORTHWEST - High Mountain Dams in Bonneville Unit, Marjorie Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

  10. 5. VIEW SHOWING INCLINED OUTLET GATE WHEEL, STEM AND STEM ...

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

    5. VIEW SHOWING INCLINED OUTLET GATE WHEEL, STEM AND STEM GUIDE (28' WIDE HARDESTY CAST IRON SLIDE HEADGATE), LOOKING NORTHEAST - High Mountain Dams in Bonneville Unit, Duck Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

  11. 4. VIEW OF INCLINED OUTLET GATE, STEM, STEM GUIDE AND ...

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

    4. VIEW OF INCLINED OUTLET GATE, STEM, STEM GUIDE AND WHEEL (10' HARDESTY VERTICAL LIFT GATE), LOOKING NORTHWEST - High Mountain Dams in Bonneville Unit, Pot Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

  12. 6. VIEW SHOWING INCLINED OUTLET GATE WHEEL, STEM AND STEM ...

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

    6. VIEW SHOWING INCLINED OUTLET GATE WHEEL, STEM AND STEM GUIDE (18' HARDESTY GATE), LOOKING SOUTHEAST - High Mountain Dams in Bonneville Unit, Long Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

  13. 58. VIEW OF CABLE INCLINE, LOCATED ON THE HILLSIDE BELOW ...

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

    58. VIEW OF CABLE INCLINE, LOCATED ON THE HILLSIDE BELOW THE FOREBAY (NORTHWEST OF FOREBAY), Print No. 156, August 1903 - Electron Hydroelectric Project, Along Puyallup River, Electron, Pierce County, WA

  14. 1. EXTERIORANGLED AND INCLINED TO AUTOMATIC PLOTTING AND ORTHOPRINTING LIMITS ...

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

    1. EXTERIOR--ANGLED AND INCLINED TO AUTOMATIC PLOTTING AND ORTHOPRINTING LIMITS Copy photograph of photogrammetric plate LC-HABS-GS05-T-4950-101L. - Lemon Building, 1729 New York Avenue, Northwest, Washington, District of Columbia, DC

  15. The Asymmetrical "Sticking" Behavior of Two Balls on an Incline.

    ERIC Educational Resources Information Center

    Mallinckrodt, A. John

    1999-01-01

    Offers a relatively simple analysis of the asymmetrical "sticking" and rolling behavior of two balls, one steel and one rubber, on an incline. Describes an Interactive Physics (TM) simulation designed to study the problem and gives rough experimental results. (WRM)

  16. 7. DETAIL VIEW OF ROCKER ARM, SHOWING POCKETS, LUGS, INCLINED ...

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

    7. DETAIL VIEW OF ROCKER ARM, SHOWING POCKETS, LUGS, INCLINED STOPPING BLOCK AT SHOREWARD END OF TRACK GIRDER - Seddon Island Scherzer Rolling Lift Bridge, Spanning Garrison Channel from Tampa to Seddon Island, Tampa, Hillsborough County, FL

  17. Detail of inside of inclined end post, with portal cross ...

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

    Detail of inside of inclined end post, with portal cross bar member. - Phoenix Iron Company, French Creek Bridge, Spanning French Creek between Gay Street & Main Street, Phoenixville, Chester County, PA

  18. Safety Case Notations: Alternatives for the Non-Graphically Inclined?

    NASA Technical Reports Server (NTRS)

    Holloway, C. M.

    2008-01-01

    This working paper presents preliminary ideas of five possible text-based notations for representing safety cases, which may be easier for non-graphically inclined people to use and understand than the currently popular graphics-based representations.

  19. On the Emmenthal distribution of highly inclined asteroids

    NASA Astrophysics Data System (ADS)

    Carruba, V.; Machuca, J. F.

    2011-12-01

    Highly inclined asteroids are objects with sin (i) > 0.3. Among highly inclined asteroids, we can distinguish between objects with inclinations smaller than that of the centre of the ν6= g - g6 secular resonance and objects at higher inclinations. Using the current mechanisms of dynamical mobility, it is not easy to increase the values of an asteroid with an initial small inclination to values higher than that of the centre of the ν6 resonance. The presence of highly inclined objects might therefore be related to the early phases of the Solar system. It has been observed that several dynamically stable regions are characterized by a very low number density of objects, unlike low-inclined bodies that tend to occupy all the dynamically viable regions. The distribution of asteroids at a high inclination in the domain of proper elements in dynamically stable regions resembles an Emmenthal cheese, with regions of low number density close to highly populated areas. While this phenomenon has been observed qualitatively in the past, no quantitative study has yet been carried out on the extent and long-term stability of these regions. In this paper, we identify two dynamically stable regions characterized by very low values of number density and permanence times of 100 Myr or more when the Yarkovsky force is considered. We show that the low number density of objects in these areas cannot be produced as a statistical fluctuation of any simple one-dimensional statistical distribution, such as the Poissonian, uniform and Gaussian distributions, or of a tri-dimensional distribution, such as the tri-variate normal distribution. The presence of unoccupied dynamically stable regions could indicate that the primordial asteroidal population might not have reached all available zones at high-i. This sets constraints on the scenarios for the early phases of the history of our Solar system.

  20. Geotechnical properties of cemented sands in steep slopes

    USGS Publications Warehouse

    Collins, B.D.; Sitar, N.

    2009-01-01

    An investigation into the geotechnical properties specific to assessing the stability of weakly and moderately cemented sand cliffs is presented. A case study from eroding coastal cliffs located in central California provides both the data and impetus for this study. Herein, weakly cemented sand is defined as having an unconfined compressive strength (UCS) of less than 100 kPa, and moderately cemented sand is defined as having UCS between 100 and 400 kPa. Testing shows that both materials fail in a brittle fashion and can be modeled effectively using linear Mohr-Coulomb strength parameters, although for weakly cemented sands, curvature of the failure envelope is more evident with decreasing friction and increasing cohesion at higher confinement. Triaxial tests performed to simulate the evolving stress state of an eroding cliff, using a reduction in confinement-type stress path, result in an order of magnitude decrease in strain at failure and a more brittle response. Tests aimed at examining the influence of wetting on steep slopes show that a 60% decrease in UCS, a 50% drop in cohesion, and 80% decrease in the tensile strength occurs in moderately cemented sand upon introduction to water. In weakly cemented sands, all compressive, cohesive, and tensile strength is lost upon wetting and saturation. The results indicate that particular attention must be given to the relative level of cementation, the effects of groundwater or surficial seepage, and the small-scale strain response when performing geotechnical slope stability analyses on these materials. ?? 2009 ASCE.

  1. Improved numerical modeling of morphodynamics of rivers with steep banks

    NASA Astrophysics Data System (ADS)

    Langendoen, Eddy J.; Mendoza, Alejandro; Abad, Jorge D.; Tassi, Pablo; Wang, Dongchen; Ata, Riadh; El kadi Abderrezzak, Kamal; Hervouet, Jean-Michel

    2016-07-01

    The flow and sediment transport processes near steep streambanks, which are commonly found in meandering, braided, and anastomosing stream systems, exhibit complex patterns that produce intricate interactions between bed and bank morphologic adjustment. Increasingly, multi-dimensional computer models of riverine morphodynamics are used to aid in the study of these processes. A number of depth-averaged two-dimensional models are available to simulate morphologic adjustment of both bed and banks. Unfortunately, these models use overly simplified conceptual models of riverbank erosion, are limited by inflexible structured mesh systems, or are unable to accurately account for the flow and sediment transport adjacent to streambanks of arbitrary geometry. A new, nonlinear model is introduced that resolves these limitations. The model combines the river morphodynamics computer models TELEMAC-2D and SISYPHE of the open source TELEMAC-MASCARET suite of solvers with the bank erosion modules of the CONCEPTS channel evolution computer model. The performance of the new model is evaluated for meander-planform initiation and development. The most important findings are: (1) the model is able to simulate a much greater variety and complexity in meander wavelengths; (2) simulated meander development agrees closely with the unified bar-bend theory of Tubino and Seminara (1990); and (3) the rate of meander planform adjustment is greatly reduced if the wavelength of alternate bars is similar to that of meanders.

  2. Radar scattering properties of steep-sided domes on Venus

    NASA Technical Reports Server (NTRS)

    Ford, Peter G.

    1994-01-01

    More than 100 quasi-circular steep-sided volcanic domes, with diameters ranging from 6 to 60 km, have been observed on the surface of Venus by the Magellan radar mapper. Assuming that they have the shape of a solidified high-viscosity Newtonian fluid, their radar scattering properties can be studied in detail from Magellan images, since a typical radar swath resolves each dome into several tens of thousands of measurements of radar cross section at incidence angles varying fom 15 deg to 55 deg. Through examination of 20 domes in detail, it appears that many of those situated on lava plains scatter radar in a manner that is indistinguishable from that of the surrounding material, suggesting that either (1) they were formed of a relatively high-density high-viscosity material, e.g., andesite, rather than a lower-density one, e.g., rhyolite or dacite; or (2) that their surfaces share a common origin with those of their surroundings, e.g., through in situ weathering or aeolian deposition.

  3. An Explanation for the High Inclinations of Amalthea and Thebe

    NASA Astrophysics Data System (ADS)

    Proctor, Amanda; Hamilton, Douglas; Rauch, Kevin

    2002-04-01

    We propose that the anomalously large inclinations of the inner moons Amalthea (I=0.33^circ) and Thebe (I=1.09^circ) result from kicks imparted by Io's strong resonances as those resonances scan across the location of the moons. Both the eccentricities and inclinations of the moons are excited during resonant passages. But while the eccentricities decay rapidly due to the large satellite tides raised by the planet, the inclinations are basically preserved since they decay slowly due to the tiny planetary tides raised by the satellite. Through analysis of our numerical simulations we were able to limit Io's formation distance from Jupiter to between 4.02 and 4.92 Jovian Radii. Io's 3:1 resonances can impart an inclination of ~ 0.3^circ to Amalthea, while the 4:2 resonance gives too large a kick. We find that either the 4:2 resonance acting alone, or in combination with the 5:3 and the 6:4, causes Thebe's inclination to rise to about 1 degree. Our theory naturally explains the high inclinations of these two small satellites.

  4. Heliospheric current sheet inclinations predicted from source surface maps

    NASA Technical Reports Server (NTRS)

    Shodhan, S.; Crooker, N. U.; Hughes, W. J.; Siscoe, G. L.

    1994-01-01

    The inclinations of the neutral line at the ecliptic plane derived from source surface model maps of coronal fields are measured for the interval from June 1976 to March 1992. The mean and median values of 53 deg and 57 deg are close to the average inclinations determined earlier from minimum variance analyses of solar wind measurements at sector boundaries, but the mode falls in the 80 deg - 90 deg bin. This result, which is based on the model assumptions implicit in deriving the source surface maps, predicts that the heliospheric current sheet typically intersects the ecliptic plane nearly at right angles, even without steepening by stream interaction regions. High inclinations dominate the solar cycle for about 7 years around solar maximum. Dips to lower inclination occur near solar minimum, but high variance admits a wide range of inclinations throughout the cycle. Compared to the smooth solar cycle variation of the maximum latitudinal excursion of the neutral line, often treated as the tilt angle of a flat heliospheric current sheet, the noisy variation of the inclinations reflects the degree to which the neutral line deviates from a sine wave, implying warps and corrugations in the current sheet. About a third of the time the neutral line so deviates that it doubles back in longitude.

  5. Deriving Stellar Inclination of Slow Rotators Using Stellar Activity

    NASA Astrophysics Data System (ADS)

    Dumusque, X.

    2014-12-01

    Stellar inclination is an important parameter for many astrophysical studies. Although different techniques allow us to estimate stellar inclination for fast rotators, it becomes much more difficult when stars are rotating slower than ~2-2.5 km s-1. By using the new activity simulation SOAP 2.0 which can reproduce the photometric and spectroscopic variations induced by stellar activity, we are able to fit observations of solar-type stars and derive their inclination. For HD 189733, we estimate the stellar inclination to be i=84+6-20 deg, which implies a star-planet obliquity of \\psi =4+18-4 considering previous measurements of the spin-orbit angle. For α Cen B, we derive an inclination of i=45+9-19, which implies that the rotational spin of the star is not aligned with the orbital spin of the α Cen binary system. In addition, assuming that α Cen Bb is aligned with its host star, no transit would occur. The inclination of α Cen B can be measured using 40 radial-velocity measurements, which is remarkable given that the projected rotational velocity of the star is smaller than 1.15 km s-1. Based on observations made with the MOST satellite, the HARPS instrument on the ESO 3.6 m telescope at La Silla Observatory (Chile), and the SOPHIE instrument at the Observatoire de Haute Provence (France).

  6. Deriving stellar inclination of slow rotators using stellar activity

    SciTech Connect

    Dumusque, X.

    2014-12-01

    Stellar inclination is an important parameter for many astrophysical studies. Although different techniques allow us to estimate stellar inclination for fast rotators, it becomes much more difficult when stars are rotating slower than ∼2-2.5 km s{sup –1}. By using the new activity simulation SOAP 2.0 which can reproduce the photometric and spectroscopic variations induced by stellar activity, we are able to fit observations of solar-type stars and derive their inclination. For HD 189733, we estimate the stellar inclination to be i=84{sub −20}{sup +6} deg, which implies a star-planet obliquity of ψ=4{sub −4}{sup +18} considering previous measurements of the spin-orbit angle. For α Cen B, we derive an inclination of i=45{sub −19}{sup +9}, which implies that the rotational spin of the star is not aligned with the orbital spin of the α Cen binary system. In addition, assuming that α Cen Bb is aligned with its host star, no transit would occur. The inclination of α Cen B can be measured using 40 radial-velocity measurements, which is remarkable given that the projected rotational velocity of the star is smaller than 1.15 km s{sup –1}.

  7. Spreading dynamics of droplet on an inclined surface

    NASA Astrophysics Data System (ADS)

    Shen, Chaoqun; Yu, Cheng; Chen, Yongping

    2016-06-01

    A three-dimensional unsteady theoretical model of droplet spreading process on an inclined surface is developed and numerically analyzed to investigate the droplet spreading dynamics via the lattice Boltzmann simulation. The contact line motion and morphology evolution for the droplet spreading on an inclined surface, which are, respectively, represented by the advancing/receding spreading factor and droplet wetted length, are evaluated and analyzed. The effects of surface wettability and inclination on the droplet spreading behaviors are examined. The results indicate that, dominated by gravity and capillarity, the droplet experiences a complex asymmetric deformation and sliding motion after the droplet comes into contact with the inclined surfaces. The droplet firstly deforms near the solid surface and mainly exhibits a radial expansion flow in the start-up stage. An evident sliding-down motion along the inclination is observed in the middle stage. And the surface-tension-driven retraction occurs during the retract stage. Increases in inclination angle and equilibrium contact angle lead to a faster droplet motion and a smaller wetted area. In addition, increases in equilibrium contact angle lead to a shorter duration time of the middle stage and an earlier entry into the retract stage.

  8. Effect of steeping conditions on the amylolytic development of some Nigerian improved sorghum cultivars.

    PubMed

    Ukwuru, M U

    2010-01-01

    Nigerian improved sorghum cultivars 'L538', 'YG5760', 'L1499', 'SSH1' and 'SSH3' were investigated for the effect of steeping conditions on their amylolytic development. The grains were steeped using 3 steep regimes SR 1, SR 2 and SR 3 which involved steeping and re-steeping in cold distilled and de-ionized water for 36, 45 and 54 h respectively. Grains in each SR were divided into 4 portions and further steeped for 6 h using final warm steep temperatures (FWST) of 30, 35, 40 and 45°C. α-and β-Amylase as well as diastatic activity were determined at different FWST. SR and FWST were correlated with enzyme development. Steeping conditions significantly (p<0.05) affected amylolytic development of the sorghum malts. Optimum moisture content (48%) was obtained at FWST of 35°C. α-Amylase was the predominant enzyme. All enzyme activities were at a peak at FWST of 30 and 35°C and at SR 2. The highest enzyme activity was recorded by cultivar 'YG5760' malt-(α-amylase 272, β-Amylase 169 μg equivalent glucose). High relationship existed between α-amylase and moderate relationship between β-Amylase and SR. Similar relationship existed between enzyme development and FWST. PMID:23572602

  9. Some observations on vortex-ring collisions upon inclined surfaces

    NASA Astrophysics Data System (ADS)

    New, T. H.; Shi, Shengxian; Zang, B.

    2016-06-01

    This paper reports upon a laser-induced fluorescence visualization and time-resolved particle image velocimetry study to resolve the detailed dynamics associated with Re = 2000 and 4000 circular vortex rings colliding with 30°-75° inclined surfaces. Two-dimensional visualization results show that larger inclination angles lead to increasingly rapid size reduction in the primary vortex-ring core closer to the surface, faster formation of the secondary vortex-ring core, and subsequent ingestion by the former. In contrast, primary vortex-ring core further away from the surface becomes physically larger and incoherent more rapidly, with slower formation and entrainment of the secondary vortex-ring core. Interestingly, a vortex dipole and small vortex-ring-like structure are produced for the largest inclination angle of 75°, possibly due to vortex disconnection and reconnection processes. Results taken along the non-inclined plane show significant bulging of the primary vortex-ring cores when the inclination angle increases from 30° onwards. More importantly, additional vortex cores are observed to entwine with the primary vortex-ring core and provide strong direct evidence for the bi-helical vortex line flow mechanism put forward by Lim (Exp Fluids 7:453-463, 1989). Lastly, the behaviour of the primary and secondary vortex-ring cores further away from the surface is highly sensitive towards the state of the bi-helical lines compressed at that region. Strong compression driven by circumferential flows due to large inclination angles may explain the unique flow structures and behaviour observed for 75° inclination angle here.

  10. Inclination flattening and the geocentric axial dipole hypothesis [rapid communication

    NASA Astrophysics Data System (ADS)

    Tauxe, Lisa

    2005-05-01

    William Gilbert first articulated what has come to be known as the geocentric axial dipole hypothesis. The GAD hypothesis is the principle on which paleogeographic reconstructions rely to constrain paleolatitude. For decades, there have been calls for permanent non-dipole contributions to the time-averaged field. Recently, these have demanded large contributions of the axial octupole, which, if valid, would call into question the general utility of the GAD hypothesis. In the process of geological recording of the geomagnetic field, "Earth filters" distort the directions. Many processes, for example, sedimentary inclination flattening and random tilting, can lead to a net shallowing of the observed direction. Therefore, inclinations that are shallower than expected from GAD can be explained by recording biases, northward transport, or non-dipole geomagnetic fields. Using paleomagnetic data from the last 5 million years from well-constrained lava flow data allows the construction of a statistical geomagnetic field model. Such a model can predict not only the average expected direction for a given latitude, but also the shape of the distribution of directions produced by secular variation. The elongation of predicted directions varies as a function of latitude (from significantly elongate in the up/down direction at the equator to circularly symmetric at the poles). Sedimentary inclination flattening also works in a predictable manner producing elongations that are stretched side to side and the degree of flattening depending on the inclination of the applied field and a "flattening factor" f. The twin tools of the predicted elongation/inclination relationship characteristic of the geomagnetic field for the past 5 million years and the distortion of the directions predicted from sedimentary inclination flattening allows us to find the flattening factor that yields corrected directions with an elongation and average inclination consistent with the statistical field

  11. TRANSIT PROBABILITIES FOR STARS WITH STELLAR INCLINATION CONSTRAINTS

    SciTech Connect

    Beatty, Thomas G.; Seager, Sara

    2010-04-01

    The probability that an exoplanet transits its host star is high for planets in close orbits, but drops off rapidly for increasing semimajor axes. This makes transit surveys for planets with large semimajor axes orbiting bright stars impractical, since one would need to continuously observe hundreds of stars that are spread out over the entire sky. One way to make such a survey tractable is to constrain the inclination of the stellar rotation axes in advance, and thereby enhance the transit probabilities. We derive transit probabilities for stars with stellar inclination constraints, considering a reasonable range of planetary system inclinations. We find that stellar inclination constraints can improve the transit probability by almost an order of magnitude for habitable-zone planets. When applied to an ensemble of stars, such constraints dramatically lower the number of stars that need to be observed in a targeted transit survey. We also consider multiplanet systems where only one planet has an identified transit and derive the transit probabilities for the second planet assuming a range of mutual planetary inclinations.

  12. Evolution of magnetic field inclination in a forming penumbra

    NASA Astrophysics Data System (ADS)

    Jurčák, Jan; Bello González, Nazaret; Schlichenmaier, Rolf; Rezaei, Reza

    2014-12-01

    As a sunspot penumbra forms, the magnetic field vector at the outer boundary of the protospot undergoes a transformation. We study the changes of the magnetic field vector at this boundary as a penumbral segment forms. We analyze a set of spectropolarimetric maps covering 2 hr during the formation of a sunspot in NOAA 11024. The data were recorded with the GFPI instrument attached to the German VTT. We observe a stationary umbra/quiet Sun boundary, where the magnetic field becomes more horizontal with time. The magnetic field inclination increases by 5°, reaching a maximum value of about 59°. The maximum inclination coincides with the onset of filament formation. In time, the penumbra filaments become longer and the penumbral bright grains protrude into the umbra, where the magnetic field is stronger and more vertical. Consequently, we observe a decrease in the magnetic field inclination at the boundary as the penumbra grows. In summary, in order to initiate the formation of the penumbra, the magnetic field at the umbral (protospot) boundary becomes more inclined. As the penumbra grows, the umbra/penumbra boundary migrates inwards, and at this boundary the magnetic field turns more vertical again, while it remains inclined in the outer penumbra.

  13. Flood and Debris Flow Hazard Predictions in Steep, Burned Landscapes

    NASA Astrophysics Data System (ADS)

    Rengers, Francis; McGuire, Luke; Kean, Jason; Staley, Dennis

    2016-04-01

    scale. The calibrated effective watershed hydraulic conductivity was low for both models, even for storms occurring several months after the fire, consistent with wildfire-induced water-repellency being retained throughout that time. Both models captured the timing of flow peaks, although neither model correctly simulated the flow depth. This study suggests that a kinematic wave model, which is simpler and more computationally efficient, is a justifiable approach for predicting flood and debris flow timing in steep, burned watersheds. By demonstrating the applicability of these models, this study takes an important step towards the development of process-based methods to assess post-wildfire flood and debris flow hazards.

  14. Effect of Wildfire on Sediment Sorting in a Steep Channel

    NASA Astrophysics Data System (ADS)

    Florsheim, J. L.; Chin, A.; O'Hirok, L.; Storesund, R.

    2014-12-01

    Wildfire is an external forcing factor in the landscape. In chaparral environments, wildfire initiates transport of well-sorted fine sediment through dry-ravel processes on hillslopes and facilitates delivery of sediment to stream channels. In turn, this periodic post-fire sediment influx governs sorting of channel-bed material during subsequent floods that mobilize and transport the sediment downstream. We investigated the effects of the May 2013 Springs Wildfire in the Santa Monica Mountains in semi-arid southern California with field measurements and terrestrial LiDAR scanning. Before the fire, sediment sorting within the heterogeneous bed material present in Big Sycamore Creek was controlled by organized step-pool bedforms. Boulders formed steps with relatively finer cobbles, gravel, and sand filling the pools. Before the fire, the grain size distribution present in the substrate between boulder steps was relatively coarse (D84 = 250 mm), in contrast to that in the influx of sediment contributed by post-fire dry-ravel processes deposited at channel margins (D84 = 8 mm). Flow shear stress during one small flood in 2014 (post-fire) was adequate to mobilize fine dry ravel- related sediment. Transport capacity was sufficient to mobilize and transport this sediment within a study reach; however, it was not adequate to flush the fine material downstream. Shear stress required to mobilize sediment contributed by dry ravel was substantially less than that required to transport the substrate material present before the wildfire. The small flood deposited fine sediment (D84 = 16 mm) as flow lost capacity. Resulting deposition buried bedforms, changing the step-pool profile to a plane bed. The relatively poorly sorted, coarse, rough bed changed to a well sorted, fine, smooth, bed. These changes have implications for sediment transport dynamics and aquatic ecology. In steep, semi-arid, chaparral fluvial systems, sediment derived from dry-ravel processes influences the

  15. Synchrotron radiation computed laminography using an inclined detector.

    PubMed

    Zhang, Jie; Li, Gang; Yi, Qiru; Chen, Yu; Gao, Zhenhua; Jiang, Xiaoming

    2015-01-01

    Synchrotron radiation computed laminography (SR-CL) has been in use in three-dimensional non-destructive imaging of flat objects for several years. A new set-up is proposed based on the traditional SR-CL method but with the detector inclined at the same angle as the sample inclination to collect projections. The results of computer simulations and real-sample experiments demonstrate that reconstructions acquired using an inclined detector are of better quality compared with those acquired using ordinary detecting methods, especially for the situation of few projections and small difference of attenuation ratio of the sample. This method could be applied to obtain high-quality images of weak-contrast samples with short measurement time and mild radiation damage. PMID:25537599

  16. On the inclination and habitability of the HD 10180 system

    SciTech Connect

    Kane, Stephen R.; Gelino, Dawn M.

    2014-09-10

    There are numerous multi-planet systems that have now been detected via a variety of techniques. These systems exhibit a range of both planetary properties and orbital configurations. For those systems without detected planetary transits, a significant unknown factor is the orbital inclination. This produces an uncertainty in the mass of the planets and their related properties, such as atmospheric scale height. Here we investigate the HD 10180 system, which was discovered using the radial velocity technique. We provide a new orbital solution for the system which allows for eccentric orbits for all planets. We show how the inclination of the system affects the mass/radius properties of the planets and how the detection of phase signatures may resolve the inclination ambiguity. We finally evaluate the Habitable Zone properties of the system and show that the g planet spends 100% of an eccentric orbit within the Habitable Zone.

  17. Interplay between geometry and temperature for inclined Casimir plates

    SciTech Connect

    Weber, Alexej; Gies, Holger

    2009-09-15

    We provide further evidence for the nontrivial interplay between geometry and temperature in the Casimir effect. We investigate the temperature dependence of the Casimir force between an inclined semi-infinite plate above an infinite plate in D dimensions using the worldline formalism. Whereas the high-temperature behavior is always found to be linear in T in accordance with dimensional-reduction arguments, different power-law behaviors at small temperatures emerge. Unlike the case of infinite parallel plates, which shows the well-known T{sup D} behavior of the force, we find a T{sup D-1} behavior for inclined plates, and a {approx}T{sup D-0.3} behavior for the edge effect in the limit where the plates become parallel. The strongest temperature dependence {approx}T{sup D-2} occurs for the Casimir torque of inclined plates. Numerical as well as analytical worldline results are presented.

  18. Low velocity impact of inclined CSM composite laminates

    SciTech Connect

    Arnold, W.S.; Madjidi, S.; Marshall, I.H.; Robb, M.D.

    1993-12-31

    The damage tolerance of composite laminates subject to low velocity impact is an important aspect of current design philosophies required to ensure the integrity of primary load bearing structures. To the authors knowledge, no work published in the open literature has addressed the damage tolerance of composites subject to impacts at non-perpendicular inclinations, which in practical situations is the most common form of impact. This paper describes an experimental study, devised to assess the influence of inclined impact on the residual strength characteristics of CSM laminates. Preliminary experimental results and comparisons with previous work on flat plate impact tests are presented. The influence of the degree of inclination and impact energy are correlated with the laminates damage area and residual tensile properties.

  19. Transit Timing Variations for Inclined and Retrograde Exoplanetary Systems

    NASA Astrophysics Data System (ADS)

    Payne, Matthew J.; Ford, Eric B.; Veras, Dimitri

    2010-03-01

    We perform numerical calculations of the expected transit timing variations (TTVs) induced on a hot-Jupiter by an Earth-mass perturber. Motivated by the recent discoveries of retrograde transiting planets, we concentrate on an investigation of the effect of varying relative planetary inclinations, up to and including completely retrograde systems. We find that planets in low-order (e.g., 2:1) mean-motion resonances (MMRs) retain approximately constant TTV amplitudes for 0° < i < 170°, only reducing in amplitude for i>170°. Systems in higher order MMRs (e.g., 5:1) increase in TTV amplitude as inclinations increase toward 45°, becoming approximately constant for 45° < i < 135°, and then declining for i>135°. Planets away from resonance slowly decrease in TTV amplitude as inclinations increase from 0° to 180°, whereas planets adjacent to resonances can exhibit a huge range of variability in TTV amplitude as a function of both eccentricity and inclination. For highly retrograde systems (135° < i <= 180°), TTV signals will be undetectable across almost the entirety of parameter space, with the exceptions occurring when the perturber has high eccentricity or is very close to an MMR. This high inclination decrease in TTV amplitude (on and away from resonance) is important for the analysis of the known retrograde and multi-planet transiting systems, as inclination effects need to be considered if TTVs are to be used to exclude the presence of any putative planetary companions: absence of evidence is not evidence of absence.

  20. Excitation of the orbital inclination of Iapetus during planetary encounters

    SciTech Connect

    Nesvorný, David; Vokrouhlický, David; Deienno, Rogerio; Walsh, Kevin J.

    2014-09-01

    Saturn's moon, Iapetus, has an orbit in a transition region where the Laplace surface is bending from the equator to the orbital plane of Saturn. The orbital inclination of Iapetus to the local Laplace plane is ≅ 8°, which is unexpected because the inclination should be ≅ 0 if Iapetus formed from a circumplanetary disk on the Laplace surface. It thus appears that some process has pumped up Iapetus's inclination while leaving its eccentricity near zero (e ≅ 0.03 at present). Here, we examined the possibility that Iapetus's inclination was excited during the early solar system instability when encounters between Saturn and ice giants occurred. We found that the dynamical effects of planetary encounters on Iapetus's orbit sensitively depend on the distance of the few closest encounters. In 4 out of 10 instability cases studied here, the orbital perturbations were too large to be plausible. In one case, Iapetus's orbit was practically unaffected. In the remaining five cases, the perturbations of Iapetus's inclination were adequate to explain its present value. In three of these cases, however, Iapetus's eccentricity was excited to >0.1-0.25, and it is not clear whether it could have been damped to its present value (≅ 0.03) by a subsequent process (e.g., tides and dynamical friction from captured irregular satellites do not seem to be strong enough). Our results therefore imply that only 2 out of 10 instability cases (∼20%) can excite Iapetus's inclination to its current value (∼30% of trials lead to >5°) while leaving its orbital eccentricity low.

  1. Joint distribution of successive wave steepness parameters. [Water wave modeling and effects on offshore oil platforms

    SciTech Connect

    Myrhaug, D. . Dept. of Marine Hydrodynamics); Rue, H. . Division of Industrial Mathematics)

    1993-08-01

    In this paper, a joint distribution of wave steepness parameters for two successive waves is presented. The wave steepness parameters considered herein are the crest front steepness and the total wave steepness. The joint distribution of wave steepness parameters for two successive waves is represented by a two-dimensional Weibull distribution with the parameters [alpha]=0.84 and [beta]=1.40. The application of the results is illustrated by an example. Overall these results seem to be physically sound, although they are valid for the particular sea state chosen. The present approach has some basis in measured wave data, but comparison with data on the joint distribution of steepness parameters for two successive waves are needed before any conclusion can be drawn on the ability of this approach to describe measured wave data. Such a data base should be established from carefully designed field measurements in order to have the possibility to measure nonlinear properties of the waves. However, at present this joint distribution of steepness parameters for two successive waves should represent a useful tool for engineering applications.

  2. Seismic wave propagation in thinly-layered media with steep reflectors

    SciTech Connect

    Deng, H.L.

    1992-05-01

    Seismic waves reflected from steep reflectors in the earth`s subsurface spend a significant amount of time travelling more or less horizontally. Therefore, accurate imaging of steep geologic structure requires knowledge of the behavior of these horizontally propagating waves. In particular, the effect of tunneling on seismic waves propagating in thinly-layered media must be understood. I describe a method for modeling seismic waves traveling in thinly-layered media. This method, a frequency-wavenumber finite-difference scheme coupled with the Born approximation, is useful in studying seismic waves reflected from steep geologic structures.

  3. Seismic wave propagation in thinly-layered media with steep reflectors

    SciTech Connect

    Deng, H.L.

    1992-05-01

    Seismic waves reflected from steep reflectors in the earth's subsurface spend a significant amount of time travelling more or less horizontally. Therefore, accurate imaging of steep geologic structure requires knowledge of the behavior of these horizontally propagating waves. In particular, the effect of tunneling on seismic waves propagating in thinly-layered media must be understood. I describe a method for modeling seismic waves traveling in thinly-layered media. This method, a frequency-wavenumber finite-difference scheme coupled with the Born approximation, is useful in studying seismic waves reflected from steep geologic structures.

  4. Critical Shields Values in Coarse-Bedded Steep Streams

    NASA Astrophysics Data System (ADS)

    Bunte, K.; Abt, S. R.; Swingle, K. W.; Cenderelli, D. A.; Schneider, J. M.

    2013-12-01

    Critical Shields values for poorly mobile, semi-alluvial mountain streams are not provided by the original Shields diagram and are still debated. This empirical study uses gravel bedload samples collected with unbiasing samplers at 22 stream sites and establishes a relation between instantaneous discharge and the largest sampled bedload particle size for each site. Using relations between flow depth and discharge, critical Shields values for particle sizes corresponding to the bed surface D50, D16, D84, and D50s sizes at each site can be backcomputed from the established critical flow or flow competence relations. Critical Shields values for all bed material particle size percentiles increase with stream gradient Sx and are stratifiable by relative flow depth d/D50 and relative roughness (D84/d) which improves prediction. Critical Shields values for the bed D16 sizes (τ*c16) are approximately three times larger than those for the D50 size (τ*c50), while those for the D84 size (τ*c84) are approximately half of τ*c50. It remains unclear to what extent physical processes or numerical artifacts contribute to determining critical Shields values. Specific critical Shields values are needed to predict the average largest particle size mobile at bankfull flow (DBmax,bf). So far, no Shields values are available for this common task, especially not in poorly mobile semi-alluvial streams. Critical bankfull Shields values (τ*cbf) backcomputed from the largest particles transported at bankfull flow approach τ*c16 at steep gradient streams and τ*c84 at low gradients and therefore increase very steeply with Sx. The relation τ*cbf = f(Sx) is stratified by bed mobility D50/DBmax,bf and predictable if bed mobility can be categorized in the field. Non-critical Shields values (τ*bf50) computed from bankfull flow depth and the bed surface D50 size differ from τ*c50 and from critical bankfull Shields values τ*cbf. Only in bankfull mobile streams where D50/DBmax,bf = 1 can

  5. Effect of an inclined magnetic field on peristaltic flow of Williamson fluid in an inclined channel with convective conditions

    NASA Astrophysics Data System (ADS)

    Hayat, T.; Bibi, Shahida; Rafiq, M.; Alsaedi, A.; Abbasi, F. M.

    2016-03-01

    This paper deals with the influence of inclined magnetic field on peristaltic flow of an incompressible Williamson fluid in an inclined channel with heat and mass transfer. Convective conditions of heat and mass transfer are employed. Viscous dissipation and Joule heating are taken into consideration. Mathematical modeling also includes Soret and Dufour effects. Channel walls have compliant properties. Analysis has been carried out through long wavelength and low Reynolds number approach. Resulting problems are solved for small Weissenberg number. Impacts of variables reflecting the salient features of wall properties, Biot numbers and Soret and Dufour on the velocity, temperature, concentration and heat transfer coefficient are pointed out. Trapping phenomenon is also analyzed.

  6. 11. VIEW SOUTHEAST, DETAIL OF INCLINED END POST, SHOWING CASTIRON ...

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

    11. VIEW SOUTHEAST, DETAIL OF INCLINED END POST, SHOWING CAST-IRON WEDGE SET INTO LOWER CHORD; FLOOR-BEAM HANGER BLOCKS TO LEFT - Meeting House Bridge, Spanning Boston & Maine Railroad 0.1 mile east of Biddleford Road, Arundel, York County, ME

  7. 1. SAND DRAINING & DRYING BUILDING (RIGHT), COVERED INCLINE CONVEYOR ...

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

    1. SAND DRAINING & DRYING BUILDING (RIGHT), COVERED INCLINE CONVEYOR (LOWER RIGHT) THAT EXTENDS TO THE SAND-SORTING BUILDING, AND REMAINS OF ORIGINAL (1917) WASHING, DRAINING & DRYING BUILDING (LEFT), VIEW LOOKING WEST FROM TOP OF SAND-SORTING BUILDING - Mill "C" Complex, Sand Draining & Drying Building, South of Dee Bennet Road, near Illinois River, Ottawa, La Salle County, IL

  8. Students' Entrepreneurial Inclination at a Malaysian Polytechnic: A Preliminary Investigation

    ERIC Educational Resources Information Center

    Yasin, Ahmad Yasruddin Md; Mahmood, Nik Abdul Aziz Nik; Jaafar, Nik Azyyati Nik

    2011-01-01

    This paper reports preliminary results of an ongoing project to examine students' inclination towards entrepreneurship at a Malaysian polytechnic. The study used a self-administered questionnaire to explore the influence of entrepreneurial intent, perceived behavioral control, self-efficacy, perceived barriers, perceived support factors and…

  9. 'Inclined abstainers': a problem for predicting health-related behaviour.

    PubMed

    Orbell, S; Sheeran, P

    1998-06-01

    A longitudinal test of the association between motivation to undertake a precautionary health action and subsequent behaviour was conducted on women's uptake of the cervical screening test. A sample of never-screened women (N = 166) completed measures derived from protection-motivation theory (PMT; Rogers, 1983). One year later, screening uptake was reliably determined from medical records. While regression analyses demonstrated that PMT variables predicted both motivation to undergo cervical screening and screening uptake, there was, nonetheless, a good deal of inconsistency between protection motivation and screening behaviour. Fifty-seven per cent of those who indicated they were willing to undergo the test did not do so within a one-year period. Discriminant analysis was therefore used to test the ability of cognitions specified by PMT to distinguish four patterns of association between motivation and behaviour: inclined actors, inclined abstainers, disinclined actors and disinclined abstainers. While PMT variables could successfully classify the four groups, it was not possible to derive a reliable discriminant function which distinguished between inclined actors and inclined abstainers. The results suggest that PMT provides a useful account of choice motivation but does not address the psychological processes by which intention is translated into action. Recent calls for the development of a social psychology of volition are discussed in the light of these findings. PMID:9639861

  10. Volumetric velocity measurements of vortex rings from inclined exits

    NASA Astrophysics Data System (ADS)

    Troolin, Daniel R.; Longmire, Ellen K.

    2010-03-01

    Vortex rings were generated by driving pistons within circular cylinders of inner diameter D = 72.8 mm at a constant velocity U 0 over a distance L = D. The Reynolds number, U 0 L/(2ν), was 2500. The flow downstream of circular and inclined exits was examined using volumetric 3-component velocimetry (V3V). The circular exit yields a standard primary vortex ring that propagates downstream at a constant velocity and a lingering trailing ring of opposite sign associated with the stopping of the piston. By contrast, the inclined nozzle yields a much more complicated structure. The data suggest that a tilted primary vortex ring interacts with two trailing rings; one associated with the stopping of the piston, and the other associated with the asymmetry of the cylinder exit. The two trailing ring structures, which initially have circulation of opposite sign, intertwine and are distorted and drawn through the center of the primary ring. This behavior was observed for two inclination angles. Increased inclination was associated with stronger interactions between the primary and trailing vortices as well as earlier breakdown.

  11. North portal and deck view, from north, showing inclined endposts, ...

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

    North portal and deck view, from north, showing inclined endposts, Pratt through trusses, north portal strut, overhead bracing, pipe rails and posts, and concrete deck with bituminous wearing surface - Castle Garden Bridge, Township Route 343 over Bennetts Branch of Sinnemahoning Creek, Driftwood, Cameron County, PA

  12. South portal and deck view from south, showing inclined endposts, ...

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

    South portal and deck view from south, showing inclined endposts, Pratt through trusses, south portal strut, overhead bracing, pipe rails and posts, and concrete deck with bituminous wearing surface - Castle Garden Bridge, Township Route 343 over Bennetts Branch of Sinnemahoning Creek, Driftwood, Cameron County, PA

  13. Inclined Planes and Motion Detectors: A Study of Acceleration.

    ERIC Educational Resources Information Center

    Tracy, Dyanne M.

    2001-01-01

    Presents an activity in which students work in cooperative groups and roll balls down inclined planes, collect data with the help of an electronic motion detector, and represent data with a graphing calculator to explore concepts such as mass, gravity, velocity, and acceleration. (Contains 12 references.) (Author/ASK)

  14. Reconstruction of Galileo Galilei's Experiment: The Inclined Plane

    ERIC Educational Resources Information Center

    Straulino, S.

    2008-01-01

    In the "Third Day" of the "Discourses and Mathematical Demonstrations Concerning Two New Sciences" Galileo Galilei describes the famous experiment of the inclined plane and uses it to bring an experimental confirmation to the laws of uniformly accelerated motion. We describe a reconstruction of the experiment and how the results can be used for…

  15. 85. INCLINED PLANE 7 EAST. FLUME AND STONE POWER HOUSE ...

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

    85. INCLINED PLANE 7 EAST. FLUME AND STONE POWER HOUSE ARE ON RIGHT SIDE OF PHOTOGRAPH. NOTE THE CABLE LEAVING THE POWER HOUSE. THIS CABLE IS ATTATCHED TO A DRUM ON THE INSIDE THE POWER HOUSE WHICH IS TURNED BY MEANS OF A WATER POWERED TURBINE. - Morris Canal, Phillipsburg, Warren County, NJ

  16. Motion on an Inclined Plane and the Nature of Science

    ERIC Educational Resources Information Center

    Pendrill, Ann-Marie; Ekström, Peter; Hansson, Lena; Mars, Patrik; Ouattara, Lassana; Ryan, Ulrika

    2014-01-01

    Friction is an important phenomenon in everyday life. All children are familiar with playground slides, which may thus be a good starting point for investigating friction. Motion on an inclined plane is a standard physics example. This paper presents an investigation of friction by a group of 11-year olds. How did they plan their investigations?…

  17. Spatio-temporal patterns in inclined layer convection

    NASA Astrophysics Data System (ADS)

    Subramanian, Priya; Brausch, Oliver; Daniels, Karen E.; Bodenschatz, Eberhard; Schneider, Tobias M.; Pesch, Werner

    2016-05-01

    This paper reports on a theoretical analysis of the rich variety of spatio-temporal patterns observed recently in inclined layer convection at medium Prandtl number when varying the inclination angle $\\gamma$ and the Rayleigh number $R$. The present numerical investigation of the inclined layer convection system is based on the standard Oberbeck-Boussinesq equations. The patterns are shown to originate from a complicated competition of buoyancy-driven and shear-flow driven pattern forming mechanisms. The former are expressed as \\rm{longitudinal} convection rolls with their axes oriented parallel to the incline, the latter as perpendicular \\rm{transverse} rolls. Along with conventional methods to study roll patterns and their stability, we employ direct numerical simulations in large spatial domains, comparable with the experimental ones. As a result, we determine the phase diagram of the characteristic complex 3D convection patterns above onset of convection in the $\\gamma-R$ plane, and find that it compares very well with the experiments. In particular we demonstrate that interactions of specific Fourier modes, characterized by a resonant interaction of their wavevectors in the layer plane, are key to understanding the pattern morphologies.

  18. Slip Potential for Commonly Used Inclined Grated Metal Walkways

    PubMed Central

    Pollard, Jonisha P.; Heberger, John R.; Dempsey, Patrick G.

    2016-01-01

    Background No specific guidelines or regulations are provided by the Mine Safety and Health Administration for the use of inclined grated metal walkways in mining plants. Mining and other companies may be using walkway materials that do not provide sufficient friction, contributing to slip and fall injuries. Purpose The purpose of this study was to determine if there are significant differences in the required friction for different grated metal walkways during walking in diverse conditions. Methods The normalized coefficients of friction were measured for 12 participants while walking up and down an instrumented walkway with different inclinations (0°, 5°, 10°, 15°, and 20°) and with and without the presence of a contaminant (glycerol). Self-reported slip events were recorded and the required coefficients of friction were calculated considering only the anterior/posterior components of the shear forces. Additionally, the available coefficients of friction for these walkway materials were measured at the 0° orientation using a tribometer, with and without the presence of the contaminant, using a boot heel as well as Neolite as the test feet. Results The number of slips increased when the inclination angle reached 10° and above. Of all materials tested, the diamond weave grating was found to have the best performance at all inclines and when contaminated or dry. A high number of slips occurred for the perforated grating and serrated bar grating at 20° when contaminated. Conclusions Results of this study suggest that the diamond weave grating provides significantly better friction compared to serrated bar and perforated gratings, especially at inclines greater than 10°. PMID:26779388

  19. Stability of stratified two-phase flows in inclined channels

    NASA Astrophysics Data System (ADS)

    Barmak, I.; Gelfgat, A. Yu.; Ullmann, A.; Brauner, N.

    2016-08-01

    Linear stability of the stratified gas-liquid and liquid-liquid plane-parallel flows in the inclined channels is studied with respect to all wavenumber perturbations. The main objective is to predict the parameter regions in which the stable stratified configuration in inclined channels exists. Up to three distinct base states with different holdups exist in the inclined flows, so that the stability analysis has to be carried out for each branch separately. Special attention is paid to the multiple solution regions to reveal the feasibility of the non-unique stable stratified configurations in inclined channels. The stability boundaries of each branch of the steady state solutions are presented on the flow pattern map and are accompanied by the critical wavenumbers and the spatial profiles of the most unstable perturbations. Instabilities of different nature are visualized by the streamlines of the neutrally stable perturbed flows, consisting of the critical perturbation superimposed on the base flow. The present analysis confirms the existence of two stable stratified flow configurations in a region of low flow rates in the countercurrent liquid-liquid flows. These configurations become unstable with respect to the shear mode of instability. It was revealed that in slightly upward inclined flows the lower and middle solutions for the holdup are stable in the part of the triple solution region, while the upper solution is always unstable. In the case of downward flows, in the triple solution region, none of the solutions are stable with respect to the short-wave perturbations. These flows are stable only in the single solution region at low flow rates of the heavy phase, and the long-wave perturbations are the most unstable ones.

  20. Deontological and utilitarian inclinations in moral decision making: a process dissociation approach.

    PubMed

    Conway, Paul; Gawronski, Bertram

    2013-02-01

    Dual-process theories of moral judgment suggest that responses to moral dilemmas are guided by two moral principles: the principle of deontology states that the morality of an action depends on the intrinsic nature of the action (e.g., harming others is wrong regardless of its consequences); the principle of utilitarianism implies that the morality of an action is determined by its consequences (e.g., harming others is acceptable if it increases the well-being of a greater number of people). Despite the proposed independence of the moral inclinations reflecting these principles, previous work has relied on operationalizations in which stronger inclinations of one kind imply weaker inclinations of the other kind. The current research applied Jacoby's (1991) process dissociation procedure to independently quantify the strength of deontological and utilitarian inclinations within individuals. Study 1 confirmed the usefulness of process dissociation for capturing individual differences in deontological and utilitarian inclinations, revealing positive correlations of both inclinations to moral identity. Moreover, deontological inclinations were uniquely related to empathic concern, perspective-taking, and religiosity, whereas utilitarian inclinations were uniquely related to need for cognition. Study 2 demonstrated that cognitive load selectively reduced utilitarian inclinations, with deontological inclinations being unaffected. In Study 3, a manipulation designed to enhance empathy increased deontological inclinations, with utilitarian inclinations being unaffected. These findings provide evidence for the independent contributions of deontological and utilitarian inclinations to moral judgments, resolving many theoretical ambiguities implied by previous research. PMID:23276267

  1. Kepler-108: A Mutually Inclined Giant Planet System

    NASA Astrophysics Data System (ADS)

    Mills, Sean M.; Fabrycky, Daniel

    2016-06-01

    The vast majority of well studied giant-planet systems, including the Solar System, are nearly coplanar which implies dissipation within a primordial gas disk. However, intrinsic instability may lead to planet-planet scattering, which often produces non-coplanar, eccentric orbits. Planet scattering theories have been developed to explain observed high eccentricity systems and possibly hot Jupiters; thus far their predictions for mutual inclination (I) have barely been tested. Here we characterize a highly mutually-inclined (I ~ 15-60 degrees), moderately eccentric (e > 0.1) giant planet system: Kepler-108. This system consists of two Saturn mass planets with periods of ~49 and ~190 days around a star with a wide (~300 AU) binary companion in an orbital configuration inconsistent with a purely disk migration origin.

  2. Control system for inclined impact-type surface seismic source

    SciTech Connect

    Karner, G.M.

    1987-07-28

    A system is described for controlling the azimuths and inclinations of the respective shooting paths of separate vehicle-transported surface seismic sources. Each source has an impact mass, means for propelling the mass along the shooting path to strike an earth contacting base plate, and means for adjusting each shooting path by rotation thereof about two mutually perpendicular gimbal axes oriented in predetermined relation to the heading of the associated vehicle. The system consists of: (a) means for determining each such vehicle heading; (b) means dependent upon each vehicle heading for calculating the angular positions of each shooting path with respect to the gimbal axes which align the shooting path with desired values of azimuth and inclination; and (c) means responsive to the calculation means for actuating each shooting path adjustment means to effect such alignment.

  3. Drop impact and rebound dynamics on an inclined superhydrophobic surface.

    PubMed

    Yeong, Yong Han; Burton, James; Loth, Eric; Bayer, Ilker S

    2014-10-14

    Due to its potential in water-repelling applications, the impact and rebound dynamics of a water drop impinging perpendicular to a horizontal superhydrophobic surface have undergone extensive study. However, drops tend to strike a surface at an angle in applications. In such cases, the physics governing the effects of oblique impact are not well studied or understood. Therefore, the objective of this study was to conduct an experiment to investigate the impact and rebound dynamics of a drop at various liquid viscosities, in an isothermal environment, and on a nanocomposite superhydrophobic surface at normal and oblique impact conditions (tilted at 15°, 30°, 45°, and 60°). This study considered drops falling from various heights to create normal impact Weber numbers ranging from 6 to 110. In addition, drop viscosity was varied by decreasing the temperature for water drops and by utilizing water-glycerol mixtures, which have similar surface tension to water but higher viscosities. Results revealed that oblique and normal drop impact behaved similarly (in terms of maximum drop spread as well as rebound dynamics) at low normal Weber numbers. However, at higher Weber numbers, normal and oblique impact results diverged in terms of maximum spread, which could be related to asymmetry and more complex outcomes. These asymmetry effects became more pronounced as the inclination angle increased, to the point where they dominated the drop impact and rebound characteristics when the surface was inclined at 60°. The drop rebound characteristics on inclined surfaces could be classified into eight different outcomes driven primarily by normal Weber number and drop Ohnesorge numbers. However, it was found that these outcomes were also a function of the receding contact angle, whereby reduced receding angles yielded tail-like structures. Nevertheless, the contact times of the drops with the coating were found to be generally independent of surface inclination. PMID:25216298

  4. Inclined fluidized bed system for drying fine coal

    DOEpatents

    Cha, Chang Y.; Merriam, Norman W.; Boysen, John E.

    1992-02-11

    Coal is processed in an inclined fluidized bed dryer operated in a plug-flow manner with zonal temperature and composition control, and an inert fluidizing gas, such as carbon dioxide or combustion gas. Recycled carbon dioxide, which is used for drying, pyrolysis, quenching, and cooling, is produced by partial decarboxylation of the coal. The coal is heated sufficiently to mobilize coal tar by further pyrolysis, which seals micropores upon quenching. Further cooling with carbon dioxide enhances stabilization.

  5. Graphs and matroids weighted in a bounded incline algebra.

    PubMed

    Lu, Ling-Xia; Zhang, Bei

    2014-01-01

    Firstly, for a graph weighted in a bounded incline algebra (or called a dioid), a longest path problem (LPP, for short) is presented, which can be considered the uniform approach to the famous shortest path problem, the widest path problem, and the most reliable path problem. The solutions for LPP and related algorithms are given. Secondly, for a matroid weighted in a linear matroid, the maximum independent set problem is studied. PMID:25126607

  6. Shock waves in Stokes flows down an inclined plate.

    PubMed

    Benilov, E S; Lapin, V N

    2011-06-01

    We consider a viscous flow on an inclined plate, such that the liquid's depth far upstream is larger than that far downstream, resulting in a "smoothed-shock wave" steadily propagating downstream. Our numerical simulations show that in a large section of the problem's parameter space all initial conditions overturn (i.e., the liquid's surface becomes vertical at some point) and thus no steady solution exists. The overturning can only be stopped by a sufficiently strong surface tension. PMID:21797491

  7. Trigonometric series representations of the orbital inclination function

    NASA Astrophysics Data System (ADS)

    El-Sayed Awad, M.

    1986-08-01

    New trigonometric representations of the orbital inclination function in multiples of cosines or sines are developed for all possible values of l, m, and p. The literal analytical expressions and the recurrence formulas which are satisfied by their coefficients are derived, and an efficient algorithm for the table formulation of the trigonometric series representations is presented. Numerical examples for the representations are demonstrated for the cases l = 2(1)4, m = 0(1)l, and p = 0(1)l.

  8. Sex Differences in Incline-Walking among Humans.

    PubMed

    Wall-Scheffler, Cara M

    2015-12-01

    Previous research has shown that people tend to walk around the speed that minimizes energy consumption when traveling a given distance. It has further been shown that men and women have different speeds that minimize energy and that women will choose slower speeds when the activity itself is a high-rate activity (e.g. carrying a load). Here we investigate what men and women will do when given a high rate walking activity, namely walking on an inclined surface. Fourteen people (nine men and five women) walked at four speeds on a level treadmill and four speeds on an inclined treadmill while their metabolic rate, kinematics and core temperature were monitored. Following the data collection, participants were asked to identify their ‘preferred’ walking speed at each of the conditions. Cost of transport (CoT) curves were calculated for each individual, and the delta between the preferred and the ‘optimal’ speeds were calculated. People chose to walk at slightly slower speeds on the level; there was minimal change in the cost to walk at these slower speeds. Women walked at absolutely slower speeds on the incline than men (P=0.06) and had significantly larger speed deltas (P=0.02), thus choosing to walk at slower rate speeds. Women also showed a significant relationship between the rate of activity and core temperature, whereas men did not. This is consistent with other research showing that women choose behavioral strategies to minimize body temperature changes. PMID:26901887

  9. ARTICULATOR-RELATED REGISTRATION AND ANALYSIS OF SAGITTAL CONDYLAR INCLINATION.

    PubMed

    Cimić, Samir; Simunković, Sonja Kraljević; Suncana Simonić Kocijan; Matijević, Jurica; Dulcić, Niksa; Catić, Amir

    2015-12-01

    The purpose of this investigation was to study sagittal condylar inclination values within a uniform sample (Angle class I occlusion) using 'articulator-related registration' and Camper's plane as a reference plane. The study was performed on a sample of 58 Angle class I subjects (mean age 25.1, SD 3.1). Measurements were performed with an ultrasonic jaw tracking device with six degrees of freedom. After a paraocclusal tray was fixed in the mouth, each subject had to make three protrusive movements and three right and left laterotrusive movements. From protrusive movements the software of the device automatically calculated the left and the right sagittal condylar inclination values used for setting of the articulator. The mean sagittal condylar inclinationvalue was 41.0° (SD 10.5) for the right joint and 40.7° (SD 9.8) for the left joint. The maximum value was 65.0° for the right and 68.6° for the left joint, and the minimum value was 13.7° for the right and 21.7° for the left joint. The results of this study suggested the average articulator setting for sagittal condylar inclination for fully dentate adult subjects to be 40° in relation to Camper's plane. This is especially important for the articulators that are set up in relation to Camper's plane. PMID:27017716

  10. ASSEMBLY OF PROTOPLANETARY DISKS AND INCLINATIONS OF CIRCUMBINARY PLANETS

    SciTech Connect

    Foucart, Francois; Lai, Dong

    2013-02-10

    The Kepler satellite has discovered a number of transiting planets around close binary stars. These circumbinary systems have highly aligned planetary and binary orbits. In this paper, we explore how the mutual inclination between the planetary and binary orbits may reflect the physical conditions of the assembly of protoplanetary disks and the interaction between protostellar binaries and circumbinary disks. Given the turbulent nature of star-forming molecular clouds, it is possible that the gas falling onto the outer region of a circumbinary disk and the central protostellar binary have different axes of rotation. Thus, the newly assembled circumbinary disk can be misaligned with respect to the binary. However, the gravitational torque from the binary produces a warp and twist in the disk, and the back-reaction torque tends to align the disk and the binary orbital plane. We present a new, analytic calculation of this alignment torque and show that the binary-disk inclination angle can be reduced appreciably after the binary accretes a few percent of its mass from the disk. Our calculation suggests that in the absence of other disturbances, circumbinary disks and planets around close (sub-AU) stellar binaries, for which mass accretion onto the proto-binary is very likely to have occurred, are expected to be highly aligned with the binary orbits, while disks and planets around wide binaries can be misaligned. Measurements of the mutual inclinations of circumbinary planetary systems can provide a clue to the birth environments of such systems.

  11. a Study of Ricochet Phenomenon for Inclined Impact of Projectile

    NASA Astrophysics Data System (ADS)

    Jo, Jong-Hyun; Lee, Young-Shin

    In this study, the numerical simulation using AUTODYN-3D program was investigated for trajectory prediction for inclined impacts of projectiles. The penetration and perforation of polycarbonate(PC) plate by 7.62 mm projectile was investigated numerically. The characteristic structure of the projectile's trajectory in the PC plates was studied. Two combined failure criteria were used in the target plate, and the target plate was modeled with the properties of polycarbonate for simulating the ricochet phenomenon. The numerical analyses were used to study the effect of the angle of inclination on the trajectory and kinetic energy of the projectile. The dynamic deformation behaviors tests of PC were compared with numerical simulation results which can be used for predictive purpose. Ricochet phenomenon for angles of inclination of 0° ≤ θ ≤ 20° in the analysis. The projectile perforated the plate for θ > 30°, thus defined a failure envelope for numerical configuration. The numerical analyses was used to study the effect under the projectile impact velocity on the depth of penetration(DOP).

  12. Technical note: Common characteristics of directional spreading-steepness joint distribution in freak wave events

    NASA Astrophysics Data System (ADS)

    Liu, Shouhua; Li, Yizhen; Yue, Xinyang

    2016-06-01

    Seven freak wave incidents previously documented in the real ocean in combination with model hindcast simulations are used to study the variations associated with freak-wave-related parameters, such as wave steepness, directional spreading, and frequency bandwidth. Unlike the strong correlations between the freak wave parameters and freak waves' occurrence which were obtained in experimental and physical research, the correlations are not clear in the freak waves occurring in the real ocean. Wave directional spreading-steepness joint distribution is introduced and common visual features were found in the joint distribution when freak waves occur among seven "freakish" sea states. The visual features show that freak wave incidents occur when the steepness is large and directional spreading is small. Besides large steepness and small directional spreading, a long-duration, relatively rough sea state is also necessary for the freak wave generation. The joint distribution is more informative than any single statistical wave parameter. The continuous sea states of local large steepness and small directional spreading are supposed to generate freak waves, and two-dimensional distribution visualization is found to be a useful tool for freak waves' forecast. The common visual features of joint distributions supply an important cue for the theoretical and experimental research.

  13. Does perceived steepness deter stair climbing when an alternative is available?

    PubMed

    Eves, Frank F; Thorpe, Susannah K S; Lewis, Amanda; Taylor-Covill, Guy A H

    2014-06-01

    Perception of hill slant is exaggerated in explicit awareness. Proffitt (Perspectives on Psychological Science 1:110-122, 2006) argued that explicit perception of the slant of a climb allows individuals to plan locomotion in keeping with their available locomotor resources, yet no behavioral evidence supports this contention. Pedestrians in a built environment can often avoid climbing stairs, the man-made equivalent of steep hills, by choosing an adjacent escalator. Stair climbing is avoided more by women, the old, and the overweight than by their comparators. Two studies tested perceived steepness of the stairs as a cue that promotes this avoidance. In the first study, participants estimated the steepness of a staircase in a train station (n = 269). Sex, age, height, and weight were recorded. Women, older individuals, and those who were heavier and shorter reported the staircase as steeper than did their comparison groups. In a follow-up study in a shopping mall, pedestrians were recruited from those who chose the stairs and those who avoided them, with the samples stratified for sex, age, and weight status. Participants (n = 229) estimated the steepness of a life-sized image of the stairs they had just encountered, presented on the wall of a vacant shop in the mall. Pedestrians who avoided stair climbing by choosing the escalator reported the stairs as steeper even when demographic differences were controlled. Perceived steepness may to be a contextual cue that pedestrians use to avoid stair climbing when an alternative is available. PMID:24197656

  14. Simple Model of a Rolling Water-Filled Bottle on an Inclined Ramp

    ERIC Educational Resources Information Center

    Lin, Shihao; Hu, Naiwen; Yao, Tianchen; Chu, Charles; Babb, Simona; Cohen, Jenna; Sangiovanni, Giana; Watt, Summer; Weisman, Danielle; Klep, James; Walecki, Wojciech J.; Walecki, Eve S.; Walecki, Peter S.

    2015-01-01

    We investigate a water-filled bottle rolling down an incline and ask the following question: is a rolling bottle better described by a model ignoring all internal motion where the bottle is approximated by a material point sliding down an incline, or is it better described by a rigid solid cylinder rolling down the incline without skidding? The…

  15. Deriving stellar inclination of slow rotators using stellar activity signal

    NASA Astrophysics Data System (ADS)

    Dumusque, Xavier

    2015-01-01

    Stellar inclination is an important parameter for many astrophysical studies. In the context of exoplanets, this allows us to derive the true obliquity of a system if the projected stellar spin-planetary orbit angle can measured via the Rossiter-Mclaughlin effect. Although different techniques allow us to estimate stellar inclination for fast rotators, it becomes much more difficult when stars are rotating slower than 2-2.5 km.s-1. By using the new activity simulation SOAP 2.0 that can reproduce the photometric and spectroscopic variations induced by stellar activity, we are able to fit the activity variation of solar-type stars and derive their inclination. The case of the equator-on star HD189733 will be presented, as well as the case of Alpha Centauri B, which present an inclination of 45+9-19 degrees, implying that the earth-mass orbiting planet is not transiting if aligned with its host star. Other exemples will also demonstrate the power of the technique, that can infer a stellar inclination, even for slow rotators like Alpha Centauri B, that present a projected rotational velocity smaller than 1.15 km.s-1. In addition, the SOAP 2.0 simulation can be used to correct for the effect of activity when one major active region is dominating the RV signal. This could enhance the detection of small mass exoplanets orbiting slightly active stars.This project is funded by ETAEARTH (European Union Seventh Framework Programme (FP7/2007-2013) under Grant Agreement n. 313014), a transnational collaboration between European countries and the US (the Swiss Space Office, the Harvard Origin of Life Initiative, the Scottish Universities Physics Alliance, the University of Geneva, the Smithsonian Astrophysical Observatory, the Italian National Astrophysical Institute, the University of St. Andrews, Queens University Belfast, and the University of Edinburgh) setup to optimize the synergy between space-and ground-based data whose scientific potential for the characterization of

  16. Compact steep-spectrum sources as the parent population of flat-spectrum radio-loud narrow-line Seyfert 1 galaxies

    NASA Astrophysics Data System (ADS)

    Berton, M.; Caccianiga, A.; Foschini, L.; Peterson, B. M.; Mathur, S.; Terreran, G.; Ciroi, S.; Congiu, E.; Cracco, V.; Frezzato, M.; La Mura, G.; Rafanelli, P.

    2016-06-01

    Narrow-line Seyfert 1 galaxies (NLS1s) are an interesting subclass of active galactic nuclei (AGN), which tipically does not exhibit any strong radio emission. Seven percent of them, though, are radio-loud and often show a flat radio-spectrum (F-NLS1s). This, along to the detection of γ-ray emission coming from them, is usually interpreted as a sign of a relativistic beamed jet oriented along the line of sight. An important aspect of these AGN that must be understood is the nature of their parent population, in other words how do they appear when observed under different angles. In the recent literature it has been proposed that a specific class of radio-galaxies, compact-steep sources (CSS) classified as high excitation radio galaxies (HERG), can represent the parent population of F-NLS1s. To test this hypothesis in a quantitative way,in this paper we analyzed the only two statistically complete samples of CSS/HERGs and F-NLS1s available in the literature. We derived the black hole mass and Eddington ratio distributions, and we built for the first time the radio luminosity function of F-NLS1s. Finally, we applied a relativistic beaming model to the luminosity function of CSS/HERGs, and compared the result with the observed function of F-NLS1s. We found that compact steep-spectrum sources are valid parent candidates and that F-NLS1s, when observed with a different inclination, might actually appear as CSS/HERGs.

  17. Rainfall and sheet power model for interrill erosion in steep slope

    NASA Astrophysics Data System (ADS)

    Shin, Seung Sook; Deog Park, Sand; Nam, Myeong Jun

    2015-04-01

    The two-phase process of interrill erosion consist of the splash and detachment of individual particles from soil mass by impact of raindrops and the transport by erosive running water. Most experimental results showed that the effect of interaction between rainfall impact and surface runoff increases soil erosion in low or gentle slope. Especially, the combination of rain splash and sheet flow is the dominant runoff and erosion mechanism occurring on most steep hillslopes. In this study, a rainfall simulation was conducted to evaluate interrill erosion in steep slope with cover or non-cover. The kinetic energy of raindrops of rainfall simulator was measured by disdrometer used to measure the drop size distribution and velocity of falling raindrops and showed about 0.563 rate of that calculated from empirical equation between rainfall kinetic energy and rainfall intensity. Surface and subsurface runoff and sediment yield depended on rainfall intensity, gradient of slope, and existence of cover. Sediment from steep plots under rainfall simulator is greatly reduced by existence of the strip cover that the kinetic energy of raindrop approximates to zero. Soil erosion in steep slope with non-cover was nearly 4.93 times of that measured in plots with strip cover although runoff was only 1.82 times. The equation of a rainfall and sheet power was used to evaluate sediment yields in steep slope with cover or non-cover. The power model successfully explained physical processes for interrill erosion that combination of raindrop impact and sheet flow increases greatly soil erosion in steep slope. This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education, Science and Technology(No. 2013R1A1A3011962).

  18. Effects of low frequency ultrasonic treatment on the maturation of steeped greengage wine.

    PubMed

    Zheng, Xinhua; Zhang, Min; Fang, Zhongxiang; Liu, Yaping

    2014-11-01

    To accelerate wine maturation, low frequency ultrasonic waves of 28 kHz and 45 kHz were used to treat the steeped greengage wine. The contents of total acid, total ester, fusel oils and the wine chromaticity were determined before and after the ultrasonic treatment. The volatile compounds were analysed by GC-MS method, and the sensory quality was evaluated by panelist. The results indicated that ultrasonic treatment of the steeped greengage wine at 45 kHz 360 W for 30 min was effective to accelerate the aging process, where the fusel oils and alcohol compounds were significantly reduced and acid and ester compounds were significantly increased. PMID:24874386

  19. Ferroelectric gate tunnel field-effect transistors with low-power steep turn-on

    NASA Astrophysics Data System (ADS)

    Lee, M. H.; Wei, Y.-T.; Lin, J.-C.; Chen, C.-W.; Tu, W.-H.; Tang, M.

    2014-10-01

    Using a ferroelectric PbZrTiO3 gate stack, the range of the steep subthreshold swing in tunnel field-effect transistors was extended by 3.5 orders of magnitude demonstrating an improvement in the swing (by approximately double the slope). The drain conductance (gd) shows only 16% enhancement with large V DS (˜-1.5V) indicates internal voltage amplification with ferroelectric negative capacitance effect beneficial to small lateral drain-source bias voltages (-0.1 V). The concept of coupling the ferroelectric polarization is proposed. The power consumption is also discussed in low-power applications of steep subthreshold slope devices.

  20. Advanced Communications Technology Satellite (ACTS) Used for Inclined Orbit Operations

    NASA Technical Reports Server (NTRS)

    Bauer, Robert A.

    2000-01-01

    The Advanced Communications Technology Satellite (ACTS) is operated by the NASA Glenn Research Center at Lewis Field 24 hours a day, 7 days a week. ACTS, which was launched in September 1993, is in its 7th year of operations, far exceeding the system s planned 2 years of operations and 4 years of designed mission life. After 5 successful years of operating as a geostationary satellite, the spacecraft s North-South stationkeeping was discontinued in August 1998. The system is now operating in an inclined orbit that increases at a rate of 0.8 /yr. With only scarce fuel remaining, operating in this mode extends the usage of the still totally functional payload. Although tracking systems are now needed on the experimenter Earth stations, experiment operations have continued with very little disruption. This is the only known geosynchronous Ka-band (30/20 GHz) spot-beam satellite operating in an inclined orbit. The project began its transition from geostationary operations to inclined operations in August 1998. This did not interrupt operations and was transparent to the experimenters on the system. For the space segment, new daily procedures were implemented to maintain the pointing of the system s narrow 0.3 spot beams while the spacecraft drifts in the North-South direction. For the ground segment, modifications were designed, developed, and fielded for the three classes of experimenter Earth stations. With the next generation of commercial satellite systems still being developed, ACTS remains the only operational testbed for Ka-band geosynchronous satellite communications over the Western hemisphere. Since inclined orbit operations began, the ACTS experiments program has supported 43 investigations by industry, Government, and academic organizations, as well as four demonstrations. The project s goals for inclined-orbit operations now reflect a narrower focus in the types of experiments that will be done. In these days of "faster, better, cheaper," NASA is seeking

  1. Intermediate inclinations of type 2 Coronal-Line Forest AGN

    NASA Astrophysics Data System (ADS)

    Rose, Marvin; Elvis, Martin; Crenshaw, Michael; Glidden, Ana

    2015-07-01

    Coronal-Line Forest Active Galactic Nuclei (CLiF AGN) are remarkable in the sense that they have a rich spectrum of dozens of coronal emission lines (e.g. [Fe VII], [Fe X] and [Ne V]) in their spectra. Rose, Elvis & Tadhunter suggest that the inner obscuring torus wall is the most likely location of the coronal line region in CLiF AGN, and the unusual strength of the forbidden high-ionization lines is due to a specific AGN-torus inclination angle. Here, we test this suggestion using mid-IR colours (4.6-22 μm) from the Wide-Field Infrared Survey Explorer for the CLiF AGN. We use the Fischer et al. result that showed that as the AGN-torus inclination becomes more face on, the Spitzer 5.5-30 μm colours become bluer. We show that the [W2-W4] colours for the CLiF AGN (<[W2-W4]> = 5.92 ± 0.12) are intermediate between Sloan Digital Sky Survey (SDSS) type 1 (<[W2-W4]> = 5.22 ± 0.01) and type 2 AGN (<[W2-W4]> = 6.35 ± 0.03). This implies that the AGN-torus inclinations for the CLiF AGN are indeed intermediate, supporting the work of Rose, Elvis & Tadhunter. The confirmed relation between CLiF AGN and their viewing angle shows that CLiF AGN may be useful for our understanding of AGN unification.

  2. Collisionless encounters and the origin of the lunar inclination

    NASA Astrophysics Data System (ADS)

    Pahlevan, Kaveh; Morbidelli, Alessandro

    2015-11-01

    The Moon is generally thought to have formed from the debris ejected by the impact of a planet-sized object with the proto-Earth towards the end of planetary accretion. Models of the impact process predict that the lunar material was disaggregated into a circumplanetary disk and that lunar accretion subsequently placed the Moon in a near-equatorial orbit. Forward integration of the lunar orbit from this initial state predicts a modern inclination at least an order of magnitude smaller than the lunar value -- a long-standing discrepancy known as the lunar inclination problem. Here we show that the modern lunar orbit provides a sensitive record of gravitational interactions with Earth-crossing planetesimals that were not yet accreted at the time of the Moon-forming event. The currently observed lunar orbit can naturally be reproduced via interaction with a small quantity of mass (corresponding to 0.0075-0.015 Earth masses eventually accreted to the Earth) carried by a few bodies, consistent with the constraints and models of late accretion. Although the encounter process has a stochastic element, the observed value of the lunar inclination is among the most likely outcomes for a wide range of parameters. The excitation of the lunar orbit is most readily reproduced via collisionless encounters of planetesimals with the Earth-Moon system with strong dissipation of tidal energy on the early Earth. This mechanism obviates the need for previously proposed (but idealized) excitation mechanisms, places the Moon-forming event in the context of the formation of Earth, and constrains the pristineness of the dynamical state of the Earth-Moon system.

  3. Critical Heat Flux in Inclined Rectangular Narrow Gaps

    SciTech Connect

    Jeong J. Kim; Yong H. Kim; Seong J. Kim; Sang W. Noh; Kune Y. Suh; Joy L. Rempe; Fan-Bill Cheung; Sang B. Kim

    2004-06-01

    In light of the TMI-2 accident, in which the reactor vessel lower head survived the attack by molten core material, the in-vessel retention strategy was suggested to benefit from cooling the debris through a gap between the lower head and the core material. The GAMMA 1D (Gap Apparatus Mitigating Melt Attack One Dimensional) tests were conducted to investigate the critical heat flux (CHF) in narrow gaps with varying surface orientations. The CHF in an inclined gap, especially in case of the downward-facing narrow gap, is dictated by bubble behavior because the departing bubbles are squeezed. The orientation angle affects the bubble layer and escape of the bubbles from the narrow gap. The test parameters include gap sizes of 1, 2, 5 and 10 mm and the open periphery, and the orientation angles range from the fully downward-facing (180o) to the vertical (90o) position. The 15 ×35 mm copper test section was electrically heated by the thin film resistor on the back. The heater assembly was installed to the tip of the rotating arm in the heated water pool at the atmospheric pressure. The bubble behavior was photographed utilizing a high-speed camera through the Pyrex glass spacer. It was observed that the CHF decreased as the surface inclination angle increased and as the gap size decreased in most of the cases. However, the opposing results were obtained at certain surface orientations and gap sizes. Transition angles, at which the CHF changed in a rapid slope, were also detected, which is consistent with the existing literature. A semi-empirical CHF correlation was developed for the inclined narrow rectangular channels through dimensional analysis. The correlation provides with best-estimate CHF values for realistically assessing the thermal margin to failure of the lower head during a severe accident involving relocation of the core material.

  4. MEASUREMENTS OF STELLAR INCLINATIONS FOR KEPLER PLANET CANDIDATES

    SciTech Connect

    Hirano, Teruyuki; Taruya, Atsushi; Suto, Yasushi; Sanchis-Ojeda, Roberto; Winn, Joshua N.; Takeda, Yoichi; Narita, Norio

    2012-09-01

    We present an investigation of spin-orbit angles for planetary system candidates reported by Kepler. By combining the rotational period P{sub s} inferred from the flux variation due to starspots and the projected rotational velocity Vsin I{sub s} and stellar radius obtained by a high-resolution spectroscopy, we attempt to estimate the inclination I{sub s} of the stellar spin axis with respect to the line of sight. For transiting planetary systems, in which planetary orbits are edge-on seen from us, the stellar inclination I{sub s} can be a useful indicator of a spin-orbit alignment/misalignment. We newly conducted spectroscopic observations with Subaru/HDS for 15 Kepler Object of Interest (KOI) systems, whose light curves show periodic flux variations. Detailed analyses of their light curves and spectra revealed that some of them are binaries, or the flux variations are too coherent to be caused by starspots, and consequently we could constrain stellar inclinations I{sub s} for eight systems. Among them, KOI-262 and 280 are in good agreement with I{sub s} 90 Degree-Sign suggesting a spin-orbit alignment, while at least one system, KOI-261, shows a possible spin-orbit misalignment. We also obtain a small I{sub s} for KOI-1463, but the transiting companion seems to be a star rather than a planet. The results for KOI-257, 269, 367, and 974 are ambiguous and can be explained with either misalignments or moderate differential rotation. Since our method can be applied to any system having starspots regardless of the planet size, future observations will allow for the expansion of the parameter space in which the spin-orbit relations are investigated.

  5. Collisionless encounters and the origin of the lunar inclination.

    PubMed

    Pahlevan, Kaveh; Morbidelli, Alessandro

    2015-11-26

    The Moon is generally thought to have formed from the debris ejected by the impact of a planet-sized object with the proto-Earth towards the end of planetary accretion. Models of the impact process predict that the lunar material was disaggregated into a circumplanetary disk and that lunar accretion subsequently placed the Moon in a near-equatorial orbit. Forward integration of the lunar orbit from this initial state predicts a modern inclination at least an order of magnitude smaller than the lunar value--a long-standing discrepancy known as the lunar inclination problem. Here we show that the modern lunar orbit provides a sensitive record of gravitational interactions with Earth-crossing planetesimals that were not yet accreted at the time of the Moon-forming event. The currently observed lunar orbit can naturally be reproduced via interaction with a small quantity of mass (corresponding to 0.0075-0.015 Earth masses eventually accreted to the Earth) carried by a few bodies, consistent with the constraints and models of late accretion. Although the encounter process has a stochastic element, the observed value of the lunar inclination is among the most likely outcomes for a wide range of parameters. The excitation of the lunar orbit is most readily reproduced via collisionless encounters of planetesimals with the Earth-Moon system with strong dissipation of tidal energy on the early Earth. This mechanism obviates the need for previously proposed (but idealized) excitation mechanisms, places the Moon-forming event in the context of the formation of Earth, and constrains the pristineness of the dynamical state of the Earth-Moon system. PMID:26607544

  6. Measurements of Stellar Inclinations for Kepler Planet Candidates

    NASA Astrophysics Data System (ADS)

    Hirano, Teruyuki; Sanchis-Ojeda, Roberto; Takeda, Yoichi; Narita, Norio; Winn, Joshua N.; Taruya, Atsushi; Suto, Yasushi

    2012-09-01

    We present an investigation of spin-orbit angles for planetary system candidates reported by Kepler. By combining the rotational period Ps inferred from the flux variation due to starspots and the projected rotational velocity Vsin Is and stellar radius obtained by a high-resolution spectroscopy, we attempt to estimate the inclination Is of the stellar spin axis with respect to the line of sight. For transiting planetary systems, in which planetary orbits are edge-on seen from us, the stellar inclination Is can be a useful indicator of a spin-orbit alignment/misalignment. We newly conducted spectroscopic observations with Subaru/HDS for 15 Kepler Object of Interest (KOI) systems, whose light curves show periodic flux variations. Detailed analyses of their light curves and spectra revealed that some of them are binaries, or the flux variations are too coherent to be caused by starspots, and consequently we could constrain stellar inclinations Is for eight systems. Among them, KOI-262 and 280 are in good agreement with Is = 90° suggesting a spin-orbit alignment, while at least one system, KOI-261, shows a possible spin-orbit misalignment. We also obtain a small Is for KOI-1463, but the transiting companion seems to be a star rather than a planet. The results for KOI-257, 269, 367, and 974 are ambiguous and can be explained with either misalignments or moderate differential rotation. Since our method can be applied to any system having starspots regardless of the planet size, future observations will allow for the expansion of the parameter space in which the spin-orbit relations are investigated.

  7. S-DARS broadcast from inclined, elliptical orbits

    NASA Astrophysics Data System (ADS)

    Briskman, Robert D.; Prevaux, Robert J.

    2004-04-01

    The first Sirius spacecraft was launched on July 1, 2000. Exactly 5 months later, on December 1, the third spacecraft was launched, completing the three satellite S-DARS (Satellite Digital Audio Radio Service) constellation. The three satellites are deployed in inclined, elliptical, geosynchronous orbits, which allow seamless broadcast coverage to mobile users in the contiguous US. Terrestrial broadcast repeaters provide service in urban cores. The system is in operation, providing the first ever S-DARS service. The constellation design results in satellite ground tracks over North America with two satellites always above the equator. High elevation look angles from the mobile ground terminals to the satellites minimize performance degradation due to blockage, foliage attenuation and multi-path. The spacecraft were built by Space Systems/Loral using the 1300 bus modified for operation in high inclination orbits. Each spacecraft was launched using a dedicated Russian Proton booster. The satellite payload is a bent pipe repeater using 7.1 GHz for the uplink and 2.3 GHz for the broadcast transmission. The repeater high-power amplification stage consists of 32 Traveling Wave Tube Amplifiers phase combined to yield a total radio frequency output power of nearly 4 kW at saturated operation. The satellite antennas are mechanically steered to maintain the transmit beam centered on the Contiguous United States and the receive beam centered on the uplink earth station located in Vernon Valley, New Jersey. The satellite payload design and performance are described. The principal spacecraft bus systems are described with emphasis on improvements made for operation in the inclined, elliptical geosynchronous orbits.

  8. On the highly inclined vW leptokurtic asteroid families

    NASA Astrophysics Data System (ADS)

    Carruba, V.; Domingos, R. C.; Aljbaae, S.; Huaman, M.

    2016-08-01

    vW leptokurtic asteroid families are families for which the distribution of the normal component of the terminal ejection velocity field vW is characterized by a positive value of the γ2 Pearson kurtosis, i.e., they have a distribution with a more concentrated peak and larger tails than the Gaussian one. Currently, eight families are known to have γ2(vW) > 0.25. Among these, three are highly inclined asteroid families, the Hansa, Barcelona, and Gallia families. As observed for the case of the Astrid family, the leptokurtic inclination distribution seems to be caused by the interaction of these families with node secular resonances. In particular, the Hansa and Gallia family are crossed by the s - sV resonance with Vesta, that significantly alters the inclination of some of their members. In this work we use the time evolution of γ2(vW) for simulated families under the gravitational influence of all planets and the three most massive bodies in the main belt to assess the dynamical importance (or lack of) node secular resonances with Ceres, Vesta, and Pallas for the considered families, and to obtain independent constraints on the family ages. While secular resonances with massive bodies in the main belt do not significantly affect the dynamical evolution of the Barcelona family, they significantly increase the γ2(vW) values of the simulated Hansa and Gallia families. Current values of the γ2(vW) for the Gallia family are reached over the estimated family age only if secular resonances with Vesta are accounted for.

  9. Flow of Slurry in the Inclined Closed Channel

    NASA Astrophysics Data System (ADS)

    Ashrafi Khorasani, Nariman; Piroozram, Parastoo

    2015-11-01

    The flow of slurry in a closed inclined circular channel is examined. The viscoelastic fluid is modeled as a derivative of typical Oldroyd-B relation of stress and velocity gradient. First, gravity is considered as the driving force for the fluid flow to simulate the existing sewage system. The complete flow field is evaluated for this case. Next, a pressure gradient is introduced to observe its effects on the flow. Velocity profile as well as stress distributions are given for different scenarios of the nonlinear fluid flowing in a closed channel with and without pressure gradient.

  10. Nonlocal effects in sand flows on an inclined plane.

    PubMed

    Malloggi, F; Andreotti, B; Clément, E

    2015-05-01

    The flow of sand on a rough inclined plane is investigated experimentally. We directly show that a jammed layer of grains spontaneously forms below the avalanche. Its properties and its relation with the rheology of the flowing layer of grains are presented and discussed. In a second part, we study the dynamics of erosion and deposition solitary waves in the domain where they are transversally stable. We characterize their shapes and velocity profiles. We relate their translational velocity to the stopping height and to the mass trapped in the avalanche. Finally, we use the velocity profile to get insight into the rheology very close to the jamming limit. PMID:26066168

  11. Trigonometric series representations of the orbital inclination function.

    NASA Astrophysics Data System (ADS)

    Awad, Mervat El-Sayed

    1986-08-01

    In this paper, new trigonometric series representations of the orbital inclination function Flmp(i) in multiples of cosines or sines are established for all possible values of l, m, and p. For such representations, the literal analytical expressions and the recurrence formulae satisfied by their coefficients are established. Moreover, an economic algorithm for the table formulation of these coefficients for the possible values of l, m, and p is given. Finally, numerical examples of the representations for l = 2(1)4; m = 0(1)l; p = 0(1)l are also included.

  12. The flow around an inclined flat plate of finite width

    NASA Astrophysics Data System (ADS)

    Narumi, A.; Kato, S.; Terada, K.; Izumi, R.; Yanase, T.

    1985-07-01

    The flow around an inclined finite width plate was experimentally studied using oil film and oil point techniques. At the front surface, leading edge separation does not occur and the flow becomes more laminar than in the case with angle of incidence zero, though the flow yaws towards the side edge and separates from it. The flow at the back surface is characterized by a side edge vortex, a flow separated near the side edge of the leading edge, and a flow separated at the middle of the leading edge. The characteristics of these flows are discussed.

  13. Slope, Rate of Change, and Steepness: Do Students Understand These Concepts?

    ERIC Educational Resources Information Center

    Teuscher, Dawn; Reys, Robert E.

    2010-01-01

    How do mathematics teachers introduce the concepts of slope, rate of change, and steepness in their classrooms? Do students understand these concepts as interchangeable or regard them as three different ideas? In this article, the authors report the results of a study of high school Advanced Placement (AP) Calculus students who displayed…

  14. Permafrost in steep bedrock slopes and its temperature-related destabilization following climate change

    NASA Astrophysics Data System (ADS)

    Gruber, S.; Haeberli, W.

    2007-06-01

    Permafrost in steep bedrock is abundant in many cold-mountain areas, and its degradation can cause slope instability that is unexpected and unprecedented in location, magnitude, frequency, and timing. These phenomena bear consequences for the understanding of landscape evolution, natural hazards, and the safe and sustainable operation of high-mountain infrastructure. Permafrost in steep bedrock is an emerging field of research. Knowledge of rock temperatures, ice content, mechanisms of degradation, and the processes that link warming and destabilization is often fragmental. In this article we provide a review and discussion of existing literature and pinpoint important questions. Ice-filled joints are common in bedrock permafrost and possibly actively widened by ice segregation. Broad evidence of destabilization by warming permafrost exists despite problems of attributing individual events to this phenomenon with certainty. Convex topography such as ridges, spurs, and peaks is often subject to faster and deeper thaw than other areas. Permafrost degradation in steep bedrock can be strongly affected by percolating water in fractures. This degradation by advection is difficult to predict and can lead to quick and deep development of thaw corridors along fractures in permafrost and potentially destabilize much greater volumes of rock than conduction would. Although most research on steep bedrock permafrost originates from the Alps, it will likely gain importance in other geographic regions with mountain permafrost.

  15. Does WEPP meet the specificity of soil erosion in steep mountain regions?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We chose the USDA-ARS-WEPP model (Water Erosion Prediction Project) to describe the soil erosion in the Urseren valley (Central Switzerland) as it seems to be one of the most promising models for steep mountain environments. Crucial model parameters were determined in the field (slope, plant species...

  16. Effects of sediment size on transport capacity of overland flow on steep slopes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sediment transport capacity is a key concept to determine rates of detachment and deposition in process-based erosion models. Few studies were conducted to evaluate the effects of sediment size on transport capacity of overland flow on steep slopes. The objective of this study was to investigate the...

  17. Sediment transport and soil detachment on steep slopes: I. Transport capacity estimation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Precise prediction of sediment transport capacity (Tc) is pivotal to develop physically based erosion models. Few data are available for predicting Tc on steep slopes. The objectives of this study were to evaluate the effects of unit flow discharge (q), slope gradient (S), and mean flow velocity on ...

  18. Erosion risk assessment of controlled burning of grasses established on steep slopes

    NASA Astrophysics Data System (ADS)

    Gyasi-Agyei, Yeboah

    2006-02-01

    It is a standard practice to establish grasses on steep slopes (batters) of embankments and cuttings to minimise erosion problems. However, the increase in grass density (high biomass) on the steep slopes poses a greater risk of fire. Controlled burning is a common fuel hazard reduction program employed to minimise the fire risks. The increased risk of erosion on the steep slopes after controlled burning has received little attention if any. This paper assesses the erosion risks associated with controlled burning of grasses established on steep slopes. Grasses, with and without the aid of waste ballast rock mulch, were established on 10 m wide railway embankment batter experiment plots. Two-and-a-half years after the grass establishment, selected plots were controlled burned. Runoff and soil loss from the experimental plots were monitored throughout the 3½-year period of the experiment. After one year the grass cover on the burned plots has hardly exceeded 60%, far below the average pre-burn levels of about 80%. All treatments achieved an incredible soil loss reduction of over 95% (compared with the bare scenario) without controlled burning at the end of the 3½-year period. This percentage value was decreased numerically by 14 where controlled burning was implemented. Compared with the 100% grass cover treatment, runoff rates tripled while erosion rates increased by nine-fold for the waste ballast treatment, and 17-fold for the non-waste ballast treatment, during the first year following controlled burning.

  19. Contour Planting: A Strategy to Reduce Soil Erosion on Steep Slopes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Practices that combine GPS-based guidance for terrain contouring and tillage for runoff detention have potential to increase water infiltration and reduce runoff. The objective of this study was to investigate contour planting as a means to reduce soil erosion on steep slopes of the Columbia Platea...

  20. 4-Hydroxyisoleucine production of recombinant Corynebacterium glutamicum ssp. lactofermentum under optimal corn steep liquor limitation.

    PubMed

    Shi, Feng; Niu, Tengfei; Fang, Huimin

    2015-05-01

    4-Hydroxyisoleucine (4-HIL) is a nonproteinogenic amino acid that exhibits insulinotropic biological activity. Here, L-isoleucine dioxygenase gene (ido) derived from Bacillus thuringiensis YBT-1520 was cloned and expressed in an L-isoleucine-producing strain, Corynebacterium glutamicum ssp. lactofermentum SN01, in order to directly convert its endogenous L-isoleucine (Ile) into 4-HIL through single-step fermentation. The effects of corn steep liquor limitation as well as ido and truncated idoΔ6 overexpression on 4-HIL production were researched. 4-HIL production by ido-overexpressing strain was improved to 65.44 ± 2.27 mM after fermented for 144 h under corn steep liquor-subsufficient condition, obviously higher than that under corn steep liquor-rich and insufficient conditions. The conversion ratio of Ile to 4-HIL increased to 0.85 mol/mol. In addition, 4-HIL production by ido-overexpressing strain was higher than that by idoΔ6-overexpressing strain, in accord with the relatively higher affinity of Ido as compared to IdoΔ6. This research generated a novel system for 4-HIL de novo biosynthesis and demonstrated corn steep liquor limitation as a useful strategy for improving 4-HIL production in recombinant C. glutamicum ssp. lactofermentum. PMID:25725632

  1. Electromagnetic torques, precession and evolution of magnetic inclination of pulsars

    NASA Astrophysics Data System (ADS)

    Zanazzi, J. J.; Lai, Dong

    2015-07-01

    We present analytic calculations of the electromagnetic torques acting on a magnetic neutron star rotating in vacuum, including near-zone torques associated with the inertia of dipole and quadrupole magnetic fields. We incorporate these torques into the rotational dynamics of a rigid-body neutron star, and show that the effects of the inertial torque can be understood as a modification of the moment of inertia tensor of the star. We apply our rotational dynamics equation to the Crab pulsar, including intrinsic distortions of the star and various electromagnetic torques, to investigate the possibility that the counter-alignment of the magnetic inclination angle, as suggested by recent observations, could be explained by pulsar precession. We find that if the effective principal axis of the pulsar is nearly aligned with either the magnetic dipole axis or the rotation axis, then precession may account for the observed counter-alignment over decade time-scales. Over the spindown time-scale of the pulsar, the magnetic inclination angle always decreases.

  2. a Modified Method for Image Triangulation Using Inclined Angles

    NASA Astrophysics Data System (ADS)

    Alsadik, Bashar

    2016-06-01

    The ongoing technical improvements in photogrammetry, Geomatics, computer vision (CV), and robotics offer new possibilities for many applications requiring efficient acquisition of three-dimensional data. Image orientation is one of these important techniques in many applications like mapping, precise measurements, 3D modeling and navigation. Image orientation comprises three main techniques of resection, intersection (triangulation) and relative orientation, which are conventionally solved by collinearity equations or by using projection and fundamental matrices. However, different problems still exist in the state - of -the -art of image orientation because of the nonlinearity and the sensitivity to proper initialization and spatial distribution of the points. In this research, a modified method is presented to solve the triangulation problem using inclined angles derived from the measured image coordinates and based on spherical trigonometry rules and vector geometry. The developed procedure shows promising results compared to collinearity approach and to converge to the global minimum even when starting from far approximations. This is based on the strong geometric constraint offered by the inclined angles that are enclosed between the object points and the camera stations. Numerical evaluations with perspective and panoramic images are presented and compared with the conventional solution of collinearity equations. The results show the efficiency of the developed model and the convergence of the solution to global minimum even with improper starting values.

  3. Exhumation by gravitational sliding up an inclined plane

    NASA Astrophysics Data System (ADS)

    Podladchikov, Yury; Schmalholz, Stefan; Burg, Jean-Pierre

    2015-04-01

    Gravity causes sliding down an inclined plane if pressure is near lithostatic. If metamorphic pressures are lithostatic pressures, the approximation is inconsistent with pressure-temperature exhumation histories of thrust nappes stacked during compression to form the thickened crust of mountain belts. Overthickened mountain roots and foreland basin-type sedimentation accompanying the downward movement component of the Moho require significant non-lithostatic pressure perturbations within the mountain belts. Relaxation of the subsequent pressure gradients can be achieved by nappe-like thrusting up an inclined plane recording near isothermal decompression and carrying young sediments to high altitudes. We present results of fully dynamic numerical modelling documenting feasibility of this process. Neither thrusting, nor large weakness zones nor S-point-type boundary conditions are kinematically prescribed in our models. Thrusting emerges spontaneously as an instability, strain localization process that may follow preexisting lithological layering or thermal gradients and able to form new zones of weakness by shear heating mechanism. The non-prescribed nature of our modeled deformation modes makes them feasible, even probable as a leading response to continental shortening. In that case, non lithostatic pressure 'cycle' is an alternative or a complement to the classical Wilson cycle invoked alone to explain elevated occurrences of deep-water sediments.

  4. Dissipative descent: rocking and rolling down an incline

    NASA Astrophysics Data System (ADS)

    Balmforth, N. J.; Bush, J. W. M.; Vener, D.; Young, W. R.

    We consider the dynamics of a hollow cylindrical shell that is filled with viscous fluid and another, nested solid cylinder, and allowed to roll down an inclined plane. A mathematical model is compared to simple experiments. Two types of behaviour are observed experimentally: on steeper slopes, the device accelerates; on shallower inclines, the cylinders rock and roll unsteadily downhill, with a speed that is constant on average. The theory also predicts runaway and unsteady rolling motions. For the rolling solutions, however, the inner cylinder cannot be suspended in the fluid by the motion of the outer cylinder, and instead falls inexorably toward the outer cylinder. Whilst only occurs after an infinite time, the system slows progressively as the gap between the cylinders narrows, owing to heightened viscous dissipation. Such a deceleration is not observed in the experiments, suggesting that some mechanism limits the approach to contact. Coating the surface of the inner cylinder with sandpaper of different grades changes the rolling speed, consistent with the notion that surface roughness is responsible for limiting the acceleration.

  5. Visualization of Boiling Phenomena in Inclined Rectangular Gap

    SciTech Connect

    J. L. Rempe

    2005-05-01

    An experimental study was performed to investigate the pool boiling critical heat flux (CHF) in one-dimensional inclined rectangular channels by changing the orientation of a copper test heater assembly. In a pool of saturated water under the atmospheric pressure, the test parameters include the gap sizes of 1, 2, 5, and 10 mm, and the surface orientation angles from the downward-facing position (1800) to the vertical position (90º), respectively. Tests were conducted on the basis of the visualization of boiling phenomena in the narrowly confined channel and open periphery utilizing a high-speed digital camera. To prevent the heat loss from the water pool and copper test heater, a state-of-the-art vacuum pumping technique was introduced. It was observed that the CHF generally decreases as the surface inclination angle increases and as the gap size decreases. In the downward-facing position (180o), however, the vapor movement was enhanced by the gap structure, which produced the opposing result, say, the CHF increases as the gap size decreases. Phenomenological characteristics regarding the interfacial instability of vapor layer were addressed in terms of visualization approaching the CHF. It was found that there exists a transition angle, around which the CHF changes with a rapid slope.

  6. Resolving Vega and the Inclination Controversy with CHARA/MIRC

    NASA Astrophysics Data System (ADS)

    Monnier, J. D.; Che, Xiao; Zhao, Ming; Ekström, S.; Maestro, V.; Aufdenberg, Jason; Baron, F.; Georgy, C.; Kraus, S.; McAlister, H.; Pedretti, E.; Ridgway, S.; Sturmann, J.; Sturmann, L.; ten Brummelaar, T.; Thureau, N.; Turner, N.; Tuthill, P. G.

    2012-12-01

    Optical and infrared interferometers definitively established that the photometric standard Vega (=α Lyrae) is a rapidly rotating star viewed nearly pole-on. Recent independent spectroscopic analyses could not reconcile the inferred inclination angle with the observed line profiles, preferring a larger inclination. In order to resolve this controversy, we observed Vega using the six-beam Michigan Infrared Combiner on the Center for High Angular Resolution Astronomy Array. With our greater angular resolution and dense (u, v)-coverage, we find that Vega is rotating less rapidly and with a smaller gravity darkening coefficient than previous interferometric results. Our models are compatible with low photospheric macroturbulence and are also consistent with the possible rotational period of ~0.71 days recently reported based on magnetic field observations. Our updated evolutionary analysis explicitly incorporates rapid rotation, finding Vega to have a mass of 2.15+0.10 - 0.15 M ⊙ and an age 700-75 + 150 Myr, substantially older than previous estimates with errors dominated by lingering metallicity uncertainties (Z = 0.006+0.003 - 0.002).

  7. Do liquid drops roll or slide on inclined surfaces?

    PubMed

    Thampi, Sumesh P; Adhikari, Ronojoy; Govindarajan, Rama

    2013-03-12

    We study the motion of a two-dimensional droplet on an inclined surface, under the action of gravity, using a diffuse interface model which allows for arbitrary equilibrium contact angles. The kinematics of motion is analyzed by decomposing the gradient of the velocity inside the droplet into a shear and a residual flow. This decomposition helps in distinguishing sliding versus rolling motion of the drop. Our detailed study confirms intuition, in that rolling motion dominates as the droplet shape approaches a circle, and the viscosity contrast between the droplet and the ambient fluid becomes large. As a consequence of kinematics, the amount of rotation in a general droplet shape follows a universal curve characterized by geometry, and independent of Bond number, surface inclination and equilibrium contact angle, but determined by the slip length and viscosity contrast. Our results open the way toward a rational design of droplet-surface properties, both when rolling motion is desirable (as in self-cleaning hydrophobic droplets) and when it must be prevented (as in insecticide sprays on leaves). PMID:23414059

  8. On the high inclination KBOs common dynamical formation

    NASA Astrophysics Data System (ADS)

    De Oliveira Brasil, Pedro Ivo I.; Gomes, Rodney S.; Nesvorny, David

    2014-11-01

    The Kuiper belt is a dynamically intriguing region. Different "classes" of objects can be defined, according to their orbital properties. These are: the classic belt (with the subclasses of cold & hot objects), resonant objects, scattered disk and extended scattered disk. In this work, we seek to investigate possible common origins, during the orbital conformation of the giant planets, for the formation of classes of objects with moderate or high inclination. Interesting results were obtained for the hot objects of the Kuiper belt and the objects belonging to the extended scattered disk. The general mechanism found for the formation of these objects can be summarized as: (i) scattering phase due to the interaction with the giant planets, during the LHB; (ii) capture into mean motion resonances (MMR) with Neptune; (iii) capture into Kozai resonance/mode; (iv) escape FROM both resonances into a mode known as "hibernation mode", in which the object has low eccentricity and high inclination; (v) fossilization in an orbit outside the resonant semi-major axis due to residual migration of Neptune. The results show good consistency between known objects with the model of dynamical formation.

  9. Online measurement system for the surface inclination of metal workpieces

    NASA Astrophysics Data System (ADS)

    Yin, Peng; Sun, Changku; Wang, Peng; Yang, Qian

    2013-12-01

    The online measurement of the metal surfaces' parameters plays an important role in many industrial fields. Because the surfaces of the machined metal pieces have the characteristics of strong reflection and high possibilities of scattered disturbing irradiation points, this paper designs an online measurement system based on the measurement principles of linear structured light to detect whether the parameters of the machined metal surfaces' height difference and inclination fulfill the compliance requirements, in which the grayscale gravity algorithm is applied to extract the sub-pixel coordinates of the center of laser, the least squares method is employed to fit the data and the Pauta criterion is utilized to remove the spurious points. The repeat accuracy of this system has been tested. The experimental results prove that the precision of inclination is 0.046° RMS under the speed of 40mm/sec, and the precision of height difference is 0.072mm RMS, which meets the design expectations. Hence, this system can be applied to online industrial detection of high speed and high precision.

  10. Experimental Investigations of an Inclined Lap-Type Bolted Joint

    SciTech Connect

    GREGORY, DANNY LYNN; RESOR, BRIAN R.; COLEMAN, RONALD G.; SMALLWOOD, DAVID ORA

    2003-04-01

    The dynamic response of critical aerospace components is often strongly dependent upon the dynamic behavior of bolted connections that attach the component to the surrounding structure. These bolted connections often provide the only structural load paths to the component. The bolted joint investigated in this report is an inclined lap-type joint with the interface inclined with respect to the line of action of the force acting on the joint. The accurate analytical modeling of these bolted connections is critical to the prediction of the response of the component to normal and high-level shock environmental loadings. In particular, it is necessary to understand and correctly model the energy dissipation (damping) of the bolted joint that is a nonlinear function of the forces acting on the joint. Experiments were designed and performed to isolate the dynamics of a single bolted connection of the component. Steady state sinusoidal and transient experiments were used to derive energy dissipation curves as a function of input force. Multiple assemblies of the bolted connection were also observed to evaluate the variability of the energy dissipation of the connection. These experiments provide insight into the complex behavior of this bolted joint to assist in the postulation and development of reduced order joint models to capture the important physics of the joint including stiffness and damping. The experiments are described and results presented that provide a basis for candidate joint model calibration and comparison.

  11. Three-dimensional, transient natural convection in inclined wellbores

    SciTech Connect

    McEligot, D.M. . Oceanic Div.); Denbow, D.A. ); Murphy, H.D. )

    1990-01-01

    The occurrence of natural conduction in a wellbore can affect geothermal gradient measurements and heat flow estimates. In the Hot Dry Rock geothermal concept, the wellbores are purposely inclined in the deep regions to enhance heat production. To simulate natural convection flow patterns in directionally drilled wellbores, experiments and analyses were conducted for a circular tube with length to diameter (L/D) ratio of 36 at angles of 0{degrees}, 20{degrees}, and 35{degrees} from the vertical. The tube was heated at the bottom and cooled at the top, and the insulation was adjusted so that approximately one- to two-thirds of the power dissipated was transferred through the tube wall to the surroundings. An aqueous solution of polyvinyl alcohol was employed as the working fluid in order to obtain low Rayleigh numbers corresponding to conditions in geothermal wellbores. Temperature distributions were measured for the three orientations and for several heating rates to demonstrate the effects of tube angle and Rayleigh number. Comparison with measurements showed good agreement of the predicted temperature levels for the maximum inclination and slightly poorer agreement for the other limit, a vertical tube. 50 refs., 9 figs.

  12. Advanced Communications Technology Satellite Now Operating in an Inclined Orbit

    NASA Technical Reports Server (NTRS)

    Bauer, Robert A.

    1999-01-01

    The Advanced Communications Technology Satellite (ACTS) system has been modified to support operation in an inclined orbit that is virtually transparent to users, and plans are to continue this final phase of its operation through September 2000. The next 2 years of ACTS will provide a new opportunity for using the technologies that this system brought online over 5 years ago and that are still being used to resolve the technical issues that face NASA and the satellite industry in the area of seamless networking and interoperability with terrestrial systems. New goals for ACTS have been defined that align the program with recent changes in NASA and industry. ACTS will be used as a testbed to: Show how NASA and other Government agencies can use commercial systems for 1. future support of their operations Test, characterize, and resolve technical issues in using advanced communications 2. protocols such as asynchronous transfer mode (ATM) and transmission control protocol/Internet protocol (TCP/IP) over long latency links as found when interoperating satellites with terrestrial systems Evaluate narrow-spot-beam Ka-band satellite operation in an inclined orbit 3. Verify Ka-band satellite technologies since no other Ka-band system is yet 4. available in the United States

  13. Recovering Grain-Boundary Inclination Parameters through Oblique Double Sectioning

    NASA Astrophysics Data System (ADS)

    Homer, E. R.; Adams, B. L.; Wagoner, R. H.

    2007-07-01

    A method for the retrieval of grain-boundary inclination parameters of the grain-boundary character distribution (GBCD) by oblique double sectioning (ODS) is proposed. In this hybrid approach, grain-boundary inclination parameters are directly measured by double sectioning, while a statistically reliable sampling of the microstructure is achieved by oblique sectioning. The solution to the fundamental equations is posed in a manner similar to the recovery of the orientation distributions from sets of incomplete pole figures, using classical Fourier representations of the distribution functions. The ODS is validated by and compared to the L A /S V stereology through simulations and experimental implementation in a sample of 439 stainless steel. Simulations show that the grain-boundary normal distributions recovered by ODS and stereology are comparable, giving errors on the order of 10-2. Experimental implementation of ODS and the L A /S V stereology in alloy 439 stainless steel demonstrate additional practical limitations of the ODS methodology when applied to materials of large or uneven grain size.

  14. Predictive Simulation Generates Human Adaptations during Loaded and Inclined Walking

    PubMed Central

    Hicks, Jennifer L.; Delp, Scott L.

    2015-01-01

    Predictive simulation is a powerful approach for analyzing human locomotion. Unlike techniques that track experimental data, predictive simulations synthesize gaits by minimizing a high-level objective such as metabolic energy expenditure while satisfying task requirements like achieving a target velocity. The fidelity of predictive gait simulations has only been systematically evaluated for locomotion data on flat ground. In this study, we construct a predictive simulation framework based on energy minimization and use it to generate normal walking, along with walking with a range of carried loads and up a range of inclines. The simulation is muscle-driven and includes controllers based on muscle force and stretch reflexes and contact state of the legs. We demonstrate how human-like locomotor strategies emerge from adapting the model to a range of environmental changes. Our simulation dynamics not only show good agreement with experimental data for normal walking on flat ground (92% of joint angle trajectories and 78% of joint torque trajectories lie within 1 standard deviation of experimental data), but also reproduce many of the salient changes in joint angles, joint moments, muscle coordination, and metabolic energy expenditure observed in experimental studies of loaded and inclined walking. PMID:25830913

  15. Pseudo 3-D P wave refraction seismic monitoring of permafrost in steep unstable bedrock

    NASA Astrophysics Data System (ADS)

    Krautblatter, Michael; Draebing, Daniel

    2014-02-01

    permafrost in steep rock walls can cause hazardous rock creep and rock slope failure. Spatial and temporal patterns of permafrost degradation that operate at the scale of instability are complex and poorly understood. For the first time, we used P wave seismic refraction tomography (SRT) to monitor the degradation of permafrost in steep rock walls. A 2.5-D survey with five 80 m long parallel transects was installed across an unstable steep NE-SW facing crestline in the Matter Valley, Switzerland. P wave velocity was calibrated in the laboratory for water-saturated low-porosity paragneiss samples between 20°C and -5°C and increases significantly along and perpendicular to the cleavage by 0.55-0.66 km/s (10-13%) and 2.4-2.7 km/s (>100%), respectively, when freezing. Seismic refraction is, thus, technically feasible to detect permafrost in low-porosity rocks that constitute steep rock walls. Ray densities up to 100 and more delimit the boundary between unfrozen and frozen bedrock and facilitate accurate active layer positioning. SRT shows monthly (August and September 2006) and annual active layer dynamics (August 2006 and 2007) and reveals a contiguous permafrost body below the NE face with annual changes of active layer depth from 2 to 10 m. Large ice-filled fractures, lateral onfreezing of glacierets, and a persistent snow cornice cause previously unreported permafrost patterns close to the surface and along the crestline which correspond to active seasonal rock displacements up to several mm/a. SRT provides a geometrically highly resolved subsurface monitoring of active layer dynamics in steep permafrost rocks at the scale of instability.

  16. Egalitarian despots: hierarchy steepness, reciprocity and the grooming-trade model in wild chimpanzees, Pan troglodytes

    PubMed Central

    Kaburu, Stefano S. K.; Newton-Fisher, Nicholas E.

    2014-01-01

    Biological market theory models the action of natural selection as a marketplace in which animals are viewed as traders with commodities to offer and exchange. Studies of female Old World monkeys have suggested that grooming might be employed as a commodity to be reciprocated or traded for alternative services, yet previous tests of this grooming-trade model in wild adult male chimpanzees have yielded mixed results. Here we provide the strongest test of the model to date for male chimpanzees: we use data drawn from two social groups (communities) of chimpanzees from different populations and give explicit consideration to variation in dominance hierarchy steepness, as such variation results in differing conditions for biological markets. First, analysis of data from published accounts of other chimpanzee communities, together with our own data, showed that hierarchy steepness varied considerably within and across communities and that the number of adult males in a community aged 20–30 years predicted hierarchy steepness. The two communities in which we tested predictions of the grooming-trade model lay at opposite extremes of this distribution. Second, in accord with the grooming-trade model, we found evidence that male chimpanzees trade grooming for agonistic support where hierarchies are steep (despotic) and consequent effective support is a rank-related commodity, but not where hierarchies are shallow (egalitarian). However, we also found that grooming was reciprocated regardless of hierarchy steepness. Our findings also hint at the possibility of agonistic competition, or at least exclusion, in relation to grooming opportunities compromising the free market envisioned by biological market theory. Our results build on previous findings across chimpanzee communities to emphasize the importance of reciprocal grooming exchanges among adult male chimpanzees, which can be understood in a biological markets framework if grooming by or with particular individuals is

  17. The relation between superior phacoemulsification incision and steep axis on astigmatic outcomes.

    PubMed

    Özyol, Erhan; Özyol, Pelin

    2012-12-01

    To evaluate the relation between superior phacoemulsification incision and different steep axis on astigmatism outcomes. This prospective, randomized study comprised three groups each with 24 eyes with age-related cataracts and underwent 3.0 mm superior clear corneal incision (CCI). The three groups of the patients were divided by the location of the steep axis. The steep axis was between 0 and 30° in group 1, 31-60° in group 2, 61-90° in group 3. The degree was accepted as the distance from the steep axis to the distal aspect of the wound. Outcome measures were including the changes in mean total astigmatism, surgically-induced astigmatism (SIA), axis deviation, uncorrected visual acuity (UCVA), and best corrected visual acuity (BCVA). Astigmatism was measured by manuel keratometry readings before surgery and day-1, week-1, week-2, week-4 and week-8 postoperatively. The surgically-induced astigmatism was calculated by the vector analysis using the Holladay-Cravy-Koch method. The magnitude of mean total astigmatism was lowest in group 1 and highest in group 3 at 8th week. Surgically-induced astigmatism was 0.52 diopter (D), 0.88 D, 1.03 D in group 1, group 2, and group 3 respectively. The change in SIA was significant in group 1 (P < 0.05). The change in the astigmatic axis deviation was highest in group 1 (31.5 ± 31.3, P < 0.05). The mean UCVA and BCVA were not significant pre and postoperatively between groups (P > 0.05). Axis deviation and SIA were stable after the week-1 and week-2 examinations respectively. Cataract surgery with CCI on or near the steep axis is resulted in decreased SIA and increased axis deviation. PMID:22825889

  18. The interplay of predefined rock mechanics and permafrost forcing in a steep alpine rock crest (Steintaelli, Mattertal, Switzerland)

    NASA Astrophysics Data System (ADS)

    Halla, Christian; Krautblatter, Michael; Draebing, Daniel

    2014-05-01

    Freeze-thaw-processes in the active layer and degrading permafrost change ice and hydraulic pressures as well as rock- and ice-mechanical properties in rock masses which can cause instabilities. The characterization of the rock mass was determined by the geological strength index and a detailed discontinuity analysis along scanlines where the active layer reached depths of 5-15m (August 2012). Rock mass deformations and accordingly the divergence and convergence of deep reaching fractures were measured along 18 extensometer transects with various lengths from 2 to 27m. (1) The Geological Strength Index provided rock mechanical parameters which indicate stable conditions on the slope scale. The friction angle of the rock mass (44°) is higher than the mean slope inclination (37°). (2) The discontinuity analysis provided six joint sets, their geometries and mechanical properties. High roughness coefficients and wall strengths of the joints result in high total friction angles (>43°) and stable conditions on the block scale. However, the locations of several joints with wide apertures, ice fillings and joints influenced by snowmelt of the cornice at the crest are used as indicators for freeze-thaw related rock mass deformations. (3) The rock mass deformation rates during late summer (2012) are multiple times (>3) higher than deformation rates for several years (2008-2012). Furthermore, the direction of deformation changes between divergence and convergence over time. Both aspects indicate that seasonal and annual changes affect the rock mass deformations. We conclude, that rock mass deformation cannot be explained solely by rock mechanical parameters without freeze-thaw and permafrost influence. The higher deformation rates during the thaw season in late summer and the heterogeneity of deformation directions indicate that seasonal and annual changes of ice- and hydraulic pressures in discontinuities affect instabilities at the Steintaelli crestline. Here we show the

  19. Vegetation controls on sediment storage and release on steep, rocky hillslopes

    NASA Astrophysics Data System (ADS)

    DiBiase, R. A.; Lamb, M. P.; Heimsath, A. M.; Whipple, K. X.

    2012-12-01

    Quantifying the processes and rates of regolith production, storage, and transport is essential to understanding hillslope response to tectonic, climatic, and anthropogenic forcing. While considerable progress has been made towards interpreting soil mantled landscapes, there are few models to explain steep, bedrock hillslopes that lack a continuous soil cover. Yet, these steep landscapes pose significant risk to encroaching population centers, and are particularly sensitive to the influence of earthquakes, fire, and climate change. Here we focus on a steep, tectonically active landscape in the San Gabriel Mountains of California to document the spatial distribution and controls on sediment cover in bedrock landscapes. A thin but patchy soil cover persists across the range, despite the widespread occurrence of slopes steeper than the angle of repose and long term erosion rates exceeding 1 mm/yr. We address the problem of sediment storage on steep hillslopes using a combination of high-resolution topographic analysis, detailed mapping of hillslope bedrock exposure, and new field measurements of sediment accumulations behind vegetation dams on slopes ranging from 35 to 45 degrees. Using LiDAR-derived slope measurements and high resolution panoramic photographs, we show that rock exposure increases systematically with published cosmogenic erosion rates, suggesting that steep, threshold hillslopes are more sensitive in recording tectonic signals than previously thought. The primary mechanism for enabling sediment storage on slopes that exceed the angle of repose appears to be the presence of vegetation dams that trap dry ravel. Measurements of pile volumes in the field show a scaling consistent with angle-of-repose wedges whose size depends on vegetation basal width and local slope. Similar measurements on slopes burned by wildfire indicate an average loss of 80% of stored sediment, and highlight the importance of the post-fire loss of hillslope sediment storage

  20. Why Is It Harder to Run on an Inclined Exercise Treadmill?

    ERIC Educational Resources Information Center

    Nave, Carla M. A. P. F.; Amoreira, Luis J. M.

    2014-01-01

    It is a known fact that it takes a greater effort to run on an exercise treadmill when it is inclined with positive slope than when it is in a horizontal position. The reason seems simple: walking on an inclined treadmill is somehow equivalent to walking up a hill with the same inclination; when we walk up a hill, our own weight does negative work…

  1. Evolution of the magnetic field inclination in a forming penumbra

    SciTech Connect

    Romano, P.; Guglielmino, S. L.; Cristaldi, A.; Falco, M.; Zuccarello, F.; Ermolli, I.

    2014-03-20

    We describe the evolution of the magnetic and velocity fields in the annular zone around a pore a few hours before the formation of its penumbra. We detected the presence of several patches at the edge of the annular zone, with a typical size of about 1''. These patches are characterized by a rather vertical magnetic field with polarity opposite to that of the pore. They correspond to regions of plasma upflow up to 2.5 km s{sup –1} and are characterized by radially outward displacements with horizontal velocities up to 2 km s{sup –1}. We interpret these features as portions of the pore magnetic field lines returning beneath the photosphere being progressively stretched and pushed down by the overlying magnetic fields. Our results confirm that the penumbra formation results from changes in the inclination of the field lines in the magnetic canopy overlying the pore, until they reach the photosphere.

  2. Inclined nanoimprinting lithography-based 3D nanofabrication

    NASA Astrophysics Data System (ADS)

    Liu, Zhan; Bucknall, David G.; Allen, Mark G.

    2011-06-01

    We report a 'top-down' 3D nanofabrication approach combining non-conventional inclined nanoimprint lithography (INIL) with reactive ion etching (RIE), contact molding and 3D metal nanotransfer printing (nTP). This integration of processes enables the production and conformal transfer of 3D polymer nanostructures of varying heights to a variety of other materials including a silicon-based substrate, a silicone stamp and a metal gold (Au) thin film. The process demonstrates the potential of reduced fabrication cost and complexity compared to existing methods. Various 3D nanostructures in technologically useful materials have been fabricated, including symmetric and asymmetric nanolines, nanocircles and nanosquares. Such 3D nanostructures have potential applications such as angle-resolved photonic crystals, plasmonic crystals and biomimicking anisotropic surfaces. This integrated INIL-based strategy shows great promise for 3D nanofabrication in the fields of photonics, plasmonics and surface tribology.

  3. Dense inclined flows: Theory and experiments. Final report

    SciTech Connect

    Jenkins, J.T.; Louge, M.Y.

    1995-12-01

    Rapid, gravity-driven flows of granular materials down inclines pose a challenge to our understanding. Even in situations in which the flow is steady and two-dimensional, the details of how momentum ad energy are balanced within the flow and at the bottom boundary are not well understood. Thus we have undertaken a research program integrating theory, computer simulation, and experiment that focuses on such flows. the effort involves the development of theory informed by the results of simultaneous computer simulations and the construction, instrumentation, and use of an experimental facility in which the variables necessary to assess the success or failure of the theory can be measured. A goal of the project is to provide a sound theoretical and experimental base for a better understanding of the behavior and properties of multiphase flow and solid transport.

  4. Rolling to a stop down an inclined plane

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2015-11-01

    Experimental and theoretical results are presented showing that a ball with a high coefficient of rolling friction can roll to a stop when it rolls without slipping down an inclined plane. The rate at which energy is dissipated is directly proportional to the rolling friction force on the ball, despite the fact that the net work done by the friction force is zero. The energy loss arises from internal friction within the ball due to compression and expansion of the ball in the contact region. Since the compression force is larger than the expansion force, an opposing torque arises that reduces the angular velocity of the ball. The work done by the opposing torque is equal to the energy that is dissipated.

  5. Inclination Dependence of Estimated Galaxy Masses and Star Formation Rates

    NASA Astrophysics Data System (ADS)

    Hernandez, Betsy; Maller, Ariyeh; McKernan, Barry; Ford, Saavik

    2016-01-01

    We examine the inclination dependence of inferred star formation rates and galaxy mass estimates in the Sloan Digital Sky Survey by combining the disk/bulge de-convolved catalog of Simard et al 2011 with stellar mass estimates catalog of Mendel et al 2014 and star formation rates measured from spectra by Brinchmann et al 2004. We know that optical star formation indicators are reddened by dust, but calculated star formation rates and stellar mass estimates should account for this. However, we find that face-on galaxies have a higher calculated average star formation rates than edge-on galaxies. We also find edge-on galaxies have ,on average, slightly smaller but similar estimated masses to face-on galaxies, suggesting that there are issues with the applied dust corrections for both models.

  6. Thermocapillary motion of a droplet on an inclined plate

    NASA Astrophysics Data System (ADS)

    Karapetsas, George; Sahu, Kirti; Matar, Omar

    2012-11-01

    We examine the dynamics of a droplet spreading on an inclined solid surface in the presence of constant wall thermal gradients. We use lubrication theory in combination with the Karman-Polhausen integral method to simplify the governing equations for the droplet motion and energy conservation leading to coupled evolution equations for the drop thickness and average temperature. An important feature of the spreading model developed here is the behaviour of the drop at the contact line; this is modeled using a constitutive relation, which is dependent on the local temperature of the wall. We use a finite-element formulation to obtain numerical solutions of the evolution equations and carry out a full parametric study. We investigate the various types of behaviour encountered due to the interplay of Marangoni stresses, gravity and the dynamics of the contact line. EPSRC Grant number EP/E046029/1.

  7. Horizontal penetration of inclined thermal buoyant water jets

    SciTech Connect

    Pantokratoras, A.

    1998-05-01

    Submerged buoyant jets occur in the discharge from thermal power plants and in the operation of pumped storage hydroelectric plants. Accurate prediction of the jet trajectory and temperature dilution are necessary if discharge structures are to be designed to meet the appropriate standards. A modified version of the integral Fan-Brooks model has been used to calculate the horizontal penetration of inclined thermal buoyant water jets. The classical densimetric Froude number F{sub 0} is substituted by a Froude number F{sub a} based on the thermal expansion coefficient of water. Using the above model, a new equation is derived which can predict the horizontal penetration of the thermal jet at a given Froude number F{sub a} and discharge angle.

  8. Flow of granular materials down an inclined plane

    SciTech Connect

    Gudhe, R.; Rajagopal, K.R.; Massoudi, M.; Chi, R.

    1993-05-01

    The mechanics of flowing granular materials such as coal, sand, fossil-fuel energy recovery, metal ores, etc., and their flow characteristics have received considerable attention in recent years because it has relevance to several technological problems. In a number of instances these materials are also heated prior to processing, or cooled after processing. The governing equations for the flow of granular materials taking into account the heat transfer mechanism are derived using the continuum model proposed by Rajagopal and Massoudi (1990). For a fully developed flow of granular materials down an inclined plane, these equations reduce to a system of coupled ordinary differential equations. The resulting boundary value problem is solved numerically and the results are presented. For a special case, it is possible to obtain an analytic solution; this is given in the Appendix A of this report.

  9. Reliability of magnetic inclination angle determinations for pulsars

    NASA Technical Reports Server (NTRS)

    Miller, M. C.; Hamilton, Russell J.

    1993-01-01

    We compare the recent estimates of the inclination angle alpha between the rotation and magnetic axes of 56 pulsars made by both Lyne and Manchester (1988) and Rankin (1990). Their results agree reasonably well when alpha is less than about 40 deg; however, there is no correlation between the two estimates of alpha if either estimate exceeds 40 deg. The correlation is better for pulsars with beams having more complicated core structure. Nevertheless, the differences between the two sets of estimates are large enough that use of these estimates to investigate pulsar physics is questionable. We discuss the method for determining alpha based on the Radhakrishnan and Cooke (1969) single-vector model, emphasizing its sensitivity to measurement errors. This method complements the approaches of Rankin and Lyne and Manchester and is preferable when accurate polarization data are available.

  10. Programmable axicon for variable inclination of the focal segment

    NASA Astrophysics Data System (ADS)

    Jaroszewicz, Z.; Climent, V.; Duran, V.; Lancis, J.; Kolodziejczyk, A.; Burvall, A.; Friberg, A. T.

    An axicon creates a long and narrow focal segment along its optical axis and therefore it is widely recognized as a cornerstone element in metrology and alignment techniques. In oblique incidence the shape of the axicon can be designed such that its sharp focal line is retained. However, when an elliptical or circular axicon is illuminated at an angle different from the nominal angle, the focal segment suffers from astigmatism and broadens significantly. The use of a spatial light modulator is proposed for real-time compensation of the ensuing aberration. The result is a diffractive axicon with its degree of ellipticity adjusted to the inclination angle of the incident light, thus producing a diffraction-limited Bessel beam for a wide range of illumination angles.

  11. An ultrasonically enhanced inclined settler for microalgae harvesting.

    PubMed

    Hincapié Gómez, Esteban; Marchese, Anthony J

    2015-01-01

    Microalgae have vast potential as a sustainable and scalable source of biofuels and bioproducts. However, algae dewatering is a critical challenge that must be addressed. Ultrasonic settling has already been exploited for concentrating various biological cells at relatively small batch volumes and/or low throughput. Typically, these designs are operated in batch or semicontinuous mode, wherein the flow is interrupted and the cells are subsequently harvested. These batch techniques are not well suited for scaleup to the throughput levels required for harvesting microalgae from the large-scale cultivation operations necessary for a viable algal biofuel industry. This article introduces a novel device for the acoustic harvesting of microalgae. The design is based on the coupling of the acoustophoretic force, acoustic transparent materials, and inclined settling. A filtration efficiency of 70 ± 5% and a concentration factor of 11.6 ± 2.2 were achieved at a flow rate of 25 mL·min(-1) and an energy consumption of 3.6 ± 0.9 kWh·m(-3) . The effects of the applied power, flow rate, inlet cell concentration, and inclination were explored. It was found that the filtration efficiency of the device is proportional to the power applied. However, the filtration efficiency experienced a plateau at 100 W L(-1) of power density applied. The filtration efficiency also increased with increasing inlet cell concentration and was inversely proportional to the flow rate. It was also found that the optimum settling angle for maximum concentration factor occurred at an angle of 50 ± 5°. At these optimum conditions, the device had higher filtration efficiency in comparison to other similar devices reported in the previous literature. PMID:25504779

  12. Design and manufacture of a bandpass filter with high transmittance and steep edge on both sides

    NASA Astrophysics Data System (ADS)

    Wang, Ruisheng; Lü, Shaobo; Yin, Xiaojun; Zhao, Shuaifeng; Sun, Yan

    2016-01-01

    By using Nb2O5 and SiO2 as the coating material, a 152 layers (12 cavities) bandpass film stack with steep edge on both sides was designed. Multiple thickness control methods, including direct optical monitoring control and time control were used in coating strategy. To confirm the feasibility of this coating strategy, a process simulation was performed using Simulator software, and the simulation result indicated that relative thickness errors for all layers were less than ±0.1%. A bandpass filter with this film stack on one side was manufactured by using a plasma assisted reactive magnetic sputtering coating machine. The measuring result shows that the peak transmittance of the filter (without AR on backside) is up to 95.4%, and the steepness of both blocking slope are less than λ/100.

  13. Empirical statistics: V Evidence on the extent of the steepness bias in visual estimation of trends.

    PubMed

    Bailey, C D

    1996-06-01

    The existence of a pervasive and pronounced steepness bias in visually fitting a line to data in a scattergraph was investigated. 262 undergraduate business students were asked to fit lines visually to scattergraphs, to correspond to a least squares regression fit. These visually estimated lines strongly overestimated the steepness of the actual trend. As visual inspection of data is an important step for the detection of linear trends and outliers prior to regression analysis, this bias in subjective perception of the line may result in inappropriate deletion or retention of outliers, transferring the subjective bias into the results of least squares regression. In addition, textbooks on management accounting discuss the use of visually fitted lines to estimate cost behavior. PMID:8774007

  14. Remotely sensed biomass over steep slopes: An evaluation among successional stands of the Atlantic Forest, Brazil

    NASA Astrophysics Data System (ADS)

    Barbosa, Jomar Magalhães; Melendez-Pastor, Ignacio; Navarro-Pedreño, Jose; Bitencourt, Marisa Dantas

    2014-02-01

    Remotely sensed images have been widely used to model biomass and carbon content on large spatial scales. Nevertheless, modeling biomass using remotely sensed data from steep slopes is still poorly understood. We investigated how topographical features affect biomass estimation using remotely sensed data and how such estimates can be used in the characterization of successional stands in the Atlantic Rainforest in southeastern Brazil. We estimated forest biomass using a modeling approach that included the use of both satellite data (LANDSAT) and topographic features derived from a digital elevation model (TOPODATA). Biomass estimations exhibited low error predictions (Adj. R2 = 0.67 and RMSE = 35 Mg/ha) when combining satellite data with a secondary geomorphometric variable, the illumination factor, which is based on hill shading patterns. This improved biomass prediction helped us to determine carbon stock in different forest successional stands. Our results provide an important source of modeling information about large-scale biomass in remaining forests over steep slopes.

  15. Topographic optical profilometry of steep slope micro-optical transparent surfaces.

    PubMed

    Antón, Juan Carlos Martínez; Alonso, Jose; Pedrero, Jose Antonio Gómez

    2015-04-01

    Optical profilometers based on light reflection may fail at surfaces presenting steep slopes and highly curved features. Missed light, interference and diffraction at steps, peaks and valleys are some of the reasons. Consequently, blind areas or profile artifacts may be observed when using common reflection micro-optical profilometers (confocal, scanning interferometers, etc…). The Topographic Optical Profilometry by Absorption in Fluids (TOPAF) essentially avoids these limitations. In this technique an absorbing fluid fills the gap between a reference surface and the surface to profile. By comparing transmission images at two different spectral bands we obtain a reliable topographic map of the surface. In this contribution we develop a model to obtain the profile under micro-optical observation, where high numerical aperture (NA) objectives are mandatory. We present several analytical and experimental results, validating the technique's capabilities for profiling steep slopes and highly curved micro-optical surfaces with nanometric height resolution. PMID:25968777

  16. IMF or Abundance Variations? Steep Gradients at the Centers of Elliptical Galaxies

    NASA Astrophysics Data System (ADS)

    McConnell, Nicholas J.; Lu, Jessica R.; Mann, Andrew

    2016-01-01

    We present high signal-to-noise spectra for six early-type galaxies with Keck/LRIS, covering 350-1050 nm and probing spatial scales from 100 pc to several kpc. Some of our objects exhibit steep absorption-line gradients within the central ~300 pc, indicating a rapid increase in [Na/Fe] and [N/Fe] toward the galaxy center. While stellar population synthesis (SPS) modeling may address whether the stellar initial mass function (IMF) varies as a function of radius, we caution that the competing effects of chemical abundance variations and IMF variations demands extreme care in interpreting SPS models of integrated-light spectra. The steep abundance variations themselves may offer insight to star formation and gas retention in progenitors of today's early-type galaxies, including the possible overabundance of stars above ~3 Msun.

  17. Conversion of Impulse Voltage Generator Into Steep Wave Impulse Test-Equipment

    NASA Astrophysics Data System (ADS)

    Khan, Mohammed Zaid; Tanwar, Surender Singh; Dayama, Ravindra; Choudhary, Rahul Raj; Mangal, Ravindra

    This paper demonstrates the alternative measures to generate the Steep wave impulse by using Impulse Voltage Generator (IVG) for high voltage testing of porcelain insulators. The modification of IVG by incorporating compensation of resistor, inductor, and capacitor has been achieved and further performance of the modified system has been analyzed by applying the generated lightning impulse and analyzing the electrical characteristics of impulse waves under standard lightning and fast rise multiple lightning waveform to determine the effect to improve rise time. The advantageous results have been received and being reported such as increase in overshoot compensation, increase in capacitive and inductive load ranges. Such further reduces the duration of oscillations of standard impulse voltages. The reduction in oscillation duration of steep front impulse voltages may be utilized in up gradation of Impulse Voltage Generator System. Stray capacitance could further be added in order to get the minimized difference of measurement between simulation and the field establishment.

  18. Turbulent flows over a modeled steep topography in a thermally-stratified boundary layer.

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Markfort, Corey; Porté-Agel, Fernando

    2015-11-01

    Turbulent flows with features of separation and reattachment, induced by topography of steep slopes, have been very challenging to predict using numerical models. The geometry of the topography, surface roughness and temperature along with the inflow characteristics (velocity, turbulence level, and atmospheric thermal stability) play important roles in determining onset of separation, reattachment location and momentum and heat flux distribution. To address the coupled effects of steep slope and thermal stability on turbulent flows over topography, series of wind-tunnel measurements of velocity fields, temperature and heat fluxes will be presented. Results will demonstrate the turbulent flow properties, including the size of the separation bubble, separated shear layers and the boundary layer recovery in different cases. Focus will be placed on correlation of momentum and heat flux distribution in the wake and turbulent kinetic energy transport.

  19. The Role of Prospection in Steep Temporal Reward Discounting in Gambling Addiction

    PubMed Central

    Wiehler, Antonius; Bromberg, Uli; Peters, Jan

    2015-01-01

    Addiction and pathological gambling (PG) have been consistently associated with high impulsivity and a steep devaluation of delayed rewards, a process that is known as temporal discounting (TD). Recent studies indicated that enhanced episodic future thinking (EFT) results in less impulsive TD in healthy controls (HCs). In a separate line of research, it has been suggested that non-linearities in time perception might contribute to reward devaluation during inter-temporal choice. Therefore, in addition to deficits in valuation processes and executive control, impairments in EFT and non-linearities in time perception have been hypothesized to contribute to steep TD in addiction. In this study, we explore such a potential association of impairments in EFT and time perception with steep TD in PG. We investigated 20 PGs and 20 matched HCs. TD was assessed via a standard computerized binary choice task. EFT was measured using a variation of the Autobiographical Memory Interview by Levine et al. (1). Time perception was assessed with a novel task, utilizing a non-linear rating procedure via circle-size adjustments. Groups did not differ in baseline EFT. In both groups, a power law accounted time perception best, and the degree of non-linearity in time perception correlated with discounting across groups. A multiple regression analysis across all predictors and covariates revealed that only group status (PG/HC) and depression were significantly associated with discounting behavior such that PG increased TD and depression attenuated TD. Our findings speak against the idea that steep TD in PG is due to a skewed perception of time or impairments in EFT, at least under the present task conditions. The lack of overall group differences in EFT does not rule out the possibility of more complex interactions of EFT and decision-making. These interactions might be diminished in pathological gambling or addiction more generally, when other task configurations are used. PMID:26379558

  20. A plethora of diffuse steep spectrum radio sources in Abell 2034 revealed by LOFAR

    NASA Astrophysics Data System (ADS)

    Shimwell, T. W.; Luckin, J.; Brüggen, M.; Brunetti, G.; Intema, H. T.; Owers, M. S.; Röttgering, H. J. A.; Stroe, A.; van Weeren, R. J.; Williams, W. L.; Cassano, R.; de Gasperin, F.; Heald, G. H.; Hoang, D. N.; Hardcastle, M. J.; Sridhar, S. S.; Sabater, J.; Best, P. N.; Bonafede, A.; Chyży, K. T.; Enßlin, T. A.; Ferrari, C.; Haverkorn, M.; Hoeft, M.; Horellou, C.; McKean, J. P.; Morabito, L. K.; Orrù, E.; Pizzo, R.; Retana-Montenegro, E.; White, G. J.

    2016-06-01

    With Low-Frequency Array (LOFAR) observations, we have discovered a diverse assembly of steep spectrum emission that is apparently associated with the intracluster medium (ICM) of the merging galaxy cluster Abell 2034. Such a rich variety of complex emission associated with the ICM has been observed in few other clusters. This not only indicates that Abell 2034 is a more interesting and complex system than previously thought but it also demonstrates the importance of sensitive and high-resolution, low-frequency observations. These observations can reveal emission from relativistic particles which have been accelerated to sufficient energy to produce observable emission or have had their high energy maintained by mechanisms in the ICM. The most prominent feature in our maps is a bright bulb of emission connected to two steep spectrum filamentary structures, the longest of which extends perpendicular to the merger axis for 0.5 Mpc across the south of the cluster. The origin of these objects is unclear, with no shock detected in the X-ray images and no obvious connection with cluster galaxies or AGNs. We also find that the X-ray bright region of the cluster coincides with a giant radio halo with an irregular morphology and a very steep spectrum. In addition, the cluster hosts up to three possible radio relics, which are misaligned with the cluster X-ray emission. Finally, we have identified multiple regions of emission with a very steep spectral index that seem to be associated with either tailed radio galaxies or a shock.

  1. Bacterial Diversity and Mycotoxin Reduction During Maize Fermentation (Steeping) for Ogi Production.

    PubMed

    Okeke, Chiamaka A; Ezekiel, Chibundu N; Nwangburuka, Cyril C; Sulyok, Michael; Ezeamagu, Cajethan O; Adeleke, Rasheed A; Dike, Stanley K; Krska, Rudolf

    2015-01-01

    Bacterial diversity and community structure of two maize varieties (white and yellow) during fermentation/steeping for ogi production, and the influence of spontaneous fermentation on mycotoxin reduction in the gruel were studied. A total of 142 bacterial isolates obtained at 24-96 h intervals were preliminarily identified by conventional microbiological methods while 60 selected isolates were clustered into 39 OTUs consisting of 15 species, 10 genera, and 3 phyla by 16S rRNA sequence analysis. Lactic acid bacteria constituted about 63% of all isolated bacteria and the genus Pediococcus dominated (white maize = 84.8%; yellow maize = 74.4%). Pediococcus acidilactici and Lactobacillus paraplantarum were found at all steeping intervals of white and yellow maize, respectively, while P. claussenii was present only at the climax stage of steeping white maize. In both maize varieties, P. pentosaceus was found at 24-72 h. Mycotoxin concentrations (μg/kg) in the unsteeped grains were: white maize (aflatoxin B1 = 0.60; citrinin = 85.8; cyclopiazonic acid = 23.5; fumonisins (B1/B2/B3) = 68.4-483; zearalenone = 3.3) and yellow maize (aflatoxins (B1/B2/M1) = 22.7-513; citrinin = 16,800; cyclopiazonic acid = 247; fumonisins (B1/B2/B3) = 252-1,586; zearalenone = 205). Mycotoxins in both maize varieties were significantly (p < 0.05) reduced across steeping periods. This study reports for the first time: (a) the association of L. paraplantarum, P. acidilactici, and P. claussenii with ogi production from maize, (b) citrinin occurrence in Nigerian maize and ogi, and PMID:26697001

  2. Bacterial Diversity and Mycotoxin Reduction During Maize Fermentation (Steeping) for Ogi Production

    PubMed Central

    Okeke, Chiamaka A.; Ezekiel, Chibundu N.; Nwangburuka, Cyril C.; Sulyok, Michael; Ezeamagu, Cajethan O.; Adeleke, Rasheed A.; Dike, Stanley K.; Krska, Rudolf

    2015-01-01

    Bacterial diversity and community structure of two maize varieties (white and yellow) during fermentation/steeping for ogi production, and the influence of spontaneous fermentation on mycotoxin reduction in the gruel were studied. A total of 142 bacterial isolates obtained at 24–96 h intervals were preliminarily identified by conventional microbiological methods while 60 selected isolates were clustered into 39 OTUs consisting of 15 species, 10 genera, and 3 phyla by 16S rRNA sequence analysis. Lactic acid bacteria constituted about 63% of all isolated bacteria and the genus Pediococcus dominated (white maize = 84.8%; yellow maize = 74.4%). Pediococcus acidilactici and Lactobacillus paraplantarum were found at all steeping intervals of white and yellow maize, respectively, while P. claussenii was present only at the climax stage of steeping white maize. In both maize varieties, P. pentosaceus was found at 24–72 h. Mycotoxin concentrations (μg/kg) in the unsteeped grains were: white maize (aflatoxin B1 = 0.60; citrinin = 85.8; cyclopiazonic acid = 23.5; fumonisins (B1/B2/B3) = 68.4–483; zearalenone = 3.3) and yellow maize (aflatoxins (B1/B2/M1) = 22.7–513; citrinin = 16,800; cyclopiazonic acid = 247; fumonisins (B1/B2/B3) = 252–1,586; zearalenone = 205). Mycotoxins in both maize varieties were significantly (p < 0.05) reduced across steeping periods. This study reports for the first time: (a) the association of L. paraplantarum, P. acidilactici, and P. claussenii with ogi production from maize, (b) citrinin occurrence in Nigerian maize and ogi, and (c) aflatoxin M1, citrinin and cyclopiazonic acid degradation/loss due to fermentation in traditional cereal-based fermented food. PMID:26697001

  3. Numerical errors in the presence of steep topography: analysis and alternatives

    SciTech Connect

    Lundquist, K A; Chow, F K; Lundquist, J K

    2010-04-15

    It is well known in computational fluid dynamics that grid quality affects the accuracy of numerical solutions. When assessing grid quality, properties such as aspect ratio, orthogonality of coordinate surfaces, and cell volume are considered. Mesoscale atmospheric models generally use terrain-following coordinates with large aspect ratios near the surface. As high resolution numerical simulations are increasingly used to study topographically forced flows, a high degree of non-orthogonality is introduced, especially in the vicinity of steep terrain slopes. Numerical errors associated with the use of terrainfollowing coordinates can adversely effect the accuracy of the solution in steep terrain. Inaccuracies from the coordinate transformation are present in each spatially discretized term of the Navier-Stokes equations, as well as in the conservation equations for scalars. In particular, errors in the computation of horizontal pressure gradients, diffusion, and horizontal advection terms have been noted in the presence of sloping coordinate surfaces and steep topography. In this work we study the effects of these spatial discretization errors on the flow solution for three canonical cases: scalar advection over a mountain, an atmosphere at rest over a hill, and forced advection over a hill. This study is completed using the Weather Research and Forecasting (WRF) model. Simulations with terrain-following coordinates are compared to those using a flat coordinate, where terrain is represented with the immersed boundary method. The immersed boundary method is used as a tool which allows us to eliminate the terrain-following coordinate transformation, and quantify numerical errors through a direct comparison of the two solutions. Additionally, the effects of related issues such as the steepness of terrain slope and grid aspect ratio are studied in an effort to gain an understanding of numerical domains where terrain-following coordinates can successfully be used and

  4. Steep-sided domes on Venus - Characteristics, geologic setting, and eruption conditions from Magellan data

    NASA Technical Reports Server (NTRS)

    Pavri, Betina; Head, James W., III; Klose, K. B.; Wilson, Lionel

    1992-01-01

    A survey of more than 95 percent of the Venus surface reveals 145 steep-sided domes which can be subdivided into a variety of morphologic forms, the most common being shaped like inverted bowls or flat-topped domes. Results of a preliminary analysis of the distribution and geologic setting of the domes are presented. The relation of the domes to analogous terrestrial features is examined, and possible models for their mode of emplacement are outlined.

  5. The effect of steepness of temporal resource gradients on spatial root allocation

    PubMed Central

    Novoplansky, Ariel; Ovadia, Ofer

    2011-01-01

    Plants are able to discriminately allocate greater biomass to organs that grow under higher resource levels. Recent evidence demonstrates that split-root plants also discriminately allocate more resources to roots that grow under dynamically improving nutrient levels, even when their other roots grow in richer patches. Here, we further tested whether, besides their responsiveness to the direction of resource gradients, plants are also sensitive to the steepness of environmental trajectories. Split-root Pisum sativum plants were grown so that one of their roots developed under constantly-high nutrient levels and the other root was subjected to dynamically improving nutrient levels of variable steepness. As expected, plants usually allocated a greater proportion of their biomass to roots that developed under constantly high resource availability; however, when given a choice, they allocated greater biomass to roots that initially experienced relatively low but steeply improving nutrient availabilities than to roots that developed under continuously-high nutrient availability. Such discrimination was not observed when the roots in the poor patch experienced only gentler improvements in nutrient availability. The results are compatible with the notion that responsiveness to the direction and steepness of environmental gradients could assist annual plants to increase their performance by anticipating resource availabilities foreseeable before the end of the growing season. The results exemplify the ability of plants to integrate and utilize environmental information and execute adaptive behaviors which, until recently, were attributed only to animals with central nervous systems. PMID:22019637

  6. ANOMALOUSLY STEEP REDDENING LAW IN QUASARS: AN EXCEPTIONAL EXAMPLE OBSERVED IN IRAS 14026+4341

    SciTech Connect

    Jiang Peng; Zhou Hongyan; Ji Tuo; Shu Xinwen; Liu Wenjuan; Dong Xiaobo; Wang Huiyuan; Wang Tinggui; Wang Jianguo

    2013-06-15

    A fraction of the heavily reddened quasars require a reddening curve that is even steeper than that of the Small Magellanic Cloud. In this paper, we thoroughly characterize the anomalously steep reddening law in quasars via an exceptional example observed in IRAS 14026+4341. By comparing the observed spectrum to the quasar composite spectrum, we derive a reddening curve in the rest-frame wavelength range of 1200-10000 A. It has a steep rise at wavelengths shorter than 3000 A, but no significant reddening at longer wavelengths. The absence of dust reddening in the optical continuum is confirmed by the normal broad-line Balmer decrement (the H{alpha}/H{beta} ratio) in IRAS 14026+4341. The anomalous reddening curve can be satisfactorily reproduced with a dust model containing silicate grains in a power-law size distribution, dn(a)/da{proportional_to}a {sup -1.4}, truncated at a maximum size of a{sub max} = 70 nm. The unusual size distribution may be caused by the destruction of large 'stardust' grains by quasar activities or a different dust formation mechanism (i.e., the in situ formation of dust grains in quasar outflows). It is also possible that the analogies of the dust grains observed near the Galactic center are responsible for the steep reddening curve. In addition, we find that IRAS 14026+4341 is a weak emission-line quasar (i.e., PHL 1811 analogies) with heavy dust reddening and blueshifted broad absorption lines.

  7. Process analysis, quantification and modelling of erosion on steep unvegetated hillslopes:

    NASA Astrophysics Data System (ADS)

    Neugirg, Fabian; Kaiser, Andreas; Schindewolf, Marcus; Schmidt, Jürgen; Becht, Michael; Haas, Florian

    2016-04-01

    Soil erosion is a problem in many parts of the world. While in agricultural environments the geomorphological drivers of soil erosion are well known, the process understanding in steep alpine environments is still lacking. Steep hillslopes in different climatic settings distributed in Germany and Italy were monitored for at least three years in order to gain better knowledge in the evolution of the unvegetated slopes. The monitoring setup was mainly based on terrestrial laserscanning (TLS) and was expanded with other monitoring methods, like aerial- and terrestrial-based structure from motion, aerial images and airborne laser scanning data. TLS data were mainly used to analyse processes on plot or hillslope scale. In order to regionalize these values, we used two different modelling approaches: a rule-based statistical and the physical-based model Erosion 3D. The latter one had to be adopted from flat agricaltural areas to steep slopes. Parameters for modeling purposes were acquired by field work. Therefore an established rainfall simulator was customized for the application in alpine terrain. The results showed clear differences in the seasonal behaviour of the acting geomorphological processes in nearly all study areas. Furthermore a quantification was possible for each process involved in hillslope development. Additionally, both models showed that an adaptation to the hillslopes was possible and provided satisfying results in all research areas. This presentation aims at summarizing the findings and key results of the three year study period.

  8. Self-adjustment of stream bed roughness and flow velocity in a steep mountain channel

    NASA Astrophysics Data System (ADS)

    Schneider, Johannes M.; Rickenmann, Dieter; Turowski, Jens M.; Kirchner, James W.

    2015-10-01

    Understanding how channel bed morphology affects flow conditions (and vice versa) is important for a wide range of fluvial processes and practical applications. We investigated interactions between bed roughness and flow velocity in a steep, glacier-fed mountain stream (Riedbach, Ct. Valais, Switzerland) with almost flume-like boundary conditions. Bed gradient increases along the 1 km study reach by roughly 1 order of magnitude (S = 3-41%), with a corresponding increase in streambed roughness, while flow discharge and width remain approximately constant due to the glacial runoff regime. Streambed roughness was characterized by semivariograms and standard deviations of point clouds derived from terrestrial laser scanning. Reach-averaged flow velocity was derived from dye tracer breakthrough curves measured by 10 fluorometers installed along the channel. Commonly used flow resistance approaches (Darcy-Weisbach equation and dimensionless hydraulic geometry) were used to relate the measured bulk velocity to bed characteristics. As a roughness measure, D84 yielded comparable results to more laborious measures derived from point clouds. Flow resistance behavior across this large range of steep slopes agreed with patterns established in previous studies for both lower-gradient and steep reaches, regardless of which roughness measures were used. We linked empirical critical shear stress approaches to the variable power equation for flow resistance to investigate the change of bed roughness with channel slope. The predicted increase in D84 with increasing channel slope was in good agreement with field observations.

  9. Evaluation of sediment transport in steep channels combining sediment impact sensors, tracer stones and TLS

    NASA Astrophysics Data System (ADS)

    Harb, Gabriele; Schneider, Josef; Sass, Oliver; Stangl, Johannes

    2016-04-01

    Torrential floods combined with sediment transport presents major hazards to human life and infrastructure in alpine catchments. Despite the importance of sediment transport due to the large damage caused in case of flood events, we lack data on sediment movement and sediment transport rates in steep channels and torrents to improve the understanding of sediment transport processes in this areas. This paper presents an improved application of sediment impact sensors (SIS) integrated in a unique measurement system in an Alpine catchment in Austria consisting of meteorological stations, runoff gauges and tracer stones. In addition sediment availability, mobilization and accumulation have been mapped and quantified by means of terrestrial laser scanning (TLS) and structure from motion using unmanned aerial vehicles (UAVs). Additionally a numerical model was used to simulate the bed load transport rates in the torrent. This contribution focuses on field measurements of bed load transport rates in steep channels based on SIS data, tracer stone data, bed load measurements, precipitation and discharge data. The measurement data was compared to several sediment transport formulae for steep slopes and validated with the observed deposited amount of sediment in the sediment retention basin at the outlet of the catchment.

  10. Experimental investigation of steep-front short duration (SFSD) surge effects on power systems components

    SciTech Connect

    Miller, D.B.

    1992-05-01

    Results are reported from experiments in which steep-front, short- duration (SFSD) voltage impulses were imposed on various electrical distribution components. These pulses were generated by switching a section of charged, high voltage coaxial cable across the component under study. Components included underground distribution cable, terminators, insulators and arresters. SFSD voltage needed to flashover 15 kV polyethylene cable with a single pulse is approximately 625 kV peak. Strength of polyethylene cable decreases with increasing number of SFSD pulses, indicating cumulative degradation of the polymer. For 15 kV and 25 kV cable terminators, the SFSD CFO was over twice the rated standard lightning BIL for the same units. Similarly, porcelain suspension insulators required more than a doubling of voltage to decrease time to flashover from 1 microsecond to .1 microsecond. Arresters were found to respond rapidly to steep-front current pulses, but the arrester material itself was found to result in a higher discharge voltage for SFSD pulses. Arresters also showed a delay in turn-on of current following the arrival of a steep-front voltage surge.

  11. Temperature and Time of Steeping Affect the Antioxidant Properties of White, Green, and Black Tea Infusions.

    PubMed

    Hajiaghaalipour, Fatemeh; Sanusi, Junedah; Kanthimathi, M S

    2016-01-01

    Tea (Camellia sinensis) is the most highly consumed beverage in the world next to water. The common way of preparation is steeping in hot water which is varying for different type of tea. We investigated the antioxidant properties of 6 type of tea leaves under different time and temperatures of extraction method used. In general, all samples tested in this study demonstrated high levels of antioxidant capacity and antioxidant activity. The results indicate that the antioxidants activity is significantly affected by time and temperature of steeping and the highest was depending on the variety. White state values, green and black teas showed different levels of antioxidants under different extraction conditions. Overall, the highest activity for white tea was in prolonged hot and in some assays prolonged hot and cold extracts, whereas for green tea the highest activity observed in prolonged cold steeping while, for black tea was in short hot water infusion. The results of this study showed the antioxidant capacity of white and green tea was greater than black tea. PMID:26613545

  12. Variations in the kinematics of deformation along the Zagros inclined transpression zone, Iran: Implications for defining a curved inclined transpression zone

    NASA Astrophysics Data System (ADS)

    Sarkarinejad, Khalil; Partabian, Abdolreza; Faghih, Ali

    2013-03-01

    The combination of inclined collision and plate boundary shape can control the nature of deformation and the sense of shear along a transpression zone. The present study investigated the effects of a boundary zone with curvilinear shape along a transpression zone on the kinematics of deformation. The kinematics of the Zagros transpression zone varies with the orientation of the zone boundary. Detailed structural and microstructural studies showed sinistral sense of shear on the southeastern part of the Zagros inclined transpression zone (Fars Arc), but dextral sense of shear on the northwestern part of the zone. It is inferred that the both senses of shear were developed coevally under a bulk general shear, regional-scale deformation along a curved inclined transpression miming the shape of the Fras Arc of the Zagros and the reentrant of the Bandar Abbas Syntaxis. The Zagros transpression zone formed by inclined continental collision between the Afro-Arabian continent and Iranian microcontinent.

  13. Thermal stability effects on the separated flow over a steep 2-D hill

    NASA Astrophysics Data System (ADS)

    Zhang, W.; Porte-Agel, F.

    2012-12-01

    Transport of momentum and scalars in turbulent boundary-layer flows over complex topography has been of great interest in the atmospheric sciences and wind engineering communities. Applications include but are not limited to weather forecasting, air pollution dispersion, aviation safety control, and wind energy project planning. Linear models have been well accepted to predict boundary-layer flows over topography with gentle slope. However, once the slope of the topography is sufficientlyo steep that flow separation occurs, linear models are not applicable. Modeling the turbulent transport of momentum and scalars in such flows has to be achieved through non-linear models, such as Reynolds-averaged Navier-Stokes solvers and large-eddy simulations (LES). Dynamics of the separated boundary-layer flows over steep topography is affected by the shape and size of the topography, surface characteristics (e.g., roughness and temperature) and atmospheric thermal stability. Most wind-tunnel experiments of boundary-layer flows over idealized topography (e.g. 2-D or 3-D hills, axisymmetric bumps) do not take thermal stability effects into account due to difficulty of physical simulation. We conducted comprehensive experimental investigation of stably- and unstably- stratified boundary layers over a steep 2-D hill in the thermally-controlled boundary-layer wind tunnel at the Saint Anthony Falls Laboratory. The 2-D model hill has a steepest slope of 0.73 and its shape follows a cosine square function: h=Hcos^2 (πx/L) for -L/2 ≤ x ≤ L/2 , where the maximum height H is 7 cm and the total width L is 15 cm. High-resolution Particle Image Velocimetry (PIV) provides dynamic information of the separated shear layer, the recirculation zone and flow reattachment. Turbulent momentum and scalar (heat) fluxes were characterized up to the top of the thermal boundary layer using a triple-wire (cross-wire and cold-wire) anemometer. Results indicate that promoted and suppressed turbulence

  14. Carrying a biological "backpack": Quasi-experimental effects of weight status and body fat change on perceived steepness.

    PubMed

    Taylor-Covill, Guy A H; Eves, Frank F

    2016-03-01

    The apparent steepness of hills and stairs is overestimated in explicit perception. These overestimations are malleable in that when physiological resources are compromised, apparent steepness is further overestimated. An alternative explanation of these experimental findings attributes them to demand characteristics. This article tests the relationship between estimated steepness and naturally occurring differences in body composition. A quasi-experimental field study revealed more exaggerated reports of staircase steepness in overweight than in healthy-weight participants in a situation where experimental demand would be an implausible explanation for any differences. A longitudinal follow-up study used dual X-ray absorptiometry to objectively measure participants' body composition at the beginning and end of a weight-loss program (N = 52). At baseline, higher levels of body fat were associated with steeper explicit estimates of staircase steepness. At follow-up, changes in body fat were associated with changes in estimated steepness such that a loss of fat mass co-occurred with shallower estimates. Discussion focuses on the malleability of perceived steepness at an individual level and the implication of these findings for the debate surrounding "embodied" models of perception. (PsycINFO Database Record PMID:26414167

  15. DETERMINING INCLINATIONS OF ACTIVE GALACTIC NUCLEI VIA THEIR NARROW-LINE REGION KINEMATICS. I. OBSERVATIONAL RESULTS

    SciTech Connect

    Fischer, T. C.; Crenshaw, D. M.; Kraemer, S. B.; Schmitt, H. R.

    2013-11-01

    Active galactic nuclei (AGNs) are axisymmetric systems to first order; their observed properties are likely strong functions of inclination with respect to our line of sight (LOS). However, except for a few special cases, the specific inclinations of individual AGNs are unknown. We have developed a promising technique for determining the inclinations of nearby AGNs by mapping the kinematics of their narrow-line regions (NLRs), which are often easily resolved with Hubble Space Telescope [O III] imaging and long-slit spectra from the Space Telescope Imaging Spectrograph. Our studies indicate that NLR kinematics dominated by radial outflow can be fit with simple biconical outflow models that can be used to determine the inclination of the bicone axis, and hence the obscuring torus, with respect to our LOS. We present NLR analysis of 53 Seyfert galaxies and the resulting inclinations from models of 17 individual AGNs with clear signatures of biconical outflows. Our model results agree with the unified model in that Seyfert 1 AGNs have NLRs inclined further toward our LOS than Seyfert 2 AGNs. Knowing the inclinations of these AGN NLRs, and thus their accretion disk and/or torus axes, will allow us to determine how their observed properties vary as a function of polar angle. We find no correlation between the inclinations of the AGN NLRs and the disks of their host galaxies, indicating that the orientation of the gas in the torus is independent of that of the host disk.

  16. The effects of orbital inclination on the scale size and evolution of tidally filling star clusters

    NASA Astrophysics Data System (ADS)

    Webb, Jeremy J.; Sills, Alison; Harris, William E.; Hurley, Jarrod R.

    2014-11-01

    We have performed N-body simulations of tidally filling star clusters with a range of orbits in a Milky Way-like potential to study the effects of orbital inclination and eccentricity on their structure and evolution. At small galactocentric distances Rgc, a non-zero inclination results in increased mass-loss rates. Tidal heating and disc shocking, the latter sometimes consisting of two shocking events as the cluster moves towards and away from the disc, help remove stars from the cluster. Clusters with inclined orbits at large Rgc have decreased mass-loss rates than the non-inclined case, since the strength of the disc potential decreases with Rgc. Clusters with inclined and eccentric orbits experience increased tidal heating due to a constantly changing potential, weaker disc shocks since passages occur at higher Rgc, and an additional tidal shock at perigalacticon. The effects of orbital inclination decrease with orbital eccentricity, as a highly eccentric cluster spends the majority of its lifetime at a large Rgc. The limiting radii of clusters with inclined orbits are best represented by the rt of the cluster when at its maximum height above the disc, where the cluster spends the majority of its lifetime and the rate of change in rt is a minimum. Conversely, the effective radius is independent of inclination in all cases.

  17. How do the substrate reaction forces acting on a gecko's limbs respond to inclines?

    NASA Astrophysics Data System (ADS)

    Wang, Zhouyi; Dai, Zhendong; Li, Wei; Ji, Aihong; Wang, Wenbao

    2015-02-01

    Locomotion is an essential character of animals, and excellent moving ability results from the delicate sensing of the substrate reaction forces (SRF) acting on body and modulating the behavior to adapt the motion requirement. The inclined substrates present in habitats pose a number of functional challenges to locomotion. In order to effectively overcome these challenges, climbing geckos execute complex and accurate movements that involve both the front and hind limbs. Few studies have examined gecko's SRF on steeper inclines of greater than 90°. To reveal how the SRFs acting on the front and hind limbs respond to angle incline changes, we obtained detailed measurements of the three-dimensional SRFs acting on the individual limbs of the tokay gecko while it climbed on an inclined angle of 0-180°. The fore-aft forces acting on the front and hind limbs show opposite trends on inverted inclines of greater than 120°, indicating propulsion mechanism changes in response to inclines. When the incline angles change, the forces exerted in the normal and fore-aft directions by gecko's front and hind limbs are reassigned to take full advantage of limbs' different roles in overcoming resistance and in propelling locomotion. This also ensures that weight acts in the angle range between the forces generated by the front and hind limbs. The change in the distribution of SRF with a change in the incline angle is directly linked to the favorable trade-off between locomotive maneuverability and stability.

  18. Dynamic Crush Behaviors Of Aluminum Honeycomb Specimens Under Compression Dominant Inclined Loads

    SciTech Connect

    Hong, Sung-tae; Pan, Jwo; Tyan, Tau; Prasad, Priya

    2008-01-01

    The quasi-static and dynamic crush behaviors of aluminum 5052-H38 honeycomb specimens under out-of-plane inclined loads are investigated by experiments. Different types of honeycomb specimens were designed for crush tests under pure compressive and inclined loads with respect to the out-of-plane direction. A test fixture was designed for both quasi-static and dynamic crush tests under inclined loads. The results of the quasi-static crush tests indicate that the normal crush and shear strengths under inclined loads are consistent with the corresponding results under combined loads. The results of the dynamic crush tests indicate that as the impact velocity increases, the normal crush strength increases and the shear strength remains nearly the same. The trends of the normalized normal crush strengths under inclined loads for specimens with different in-plane orientation angles as functions of the impact velocity are very similar to each other. Based on the experimental results, a macroscopic yield criterion as a function of the impact velocity is proposed. The experimental results suggest that as the impact velocity increases, the shape of the macroscopic yield surface changes, or more specifically, the curvature of the yield surface increases near the pure compression state. The experimental results also show similar microscopic progressive folding mechanisms in honeycomb specimens under pure compressive and inclined loads. However, honeycomb specimens under inclined loads show inclined stacking patterns of folds due to the asymmetric location of horizontal plastic hinge lines.

  19. Analysis of high-speed growth of silicon sheet in inclined-meniscus configuration

    NASA Technical Reports Server (NTRS)

    Thomas, P. D.; Brown, R. A.

    1985-01-01

    The study of high speed growth of silicon sheet in inclined-meniscus configurations is discussed. It was concluded that the maximum growth rates in vertical and inclined growth are set by thermal-capillary limits. Also, the melt/crystal interface was determined to be flat. And, vertical growth is qualitatively modelled by one dimensional heat transfer.

  20. How do the substrate reaction forces acting on a gecko's limbs respond to inclines?

    PubMed

    Wang, Zhouyi; Dai, Zhendong; Li, Wei; Ji, Aihong; Wang, Wenbao

    2015-02-01

    Locomotion is an essential character of animals, and excellent moving ability results from the delicate sensing of the substrate reaction forces (SRF) acting on body and modulating the behavior to adapt the motion requirement. The inclined substrates present in habitats pose a number of functional challenges to locomotion. In order to effectively overcome these challenges, climbing geckos execute complex and accurate movements that involve both the front and hind limbs. Few studies have examined gecko's SRF on steeper inclines of greater than 90°. To reveal how the SRFs acting on the front and hind limbs respond to angle incline changes, we obtained detailed measurements of the three-dimensional SRFs acting on the individual limbs of the tokay gecko while it climbed on an inclined angle of 0-180°. The fore-aft forces acting on the front and hind limbs show opposite trends on inverted inclines of greater than 120°, indicating propulsion mechanism changes in response to inclines. When the incline angles change, the forces exerted in the normal and fore-aft directions by gecko's front and hind limbs are reassigned to take full advantage of limbs' different roles in overcoming resistance and in propelling locomotion. This also ensures that weight acts in the angle range between the forces generated by the front and hind limbs. The change in the distribution of SRF with a change in the incline angle is directly linked to the favorable trade-off between locomotive maneuverability and stability. PMID:25645733

  1. Flow characteristics of an inclined air-curtain range hood in a draft

    PubMed Central

    CHEN, Jia-Kun

    2015-01-01

    The inclined air-curtain technology was applied to build an inclined air-curtain range hood. A draft generator was applied to affect the inclined air-curtain range hood in three directions: lateral (θ=0°), oblique (θ=45°), and front (θ=90°). The three suction flow rates provided by the inclined air-curtain range hood were 10.1, 10.9, and 12.6 m3/min. The laser-assisted flow visualization technique and the tracer-gas test method were used to investigate the performance of the range hood under the influence of a draft. The results show that the inclined air-curtain range hood has a strong ability to resist the negative effect of a front draft until the draft velocity is greater than 0.5 m/s. The oblique draft affected the containment ability of the inclined air-curtain range hood when the draft velocity was larger than 0.3 m/s. When the lateral draft effect was applied, the capture efficiency of the inclined air-curtain range hood decreased quickly in the draft velocity from 0.2 m/s to 0.3 m/s. However, the capture efficiencies of the inclined air-curtain range hood under the influence of the front draft were higher than those under the influence of the oblique draft from 0.3 m/s to 0.5 m/s. PMID:25810445

  2. 77 FR 28770 - Safety Zone; Red, White, and Tahoe Blue Fireworks, Incline Village, NV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-16

    ... SECURITY Coast Guard 33 CFR Part 165 Safety Zone; Red, White, and Tahoe Blue Fireworks, Incline Village, NV... enforce the safety zone for the Incline Village, NV Red, White, and Tahoe Blue Fireworks display in the..., White, and Tahoe Blue Fireworks display in 33 CFR 165.1191. This safety zone will be in effect from 7...

  3. Runoff generation and flow paths on an inclined cultivated soil

    NASA Astrophysics Data System (ADS)

    Zumr, David; Strouhal, Luděk; Kavka, Petr

    2015-04-01

    The hydrology of cultivated catchments has its specific features due to the temporary variable topsoil properties and a sharp divide between topsoil and compacted subsoil. Under various conditions (actual topsoil physical properties, initial soil saturation, rainfall characteristics, surface roughness or vegetation stage) the prevailing runoff mechanisms may vary from surface runoff to subsurface runoff or deep percolation. To investigate the runoff generation and flow pathways and to quantify the runoff components on an inclined cultivated field under various rainfall and field conditions we conducted plot scale rainfall simulations. The experiments were done on the experimental plots Bykovice in Central Bohemia (Czech Republic), where the soil is classified as Cambisol with a clear divide between the topsoil and compacted subsoil at a depth of approximately 14 cm. We used a mobile rainfall simulator (designed at the CTU in Prague) equipped with four solenoid-controlled nozzles positioned 2.65 m above the soil. An inclined experimental plot (8 x 2 m, 9% slope) was successively exposed to uniform simulated rainfall with intensity ranging from 23 to 64 mm h-1 and duration ranging from 1 h to 2.5 h. These simulated rainfall parameters were selected to represent intensive rainfall events observed in the study locality, to generate surface runoff and to initiate soil erosion. The dynamics of surface and shallow subsurface runoff and the soil water regime at three soil depths were monitored. Various initial soil moisture conditions, and vegetation stages; from cultivated fallow to stubble, delimited the simulations. Variable proportions of both monitored runoff components were observed in relation to rainfall intensity and duration, ranging from zero surface runoff to a distinct dominance of surface runoff. Both components reacted very dynamically to the precipitation: shallow subsurface runoff was formed first under all tested conditions on the given soil profile. Even

  4. Space Station Freedom assembly and operation at a 51.6 degree inclination orbit

    NASA Technical Reports Server (NTRS)

    Troutman, Patrick A.; Brewer, Laura M.; Heck, Michael L.; Kumar, Renjith R.

    1993-01-01

    This study examines the implications of assembling and operating Space Station Freedom at a 51.6 degree inclination orbit utilizing an enhanced lift Space Shuttle. Freedom assembly is currently baselined at a 220 nautical mile high, 28.5 degree inclination orbit. Some of the reasons for increasing the orbital inclination are (1) increased ground coverage for Earth observations, (2) greater accessibility from Russian and other international launch sites, and (3) increased number of Assured Crew Return Vehicle (ACRV) landing sites. Previous studies have looked at assembling Freedom at a higher inclination using both medium and heavy lift expendable launch vehicles (such as Shuttle-C and Energia). The study assumes that the shuttle is used exclusively for delivering the station to orbit and that it can gain additional payload capability from design changes such as a lighter external tank that somewhat offsets the performance decrease that occurs when the shuttle is launched to a 51.6 degree inclination orbit.

  5. Numerical modeling of incline plate LiBr absorber

    NASA Astrophysics Data System (ADS)

    Karami, Shahram; Farhanieh, Bijan

    2011-03-01

    Among major components of LiBr-H2O absorption chillers is the absorber, which has a direct effect on the chillier size and whose characteristics have significant effects on the overall efficiency of absorption machines. In this article, heat and mass transfer process in absorption of refrigerant vapor into a lithium bromide solution of water-cooled incline plate absorber in the Reynolds number range of 5 < Re < 150 is performed numerically. The boundary layer assumptions are used for the mass, momentum and energy transport equations and the fully implicit finite difference method is employed to solve the governing equations. Dependence of lithium bromide aqueous properties to the temperature and concentration is employed as well as dependence of film thickness to vapor absorption. An analysis for linear distribution of wall temperature condition carries out to investigate the reliability of the present numerical method through comparing with previous investigation. The effect of plate angle on heat and mass transfer parameters is investigated and the results show that absorption mass flux and heat and mass transfer coefficient increase as the angle of the plate increase. The main parameters of absorber design, namely Nusselt and Sherwood numbers, are correlated as a function of Reynolds Number and the plate angle.

  6. Studies of granular flow down an inclined chute

    SciTech Connect

    Hanes, D.M.

    1992-01-01

    A preliminary series of experiments were run in order to examine the effects sidewalls have on the steady-state mass flow rate of granular material in a rectangular, inclined chute. These experiments also serve to assess the problems associated with the initial operation of the granular flow apparatus. Presumably, the friction between the sidewalls and the flowing material will slow the flow rate of that material. The relative effect of the sidewalls should decrease with increasing width for a given flow entrance condition. For instance, when the width of the chute is at a minimum (one grain diameter), the sidewalls will have a maximum frictional effect. And as the width approaches infinity, the sidewalls will have a minimum frictional effect. It is desired to know at what chute widths the sidewall effects will reasonably approach this minimum, if this condition can even be approached with the existing apparatus. The relationship between chute width and flow rate will be important to know during more involved experiments which will follow this initial investigation. These experiments will include the measurement of localized grain density, local velocity and individual grain dynamics (rotation and translation) and collisions. The secondary objective, to observe and correct problems with the system, is a more general and qualitative goal.

  7. Droplet impact patterns on inclined surfaces with variable properties

    NASA Astrophysics Data System (ADS)

    Lockard, Michael; Neitzel, G. Paul; Smith, Marc K.

    2014-11-01

    Bloodstain pattern analysis is used in the investigation of a crime scene to infer the impact velocity and size of an impacting droplet and, from these, the droplet's point and cause of origin. The final pattern is the result of complex fluid mechanical processes involved in the impact and spreading of a blood drop on a surface coupled with the wetting properties of the surface itself. Experiments have been designed to study these processes and the resulting patterns for the case of a single Newtonian water droplet impacting a planar, inclined surface with variable roughness and wetting properties. Results for Reynolds numbers in the range of (9,000 - 27,000) and Weber numbers in the range of (300 - 2,600) will be presented. Transient video images and final impact patterns will be analyzed and compared with results from traditional bloodstain pattern-analysis techniques used by the forensics community. In addition, preliminary work with a new Newtonian blood simulant designed to match the viscosity and surface tension of blood will be presented. Supported by the National Institute of Justice.

  8. A conservation law model for bidensity suspensions on an incline

    NASA Astrophysics Data System (ADS)

    Wong, Jeffrey T.; Bertozzi, Andrea L.

    2016-09-01

    We study bidensity suspensions of a viscous fluid on an incline. The particles migrate within the fluid due to a combination of gravity-induced settling and shear induced migration. We propose an extension of a recent model (Murisic et al., 2013) for monodisperse suspensions to two species of particles, resulting in a hyperbolic system of three conservation laws for the height and particle concentrations. We analyze the Riemann problem and show that the system exhibits three-shock solutions representing distinct fronts of particles and liquid traveling at different speeds as well as singular shock solutions for sufficiently large concentrations, for which the mechanism is essentially the same as the single-species case. We also consider initial conditions describing a fixed volume of fluid, where solutions are rarefaction-shock pairs, and present a comparison to recent experimental results. The long-time behavior of solutions is identified for settled mono- and bidisperse suspensions and some leading-order asymptotics are derived in the single-species case for moderate concentrations.

  9. Impact of droplets on inclined flowing liquid films.

    PubMed

    Che, Zhizhao; Deygas, Amandine; Matar, Omar K

    2015-08-01

    The impact of droplets on an inclined falling liquid film is studied experimentally using high-speed imaging. The falling film is created on a flat substrate with controllable thicknesses and flow rates. Droplets with different sizes and speeds are used to study the impact process under various Ohnesorge and Weber numbers, and film Reynolds numbers. A number of phenomena associated with droplet impact are identified and analyzed, such as bouncing, partial coalescence, total coalescence, and splashing. The effects of droplet size, speed, as well the film flow rate are studied culminating in the generation of an impact regime map. The analysis of the lubrication force acted on the droplet via the gas layer shows that a higher flow rate in the liquid film produces a larger lubrication force, slows down the drainage process, and increases the probability of droplet bouncing. Our results demonstrate that the flowing film has a profound effect on the droplet impact process and associated phenomena, which are markedly more complex than those accompanying impact on initially quiescent films. PMID:26382528

  10. Development of coated conductors by inclined substrate deposition

    NASA Astrophysics Data System (ADS)

    Balachandran, U.; Ma, B.; Li, M.; Fisher, B. L.; Koritala, R. E.; Miller, D. J.; Dorris, S. E.

    2003-10-01

    Inclined substrate deposition (ISD) offers the potential for rapid production of high-quality biaxially textured buffer layers suitable for YBa 2Cu 3O 7- δ (YBCO)-coated conductors. We have grown biaxially textured magnesium oxide (MgO) films on Hastelloy C276 (HC) substrates by ISD at deposition rates of 20-100 Å/s. Scanning electron microscopy of the ISD MgO films showed columnar grain structures with a roof-tile-shaped surface. X-ray pole figure analysis revealed that the c-axis of the ISD MgO films is titled at an angle ≈32° from the substrate normal. A small full-width at half maximum of ≈9° was observed for the φ-scan of MgO films. YBCO films were grown on ISD MgO buffered HC substrates by pulsed laser deposition and were determined to be biaxially aligned with the c-axis parallel to the substrate normal. The orientation relationship between the ISD template and the top YBCO film was investigated by X-ray pole figure analysis and transmission electron microscopy. A transport critical current density of Jc=5.5×10 5 A/cm 2 at 77 K in self-field was measured on a YBCO film that was 0.46-μm thick, 4-mm wide, 10-mm long.

  11. Droplet Impact on Inclined Surfaces for Forensic Bloodstain Analysis

    NASA Astrophysics Data System (ADS)

    Smith, Marc; Lockard, Michael; Neitzel, G. Paul

    2015-11-01

    During a crime scene investigation, bloodstains are used to infer the size, impact angle, and velocity of the blood droplet that produced the stain. This droplet impact process was explored using experiments and numerical simulations of droplets impacting planar, inclined surfaces with different roughness and wetting properties over a range of Reynolds numbers (1,000 - 5,500) and Weber numbers (200 - 2,000) typical of some forensics applications. Results will be presented showing how the size and shape of the final elliptical bloodstain varies with impact angle and surface roughness. The common forensics practice to predict the impact angle is fairly accurate for near-normal impacts, but it under-predicts the angle for oblique impacts less than about 40° and this effect worsens for rougher surfaces. The spreading of the droplet normal to the impact plane is shown to follow that of a droplet under normal impact as the impact velocity increases. This effect is also lessened by increased surface roughness. The reasons for these effects will be explored using a new GPU-based wavelet-adaptive flow simulation, which can resolve the flows near the solid surface and near the moving contact line of these droplets for the large Reynolds and Weber numbers of these experiments. Supported by the National Institute of Justice.

  12. On oblique and parallel shedding behind an inclined plate

    NASA Astrophysics Data System (ADS)

    Yang, Dan; Pettersen, Bjørnar; Andersson, Helge I.; Narasimhamurthy, Vagesh D.

    2013-05-01

    Three-dimensional wake instabilities in the form of oblique shedding and vortex dislocations in the flow past an inclined flat plate of angle of attack 20° and Reynolds number 1000 have been reported earlier [D. Yang, B. Pettersen, H. I. Andersson, and V. D. Narasimhamurthy, Phys. Fluids 24, 084103 (2012)], 10.1063/1.4744982. In the current study, direct numerical simulations were performed to further explore this bifurcation. At lower Reynolds numbers, i.e., well below 525, the three-dimensional wake was found to be stable and in a parallel shedding mode. However, as the Reynolds number increases, it was observed that both parallel and oblique vortex sheddings arose naturally. Vortex dislocations appeared at the juxtaposition of oblique and parallel shedding modes. The velocity signals were analyzed by a wavelet transformation, from which the instantaneous characteristics of three-dimensional vortex shedding were obtained and examined. Results show that the phase difference of shed vortex rollers in the spanwise direction gave a symmetric probability density function. This indicates that both positive and negative shedding angles (relative to the axis of the plate) occur with equal likelihood.

  13. Development and evaluation of the modular inclined screen (MIS)

    SciTech Connect

    Taft, E.P.; Winchell, F.C.; Plizga, A.W.

    1995-12-31

    The Electric Power Research Institute (EPRI) has developed and biologically evaluated a new type of fish diversion screen known as the Modular Inclined Screen (MIS). The MIS is designed to operate at any type of water intake with water velocities approaching the screen of up to 3.1 ms{sup -1}. The biological evaluation of the MIS was conducted in the laboratory with juveniles of eleven species. Fish passage was evaluated at five module velocities ranging from 0.6 to 3.1 ms{sup -1}. Net passage survival with a clean screen typically exceeded 99% at velocities up to 1.8 ms{sup -1} for most species, and exceeded 99% overall (all velocities combined) for channel catfish, coho salmon, brown trout, and Atlantic salmon. Fish passage tests with debris accumulation demonstrated that increases in screen head loss up to 12 cm did not reduce the ability of the MIS to safely and effectively divert fish, depending on species and module velocity. On the basis of these results, EPRI, Niagara Mohawk Power Corporation (NMPC) and other contributors have constructed a prototype MIS at NMPC`s Green Island Hydroelectric Project on the Hudson River. Field evaluations of this first MIS will be conducted in the fall of 1995. In addition to the MIS, the effectiveness of a strobe light system will be studied to determine its ability to divert blueback herring from the river to the MIS.

  14. Evolution of Electrified Films on a Porous Inclined Plane

    NASA Astrophysics Data System (ADS)

    Balakrishnan, Uma; Ranganathan, Usha

    2009-03-01

    The nonlinear stability of a thin conducting film flow down a porous inclined plane, when an electric field acts normal to the plane is considered. It is assumed that the flow through the porous medium is governed by Darcy's law and the characteristic length of the pore space is much smaller than the depth of the fluid layer above. Integral Boundary Layer method is employed in obtaining a set of exact averaged equations for the film flow system. Linear stability results through normal mode analysis reveal that the destabilizing influence of the electric field is further enhanced by the porosity of the medium. Critical Reynolds number for the onset of instability decreases with the increase in the permeability of the porous plane. Weakly nonlinear stability analysis using method of multiple scales divulges the existence of zones due to supercritical stability and subcritical instability. Permanent finite-amplitude waves in the supercritical stable region are portrayed by solving the nonlinear evolution equation numerically in a periodic domain. The parameter ranges that support complex nonlinear dynamics is obtained through a combination of theoretical analysis and numerical experiments.

  15. Numerical Analysis of Orbital Perturbation Effects on Inclined Geosynchronous SAR.

    PubMed

    Dong, Xichao; Hu, Cheng; Long, Teng; Li, Yuanhao

    2016-01-01

    The geosynchronous synthetic aperture radar (GEO SAR) is susceptible to orbit perturbations, leading to orbit drifts and variations. The influences behave very differently from those in low Earth orbit (LEO) SAR. In this paper, the impacts of perturbations on GEO SAR orbital elements are modelled based on the perturbed dynamic equations, and then, the focusing is analyzed theoretically and numerically by using the Systems Tool Kit (STK) software. The accurate GEO SAR slant range histories can be calculated according to the perturbed orbit positions in STK. The perturbed slant range errors are mainly the first and second derivatives, leading to image drifts and defocusing. Simulations of the point target imaging are performed to validate the aforementioned analysis. In the GEO SAR with an inclination of 53° and an argument of perigee of 90°, the Doppler parameters and the integration time are different and dependent on the geometry configurations. Thus, the influences are varying at different orbit positions: at the equator, the first-order phase errors should be mainly considered; at the perigee and apogee, the second-order phase errors should be mainly considered; at other positions, first-order and second-order exist simultaneously. PMID:27598168

  16. Film flow of a suspension down an inclined plane.

    PubMed

    Li, Xiaofan; Pozrikidis, C

    2003-05-15

    A method is developed for simulating the film flow of a suspension of rigid particles with arbitrary shapes down an inclined plane in the limit of vanishing Reynolds number. The problem is formulated in terms of a system of integral equations of the first and second kind for the free-surface velocity and the traction distribution along the particle surfaces involving the a priori unknown particle linear velocity of translation and angular velocity of rotation about designated centres. The problem statement is completed by introducing scalar constraints that specify the force and torque exerted on the individual particles. A boundary-element method is implemented for solving the governing equations for the case of a two-dimensional periodic suspension. The system of linear equations arising from numerical discretization is solved using a preconditioner based on a particle-cluster iterative method recently developed by Pozrikidis (2000 Engng Analysis Bound. Elem. 25, 19-30). Numerical investigations show that the generalized minimal residual (GMRES) method with this preconditioner is significantly more efficient than the plain GMRES method used routinely in boundary-element implementations. Extensive numerical simulations for solitary particles and random suspensions illustrate the effect of the particle shape, size and aspect ratio in semi-finite shear flow, and the effect of free-surface deformability in film flow. PMID:12804218

  17. The Performance of RAMS in Representing the Convective Boundary Layer Structure in a Very Steep Valley

    SciTech Connect

    De Wekker, Stephan; Steyn, D. G.; Fast, Jerome D.; Rotach, Mathias W.; Zhong, Shiyuan

    2005-04-01

    Data from a comprehensive field study in the Riviera Valley of Southern Switzerland are used to investigate convective boundary layer structure in a steep valley and to evaluate wind and temperature fields, convective boundary layer height, and surface sensible heat fluxes as predicted by the mesoscale model RAMS. Current parameterizations of surface and boundary layer processes in RAMS, as well as in other mesoscale models, are based on scaling laws strictly valid only for flat topography and uniform land cover. Model evaluation is required to investigate whether this limits the applicability of RAMS in steep, inhomogeneous terrain. One clear-sky day with light synoptic winds is selected from the field study. Observed temperature structure across and along the valley is nearly homogeneous while wind structure is complex with a wind speed maximum on one side of the valley. Upvalley flows are not purely thermally driven and mechanical effects near the valley entrance also affect the wind structure. RAMS captured many of the observed boundary layer characteristics within the steep valley. The wind field, temperature structure, and convective boundary layer height in the valley are qualitatively simulated by RAMS, but the horizontal temperature structure across and along the valley is less homogeneous in the model than in the observations. The model reproduced the observed net radiation, except around sunset and sunrise when RAMS does not take into account the shadows cast by the surrounding topography. The observed sensible heat fluxes fall within the range of simulated values at grid points surrounding the measurement sites. Some of the scatter between observed and simulated turbulent sensible heat fluxes are due to sub-grid scale effects related to local topography.

  18. Comparison of Scheimpflug imaging parameters between steep and keratoconic corneas of Caucasian eyes

    PubMed Central

    Huseynova, Tukezban; Abdulaliyeva, Farah; Lanza, Michele

    2016-01-01

    Purpose To compare the keratometric and pachymetric parameters of healthy eyes with those affected by steep cornea and keratoconus (KC) using Scheimpflug camera. Setting Briz-L Eye Clinic, Baku, Azerbaijan. Design A cross-sectional study. Methods In this study, 49 KC (Amsler–Krumeich stage 1) eyes and 36 healthy eyes were enrolled. A complete ophthalmic evaluation and a Scheimpflug camera scan were performed in every eye included in the study. Tomographic parameters such as parameters from the front and back cornea, maximum keratometry reading (Kmax), corneal volume (CV), anterior chamber volume (ChV), anterior chamber depth (ACD), anterior chamber angle (AC angle), keratometric power deviation (KPD), maximum front elevation (Max FE), and maximum back elevation (Max BE), as well as pachymetric progression indices (PPI), Ambrosio relational thickness (ART), index of surface variance (ISV), index of vertical asymmetry (IVA), center keratoconus index (CKI), index of height asymmetry (IHA), index of height decentration (IHD), and radius minimum (RM) were collected and statistically compared between the two groups. Results PPI, ART, ISV, IVA, CKI, IHA, IHD, and RM parameter values were significantly different (P<0.05) between the KC and healthy eyes. There were no significant differences in K mean and Q values of the frontal corneal parameters, as well as in Kmax, AC angle, RM, back, and front astigmatism, between stage 1 keratoconic and normal Caucasian eyes with steep cornea. All other parameters such as K mean and Q values of the back corneal parameters, Max FE, Max BE, ACD, ChV, and CV showed significant differences between the groups (P<0.05 for all). Conclusion Scheimpflug imaging is able to detect corneal morphological differences between stage 1 KC eyes and healthy eyes with steep cornea, in Caucasians. PMID:27099469

  19. Analogue modelling of inclined, brittle-ductile transpression: Testing analytical models through natural shear zones (external Betics)

    NASA Astrophysics Data System (ADS)

    Barcos, L.; Díaz-Azpiroz, M.; Balanyá, J. C.; Expósito, I.; Jiménez-Bonilla, A.; Faccenna, C.

    2016-07-01

    The combination of analytical and analogue models gives new opportunities to better understand the kinematic parameters controlling the evolution of transpression zones. In this work, we carried out a set of analogue models using the kinematic parameters of transpressional deformation obtained by applying a general triclinic transpression analytical model to a tabular-shaped shear zone in the external Betic Chain (Torcal de Antequera massif). According to the results of the analytical model, we used two oblique convergence angles to reproduce the main structural and kinematic features of structural domains observed within the Torcal de Antequera massif (α = 15° for the outer domains and α = 30° for the inner domain). Two parallel inclined backstops (one fixed and the other mobile) reproduce the geometry of the shear zone walls of the natural case. Additionally, we applied digital particle image velocimetry (PIV) method to calculate the velocity field of the incremental deformation. Our results suggest that the spatial distribution of the main structures observed in the Torcal de Antequera massif reflects different modes of strain partitioning and strain localization between two domain types, which are related to the variation in the oblique convergence angle and the presence of steep planar velocity - and rheological - discontinuities (the shear zone walls in the natural case). In the 15° model, strain partitioning is simple and strain localization is high: a single narrow shear zone is developed close and parallel to the fixed backstop, bounded by strike-slip faults and internally deformed by R and P shears. In the 30° model, strain partitioning is strong, generating regularly spaced oblique-to-the backstops thrusts and strike-slip faults. At final stages of the 30° experiment, deformation affects the entire model box. Our results show that the application of analytical modelling to natural transpressive zones related to upper crustal deformation

  20. Evidences of inclined transpression at the contact between Vinjamuru group and Udayagiri group of Nellore Schist Belt, Andhra Pradesh, India

    NASA Astrophysics Data System (ADS)

    Das, Sankha; Shukla, Devasheesh; Mitra, S. K.

    2016-07-01

    The Nellore Schist Belt (NSB) is a curvilinear Archaean schist belt, approximately 350 km long and 8-50 km wide. The Nellore Schist Belt is considered to be Neoarchean in age and stratigraphically NSB is classified as the western Udayagiri group (dominated by metasediments) and underlying eastern Vinjamuru group (dominated by metabasalts). There is a long controversy regarding the contact relationship between Udayagiri and Vinjamuru groups. Earlier researchers regarded the contact between two groups as tectonic on the basis of metamorphism. A shear zone and a possible thrust contact between the two groups have also been reported. On the basis of present study, an NNW-SSE trending, westerly dipping inclined transpressional zone is found at the contact between Udayagiri and Vinjamuru groups in the central western part of the NSB. Kinematic analysis of both the hanging wall and foot wall of the westerly dipping thrust zone shows presence of strong S1 schistosity, shear bands and S-C fabric in both strike and dip section along with east-verging overturned fold, westerly dipping inverted beds, suggesting partitioning of non-coaxial deformation in strike-slip and dip-slip component along with a pure shear component. Strike-slip is more prominent in the northern part of the contact than the southern part. The presence of steep to moderate northerly plunging non-orthogonal stretching/mineral elongation lineation all along the contact and clockwise shift of plot of the same in stereo net from its orthogonal position and presence of other kinematic indicators in plan suggests a right lateral strike-slip component. As a whole, it is suggested that Udayagiri group is thrusted over Vinjamuru group along a westerly dipping thrust plane with a right lateral strike-slip motion and simultaneous E-W contraction.

  1. Mechanism of generating fast electrons by an intense laser at a steep overdense interface.

    PubMed

    May, J; Tonge, J; Fiuza, F; Fonseca, R A; Silva, L O; Ren, C; Mori, W B

    2011-08-01

    The acceleration and heating of electrons by an intense laser normally incident on a steep overdense plasma interface is investigated using the particle-in-cell code osiris. Energetic electrons are generated by the laser's electric field in the vacuum region within λ/4 of the surface. Only those electrons which originate within the plasma with a sufficiently large transverse momentum can escape the plasma. This mechanism relies on the standing wave structure created by the incoming and reflected wave and is therefore very different for linear and circularly polarized light. PMID:21929052

  2. In situ measurements of particle friction angles in steep, narrow channels

    NASA Astrophysics Data System (ADS)

    Prancevic, J.; Lamb, M. P.

    2013-12-01

    The persistent observation that sediment requires increased fluid stresses to move on steeper channels has inspired a wide range of explanations, which can loosely be divided into those that invoke increased grain stability (friction angle, φ) and those that require altered flow hydraulics in steep channels. Measurements of bulk fluid forces over a wide range of channel slopes (θ ≤ 22°) have been obtained using laboratory flume experiments that can control for grain stability and show that altered flow hydraulics do play a role in increased critical shear stress. However, measurements of grain stability are almost all limited to channel slopes less than a few degrees. These friction angle studies have been conducted by tilting a fixed gravel bed with a single loose particle until dislodgment, or by directly measuring the forces required to dislodge a particle using a load cell. The latter methodology is less common but offers the advantage of quickly measuring the friction angles of in situ grains in natural river channels. Indeed, it has enabled the collection of extremely large datasets at low slopes [e.g., Johnston et al., 1998]. We are adding to this dataset with measurements from several natural steep channels in the San Gabriel Mountains, CA to test if the particle friction angle changes systematically as a function of slope or width-to-grain size ratio (W/D50), which is thought to determine the propensity for particle jamming. Using a load cell that records peak forces we measure the minimum force required to pull a particle from its pocket in the downstream direction and the particle weight. Particles are sampled over a regular grid and we record the percentage of the particle buried by fines and the qualitative degree of interlocking. Preliminary results from three sites with bed slopes of θ = 2.9°, 3.2°, and 9.0° suggest that the at-a-site variability in friction angle is much higher than between-site variability, and that median values do not

  3. Steep Satellite Altimetry Gradients as a Proxy to the Edge of the Continental Crust

    NASA Astrophysics Data System (ADS)

    Lawver, L. A.; Gahagan, L. M.

    2005-05-01

    Tight-fit plate reconstructions are produced using a global database constrained by marine magnetic anomalies tied to a consistent timescale, paleomagnetic poles, seafloor age dates based on drilling results, and fracture zone and transform fault lineations picked from ship-track and satellite altimetry data. Where a prominent steep gradient in the satellite altimetry data is present near the continental-ocean transition, it is used as a proxy to the continental shelf break [CSB]. Continental block outlines are based on digitization of the steep gradient. In some places, notably off Namibia, there is a very close correlation between that gradient and the ocean-continent boundary deduced from seismic refraction and reflection data. In other regions, there may be some stretched continental crust oceanward of the steep gradient but for reconstruction purposes we assume the crust to be predominantly continental landward of the boundary and oceanic, seaward of the line. Good matchs for conjugate CSBs are found in many places world-wide along passive margins and these will be highlighted. Particularly good matches are observed between the cratonic edges of East Antarctica as determined by sub-ice topographic highs seen along the margins of East Antarctica with respect to Madagascar, Sri Lanka, the southern half of the eastern margin of India, and the region of Australia between 124° E and 133° E along the Great Australian Bight (GAB). There are overlaps of the reconstructed conjugate CSBs, with one overlap between India and East Antarctica (70° E to 85° E) and one between East Antarctica and the western section of the GAB (105° E to 120° E). These two overlaps are coincident with the outer margins of the Lambert Graben - Prydz Bay Basin and the Aurora Subglacial Basin, respectively. It is known that there are substantial glacially-derived sediments prograded off the continental margin onto oceanic crust at Prydz Bay where there may be as much as 200 km in width of

  4. Steep microbial boundstone-dominated platform margins—examples and implications

    NASA Astrophysics Data System (ADS)

    Kenter, Jeroen A. M.; Harris, Paul M. (Mitch); Della Porta, Giovanna

    2005-07-01

    Seaward progradation of several kilometers has been documented mostly for leeward margin low-angle carbonate slope systems with a dominant platform top sediment source. However, steep and high-relief margins fronting deep basins can also prograde and as such are somewhat perplexing. Characteristics of two prograding Carboniferous examples provide a model which may apply elsewhere: (1) outcrops in Asturias, northern Spain serve as important analogs for (2) hydrocarbon reservoirs in steep-sided isolated platforms of the North Caspian Basin, Kazakhstan, such as Tengiz. Seismic and well data from Tengiz corroborate outcrop patterns for slope development, showing progradation of up to 5 and more than 10 km, respectively, despite the high-relief (up to 600 m) and steep (˜20-35°) nature of these margins. The two examples share a highly productive microbial boundstone factory extending from the platform break down the slope to nearly 300 m (or more) depth and a lower slope dominated by (mega)breccias and grain flow deposits derived from the margin and slope itself. The broad depth range of microbial boundstone increases the potential for production during both lowstands and high stands of sea level and thereby facilitates progradation independent from platform-top-derived sediment. Rapid in situ lithification of the boundstone provides stability to the steep slopes, but also leads to readjustment through shearing and avalanching. What controls the microbial cement boundstone formation remains a debate but its presence is a key factor controlling the progradational geometry of these and possibly other margins. This new model of "slope" shedding has implications for slope readjustment processes and resulting architecture, sequence stratigraphic interpretation, reservoir characterization, and reservoir modeling. Especially the isotropic character of microbial boundstone will reduce the potential for coherent seismic reflections to develop and possibly invoke, under certain

  5. Low-Power RIE of SiO2 in CHF3 To Obtain Steep Sidewalls

    NASA Technical Reports Server (NTRS)

    Turner, Tasha; Wu, Chi

    2003-01-01

    A reactive-ion etching (RIE) process has been developed to enable the formation of holes with steep sidewalls in a layer of silicon dioxide that covers a silicon substrate. The holes in question are through the thickness of the SiO2 and are used to define silicon substrate areas to be etched or to be built upon through epitaxial deposition of silicon. The sidewalls of these holes are required to be vertical in order to ensure that the sidewalls of the holes to be etched in the substrate or the sidewalls of the epitaxial deposits, respectively, also turn out to be vertical.

  6. Radio properties of Compact Steep Spectrum and GHz-Peaked Spectrum radio sources

    NASA Astrophysics Data System (ADS)

    Orienti, M.

    2016-02-01

    Compact steep spectrum (CSS) and GHz-peaked spectrum (GPS) radio sources represent a large fraction of the extragalactic objects in flux density-limited samples. They are compact, powerful radio sources whose synchrotron peak frequency ranges between a few hundred MHz to several GHz. CSS and GPS radio sources are currently interpreted as objects in which the radio emission is in an early evolutionary stage. In this contribution I review the radio properties and the physical characteristics of this class of radio sources, and the interplay between their radio emission and the ambient medium of the host galaxy.

  7. Mechanism of generating fast electrons by an intense laser at a steep overdense interface

    SciTech Connect

    May, J.; Tonge, J.; Fiuza, F.; Fonseca, R. A.; Silva, L. O.; Mori, W. B.

    2011-08-15

    The acceleration and heating of electrons by an intense laser normally incident on a steep overdense plasma interface is investigated using the particle-in-cell code osiris. Energetic electrons are generated by the laser's electric field in the vacuum region within {lambda}/4 of the surface. Only those electrons which originate within the plasma with a sufficiently large transverse momentum can escape the plasma. This mechanism relies on the standing wave structure created by the incoming and reflected wave and is therefore very different for linear and circularly polarized light.

  8. The effect of an inclined landing surface on biomechanical variables during a jumping task

    PubMed Central

    Hagins, Marshall; Pappas, Evangelos; Kremenic, Ian; Orishimo, Karl F.; Rundle, Andrew

    2009-01-01

    Background Professional dancers sustain a high number of injuries. Epidemiological studies have suggested that performing on inclined “raked” stages increases the likelihood of injury. However, no studies have examined if biomechanical differences exist between inclined and flat surfaces during functional tasks, such as landing from a jump. Such differences may provide a biomechanical rationale for differences in injury risk for raked stages. Methods Eight professional dancers performed drop jumps from a 40 cm platform on flat and inclined surfaces while forces, lower extremity kinematics, and electromyographic activity were collected in a controlled laboratory environment. Findings Dancers landed on the laterally inclined surface with significantly higher knee valgus, peak knee flexion, and medial-lateral ground reaction force (GRF) compared to the flat condition. The posterior GRF was higher in the anterior inclined condition compared to the flat condition. In the anterior inclined condition, subjects landed with 1.4° higher knee valgus, 4° more plantarflexion at initial contact, and 3° less dorsiflexion at the end of landing. Interpretation Biomechanical variables that have been suggested to contribute to injury in previous studies are increased in the inclined floor conditions. These findings provide a preliminary biomechanical rationale for differences in injury rates found in observational studies of raked stages. PMID:17826875

  9. Walking on inclines: energetics of locomotion in the ant Camponotus.

    PubMed

    Lipp, Alexandra; Wolf, Harald; Lehmann, Fritz-Olaf

    2005-02-01

    To assess energetic costs during rest and locomotion in a small insect, we measured metabolic rate in freely moving ants Camponotus sp. (average body mass 11.9 mg). The animals ran in a straight respirometric chamber in which locomotor speed and CO2 release were monitored simultaneously using flow-through respirometry and conventional video analysis. In resting intact ants, standard metabolic rate was on average 0.32 ml CO2 g(-1) body mass h(-1). During walking, the ants breathed continuously and metabolic rate increased between 4.3 times (level walking at 0-5 mm s(-1)) and 6.9 times (30 degrees ascent at 85-95 mm s(-1)) over resting rates. Metabolic rate increased linearly with increasing walking speed but superficially leveled off beyond speeds of about 70 mm s(-1). Walking on incline (uphill) or decline slopes (downhill) of up to 60 degrees had only a small effect on energy consumption compared to level walking. During slope walking, total metabolic rate averaged over all running speeds ranged from a minimum of 1.55+/-0.4 (horizontal running) to a maximum of 1.89+/-0.7 ml CO2 h(-1) g(-1) body mass (30 degrees downhill). The mean cost of transport in Camponotus was approximately 130 J g(-1) km(-1). The metabolic requirements in the comparatively small insect Camponotus for walking were mostly in the range expected from data obtained from other insects and small poikilotherms, and from allometric scaling laws. PMID:15695763

  10. Reidar Løvlie and Plate Tectonic consequences of sedimentary inclination shallowing

    NASA Astrophysics Data System (ADS)

    Torsvik, Trond H.

    2014-05-01

    Reidar Løvlie was my mentor and supervisor in the early 1980s and he thought me all about laboratory experiments and palaeomagnetic methods, but also various aspects of science philosophy. My first fieldworks were together with him and I enjoyed memorable trips to the Bear Island, Spitsbergen and Scotland. Acquisition of magnetism in sediments was always a favourite topic of Reidar and in the early 1980s he was particularly interested in sedimentary inclination shallowing. From one of our fieldtrips to Spitsbergen we sampled unconsolidated flood-plain deposits of hematite-bearing Devonian red sand/siltstone from Dicksonfjorden. These were used for redeposition experiments in a coil system that could simulate different latitudes (field inclinations) and in 1994 we published a paper entitled"Magnetic remanence and fabric properties of laboratory-deposited hematite-bearing red sandstone" that demonstrated the tangent relationship between inclinations of detrital remanent magnetization and the ambient magnetic field. Inclination (I) error in sediments is latitude dependent, antisymmetric and the bias closely mimics errors produced by octupole fields of the same sign as the dipole field. Inclination shallowing is commonly predicted from tan (Observed Inclination) = f * tan (Field Inclination) where f is the degree of inclination error. In our study we calculated a f value of 0.4 and this laboratory value (and many others) is significant lower than those estimated from the E/I or the magnetic fabric methods developed in the past decade (f typically around 0.6). There is now little doubt that inclination shallowing in detrital sediments is a serious problem that affects plate reconstructions and apparent polar wander paths. As an example, a f value of 0.6 amounts to a latitude error of 1600 km at around 50 degrees N or S (comparable to the effects of octupole contributions as high as 22%) and this have led to erroneous Pangea reconstructions.

  11. Riparian hydraulic gradient and stream-groundwater exchange dynamics in steep headwater valleys

    NASA Astrophysics Data System (ADS)

    Voltz, Thomas; Gooseff, Michael; Ward, Adam S.; Singha, Kamini; Fitzgerald, Michael; Wagener, Thorsten

    2013-06-01

    of riparian hydraulic gradients and stream-groundwater exchange in headwater catchments provide the hydrologic context for important ecological processes. Although the controls are relatively well understood, their dynamics during periods of hydrologic change is not. We investigate riparian hydraulic gradients over three different time scales in two steep, forested, headwater catchments in Oregon (WS01 and WS03) to determine the potential controls of reach-scale valley slope and cross-sectional valley geometry. Groundwater and stream stage data collected at high spatial and temporal resolutions over a period encompassing a 1.25 year storm and subsequent seasonal baseflow recession indicate that hydraulic gradients in both riparian aquifers exhibit strong persistence of down-valley dominance. Responses to rainfall do not support the simple conceptual models of increased riparian hydraulic gradient toward streams. Hydraulic gradient response in WS01 to both the seasonal baseflow recession and the storm suggested the potential for increased stream-groundwater exchange, but there was less evidence for this in WS03. Results from four constant-rate tracer injections in each stream showed a high baseline level of exchange overall, and both a slight seasonal increase (WS01) and slight decrease (WS03) in the riparian intrusion of tracer-labeled stream water as stream discharge receded. These results indicate that steep headwater valley floors host extensive stream water exchange and very little change in the water table gradients over 3 orders of magnitude of stream discharge.

  12. An Inconvenient Sea Truth: Spread, Steepness, and Skewness of Surface Slopes

    NASA Astrophysics Data System (ADS)

    Munk, Walter

    2009-01-01

    Bréon and Henriot (BH) have collected eight million globally distributed satellite images of sunglitter, which yield a few simple, robust rules about the statistics of surface slopes: 1) constant angular spread, 2) linear steepness, and 3) sigmoid (near stepwise) skewness (all with respect to wind speed). Yet the information is sparse because it says nothing about time and space scales. The BH rules are an inconvenient sea truth, too fundamental to be ignored, too incomplete to be understood. With regard to BH rule 1 (BH:1), I suggest that the constant spread is associated with a wake-like geometry of the short gravities. Steepness linearity (BH:2) remains an enigma. Skewness (BH:3) appears to be correlated with a rather sudden onset of breaking for winds above 4 m s-1. I do not think that skewness comes from parasitic capillaries. These are tentative conclusions; I look forward to intensive sea-going experiments over the next few years demolishing the proposed interpretations.

  13. An inconvenient sea truth: spread, steepness, and skewness of surface slopes.

    PubMed

    Munk, Walter

    2009-01-01

    Bréon and Henriot (BH) have collected eight million globally distributed satellite images of sunglitter, which yield a few simple, robust rules about the statistics of surface slopes: 1) constant angular spread, 2) linear steepness, and 3) sigmoid (near stepwise) skewness (all with respect to wind speed). Yet the information is sparse because it says nothing about time and space scales. The BH rules are an inconvenient sea truth, too fundamental to be ignored, too incomplete to be understood. With regard to BH rule 1 (BH:1), I suggest that the constant spread is associated with a wake-like geometry of the short gravities. Steepness linearity (BH:2) remains an enigma. Skewness (BH:3) appears to be correlated with a rather sudden onset of breaking for winds above 4 m s(-1). I do not think that skewness comes from parasitic capillaries. These are tentative conclusions; I look forward to intensive sea-going experiments over the next few years demolishing the proposed interpretations. PMID:21141042

  14. Hot electron generation forming a steep interface in superintense laser-matter interaction

    NASA Astrophysics Data System (ADS)

    Mishra, R.; Sentoku, Y.; Kemp, A. J.

    2009-11-01

    Superintense laser light (>1020 W/cm2) is able to sweep the preplasma over short times and compress the preplasma density gradient typically generated by the prepulse of today's high-intensity, high energy laser systems. Hot electron generation at steep plasma density gradients has been studied in a previous paper [A. J. Kemp, Y. Sentoku, and M. Tabak, Phys. Rev. Lett. 101, 075004 (2008)], which identified a mode of hot electron acceleration that is characterized by the formation of low-density shelf in front of the target. In this paper, we deal with laser incidence on slab target in one-dimensional situation and follow the formation of a steep interface and hot electron acceleration up to later stages of the interaction. We find that a novel mode of absorption appears during which the coupling efficiency drops, while a large number of sub-MeV hot electrons is produced at the interface. These dc-ponderomotive electrons play a dominant role in the bulk heating of solid density targets. We propose an analytical model to describe this absorption mode, explain electron energy spectra, and identify the parameter regime where it appears.

  15. Fully-coupled hydrologic/geomechanical simulations of slope failure in a prototypical steep mountain catchment

    NASA Astrophysics Data System (ADS)

    White, J. A.; Borja, R. I.; Ebel, B. A.; Loague, K.

    2009-12-01

    This work presents a physics-based framework for continuum modeling of hydrologically-driven slope failure. The analyses employ a mixed finite element formulation for variably-saturated geomaterials undergoing elastoplastic deformations. The deforming soil mass is treated as a multiphase continuum, and the governing mass and momentum balance equations are solved in a fully-coupled manner. This tight coupling is necessary to capture key features of slope behavior. To test the coupled formulation, we present a three-dimensional slope analysis motivated by a 1996 landslide that occurred at a steep experimental catchment (CB1) near Coos Bay, Oregon. Simulations are used to quantify the rainfall-induced slope deformation and assess the failure potential. Results of parametric studies suggest that for a steep hillslope underlain by bedrock, similar to the CB1 site, failure would occur by a multiple slide block mechanism, with progressive failure surfaces forming at the bedrock interface and propagating to the surface. Extensive field observations and experimental measurements made at the CB1 site provide a rich data set to calibrate and evaluate the proposed numerical model. We take the opportunity, however, to point out those features of the model that are not well-constrained by available field data, but which may play an important role in determing the timing and location of failure. These observations are used to assess the current state of predictive capability of the slope simulations, and to inform the design of future field experiments.

  16. Experimental study of non-linear loads on vertical cylinders in steep random waves

    SciTech Connect

    Stansberg, C.T.; Huse, E.; Krokstad, J.R.; Lehn, E.

    1995-12-31

    A description of laboratory experiments carried out with fixed, vertical truncated cylinders in irregular waves is given. With a model scale about 1:50, the tested models correspond approximately to North Sea large-volume platform dimensions. Tests with a single cylinder as well as with an array of cylinders are performed. Global horizontal forces and pitch moments on individual cylinders were measured. In the present report, analysis of surge force measurements are presented and discussed. The background of the study is the need for research on the hydrodynamic excitation of ringing phenomena. Thus one has emphasized the study of non-linear high-frequency (HF) force contributions generated by steep random waves. It is observed that although they are negligible in the frequency domain, the magnitude of such force components may be up to 10--20% of the total extreme forces, for this particular cylinder. Tests with the multi-column model show that diffraction effects can be important for the magnitude of the HF excitation, but not for the occurrence and nature of such events in itself. Force measurements on the different individual columns show that the HF force signal due to a particular steep wave passing through the structure, is recognized on all the columns, but shape of the signal changes in space.

  17. Perioperative dorzolamide-timolol intervention for rising intraocular pressure during steep Trendelenburg positioned surgery.

    PubMed

    Molloy, Bonnie; Cong, Xiaomei

    2014-06-01

    Elevated intraocular pressure (IOP) and venous congestion may produce a low ocular perfusion state that can lead to postoperative visual loss (POVL). The literature cites the importance of early IOP reduction to prevent optic nerve damage and visual loss. This study examined dorzolamide hydrochloride and timolol maleate (Cosopt) eyedrops on reducing elevated IOP during laparoscopic surgery with the patient in steep Trendelenburg position. A quasi-experimental study design was used. Subjects involving robotic urologic and gynecologic procedures at 3 separate medical centers were included. The medication was administered topically to both eyes at time points when IOP approached 40 mm Hg. The IOP was measured at 30-minute intervals compared with a supine, anesthetized baseline and final postprocedure supine measurements. A total of 194 patients were recruited, and 63 patients received dorzolamide-timolol treatment when IOP levels reached 38 to 40 mm Hg. Repeated-measures analysis of variance showed that IOP values dropped significantly after drug intervention at 60, 90, and 120 minutes (P < .001). Effect sizes of pharmacologic intervention on IOP reduction were strong (partial eta2 of 0.60 to 0.66). Treatment with dorzolamide-timolol eyedrops significantly reduces elevated IOP of patients who undergo lengthy laparoscopic surgery in the steep Trendelenburg position. PMID:25109158

  18. Predicting Sediment Flux from Hillslopes by Dry Ravel Following Wildfires in Steep Terrain

    NASA Astrophysics Data System (ADS)

    Levina, M.; Lamb, M. P.

    2010-12-01

    Sediment flux from hillslopes to channels increases after fires, and this can lead to debris flows during high intensity rainstorms. Much of this material is transported on steep hillslopes via the process of dry ravel, the rolling, bouncing and sliding of material, which occurs as a result of vegetation loss. Models to predict sediment flux by dry ravel have not been formulated for slopes greater than the angle of repose, and these slopes represent a significant part of the landscape. On these steep slopes we propose that the sediment flux to channels after fires is controlled by the amount of material stored behind vegetation prior to the burn. To test this hypothesis we have performed a series of tilt-table experiments to quantify the amount of sediment stored behind vegetation under a range of slopes, grain sizes, bed roughness, and vegetation widths. Our results show that the volume of the stored material scales with the cube of the width of the vegetation blocking it, but that there are secondary effects when the grain size is comparable to the blocker width. The slope has a much smaller effect on the volume than the width of the blocker, although bed roughness does influence volume at slopes close to the friction angle. Model results might be used to predict sediment fluxes after fires by taking into account the type and density of vegetation and the size distribution of sediment produced on the hillslope.

  19. Wide-field profiling of smooth steep surfaces by structured illumination

    NASA Astrophysics Data System (ADS)

    Wang, Hongting; Tan, Jiubin; Liu, Chenguang; Liu, Jian; Li, Yong

    2016-05-01

    We propose sectioning structured illumination wide-field microscopy (SSIWM) combined with the coating of a readily removable thin fluorescent film (RTFF) for smooth steep surfaces. The profiling of smooth steep surfaces is difficult to achieve using conventional optical systems because these surfaces reflect lights away from the collective lens. In particular, when the angle between optical axis and the normal line of the surface is larger than sin-1(NA), no light reflected from the area can be collected by the collective lens. The proposed method employing an RTFF to the SSIWM can overcome the poor collection barrier and be used to measure the shape of the surface owing to the isotropic incoherent scattering property. Additionally, conventional SSIWM is a promising wide-field imaging technique with high axial sectioning ability and low cost; however, it cannot be introduced to measure a reflective surface because of the non-sectioning characteristic in using a laser (coherent). However, the proposed method can extend the application scope of SSIWM owing to the incoherent property of the coating surface. Simulations and experimental results are presented to show the validity of the proposed method.

  20. Hot electron generation forming a steep interface in superintense laser-matter interaction

    SciTech Connect

    Mishra, R.; Sentoku, Y.; Kemp, A. J.

    2009-11-15

    Superintense laser light (>10{sup 20} W/cm{sup 2}) is able to sweep the preplasma over short times and compress the preplasma density gradient typically generated by the prepulse of today's high-intensity, high energy laser systems. Hot electron generation at steep plasma density gradients has been studied in a previous paper [A. J. Kemp, Y. Sentoku, and M. Tabak, Phys. Rev. Lett. 101, 075004 (2008)], which identified a mode of hot electron acceleration that is characterized by the formation of low-density shelf in front of the target. In this paper, we deal with laser incidence on slab target in one-dimensional situation and follow the formation of a steep interface and hot electron acceleration up to later stages of the interaction. We find that a novel mode of absorption appears during which the coupling efficiency drops, while a large number of sub-MeV hot electrons is produced at the interface. These dc-ponderomotive electrons play a dominant role in the bulk heating of solid density targets. We propose an analytical model to describe this absorption mode, explain electron energy spectra, and identify the parameter regime where it appears.

  1. Rehabilitation and flood management planning in a steep, boulder-bedded stream.

    PubMed

    Caruso, Brian S; Downs, Peter W

    2007-08-01

    This study demonstrates the integration of rehabilitation and flood management planning in a steep, boulder-bedded stream in a coastal urban catchment on the South Island of New Zealand. The Water of Leith, the primary stream flowing through the city of Dunedin, is used as a case study. The catchment is steep, with a short time of concentration and rapid hydrologic response, and the lower stream reaches are highly channelized with floodplain encroachment, a high potential for debris flows, significant flood risks, and severely degraded aquatic habitat. Because the objectives for rehabilitation and flood management in urban catchments are often conflicting, a number of types of analyses at both the catchment and the reach scales and careful planning with stakeholder consultation were needed for successful rehabilitation efforts. This included modeling and analysis of catchment hydrology, fluvial geomorphologic assessment, analysis of water quality and aquatic ecology, hydraulic modeling and flood risk evaluation, detailed feasibility studies, and preliminary design to optimize multiple rehabilitation and flood management objectives. The study showed that all of these analyses were needed for integrated rehabilitation and flood management and that some incremental improvements in stream ecological health, aesthetics, and public recreational opportunities could be achieved in this challenging environment. These methods should be considered in a range of types of stream rehabilitation projects. PMID:17602254

  2. Evidence for Holocene stability of steep slopes, northern Peruvian Andes, based on soils and radiocarbon dates

    USGS Publications Warehouse

    Miller, D.C.; Birkeland, P.W.; Rodbell, D.T.

    1993-01-01

    Radiocarbon dating and soil relationships indicate that landscapes in highaltitude glaciated valleys of the northern Peruvian Andes have been remarkably stable during the Holocene. Radiocarbon dates show that deglaciation was underway by 12 ka, and that slopes and alluvial fans at the bases of slopes were essentially stabilized by at least 8 ka. The soils consist of fine-grained loessial A horizons overlying Bw horizons in gravelly till or alluvial-fan gravel. Following deglaciation, widespread gullying took place in till on the steep (maximum angle: 37??) sideslopes of most valleys; the eroded material was deposited as fans at the bases of the slopes. Loess was then deposited as a fairly uniform blanket across most elements of the landscape. Soil formation began during or following loess deposition, and because soil-profile morphology is sufficiently similar at most sites, soil formation has been a dominant process during much of the Holocene. This remarkable stability, especially for such steep slopes, is attributed to a combination of tight packing of the till, permeability of the capping loess, rapid revegetation following ice retreat, and roots from the present grassland vegetation and possibly former forests. ?? 1993.

  3. Rapid growth rates of syndepositional marine aragonite cements in steep marginal slope deposits, Bahamas and Belize

    SciTech Connect

    Grammer, G.M.; Ginsburg, R.N.; Swart, P.K.; McNeill, D.F. . Div. of Marine Geology); Jull, A.J.T. . NSF Accelerator Facility); Prezbindowski, D.R. )

    1993-09-01

    Growth rates of marine botryoidal aragonite cements from steep (35-45[degree]) marginal slope deposits in the Bahamas and Belize have been determined by accelerator mass spectrometer radiocarbon dating of samples taken at the base and top of individual botryoids. The pore-filling cements, which range from approximately 11,000-13,000 years old, grew at average rates of 8-10mm/100 yr with maximum rates > 25mm/100 yr. Radiocarbon dating of coexisting skeletal components indicates that cementation was syndepositional. Microsampling transects across individual botryoids for stable-isotope analyses show little variation in [delta][sup 31]C and [delta][sup 18]O, supporting the conclusion that cementation was extremely rapid. Although the cements show a progressive depletion in isotopic composition of approximately 1[per thousand]([delta][sup 13]C) and 2[per thousand]([delta][sup 18]O) from 13 ka to 11 ka, the average variation ([delta][sub 1]) within individual pore-filling cements, ranging in size 2 mm to 32 mm (bottom to top), was 0.11[per thousand]([delta][sup 13]C) and 0.14[per thousand]([delta][sup 18]O). Results of this study provide the first quantitative data on growth rates of marine carbonate cements in a marginal slope environment. The data indicate that marginal slope deposits may lithify within several tens of years and suggest that geologically instantaneous cementation may be critical in stabilizing steep carbonate slope deposits at or above angles of repose.

  4. Hybrid integrated photodetector with flat-top steep-edge spectral response.

    PubMed

    Fan, Xinye; Huang, Yongqing; Ren, Xiaomin; Duan, Xiaofeng; Hu, Fuquan; Wang, Qi; Cai, Shiwei; Zhang, Xia

    2012-08-20

    Hybrid integrated photodetectors with flat-top steep-edge spectral responses that consist of an Si-based multicavity Fabry-Perot (F-P) filter and an InP-based p-i-n absorption structure (with a 0.2 μm In(0.53)Ga(0.47)As absorption layer), have been designed and fabricated. The performance of the hybrid integrated photodetectors is theoretically investigated by including key factors such as the thickness of each cavity, the pairs of each reflecting mirror, and the thickness of the benzocyclobutene bonding layer. The device is fabricated by bonding an Si-based multicavity F-P filter with an InP-based p-i-n absorption structure. A hybrid integrated photodetector with a peak quantum efficiency of 55% around 1549.2 nm, the -0.5 dB band of 0.43 nm, the 25 dB band of 1.06 nm, and 3 dB bandwidth more than 16 GHz, is simultaneously obtained. Based on multicavity F-P structure, this device has good flat-top steep-edge spectral response. PMID:22907001

  5. Sediment storage by vegetation in steep bedrock landscapes: Theory, experiments, and implications for postfire sediment yield

    NASA Astrophysics Data System (ADS)

    Lamb, Michael P.; Levina, Mariya; Dibiase, Roman A.; Fuller, Brian M.

    2013-06-01

    models for sediment transport on hillslopes are needed for applications ranging from landscape evolution to debris-flow hazards. Progress has been made for soil-mantled landscapes; however, little is known about sediment production and transport in bedrock landscapes that often maintain a patchy soil mantle, even though slopes exceed the angle of repose. Herein we investigate the hypothesis that patchy soil cover is stable on steep slopes due to local roughness such as vegetation dams that trap sediment upslope. To quantify local sediment storage, we developed a new theory and tested it against tilt-table experiments. Results show that trapped sediment volume scales with the cube of dam width. Where the dam width is less than about fifty grain diameters, particle force chains appear to enhance stability, resulting in greater trapped volumes and sediment-pile slopes that exceed the angle of repose. Trapped volumes are greatest for hillslopes that just exceed the friction slope and are independent of hillslope gradient for gradients greater than about twice the friction slope. For neighboring dams spaced less than about five grain diameters apart, grain bridging results in a single sediment pile that is larger than the sum of individual piles. This work provides a mass-conserving framework for quantifying sediment storage and nonlocal transport in bedrock landscapes. Results may explain the rapid increase in sediment yield following wildfire in steep terrain in the absence of rainfall; as sediment dams are incinerated, particles become gravitationally unstable and move rapidly downslope as dry ravel.

  6. Typhoon-Mediated Organic Carbon Export in the Western Pacific: The Role of Steep Mountainous Rivers

    NASA Astrophysics Data System (ADS)

    Hemingway, J. D.; Galy, V.; Hilton, R. G.; Hovius, N.

    2014-12-01

    Steep, mountainous rivers draning recently uplifted lithology on high standing islands within the Inter Tropical Convergence Zone export a disproportionately high amount of sediment given their small area; up to 20% of global export in 3% of the total exorheic land area. Typhoons strongly influence climate in this region, leading to increased sediment discharge, hyperpycnal flow, and efficient deposition of terrestrial particulate organic carbon in marine sediments. If this material escapes benthic remineralization - as is expected due to the lack of a continental shelf - typhoon mediated export of plant-derived POC is a net atmospheric CO2 sink. Here we report results from high-resolution (~hours) sampling on the LiWu River, Taiwan, during three sequential typhoons in 2008, and re-examine previous soil samples using more in-depth methods. Using a combination of bulk carbon isotopes (δ13C, ∆14C), vascular plant biomarker concentrations and δ13C, and ramped oxidation radiocarbon analysis, we describe the source and age of exported POC over a range of discharge conditions. We show that previous results indicating an increase in biospheric POC export during typhoons is an oversimplification; pre-aged soil OC complicates export. We offer an updated view of steep, mountainous rivers as a negative feedback loop to increased atmospheric CO2 and estimate for the first time the contribution and residence time of pre-aged soil OC in such a system.

  7. Numerical simulation of a sphere moving down an incline with identical spheres placed equally apart

    USGS Publications Warehouse

    Ling, Chi-Hai; Jan, Chyan-Deng; Chen, Cheng-lung; Shen, Hsieh Wen

    1992-01-01

    This paper describes a numerical study of an elastic sphere moving down an incline with a string of identical spheres placed equally apart. Two momentum equations and a moment equation formulated for the moving sphere are solved numerically for the instantaneous velocity of the moving sphere on an incline with different angles of inclination. Input parameters for numerical simulation include the properties of the sphere (the radius, density, Poison's ratio, and Young's Modulus of elasticity), the coefficient of friction between the spheres, and a damping coefficient of the spheres during collision.

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

    PubMed

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

    2014-02-01

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

  9. Height compensation using ground inclination estimation in inertial sensor-based pedestrian navigation.

    PubMed

    Park, Sang Kyeong; Suh, Young Soo

    2011-01-01

    In an inertial sensor-based pedestrian navigation system, the position is estimated by double integrating external acceleration. A new algorithm is proposed to reduce z axis position (height) error. When a foot is on the ground, a foot angle is estimated using accelerometer output. Using a foot angle, the inclination angle of a road is estimated. Using this road inclination angle, height difference of one walking step is estimated and this estimation is used to reduce height error. Through walking experiments on roads with different inclination angles, the usefulness of the proposed algorithm is verified. PMID:22164061

  10. Effects of different steeping methods and storage on caffeine, catechins and gallic acid in bag tea infusions.

    PubMed

    Yang, Deng-Jye; Hwang, Lucy Sun; Lin, Jau-Tien

    2007-07-13

    Bag teas, packed 3g of ground black, green, oolong, paochoung and pu-erh tea leaves (the particle size used was 1-2mm), were steeped in 150 mL of 70, 85 or 100 degrees C hot water to study the effects of the number of steeping (the same bag tea was steeped repeatedly eight times, 30s each time, as done in China for making ceremonial tea) and varied steeping durations (0.5-4 min) on caffeine, catechins and gallic acid in tea infusions. The changes in tea infusions during storage at 4 or 25 degrees C for 0-48 h and the variations in these compounds of bag tea infused with 150 mL of 4 or 25 degrees C cold water for 0.5-16 h were also investigated. A HPLC method with a C18 column and a step gradient solvent system consisting of acetonitrile and 0.9% acetic acid in deionized water was used for analysis. Results for all kinds of tea samples showed that the second tea infusion contained the highest contents of caffeine, catechins and gallic acid when bag teas were steeped in 70 degrees C water. It was different from that steeped at 85 and 100 degrees C, the highest contents existed in the first infusion. These compounds decreased gradually in later infusions. Higher amounts of caffeine, catechins and gallic acid could be released from bag teas as hotter water was used. As steeping duration prolonged, these ingredients increased progressively, however, their levels were lower than that cumulated from the infusions with the identical bag tea prepared recurrently at the same temperature and time points. (-)-Gallocatechin gallate and (+)-catechin existed in these tea infusions rarely and could not be detected until a certain amount of them infusing. Except gallic acid that showed a significant increase and caffeine that exhibited no significant change, all kinds of catechins decreased appreciably after tea infusions were stored at 25 degrees C for 36 h; nevertheless, all of them showed no evident changes at 4 degrees C storage. The caffeine, catechins and gallic acid in tea

  11. Film cooling from inclined cylindrical holes using large eddy simulations

    NASA Astrophysics Data System (ADS)

    Peet, Yulia V.

    2006-12-01

    The goal of the present study is to investigate numerically the physics of the flow, which occurs during the film cooling from inclined cylindrical holes, Film cooling is a technique used in gas turbine industry to reduce heat fluxes to the turbine blade surface. Large Eddy Simulation (LES) is performed modeling a realistic film cooling configuration, which consists of a large stagnation-type reservoir, feeding an array of discrete cooling holes (film holes) flowing into a flat plate turbulent boundary layer. Special computational methodology is developed for this problem, involving coupled simulations using multiple computational codes. A fully compressible LES code is used in the area above the flat plate, while a low Mach number LES code is employed in the plenum and film holes. The motivation for using different codes comes from the essential difference in the nature of the flow in these different regions. Flowfield is analyzed inside the plenum, film hole and a crossflow region. Flow inside the plenum is stagnating, except for the region close to the exit, where it accelerates rapidly to turn into the hole. The sharp radius of turning at the trailing edge of the plenum pipe connection causes the flow to separate from the downstream wall of the film hole. After coolant injection occurs, a complex flowfield is formed consisting of coherent vortical structures responsible for bringing hot crossflow fluid in contact with the walls of either the film hole or the blade, thus reducing cooling protection. Mean velocity and turbulent statistics are compared to experimental measurements, yielding good agreement for the mean flowfield and satisfactory agreement for the turbulence quantities. LES results are used to assess the applicability of basic assumptions of conventional eddy viscosity turbulence models used with Reynolds-averaged (RANS) approach, namely the isotropy of an eddy viscosity and thermal diffusivity. It is shown here that these assumptions do not hold

  12. Electrified film on a porous inclined plane: Dynamics and stability

    NASA Astrophysics Data System (ADS)

    Uma, B.; Usha, R.

    2010-07-01

    The time evolution of a thin conducting liquid film flowing down a porous inclined substrate is investigated when an electric field acts normal to the substrate. It is assumed that the flow through the porous medium is governed by Darcy’s law together with Beavers-Joseph condition. Under the assumption of small permeability relative to the thickness of the overlying fluid layer, the flow is decoupled from the filtration flow through the porous medium. A slip condition at the bottom is used to incorporate the effects of the permeability of the substrate. From the set of exact averaged equations derived using integral boundary method for the film thickness and for the flow rate, a nonlinear evolution equation for the film thickness is derived through a long-wave approximation. A linear stability analysis of the base flow is performed and the critical Reynolds number is obtained. The results reveal that the substrate porosity in general destabilizes the liquid film flow and the presence of the electric field enhances this destabilizing effect. A weakly nonlinear stability analysis divulges the existence of supercritical stable and subcritical unstable zones in the wave number/Reynolds number parameter space and the results demonstrate how the neutral curves change as the intensity of the electric filed or the permeability of the porous medium is varied. The numerical solution of the nonlinear evolution equation in a periodic domain reveals that the base flow yields to surface structures that are either time independent waves of permanent form that propagate or time-dependent modes that oscillate slightly in the amplitude. Further, it is observed that the shape and amplitude of long-time waveforms are influenced by the permeability of the porous medium as well as by the applied electric field. The results reveal that the destabilization induced by the electric field in an otherwise stable film over a porous medium is exhibited in the form of traveling waves of finite

  13. Electrified film on a porous inclined plane: dynamics and stability.

    PubMed

    Uma, B; Usha, R

    2010-07-01

    The time evolution of a thin conducting liquid film flowing down a porous inclined substrate is investigated when an electric field acts normal to the substrate. It is assumed that the flow through the porous medium is governed by Darcy's law together with Beavers-Joseph condition. Under the assumption of small permeability relative to the thickness of the overlying fluid layer, the flow is decoupled from the filtration flow through the porous medium. A slip condition at the bottom is used to incorporate the effects of the permeability of the substrate. From the set of exact averaged equations derived using integral boundary method for the film thickness and for the flow rate, a nonlinear evolution equation for the film thickness is derived through a long-wave approximation. A linear stability analysis of the base flow is performed and the critical Reynolds number is obtained. The results reveal that the substrate porosity in general destabilizes the liquid film flow and the presence of the electric field enhances this destabilizing effect. A weakly nonlinear stability analysis divulges the existence of supercritical stable and subcritical unstable zones in the wave number/Reynolds number parameter space and the results demonstrate how the neutral curves change as the intensity of the electric filed or the permeability of the porous medium is varied. The numerical solution of the nonlinear evolution equation in a periodic domain reveals that the base flow yields to surface structures that are either time independent waves of permanent form that propagate or time-dependent modes that oscillate slightly in the amplitude. Further, it is observed that the shape and amplitude of long-time waveforms are influenced by the permeability of the porous medium as well as by the applied electric field. The results reveal that the destabilization induced by the electric field in an otherwise stable film over a porous medium is exhibited in the form of traveling waves of finite

  14. Formation of Close-in Super-Earths by Giant Impacts: Effects of Initial Eccentricities and Inclinations of Protoplanets

    NASA Astrophysics Data System (ADS)

    Matsumoto, Yuji; Kokubo, Eiichiro

    2015-12-01

    Recent exoplanet observations are revealing the eccentricity and inclination distributions of exoplanets. Most of observed super-Earths have small eccentricities ~ 0.01 - 0.1 and small inclinations ~ 0.03 rad (e.g., Fabrycky et al., 2014). These distributions are results of their formation processes. N-body simulations have been used to investigate accretion of close-in super-Earths (e.g., Hansen & Murray 2012, Ogihara et al. 2015). Hansen & Murray (2013) showed that the averaged eccentricity of close-in super-Earths formed through giant impacts in gas-free and no planetesimal environment is around 0.1. In the giant impact stage, the eccentricities and inclinations are pumped up by gravitational scattering and damped by collisions. Matsumoto et al. (2015) found that the eccentricity damping rate by a collision depends on the eccentricity and inclination and thus affects the eccentricity and inclination of planets. We investigate the effect of initial eccentricities and inclinations of protoplanets on eccentricities and inclinations of planets. We perform N-body simulations with systematically changing initial eccentricities and inclinations of protoplanets independently. We find that the eccentricities and inclinations of planets barely depend on the initial eccentricities of protoplanets although the collision timescale is changed. This means that initial eccentricities of protoplanets are well relaxed through scattering and collisions. On the other hand, the initial inclinations of protoplanets affect the inclination of planets since they are not relaxed during the giant impact stage. Since the collisional timescale increases with inclinations, protoplanets with high inclinations tend to interact longer until they collide with each other. As a result, planets get large eccentricities, and the number of planets becomes small. The observed eccentricities and inclinations of super-Earths can be reproduced by giant impacts of protoplanets with inclinations ~ 10-3 -10

  15. Comparison of femoral inclination angle measurements in dysplastic and nondysplastic dogs of different breeds.

    PubMed

    Sarierler, M

    2004-01-01

    In this study, inclination angle of the femoral head and neck was measured on 484 limbs of 242 dogs belonging to 7 breeds, examined for hip dysplasia. These inclination angles were compared according to age, sex and joint laxity, evaluated with Subluxation Index (SI) and Norberg angle (NA) results. The findings indicate that (a) there was a minimal (nonsignificant) difference in femoral inclination angle between the dysplastic and nondysplastic dogs belonging to 7 breeds; (b) although there was no significant difference in femoral inclination angle between the nondysplastic dogs belonging to 4 breeds (Pointer, Irish Setter, Golden Retriever and German Shepherd), a significant difference was observed between Doberman and Labrador, and between Anatolian Karabash and the other six breeds (p < 0.001). Age and sex did not affect the femoral neck angle. PMID:15168756

  16. Muscular activity of lower limb muscles associated with working on inclined surfaces

    PubMed Central

    Lu, Ming-Lun; Kincl, Laurel; Lowe, Brian; Succop, Paul; Bhattacharya, Amit

    2015-01-01

    This study investigated effects of visual cues, muscular fatigue, task performance and experience of working on inclined surfaces on activity of postural muscles in the lower limbs associated with maintaining balance on three inclined surfaces—0°, 14° and 26°. Normalized electromyographic (NEMG) data were collected on 44 professional roofers bilaterally from the rectus femoris, biceps femoris, tibialii anterior, and gastrocnemii medial muscle groups. The 50th and 95th percentile normalized EMG amplitudes were used as EMG variables. Results showed that inclination angle and task performance caused a significant increase in the NEMG amplitudes of all postural muscles. Visual cues were significantly associated with a decrease in the 95th percentile EMG amplitude for the right gastrocnemius medial and tibialis anterior. Fatigue was related to a significant decrease in the NEMG amplitude for the rectus femoris. Experience of working on inclined surfaces did not have a significant effect on the NEMG amplitude. PMID:25331562

  17. 30 CFR 250.461 - What are the requirements for directional and inclination surveys?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling... of the directionally computed inclinations and azimuths. (e) If you drill within 500 feet of...

  18. Declination and inclination errors in experimentally deposited specularite-bearing sand

    USGS Publications Warehouse

    Bressler, S.L.; Elston, D.P.

    1980-01-01

    Naturally disaggregated specularite-bearing sandstone from the Triassic Moenkopi Formation, artificially deposited in controlled magnetic fields of ???5 ?? 10-2 mT, acquires a stable remanent magnetization that has systematic errors in inclination and declination. Inclinations about 12?? shallower than the applied fields are produced by deposition on a horizontal surface in still water. Deposition from flowing water on a surface inclined 6-10?? results in inclination errors of as much as 20??. Water flowing obliquely to the applied field results in declination errors of about 10??, with declinations systematically rotated toward the upstream direction of current flow. These experimental results indicate that specularite-bearing sediment responds to the earth's field in a manner similar to magnetite-bearing sediment, and support observational evidence for a primary magnetization of depositional origin in specularite in red beds of the Moenkopi Formation. ?? 1980.

  19. Numerical investigation of mixed convective hydromagnetic nonlinear nanofluid flow past an inclined plate

    NASA Astrophysics Data System (ADS)

    Anjali Devi, S. P.; Suriyakumar, P.

    2013-09-01

    The nonlinear, steady, mixed convective, two-dimensional laminar hydromagnetic boundary layer flow of copper-water and alumina-water nanofluids over an inclined flat plate with an angle of inclination α in the presence of uniform transverse magnetic field is investigated in this work. The governing nonlinear partial differential equations of the problem are transformed into nonlinear ordinary differential equations by utilizing suitable similarity transformations and the resulting nonlinear ordinary differential equations are solved numerically using MATLAB. Numerical results for dimensionless velocity and temperature of the nanofluid flows are obtained and computations for the various values of Magnetic interaction parameter, angle of inclination, volume fraction, Prandtl number and mixed convection parameter. The range of volume fraction of nanofluids and the angle of inclination under study are as follows: 0.00 ≤ φ ≤ 0.10 and 0° ≤ α ≤ 60°. The results are displayed graphically to show the interesting aspects of the nanofluids.

  20. Vortex-induced vibrations of a flexibly-mounted inclined cylinder

    NASA Astrophysics Data System (ADS)

    Jain, Anil; Modarres-Sadeghi, Yahya

    2013-11-01

    The majority of studies on vortex-induced vibrations of a flexibly-mounted rigid cylinder are for the cases where the flow direction is perpendicular to the long axis of the structure. However, in many engineering applications, such as cable stays in bridges and mooring lines of floating offshore wind turbines, the flow direction may not be perpendicular to the structure. To understand the vortex shedding behind a fixed inclined cylinder, the Independence Principle (IP) has been used. The IP assumes that an inclined cylinder behaves similarly to a normal-incidence case, if only the component of the free stream velocity normal to the cylinder axis is considered. The IP neglects the effect of the axial component of the flow, which seems reasonable for small angles of inclination, but not for large angles. In the present study, a series of experiments have been conducted on a flexibly-mounted rigid cylinder placed inclined to the oncoming flow with various angles of inclination (0°<θ<75°) in a range of Reynolds numbers from 500 to 4000 to investigate how the angle of inclination affects VIV. A rigid cylinder was mounted on springs, and air bearings were used to reduce the structural damping of the system. The system was placed in the test-section of a recirculating water tunnel and the crossflow displacements were measured at each flow velocity. Even at high angles of inclination, large-amplitude oscillations were observed. As the angle of inclination was increased, the lock-in range (the range of reduced flow velocities for which the cylinder oscillates with a large amplitude) started at a higher reduced velocity. When only the normal component of the oncoming flow was considered, the onset of lock-in was observed to be at the same normalized flow velocity for all angles of inclination except for 75°. However, the width of the lock-in region, its pattern, the maximum amplitude of oscillations and its corresponding normalized reduced velocity were not following

  1. Physically-based Hydrologic-response Simulation of a Steep, Zero-Order Catchment

    NASA Astrophysics Data System (ADS)

    Ebel, B. A.; Loague, K. M.; Dietrich, W. E.; Montgomery, D. R.; Torres, R.; Anderson, S. P.; Giambelluca, T. W.; Vanderkwaak, J. E.

    2005-12-01

    Near-surface hydrologic response plays a critical role in landscape evolution, particularly in steep terrain where hydrologically-driven slope instability is the predominant mechanism of sediment removal. Despite the importance of hydrology in governing the timing and extent of slope failure, the majority of slope stability modeling efforts utilize steady-state approximations to the 1D or 2D saturated subsurface flow equations to generate pore pressures. The effort reported here employs the comprehensive, physics-based Integrated Hydrology Model (InHM) to rigorously simulate near-surface hydrologic response. InHM simulates, in a fully-coupled approach, 3D transient variably-saturated flow and solute transport in porous media and macropores and 2D transient flow and solute transport over the land surface and in open channels. Our modeling approach is tested with the extensive data sets from the 860 m2 Coos Bay experimental catchment (CB1) in the Oregon Coast Range for both sprinkling experiments (event-based simulation) and natural storms (continuous simulation). The instrumentation at CB1 for characterizing the spatial and temporal variability in hydrologic response includes an exhaustive array of rain gages, piezometers, tensiometers, TDR wave guide pairs, lysimeters, meteorological sensors, and two weirs all monitored during three, week-long sprinkling experiments. Continuous measurements of rainfall, discharge, and total head (from selected piezometers) are available from 1990 through 1996. Extensive site characterization at CB1 provides high resolution topography and soil characteristics (e.g., geometry/thickness, saturated hydraulic conductivity, soil-water content, porosity, and hysteretic capillary pressure relationships). CB1 provides one of the most comprehensive hydrologic response data sets in existence for a steep catchment that has experienced slope failure. Results from 3D InHM simulations include comparisons of observed versus simulated runoff

  2. Effects of Sediment Patches on Sediment Transport Predictions in Steep Mountain Channels

    NASA Astrophysics Data System (ADS)

    Monsalve Sepulveda, A.; Yager, E.

    2013-12-01

    Bed surface patches occur in most gravel-bedded rivers and in steep streams can be divided between relatively immobile boulders and more mobile patches of cobbles and gravel. This spatial variability in grain size, roughness and sorting impact bed load transport by altering the relative local mobility of different grain sizes and creating complex local flow fields. Large boulders also bear a significant part of the total shear stress and we hypothesize that the remaining shear stress on a given mobile patch is a distribution of values that depend on the local topography, patch type and location relative to the large roughness elements and thalweg. Current sediment transport equations do not account for the variation in roughness, local flow and grain size distributions on and between patches and often use an area-weighted approach to obtain a representative grain size distribution and reach-averaged shear stress. Such equations also do not distinguish between active (patches where at least one grain size is in motion) and inactive patches or include the difference in mobility between patch classes as result of spatial shear stress distributions. To understand the effects of sediment patches on sediment transport in steep channels, we calculated the shear stress distributions over a range of patch classes in a 10% gradient step-pool stream. We surveyed the bed with a high density resolution (every 5 cm in horizontal and vertical directions over a 40 m long reach) using a total station and terrestrial LiDAR, mapped and classified patches by their grain size distributions, and measured water surface elevations and mean velocities for low to moderate flow events. Using these data we calibrated a quasi-three dimensional model (FaSTMECH) to obtain shear stress distributions over each patch for a range of flow discharges. We modified Parker's (1990) equations to use the calculated shear stress distribution, measured grain sizes, and a specific hiding function for each

  3. Spatial Distribution of Acid Neutralizing Processes in Steep Headwater Catchments in Tanakami Mountains, Central Japan

    NASA Astrophysics Data System (ADS)

    Asano, Y.; Uchida, T.; Ohte, N.; Tani, M.

    2001-05-01

    The areas characterized by steep slope, thin soils, and unreactive bedrock types are often considered as acid-sensitive. The purpose of this study is to investigate the spatial distribution of acid neutralizing processes in steep headwater catchment in the humid temperate region, and to discuss the long-term change in acid neutralizing processes associated with the forest growth and soil development. The observations were conducted at two adjacent unchannelled steep catchment, Fudoji (0.10ha) and Rachidani (0.18ha). Two catchments share similar climatic condition and the same bedrock geology (granite). The mean hollow gradient is 37degrees in Fudoji and 34degrees in Rachidani. Fudoji is forested with mean soil depth of 77cm, while Rachidani is non-vegetated with mean soil depth of about 10cm. In both catchments, hydrometric and isotopic measurements illustrated the substantial downward water flux into the bedrock in upslope area and emerging of this water from bedrock to soil layer within 2m from the perennial spring points. The mean pH of soil water and groundwater were dispersed over a wide range of 4.00 to 5.84 in Fudoji and 5.29 to 6.28 in Rachidani, while stream pHs converged very closely to neutral value in two catchments. In both catchments, major H+ sources distributed at the near-surface soil layer and the intensity of internal H+ production was greater in forested Fudoji than non-vegetated Rachidani, attributed to the biological cycles in forest ecosystems. Calculation of budget for base cations (Na+, K+, Ca2+ and Mg2+) presented that 72 to 84 percent (Fudoji) and 34percent (Rachidani) of the net base cation production in each catchment was derived from the bedrock, indicating that a considerable amount of the H+ was consumed within the bedrock. Moreover, the H+ consumption rate per unit volume of soil in Fudoji was almost one order of magnitude smaller than that of Rachidani. These results suggested that the dominant H+ sink in catchments shifted from

  4. Physically-based quantitative analysis of soil erosion induced by heavy rainfall on steep slopes

    NASA Astrophysics Data System (ADS)

    Della Sala, Maria; Cuomo, Sabatino; Novità, Antonio

    2014-05-01

    Heavy rainstorms cause either shallow landslides or soil superficial erosion in steep hillslopes covered by coarse unsaturated soils (Cascini et al., 2013), even over large areas (Cuomo and Della Sala, 2013a). The triggering stage of both phenomena is related to ground infiltration, runoff and overland flow (Cuomo and Della Sala, 2013), which are key processes to be investigated. In addition, the mobilization of solid particles deserves a proper physical-based modeling whether a quantitative estimation of solid particles discharge at the outlet of mountain basin is required. In this work, the approaches for soil superficial erosion analysis are firstly reviewed; then, a relevant case study of two medium-sized mountain basins, affected by flow-like phenomena with huge consequences (Cascini et al., 2009) is presented, which motivates a parametric numerical analysis with a physically-based model carried out for a wide class of soil properties and rainfall scenarios (Cuomo et al., 2013b). The achieved results outline that the peak discharge of water and solid particles driven by overland flow depends on rainfall intensity while volumetric solid concentration within the washout is related to the morphometric features of the whole mountain basin. Furthermore, soil suction is outlined as a key factor for the spatial-temporal evolution of infiltration and runoff in the basin, also affecting the discharge of water and solid particles at the outlet of the basin. Based on these insights, selected cases are analyzed aimed to provide a wide class of possible slope erosion scenarios. It is shown that, provided the same amount of cumulated rainfall, the sequence of high and low intensity rainfall events strongly affects the time-discharge at the outlet of the basin without significant variations of the maximum volumetric solid concentration. References Cascini, L., Cuomo, S., Ferlisi, S., Sorbino, G. (2009). Detection of mechanisms for destructive landslides in Campania region

  5. Phase states of a 2D easy-plane ferromagnet with strong inclined anisotropy

    SciTech Connect

    Fridman, Yu. A. Klevets, F. N.; Gorelikov, G. A.; Meleshko, A. G.

    2012-12-15

    We investigate the spin states of a 2D film exhibiting easy-axis anisotropy and a strong single-ion inclined anisotropy whose axis forms a certain angle with the normal to the film surface. Such a system may have an angular ferromagnetic phase, a spatially inhomogeneous state, and a quadrupole phase, whose realization depends substantially on the inclined anisotropy and the orientation of the wavevector in the film plane.

  6. Inclined edge crack in two bonded elastic quarter planes under out-of-plane loading

    NASA Astrophysics Data System (ADS)

    Hwang, E. H.; Choi, S. R.; Earmme, Y. Y.

    1992-08-01

    The problem of the interfacial edge crack in which the crack-inclination angle = zero is solved analytically by means of the Wiener-Hopf technique with the Mellin transform. The results are found to confirm the result by Bassani and Erdogan (1979) showing that there is no stress singularity for the interface perpendicular to the free boundary at the junction with a straight inclined interface with no crack.

  7. INTERACTION OF A GIANT PLANET IN AN INCLINED ORBIT WITH A CIRCUMSTELLAR DISK

    SciTech Connect

    Marzari, F.; Nelson, Andrew F. E-mail: andy.nelson@lanl.go

    2009-11-10

    We investigate the dynamical evolution of a Jovian-mass planet injected into an orbit highly inclined with respect to its nesting gaseous disk. Planet-planet scattering induced by convergent planetary migration and mean motion resonances may push a planet into such an out-of-plane configuration with inclinations as large as 20{sup 0}-30{sup 0}. In this scenario, the tidal interaction of the planet with the disk is more complex and, in addition to the usual Lindblad and corotation resonances, it also involves inclination resonances responsible for bending waves. We have performed three-dimensional hydrodynamic simulations of the disk and of its interactions with the planet with a smoothed particle hydrodynamics code. A main result is that the initial large eccentricity and inclination of the planetary orbit are rapidly damped on a timescale of the order of 10{sup 3} yr, almost independently of the initial semimajor axis and eccentricity of the planet. The disk is warped in response to the planet perturbations and it precesses. Inward migration also occurs when the planet is inclined, and it has a drift rate that is intermediate between type I and type II migration. The planet is not able to open a gap until its inclination becomes lower than approx10{sup 0}, when it also begins to accrete a significant amount of mass from the disk.

  8. Simulations of Seasonal and Latitudinal Variations in Leaf Inclination Angle Distribution: Implications for Remote Sensing

    NASA Technical Reports Server (NTRS)

    Huemmrich, Karl F.

    2013-01-01

    The leaf inclination angle distribution (LAD) is an important characteristic of vegetation canopy structure affecting light interception within the canopy. However, LADs are difficult and time consuming to measure. To examine possible global patterns of LAD and their implications in remote sensing, a model was developed to predict leaf angles within canopies. Canopies were simulated using the SAIL radiative transfer model combined with a simple photosynthesis model. This model calculated leaf inclination angles for horizontal layers of leaves within the canopy by choosing the leaf inclination angle that maximized production over a day in each layer. LADs were calculated for five latitude bands for spring and summer solar declinations. Three distinct LAD types emerged: tropical, boreal, and an intermediate temperate distribution. In tropical LAD, the upper layers have a leaf angle around 35 with the lower layers having horizontal inclination angles. While the boreal LAD has vertical leaf inclination angles throughout the canopy. The latitude bands where each LAD type occurred changed with the seasons. The different LADs affected the fraction of absorbed photosynthetically active radiation (fAPAR) and Normalized Difference Vegetation Index (NDVI) with similar relationships between fAPAR and leaf area index (LAI), but different relationships between NDVI and LAI for the different LAD types. These differences resulted in significantly different relationships between NDVI and fAPAR for each LAD type. Since leaf inclination angles affect light interception, variations in LAD also affect the estimation of leaf area based on transmittance of light or lidar returns.

  9. A secular model for efficient exploration of mutually-inclined planetary systems

    NASA Astrophysics Data System (ADS)

    Deitrick, Russell; Barnes, Rory

    2015-01-01

    Dynamical studies of exoplanets largely assume coplanarity because of the lack of inclination information in many cases. However, the multiplanet system Upsilon Andromedae has orbital planes inclined by 30 degrees, models of planet-planet scattering predict large mutual inclinations, and astrometry missions such as Gaia have the power to reveal the 3 dimensional architecture of planetary systems. As the dynamics of systems with non-planar orbits will be key to understanding origins, and ultimately habitability where applicable, we present a computationally efficient model for the orbital evolution of planetary systems with modest inclinations and eccentricities which are not in a mean motion resonance. Specifically, our model is based on the disturbing function and extends to 4th order in eccentricity and inclination. We present comparisons to N-body models for known systems, such as the Solar System and Upsilon Andromedae, and hypothetical systems with a range of orbital configurations. We describe the eccentricity and inclination conditions under which the model is valid. We further calculate the rotational evolution of planets based on the orbital evolution and the stellar torque and find a wide range of obliquity evolution is possible. As obliquity is a key driver of planetary climate, Earth-like planets in non-planar systems may have climates dominated by their orbital evolution.

  10. Proposal of a novel compact P-band magnetically insulated transmission line oscillator with inclined vanes

    SciTech Connect

    Zhang, Xiaoping Dang, Fangchao; Li, Yangmei; Jin, Zhenxing

    2015-06-15

    In this paper, we present a novel compact P-band magnetically insulated transmission line oscillator (MILO) with specially inclined slow-wave-structure (SWS) vanes to decrease its total dimension and weight. The dispersion characteristics of the inclined SWS are investigated in detail and made comparisons with that of the traditional straight SWS. The results show that the inclined SWS is more advantageous in operating on a steady frequency in a wide voltage range and has a better asymmetric mode segregation and a relatively large band-gap between the TM{sub 00} and TM{sub 01} modes which are in favor of avoiding the asymmetric and transverse mode competition. Besides, the transverse dimension of the proposed novel inclined SWS with the same operation frequency is decreased by about 50%, and correspondingly the device volume shrinks remarkably to its 0.35 times. In particle-in-cell simulation, the electron bunching spokes are obviously formed in the inclined SWS, and a P-band high-power microwave with a power of 5.8 GW, frequency of 645 MHz, and efficiency of 17.2% is generated by the proposed device, which indicates the feasibility of the compact design with the inclined vanes at the P-band.

  11. Collisional Evolution of High-Inclination Asteroids: Implications for Asteroid Strength

    NASA Astrophysics Data System (ADS)

    O'Brien, David P.; Michel, P.; Jutzi, M.

    2009-09-01

    Asteroids with inclinations larger than 20 degrees collide with one another, and with lower-inclination asteroids, with a velocity roughly twice as large as the average collisional velocity in the asteroid belt ( 10 km/sec for high-inclination bodies vs. 5 km/sec main belt average). Thus, their size distribution can potentially evolve differently than the main belt as a whole, for two reasons: 1) the larger collision velocity means that a smaller impactor can lead to their catastrophic disruption; and 2) the energy needed for catastrophic disruption is likely a function of collision velocity [1]. Using a collisional evolution model [2,3] modified to treat two interacting populations, as well as new velocity-dependent scaling laws for asteroid collisional disruption, we study the possible differences in the size distribution of high-inclination asteroids that may result from their increased collision velocity. Recent observations suggest that the size distribution of asteroids around a kilometer in diameter may be shallower for high-inclination asteroids than for low-inclination asteroids [4]. We will discuss the implications that such observational constraints have for the collisional properties of asteroids, namely their strength against catastrophic disruption and how it varies with impact velocity. References: [1] Benz and Asphaug (1999), Icarus 142, 5-20. [2] Bottke et al. (2005), Icarus 175, 111-140. [3] O'Brien (2009), Icarus, in press. [4] Terai and Itoh (2008), ACM 2008, abstract #8215.

  12. The effects of forward and backward walking according to treadmill inclination in children with cerebral palsy

    PubMed Central

    Kim, Won-hyo; Kim, Won-bok; Yun, Chang-kyo

    2016-01-01

    [Purpose] This study investigated the effects of forward and backward walking using different treadmill incline positions on lower muscle activity in children with cerebral palsy, to provide baseline data for gait training intensity. [Subjects and Methods] Nineteen subjects with cerebral palsy walked forward and backward at a self-selected pace on a treadmill with inclines of 0%, 5%, 10%, and 15%. Activation of the rectus femoris, biceps femoris, tibialisanterior, and lateral gastrocnemius was measured using surface electromyography during the stance phase. [Results] As treadmill incline increased during forward walking, muscle activation of the paralyzed lower limbs did not significantly change. However, as treadmill incline increased during backward walking, rectus femoris activation significantly increased and a significant difference was found between treadmill inclines of 0% and 10%. A comparison of backward and forward walking showed a significant difference in rectus femoris activation at treadmill inclines of 0%, 5%, and 10%. Activation of the tibialis anterior was only significantly higher for backward walking at the 10% gradient. [Conclusion] Backward walking may strengthen the rectus femoris and tibialis anterior in walking training for cerebral palsy. Gradient adjustment of the treadmill can be used to select the intensity of walking training. PMID:27313373

  13. The metabolic cost of walking on an incline in the Peacock (Pavo cristatus)

    PubMed Central

    Wilkinson, Holly; Thavarajah, Nathan

    2015-01-01

    Altering speed and moving on a gradient can affect an animal’s posture and gait, which in turn can change the energetic requirements of terrestrial locomotion. Here, the energetic and kinematic effects of locomoting on an incline were investigated in the Indian peacock, Pavo cristatus. The mass-specific metabolic rate of the Indian peacock was elevated on an incline, but this change was not dependent on the angle ascended and the cost of lifting remained similar between the two inclines (+5 and +7°). Interestingly, the Indian peacock had the highest efficiency when compared to any other previously studied avian biped, despite the presence of a large train. Duty factors were higher for birds moving on an incline, but there was no difference between +5 and +7°. Our results highlight the importance of investigating kinematic responses during energetic studies, as these may enable explanation of what is driving the underlying metabolic differences when moving on inclines. Further investigations are required to elucidate the underlying mechanical processes occurring during incline movement. PMID:26056619

  14. DEEP 1.4 GHz FOLLOW-UP OF THE STEEP SPECTRUM RADIO HALO IN A521

    SciTech Connect

    Dallacasa, D.; Macario, G.; Setti, G.; Brunetti, G.; Cassano, R.; Venturi, T.; Giacintucci, S.; Kassim, N. E.; Lane, W.

    2009-07-10

    In a recent paper, we reported on the discovery of a radio halo with very steep spectrum in the merging galaxy cluster A521 through observations with the Giant Metrewave Radio Telescope. We showed that the steep spectrum of the halo is inconsistent with a secondary origin of the relativistic electrons and supports a turbulent acceleration scenario. At that time, due to the steep spectrum, the available observations at 1.4 GHz (archival NRAO-Very Large Array-VLA-CnB-configuration data) were not adequate to accurately determine the flux density associated with the radio halo. In this paper, we report the detection at 1.4 GHz of the radio halo in A521 using deep VLA observations in the D configuration. We use these new data to confirm the steep spectrum of the object. We consider A521 the prototype of a population of very steep spectrum halos. This population is predicted assuming that turbulence plays an important role in the acceleration of relativistic particles in galaxy clusters, and we expect it will be unveiled by future surveys at low frequencies with the LOFAR and LWA radio telescopes.

  15. Troll oil pipeline: Assessment of slope and gravel sleeper stability in steep fjord areas

    SciTech Connect

    Eide, A.; Gudmestad, O.T.; Nadim, F.

    1996-12-01

    This paper describes the slope stability evaluation in the steep areas of the Fensfjord. The main focus in the study has been to establish appropriate undrained shear strength for static and dynamic stability analyses, make a reasonable prediction of the earthquake induced permanent deformation and evaluate the post-earthquake static stability. The special laboratory testing and analysis conducted showed that the only consequence of earthquake loading is limited permanent deformations. Analysis of gravel supports on soft clay showed that three supports needed counter fills in order to fulfill the design requirements. At the tunnel entrance point of the pipeline at Mongstad, the soft clay at the seabed had to be excavated in order to attain satisfactory stability for the gravel support.

  16. Interactions of steep and breaking waves with winds and solid bodies

    NASA Astrophysics Data System (ADS)

    Yang, Zixuan; Shen, Lian

    2015-11-01

    The interactions of steep and breaking waves with winds and solid bodies at sea surface is important to many problems in ocean science and engineering. In this study, we perform large-eddy simulations using a finite-difference code with high-performance parallel computing. The air-water interface is captured using a coupled level set and volume of fluid method. A sharp interface immersed boundary method is applied to capture the effect due to the presence of solid bodies. A wall layer model is employed to address high Reynolds numbers. A numerical wave generator is utilized to accurately produce waves with specified parameters. The results are validated for a number of canonical problems, and the performances of different wall-layer model schemes are evaluated using a priori and a posteriori tests. Based on the simulation data, the flow details and interaction mechanisms are analyzed.

  17. Detachment and steep normal faulting in Atlantic oceanic crust west of Africa

    USGS Publications Warehouse

    Reston, T.J.; Ruoff, O.; McBride, J.H.; Ranero, C.R.; White, Robert S.

    1996-01-01

    Improved images of the internal structure of Early Cretaceous North Atlantic crust reveal both probable detachment faults and more steeply dipping normal faults. The detachment faults occur as subhorizontal structures passing ???1.5 km beneath fault blocks without offset; several steeper block-bounding faults appear to detach onto these structures. However, the detachments are bounded to the west (ridgeward) by presumably younger, more steeply west-dipping normal faults. In one possible interpretation, the detachment and the steep faults belong to the same "rolling-hinge" extension system. An intriguing alternative is that a phase of detachment faulting, perhaps related to increased magmatic activity, was succeeded by localized amagmatic extension along steeper and more deeply penetrating faults.

  18. Back bias induced dynamic and steep subthreshold swing in junctionless transistors

    SciTech Connect

    Parihar, Mukta Singh; Kranti, Abhinav

    2014-07-21

    In this work, we analyze back bias induced steep and dynamic subthreshold swing in junctionless double gate transistors operated in the asymmetric mode. This impact ionization induced dynamic subthreshold swing is explained in terms of the ratio between minimum hole concentration and peak electron concentration, and the dynamic change in the location of the conduction channel with applied front gate voltage. The reason for the occurrence of impact ionization at sub-bandgap drain voltages in silicon junctionless transistors is also accounted for. The optimum junctionless transistor operating at a back gate bias of −0.9 V, achieves over 5 orders of change in drain current at a gate overdrive of 200 mV and drain bias of 1 V. These results for junctionless transistors are significantly better than those exhibited by silicon tunnel field effect transistors operating at the same drain bias.

  19. Spectroscopic Observations of Steep Spectrum Narrow-Line Seyfert 1 Galaxies

    NASA Technical Reports Server (NTRS)

    Leighly, Karen

    1999-01-01

    ROSAT observations of narrow-line Seyfert 1s found consistently steep spectra and rapid variability, but ASCA observations show more diversity, very different to classical Seyfert 1s. However, in 3 NLS1s, ASCA finds common characteristics of these exciting new class of AGN (active galactic nuclei): a very strong high temperature soft excess, weak hard tail, a possible blue shifted ionized oxygen edge, and rapid large amplitude variability characterized by flares and quiescent periods. It is necessary to observe many more such objects in order to understand the physical processes underlying the different phenomenology in ASCA. ASCA observations of two NLS1s discovered by ROSAT's all sky survey were proposed and an observation of one of these objects, RX J0439-45, was awarded. The results of spectral and variability analysis are included in Leighly 1999ab, and preliminary results are found in Leighly 1998ab.

  20. Effects of bedrock groundwater on landslide occurrences in a steep headwater catchment

    NASA Astrophysics Data System (ADS)

    Kosugi, K.; Fujimoto, M.; Sando, Y.; Mizuyama, T.; Kinoshita, A.

    2011-12-01

    Previous studies have shown that the formation of groundwater in the soil mantle greatly affects slope instability on steep landscapes. To predict landslides, mathematical models based on a geographic information system, which organize geographic data such as information on upslope contributing areas and the local slope gradient, have been developed and tested. Although such models can be used to calculate the topographically driven convergence of rainwater and groundwater table developments in the soil mantle, thus providing a spatially distributed prediction of landslide occurrences, the accuracy of these mathematical models is still limited, mainly because they ignore storm responses in underlying bedrock. Recent research has provided credible information on the importance of bedrock groundwater on surface hydrological processes in headwater catchments. To elucidate the effects of bedrock groundwater, the dynamics of bedrock groundwater should be measured directly. However, intensive monitoring of bedrock groundwater is rare in mountains with steep topography. Consequently, how bedrock groundwater controls landslides in a steep headwater catchment is in dispute. In this study, we conducted long-term hydrological observations using densely nested bedrock wells along with monitoring of discharge hydrograph and soil mantle groundwater in a steep headwater catchment underlain by granitic bedrock. Bedrock wells with depths of 7-78 m were drilled at 31 points within the 2.10-ha catchment. Results showed that a hollow of bedrock aquifer was located at a ridge in the surface topography, clearly indicating bedrock groundwater flow across topographic divides. Around a point where the bedrock groundwater exfiltrated, we found scars of landslides. Such landslides cannot be explained by mathematical hydrology models, which calculate the topographically driven convergence of rainwater in the soil mantle. Moreover, at a point along the main hollow of the watershed, we observed

  1. Development of a digital automatic control law for steep glideslope capture and flare

    NASA Technical Reports Server (NTRS)

    Halyo, N.

    1977-01-01

    A longitudinal digital guidance and control law for steep glideslopes using MLS (Microwave Landing System) data is developed for CTOL aircraft using modern estimation and control techniques. The control law covers the final approach phases of glideslope capture, glideslope tracking, and flare to touchdown for automatic landings under adverse weather conditions. The control law uses a constant gain Kalman filter to process MLS and body-mounted accelerometer data to form estimates of flight path errors and wind velocities including wind shear. The flight path error estimates and wind estimates are used for feedback in generating control surface commands. Results of a digital simulation of the aircraft dynamics and the guidance and control law are presented for various wind conditions.

  2. Dosimetry in steep dose-rate gradient radiation fields: A challenge in clinical applications

    SciTech Connect

    Massillon-JL, G.

    2010-12-07

    The fundamental goal of radiotherapy is to reduce the damage to normal tissue and optimize the dose to the tumor with an associated high probability of cure. Because of this, an accurate and precise knowledge of the radiation dose distribution delivered around the tumor volume during radiotherapy treatments such as stereotactic radiosurgery, intensity modulated radiotherapy or brachytherapy with low-energy X-ray and beta particle sources is of great importance. However, in each of these radiation fields, there exists a steep dose-rate gradient which makes it very difficult to perform accurate dose measurements. In this work, the physics phenomena involved in the energy absorption for each of these situations are discussed, and a brief revision of what the Medical Physics community is doing is presented.

  3. Dosimetry in steep dose-rate gradient radiation fields: A challenge in clinical applications

    NASA Astrophysics Data System (ADS)

    Massillon-JL, G.

    2010-12-01

    The fundamental goal of radiotherapy is to reduce the damage to normal tissue and optimize the dose to the tumor with an associated high probability of cure. Because of this, an accurate and precise knowledge of the radiation dose distribution delivered around the tumor volume during radiotherapy treatments such as stereotactic radiosurgery, intensity modulated radiotherapy or brachytherapy with low-energy X-ray and beta particle sources is of great importance. However, in each of these radiation fields, there exists a steep dose-rate gradient which makes it very difficult to perform accurate dose measurements. In this work, the physics phenomena involved in the energy absorption for each of these situations are discussed, and a brief revision of what the Medical Physics community is doing is presented.

  4. 2D simulation of granular flow over irregular steep slopes using global and local coordinates

    NASA Astrophysics Data System (ADS)

    Juez, C.; Murillo, J.; García-Navarro, P.

    2013-12-01

    In this work approximate augmented Riemann solvers are formulated providing appropriate numerical schemes for mathematical models of granular flow on irregular steep slopes. Fluxes and source terms are discretized to ensure steady state configurations including correct modeling of start/stop flow conditions, both in a global and a local system of coordinates. The weak solutions presented involve the effect of bed slope in pressure distribution and frictional effects by means of the adequate gravity acceleration components. The numerical solvers proposed are first tested against 1D cases with exact solution and then their results are compared with experimental data in order to check the suitability of the mathematical models described in this work. Comparisons between results provided when using global and local system of coordinates are presented. The obtained results point out that both the global and the local system of coordinates can be used to predict faithfully the overall behavior of the phenomena considered in this work.

  5. Application of a new cellular model for bedload transporting extreme events at steep slopes

    NASA Astrophysics Data System (ADS)

    Chiari, M.; Scheidl, C.

    2015-10-01

    A cellular model for bedload transport at steep channel gradients and alluvial fans has been developed to simulate lateral distribution of erosion and deposition on alluvial fans of mountain streams. The cellular model, named FluviSed, applies a quasi-steady-state routing of a flood hydrograph over a rectangular grid. Bedload transport is calculated and the morphological changes are updated after each time step. FluviSed is designed to complement existing one-dimensional bedload transport simulation tools by using their outcome as an input for the simulation of inundated areas. The model has been evaluated against TomSed, a one-dimensional bedload transport model. Further, a back-calculation of a laboratory bedload experiment and a real flood event from 2005 at Schnannerbach in Austria are provided to test the model's suitability for reproducing morphological changes caused by flood events at high channel gradients.

  6. VizieR Online Data Catalog: Ultra-steep spectrum radio sources (Gopal-Krishna+, 2005)

    NASA Astrophysics Data System (ADS)

    Gopal-Krishna; Ledoux, C.; Melnick, J.; Giraud, E.; Kulkarni, V.; Altieri, B.

    2006-09-01

    We present the results of radio (VLA) and optical (ESO/La Silla) imaging of a sample of 52 radio sources having an ultra-steep radio spectrum with {alpha} mostly steeper than -1.1 at decimetre wavelengths (median {alpha}=-1.22). Radio-optical overlays are presented to an astrometric accuracy of ~1". For 41 of the sources, radio spectral indices are newly determined using unpublished observations made with the 100-m Effelsberg radio telescope. For 14 of the sources identified with relatively brighter optical counterparts, spectroscopic observations were also carried out at La Silla and their redshifts are found to lie in the range 0.4 to 2.6. (2 data files).

  7. Dual-Gate p-GaN Gate High Electron Mobility Transistors for Steep Subthreshold Slope.

    PubMed

    Bae, Jong-Ho; Lee, Jong-Ho

    2016-05-01

    A steep subthreshold slope characteristic is achieved through p-GaN gate HEMT with dual-gate structure. Obtained subthreshold slope is less than 120 μV/dec. Based on the measured and simulated data obtained from single-gate device, breakdown of parasitic floating-base bipolar transistor and floating gate charged with holes are responsible to increase abruptly in drain current. In the dual-gate device, on-current degrades with high temperature but subthreshold slope is not changed. To observe the switching speed of dual-gate device and transient response of drain current are measured. According to the transient responses of drain current, switching speed of the dual-gate device is about 10(-5) sec. PMID:27483846

  8. Mechanics of gravitational spreading of steep-sided ridges («sackung»)

    USGS Publications Warehouse

    Savage, W.Z.; Varnes, D.J.

    1987-01-01

    Large-scale gravitational spreading of steep-sided ridges characterized by linear fissures, trenches, and uphill-facing scarps high on the sides and tops of ridges are known worldwide. Such spreading, termed sackung, is commonly attributed to pervasive plastic deformation of a rock mass, and is here analyzed as such. Beginning with a previously developed exact elastic solution for gravity-induced stresses in a symmetric ridge, stresses calculated from the exact solution are used in the Coulomb failure criterion to determine the extent of ridge failure under self-weight. Finally, when the regions of failure are established, a plastic flow solution is applied to predict the location of and sense of movement on upward-facing scarps near ridge crests and other features common in sackung. ?? 1987 International Assocaition of Engineering Geology.

  9. Impact of steep-front short-duration impulse on electric power system insulation

    SciTech Connect

    Burrage, L M; Veverka, E F; Shaw, J H; McConnell, B W

    1991-04-01

    This research effort required the performance evaluation of three specific insulation systems in common usage by electric power transmission and distribution utilities under stresses imposed by: three characteristic impulse waveforms (two waves representative of steep-front short duration (SFSD) impulses and one representative of lightning), the cumulative effect of multiple shots'' of each pulse, 60 Hz voltage, and, where appropriate, and mechanical load. The insulation systems evaluated are the cellulose-paper/oil combination typical of power transformer and condenser bushing usage, the cellulose-paper/enamel/oil combination used in distribution transformer construction, and the porcelain/air combination representing transmission and distribution line structural insulation. 4 refs., 94 figs., 11 tabs.

  10. Piloted simulator investigations of a civil tilt-rotor aircraft on steep instrument approaches

    NASA Technical Reports Server (NTRS)

    Decker, William A.

    1992-01-01

    NASA-Ames has used its Vertical Motion Simulator to investigate steep-glideslope instrument approaches for a civil transport tilt-rotor aircraft in two different cases: (1) where pilots used raw glideslope and localized error data for 6-25 deg slopes, terminating in slow roll-on landings, and (2) where a flight director commanded manual conversion from fixed-wing to helicopter modes and a deceleration on the glideslope led to a vertical landing on a small urban helipad. In the former, there occurred control problems directly ascribable to the slow approach speed; in the latter, the four-cue flight director's cockpit augmentation furnished adequate pilot ratings up to 15-deg glideslope.

  11. The effects of steep-front, short-duration impulses on power distribution components

    SciTech Connect

    Miller, D.B.; Lux, A.E.; Grzybowski, Stanislaw; Barnes, P.R.

    1989-07-01

    A line type pulser has been developed to test the effects of steep-front, short duration (SFSD) pulses on distribution components. Risetime is 50-100 ns, and pulse duration is on the order of 300 ns. Terminators often shattered or punctured rather than flashing over. Insulator flashover voltage is approximately 1.5 times CFO for standard lightning impulses. Arresters exhibit an inductive character, with SFSD peak voltage at 10 kA approximately 4--5 times the 8 /times/ 20 microsecond 10 kA discharge voltage. Polyethylene insulated cable has a characteristic degradation in which failure voltage decreases with number of SFSD pulses. 7 refs., 12 figs., 2 tabs.

  12. A sample of southern Compact Steep Spectrum radio sources: The VLBI observations

    NASA Astrophysics Data System (ADS)

    Tzioumis, A.; King, E.; Morganti, R.; Dallacasa, D.; Tadhunter, C.; Fanti, C.; Reynolds, J.; Jauncey, D.; Preston, R.; McCulloch, P.; Tingay, S.; Edwards, P.; Costa, M.; Jones, D.; Lovell, J.; Clay, R.; Meier, D.; Murphy, D.; Gough, R.; Ferris, R.; White, G.; Jones, P.

    2002-09-01

    A small sample of 7 southern Compact Steep Spectrum (CSS) radio sources has been selected as part of the study of a larger flux-limited complete sample of radio sources. High resolution images, using the VLBI network in the southern hemisphere and the high resolution MERLIN array, are presented for all sources in the CSS sample. The overall morphology of each source consists of well-defined double lobes but with substantial diffuse and extended components present. In the majority of cases only a fraction of the total flux density is detected on the VLBI baselines, indicating the presence of larger extended radio structures. However, all sources are unresolved at arcsecond scales and are of sub-galactic size, with linear size in the range 0.1-2 kpc. The radio properties of the sources agree well with CSS sources in other samples. Based on observations with the Southern Hemisphere VLBI Network (SHEVE) and the MERLIN.

  13. Applications of DBV (design-based verification) for steep ramp-up manufacture

    NASA Astrophysics Data System (ADS)

    Kim, Tae Heon; Han, Dae-Han; Kim, Yong-Hyeon; Han, Min-Chul; Lee, Hong-Ji; Hong, Ae-Ran; Kim, Yoon-Min; Nam, In-Ho; Park, Yong-Jik; Oh, Kyung-Seok

    2011-04-01

    Semiconductor industry has been experiencing rapid and continuous shrinkage of feature size along with Moore's law. As the VLSI technology scales down to sub 40nm process node. Control of critical dimension (CD) and Extraction of Unanticipated weak point pattern effects known as "hot spots" becoming more challenging and difficult. Therefore, experimental full-chip inspection methodologies for Control of critical dimension (CD) and hotspots extraction are necessary in order to reduce Turn-Around-Time (TAT) for steep ramp up Manufacture. In this paper, we introduce the concepts of an innovative reduction Turn-around-time (TAT) in manufacture production with applications of DBV (Design Based Verification). The noble methodologies employed by our own technology with application of DBV are highly advantageous for exactly determining for process judgment go or no-go about wafer process in mass-production of memory device.

  14. Research on the influence of waveguide's exposure steepness on 0.345THz FWGTWT's performance

    NASA Astrophysics Data System (ADS)

    Zhang, Fang; Dong, Zhiwei; Dong, Ye

    2013-08-01

    In the MEMS fabrication process of 0.345THz micro-electric vacuum FWG-TWT, the periodic FWG slow wave structure is assembled by joining two symmetrical metal pieces with grooves. In ideal design, these grooves' profiles should be perpendicular to their symmetrical plane while the device' performance can be best, however those slope angles are actually more than 90 degrees because of their molds' insufficient exposure. This paper does research on the influence of waveguide's exposure steepness on the performance of FWG circuit through theoretical analysis and numerical simulation. The range of slope angle studied in this paper is from 0 to 5 degrees, and as the slope angle becomes larger, electromagnetic signal's transmission attenuation increases. But by adjusting other working parameters of the circuit, the high net gain can be maintained while its bandwidth is going to decrease. These results will be helpful for the experiment.

  15. Laboratory investigation and direct numerical simulation of wind effect on steep surface waves

    NASA Astrophysics Data System (ADS)

    Troitskaya, Yuliya; Sergeev, Daniil; Druzhinin, Oleg; Ermakova, Olga

    2015-04-01

    The small scale ocean-atmosphere interaction at the water-air interface is one of the most important factors determining the processes of heat, mass, and energy exchange in the boundary layers of both geospheres. Another important aspect of the air-sea interaction is excitation of surface waves. One of the most debated open questions of wave modeling is concerned with the wind input in the wave field, especially for the case of steep and breaking waves. Two physical mechanisms are suggested to describe the excitation of finite amplitude waves. The first one is based on the treatment of the wind-wave interaction in quasi-linear approximation in the frameworks of semi-empirical models of turbulence of the low atmospheric boundary layer. An alternative mechanism is associated with separation of wind flow at the crests of the surface waves. The "separating" and "non-separating" mechanisms of wave generation lead to different dependences of the wind growth rate on the wave steepness: the latter predicts a decrease in the increment with wave steepness, and the former - an increase. In this paper the mechanism of the wind-wave interaction is investigated basing on physical and numerical experiments. In the physical experiment, turbulent airflow over waves was studied using the video-PIV method, based on the application of high-speed video photography. Alternatively to the classical PIV technique this approach provides the statistical ensembles of realizations of instantaneous velocity fields. Experiments were performed in a round wind-wave channel at Institute of Applied Physics, Russian Academy of Sciences. A fan generated the airflow with the centerline velocity 4 m/s. The surface waves were generated by a programmed wave-maker at the frequency of 2.5 Hz with the amplitudes of 0.65 cm, 1.4 cm, and 2 cm. The working area (27.4 × 10.7 cm2) was at a distance of 3 m from the fan. To perform the measurements of the instantaneous velocity fields, spherical polyamide

  16. Buoyant Turbulent Kinetic Energy Production in Steep-Slope Katabatic Flow

    NASA Astrophysics Data System (ADS)

    Oldroyd, Holly J.; Pardyjak, Eric R.; Higgins, Chad W.; Parlange, Marc B.

    2016-07-01

    We develop several critical concepts that should be considered when interpreting, modelling and designing future experiments for flows over sloping terrain. Vertical buoyancy fluxes in katabatic flows can be positive and a source of turbulent kinetic energy (TKE) despite the statically stable, thermal stratification that drives these flows. This phenomenon occurs when the ratio of along-slope to slope-normal kinematic heat fluxes is greater than the cotangent of the slope angle, suggesting a critical value of slope-angle steepness found in earlier studies. We provide field-data-based evidence that the along-slope heat flux may dominate the variables in this inequality, and therefore in generating buoyant TKE production or suppression over a steep slope. These data show the along-slope heat flux can be more variable and significantly larger in magnitude than the slope-normal component. The gradient Richardson number does not include the effects of the along-slope buoyancy; furthermore, none of the canonical stability parameters can properly reflect the TKE redistribution from turbulent transport divergence and the sink of TKE in cases of counter-gradient momentum fluxes, which we frequently observe near the peak of the katabatic jet. In such cases, canonical stability parameters inadequately represent the physical mechanisms associated with stability. These results have broad implications related to accurately modelling turbulence and surface exchanges over sloping terrain and illustrate the need to more thoroughly investigate the along-slope heat flux and its drivers, the meaning and definitions of stability, and the effects of non-local turbulent transport.

  17. Strong impact of neutrals on anomalous inward drift and width of steep gradient zone

    NASA Astrophysics Data System (ADS)

    Becker, G.

    1999-01-01

    The fundamental properties of the anomalous inward drift and the width of the steep gradient zone in H mode plasmas are explored. A special version of the 1.5-D BALDUR transport code is used to determine the profiles of the electron heat diffusivity and vin/D by transport analysis. The strong rise with radius of vin/D in the edge region is explained by a linear dependence on the neutral deuterium density n0, resulting in a new scaling expression vin(x)/D(x) = F0Zeff(x)n0(x)2x/(ρwxs2). Applying this in simulations reproduces the empirical fit of the vin/D profile not only in the edge plasma but also in the bulk plasma. Modellings with this scaling yield the observed flattening of density profiles with rising line averaged density. The decreasing penetration of deuterium atoms to the core causes a decline of the inward drift. The new scaling is shown to be compatible with gas oscillation experiments, while n0-independent scalings are not. This further explains the strong density profile peaking and rise of vin/D during and after pellet injection by the increase in neutral density. The width of the steep gradient zone is found to be connected with the penetration of neutrals at the edge and the presence of high inward drift velocities. The anomalous inward drift is attributed to ion dynamics, i.e. to the friction between fluctuating deuterons and deuterium atoms diffusing inward. A more general vin/D scaling including impurity effects is presented.

  18. The supercritical pile gamma-ray burst model: The GRB afterglow steep decline and plateau phase

    SciTech Connect

    Sultana, J.; Kazanas, D.

    2013-12-10

    We present a process that accounts for the steep decline and plateau phase of the Swift X-Ray Telescope (XRT) light curves, vexing features of gamma-ray burst (GRB) phenomenology. This process is an integral part of the 'supercritical pile' GRB model, proposed a few years ago to account for the conversion of the GRB kinetic energy into radiation with a spectral peak at E {sub pk} ∼ m{sub e}c {sup 2}. We compute the evolution of the relativistic blast wave (RBW) Lorentz factor Γ to show that the radiation-reaction force due to the GRB emission can produce an abrupt, small (∼25%) decrease in Γ at a radius that is smaller (depending on conditions) than the deceleration radius R{sub D} . Because of this reduction, the kinematic criticality criterion of the 'supercritical pile' is no longer fulfilled. Transfer of the proton energy into electrons ceases and the GRB enters abruptly the afterglow phase at a luminosity smaller by ∼m{sub p} /m{sub e} than that of the prompt emission. If the radius at which this slow-down occurs is significantly smaller than R{sub D} , the RBW internal energy continues to drive the RBW expansion at a constant (new) Γ and its X-ray luminosity remains constant until R{sub D} is reached, at which point it resumes its more conventional decay, thereby completing the 'unexpected' XRT light curve phase. If this transition occurs at R ≅ R{sub D} , the steep decline is followed by a flux decrease instead of a 'plateau,' consistent with the conventional afterglow declines. Besides providing an account of these peculiarities, the model suggests that the afterglow phase may in fact begin before the RBW reaches R ≅ R{sub D} , thus providing novel insights into GRB phenomenology.

  19. Model simulations of flood and debris flow timing in steep catchments after wildfire

    USGS Publications Warehouse

    Rengers, Francis; Mcguire, Luke; Kean, Jason W.; Staley, Dennis M.; Hobley, D.E.J

    2016-01-01

    Debris flows are a typical hazard on steep slopes after wildfire, but unlike debris flows that mobilize from landslides, most post-wildfire debris flows are generated from water runoff. The majority of existing debris-flow modeling has focused on landslide-triggered debris flows. In this study we explore the potential for using process-based rainfall-runoff models to simulate the timing of water flow and runoff-generated debris flows in recently burned areas. Two different spatially distributed hydrologic models with differing levels of complexity were used: the full shallow water equations and the kinematic wave approximation. Model parameter values were calibrated in two different watersheds, spanning two orders of magnitude in drainage area. These watersheds were affected by the 2009 Station Fire in the San Gabriel Mountains, CA, USA. Input data for the numerical models were constrained by time series of soil moisture, flow stage, and rainfall collected at field sites, as well as high-resolution lidar-derived digital elevation models. The calibrated parameters were used to model a third watershed in the burn area, and the results show a good match with observed timing of flow peaks. The calibrated roughness parameter (Manning's $n$) was generally higher when using the kinematic wave approximation relative to the shallow water equations, and decreased with increasing spatial scale. The calibrated effective watershed hydraulic conductivity was low for both models, even for storms occurring several months after the fire, suggesting that wildfire-induced changes to soil-water infiltration were retained throughout that time. Overall the two model simulations were quite similar suggesting that a kinematic wave model, which is simpler and more computationally efficient, is a suitable approach for predicting flood and debris flow timing in steep, burned watersheds.

  20. Rapid measurement of a high step microstructure with 90° steep sidewall.

    PubMed

    Ju, Bing-Feng; Chen, Yuan-Liu; Zhang, Wei; Fang, F Z

    2012-01-01

    A prototype STM system with high aspect ratio measurement capability is developed to fulfill accurate profile measurement of a high step microstructure with 90° steep sidewall. Distinguished from the traditional STM, the new system consists of a long range piezoelectric (PZT) actuator with full stroke of 60 μm as Z-direction servo scanner, a specially customized high aspect ratio STM probe with effective tip length of 300 μm, and an X-Y motorized driven stage for planar scanning. A tilt stage is used to adjust the probe-sample relative angle to compensate the evitable non-parallel effects. Based on the new STM system, sample-tilt-scanning methodology is proposed for eliminating the scanning blind region between the probe and the microstructure. A high step microstructure with height of 23 μm, 90° steep sidewall and width of 50μm has been successfully measured. The slope angle of the sidewall has been achieved to be 85° and the step height at the rising edge and the trench depth at the falling edge are both measured to be 22.96 μm. The whole measuring process only spent less than 10 min. It provides an effective and nondestructive solution for the measurement of high step or deep trench microstructures. In addition, this work also opens the way for further study on sidewall roughness and the tip-sample interaction at the edge of the sidewall, which are highly valuable for fabrication and quality control of high step microstructures. PMID:22299961

  1. Correction of Excessive Precipitation Over Steep and High Mountains in a General Circulation Model

    NASA Technical Reports Server (NTRS)

    Chao, Winston C.

    2012-01-01

    Excessive precipitation over steep and high mountains (EPSM) is a well-known problem in GCMs and meso-scale models. This problem impairs simulation and data assimilation products. Among the possible causes investigated in this study, we found that the most important one, by far, is a missing upward transport of heat out of the boundary layer due to the vertical circulations forced by the daytime upslope winds, which are forced by the heated boundary layer on subgrid-scale slopes. These upslope winds are associated with large subgrid-scale topographic variation, which is found over steep and high mountains. Without such subgridscale heat ventilation, the resolvable-scale upslope flow in the boundary layer generated by surface sensible heat flux along the mountain slopes is excessive. Such an excessive resolvablescale upslope flow combined with the high moisture content in the boundary layer results in excessive moisture transport toward mountaintops, which in turn gives rise to EPSM. Other possible causes of EPSM that we have investigated include 1) a poorly-designed horizontal moisture flux in the terrain-following coordinates, 2) the condition for cumulus convection being too easily satisfied at mountaintops, 3) the presence of conditional instability of the computational kind, and 4) the absence of blocked flow drag. These are all minor or inconsequential. We have parameterized the ventilation effects of the subgrid-scale heated-slope-induced vertical circulation (SHVC) by removing heat from the boundary layer and depositing it in layers higher up when the topographic variance exceeds a critical value. Test results using NASA/Goddard's GEOS-S GCM have shown that this largely solved the EPSM problem.

  2. A novel ultra steep dynamically reconfigurable electrostatically doped silicon nanowire Schottky Barrier FET

    NASA Astrophysics Data System (ADS)

    Singh, Sangeeta; Sinha, Ruchir; Kondekar, P. N.

    2016-05-01

    In this paper, an ultra steep, symmetric and dynamically configurable, electrostatically doped silicon nanowire Schottky FET (E-SiNW-SB-FET) based on dopant-free technology is investigated. It achieves the ultra steep sub-threshold slope (SS) due to the cumulative effect of weak impact-ionization induced positive feedback and electrostatic modulation of Schottky barrier heights at both source and drain terminals. It consists of axial nanowire heterostructure (silicide-intrinsic silicon-silicide) with three independent all-around gates, two gates are polarity control gates for dynamically reconfiguring the device polarity by modulating the effective Schottky barrier heights and a control gate switches the device ON and OFF. The most interesting features of the proposed structure are simplified fabrication process as the state-of-the-art for ion implantation and high thermal budget no more required for annealing. It is highly immune to process variations, doping control issues and random dopant fluctuations (RDF) and there are no mobility degradation issues related to high doping. A calibrated 3-D TCAD simulation results exhibit the SS of 2 mV/dec for n-type E-SiNW-SB-FET and 9 mV/dec for p-type E-SiNW-SB-FET for about five decades of current. Further, it resolves all the reliability related issues of IMOS as hot electron effects are no more limiting our device performance. It offers significant drive current of the order of 10-5-10-4 A and magnificently high ION/IOFF ratio of ∼108 along with the inherent advantages of symmetric device structure for its circuit realization.

  3. Steep, cheap and deep: an ideotype to optimize water and N acquisition by maize root systems

    PubMed Central

    Lynch, Jonathan P.

    2013-01-01

    Background A hypothetical ideotype is presented to optimize water and N acquisition by maize root systems. The overall premise is that soil resource acquisition is optimized by the coincidence of root foraging and resource availability in time and space. Since water and nitrate enter deeper soil strata over time and are initially depleted in surface soil strata, root systems with rapid exploitation of deep soil would optimize water and N capture in most maize production environments. • The ideotype Specific phenes that may contribute to rooting depth in maize include (a) a large diameter primary root with few but long laterals and tolerance of cold soil temperatures, (b) many seminal roots with shallow growth angles, small diameter, many laterals, and long root hairs, or as an alternative, an intermediate number of seminal roots with steep growth angles, large diameter, and few laterals coupled with abundant lateral branching of the initial crown roots, (c) an intermediate number of crown roots with steep growth angles, and few but long laterals, (d) one whorl of brace roots of high occupancy, having a growth angle that is slightly shallower than the growth angle for crown roots, with few but long laterals, (e) low cortical respiratory burden created by abundant cortical aerenchyma, large cortical cell size, an optimal number of cells per cortical file, and accelerated cortical senescence, (f) unresponsiveness of lateral branching to localized resource availability, and (g) low Km and high Vmax for nitrate uptake. Some elements of this ideotype have experimental support, others are hypothetical. Despite differences in N distribution between low-input and commercial maize production, this ideotype is applicable to low-input systems because of the importance of deep rooting for water acquisition. Many features of this ideotype are relevant to other cereal root systems and more generally to root systems of dicotyledonous crops. PMID:23328767

  4. The Supercritical Pile Gamma-Ray Burst Model: The GRB Afterglow Steep Decline and Plateau Phase

    NASA Astrophysics Data System (ADS)

    Sultana, J.; Kazanas, D.; Mastichiadis, A.

    2013-12-01

    We present a process that accounts for the steep decline and plateau phase of the Swift X-Ray Telescope (XRT) light curves, vexing features of gamma-ray burst (GRB) phenomenology. This process is an integral part of the "supercritical pile" GRB model, proposed a few years ago to account for the conversion of the GRB kinetic energy into radiation with a spectral peak at E pk ~ mec 2. We compute the evolution of the relativistic blast wave (RBW) Lorentz factor Γ to show that the radiation-reaction force due to the GRB emission can produce an abrupt, small (~25%) decrease in Γ at a radius that is smaller (depending on conditions) than the deceleration radius RD . Because of this reduction, the kinematic criticality criterion of the "supercritical pile" is no longer fulfilled. Transfer of the proton energy into electrons ceases and the GRB enters abruptly the afterglow phase at a luminosity smaller by ~mp /me than that of the prompt emission. If the radius at which this slow-down occurs is significantly smaller than RD , the RBW internal energy continues to drive the RBW expansion at a constant (new) Γ and its X-ray luminosity remains constant until RD is reached, at which point it resumes its more conventional decay, thereby completing the "unexpected" XRT light curve phase. If this transition occurs at R ~= RD , the steep decline is followed by a flux decrease instead of a "plateau," consistent with the conventional afterglow declines. Besides providing an account of these peculiarities, the model suggests that the afterglow phase may in fact begin before the RBW reaches R ~= RD , thus providing novel insights into GRB phenomenology.

  5. The Supercritical Pile Gamma-Ray Burst Model: The GRB Afterglow Steep Decline and Plateau Phase

    NASA Technical Reports Server (NTRS)

    Sultana, Joseph; Kazanas, D.; Mastichiadis, A.

    2013-01-01

    We present a process that accounts for the steep decline and plateau phase of the Swift X-Ray Telescope (XRT) light curves, vexing features of gamma-ray burst (GRB) phenomenology. This process is an integral part of the "supercritical pile" GRB model, proposed a few years ago to account for the conversion of the GRB kinetic energy into radiation with a spectral peak at E(sub pk) is approx. m(sub e)C(exp 2). We compute the evolution of the relativistic blast wave (RBW) Lorentz factor Gamma to show that the radiation-reaction force due to the GRB emission can produce an abrupt, small (approx. 25%) decrease in Gamma at a radius that is smaller (depending on conditions) than the deceleration radius R(sub D). Because of this reduction, the kinematic criticality criterion of the "supercritical pile" is no longer fulfilled. Transfer of the proton energy into electrons ceases and the GRB enters abruptly the afterglow phase at a luminosity smaller by approx. m(sub p)/m(sub e) than that of the prompt emission. If the radius at which this slow-down occurs is significantly smaller than R(sub D), the RBW internal energy continues to drive the RBW expansion at a constant (new) Gamma and its X-ray luminosity remains constant until R(sub D) is reached, at which point it resumes its more conventional decay, thereby completing the "unexpected" XRT light curve phase. If this transition occurs at R is approx. equal to R(sub D), the steep decline is followed by a flux decrease instead of a "plateau," consistent with the conventional afterglow declines. Besides providing an account of these peculiarities, the model suggests that the afterglow phase may in fact begin before the RBW reaches R is approx. equal to R(sub D), thus providing novel insights into GRB phenomenology.

  6. The use of caesium-137 to estimate agricultural erosion on steep slopes in a tropical watershed

    NASA Astrophysics Data System (ADS)

    Nagle, Gregory N.; Lassoie, James P.; Fahey, Timothy J.; McIntyre, Sherwood C.

    2000-04-01

    The estimation of erosion and sediment delivery rates in tropical mountain watersheds is difficult and most of the methods widely used for estimating soil erosion over large areas have serious limitations. The 137Cs approach has potential for quantifying soil erosion because it can provide retrospective estimates of long-term (since 1963) net sediment redistribution relatively quickly. Despite its great potential, 137Cs has not yet been used in an extensive, reconnaissance level survey of erosion in complex tropical mountain environments. The objective of this study was to examine the applicability of the 137Cs method to estimate erosion on steep tropical agricultural lands (23 to 80% slopes) in the Nizao watershed, a humid, tropical mountain area of the Dominican Republic. In this study we (i) examine the variation of 137Cs in ten reference sites - eight coffee groves and two forested sites - and (ii) estimate erosion from 14 cultivated fields.The soil pool of 137Cs ranged from to 150 to 192 mBq cm-2 on reference sites with minimal erosion. Variability among reference sites was less than expected for such complex mountain terrain. The variability within coffee and forested reference (average CV=28%) sites was similar to the variability found on grassland and forested reference sites in the temperate zone.The estimated annual soil loss from 14 sampled fields ranged from 6 to 61 t ha-1 year-1 with an overall mean of 26 t ha-1 year-1. Overall, the soil erosion estimates found using the steep tropical hillsides. These erosion estimates account for soil loss since 1963 only and it seems likely that soil losses may have been much higher in earlier decades immediately after initial forest clearing earlier in the 20th century.

  7. Models of the geodynamo over geologic time and the inclination test of the GAD hypothesis

    NASA Astrophysics Data System (ADS)

    Heimpel, M. H.

    2012-12-01

    The assumption that Earth's mean magnetic field has been a geocentric axial dipole (GAD) over geologic time is fundamental to paleomagnetism and plate-tectonics. Previous models have linked inclination distributions to latitudinal heat flow variations (Bloxham, 2000). While verifying and extending those previous results, I show here that radial heat flow structure controls geomagnetic field morphology as well. The inclination test of the GAD hypothesis (Evans,1976) is used to interpret numerical dynamo models, some with latitudinally variable buoyancy flux boundary conditions and others with uniform flux boundary conditions. All of the models are chosen to be Earth-like, and at or near the polarity reversing dynamical regime. As was found in previous work, the global inclination distribution is a function of the buoyancy flux at the core-mantle boundary (CMB). However, I find here that the sign of a latitudinally quadrupolar variable flux condition is critical for dynamo stability. Enhanced polar cooling causes inclination shallowing and tends to stabilize the dynamos to reversals, while enhanced equatorial cooling destabilizes the dynamo, resulting in complex field morphology and high reversal frequency. The uniform flux models represent three convective states of the mantle and core. 1. Present era Earth - likely a typical state of the geodynamo. 2. Global convective overturn, associated with flood basalt volcanism, anomalous magnetic reversal frequency, climate change and mass extinctions. 3. Ancient Earth prior to solid inner core formation. For these uniform flux models the inclination distribution anomaly scales with the relative buoyancy flux at the CMB versus the inner core boundary. Consistent with the CALS10k model of Earth's magnetic field over the past ten millennia (Korte et al., 2011), the present era Earth-like dynamos are GAD-like, with very small time-averaged inclination anomalies. In contrast, the global overturn and ancient Earth dynamos show

  8. When what we need influences what we see: choice of energetic replenishment is linked with perceived steepness.

    PubMed

    Taylor-Covill, Guy A H; Eves, Frank F

    2014-06-01

    The apparent steepness of the locomotor challenge presented by hills and staircases is overestimated in explicit awareness. Experimental evidence suggests the visual system may rescale our conscious experience of steepness in line with available energy resources. Skeptics of this "embodied" view argue that such findings reflect experimental demand. This article tested whether perceived steepness was related to resource choices in the built environment. Travelers in a station estimated the slant angle of a 6.45 m staircase (23.4°) either before (N = 302) or after (N = 109) choosing from a selection of consumable items containing differing levels of energetic resources. Participants unknowingly allocated themselves to a quasi-experimental group based on the energetic resources provided by the item they chose. Consistent with a resource based model, individuals that chose items with a greater energy density, or more rapidly available energy, estimated the staircase as steeper than those opting for items that provided less energetic resources. PMID:24548310

  9. The stratigraphy of the Steep Rock Group, N.W. Ontario, with evidence of a major unconformity

    NASA Technical Reports Server (NTRS)

    Wilks, M. E.; Nisbet, E. G.

    1986-01-01

    The Steep Rock Group is exposed 6 km north of Atikokan, 200 km west of Thunder Bay. It is situated on the southern margin of the Wabigoon Belt of the Archaean Superior Province, N. W. Ontario. Reinvestigation of the geology of the Group has shown that the Group lies unconformably on the Tonalite Complex to the east. This unconformity has been previously suspected, from regional and ine mapping but no conclusive outcrop evidence for its existence has as yet been published. The strike of the group, comprised of Basal Conglomerate, Carbonate Member, Ore Zone and Ashrock is generally north-northwest dipping steeply to the southwest. Of the 7 contacts between the Steep Rock Group and the Tonalite Complex, 3 expose the unconformity (The Headland, S. Roberts Pit, Trueman Point), and 4 are faulted. These three outcrops demonstrate unequivocally that the Steep Rock group was laid down unconformably on the underlying Tonalite Complex, which is circa 3 Ga old.

  10. Steep wave, turbulence, and sediment concentration statistics beneath a breaking wave field and their implications for sediment transport

    NASA Astrophysics Data System (ADS)

    Scott, Nicholas V.; Hsu, Tian-Jian; Cox, Daniel

    2009-11-01

    A new methodology based on wavelet analysis is used to estimate steep wave statistics under depth-limited conditions and the corresponding high concentration sediment statistics. Steep waves here are defined as wave crests within the wavelet transform exceeding a root mean square derived acceleration threshold. The method is applied to laboratory data obtained in a large-scale wave-flume experiment conducted in 2005 at Oregon State University's O. H. Hinsdale Wave Research Laboratory from an acoustic Doppler velocimeter and a fiber optic backscatter sensor array above a mobile sand bed. The steep wave and high concentration statistical results for the erosive condition suggest that sand suspensions are intermittent when a wave-breaking timescale (the ratio of breaking wave height and rms wave velocity) is used to detect the concurrence among steep wave, high velocity turbulent fluctuations, and sand concentration events near the bed. More importantly, at 1 cm above the bed, though the accretive case has more steep wave events, the erosive case has more steep waves and concurrent high concentration events, suggesting a more intense breaking wave process near the sensors. The use of a longer time window, based on the dominant wave period in the detection process of steep wave and high concentration events at 1 cm above the bed, does not change the resulting statistics for the erosive condition. However, increased percentages of high concentration events correlated with steep wave and high velocity turbulence events for the accretive condition are obtained. These increased percentages are conjectured to be due to advection of non-local turbulent events and sediment concentration peaks from upstream. A one-dimensional vertical two-phase model for sand transport is modified here to take measured breaking wave turbulence quantities as top boundary conditions to simulate the effect of breaking wave-turbulence on bottom sediment transport. Model results suggest that high

  11. EXTINCTION IN STAR-FORMING DISK GALAXIES FROM INCLINATION-DEPENDENT COMPOSITE SPECTRA

    SciTech Connect

    Yip, Ching-Wa; Szalay, Alex S.; Wyse, Rosemary F. G.; Budavari, Tamas; Dobos, Laszlo; Csabai, Istvan E-mail: szalay@pha.jhu.ed

    2010-02-01

    Extinction in galaxies affects their observed properties. In scenarios describing the distribution of dust and stars in individual disk galaxies, the amplitude of the extinction can be modulated by the inclination of the galaxies. In this work, we investigate the inclination dependency in composite spectra of star-forming disk galaxies from the Sloan Digital Sky Survey Data Release 5. In a volume-limited sample within a redshift range 0.065-0.075 and a r-band Petrosian absolute magnitude range -19.5 to -22 mag which exhibits a flat distribution of inclination, the inclined relative to face-on extinction in the stellar continuum is found empirically to increase with inclination in the g, r, and i bands. Within the central 0.5 intrinsic half-light radius of the galaxies, the g-band relative extinction in the stellar continuum for the highly inclined objects (axis ratio b/a = 0.1) is 1.2 mag, agreeing with previous studies. The extinction curve of the disk galaxies is given in the rest-frame wavelengths 3700-8000 A, identified with major optical emission and absorption lines in diagnostics. The Balmer decrement, Halpha/Hbeta, remains constant with inclination, suggesting a different kind of dust configuration and/or reddening mechanism in the H II region from that in the stellar continuum. One factor is shown to be the presence of spatially non-uniform interstellar extinction, presumably caused by clumped dust in the vicinity of the H II region.

  12. Laboratory investigation and direct numerical simulation of wind effect on steep surface waves

    NASA Astrophysics Data System (ADS)

    Troitskaya, Yuliya; Sergeev, Daniil; Druzhinin, Oleg; Ermakova, Olga

    2015-04-01

    The small scale ocean-atmosphere interaction at the water-air interface is one of the most important factors determining the processes of heat, mass, and energy exchange in the boundary layers of both geospheres. Another important aspect of the air-sea interaction is excitation of surface waves. One of the most debated open questions of wave modeling is concerned with the wind input in the wave field, especially for the case of steep and breaking waves. Two physical mechanisms are suggested to describe the excitation of finite amplitude waves. The first one is based on the treatment of the wind-wave interaction in quasi-linear approximation in the frameworks of semi-empirical models of turbulence of the low atmospheric boundary layer. An alternative mechanism is associated with separation of wind flow at the crests of the surface waves. The "separating" and "non-separating" mechanisms of wave generation lead to different dependences of the wind growth rate on the wave steepness: the latter predicts a decrease in the increment with wave steepness, and the former - an increase. In this paper the mechanism of the wind-wave interaction is investigated basing on physical and numerical experiments. In the physical experiment, turbulent airflow over waves was studied using the video-PIV method, based on the application of high-speed video photography. Alternatively to the classical PIV technique this approach provides the statistical ensembles of realizations of instantaneous velocity fields. Experiments were performed in a round wind-wave channel at Institute of Applied Physics, Russian Academy of Sciences. A fan generated the airflow with the centerline velocity 4 m/s. The surface waves were generated by a programmed wave-maker at the frequency of 2.5 Hz with the amplitudes of 0.65 cm, 1.4 cm, and 2 cm. The working area (27.4 × 10.7 cm2) was at a distance of 3 m from the fan. To perform the measurements of the instantaneous velocity fields, spherical polyamide

  13. THE PHOTOMETRIC AND KINEMATIC STRUCTURE OF FACE-ON DISK GALAXIES. III. KINEMATIC INCLINATIONS FROM H{alpha} VELOCITY FIELDS

    SciTech Connect

    Andersen, David R.; Bershady, Matthew A. E-mail: mab@astro.wisc.edu

    2013-05-01

    Using the integral field unit DensePak on the WIYN 3.5 m telescope we have obtained H{alpha} velocity fields of 39 nearly face-on disks at echelle resolutions. High-quality, uniform kinematic data and a new modeling technique enabled us to derive accurate and precise kinematic inclinations with mean i{sub kin} = 23 Degree-Sign for 90% of these galaxies. Modeling the kinematic data as single, inclined disks in circular rotation improves upon the traditional tilted-ring method. We measure kinematic inclinations with a precision in sin i of 25% at 20 Degree-Sign and 6% at 30 Degree-Sign . Kinematic inclinations are consistent with photometric and inverse Tully-Fisher inclinations when the sample is culled of galaxies with kinematic asymmetries, for which we give two specific prescriptions. Kinematic inclinations can therefore be used in statistical ''face-on'' Tully-Fisher studies. A weighted combination of multiple, independent inclination measurements yield the most precise and accurate inclination. Combining inverse Tully-Fisher inclinations with kinematic inclinations yields joint probability inclinations with a precision in sin i of 10% at 15 Degree-Sign and 5% at 30 Degree-Sign . This level of precision makes accurate mass decompositions of galaxies possible even at low inclination. We find scaling relations between rotation speed and disk-scale length identical to results from more inclined samples. We also observe the trend of more steeply rising rotation curves with increased rotation speed and light concentration. This trend appears to be uncorrelated with disk surface brightness.

  14. Instream wood in a steep headwater channel: geomorphic significance of large and small wood

    NASA Astrophysics Data System (ADS)

    Galia, Tomáš; Šilhán, Karel; Ruiz-Villanueva, Virginia; Tichavský, Radek

    2016-04-01

    Besides the well-known significance of large wood (LW), also small woody pieces (SW; here defined as pieces with dimensions at least 0.5 m length and 0.05 m diameter), can play an important role in steep narrow headwaters. We inventoried instream wood in the 0.4 km long Mazák headwater channel, Moravskoslezské Beskydy Mts, Czech Republic (2steep adjacent hillslopes (0.6

  15. Alternative Paths for Insertion of Probes in High Inclination Lunar Orbits

    NASA Astrophysics Data System (ADS)

    de Melo, C. F.; Winter, O. C.

    The dynamics of the circular planar restricted three-body Earth-Moon-particle problem predicts the existence of direct periodic orbits around the Lagrangian equilibrium point L1 From these orbits derive a group of paths that form links between the Earth and the Moon Moreover they are capable of carrying out transfers between terrestrial and lunar orbits of low altitudes When we considered more complex dynamical systems such as the three-dimensional full four-body Sun-Earth-Moon-probe problem which takes into account besides other factors the inclination of the orbit of the Moon these paths leaving terrestrial orbits of low altitudes LEO gain inclination when they penetrate in the sphere of lunar influence allowing the insertion of probes in lunar orbits of high inclinations and low altitudes We studied this property giving emphasis to two types of transfer maneuvers Firstly we investigated direct transfers by inserting probes in lunar orbits with inclinations varying between 29 o and 42 o Next we investigated directed transfers with the application of a Delta V along of the trajectory in order to lead the probe into lunar orbits with inclinations between 0 o and 180 o The results allowed the definition of a group of paths capable of carrying out Earth-moon transfers with flight time between 13 and 16 days with relatively low costs

  16. Walking on inclines: how do desert ants monitor slope and step length

    PubMed Central

    Seidl, Tobias; Wehner, Rüdiger

    2008-01-01

    Background During long-distance foraging in almost featureless habitats desert ants of the genus Cataglyphis employ path-integrating mechanisms (vector navigation). This navigational strategy requires an egocentric monitoring of the foraging path by incrementally integrating direction, distance, and inclination of the path. Monitoring the latter two parameters involves idiothetic cues and hence is tightly coupled to the ant's locomotor behavior. Results In a kinematic study of desert ant locomotion performed on differently inclined surfaces we aimed at pinpointing the relevant mechanisms of estimating step length and inclination. In a behavioral experiment with ants foraging on slippery surfaces we broke the otherwise tightly coupled relationship between stepping frequency and step length and examined the animals' ability to monitor distances covered even under those adverse conditions. We show that the ants' locomotor system is not influenced by inclined paths. After removing the effect of speed, slope had only marginal influence on kinematic parameters. Conclusion From the obtained data we infer that the previously proposed monitoring of angles of the thorax-coxa joint is not involved in inclinometry. Due to the tiny variations in cycle period, we also argue that an efference copy of the central pattern generator coding the step length in its output frequency will most likely not suffice for estimating step length and complementing the pedometer. Finally we propose that sensing forces acting on the ant's legs could provide the desired neuronal correlate employed in monitoring inclination and step length. PMID:18518946

  17. A Study of the Inclination of Satellites of a Planet After Spin Axis Forced Tumbling

    NASA Astrophysics Data System (ADS)

    Boldrin, Luiz Augusto; Winter, O.; Vieira Neto, E.

    2013-05-01

    Abstract (2,250 Maximum Characters): In order to analyze the theory of satellite loss resulting from a giant impact on Uranus, we decided to do few a study about this problem using forced tumbling of the spin axis of planet. We used two different kinds of forced tumbling to simulate the obliquity variation: linear variation and damped variation. To do this, we made numerical simulations of N-body problem with J2 oblateness coefficient of the central body. First, we studied the relation of the time tumbling of Uranus' spin axis and the semi-major axis of the hypothetical satellite with a specific final inclination. In both cases the results are a power law. Later we study the final inclination of the satellite in relation to the number of collisions (pseudo collision). And finally we studied the final inclination of several different initial conditions (orbital elements) of the satellites. We concluded that the initial inclination and initial longitude of ascending node are important to the final satellite inclination. For future studies we want implement a more realistic model using the attitude equations of the central body and study the origin of the obliquity of the others planets of the solar system. Aknowledments: FAPESP, CAPES and CNPq.

  18. ORIGIN AND DYNAMICS OF THE MUTUALLY INCLINED ORBITS OF {upsilon} ANDROMEDAE c AND d

    SciTech Connect

    Barnes, Rory; Quinn, Thomas R.; Greenberg, Richard; McArthur, Barbara E.; Benedict, G. Fritz

    2011-01-10

    We evaluate the orbital evolution and several plausible origin scenarios for the mutually inclined orbits of {upsilon} And c and d. These two planets have orbital elements that oscillate with large amplitudes and lie close to the stability boundary. This configuration, and in particular the observed mutual inclination, demands an explanation. The planetary system may be influenced by a nearby low-mass star, {upsilon} And B, which could perturb the planetary orbits, but we find it cannot modify two coplanar orbits into the observed mutual inclination of 30 deg. However, it could incite ejections or collisions between planetary companions that subsequently raise the mutual inclination to >30 deg. Our simulated systems with large mutual inclinations tend to be further from the stability boundary than {upsilon} And, but we are able to produce similar systems. We conclude that scattering is a plausible mechanism to explain the observed orbits of {upsilon} And c and d, but we cannot determine whether the scattering was caused by instabilities among the planets themselves or by perturbations from {upsilon} And B. We also develop a procedure to quantitatively compare numerous properties of the observed system to our numerical models. Although we only implement this procedure to {upsilon} And, it may be applied to any exoplanetary system.

  19. Critical inclination for absolute/convective instability transition in inverted falling films

    NASA Astrophysics Data System (ADS)

    Scheid, Benoit; Kofman, Nicolas; Rohlfs, Wilko

    2016-04-01

    Liquid films flowing down the underside of inclined plates are subject to the interaction between the hydrodynamic and the Rayleigh-Taylor (R-T) instabilities causing a patterned and wavy topology at the free surface. The R-T instability results from the denser liquid film being located above a less dense ambient gas, and deforming into an array of droplets, which eventually drip if no saturation mechanism arises. Such saturation mechanism can actually be provided by a fluid motion along the inclined plate. Using a weighted integral boundary layer model, this study examines the critical inclination angle, measured from the vertical, that separates regimes of absolute and convective instability. If the instability is of absolute type, growing perturbations stay localized in space potentially leading to dripping. If the instability is of convective type, growing perturbations move downwards the inclined plate, forming waves and eventually, but not necessarily, droplets. Remarkably, there is a minimum value of the critical angle below which a regime of absolute instability cannot exist. This minimum angle decreases with viscosity: it is about 85° for water, about 70° for silicon oil 20 times more viscous than water, and reaches a limiting value for liquid with a viscosity larger than about 1000 times the one of water. It results that for any fluid, absolute dripping can only exist for inclination angle (taken from the vertical) larger than 57.4°.

  20. Emittance, brilliance, and bandpass issues related to an inclined crystal monochromator

    SciTech Connect

    Macrander, A.T.; Haeffner, D.R.; Cowan, P.L.

    1992-07-01

    The inclined double crystal monochromator arrangement is very effective in handling high heat loads and holds considerable promise as a monochromator for undulator beams at third generation synchrotrons. Results for the ideal inclined crystal case have been obtained by dynamical diffraction calculations, and diffraction results for the (111) reflection of silicon are presented for an inclination angle of 85{degree}0 and energies of 5 key and 13.84 key. The diffraction characteristics resemble closely diffraction from-asymmetric (111) plane of silicon. However, the inclined and noninclined cases are not identical. Diffraction in the inclined case is slightly different due to refraction. The full width at half maximum of the Darwin-Prins reflectivity curve is slightly increased ({approximately}l%), and the angles of the outgoing beam after one reflection are slightly altered. That is, except for a wave incident at the Laue point in reciprocal space, the diffraction is always slightly asymmetric. The effect can be exactly reversed by an identical second crystal in the (+,{minus}) arrangement.

  1. Emittance, brilliance, and bandpass issues related to an inclined crystal monochromator

    SciTech Connect

    Macrander, A.T.; Haeffner, D.R.; Cowan, P.L.

    1992-07-31

    The inclined double crystal monochromator arrangement is very effective in handling high heat loads and holds considerable promise as a monochromator for undulator beams at third generation synchrotrons. Results for the ideal inclined crystal case have been obtained by dynamical diffraction calculations, and diffraction results for the (111) reflection of silicon are presented for an inclination angle of 85{degrees} and energies of 5 keV and 13.84 keV. The diffraction characteristics resemble closely diffraction from a symmetric (111) plane of silicon. However, the inclined and noninclined cases are not identical. Diffraction in the inclined case is slightly different due to refraction. The full width at half maximum of the Darwin-Prins reflectivity curve is slightly increased ({approximately} 1%), and the angles of the outgoing beam after one reflection are slightly altered. That is, except for a wave incident at the Laue point in reciprocal space, the diffraction is always slightly asymmetric. The effect can be exactly reversed by an identical second crystal in the (+,-) arrangement.

  2. A Stochastic Analysis of Glenoid Inclination Angle and Superior Migration of the Humeral Head

    PubMed Central

    Flieg, Nicholas G.; Gatti, Christopher J.; Doro, Lisa Case; Langenderfer, Joseph E.; Carpenter, James E.; Hughes, Richard E.

    2008-01-01

    Background Superior glenoid inclination, which is a relatively upward facing of the glenoid in the plane of the scapula, has been associated with rotator cuff pathology. Increased glenoid inclination may cause superior humeral head migration, which can cause impingement of the supraspinatus tendon. The purpose of this study was to test the hypothesis that inclination angle affects the probability of superior humeral head migration. Methods A three-dimensional model of the glenohumeral joint was developed in which muscle forces were modeled as random variables. Monte Carlo simulation was used to compute the probability that the glenohumeral reaction force was directed such that superior humeral head migration should occur. An electromyogram-driven model was used to estimate shoulder muscle forces in healthy volunteers performing arm elevation. Findings The model predicted that the probability of superior humeral head migration increased as glenoid inclination angle was increased. This finding was independent of the assumed shape of the muscle force probability distributions. Interpretation The results support the theory that glenoid inclination may be a risk factor for rotator cuff pathology. PMID:18280016

  3. Role of inclined threading dislocations in stress relaxation in mismatched layers

    NASA Astrophysics Data System (ADS)

    Cantu, P.; Wu, F.; Waltereit, P.; Keller, S.; Romanov, A. E.; DenBaars, S. P.; Speck, J. S.

    2005-05-01

    (0001)-oriented epitaxial wurtzite III-nitride layers grown on mismatched substrates have no resolved shear stress on the natural basal and prismatic slip planes; however, strained III-nitride layers may gradually relax. We report on the stress relaxation of Al0.49Ga0.51N layers grown on nominally relaxed Al0.62Ga0.38N buffer layers on sapphire. The reduction in elastic strain of the Al0.49Ga0.51N was enhanced by Si doping which caused an increased surface roughness. Despite the Si doping, the films always sustained step-flow growth. The extent of relaxation of the Al0.49Ga0.51N layer was determined by on-axis ω-2θ scans of (000l ) peaks and reciprocal space maps of inclined (off-axis) peaks. Cross-section and plan-view transmission electron microscopy studies showed that the threading dislocations in the Al0.49Ga0.51N layer inclined from the [0001] direction towards ⟨11¯00⟩ directions by ˜15-25°, perpendicular to their Burgers vector (1/3⟨112¯0⟩). These inclined threading dislocations have a misfit dislocation component and thus provide stress relief. The contribution of the dislocation inclination to the degree of relaxation has been formulated and the energy release has been determined for dislocation inclination in mismatched stressed layers.

  4. Early, steep subduction of India beneath Asia required by timing of UHP metamorphism

    NASA Astrophysics Data System (ADS)

    Leech, M. L.; Klemperer, S. L.; Singh, S.; Jain, A. K.

    2004-12-01

    Ultrahigh-pressure (UHP) rocks in the NW Himalaya are the youngest on earth, and allow testing of critical questions of UHP formation and exhumation and the India-Asia collision. The Tso Morari Complex (TMC) is a UHP subduction zone complex in eastern Ladakh in the western Himalaya, south of the Indus-Tsangpo suture zone. New U-Pb SHRIMP data from zircon shows the TMC has a Proterozoic protolith with a Pan-African history, and defines three stages in the Eocene history of the TMC, hence constraining the timing of collision, subduction, and exhumation in the western Himalaya. Our precise new single zircon U-Pb ages indicate that UHP eclogite-facies metamorphism occurred at 53.3±0.7 Ma followed by a HP eclogite-facies event at 50.0±0.6 Ma, and amphibolite-facies metamorphism at 47.5±0.5 Ma. Retrograde zircon growth may result from dehydration reaction-related fluids evolved during exhumation; the intermittent presence of these fluids would allow zircon crystallization during exhumation that would document the changing P-T conditions. Today India subducts beneath Tibet at an angle of only c. 10° ; at this low angle, rocks must travel over 500 km along the subduction thrust to reach the depth of c. 100 km required for UHP metamorphism. Initial collision of India with Asia, based on stratigraphic and paleomagnetic data, is widely cited as being at 55±1 Ma. Here we show that Indian rocks reached UHP depths at 53.3±0.7 Ma. Given the fast India-Asia convergence rate of 69 km/m.y., our result implies an earlier onset of collision (c. 57 Ma) and that UHP rocks must have traveled a short, hence steep path into the mantle. We infer that early continental subduction was at a steep angle, probably vertical, comparable to modern continental subduction in the Hindu Kush.

  5. The Latemar: A flat-topped, steep fronted platform dominated by microbialites and synsedimentary cements

    NASA Astrophysics Data System (ADS)

    Marangon, A.; Gattolin, G.; Della Porta, G.; Preto, N.

    2011-10-01

    Facies analyses on the Latemar isolated carbonate platform suggest a higher proportion of microbial carbonates compared to literature. This is evident especially in the margin-upper slope zone, where microbial boundstone associated with Tubiphytes, calcareous sponges, botryoidal aragonite and radiaxial fibrous cements extended down to 250 m water depth. The Latemar flat-topped high-relief platform has been subdivided into five different facies belts: inner and outermost platform, margin, upper and lower slope. Each facies belt represents subtidal environments except for the inner platform, which is characterized by a peritidal facies association. Point counting analysis was carried out on ca. 90 thin sections to quantify the different platform components. Microbialite and cements are most abundant: they represent, respectively, ca. 40% and ca. 34% of the whole platform volume. These results suggest that carbonate production at Latemar occurred in a M-Factory. Microbial carbonates, as well as early marine cements are most abundant on the upper slope, margin and outermost platform, although microbialites are found in all facies belts. The presence of supratidal sedimentary facies restricted only to the inner platform and of a completely subtidal outermost platform suggests a new depositional profile for the Latemar. The central portion is occupied by the flat platform interior, cyclically subaerially exposed. Facies of the subtidal outermost platform surround the inner platform and display a progressive increase in depth toward the margin. The margin is submerged and essentially constituted by microbial and cement boundstone. The slope is characterized by steep clinoforms (~ 35°) dominated by in situ microbialites in the upper-middle portion (0-250 m depth), evidently precipitated by non light-dependent microbially influenced processes. The lower slope is mostly detrital, poor in platform top-derived sediments and dominated by margin and upper-slope derived rudstone

  6. Tracking water pathways in steep hillslopes by δ18O depth profiles of soil water

    NASA Astrophysics Data System (ADS)

    Mueller, Matthias H.; Alaoui, Abdallah; Kuells, Christoph; Leistert, Hannes; Meusburger, Katrin; Stumpp, Christine; Weiler, Markus; Alewell, Christine

    2014-11-01

    Assessing temporal variations in soil water flow is important, especially at the hillslope scale, to identify mechanisms of runoff and flood generation and pathways for nutrients and pollutants in soils. While surface processes are well considered and parameterized, the assessment of subsurface processes at the hillslope scale is still challenging since measurement of hydrological pathways is connected to high efforts in time, money and personnel work. The latter might not even be possible in alpine environments with harsh winter processes. Soil water stable isotope profiles may offer a time-integrating fingerprint of subsurface water pathways. In this study, we investigated the suitability of soil water stable isotope (δ18O) depth profiles to identify water flow paths along two transects of steep subalpine hillslopes in the Swiss Alps. We applied a one-dimensional advection-dispersion model using δ18O values of precipitation (ranging from -24.7 to -2.9‰) as input data to simulate the δ18O profiles of soil water. The variability of δ18O values with depth within each soil profile and a comparison of the simulated and measured δ18O profiles were used to infer information about subsurface hydrological pathways. The temporal pattern of δ18O in precipitation was found in several profiles, ranging from -14.5 to -4.0‰. This suggests that vertical percolation plays an important role even at slope angles of up to 46°. Lateral subsurface flow and/or mixing of soil water at lower slope angles might occur in deeper soil layers and at sites near a small stream. The difference between several observed and simulated δ18O profiles revealed spatially highly variable infiltration patterns during the snowmelt periods: The δ18O value of snow (-17.7 ± 1.9‰) was absent in several measured δ18O profiles but present in the respective simulated δ18O profiles. This indicated overland flow and/or preferential flow through the soil profile during the melt period. The applied

  7. Tracing bed load sediment using PIT tags in a steep headwater channel.

    NASA Astrophysics Data System (ADS)

    Kubo, Y.; Hiraoka, M.; Gomi, T.; Nidaira, K.; Uchiyama, Y.

    2015-12-01

    Bed load transport in steep headwater channels is complex because of the particle size distribution, topography, channel roughness, and sediment supply from adjacent hillslope. We monitored movement bed load sediment using PIT tags in a steep headwater channel segments. Study area is located in 7.0ha Oobora-sawa observatory from 50km west of Tokyo metropolitan. Annual precipitation is 3000mm and mean temperature is 10°. Annual bed load sediment yields in the study catchment was from 6.5 to 7.6 t/ha/yr. Mean channel gradient is 24° with 0.5m low flow width. The channel is consisted by 0.2 to 1.6m interval of step-pool sequences. Based on pebble count method, D10, D50 and D90 of channel substrate were 8, 28 and 206mm respectively. We deployed 134 bed load tracers with five classes of diameter ranges (Class1:17.7, Class2:24.8, Class3:35.8, Class4:54.1 and Class5:83.8mm). Selected tracers represented from D20 to D77 of channel bed substrates. PIT tags (diameter 2mm, length 9mm and weight 0.1g) were placed into the particles by drilling and refilled with non-corrosive epoxy. We investigated the movement of bed load tracers every major storm event since February 2015. Channel morphology was measured using photographic survey and topographic model was developed using software of Surface from motion (PhotoScan). Mean bed load movement in the 5 storm event with 438 mm total and 33 mm maximum intensity was 168 mm. Then 51 mm of bed load movement occurred in 43 mm total and 16 mm intensity of rainfall. Recurrence interval of the two storm event was 1 and 4 year respectively. Receivable rates of bed load tracers was 70 and 74 % in the two events. Mobilized bed load (7 to 18%) deposited at cascade, pool and riffle, and among step clusters. Mobilized bed load tracers is rather random and we do not find any patterns for particle size for the movement and distance. Our field monitoring showed that bed load tracers were not mobilized for storm events with 10.5mm/h intensity of

  8. New approaches to inferences for steep-sided domes on Venus

    NASA Astrophysics Data System (ADS)

    Quick, Lynnae C.; Glaze, Lori S.; Baloga, Stephen M.; Stofan, Ellen R.

    2016-06-01

    New mathematical approaches for the relaxation and emplacement of viscous lava domes are presented and applied to steep-sided domes on Venus. A similarity solution approach is applied to the governing equation for fluid flow in a cylindrical geometry for two distinct scenarios. In the first scenario, dome relaxation is explored assuming a constant volume of fluid (i.e. lava) has been rapidly emplaced onto the surface. Cooling of lava is represented by a time-variable viscosity and singularities inherent in previous models for dome relaxation have been eliminated. At the onset of relaxation, bulk dynamic viscosities lie in the range between 1010-1016 Pa s, consistent with basaltic-andesite to rhyolitic compositions. Plausible relaxation times range from 5 to 5000 years, depending on initial lava viscosity. The first scenario, however, is only valid during the final stages of dome relaxation and does not consider the time taken for lava to be extruded onto the surface. In the second scenario, emplacement and growth of a steep-sided dome is considered when the volume of lava on the surface increases over time (i.e. time-variable volume approach). The volumetric flowrate may depend on an arbitrary power of the dome thickness, thus embracing Newtonian as well as other rheologies for describing terrestrial and planetary mass flows. The approach can be used to distinguish between basic flowrate models for fluid emplacement. The formalism results in radial expansion of a dome proportional to t1/2, consistent with the diffusive nature of the governing equation. The flow at the front is shown to thicken as the front advances for a constant rate of lava supply. Emplacement times are intimately correlated with the bulk rheology. Comparison of the theoretical profiles with the shape of a typical dome on Venus indicates that a Newtonian bulk rheology is most appropriate, consistent with prior studies. However, results here suggest a bulk dynamic viscosity of 1012-1013 Pa s and

  9. Use of corn steep liquor as an economical nitrogen source for biosuccinic acid production by Actinobacillus succinogenes

    NASA Astrophysics Data System (ADS)

    Tan, J. P.; Jahim, J. M.; Wu, T. Y.; Harun, S.; Mumtaz, T.

    2016-06-01

    Expensive raw materials are the driving force that leads to the shifting of the petroleum-based succinic acid production into bio-based succinic acid production by microorganisms. Cost of fermentation medium is among the main factors contributing to the total production cost of bio-succinic acid. After carbon source, nitrogen source is the second largest component of the fermentation medium, the cost of which has been overlooked for the past years. The current study aimed at replacing yeast extract- a costly nitrogen source with corn steep liquor for economical production of bio-succinic acid by Actinobacillus succinogenes 130Z. In this study, a final succinic acid concentration of 20.6 g/L was obtained from the use of corn steep liquor as the nitrogen source, which was comparable with the use of yeast extract as the nitrogen source that had a final succinate concentration of 21.4 g/l. In terms of economical wise, corn steep liquor was priced at 200 /ton, which was one fifth of the cost of yeast extract at 1000 /ton. Therefore, corn steep liquor can be considered as a potential nitrogen source in biochemical industries instead of the costly yeast extract.

  10. Adapting Tilt Corrections and the Governing Flow Equations for Steep, Fully Three-Dimensional, Mountainous Terrain

    NASA Astrophysics Data System (ADS)

    Oldroyd, Holly J.; Pardyjak, Eric R.; Huwald, Hendrik; Parlange, Marc B.

    2016-06-01

    In recent studies of atmospheric turbulent surface exchange in complex terrain, questions arise concerning velocity-sensor tilt corrections and the governing flow equations for coordinate systems aligned with steep slopes. The standard planar-fit method, a popular tilt-correction technique, must be modified when applied to complex mountainous terrain. The ramifications of these adaptations have not previously been fully explored. Here, we carefully evaluate the impacts of the selection of sector size (the range of flow angles admitted for analysis) and planar-fit averaging time. We offer a methodology for determining an optimized sector-wise planar fit (SPF), and evaluate the sensitivity of momentum fluxes to varying these SPF input parameters. Additionally, we clarify discrepancies in the governing flow equations for slope-aligned coordinate systems that arise in the buoyancy terms due to the gravitational vector no longer acting along a coordinate axis. New adaptions to the momentum equations and turbulence kinetic energy budget equation allow for the proper treatment of the buoyancy terms for purely upslope or downslope flows, and for slope flows having a cross-slope component. Field data show that new terms in the slope-aligned forms of the governing flow equations can be significant and should not be omitted. Since the optimized SPF and the proper alignment of buoyancy terms in the governing flow equations both affect turbulent fluxes, these results hold implications for similarity theory or budget analyses for which accurate flux estimates are important.

  11. The interaction between steep waves and a surface-piercing column.

    PubMed

    Swan, C; Sheikh, R

    2015-01-28

    Experimental observations are presented of a single surface-piercing column subject to a wide range of surface gravity waves. With the column diameter, D, chosen such that the flow lies within the drag-inertia regime, two types of high-frequency wave scattering are identified. The first is driven by the run-up and wash-down on the surface of the column in the vicinity of the upstream and downstream stagnation points. The second concerns the circulation of fluid around the column, leading to the scattering of a pair of non-concentric wavefronts. The phasing of the wave cycle at which this second mode evolves is dependent upon the time taken for fluid to move around the column. This introduces an additional time-scale, explaining why existing diffraction solutions, based upon a harmonic analysis of the incident waves, cannot describe this scattered component. The interaction between the scattered waves and the next (steep) incident wave can produce a large amplification of the scattered waves, particularly the second type. Evidence is provided to show that these interactions can produce highly localized free-surface effects, including vertical jetting, with important implications for the setting of deck elevations, the occurrence of wave slamming and the development of large run-up velocities. PMID:25512588

  12. Evaluation of two cockpit display concepts for civil tiltrotor instrument operations on steep approaches

    NASA Technical Reports Server (NTRS)

    Decker, William A.; Bray, Richard S.; Simmons, Rickey C.; Tucker, George E.

    1993-01-01

    A piloted simulation experiment was conducted using the NASA Ames Research Center Vertical Motion Simulator to evaluate two cockpit display formats designed for manual control on steep instrument approaches for a civil transport tiltrotor aircraft. The first display included a four-cue (pitch, roll, power lever position, and nacelle angle movement prompt) flight director. The second display format provided instantaneous flight path angle information together with other symbols for terminal area guidance. Pilots evaluated these display formats for an instrument approach task which required a level flight conversion from airplane-mode flight to helicopter-mode flight while decelerating to the nominal approach airspeed. Pilots tracked glide slopes of 6, 9, 15 and 25 degrees, terminating in a hover for a vertical landing on a 150 feet square vertipad. Approaches were conducted with low visibility and ceilings and with crosswinds and turbulence, with all aircraft systems functioning normally and were carried through to a landing. Desired approach and tracking performance was achieved with generally satisfactory handling qualities using either display format on glide slopes up through 15 degrees. Evaluations with both display formats for a 25 degree glide slope revealed serious problems with glide slope tracking at low airspeeds in crosswinds and the loss of the intended landing spot from the cockpit field of view.

  13. Cost-effective temporary microirrigation system for grass establishment on environmentally sensitive steep slopes

    SciTech Connect

    Gyasi-Agyei, Y.

    2004-05-15

    An advanced technology cost-effective drip irrigation system design and setup on environmentally sensitive elevated steep slopes (batters) of a coal train derailment site in Central Queensland, Australia, are presented. The final profile of the coal burial site consists of six batters and associated berms with a drop in elevation of about 35 m. A small dam constructed downstream of the confluence of the two main drainage channels at the site supplied water for irrigation of the batters to aid the establishment of grass to control erosion. Water was periodically pumped from the small dam to three storage tanks using a petrol (gas) pump. Three solar pumps drew water from the storage tanks and dam to irrigate the top four batters. Contactors, pressure switches and irrigation control valves in turn shared a single solar power source between the solar pumps. Level balls (floating switches) placed in the storage tanks cut the solar power supply to the pumps when the storage tanks were nearly empty. On the whole, the irrigation system worked very well and excellent grass cover was established within 12 weeks. Given the environmental risks associated with the on-site burying of coal, and the estimated cost of about AU$11.73/m{sup 2} (every 10 years) in maintenance if the railway batters are not treated, the estimated total cost of AU$4.61/m{sup 2} of batter area treated with irrigation, including AU$3.08/m{sup 2} in irrigation cost, is justified.

  14. Steep-Slope Assembly Testing of Clay and Concrete Tile With and Without Cool Pigmented Colors

    SciTech Connect

    Miller, William A

    2005-11-01

    Cool color pigments and sub-tile venting of clay and concrete tile roofs significantly impact the heat flow crossing the roof deck of a steep-slope roof. Field measures for the tile roofs revealed a 70% drop in the peak heat flow crossing the deck as compared to a direct-nailed asphalt shingle roof. The Tile Roofing Institute (TRI) and its affiliate members are keenly interested in documenting the magnitude of the drop for obtaining solar reflectance credits with state and federal "cool roof" building efficiency standards. Tile roofs are direct-nailed or are attached to a deck with batten or batten and counter-batten construction. S-Misson clay and concrete tile roofs, a medium-profile concrete tile roof, and a flat slate tile roof were installed on fully nstrumented attic test assemblies. Temperature measures of the roof, deck, attic, and ceiling, heat flows, solar reflectance, thermal emittance, and the ambient weather were recorded for each of the tile roofs and also on an adjacent attic cavity covered with a conventional pigmented and directnailed asphalt shingle roof. ORNL measured the tile's underside temperature and the bulk air temperature and heat flows just underneath the tile for batten and counter-batten tile systems and compared the results to the conventional asphalt shingle.

  15. Gravitational spreading of steep-sided ridges ("sackung") in Western United States

    USGS Publications Warehouse

    Radbruch-Hall, D. H.; Varnes, D.J.; Savage, W.Z.

    1976-01-01

    Large-scale gravitational spreading and movement along fractures of steep-sided ridges in the mountainous areas of the western United States are characterized by linear fissures, trenches, and uphill-facing scarps on tops and sides of ridges. Spreading appears to take place by movement along disconnected planes and/or by slow plastic deformation of a rock mass. In some places, valleyward squeezing out of weak shales overlain by rigid rocks causes extensional fracturing and outward movement of the rigid layers, as illustrated by extension of two laccoliths overlying Mancos Shale, one at Dolores Peak and another at Crested Butte in western Colorado. Gravitational forces acting on a ridge of more homogeneous material causes tensional spreading of the ridge parallel to its long axis, for example in fractured granitic rock north of Mt. Massive in central Colorado, where a survey course has been established to monitor the movement. Recognition and understanding of these large-scale gravitational features and the mechanism that causes them are pertinent to site selection and design of engineering structures in high mountains. If fractures extend to considerable depth and if movement is continuing, engineering structures in valleys or tunnels through the spreading ridges could be damaged. ?? 1976 International Association of Engineering Geology.

  16. Time series modeling of soil moisture dynamics on a steep mountainous hillside

    NASA Astrophysics Data System (ADS)

    Kim, Sanghyun

    2016-05-01

    The response of soil moisture to rainfall events along hillslope transects is an important hydrologic process and a critical component of interactions between soil vegetation and the atmosphere. In this context, the research described in this article addresses the spatial distribution of soil moisture as a function of topography. In order to characterize the temporal variation in soil moisture on a steep mountainous hillside, a transfer function, including a model for noise, was introduced. Soil moisture time series with similar rainfall amounts, but different wetness gradients were measured in the spring and fall. Water flux near the soil moisture sensors was modeled and mathematical expressions were developed to provide a basis for input-output modeling of rainfall and soil moisture using hydrological processes such as infiltration, exfiltration and downslope lateral flow. The characteristics of soil moisture response can be expressed in terms of model structure. A seasonal comparison of models reveals differences in soil moisture response to rainfall, possibly associated with eco-hydrological process and evapotranspiration. Modeling results along the hillslope indicate that the spatial structure of the soil moisture response patterns mainly appears in deeper layers. Similarities between topographic attributes and stochastic model structures are spatially organized. The impact of temporal and spatial discretization scales on parameter expression is addressed in the context of modeling results that link rainfall events and soil moisture.

  17. The effect of surface cover on infiltration rate in steep forest plantations

    NASA Astrophysics Data System (ADS)

    Hiraoka, M.; Onda, Y.; Kato, H.; Ito, S.; Mizugaki, S.

    2007-12-01

    The Japanese cypress (Hinoki; Chamaecyparis obtusa) is a major commercial tree species in Japan, and without thinning of high-density stands, canopy closure prevents development of understory vegetation. Therefore there is a concern for overlandflow and sediment yield due to infiltration rate lowering from steep hillslopes of Japanese cypress plantation. We developed a light-weight rainfall simulator based on the design of Meyer and Harmon (1979). A flat fan Veejet 80150 spraying nozzle (Spraying systems Co., USA) is mounted on the manifold at 2.13 m high from the plot surface. The nozzle oscillates so that the spray fans swept across the targeting 1m x 1m plot. The Veejet 80150 spraying nozzle produces large raindrops larger than 2 mm in diameter, and can simulate the high raindrop kinetic energy of natural storm. A targeted rainfall rate is 180 mm/h. Total 25 sprinkling experiments have been conducted on 35-degree hillslopes with varying surface cover. We obtained the minimum infiltration rate of 14 mm/h where the surface cover is very little. The infiltration rates were plotted against the total understory vegetation and dry weight of total surface cover including litter. The infiltration rate increased with the increasing total surface cover, and higher regression coefficient is obtained for the case of the total surface cover. These results will contribute to the future modeling studies of overlandflow occurrences for the catchment scales.

  18. B-737 flight test of curved-path and steep-angle approaches using MLS guidance

    NASA Technical Reports Server (NTRS)

    Branstetter, J. R.; White, W. F.

    1989-01-01

    A series of flight tests were conducted to collect data for jet transport aircraft flying curved-path and steep-angle approaches using Microwave Landing System (MLS) guidance. During the test, 432 approaches comprising seven different curved-paths and four glidepath angles varying from 3 to 4 degrees were flown in NASA Langley's Boeing 737 aircraft (Transport Systems Research Vehicle) using an MLS ground station at the NASA Wallops Flight Facility. Subject pilots from Piedmont Airlines flew the approaches using conventional cockpit instrumentation (flight director and Horizontal Situation Indicator (HSI). The data collected will be used by FAA procedures specialists to develop standards and criteria for designing MLS terminal approach procedures (TERPS). The use of flight simulation techniques greatly aided the preliminary stages of approach development work and saved a significant amount of costly flight time. This report is intended to complement a data report to be issued by the FAA Office of Aviation Standards which will contain all detailed data analysis and statistics.

  19. Beach steepness effects on nonlinear infragravity-wave interactions: A numerical study

    NASA Astrophysics Data System (ADS)

    de Bakker, A. T. M.; Tissier, M. F. S.; Ruessink, B. G.

    2016-01-01

    The numerical model SWASH is used to investigate nonlinear energy transfers between waves for a diverse set of beach profiles and wave conditions, with a specific focus on infragravity waves. We use bispectral analysis to study the nonlinear triad interactions, and estimate energy transfers to determine energy flows within the spectra. The energy transfers are divided into four types of triad interactions, with triads including either one, two or three infragravity-frequency components, and triad interactions solely between sea-swell wave frequencies. The SWASH model is validated with a high-resolution laboratory data set on a gently sloping beach, which shows that SWASH is capable of modeling the detailed nonlinear interactions. From the simulations, we observe that especially the beach slope affects nonlinear infragravity-wave interactions. On a low-sloping beach, infragravity-wave energy dominates the water motion close to shore. Here infragravity-infragravity interactions dominate and generate higher harmonics that lead to the steepening of the infragravity wave and eventually breaking, causing large infragravity energy dissipation. On the contrary, on a steep-sloping beach, sea-swell wave energy dominates the water motion everywhere. Here infragravity frequencies interact with the spectral peak and spread energy to a wide range of higher frequencies, with relatively less infragravity energy dissipation. Although both beach types have different nonlinear interaction patterns during infragravity-wave dissipation, the amount of infragravity-wave reflection can be estimated by a single parameter, the normalized bed slope.

  20. Biosurfactant production by Bacillus subtilis using corn steep liquor as culture medium.

    PubMed

    Gudiña, Eduardo J; Fernandes, Elisabete C; Rodrigues, Ana I; Teixeira, José A; Rodrigues, Lígia R

    2015-01-01

    In this work, biosurfactant production by Bacillus subtilis #573 was evaluated using corn steep liquor (CSL) as culture medium. The best results were obtained in a culture medium consisting of 10% (v/v) of CSL, with a biosurfactant production of about 1.3 g/l. To the best of our knowledge, this is the first report describing biosurfactant production by B. subtilis using CSL as culture medium. Subsequently, the effect of different metals (iron, manganese, and magnesium) on biosurfactant production was evaluated using the medium CSL 10%. It was found that for all the metals tested, the biosurfactant production was increased (up to 4.1, 4.4, and 3.5 g/l for iron, manganese, and magnesium, respectively). When the culture medium was supplemented with the optimum concentration of the three metals simultaneously, the biosurfactant production was increased up to 4.8 g/l. Furthermore, the biosurfactant exhibited a good performance in oil recovery assays when compared with chemical surfactants, which suggests its possible application in microbial enhanced oil recovery or bioremediation. PMID:25705209

  1. A steep-slope transistor based on abrupt electronic phase transition

    PubMed Central

    Shukla, Nikhil; Thathachary, Arun V.; Agrawal, Ashish; Paik, Hanjong; Aziz, Ahmedullah; Schlom, Darrell G.; Gupta, Sumeet Kumar; Engel-Herbert, Roman; Datta, Suman

    2015-01-01

    Collective interactions in functional materials can enable novel macroscopic properties like insulator-to-metal transitions. While implementing such materials into field-effect-transistor technology can potentially augment current state-of-the-art devices by providing unique routes to overcome their conventional limits, attempts to harness the insulator-to-metal transition for high-performance transistors have experienced little success. Here, we demonstrate a pathway for harnessing the abrupt resistivity transformation across the insulator-to-metal transition in vanadium dioxide (VO2), to design a hybrid-phase-transition field-effect transistor that exhibits gate controlled steep (‘sub-kT/q') and reversible switching at room temperature. The transistor design, wherein VO2 is implemented in series with the field-effect transistor's source rather than into the channel, exploits negative differential resistance induced across the VO2 to create an internal amplifier that facilitates enhanced performance over a conventional field-effect transistor. Our approach enables low-voltage complementary n-type and p-type transistor operation as demonstrated here, and is applicable to other insulator-to-metal transition materials, offering tantalizing possibilities for energy-efficient logic and memory applications. PMID:26249212

  2. Sediment dynamics on a steep, megatidal, mixed sand-gravel-cobble beach

    NASA Astrophysics Data System (ADS)

    Hay, A. E.; Zedel, L.; Stark, N.

    2014-08-01

    Results are presented from a pilot study of shore-face sediment dynamics on a steep, poorly sorted, coarse-grained, megatidal beach at the head of the Bay of Fundy, Nova Scotia, Canada. The experiment involved the first field deployment of a prototype wideband, pulse-coherent, bistatic acoustic Doppler profiling system. Measurements of the vertical structure of flow and turbulence above a sloping bed, as well as bed material velocity, demonstrate the capabilities of this instrument vis-à-vis studies of nearshore sediment dynamics at the field scale. The second focus of the paper is the unexpected observation that the surficial sediment median diameter, across the lower two-thirds of the intertidal zone, underwent a pronounced decrease when wave forcing was more energetic, compared to values observed during calmer conditions. The explanation for this result appears to involve the formation - in wave-dominated conditions - of metre-scale wavelength, 20 cm high ripples on the rising tide, which are then planed flat by the swash and/or the shore break on the subsequent ebb.

  3. Biosurfactant production by Bacillus subtilis using corn steep liquor as culture medium

    PubMed Central

    Gudiña, Eduardo J.; Fernandes, Elisabete C.; Rodrigues, Ana I.; Teixeira, José A.; Rodrigues, Lígia R.

    2015-01-01

    In this work, biosurfactant production by Bacillus subtilis #573 was evaluated using corn steep liquor (CSL) as culture medium. The best results were obtained in a culture medium consisting of 10% (v/v) of CSL, with a biosurfactant production of about 1.3 g/l. To the best of our knowledge, this is the first report describing biosurfactant production by B. subtilis using CSL as culture medium. Subsequently, the effect of different metals (iron, manganese, and magnesium) on biosurfactant production was evaluated using the medium CSL 10%. It was found that for all the metals tested, the biosurfactant production was increased (up to 4.1, 4.4, and 3.5 g/l for iron, manganese, and magnesium, respectively). When the culture medium was supplemented with the optimum concentration of the three metals simultaneously, the biosurfactant production was increased up to 4.8 g/l. Furthermore, the biosurfactant exhibited a good performance in oil recovery assays when compared with chemical surfactants, which suggests its possible application in microbial enhanced oil recovery or bioremediation. PMID:25705209

  4. A steep-slope transistor based on abrupt electronic phase transition

    NASA Astrophysics Data System (ADS)

    Shukla, Nikhil; Thathachary, Arun V.; Agrawal, Ashish; Paik, Hanjong; Aziz, Ahmedullah; Schlom, Darrell G.; Gupta, Sumeet Kumar; Engel-Herbert, Roman; Datta, Suman

    2015-08-01

    Collective interactions in functional materials can enable novel macroscopic properties like insulator-to-metal transitions. While implementing such materials into field-effect-transistor technology can potentially augment current state-of-the-art devices by providing unique routes to overcome their conventional limits, attempts to harness the insulator-to-metal transition for high-performance transistors have experienced little success. Here, we demonstrate a pathway for harnessing the abrupt resistivity transformation across the insulator-to-metal transition in vanadium dioxide (VO2), to design a hybrid-phase-transition field-effect transistor that exhibits gate controlled steep (`sub-kT/q') and reversible switching at room temperature. The transistor design, wherein VO2 is implemented in series with the field-effect transistor's source rather than into the channel, exploits negative differential resistance induced across the VO2 to create an internal amplifier that facilitates enhanced performance over a conventional field-effect transistor. Our approach enables low-voltage complementary n-type and p-type transistor operation as demonstrated here, and is applicable to other insulator-to-metal transition materials, offering tantalizing possibilities for energy-efficient logic and memory applications.

  5. Parameterization of intrawave ripple-averaged sediment pickup above steep ripples

    NASA Astrophysics Data System (ADS)

    Amoudry, L. O.; Souza, A. J.; Thorne, P. D.; Liu, P. L.-F.

    2016-01-01

    Near-bed sediment pickup is critical for predictions of intrawave suspension and in turn net sediment transport in coastal models. In the present study, numerical results from a two-dimensional Reynolds-averaged Navier-Stokes model are used to assess the functional relationship of intrawave ripple-averaged sediment pickup above steep ripples. The numerical model provides intrawave time histories of ripple-averaged near-bed velocities and turbulence, which are qualitatively interrogated to determine pickup functional relationships. Several specific sediment pickup formulations are implemented within the numerical model: expressions relating pickup to near-bed velocity or near-bed turbulent kinetic energy via the bed shear stress; and expressions relating pickup to near-bed shear production of turbulent kinetic energy. These are then tested via model-data comparisons of near-bed suspended sediment concentration. The results show that the traditional functions relating sediment pickup to near-bed velocity cannot lead to reasonable intrawave suspension predictions above vortex ripples under a ripple-averaged framework. Instead, relating sediment pickup to near-bed turbulence quantities, such as turbulent kinetic energy or shear production of turbulent kinetic energy, significantly improves the numerical predictions for these conditions.

  6. A Plausible Explanation for the Steep Redshift Decline in Barred Spirals: Dynamically Hot Disks

    NASA Astrophysics Data System (ADS)

    Sheth, Kartik; Melbourne, J.; Kassin, S.; Elmegreen, D. M.; Elmegreen, B. G.; Athanassoula, E.; Abraham, R. G.; Ellis, R. S.; Weiner, B.

    2012-05-01

    We present the first observational evidence for the inhibition of bar formation in dispersion dominated (dynamically hot) galaxies. We compare the presence of galactic structures (bars) and the host galaxy kinematics in a sample of 200 disk galaxies from the All-Wavelength Extended Groth Strip International Survey (AEGIS) and the Deep Extragalactic Evolutionary Probe 2 (DEEP2) survey. We find that bars are preferentially found in galaxies that lie on the Tully-Fisher relationship and are rotation-dominated, whereas few bars are found in galaxies that are dispersion dominated. The data provide at least one explanation for the steep (x3) decline in the bar fraction from z=0 to z=0.84 previously observed in L* disk galaxies in the COSMOS field. In the COSMOS data, the decline in bars is primarily found in the low mass, late-type systems. A proposed explanation for the trend was that at higher redshifts, lower mass systems were more dispersion dominated because they were more easily harassed by the increased interaction and merger rate. The data presented here provides observational support for this hypothesis.

  7. Preventive Dorzolamide-Timolol for Rising Intraocular Pressure During Steep Trendelenburg Position Surgery.

    PubMed

    Molloy, Bonnie Lee; Cong, Xiamei; Watson, Charles

    2016-06-01

    The study purpose was to evaluate preventive use of dorzolamide-timolol ophthalmic solution (Cosopt) during laparoscopic surgery with the patient in steep Trendelenburg (ST) position. Periorbital swelling, venous congestion, and elevated intraocular pressure (IOP) may produce low ocular perfusion. Prompt IOP reduction is important because 30- to 40-minute episodes of acute IOP elevations can result in retinal ganglion cell dysfunction. Dorzolamide-timolol ophthalmic drops reduce IOP and may ameliorate this effect. A double-blind randomized experimental study was conducted to test the effect of dorzolamide-timolol on IOP elevation during laparoscopic surgeries in ST position. Patients were randomly assigned to receive dorzolamide-timolol treatment or balanced salt solution following anesthesia induction. The IOP levels were measured at baseline and 30-minutes intervals throughout surgery. The generalized estimating equations model was used to analyze treatment and time effects and treatment by time interactions. Ninety patients were recruited, with 46 receiving dorzolamide-timolol treatment and 44 receiving balanced salt solution. Statistical analysis revealed significant treatment and time effects and treatment-time interactions on IOP. Patients' IOP was significantly lower in the treatment group than controls (P < .05 to P < .001). Treatment effects were medium to strong. Prophylactic therapy with dorzolamide-timolol significantly reduced IOP of surgical patients during ST positioning. PMID:27501654

  8. Negative Capacitance in Organic/Ferroelectric Capacitor to Implement Steep Switching MOS Devices.

    PubMed

    Jo, Jaesung; Choi, Woo Young; Park, Jung-Dong; Shim, Jae Won; Yu, Hyun-Yong; Shin, Changhwan

    2015-07-01

    Because of the "Boltzmann tyranny" (i.e., the nonscalability of thermal voltage), a certain minimum gate voltage in metal-oxide-semiconductor (MOS) devices is required for a 10-fold increase in drain-to-source current. The subthreshold slope (SS) in MOS devices is, at best, 60 mV/decade at 300 K. Negative capacitance in organic/ferroelectric materials is proposed in order to address this physical limitation in MOS technology. Here, we experimentally demonstrate the steep switching behavior of a MOS device-that is, SS ∼ 18 mV/decade (much less than 60 mV/decade) at 300 K-by taking advantage of negative capacitance in a MOS gate stack. This negative capacitance, originating from the dynamics of the stored energy in a phase transition of a ferroelectric material, can achieve the step-up conversion of internal voltage (i.e., internal voltage amplification in a MOS device). With the aid of a series-connected negative capacitor as an assistive device, the surface potential in the MOS device becomes higher than the applied gate voltage, so that a SS of 18 mV/decade at 300 K is reliably observed. PMID:26103511

  9. Shallow plumbing and eruptive processes of a scoria cone built on steep terrain

    NASA Astrophysics Data System (ADS)

    Harp, A. G.; Valentine, G. A.

    2015-03-01

    Dark Peak (Lunar Crater Volcanic Field, central Nevada, USA) is an eroded Pliocene, monogenetic basaltic volcano that exposes intrusions while preserving some pyroclastic deposits and lavas, allowing reconstruction of the shallow magma feeding system and its relation to eruptive processes. Variably welded agglomerates record Strombolian and Hawaiian fountaining. Dikes fed degassed magma to a bocca on the lower cone slopes and fed a small lava field. The cone was built on the side of a steep ridge with small side drainages, had a maximum diameter of about 1 km, and was ~ 125 m high above the highest point on the paleotopography. The eruption was fed by an ~ 1 km long, narrow (1-3 m) feeder dike that locally flared in the upper tens of meters to form an ~ 30 m wide conduit around which the cone was built. The conduit shape and the transition depth from feeder dike to conduit are consistent with data from other exposed plumbing systems of small volume basaltic volcanoes that were dominated by magmatic volatile-driven eruption styles, supporting inferences that their conduits are relatively shallow features (upper ~ 150 m).

  10. Experimental investigation of turbulent flow in a channel with the backward-facing inclined step

    NASA Astrophysics Data System (ADS)

    Příhoda, Jaromír; Kotek, Michal; Uruba, Václav; Kopecký, Václav; Hladík, Ondřej

    2012-04-01

    The work deals with the experimental investigation of turbulent flow in a closed channel with the backward-facing inclined step. Experiments were carried by means of the PIV optical measuring method in the channel of the rectangular cross-section in the inlet part and with inclined steps of the constant height H mm and various inclination angles for a wide range of the Reynolds number. The attention was paid especially to the separation region behind the step and to the relaxation of the shear layer after the reattachment in the outlet part of the channel. The dependence of the length of the separation region on the Reynolds number was obtained for various step angles. Optical measurements were completed by the measurement of static pressure distribution in the inlet and outlet part of the channel to estimate energy losses.

  11. Aerodynamics of flapping insect wing in inclined stroke plane hovering with ground effect

    NASA Astrophysics Data System (ADS)

    Gowda v, Krishne; Vengadesan, S.

    2014-11-01

    This work presents the time-varying aerodynamic forces and the unsteady flow structures of flapping insect wing in inclined stroke plane hovering with ground effect. Two-dimensional dragonfly model wing is chosen and the incompressible Navier-Stokes equations are solved numerically by using immersed boundary method. The main objective of the present work is to analyze the ground effect on the unsteady forces and vortical structures for the inclined stroke plane motions. We also investigate the influences of kinematics parameters such as Reynolds number (Re), stroke amplitude, wing rotational timing, for various distances between the airfoil and the ground. The effects of aforementioned parameters together with ground effect, on the stroke averaged force coefficients and regimes of force behavior are similar in both normal (horizontal) and inclined stroke plane motions. However, the evolution of the vortex structures which produces the effects are entirely different.

  12. Application of the theory of coupled waves for analysis of inclined reflectors in optical waveguides

    SciTech Connect

    Kolosovskii, E A; Tsarev, A V

    2008-09-30

    A new method for analysing the transmission and scattering of the guided TE mode in an inclined reflector located in an optical waveguide is proposed and studied. The reflection of an inhomogeneous optical beam from the inclined reflector is described semi-analytically for the first time by using the theory of coupled waves and taking into account the interrelation and transformation of energy between all the waves of the discrete and continuous spectra of the optical 2D-waveguide (even and odd guided, radiation, and evanescent waves). The results of calculations of the propagation of light through the inclined reflector in the form of a thin (10-500 nm) homogeneous strip obtained by our method and by the finite difference time domain (FDTD) method are in excellent quantitative agreement. The calculation rate of our method considerably (by one-two orders of magnitude) exceeds that of the FDTD method and our method has a better accuracy. (optical waveguides)

  13. Plastic Limit Load Analysis of Cylindrical Pressure Vessels with Different Nozzle Inclination

    NASA Astrophysics Data System (ADS)

    Prakash, Anupam; Raval, Harit Kishorchandra; Gandhi, Anish; Pawar, Dipak Bapu

    2016-04-01

    Sudden change in geometry of pressure vessel due to nozzle cutout, leads to local stress concentration and deformation, decreasing its strength. Elastic plastic analysis of cylindrical pressure vessels with different inclination angles of nozzle is important to estimate plastic limit load. In the present study, cylindrical pressure vessels with combined inclination of nozzles (i.e. in longitudinal and radial plane) are considered for elastic plastic limit load analysis. Three dimensional static nonlinear finite element analyses of cylindrical pressure vessels with nozzle are performed for incremental pressure loading. The von Mises stress distribution on pressure vessel shows higher stress zones at shell-nozzle junction. Approximate plastic limit load is obtained by twice elastic slope method. Variation in limit pressure with different combined inclination angle of nozzle is analyzed and found to be distinct in nature. Reported results can be helpful in optimizing pressure vessel design.

  14. Distribution of solar irradiance on inclined surfaces caused by moving clouds

    NASA Astrophysics Data System (ADS)

    Tomson, Teolan

    2016-05-01

    The distribution of solar irradiance in shadows of discrete (broken) clouds differs from the distribution calculated for inclined surfaces on the basis of traditional transposition models and changes fast. This phenomenon is studied in this paper. For calculations of dynamic distributions of irradiance on inclined surfaces, a formal point source of direct radiation near the real position of the sun is defined as the source of the "imaginable radiation." This notion is used to create a one-dimensional (1D) simulation model, which allows the fast-changing distribution of irradiance to be calculated. In general, the coincidence of calculated and measured irradiance on inclined surfaces is good. The paper also shows how the current value of the diffuse component of solar radiation can be derived from measurements of total radiation in four differently tilted planes.

  15. Transformation of short-periodic high-inclination orbits of circumsolar submillimeter dust

    SciTech Connect

    Bazei, A.A.; Kramer, E.N.

    1995-11-01

    Disintegration of short-periodic comets is one of the sources of cosmic dust in the Solar System. Initially dust particles move approximately in the orbits of parent comets, in particular, in high-inclination orbits. In a few million years, some of these particles (the smallest ones) go over to the short-periodic, high-inclination orbits due to the Poynting-Robertson effect. The numerical integration of the equations of motion at this stage of evolution gives rise to somewhat surprising results. For example, when integrating the equations of motion as far back as 6000 years from the time of meteor observation, the real meteor particle gains the perihelion distance smaller than the solar radius (!). Our calculations show that the time of falling onto the Sun is shorter for a article moving in a high-inclination orbit. This is due to the superposition of gravitational perturbation and radiation effects.

  16. Numerical investigation of transient flow-mode transition of laminar natural convection in an inclined enclosure

    SciTech Connect

    Tzeng, P.Y.; Soong, C.Y.; Sheu, T.S.

    1997-02-07

    The present work is concerned with a numerical investigation of transient laminar natural convection and the associated flow-mode transition in a two-dimensional rectangular enclosure. Navier-Stokes/Boussinesq equations for fluid flow and energy balance are solved by using the SIMPLE-C algorithm. Air of Pr = 0.71 in a differentially heated enclose of length-to-height aspect ratio As = 4 and at Ra = 5,000 is chosen as the flow model to examine the influences of the inclination. Calculations of time accuracy are performed to investigate the transient procedure of the flow-mode transition with increasing or decreasing inclination. The present results reveal that, at some critical situations, natural convection in inclined enclosures is very sensitive to the change in tilt angle, and the associated heat transfer rates are closely related to the correspondent cellular flow patterns.

  17. Orbital influence on Earth's magnetic field: 100,000-year periodicity in inclination.

    PubMed

    Yamazaki, Toshitsugu; Oda, Hirokuni

    2002-03-29

    A continuous record of the inclination and intensity of Earth's magnetic field, during the past 2.25 million years, was obtained from a marine sediment core of 42 meters in length. This record reveals the presence of 100,000-year periodicity in inclination and intensity, which suggests that the magnetic field is modulated by orbital eccentricity. The correlation between inclination and intensity shifted from antiphase to in-phase, corresponding to a magnetic polarity change from reversed to normal. To explain the observation, we propose a model in which the strength of the geocentric axial dipole field varies with 100,000-year periodicity, whereas persistent nondipole components do not. PMID:11923535

  18. Heat transfer enhancement induced by wall inclination in turbulent thermal convection.

    PubMed

    Kenjereš, Saša

    2015-11-01

    We present a series of numerical simulations of turbulent thermal convection of air in an intermediate range or Rayleigh numbers (10(6)≤Ra≤10(9)) with different configurations of a thermally active lower surface. The geometry of the lower surface is designed in such a way that it represents a simplified version of a mountain slope with different inclinations (i.e., "Λ"- and "V"-shaped geometry). We find that different wall inclinations significantly affect the local heat transfer by imposing local clustering of instantaneous thermal plumes along the inclination peaks. The present results reveal that significant enhancement of the integral heat transfer can be obtained (up to 32%) when compared to a standard Rayleigh-Bénard configuration with flat horizontal walls. This is achieved through combined effects of the enlargement of the heated surface and reorganization of the large-scale flow structures. PMID:26651778

  19. Comparative analysis of trunk muscle activities in climbing of during upright climbing at different inclination angles

    PubMed Central

    Park, Byung-Joon; Kim, Joong-Hwi; Kim, Jang-Hwan; Choi, Byeong-Ho

    2015-01-01

    [Purpose] This study was performed to provide evidence for the therapeutic exercise approach through a compative analysis of muscle activities according to climbing wall inclination. [Subjects and Methods] Twentyfour healthy adult subjects without climbing experience performed static exercises at a therapeutic climbing at with various inclination angles (0°, 10°, 20°), and the activities of the trunk muscles (rectus abdominis, obliquus externus abdominis, obliquus internus abdominis, erector spinae) were measured using surface electromyography (EMG) for 7 seconds. [Results] Significant differences were found between the inclination angles of 10° and 0°, as well as 20° in the rectus abdominis, obliquus internus abdominis, right obliquus externus abdominis, and right erector spinae. [Conclusion] Based on measurements of trunk muscle activity in a static climbing standing position at different angles, significant changes in muscle activity appear to be induced at 10 degrees. Therefore, the results appear to provide clinically relevant evidence. PMID:26644661

  20. Measuring relative-story displacement and local inclination angle using multiple position-sensitive detectors.

    PubMed

    Matsuya, Iwao; Katamura, Ryuta; Sato, Maya; Iba, Miroku; Kondo, Hideaki; Kanekawa, Kiyoshi; Takahashi, Motoichi; Hatada, Tomohiko; Nitta, Yoshihiro; Tanii, Takashi; Shoji, Shuichi; Nishitani, Akira; Ohdomari, Iwao

    2010-01-01

    We propose a novel sensor system for monitoring the structural health of a building. The system optically measures the relative-story displacement during earthquakes for detecting any deformations of building elements. The sensor unit is composed of three position sensitive detectors (PSDs) and lenses capable of measuring the relative-story displacement precisely, even if the PSD unit was inclined in response to the seismic vibration. For verification, laboratory tests were carried out using an Xθ-stage and a shaking table. The static experiment verified that the sensor could measure the local inclination angle as well as the lateral displacement. The dynamic experiment revealed that the accuracy of the sensor was 150 μm in the relative-displacement measurement and 100 μrad in the inclination angle measurement. These results indicate that the proposed sensor system has sufficient accuracy for the measurement of relative-story displacement in response to the seismic vibration. PMID:22163434

  1. Is the earth's dipole actually inclined with respect to the rotation axis?

    NASA Technical Reports Server (NTRS)

    Akasofu, S.-I.; Saito, T.

    1990-01-01

    Planetary exploration by deep space probes in recent years has shown that the dipole moment of some magnetized planets has a surprisingly large inclination angle with respect to the rotation axis. Applying the method developed for the source surface magnetic field of the sun (a spherical surface of 2.5 solar radii), it is suggested that the main dipole of the earth and the magnetized planets may actually be axial (the magnetic moment being parallel or antiparallel to the rotation axis), and that two or three smaller dipoles near the core surface could be responsible for the apparent inclination of the main dipole. In formulating a dynamo theory of the planetary magnetic field, such a possibility should be considered, as well as the inclined dipole case.

  2. Analysis of Flow Characteristics of the Blood Flowing through an Inclined Tapered Porous Artery with Mild Stenosis under the Influence of an Inclined Magnetic Field.

    PubMed

    Srivastava, Neetu

    2014-01-01

    Analytical investigation of MHD blood flow in a porous inclined stenotic artery under the influence of the inclined magnetic field has been done. Blood is considered as an electrically conducting Newtonian fluid. The physics of the problem is described by the usual MHD equations along with appropriate boundary conditions. The flow governing equations are finally transformed to nonhomogeneous second-order ordinary differential equations. This model is consistent with the principles of magnetohydrodynamics. Analytical expressions for the velocity profile, volumetric flow rate, wall shear stress, and pressure gradient have been derived. Blood flow characteristics are computed for a specific set of values of the different parameters involved in the model analysis and are presented graphically. Some of the obtained results show that the flow patterns in converging region (ξ < 0), diverging region (ξ > 0), and nontapered region (ξ = 0) are effectively influenced by the presence of magnetic field and change in inclination of artery as well as magnetic field. There is also a significant effect of permeability on the wall shear stress as well as volumetric flow rate. PMID:24719614

  3. Analysis of Flow Characteristics of the Blood Flowing through an Inclined Tapered Porous Artery with Mild Stenosis under the Influence of an Inclined Magnetic Field

    PubMed Central

    Srivastava, Neetu

    2014-01-01

    Analytical investigation of MHD blood flow in a porous inclined stenotic artery under the influence of the inclined magnetic field has been done. Blood is considered as an electrically conducting Newtonian fluid. The physics of the problem is described by the usual MHD equations along with appropriate boundary conditions. The flow governing equations are finally transformed to nonhomogeneous second-order ordinary differential equations. This model is consistent with the principles of magnetohydrodynamics. Analytical expressions for the velocity profile, volumetric flow rate, wall shear stress, and pressure gradient have been derived. Blood flow characteristics are computed for a specific set of values of the different parameters involved in the model analysis and are presented graphically. Some of the obtained results show that the flow patterns in converging region (ξ < 0), diverging region (ξ > 0), and nontapered region (ξ = 0) are effectively influenced by the presence of magnetic field and change in inclination of artery as well as magnetic field. There is also a significant effect of permeability on the wall shear stress as well as volumetric flow rate. PMID:24719614

  4. Differences in articular-eminence inclination between medieval and contemporary human populations.

    PubMed

    Kranjčić, Josip; Vojvodić, Denis; Žabarović, Domagoj; Vodanović, Marin; Komar, Daniel; Mehulić, Ketij

    2012-08-01

    The articular-eminence inclination is an important element in the biomechanics of the temporomandibular joint and the entire masticatory system; however, very little is known about this inclination in archaeological human populations. Therefore, the aim of this study was to determine the values of, in addition to the differences between, the articular-eminence inclination in medieval and contemporary human populations. The study was carried out on two dry skull groups. The first group consisted of 14 dry skulls from the medieval culture group Bijelo Brdo (BB) of East Croatia, and the other consisted of 137 recent dry skulls from the osteologic collection of the Institute of Anatomy (IA) in Zagreb. All BB skulls were dentulous, whereas the IA skulls were divided into dentulous and edentulous groups. The articular-eminence inclination was measured in relation to the Frankfurt horizontal plane on digital images of the skull's two lateral views using AutoCAD computer software. The mean value of the articular-eminence inclination in the BB sample group (49.57°) was lower, with a statistical significance (p<0.01), than those of the IA dentulous (61.56°), the IA edentulous (62.54°), and all the combined IA (61.99°) specimens. Because the values of the articular-eminence inclination can vary a lot with reference to the number of specimens and the different methods used for measuring, the obtained values yield only orientational information. Further investigations including a larger number of medieval specimens are needed to confirm the results obtained from this study. PMID:22721644

  5. MECHANISM FOR EXCITING PLANETARY INCLINATION AND ECCENTRICITY THROUGH A RESIDUAL GAS DISK

    SciTech Connect

    Chen Yuanyuan; Liu Huigen; Zhao Gang; Zhou Jilin E-mail: zhoujl@nju.edu.cn

    2013-05-20

    According to the theory of Kozai resonance, the initial mutual inclination between a small body and a massive planet in an outer circular orbit is as high as {approx}39. Degree-Sign 2 for pumping the eccentricity of the inner small body. Here we show that with the presence of a residual gas disk outside two planetary orbits, the inclination can be reduced to as low as a few degrees. The presence of the disk changes the nodal precession rates and directions of the planet orbits. At the place where the two planets achieve the same nodal processing rate, vertical secular resonance (VSR) occurs so that the mutual inclination of the two planets will be excited, which might further trigger the Kozai resonance between the two planets. However, in order to pump an inner Jupiter-like planet, the conditions required for the disk and the outer planet are relatively strict. We develop a set of evolution equations, which can fit the N-body simulation quite well but can be integrated within a much shorter time. By scanning the parameter spaces using the evolution equations, we find that a massive planet (10 M{sub J} ) at 30 AU with an inclination of 6 Degree-Sign to a massive disk (50 M{sub J} ) can finally enter the Kozai resonance with an inner Jupiter around the snowline. An inclination of 20 Degree-Sign of the outer planet to the disk is required for flipping the inner one to a retrograde orbit. In multiple planet systems, the mechanism can happen between two nonadjacent planets or can inspire a chain reaction among more than two planets. This mechanism could be the source of the observed giant planets in moderate eccentric and inclined orbits, or hot Jupiters in close-in, retrograde orbits after tidal damping.

  6. Detecting and correcting for paleomagnetic inclination shallowing of sedimentary rocks: A review

    NASA Astrophysics Data System (ADS)

    Li, Yong-Xiang; Kodama, Kenneth

    2016-02-01

    Magnetic anisotropy and the elongation/inclination (E-I) approaches have been increasingly employed as two important means for detecting and correcting the paleomagnetic inclination shallowing in sedimentary rocks that was first recognized sixty years ago. Both approaches are based on certain assumptions, and thus have advantages and intrinsic limitations in investigating shallow inclinations in sedimentary rocks. The E-I approach is relatively easy to use, but it needs a large dataset to adequately sample paleomagnetic directions due to paleosecular variation of the geomagnetic field. Also, slow sediment accumulation rates and local tectonics could lead to under- or over-corrections using the E-I approach. For the magnetic anisotropy technique, labor-intensive, sophisticated laboratory rock magnetic experiments are required in order to accurately determine both bulk magnetic anisotropy of remanence-carrying grains and magnetic anisotropy of an individual particle, i.e., "a" factor, of samples. Our review shows that, despite the intensive laboratory work necessary for applying anisotropy-based inclination corrections, it is worth investing the effort. In addition, the joint use of magnetic susceptibility and remanence anisotropy measurements as well as detailed rock magnetic measurements for determining the particle anisotropy "a" factor have the advantage of retrieving direct evidence of inclination shallowing and correcting for it with high confidence. We caution against use of either of the two approaches without full appreciation of the underlying assumptions and intrinsic limitations of each technique. The use and comparison of both techniques could provide the most robust inclination shallowing correction for sedimentary rocks.

  7. Neural Extrapolation of Motion for a Ball Rolling Down an Inclined Plane

    PubMed Central

    La Scaleia, Barbara; Lacquaniti, Francesco; Zago, Myrka

    2014-01-01

    It is known that humans tend to misjudge the kinematics of a target rolling down an inclined plane. Because visuomotor responses are often more accurate and less prone to perceptual illusions than cognitive judgments, we asked the question of how rolling motion is extrapolated for manual interception or drawing tasks. In three experiments a ball rolled down an incline with kinematics that differed as a function of the starting position (4 different positions) and slope (30°, 45° or 60°). In Experiment 1, participants had to punch the ball as it fell off the incline. In Experiment 2, the ball rolled down the incline but was stopped at the end; participants were asked to imagine that the ball kept moving and to punch it. In Experiment 3, the ball rolled down the incline and was stopped at the end; participants were asked to draw with the hand in air the trajectory that would be described by the ball if it kept moving. We found that performance was most accurate when motion of the ball was visible until interception and haptic feedback of hand-ball contact was available (Experiment 1). However, even when participants punched an imaginary moving ball (Experiment 2) or drew in air the imaginary trajectory (Experiment 3), they were able to extrapolate to some extent global aspects of the target motion, including its path, speed and arrival time. We argue that the path and kinematics of a ball rolling down an incline can be extrapolated surprisingly well by the brain using both visual information and internal models of target motion. PMID:24940874

  8. Impact of inclination on quasi-periodic oscillations from spiral structures

    NASA Astrophysics Data System (ADS)

    Varniere, P.; Vincent, F. H.

    2016-06-01

    Context. Quasi-periodic oscillations (QPOs) are a common feature of the power spectrum of X-ray binaries. Currently it is not possible to unambiguously differentiate the large number of proposed models to explain these phenomena through existing observations. Aims: We investigate the observable predictions of a simple model that generates flux modulation: a spiral instability rotating in a thin accretion disk. This model is motivated by the accretion ejection instability (AEI) model for low-frequency QPOs (LFQPOs). We are particularly interested in the inclination dependence of the observables that are associated with this model. Methods: We develop a simple analytical model of an accretion disk, which features a spiral instability. The disk is assumed to emit blackbody radiation, which is ray-traced to a distant observer. We compute pulse profiles and power spectra as observed from infinity. Results: We show that the amplitude of the modulation associated with the spiral rotation is a strong function of inclination and frequency. The pulse profile is quasi-sinusoidal only at low inclination (face-on source). As a consequence, a higher-inclination geometry leads to a stronger and more diverse harmonic signature in the power spectrum. Conclusions: We present how the amplitude depends on the inclination when the flux modulation comes from a spiral in the disk. We also include new observables that could potentially differentiate between models, such as the pulse profile and the harmonic content of the power spectra of high-inclination sources that exhibit LFQPOs. These might be important observables to explore with existing and new instruments.

  9. Characterizing soil water dynamics on steep hillslopes from long-term lysimeter data

    NASA Astrophysics Data System (ADS)

    Augenstein, Michael; Goeppert, Nadine; Goldscheider, Nico

    2015-10-01

    Understanding soil water dynamics on hillslopes is of crucial importance to the prediction of floods and other hydrological events in mountainous catchments, to the identification of natural vegetation patterns, and to the optimization of agricultural land use. In principle, such information can be obtained from lysimeters, but most experimental lysimeter facilities have been installed on flat terrain. This study presents a long-term and high-resolution investigation of soil moisture, surface and subsurface flow using three large-scale lysimeters on a slope with 23.5° inclination on a landfill site in Karlsruhe, Germany. Data from a 10-year observation period were evaluated for this study, including weekly soil moisture data obtained by neutron probes, continuous discharge data from the land surface and several layers within the soil zone, and hydrometeorological data from a climate station. The results reveal (i) clear temporal and spatial patterns of soil moisture variations down to a depth of 250 cm, (ii) substantially higher discharge and faster percolation rates in the lower part of the lysimeter field, indicating significant downhill flow at various depths within the soil profile, (iii) characteristic threshold values for flow processes in the soil, associated with a hysteresis effect between soil moisture and flow processes. These results can be used as a basis of improved numerical models for the simulation of floods, soil moisture distributions, and vegetation patterns.

  10. Fiber optic inclination detector system having a weighted sphere with reference points

    DOEpatents

    Cwalinski, Jeffrey P.

    1995-01-01

    A fiber optic inclination detector system for determining the angular displacement of an object from a reference surface includes a simple mechanical transducer which requires a minimum number of parts and no electrical components. The system employs a single light beam which is split into two light beams and provided to the transducer. Each light beam is amplitude modulated upon reflecting off the transducer to detect inclination. The power values associated with each of the reflected light beams are converted by a pair of photodetectors into voltage signals, and a microprocessor manipulates the voltage signals to provide a measure of the angular displacement between the object and the reference surface.

  11. Peristaltic transport of a fractional Burgers' fluid with variable viscosity through an inclined tube

    NASA Astrophysics Data System (ADS)

    Rachid, Hassan

    2015-12-01

    In the present study,we investigate the unsteady peristaltic transport of a viscoelastic fluid with fractional Burgers' model in an inclined tube. We suppose that the viscosity is variable in the radial direction. This analysis has been carried out under low Reynolds number and long-wavelength approximations. An analytical solution to the problem is obtained using a fractional calculus approach. Figures are plotted to show the effects of angle of inclination, Reynolds number, Froude number, material constants, fractional parameters, parameter of viscosity and amplitude ratio on the pressure gradient, pressure rise, friction force, axial velocity and on the mechanical efficiency.

  12. Ion Feedback Suppression Using Inclined MCP Holes in a _Single-MCP+Micromegas+Pads_ Detector

    SciTech Connect

    Va'vra, J.; Sumiyoshi, T.; /Tokyo Metropolitan U.

    2005-09-30

    We show that the ion backflow to photocathode can be completely suppressed if one uses inclined MCP holes in a presence of magnetic field. The inclined hole angles are chosen to be aligned with the Lorentz electron angle allowing the electron transmission and amplification, while positive ions, traveling along a different angle, are caught on the MCP hole walls. The detector under investigation is a new gaseous detector structure based on a tandem of two parts, a single MCP (Microchannel) plate, a Micromegas with pad readout. We are aiming to develop a gaseous photon detector with the Bialkali photocathode, however, one could use some ideas in the paper for other types of detectors.

  13. Long-term motion of resonant satellites with arbitrary eccentricity and inclination

    NASA Technical Reports Server (NTRS)

    Nacozy, P. E.; Diehl, R. E.

    1982-01-01

    A first-order, semi-analytical method for the long-term motion of resonant satellites is introduced. The method provides long-term solutions, valid for nearly all eccentricities and inclinations, and for all commensurability ratios. The method allows the inclusion of all zonal and tesseral harmonics of a nonspherical planet. We present here an application of the method to a synchronous satellite including J2 and J22 harmonics. Global, long-term solutions for this problem are given for arbitrary values of eccentricity, argument of perigee and inclination.

  14. Solutions of the motion of synchronous satellites with arbitrary eccentricity and inclination

    NASA Technical Reports Server (NTRS)

    Nacozy, P. E.; Diehl, R. E.

    1975-01-01

    A first order, semianalytical theory for the long term motion of resonant satellites is presented. The theory is valid for all eccentricities and inclinations and for all commensurability ratios. The method allows the inclusion of all the zonal and tesseral harmonics as well as luni solar perturbations and radiation pressure. The method is applied to a synchronous satellite including only the J sub 2 and J sub 22 harmonics. Global, long term solutions for this problem, eccentricity, argument of perigee, and inclination are obtained.

  15. Projectile motion on an inclined misty surface: II. Scoring a goal

    NASA Astrophysics Data System (ADS)

    Foong, S. K.; Lim, C. C.; Kuppan, L.

    2009-05-01

    Feedback on part I of this series (Ho et al 2009 Phys. Educ. 44 253) motivated us to make hitting the target more interesting with a simple innovation: changing the target to a ring shaped hoop or goalpost and shooting for it in the 'air', as if playing basketball on the inclined plane. We discuss in detail the demarcation of the boundary (safety parabola) between the accessible region and the inaccessible region for a projectile on the surface of the inclined plane, and derive the angle of projection for scoring a goal. We also consider the orientation of the rings for maximizing the chance of scoring.

  16. Effect of transient pinning on stability of drops sitting on an inclined plane.

    PubMed

    Berejnov, Viatcheslav; Thorne, Robert E

    2007-06-01

    We report on new instabilities of the quasistatic equilibrium of water drops pinned by a hydrophobic inclined substrate. The contact line of a statically pinned drop exhibits three transitions of partial depinning: depinning of the advancing and receding parts of the contact line and depinning of the entire contact line leading to the drop's translational motion. We find a region of parameters where the classical Macdougall-Ockrent-Frenkel approach fails to estimate the critical volume of the statically pinned inclined drop. PMID:17677358

  17. Mixed Convection Flow of Nanofluid in Presence of an Inclined Magnetic Field

    PubMed Central

    Noreen, Saima; Ahmed, Bashir; Hayat, Tasawar

    2013-01-01

    This research is concerned with the mixed convection peristaltic flow of nanofluid in an inclined asymmetric channel. The fluid is conducting in the presence of inclined magnetic field. The governing equations are modelled. Mathematical formulation is completed through long wavelength and low Reynolds number approach. Numerical solution to the nonlinear analysis is made by shooting technique. Attention is mainly focused to the effects of Brownian motion and thermophoretic diffusion of nanoparticle. Results for velocity, temperature, concentration, pumping and trapping are obtained and analyzed in detail. PMID:24086276

  18. Experimental and theoretical analysis on the effect of inclination on metal powder sintered heat pipe radiator with natural convection cooling

    NASA Astrophysics Data System (ADS)

    Cong, Li; Qifei, Jian; Wu, Shifeng

    2016-06-01

    An experimental study and theoretical analysis of heat transfer performance of a sintered heat pipe radiator that implemented in a 50 L domestic semiconductor refrigerator have been conducted to examine the effect of inclination angle, combined with a minimum entropy generation analysis. The experiment results suggest that inclination angle has influences on both the evaporator and condenser section, and the performance of the heat pipe radiator is more sensitive to the inclination change in negative inclined than in positive inclined position. When the heat pipe radiator is in negative inclination angle position, large amplitude of variation on the thermal resistance of this heat pipe radiator is observed. As the thermal load is below 58.89 W, the influence of inclination angle on the overall thermal resistance is not that apparent as compared to the other three thermal loads. Thermal resistance of heat pipe radiator decreases by 82.86 % in inclination of 60° at the set of 138.46 W, compared to horizontal position. Based on the analysis results in this paper, in order to achieve a better heat transfer performance of the heat pipe radiator, it is recommended that the heat pipe radiator be mounted in positive inclination angle positions (30°-90°), where the condenser is above the evaporator.

  19. Bedload transport in steep glacier-fed streams: from incipient motion to floods

    NASA Astrophysics Data System (ADS)

    Comiti, Francesco; Dell'Agnese, Andrea; Lucia, Ana; Vignoli, Gianluca; Simoni, Silvia; Bertoldi, Walter; Mao, Luca; Macconi, Pierpaolo; Mazzorana, Bruno; Dinale, Roberto

    2015-04-01

    The current understanding of bedload dynamics in mountain channels is rather scarce, and the capability to predict it over a range of discharges and under different morphological conditions is still very poor despite the headways made during the last decade. Indeed, there has been an increased recognition of the highly stochastic nature of bedload transport in steep streams, especially at low to medium flows (i.e. up to ordinary events). On the other hand, considerable efforts have been made to model the effective energy available for bedload in steep channels, in order to reduce the large overestimation in bedload rates produced by transport capacity equations. Nonetheless, because high-gradient channels are notoriously sediment supply-limited, largely varying bedload rates can be observed at the same stream cross-section under nearly identical morphological and hydraulic conditions, as a consequence of different sediment supply regimes/events. Therefore, the use of a single bedload transport equation even for the same stream is becoming strongly questioned by researchers, whereas most river agencies and consultants - and numerical models - still rely on "classical" transport capacity equations. Remarkably, glacial streams offer the possibility to investigate how seasonal changes in sediment supply at the basin scale - deriving from the periglacial and glacial areas - affects bedload transport rates in the main channel. However, little quantitative bedload data from these systems are available. This contribution intends to share the recent results obtained in two glaciarized basins in the Eastern Italian Alps, which range from about 10 km2 (upper Saldur river basin) to 130 km2 (Sulden river basin) in drainage area. Different monitoring methodologies encompassing PIT-tagged clasts tracking (by both portable and stationary antennas), geophone plates, acoustic pipe sensor and direct sampling by portable traps have been deployed in these two mountain streams. Our

  20. Seismic component of the STEEP project, Alaska: Results of the first field season

    NASA Astrophysics Data System (ADS)

    Hansen, R. A.; Estes, S.; Stachnik, J.; Lafevers, M.; Roush, J.; Sanches, R.; Fuerst, E.; Sandru, J.; Ruppert, N.; Pavlis, G.; Bauer, M.

    2005-12-01

    STEEP (SainT Elias Erosion/tectonics Project) is a five year, multi-disciplinary study that addresses evolution of the highest coastal mountain range on Earth - the St. Elias Mountains of southern Alaska and northwestern Canada. The overall goal of the project is to develop a comprehensive model for the St. Elias orogen that accounts for the interaction of regional plate tectonic processes, structural development, and rapid erosion. The seismic component of this project includes passive seismic experiment utilizing the IRIS PASSCAL Program instruments. The total project consists of 22 new, telemetered, digital broad band seismic stations, most accessible by helicopter only. There are 12 existing short period stations in the area. Eight new stations were installed in the coastal region in June 2005. Freewave IP radios provide the telemetry to the newly installed VSAT at the Bering Glacier camp site. The challenge was to find ice-free locations, on bedrock, large enough to install equipment and still have a helicopter landing zone nearby. The stations consist of Quanterra Q330 digitizers with baler, a STS-2 seismometer installed in a vault, a Freewave IP radio, a Scala 900 Mhz antenna, twenty 100 AH rechargeable batteries with a 2400AH backup Celair primary battery, and three solar panels mounted on hut. The acquired data is recorded in real time at the Alaska Earthquake Information Center located in Fairbanks and is incorporated into the standard data processing procedures. High quality data allows for more reliable automatic earthquake detections in the region with lower magnitude threshold. In addition to tectonic earthquakes, glacial events that occur within the vast ice fields of the region are also regularly detected. Broadband instruments complement regional broadband network for more reliable calculations of the regional moment tensors.