Run-up of Tsunamis in the Gulf of Mexico caused by the Chicxulub Impact Event

NASA Astrophysics Data System (ADS)

Weisz, R.; Wünnenmann, K.; Bahlburg, H.

2003-04-01

The Chicxulub impact event can be investigated on (1) local, (2) regional and in (3) global scales. Our investigations focus on the regional scale, especially on the run-up of tsunami waves on the coast around the Gulf of Mexico caused by the impact. An impact produces two types of tsunami waves: (1) the rim wave, (2) the collapse wave. Both waves propagate over long distances and reach coastal areas. Depending on the tsunami wave characteristics, they have a potentionally large influence on the coastal areas. Run-up distance and run-up height can be used as parameters for assessing this influence. To calculate these parameters, we are using a multi-material hydrocode (SALE) to simulate the generation of the tsunami wave, a non-linear shallow water approach for the propagation, and we implemented a special open boundary for considering the run-up of tsunami waves. With the help of the one-dimensional shallow water approach, we will give run-up heights and distances for the coastal area around the Gulf of Mexico. The calculations are done along several sections from the impact site towards the coast. These are a first approximation to run-up calculations for the entire coast of the Gulf of Mexico. The bathymetric data along the sections, used in the wave propagation and run-up, correspond to a linearized bathymetry of the recent Gulf of Mexico. Additionally, we will present preliminary results from our first two-dimensional experiments of propagation and run-up. These results will be compared with the one-dimensional approach.

Swell-generated Set-up and Infragravity Wave Propagation Over a Fringing Coral Reef: Implications for Wave-driven Inundation of Atoll Islands

NASA Astrophysics Data System (ADS)

Cheriton, O. M.; Storlazzi, C. D.; Rosenberger, K. J.; Quataert, E.; van Dongeren, A.

2014-12-01

The Republic of the Marshall Islands is comprised of 1156 islands on 29 low-lying atolls with a mean elevation of 2 m that are susceptible to sea-level rise and often subjected to overwash during large wave events. A 6-month deployment of wave and tide gauges across two shore-normal sections of north-facing coral reef on the Roi-Namur Island on Kwajalein Atoll was conducted during 2013-2014 to quantify wave dynamics and wave-driven water levels on the fringing coral reef. Wave heights and periods on the reef flat were strongly correlated to the water levels. On the fore reef, the majority of wave energy was concentrated in the incident band (5-25 s); due to breaking at the reef crest, however, the wave energy over the reef flat was dominated by infragravity-band (25-250 s) motions. Two large wave events with heights of 6-8 m at 15 s over the fore reef were observed. During these events, infragravity-band wave heights exceeded the incident band wave heights and approximately 1.0 m of set-up was established over the innermost reef flat. This set-up enabled the propagation of large waves across the reef flat, reaching maximum heights of nearly 2 m on the innermost reef flat adjacent to the toe of the beach. XBEACH models of the instrument transects were able to replicate the incident waves, infragravity waves, and wave-driven set-up across the reef when the hydrodynamic roughness of the reef was correctly parameterized. These events led to more than 3 m of wave-driven run-up and inundation of the island that drove substantial morphological change to the beach face.

Asymmetry between the Dominant and Non-Dominant Legs in the Kinematics of the Lower Extremities during a Running Single Leg Jump in Collegiate Basketball Players.

PubMed

Sugiyama, Takashi; Kameda, Mai; Kageyama, Masahiro; Kiba, Kazufusa; Kanehisa, Hiroaki; Maeda, Akira

2014-12-01

The present study aimed to clarify the asymmetry between the dominant (DL) and non-dominant takeoff legs (NDL) in terms of lower limb behavior during running single leg jumps (RSJ) in collegiate male basketball players in relation to that of the jump height. Twenty-seven players performed maximal RSJ with a 6 m approach. Three-dimensional kinematics data during RSJ was collected using a 12 Raptor camera infrared motion analysis system (MAC 3D system) at a sampling frequency of 500 Hz. The symmetry index in the jump heights and the kinematics variables were calculated as {2 × (DL - NDL) / (DL + NDL)} × 100. The run-up velocity was similar between the two legs, but the jump height was significantly higher in the DL than in the NDL. During the takeoff phase, the joint angles of the ankle and knee were significantly larger in the DL than the NDL. In addition, the contact time for the DL was significantly shorter than that for the NDL. The symmetry index of the kinematics for the ankle joint was positively correlated with that of jump height, but that for the knee joint was not. The current results indicate that, for collegiate basketball players, the asymmetry in the height of a RSJ can be attributed to that in the joint kinematics of the ankle during the takeoff phase, which may be associated with the ability to effectively transmit run-up velocity to jump height. Key pointsAsymmetry of height during running single leg jump between two legs is due to the behavior of the ankle joint (i.e. stiffer the ankle joint and explosive bounding).The dominant leg can transmit run-up velocity into the vertical velocity at takeoff phase to jump high compared with the non-dominant leg.Basketball players who have a greater asymmetry of the RSJ at the collegiate level could be assessed as non-regulars judging by the magnitude of asymmetry.

76 FR 22719 - Cape Wind Energy Project

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-22

... with a maximum blade height of 440 feet (ft), to be constructed in a grid pattern on the OCS in.... The proposed submarine transmission cable system (115 kilovolt) running from the ESP to the landfall...

Rearfoot eversion has indirect effects on plantar fascia tension by changing the amount of arch collapse.

PubMed

Lee, Sae Yong; Hertel, Jay; Lee, Sung Cheol

2010-01-01

Rearfoot eversion motion and arch height are believed to contribute to increased tension on the plantar fascia and arch collapse during gait but the specifics of these relationships are not clear. To examine the relationships among static arch height, rearfoot eversion, dynamic arch height, and plantar fascia tension. 28 healthy males participated. After static arch height was measured, the subjects were asked to run at 4.5m/s while frontal plane rearfoot motion, dynamic arch height, and ground reaction forces were collected. The relationships among variables were examined with bivariate correlations and path analysis. The results indicated a high correlation between dynamic arch height and static arch height (r=0.642), plantar fascia tension (r=-0.797), and maximum rearfoot eversion motion during gait (r=-0.518). The path analysis model without the direct rearfoot eversion effect explained 81.2% of the variance in plantar fascia tension, while the model with the direct rearfoot eversion effect explained 82.1% of the variance in plantar fascia tension. Including the indirect effect of maximum rearfoot eversion motion on plantar fascia tension through control of dynamic arch height is the model that best explains the interrelationships of these foot characteristics. The amount of maximum rearfoot eversion motion itself is not a good predictor of plantar fascia tension, however, together with the arch height, maximum rearfoot eversion motion is a good predictor because it has a pronounced indirect effect on plantar fascia tension. Copyright 2010. Published by Elsevier Ltd.

The 2004 Indian Ocean Tsunami in Maldives: waves and disaster affected by shape of coral reefs and islands

NASA Astrophysics Data System (ADS)

Kan, H.; Ali, M.; Riyaz, M.

2005-12-01

In Maldives, 39 islands are significantly damaged among 200 inhabited islands and nearly a third of the Maldivian people are severely affected by the Indian Ocean Tsunami in 26 December 2004. We surveyed tsunami impact in 43 islands by measuring island topography and run-up height, interview to local people and mapping of the flooded and destructed areas. The differences in tsunami height and disaster corresponding to the atoll shape and island topography are observed. In the northern atolls, atoll rims consist of many ring-shaped reefs, i.e. miniature atolls called `faro', and interrupted many channels between them. The interrupted atoll rim may play an important role to reducing tsunami run-up height. Severe damage was not observed in the eastern coast of the islands. Beach ridge also contribute to the protection against tsunami. However, in some islands, houses beside the lagoon are damaged by backwashing floodwater from the lagoon. Water marks show the run-up height of -1.8m above MSL. The lagoon water-level seems to set-up by tsunami which permeates into the lagoon through the interrupted atoll rim. The disaster was severe at the southern atolls of Meemu, Thaa and Laamu. The higher run-up heights of up to 3.2m above MSL and enormous building damages were observed at the islands on the eastern atoll rims. The continuous atoll rim of these atolls may reinforce tsunami impact at the eastern islands. In addition, tsunami surge washed the islands totally because of low island topography without beach ridge. Significant floodwater from lagoon was not observed in these atolls. It seems the lagoon water-level was not set-up largely. The continuous atoll rim reduces the tsunami influence to the lagoon and the western side of the atolls. The continuity of atoll rim is probably the major factor to cause the difference in water movement, i.e. tsunami run-up and lagoon set-up, which affects the disaster in the islands. Beach ridge contribute to reduce the tsunami impact to the settlement and agricultural land. Our results may elucidate secure atoll and island type to mitigate the risk of future tsunamis on atoll nations/districts in the Pacific and the Indian Ocean.

Sheet-gravel evidence for a late Holocene tsunami run-up on beach dunes, Great Barrier Island, New Zealand

NASA Astrophysics Data System (ADS)

Nichol, Scott L.; Lian, Olav B.; Carter, Charles H.

2003-01-01

A semi-continuous sheet of granule to cobble-size clasts forms a distinctive deposit on sand dunes located on a coastal barrier in Whangapoua Bay, Great Barrier Island, New Zealand. The gravel sheet extends from the toe of the foredune to 14.3 m above mean sea level and 200 m landward from the beach. Clasts are rounded to sub-rounded and comprise lithologies consistent with local bedrock. Terrestrial sources for the gravel are considered highly unlikely due to the isolation of the dunes from hillslopes and streams. The only source for the clasts is the nearshore to inner shelf of Whangapoua Bay, where gravel sediments have been previously documented. The mechanism for transport of the gravel is unlikely to be storm surge due to the elevation of the deposit; maximum-recorded storm surge on this coast is 0.8 m above mean high water spring tide. Aeolian processes are also discounted due to the size of clasts and the elevation at which they occur. Tsunami is therefore considered the most probable mechanism for gravel transport. Minimum run-up height of the tsunami was 14.3 m, based on maximum elevation of gravel deposits. Optical ages on dune sands beneath and covering the gravel allow age bracketing to 0-4.7 ka. Within this time frame, numerous documented regional seismic and volcanic events could have generated the tsunami, notably submarine volcanism along the southern Kermadec arc to the east-southeast of Great Barrier Island where large magnitude events are documented for the late Holocene. Radiocarbon ages on shell from Maori middens that appear to have been reworked by tsunami run-up constrain the age of this event to post ca. 1400 AD. Regardless of the precise age of this event, the well-preserved nature of the Whangapoua gravel deposit provides for an improved understanding of the high degree of spatial variability in tsunami run-up.

Assessing Potential Tsunami Sources for Extreme Wave Deposits on Southwest Isla de Mona, Puerto Rico, Using Numerical Simulations and Hydrodynamic Boulder Transport Equations

NASA Astrophysics Data System (ADS)

Matos-Llavona, P. I.; Lopez, A. M.; Jaffe, B. E.; Richmond, B. M.

2017-12-01

Extreme waves on coastlines pose a threat to human life, habitats, and critical coastal infrastructure. Geological evidence of extreme waves can provide valuable information on the magnitude, frequency, wave characteristics and source of past events, thus improving coastal hazard assessment. Reef-rock boulders, as much as 5m in diameter, are found up to 500 m inland on the southwestern coast of Isla de Mona, Puerto Rico. These boulders were emplaced 4000 years ago based on age dates from encrusting corals (Taggart et al., 1993). This study aims to identify an event capable of forming these deposits. For this, a numerical model of the 1918 Mona Passage tsunami was constructed using the New Evolution of Ocean Wave (NEOWAVE) model with three nested grids of 3, 1 and 1/3 arc-second resolution, respectively. A second simulation of a submarine landslide (1km3 volume) located 300m from the southwestern Mona shoreline was run using 3D Tsunami Solution Using Navier-Stokes Algorithm with Multiple Interfaces (TSUNAMI3D). The resulting inundation and wave heights at the shoreline are compared to minimum wave heights required to initiate transport (sub-aerial and submerged) of measured boulders and idealized cubic boulders with varying volumes. The 1918 Mona Passage tsunami simulation shows no significant inundation on the SSW Mona coast and a maximum wave height of 1.3m, which is below the minimum wave height required to initiate transport of a 1m diameter boulder. This result suggests that a tsunami like the one generated in 1918 is not capable of transporting even the smaller boulders. However, the submarine landslide generated extensive inundation on the SW coast with maximum wave height of 10m at the shoreline, 20m run-up, and 900m inundation distance. This is greater than the minimum wave height needed to initiate transport in both submerged and subaerial pre-transport settings; therefore, a submarine landslide with characteristics of the modeled landslide can form the boulder deposits observed. Marine geological surveys providing dates of landslides found in deep waters south of Mona Island will be required to validate this hypothesis. Taggart, B.E. et al., 1993, Holocene reef-rock boulders on Isla de Mona, Puerto Rico, transported by a hurricane or seismic sea wave. GSA, Abstract with Programs v. 25(6), p. 61.

Reduced prosthetic stiffness lowers the metabolic cost of running for athletes with bilateral transtibial amputations.

PubMed

Beck, Owen N; Taboga, Paolo; Grabowski, Alena M

2017-04-01

Inspired by the springlike action of biological legs, running-specific prostheses are designed to enable athletes with lower-limb amputations to run. However, manufacturer's recommendations for prosthetic stiffness and height may not optimize running performance. Therefore, we investigated the effects of using different prosthetic configurations on the metabolic cost and biomechanics of running. Five athletes with bilateral transtibial amputations each performed 15 trials on a force-measuring treadmill at 2.5 or 3.0 m/s. Athletes ran using each of 3 different prosthetic models (Freedom Innovations Catapult FX6, Össur Flex-Run, and Ottobock 1E90 Sprinter) with 5 combinations of stiffness categories (manufacturer's recommended and ± 1) and heights (International Paralympic Committee's maximum competition height and ± 2 cm) while we measured metabolic rates and ground reaction forces. Overall, prosthetic stiffness [fixed effect (β) = 0.036; P = 0.008] but not height ( P ≥ 0.089) affected the net metabolic cost of transport; less stiff prostheses reduced metabolic cost. While controlling for prosthetic stiffness (in kilonewtons per meter), using the Flex-Run (β = -0.139; P = 0.044) and 1E90 Sprinter prostheses (β = -0.176; P = 0.009) reduced net metabolic costs by 4.3-4.9% compared with using the Catapult prostheses. The metabolic cost of running improved when athletes used prosthetic configurations that decreased peak horizontal braking ground reaction forces (β = 2.786; P = 0.001), stride frequencies (β = 0.911; P < 0.001), and leg stiffness values (β = 0.053; P = 0.009). Remarkably, athletes did not maintain overall leg stiffness across prosthetic stiffness conditions. Rather, the in-series prosthetic stiffness governed overall leg stiffness. The metabolic cost of running in athletes with bilateral transtibial amputations is influenced by prosthetic model and stiffness but not height. NEW & NOTEWORTHY We measured the metabolic rates and biomechanics of five athletes with bilateral transtibial amputations while running with different prosthetic configurations. The metabolic cost of running for these athletes is minimized by using an optimal prosthetic model and reducing prosthetic stiffness. The metabolic cost of running was independent of prosthetic height, suggesting that longer legs are not advantageous for distance running. Moreover, the in-series prosthetic stiffness governs the leg stiffness of athletes with bilateral leg amputations.

75 FR 3922 - Notice of Availability of the Revised Minerals Management Service Documentation of Section 106...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-25

... megawatt (MW) wind turbine generators, each with a maximum blade height of 440 feet, to be arranged in a... cables running through Massachusetts territorial waters ashore. For reference, the northernmost turbines...

75 FR 37311 - Airplane and Engine Certification Requirements in Supercooled Large Drop, Mixed Phase, and Ice...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-29

... maximum time interval between any engine run-ups from idle and the minimum ambient temperature associated with that run-up interval. This limitation is necessary because we do not currently have any specific requirements for run-up procedures for engine ground operation in icing conditions. The engine run-up procedure...

A Study of the Effects of Seafloor Topography on Tsunami Propagation

NASA Astrophysics Data System (ADS)

Ohata, T.; Mikada, H.; Goto, T.; Takekawa, J.

2011-12-01

For tsunami disaster mitigation, we consider the phenomena related to tsunami in terms of the generation, propagation, and run-up to the coast. With consideration for these three phenomena, we have to consider tsunami propagation to predict the arrival time and the run-up height of tsunami. Numerical simulations of tsunami that propagates from the source location to the coast have been widely used to estimate these important parameters. When a tsunami propagates, however, reflected and scattered waves arrive as later phases of tsunami. These waves are generated by the changes of water depth, and could influence the height estimation, especially in later phases. The maximum height of tsunami could be observed not as the first arrivals but as the later phases, therefore it is necessary to consider the effects of the seafloor topography on tsunami propagation. Since many simulations, however, mainly focus on the prediction of the first arrival times and the initial height of tsunami, it is difficult to simulate the later phases that are important for the tsunami disaster mitigation in the conventional methods. In this study, we investigate the effects of the seafloor topography on tsunami propagation after accommodating a tsunami simulation to the superposition of reflected and refracted waves caused by the smooth changes of water depths. Developing the new numerical code, we consider how the effects of the sea floor topography affect on the tsunami propagation, comparing with the tsunami simulated by the conventional method based on the liner long wave theory. Our simulation employs the three dimensional in-equally spaced grids in finite difference method (FDM) to introduce the real seafloor topography. In the simulation, we import the seafloor topography from the real bathymetry data near the Sendai-Bay, off the northeast Tohoku region, Japan, and simulate the tsunami propagation over the varying seafloor topography there. Comparing with the tsunami simulated by the conventional method based on the liner long wave theory, we found that the amplitudes of tsunamis are different from each other for the two simulations. The degree of the amplification of the height of tsunami in our method is larger than that in the conventional one. The height of the later phases of the tsunamis shows the discrepancy between the two results. We would like to conclude that the real changes of water depth affect the prediction of tsunami propagation and the maximum height. Because of the effects of the seafloor topography, the amplitude of the later phases is sometimes larger than the former ones. Due to the inclusion of such effects by the real topography, we believe our method lead to a higher accuracy of prediction of tsunami later phases, which would be effective for tsunami disaster mitigation.

75 FR 23798 - Environmental Assessment Prepared for Proposed Cape Wind Energy Project in Nantucket Sound...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-04

... calls for 130, 3.6 megawatt (MW) wind turbine generators, each with a maximum blade height of 440 feet... transmission cables, which would run through Massachusetts' territory to shore. For reference, the northernmost...

75 FR 10500 - Environmental Assessment Prepared for Proposed Cape Wind Energy Project in Nantucket Sound, MA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-08

... calls for 130, 3.6 megawatt (MW) wind turbine generators, each with a maximum blade height of 440 feet... in Federal waters, aside from transmission cables running through Massachusetts waters ashore. For...

Deterministic approach for multiple-source tsunami hazard assessment for Sines, Portugal

NASA Astrophysics Data System (ADS)

Wronna, M.; Omira, R.; Baptista, M. A.

2015-11-01

In this paper, we present a deterministic approach to tsunami hazard assessment for the city and harbour of Sines, Portugal, one of the test sites of project ASTARTE (Assessment, STrategy And Risk Reduction for Tsunamis in Europe). Sines has one of the most important deep-water ports, which has oil-bearing, petrochemical, liquid-bulk, coal, and container terminals. The port and its industrial infrastructures face the ocean southwest towards the main seismogenic sources. This work considers two different seismic zones: the Southwest Iberian Margin and the Gloria Fault. Within these two regions, we selected a total of six scenarios to assess the tsunami impact at the test site. The tsunami simulations are computed using NSWING, a Non-linear Shallow Water model wIth Nested Grids. In this study, the static effect of tides is analysed for three different tidal stages: MLLW (mean lower low water), MSL (mean sea level), and MHHW (mean higher high water). For each scenario, the tsunami hazard is described by maximum values of wave height, flow depth, drawback, maximum inundation area and run-up. Synthetic waveforms are computed at virtual tide gauges at specific locations outside and inside the harbour. The final results describe the impact at the Sines test site considering the single scenarios at mean sea level, the aggregate scenario, and the influence of the tide on the aggregate scenario. The results confirm the composite source of Horseshoe and Marques de Pombal faults as the worst-case scenario, with wave heights of over 10 m, which reach the coast approximately 22 min after the rupture. It dominates the aggregate scenario by about 60 % of the impact area at the test site, considering maximum wave height and maximum flow depth. The HSMPF scenario inundates a total area of 3.5 km2.

Tsunami Risk Assessment Modelling in Chabahar Port, Iran

NASA Astrophysics Data System (ADS)

Delavar, M. R.; Mohammadi, H.; Sharifi, M. A.; Pirooz, M. D.

2017-09-01

The well-known historical tsunami in the Makran Subduction Zone (MSZ) region was generated by the earthquake of November 28, 1945 in Makran Coast in the North of Oman Sea. This destructive tsunami killed over 4,000 people in Southern Pakistan and India, caused great loss of life and devastation along the coasts of Western India, Iran and Oman. According to the report of "Remembering the 1945 Makran Tsunami", compiled by the Intergovernmental Oceanographic Commission (UNESCO/IOC), the maximum inundation of Chabahar port was 367 m toward the dry land, which had a height of 3.6 meters from the sea level. In addition, the maximum amount of inundation at Pasni (Pakistan) reached to 3 km from the coastline. For the two beaches of Gujarat (India) and Oman the maximum run-up height was 3 m from the sea level. In this paper, we first use Makran 1945 seismic parameters to simulate the tsunami in generation, propagation and inundation phases. The effect of tsunami on Chabahar port is simulated using the ComMIT model which is based on the Method of Splitting Tsunami (MOST). In this process the results are compared with the documented eyewitnesses and some reports from researchers for calibration and validation of the result. Next we have used the model to perform risk assessment for Chabahar port in the south of Iran with the worst case scenario of the tsunami. The simulated results showed that the tsunami waves will reach Chabahar coastline 11 minutes after generation and 9 minutes later, over 9.4 Km2 of the dry land will be flooded with maximum wave amplitude reaching up to 30 meters.

View from intersection. Ninestory reinforced concrete building infilled with brick. ...

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

View from intersection. Nine-story reinforced concrete building infilled with brick. The street facades on beaubien and east grand are faced with stone accents and elaborate brick work. Brick pilasters run the entire height of the building. Steel tiebacks are apparent running up the height of the building on the east side. The large tower appears at the northeast and southeast corners - Detroit Storage Company, 2937 East Grand Boulevard, Detroit, MI

Small Landslides in Aram-Ares Channel, Mars

NASA Astrophysics Data System (ADS)

Kraal, E. R.; Shoup, J.

2014-12-01

An east-west channel (located at 341°E and 3°N) connects Aram Chaos to Ares Valles. The valley is approximately 80 km long, 12 km wide, and 1.5 km deep. The channel is filled with a series of slope failures or landslides that form lobate aprons covering the valley floor. Preliminary studies of the valley on the north wall of the valley (south facing) characterized 6 landslides using gridded MOLA topography from JMARS, including area, drop height and run out distance. These relatively small landslides have surface areas ranging from 5.6 to 55 km2. Their aprons run out ~ 10 km, often covering the entire width of the valley floor. Drop height was measured using both maximum and minimum estimates due to resolution limits of the topography and ranged from 1200 to 2200 meters. Using the drop height and run out distance, we determine the coefficient of friction and maximum velocity for two of the landslides using previously established landslide equations based on physical properties. The coefficient of friction for the landslide events ranged from 0.5 to 1.5, which corresponds to a maximum landslide velocity of 87 m/s2 to 96 m/s2. The variations in the coefficients may be due to landslides size, relative size, or possible volatile or ice content. Preliminary geomorphic surface mapping is currently under way to identify the relationship between the aprons and the channel floor, relative age of the landslides, and other characteristics. Initial analysis indicates the channel floor and depositional aprons have experienced deflation and eolian processes and aprons have a variable level of erosion indicating that the landslides did not form during a single event.

Fundamentals of Zoological Scaling.

ERIC Educational Resources Information Center

Lin, Herbert

1982-01-01

The following animal characteristics are considered to determine how properties and characteristics of various systems change with system size (scaling): skeletal weight, speed of running, height and range of jumping, food consumption, heart rate, lifetime, locomotive efficiency, frequency of wing-flapping, and maximum sizes of flying and hovering…

Near-field survey of the 1946 Aleutian tsunami on Unimak and Sanak Islands

USGS Publications Warehouse

Okal, E.A.; Plafker, G.; Synolakis, C.E.; Borrero, J.C.

2003-01-01

The 1946 Aleutian earthquake stands out among tsunamigenic events because it generated both very high run-up near the earthquake source region and a destructive trans-Pacific tsunami. We obtained new data on the distribution of its tsunami in the near field along south-facing coasts between Unimak Pass on the west and Sanak Island on the east by measuring the height of driftwood and beach materials that were deposited by the tsunami above the extreme storm tide level. Our data indicate that (1) the highest measured run-up, which is at the Scotch Cap lighthouse, was 42 m above tide level or about 37 m above present storm tide elevation; (2) run-up along the rugged coast from Scotch Cap for 12 km northwest to Sennett Point is 12-18 m, and for 30 km east of Scotch Cap to Cape Lutke it is 24-42 m; (3) run-up along the broad lowlands bordering Unimak Bight is 10-20 m, and in-undation is locally more than 2 km; (5) run-up diminishes to 8 m or less at the southeast corner of Unimak Island; (6) no evidence was found for run-up above present storm tides (about 4-5 m above MLLW) on the Ikatan Peninsula or areas along the coast to the west; and (7) run-up above storm tide level in the Sanak Island group is restricted to southwest-facing coasts of Sanak, Long, and Clifford Islands, where it is continuous and locally up to 24 m high. Generation of the tsunami by one or more major earthquake-triggered submarine landslides near the shelf edge south of Unimak Island seems to be the only viable mechanism to account for the data on wave arrival time, run-up heights, and distribution, as well as for unconfirmed anecdotal reports of local postquake increases in water depth and diminished bottom-fisheries productivity. A preliminary hydrodynamic simulation of the local tsunami propagation and run-up using a dipolar model of a possible landslide off Davidson Bank provides an acceptable fit to the characteristics of the distribution of local run-up, with a value at 34 m at the Scotch Cap lighthouse.

Numerical and Experimental Study on the Effect of Coral Reef and Beach Vegetation on Reduction of Long Wave Run-Up

NASA Astrophysics Data System (ADS)

Mohandie, R. K.; Teng, M. H.

2009-12-01

Numerical and experimental studies were carried out to examine the mitigating capabilities of coral reefs and vegetations on tsunami and storm surge inundation. For long waves propagating over variable depth such as that over a reef, the nonlinear and dispersive Boussinesq equations were applied. For run-up onto dry land where the nonlinear effect dominates, the nonlinear and nondispersive shallow water equations were used. Long waves with various amplitudes and wavelengths propagating over coral reefs of different length and height were investigated to quantify under which conditions a coral reef may be effective in reducing the wave impact. It was observed that a reef can make a long wave separate into several smaller waves and it can also cause wave breaking resulting in energy dissipation. Our data suggest that both wave separation and breaking induced by coral reefs are effective at mitigating long wave run-up, with the latter being noticeably more effective than the former. As expected, it was observed that the higher the coral reef height, the more the reduction in wave run-up especially when the reef height is greater than 50% of the water depth. For reefs to be effective as a barrier for long waves such as tsunamis and storm surges, it was found that the reefs must be sufficiently long in the wave propagation direction, for example, with its length to be at least of the same magnitude as the wavelength or longer. In this study, it was shown that an effective reef can reduce the long wave run-up by as much as 25% and 50% by wave separation and wave breaking, respectively. Three types of vegetation, namely, grass, shrub and coconut trees, were modeled and tested in a wave tank against various initial wave amplitude and beach slopes in the Hydraulics Lab at the University of Hawaii (UH) to examine each particular type’s effectiveness in reducing wave run-up and to determine its roughness coefficient for wave run-up through numerical simulation and experimental measurement. These roughness coefficients were shown to be higher than the traditional Manning’s coefficient values for vegetation in channel flows. Also, the coefficients were shown to be a function of the ratio of the initial wave amplitude over the vegetation height and are relatively independent of the beach slope. The vegetation spacing and tree diameters in the lab models were selected based on the typical spacing and tree diameter observed in the field through a reduced scale. All three types of vegetation were found to be effective in reducing wave run-up especially on mildly sloped beaches with a reduction rate ranging from 20% to more than 50%. A numerical simulation that incorporated the effects of coral reef and the combined vegetation types showed that on a 5 degree slope the reduction in run-up was 61% as compared to an unprotected scenario. A larger scale experimental study on coconut and bushes in the NSF-funded tsunami basin at the OSU also showed these vegetations are effective at reducing wave run-up. These results can be helpful in achieving a better understanding of the role that coral reefs and vegetation play in tsunami and storm surge mitigation.

Estimating canopy bulk density and canopy base height for conifer stands in the interior Western United States using the Forest Vegetation Simulator Fire and Fuels Extension.

Treesearch

Seth Ex; Frederick Smith; Tara Keyser; Stephanie Rebain

2017-01-01

The Forest Vegetation Simulator Fire and Fuels Extension (FFE-FVS) is often used to estimate canopy bulk density (CBD) and canopy base height (CBH), which are key indicators of crown fire hazard for conifer stands in the Western United States. Estimated CBD from FFE-FVS is calculated as the maximum 4 m running mean bulk density of predefined 0.3 m thick canopy layers (...

Simulations of Tsunami Triggered by the 1883 Krakatau Volcanic Eruption: Implications for Tsunami Hazard in the South China Sea

NASA Astrophysics Data System (ADS)

Tan, Y.; Lin, J.

2013-12-01

The 1883 Krakatau eruption in Indonesia is one of the largest recorded volcanic eruptions in recent history. The associated tsunami claimed about 36,000 lives and recorded run-up heights up to 30 m along the coastal regions in the Sunda Straits between the Indian Ocean and the South China Sea. Our study aims to better understand the generation and propagation mechanisms of this volcano-induced tsunami through modeling quantitatively the tsunami triggering processes at the source region. Comparison of non-linear simulations using the Cornell Multi-grid Coupled Tsunami Model (COMCOT) with observations reveals that a donut-shape 'hole and ring' initial condition for the tsunami source is able to explain the key characteristics of the observed tsunami: A 'hole' of about 6 km in diameter and 270 m in depth corresponds to the collapse of the Krakatau volcano on August 27, 1883, while a 'ring' of uplift corresponds to the deposition of the erupted volcanic materials. We found that the shallowness and narrowness of the entrance pathway of the Sunda Straits limited the northward transfer of the tsunami energy from the source region into the South China Sea. Instead, the topographic and bathymetric characteristics favored the southward transfer of the energy into the Indian Ocean. This might explain why Sri Lanka and India suffered casualties from this event, while areas inside the South China Sea, such as Singapore, did not record significant tsunami signals. Modeling results further suggest that the shallow topography of the surrounding islands around the Krakatau source region might have contributed to a reduction in maximum run-up heights in the coastal regions of the Sunda Straits.

Wave run-up on a high-energy dissipative beach

USGS Publications Warehouse

Ruggiero, P.; Holman, R.A.; Beach, R.A.

2004-01-01

Because of highly dissipative conditions and strong alongshore gradients in foreshore beach morphology, wave run-up data collected along the central Oregon coast during February 1996 stand in contrast to run-up data currently available in the literature. During a single data run lasting approximately 90 min, the significant vertical run-up elevation varied by a factor of 2 along the 1.6 km study site, ranging from 26 to 61% of the offshore significant wave height, and was found to be linearly dependent on the local foreshore beach slope that varied by a factor of 5. Run-up motions on this high-energy dissipative beach were dominated by infragravity (low frequency) energy with peak periods of approximately 230 s. Incident band energy levels were 2.5 to 3 orders of magnitude lower than the low-frequency spectral peaks and typically 96% of the run-up variance was in the infragravity band. A broad region of the run-up spectra exhibited an f-4 roll off, typical of saturation, extending to frequencies lower than observed in previous studies. The run-up spectra were dependent on beach slope with spectra for steeper foreshore slopes shifted toward higher frequencies than spectra for shallower foreshore slopes. At infragravity frequencies, run-up motions were coherent over alongshore length scales in excess of 1 km, significantly greater than decorrelation length scales on moderate to reflective beaches. Copyright 2004 by the American Geophysical Union.

14 CFR 77.17 - Obstruction standards.

Code of Federal Regulations, 2013 CFR

2013-01-01

... proportion of 100 feet for each additional nautical mile from the airport up to a maximum of 499 feet. (3) A... greater height than any of the following heights or surfaces: (1) A height of 499 feet AGL at the site of the object. (2) A height that is 200 feet AGL, or above the established airport elevation, whichever...

Tsunami run-up and inundation along the coast of Sabah and Sarawak, Malaysia due to a potential Brunei submarine mass failure.

PubMed

Tan, Wai Kiat; Teh, Su Yean; Koh, Hock Lye

2017-07-01

Submarine landslides, also known as submarine mass failures (SMFs), are major natural marine disasters that could critically damage coastal facilities such as nuclear power plants and oil and gas platforms. It is therefore essential to investigate submarine landslides for potential tsunami hazard assessment. Three-dimensional seismic data from offshore Brunei have revealed a giant seabed mass deposited by a previous SMF. The submarine mass extends over 120 km from the continental slope of the Baram Canyon at 200 m water depth to the deep basin floor of the Northwest Borneo Trough. A suite of in-house two-dimensional depth-averaged tsunami simulation model TUNA (Tsunami-tracking Utilities and Application) is developed to assess the vulnerability of coastal communities in Sabah and Sarawak subject to potential SMF tsunami. The submarine slide is modeled as a rigid body moving along a planar slope with the center of mass motion parallel to the planar slope and subject to external forces due to added mass, gravity, and dissipation. The nonlinear shallow water equations are utilized to simulate tsunami propagation from deepwater up to the shallow offshore areas. A wetting-drying algorithm is used when a tsunami wave reaches the shoreline to compute run up of tsunami along the shoreline. Run-up wave height and inundation maps are provided for seven densely populated locations in Sabah and Sarawak to highlight potential risks at each location, subject to two scenarios of slide slopes: 2° and 4°. The first wave may arrive at Kudat as early as 0.4 h after the SMF, giving local communities little time to evacuate. Over a small area, maximum inundated depths reaching 20.3 m at Kudat, 26.1 m at Kota Kinabalu, and 15.5 m at Miri are projected, while the maximum inundation distance of 4.86 km is expected at Miri due to its low-lying coast. In view of the vulnerability of some locations to the SMF tsunami, it is important to develop and implement community resilience program to reduce the potential damage that could be inflicted by SMF tsunamis.

Maximum height and minimum time vertical jumping.

PubMed

Domire, Zachary J; Challis, John H

2015-08-20

The performance criterion in maximum vertical jumping has typically been assumed to simply raise the center of mass as high as possible. In many sporting activities minimizing movement time during the jump is likely also critical to successful performance. The purpose of this study was to examine maximum height jumps performed while minimizing jump time. A direct dynamics model was used to examine squat jump performance, with dual performance criteria: maximize jump height and minimize jump time. The muscle model had activation dynamics, force-length, force-velocity properties, and a series of elastic component representing the tendon. The simulations were run in two modes. In Mode 1 the model was placed in a fixed initial position. In Mode 2 the simulation model selected the initial squat configuration as well as the sequence of muscle activations. The inclusion of time as a factor in Mode 1 simulations resulted in a small decrease in jump height and moderate time savings. The improvement in time was mostly accomplished by taking off from a less extended position. In Mode 2 simulations, more substantial time savings could be achieved by beginning the jump in a more upright posture. However, when time was weighted more heavily in these simulations, there was a more substantial reduction in jump height. Future work is needed to examine the implications for countermovement jumping and to examine the possibility of minimizing movement time as part of the control scheme even when the task is to jump maximally. Copyright © 2015 Elsevier Ltd. All rights reserved.

Coastal Evolution Modeling at Multiple Scales in Regional Sediment Management Applications

DTIC Science & Technology

2011-05-01

run-up height (including setup), ∆h is the surge level (including tide elevation relative to mean sea level (MSL)); zD is the dune toe elevation...interactive shoreline, dune , and inlet evolution, on the scale of hundreds of years, a regional and long-term perspective. The regional model...side by subscript r. Dune Erosion As waves run up on the beach and reach the foot of the dune , the dune will be subject to erosion. If it is assumed

Local variation of inundation, sedimentary characteristics, and mineral assemblages of the 2011 Tohoku-oki tsunami on the Misawa coast, Aomori, Japan

NASA Astrophysics Data System (ADS)

Nakamura, Yugo; Nishimura, Yuichi; Putra, Purna Sulastya

2012-12-01

The 2011 Tohoku-oki tsunami caused severe damage to the coastal regions of eastern Japan and left a sediment veneer over affected areas. We discuss differences in depositional characteristics of the 2011 Tohoku-oki tsunami from the viewpoint of the sediment source, coastal topography and flow height. The study area on the Misawa coast, northern Tohoku, includes a 20 km long coastline with sandy beaches, coastal dunes and a gently sloping lowland. This landscape assemblage provides an opportunity to examine the effects of topography on the characteristics of the tsunami deposit. During field surveys conducted from April 10 to May 2, 2011, we described the thickness, facies, and structure of the tsunami deposit. We also collected sand samples at approximately 20 m intervals along 13 shore-perpendicular transects extending up to 550 m inland, for grain size and mineral assemblage analysis. The tsunami flow height was estimated by measuring the elevation of debris found in trees, broken tree limbs, or water marks on buildings. The nature of the coastal lowland affected the flow height and inundation distance. In the southern part of the study area, where there is a narrow, 100 m wide low-lying coastal strip, the run-up height reached 10 m on the landward terrace slopes. To the north, the maximum inundation reached 550 m with a run-up height of 3.2 m on the wider, low-lying coastal topography. The average flow height was 4-5 m. The tsunami eroded coastal dunes and formed small scarps along the coast. Immediately landward of the coastal dunes the tsunami deposit was more than 20 cm thick, but thinned markedly inland from this point. Close to the dunes the deposit was composed largely of medium sand (1-2 Φ) with planar and parallel bedding, but with no apparent upward fining or coarsening. The grain size was similar to that of the coastal dune and we infer that the dunes were the local source material for the tsunami deposit at this point. The mineral assemblage of the tsunami deposit was dominated by orthopyroxene and clinopyroxene and was also similar to the dune and beach sand. At sites more than half the inundation distance inland, the thinner tsunami deposit consisted mainly of fine sand (2.375 Φ) with some upward fining. The difference in grain size and sedimentary characteristics was probably caused by differences in sediment transportation and depositional processes. We infer that the well-sorted, finer sediments were deposited out of suspension, whereas the relatively coarse sands were laid down from traction flows. The depositional characteristics of the 2011 Tohoku-oki tsunami deposit appeared to have been affected mainly by the coastal topography and the extent of erosion at any one point, as opposed to flow height.

14 CFR 77.23 - Standards for determining obstructions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... each additional nautical mile of distance from the airport up to a maximum of 500 feet. (3) A height... surfaces: (1) A height of 500 feet above ground level at the site of the object. (2) A height that is 200 feet above ground level or above the established airport elevation, whichever is higher, within 3...

14 CFR 77.23 - Standards for determining obstructions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... feet for each additional nautical mile of distance from the airport up to a maximum of 500 feet. (3) A... heights or surfaces: (1) A height of 500 feet above ground level at the site of the object. (2) A height that is 200 feet above ground level or above the established airport elevation, whichever is higher...

2011 Tohoku Earthquake and Japan's Nuclear Disaster - Implications for Indian Ocean Rim countries

NASA Astrophysics Data System (ADS)

Chadha, R. K.

2011-12-01

The Nuclear disaster in Japan after the M9.0 Tohoku earthquake on March 11, 2011 has elicited global response to have a relook at the safety aspects of the nuclear power plants from all angles including natural hazards like earthquakes and tsunami. Several countries have gone into safety audits of their nuclear programs in view of the experience in Japan. Tectonically speaking, countries located close to subduction zones or in direct line of impact of the subduction zones are the most vulnerable to earthquake or tsunami hazard, as these regions are the locale of great tsunamigenic earthquakes. The Japan disaster has also cautioned to the possibility of great impact to the critical structures along the coasts due to other ocean processes caused by ocean-atmosphere interactions and also due to global warming and sea level rise phenomena in future. This is particular true for island countries. The 2011 Tohoku earthquake in Japan will be remembered more because of its nuclear tragedy and tsunami rather than the earthquake itself. The disaster happened as a direct impact of a tsunami generated by the earthquake 130 km off the coast of Sendai in the Honshu region of Japan. The depth of the earthquake was about 25 km below the ocean floor and it occurred on a thrust fault causing a displacement of more than 20 meters. At few places, water is reported to have inundated areas up to 8-10 km inland. The height of the tsunami varied between 10 and 3 meters along the coast. Generally, during an earthquake damage to buildings or other structures occur due to strong shaking which is expressed in the form of ground accelerations 'g'. Although, Peak Ground Accelerations (PGA) consistently exceeded 2g at several places from Sendai down south, structures at the Fukushima Daiichi Nuclear Power Plant did not collapse due to the earthquake. In the Indian Ocean Rim countries, Indian, Pakistan and South Africa are the three countries where Nuclear power plants are operational, few of them along the coasts. There are a few countries where nuclear installations are planned and hence, a critical analysis is required to know the realistic hazard due to earthquakes and tsunami in these countries. The December 2004 Indian Ocean tsunami generated due to Sumatra earthquake of M9.3 claimed more than 250,000 lives but did not caused a situation like in Japan. We studied the tsunami run-up heights and inundation along the east coast of India. The maximum run-up height of 5.2 meters was observed at Nagapattinam with lateral inundation up to 800 meters and the minimum was at Devanaampatnam with a lateral inundation up to 340 meters. At Kalpakkam Nuclear Power Plant, the tsunami run-up height was 4.1 meters and water entered up to 360 meters inside the campus. Using the observed data we modeled several scenarios for Indian coast line for different earthquakes along the subduction zone of Andaman-Sumatra in the east and Makran in south Pakistan in the western side using N2 Tsunami Model. The results obtained for few critical structures will be presented with an overview of scenarios for other countries.

Relationship Between Body Fat and Physical Fitness in Army ROTC Cadets.

PubMed

Steed, Carly L; Krull, Benjamin R; Morgan, Amy L; Tucker, Robin M; Ludy, Mary-Jon

2016-09-01

The Army Physical Fitness Test (APFT), including timed push-ups, sit-ups, and run, assesses physical performance for the Army. Percent body fat is estimated using height and circumference measurements. The objectives of the study were to (a) compare the accuracy of height and circumference measurements to other, more accepted, body fat assessment methods and (b) determine the relationships between body composition and APFT results. Participants included Reserve Officer Training Corps (ROTC) cadets (n = 11 males, 2 females, 21.6 ± 3.5 years) from a midwestern university). At one visit, percent body fat was assessed using height and circumference measurements, air-displacement plethysmography, and bioelectrical impedance analysis. APFT results were provided by the ROTC director. All assessment methods for percent body fat were strongly associated (r ≥ 0.7, p < 0.01), implying that height and circumference measurement is a practical tool to estimate percent body fat of ROTC cadets. Total APFT score was not associated with any body fat assessment method. Push-up number was negatively associated with percent body fat by all assessment methods (r ≥ -0.8, p = 0.001), although run time was positively associated (r ≥ 0.6, p < 0.05). This suggests that percent body fat may be an important variable in determining or improving cardiovascular and muscular endurance, but not APFT performance. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

The limits to tree height.

PubMed

Koch, George W; Sillett, Stephen C; Jennings, Gregory M; Davis, Stephen D

2004-04-22

Trees grow tall where resources are abundant, stresses are minor, and competition for light places a premium on height growth. The height to which trees can grow and the biophysical determinants of maximum height are poorly understood. Some models predict heights of up to 120 m in the absence of mechanical damage, but there are historical accounts of taller trees. Current hypotheses of height limitation focus on increasing water transport constraints in taller trees and the resulting reductions in leaf photosynthesis. We studied redwoods (Sequoia sempervirens), including the tallest known tree on Earth (112.7 m), in wet temperate forests of northern California. Our regression analyses of height gradients in leaf functional characteristics estimate a maximum tree height of 122-130 m barring mechanical damage, similar to the tallest recorded trees of the past. As trees grow taller, increasing leaf water stress due to gravity and path length resistance may ultimately limit leaf expansion and photosynthesis for further height growth, even with ample soil moisture.

A Bayesian rupture model of the 2007 Mw 8.1 Solomon Islands earthquake in Southwest Pacific with coral reef displacement measurements

NASA Astrophysics Data System (ADS)

Chen, Ting; Luo, Haipeng; Furlong, Kevin P.

2017-05-01

On 1st April 2007 a Mw 8.1 megathrust earthquake occurred in the western Solomon Islands of the Southwest Pacific and generated a regional tsunami with run-up heights of up to 12 m. A Bayesian inversion model is constructed to derive fault dip angle and cumulative co-seismic and early post-seismic slip using coral reef displacement measurements, in which both data misfit and moment magnitude are used as constraints. Results show three shallow, high-slip patches concentrated along the trench from west of Ranongga Island to Rendova Island on a fault plane dipping 20°, and a maximum dip slip of 11.6 m beneath Ranongga Island. Considerable subsidence on Simbo Island outboard of the trench on the subducting plate is not well explained with this model, but may be related to the effects of afterslip and/or Simbo Island's location near the triple junction among the Australia, Woodlark and Pacific plates.

Regional Impact of the 29 September 2009 North Tonga Tsunami on the Futuna and Alofi Islands (Wallis & Futuna)

NASA Astrophysics Data System (ADS)

Lamarche, G.; Pelletier, B.; Goff, J. R.

2009-12-01

The north Tonga earthquake occurred at 5:48am on 30 September local time in Futuna, ~650 km west of the epicentre. The PTWC issued a warning at 6:04am for tsunami arrival in Wallis (Wallis & Futuna) at 6.35am. No warning was issued by the territorial authorities for Wallis nor for Futuna, located 230 km to the south-west. There was no reported tsunami on Wallis. However a tsunami hit the archipelago of Futuna (islands of Futuna and Alofi) between 7.00 and 7.20am on 30 September. The tide was approximately 3/4 out. We took advantage of an 8 days survey funded by the French Ministry of Foreign Affairs, previously planned for investigating palaeotsunamis on Futuna and Alofi. We measured run-up and inundation from the mid- to low-tide mark, as well as flow depths, and sediments associated with the 30 September tsunami at 41 sites around the islands. Run-ups were estimated based on visual evidence of recent coastal impact - burnt grasses and plants, sand and other displaced debris (e.g., on the road). We interviewed the population on multiple occasions. The maximum run-up of 4.5 m was observed on the eastern beach of Alofitai in Alofi, associated with an inundation of 85 m and a flow depth of 3m at the coast. On Futuna, we measured maximum run-ups of 4.4 m on the eastern tip and 4.3 m on the NW tip of the island, with maximum inundations of 95 and 72m, respectively. A flow depth of 2 m was inferred on the NE tip. Overall, the tsunami impact was more severe on the northern coast of Futuna, with run-ups ranging from 2.1 to 4.3 m. Very small run-ups and inundations were observed along the southern coast, with a 1.0 m run-up and 10 m inundation measured in Léava, the capital of Futuna. Most witnesses report two main waves equivalent in amplitude, the second one being sometimes described as the largest. All witnesses indicate that the sea withdrew first. A video suggests only a few minutes between the successive waves (likely not the first) in Léava. The video shows the reef exposed well below the lowest tides. There were no casualties. One inhabitant was warned by LCI television at 06:30am and was able to witness the tsunami. There were unconfirmed reports of two women taken by surprise by the arrival of the tsunami on the reef near the eastern end of Futuna, but who managed to hold on to trees to avoid being taken out to sea by the backwash. A significant disaster was avoided essentially because it was early and the tide was low when the tsunami hit. Such an event at high tide would have added about 0.8-1m in height to the wave and have undoubtedly resulted in severe damage, injuries and possibly deaths. This event, together with a small tsunami triggered by a Mw 6.4 local earthquake in March 1993 and an oral legend about a deadly and destructive wave indicate that the tsunami risk for Futuna is high for the >4000 inhabitants who live almost exclusively on a 50-400 m-wide coastal strip, between a narrow reef and landward coastal cliffs. However, the hour and 10 minutes that the 30 September tsunami took to reach the island provided sufficient time to issue a warning to the population who can rapidly reach safety on this mountainous landscape.

Effects of Short or Long Warm-up on Intermediate Running Performance.

PubMed

van den Tillaar, Roland; Vatten, Tormod; von Heimburg, Erna

2017-01-01

van den Tillaar, R, Vatten, T, and von Heimburg, E. Effects of short or long warm-up on intermediate running performance. J Strength Cond Res 31(1): 37-44, 2017-The aim of the study was to compare the effects of a long warm-up (general + specific) and a short warm-up (specific) on intermediate running performance (3-minute run). Thirteen experienced endurance-trained athletes (age 23.2 ± 2.3 years, body mass 79.8 ± 8.2 kg, body height 1.82 ± 0.05 m) conducted 2 types of warm-ups in a crossover design with 1 week in between: a long warm-up (10 minutes, 80% maximal heart rate, and 8 × 60 m sprint with increasing intensity and 1 minute rest in between) and a short warm-up (8 × 60 m sprint with increasing intensity and 1 minute rest in between). Each warm-up was followed by a 3-minute running test on a nonmotorized treadmill. Total running distance, running velocity at each 30 seconds, heart rate, blood lactate concentration, oxygen uptake, and rate of perceived exertion were measured. No significant differences in running performance variables and physiological parameters were found between the 2 warm-up protocols, except for the rate of perceived exertion and heart rate, which were higher after the long warm-up and after the 3-minute running test compared with the short warm-up. It was concluded that a short warm-up is as effective as a long warm-up for intermediate performance. Therefore, athletes can choose for themselves if they want to include a general part in their warm-up routines, even though it would not enhance their running performance more compared with only using a short, specific warm-up. However, to increase efficiency of time for training or competition, these short, specific warm-ups should be performed instead of long warm-ups.

D Modelling of the Lusatian Borough in Biskupin Using Archival Data

NASA Astrophysics Data System (ADS)

Zawieska, D.; Markiewicz, J. S.; Kopiasz, J.; Tazbir, J.; Tobiasz, A.

2017-02-01

The paper presents the results of 3D modelling in the Lusatian Borough, Biskupin, using archival data. Pre-war photographs acquired from different heights, e.g., from a captive balloon (maximum height up to 150 m), from a blimp (at a height of 50-110 m) and from an aeroplane (at a height of 200 m, 300 m and up to 3 km). In order to generate 3D models, AgiSoft tools were applied, as they allow for restoring shapes using triangular meshes. Individual photographs were processed using Google SketchUp software and the "shape from shadow" method. The usefulness of these particular models in archaeological research work was also analysed.

Run-up parameterization and beach vulnerability assessment on a barrier island: a downscaling approach

NASA Astrophysics Data System (ADS)

Medellín, G.; Brinkkemper, J. A.; Torres-Freyermuth, A.; Appendini, C. M.; Mendoza, E. T.; Salles, P.

2016-01-01

We present a downscaling approach for the study of wave-induced extreme water levels at a location on a barrier island in Yucatán (Mexico). Wave information from a 30-year wave hindcast is validated with in situ measurements at 8 m water depth. The maximum dissimilarity algorithm is employed for the selection of 600 representative cases, encompassing different combinations of wave characteristics and tidal level. The selected cases are propagated from 8 m water depth to the shore using the coupling of a third-generation wave model and a phase-resolving non-hydrostatic nonlinear shallow-water equation model. Extreme wave run-up, R2%, is estimated for the simulated cases and can be further employed to reconstruct the 30-year time series using an interpolation algorithm. Downscaling results show run-up saturation during more energetic wave conditions and modulation owing to tides. The latter suggests that the R2% can be parameterized using a hyperbolic-like formulation with dependency on both wave height and tidal level. The new parametric formulation is in agreement with the downscaling results (r2 = 0.78), allowing a fast calculation of wave-induced extreme water levels at this location. Finally, an assessment of beach vulnerability to wave-induced extreme water levels is conducted at the study area by employing the two approaches (reconstruction/parameterization) and a storm impact scale. The 30-year extreme water level hindcast allows the calculation of beach vulnerability as a function of return periods. It is shown that the downscaling-derived parameterization provides reasonable results as compared with the numerical approach. This methodology can be extended to other locations and can be further improved by incorporating the storm surge contributions to the extreme water level.

Characterizing acoustic shocks in high-performance jet aircraft flyover noise.

PubMed

Reichman, Brent O; Gee, Kent L; Neilsen, Tracianne B; Downing, J Micah; James, Michael M; Wall, Alan T; McInerny, Sally Anne

2018-03-01

Acoustic shocks have been previously documented in high-amplitude jet noise, including both the near and far fields of military jet aircraft. However, previous investigations into the nature and formation of shocks have historically concentrated on stationary, ground run-up measurements, and previous attempts to connect full-scale ground run-up and flyover measurements have omitted the effect of nonlinear propagation. This paper shows evidence for nonlinear propagation and the presence of acoustic shocks in acoustical measurements of F-35 flyover operations. Pressure waveforms, derivatives, and statistics indicate nonlinear propagation, and the resulting shock formation is significant at high engine powers. Variations due to microphone size, microphone height, and sampling rate are considered, and recommendations for future measurements are made. Metrics indicating nonlinear propagation are shown to be influenced by changes in sampling rate and microphone size, and exhibit less variation due to microphone height.

Alterations of Vertical Jump Mechanics after a Half-Marathon Mountain Running Race

PubMed Central

Rousanoglou, Elissavet N.; Noutsos, Konstantinos; Pappas, Achilleas; Bogdanis, Gregory; Vagenas, Georgios; Bayios, Ioannis A.; Boudolos, Konstantinos D.

2016-01-01

The fatiguing effect of long-distance running has been examined in the context of a variety of parameters. However, there is scarcity of data regarding its effect on the vertical jump mechanics. The purpose of this study was to investigate the alterations of countermovement jump (CMJ) mechanics after a half-marathon mountain race. Twenty-seven runners performed CMJs before the race (Pre), immediately after the race (Post 1) and five minutes after Post 1 (Post 2). Instantaneous and ensemble-average analysis focused on jump height and, the maximum peaks and time-to-maximum peaks of: Displacement, vertical force (Fz), anterior-posterior force (Fx), Velocity and Power, in the eccentric (tECC) and concentric (tCON) phase of the jump, respectively. Repeated measures ANOVAs were used for statistical analysis (p ≤ 0.05). The jump height decrease was significant in Post 2 (-7.9%) but not in Post 1 (-4.1%). Fx and Velocity decreased significantly in both Post 1 (only in tECC) and Post 2 (both tECC and tCON). Α timing shift of the Fz peaks (earlier during tECC and later during tCON) and altered relative peak times (only in tECC) were also observed. Ensemble-average analysis revealed several time intervals of significant post-race alterations and a timing shift in the Fz-Velocity loop. An overall trend of lowered post-race jump output and mechanics was characterised by altered jump timing, restricted anterior-posterior movement and altered force-velocity relations. The specificity of mountain running fatigue to eccentric muscle work, appears to be reflected in the different time order of the post-race reductions, with the eccentric phase reductions preceding those of the concentric one. Thus, those who engage in mountain running should particularly consider downhill training to optimise eccentric muscular action. Key points The 4.1% reduction of jump height immediately after the race is not statistically significant The eccentric phase alterations of jump mechanics precede those of the concentric ones. Force-velocity alterations present a timing shift rather than a change in force or velocity magnitude. PMID:27274665

Alterations of Vertical Jump Mechanics after a Half-Marathon Mountain Running Race.

PubMed

Rousanoglou, Elissavet N; Noutsos, Konstantinos; Pappas, Achilleas; Bogdanis, Gregory; Vagenas, Georgios; Bayios, Ioannis A; Boudolos, Konstantinos D

2016-06-01

The fatiguing effect of long-distance running has been examined in the context of a variety of parameters. However, there is scarcity of data regarding its effect on the vertical jump mechanics. The purpose of this study was to investigate the alterations of countermovement jump (CMJ) mechanics after a half-marathon mountain race. Twenty-seven runners performed CMJs before the race (Pre), immediately after the race (Post 1) and five minutes after Post 1 (Post 2). Instantaneous and ensemble-average analysis focused on jump height and, the maximum peaks and time-to-maximum peaks of: Displacement, vertical force (Fz), anterior-posterior force (Fx), Velocity and Power, in the eccentric (tECC) and concentric (tCON) phase of the jump, respectively. Repeated measures ANOVAs were used for statistical analysis (p ≤ 0.05). The jump height decrease was significant in Post 2 (-7.9%) but not in Post 1 (-4.1%). Fx and Velocity decreased significantly in both Post 1 (only in tECC) and Post 2 (both tECC and tCON). Α timing shift of the Fz peaks (earlier during tECC and later during tCON) and altered relative peak times (only in tECC) were also observed. Ensemble-average analysis revealed several time intervals of significant post-race alterations and a timing shift in the Fz-Velocity loop. An overall trend of lowered post-race jump output and mechanics was characterised by altered jump timing, restricted anterior-posterior movement and altered force-velocity relations. The specificity of mountain running fatigue to eccentric muscle work, appears to be reflected in the different time order of the post-race reductions, with the eccentric phase reductions preceding those of the concentric one. Thus, those who engage in mountain running should particularly consider downhill training to optimise eccentric muscular action. Key pointsThe 4.1% reduction of jump height immediately after the race is not statistically significantThe eccentric phase alterations of jump mechanics precede those of the concentric ones.Force-velocity alterations present a timing shift rather than a change in force or velocity magnitude.

How do prosthetic stiffness, height and running speed affect the biomechanics of athletes with bilateral transtibial amputations?

PubMed Central

Taboga, Paolo; Grabowski, Alena M.

2017-01-01

Limited available information describes how running-specific prostheses and running speed affect the biomechanics of athletes with bilateral transtibial amputations. Accordingly, we quantified the effects of prosthetic stiffness, height and speed on the biomechanics of five athletes with bilateral transtibial amputations during treadmill running. Each athlete performed a set of running trials with 15 different prosthetic model, stiffness and height combinations. Each set of trials began with the athlete running on a force-measuring treadmill at 3 m s−1, subsequent trials incremented by 1 m s−1 until they achieved their fastest attainable speed. We collected ground reaction forces (GRFs) during each trial. Prosthetic stiffness, height and running speed each affected biomechanics. Specifically, with stiffer prostheses, athletes exhibited greater peak and stance average vertical GRFs (β = 0.03; p < 0.001), increased overall leg stiffness (β = 0.21; p < 0.001), decreased ground contact time (β = −0.07; p < 0.001) and increased step frequency (β = 0.042; p < 0.001). Prosthetic height inversely associated with step frequency (β = −0.021; p < 0.001). Running speed inversely associated with leg stiffness (β = −0.58; p < 0.001). Moreover, at faster running speeds, the effect of prosthetic stiffness and height on biomechanics was mitigated and unchanged, respectively. Thus, prosthetic stiffness, but not height, likely influences distance running performance more than sprinting performance for athletes with bilateral transtibial amputations. PMID:28659414

How do prosthetic stiffness, height and running speed affect the biomechanics of athletes with bilateral transtibial amputations?

PubMed

Beck, Owen N; Taboga, Paolo; Grabowski, Alena M

2017-06-01

Limited available information describes how running-specific prostheses and running speed affect the biomechanics of athletes with bilateral transtibial amputations. Accordingly, we quantified the effects of prosthetic stiffness, height and speed on the biomechanics of five athletes with bilateral transtibial amputations during treadmill running. Each athlete performed a set of running trials with 15 different prosthetic model, stiffness and height combinations. Each set of trials began with the athlete running on a force-measuring treadmill at 3 m s -1 , subsequent trials incremented by 1 m s -1 until they achieved their fastest attainable speed. We collected ground reaction forces (GRFs) during each trial. Prosthetic stiffness, height and running speed each affected biomechanics. Specifically, with stiffer prostheses, athletes exhibited greater peak and stance average vertical GRFs ( β = 0.03; p < 0.001), increased overall leg stiffness ( β = 0.21; p < 0.001), decreased ground contact time ( β = -0.07; p < 0.001) and increased step frequency ( β = 0.042; p < 0.001). Prosthetic height inversely associated with step frequency ( β = -0.021; p < 0.001). Running speed inversely associated with leg stiffness ( β = -0.58; p < 0.001). Moreover, at faster running speeds, the effect of prosthetic stiffness and height on biomechanics was mitigated and unchanged, respectively. Thus, prosthetic stiffness, but not height, likely influences distance running performance more than sprinting performance for athletes with bilateral transtibial amputations. © 2017 The Author(s).

Comparison between Observed Tsunami Heights and Numerical Simulation of the 1854 Ansei-Tokai Earthquake Tsunami in Gokasho Bay, central Japan

NASA Astrophysics Data System (ADS)

Naruhashi, R.; Satake, K.; Heidarzadeh, M.; Harada, T.

2014-12-01

　Gokasho Bay is a blockade inner bay which has typical ria coasts and drowned valleys. It is located in the central Kii Peninsula and faces the Nankai Trough subduction zone. This Kumano-nada coastal area has been repeatedly striked by historical great tsunamis. For the 1854 Ansei-Tokai earthquake and its tsunami, there are comparatively many historical records including historical documents and oral traditions for tsunami behavior and damages along the coast.　Based on these records, a total of 42 tsunami heights were measured by using a laser range finder and a hand level on the basis of spot elevation given by 1/2500 topographical maps. The average inundation height of whole bay area was approximately 4 - 5 m. On the whole, in the closed-off section of the bay, large values were obtained. For example, the average value in Gokasho-ura town area was 4 m, and the maximum run-up height along the Gokasho river was 6.8 m. Particularly in Konsa, located in the most closed-off section of the bay, tsunami heights ranged between 4 - 11 m, and were higher than those in other districts. It was comparatively high along the eastern coast and eastern baymouth.　We simulate the distribution of the tsunami wave heights using numerical modeling, and compare the simulation results and above-mentioned actual historical data and results of our field survey. Based on fault models by Ando (1975), Aida (1981), and Annaka et al. (2003), the tsunami simulation was performed.　After comparing the calculated results by three fault models, the wave height based on the model by Annaka et al. (2003) was found to have better agreement with observations. Moreover, the wave height values in a closed-off section of bay and at the eastern baymouth are high consistent with our survey data.

Shoreline to Height (S2H): an algorithm to monitor reservoirs' water height from satellite images. A flood risk management application

NASA Astrophysics Data System (ADS)

Cenci, Luca; Boni, Giorgio; Pulvirenti, Luca; Gabellani, Simone; Gardella, Fabio; Squicciarino, Giuseppe; Pierdicca, Nazzareno; Benedetto, Catia

2016-04-01

In a reservoir, water level monitoring is important for emergency management purposes. This information can be used to estimate the degree of filling of the water body, thus helping decision makers in flood control operations. Furthermore, if assimilated in hydrological models and coupled with rainfall forecasts, this information can be used for flood forecast and early warning. In many cases, water level is not known (e.g. data-scarce environments), or not shared by operators. Remote sensing may allow overcoming these limitations, enabling its estimation. The objective of this work is to present the Shoreline to Height (S2H) algorithm, developed to retrieve the height of the water stored in reservoirs from satellite images. To this aim, some auxiliary data are needed: a DEM and the maximum/minimum height that can be reached by the water. In data-scarce environments, these information can be easily obtained on the Internet (e.g. free, worldwide DEM and design data for artificial reservoirs). S2H was tested with different satellite data, both optical and SAR (Landsat and Cosmo SkyMed®-CSK®) in order to assess the impact of different sensors on the final estimates. The study area was the Place-Moulin Lake (Valle d'Aosta-VdA, Italy), where it is present a monitoring network that can provide reliable ground-truths for validating the algorithm and assessing its accuracy. When the algorithm was developed, it was assumed to be in absence of any "official"-auxiliary data. Therefore, two DEMs (SRTM 1 arc-second and ASTER GDEM) were used to evaluate their performances. The maximum/minimum water height values were found on the website of VdA Region. The S2H is based on three steps: i) satellite data preprocessing (Landsat: atmospheric correction; CSK®: geocoding and speckle filtering); ii) water mask generation (using a thresholding and region growing algorithm) and shoreline extraction; iii) retrieval of the shoreline height according to the reference DEMs (adopting a statistical approach). The algorithm was tested for different water heights and results were compared against ground-truths. Findings showed that the combination CSK®-SRTM provided more reliable results. It was also found that the overall quality of the estimates increases as the water height increases, reaching an accuracy up to some centimetres. This result is particularly interesting for flood control applications, where it is important to be accurate when the reservoir's degree of filling is high. The potentialities of S2H for operational hydrology purposes were tested in a real-case simulation, in which the river discharge's prediction downstream of the dam was needed for flood risk management purposes. The water height value retrieved with S2H was assimilated within a semi-distributed, event-based, hydrological model (DRiFt) by using a simple direct insertion algorithm. DRiFt is usually run in operative way on the reservoir by using ground-truths as input data. The result of the data assimilation experiment was compared with the "real", operative run of the model. Findings showed a high agreement between the two simulations, proving the utility/quality of the S2H algorithm. "Project carried out using CSK® Products, © of the Italian Space Agency (ASI), delivered under a license to use by ASI."

A comparison of training and physical performance of police students at the start and the end of three-year police education.

PubMed

Lagestad, Pål; van den Tillaar, Roland

2014-05-01

The purpose was to compare male and female police students exercise and physical performances at the beginning and the end of a 3-year police education. Two hundred thirty-five subjects answered the survey about exercise and 85 subjects (58 men: age = 23.7 ± 2.8 years, body mass = 82.1 ± 7.8 kg, height = 1.83 ± 0.06 m; 27 women: age = 24.9 ± 3.1 years, body mass = 66 ± 8.5 kg, height = 1.70 ± 0.09 m) participated in the 4 physical exercises (bench press, pull-ups, standing long jump, and 3,000-m run). It was found that the priority of maximum strength training increased (p < 0.001), whereas the priority of endurance and sprint training decreased during the 3-year period, with no differences between gender (p ≥ 0.28). The performances in the strength-related physical tests, bench press, and pull-ups also increased in the same period. These changes were the same for both genders. Findings showed a discrepancy between what is reported as necessary physical skills in police work and what actually is trained during the police education. This discrepancy was caused by the large focus upon maximal strength in the physical examination program in the police education.

SU-E-T-399: Evaluation of Selection Criteria for Computational Human Phantoms for Use in Out-Of-Field Organ Dosimetry for Radiotherapy Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pelletier, C; Jung, J; Lee, C

2015-06-15

Purpose: To quantify the dosimetric uncertainty due to organ position errors when using height and weight as phantom selection criteria in the UF/NCI Hybrid Phantom Library for the purpose of out-of-field organ dose reconstruction. Methods: Four diagnostic patient CT images were used to create 7-field IMRT plans. For each patient, dose to the liver, right lung, and left lung were calculated using the XVMC Monte Carlo code. These doses were taken to be the ground truth. For each patient, the phantom with the most closely matching height and weight was selected from the body size dependent phantom library. The patientmore » plans were then transferred to the computational phantoms and organ doses were recalculated. Each plan was also run on 4 additional phantoms with reference heights and or weights. Maximum and mean doses for the three organs were computed, and the DVHs were extracted and compared. One sample t-tests were performed to compare the accuracy of the height and weight matched phantoms against the additional phantoms in regards to both maximum and mean dose. Results: For one of the patients, the height and weight matched phantom yielded the most accurate results across all three organs for both maximum and mean doses. For two additional patients, the matched phantom yielded the best match for one organ only. In 13 of the 24 cases, the matched phantom yielded better results than the average of the other four phantoms, though the results were only statistically significant at the .05 level for three cases. Conclusion: Using height and weight matched phantoms does yield better results in regards to out-of-field dosimetry than using average phantoms. Height and weight appear to be moderately good selection criteria, though this selection criteria failed to yield any better results for one patient.« less

Bed forms created by simulated waves and currents in a large flume

USGS Publications Warehouse

Lacy, Jessica R.; Rubin, David M.; Ikeda, Hiroshi; Mokudai, Kuniyasu; Hanes, Daniel M.

2007-01-01

The morphology and evolution of bed forms created by combinations of waves and currents were investigated using an oscillating plate in a 4-m-wide flume. Current speed ranged from 0 to 30 cm/s, maximum oscillatory velocity ranged from 20 to 48 cm/s, oscillation period was 8 s (except for one run with 12 s period), and the median grain size was 0.27 mm. The angle between oscillations and current was 90°, 60°, or 45°. At the end of each run the sand bed was photographed and ripple dimensions were measured. Ripple wavelength was also determined from sonar images collected throughout the runs. Increasing the ratio of current to wave (i.e., oscillatory) velocity decreased ripple height and wavelength, in part because of the increased fluid excursion during the wave period. Increasing the ratio of current to waves, or decreasing the angle between current and waves, increased the three-dimensionality of bed forms. During the runs, ripple wavelength increased by a factor of about 2. The average number of wave periods for evolution of ripple wavelength to 90% of its final value was 184 for two-dimensional ripples starting from a flat bed. Bed form orientations at the end of each run were compared to four potential controlling factors: the directions of waves, current, maximum instantaneous bed shear stress, and maximum gross bed form normal transport (MGBNT). The directions of waves and of MGBNT were equally good predictors of bed form orientations, and were significantly better than the other two factors.

Analysis of the Tangjiaxi landslide-generated waves in the Zhexi Reservoir, China, by a granular flow coupling model

NASA Astrophysics Data System (ADS)

Huang, Bolin; Yin, Yueping; Wang, Shichang; Tan, Jianmin; Liu, Guangning

2017-05-01

A rocky granular flow is commonly formed after the failure of rocky bank slopes. An impulse wave disaster may also be initiated if the rocky granular flow rushes into a river with a high velocity. Currently, the granular mass-water body coupling study is an important trend in the field of landslide-induced impulse waves. In this paper, a full coupling numerical model for landslide-induced impulse waves is developed based on a non-coherent granular flow equation, i.e., the Mih equation. In this model, the Mih equation for continuous non-coherent granular flow controls movements of sliding mass, the two-phase flow equation regulates the interaction between sliding mass and water, and the renormalization group (RNG) turbulence model governs the movement of the water body. The proposed model is validated and applied for the 2014 Tangjiaxi landslide of the Zhexi Reservoir located in Hunan Province, China, to analyze the characteristics of both landslide motion and its following impulse waves. On 16 July 2014, a rocky debris flow was formed after the failure of the Tangjiaxi landslide, damming the Tangjiaxi stream and causing an impulse wave disaster with three dead and nine missing bodies. Based on the full coupling numerical analysis, the granular flow impacts the water with a maximum velocity of about 22.5 m s-1. Moreover, the propagation velocity of the generated waves reaches up to 12 m s-1. The maximum calculated run-up of 21.8 m is close enough to the real value of 22.7 m. The predicted landslide final deposit and wave run-up heights are in a good agreement with the field survey data. These facts verify the ability of the proposed model for simulating the real impulse wave generated by rocky granular flow events.

A physiological evaluation of professional soccer players.

PubMed

Raven, P B; Gettman, L R; Pollock, M L; Cooper, K H

1976-12-01

The purpose of this study was to evaluate the physiological functions of a professional soccer team in the North American Soccer League (NASL). Eighteen players were evaluated on cardiorespiratory function, endurance performance, body composition, blood chemistry, and motor fitness measures near the end of their competitive season. The following means were observed: age, 26 yrs; height, 176 cm; weight 75.5 kg; resting heart rate, 50 beats/min; maximum heart rate (MHR), 188 beats/min; maximum oxygen intake (VO2 max), 58.4 ml/kg-min-1; maximum ventilation (VEmax BTPS), 154 L/min; body fat, 9.59%; 12-min run, 1.86 miles; and Illinois agility run, 15.6 secs. Results on resting blood pressure, serum lipids, vital capacity, flexibility, upper body strength, and vertical jump tests were comparable to values found for the sedentary population. Comparing the results with previously collected data on professional American Football backs indicated that the soccer players were shorter; lighter in body weight; higher in VO2 max (4 ml/kg-min-1) and body fat (1.8%); and similar in MHR, VE max, and VC. The 12-min run scores were similar to the initial values observed for the 1970 Brazilian World Cup Team. The agility run results were superior to data collected from other groups. Their endurance capabilities, agility, and low percent of body fat clearly differentiate them from the sedentary population and show them to be similar to that of professional American football backs.

A physiological evaluation of professional soccer players.

PubMed Central

Raven, P. B.; Gettman, L. R.; Pollock, M. L.; Cooper, K. H.

1976-01-01

The purpose of this study was to evaluate the physiological functions of a professional soccer team in the North American Soccer League (NASL). Eighteen players were evaluated on cardiorespiratory function, endurance performance, body composition, blood chemistry, and motor fitness measures near the end of their competitive season. The following means were observed: age, 26 yrs; height, 176 cm; weight 75.5 kg; resting heart rate, 50 beats/min; maximum heart rate (MHR), 188 beats/min; maximum oxygen intake (VO2 max), 58.4 ml/kg-min-1; maximum ventilation (VEmax BTPS), 154 L/min; body fat, 9.59%; 12-min run, 1.86 miles; and Illinois agility run, 15.6 secs. Results on resting blood pressure, serum lipids, vital capacity, flexibility, upper body strength, and vertical jump tests were comparable to values found for the sedentary population. Comparing the results with previously collected data on professional American Football backs indicated that the soccer players were shorter; lighter in body weight; higher in VO2 max (4 ml/kg-min-1) and body fat (1.8%); and similar in MHR, VE max, and VC. The 12-min run scores were similar to the initial values observed for the 1970 Brazilian World Cup Team. The agility run results were superior to data collected from other groups. Their endurance capabilities, agility, and low percent of body fat clearly differentiate them from the sedentary population and show them to be similar to that of professional American football backs. PMID:1009297

Body-terrain interaction affects large bump traversal of insects and legged robots.

PubMed

Gart, Sean W; Li, Chen

2018-02-02

Small animals and robots must often rapidly traverse large bump-like obstacles when moving through complex 3D terrains, during which, in addition to leg-ground contact, their body inevitably comes into physical contact with the obstacles. However, we know little about the performance limits of large bump traversal and how body-terrain interaction affects traversal. To address these, we challenged the discoid cockroach and an open-loop six-legged robot to dynamically run into a large bump of varying height to discover the maximal traversal performance, and studied how locomotor modes and traversal performance are affected by body-terrain interaction. Remarkably, during rapid running, both the animal and the robot were capable of dynamically traversing a bump much higher than its hip height (up to 4 times the hip height for the animal and 3 times for the robot, respectively) at traversal speeds typical of running, with decreasing traversal probability with increasing bump height. A stability analysis using a novel locomotion energy landscape model explained why traversal was more likely when the animal or robot approached the bump with a low initial body yaw and a high initial body pitch, and why deflection was more likely otherwise. Inspired by these principles, we demonstrated a novel control strategy of active body pitching that increased the robot's maximal traversable bump height by 75%. Our study is a major step in establishing the framework of locomotion energy landscapes to understand locomotion in complex 3D terrains.

Cockroaches traverse crevices, crawl rapidly in confined spaces, and inspire a soft, legged robot

PubMed Central

Jayaram, Kaushik; Full, Robert J.

2016-01-01

Jointed exoskeletons permit rapid appendage-driven locomotion but retain the soft-bodied, shape-changing ability to explore confined environments. We challenged cockroaches with horizontal crevices smaller than a quarter of their standing body height. Cockroaches rapidly traversed crevices in 300–800 ms by compressing their body 40–60%. High-speed videography revealed crevice negotiation to be a complex, discontinuous maneuver. After traversing horizontal crevices to enter a vertically confined space, cockroaches crawled at velocities approaching 60 cm⋅s−1, despite body compression and postural changes. Running velocity, stride length, and stride period only decreased at the smallest crevice height (4 mm), whereas slipping and the probability of zigzag paths increased. To explain confined-space running performance limits, we altered ceiling and ground friction. Increased ceiling friction decreased velocity by decreasing stride length and increasing slipping. Increased ground friction resulted in velocity and stride length attaining a maximum at intermediate friction levels. These data support a model of an unexplored mode of locomotion—“body-friction legged crawling” with body drag, friction-dominated leg thrust, but no media flow as in air, water, or sand. To define the limits of body compression in confined spaces, we conducted dynamic compressive cycle tests on living animals. Exoskeletal strength allowed cockroaches to withstand forces 300 times body weight when traversing the smallest crevices and up to nearly 900 times body weight without injury. Cockroach exoskeletons provided biological inspiration for the manufacture of an origami-style, soft, legged robot that can locomote rapidly in both open and confined spaces. PMID:26858443

Full-scale Wind-tunnel and Flight Tests of a Fairchild 22 Airplane Equipped with External-airfoil Flaps

NASA Technical Reports Server (NTRS)

Reed, Warren D; Clay, William C

1937-01-01

Wind-tunnel and flight tests have been made of a Fairchild 22 airplane equipped with a wing having external-airfoil flaps that also perform the function of ailerons. Lift, drag, and pitching-moment coefficients of the airplane with several flap settings, and the rolling- and yawing-moment coefficients with the flaps deflected as ailerons were measured in the full-scale tunnel with the horizontal tail surfaces and propeller removed. The effect of the flaps on the low speed and on the take-off and landing characteristics, the effectiveness of flaps when used as ailerons, and the forces required to operate them as ailerons were determined in flight. The wind-tunnel tests showed that the flaps increased the maximum lift coefficient of the airplane from 1.51 with the flap in the minimum drag position to 2.12 with the flap in the minimum drag position to 2.12 with the flap deflected 30 degrees. In the flight tests the minimum speed decreased from 46.8 miles per hour with the flaps up to 41.3 miles per hour with the flaps deflected. The required take-off run to attain a height of 50 feet was reduced from 820 to 750 feet and the landing run from a height of 50 feet was reduced from 930 to 480 feet. The flaps for this installation gave lateral control that was not entirely satisfactory. Their rolling action was good but the adverse yaw resulting from their use was greater than is considerable, and the stick forces required to operate them increased too rapidly with speed.

Cockroaches traverse crevices, crawl rapidly in confined spaces, and inspire a soft, legged robot.

PubMed

Jayaram, Kaushik; Full, Robert J

2016-02-23

Jointed exoskeletons permit rapid appendage-driven locomotion but retain the soft-bodied, shape-changing ability to explore confined environments. We challenged cockroaches with horizontal crevices smaller than a quarter of their standing body height. Cockroaches rapidly traversed crevices in 300-800 ms by compressing their body 40-60%. High-speed videography revealed crevice negotiation to be a complex, discontinuous maneuver. After traversing horizontal crevices to enter a vertically confined space, cockroaches crawled at velocities approaching 60 cm⋅s(-1), despite body compression and postural changes. Running velocity, stride length, and stride period only decreased at the smallest crevice height (4 mm), whereas slipping and the probability of zigzag paths increased. To explain confined-space running performance limits, we altered ceiling and ground friction. Increased ceiling friction decreased velocity by decreasing stride length and increasing slipping. Increased ground friction resulted in velocity and stride length attaining a maximum at intermediate friction levels. These data support a model of an unexplored mode of locomotion--"body-friction legged crawling" with body drag, friction-dominated leg thrust, but no media flow as in air, water, or sand. To define the limits of body compression in confined spaces, we conducted dynamic compressive cycle tests on living animals. Exoskeletal strength allowed cockroaches to withstand forces 300 times body weight when traversing the smallest crevices and up to nearly 900 times body weight without injury. Cockroach exoskeletons provided biological inspiration for the manufacture of an origami-style, soft, legged robot that can locomote rapidly in both open and confined spaces.

Predicting location-specific extreme coastal floods in the future climate by introducing a probabilistic method to calculate maximum elevation of the continuous water mass caused by a combination of water level variations and wind waves

NASA Astrophysics Data System (ADS)

Leijala, Ulpu; Björkqvist, Jan-Victor; Johansson, Milla M.; Pellikka, Havu

2017-04-01

Future coastal management continuously strives for more location-exact and precise methods to investigate possible extreme sea level events and to face flooding hazards in the most appropriate way. Evaluating future flooding risks by understanding the behaviour of the joint effect of sea level variations and wind waves is one of the means to make more comprehensive flooding hazard analysis, and may at first seem like a straightforward task to solve. Nevertheless, challenges and limitations such as availability of time series of the sea level and wave height components, the quality of data, significant locational variability of coastal wave height, as well as assumptions to be made depending on the study location, make the task more complicated. In this study, we present a statistical method for combining location-specific probability distributions of water level variations (including local sea level observations and global mean sea level rise) and wave run-up (based on wave buoy measurements). The goal of our method is to obtain a more accurate way to account for the waves when making flooding hazard analysis on the coast compared to the approach of adding a separate fixed wave action height on top of sea level -based flood risk estimates. As a result of our new method, we gain maximum elevation heights with different return periods of the continuous water mass caused by a combination of both phenomena, "the green water". We also introduce a sensitivity analysis to evaluate the properties and functioning of our method. The sensitivity test is based on using theoretical wave distributions representing different alternatives of wave behaviour in relation to sea level variations. As these wave distributions are merged with the sea level distribution, we get information on how the different wave height conditions and shape of the wave height distribution influence the joint results. Our method presented here can be used as an advanced tool to minimize over- and underestimation of the combined effect of sea level variations and wind waves, and to help coastal infrastructure planning and support smooth and safe operation of coastal cities in a changing climate.

Computed inundation heights of the 2011 Tohoku tsunami compared to measured run-up data: hints for tsunami source inversion

NASA Astrophysics Data System (ADS)

Pagnoni, G.; Tinti, S.; Armigliato, A.

2012-04-01

The 11 March 2011 earthquake that took place off the Pacific coast of Tohoku, North Honshu, with Mw = 9.0, is the largest earthquake ever occurred in Japan, and generated a big tsunami that spread across the Pacific Ocean, causing devastating effects in the prefectures of Aomori, Iwate, Miyagi and Fukushima. It caused more than 15,000 casualties, swept away the low-land quarters of several villages and moreover was the primary cause of the severe nuclear accident in the Fukushima Nuclear Power Plant. There is a very large set of observations covering both the earthquake and the tsunami, and almost certainly this is the case with the most abundant dataset of high-quality data in the history of seismology and of tsunami science. Local and global seismic networks, continuous GPS networks, coastal tide gauges in Japan ports and across the Pacific, local buoys cabled deep ocean-bottom pressure gauges (OBPG) and deep-ocean buoys (such as DART) mainly along the foot of the margins of the pacific continents, all contributed essential data to constrain the source of the earthquake and of the tsunami. In this paper we will use also the observed run-up data to put further constraints on the source and to better determine the distribution of the slip on the offshore fault. This will be done through trial-and-error forward modeling, that is by comparing inundation data calculated by means of numerical tsunami simulations in the near field to tsunami run-up heights measured during field surveys conducted by several teams and made available on the net. Major attention will be devoted to reproduce observations in the prefectures that were more affected and where run-up heights are very large (namely Iwate and Miyagi). The simulations are performed by means of the finite-difference code UBO-TSUFD, developed and maintained by the Tsunami Research Team of the University of Bologna, Italy, that can solve both the linear and non-linear versions of the shallow-water equations on nested grids and with dynamically moving shorelines.

Warm-Up Exercises May Not Be So Important for Enhancing Submaximal Running Performance.

PubMed

Takizawa, Kazuki; Yamaguchi, Taichi; Shibata, Keisuke

2018-05-01

Takizawa, K, Yamaguchi, T, and Shibata, K. Warm-up exercises may not be so important for enhancing submaximal running performance. J Strength Cond Res 32(5): 1383-1390, 2018-The purpose of this study was to determine an appropriate warm-up intensity for enhancing performance in submaximal running at 90% vV[Combining Dot Above]O2max (it assumes 3,000-5,000 m in track events). Seven trained male university athletes took part in this study (age: 21.3 ± 2.1 years, height: 169.3 ± 4.7 cm, body mass: 58.4 ± 5.6 kg, V[Combining Dot Above]O2max: 73.33 ± 5.46 ml·kg·min). Each subject ran on a treadmill at 90% vV[Combining Dot Above]O2max until exhaustion after 1 of 4 warm-up treatments. The 4 warm-up treatments were no warm-up, 15 minutes running at 60% vV[Combining Dot Above]O2max, at 70% vV[Combining Dot Above]O2max, and at 80% vV[Combining Dot Above]O2max. The running performance was evaluated by time to exhaustion (TTE). V[Combining Dot Above]O2, and vastus lateralis muscle temperature were also measured. There were no significant differences in TTE among the warm-up exercises (p > 0.05). V[Combining Dot Above]O2 in no warm-up showed slower reaction than the other warm-up exercises. Regarding, the vastus lateralis muscle temperature immediately after warm-up, no warm-up was significantly (p < 0.01) lower compared with the other warm-up exercises. Our results suggested that submaximal running performance was not affected by the presence or absence of a warm-up or by warm-up intensity, although physiological changes occurred.

The July 17, 2006 Java Tsunami: Tsunami Modeling and the Probable Causes of the Extreme Run-up

NASA Astrophysics Data System (ADS)

Kongko, W.; Schlurmann, T.

2009-04-01

On 17 July 2006, an Earthquake magnitude Mw 7.8 off the south coast of west Java, Indonesia generated tsunami that affected over 300 km of south Java coastline and killed more than 600 people. Observed tsunami heights and field measurement of run-up distributions were uniformly scattered approximately 5 to 7 m along a 200 km coastal stretch; remarkably, a locally focused tsunami run-up height exceeding 20 m at Nusakambangan Island has been observed. Within the framework of the German Indonesia Tsunami Early Warning System (GITEWS) Project, a high-resolution near-shore bathymetrical survey equipped by multi-beam echo-sounder has been recently conducted. Additional geodata have been collected using Intermap Technologies STAR-4 airborne interferometric SAR data acquisition system on a 5 m ground sample distance basis in order to establish a most-sophisticated Digital Terrain Model (DTM). This paper describes the outcome of tsunami modelling approaches using high resolution data of bathymetry and topography being part of a general case study in Cilacap, Indonesia, and medium resolution data for other area along coastline of south Java Island. By means of two different seismic deformation models to mimic the tsunami source generation, a numerical code based on the 2D nonlinear shallow water equations is used to simulate probable tsunami run-up scenarios. Several model tests are done and virtual points in offshore, near-shore, coastline, as well as tsunami run-up on the coast are collected. For the purpose of validation, the model results are compared with field observations and sea level data observed at several tide gauges stations. The performance of numerical simulations and correlations with observed field data are highlighted, and probable causes for the extreme wave heights and run-ups are outlined. References Ammon, C.J., Kanamori, K., Lay, T., and Velasco, A., 2006. The July 2006 Java Tsunami Earthquake, Geophysical Research Letters, 33(L24308). Fritz, H.M., Kongko, W., Moore, A., McAdoo, B., Goff, J., Harbitz, C., Uslu, B., Kalligeris, N., Suteja, D., Kalsum, K., Titov, V., Gusman, A., Latief, H., Santoso, E., Sujoko, S., Djulkarnaen, D., Sunendar, H., and Synolakis, C., 2007. Extreme Run-up from the 17 July 2006 Java Tsunami. Geophysical Research Letters, 34(L12602). Fujii, Y., and Satake, K., 2006. Source of the July 2006 Java Tsunami Estimated from Tide Gauge Records. Geophysical Research Letters, 33(L23417). Intermap Federal Services Inc., 2007. Digital Terrain Model Cilacap, version 1. Project of GITEWS, DLR Germany. Kongko, W., and Leschka, S., 2008. Nearshore Bathymetry Measurements in Indonesia: Part 1. Cilacap, Technical Report, DHI-WASY GmbH Syke Germany. Kongko, W., Suranto, Chaeroni, Aprijanto, Zikra, and SUjantoko, 2006, Rapid Survey on Tsunami Jawa 17 July 2006, http://nctr.pmel.noaa.gov/java20060717/tsunami-java170706_e.pdf Lavigne, F., Gomes, C., Giffo, M., Wassmer, P., Hoebreck, C., Mardiatno, D., Prioyono, J., and Paris R., 2007. Field Observation of the 17 July 2006 Tsunami in Java. Natural Hazards and Earth Systems Sciences, 7: 177-183.

Leg stiffness and expertise in men jumping.

PubMed

Laffaye, Guillaume; Bardy, Benoît G; Durey, Alain

2005-04-01

The aim of the present study is to investigate: a) the leg spring behavior in the one-leg vertical jump, b) the contribution of impulse parameters to this behavior, and c) the effect of jumping expertise on leg stiffness. Four categories of experts (handball, basketball, volleyball players, and Fosbury athletes), as well as novice subjects performed a run-and-jump test to touch a ball with the head. Five experimental conditions were tested from 55 to 95% of the maximum jump height. Kinematic and kinetic data were collected using six cameras and a force plate. The mechanical behavior of the musculoskeleton component of the human body can be modeled as a simple mass-spring system, from which leg stiffness values can be extracted to better understand energy transfer during running or jumping. The results indicate that leg stiffness (mean value of 11.5 kN.m) decreased with jumping height. Leg shortening at takeoff also increased with jumping height, whereas contact time decreased (-18%). No difference was found between experts and novices for leg stiffness. However, a principal components analysis (PCA) indicated the contribution of two main factors to the performance. The first factor emerged out of vertical force, stiffness, and duration of impulse. The second factor included leg shortening and jumping height. Differences between experts and novices were observed in terms of the contribution of leg stiffness to jump height, and more importantly, clear differences existed between experts in jumping parameters. The analysis performed on the sport categories indeed revealed different jumping profiles, characterized by specific, sport-related impulse parameters.

Projected atoll shoreline and run-up changes in response to sea-level rise and varying large wave conditions at Wake and Midway Atolls, Northwestern Hawaiian Islands

USGS Publications Warehouse

Shope, James B.; Storlazzi, Curt; Hoeke, Ron

2017-01-01

Atoll islands are dynamic features that respond to seasonal alterations in wave conditions and sea level. It is unclear how shoreline wave run-up and erosion patterns along these low elevation islands will respond to projected sea-level rise (SLR) and changes in wave climate over the next century, hindering communities' preparation for the future. To elucidate how these processes may respond to climate change, extreme boreal winter and summer wave conditions under future sea-level rise (SLR) and wave climate scenarios were simulated at two atolls, Wake and Midway, using a shallow-water hydrodynamic model. Nearshore wave conditions were used to compute the potential longshore sediment flux along island shorelines via the CERC empirical formula and wave-driven erosion was calculated as the divergence of the longshore drift; run-up and the locations where the run-up exceed the berm elevation were also determined. SLR is projected to predominantly drive future island morphological change and flooding. Seaward shorelines (i.e., ocean fronted shorelines directly facing incident wave energy) were projected to experience greater erosion and flooding with SLR and in hypothetical scenarios where changes to deep water wave directions were altered, as informed by previous climate change forced Pacific wave modeling efforts. These changes caused nearshore waves to become more shore-normal, increasing wave attack along previously protected shorelines. With SLR, leeward shorelines (i.e., an ocean facing shoreline but sheltered from incident wave energy) became more accretive on windward islands and marginally more erosive along leeward islands. These shorelines became more accretionary and subject to more flooding with nearshore waves becoming more shore-normal. Lagoon shorelines demonstrated the greatest SLR-driven increase in erosion and run-up. They exhibited the greatest relative change with increasing wave heights where both erosion and run-up magnitudes increased. Wider reef flat-fronted seaward shorelines became more accretive as all oceanographic forcing parameters increased in magnitude and exhibited large run-up increases following increasing wave heights. Island end shorelines became subject to increased flooding, erosion at Wake, and accretion at Midway with SLR. Under future conditions, windward and leeward islands are projected to become thinner as ocean facing and lagoonal shorelines erode, with leeward islands becoming more elongate. Island shorelines will change dramatically over the next century as SLR and altered wave climates drive new erosional regimes. It is vital to the sustainability of island communities that the relative magnitudes of these effects are addressed when planning for projected future climates.

Projected atoll shoreline and run-up changes in response to sea-level rise and varying large wave conditions at Wake and Midway Atolls, Northwestern Hawaiian Islands

NASA Astrophysics Data System (ADS)

Shope, James B.; Storlazzi, Curt D.; Hoeke, Ron K.

2017-10-01

Atoll islands are dynamic features that respond to seasonal alterations in wave conditions and sea level. It is unclear how shoreline wave run-up and erosion patterns along these low elevation islands will respond to projected sea-level rise (SLR) and changes in wave climate over the next century, hindering communities' preparation for the future. To elucidate how these processes may respond to climate change, extreme boreal winter and summer wave conditions under future sea-level rise (SLR) and wave climate scenarios were simulated at two atolls, Wake and Midway, using a shallow-water hydrodynamic model. Nearshore wave conditions were used to compute the potential longshore sediment flux along island shorelines via the CERC empirical formula and wave-driven erosion was calculated as the divergence of the longshore drift; run-up and the locations where the run-up exceed the berm elevation were also determined. SLR is projected to predominantly drive future island morphological change and flooding. Seaward shorelines (i.e., ocean fronted shorelines directly facing incident wave energy) were projected to experience greater erosion and flooding with SLR and in hypothetical scenarios where changes to deep water wave directions were altered, as informed by previous climate change forced Pacific wave modeling efforts. These changes caused nearshore waves to become more shore-normal, increasing wave attack along previously protected shorelines. With SLR, leeward shorelines (i.e., an ocean facing shoreline but sheltered from incident wave energy) became more accretive on windward islands and marginally more erosive along leeward islands. These shorelines became more accretionary and subject to more flooding with nearshore waves becoming more shore-normal. Lagoon shorelines demonstrated the greatest SLR-driven increase in erosion and run-up. They exhibited the greatest relative change with increasing wave heights where both erosion and run-up magnitudes increased. Wider reef flat-fronted seaward shorelines became more accretive as all oceanographic forcing parameters increased in magnitude and exhibited large run-up increases following increasing wave heights. Island end shorelines became subject to increased flooding, erosion at Wake, and accretion at Midway with SLR. Under future conditions, windward and leeward islands are projected to become thinner as ocean facing and lagoonal shorelines erode, with leeward islands becoming more elongate. Island shorelines will change dramatically over the next century as SLR and altered wave climates drive new erosional regimes. It is vital to the sustainability of island communities that the relative magnitudes of these effects are addressed when planning for projected future climates.

2011 Tohoku, Japan tsunami data available from the National Oceanic and Atmospheric Administration/National Geophysical Data Center

NASA Astrophysics Data System (ADS)

Dunbar, P. K.; Mccullough, H. L.; Mungov, G.; Harris, E.

2012-12-01

The U.S. National Oceanic and Atmospheric Administration (NOAA) has primary responsibility for providing tsunami warnings to the Nation, and a leadership role in tsunami observations and research. A key component of this effort is easy access to authoritative data on past tsunamis, a responsibility of the National Geophysical Data Center (NGDC) and collocated World Service for Geophysics. Archive responsibilities include the global historical tsunami database, coastal tide-gauge data from US/NOAA operated stations, the Deep-ocean Assessment and Reporting of Tsunami (DART®) data, damage photos, as well as other related hazards data. Taken together, this integrated archive supports tsunami forecast, warning, research, mitigation and education efforts of NOAA and the Nation. Understanding the severity and timing of tsunami effects is important for tsunami hazard mitigation and warning. The global historical tsunami database includes the date, time, and location of the source event, magnitude of the source, event validity, maximum wave height, the total number of fatalities and dollar damage. The database contains additional information on run-ups (locations where tsunami waves were observed by eyewitnesses, field reconnaissance surveys, tide gauges, or deep ocean sensors). The run-up table includes arrival times, distance from the source, measurement type, maximum wave height, and the number of fatalities and damage for the specific run-up location. Tide gauge data are required for modeling the interaction of tsunami waves with the coast and for verifying propagation and inundation models. NGDC is the long-term archive for all NOAA coastal tide gauge data and is currently archiving 15-second to 1-minute water level data from the NOAA Center for Operational Oceanographic Products and Services (CO-OPS) and the NOAA Tsunami Warning Centers. DART® buoys, which are essential components of tsunami warning systems, are now deployed in all oceans, giving coastal communities faster and more accurate tsunami warnings. NOAA's National Data Buoy Center disseminates real-time DART® data and NGDC processes and archives post-event 15-second high-resolution bottom pressure time series data. An event-specific archive of DART® observations recorded during recent significant tsunamis, including the March 2011 Tohoku, Japan event, are now available through new tsunami event pages integrated with the NGDC global historical tsunami database. These pages are developed to deliver comprehensive summaries of each tsunami event, including socio-economic impacts, tsunami travel time maps, raw observations, de-tided residuals, spectra of the tsunami signal compared to the energy of the background noise, and wavelets. These data are invaluable to tsunami researchers and educators as they are essential to providing a more thorough understanding of tsunamis and their propagation in the open ocean and subsequent inundation of coastal communities. NGDC has collected 289 tide gauge observations, 34 Deep-ocean Assessment and Reporting of Tsunami (DART®) and bottom pressure recorder (BPR) station observations, and over 5,000 eyewitness reports and post-tsunami field survey measurements for the 2011 Tohoku event.

The repeated bout effect of traditional resistance exercises on running performance across 3 bouts.

PubMed

Doma, Kenji; Schumann, Moritz; Leicht, Anthony Scott; Heilbronn, Brian Edward; Damas, Felipe; Burt, Dean

2017-09-01

This study investigated the repeated bout effect of 3 typical lower body resistance-training sessions on maximal and submaximal effort running performance. Twelve resistance-untrained men (age, 24 ± 4 years; height, 1.81 ± 0.10 m; body mass, 79.3 ± 10.9 kg; peak oxygen uptake, 48.2 ± 6.5 mL·kg -1 ·min -1 ; 6-repetition maximum squat, 71.7 ± 12.2 kg) undertook 3 bouts of resistance-training sessions at 6-repetitions maximum. Countermovement jump (CMJ), lower-body range of motion (ROM), muscle soreness, and creatine kinase (CK) were examined prior to and immediately, 24 h (T24), and 48 h (T48) after each resistance-training bout. Submaximal (i.e., below anaerobic threshold (AT)) and maximal (i.e., above AT) running performances were also conducted at T24 and T48. Most indirect muscle damage markers (i.e., CMJ, ROM, and muscle soreness) and submaximal running performance were significantly improved (P < 0.05; 1.9%) following the third resistance-training bout compared with the second bout. Whilst maximal running performance was also improved following the third bout (P < 0.05; 9.8%) compared with other bouts, the measures were still reduced by 12%-20% versus baseline. However, the increase in CK was attenuated following the second bout (P < 0.05) with no further protection following the third bout (P > 0.05). In conclusion, the initial bout induced the greatest change in CK; however, at least 2 bouts were required to produce protective effects on other indirect muscle damage markers and submaximal running performance measures. This suggests that submaximal running sessions should be avoided for at least 48 h after resistance training until the third bout, although a greater recovery period may be required for maximal running sessions.

Nearshore Tsunami Inundation Model Validation: Toward Sediment Transport Applications

USGS Publications Warehouse

Apotsos, Alex; Buckley, Mark; Gelfenbaum, Guy; Jaffe, Bruce; Vatvani, Deepak

2011-01-01

Model predictions from a numerical model, Delft3D, based on the nonlinear shallow water equations are compared with analytical results and laboratory observations from seven tsunami-like benchmark experiments, and with field observations from the 26 December 2004 Indian Ocean tsunami. The model accurately predicts the magnitude and timing of the measured water levels and flow velocities, as well as the magnitude of the maximum inundation distance and run-up, for both breaking and non-breaking waves. The shock-capturing numerical scheme employed describes well the total decrease in wave height due to breaking, but does not reproduce the observed shoaling near the break point. The maximum water levels observed onshore near Kuala Meurisi, Sumatra, following the 26 December 2004 tsunami are well predicted given the uncertainty in the model setup. The good agreement between the model predictions and the analytical results and observations demonstrates that the numerical solution and wetting and drying methods employed are appropriate for modeling tsunami inundation for breaking and non-breaking long waves. Extension of the model to include sediment transport may be appropriate for long, non-breaking tsunami waves. Using available sediment transport formulations, the sediment deposit thickness at Kuala Meurisi is predicted generally within a factor of 2.

The effect of sprinting after each set of heavy resistance training on the running speed and jumping performance of young basketball players.

PubMed

Tsimahidis, Konstantinos; Galazoulas, Christos; Skoufas, Dimitrios; Papaiakovou, Georgios; Bassa, Eleni; Patikas, Dimitrios; Kotzamanidis, Christos

2010-08-01

The purpose of this study was to investigate the effect of a 10-week heavy resistance combined with a running training program on the strength, running speed (RS), and vertical jump performance of young basketball players. Twenty-six junior basketball players were equally divided in 2 groups. The control (CON) group performed only technical preparation and the group that followed the combined training program (CTP) performed additionally 5 sets of 8-5 repetition maximum (RM) half squat with 1 30-m sprint after each set. The evaluation took place before training and after the 5th and 10th weeks of training. Apart from the 1RM half squat test, the 10- and 30-m running time was measured using photocells and the jump height (squat, countermovement jump, and drop jump) was estimated taking into account the flight time. The 1RM increased by 30.3 +/- 1.5% at the 10th week of training for the CTP group (p < 0.05), whereas the CON group showed no significant increase (1.1 +/- 1.6%, p > 0.05). In general, all measured parameters showed a statistically significant increase after the 5th and 10th weeks (p < 0.05), in contrast to the CON group (p > 0.05). This suggests that the applied CTP is beneficial for the strength, RS, and jump height of young basketball players. The observed adaptations in the CTP group could be attributed to learning factors and to a more optimal transfer of the strength gain to running and jumping performance.

Experimental and theoretical investigation of the role of clay in subaqueous sediment flows and its effect on run-out distance

NASA Astrophysics Data System (ADS)

Hermidas, Navid; Luthi, Stefan; Eggenhuisen, Joris; Silva Jacinto, Ricardo; Toth, Ferenc; Pohl, Florian; de Leeuw, Jan

2016-04-01

Debris flows are driven by gravity, which in the tail region is overcome by the yield strength of the flow, forcing it to freeze. These flows are capable of achieving staggeringly large run-out distances on low gradients. The case in point, described in previous publications, is the flow which resulted in the deposit of Bed 5 of the Agadir megaslide on the north-west African margin. Debrites of this flow have been recorded several hundred kilometres away from the original landslide. Previous studies have attributed such long run-out distances to hydroplaning, low yield strength, and flow transformation. It is known that the net force acting on a volume of fluid in equilibrium is zero. In this work we show that clay-laden flows are capable of approaching equilibrium. The flows which can achieve the maximum run-out distance are cohesive enough to resist some of the surrounding disturbances, that can upset the equilibrium, and reach close to equilibrium conditions, yet are dilute enough to have low viscous stress, and relatively low yield strength and lose little sediment due to deposition. A flow that is not in equilibrium will always seek to approach equilibrium conditions by speeding up or slowing down, depositing sediment, eroding the substrate, contracting in the form of the tail approaching the head, stretching, entraining water and growing in height, or dewatering and collapsing. Here we present a theory that shows that two dimensional (2D) flows in equilibrium do not grow in height. 2D flume experiments were conducted on different mixtures of kaolinite, sand, silt, and water, on varying slopes and a transitionally rough bed (sand glued), and using various discharge rates, in order to map out different stages in the evolution of a density flow from a cohesive plug flow into a turbidity current. The following flow types were observed: high density turbidity currents, plug flows, and no flow. From the velocity profiles, certain runs demonstrated close to equilibrium behaviour. For these flows, very little flow height growth and velocity variation was observed over the length of the flume. In all cases the flow appeared to be laminar within the boundary layer with Kelvin-Helmholtz instabilities at the top which were suppressed to a large extent for higher sediment concentrations. A deposit consisting of thick muddy sand, with approximately uniform thickness, was observed for higher sediment concentrations, indicating relatively higher yield strength values, while a thinner more sandy deposit was observed for more dilute flows. It was concluded that high sediment concentrations on more moderate slopes result in slower moving plug flows which are capable of suppressing turbulence at the top, while lower sediment concentrations on steeper slopes result in faster moving, more turbulent currents. The flows which can achieve the largest run-out distance are located between these two extremes.

47 CFR 2.1511 - Measurements of radiated emissions.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) General set-up instructions. Measurements of radiated electromagnetic emissions (EME) are to be performed... receiver reading in dBm and the instrument settings, antenna height and direction for maximum radiation...

A global probabilistic tsunami hazard assessment from earthquake sources

USGS Publications Warehouse

Davies, Gareth; Griffin, Jonathan; Lovholt, Finn; Glimsdal, Sylfest; Harbitz, Carl; Thio, Hong Kie; Lorito, Stefano; Basili, Roberto; Selva, Jacopo; Geist, Eric L.; Baptista, Maria Ana

2017-01-01

Large tsunamis occur infrequently but have the capacity to cause enormous numbers of casualties, damage to the built environment and critical infrastructure, and economic losses. A sound understanding of tsunami hazard is required to underpin management of these risks, and while tsunami hazard assessments are typically conducted at regional or local scales, globally consistent assessments are required to support international disaster risk reduction efforts, and can serve as a reference for local and regional studies. This study presents a global-scale probabilistic tsunami hazard assessment (PTHA), extending previous global-scale assessments based largely on scenario analysis. Only earthquake sources are considered, as they represent about 80% of the recorded damaging tsunami events. Globally extensive estimates of tsunami run-up height are derived at various exceedance rates, and the associated uncertainties are quantified. Epistemic uncertainties in the exceedance rates of large earthquakes often lead to large uncertainties in tsunami run-up. Deviations between modelled tsunami run-up and event observations are quantified, and found to be larger than suggested in previous studies. Accounting for these deviations in PTHA is important, as it leads to a pronounced increase in predicted tsunami run-up for a given exceedance rate.

Forecasting the impact of storm waves and sea-level rise on Midway Atoll and Laysan Island within the Papahānaumokuākea Marine National Monument—a comparison of passive versus dynamic inundation models

USGS Publications Warehouse

Storlazzi, Curt D.; Berkowitz, Paul; Reynolds, Michelle H.; Logan, Joshua B.

2013-01-01

Two inundation events in 2011 underscored the potential for elevated water levels to damage infrastructure and affect terrestrial ecosystems on the low-lying Northwestern Hawaiian Islands in the Papahānaumokuākea Marine National Monument. The goal of this study was to compare passive "bathtub" inundation models based on geographic information systems (GIS) to those that include dynamic water levels caused by wave-induced set-up and run-up for two end-member island morphologies: Midway, a classic atoll with islands on the shallow (2-8 m) atoll rim and a deep, central lagoon; and Laysan, which is characterized by a deep (20-30 m) atoll rim and an island at the center of the atoll. Vulnerability to elevated water levels was assessed using hindcast wind and wave data to drive coupled physics-based numerical wave, current, and water-level models for the atolls. The resulting model data were then used to compute run-up elevations using a parametric run-up equation under both present conditions and future sea-level-rise scenarios. In both geomorphologies, wave heights and wavelengths adjacent to the island shorelines increased more than three times and four times, respectively, with increasing values of sea-level rise, as more deep-water wave energy could propagate over the atoll rim and larger wind-driven waves could develop on the atoll. Although these increases in water depth resulted in decreased set-up along the islands’ shorelines, the larger wave heights and longer wavelengths due to sea-level rise increased the resulting wave-induced run-up. Run-up values were spatially heterogeneous and dependent on the direction of incident wave direction, bathymetry, and island configuration. Island inundation was modeled to increase substantially when wave-driven effects were included, suggesting that inundation and impacts to infrastructure and terrestrial habitats will occur at lower values of predicted sea-level rise, and thus sooner in the 21st century, than suggested by passive GIS-based "bathtub" inundation models. Lastly, observations and the modeling results suggest that classic atolls with islands on a shallow atoll rim are more susceptible to the combined effects of sea-level rise and wave-driven inundation than atolls characterized by a deep atoll rim.

Shoe collar height effect on athletic performance, ankle joint kinematics and kinetics during unanticipated maximum-effort side-cutting performance.

PubMed

Lam, Gilbert Wing Kai; Park, Eun Jung; Lee, Ki-Kwang; Cheung, Jason Tak-Man

2015-01-01

Side-step cutting manoeuvres comprise the coordination between planting and non-planting legs. Increased shoe collar height is expected to influence ankle biomechanics of both legs and possibly respective cutting performance. This study examined the shoe collar height effect on kinematics and kinetics of planting and non-planting legs during an unanticipated side-step cutting. Fifteen university basketball players performed maximum-effort side-step cutting to the left 45° direction or a straight ahead run in response to a random light signal. Seven successful cutting trials were collected for each condition. Athletic performance, ground reaction force, ankle kinematics and kinetics of both legs were analysed using paired t-tests. Results indicated that high-collar shoes resulted in less ankle inversion and external rotation during initial contact for the planting leg. The high-collar shoes also exhibited a smaller ankle range of motion in the sagittal and transverse planes for both legs, respectively. However, no collar effect was found for ankle moments and performance indicators including cutting performance time, ground contact time, propulsion ground reaction forces and impulses. These findings indicated that high-collar shoes altered ankle positioning and restricted ankle joint freedom movements in both legs, while no negative effect was found for athletic cutting performance.

Roystonea borinquena O.F.

Treesearch

K.F Connor

2002-01-01

Roystonea borinquena is a rapidly growing tree with an average height of 12-18 m but it can reach up to 26.4 m. Young trees can average 1 m height growth annually. Diameters range from 25 to 70 cm; maximum age is 80-110 yrs. The tree has a smooth, gray trunk with a swollen base and gracefully drooping fronds. It is native to Puerto Rico, the...

Wave Overtopping of a Barrier Beach

DTIC Science & Technology

2009-09-01

but can result in increased dune erosion along Scenic Road as occurred in 1993, 1997, and 2005 (James, 2005). Field data and observations for...factors are equal to 1. The equations for these run-up formulas are parameterized on significant wave height at the toe of the structure as measured in...3 exp C r SS RQ C D HgH γ ⎛ ⎞ = −⎜ ⎟ ⎝ ⎠ 2pξ > where the significant wave height at the toe of the structure, SH and pT are used. Again the

Shallow-Water Nitrox Diving, the NASA Experience

NASA Technical Reports Server (NTRS)

Fitzpatrick, Daniel T.

2009-01-01

NASA s Neutral Buoyancy Laboratory (NBL) contains a 6.2 million gallon, 12-meter deep pool where astronauts prepare for space missions involving space walks (extravehicular activity EVA). Training is conducted in a space suit (extravehicular mobility unit EMU) pressurized to 4.0 - 4.3 PSI for up to 6.5 hours while breathing a 46% NITROX mix. Since the facility opened in 1997, over 30,000 hours of suited training has been completed with no occurrence of decompression sickness (DCS) or oxygen toxicity. This study examines the last 5 years of astronaut suited training runs. All suited runs are computer monitored and data is recorded in the Environmental Control System (ECS) database. Astronaut training runs from 2004 - 2008 were reviewed and specific data including total run time, maximum depth and average depth were analyzed. One hundred twenty seven astronauts and cosmonauts completed 2,231 training runs totaling 12,880 exposure hours. Data was available for 96% of the runs. It was revealed that the suit configuration produces a maximum equivalent air depth of 7 meters, essentially eliminating the risk of DCS. Based on average run depth and time, approximately 17% of the training runs exceeded the NOAA oxygen maximum single exposure limits, with no resulting oxygen toxicity. The NBL suited training protocols are safe and time tested. Consideration should be given to reevaluate the NOAA oxygen exposure limits for PO2 levels at or below 1 ATA.

Variation of maximum tree height and annual shoot growth of Smith fir at various elevations in the Sygera Mountains, southeastern Tibetan Plateau.

PubMed

Wang, Yafeng; Čufar, Katarina; Eckstein, Dieter; Liang, Eryuan

2012-01-01

Little is known about tree height and height growth (as annual shoot elongation of the apical part of vertical stems) of coniferous trees growing at various altitudes on the Tibetan Plateau, which provides a high-elevation natural platform for assessing tree growth performance in relation to future climate change. We here investigated the variation of maximum tree height and annual height increment of Smith fir (Abies georgei var. smithii) in seven forest plots (30 m×40 m) along two altitudinal transects between 3,800 m and 4,200/4,390 m above sea level (a.s.l.) in the Sygera Mountains, southeastern Tibetan Plateau. Four plots were located on north-facing slopes and three plots on southeast-facing slopes. At each site, annual shoot growth was obtained by measuring the distance between successive terminal bud scars along the main stem of 25 trees that were between 2 and 4 m high. Maximum/mean tree height and mean annual height increment of Smith fir decreased with increasing altitude up to the tree line, indicative of a stress gradient (the dominant temperature gradient) along the altitudinal transect. Above-average mean minimum summer (particularly July) temperatures affected height increment positively, whereas precipitation had no significant effect on shoot growth. The time series of annual height increments of Smith fir can be used for the reconstruction of past climate on the southeastern Tibetan Plateau. In addition, it can be expected that the rising summer temperatures observed in the recent past and anticipated for the future will enhance Smith fir's growth throughout its altitudinal distribution range.

Validity of Self-Reported Physical Fitness and Body Mass Index in a Military Population.

PubMed

Martin, Robyn C; Grier, Tyson; Canham-Chervak, Michelle; Anderson, Morgan K; Bushman, Timothy T; DeGroot, David W; Jones, Bruce H

2016-01-01

Many epidemiological studies rely on valid physical fitness data. The purpose of this investigation was to assess the validity of self-reported Army Physical Fitness Test (APFT) data and determine whether men and women recall APFT performance differently. U.S. Army soldiers (N = 1,047) completed a survey, including questions on height, weight, and most recent APFT performance. Height, weight, and APFT performance were also obtained from unit records. The mean ± SDs for unit and self-reported push-up repetitions were 63.5 ± 13.1 and 66.3 ± 14.0 for men and 37.7 ± 12.8 and 40.2 ± 12.8 for women, respectively. The mean ± SD for unit- and self-reported sit-up repetitions were 66.3 ± 11.4 and 68.1 ± 12.1 for men and 64.2 ± 13.6 and 66.5 ± 12.9 for women, respectively. The mean ± SD unit- and self-reported 2-mile run times were 15.2 ± 1.8 and 14.9 ± 1.6 minutes for men, and 18.0 ± 2.9 and 17.4 ± 1.9 minutes for women, respectively. Unit- and self-reported body mass indices (BMIs) (calculated by height and weight) were 26.4 ± 3.4 and 26.3 ± 3.6 for men and 24.6 ± 2.8 and 24.2 ± 3.3 for women. Correlations between unit- and self-reported scores for push-ups, sit-ups, 2-mile run, height, weight, and BMI were 0.82, 0.78, 0.85, 0.87, 0.97, and 0.88 for men and 0.86, 0.84, 0.87, 0.78, 0.98, and 0.78 for women, respectively. On average, men and women slightly overreported performance on the APFT and overestimated height, resulting in underestimated BMI. There was no difference in recall ability between men and women (p > 0.05). The very good to excellent correlations (r = 0.78-0.98) between unit- and self-reported scores indicate that self-reported data are valid for capturing physical fitness performance in this population.

Effect of resistance training regimens on treadmill running and neuromuscular performance in recreational endurance runners.

PubMed

Mikkola, Jussi; Vesterinen, Ville; Taipale, Ritva; Capostagno, Benoit; Häkkinen, Keijo; Nummela, Ari

2011-10-01

The purpose of this study was to assess the effects of heavy resistance, explosive resistance, and muscle endurance training on neuromuscular, endurance, and high-intensity running performance in recreational endurance runners. Twenty-seven male runners were divided into one of three groups: heavy resistance, explosive resistance or muscle endurance training. After 6 weeks of preparatory training, the groups underwent an 8-week resistance training programme as a supplement to endurance training. Before and after the 8-week training period, maximal strength (one-repetition maximum), electromyographic activity of the leg extensors, countermovement jump height, maximal speed in the maximal anaerobic running test, maximal endurance performance, maximal oxygen uptake ([V·]O(₂max)), and running economy were assessed. Maximal strength improved in the heavy (P = 0.034, effect size ES = 0.38) and explosive resistance training groups (P = 0.003, ES = 0.67) with increases in leg muscle activation (heavy: P = 0.032, ES = 0.38; explosive: P = 0.002, ES = 0.77). Only the heavy resistance training group improved maximal running speed in the maximal anaerobic running test (P = 0.012, ES = 0.52) and jump height (P = 0.006, ES = 0.59). Maximal endurance running performance was improved in all groups (heavy: P = 0.005, ES = 0.56; explosive: P = 0.034, ES = 0.39; muscle endurance: P = 0.001, ES = 0.94), with small though not statistically significant improvements in [V·]O(₂max) (heavy: ES = 0.08; explosive: ES = 0.29; muscle endurance: ES = 0.65) and running economy (ES in all groups < 0.08). All three modes of strength training used concurrently with endurance training were effective in improving treadmill running endurance performance. However, both heavy and explosive strength training were beneficial in improving neuromuscular characteristics, and heavy resistance training in particular contributed to improvements in high-intensity running characteristics. Thus, endurance runners should include heavy resistance training in their training programmes to enhance endurance performance, such as improving sprinting ability at the end of a race.

HSTRESS: A computer program to calculate the height of a hydraulic fracture in a multi-layered stress medium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warpinski, N.R.

A computer code for calculating hydraulic fracture height and width in a stressed-layer medium has been modified for easy use on a personal computer. HSTRESS allows for up to 51 layers having different thicknesses, stresses and fracture toughnesses. The code can calculate fracture height versus pressure or pressure versus fracture height, depending on the design model in which the data will be used. At any pressure/height, a width profile is calculated and an equivalent width factor and flow resistance factor are determined. This program is written in FORTRAN. Graphics use PLOT88 software by Plotworks, Inc., but the graphics software mustmore » be obtained by the user because of licensing restrictions. A version without graphics can also be run. This code is available through the National Energy Software Center (NESC), operated by Argonne National Laboratory. 14 refs., 21 figs.« less

Moderate-intensity running causes intervertebral disc compression in young adults.

PubMed

Kingsley, Michael Ian; D'Silva, Lindsay Antonio; Jennings, Cameron; Humphries, Brendan; Dalbo, Vincent James; Scanlan, Aaron Terrance

2012-11-01

Decreased intervertebral disc (IVD) volume can result in diminished load-carrying capacity of the spinal region. Although moderate-intensity running is generally advocated for apparently healthy adults, running causes a loss in stature that is thought to reflect IVD compression. The aim of this investigation was to use magnetic resonance imaging (MRI) to quantify the influence of moderate-intensity treadmill running on IVD height and volume in the thoracic and lumbar regions of the vertebral column. A clinic-based repeated-measures design was used in eight healthy young asymptomatic adults. After preliminary measurements and familiarization (day 1), participants reported to the clinic on two further occasions. MRI scans and stature measurements were completed at baseline (day 2), preexercise (day 3), and after 30 min of moderate-intensity treadmill running (postexercise, day 3). Mean height and volume were derived for all thoracic and lumbar IVDs from digitized MRIs, and stature was determined with a stadiometer. Moderate-intensity running resulted in 6.3% ± 0.9% reduction in mean IVD height and 6.9% ± 1.0% reduction in calculated IVD volume. The day-to-day variation in mean IVD height and volume were 0.6% ± 0.6% and 0.4% ± 0.6%, respectively. This is the first study to quantify the influence of moderate-intensity running on IVD height and volume. Changes in IVD height and volume were observed throughout the thoracic and lumbar vertebral regions. These findings suggest that future studies evaluating the influence of various loading activities and recovery techniques on IVD structure should consider thoracic as well as lumbar regions of the spine.

Trunk muscle activation during moderate- and high-intensity running.

PubMed

Behm, David G; Cappa, Dario; Power, Geoffrey A

2009-12-01

Time constraints are cited as a barrier to regular exercise. If particular exercises can achieve multiple training functions, the number of exercises and the time needed to achieve a training goal may be decreased. It was the objective of this study to compare the extent of trunk muscle electromyographic (EMG) activity during running and callisthenic activities. EMG activity of the external obliques, lower abdominals (LA), upper lumbar erector spinae (ULES), and lumbosacral erector spinae (LSES) was monitored while triathletes and active nonrunners ran on a treadmill for 30 min at 60% and 80% of their maximum heart rate (HR) reserve, as well as during 30 repetitions of a partial curl-up and 3 min of a modified Biering-Sørensen back extension exercise. The mean root mean square (RMS) amplitude of the EMG signal was monitored over 10-s periods with measures normalized to a maximum voluntary contraction rotating curl-up (external obliques), hollowing exercise (LA), or back extension (ULES and LSES). A main effect for group was that triathletes had greater overall activation of the external obliques (p < 0.05), LA (p = 0.01), and LSES (p < 0.05) than did nonrunners. Main effects for exercise type showed that the external obliques had less EMG activity during 60% and 80% runs, respectively, than with the curl-ups (p = 0.001). The back extension exercise provided less ULES (p = 0.009) and LSES (p = 0.0001) EMG activity than the 60% and 80% runs, respectively. In conclusion, triathletes had greater trunk activation than nonrunners did while running, which could have contributed to their better performance. Back-stabilizing muscles can be activated more effectively with running than with a prolonged back extension activity. Running can be considered as an efficient, multifunctional exercise combining cardiovascular and trunk endurance benefits.

Time-dependent onshore tsunami response

USGS Publications Warehouse

Apotsos, Alex; Gelfenbaum, Guy R.; Jaffe, Bruce E.

2012-01-01

While bulk measures of the onshore impact of a tsunami, including the maximum run-up elevation and inundation distance, are important for hazard planning, the temporal evolution of the onshore flow dynamics likely controls the extent of the onshore destruction and the erosion and deposition of sediment that occurs. However, the time-varying dynamics of actual tsunamis are even more difficult to measure in situ than the bulk parameters. Here, a numerical model based on the non-linear shallow water equations is used to examine the effects variations in the wave characteristics, bed slope, and bottom roughness have on the temporal evolution of the onshore flow. Model results indicate that the onshore flow dynamics vary significantly over the parameter space examined. For example, the flow dynamics over steep, smooth morphologies tend to be temporally symmetric, with similar magnitude velocities generated during the run-up and run-down phases of inundation. Conversely, on shallow, rough onshore topographies the flow dynamics tend to be temporally skewed toward the run-down phase of inundation, with the magnitude of the flow velocities during run-up and run-down being significantly different. Furthermore, for near-breaking tsunami waves inundating over steep topography, the flow velocity tends to accelerate almost instantaneously to a maximum and then decrease monotonically. Conversely, when very long waves inundate over shallow topography, the flow accelerates more slowly and can remain steady for a period of time before beginning to decelerate. These results indicate that a single set of assumptions concerning the onshore flow dynamics cannot be applied to all tsunamis, and site specific analyses may be required.

Zonal Wave Number 2 Rossby Wave (3.5-day oscillation) Over The Martian Lower Atmosphere

NASA Astrophysics Data System (ADS)

Ghosh, P.; Thokuluwa, R. K.

2013-12-01

Over the Mars, height (800-50 Pascal pressure coordinate) profiles of temperature (K), measured by radio occultation technique during the MGS (Mars Global Surveyor) mission, obtained for the period of 1-10 January 2006 at the Martian latitude of ~63N in almost all the longitudes are analyzed to study the characteristics of the 3.5-day oscillation. To avoid significant data gaps in a particular longitude sector, we selected a set of 7 Mars longitude regions with ranges of 0-30E, 35-60E, 65-95E, 190-230E, 250-280E, 290-320E, and 325-360E to study the global characteristics of the 3.5-day oscillation. The 3.5-day oscillation is not selected as a-priori but observed as a most significant oscillation during this period of 1-10 January 2006. It is observed that in the longitude of 0-30E, the 3.5-day oscillation shows statistically significant power (above the 95% confidence level white noise) from the lowest height (800 Pascal, 8 hPa) itself and up to the height of 450 Pascal level with the maximum power of ~130 K^2 at the 600 & 650 Pascal levels. It started to grow from the power of ~ 50 K^2 at the lowest height of 800 Pascal level and reached the maximum power in the height of 600-650 Pascal level and then it started to get lessened monotonously up to the height of 450 Pascal level where its power is ~ 20 K^2. Beyond this height and up to the height of 50 Pascal level, the wave amplitude is below the white noise level. As the phase of the wave is almost constant at all the height levels, it seems that the observed 3.5-day oscillation is a stationary wave with respect to the height. In the 35-60 E longitude sector, the vertical structure of the 3.5-day oscillation is similar to what observed for the 0-30 E longitude region but the power is statistically insignificant at all the heights. However in the 65-95E longitude sector, the wave grows from the lowest level (70 K^2) of 800 Pascal to its maximum power of 280 K^2 in the height of 700 Pascal level and then it started to get decreasing monotonously to the statistically significant lowest power of 20 K^2 in the height of 450 Pascal level. Similar to the 0-30E longitude region, there is no significant wave in all the heights above the 450 Pascal level. The 190-230 E region shows similar wave characteristics (both the power and height structure) as observed for the 0-30 E region. This would indicate that the here reporting 3.5 day wave might be associated with eastward propagating (observed the zonal phase speed of ~0.5 days per 30 degree longitude) wave number 2 Rossby wave as the wave shows similar characteristics in the two longitude regions of 0-30E and 190-230 E with the longitudinal interval of 180 degrees. Peculiarly, in the 250-280 E region, the wave shows maximum power (120 K^2) in the two heights of 550 and 700 Pascal levels. As a further support for the zonal wave number 2 structure, there is no significant 3.5-day oscillation in all the height levels in the 290-320 E longitude region which is similar to what observed in the 35-60E longitude sector. A detailed investigation of this 3.5 day oscillation will be presented also for other periods of different years.

A Temporal Assessment of Barrier Island Vulnerability to Extreme Wave Events, Virginia Coast Reserve

NASA Astrophysics Data System (ADS)

Oster, D. J.; Moore, L. J.; Doran, K. J.; Stockdon, H. F.

2010-12-01

Barrier island vulnerability to storm-generated waves is directly related to interactions between shoreface morphology and surf-zone dynamics. During storms, the seaward-most dune often limits the landward extent of wave energy; however, if maximum wave run-up exceeds the elevation of the top of the dune, overwash or inundation may occur. The ‘Storm Impact Scale’ presented by Sallenger (2000) classifies barrier beach vulnerability to individual storm events based on the elevation of the frontal dune crest and toe relative to maximum wave run-up. Changes to the dune and beachface can occur over a range of time scales, altering local vulnerability to extreme waves from storms, even as a storm is occurring. As sea level continues to rise, barrier beaches will become increasingly vulnerable to overwash and inundation from a greater number of storms. Our objective is to assess temporal trends in barrier island vulnerability while also exploring island-chain-wide response and recovery from two notably different storm events (Nor’Ida and Hurricane Bonnie) along the undeveloped barrier islands of the Virginia Coast Reserve (VCR). We compare shoreline position and elevations of the frontal dune crest (DHIGH) and dune toe (DLOW) across four lidar data sets collected between 1998-2010. Observed significant wave height and period from the National Data Buoy Center and the Duck, NC Field Research Facility for the time period between 1985 and 2009 are classified to represent one-year, five-year, and ten-year storm events that serve as the basis for comparison of island vulnerability through time to a range of storm severity. Initial results reveal significant spatial and temporal variation in barrier island vulnerability to storms throughout the VCR. Despite the range of variability, all three beach features (i.e., shoreline position, DHIGH and DLOW), have moved landward indicating large-scale, widespread migration, or narrowing, of VCR barrier island landforms over the last 10 years. Potentially evolving long-term trends in island vulnerability appear to be difficult to detect, likely due to the short time window of analysis and the preferential capture of short-term variations as two out of the four lidar data sets were collected immediately following a storm event. Further statistical analysis of changes in frontal dune height (DHIGH) and the distance between the dune toe (DLOW) and shoreline will provide insight into short-term responses to individual storms as well as the potential for future long-term changes in barrier island vulnerability, contributing to a better understanding of barrier island response to rising seas and severe storms.

A Global Sensitivity Analysis Method on Maximum Tsunami Wave Heights to Potential Seismic Source Parameters

NASA Astrophysics Data System (ADS)

Ren, Luchuan

2015-04-01

A Global Sensitivity Analysis Method on Maximum Tsunami Wave Heights to Potential Seismic Source Parameters Luchuan Ren, Jianwei Tian, Mingli Hong Institute of Disaster Prevention, Sanhe, Heibei Province, 065201, P.R. China It is obvious that the uncertainties of the maximum tsunami wave heights in offshore area are partly from uncertainties of the potential seismic tsunami source parameters. A global sensitivity analysis method on the maximum tsunami wave heights to the potential seismic source parameters is put forward in this paper. The tsunami wave heights are calculated by COMCOT ( the Cornell Multi-grid Coupled Tsunami Model), on the assumption that an earthquake with magnitude MW8.0 occurred at the northern fault segment along the Manila Trench and triggered a tsunami in the South China Sea. We select the simulated results of maximum tsunami wave heights at specific sites in offshore area to verify the validity of the method proposed in this paper. For ranking importance order of the uncertainties of potential seismic source parameters (the earthquake's magnitude, the focal depth, the strike angle, dip angle and slip angle etc..) in generating uncertainties of the maximum tsunami wave heights, we chose Morris method to analyze the sensitivity of the maximum tsunami wave heights to the aforementioned parameters, and give several qualitative descriptions of nonlinear or linear effects of them on the maximum tsunami wave heights. We quantitatively analyze the sensitivity of the maximum tsunami wave heights to these parameters and the interaction effects among these parameters on the maximum tsunami wave heights by means of the extended FAST method afterward. The results shows that the maximum tsunami wave heights are very sensitive to the earthquake magnitude, followed successively by the epicenter location, the strike angle and dip angle, the interactions effect between the sensitive parameters are very obvious at specific site in offshore area, and there exist differences in importance order in generating uncertainties of the maximum tsunami wave heights for same group parameters at different specific sites in offshore area. These results are helpful to deeply understand the relationship between the tsunami wave heights and the seismic tsunami source parameters. Keywords: Global sensitivity analysis; Tsunami wave height; Potential seismic tsunami source parameter; Morris method; Extended FAST method

Semantic 3d City Model to Raster Generalisation for Water Run-Off Modelling

NASA Astrophysics Data System (ADS)

Verbree, E.; de Vries, M.; Gorte, B.; Oude Elberink, S.; Karimlou, G.

2013-09-01

Water run-off modelling applied within urban areas requires an appropriate detailed surface model represented by a raster height grid. Accurate simulations at this scale level have to take into account small but important water barriers and flow channels given by the large-scale map definitions of buildings, street infrastructure, and other terrain objects. Thus, these 3D features have to be rasterised such that each cell represents the height of the object class as good as possible given the cell size limitations. Small grid cells will result in realistic run-off modelling but with unacceptable computation times; larger grid cells with averaged height values will result in less realistic run-off modelling but fast computation times. This paper introduces a height grid generalisation approach in which the surface characteristics that most influence the water run-off flow are preserved. The first step is to create a detailed surface model (1:1.000), combining high-density laser data with a detailed topographic base map. The topographic map objects are triangulated to a set of TIN-objects by taking into account the semantics of the different map object classes. These TIN objects are then rasterised to two grids with a 0.5m cell-spacing: one grid for the object class labels and the other for the TIN-interpolated height values. The next step is to generalise both raster grids to a lower resolution using a procedure that considers the class label of each cell and that of its neighbours. The results of this approach are tested and validated by water run-off model runs for different cellspaced height grids at a pilot area in Amersfoort (the Netherlands). Two national datasets were used in this study: the large scale Topographic Base map (BGT, map scale 1:1.000), and the National height model of the Netherlands AHN2 (10 points per square meter on average). Comparison between the original AHN2 height grid and the semantically enriched and then generalised height grids shows that water barriers are better preserved with the new method. This research confirms the idea that topographical information, mainly the boundary locations and object classes, can enrich the height grid for this hydrological application.

Ground reaction force adaptations during cross-slope walking and running.

PubMed

Damavandi, Mohsen; Dixon, Philippe C; Pearsall, David J

2012-02-01

Though transversely inclined (cross-sloped) surfaces are prevalent, our understanding of the biomechanical adaptations required for cross-slope locomotion is limited. The purpose of this study was to examine ground reaction forces (GRF) in cross-sloped and level walking and running. Nine young adult males walked and ran barefoot along an inclinable walkway in both level (0°) and cross-slope (10°) configurations. The magnitude and time of occurrence of selected features of the GRF were extracted from the force plate data. GRF data were collected in level walking and running (LW and LR), inclined walking and running up-slope (IWU and IRU), and down-slope (IWD and IRD), respectively. The GRF data were then analyzed using repeated measures MANOVA. In the anteroposterior direction, the timing of the peak force values differed across conditions during walking (p=.041), while the magnitude of forces were modified across conditions for running (p=.047). Most significant differences were observed in the mediolateral direction, where generally force values were up to 390% and 530% (p<.001) larger during the cross-slope conditions compared to level for walking and running, respectively. The maximum force peak during running occurred earlier at IRU compared to the other conditions (p≤.031). For the normal axis a significant difference was observed in the first maximum force peak during walking (p=.049). The findings of this study showed that compared to level surfaces, functional adaptations are required to maintain forward progression and dynamic stability in stance during cross-slope walking and running. Copyright © 2011 Elsevier B.V. All rights reserved.

Spatial variability in the trends in extreme storm surges and weekly-scale high water levels in the eastern Baltic Sea

NASA Astrophysics Data System (ADS)

Soomere, Tarmo; Pindsoo, Katri

2016-03-01

We address the possibilities of a separation of the overall increasing trend in maximum water levels of semi-enclosed water bodies into associated trends in the heights of local storm surges and basin-scale components of the water level based on recorded and modelled local water level time series. The test area is the Baltic Sea. Sequences of strong storms may substantially increase its water volume and raise the average sea level by almost 1 m for a few weeks. Such events are singled out from the water level time series using a weekly-scale average. The trends in the annual maxima of the weekly average have an almost constant value along the entire eastern Baltic Sea coast for averaging intervals longer than 4 days. Their slopes are ~4 cm/decade for 8-day running average and decrease with an increase of the averaging interval. The trends for maxima of local storm surge heights represent almost the entire spatial variability in the water level maxima. Their slopes vary from almost zero for the open Baltic Proper coast up to 5-7 cm/decade in the eastern Gulf of Finland and Gulf of Riga. This pattern suggests that an increase in wind speed in strong storms is unlikely in this area but storm duration may have increased and wind direction may have rotated.

Sport-specific functional movement can simulate aspects of neuromuscular fatigue occurring in team sports.

PubMed

Wilke, Jan; Fleckenstein, Johannes; Krause, Frieder; Vogt, Lutz; Banzer, Winfried

2016-06-01

Fatigue protocols have been used over the years to examine muscular exhaustion. As an alternative to approaches in laboratory settings, functional agility protocols claiming to mimic the multifaceted loads of athletic activity have been proposed. This study aimed to examine the effects of a functional agility short-term fatigue protocol (FAST-FP) on neuromuscular function. Twenty-eight healthy sports students (15 males, aged 24.3 ± 2.4 years) completed the FAST-FP, which consists of four components: three counter-movement jumps (90% of individual maximum), a 20-s bout of step-ups, three bodyweight squats and an agility run. Tasks were repeated until the participants no longer achieved the required jump height in two consecutive sets. Outcomes (pre-post) encompassed subjective exhaustion (visual analogue scale [VAS]), maximum isometric voluntary force of the knee extensors (MIVF), reactive strength index (RSI), mean power frequency (MPF, measured using surface electromyography) and maximum knee range of motion (ROM). Post-intervention, VAS (+54 mm) increased significantly, while MIVF (-6.1%), RSI (-10.7%) and MPF (-4.1%) were reduced (p < 0.05). No changes were observed for ROM (p > 0.05). The FAST-FP induces small-to-moderate impairments in neuromuscular function and considerable self-perceived fatigue. Current evidence on exhaustion developing in team sports suggests that this magnitude of fatigue is similar. The protocol might thus be valuable in the evaluation of treatments counteracting post-match fatigue in team sports.

Prosthetic model, but not stiffness or height, affects the metabolic cost of running for athletes with unilateral transtibial amputations.

PubMed

Beck, Owen N; Taboga, Paolo; Grabowski, Alena M

2017-07-01

Running-specific prostheses enable athletes with lower limb amputations to run by emulating the spring-like function of biological legs. Current prosthetic stiffness and height recommendations aim to mitigate kinematic asymmetries for athletes with unilateral transtibial amputations. However, it is unclear how different prosthetic configurations influence the biomechanics and metabolic cost of running. Consequently, we investigated how prosthetic model, stiffness, and height affect the biomechanics and metabolic cost of running. Ten athletes with unilateral transtibial amputations each performed 15 running trials at 2.5 or 3.0 m/s while we measured ground reaction forces and metabolic rates. Athletes ran using three different prosthetic models with five different stiffness category and height combinations per model. Use of an Ottobock 1E90 Sprinter prosthesis reduced metabolic cost by 4.3 and 3.4% compared with use of Freedom Innovations Catapult [fixed effect (β) = -0.177; P < 0.001] and Össur Flex-Run (β = -0.139; P = 0.002) prostheses, respectively. Neither prosthetic stiffness ( P ≥ 0.180) nor height ( P = 0.062) affected the metabolic cost of running. The metabolic cost of running was related to lower peak (β = 0.649; P = 0.001) and stance average (β = 0.772; P = 0.018) vertical ground reaction forces, prolonged ground contact times (β = -4.349; P = 0.012), and decreased leg stiffness (β = 0.071; P < 0.001) averaged from both legs. Metabolic cost was reduced with more symmetric peak vertical ground reaction forces (β = 0.007; P = 0.003) but was unrelated to stride kinematic symmetry ( P ≥ 0.636). Therefore, prosthetic recommendations based on symmetric stride kinematics do not necessarily minimize the metabolic cost of running. Instead, an optimal prosthetic model, which improves overall biomechanics, minimizes the metabolic cost of running for athletes with unilateral transtibial amputations. NEW & NOTEWORTHY The metabolic cost of running for athletes with unilateral transtibial amputations depends on prosthetic model and is associated with lower peak and stance average vertical ground reaction forces, longer contact times, and reduced leg stiffness. Metabolic cost is unrelated to prosthetic stiffness, height, and stride kinematic symmetry. Unlike nonamputees who decrease leg stiffness with increased in-series surface stiffness, biological limb stiffness for athletes with unilateral transtibial amputations is positively correlated with increased in-series (prosthetic) stiffness.

Shoulder muscle activation during stable and suspended push-ups at different heights in healthy subjects.

PubMed

Borreani, Sebastien; Calatayud, Joaquin; Colado, Juan C; Tella, Victor; Moya-Nájera, Diego; Martin, Fernando; Rogers, Michael E

2015-08-01

To analyze shoulder muscle activation when performing push-ups under different stability conditions and heights. Comparative study by repeated measures. Valencia University laboratory. 29 healthy males participated. Subjects performed 3 push-ups each with their hands at 2 different heights (10 vs. 65 cm) under stable conditions and using a suspension device. Push-up speed was controlled and the testing order was randomized. The average amplitudes of the electromyographic root mean square of the long head of the triceps brachii (TRICEP), upper trapezius (TRAPS), anterior deltoid (DELT) and clavicular pectoralis (PEC) were recorded. The electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC). Suspended push-ups at 10 cm resulted in greater activation in the TRICEP (17.14 ± 1.31 %MVIC vs. 37.03 ± 1.80 %MVIC) and TRAPS (5.83 ± 0.58 %MVIC vs. 14.69 ± 1.91 %MVIC) than those performed on the floor. For DELT and PEC similar or higher activation was found performing the push-ups on the floor, respectively. Height determines different muscle activation patterns. Stable push-ups elicit similar PEC and higher DELT muscle activation, being greater at 10 cm; whereas suspended push-ups elicit greater TRAPS and TRICEP muscle activation, being greater at 65 cm. Copyright © 2014 Elsevier Ltd. All rights reserved.

PULSE AMPLITUDE ANALYZER

DOEpatents

Greenblatt, M.H.

1958-03-25

This patent pertains to pulse amplitude analyzers for sorting and counting a serles of pulses, and specifically discloses an analyzer which ls simple in construction and presents the puise height distribution visually on an oscilloscope screen. According to the invention, the pulses are applied to the vertical deflection plates of an oscilloscope and trigger the horizontal sweep. Each pulse starts at the same point on the screen and has a maximum amplitude substantially along the same vertical line. A mask is placed over the screen except for a slot running along the line where the maximum amplitudes of the pulses appear. After the slot has been scanned by a photocell in combination with a slotted rotating disk, the photocell signal is displayed on an auxiliary oscilloscope as vertical deflection along a horizontal time base to portray the pulse amplitude distribution.

Factors affecting running performance in 6-12-year-olds: The Health Oriented Pedagogical Project (HOPP).

PubMed

Fredriksen, Per Morten; Mamen, Asgeir; Gammelsrud, Heidi; Lindberg, Morten; Hjelle, Ole Petter

2018-05-01

The purpose of this study was to examine factors affecting running performance in children. A cross-sectional study exploring the relationships between height, weight, waist circumference, muscle mass, body fat percentage, relevant biomarkers, and the Andersen intermittent running test in 2272 children aged 6 to 12 years. Parental education level was used as a non-physiological explanatory variable. Mean values (SD) and percentiles are presented as reference values. Height (β = 6.4, p < .0001), high values of haemoglobin (β = 18, p = .013) and low percentage of body fat (β = -7.5, p < .0001) showed an association with results from the running test. In addition, high parental education level showed a positive association with the running test. Boys display better running performance than girls at all age ages, except 7 years old, probably because of additional muscle mass and less fatty tissue. Height and increased level of haemoglobin positively affected running performance. Lower body fat percentage and high parental education level correlated with better running performance.

Climatology and inter-annual variability of the polar mesospheric winds inferred from meteor radar observations over Sodankylä (67N, 26E) during solar cycle 24

NASA Astrophysics Data System (ADS)

Lukianova, Renata; Kozlovsky, Alexander; Lester, Mark

2018-06-01

The inter-annual variability, climatological mean wind and tide fields in the northern polar mesosphere/lower thermosphere region of 82-98 km height are studied using observations by the meteor radar which has operated continuously during solar cycle 24 (from December 2008 onward) at the Sodankylä Geophysical Observatory (67N, 26E). Summer mean zonal winds are characterized by westward flow, up to 25 m/s, at lower heights and eastward flow, up to 30 m/s, at upper heights. In the winter an eastward flow, up to 10 m/s, dominates at all heights. The meridional winds are characterized by a relatively weak poleward flow (few m/s) in the winter and equatorward flow in the summer, with a jet core (∼15 m/s) located slightly below 90 km. These systematically varying winds are dominated by the semidiurnal tides. The largest amplitudes, up to 30 m/s, are observed at higher altitudes in winter and a secondary maximum is seen in August-September. The diurnal tides are almost a factor of two weaker and peak in summer. The variability of individual years is dominated by the winter perturbations. During the period of observations major sudden stratospheric warmings (SSW) occurred in January 2009 and 2013. During these events the wind fields were strongly modified. The lowest altitude eastward winds maximized up to 25 m/s, that is by more twice that of the non-SSW years. The poleward flow considerably increases (up 10 m/s) and extends from the lower heights throughout the whole altitude range. The annual pattern in temperature at ∼90 km height over Sodankyla consists of warm winters (up to 200 K) and cold summers (∼120 K).

Hazard potential of volcanic flank collapses raised by new megatsunami evidence

PubMed Central

Ramalho, Ricardo S.; Winckler, Gisela; Madeira, José; Helffrich, George R.; Hipólito, Ana; Quartau, Rui; Adena, Katherine; Schaefer, Joerg M.

2015-01-01

Large-scale gravitational flank collapses of steep volcanic islands are hypothetically capable of triggering megatsunamis with highly catastrophic effects. Yet, evidence for the generation and impact of collapse-triggered megatsunamis and their high run-ups remains scarce or is highly controversial. Therefore, doubts remain on whether island flank failures truly generate enough volume flux to trigger giant tsunamis, leading to diverging opinions concerning the real hazard potential of such collapses. We show that one of the most prominent oceanic volcanoes on Earth—Fogo, in the Cape Verde Islands—catastrophically collapsed and triggered a megatsunami with devastating effects ~73,000 years ago. Our deductions are based on the recent discovery and cosmogenic 3He dating of tsunamigenic deposits found on nearby Santiago Island, which attest to the impact of this giant tsunami and document wave run-up heights exceeding 270 m. The evidence reported here implies that Fogo’s flank failure involved at least one fast and voluminous event that led to a giant tsunami, in contrast to what has been suggested before. Our observations therefore further demonstrate that flank collapses may indeed catastrophically happen and are capable of triggering tsunamis of enormous height and energy, adding to their hazard potential. PMID:26601287

Wave Overtopping of a Barrier Beach

NASA Astrophysics Data System (ADS)

Thornton, E. B.; Laudier, N.; Macmahan, J. H.

2009-12-01

The rate of wave overtopping of a barrier beach is measured and modeled as a first step in modeling the breaching of a beach impounding an ephemeral river. Unique rate of wave overtopping data are obtained from the measure of the Carmel River, California, lagoon filling during a time when the lagoon is closed-off and there is no river inflow. Volume changes are calculated from measured lagoon height changes owing to wave overtopping by a stage-volume curve, then center differenced and averaged to provide volume rates of change in the lagoon. Wave height and period are obtained from CDIP MOPS directional wave spectra data in 15m fronting the beach. Beach morphology was measured by GPS walking surveys and interpolated for beach slopes and berm heights. Three empirical overtopping models by van der Meer and Janssen (1995), Hedges and Reis (1998) and Pullen et al. (2007) with differing parameterizations on wave height, period and beach slope and calibrated using extensive laboratory data obtained over plane, impermeable beaches are compared with the data. In addition, the run-up model by Stockdon et al. (2006) based on field data is examined. Three wave overtopping storm events are considered when morphology data were available less than 2 weeks prior to the event. The models are tuned to fit the data using a reduction factor to account for beach permeability, berm characteristics, non-normal wave incidence and surface roughness influence. It is concluded that the Stockdon et al. (2006) model underestimates run-up as no overtopping is predicted with this model. The three empirical overtopping models behaved similarly well with regression coefficients ranging 0.72 to 0.86 using a reasonable range of reduction factors 0.66 - 0.81 with an average of 0.74.

Challenges in Defining Tsunami Wave Height

NASA Astrophysics Data System (ADS)

Stroker, K. J.; Dunbar, P. K.; Mungov, G.; Sweeney, A.; Arcos, N. P.

2017-12-01

The NOAA National Centers for Environmental Information (NCEI) and co-located World Data Service for Geophysics maintain the global tsunami archive consisting of the historical tsunami database, imagery, and raw and processed water level data. The historical tsunami database incorporates, where available, maximum wave heights for each coastal tide gauge and deep-ocean buoy that recorded a tsunami signal. These data are important because they are used for tsunami hazard assessment, model calibration, validation, and forecast and warning. There have been ongoing discussions in the tsunami community about the correct way to measure and report these wave heights. It is important to understand how these measurements might vary depending on how the data were processed and the definition of maximum wave height. On September 16, 2015, an 8.3 Mw earthquake located 48 km west of Illapel, Chile generated a tsunami that was observed all over the Pacific region. We processed the time-series water level data for 57 tide gauges that recorded this tsunami and compared the maximum wave heights determined from different definitions. We also compared the maximum wave heights from the NCEI-processed data with the heights reported by the NOAA Tsunami Warning Centers. We found that in the near field different methods of determining the maximum tsunami wave heights could result in large differences due to possible instrumental clipping. We also found that the maximum peak is usually larger than the maximum amplitude (½ peak-to-trough), but the differences for the majority of the stations were <20 cm. For this event, the maximum tsunami wave heights determined by either definition (maximum peak or amplitude) would have validated the forecasts issued by the NOAA Tsunami Warning Centers. Since there is currently only one field in the NCEI historical tsunami database to store the maximum tsunami wave height, NCEI will consider adding an additional field for the maximum peak measurement.

Challenges in Defining Tsunami Wave Heights

NASA Astrophysics Data System (ADS)

Dunbar, Paula; Mungov, George; Sweeney, Aaron; Stroker, Kelly; Arcos, Nicolas

2017-08-01

The National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information (NCEI) and co-located World Data Service for Geophysics maintain the global tsunami archive consisting of the historical tsunami database, imagery, and raw and processed water level data. The historical tsunami database incorporates, where available, maximum wave heights for each coastal tide gauge and deep-ocean buoy that recorded a tsunami signal. These data are important because they are used for tsunami hazard assessment, model calibration, validation, and forecast and warning. There have been ongoing discussions in the tsunami community about the correct way to measure and report these wave heights. It is important to understand how these measurements might vary depending on how the data were processed and the definition of maximum wave height. On September 16, 2015, an 8.3 M w earthquake located 48 km west of Illapel, Chile generated a tsunami that was observed all over the Pacific region. We processed the time-series water level data for 57 coastal tide gauges that recorded this tsunami and compared the maximum wave heights determined from different definitions. We also compared the maximum wave heights from the NCEI-processed data with the heights reported by the NOAA Tsunami Warning Centers. We found that in the near field different methods of determining the maximum tsunami wave heights could result in large differences due to possible instrumental clipping. We also found that the maximum peak is usually larger than the maximum amplitude (½ peak-to-trough), but the differences for the majority of the stations were <20 cm. For this event, the maximum tsunami wave heights determined by either definition (maximum peak or amplitude) would have validated the forecasts issued by the NOAA Tsunami Warning Centers. Since there is currently only one field in the NCEI historical tsunami database to store the maximum tsunami wave height for each tide gauge and deep-ocean buoy, NCEI will consider adding an additional field for the maximum peak measurement.

47 CFR 90.377 - Frequencies available; maximum EIRP and antenna height, and priority communications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Frequencies available; maximum EIRP and antenna...; maximum EIRP and antenna height, and priority communications. (a) Licensees shall transmit only the power... maximum EIRP permitted for an RSU with an antenna height not exceeding 8 meters above the roadway bed...

47 CFR 90.377 - Frequencies available; maximum EIRP and antenna height, and priority communications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 5 2012-10-01 2012-10-01 false Frequencies available; maximum EIRP and antenna...; maximum EIRP and antenna height, and priority communications. (a) Licensees shall transmit only the power... maximum EIRP permitted for an RSU with an antenna height not exceeding 8 meters above the roadway bed...

47 CFR 90.377 - Frequencies available; maximum EIRP and antenna height, and priority communications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 5 2013-10-01 2013-10-01 false Frequencies available; maximum EIRP and antenna...; maximum EIRP and antenna height, and priority communications. (a) Licensees shall transmit only the power... maximum EIRP permitted for an RSU with an antenna height not exceeding 8 meters above the roadway bed...

47 CFR 90.377 - Frequencies available; maximum EIRP and antenna height, and priority communications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Frequencies available; maximum EIRP and antenna...; maximum EIRP and antenna height, and priority communications. (a) Licensees shall transmit only the power... maximum EIRP permitted for an RSU with an antenna height not exceeding 8 meters above the roadway bed...

40 CFR 60.386 - Test methods and procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... The sample volume for each run shall be at least 1.70 dscm (60 dscf). The sampling probe and filter... probe and filter temperature slightly above the effluent temperature (up to a maximum filter temperature...

40 CFR 60.386 - Test methods and procedures.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... The sample volume for each run shall be at least 1.70 dscm (60 dscf). The sampling probe and filter... probe and filter temperature slightly above the effluent temperature (up to a maximum filter temperature...

40 CFR 60.386 - Test methods and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... The sample volume for each run shall be at least 1.70 dscm (60 dscf). The sampling probe and filter... probe and filter temperature slightly above the effluent temperature (up to a maximum filter temperature...

40 CFR 60.386 - Test methods and procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... The sample volume for each run shall be at least 1.70 dscm (60 dscf). The sampling probe and filter... probe and filter temperature slightly above the effluent temperature (up to a maximum filter temperature...

Hip-Extensor Strength, Trunk Posture, and Use of the Knee-Extensor Muscles During Running.

PubMed

Teng, Hsiang-Ling; Powers, Christopher M

2016-07-01

Diminished hip-muscle performance has been proposed to contribute to various knee injuries. To determine the association between hip-extensor muscle strength and sagittal-plane trunk posture and the relationships among hip-extensor muscle strength and hip- and knee-extensor work during running. Descriptive laboratory study. Musculoskeletal biomechanical laboratory. A total of 40 asymptomatic recreational runners, 20 men (age = 27.1 ± 7.0 years, height = 1.74 ± 0.69 m, mass = 71.1 ± 8.2 kg) and 20 women (age = 26.2 ± 5.8 years, height = 1.65 ± 0.74 m, mass = 60.6 ± 6.6 kg), participated. Maximum isometric strength of the hip extensors was assessed using a dynamometer. Sagittal-plane trunk posture (calculated relative to the global vertical axis) and hip- and knee-extensor work (sum of energy absorption and generation) during the stance phase of running were quantified while participants ran over ground at a controlled speed of 3.4 m/s. We used Pearson product moment correlations to examine the relationships among hip-extensor strength, mean sagittal-plane trunk-flexion angle, hip-extensor work, and knee-extensor work. Hip-extensor strength was correlated positively with trunk-flexion angle (r = 0.55, P < .001) and hip-extensor work (r = 0.46, P = .003). It was correlated inversely with knee-extensor work (r = -0.39, P = .01). All the correlations remained after adjusting for sex. Our findings suggest that runners with hip-extensor weakness used a more upright trunk posture. This strategy led to an overreliance on the knee extensors and may contribute to overuse running injuries at the knee.

Hip-Extensor Strength, Trunk Posture, and Use of the Knee-Extensor Muscles During Running

PubMed Central

Teng, Hsiang-Ling; Powers, Christopher M.

2016-01-01

Context:  Diminished hip-muscle performance has been proposed to contribute to various knee injuries. Objective:  To determine the association between hip-extensor muscle strength and sagittal-plane trunk posture and the relationships among hip-extensor muscle strength and hip- and knee-extensor work during running. Design:  Descriptive laboratory study. Setting:  Musculoskeletal biomechanical laboratory. Patients or Other Participants:  A total of 40 asymptomatic recreational runners, 20 men (age = 27.1 ± 7.0 years, height = 1.74 ± 0.69 m, mass = 71.1 ± 8.2 kg) and 20 women (age = 26.2 ± 5.8 years, height = 1.65 ± 0.74 m, mass = 60.6 ± 6.6 kg), participated. Main Outcome Measure(s):  Maximum isometric strength of the hip extensors was assessed using a dynamometer. Sagittal-plane trunk posture (calculated relative to the global vertical axis) and hip- and knee-extensor work (sum of energy absorption and generation) during the stance phase of running were quantified while participants ran over ground at a controlled speed of 3.4 m/s. We used Pearson product moment correlations to examine the relationships among hip-extensor strength, mean sagittal-plane trunk-flexion angle, hip-extensor work, and knee-extensor work. Results:  Hip-extensor strength was correlated positively with trunk-flexion angle (r = 0.55, P < .001) and hip-extensor work (r = 0.46, P = .003). It was correlated inversely with knee-extensor work (r = −0.39, P = .01). All the correlations remained after adjusting for sex. Conclusions:  Our findings suggest that runners with hip-extensor weakness used a more upright trunk posture. This strategy led to an overreliance on the knee extensors and may contribute to overuse running injuries at the knee. PMID:27513169

Deformation relief evolution during sliding friction of Hadfield steel single crystal

NASA Astrophysics Data System (ADS)

Lychagin, D. V.; Filippov, A. V.; Novitskaya, O. S.; Kolubaev, A. V.; Sizova, O. V.

2017-12-01

The paper deals with the evolution of the deformation relief formed on lateral faces of single crystals of Hadfield steel during dry sliding friction. The use of single crystals with the predetermined orientation enables to analyze the development of shear systems subject to the duration of tribological tests. As the test duration increases, slip bands are curved and thicken in the near-surface region. After 24 hours of friction, single crystals of Hadfield steel demonstrate the maximum hardening. Afterwards, the wear process begins, which is followed by the repeated strain hardening of the specimens. After 48 hours of friction, the height of the deformation relief nearly halves on all of the three faces, as compared to that observed after 24 hours of friction. Differences in the propagation height of slip bands on the faces occur due to the uneven running-in as well as the complex involvement pattern of shear systems into the deformation process.

Is midsole thickness a key parameter for the running pattern?

PubMed

Chambon, Nicolas; Delattre, Nicolas; Guéguen, Nils; Berton, Eric; Rao, Guillaume

2014-01-01

Many studies have highlighted differences in foot strike pattern comparing habitually shod runners who ran barefoot and with running shoes. Barefoot running results in a flatter foot landing and in a decreased vertical ground reaction force compared to shod running. The aim of this study was to investigate one possible parameter influencing running pattern: the midsole thickness. Fifteen participants ran overground at 3.3 ms(-1) barefoot and with five shoes of different midsole thickness (0 mm, 2 mm, 4 mm, 8 mm, 16 mm) with no difference of height between rearfoot and forefoot. Impact magnitude was evaluated using transient peak of vertical ground reaction force, loading rate, tibial acceleration peak and rate. Hip, knee and ankle flexion angles were computed at touch-down and during stance phase (range of motion and maximum values). External net joint moments and stiffness for hip, knee and ankle joints were also observed as well as global leg stiffness. No significant effect of midsole thickness was observed on ground reaction force and tibial acceleration. However, the contact time increased with midsole thickness. Barefoot running compared to shod running induced ankle in plantar flexion at touch-down, higher ankle dorsiflexion and lower knee flexion during stance phase. These adjustments are suspected to explain the absence of difference on ground reaction force and tibial acceleration. This study showed that the presence of very thin footwear upper and sole was sufficient to significantly influence the running pattern. Copyright © 2014 Elsevier B.V. All rights reserved.

Changes in Running Mechanics During a 6-Hour Running Race.

PubMed

Giovanelli, Nicola; Taboga, Paolo; Lazzer, Stefano

2017-05-01

To investigate changes in running mechanics during a 6-h running race. Twelve ultraendurance runners (age 41.9 ± 5.8 y, body mass 68.3 ± 12.6 kg, height 1.72 ± 0.09 m) were asked to run as many 874-m flat loops as possible in 6 h. Running speed, contact time (t c ), and aerial time (t a ) were measured in the first lap and every 30 ± 2 min during the race. Peak vertical ground-reaction force (F max ), stride length (SL), vertical downward displacement of the center of mass (Δz), leg-length change (ΔL), vertical stiffness (k vert ), and leg stiffness (k leg ) were then estimated. Mean distance covered by the athletes during the race was 62.9 ± 7.9 km. Compared with the 1st lap, running speed decreased significantly from 4 h 30 min onward (mean -5.6% ± 0.3%, P < .05), while t c increased after 4 h 30 min of running, reaching the maximum difference after 5 h 30 min (+6.1%, P = .015). Conversely, k vert decreased after 4 h, reaching the lowest value after 5 h 30 min (-6.5%, P = .008); t a and F max decreased after 4 h 30 min through to the end of the race (mean -29.2% and -5.1%, respectively, P < .05). Finally, SL decreased significantly (-5.1%, P = .010) during the last hour of the race. Most changes occurred after 4 h continuous self-paced running, suggesting a possible time threshold that could affect performance regardless of absolute running speed.

The Samoa tsunami of 29 September 2009: Field survey in Tonga and preliminary modeling

NASA Astrophysics Data System (ADS)

Okal, E. A.; Fritz, H. M.; Borrero, J. C.

2010-05-01

The two northernmost islands in Tonga, Niuatoputapu and Tafahi, were hit hard by the Samoa tsunami of 29 September 2009, with considerable devastation on the former, where nine people were killed. A surveying team consisting of HMF and EAO visited the islands in late November. On Niuatoputapu, we document extreme inundation reaching 600 m on the Southern coast, and a complete overrun of the Northeastern tip at Hikuniu Point, with flow depths reaching 10 m for a total wave height of 16 m. The forests were totally destroyed, and apparently provided no barrier to waves of such height. On the small stratovolcano island of Tafahi, run-up reached 22.8 m on the lee side of the island. The three villages of Niuatoputapu were provided a relative level of protection by the fringing coral reef present on the Northern shore. Seven of the nine victims were riding in a pick-up truck on a road parallel to the coast. One point, with run-up of 4 m, was also surveyed on the island of Niuafo'ou, 200 km further West. We present a number of numerical simulations, using several models of the seismic source, which correctly predict enhanced amplitudes in the direction of the Northern Tonga Islands as a result of focusing by shallow bathymetry at the bend marking the Northern end of the Tonga subduction zone.

Differences in anthropometric characteristics in relation to throwing velocity and competitive level in professional male team handball: a tool for talent profiling.

PubMed

Fieseler, Georg; Hermassi, Souhail; Hoffmeyer, Birgit; Schulze, Stephan; Irlenbusch, Lars; Bartels, Thomas; Delank, Karl-Stefan; Laudner, Kevin G; Schwesig, René

2017-01-01

The primary aim of the study was to examine the anthropometric characteristics as well as throwing and sprinting performance of professional handball players classified by playing position and competition level. 21 male players (age: 25.2±5.1 years) from the first German handball league (FGL) and 34 male players (age: 26.1±4.1 years) from the third German handball league (TGL) were categorized as backs, pivots, wings and goalkeepers. Measurements included anthropometric data (height, mass and body mass index (BMI)), throwing and sprinting performance selected out of a complex handball test (HBCT), which was conducted twice (2 rounds). During the HBCT, the subjects performed two sprints (10, 20 m), two standing throws with run-up (ST) and four vertical jump throws (VJT) over a hurdle (20 cm) with and without precision for goal shot. The anthropometric data revealed a significantly (P=0.038 and η2=0.079) shorter body height for TGL than for FGL players. In the cohort of first league athletes the pivots were the tallest (1.98±0.04 m), backs in the third league showed the maximum body height (1.90±0.05 m). Regarding body mass, pivots were the heaviest players independent from the league membership. The FGL players showed a significantly (P<0.05 and η2>0.10) higher throwing velocity in all type of throws. Body height was significantly related to ST (r=0.53) and VJT (r=0.52) in the first round of HBCT but only for the FGL athletes. Throwing velocity was also correlated with BMI (r=-0.50) among the TGL players. Substantial differences of body characteristics, throwing and sprinting performance between playing positions and competitive levels underline the importance of a careful scouting and position-specific training for professional handball players.

Investigation of Wave Energy Converter Effects on the Nearshore Environment: A Month-Long Study in Monterey Bay CA.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roberts, Jesse D.; Chang, Grace; Magalen, Jason

2014-09-01

A modified version of an indust ry standard wave modeling tool, SNL - SWAN, was used to perform model simulations for hourly initial wave conditio ns measured during the month of October 2009. The model was run with an array of 50 wave energy converters (WECs) and compared with model runs without WECs. Maximum changes in H s were found in the lee of the WEC array along the angles of incident wave dire ction and minimal changes were found along the western side of the model domain due to wave shadowing by land. The largest wave height reductions occurredmore » during observed typhoon conditions and resulted in 14% decreases in H s along the Santa Cruz shoreline . Shoreline reductions in H s were 5% during s outh swell wave conditions and negligible during average monthly wave conditions.« less

Inverse and Forward Modeling of The 2014 Iquique Earthquake with Run-up Data

NASA Astrophysics Data System (ADS)

Fuentes, M.

2015-12-01

The April 1, 2014 Mw 8.2 Iquique earthquake excited a moderate tsunami which turned on the national alert of tsunami threat. This earthquake was located in the well-known seismic gap in northern Chile which had a high seismic potential (~ Mw 9.0) after the two main large historic events of 1868 and 1877. Nonetheless, studies of the seismic source performed with seismic data inversions suggest that the event exhibited a main patch located around 19.8° S at 40 km of depth with a seismic moment equivalent to Mw = 8.2. Thus, a large seismic deficit remains in the gap being capable to release an event of Mw = 8.8-8.9. To understand the importance of the tsunami threat in this zone, a seismic source modeling of the Iquique Earthquake is performed. A new approach based on stochastic k2 seismic sources is presented. A set of those sources is generated and for each one, a full numerical tsunami model is performed in order to obtain the run-up heights along the coastline. The results are compared with the available field run-up measurements and with the tide gauges that registered the signal. The comparison is not uniform; it penalizes more when the discrepancies are larger close to the peak run-up location. This criterion allows to identify the best seismic source from the set of scenarios that explains better the observations from a statistical point of view. By the other hand, a L2 norm minimization is used to invert the seismic source by comparing the peak nearshore tsunami amplitude (PNTA) with the run-up observations. This method searches in a space of solutions the best seismic configuration by retrieving the Green's function coefficients in order to explain the field measurements. The results obtained confirm that a concentrated down-dip patch slip adequately models the run-up data.

Foot clearance in walking and running in individuals with ankle instability.

PubMed

Brown, Cathleen

2011-08-01

Foot positioning before heel strike has been attributed to chronic ankle instability injury mechanics, and may play a role in developing and perpetuating chronic ankle instability. This study was undertaken to determine if a group of individuals with mechanical instability (MI) or a group with functional instability (FI) of the ankle joint demonstrate less foot-floor clearance and a more inverted and plantar flexed position of the foot during the terminal swing phase of the running and walking cycles when compared with a group of ankle sprain copers who had an injury but no residual instability. Controlled laboratory study. Three-dimensional motion analysis was performed on 3 groups (n = 11 male athletes each) differentiated based on ankle injury history and ligamentous laxity during walking and running on a raised platform. The MI group (14.8° ± 12.0°) demonstrated greater maximum foot external rotation than the FI (3.2° ± 6.0°) and coper groups (2.9° ± 11.0°) (P = .01; η(p) (2) = .25) during running and greater rotation than the coper group during walking (3.3° ± 6.1° vs -4.5° ± 4.1°; P = .03; η(p) (2) = .21). The FI group (6.1° ± 3.2°) had greater plantar flexion at minimum than the MI group (0.1° ± 3.5°) during walking (P = .02; η(p) (2) = .25). Other group differences demonstrated large effect sizes, but not statistical significance, including unstable groups having lower minimum metatarsal height than copers during running. Differences in foot and leg position during terminal swing were observed between MI and FI groups and copers. Greater plantar flexion and lower minimum metatarsal height may increase risk for inadvertent contact and thus episodes of instability. Rehabilitation programs may need to address terminal swing to improve mechanics and avoid potential episodes of giving way at the ankle.

The Rise of the Hindu Kush and its Role in the South Asian Monsoon

NASA Astrophysics Data System (ADS)

Molnar, P. H.; Bendick, R. O.; Boos, W. R.

2017-12-01

The emergence of the Hindu Kush to its mean elevation of 3000 m since 10 Ma may have profoundly affected summer rainfall over the Indian subcontinent - the South Asian Monsoon. General Circulation Model runs of climate with different surface heights suggest that the Hindu Kush in Afghanistan may be the most important high terrain that affects the timing and strength of the South Asian monsoon [Chakraborty, Nanjundiah, and Srinivasan, 2002, 2006]. That high terrain, more than the Tibetan Plateau and the Himalaya, blocks warm dry air, with low moist static energy, from mixing with warm moist air from the Bay of Bengal and over India, and therefore enables a moist static energy maximum to be generated by local sources in the northern edges of the Indian subcontinent, facilitating a strong monsoon circulation. Boos and Hurley [2013] showed that if the Hindu Kush is smoothed too much, so that its maximum height is only 1000 m, nearly all General Circulation Model runs yield atmospheric temperature profiles inconsistent with those of monsoons. Fault plane solutions of earthquakes show underthrusting of the Tajik Depression beneath the Hindu Kush, and GPS velocities require 30-35 mm/yr of convergence between India and the Depression. Some of that convergence might be absorbed by subduction of lithosphere with thin crust, but GPS measurements suggest at least 10 and more likely 20 mm/yr of shortening across the Hindu Kush. For a belt 300 km wide with a mean elevation of its crest of 3 km, isostatic balance of 900 km^2 of excess elevation calls for 6000 km^2 of excess crust in a transect across the Hindu Kush. If crust 30-40 km in thickness were shortened horizontally at 20 (10) km/Myr, then 10-7.5 (20-15) Myr would be needed to build the entire range. If a range 1000 m high would have had little effect on the South Asian Monsoon, and if a height of 2000 m were necessary, at current rates of convergence only a few million years would be needed to raise the Hindu Kush from a height of 1000 m to 2000 (or 3000) m. If the South Asian monsoon strengthened at 10 Ma, a rise of the Hindu Kush since 10 Ma may have played a key role in that event.

Acceleration of high resolution temperature based optimization for hyperthermia treatment planning using element grouping.

PubMed

Kok, H P; de Greef, M; Bel, A; Crezee, J

2009-08-01

In regional hyperthermia, optimization is useful to obtain adequate applicator settings. A speed-up of the previously published method for high resolution temperature based optimization is proposed. Element grouping as described in literature uses selected voxel sets instead of single voxels to reduce computation time. Elements which achieve their maximum heating potential for approximately the same phase/amplitude setting are grouped. To form groups, eigenvalues and eigenvectors of precomputed temperature matrices are used. At high resolution temperature matrices are unknown and temperatures are estimated using low resolution (1 cm) computations and the high resolution (2 mm) temperature distribution computed for low resolution optimized settings using zooming. This technique can be applied to estimate an upper bound for high resolution eigenvalues. The heating potential of elements was estimated using these upper bounds. Correlations between elements were estimated with low resolution eigenvalues and eigenvectors, since high resolution eigenvectors remain unknown. Four different grouping criteria were applied. Constraints were set to the average group temperatures. Element grouping was applied for five patients and optimal settings for the AMC-8 system were determined. Without element grouping the average computation times for five and ten runs were 7.1 and 14.4 h, respectively. Strict grouping criteria were necessary to prevent an unacceptable exceeding of the normal tissue constraints (up to approximately 2 degrees C), caused by constraining average instead of maximum temperatures. When strict criteria were applied, speed-up factors of 1.8-2.1 and 2.6-3.5 were achieved for five and ten runs, respectively, depending on the grouping criteria. When many runs are performed, the speed-up factor will converge to 4.3-8.5, which is the average reduction factor of the constraints and depends on the grouping criteria. Tumor temperatures were comparable. Maximum exceeding of the constraint in a hot spot was 0.24-0.34 degree C; average maximum exceeding over all five patients was 0.09-0.21 degree C, which is acceptable. High resolution temperature based optimization using element grouping can achieve a speed-up factor of 4-8, without large deviations from the conventional method.

Criterion-Related Validity of the Distance- and Time-Based Walk/Run Field Tests for Estimating Cardiorespiratory Fitness: A Systematic Review and Meta-Analysis.

PubMed

Mayorga-Vega, Daniel; Bocanegra-Parrilla, Raúl; Ornelas, Martha; Viciana, Jesús

2016-01-01

The main purpose of the present meta-analysis was to examine the criterion-related validity of the distance- and time-based walk/run tests for estimating cardiorespiratory fitness among apparently healthy children and adults. Relevant studies were searched from seven electronic bibliographic databases up to August 2015 and through other sources. The Hunter-Schmidt's psychometric meta-analysis approach was conducted to estimate the population criterion-related validity of the following walk/run tests: 5,000 m, 3 miles, 2 miles, 3,000 m, 1.5 miles, 1 mile, 1,000 m, ½ mile, 600 m, 600 yd, ¼ mile, 15 min, 12 min, 9 min, and 6 min. From the 123 included studies, a total of 200 correlation values were analyzed. The overall results showed that the criterion-related validity of the walk/run tests for estimating maximum oxygen uptake ranged from low to moderate (rp = 0.42-0.79), with the 1.5 mile (rp = 0.79, 0.73-0.85) and 12 min walk/run tests (rp = 0.78, 0.72-0.83) having the higher criterion-related validity for distance- and time-based field tests, respectively. The present meta-analysis also showed that sex, age and maximum oxygen uptake level do not seem to affect the criterion-related validity of the walk/run tests. When the evaluation of an individual's maximum oxygen uptake attained during a laboratory test is not feasible, the 1.5 mile and 12 min walk/run tests represent useful alternatives for estimating cardiorespiratory fitness. As in the assessment with any physical fitness field test, evaluators must be aware that the performance score of the walk/run field tests is simply an estimation and not a direct measure of cardiorespiratory fitness.

Simple estimation of linear 1+1 D tsunami run-up

NASA Astrophysics Data System (ADS)

Fuentes, M.; Campos, J. A.; Riquelme, S.

2016-12-01

An analytical expression is derived concerning the linear run-up for any given initial wave generated over a sloping bathymetry. Due to the simplicity of the linear formulation, complex transformations are unnecessay, because the shoreline motion is directly obtained in terms of the initial wave. This analytical result not only supports maximum run-up invariance between linear and non-linear theories, but also the time evolution of shoreline motion and velocity. The results exhibit good agreement with the non-linear theory. The present formulation also allows computing the shoreline motion numerically from a customised initial waveform, including non-smooth functions. This is useful for numerical tests, laboratory experiments or realistic cases in which the initial disturbance might be retrieved from seismic data rather than using a theoretical model. It is also shown that the real case studied is consistent with the field observations.

47 CFR 2.1511 - Measurements of radiated emissions.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) General set-up instructions. Measurements of radiated electromagnetic emissions (EME) are to be performed... meters in both vertical and horizontal polarization. Record the highest receiver reading in dBm as the... receiver reading in dBm and the instrument settings, antenna height and direction for maximum radiation...

Light extraction block with curved surface

DOEpatents

Levermore, Peter; Krall, Emory; Silvernail, Jeffrey; Rajan, Kamala; Brown, Julia J.

2016-03-22

Light extraction blocks, and OLED lighting panels using light extraction blocks, are described, in which the light extraction blocks include various curved shapes that provide improved light extraction properties compared to parallel emissive surface, and a thinner form factor and better light extraction than a hemisphere. Lighting systems described herein may include a light source with an OLED panel. A light extraction block with a three-dimensional light emitting surface may be optically coupled to the light source. The three-dimensional light emitting surface of the block may includes a substantially curved surface, with further characteristics related to the curvature of the surface at given points. A first radius of curvature corresponding to a maximum principal curvature k.sub.1 at a point p on the substantially curved surface may be greater than a maximum height of the light extraction block. A maximum height of the light extraction block may be less than 50% of a maximum width of the light extraction block. Surfaces with cross sections made up of line segments and inflection points may also be fit to approximated curves for calculating the radius of curvature.

Biomechanical and clinical factors related to stage I posterior tibial tendon dysfunction.

PubMed

Rabbito, Melissa; Pohl, Michael B; Humble, Neil; Ferber, Reed

2011-10-01

Case control. To investigate differences in arch height, ankle muscle strength, and biomechanical factors in individuals with stage I posterior tibial tendon dysfunction (PTTD) in comparison to healthy individuals. PTTD is a progressive condition, so early recognition and treatment are essential to help delay or reverse the progression. However, no previous studies have investigated stage I PTTD, and no single study has measured static anatomical structure, muscle strength, and gait mechanics in this population. Twelve individuals with stage I PTTD and 12 healthy, age- and gender-matched control subjects, who were engaged in running-related activities, participated in this study. Measurements of arch height index, maximum voluntary ankle invertor muscle strength, and 3-dimensional rearfoot and medial longitudinal arch kinematics during walking were obtained. The runners with PTTD demonstrated significantly lower seated arch height index (P = .02) and greater (P = .03) and prolonged (P = .05) peak rearfoot eversion angle during gait, compared to the healthy runners. No differences were found in standing arch height index values (P = .28), arch rigidity index (P = .06), ankle invertor strength (P = .49), or peak medial longitudinal arch values (P = .49) between groups. The increased foot pronation is hypothesized to place greater strain on the posterior tibialis muscle, which may partially explain the progressive nature of this condition.

Source of 1629 Banda Mega-Thrust Earthquake and Tsunami: Implications for Tsunami Hazard Evaluation in Eastern Indonesia

NASA Astrophysics Data System (ADS)

Major, J. R.; Liu, Z.; Harris, R. A.; Fisher, T. L.

2011-12-01

Using Dutch records of geophysical events in Indonesia over the past 400 years, and tsunami modeling, we identify tsunami sources that have caused severe devastation in the past and are likely to reoccur in the near future. The earthquake history of Western Indonesia has received much attention since the 2004 Sumatra earthquakes and subsequent events. However, strain rates along a variety of plate boundary segments are just as high in eastern Indonesia where the earthquake history has not been investigated. Due to the rapid population growth in this region it is essential and urgent to evaluate its earthquake and tsunami hazards. Arthur Wichmann's 'Earthquakes of the Indian Archipelago' shows that there were 30 significant earthquakes and 29 tsunami between 1629 to 1877. One of the largest and best documented is the great earthquake and tsunami effecting the Banda islands on 1 August, 1629. It caused severe damage from a 15 m tsunami that arrived at the Banda Islands about a half hour after the earthquake. The earthquake was also recorded 230 km away in Ambon, but no tsunami is mentioned. This event was followed by at least 9 years of aftershocks. The combination of these observations indicates that the earthquake was most likely a mega-thrust event. We use a numerical simulation of the tsunami to locate the potential sources of the 1629 mega-thrust event and evaluate the tsunami hazard in Eastern Indonesia. The numerical simulation was tested to establish the tsunami run-up amplification factor for this region by tsunami simulations of the 1992 Flores Island (Hidayat et al., 1995) and 2006 Java (Katoet al., 2007) earthquake events. The results yield a tsunami run-up amplification factor of 1.5 and 3, respectively. However, the Java earthquake is a unique case of slow rupture that was hardly felt. The fault parameters of recent earthquakes in the Banda region are used for the models. The modeling narrows the possibilities of mega-thrust events the size of the one in 1629 to the Seram and Timor Troughs. For the Seram Trough source a Mw 8.8 produces run-up heights in the Banda Islands of 15.5 m with an arrival time of 17 minuets. For a Timor Trough earthquake near the Tanimbar Islands a Mw 9.2 is needed to produce a 15 m run-up height with an arrival time of 25 minuets. The main problem with the Timor Trough source is that it predicts run-up heights in Ambon of 10 m, which would likely have been recorded. Therefore, we conclude that the most likely source of the 1629 mega-thrust earthquake is the Seram Trough. No large earthquakes are reported along the Seram Trough for over 200 years although high rates of strain are measured across it. This study suggests that the earthquake triggers from this fault zone could be extremely devastating to Eastern Indonesia. We strive to raise the awareness to the local government to not underestimate the natural hazard of this region based on lessons learned from the 2004 Sumatra and 2011 Tohoku tsunamigenic mega-thrust earthquakes.

A Comparison of 2 Current-Issue Army Boots.

DTIC Science & Technology

2000-01-01

at 3.5 mph, mean (SD) 32 21 .Maximum heel- strike vertical force (N) while walking at 3.5 mph, mean (SD) 33 22 Maximum heel- strike braking force...while running at 6.5 mph, mean (SD) 38 34 Maximum force on the hip (N) while running at 6.5 mph, mean (SD) 38 35 Maximum vertical heel- strike force (N...during 6.5 mph running, mean (SD) 39 36. Maximum heel- strike braking force (N) while running at 6.5 mph, mean (SD) 39 37. Maximum vertical push

Lawrence Livermore National Laboratory and Sandia National Laboratory Nuclear Accident Dosimetry Support of IER 252 and the Dose Characterization of the Flattop Reactor at the DAF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hickman, D. P.; Jeffers, K. L.; Radev, R. P.

In support of IER 252 “Characterization of the Flattop Reactor at the NCERC”, LLNL performed ROSPEC measurements of the neutron spectrum and deployed 129 Personnel Nuclear Accident Dosimeters (PNAD) to establish the need for height corrections and verification of neutron spectrum evaluation of the fluences and dose. A very limited number of heights (typically only one or two heights) can be measured using neutron spectrometers, therefore it was important to determine if any height correction would be needed in future intercomparisons and studies. Specific measurement positions around the Flatttop reactor are provided in Figure 1. Table 1 provides run andmore » position information for LLNL measurements. The LLNL ROSPEC (R2) was used for run numbers 1 – 7, and vi. PNADs were positioned on trees during run numbers 9, 11, and 13.« less

Foot strike patterns after obstacle clearance during running.

PubMed

Scholten, Shane D; Stergiou, Nicholas; Hreljac, Alan; Houser, Jeremy; Blanke, Daniel; Alberts, L Russell

2002-01-01

Running over obstacles of sufficient height requires heel strike (HS) runners to make a transition in landing strategy to a forefoot (FF) strike, resulting in similar ground reaction force patterns to those observed while landing from a jump. Identification of the biomechanical variables that distinguish between the landing strategies may offer some insight into the reasons that the transition occurs. The purpose of this study was to investigate the difference in foot strike patterns and kinetic parameters of heel strike runners between level running and running over obstacles of various heights. Ten heel strike subjects ran at their self-selected pace under seven different conditions: unperturbed running (no obstacle) and over obstacles of six different heights (10%, 12.5%, 15%, 17.5%, 20%, and 22.5% of their standing height). The obstacle was placed directly before a Kistler force platform. Repeated measures ANOVAs were performed on the subject means of selected kinetic parameters. The statistical analysis revealed significant differences (P < 0.004) for all of the parameters analyzed. The evaluation of the center of pressure and the ground reaction forces indicated that the foot strike patterns were affected by the increased obstacle height. Between the 12.5% and 15% obstacle conditions, the group response changed from a heel strike to a forefoot strike pattern. At height > 15%, the pattern was more closely related to the foot strike patterns found in jumping activities. This strategy change may represent a gait transition effected as a mechanism to protect against increased impact forces. Greater involvement of the ankle and the calf muscles could have assisted in attenuating the increased impact forces while maintaining speed after clearing the obstacle.

How a European network may help with estimating methane emissions on the French national scale

NASA Astrophysics Data System (ADS)

Pison, Isabelle; Berchet, Antoine; Saunois, Marielle; Bousquet, Philippe; Broquet, Grégoire; Conil, Sébastien; Delmotte, Marc; Ganesan, Anita; Laurent, Olivier; Martin, Damien; O'Doherty, Simon; Ramonet, Michel; Spain, T. Gerard; Vermeulen, Alex; Yver Kwok, Camille

2018-03-01

Methane emissions on the national scale in France in 2012 are inferred by assimilating continuous atmospheric mixing ratio measurements from nine stations of the European network ICOS located in France and surrounding countries. To assess the robustness of the fluxes deduced by our inversion system based on an objectified quantification of uncertainties, two complementary inversion set-ups are computed and analysed: (i) a regional run correcting for the spatial distribution of fluxes in France and (ii) a sectorial run correcting fluxes for activity sectors on the national scale. In addition, our results for the two set-ups are compared with fluxes produced in the framework of the inversion inter-comparison exercise of the InGOS project. The seasonal variability in fluxes is consistent between different set-ups, with maximum emissions in summer, likely due to agricultural activity. However, very high monthly posterior uncertainties (up to ≈ 65 to 74 % in the sectorial run in May and June) make it difficult to attribute maximum emissions to a specific sector. On the yearly and national scales, the two inversions range from 3835 to 4050 Gg CH4 and from 3570 to 4190 Gg CH4 for the regional and sectorial runs, respectively, consistently with the InGOS products. These estimates are 25 to 55 % higher than the total national emissions from bottom-up approaches (biogeochemical models from natural emissions, plus inventories for anthropogenic ones), consistently pointing at missing or underestimated sources in the inventories and/or in natural sources. More specifically, in the sectorial set-up, agricultural emissions are inferred as 66% larger than estimates reported to the UNFCCC. Uncertainties in the total annual national budget are 108 and 312 Gg CH4, i.e, 3 to 8 %, for the regional and sectorial runs respectively, smaller than uncertainties in available bottom-up products, proving the added value of top-down atmospheric inversions. Therefore, even though the surface network used in 2012 does not allow us to fully constrain all regions in France accurately, a regional inversion set-up makes it possible to provide estimates of French methane fluxes with an uncertainty in the total budget of less than 10 % on the yearly timescale. Additional sites deployed since 2012 would help to constrain French emissions on finer spatial and temporal scales and attributing missing emissions to specific sectors.

Reattachment Zone Characterisation Under Offshore Winds With Flow Separation On The Lee Side Of Coastal Dunes

NASA Astrophysics Data System (ADS)

Delgado-Fernandez, I.; Jackson, D.; Cooper, J. A.; Baas, A. C.; Lynch, K.; Beyers, M.

2010-12-01

Airflow separation, lee-side eddies and secondary flows play an essential role on the formation and maintenance of sand dunes. Downstream from dune crests the flow surface layer detaches from the ground and generates an area characterised by turbulent eddies in the dune lee slope (the wake). At some distance downstream from the dune crest, flow separates into a reversed component directed toward the dune toe and an offshore “re-attached” component. This reattachment zone (RZ) has been documented in fluvial and desert environments, wind tunnel experiments and numerical simulations, but not yet characterised in coastal dunes. This study examines the extent and temporal evolution of the RZ and its implications for beach-dune interaction at Magilligan, Northern Ireland. Wind parameters were measured over a profile extending from an 11 m height dune crest towards the beach, covering a total distance of 65 m cross-shore. Data was collected using an array of nine ultrasonic anemometers (UAs) deployed in April-May 2010, as part of a larger experiment to capture airflow data under a range of incident wind velocities and offshore directions. UAs were located along the profile (5 m tower spacing) over the beach, which allowed a detailed examination of the RZ with empirical data. Numerical modelling using Computational Fluid Dynamics (CFD) software was also conducted with input data from anemometer field measurements, running over a surface mesh generated from LiDAR and DGPS surveys. Results demonstrate that there is a wind threshold of approximately 5-6 ms-1 under which no flow separation exists with offshore winds. As wind speed increases over the threshold, a flow reversal area is quickly formed, with the maximum extent of the RZ at approximately 3.5 dune heights (h). The maximum extent of the RZ increases up to 4.5h with stronger wind speeds of 8-10 ms-1 and remains relatively constant as wind speed further increases. This suggests that the spatial extent of the RZ is independent of incident wind speed and is located between 4-5h. The magnitude of the maximum extent of the RZ is similar to that simulated using CFD and is consistent with previous studies conducted in desert dunes and wind tunnel simulations for offshore winds blowing over tall and sharp-crested dunes. Ongoing analyses are being conducted to evaluate the effect of changing wind direction, dune height and shape.

Ceilometer signal performance with height in high aerosol loads

NASA Astrophysics Data System (ADS)

Bachour, D.; Perez-Astudillo, D.

2016-02-01

This paper is dedicated to the study of the Vaisala CL51 ceilometer backscatter signals during a one-year period, in particular the study of the noise embedded in the signals measured by the ceilometer, under cloudless conditions. The noise analysis is done to provide indication about the maximum atmospheric height up to which the ceilometer signal is still reliable enough in clear-sky conditions, for the detection of changing aerosol contents. The experiment was carried out in Doha, Qatar, for a period of 12 months, from December 2012 to November 2013. 214 clear days were selected during this year. Several tests were performed in order to assess the variability of the backscatter signals from day to day and between different heights in the atmosphere. To the authors' knowledge, it is the first time that the signal performance of a ceilometer is studied in a highly aerosol-loaded region, and for a relatively extended period of time. Considering the whole year, it is found that a height of 5 or 6 km represents a good compromise between including the signals arising from the dynamicity of the atmosphere and removing as much as possible the signal dominated by noise at higher heights. In winter months, however, this limit can be extended up to a height of 7 km.

Injury-reduction effectiveness of prescribing running shoes on the basis of foot arch height: summary of military investigations.

PubMed

Knapik, Joseph J; Trone, Daniel W; Tchandja, Juste; Jones, Bruce H

2014-10-01

Secondary analysis of 3 randomized controlled trials. Objective Analysis of studies that examined whether prescribing running shoes on the basis of foot arch height influenced injury risk during military basic training. Prior to 2007, running magazines and running-shoe companies suggested that imprints of the bottom of the feet (plantar shape) could be used as an indication of foot arch height and that this could be used to select individually appropriate types of running shoes. Similar studies were conducted in US Army (2168 men, 951 women), Air Force (1955 men, 718 women), and Marine Corps (840 men, 571 women) basic training. After foot examinations, recruits were randomized to either an experimental or a control group. Recruits in the experimental group selected or were assigned motion-control, stability, or cushioned shoes to match their plantar shape, which represented a low, medium, or high foot arch, respectively. The control group received a stability shoe regardless of plantar shape. Injuries during basic training were assessed from outpatient medical records. Meta-analyses that pooled results of the 3 investigations showed little difference between the experimental and control groups in the injury rate (injuries per 1000 person-days) for either men (summary rate ratio = 0.97; 95% confidence interval [CI]: 0.88, 1.06) or women (summary rate ratio = 0.97; 95% CI: 0.85, 1.08). When injury rates for specific types of running shoes were compared, there were no differences. Selecting running shoes based on arch height had little influence on injury risk in military basic training. Prevention, level 1b.

A single peptide loop in an alpha-Helix

USDA-ARS?s Scientific Manuscript database

Pitch is not a height but a ratio of rise/run. In an alpha-helix, run can be as the radius (r) from the center of the circle, as a diameter (d) measured across/bisecting a circumference, or as a distance (c) along a circumference; rise in each case can corresponds to same height (h) increase. For ...

The effects of prolonged running on foot posture: a repeated measures study of half marathon runners using the foot posture index and navicular height

PubMed Central

2013-01-01

Background Different foot postures are associated with alterations in foot function, kinetics and the subsequent occurrence of injury. Little is known about changes in foot posture following prolonged weightbearing exercise. This study aimed to identify changes in foot posture after running a half marathon. Methods Foot posture was measured using the Foot Posture Index (FPI-6) and navicular height in thirty volunteer participants before and after running a half marathon. FPI-6 scores were converted to Rasch logit values and means compared for these and navicular height using an ANOVA. Results There was a 5 mm drop in navicular height in both feet when measured after the half marathon (P < 0.05). The FPI-6 showed a side x time interaction with an increase in score indicating a more ‘pronated’ position in the left foot of + 2 [Rasch value + 1.7] but no change in the right foot (+ 0.4 [+ 0.76]) following the half marathon. Conclusion The apparent differences between the FPI-6 and navicular height on the right foot may be because the FPI-6 takes soft tissue contour changes into consideration whilst the navicular height focuses on skeletal changes. The changes in foot posture towards a more pronated position may have implications for foot function, and therefore risk of injury; shoe fit and comfort and also the effect of therapeutic orthoses worn during prolonged running. PMID:23705863

Complementary code and digital filtering for detection of weak VHF radar signals from the mesoscale. [SOUSY-VHF radar, Harz Mountains, Germany

NASA Technical Reports Server (NTRS)

Schmidt, G.; Ruster, R.; Czechowsky, P.

1983-01-01

The SOUSY-VHF-Radar operates at a frequency of 53.5 MHz in a valley in the Harz mountains, Germany, 90 km from Hanover. The radar controller, which is programmed by a 16-bit computer holds 1024 program steps in core and controls, via 8 channels, the whole radar system: in particular the master oscillator, the transmitter, the transmit-receive-switch, the receiver, the analog to digital converter, and the hardware adder. The high-sensitivity receiver has a dynamic range of 70 dB and a video bandwidth of 1 MHz. Phase coding schemes are applied, in particular for investigations at mesospheric heights, in order to carry out measurements with the maximum duty cycle and the maximum height resolution. The computer takes the data from the adder to store it in magnetic tape or disc. The radar controller is programmed by the computer using simple FORTRAN IV statements. After the program has been loaded and the computer has started the radar controller, it runs automatically, stopping at the program end. In case of errors or failures occurring during the radar operation, the radar controller is shut off caused either by a safety circuit or by a power failure circuit or by a parity check system.

The Deterministic Mine Burial Prediction System

DTIC Science & Technology

2009-01-12

or below the water-line, initial linear and angular velocities, and fall angle relative to the mine’s axis of symmetry. Other input data needed...c. Run_DMBP.m: start-up MATLAB script for the program 2. C:\\DMBP\\DMBP_src: This directory contains source code, geotechnical databases, and...approved for public release). b. \\Impact_35: The IMPACT35 model c. \\MakeTPARfiles: scripts for creating wave height and wave period input data from

Running stride peak forces inversely determine running economy in elite runners.

PubMed

Støren, Øyvind; Helgerud, Jan; Hoff, Jan

2011-01-01

The present study investigated the relationship between running economy (RE) at 15 km/h(-1) , 3.000-m race time, maximal strength, and a number of physiological, anthropometrical, and mechanical variables. The variables measured included RE, maximal oxygen consumption, heart rate, step length and frequency, contact time, and the peak horizontal and vertical forces of each step. Maximal strength was measured as the 1 repetition maximum (1RM) half-squat using a leg press machine. Eleven male elite endurance athletes with a V(O2)max of 75.8 ± 6.2 mL/kg(-1)/min(-1) participated in this study. After the anthropometric data were collected, they were tested for RE, running characteristics, and force measures on a level treadmill at 15 km/h(-1). The athletes wore contact soles, and the treadmill was placed on a force platform. Maximal oxygen consumption and 1RM were tested after the RE measurements. The sum of horizontal and vertical peak forces revealed a significant inverse correlation (p < 0.05) both with 3,000-m performance (R = 0.71) and RE (R = 0.66). Inverse correlations were also found (p < 0.05) between RE and body height (R = 0.61) and between RE and body fat percentage (R = 0.62). In conclusion, the sum of horizontal and vertical peak forces was found to be negatively correlated to running economy and 3,000-m running performance, indicating that avoiding vertical movements and high horizontal braking force is crucial for a positive development of RE.

Relationship between boundary layer heights and growth rates with ground-level ozone in Houston, Texas

NASA Astrophysics Data System (ADS)

Haman, C. L.; Couzo, E.; Flynn, J. H.; Vizuete, W.; Heffron, B.; Lefer, B. L.

2014-05-01

Measurements and predictions of ambient ozone (O3), planetary boundary layer (PBL) height, the surface energy budget, wind speed, and other meteorological parameters were made near downtown Houston, Texas, and were used to investigate meteorological controls on elevated levels of ground-level O3. Days during the study period (1 April 2009 to 31 December 2010 for measurements and 15 April 2009 to 17 October 2009 for modeled) were classified into low (LO3) and high ozone (HO3) days. The majority of observed high HO3 days occurred in a postfrontal environment. Observations showed there is not a significant difference in daily maximum PBL heights on HO3 and LO3 days. Modeling results showed large differences between maximum PBL heights on HO3 and LO3 days. Nighttime and early morning observed and modeled PBL heights are consistently lower on HO3 days than on LO3 days. The observed spring LO3 days had the most rapid early morning PBL growth (~350 m h-1) while the fall HO3 group had the slowest (~200 m h-1). The predicted maximum average hourly morning PBL growth rates were greater on HO3 (624 m h-1) days than LO3 days (361 m h-1). Observed turbulent mixing parameters were up to 2-3 times weaker on HO3 days, which indicate large-scale subsidence associated with high-pressure systems (leading to clear skies and weak winds) substantially suppresses mixing. Lower surface layer ventilation coefficients were present in the morning on HO3 days in the spring and fall, which promotes the accumulation of O3 precursors near the surface.

Assessing the debris flow run-out frequency of a catchment in the French Alps using a parameterization analysis with the RAMMS numerical run-out model

NASA Astrophysics Data System (ADS)

Hussin, H. Y.; Luna, B. Quan; van Westen, C. J.; Christen, M.; Malet, J.-P.; van Asch, Th. W. J.

2012-04-01

Debris flows occurring in the European Alps frequently cause significant damage to settlements, power-lines and transportation infrastructure which has led to traffic disruptions, economic loss and even death. Estimating the debris flow run-out extent and the parameter uncertainty related to run-out modeling are some of the difficulties found in the Quantitative Risk Assessment (QRA) of debris flows. Also, the process of the entrainment of material into a debris flow is until now not completely understood. Debris flows observed in the French Alps entrain 5 - 50 times the amount of volume compared to the initially mobilized source volume. In this study we analyze a debris flow that occurred in 2003 at the Faucon catchment in the Barcelonnette Basin (Southern French Alps). The analysis was carried out using the Voellmy rheology and an entrainment model imbedded in the RAMMS 2D numerical modeling software. The historic event was back calibrated based on source, entrainment and deposit volumes, including the run-out distance, velocities and deposit heights of the debris flow. This was then followed by a sensitivity analysis of the rheological and entrainment parameters to produce 120 debris flow scenarios leading to a frequency assessment of the run-out distance and deposit height at the debris fan. The study shows that the Voellmy frictional parameters mainly influence the run-out distance and velocity of the flow, while the entrainment parameter has a major impact on the debris flow height. The frequency assessment of the 120 simulated scenarios further gives an indication on the most likely debris flow run-out extents and heights for this catchment. Such an assessment can be an important link between the rheological model parameters and the spatial probability of the run-out for the Quantitative Risk Assessment (QRA) of debris flows.

Generation, propagation and run-up of tsunamis due to the Chicxulub impact event

NASA Astrophysics Data System (ADS)

Weisz, R.; Wuennenmann, K.; Bahlburg, H.

2003-04-01

The Chicxulub impact event can be investigated in (1) local, (2) regional and in (3) global scales. Our investigations focus on the regional scale, especially on the influence of tsunami waves on the coast around the Gulf of Mexico caused by the impact. During an impact two types of tsunamis are generated. The first wave is known as the "rim wave" and is generated in front of the ejecta curtain. The second one is linked to the late modification stage of the impact and results from the collapsing cavity of water. We designate this wave as "collapse wave". The "rim wave" and "collapse wave" are able to propagate over long distances, without a significant loss of wave amplitude. Corresponding to the amplitudes, the waves have a potentially large influence on the coastal areas. Run-up distance and run-up height can be used as parameters for describing this influence. We are utilizing a multimaterial hydrocode (SALE) to simulate the generation of tsunami waves. The propagation of the waves is based on the non-linear shallow water theory, because tsunami waves are defined to be long waves. The position of the coast line varies according to the tsunami run-up and is implemented with open boundary conditions. We show with our investigations (1) the generation of tsunami waves due to shallow water impacts, (2) wave damping during propagation, and (3) the influence of the "rim wave" and the "collapse wave" on the coastal areas. Here, we present our first results from numerical modeling of tsunami waves owing to a Chicxulub sized impactor. The characteristics of the “rim wave” depend on the size of the bolide and the water depth. However, the amplitude and velocity of the “collapse wave” is only determined by the water depth in the impact area. The numerical modeling of the tsunami propagation and run-up is calculated along a section from the impact point towards to the west and gives the moderate damping of both waves and the run-up on the coastal area. As a first approximation, the bathymetric data, used in the wave propagation and run-up, correspond to a linearized bathymetry of the Recent Gulf of Mexico. The linearized bathymetry allows to study the influence of the bathymetry on wave propagation and run-up. Additionally, we give preliminary results of the implementation of the two-dimensional propagation and run-up model for arbitrary bathymetries. The two-dimensional wave propagation model will enable us to more realistically asses the influence of the impact-related tsunamis on the coasts around the Gulf of Mexico due to the Chicxulub impact event.

The Trajectory, Orbit and Preliminary Fall Data of the JUNE BOOTID Superbolide of July 23, 2008

NASA Technical Reports Server (NTRS)

Konovalova, N. A.; Madiedo, J. M.; Trigo-Rodriguez, J. M.

2011-01-01

The results of the atmospheric trajectory, radiant, orbit and preliminary fall data calculations of an extremely bright slow-moving fireball are presented. The fireball had a -20.7 maximum absolute magnitude and the spectacular long-persistence dust trail (Fig 1 and 2) was observed in a widespread region of Tajikistan twenty eight minutes after sunset, precisely at 14h 45m 25s UT on July 23, 2008. The bolide was first recorded at a height of 38.2 km, and attained its maximum brightness at a height of 35.0 km and finished at a height of 19.6 km. These values are very much in line with other well-known fireballs producing meteorites. The first break-up must have occurred under an aerodynamic pressure Pdyn of about 1.5 MPa, similar to those derived from the study of atmospheric break-ups of previously reported meteorite-dropping bolides. Our trajectory, and dynamic results suggest that one might well expect to find meteorites on the ground in this case. The heliocentric orbit of the meteoroid determined from the observations is very similar to the mean orbit of the June Bootid meteor shower, whose parental comet is 7P/Pons-Winnecke (Lindblad et al. 2003). If the parent was indeed a comet, this has implications for the internal structure of comets, and for the survivability of cometary meteorites.

Landing Characteristics in Waves of Three Dynamic Models of Flying Boats

NASA Technical Reports Server (NTRS)

Benson, James M.; Havens, Robert F.; Woodward, David R.

1947-01-01

Powered models of three different flying boats were landed in oncoming wave of various heights and lengths. The resulting motions and acceleration were recorded to survey the effects of varying the trim at landing, the deceleration after landing, and the size of the waves. One of the models had an unusually long afterbody. The data for landing with normal rates of deceleration indicated that the most severe motions and accelerations were likely to occur at some period of the landing run subsequent to the initial impact. Landings made at abnormally low trims led to unusually severe bounces during the runout. The least severe landing occurred after a small lending when the model was rapidly decelerated at about 0.4 g in a simulation of the proposed use of braking devices. The severity of the landings increased with wave height and was at a maximum when the wave length was of the order of from one and one-half to twice the over-all length of the model. The models with afterbodies of moderate length frequently bounced clear of the water into a stalled attitude at speeds below flying speed. The model with the long afterbody had less tendency to bounce from the waves and consequently showed less severe accelerations during the landing run than the models with moderate lengths of afterbody.

Hazard Potential of Volcanic Flank Collapses Raised by New Megatsunami Evidence

NASA Astrophysics Data System (ADS)

Ramalho, R. S.; Winckler, G.; Madeira, J.; Helffrich, G. R.; Hipólito, A.; Quartau, R.; Adena, K.; Schaefer, J. M.

2015-12-01

Large-scale gravitational flank collapses of steep volcanic islands are hypothetically capable of triggering megatsunamis with highly catastrophic effects. Yet evidence for the existence and impact of collapsed-triggered megatsunamis and their run-up heights remains scarce and/or is highly contentious. Therefore a considerable debate still exists over the potential magnitude of collapse-triggered tsunamis and their inherent hazard. In particular, doubts still remain whether or not large-scale flank failures typically generate enough volume flux to result in megatsunamis, or alternatively operate by slow-moving or multiple smaller episodic failures with much lower tsunamigenic potential. Here we show that one of the tallest and most active oceanic volcanoes on Earth - Fogo, in the Cape Verde Islands - collapsed catastrophically and triggered a megatsunami with devastating near-field effects ~73,000 years ago. Our deductions are based on the recent discovery and cosmogenic 3He dating of tsunamigenic deposits - comprising fields of stranded megaclasts, chaotic conglomerates, and sand sheets - found on the adjacent Santiago Island, which attest to the impact of this megatsunami and document wave run-up heights exceeding 270 m. The evidence reported here implies that Fogo's flank failure involved at least one sudden and voluminous event that resulted in a megatsunami, in contrast to what has been suggested before. Our work thus provides another line of evidence that large-scale flank failures at steep volcanic islands may indeed happen catastrophically and are capable of triggering tsunamis of enormous height and energy. This new line of evidence therefore reinforces the hazard potential of volcanic island collapses and stands as a warning that such hazard should not be underestimated, particularly in areas where volcanic island edifices are close to other islands or to highly populated continental margins.

A simple parameterization for the height of maximum ozone heating rate

NASA Astrophysics Data System (ADS)

Zhang, Feng; Hou, Can; Li, Jiangnan; Liu, Renqiang; Liu, Cuiping

2017-12-01

It is well-known that the height of the maximum ozone heating rate is much higher than the height of the maximum ozone concentration in the stratosphere. However, it lacks an analytical expression to explain it. A simple theoretical model has been proposed to calculate the height of maximum ozone heating rate and further understand this phenomenon. Strong absorption of ozone causes the incoming solar flux to be largely attenuated before reaching the location of the maximum ozone concentration. By comparing with the exact radiative transfer calculations, the heights of the maximum ozone heating rate produced by the theoretical model are generally very close to the true values. When the cosine of solar zenith angle μ0 = 1.0 , in US Standard atmosphere, the heights of the maximum ozone heating rate by the theoretical model are 41.4 km in the band 0.204-0.233 μm, 47.9 km in the band 0.233-0.270 μm, 44.5 km in the band 0.270-0.286 μm, 37.1 km in the band 0.286-0.303 μm, and 30.2 km in the band 0.303-0.323 μm, respectively. The location of the maximum ozone heating rate is sensitive to the solar spectral range. In band 1, the heights of the maximum ozone heating rate by the theoretical model are 52.3 km for μ0 = 0.1 , 47.1 km for μ0 = 0.3 , 44.6 km for μ0 = 0.5 , 43.1 km for μ0 = 0.7 , 41.9 km for μ0 = 0.9 , 41.4 km for μ0 = 1.0 in US Standard atmosphere, respectively. This model also illustrates that the location of the maximum ozone heating rate is sensitive to the solar zenith angle.

Gender differences in the relationship between socioeconomic status and height loss among the elderly in South Korea: Korean National Health and Nutrition Examination Survey 2008-2010.

PubMed

Kim, Yang-Hyun; Ahn, Kyung-Sik; Cho, Kyung-Hwan; Kang, Chang Ho; Cho, Sung Bum; Han, Kyungdo; Rho, Yong-Kyun; Park, Yong-Gyu

2017-08-01

This study aimed to examine average height loss and the relationship between height loss and socioeconomic status (SES) among the elderly in South Korea.Data were obtained from the Korean National Health and Nutrition Examination Survey 2008-2010. A total of 5265 subjects (2818 men and 2447 women) were included. Height loss was calculated as the difference between the subject's self-reported maximum adult height and their measured current height. The height loss values were divided into quartiles (Q1-Q4) for men and women. SES was determined using a self-reported questionnaire for education level, family income, and occupation.Height loss was associated with SES in all age groups, and mean height loss increased with age. In the relationship between education level and maximum height loss (Q4), men with ≤6, 7-9, or 10-12 years of education had higher odds ratios for the prevalence of height loss (Q4) than men with the highest education level (≥13 years). With regard to the relationship between the income level and height loss (Q4), the subjects with the lowest income had an increased prevalence of maximum height loss (Q4) than the subjects with the highest income (odds ratios = 2.03 in men and 1.94 in women). Maximum height loss (Q4) was more prevalent in men and women with a low SES and less prevalent in men with a high SES than in men with a middle SES.Height loss (Q4) was associated with education level in men and with income level (especially low income) in men and women. Height loss was also associated with a low SES in men and women.

Maximum height in a conifer is associated with conflicting requirements for xylem design

Treesearch

Jean-Chrisophe Domec; Barbara Lachenbruch; Frederick Meinzer; David R. Woodruff; Jeffrey M. Warren; Katherine A. McCulloh

2008-01-01

Despite renewed interest in the nature of limitations on maximum tree height, the mechanisms governing ultimate and species-specific height limits are not yet understood, but they likely involve water transport dynamics. Tall trees experience increased risk of xylem embolism from air-seeding because tension in their water column increases with height owing to path-...

A comparison of hydraulic architecture in three similarly sized woody species differing in their maximum potential height.

PubMed

McCulloh, Katherine A; Johnson, Daniel M; Petitmermet, Joshua; McNellis, Brandon; Meinzer, Frederick C; Lachenbruch, Barbara

2015-07-01

The physiological mechanisms underlying the short maximum height of shrubs are not understood. One possible explanation is that differences in the hydraulic architecture of shrubs compared with co-occurring taller trees prevent the shrubs from growing taller. To explore this hypothesis, we examined various hydraulic parameters, including vessel lumen diameter, hydraulic conductivity and vulnerability to drought-induced embolism, of three co-occurring species that differed in their maximum potential height. We examined one species of shrub, one short-statured tree and one taller tree. We worked with individuals that were approximately the same age and height, which was near the maximum for the shrub species. A number of variables correlated with the maximum potential height of the species. For example, vessel diameter and vulnerability to embolism both increased while wood density declined with maximum potential height. The difference between the pressure causing 50% reduction in hydraulic conductance in the leaves and the midday leaf water potential (the leaf's hydraulic safety margin) was much larger in the shrub than the other two species. In general, trends were consistent with understory shrubs having a more conservative life history strategy than co-occurring taller species. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Criterion-Related Validity of the Distance- and Time-Based Walk/Run Field Tests for Estimating Cardiorespiratory Fitness: A Systematic Review and Meta-Analysis

PubMed Central

Mayorga-Vega, Daniel; Bocanegra-Parrilla, Raúl; Ornelas, Martha; Viciana, Jesús

2016-01-01

Objectives The main purpose of the present meta-analysis was to examine the criterion-related validity of the distance- and time-based walk/run tests for estimating cardiorespiratory fitness among apparently healthy children and adults. Materials and Methods Relevant studies were searched from seven electronic bibliographic databases up to August 2015 and through other sources. The Hunter-Schmidt’s psychometric meta-analysis approach was conducted to estimate the population criterion-related validity of the following walk/run tests: 5,000 m, 3 miles, 2 miles, 3,000 m, 1.5 miles, 1 mile, 1,000 m, ½ mile, 600 m, 600 yd, ¼ mile, 15 min, 12 min, 9 min, and 6 min. Results From the 123 included studies, a total of 200 correlation values were analyzed. The overall results showed that the criterion-related validity of the walk/run tests for estimating maximum oxygen uptake ranged from low to moderate (rp = 0.42–0.79), with the 1.5 mile (rp = 0.79, 0.73–0.85) and 12 min walk/run tests (rp = 0.78, 0.72–0.83) having the higher criterion-related validity for distance- and time-based field tests, respectively. The present meta-analysis also showed that sex, age and maximum oxygen uptake level do not seem to affect the criterion-related validity of the walk/run tests. Conclusions When the evaluation of an individual’s maximum oxygen uptake attained during a laboratory test is not feasible, the 1.5 mile and 12 min walk/run tests represent useful alternatives for estimating cardiorespiratory fitness. As in the assessment with any physical fitness field test, evaluators must be aware that the performance score of the walk/run field tests is simply an estimation and not a direct measure of cardiorespiratory fitness. PMID:26987118

Adhesive behavior of micro/nano-textured surfaces

NASA Astrophysics Data System (ADS)

Zhang, Yuyan; Wang, Xiaoli; Li, Hanqing; Wang, Ben

2015-02-01

A numerical model of the adhesive contact between a rigid smooth sphere and an elastic textured surface based on the Lennard-Jones interatomic potential law and the Hamaker summation method is established. Textures are considered by introducing the texture height distribution into the gap equation. Simulation results show that the pull-off force on textured surfaces decreases compared to that on smooth surfaces. Furthermore, effects of sphere-shaped textures on reducing adhesion are more obvious than cylinder-shaped or cube-shaped textures when the coverage area ratio, maximum height and interval of textures are fixed. For surfaces with sphere-shaped textures, variation trends of the mean pull-off force with texture density are not monotonous, and there exists a certain range of texture densities in which the mean pull-off force is small and its variation is insignificant. In addition, the pull-off force depends also on the maximum height and radius of textures. On one hand, if the texture radius is fixed, larger maximum height results in smaller pull-off force, and if the maximum height is fixed, the pull-off force tends to increase almost linearly with increases in texture radius. On the other hand, if the height-diameter ratio of textures is fixed, the pull-off force reaches a minimum at an optimum texture radius or maximum height.

A numerical study of tsunami wave impact and run-up on coastal cliffs using a CIP-based model

NASA Astrophysics Data System (ADS)

Zhao, Xizeng; Chen, Yong; Huang, Zhenhua; Hu, Zijun; Gao, Yangyang

2017-05-01

There is a general lack of understanding of tsunami wave interaction with complex geographies, especially the process of inundation. Numerical simulations are performed to understand the effects of several factors on tsunami wave impact and run-up in the presence of gentle submarine slopes and coastal cliffs, using an in-house code, a constrained interpolation profile (CIP)-based model. The model employs a high-order finite difference method, the CIP method, as the flow solver; utilizes a VOF-type method, the tangent of hyperbola for interface capturing/slope weighting (THINC/SW) scheme, to capture the free surface; and treats the solid boundary by an immersed boundary method. A series of incident waves are arranged to interact with varying coastal geographies. Numerical results are compared with experimental data and good agreement is obtained. The influences of gentle submarine slope, coastal cliff and incident wave height are discussed. It is found that the tsunami amplification factor varying with incident wave is affected by gradient of cliff slope, and the critical value is about 45°. The run-up on a toe-erosion cliff is smaller than that on a normal cliff. The run-up is also related to the length of a gentle submarine slope with a critical value of about 2.292 m in the present model for most cases. The impact pressure on the cliff is extremely large and concentrated, and the backflow effect is non-negligible. Results of our work are highly precise and helpful in inverting tsunami source and forecasting disaster.

Evaluation of helicity generation in the tropical storm Gonu

NASA Astrophysics Data System (ADS)

Farahani, Majid M.; Khansalari, Sakineh; Azadi, Majid

2017-06-01

Helicity is a valuable dynamical concept for the study of rotating flows. Consequently helicity flux, indicative of the source or sink of helicity, owns comparable importance. In this study, while reviewing the existing methods, a mathematical relation between helicity and helicity-flux is introduced, discussed and examined. The computed values of helicity and helicity fluxes in an actual case, using the classical and this proposed method are compared. The down-stream helicity flux including sources and sinks of helicity is considered for the tropical storm Gonu that occurred over the coasts of Oman and Iran on June 2-7, 2007. Results show that the buoyancy, through the upper troposphere down to a height within boundary layer, is the main source in producing helicity, and surface friction from earth surface up to a height within boundary layer, is the main dissipating element of helicity. The dominance of buoyancy forcing over the dissipative friction forcing results in generation of vortex or enhancement of it after bouncing the land. Furthermore, the increase (decrease) of helicity results in an increase (decrease) in the height of the level in which maximum helicity flux occurs. It is suggested that the maximum helicity flux occurs at the top of the turbulent boundary layer, so that the height of boundary layer could be obtained.

Build your own low-cost seismic/bathymetric recorder annotator

USGS Publications Warehouse

Robinson, W.

1994-01-01

An inexpensive programmable annotator, completely compatible with at least three models of widely used graphic recorders (Raytheon LSR-1811, Raytheon LSR-1807 M, and EDO 550) has been developed to automatically write event marks and print up to sixteen numbers on the paper record. Event mark and character printout intervals, character height and character position are all selectable with front panel switches. Operation is completely compatible with recorders running in either continuous or start-stop mode. ?? 1994.

Effects of Heavy Strength Training on Running Performance and Determinants of Running Performance in Female Endurance Athletes

PubMed Central

Vikmoen, Olav; Raastad, Truls; Seynnes, Olivier; Bergstrøm, Kristoffer; Ellefsen, Stian; Rønnestad, Bent R.

2016-01-01

Purpose The purpose of the current study was to investigate the effects of adding strength training to normal endurance training on running performance and running economy in well-trained female athletes. We hypothesized that the added strength training would improve performance and running economy through altered stiffness of the muscle-tendon complex of leg extensors. Methods Nineteen female endurance athletes [maximal oxygen consumption (VO2max): 53±3 ml∙kg-1∙min-1, 5.8 h weekly endurance training] were randomly assigned to either normal endurance training (E, n = 8) or normal endurance training combined with strength training (E+S, n = 11). The strength training consisted of four leg exercises [3 x 4–10 repetition maximum (RM)], twice a week for 11 weeks. Muscle strength, 40 min all-out running distance, running performance determinants and patellar tendon stiffness were measured before and after the intervention. Results E+S increased 1RM in leg exercises (40 ± 15%) and maximal jumping height in counter movement jump (6 ± 6%) and squat jump (9 ± 7%, p < 0.05). This was accompanied by increased muscle fiber cross sectional area of both fiber type I (13 ± 7%) and fiber type II (31 ± 20%) in m. vastus lateralis (p < 0.05), with no change in capillary density in m. vastus lateralis or the stiffness of the patellar tendon. Neither E+S nor E changed running economy, fractional utilization of VO2max or VO2max. There were also no change in running distance during a 40 min all-out running test in neither of the groups. Conclusion Adding heavy strength training to endurance training did not affect 40 min all-out running performance or running economy compared to endurance training only. PMID:26953893

Students Learning Physics While Lifting Themselves: A Simple Analysis of a Scissors Jack

ERIC Educational Resources Information Center

Haugland, Ole Anton

2017-01-01

Every time I have to jack up my car, I am a bit surprised by how slowly the scissors jack works the higher I raise it, and close to maximum height I need very little force to turn the crank. This agrees well with the principle of simple machines. Since I have to jack up my car at least twice a year to change between winter tires and summer tires,…

Full-scale Wind-tunnel and Flight Tests of a Fairchild 22 Airplane Equipped with a Fowler Flap

NASA Technical Reports Server (NTRS)

Dearborn, C H; Soule, H A

1936-01-01

Full-scale wind-tunnel and flight tests were made of a Fairchild 22 airplane equipped with a Fowler flap to determine the effect of the flap on the performance and control characteristics of the airplane. In the wind-tunnel tests of the airplane with the horizontal tail surfaces removed, the flap was found to increase the maximum lift coefficient from 1.27 to 2.41. In the flight test, the flap was found to decrease the minimum speed from 58.8 to 44.4 miles per hour. The required take-off run to attain an altitude of 50 feet was reduced from 935 feet to 700 feet by the use of the flap, the minimum distance being obtained with five-sixths full deflection. The landing run from a height of 50 feet was reduced one-third. The longitudinal and directional control was adversely affected by the flap, indicating that the design of the tail surfaces is more critical with a flapped than a plain wing.

The Run-Up of Subduction Zones

NASA Astrophysics Data System (ADS)

Riquelme, S.; Bravo, F. J.; Fuentes, M.; Matias, M.; Medina, M.

2016-12-01

Large earthquakes in subduction zones are liable to produce tsunamis that can cause destruction and fatalities. The Run-up is a geophysical parameter that quantifies damage and if critical facilities or population are exposed to. Here we use the coupling for certain subduction regions measured by different techniques (Potency and GPS observations) to define areas where large earthquakes can occur. Taking the slab 1.0 from the United States Geological Survey (USGS), we can define the geometry of the area including its tsunamigenic potential. By using stochastic earthquakes sources for each area with its maximum tsunamigenic potential, we calculate the numerical and analytical run-up for each case. Then, we perform a statistical analysis and calculate the envelope for both methods. Furthermore, we build an index of risk using: the closest slope to the shore in a piecewise linear approach (last slopecriteria) and the outputsfrom tsunami modeling. Results show that there are areas prone to produce higher run-up than others based on the size of the earthquake, geometrical constraints of the source, tectonic setting and the coast last slope. Based on these results, there are zones that have low risk index which can define escape routes or secure coastal areas for tsunami early warning, urban and planning purposes when detailed data is available.

Determination of the maximum MGS mounting height : phase II detailed analysis with LS-DYNA.

DOT National Transportation Integrated Search

2012-12-01

Determination of the maximum Midwest Guardrail System (MGS) mounting height was performed in two phases. : Phase I concentrated on crash testing: two full-scale crash tests were performed on the MGS with top-rail mounting heights : of 34 in. (864 mm)...

Dual Endotemponade for Extensive Long-standing Cyclodialysis Using Sulcus-fixated Cionni Ring and PCIOL.

PubMed

Gupta, Shikha; Sagar, Pradeep; Gogia, Varun; Khokhar, Sudarshan; Dada, Tanuj

2016-03-01

A young patient presented with visual acuity of hand movements only, unrecordable intraocular pressure, and total cataract after trauma 12 months ago. She reported failure to improve with conservative therapy as well as a direct cycloplexy elsewhere. After cleft localization on preoperative gonioscopy, ultrasound biomicroscopy (UBM), and intraoperative gonioscopy, a partial-thickness scleral flap was fashioned at the site of maximum cleft height. Following phacoaspiration, a multipiece intraocular lens was implanted in the sulcus; its haptics aligned to the axis with maximum height of cyclodialysis. A Cionni ring placed in sulcus was sutured to sclera under the flap to provide additional tamponading effect. Postoperative UBM and gonioscopy confirmed cleft closure. Normalization of intraocular pressure was found on repeated follow-ups till 1 year (12 to 14 mm Hg). UBM showed increase in sulcus diameter, and "double indentation sign" on the ciliary body.

49 CFR 219.211 - Analysis and follow-up.

Code of Federal Regulations, 2014 CFR

2014-10-01

... establishing maximum periods for charging employees with rule violations, or for holding an investigation, may not be deemed to run as to any offense involving the accident or incident (i.e., such periods must be... (including each split specimen) provided under this subpart is retained for not less than three months...

2007 Insensitive Munitions and Energetic Materials Technology Symposium

DTIC Science & Technology

2007-10-18

Flat end rod Round end rod Flat cookie -cutter Spherical fragment Simple shaped charge jet Real shaped charge jet Thin plate Constant Temperature...while the press is running • No one allowed in the facility before dough -up • Maximum pressures, torque and temperatures set. • First warnings and

Effects of EDU and Ozoban on the growth of shortleaf pine seedlings in the field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flagler, R.B.; Lock, J.E.

Two field studies were conducted to determine the response of shortleaf pine seedlings planted in the field to ethylenediurea (EDU) and sodium erythorbate (Ozoban), both of which possess antioxidant properties, and were developed to protect plants from ozone (O[sub 3]). Seedlings originated from two half-sib families of shortleaf pine, S2PE3 and S3PE9, and a third [open quotes]woods-run[close quotes] selection. For the EDU study, the chemical treatment levels were 0 and 300 ppm EDU. For the Ozoban study, the chemical treatment levels were 0, 515, 1030, 1545, and 2060 ppm Ozoban. Seedlings were sprayed monthly with the appropriate concentration of antioxidantmore » chemical for two years. EDU increased leaf area and foliage, stem and root biomass for all three selections; the response of the woods-run selection was the greatest. Height growth was increased by EDU only in the woods-run selection. Diameter growth was not affected by EDU. In the Ozoban study, only family S2PE3 exhibited a biomass response to Ozobon, with increased biomass as Ozoban application rate increased up to the highest rat, at which point there was a small decrease. Height growth was not affected by Ozoban. Diameter growth of the woods-run selection increased as Ozoban applications rate increased, with a slight decrease at the highest application rate. Diameter of the other selections was not affected by Ozoban. Both chemicals appeared to provide some protection to shortleaf pine against ambient O[sub 3].« less

Does a crouched leg posture enhance running stability and robustness?

PubMed

Blum, Yvonne; Birn-Jeffery, Aleksandra; Daley, Monica A; Seyfarth, Andre

2011-07-21

Humans and birds both walk and run bipedally on compliant legs. However, differences in leg architecture may result in species-specific leg control strategies as indicated by the observed gait patterns. In this work, control strategies for stable running are derived based on a conceptual model and compared with experimental data on running humans and pheasants (Phasianus colchicus). From a model perspective, running with compliant legs can be represented by the planar spring mass model and stabilized by applying swing leg control. Here, linear adaptations of the three leg parameters, leg angle, leg length and leg stiffness during late swing phase are assumed. Experimentally observed kinematic control parameters (leg rotation and leg length change) of human and avian running are compared, and interpreted within the context of this model, with specific focus on stability and robustness characteristics. The results suggest differences in stability characteristics and applied control strategies of human and avian running, which may relate to differences in leg posture (straight leg posture in humans, and crouched leg posture in birds). It has been suggested that crouched leg postures may improve stability. However, as the system of control strategies is overdetermined, our model findings suggest that a crouched leg posture does not necessarily enhance running stability. The model also predicts different leg stiffness adaptation rates for human and avian running, and suggests that a crouched avian leg posture, which is capable of both leg shortening and lengthening, allows for stable running without adjusting leg stiffness. In contrast, in straight-legged human running, the preparation of the ground contact seems to be more critical, requiring leg stiffness adjustment to remain stable. Finally, analysis of a simple robustness measure, the normalized maximum drop, suggests that the crouched leg posture may provide greater robustness to changes in terrain height. Copyright © 2011 Elsevier Ltd. All rights reserved.

Studying Maximum Plantar Stress per Insole Design Using Foot CT-Scan Images of Hyperelastic Soft Tissues

PubMed Central

Sarikhani, Ali; Motalebizadeh, Abbas; Kamali Doost Azad, Babak

2016-01-01

The insole shape and the resulting plantar stress distribution have a pivotal impact on overall health. In this paper, by Finite Element Method, maximum stress value and stress distribution of plantar were studied for different insoles designs, which are the flat surface and the custom-molded (conformal) surface. Moreover, insole thickness, heel's height, and different materials were used to minimize the maximum stress and achieve the most uniform stress distribution. The foot shape and its details used in this paper were imported from online CT-Scan images. Results show that the custom-molded insole reduced maximum stress 40% more than the flat surface insole. Upon increase of thickness in both insole types, stress distribution becomes more uniform and maximum stress value decreases up to 10%; however, increase of thickness becomes ineffective above a threshold of 1 cm. By increasing heel height (degree of insole), maximum stress moves from heel to toes and becomes more uniform. Therefore, this scenario is very helpful for control of stress in 0.2° to 0.4° degrees for custom-molded insole and over 1° for flat insole. By changing the material of the insole, the value of maximum stress remains nearly constant. The custom-molded (conformal) insole which has 0.5 to 1 cm thickness and 0.2° to 0.4° degrees is found to be the most compatible form for foot. PMID:27843284

Temporal dynamics of CO2 fluxes and profiles over a Central European city

NASA Astrophysics Data System (ADS)

Vogt, R.; Christen, A.; Rotach, M. W.; Roth, M.; Satyanarayana, A. N. V.

2006-02-01

In Summer 2002 eddy covariance flux measurements of CO2 were performed over a dense urban surface. The month-long measurements were carried out in the framework of the Basel Urban Boundary Layer Experiment (BUBBLE). Two Li7500 open path analysers were installed at z/z H = 1.0 and 2.2 above a street canyon with z H the average building height of 14.6 m and z the height above street level. Additionally, profiles of CO2 concentration were sampled at 10 heights from street level up to 2 z H . The minimum and maximum of the average diurnal course of CO2 concentration at 2 z H were 362 and 423 ppmv in late afternoon and early morning, respectively. Daytime CO2 concentrations were not correlated to local sources, e.g. the minimum occurred together with the maximum in traffic load. During night-time CO2 is in general accumulated, except when inversion development is suppressed by frontal passages. CO2 concentrations were always decreasing with height and correspondingly, the fluxes on average always directed upward. At z/z H = 2.2 low values of about 3 µmol m-2 s-1 were measured during the second half of the night. During daytime average values reached up to 14 µmol m-2 s-1. The CO2 fluxes are well correlated with the traffic load, with their maxima occurring together in late afternoon. Daytime minimum CO2 concentrations fell below regional background values. Besides vertical mixing and entrainment, it is suggested that this is also due to advection of rural air with reduced CO2 concentration. Comparison with other urban observations shows a large range of differences among urban sites in terms of both CO2 fluxes and concentrations.

On High-Frequency Topography-Implied Gravity Signals for a Height System Unification Using GOCE-Based Global Geopotential Models

NASA Astrophysics Data System (ADS)

Grombein, Thomas; Seitz, Kurt; Heck, Bernhard

2017-03-01

National height reference systems have conventionally been linked to the local mean sea level, observed at individual tide gauges. Due to variations in the sea surface topography, the reference levels of these systems are inconsistent, causing height datum offsets of up to ±1-2 m. For the unification of height systems, a satellite-based method is presented that utilizes global geopotential models (GGMs) derived from ESA's satellite mission Gravity field and steady-state Ocean Circulation Explorer (GOCE). In this context, height datum offsets are estimated within a least squares adjustment by comparing the GGM information with measured GNSS/leveling data. While the GNSS/leveling data comprises the full spectral information, GOCE GGMs are restricted to long wavelengths according to the maximum degree of their spherical harmonic representation. To provide accurate height datum offsets, it is indispensable to account for the remaining signal above this maximum degree, known as the omission error of the GGM. Therefore, a combination of the GOCE information with the high-resolution Earth Gravitational Model 2008 (EGM2008) is performed. The main contribution of this paper is to analyze the benefit, when high-frequency topography-implied gravity signals are additionally used to reduce the remaining omission error of EGM2008. In terms of a spectral extension, a new method is proposed that does not rely on an assumed spectral consistency of topographic heights and implied gravity as is the case for the residual terrain modeling (RTM) technique. In the first step of this new approach, gravity forward modeling based on tesseroid mass bodies is performed according to the Rock-Water-Ice (RWI) approach. In a second step, the resulting full spectral RWI-based topographic potential values are reduced by the effect of the topographic gravity field model RWI_TOPO_2015, thus, removing the long to medium wavelengths. By using the latest GOCE GGMs, the impact of topography-implied gravity signals on the estimation of height datum offsets is analyzed in detail for representative GNSS/leveling data sets in Germany, Austria, and Brazil. Besides considerable changes in the estimated offset of up to 3 cm, the conducted analyses show that significant improvements of 30-40% can be achieved in terms of a reduced standard deviation and range of the least squares adjusted residuals.

Simulating Various Terrestrial and Uav LIDAR Scanning Configurations for Understory Forest Structure Modelling

NASA Astrophysics Data System (ADS)

Hämmerle, M.; Lukač, N.; Chen, K.-C.; Koma, Zs.; Wang, C.-K.; Anders, K.; Höfle, B.

2017-09-01

Information about the 3D structure of understory vegetation is of high relevance in forestry research and management (e.g., for complete biomass estimations). However, it has been hardly investigated systematically with state-of-the-art methods such as static terrestrial laser scanning (TLS) or laser scanning from unmanned aerial vehicle platforms (ULS). A prominent challenge for scanning forests is posed by occlusion, calling for proper TLS scan position or ULS flight line configurations in order to achieve an accurate representation of understory vegetation. The aim of our study is to examine the effect of TLS or ULS scanning strategies on (1) the height of individual understory trees and (2) understory canopy height raster models. We simulate full-waveform TLS and ULS point clouds of a virtual forest plot captured from various combinations of max. 12 TLS scan positions or 3 ULS flight lines. The accuracy of the respective datasets is evaluated with reference values given by the virtually scanned 3D triangle mesh tree models. TLS tree height underestimations range up to 1.84 m (15.30 % of tree height) for single TLS scan positions, but combining three scan positions reduces the underestimation to maximum 0.31 m (2.41 %). Combining ULS flight lines also results in improved tree height representation, with a maximum underestimation of 0.24 m (2.15 %). The presented simulation approach offers a complementary source of information for efficient planning of field campaigns aiming at understory vegetation modelling.

Evolution of potentially eroding events along the northern coast of the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Rasilla Álvarez, D.; García Codrón, J. C.

2009-09-01

The anthropogenic global warming is expected to result in a rise in sea-level, accompanied by changes in extreme climate events, such as the frequency and intensity of storms. Such scenario would result in an acceleration of coastal erosion. The aim of the present study is to assess the temporal evolution of potentially eroding events along the northern coast of the Iberian Peninsula during the second half of the 20th century, and to investigate changes in forcing processes such as the frequency and magnitude of storm surges and high wave events. To characterize the potentially eroding events, the total elevation of the water level was selected, being calculated as the sum of the contributions of the average water level, wave run up and the storm surges. Potentially eroding events were identified and quantified following a two-step procedure. Through the first step the potential flood induced by a given storm was estimated by simulating its effects on a theoretical beach profile (intermediate) using an empirical parameterization for extreme run-up approach. The second step consisted on characterizing the maximum storm surge registered during a storm. Those parameters were calculated from hindcasted data (storm surge, wave heights and period, wind speed and direction), retrieved from the SIMAR-44 database (Puertos del Estado), and validated against actual tide gauge measurements and buoy data (RedMar and RedExt networks). Analyses of total water levels showed a long term increase since 1958, resulting from the increase of mean sea level; conversely, a reduction of the frequency and the intensity of the storm events were deduced from the analysis of meteorological records. Since the impact of the storms on macro- and meso- tidal coast closely depend on the tides, a storm impact index was computed taking into account the storm surge magnitude, the wave heights and time duration during which a predefined threshold was exceeded by the sea level. The results are consistent with the analysis of the shoreline evolution on a specific sector of Cantabria (Oyambre) through the comparison of aerial photographs taken between 1957 and 2005. From the late 50´s to late 70’s, the shoreline significantly retreated, in correspondence with the period of maximum storm activity. Conversely, shoreline retreat slowed down during the late 1980s and 1990s while storm activity considerably decreased. Thus long-term coastal erosion, due to the occurrences of high water levels embedded into a long trend term of sea level rise, has been balanced by the reduction of the frequency and intensity of the Atlantic storms. Since relative sea-level will continue rising in the future, most of the coastal morphologies will probably be more frequently reached by the sea, increasing the flooding risk in low-lying sectors and promoting landslides along the cliffs.

Frequency dependence of the maximum operating temperature for quantum-cascade lasers up to 5.4 THz

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wienold, M.; Humboldt Universität zu Berlin, Institut für Physik, Newtonstr. 15, 12489 Berlin; Deutsches Zentrum für Luft und Raumfahrt, Rutherfordstr. 2, 12489 Berlin

2015-11-16

We report on the observation of an approximately linear reduction in the maximum operating temperature with an increasing emission frequency for terahertz quantum-cascade lasers between 4.2 and 5.4 THz. These lasers are based on the same design type, but vary in period length and barrier height for the cascade structure. The sample emitting at the highest frequency around 5.4 THz can be operated in pulsed mode up to 56 K. We identify an additional relaxation channel for electrons by longitudinal optical phonon scattering from the upper to the lower laser level and increasing optical losses toward higher frequencies as major processes,more » leading to the observed temperature behavior.« less

Trends in New U.S. Marine Corps Accessions During the Recent Conflicts in Iraq and Afghanistan

DTIC Science & Technology

2014-01-01

modest changes over the study period. Favorable trends included recent (2009-2010) improvernents in body mass index and physical activity levels...height, body mass index (BMI) in kg/m^ was calculated. Frequency of physical activity before service entry was assessed from self-report. Initial run...Test; BMI, body mass index; mph, miles per hour; SD, standard deviation. "Numbers (n) may not add up to 131,961 because of missing self-reported data for

Sensor set-up for wireless measurement of automotive rim and wheel parameters in laboratory conditions

NASA Astrophysics Data System (ADS)

Borecki, M.; Prus, P.; Korwin-Pawlowski, M. L.; Rychlik, A.; Kozubel, W.

2017-08-01

Modern rims and wheels are tested at the design and production stages. Tests can be performed in laboratory conditions and on the ride. In the laboratory, complex and costly equipment is used, as for example wheel balancers and impact testers. Modern wheel balancers are equipped with electronic and electro-mechanical units that enable touch-less measurement of dimensions, including precision measurement of radial and lateral wheel run-out, automatic positioning and application of the counterweights, and vehicle wheel set monitoring - tread wear, drift angles and run-out unbalance. Those tests are performed by on-wheel axis measurements with laser distance meters. The impact tester enables dropping of weights from a defined height onto a wheel. Test criteria are the loss of pressure of the tire and generation of cracks in the wheel without direct impact of the falling weights. In the present paper, a set up composed of three accelerometers, a temperature sensor and a pressure sensor is examined as the base of a wheel tester. The sensor set-up configuration, on-line diagnostic and signal transmission are discussed.

Cardiorespiratory Fitness and Blood Pressure: A Longitudinal Analysis.

PubMed

Agostinis-Sobrinho, César; Ruiz, Jonatan R; Moreira, Carla; Abreu, Sandra; Lopes, Luís; Oliveira-Santos, José; Mota, Jorge; Santos, Rute

2018-01-01

To examine the association between cardiorespiratory fitness and cardiovascular indices 2 years later, and to determine whether changes in cardiorespiratory fitness are associated with cardiovascular indices at a 2-year follow-up in adolescents. The sample comprised 734 adolescents (349 girls) aged 12-18 years followed for 3 years from the LabMed Physical Activity Study. Cardiorespiratory fitness was assessed by the 20-meter shuttle run test. Height, weight, waist circumference, and resting blood pressure (BP) were measured according to standard procedures. Regression analyses showed a significant inverse association between cardiorespiratory fitness at baseline and systolic BP (B = -0.126; P = .047) and rate pressure product (B = -29.94; P = .016), at follow-up after adjustments for age, sex, height, pubertal stage, socioeconomic status, and waist circumference. Significant differences were found between cardiorespiratory fitness groups (fit vs unfit) at baseline and systolic BP and rate pressure product at follow-up (P < .05 for all). Analysis of covariance showed a significant association between cardiorespiratory fitness changes and systolic BP (P = .024) and rate pressure product (P = .014), after adjustment for age, sex, height, pubertal status, socioeconomic status, and waist circumference. Changes in cardiorespiratory fitness during adolescence were associated with cardiovascular indices over a 2-year period. Adolescents with persistently low levels of cardiorespiratory fitness exhibited the highest levels of systolic BP and rate pressure product. Copyright © 2017 Elsevier Inc. All rights reserved.

Stereo Refractive Imaging of Breaking Free-Surface Waves in the Surf Zone

NASA Astrophysics Data System (ADS)

Mandel, Tracy; Weitzman, Joel; Koseff, Jeffrey; Environmental Fluid Mechanics Laboratory Team

2014-11-01

Ocean waves drive the evolution of coastlines across the globe. Wave breaking suspends sediments, while wave run-up, run-down, and the undertow transport this sediment across the shore. Complex bathymetric features and natural biotic communities can influence all of these dynamics, and provide protection against erosion and flooding. However, our knowledge of the exact mechanisms by which this occurs, and how they can be modeled and parameterized, is limited. We have conducted a series of controlled laboratory experiments with the goal of elucidating these details. These have focused on quantifying the spatially-varying characteristics of breaking waves and developing more accurate techniques for measuring and predicting wave setup, setdown, and run-up. Using dynamic refraction stereo imaging, data on free-surface slope and height can be obtained over an entire plane. Wave evolution is thus obtained with high spatial precision. These surface features are compared with measures of instantaneous turbulence and mean currents within the water column. We then use this newly-developed ability to resolve three-dimensional surface features over a canopy of seagrass mimics, in order to validate theoretical formulations of wave-vegetation interactions in the surf zone.

Combining Probability Distributions of Wind Waves and Sea Level Variations to Assess Return Periods of Coastal Floods

NASA Astrophysics Data System (ADS)

Leijala, U.; Bjorkqvist, J. V.; Pellikka, H.; Johansson, M. M.; Kahma, K. K.

2017-12-01

Predicting the behaviour of the joint effect of sea level and wind waves is of great significance due to the major impact of flooding events in densely populated coastal regions. As mean sea level rises, the effect of sea level variations accompanied by the waves will be even more harmful in the future. The main challenge when evaluating the effect of waves and sea level variations is that long time series of both variables rarely exist. Wave statistics are also highly location-dependent, thus requiring wave buoy measurements and/or high-resolution wave modelling. As an initial approximation of the joint effect, the variables may be treated as independent random variables, to achieve the probability distribution of their sum. We present results of a case study based on three probability distributions: 1) wave run-up constructed from individual wave buoy measurements, 2) short-term sea level variability based on tide gauge data, and 3) mean sea level projections based on up-to-date regional scenarios. The wave measurements were conducted during 2012-2014 on the coast of city of Helsinki located in the Gulf of Finland in the Baltic Sea. The short-term sea level distribution contains the last 30 years (1986-2015) of hourly data from Helsinki tide gauge, and the mean sea level projections are scenarios adjusted for the Gulf of Finland. Additionally, we present a sensitivity test based on six different theoretical wave height distributions representing different wave behaviour in relation to sea level variations. As these wave distributions are merged with one common sea level distribution, we can study how the different shapes of the wave height distribution affect the distribution of the sum, and which one of the components is dominating under different wave conditions. As an outcome of the method, we obtain a probability distribution of the maximum elevation of the continuous water mass, which enables a flexible tool for evaluating different risk levels in the current and future climate.

Manifestations of Proprioception During Vertical Jumps to Specific Heights

PubMed Central

Struzik, Artur; Pietraszewski, Bogdan; Winiarski, Sławomir; Juras, Grzegorz; Rokita, Andrzej

2017-01-01

Abstract Artur, S, Bogdan, P, Kawczyński, A, Winiarski, S, Grzegorz, J, and Andrzej, R. Manifestations of proprioception during vertical jumps to specific heights. J Strength Cond Res 31(6): 1694–1701, 2017—Jumping and proprioception are important abilities in many sports. The efficiency of the proprioceptive system is indirectly related to jumps performed at specified heights. Therefore, this study recorded the ability of young athletes who play team sports to jump to a specific height compared with their maximum ability. A total of 154 male (age: 14.8 ± 0.9 years, body height: 181.8 ± 8.9 cm, body weight: 69.8 ± 11.8 kg, training experience: 3.8 ± 1.7 years) and 151 female (age: 14.1 ± 0.8 years, body height: 170.5 ± 6.5 cm, body weight: 60.3 ± 9.4 kg, training experience: 3.7 ± 1.4 years) team games players were recruited for this study. Each participant performed 2 countermovement jumps with arm swing to 25, 50, 75, and 100% of the maximum height. Measurements were performed using a force plate. Jump height and its accuracy with respect to a specified height were calculated. The results revealed no significant differences in jump height and its accuracy to the specified heights between the groups (stratified by age, sex, and sport). Individuals with a higher jumping accuracy also exhibited greater maximum jump heights. Jumps to 25% of the maximum height were approximately 2 times higher than the target height. The decreased jump accuracy to a specific height when attempting to jump to lower heights should be reduced with training, particularly among athletes who play team sports. These findings provide useful information regarding the proprioceptive system for team sport coaches and may shape guidelines for training routines by working with submaximal loads. PMID:28538322

Aneurysm Characteristics Associated with the Rupture Risk of Intracranial Aneurysms: A Self-Controlled Study.

PubMed

Kang, Huibin; Ji, Wenjun; Qian, Zenghui; Li, Youxiang; Jiang, Chuhan; Wu, Zhongxue; Wen, Xiaolong; Xu, Wenjuan; Liu, Aihua

2015-01-01

This study analyzed the rupture risk of intracranial aneurysms (IAs) according to aneurysm characteristics by comparing the differences between two aneurysms in different locations within the same patient. We utilized this self-controlled model to exclude potential interference from all demographic factors to study the risk factors related to IA rupture. A total of 103 patients were diagnosed with IAs between January 2011 and April 2015 and were enrolled in this study. All enrolled patients had two IAs. One IA (the case) was ruptured, and the other (the control) was unruptured. Aneurysm characteristics, including the presence of a daughter sac, the aneurysm neck, the parent artery diameter, the maximum aneurysm height, the maximum aneurysm width, the location, the aspect ratio (AR, maximum perpendicular height/average neck diameter), the size ratio (SR, maximum aneurysm height/average parent diameter) and the width/height ratio (WH ratio, maximum aneurysm width/maximum aneurysm height), were collected and analyzed to evaluate the rupture risks of the two IAs within each patient and to identify the independent risk factors associated with IA rupture. Multivariate, conditional, backward, stepwise logistic regression analysis was performed to identify the independent risk factors associated with IA rupture. The multivariate analysis identified the presence of a daughter sac (odds ratio [OR], 13.80; 95% confidence interval [CI], 1.65-115.87), a maximum aneurysm height ≥7 mm (OR, 4.80; 95% CI, 1.21-18.98), location on the posterior communicating artery (PCOM) or anterior communicating artery (ACOM; OR, 3.09; 95% CI, 1.34-7.11) and SR (OR, 2.13; 95% CI, 1.16-3.91) as factors that were significantly associated with IA rupture. The presence of a daughter sac, the maximum aneurysm height, PCOM or ACOM locations and SR (>1.5±0.7) of unruptured IAs were significantly associated with IA rupture.

The importance of plume rise on the concentrations and atmospheric impacts of biomass burning aerosol

NASA Astrophysics Data System (ADS)

Walter, Carolin; Freitas, Saulo R.; Kottmeier, Christoph; Kraut, Isabel; Rieger, Daniel; Vogel, Heike; Vogel, Bernhard

2016-07-01

We quantified the effects of the plume rise of biomass burning aerosol and gases for the forest fires that occurred in Saskatchewan, Canada, in July 2010. For this purpose, simulations with different assumptions regarding the plume rise and the vertical distribution of the emissions were conducted. Based on comparisons with observations, applying a one-dimensional plume rise model to predict the injection layer in combination with a parametrization of the vertical distribution of the emissions outperforms approaches in which the plume heights are initially predefined. Approximately 30 % of the fires exceed the height of 2 km with a maximum height of 8.6 km. Using this plume rise model, comparisons with satellite images in the visible spectral range show a very good agreement between the simulated and observed spatial distributions of the biomass burning plume. The simulated aerosol optical depth (AOD) with data of an AERONET station is in good agreement with respect to the absolute values and the timing of the maximum. Comparison of the vertical distribution of the biomass burning aerosol with CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) retrievals also showed the best agreement when the plume rise model was applied. We found that downwelling surface short-wave radiation below the forest fire plume is reduced by up to 50 % and that the 2 m temperature is decreased by up to 6 K. In addition, we simulated a strong change in atmospheric stability within the biomass burning plume.

Observational characteristics of the tropopause inversion layer derived from CHAMP/GRACE radio occultations and MOZAIC aircraft data

NASA Astrophysics Data System (ADS)

Schmidt, T.; Cammas, J.-P.; Smit, H. G. J.; Heise, S.; Wickert, J.; Haser, A.

2010-12-01

In this study we discuss characteristics of the Northern Hemisphere (NH) midlatitude (40°N-60°N) tropopause inversion layer (TIL) based on two data sets. First, temperature measurements from GPS radio occultation data (CHAMP and GRACE) for the time interval 2001-2009 are used to exhibit seasonal properties of the TIL bottom height defined here as the height of the squared buoyancy frequency minimum N2 below the thermal tropopause, the TIL maximum height as the height of the N2 maximum above the tropopause, and the TIL top height as the height of the temperature maximum above the tropopause. Mean values of the TIL bottom, TIL maximum, and TIL top heights relative to the thermal tropopause for the NH midlatitudes are (-2.08 ± 0.35) km, (0.52 ± 0.10) km and (2.10 ± 0.23) km, respectively. A seasonal cycle of the TIL bottom and TIL top height is observed with values closer to the thermal tropopause during summer. Secondly, high-resolution temperature and trace gas profile measurements on board commercial aircrafts (Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft (MOZAIC) program) from 2001-2008 for the NH midlatitude (40°N-60°N) region are used to characterize the TIL as a mixing layer around the tropopause. Mean TIL bottom, TIL maximum, and TIL top heights based on the MOZAIC temperature (N2) measurements confirm the results from the GPS data, even though most of the MOZAIC profiles used here are available under cyclonic situations. Further, we demonstrate that the mixing ratio gradients of ozone (O3) and carbon monoxide (CO) are suitable parameters for characterizing the TIL structure.

Characterizing the Mechanical Properties of Running-Specific Prostheses

PubMed Central

Beck, Owen N.; Taboga, Paolo; Grabowski, Alena M.

2016-01-01

The mechanical stiffness of running-specific prostheses likely affects the functional abilities of athletes with leg amputations. However, each prosthetic manufacturer recommends prostheses based on subjective stiffness categories rather than performance based metrics. The actual mechanical stiffness values of running-specific prostheses (i.e. kN/m) are unknown. Consequently, we sought to characterize and disseminate the stiffness values of running-specific prostheses so that researchers, clinicians, and athletes can objectively evaluate prosthetic function. We characterized the stiffness values of 55 running-specific prostheses across various models, stiffness categories, and heights using forces and angles representative of those measured from athletes with transtibial amputations during running. Characterizing prosthetic force-displacement profiles with a 2nd degree polynomial explained 4.4% more of the variance than a linear function (p<0.001). The prosthetic stiffness values of manufacturer recommended stiffness categories varied between prosthetic models (p<0.001). Also, prosthetic stiffness was 10% to 39% less at angles typical of running 3 m/s and 6 m/s (10°-25°) compared to neutral (0°) (p<0.001). Furthermore, prosthetic stiffness was inversely related to height in J-shaped (p<0.001), but not C-shaped, prostheses. Running-specific prostheses should be tested under the demands of the respective activity in order to derive relevant characterizations of stiffness and function. In all, our results indicate that when athletes with leg amputations alter prosthetic model, height, and/or sagittal plane alignment, their prosthetic stiffness profiles also change; therefore variations in comfort, performance, etc. may be indirectly due to altered stiffness. PMID:27973573

Tsunami field survey in French Polynesia of the 2015 Chilean earthquake Mw = 8.2 and what we learned.

NASA Astrophysics Data System (ADS)

Jamelot, Anthony; Reymond, Dominique; Savigny, Jonathan; Hyvernaud, Olivier

2016-04-01

The tsunami generated by the earthquake of magnitude Mw=8.2 near the coast of central Chile on the 16th September 2015 was observed on 7 tide gauges distributed over the five archipelagoes composing French Polynesia, a territory as large as Europe. We'll sum up all the observations of the tsunami and the field survey done in Tahiti (Society islands) and Hiva-Oa (Marquesas islands) to evaluate the preliminary tsunami forecast tool (MERIT) and the detailed tsunami forecast tool (COASTER) of the French Polynesian Tsunami Warning Center. The preliminary tool forecasted a maximal tsunami height between 0.5m to 2.3 m all over the Marquesas Islands. But only the island of Hiva-Oa had a tsunami forecast greater than 1 meter especially in the Tahauku Bay well known for its local response due to its resonance properties. In Tahauku bay, the tide gauge located at the entrance of the bay recorded a maximal tsunami height above mean sea level ~ 1.7 m; and we measured at the bottom of the bay a run-up about 2.8 m at 388 m inland from the shoreline in the river bed, and a run-up of 2.5 m located 155 m inland. The multi-grid simulation over Tahiti was done one hour after the origin time of the earthquake and gave a very localized tsunami impact on the North shore. Our forecast indicated an inundation about 10 m inland that lead Civil Authorities to evacuate 6 houses. It was the first operational use of this new fine grid covering the north part of Tahiti that is not protected by a coral reef. So we were attentive to the feed back of the alert that confirm the forecast of the maximal height arrival 1 hour after the first arrival. The tsunami warning system forecast well strong impact as well as low impact as long as we have an early robust description of the seismic parameters and fine grids about 10 m spatial resolution to simulate tsunami impact. In January of 2016 we are able to forecast tsunami heights for 72 points located over 35 islands of French Polynesia.

Evaluation of stress distribution of implant-retained mandibular overdenture with different vertical restorative spaces: A finite element analysis

PubMed Central

Ebadian, Behnaz; Farzin, Mahmoud; Talebi, Saeid; Khodaeian, Niloufar

2012-01-01

Background: Available restorative space and bar height is an important factor in stress distribution of implant-supported overdentures. The purpose of this study was to evaluate the effect of different vertical restorative spaces and different bar heights on the stress distribution around implants by 3D finite element analysis. Materials and Methods: 3D finite element models were developed from mandibular overdentures with two implants in the interforaminal region. In these models, four different bar heights from gingival crest (0.5, 1, 1.5, 2 mm) with 15 mm occlusal plane height and three different occlusal plane heights from gingival crest (9, 12, 15 mm) with 2 mm bar height were analyzed. A vertical unilateral and a bilateral load of 150 N were applied to the central occlusal fossa of the first molar and the stress of bone around implant was analyzed by finite element analysis. Results: By increasing vertical restorative space, the maximum stress values around implants were found to be decreased in unilateral loading models but slightly increased in bilateral loading cases. By increasing bar height from gingival crest, the maximum stress values around implants were found to be increased in unilateral loading models but slightly decreased in bilateral loading cases. In unilateral loading models, maximum stress was found in a model with 9 mm occlusal plane height and 1.5 mm bar height (6.254 MPa), but in bilateral loading cases, maximum stress was found in a model with 15 mm occlusal plane height and 0.5 mm bar height (3.482 MPa). Conclusion: The reduction of bar height and increase in the thickness of acrylic resin base in implant-supported overdentures are biomechanically favorable and may result in less stress in periimplant bone. PMID:23559952

Sea-level rise induced amplification of coastal protection design heights.

PubMed

Arns, Arne; Dangendorf, Sönke; Jensen, Jürgen; Talke, Stefan; Bender, Jens; Pattiaratchi, Charitha

2017-01-06

Coastal protection design heights typically consider the superimposed effects of tides, surges, waves, and relative sea-level rise (SLR), neglecting non-linear feedbacks between these forcing factors. Here, we use hydrodynamic modelling and multivariate statistics to show that shallow coastal areas are extremely sensitive to changing non-linear interactions between individual components caused by SLR. As sea-level increases, the depth-limitation of waves relaxes, resulting in waves with larger periods, greater amplitudes, and higher run-up; moreover, depth and frictional changes affect tide, surge, and wave characteristics, altering the relative importance of other risk factors. Consequently, sea-level driven changes in wave characteristics, and to a lesser extent, tides, amplify the resulting design heights by an average of 48-56%, relative to design changes caused by SLR alone. Since many of the world's most vulnerable coastlines are impacted by depth-limited waves, our results suggest that the overall influence of SLR may be greatly underestimated in many regions.

Effect of table top slope and height on body posture and muscular activity pattern.

PubMed

Hassaïne, M; Hamaoui, A; Zanone, P-G

2015-04-01

The objective of this study was to assess the effect of table top slope and height on body posture and muscular activity pattern. Twelve asymptomatic participants performed a 5-min reading task while sitting, in six experimental conditions manipulating the table top slope (20° backward slope, no slope) and its height (low, medium, up). EMGs recordings were taken on 9 superficial muscles located at the trunk and shoulder level, and the angular positions of the head, trunk and pelvis were assessed using an inertial orientation system. Results revealed that the sloping table top was associated with a higher activity of deltoideus pars clavicularis (P<0.05) and a smaller flexion angle of the head (P<0.05). A tentative conclusion is that a sloping table top induces a more erect posture of the head and the neck, but entails an overload of the shoulder, which might be harmful on the long run. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Injuries and Footwear (Part 1): Athletic Shoe History and Injuries in Relation to Foot Arch Height and Training in Boots.

PubMed

Knapik, Joseph J; Pope, Rodney; Orr, Robin; Grier, Tyson

2015-01-01

This article traces the history of the athletic shoe, examines whether selecting running shoes based on foot arch height influences injuries, and examines historical data on injury rates when physical training (PT) is performed in boots versus running shoes. In the 1980s and into the 2000s, running shoe companies were advertising specialized shoes with "motion control," "stability," and "cushioning," designed for individuals with low, normal, and high arches, respectively. Despite marketing claims that these shoes would reduce injury rates, coordinated studies in Army, Air Force, and Marine Corps basic training showed that assigning or selecting shoes on this basis had no effect on injury rates. Consistent with this finding, biomechanical studies have shown that the relationships between arch height, foot joint mobility, and rear-foot motion are complex, variable, and frequently not as strong as often assumed. In 1982, the US Army switched from PT in boots to PT in running shoes because of the belief that boots were causing injuries and that running shoes would reduce injury rates. However, a historical comparison of injury rates before and after the switch to running shoes showed virtually no difference in injury risk between the two periods. It is not clear at this point if the type of footwear effects injury incidence. 2015.

Evaluation of the Relationship Between Coral Damage and Tsunami Dynamics; Case Study: 2009 Samoa Tsunami

NASA Astrophysics Data System (ADS)

Dilmen, Derya I.; Titov, Vasily V.; Roe, Gerard H.

2015-12-01

On September 29, 2009, an Mw = 8.1 earthquake at 17:48 UTC in Tonga Trench generated a tsunami that caused heavy damage across Samoa, American Samoa, and Tonga islands. Tutuila island, which is located 250 km from the earthquake epicenter, experienced tsunami flooding and strong currents on the north and east coasts, causing 34 fatalities (out of 192 total deaths from this tsunami) and widespread structural and ecological damage. The surrounding coral reefs also suffered heavy damage. The damage was formally evaluated based on detailed surveys before and immediately after the tsunami. This setting thus provides a unique opportunity to evaluate the relationship between tsunami dynamics and coral damage. In this study, estimates of the maximum wave amplitudes and coastal inundation of the tsunami are obtained with the MOST model (T itov and S ynolakis, J. Waterway Port Coast Ocean Eng: pp 171, 1998; T itov and G onzalez, NOAA Tech. Memo. ERL PMEL 112:11, 1997), which is now the operational tsunami forecast tool used by the National Oceanic and Atmospheric Administration (NOAA). The earthquake source function was constrained using the real-time deep-ocean tsunami data from three DART® (Deep-ocean Assessment and Reporting for Tsunamis) systems in the far field, and by tide-gauge observations in the near field. We compare the simulated run-up with observations to evaluate the simulation performance. We present an overall synthesis of the tide-gauge data, survey results of the run-up, inundation measurements, and the datasets of coral damage around the island. These data are used to assess the overall accuracy of the model run-up prediction for Tutuila, and to evaluate the model accuracy over the coral reef environment during the tsunami event. Our primary findings are that: (1) MOST-simulated run-up correlates well with observed run-up for this event ( r = 0.8), it tends to underestimated amplitudes over coral reef environment around Tutuila (for 15 of 31 villages, run-up is underestimated by more than 10 %; in only 5 was run-up overestimated by more than 10 %), and (2) the locations where the model underestimates run-up also tend to have experienced heavy or very heavy coral damage (8 of the 15 villages), whereas well-estimated run-up locations characteristically experience low or very low damage (7 of 11 villages). These findings imply that a numerical model may overestimate the energy loss of the tsunami waves during their interaction with the coral reef. We plan future studies to quantify this energy loss and to explore what improvements can be made in simulations of tsunami run-up when simulating coastal environments with fringing coral reefs.

Chronic and acute inspiratory muscle loading augment the effect of a 6-week interval program on tolerance of high-intensity intermittent bouts of running.

PubMed

Tong, Tom K; Fu, Frank H; Eston, Roger; Chung, Pak-Kwong; Quach, Binh; Lu, Kui

2010-11-01

This study examined the hypothesis that chronic (training) and acute (warm-up) loaded ventilatory activities applied to the inspiratory muscles (IM) in an integrated manner would augment the training volume of an interval running program. This in turn would result in additional improvement in the maximum performance of the Yo-Yo intermittent recovery test in comparison with interval training alone. Eighteen male nonprofessional athletes were allocated to either an inspiratory muscle loading (IML) group or control group. Both groups participated in a 6-week interval running program consisting of 3-4 workouts (1-3 sets of various repetitions of selected distance [100-2,400 m] per workout) per week. For the IML group, 4-week IM training (30 inspiratory efforts at 50% maximal static inspiratory pressure [P0] per set, 2 sets·d-1, 6 d·wk-1) was applied before the interval program. Specific IM warm-up (2 sets of 30 inspiratory efforts at 40% P0) was performed before each workout of the program. For the control group, neither IML was applied. In comparison with the control group, the interval training volume as indicated by the repeatability of running bouts at high intensity was approximately 27% greater in the IML group. Greater increase in the maximum performance of the Yo-Yo test (control: 16.9 ± 5.5%; IML: 30.7 ± 4.7% baseline value) was also observed after training. The enhanced exercise performance was partly attributable to the greater reductions in the sensation of breathlessness and whole-body metabolic stress during the Yo-Yo test. These findings show that the combination of chronic and acute IML into a high-intensity interval running program is a beneficial training strategy for enhancing the tolerance to high-intensity intermittent bouts of running.

Biological and environmental determinants of 12-minute run performance in youth.

PubMed

Freitas, Duarte; Maia, José; Stasinopoulos, Mikis; Gouveia, Élvio Rúbio; Antunes, António M; Thomis, Martine; Lefevre, Johan; Claessens, Albrecht; Hedeker, Donald; Malina, Robert M

2017-11-01

The 12-minute run is a commonly used indicator of cardiorespiratory fitness in youth. Variation in growth and maturity status as potential correlates of test performance has not been systematically addressed. To evaluate biological and environmental determinants of 12-minute run performance in Portuguese youth aged 7-17 years. Mixed-longitudinal samples of 187 boys and 142 girls were surveyed in 1996, 1997 and 1998. The 12-minute run was the indicator of cardiorespiratory fitness. Height, body mass and five skinfolds were measured and skeletal maturity was assessed. Physical activity, socioeconomic status and area of residence were obtained with a questionnaire. Multi-level modelling was used for the analysis. Chronological age and sum of five skinfolds were significant predictors of 12-minute run performance. Older boys and girls ran longer distances than younger peers, while high levels of subcutaneous fat were associated with shorter running distances. Rural boys were more proficient in the 12-minute run than urban peers. Skeletal maturity, height, body mass index, physical activity and socioeconomic status were not significant predictors of 12-minute run performances. Age and sum of skinfolds in both sexes and rural residence in boys are significant predictors of 12-minute run performance in Portuguese youth.

Changes in fitness and shipboard task performance following circuit weight training programs featuring continuous or interval running.

PubMed

Marcinik, E J; Hodgdon, J A; Englund, C E; O'Brien, J J

1987-01-01

Pre- and post-physiological data were collected on 57 Navy men (mean age = 19.5 years) who participated in either circuit weight training/continuous run (CWT/CR) (N = 31) or circuit weight training/interval run (CWT/IR) (N = 26) programs. Measured variables included 4 measures of upper torso dynamic strength (one repetition maximum [1 RM] for arm curl, bench press, shoulder press, and lat pull-down); two measures of lower torso dynamic strength (1 RM) for knee extension and leg press); one measure of power (number of revolutions completed on an arm ergometer (Monark) at maximum drag); three measures of muscular endurance (number of repetitions at 60% 1 RM for bench press and leg press and maximal number of bent-knee sit-ups in 120 s); one stamina measure (time to exhaustion on a cycle ergometer (Monark) maximal work capacity [MWC] test; and three simulated shipboard tasks: manikin shoulder drag, open/secure a water tight door and paint bucket carry. Composite shipboard performance derived from the summed time (s) required to complete the three tasks was also calculated. Results show performance on the manikin shoulder drag and majority of evaluative fitness measures was significantly (p less than 0.05) enhanced following both circuit weight training/run formats. Significantly (p less than 0.05) higher values for shoulder press (F = 7.2), arm ergometer (F = 5.3), and sit-ups (F = 6.8) and lower values for leg press muscular endurance (F = 5.1) were observed in CWT/IR when compared to CWT/CR.(ABSTRACT TRUNCATED AT 250 WORDS)

Choice of optimum heights for registration of ionospheric response onto earthquakes

NASA Astrophysics Data System (ADS)

Krasnov, Valerii; Gotur, Ivan; Kuleshov, Yurii; Cherny, Sergei

2017-10-01

To investigate the dependence of ionospheric disturbances on height we used model calculations, and the data of seismic and ionospheric observations during the Tohoku-Oki earthquake. High-altitude dependences of "portraits" of ionospheric disturbances are calculated for a case of influence of a seismic P-wave onto the ionosphere. We compared the "portraits" of ionospheric disturbances with the "portraits" of the seismic recording. The correlation coefficient of the recordings for the height of 100 km was about 0.81, for 130 km - 0.85, for 160 km - 0.77, for 180 km - 0.76, for 200 km - 0.7, for 230 km -0.54 and for 250 km - 0.41. At the same time the maximum of F2-layer was at the height about 250 km. Thus, the height of a maximum of F2-layer was not optimum for registration of ionospheric disturbances due to the earthquake. It was preferable to carry out measurements of the ionospheric disturbances at the heights below 200 km. The profile of amplitude of the ionospheric disturbance had no sharply expressed maximum at the height of a maximum of F2-layer. Therefore it is problematic to use the approach of the thin layer for interpretation of TEC disturbances.

Wind-influenced projectile motion

NASA Astrophysics Data System (ADS)

Bernardo, Reginald Christian; Perico Esguerra, Jose; Day Vallejos, Jazmine; Jerard Canda, Jeff

2015-03-01

We solved the wind-influenced projectile motion problem with the same initial and final heights and obtained exact analytical expressions for the shape of the trajectory, range, maximum height, time of flight, time of ascent, and time of descent with the help of the Lambert W function. It turns out that the range and maximum horizontal displacement are not always equal. When launched at a critical angle, the projectile will return to its starting position. It turns out that a launch angle of 90° maximizes the time of flight, time of ascent, time of descent, and maximum height and that the launch angle corresponding to maximum range can be obtained by solving a transcendental equation. Finally, we expressed in a parametric equation the locus of points corresponding to maximum heights for projectiles launched from the ground with the same initial speed in all directions. We used the results to estimate how much a moderate wind can modify a golf ball’s range and suggested other possible applications.

Landslides and tsunamis predicted by incompressible smoothed particle hydrodynamics (SPH) with application to the 1958 Lituya Bay event and idealized experiment.

PubMed

Xenakis, A M; Lind, S J; Stansby, P K; Rogers, B D

2017-03-01

Tsunamis caused by landslides may result in significant destruction of the surroundings with both societal and industrial impact. The 1958 Lituya Bay landslide and tsunami is a recent and well-documented terrestrial landslide generating a tsunami with a run-up of 524 m. Although recent computational techniques have shown good performance in the estimation of the run-up height, they fail to capture all the physical processes, in particular, the landslide-entry profile and interaction with the water. Smoothed particle hydrodynamics (SPH) is a versatile numerical technique for describing free-surface and multi-phase flows, particularly those that exhibit highly nonlinear deformation in landslide-generated tsunamis. In the current work, the novel multi-phase incompressible SPH method with shifting is applied to the Lituya Bay tsunami and landslide and is the first methodology able to reproduce realistically both the run-up and landslide-entry as documented in a benchmark experiment. The method is the first paper to develop a realistic implementation of the physics that in addition to the non-Newtonian rheology of the landslide includes turbulence in the water phase and soil saturation. Sensitivity to the experimental initial conditions is also considered. This work demonstrates the ability of the proposed method in modelling challenging environmental multi-phase, non-Newtonian and turbulent flows.

Landslides and tsunamis predicted by incompressible smoothed particle hydrodynamics (SPH) with application to the 1958 Lituya Bay event and idealized experiment

PubMed Central

Lind, S. J.; Stansby, P. K.; Rogers, B. D.

2017-01-01

Tsunamis caused by landslides may result in significant destruction of the surroundings with both societal and industrial impact. The 1958 Lituya Bay landslide and tsunami is a recent and well-documented terrestrial landslide generating a tsunami with a run-up of 524 m. Although recent computational techniques have shown good performance in the estimation of the run-up height, they fail to capture all the physical processes, in particular, the landslide-entry profile and interaction with the water. Smoothed particle hydrodynamics (SPH) is a versatile numerical technique for describing free-surface and multi-phase flows, particularly those that exhibit highly nonlinear deformation in landslide-generated tsunamis. In the current work, the novel multi-phase incompressible SPH method with shifting is applied to the Lituya Bay tsunami and landslide and is the first methodology able to reproduce realistically both the run-up and landslide-entry as documented in a benchmark experiment. The method is the first paper to develop a realistic implementation of the physics that in addition to the non-Newtonian rheology of the landslide includes turbulence in the water phase and soil saturation. Sensitivity to the experimental initial conditions is also considered. This work demonstrates the ability of the proposed method in modelling challenging environmental multi-phase, non-Newtonian and turbulent flows. PMID:28413334

Height restoration and maintenance after treating unstable osteoporotic vertebral compression fractures by cement augmentation is dependent on the cement volume used.

PubMed

Krüger, Antonio; Baroud, Gamal; Noriega, David; Figiel, Jens; Dorschel, Christine; Ruchholtz, Steffen; Oberkircher, Ludwig

2013-08-01

Two different procedures, used for percutaneous augmentation of vertebral compression fractures were compared, with respect to height restoration and maintenance after cyclic loading. Additionally the impact of the cement volume used was investigated. Wedge compression fractures were created in 36 human cadavaric vertebrae (T10-L3). Twenty-seven vertebrae were treated with the SpineJack® with different cement volumes (maximum, intermediate, and no cement), and 9 vertebrae were treated with Balloon Kyphoplasty. Vertebral heights were measured pre- and postfracture as well as after treatment and loading. Cyclic loading was performed with 10,000cycles (1Hz, 100-600N). The average anterior height after restoration was 85.56% for Kyphoplasty; 96.20% for SpineJack® no cement; 93.44% for SpineJack® maximum and 96% for the SpineJack® intermediate group. The average central height after restoration was 93.89% for Kyphoplasty; 100.20% for SpineJack® no cement; 99.56% for SpineJack® maximum and 101.13% for the SpineJack® intermediate group. The average anterior height after cyclic loading was 85.33 % for Kyphoplasty; 87.30% in the SpineJack® no cement, 92% in the SpineJack® maximum and 87% in the SpineJack® intermediate group. The average central height after cyclic loading was 92% for Kyphoplasty; 93.80% in the SpineJack® no cement; 98.56% in the SpineJack® maximum and 94.25% in the SpineJack® intermediate group. Height restoration was significantly better for the SpineJack® group compared to Kyphoplasty. Height maintenance was dependent on the cement volume used. The group with the SpineJack® without cement nevertheless showed better results in height maintenance, yet the statistical significance could not be demonstrated. Copyright © 2013 Elsevier Ltd. All rights reserved.

Free-running waveform characterization using a delay-time tunable laser based delay-line-free electro-optic sampling oscilloscope

NASA Astrophysics Data System (ADS)

Lin, Gong-Ru

2002-12-01

We develop a delay-line-free and frequency traceable electro-optic sampling oscilloscope by use of a digital phase-locked loop phase shifter (PLL-PS) controlled delay-time-tunable gain-switched laser diode (GSLD). The home-made voltage-controllable PLL-PS exhibits a linear transfer function with ultra-wide phase shifting range of ±350° and tuning error of <±5%, which benefits the advantages of frequency tracking to free-running signals with suppressed timing-jitter. The maximum delay-time of PLL-PS controlled GSLD is up to 1.95 periods by changing the controlling voltage ( VREF) from -3.5 to 3.5 V, which corresponds to 3.9 ns at repetition frequency of 500 MHz. The tuning responsivity and resolution are about 0.56 ns/V and 0.15˜0.2 ps, respectively. The maximum delay-time switching bandwidth of 100 Hz is determined under the control of a saw-tooth modulated VREF function. The waveform sampling of microwave PECL signals generated from a free-running digital frequency divider is performed with acceptable measuring deviation.

Evaluation of Tsunami Run-Up on Coastal Areas at Regional Scale

NASA Astrophysics Data System (ADS)

González, M.; Aniel-Quiroga, Í.; Gutiérrez, O.

2017-12-01

Tsunami hazard assessment is tackled by means of numerical simulations, giving as a result, the areas flooded by tsunami wave inland. To get this, some input data is required, i.e., the high resolution topobathymetry of the study area, the earthquake focal mechanism parameters, etc. The computational cost of these kinds of simulations are still excessive. An important restriction for the elaboration of large scale maps at National or regional scale is the reconstruction of high resolution topobathymetry on the coastal zone. An alternative and traditional method consists of the application of empirical-analytical formulations to calculate run-up at several coastal profiles (i.e. Synolakis, 1987), combined with numerical simulations offshore without including coastal inundation. In this case, the numerical simulations are faster but some limitations are added as the coastal bathymetric profiles are very simply idealized. In this work, we present a complementary methodology based on a hybrid numerical model, formed by 2 models that were coupled ad hoc for this work: a non-linear shallow water equations model (NLSWE) for the offshore part of the propagation and a Volume of Fluid model (VOF) for the areas near the coast and inland, applying each numerical scheme where they better reproduce the tsunami wave. The run-up of a tsunami scenario is obtained by applying the coupled model to an ad-hoc numerical flume. To design this methodology, hundreds of worldwide topobathymetric profiles have been parameterized, using 5 parameters (2 depths and 3 slopes). In addition, tsunami waves have been also parameterized by their height and period. As an application of the numerical flume methodology, the coastal parameterized profiles and tsunami waves have been combined to build a populated database of run-up calculations. The combination was tackled by means of numerical simulations in the numerical flume The result is a tsunami run-up database that considers real profiles shape, realistic tsunami waves, and optimized numerical simulations. This database allows the calculation of the run-up of any new tsunami wave by interpolation on the database, in a short period of time, based on the tsunami wave characteristics provided as an output of the NLSWE model along the coast at a large scale domain (regional or National scale).

Simulation of Groundwater Mounding Beneath Hypothetical Stormwater Infiltration Basins

USGS Publications Warehouse

Carleton, Glen B.

2010-01-01

Groundwater mounding occurs beneath stormwater management structures designed to infiltrate stormwater runoff. Concentrating recharge in a small area can cause groundwater mounding that affects the basements of nearby homes and other structures. Methods for quantitatively predicting the height and extent of groundwater mounding beneath and near stormwater Finite-difference groundwater-flow simulations of infiltration from hypothetical stormwater infiltration structures (which are typically constructed as basins or dry wells) were done for 10-acre and 1-acre developments. Aquifer and stormwater-runoff characteristics in the model were changed to determine which factors are most likely to have the greatest effect on simulating the maximum height and maximum extent of groundwater mounding. Aquifer characteristics that were changed include soil permeability, aquifer thickness, and specific yield. Stormwater-runoff variables that were changed include magnitude of design storm, percentage of impervious area, infiltration-structure depth (maximum depth of standing water), and infiltration-basin shape. Values used for all variables are representative of typical physical conditions and stormwater management designs in New Jersey but do not include all possible values. Results are considered to be a representative, but not all-inclusive, subset of likely results. Maximum heights of simulated groundwater mounds beneath stormwater infiltration structures are the most sensitive to (show the greatest change with changes to) soil permeability. The maximum height of the groundwater mound is higher when values of soil permeability, aquifer thickness, or specific yield are decreased or when basin depth is increased or the basin shape is square (and values of other variables are held constant). Changing soil permeability, aquifer thickness, specific yield, infiltration-structure depth, or infiltration-structure shape does not change the volume of water infiltrated, it changes the shape or height of the groundwater mound resulting from the infiltration. An aquifer with a greater soil permeability or aquifer thickness has an increased ability to transmit water away from the source of infiltration than aquifers with lower soil permeability; therefore, the maximum height of the groundwater mound will be lower, and the areal extent of mounding will be larger. The maximum height of groundwater mounding is higher when values of design storm magnitude or percentage of impervious cover (from which runoff is captured) are increased (and other variables are held constant) because the total volume of water to be infiltrated is larger. The larger the volume of infiltrated water the higher the head required to move that water away from the source of recharge if the physical characteristics of the aquifer are unchanged. The areal extent of groundwater mounding increases when soil permeability, aquifer thickness, design-storm magnitude, or percentage of impervious cover are increased (and values of other variables are held constant). For 10-acre sites, the maximum heights of the simulated groundwater mound range from 0.1 to 18.5 feet (ft). The median of the maximum-height distribution from 576 simulations is 1.8 ft. The maximum areal extent (measured from the edge of the infiltration basins) of groundwater mounding of 0.25-ft ranges from 0 to 300 ft with a median of 51 ft for 576 simulations. Stormwater infiltration at a 1-acre development was simulated, incorporating the assumption that the hypothetical infiltration structure would be a pre-cast concrete dry well having side openings and an open bottom. The maximum heights of the simulated groundwater-mounds range from 0.01 to 14.0 ft. The median of the maximum-height distribution from 432 simulations is 1.0 ft. The maximum areal extent of groundwater mounding of 0.25-ft ranges from 0 to 100 ft with a median of 10 ft for 432 simulations. Simulated height and extent of groundwater mounding associ

Extreme waves under Hurricane Ivan.

PubMed

Wang, David W; Mitchell, Douglas A; Teague, William J; Jarosz, Ewa; Hulbert, Mark S

2005-08-05

Hurricane Ivan, a category 4 storm, passed directly over six wave-tide gauges deployed by the Naval Research Laboratory on the outer continental shelf in the northeastern Gulf of Mexico. Waves were observed with significant wave heights reaching 17.9 meters and maximum crest-to-trough individual wave heights of 27.7 meters (91 feet). Analysis suggests that significant wave heights likely surpassed 21 meters (69 feet) and that maximum crest-to-trough individual wave heights exceeded 40 meters (132 feet) near the eyewall.

Adaptive use of research aircraft data sets for hurricane forecasts

NASA Astrophysics Data System (ADS)

Biswas, M. K.; Krishnamurti, T. N.

2008-02-01

This study uses an adaptive observational strategy for hurricane forecasting. It shows the impacts of Lidar Atmospheric Sensing Experiment (LASE) and dropsonde data sets from Convection and Moisture Experiment (CAMEX) field campaigns on hurricane track and intensity forecasts. The following cases are used in this study: Bonnie, Danielle and Georges of 1998 and Erin, Gabrielle and Humberto of 2001. A single model run for each storm is carried out using the Florida State University Global Spectral Model (FSUGSM) with the European Center for Medium Range Weather Forecasts (ECMWF) analysis as initial conditions, in addition to 50 other model runs where the analysis is randomly perturbed for each storm. The centers of maximum variance of the DLM heights are located from the forecast error variance fields at the 84-hr forecast. Back correlations are then performed using the centers of these maximum variances and the fields at the 36-hr forecast. The regions having the highest correlations in the vicinity of the hurricanes are indicative of regions from where the error growth emanates and suggests the need for additional observations. Data sets are next assimilated in those areas that contain high correlations. Forecasts are computed using the new initial conditions for the storm cases, and track and intensity skills are then examined with respect to the control forecast. The adaptive strategy is capable of identifying sensitive areas where additional observations can help in reducing the hurricane track forecast errors. A reduction of position error by approximately 52% for day 3 of forecast (averaged over 7 storm cases) over the control runs is observed. The intensity forecast shows only a slight positive impact due to the model’s coarse resolution.

Knee Joint Kinematics and Kinetics During a Lateral False-Step Maneuver

PubMed Central

Golden, Grace M.; Pavol, Michael J.; Hoffman, Mark A.

2009-01-01

Abstract Context: Cutting maneuvers have been implicated as a mechanism of noncontact anterior cruciate ligament (ACL) injuries in collegiate female basketball players. Objective: To investigate knee kinematics and kinetics during running when the width of a single step, relative to the path of travel, was manipulated, a lateral false-step maneuver. Design: Crossover design. Setting: University biomechanics laboratory. Patients or Other Participants: Thirteen female collegiate basketball athletes (age  =  19.7 ± 1.1 years, height  =  172.3 ± 8.3 cm, mass  =  71.8 ± 8.7 kg). Intervention(s): Three conditions: normal straight-ahead running, lateral false step of width 20% of body height, and lateral false step of width 35% of body height. Main Outcome Measure(s): Peak angles and internal moments for knee flexion, extension, abduction, adduction, internal rotation, and external rotation. Results: Differences were noted among conditions in peak knee angles (flexion [P < .01], extension [P  =  .02], abduction [P < .01], and internal rotation [P < .01]) and peak internal knee moments (abduction [P < .01], adduction [P < .01], and internal rotation [P  =  .03]). The lateral false step of width 35% of body height was associated with larger peak flexion, abduction, and internal rotation angles and larger peak abduction, adduction, and internal rotation moments than normal running. Peak flexion and internal rotation angles were also larger for the lateral false step of width 20% of body height than for normal running, whereas peak extension angle was smaller. Peak internal rotation angle increased progressively with increasing step width. Conclusions: Performing a lateral false-step maneuver resulted in changes in knee kinematics and kinetics compared with normal running. The differences observed for lateral false steps were consistent with proposed mechanisms of ACL loading, suggesting that lateral false steps represent a hitherto neglected mechanism of noncontact ACL injury. PMID:19771289

40 CFR 60.386 - Test methods and procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... The sample volume for each run shall be at least 1.70 dscm (60 dscf). The sampling probe and filter... probe and filter temperature slightly above the effluent temperature (up to a maximum filter temperature of 121 °C (250 °F)) in order to prevent water condensation on the filter. (2) Method 9 and the...

Chlorhexidine droplet splash from a skin preparation gallipot: effect of height of pouring.

PubMed

Evans, L; Cunningham, M; Tilakaratna, P

2013-12-01

Chlorhexidine contamination of equipment used in central neuraxial anaesthesia has been implicated in causing adhesive arachnoiditis. We measured the extent of chlorhexidine splash during pouring into a gallipot (antiseptic skin preparation container) from heights of 5 cm, 10 cm, 15 cm and 20 cm. Twenty experiments were performed at each height. Measurements made up to a horizontal distance of 40 cm radius from the gallipot showed a median (IQR [range]) maximum spread of splash droplets ≥ 2 mm diameter of 26.2 (10.2-36.4 [0-40]) cm. The 40-cm radius measurement area was divided into 5-cm-wide zones to assess spread. At pouring heights of 15 cm and 20 cm, all zones were contaminated. These results demonstrate that pouring chlorhexidine into a gallipot generates significant splash, and we recommend that this should be avoided near equipment used for neuraxial anaesthesia. © 2013 The Association of Anaesthetists of Great Britain and Ireland.

Height Distribution Between Cloud and Aerosol Layers from the GLAS Spaceborne Lidar in the Indian Ocean Region

NASA Technical Reports Server (NTRS)

Hart, William D.; Spinhirne, James D.; Palm, Steven P.; Hlavka, Dennis L.

2005-01-01

The Geoscience Laser Altimeter System (GLAS), a nadir pointing lidar on the Ice Cloud and land Elevation Satellite (ICESat) launched in 2003, now provides important new global measurements of the relationship between the height distribution of cloud and aerosol layers. GLAS data have the capability to detect, locate, and distinguish between cloud and aerosol layers in the atmosphere up to 40 km altitude. The data product algorithm tests the product of the maximum attenuated backscatter coefficient b'(r) and the vertical gradient of b'(r) within a layer against a predetermined threshold. An initial case result for the critical Indian Ocean region is presented. From the results the relative height distribution between collocated aerosol and cloud shows extensive regions where cloud formation is well within dense aerosol scattering layers at the surface. Citation: Hart, W. D., J. D. Spinhime, S. P. Palm, and D. L. Hlavka (2005), Height distribution between cloud and aerosol layers from the GLAS spaceborne lidar in the Indian Ocean region,

Evidence of seasonal variation in longitudinal growth of height in a sample of boys from Stuttgart Carlsschule, 1771-1793, using combined principal component analysis and maximum likelihood principle.

PubMed

Lehmann, A; Scheffler, Ch; Hermanussen, M

2010-02-01

Recent progress in modelling individual growth has been achieved by combining the principal component analysis and the maximum likelihood principle. This combination models growth even in incomplete sets of data and in data obtained at irregular intervals. We re-analysed late 18th century longitudinal growth of German boys from the boarding school Carlsschule in Stuttgart. The boys, aged 6-23 years, were measured at irregular 3-12 monthly intervals during the period 1771-1793. At the age of 18 years, mean height was 1652 mm, but height variation was large. The shortest boy reached 1474 mm, the tallest 1826 mm. Measured height closely paralleled modelled height, with mean difference of 4 mm, SD 7 mm. Seasonal height variation was found. Low growth rates occurred in spring and high growth rates in summer and autumn. The present study demonstrates that combining the principal component analysis and the maximum likelihood principle enables growth modelling in historic height data also. Copyright (c) 2009 Elsevier GmbH. All rights reserved.

Numerical modelling of edge-driven convection during rift-to-drift transition: application to the Red Sea

NASA Astrophysics Data System (ADS)

Fierro, Elisa; Capitanio, Fabio A.; Schettino, Antonio; Morena Salerno, V.

2017-04-01

We use numerical modeling to investigate the coupling of mantle instabilities and surface tectonics along lithospheric steps developing during rifting. We address whether edge driven convection (EDC) beneath rifted continental margins and shear flow during rift-drift transition can play a role in the observed post-rift compressive tectonic evolution of the divergent continental margins along the Red Sea. We run a series of 2D simulations to examine the relationship between the maximum compression and key geometrical parameters of the step beneath continental margins, such as the step height due to lithosphere thickness variation and the width of the margins, and test the effect of rheology varying temperature- and stress-dependent viscosity in the lithosphere and asthenosphere. The development of instabilities is initially illustrated as a function of these parameters, to show the controls on the lithosphere strain distribution and magnitude. We then address the transient evolution of the instabilities to characterize their duration. In an additional suite of models, we address the development of EDC during plate motions, thus accounting for the mantle shearing due to spreading. Our results show an increase of strain with the step height as well as with the margin width up to 200 km. After this value the influence of ridge margin can be neglected. Strain rates are, then, quantified for a range of laboratory-constrained constitutive laws for mantle and lithosphere forming minerals. These models propose a viable mechanism to explain the post-rift tectonic inversion observed along the Arabian continental margin and the episodic ultra-fast sea floor spreading in the central Red Sea, where the role of EDC has been invoked.

The role of baryons in creating statistically significant planes of satellites around Milky Way-mass galaxies

NASA Astrophysics Data System (ADS)

Ahmed, Sheehan H.; Brooks, Alyson M.; Christensen, Charlotte R.

2017-04-01

We investigate whether the inclusion of baryonic physics influences the formation of thin, coherently rotating planes of satellites such as those seen around the Milky Way and Andromeda. For four Milky Way-mass simulations, each run both as dark matter-only and with baryons included, we are able to identify a planar configuration that significantly maximizes the number of plane satellite members. The maximum plane member satellites are consistently different between the dark matter-only and baryonic versions of the same run due to the fact that satellites are both more likely to be destroyed and to infall later in the baryonic runs. Hence, studying satellite planes in dark matter-only simulations is misleading, because they will be composed of different satellite members than those that would exist if baryons were included. Additionally, the destruction of satellites in the baryonic runs leads to less radially concentrated satellite distributions, a result that is critical to making planes that are statistically significant compared to a random distribution. Since all planes pass through the centre of the galaxy, it is much harder to create a plane of a given height from a random distribution if the satellites have a low radial concentration. We identify Andromeda's low radial satellite concentration as a key reason why the plane in Andromeda is highly significant. Despite this, when corotation is considered, none of the satellite planes identified for the simulated galaxies are as statistically significant as the observed planes around the Milky Way and Andromeda, even in the baryonic runs.

Neuromuscular fatigue and recovery dynamics following prolonged continuous run at anaerobic threshold.

PubMed

Skof, B; Strojnik, V

2006-03-01

The aim of this study was to determine the influence of intensive aerobic running on some muscle contractile characteristics and the dynamics of their recovery during a 2 hour period afterwards. Seven well trained runners performed a 6 km run at anaerobic threshold (V(OBLA)). Knee torque during single twitch, low and high frequency electrical stimulation (ES), maximum voluntary knee extension, and muscle activation level test of the quadriceps femoris muscles were measured before and immediately after the run, and at several time points during a 120 minute interval that followed the run. After exercise, the mean (SE) maximum twitch torque (T(TW)) and torque at ES with 20 Hz (low frequency ES; T(F20)) dropped by 14.1 (5.1)% (p<0.05) and 20.6 (7.9)% (p<0.05) respectively, while torque at stimulation with 100 Hz (high frequency ES; T(F100)), maximum isometric knee extension torque (maximum voluntary contraction torque; T(MVC)), and activation level did not change significantly. Twitch contraction time was shortened by 8 (2)% (p<0.05). Ten minutes after the run, T(TW) was 40% higher than immediately after the run and 10% (p<0.05) higher than before the run. T(F20), T(F100), and T(MVC) remained lower for 60 minutes (p<0.05) than before the run. A 6 km continuous run at V(OBLA) caused peripheral fatigue by impairing excitation-contraction coupling. Twitch torque recovered very quickly. However, the process of torque restoration at maximum isometric knee extension torque and at high and low frequency ES took much longer.

Morphology of Two-Phase Layers with Large Bubbles

NASA Astrophysics Data System (ADS)

Vékony, Klára; Kiss, László I.

2010-10-01

The understanding of formation and movement of bubbles nucleated during aluminum reduction is essential for a good control of the electrolysis process. In our experiments, we filmed and studied the formation of a bubble layer under the anode in a real-size air-water electrolysis cell model. The maximum height of the bubbles was found to be up to 2 cm because of the presence of the so-called Fortin bubbles. Also, the mean height of the bubble layer was found to be much higher than published previously. The Fortin bubbles were investigated more closely, and their shape was found to be induced by a gravity wave formed at the gas-liquid interface. In addition, large bubbles were always observed to break up into smaller parts right before escaping from under the anode. This breakup and escape led to a large momentum transfer in the bath.

Comparison of Body Composition Metrics for United States Air Force Airmen.

PubMed

Griffith, J R; White, Edward D; Fass, R David; Lucas, Brandon M

2018-03-01

The United States Air Force currently uses AFI 36-2905 for cardiovascular fitness standards and evaluation. Regarding its fitness test, the Air Force considers waist circumference (WC) twice as important as push-ups or sit-ups. Because of this weighting, one assumes that the Air Force considers WC relatively correlated with overall fitness or at least cardiovascular fitness. To our knowledge, the Air Force has not considered on a large scale how body mass index (BMI), height-to-weight ratio (H-W), or waist-to-height ratio (WHtR) compares with WC with respect to its fitness test. Using a 5.38 million record database from the Air Force Fitness Management System, we evaluated how WC, BMI, WHtR, and H-W correlate with fitness as assessed by the 1.5-mile run in addition to total fitness, which incorporates the 1.5-mile run time, number of push-ups and sit-ups. As this previously collected data were anonymous to us, this study fell under the definition of exempt status and approved by the institutional review board overseeing Joint Base San Antonio. For each waist metric, we performed a simple ordinary least squares regression to ascertain the correlation between that particular metric and either run time or total fitness; when incorporating more than one explanatory variable or covariate (to control for age and/or sex), we performed multiple ordinary least squares regressions. Due to the large database size and to mitigate against a type I error, we used an alpha of 0.001 for all statistical hypothesis tests. Approximately 18% of the 5.38 million records belonged to women. With respect to sex differences, males appeared noticeably faster and performed more push-ups on average than females. The number of sit-ups completed was more comparable, with males having a slight advantage. Males also appeared to have larger WC, BMI, H-W, and WHtR measurements. We compared the ordinary least squares results between WC, H-W, WHtR, and BMI and ranked them by R2. Models varied in R2 from 1% to 46% depending on the covariates in the model, with sex having a greater effect than age. Whether individually or adjusting for age and sex, WHtR performed better than the other body composition variables with an average rank score of 1.1 and a median improvement of approximately 4% to the current Air Force metric of WC. From our findings, we present a 20-point WHtR scoring system for the Air Force to use in lieu of its traditional usage of WC. We used this assessment chart to score all Airmen in our database and compared the results to their current scores on the abdominal circumference portion of the test with respect to predicting run time, after accounting for sex, age, and number of push-ups and sit-ups. The R2 value improved from 40.3 to 43.6, a relative improvement of approximately 8%, a fairly significant effect given the database consisted of over 5 million records. Future studies should investigate the longitudinal effect of varying waist metrics over time on run time or total fitness performance. Published by Oxford University Press on behalf of the Association of Military Surgeons of the United States 2018. This work is written by (a) US Government employee(s) and is in the public domain in the US.

The turbulence structure of katabatic flows below and above wind-speed maximum

NASA Astrophysics Data System (ADS)

Grachev, Andrey; Leo, Laura; Di Sabatino, Silvana; Fernando, Harindra; Pardyjak, Eric; Fairall, Christopher

2015-04-01

Measurements of atmospheric small-scale turbulence made over the complex-terrain at the US Army Dugway Proving Grounds in Utah during the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) Program are used to describe the turbulence structure of katabatic flows. Turbulent and mean meteorological data were continuously measured at multiple levels (up to seven) on four towers deployed along East lower slope (2-4 degrees) of Granite Mountain. The multi-level, multi-tower observations obtained during a 30-day long MATERHORN-Fall field campaign in September-October 2102 allow studying temporal and spatial structure of nocturnal slope flows in detail. In this study, we focus on the various statistics (fluxes, variances, spectra, cospectra, etc.) of the small-scale turbulence of katabatic winds. Observed vertical profiles of velocity, turbulent fluxes, and other quantities show steep gradients near the surface but in the layer above the slope jet these variables vary with height more slowly than near the surface. It is found that vertical momentum flux and horizontal heat (buoyancy) flux in a slope-following coordinate system change their sign below and above the wind maximum of a katabatic flow. The vertical momentum flux is directed downward (upward) whereas the horizontal heat flux is downslope (upslope) below (above) the wind maximum. Our study, therefore, suggests that a position of the jet speed maximum can be derived from linear interpolation between positive and negative values of the momentum flux (or the horizontal heat flux) and determination of a height where a flux becomes zero. It is shown that the standard deviations of all wind speed components (and therefore the turbulent kinetic energy) and the dissipation rate of turbulent kinetic energy have a local minimum, whereas the standard deviation of air temperature has an absolute maximum at the height of wind speed maximum. We report several cases when the destructive effect of vertical heat (buoyancy) flux is completely cancelled by the generation of turbulence due to the horizontal heat (buoyancy) flux. Turbulence in the layer above the wind-speed maximum is decoupled from the surface and it is consistent with the classical local z-less predictions for stably stratified boundary layer.

Online measurement for geometrical parameters of wheel set based on structure light and CUDA parallel processing

NASA Astrophysics Data System (ADS)

Wu, Kaihua; Shao, Zhencheng; Chen, Nian; Wang, Wenjie

2018-01-01

The wearing degree of the wheel set tread is one of the main factors that influence the safety and stability of running train. Geometrical parameters mainly include flange thickness and flange height. Line structure laser light was projected on the wheel tread surface. The geometrical parameters can be deduced from the profile image. An online image acquisition system was designed based on asynchronous reset of CCD and CUDA parallel processing unit. The image acquisition was fulfilled by hardware interrupt mode. A high efficiency parallel segmentation algorithm based on CUDA was proposed. The algorithm firstly divides the image into smaller squares, and extracts the squares of the target by fusion of k_means and STING clustering image segmentation algorithm. Segmentation time is less than 0.97ms. A considerable acceleration ratio compared with the CPU serial calculation was obtained, which greatly improved the real-time image processing capacity. When wheel set was running in a limited speed, the system placed alone railway line can measure the geometrical parameters automatically. The maximum measuring speed is 120km/h.

Observational Characteristics of the Tropopause Inversion Layer derived from CHAMP/GRACE Radio Occultations and MOZAIC Aircraft Data

NASA Astrophysics Data System (ADS)

Schmidt, T.; Cammas, J.; Heise, S.; Wickert, J.; Haser, A.

2010-12-01

In this study we discuss characteristics of the northern hemisphere (NH) midlatitude (40°N-60°N) tropopause inversion layer (TIL) based on two datasets. First, temperature measurements from GPS radio occultation data (CHAMP and GRACE) for the time interval 2001-2009 are used to exhibit seasonal properties of the TIL bottom height defined here as the height of the squared buoyancy frequency minimum N2 below the thermal tropopause, the TIL maximum height as the height of the N2 maximum above the tropopause and the TIL top height as the height of the temperature maximum above the tropopause. Mean values of the TIL bottom, TIL maximum and TIL top heights relative to the thermal tropopause for the NH midlatitudes are (-2.08±0.35) km, (0.52±0.10) km and (2.10±0.23) km, respectively. A seasonal cycle of the TIL bottom and TIL top height is observed with values closer to the thermal tropopause during summer. Secondly, high-resolution temperature and trace gas profile measurements onboard commercial aircrafts (MOZAIC program) from 2001-2008 for the NH midlatitude (40°N-60°N) region are used to characterize the TIL as a mixing layer around the tropopause. Mean TIL bottom, TIL maximum and TIL top heights based on the MOZAIC temperature (N2) measurements confirm the results from the GPS data, even though most of the MOZAIC profiles used here are available under cyclonic situations. Further, we demonstrate that the mixing ratio gradients of ozone (O3) and carbon monoxide (CO) are suitable parameters for characterizing the TIL structure. Using O3-CO correlations we also show that on average the highest mixing occurs in a layer less than 1 km above the thermal tropopause, i.e., within the TIL.

Developing an event-tree probabilistic tsunami inundation model for NE Atlantic coasts: Application to case studies

NASA Astrophysics Data System (ADS)

Omira, Rachid; Baptista, Maria Ana; Matias, Luis

2015-04-01

This study constitutes the first assessment of probabilistic tsunami inundation in the NE Atlantic region, using an event-tree approach. It aims to develop a probabilistic tsunami inundation approach for the NE Atlantic coast with an application to two test sites of ASTARTE project, Tangier-Morocco and Sines-Portugal. Only tsunamis of tectonic origin are considered here, taking into account near-, regional- and far-filed sources. The multidisciplinary approach, proposed here, consists of an event-tree method that gathers seismic hazard assessment, tsunami numerical modelling, and statistical methods. It presents also a treatment of uncertainties related to source location and tidal stage in order to derive the likelihood of tsunami flood occurrence and exceedance of a specific near-shore wave height during a given return period. We derive high-resolution probabilistic maximum wave heights and flood distributions for both test-sites Tangier and Sines considering 100-, 500-, and 1000-year return periods. We find that the probability that a maximum wave height exceeds 1 m somewhere along the Sines coasts reaches about 55% for 100-year return period, and is up to 100% for 1000-year return period. Along Tangier coast, the probability of inundation occurrence (flow depth > 0m) is up to 45% for 100-year return period and reaches 96% in some near-shore costal location for 500-year return period. Acknowledgements: This work is funded by project ASTARTE - Assessment, STrategy And Risk Reduction for Tsunamis in Europe. Grant 603839, 7th FP (ENV.2013.6.4-3 ENV.2013.6.4-3).

View northnortheast of drydock no. 2 and its portal cranes. ...

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

View north-northeast of drydock no. 2 and its portal cranes. Main crane, 50 long tons capacity/maximum height 118 "2", is at left; whip crane, 53 long tons capacity maximum height 173 "8" is at center; auxiliary crane, 15 long tons capacity/maximum height 161 "0" is at right. Building at left is the turret shed. The vessel at the lower right of the photograph is a receiving ship formerly used for processing and temporary housing of naval personnel. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Drydock No. 2, League Island, Philadelphia, Philadelphia County, PA

A wearable sensor based on CLYC scintillators

NASA Astrophysics Data System (ADS)

McDonald, Benjamin S.; Myjak, Mitchell J.; Zalavadia, Mital A.; Smart, John E.; Willett, Jesse A.; Landgren, Peter C.; Greulich, Christopher R.

2016-06-01

We have developed a wearable radiation sensor using Cs2LiYCl6:Ce (CLYC) for simultaneous gamma-ray and neutron detection. The system includes two ∅ 2.5 × 2.5cm3 crystals coupled to small, metal-body photomultiplier tubes. A custom, low-power electronics base digitizes the output signal at three time points and enables both pulse height and pulse shape discrimination of gamma rays and neutrons. The total counts, anomaly detection metrics, and identified isotopes are displayed on a small screen. Users may leave the device in unattended mode to collect long-dwell energy spectra. The system stores up to 18 h of one-second data, including energy spectra, and may transfer the data to a remote computer via a wired or wireless connection. The prototype is 18 × 13 × 7.5cm3, weighs 1.3 kg, not including the protective pouch, and runs on six AA alkaline batteries for 29 h with the wireless link active, or 41 h with the wireless link disabled. In this paper, we summarize the system design and present characterization results from the detector modules. The energy resolution is about 6.5% full width at half maximum at 662 keV due to the small photomultiplier tube selected, and the linearity and pulse shape discrimination performance are very good.

Heterogeneous coupling along Makran subduction zone

NASA Astrophysics Data System (ADS)

Zarifi, Z.; Raeesi, M.

2010-12-01

The Makran subduction zone, located in the southeast of Iran and southern Pakistan, extends for almost 900 km along the Eurasian-Arabian plate boundary. The seismic activities in the eastern and western Makran exhibit very different patterns. The eastern Makran characterized by infrequent large earthquakes and low level of seismicity. The only large instrumentally recorded earthquake in the eastern Makran, the 27 Nov. 1945 (Mw=8.1) earthquake, was followed by tsunami waves with the maximum run-up height of 13 m and disastrous effects in Pakistan, India, Iran and Oman. The western Makran, however, is apparently quiescent without strong evidence on occurrence of large earthquakes in historical times, which makes it difficult to ascertain whether the slab subducts aseismically or experiences large earthquakes separated by long periods exceeding the historical records. We used seismicity and Trench Parallel Free air and Bouguer Anomalies (TPGA and TPBA) to study the variation in coupling in the slab interface. Using a 3D mechanical Finite Element (FE) model, we show how heterogeneous coupling can influence the rate of deformation in the overriding lithosphere and the state of stress in the outer rise, overriding, and subducting plates within the shortest expected cycle of earthquake. We test the results of FE model against the observed focal mechanism of earthquakes and available GPS measurements in Makran subduction zone.

Investigation of the M6.6 Niigata-Chuetsu Oki, Japan, earthquake of July 16, 2007

USGS Publications Warehouse

Kayen, Robert; Collins, Brian D.; Abrahamson, Norm; Ashford, Scott; Brandenberg, Scott J.; Cluff, Lloyd; Dickenson, Stephen; Johnson, Laurie; Tanaka, Yasuo; Tokimatsu, Kohji; Kabeyasawa, Toshimi; Kawamata, Yohsuke; Koumoto, Hidetaka; Marubashi, Nanako; Pujol, Santiago; Steele, Clint; Sun, Joseph I.; Tsai, Ben; Yanev, Peter; Yashinsky, Mark; Yousok, Kim

2007-01-01

The M6.6 mainshock of the Niigata Chuetsu Oki (offshore) earthquake occurred at 10:13 a.m. local time on July 16, 2007, and was followed by a sequence of aftershocks that were felt during the entire time of the reconnaissance effort. The mainshock had an estimated focal depth of 10 km and struck in the Japan Sea offshore Kariwa. Analysis of waveforms from source inversion studies indicates that the event occurred along a thrust fault with a NE trend. The fault plane is either a strike of 34 degrees with a dip of 51 degrees or a strike of 238 degrees with a dip of 41 degrees. Which of these two planes is associated with the mainshock rupture is unresolved, although attenuation relationship analysis indicates that the northwest-dipping fault is favored. The quake affected an approximately 100-km-wide area along the coastal areas of southwestern Niigata prefecture. The event triggered ground failures as far as the Unouma Hills, located in central Niigata approximately 50 km from the shore and the source area of the 2004 Niigata Chuetsu earthquake. The primary event produced tsunami run-ups that reached maximum runup heights of about 20 centimeters along the shoreline of southern Niigata Prrefecture.

Stand density, tree social status and water stress influence allocation in height and diameter growth of Quercus petraea (Liebl.).

PubMed

Trouvé, Raphaël; Bontemps, Jean-Daniel; Seynave, Ingrid; Collet, Catherine; Lebourgeois, François

2015-10-01

Even-aged forest stands are competitive communities where competition for light gives advantages to tall individuals, thereby inducing a race for height. These same individuals must however balance this competitive advantage with height-related mechanical and hydraulic risks. These phenomena may induce variations in height-diameter growth relationships, with primary dependences on stand density and tree social status as proxies for competition pressure and access to light, and on availability of local environmental resources, including water. We aimed to investigate the effects of stand density, tree social status and water stress on the individual height-circumference growth allocation (Δh-Δc), in even-aged stands of Quercus petraea Liebl. (sessile oak). Within-stand Δc was used as surrogate for tree social status. We used an original long-term experimental plot network, set up in the species production area in France, and designed to explore stand dynamics on a maximum density gradient. Growth allocation was modelled statistically by relating the shape of the Δh-Δc relationship to stand density, stand age and water deficit. The shape of the Δh-Δc relationship shifted from linear with a moderate slope in open-grown stands to concave saturating with an initial steep slope in closed stands. Maximum height growth was found to follow a typical mono-modal response to stand age. In open-grown stands, increasing summer soil water deficit was found to decrease height growth relative to radial growth, suggesting hydraulic constraints on height growth. A similar pattern was found in closed stands, the magnitude of the effect however lowering from suppressed to dominant trees. We highlight the high phenotypic plasticity of growth in sessile oak trees that further adapt their allocation scheme to their environment. Stand density and tree social status were major drivers of growth allocation variations, while water stress had a detrimental effect on height in the Δh-Δc allocation. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Sedimentology of Coastal Deposits in the Seychelles Islands—Evidence of the Indian Ocean Tsunami 2004

NASA Astrophysics Data System (ADS)

Nentwig, Vanessa; Bahlburg, Heinrich; Monthy, Devis

2015-03-01

The Seychelles, an archipelago in the Indian Ocean at a distance of 4,500-5,000 km from the west coast of Sumatra, were severely affected by the December 26, 2004 tsunami with wave heights up to 4 m. Since the tsunami history of small islands often remains unclear due to a young historical record, it is important to study the geological traces of high energy events preserved along their coasts. We conducted a survey of the impact of the 2004 Indian Ocean tsunami on the inner Seychelles islands. In detail we studied onshore tsunami deposits in the mangrove forest at Old Turtle Pond in the Curieuse Marine National Park on the east coast of Curieuse Island. It is thus protected from anthropogenic interference. Towards the sea it was shielded until the tsunami in 2004 by a 500 m long and 1.5 m high causeway which was set up in 1909 as a sediment trap and assuring a low energetic hydrodynamic environment for the protection of the mangroves. The causeway was destroyed by the 2004 Indian Ocean Tsunami. The tsunami caused a change of habitat by the sedimentation of sand lobes in the mangrove forest. The dark organic rich mangrove soil (1.9 Φ) was covered by bimodal fine to medium carbonate sand (1.7-2.2 Φ) containing coarser carbonate shell fragments and debris. Intertidal sediments and the mangrove soil acted as sources of the lobe deposits. The sand sheet deposited by the tsunami is organized into different lobes. They extend landwards to different inundation distances as a function of the morphology of the onshore area. The maximum extent of 180 m from the shoreline indicates the minimum inundation distance to the tsunami. The top parts of the sand lobes cover the pneumatophores of the mangroves. There is no landward fining trend along the sand lobes and normal grading of the deposits is rare, occurring only in 1 of 7 sites. The sand lobe deposits also lack sedimentary structures. On the surface of the sand lobes numerous mostly fragmented shells of bivalves and molluscs were distributed up to 150 m from the coastline. Intact bivalve shells were mostly found positioned with the convex side upwards. On small ledges of a granitic body at 130-150 m from the shore mostly fragmented and gravel sized shells were deposited at different elevations up to 4 m above sea level. This implies a run up height of at least 4 m above sea level up to 150 m from the present shoreline.

Passive energy absorption by human muscle-tendon unit is unaffected by increase in intramuscular temperature.

PubMed

Magnusson, S P; Aagaard, P; Larsson, B; Kjaer, M

2000-04-01

The present study measured hamstring intramuscular temperature and muscle-tendon unit viscoelastic properties in healthy young men before and after 10 and 30 min of running with (day S) or without stretch (day NS). On day NS, passive energy absorption and intramuscular temperature were measured before running (Preex), after 10 min of running at 70% of maximum O(2) uptake (Postex10), and after 30 min of running at 75% of maximum O(2) uptake (Postex30). On day S, the protocol was repeated with three stretches (stretches 1-3) added after Postex10. Intramuscular temperature was elevated Postex10 (P < 0.01) and further Postex30 (P < 0.05). On day NS, the total energy absorbed Preex (14.3 +/- 2.3 J), Postex10 (14.5 +/- 3.2 J), and Postex30 (13.5 +/- 2.4 J) was not different. On day S, the total energy absorbed in stretch 3 (10.8 +/- 1.8 J) was lower than that Preex (14.5 +/- 1.7 J, P < 0.01) and Postex10 (13.5 +/- 1.9 J, P < 0.05) but not Postex30 (13.3 +/- 1.8 J). The total energy absorbed Postex30 did not differ from Preex. In conclusion, warm-up and continuous running elevated intramuscular temperature but did not affect the passive energy absorption. Repeated passive stretching reduced the energy absorption immediately; however, the effect did not remain after 30 min of running. These data suggest that passive energy absorption of the human skeletal muscle is insensitive to physiological increases in intramuscular temperature.

Geomorphic impact of the 16S 2015 tsunami event in the Coquimbo Bay (Northern Chile)

NASA Astrophysics Data System (ADS)

Abad, Manuel; Izquierdo, Tatiana; Lock, Suan-lin; Rojas, Diego; Fritis, Eduardo

2017-04-01

On September 16, 2105 a Mw 8.3 earthquake occurred at 22:55 GTM with a focal depth of 23 km and an epicenter located 31.570°S, W 71.670°, in the Coquimbo Region (northern Chile). This event triggered a tsunami with wave heights of more than 6 m that caused damages and flooding in the northern Chilean coast, mainly in the cities of Tongoy and Coquimbo - La Serena. The vertical run-up shows an important saw-tooth like variation due to the sharp changes in the topography, specially towards both ends of the bay. The highest and more irregular values occurred in the South sector, that presents a higher topographic gradient, and progressively decrease towards the North were the topography is flatter. The horizontal flooding reached its maximum values in the bay fluvial valleys where the tsunami wave entered along the river channels. The waves, favored by the confining conditions, entered more than 950 m in the Elqui River mouth and almost 700 m in the Culebrón Stream. Coquimbo Bay comprises a wide and convex littoral zone of approximately 18 km long only interrupted by the mouths of the Elqui River and the Culebrón Stream where small saltmarshes have developed. According to the tide gauge data, the first wave reached the Coquimbo coast only 20 minutes after the earthquake with a maximum height of 0.85 m. 22 minutes later, a second wave arrived with a much higher height (4.3 m) causing the first damages on the littoral and the city. The last wave, the 4th one, occurred 35 minutes after the earthquake and was the highest reaching 4.68 m as well as the most damaging. Despite the existence of works that analyze the characteristics of this event, a more deep and thorough study is still needed of the tsunami geological record in the Coquimbo Bay where a wide variety of forms and deposits were preserved. The making of a geomorphological map has allowed us to differentiate the geological features related with the tsunamigenic event such as sand sheets and debris-boulder fields (tsunamites), littoral erosion scars developed on the saltmarshes, beaches and coastal dunes, erosive backwash channels, degraded wetlands, flooding lagoons or the appearance of new fluvial channels. This morpho-sedimentary assemblage, all together, has enabled us to characterize the conditions in which the tsunami occurred and to quantify it effects along this coastal zone as well their potential preservation.

Maximum height in a conifer is associated with conflicting requirements for xylem design.

PubMed

Domec, Jean-Christophe; Lachenbruch, Barbara; Meinzer, Frederick C; Woodruff, David R; Warren, Jeffrey M; McCulloh, Katherine A

2008-08-19

Despite renewed interest in the nature of limitations on maximum tree height, the mechanisms governing ultimate and species-specific height limits are not yet understood, but they likely involve water transport dynamics. Tall trees experience increased risk of xylem embolism from air-seeding because tension in their water column increases with height because of path-length resistance and gravity. We used morphological measurements to estimate the hydraulic properties of the bordered pits between tracheids in Douglas-fir trees along a height gradient of 85 m. With increasing height, the xylem structural modifications that satisfied hydraulic requirements for avoidance of runaway embolism imposed increasing constraints on water transport efficiency. In the branches and trunks, the pit aperture diameter of tracheids decreases steadily with height, whereas torus diameter remains relatively constant. The resulting increase in the ratio of torus to pit aperture diameter allows the pits to withstand higher tensions before air-seeding but at the cost of reduced pit aperture conductance. Extrapolations of vertical trends for trunks and branches show that water transport across pits will approach zero at a heights of 109 m and 138 m, respectively, which is consistent with historic height records of 100-127 m for this species. Likewise, the twig water potential corresponding to the threshold for runaway embolism would be attained at a height of approximately 107 m. Our results suggest that the maximum height of Douglas-fir trees may be limited in part by the conflicting requirements for water transport and water column safety.

Esr Observations of Tid In The Polar Cusp/cap Ionosphere

NASA Astrophysics Data System (ADS)

Yin, F.; Ma, S. Y.; Schlegel, K.

EISCAT-Svalbard radar provides new opportunity to study TIDs in the polar cusp/cap ionosphere. Propagation characteristics of AGW-caused TIDs in quiet days are stud- ied by means of maximum entropy cross-spectral analysis of ESR CP1 and CP2 data. Apparent vertical wave-number of the TIDs as a function of height and the horizontal wave-number vector are obtained for main period of disturbances. It is observed as the first time that some of TIDs in the polar cap/cusp ionosphere can propagate vertically from the height lower than 200 km up to as high as about 700 km with little attenu- ation. In the auroral ionosphere, however, they usually fade away below 500 km. In the region from about 100 to 180 km height, downward propagating mode is seen ob- viously. The possible relations of the TIDs with cusp particle precipitation and upper E-region heating are discussed.

Maximum plant height and the biophysical factors that limit it.

PubMed

Niklas, Karl J

2007-03-01

Basic engineering theory and empirically determined allometric relationships for the biomass partitioning patterns of extant tree-sized plants show that the mechanical requirements for vertical growth do not impose intrinsic limits on the maximum heights that can be reached by species with woody, self-supporting stems. This implies that maximum tree height is constrained by other factors, among which hydraulic constraints are plausible. A review of the available information on scaling relationships observed for large tree-sized plants, nevertheless, indicates that mechanical and hydraulic requirements impose dual restraints on plant height and thus, may play equally (but differentially) important roles during the growth of arborescent, large-sized species. It may be the case that adaptations to mechanical and hydraulic phenomena have optimized growth, survival and reproductive success rather than longevity and mature size.

Hydraulic constraints modify optimal photosynthetic profiles in giant sequoia trees.

PubMed

Ambrose, Anthony R; Baxter, Wendy L; Wong, Christopher S; Burgess, Stephen S O; Williams, Cameron B; Næsborg, Rikke R; Koch, George W; Dawson, Todd E

2016-11-01

Optimality theory states that whole-tree carbon gain is maximized when leaf N and photosynthetic capacity profiles are distributed along vertical light gradients such that the marginal gain of nitrogen investment is identical among leaves. However, observed photosynthetic N gradients in trees do not follow this prediction, and the causes for this apparent discrepancy remain uncertain. Our objective was to evaluate how hydraulic limitations potentially modify crown-level optimization in Sequoiadendron giganteum (giant sequoia) trees up to 90 m tall. Leaf water potential (Ψ l ) and branch sap flow closely followed diurnal patterns of solar radiation throughout each tree crown. Minimum leaf water potential correlated negatively with height above ground, while leaf mass per area (LMA), shoot mass per area (SMA), leaf nitrogen content (%N), and bulk leaf stable carbon isotope ratios (δ(13)C) correlated positively with height. We found no significant vertical trends in maximum leaf photosynthesis (A), stomatal conductance (g s), and intrinsic water-use efficiency (A/g s), nor in branch-averaged transpiration (E L), stomatal conductance (G S), and hydraulic conductance (K L). Adjustments in hydraulic architecture appear to partially compensate for increasing hydraulic limitations with height in giant sequoia, allowing them to sustain global maximum summer water use rates exceeding 2000 kg day(-1). However, we found that leaf N and photosynthetic capacity do not follow the vertical light gradient, supporting the hypothesis that increasing limitations on water transport capacity with height modify photosynthetic optimization in tall trees.

Vehicle Detection with Occlusion Handling, Tracking, and OC-SVM Classification: A High Performance Vision-Based System

PubMed Central

Velazquez-Pupo, Roxana; Sierra-Romero, Alberto; Torres-Roman, Deni; Shkvarko, Yuriy V.; Romero-Delgado, Misael

2018-01-01

This paper presents a high performance vision-based system with a single static camera for traffic surveillance, for moving vehicle detection with occlusion handling, tracking, counting, and One Class Support Vector Machine (OC-SVM) classification. In this approach, moving objects are first segmented from the background using the adaptive Gaussian Mixture Model (GMM). After that, several geometric features are extracted, such as vehicle area, height, width, centroid, and bounding box. As occlusion is present, an algorithm was implemented to reduce it. The tracking is performed with adaptive Kalman filter. Finally, the selected geometric features: estimated area, height, and width are used by different classifiers in order to sort vehicles into three classes: small, midsize, and large. Extensive experimental results in eight real traffic videos with more than 4000 ground truth vehicles have shown that the improved system can run in real time under an occlusion index of 0.312 and classify vehicles with a global detection rate or recall, precision, and F-measure of up to 98.190%, and an F-measure of up to 99.051% for midsize vehicles. PMID:29382078

47 CFR 101.1333 - Interference protection criteria.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Maximum EIRP Watts dBW Maximum ERP 1 Watts dBW Master 941.0-941.5 1000 30 600 27.8 Fixed Remote and Master 932.0-932.5 50 17 30 14.8 1 Where ERP = EIRP/1.64.> (ii) Maximum antenna height above average terrain... Reduction Table Antenna height above average terrain (meters) EIRP Watts dBW ERP Watts dBW Above 305 200 23...

Neck length and mean arterial pressure in the sauropod dinosaurs.

PubMed

Hughes, Stephen; Barry, John; Russell, Jeremy; Bell, Robert; Gurung, Som

2016-04-15

How blood was able to reach the heads of the long-necked sauropod dinosaurs has long been a matter of debate and several hypotheses have been presented. For example, it has been proposed that sauropods had exceptionally large hearts, multiple 'normal' sized hearts spaced at regular intervals up the neck or held their necks horizontal, or that the siphon effect was in operation. By means of an experimental model, we demonstrate that the siphon principle is able to explain how blood was able to adequately perfuse the sauropod brain. The return venous circulation may have been protected from complete collapse by a structure akin to the vertebral venous plexus. We derive an equation relating neck height and mean arterial pressure, which indicates that with a mean arterial pressure similar to that of the giraffe, the maximum safe vertical distance between heart and head would have been about 12 m. A hypothesis is presented that the maximum neck length in the fossil record is due to the siphon height limit. The equation indicates that to migrate over high ground, sauropods would have had to either significantly increase their mean arterial pressure or keep their necks below a certain height dependent on altitude. © 2016. Published by The Company of Biologists Ltd.

Strength Determinants of Jump Height in the Jump Throw Movement in Women Handball Players.

PubMed

McGhie, David; Østerås, Sindre; Ettema, Gertjan; Paulsen, Gøran; Sandbakk, Øyvind

2018-06-08

McGhie, D, Østerås, S, Ettema, G, Paulsen, G, and Sandbakk, Ø. Strength determinants of jump height in the jump throw movement in women handball players. J Strength Cond Res XX(X): 000-000, 2018-The purpose of the study was to improve the understanding of the strength demands of a handball-specific jump through examining the associations between jump height in a jump throw jump (JTJ) and measures of lower-body maximum strength and impulse in handball players. For comparison, whether the associations between jump height and strength differed between the JTJ and the customarily used countermovement jump (CMJ) was also examined. Twenty women handball players from a Norwegian top division club participated in the study. Jump height was measured in the JTJ and in unilateral and bilateral CMJ. Lower-body strength (maximum isometric force, one-repetition maximum [1RM], impulse at ∼60% and ∼35% 1RM) was measured in seated leg press. The associations between jump height and strength were assessed with correlation analyses and t-tests of dependent r's were performed to determine if correlations differed between jump tests. Only impulse at ∼35% 1RM correlated significantly with JTJ height (p < 0.05), whereas all strength measures correlated significantly with CMJ heights (p < 0.001). The associations between jump height and strength were significantly weaker in the JTJ than in both CMJ tests for all strength measures (p = 0.001-0.044) except one. Maximum strength and impulse at ∼60% 1RM did not seem to sufficiently capture the capabilities associated with JTJ height, highlighting the importance of employing tests targeting performance-relevant neuromuscular characteristics when assessing jump-related strength in handball players. Further, CMJ height seemed to represent a wider range of strength capabilities and care should be taken when using it as a proxy for handball-specific movements.

Titanium-scaffolded organic-monolithic stationary phases for ultra-high-pressure liquid chromatography.

PubMed

Vonk, Rudy J; Vaast, Axel; Eeltink, Sebastiaan; Schoenmakers, Peter J

2014-09-12

Organic-polymer monoliths with overall dimensions larger than one millimetre are prone to rupture - either within the monolith itself or between the monoliths and the containing wall - due to the inevitable shrinkage accompanying the formation of a cross-linked polymeric network. This problem has been addressed by creating titanium-scaffolded poly(styrene-co-divinylbenzene) (S-co-DVB) monoliths. Titanium-scaffolded monoliths were successfully used in liquid chromatography at very high pressures (up to 80MPa) and using gradients spanning the full range of water-acetonitrile compositions (0 to 100%). The kinetic-performance of (50-mm long) titanium-scaffolded monoliths was compared to that of similar monolith created in 1-mm i.d. glass-lined tubing at pressures up to 50MPa. The peak capacities obtained with the titanium-scaffolded column was about 30% lower. An increased Eddy-diffusion, due to the pillar-structure, and a decreased permeability are thought to be the main reasons for this reduced kinetic-performance. No decrease in performance was observed when the titanium-scaffolded columns were operated at pressures of 80MPa for up to 12h. The column-to-column repeatability (n=5) was acceptable in terms of observed peak widths at half heights (RSD ca. 10%) The run-to-run repeatability (n=135) in terms of retention times and peak widths at half height were found to be good. Titanium-scaffolded columns coupled in series up to a combined length of (200mm) were used for the analyses of a complex Escherichia coli protein sample. Our experiments demonstrate that columns based on titanium-scaffolded organic-polymer monolith can be operated under strenuous conditions without loss in performance. The titanium-scaffolded approach makes it feasible to create organic-polymer monoliths in wide-bore columns with accurate temperature control. Copyright © 2014 Elsevier B.V. All rights reserved.

Muscular fatigue in response to different modalities of CrossFit sessions

PubMed Central

Maté-Muñoz, José Luis; Lougedo, Juan H.; Barba, Manuel; García-Fernández, Pablo

2017-01-01

Background CrossFit is a new strength and conditioning regimen involving short intense daily workouts called workouts of the day (WOD). This study assesses muscular fatigue levels induced by the three modalities of CrossFit WOD; gymnastics (G), metabolic conditioning (M) and weightlifting (W). Material and methods 34 healthy subjects undertook three WOD (one per week): a G WOD consisting of completing the highest number of sets of 5 pull-ups, 10 push-ups and 15 air squats in 20 min; an M WOD, in which the maximum number of double skipping rope jumps was executed in 8 sets (20 s), resting (10 s) between sets; and finally, a W WOD in which the maximum number of power cleans was executed in 5 min, lifting a load equivalent to 40% of the individual's 1RM. Before and after each WOD, blood lactate concentrations were measured. Also, before, during, and after each WOD, muscular fatigue was assessed in a countermovement jump test (CMJ). Results Significant reductions were produced in the mechanical variables jump height, average power and maximum velocity in response to G; and in jump height, mean and peak power, maximum velocity and maximum force in response to W (P<0.01). However, in M, significant reductions in mechanical variables were observed between pre- and mid session (after sets 2, 4, 6 and 8), but not between pre- and post session. Conclusions Muscular fatigue, reflected by reduced CMJ variables, was produced following the G and W sessions, while recovery of this fatigue was observed at the end of M, likely attributable to rest intervals allowing for the recovery of phosphocreatine stores. Our findings also suggest that the high intensity and volume of exercise in G and W WODs could lead to reduced muscular-tendon stiffness causing a loss of jump ability, related here to a longer isometric phase during the CMJ. PMID:28753624

Muscular fatigue in response to different modalities of CrossFit sessions.

PubMed

Maté-Muñoz, José Luis; Lougedo, Juan H; Barba, Manuel; García-Fernández, Pablo; Garnacho-Castaño, Manuel V; Domínguez, Raúl

2017-01-01

CrossFit is a new strength and conditioning regimen involving short intense daily workouts called workouts of the day (WOD). This study assesses muscular fatigue levels induced by the three modalities of CrossFit WOD; gymnastics (G), metabolic conditioning (M) and weightlifting (W). 34 healthy subjects undertook three WOD (one per week): a G WOD consisting of completing the highest number of sets of 5 pull-ups, 10 push-ups and 15 air squats in 20 min; an M WOD, in which the maximum number of double skipping rope jumps was executed in 8 sets (20 s), resting (10 s) between sets; and finally, a W WOD in which the maximum number of power cleans was executed in 5 min, lifting a load equivalent to 40% of the individual's 1RM. Before and after each WOD, blood lactate concentrations were measured. Also, before, during, and after each WOD, muscular fatigue was assessed in a countermovement jump test (CMJ). Significant reductions were produced in the mechanical variables jump height, average power and maximum velocity in response to G; and in jump height, mean and peak power, maximum velocity and maximum force in response to W (P<0.01). However, in M, significant reductions in mechanical variables were observed between pre- and mid session (after sets 2, 4, 6 and 8), but not between pre- and post session. Muscular fatigue, reflected by reduced CMJ variables, was produced following the G and W sessions, while recovery of this fatigue was observed at the end of M, likely attributable to rest intervals allowing for the recovery of phosphocreatine stores. Our findings also suggest that the high intensity and volume of exercise in G and W WODs could lead to reduced muscular-tendon stiffness causing a loss of jump ability, related here to a longer isometric phase during the CMJ.

Multi-factor evaluation indicator method for the risk assessment of atmospheric and oceanic hazard group due to the attack of tropical cyclones

NASA Astrophysics Data System (ADS)

Qi, Peng; Du, Mei

2018-06-01

China's southeast coastal areas frequently suffer from storm surge due to the attack of tropical cyclones (TCs) every year. Hazards induced by TCs are complex, such as strong wind, huge waves, storm surge, heavy rain, floods, and so on. The atmospheric and oceanic hazards cause serious disasters and substantial economic losses. This paper, from the perspective of hazard group, sets up a multi-factor evaluation method for the risk assessment of TC hazards using historical extreme data of concerned atmospheric and oceanic elements. Based on the natural hazard dynamic process, the multi-factor indicator system is composed of nine natural hazard factors representing intensity and frequency, respectively. Contributing to the indicator system, in order of importance, are maximum wind speed by TCs, attack frequency of TCs, maximum surge height, maximum wave height, frequency of gusts ≥ Scale 8, rainstorm intensity, maximum tidal range, rainstorm frequency, then sea-level rising rate. The first four factors are the most important, whose weights exceed 10% in the indicator system. With normalization processing, all the single-hazard factors are superposed by multiplying their weights to generate a superposed TC hazard. The multi-factor evaluation indicator method was applied to the risk assessment of typhoon-induced atmospheric and oceanic hazard group in typhoon-prone southeast coastal cities of China.

The morphology of transverse aeolian ridges on Mars

NASA Astrophysics Data System (ADS)

Geissler, Paul E.; Wilgus, Justin T.

2017-06-01

A preliminary survey of publicly released high resolution digital terrain models (DTMs) produced by the High Resolution Imaging Science Experiment (HiRISE) camera on Mars Reconnaissance Orbiter identified transverse aeolian ridges (TARs) in 154 DTMs in latitudes from 50°S to 40°N. Consistent with previous surveys, the TARs identified in HiRISE DTMs are found at all elevations, irrespective of the regional thermal inertia of the surface. Ten DTMs were selected for measuring the characteristics of the TARs, including maximum height, mean height, mean spacing (wavelength), and the slope of the surface where they are located. We confined our measurements to features that were taller than 1 m and spaced more than 10 m apart. We found a surprisingly wide variability of TAR sizes within each local region (typically 5 km by 25 km), with up to a factor of 7 difference in TAR wavelengths in a single DTM. The TAR wavelengths do not appear to be correlated to latitude or elevation, but the largest TARs in our small survey were found at lower elevations. The tallest TARs we measured were on the flat floor of Moni crater, within Kaiser crater in the southern highlands. These TARs are up to 14 m tall, with a typical wavelength of 120 m. TAR heights are weakly correlated with their wavelengths. The height-to-wavelength ratios for most TARs are far less than 1/2π (the maximum predicted for antidunes), however in two cases the ratio is close to 1/2π, and in one case (in the bend of a channel) the ratio exceeds 1/2π. TAR wavelengths are uncorrelated with surface slope, both on local and regional scales. TAR heights are weakly anti-correlated with local slope. These results help constrain models of TAR formation, particularly a new hypothesis (Geissler, 2014) that suggests that TARs were formed from micron-sized dust that was transported in suspension. The lack of correlation between TAR wavelength and surface slope seems to rule out formation by gravity-driven dust flows such as avalanches or density currents, and suggests that the TARs were instead produced by the Martian winds.

Determining suitable dimensions for dairy goat feeding places by evaluating body posture and feeding reach.

PubMed

Keil, Nina M; Pommereau, Marc; Patt, Antonia; Wechsler, Beat; Gygax, Lorenz

2017-02-01

Confined goats spend a substantial part of the day feeding. A poorly designed feeding place increases the risk of feeding in nonphysiological body postures, and even injury. Scientifically validated information on suitable dimensions of feeding places for loose-housed goats is almost absent from the literature. The aim of the present study was, therefore, to determine feeding place dimensions that would allow goats to feed in a species-appropriate, relaxed body posture. A total of 27 goats with a height at the withers of 62 to 80 cm were included in the study. Goats were tested individually in an experimental feeding stall that allowed the height difference between the feed table, the standing area of the forelegs, and a feeding area step (difference in height between forelegs and hind legs) to be varied. The goats accessed the feed table via a palisade feeding barrier. The feed table was equipped with recesses at varying distances to the feeding barrier (5-55 cm in 5-cm steps) at angles of 30°, 60°, 90°, 120°, or 150° (feeding angle), which were filled with the goats' preferred food. In 18 trials, balanced for order across animals, each animal underwent all possible combinations of feeding area step (3 levels: 0, 10, and 20 cm) and of difference in height between feed table and standing area of forelegs (6 levels: 0, 5, 10, 15, 20, and 25 cm). The minimum and maximum reach at which the animals could reach feed on the table with a relaxed body posture was determined for each combination. Statistical analysis was performed using mixed-effects models. The animals were able to feed with a relaxed posture when the feed table was at least 10 cm higher than the standing height of the goats' forelegs. Larger goats achieved smaller minimum reaches and minimum reach increased if the goats' head and neck were angled. Maximum reach increased with increasing height at withers and height of the feed table. The presence of a feeding area step had no influence on minimum and maximum reach. Based on these results, the goats' feeding place can be designed to ensure that the animals are able to reach all of the feed in the manger or on the feed table with a relaxed posture, thus avoiding injuries and nonphysiological stress on joints and hooves. A feeding area step up to a maximum of 20 cm need not be taken into account in terms of feeding reach. However, the feed table must be raised at least 10 cm above the standing area to allow the goats to feed in a species-appropriate, relaxed posture. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Repeated sprint ability related to recovery time in young soccer players.

PubMed

Padulo, J; Tabben, M; Ardigò, L P; Ionel, M; Popa, C; Gevat, C; Zagatto, A M; Dello Iacono, A

2015-01-01

This study aimed to describe the influence of recovery duration during a repeated sprint ability (RSA) test (6 × 40 m) by investigating a number of variables, such as general performance, metabolic demand, and muscular stretch-shortening performance. Seventeen male soccer outfield players (16 ± 0 years, 66 ± 10 kg) performed three field shuttle-running tests with 15, 20, and 25-sec recoveries. In addition to specific shuttle test's variables, blood lactate concentration and vertical jump height were assessed. Resulting measures were highly reliable (intra-class correlation coefficient up to 0.86). 25-sec recovery improved test performance (-3% total time from 15-sec to 25-sec recovery), vertical jump height (+7% post-test height from 15-sec to 25-sec recovery), and decreased blood lactate accumulation (-33% post-test from 15-sec to 25-sec recovery). Study findings suggest that metabolic acidosis plays a role in worsening performance and fatigue development during the shuttle test. A 25-sec recovery duration maximized performance, containing metabolic-anaerobic power involvement and muscular stretch-shortening performance deterioration during a RSA test.

Differences in physical fitness and throwing velocity among elite and amateur male handball players.

PubMed

Gorostiaga, E M; Granados, C; Ibáñez, J; Izquierdo, M

2005-04-01

This study compared physical characteristics (body height, body mass [BM], body fat [BF], and free fatty mass [FFM]), one repetition maximum bench-press (1RM (BP)), jumping explosive strength (VJ), handball throwing velocity, power-load relationship of the leg and arm extensor muscles, 5- and 15-m sprint running time, and running endurance in two handball male teams: elite team, one of the world's leading teams (EM, n = 15) and amateur team, playing in the Spanish National Second Division (AM, n = 15). EM had similar values in body height, BF, VJ, 5- and 15-m sprint running time and running endurance than AM. However, the EM group gave higher values in BM (95.2 +/- 13 kg vs. 82.4 +/- 10 kg, p < 0.05), FFM (81.7 +/- 9 kg vs. 72.4 +/- 7 kg, p < 0.05), 1RM (BP) (107 +/- 12 kg vs. 83 +/- 10 kg, p < 0.001), muscle power during bench-press (18 - 21 %, p < 0.05) and half squat (13 - 17 %), and throwing velocities at standing (23.8 +/- 1.9 m . s (-1) vs. 21.8 +/- 1.6 m . s (-1), p < 0.05) and 3-step running (25.3 +/- 2.2 m . s (-1) vs. 22.9 +/- 1.4 m . s (-1), p < 0.05) actions than the AM group. Significant correlations (r = 0.67 - 0.71, p < 0.05 - 0.01) were observed in EM and AM between individual values of velocity at 30 % of 1RM (BP) and individual values of ball velocity during a standing throw. Significant correlations were observed in EM, but not in AM, between the individual values of velocity during 3-step running throw and the individual values of velocity at 30 % of 1RM (BP) (r = 0.72, p < 0.05), as well as the individual values of power at 100 % of body mass during half-squat actions (r = 0.62, p < 0.05). The present results suggest that more muscular and powerful players are at an advantage in handball. The differences observed in free fatty mass could partly explain the differences observed between groups in absolute maximal strength and muscle power. In EM, higher efficiency in handball throwing velocity may be associated with both upper and lower extremity power output capabilities, whereas in AM this relationship may be different. Endurance capacity does not seem to represent a limitation for elite performance in handball.

Toward an automated low-cost three-dimensional crop surface monitoring system using oblique stereo imagery from consumer-grade smart cameras

NASA Astrophysics Data System (ADS)

Brocks, Sebastian; Bendig, Juliane; Bareth, Georg

2016-10-01

Crop surface models (CSMs) representing plant height above ground level are a useful tool for monitoring in-field crop growth variability and enabling precision agriculture applications. A semiautomated system for generating CSMs was implemented. It combines an Android application running on a set of smart cameras for image acquisition and transmission and a set of Python scripts automating the structure-from-motion (SfM) software package Agisoft Photoscan and ArcGIS. Only ground-control-point (GCP) marking was performed manually. This system was set up on a barley field experiment with nine different barley cultivars in the growing period of 2014. Images were acquired three times a day for a period of two months. CSMs were successfully generated for 95 out of 98 acquisitions between May 2 and June 30. The best linear regressions of the CSM-derived plot-wise averaged plant-heights compared to manual plant height measurements taken at four dates resulted in a coefficient of determination R2 of 0.87 and a root-mean-square error (RMSE) of 0.08 m, with Willmott's refined index of model performance dr equaling 0.78. In total, 103 mean plot heights were used in the regression based on the noon acquisition time. The presented system succeeded in semiautomatedly monitoring crop height on a plot scale to field scale.

Computer-aided teniae coli detection using height maps from computed tomographic colonography images

NASA Astrophysics Data System (ADS)

Wei, Zhuoshi; Yao, Jianhua; Wang, Shijun; Summers, Ronald M.

2011-03-01

Computed tomographic colonography (CTC) is a minimally invasive technique for colonic polyps and cancer screening. Teniae coli are three bands of longitudinal smooth muscle on the colon surface. They are parallel, equally distributed on the colon wall, and form a triple helix structure from the appendix to the sigmoid colon. Because of their characteristics, teniae coli are important anatomical meaningful landmarks on human colon. This paper proposes a novel method for teniae coli detection on CT colonography. We first unfold the three-dimensional (3D) colon using a reversible projection technique and compute the two-dimensional (2D) height map of the unfolded colon. The height map records the elevation of colon surface relative to the unfolding plane, where haustral folds corresponding to high elevation points and teniae to low elevation points. The teniae coli are detected on the height map and then projected back to the 3D colon. Since teniae are located where the haustral folds meet, we break down the problem by first detecting haustral folds. We apply 2D Gabor filter banks to extract fold features. The maximum response of the filter banks is then selected as the feature image. The fold centers are then identified based on piecewise thresholding on the feature image. Connecting the fold centers yields a path of the folds. Teniae coli are finally extracted as lines running between the fold paths. Experiments were carried out on 7 cases. The proposed method yielded a promising result with an average normalized RMSE of 5.66% and standard deviation of 4.79% of the circumference of the colon.

Countermovement depth - a variable which clarifies the relationship between the maximum power output and height of a vertical jump.

PubMed

Gajewski, Jan; Michalski, Radosław; Buśko, Krzysztof; Mazur-Różycka, Joanna; Staniak, Zbigniew

2018-01-01

The aim of this study was to identify the determinants of peak power achieved during vertical jumps in order to clarify relationship between the height of jump and the ability to exert maximum power. One hundred young (16.8±1.8 years) sportsmen participated in the study (body height 1.861 ± 0.109 m, body weight 80.3 ± 9.2 kg). Each participant performed three jump tests: countermovement jump (CMJ), akimbo countermovement jump (ACMJ), and spike jump (SPJ). A force plate was used to measure ground reaction force and to determine peak power output. The following explanatory variables were included in the model: jump height, body mass, and the lowering of the centre of mass before launch (countermovement depth). A model was created using multiple regression analysis and allometric scaling. The model was used to calculate the expected power value for each participant, which correlated strongly with real values. The value of the coefficient of determination R2 equalled 0.89, 0.90 and 0.98, respectively, for the CMJ, ACMJ, and SPJ jumps. The countermovement depth proved to be a variable strongly affecting the maximum power of jump. If the countermovement depth remains constant, the relative peak power is a simple function of jump height. The results suggest that the jump height of an individual is an exact indicator of their ability to produce maximum power. The presented model has a potential to be utilized under field condition for estimating the maximum power output of vertical jumps.

Direct measurement of a patient's entrance skin dose during pediatric cardiac catheterization

PubMed Central

Sun, Lue; Mizuno, Yusuke; Iwamoto, Mari; Goto, Takahisa; Koguchi, Yasuhiro; Miyamoto, Yuka; Tsuboi, Koji; Chida, Koichi; Moritake, Takashi

2014-01-01

Children with complex congenital heart diseases often require repeated cardiac catheterization; however, children are more radiosensitive than adults. Therefore, radiation-induced carcinogenesis is an important consideration for children who undergo those procedures. We measured entrance skin doses (ESDs) using radio-photoluminescence dosimeter (RPLD) chips during cardiac catheterization for 15 pediatric patients (median age, 1.92 years; males, n = 9; females, n = 6) with cardiac diseases. Four RPLD chips were placed on the patient's posterior and right side of the chest. Correlations between maximum ESD and dose–area products (DAP), total number of frames, total fluoroscopic time, number of cine runs, cumulative dose at the interventional reference point (IRP), body weight, chest thickness, and height were analyzed. The maximum ESD was 80 ± 59 (mean ± standard deviation) mGy. Maximum ESD closely correlated with both DAP (r = 0.78) and cumulative dose at the IRP (r = 0.82). Maximum ESD for coiling and ballooning tended to be higher than that for ablation, balloon atrial septostomy, and diagnostic procedures. In conclusion, we directly measured ESD using RPLD chips and found that maximum ESD could be estimated in real-time using angiographic parameters, such as DAP and cumulative dose at the IRP. Children requiring repeated catheterizations would be exposed to high radiation levels throughout their lives, although treatment influences radiation dose. Therefore, the radiation dose associated with individual cardiac catheterizations should be analyzed, and the effects of radiation throughout the lives of such patients should be followed. PMID:24968708

Atomic force microscopic study of step bunching and macrostep formation during the growth of L-arginine phosphate monohydrate single crystals

NASA Astrophysics Data System (ADS)

Sangwal, K.; Torrent-Burgues, J.; Sanz, F.; Gorostiza, P.

1997-02-01

The experimental results of the formation of step bunches and macrosteps on the {100} face of L-arginine phosphate monohydrate crystals grown from aqueous solutions at different supersaturations studied by using atomic force microscopy are described and discussed. It was observed that (1) the step height does not remain constant with increasing time but fluctuates within a particular range of heights, which depends on the region of step bunches, (2) the maximum height and the slope of bunched steps increases with growth time as well as supersaturation used for growth, and that (3) the slope of steps of relatively small heights is usually low with a value of about 8° and does not depend on the region of formation of step bunches, but the slope of steps of large heights is up to 21°. Analysis of the experimental results showed that (1) at a particular value of supersaturation the ratio of the average step height to the average step spacing is a constant, suggesting that growth of the {100} face of L-arginine phosphate monohydrate crystals occurs by direct integration of growth entities to growth steps, and that (2) the formation of step bunches and macrosteps follows the dynamic theory of faceting, advanced by Vlachos et al.

Electromyographic Analysis of Single-Leg, Closed Chain Exercises: Implications for Rehabilitation After Anterior Cruciate Ligament Reconstruction

PubMed Central

Beutler, Anthony I.; Cooper, Leslie W.; Kirkendall, Don T.; Garrett, William E.

2002-01-01

Objective: Many knee rehabilitation studies have examined open and closed kinetic chain exercises. However, most studies focus on 2-legged, closed chain exercise. The purpose of our study was to characterize 1-legged, closed chain exercise in young, healthy subjects. Subjects: Eighteen normal subjects (11 men, 7 women; age, 24.6 ± 1.6 years) performed unsupported, 1-legged squats and step-ups to approximately tibial height. Measurements: Knee angle data and surface electromyographic activity from the thigh muscles were recorded. Results: The maximum angle of knee flexion was 111 ± 23° for squats and 101 ± 16° for step-ups. The peak quadriceps activation was 201 ± 66% maximum voluntary isometric contraction, occurring at an angle of 96 ± 16° for squats. Peak quadriceps activation was 207 ± 50% maximum voluntary isometric contraction and occurred at 83 ± 12° for step-ups. Conclusions: The high and sustained levels of quadriceps activation indicate that 1-legged squats and step-ups would be effective in muscle rehabilitation. As functional, closed chain activities, they may also be protective of anterior cruciate ligament grafts. Because these exercises involve no weights or training equipment, they may prove more cost effective than traditional modes of rehabilitation. PMID:12937438

Development of wave and surge atlases for the design and protection of coastal bridges in South Louisiana.

DOT National Transportation Integrated Search

2011-05-01

The objectives of this proposed research are to: 1. Develop a 100-year design. a. maximum water surface elevation and associated wave height, b. maximum wave height and associated water elevation atlases for South Louisiana coastal waters. 2. Obtain ...

A Macroecological Analysis of SERA Derived Forest Heights and Implications for Forest Volume Remote Sensing

PubMed Central

Brolly, Matthew; Woodhouse, Iain H.; Niklas, Karl J.; Hammond, Sean T.

2012-01-01

Individual trees have been shown to exhibit strong relationships between DBH, height and volume. Often such studies are cited as justification for forest volume or standing biomass estimation through remote sensing. With resolution of common satellite remote sensing systems generally too low to resolve individuals, and a need for larger coverage, these systems rely on descriptive heights, which account for tree collections in forests. For remote sensing and allometric applications, this height is not entirely understood in terms of its location. Here, a forest growth model (SERA) analyzes forest canopy height relationships with forest wood volume. Maximum height, mean, H100, and Lorey's height are examined for variability under plant number density, resource and species. Our findings, shown to be allometrically consistent with empirical measurements for forested communities world-wide, are analyzed for implications to forest remote sensing techniques such as LiDAR and RADAR. Traditional forestry measures of maximum height, and to a lesser extent H100 and Lorey's, exhibit little consistent correlation with forest volume across modeled conditions. The implication is that using forest height to infer volume or biomass from remote sensing requires species and community behavioral information to infer accurate estimates using height alone. SERA predicts mean height to provide the most consistent relationship with volume of the height classifications studied and overall across forest variations. This prediction agrees with empirical data collected from conifer and angiosperm forests with plant densities ranging between 102–106 plants/hectare and heights 6–49 m. Height classifications investigated are potentially linked to radar scattering centers with implications for allometry. These findings may be used to advance forest biomass estimation accuracy through remote sensing. Furthermore, Lorey's height with its specific relationship to remote sensing physics is recommended as a more universal indicator of volume when using remote sensing than achieved using either maximum height or H100. PMID:22457800

A macroecological analysis of SERA derived forest heights and implications for forest volume remote sensing.

PubMed

Brolly, Matthew; Woodhouse, Iain H; Niklas, Karl J; Hammond, Sean T

2012-01-01

Individual trees have been shown to exhibit strong relationships between DBH, height and volume. Often such studies are cited as justification for forest volume or standing biomass estimation through remote sensing. With resolution of common satellite remote sensing systems generally too low to resolve individuals, and a need for larger coverage, these systems rely on descriptive heights, which account for tree collections in forests. For remote sensing and allometric applications, this height is not entirely understood in terms of its location. Here, a forest growth model (SERA) analyzes forest canopy height relationships with forest wood volume. Maximum height, mean, H₁₀₀, and Lorey's height are examined for variability under plant number density, resource and species. Our findings, shown to be allometrically consistent with empirical measurements for forested communities world-wide, are analyzed for implications to forest remote sensing techniques such as LiDAR and RADAR. Traditional forestry measures of maximum height, and to a lesser extent H₁₀₀ and Lorey's, exhibit little consistent correlation with forest volume across modeled conditions. The implication is that using forest height to infer volume or biomass from remote sensing requires species and community behavioral information to infer accurate estimates using height alone. SERA predicts mean height to provide the most consistent relationship with volume of the height classifications studied and overall across forest variations. This prediction agrees with empirical data collected from conifer and angiosperm forests with plant densities ranging between 10²-10⁶ plants/hectare and heights 6-49 m. Height classifications investigated are potentially linked to radar scattering centers with implications for allometry. These findings may be used to advance forest biomass estimation accuracy through remote sensing. Furthermore, Lorey's height with its specific relationship to remote sensing physics is recommended as a more universal indicator of volume when using remote sensing than achieved using either maximum height or H₁₀₀.

Ribbon growing method and apparatus

NASA Technical Reports Server (NTRS)

Morrison, Andrew D. (Inventor)

1989-01-01

A method and apparatus are described which facilitate the growing of silicon ribbon. A container for molten silicon has a pair of passages in its bottom through which filaments extend to a level above the molten silicon, so as the filaments are pulled up they drag up molten silicon to form a ribbon. A pair of guides surround the filaments along most of the height of the molten silicon, so that the filament contacts only the upper portion of the melt. This permits a filament to be used which tends to contaminate the melt if it is in long term contact with the melt. This arrangement also enables a higher melt to be used without danger that the molten silicon will run out of any bottom hole.

Scale inhibition in geothermal operations: experiments with Dequest 2060 phosphonate in Republic's East Mesa Field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vetter, O.J.; Campbell, D.A.

Two calcium carbonate (CaCO/sub 3/) scale inhibition tests have been performed at East Mesa wells number 16-29 and number 56-30. The first test at well number 16-29 could not be finished due to downhole pump problems. However, two inhibitor concentration runs were completed and a third run started before the pump failed. A follow-up test at well number 56-30 was completed according to the original plan. Typical power plant conditions (i.e., pressure and temperature drops, flow conditions) were simulated by using test loops (pipe diameters of eight inches at well number 16-29 and twelve inches at well number 56-30) andmore » field separators. Untreated East Mesa brine exhibits a calcium carbonate scale tendency as soon as the pressure is dropped below 75 psig. The uninhibited brine from well number 16-29 formed a maximum scale thickness of 0.5 inch in an eight inch ID pipe after a 92.75 hour test run at an average production rate of 375,000 lb/hr. The brine from well number 56-30 formed a maximum scale thickness of 1.25 inches in a twelve inch ID pipe after a 104 hour test run at an average production rate of 722,000 lb/hr. The principal conclusions of this test work are listed.« less

Comparison of Coastal Inundation in the Outer Banks during Three Recent Hurricanes

NASA Astrophysics Data System (ADS)

Liu, T.; Sheng, Y.

2012-12-01

Coastal inundation in the Outer Banks and Chesapeake Bay during several recent hurricanes - Isabel, Earl and Irene, in 2005, 2010 and 2011, respectively, have been successfully simulated using the storm surge modeling system, CH3D-SSMS, which includes coupled coastal and basin-scale storm surge and wave models. Hurricane Isabel, which made landfall at the Outer Banks area in 2005, generated high waves up to 20 m offshore and 2.5 m inside the Chesapeake Bay which significantly affected the peak surge, with wave induced set-up contributing up to about 20% of the peak surge. During Isabel, the observed wave height at Duck station (1 km offshore) reached over 6 meters at landfall time, while Earl and Irene generated relatively moderate waves, with peak wave height around 4 meters at that station but a much lower wave height before landfall. Simulations show that during Earl and Irene, wave induced set-up did not contribute as much as that during Isabel. At Duck Pier, wave effects accounted for ~36 cm or 20% of the peak surge of 1.71 m during Isabel, while waves contributed ~10 cm (10%) toward the peak surge of 1 m during Irene and even less during Earl. The maximum surge during Irene was largely caused by the strong wind, as confirmed by the model using H* wind. Inundation maps have been generated and compared based on the simulations of Isabel, Earl and Irene.

47 CFR 90.635 - Limitations on power and antenna height.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 5 2012-10-01 2012-10-01 false Limitations on power and antenna height. 90.635... and antenna height. (a) The effective radiated power and antenna height for base stations may not... justify power levels and antenna heights requested. (b) The maximum output power of the transmitter for...

47 CFR 90.635 - Limitations on power and antenna height.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Limitations on power and antenna height. 90.635... and antenna height. (a) The effective radiated power and antenna height for base stations may not... justify power levels and antenna heights requested. (b) The maximum output power of the transmitter for...

47 CFR 90.635 - Limitations on power and antenna height.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 5 2014-10-01 2014-10-01 false Limitations on power and antenna height. 90.635... and antenna height. (a) The effective radiated power and antenna height for base stations may not... justify power levels and antenna heights requested. (b) The maximum output power of the transmitter for...

47 CFR 90.635 - Limitations on power and antenna height.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Limitations on power and antenna height. 90.635... and antenna height. (a) The effective radiated power and antenna height for base stations may not... justify power levels and antenna heights requested. (b) The maximum output power of the transmitter for...

47 CFR 90.635 - Limitations on power and antenna height.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 5 2013-10-01 2013-10-01 false Limitations on power and antenna height. 90.635... and antenna height. (a) The effective radiated power and antenna height for base stations may not... justify power levels and antenna heights requested. (b) The maximum output power of the transmitter for...

[The concept and definition of locomotive syndrome in a super-aged society].

PubMed

Nakamura, Kozo; Yoshimura, Noriko; Akune, Toru; Ogata, Toru; Tanaka, Sakae

2014-10-01

The population of elderly individuals who need nursing care is rapidly increasing in Japan. Locomotive syndrome involves a decrease in mobility due to locomotive organ dysfunction, and increases risk for dependency on nursing care service. Because gait speed and chair stand time are correlated with such risks, patients with locomotive syndrome are assessed using brief methods such as the two-step test, which involves dividing the maximum stride length by the height of the patient, and the stand-up test, which involves standing on one or both legs at different heights. One leg standing and squatting are recommended as beneficial locomotive home exercises. Locomotive syndrome has been recognized widely in Japan, and included in the National Health Promotion Movement (2013-2022).

The repeated bout effect of typical lower body strength training sessions on sub-maximal running performance and hormonal response.

PubMed

Doma, Kenji; Schumann, Moritz; Sinclair, Wade H; Leicht, Anthony S; Deakin, Glen B; Häkkinen, Keijo

2015-08-01

This study examined the effects of two typical strength training sessions performed 1 week apart (i.e. repeated bout effect) on sub-maximal running performance and hormonal. Fourteen resistance-untrained men (age 24.0 ± 3.9 years; height 1.83 ± 0.11 m; body mass 77.4 ± 14.0 kg; VOpeak 48.1 ± 6.1 M kg(-1) min(-1)) undertook two bouts of high-intensity strength training sessions (i.e. six-repetition maximum). Creatine kinase (CK), delayed-onset muscle soreness (DOMS), counter-movement jump (CMJ) as well as concentrations of serum testosterone, cortisol and testosterone/cortisol ratio (T/C) were examined prior to and immediately post, 24 (T24) and 48 (T48) h post each strength training bout. Sub-maximal running performance was also conducted at T24 and T48 of each bout. When measures were compared between bouts at T48, the degree of elevation in CK (-58.4 ± 55.6 %) and DOMS (-31.43 ± 42.9 %) and acute reduction in CMJ measures (4.1 ± 5.4 %) were attenuated (p < 0.05) following the second bout. Cortisol was increased until T24 (p < 0.05) although there were no differences between bouts and no differences were found for testosterone and T/C ratio (p > 0.05). Sub-maximal running performance was impaired until T24, although changes were not attenuated following the second bout. The initial bout appeared to provide protection against a number of muscle damage indicators suggesting a greater need for recovery following the initial session of typical lower body resistance exercises in resistance-untrained men although sub-maximal running should be avoided following the first two sessions.

Integrative Neuromuscular Training and Sex-Specific Fitness Performance in 7-Year-Old Children: An Exploratory Investigation

PubMed Central

Faigenbaum, Avery D.; Myer, Gregory D.; Farrell, Anne; Radler, Tracy; Fabiano, Marc; Kang, Jie; Ratamess, Nicholas; Khoury, Jane; Hewett, Timothy E

2014-01-01

Context: Integrative neuromuscular training (INT) has successfully enhanced physical fitness and reduced abnormal biomechanics, which appear to decrease injury rates in adolescent female athletes. If not addressed at the proper time, low levels of physical fitness and abnormal mechanics may predispose female athletes to an increased risk of musculoskeletal injuries. Objectives To evaluate sex-specific effects of INT on selected measures of health- and skill-related fitness in children during physical education (PE). Design: Cohort study. Setting: Public primary school. Patients or Other Participants: Forty children (16 boys, 24 girls; age = 7.6 ± 0.3 years, height = 124.5 ± 6.4 cm, mass = 29.5 ± 7.6 kg) from 2 second-grade PE classes. Intervention(s): The classes were randomized into the PE-plus-INT group (10 boys, 11 girls) or the control group (6 boys, 13 girls) that participated in traditional PE. The INT was performed 2 times per week during the first approximately 15 minutes of each PE class and consisted of body weight exercises. Main Outcome Measure(s): Push-up, curl-up, standing long jump, single-legged hop, single-legged balance, sit-and-reach flexibility test, shuttle run, and 0.8-km run. Results: At baseline, the boys demonstrated higher levels of performance in most of the fitness measurements as evidenced by greater performance on the push-up, standing long jump, single-legged hop, shuttle run, and 0.8-km run (P < .05). In the evaluation of the training effects, we found intervention effects in the girls for enhanced INT-induced gains in performance relative to the control group on the curl-up, long jump, single-legged hop, and 0.8-km run (P < .05) after controlling for baseline. Boys did not demonstrate similar adaptations from the INT program (P ≥ .05). Conclusions: These data indicate that INT is an effective and time-efficient addition to PE for enhancing motor skills and promoting physical activity in children. Seven-year-old girls appeared to be more sensitive to the effects of INT than 7-year-old boys. Future research is warranted to confirm these effects in larger cohorts of children. PMID:24490841

Integrative neuromuscular training and sex-specific fitness performance in 7-year-old children: an exploratory investigation.

PubMed

Faigenbaum, Avery D; Myer, Gregory D; Farrell, Anne; Radler, Tracy; Fabiano, Marc; Kang, Jie; Ratamess, Nicholas; Khoury, Jane; Hewett, Timothy E

2014-01-01

Integrative neuromuscular training (INT) has successfully enhanced physical fitness and reduced abnormal biomechanics, which appear to decrease injury rates in adolescent female athletes. If not addressed at the proper time, low levels of physical fitness and abnormal mechanics may predispose female athletes to an increased risk of musculoskeletal injuries. To evaluate sex-specific effects of INT on selected measures of health- and skill-related fitness in children during physical education (PE). Cohort study. Public primary school. Forty children (16 boys, 24 girls; age = 7.6 ± 0.3 years, height = 124.5 ± 6.4 cm, mass = 29.5 ± 7.6 kg) from 2 second-grade PE classes. The classes were randomized into the PE-plus-INT group (10 boys, 11 girls) or the control group (6 boys, 13 girls) that participated in traditional PE. The INT was performed 2 times per week during the first approximately 15 minutes of each PE class and consisted of body weight exercises. Push-up, curl-up, standing long jump, single-legged hop, single-legged balance, sit-and-reach flexibility test, shuttle run, and 0.8-km run. At baseline, the boys demonstrated higher levels of performance in most of the fitness measurements as evidenced by greater performance on the push-up, standing long jump, single-legged hop, shuttle run, and 0.8-km run (P < .05). In the evaluation of the training effects, we found intervention effects in the girls for enhanced INT-induced gains in performance relative to the control group on the curl-up, long jump, single-legged hop, and 0.8-km run (P < .05) after controlling for baseline. Boys did not demonstrate similar adaptations from the INT program (P ≥ .05). These data indicate that INT is an effective and time-efficient addition to PE for enhancing motor skills and promoting physical activity in children. Seven-year-old girls appeared to be more sensitive to the effects of INT than 7-year-old boys. Future research is warranted to confirm these effects in larger cohorts of children.

Numerical Modeling of Infragravity Wave Runup on Steep and Mildly Sloping Natural Beaches

NASA Astrophysics Data System (ADS)

Fiedler, J. W.; Smit, P.; Brodie, K. L.; McNinch, J.; Guza, R. T.; Gallien, T.

2016-12-01

We present ongoing work which aims to validate the non-hydrostatic model SWASH for wave runup and infragravity waves generated by a range of different incident wave spectra at the offshore boundary, including the effect of finite directional spread. Flume studies of wave runup are limited to normally incident (1D) sea and infragravity waves, but natural waves are directionally spread (2D), with substantially different dynamics from 1D. For example, refractive trapping (edge waves) is only possible with 2D waves, and the bound infragravity wave response to short wave groups is highly amplified for the special case of normal incidence. Selected case studies are modeled at Agate Beach, Oregon, a low slope (1:80) beach with maximum offshore wave heights greater than 7m, and Cardiff, California, a steep (1:8) beach with maximum wave heights of 2m. Peak periods ranged between 5-20 s at both sites. On both beaches, waves were measured on a transect from approximately 10m depth to the runup, using pressure sensors, current meters, and a scanning lidar. Bulk short wave quantities, wave runup, infragravity frequency spectra and energy fluxes are compared with SWASH. On the low slope beach with energetic incident waves, the observed horizontal runup excursions reach 140m ( 100s periods). Swash front velocities reached up to several m/s, causing short waves to stack up during runup drawdown. On reversal of the infragravity phase, the stacked short waves are swept onshore with the long wave front, effectively enhancing runup by phase coupling long and short waves. Statistical variability and nonlinearity in swash generation lead to time-varying runup heights. Here, we test these observations with 2D SWASH, as well as the sensitivity of modeled runup to the parameterization of bottom friction.

Silicon web process development

NASA Technical Reports Server (NTRS)

Duncan, C. S.; Seidensticker, R. G.; Mchugh, J. P.; Hill, F. E.; Skutch, M. E.; Driggers, J. M.; Hopkins, R. H.

1980-01-01

A barrier crucible design which consistently maintains melt stability over long periods of time was successfully tested and used in long growth runs. The pellet feeder for melt replenishment was operated continuously for growth runs of up to 17 hours. The liquid level sensor comprising a laser/sensor system was operated, performed well, and meets the requirements for maintaining liquid level height during growth and melt replenishment. An automated feedback loop connecting the feed mechanism and the liquid level sensing system was designed and constructed and operated successfully for 3.5 hours demonstrating the feasibility of semi-automated dendritic web growth. The sensitivity of the cost of sheet, to variations in capital equipment cost and recycling dendrites was calculated and it was shown that these factors have relatively little impact on sheet cost. Dendrites from web which had gone all the way through the solar cell fabrication process, when melted and grown into web, produce crystals which show no degradation in cell efficiency. Material quality remains high and cells made from web grown at the start, during, and the end of a run from a replenished melt show comparable efficiencies.

Evaluation of an atmospheric model with surface and ABL meteorological data for energy applications in structured areas

NASA Astrophysics Data System (ADS)

Triantafyllou, A. G.; Kalogiros, J.; Krestou, A.; Leivaditou, E.; Zoumakis, N.; Bouris, D.; Garas, S.; Konstantinidis, E.; Wang, Q.

2018-03-01

This paper provides the performance evaluation of the meteorological component of The Air Pollution Model (TAPM), a nestable prognostic model, in predicting meteorological variables in urban areas, for both its surface layer and atmospheric boundary layer (ABL) turbulence parameterizations. The model was modified by incorporating four urban land surface types, replacing the existing single urban surface. Control runs were carried out over the wider area of Kozani, an urban area in NW Greece. The model was evaluated for both surface and ABL meteorological variables by using measurements of near-surface and vertical profiles of wind and temperature. The data were collected by using monitoring surface stations in selected sites as well as an acoustic sounder (SOnic Detection And Ranging (SODAR), up to 300 m above ground) and a radiometer profiler (up to 600 m above ground). The results showed the model demonstrated good performance in predicting the near-surface meteorology in the Kozani region for both a winter and a summer month. In the ABL, the comparison showed that the model's forecasts generally performed well with respect to the thermal structure (temperature profiles and ABL height) but overestimated wind speed at the heights of comparison (mostly below 200 m) up to 3-4 ms-1.

Sedimentation from Particle-Laden Plumes in Stratified Fluid

NASA Astrophysics Data System (ADS)

Sutherland, Bruce; Hong, Youn Sub

2015-11-01

Laboratory experiments are performed in which a mixture of particles, water and a small amount of dye is continuously injected upwards from a localized source into a uniformly stratified ambient. The particle-fluid mixture initially rises as a forced plume (which in most cases is buoyant, though in some cases due to high particle concentration is negative-buoyant at the source), reaches a maximum height, collapses upon itself and then spreads as a radial intrusion. The particles are observed to rain out of the descending intrusion and settle upon the floor of the tank. Using light attenuation, the depth of the particle mound is measured after the experiment has run for a fixed amount of time. In most experiments the distribution of particles is found to be approximately axisymmetric about the source with a near Gaussian structure for height as a function of radius. The results are compared with a code that combines classical plume theory with an adaptation to stratified fluids of the theory of Carey, Sigurdsson and Sparks (JGR, 1988) for the spread and fall of particles from a particle-laden plume impacting a rigid ceiling. Re-entrainment of particles into the plume is also taken into account.

Affordance Boundaries Are Defined by Dynamic Capabilities of Parkour Athletes in Dropping from Various Heights

PubMed Central

Croft, James L.; Bertram, John E. A.

2017-01-01

Available behaviors are determined by the fit between features of the individual and reciprocal features of the environment. Beyond some critical boundary certain behaviors become impossible causing sudden transitions from one movement pattern to another. Parkour athletes have developed multiple movement patterns to deal with their momentum during landing. We were interested in whether drop distance would cause a sudden transition between a two-footed (precision) landing and a load-distributing roll and whether the transition height could be predicted by dynamic and geometric characteristics of individual subjects. Kinematics and ground reaction forces were measured as Parkour athletes stepped off a box from heights that were incrementally increased or decreased from 0.6 to 2.3 m. Individuals were more likely to roll from higher drops; those with greater body mass and less explosive leg power, were more likely to transition to a roll landing at a lower height. At some height a two-footed landing is no longer feasible but for some athletes this height was well within the maximum drop height used in this study. During low drops the primary task constraint of managing momentum could be achieved with either a precision landing or a roll. This meant that participants were free to select their preferred landing strategy, which was only partially influenced by the physical demands of the task. However, athletes with greater leg power appeared capable of managing impulse absorption through a leg mediated strategy up to a greater drop height. PMID:28979219

47 CFR 73.614 - Power and antenna height requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 4 2013-10-01 2013-10-01 false Power and antenna height requirements. 73.614... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.614 Power and antenna height requirements.... No minimum antenna height above average terrain is specified. (b) Maximum power. Applications will...

47 CFR 73.614 - Power and antenna height requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 4 2014-10-01 2014-10-01 false Power and antenna height requirements. 73.614... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.614 Power and antenna height requirements.... No minimum antenna height above average terrain is specified. (b) Maximum power. Applications will...

47 CFR 73.614 - Power and antenna height requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 4 2012-10-01 2012-10-01 false Power and antenna height requirements. 73.614... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.614 Power and antenna height requirements.... No minimum antenna height above average terrain is specified. (b) Maximum power. Applications will...

47 CFR 73.614 - Power and antenna height requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false Power and antenna height requirements. 73.614... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.614 Power and antenna height requirements.... No minimum antenna height above average terrain is specified. (b) Maximum power. Applications will...

47 CFR 73.614 - Power and antenna height requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Power and antenna height requirements. 73.614... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.614 Power and antenna height requirements.... No minimum antenna height above average terrain is specified. (b) Maximum power. Applications will...

[Facts and fiction about running shoes].

PubMed

Schelde, Jacob

2012-11-26

Running as a means of exercise is becoming increasingly popular, but the rate of injury is very high among runners. To prevent running-related injuries much attention has been given the running shoe and its construction, particular its shock-absorbing capabilities and motion control features. It is recommended that running shoes should be purchased based on the runner's medial arch height and degree of pronation, and that the shoes should be changed frequently as their shock-absorbing capabilities decrease with usage. Randomized controlled trials and other studies in the scientific literature do not support these recommendations.

Increased medial longitudinal arch mobility, lower extremity kinematics, and ground reaction forces in high-arched runners.

PubMed

Williams, D S Blaise; Tierney, Robin N; Butler, Robert J

2014-01-01

Runners with high medial longitudinal arch structure demonstrate unique kinematics and kinetics that may lead to running injuries. The mobility of the midfoot as measured by the change in arch height is also suspected to play a role in lower extremity function during running. The effect of arch mobility in high-arched runners is an important factor in prescribing footwear, training, and rehabilitating the running athlete after injury. To examine the effect of medial longitudinal arch mobility on running kinematics, ground reaction forces, and loading rates in high-arched runners. Cross-sectional study. Human movement research laboratory. A total of 104 runners were screened for arch height. Runners were then identified as having high arches if the arch height index was greater than 0.5 SD above the mean. Of the runners with high arches, 11 rigid runners with the lowest arch mobility (R) were compared with 8 mobile runners with the highest arch mobility (M). Arch mobility was determined by calculating the left arch height index in all runners. Three-dimensional motion analysis of running over ground. Rearfoot and tibial angular excursions, eversion-to-tibial internal-rotation ratio, vertical ground reaction forces, and the associated loading rates. Runners with mobile arches exhibited decreased tibial internal-rotation excursion (mobile: 5.6° ± 2.3° versus rigid: 8.0° ± 3.0°), greater eversion-to-tibial internal-rotation ratio (mobile: 2.1 ± 0.8 versus rigid: 1.5 ± 0.5), decreased second peak vertical ground reaction force values (mobile: 2.3 ± 0.2 × body weight versus rigid: 2.4 ± 0.1 × body weight), and decreased vertical loading rate values (mobile: 55.7 ± 14.1 × body weight/s versus rigid: 65.9 ± 11.4 × body weight/s). Based on the results of this study, it appears that runners with high arch structure but differing arch mobility exhibited differences in select lower extremity movement patterns and forces. Future authors should investigate the impact of arch mobility on running-related injuries.

The influence of maximum running speed on eye size: a test of Leuckart's Law in mammals.

PubMed

Heard-Booth, Amber N; Kirk, E Christopher

2012-06-01

Vertebrate eye size is influenced by many factors, including body or head size, diet, and activity pattern. Locomotor speed has also been suggested to influence eye size in a relationship known as Leuckart's Law. Leuckart's Law proposes that animals capable of achieving fast locomotor speeds require large eyes to enhance visual acuity and avoid collisions with environmental obstacles. The selective influence of rapid flight has been invoked to explain the relatively large eyes of birds, but Leuckart's Law remains untested in nonavian vertebrates. This study investigates the relationship between eye size and maximum running speed in a diverse sample of mammals. Measures of axial eye diameter, maximum running speed, and body mass were collected from the published literature for 50 species from 10 mammalian orders. This analysis reveals that absolute eye size is significantly positively correlated with maximum running speed in mammals. Moreover, the relationship between eye size and running speed remains significant when the potentially confounding effects of body mass and phylogeny are statistically controlled. The results of this analysis are therefore consistent with the expectations of Leuckart's Law and demonstrate that faster-moving mammals have larger eyes than their slower-moving close relatives. Accordingly, we conclude that maximum running speed is one of several key selective factors that have influenced the evolution of eye size in mammals. Copyright © 2012 Wiley Periodicals, Inc.

Bedload transport over run-of-river dams, Delaware, U.S.A.

NASA Astrophysics Data System (ADS)

Pearson, Adam J.; Pizzuto, Jim

2015-11-01

We document the detailed morphology and bed sediment size distribution of a stream channel upstream and downstream of a 200-year-old run-of-river dam on the Red Clay Creek, a fifth order stream in the Piedmont of northern Delaware, and combine these data with HEC-RAS modeling and bedload transport computations. We hypothesize that coarse bed material can be carried through run-of-river impoundments before they completely fill with sediment, and we explore mechanisms to facilitate this transport. Only 25% of the accommodation space in our study site is filled with sediment, and maximum water depths are approximately equal to the dam height. All grain-size fractions present upstream of the impoundment are also present throughout the impoundment. A characteristic coarse-grained sloping ramp leads from the floor of the impoundment to the crest of the dam. A 2.3-m-deep plunge pool has been excavated below the dam, followed immediately downstream by a mid-channel bar composed of coarse bed material similar in size distribution to the bed material of the impoundment. The mid-channel bar stores 1472 m3 of sediment, exceeding the volume excavated from the plunge pool by a factor of 2.8. These field observations are typical of five other sites nearby and suggest that all bed material grain-size fractions supplied from upstream can be transported through the impoundment, up the sloping ramp, and over the top of the dam. Sediment transport computations suggest that all grain sizes are in transport upstream and within the impoundment at all discharges with return periods from 1 to 50 years. Our computations suggest that transport of coarse bed material through the impoundment is facilitated by its smooth, sandy bed. Model results suggest that the impoundment is currently aggrading at 0.26 m/year, but bed elevations may be recovering after recent scour from a series of large floods during water year 2011-2012. We propose that impoundments upstream of these run-of-river dams behave as long pools that adjust their bed elevation and texture to transport the load supplied by the watershed, rather than as impounded reservoirs with little bed material transport capacity. Scour may only occur during episodic high flows, followed by aggradation during periods of low flow.

Body acceleration distribution and O2 uptake in humans during running and jumping

NASA Technical Reports Server (NTRS)

Bhattacharya, A.; Mccutcheon, E. P.; Shvartz, E.; Greenleaf, J. E.

1980-01-01

The distribution of body acceleration and associated oxygen uptake and heart rate responses are investigated in treadmill running and trampoline jumping. Accelerations in the +Gz direction were measured at the lateral ankle, lumbosacral region and forehead of eight young men during level treadmill walking and running at four speeds and trampoline jumping at four heights, together with corresponding oxygen uptake and heart rate. With increasing treadmill speed, peak acceleration at the ankle is found always to exceed that at the back and forehead, and acceleration profiles with higher frequency components than those observed during jumping are observed. Acceleration levels are found to be more uniformly distributed with increasing height in jumping, although comparable oxygen uptake and heat rates are obtained. Results indicate that the magnitude of the biomechanical stimuli is greater in trampoline jumping than in running, which finding could be of use in the design of procedures to avert deconditioning in persons exposed to weightlessness.

PFLOTRAN User Manual: A Massively Parallel Reactive Flow and Transport Model for Describing Surface and Subsurface Processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lichtner, Peter C.; Hammond, Glenn E.; Lu, Chuan

PFLOTRAN solves a system of generally nonlinear partial differential equations describing multi-phase, multicomponent and multiscale reactive flow and transport in porous materials. The code is designed to run on massively parallel computing architectures as well as workstations and laptops (e.g. Hammond et al., 2011). Parallelization is achieved through domain decomposition using the PETSc (Portable Extensible Toolkit for Scientific Computation) libraries for the parallelization framework (Balay et al., 1997). PFLOTRAN has been developed from the ground up for parallel scalability and has been run on up to 218 processor cores with problem sizes up to 2 billion degrees of freedom. Writtenmore » in object oriented Fortran 90, the code requires the latest compilers compatible with Fortran 2003. At the time of this writing this requires gcc 4.7.x, Intel 12.1.x and PGC compilers. As a requirement of running problems with a large number of degrees of freedom, PFLOTRAN allows reading input data that is too large to fit into memory allotted to a single processor core. The current limitation to the problem size PFLOTRAN can handle is the limitation of the HDF5 file format used for parallel IO to 32 bit integers. Noting that 2 32 = 4; 294; 967; 296, this gives an estimate of the maximum problem size that can be currently run with PFLOTRAN. Hopefully this limitation will be remedied in the near future.« less

Modeling Kicks from the Merger of Generic Black-hole Binaries

NASA Technical Reports Server (NTRS)

Baker, John G.; Boggs, William D.; Centrella, Joan; Kelly, Bernard J.; McWilliams, Sean T.; Miller, M. Coleman; vanMeter, James R.

2008-01-01

Recent numerical relativistic results demonstrate that the merger of comparable-mass spinning black holes has a maximum "recoil kick" of up to approx. 4000 km/s. However the scaling of these recoil velocities with mass ratio is poorly understood. We present new runs showing that the maximum possible kick parallel to the orbital axis does not scale as approx. eta(sup 2) (where eta is the symmetric mass ratio), as previously proposed, but is more consistent with approx. eta(sup 3). We discuss the effect of this dependence on galactic ejection scenarios and retention of intermediate-mass black holes in globular clusters. S

A comparison of hydraulic architecture in three similarly sized woody species differing in their maximum potential height

Treesearch

Katherine A. McCulloh; Daniel M. Johnson; Joshua Petitmermet; Brandon McNellis; Frederick C. Meinzer; Barbara Lachenbruch; Nathan Phillips

2015-01-01

The physiological mechanisms underlying the short maximum height of shrubs are not understood. One possible explanation is that differences in the hydraulic architecture of shrubs compared with co-occurring taller trees prevent the shrubs from growing taller. To explore this hypothesis, we examined various hydraulic parameters, including vessel lumen diameter,...

No Dose-Response Effect of Carbohydrate Mouth Rinse Concentration on 5-km Running Performance in Recreational Athletes.

PubMed

Clarke, Neil D; Thomas, James R; Kagka, Marion; Ramsbottom, Roger; Delextrat, Anne

2017-03-01

Clarke, ND, Thomas, JR, Kagka, M, Ramsbottom, R, and Delextrat, A. No dose-response effect of carbohydrate mouth rinse concentration on 5-km running performance in recreational athletes. J Strength Cond Res 31(3): 715-720, 2017-Oral carbohydrate rinsing has been demonstrated to provide beneficial effects on exercise performance of durations of up to 1 hour, albeit predominately in a laboratory setting. The aim of the present study was to investigate the effects of different concentrations of carbohydrate solution mouth rinse on 5-km running performance. Fifteen healthy men (n = 9; mean ± SD age; 42 ± 10 years; height, 177.6 ± 6.1 cm; body mass, 73.9 ± 8.9 kg) and women (n = 6; mean ± SD age, 43 ± 9 years; height, 166.5 ± 4.1 cm; body mass, 65.7 ± 6.8 kg) performed a 5-km running time trial on a track on 4 separate occasions. Immediately before starting the time trial and then after each 1 km, subjects rinsed 25 ml of 0, 3, 6, or 12% maltodextrin for 10 seconds. Mouth rinsing with 0, 3, 6, or 12% maltodextrin did not have a significant effect on the time to complete the time trial (0%, 26:34 ± 4:07 minutes:seconds; 3%, 27:17 ± 4:33 minutes:seconds; 6%, 27:05 ± 3:52 minutes:seconds; 12%, 26:47 ± 4.31 minutes:seconds; p = 0.071; (Equation is included in full-text article.)= 0.15), heart rate (p = 0.095; (Equation is included in full-text article.)= 0.16), rating of perceived exertion (p = 0.195; (Equation is included in full-text article.)= 0.11), blood glucose (p = 0.920; (Equation is included in full-text article.)= 0.01), and blood lactate concentration (p = 0.831; (Equation is included in full-text article.)= 0.02), with only nonsignificant trivial to small differences between concentrations. Results of this study suggest that carbohydrate mouth rinsing provides no ergogenic advantage over an acaloric placebo (0%) and that there is no dose-response relationship between carbohydrate solution concentration and 5-km track running performance.

Arch-Taping Techniques for Altering Navicular Height and Plantar Pressures During Activity

PubMed Central

Newell, Tim; Simon, Janet; Docherty, Carrie L.

2015-01-01

Context Arch tapings have been used to support the arch by increasing navicular height. Few researchers have studied navicular height and plantar pressures after physical activity. Objective To determine if taping techniques effectively support the arch during exercise. Design Crossover study. Setting Athletic training research laboratory. Patients or Other Participants Twenty-five individuals (13 men, 12 women; age = 20.0 ± 1.0 years, height = 172.3 ± 6.6 cm, mass = 70.1 ± 10.2 kg) with a navicular drop of more than 8 mm (12.9 ± 3.3 mm) volunteered. Intervention(s) All individuals participated in 3 days of testing, with 1 day for each tape condition: no tape, low dye, and navicular sling. On each testing day, navicular height and plantar pressures were measured at 5 intervals: baseline; posttape; and after 5, 10, and 15 minutes of running. The order of tape condition was counterbalanced. Main Outcome Measure(s) The dependent variables were navicular height in millimeters and plantar pressures in kilopascals. Plantar pressures were divided into 5 regions: medial forefoot, lateral forefoot, lateral midfoot, lateral rearfoot, and medial rearfoot. Separate repeated-measures analyses of variance were conducted for each dependent variable. Results Navicular height was higher immediately after application of the navicular-sling condition (P = .004) but was reduced after 5 minutes of treadmill running (P = .12). We observed no differences from baseline to posttape for navicular height for the low-dye (P = .30) and no-tape conditions (P = .25). Both the low-dye and navicular-sling conditions increased plantar pressures in the lateral midfoot region compared with the no-tape condition. The low-dye condition created decreased pressure in the medial and lateral forefoot regions compared with the no-tape condition. All changes were identified immediately after application and were maintained during running. No changes were noted in plantar pressures for the no-tape condition (P > .05). Conclusions Both taping techniques effectively changed plantar pressures in the lateral midfoot, and these changes were sustained throughout the 15 minutes of exercise. PMID:26098272

SCINFUL: A Monte Carlo based computer program to determine a scintillator full energy response to neutron detection for E/sub n/ between 0. 1 and 80 MeV: Program development and comparisons of program predictions with experimental data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dickens, J.K.

1988-04-01

This document provides a discussion of the development of the FORTRAN Monte Carlo program SCINFUL (for scintillator full response), a program designed to provide a calculated full response anticipated for either an NE-213 (liquid) scintillator or an NE-110 (solid) scintillator. The program may also be used to compute angle-integrated spectra of charged particles (p, d, t, /sup 3/He, and ..cap alpha..) following neutron interactions with /sup 12/C. Extensive comparisons with a variety of experimental data are given. There is generally overall good agreement (<10% differences) of results from SCINFUL calculations with measured detector responses, i.e., N(E/sub r/) vs E/sub r/more » where E/sub r/ is the response pulse height, reproduce measured detector responses with an accuracy which, at least partly, depends upon how well the experimental configuration is known. For E/sub n/ < 16 MeV and for E/sub r/ > 15% of the maximum pulse height response, calculated spectra are within +-5% of experiment on the average. For E/sub n/ up to 50 MeV similar good agreement is obtained with experiment for E/sub r/ > 30% of maximum response. For E/sub n/ up to 75 MeV the calculated shape of the response agrees with measurements, but the calculations underpredicts the measured response by up to 30%. 65 refs., 64 figs., 3 tabs.« less

Unravelling the limits to tree height: a major role for water and nutrient trade-offs.

PubMed

Cramer, Michael D

2012-05-01

Competition for light has driven forest trees to grow exceedingly tall, but the lack of a single universal limit to tree height indicates multiple interacting environmental limitations. Because soil nutrient availability is determined by both nutrient concentrations and soil water, water and nutrient availabilities may interact in determining realised nutrient availability and consequently tree height. In SW Australia, which is characterised by nutrient impoverished soils that support some of the world's tallest forests, total [P] and water availability were independently correlated with tree height (r = 0.42 and 0.39, respectively). However, interactions between water availability and each of total [P], pH and [Mg] contributed to a multiple linear regression model of tree height (r = 0.72). A boosted regression tree model showed that maximum tree height was correlated with water availability (24%), followed by soil properties including total P (11%), Mg (10%) and total N (9%), amongst others, and that there was an interaction between water availability and total [P] in determining maximum tree height. These interactions indicated a trade-off between water and P availability in determining maximum tree height in SW Australia. This is enabled by a species assemblage capable of growing tall and surviving (some) disturbances. The mechanism for this trade-off is suggested to be through water enabling mass-flow and diffusive mobility of P, particularly of relatively mobile organic P, although water interactions with microbial activity could also play a role.

Ages of Quaternary Rio Grande terrace-fill deposits, Albuquerque area, New Mexico

USGS Publications Warehouse

,; Mahan, Shannon; Stone, Byron D.; Shroba, Ralph R.

2007-01-01

Results from luminescence dating on 13 samples from the Albuquerque area show that major-drainage fluvial deposits represent significant periods of aggradation that formed paired, correlatable terraces on the east and west margins of the Rio Grande valley . The youngest terrace fills (Primero Alto) formed during late Pleistocene as a result of streamflow variations with climate cooling during Marine Oxygen-Isotope Stage 3; our ages suggest aggradation of the upper part of the fill occurred at about 47–40 ka . Deposits of the second (Segundo Alto) terraces reached maximum height during climate cooling in the early part of Marine Oxygen-Isotope Stage 5 as late as 90–98 ka (based on dated basalt flows) . Our luminescence ages show considerable scatter and tend to be younger (range from 63 ka to 162 ka) . The third (Tercero Alto) and fourth (Cuarto Alto) terraces are dated on the basis of included volcanic tephra. Tercero Alto terrace-fill deposits contain the Lava Creek B tephra (639 ka), and Cuarto Alto terrace-fill deposits contain tephra of the younger Bandelier Tuff eruption (1 .22 Ma), the Cerro Toledo Rhyolite (1 .47 Ma), and the older Bandelier Tuff eruption (1 .61 Ma). These periods of aggradation culminated in fluvial terraces that are preserved at maximum heights of 360 ft (Cuarto Alto), 300 ft. (Tercero Alto), 140 ft (Segundo Alto), and 60 ft. (Primero Alto) above the modern floodplain. Despite lithologic differences related to local source-area contributions, these terracefill deposits can be correlated across the Rio Grande and up- and down-valley for tens of miles based on maximum height of the terrace above the modern floodplain.

Influence of Military Training and Standardized Nutrition in Military Unit on Soldiers' Nutritional Status and Physical Fitness.

PubMed

Tomczak, Andrzej; Bertrandt, Jerzy; Kłos, Anna; Kłos, Krzysztof

2016-10-01

Tomczak, A, Bertrandt, J, Kłos, A, and Kłos, K. Influence of military training and standardized nutrition in military unit on soldiers' nutritional status and physical fitness. J Strength Cond Res 30(10): 2774-2780, 2016-Despite suspension of conscription in Polish Army, trainings of soldiers are still carried out. It is expected that they will be effective and will contribute to obtaining optimum level of psychophysical efficiency that enables fulfillment of military tasks. Total of 60 soldiers took part in the study. During the 9-month military service, soldiers had 200 hours of physical training and basic military training (shooting, drill, anti-chemical training, topography, general tactics, and military equipment operation). The training lasted 8 hours everyday. To assess fitness level, 4 trials were done: long jump, pull-ups, sit-ups, and 1,000 m run. Evaluation of food was based on the analysis of full board menus using the "Tables of composition and nutritional value of food products." Energy value was assessed, and content of basic nutrients was calculated. Assessment of nutritional status was based on anthropometric measurements, such as body height, body mass, and thickness of 4 selected skinfolds. Body height and body mass were the basis for the body mass index calculation. Soldiers serving in the mechanized infantry unit, after completing the training, got better results only in 1,000 m run (from 250.3 to 233.61 seconds). During the research, an average energy value of a daily food ration planned for consumption was 4,504 kcal. This value consisted of 13.2% of energy from protein, 31.9% of energy from fat, and 54.9% from carbohydrates. In the course of military service, percentage of subjects indicating overweight increased from 10.2 to 25.4%.

The effect of footwear on running performance and running economy in distance runners.

PubMed

Fuller, Joel T; Bellenger, Clint R; Thewlis, Dominic; Tsiros, Margarita D; Buckley, Jonathan D

2015-03-01

The effect of footwear on running economy has been investigated in numerous studies. However, no systematic review and meta-analysis has synthesised the available literature and the effect of footwear on running performance is not known. The aim of this systematic review and meta-analysis was to investigate the effect of footwear on running performance and running economy in distance runners, by reviewing controlled trials that compare different footwear conditions or compare footwear with barefoot. The Web of Science, Scopus, MEDLINE, CENTRAL (Cochrane Central Register of Controlled Trials), EMBASE, AMED (Allied and Complementary Medicine), CINAHL and SPORTDiscus databases were searched from inception up until April 2014. Included articles reported on controlled trials that examined the effects of footwear or footwear characteristics (including shoe mass, cushioning, motion control, longitudinal bending stiffness, midsole viscoelasticity, drop height and comfort) on running performance or running economy and were published in a peer-reviewed journal. Of the 1,044 records retrieved, 19 studies were included in the systematic review and 14 studies were included in the meta-analysis. No studies were identified that reported effects on running performance. Individual studies reported significant, but trivial, beneficial effects on running economy for comfortable and stiff-soled shoes [standardised mean difference (SMD) <0.12; P < 0.05), a significant small beneficial effect on running economy for cushioned shoes (SMD = 0.37; P < 0.05) and a significant moderate beneficial effect on running economy for training in minimalist shoes (SMD = 0.79; P < 0.05). Meta-analysis found significant small beneficial effects on running economy for light shoes and barefoot compared with heavy shoes (SMD < 0.34; P < 0.01) and for minimalist shoes compared with conventional shoes (SMD = 0.29; P < 0.01). A significant positive association between shoe mass and metabolic cost of running was identified (P < 0.01). Footwear with a combined shoe mass less than 440 g per pair had no detrimental effect on running economy. Certain models of footwear and footwear characteristics can improve running economy. Future research in footwear performance should include measures of running performance.

Probabilistic tsunami hazard analysis: Multiple sources and global applications

USGS Publications Warehouse

Grezio, Anita; Babeyko, Andrey; Baptista, Maria Ana; Behrens, Jörn; Costa, Antonio; Davies, Gareth; Geist, Eric L.; Glimsdal, Sylfest; González, Frank I.; Griffin, Jonathan; Harbitz, Carl B.; LeVeque, Randall J.; Lorito, Stefano; Løvholt, Finn; Omira, Rachid; Mueller, Christof; Paris, Raphaël; Parsons, Thomas E.; Polet, Jascha; Power, William; Selva, Jacopo; Sørensen, Mathilde B.; Thio, Hong Kie

2017-01-01

Applying probabilistic methods to infrequent but devastating natural events is intrinsically challenging. For tsunami analyses, a suite of geophysical assessments should be in principle evaluated because of the different causes generating tsunamis (earthquakes, landslides, volcanic activity, meteorological events, and asteroid impacts) with varying mean recurrence rates. Probabilistic Tsunami Hazard Analyses (PTHAs) are conducted in different areas of the world at global, regional, and local scales with the aim of understanding tsunami hazard to inform tsunami risk reduction activities. PTHAs enhance knowledge of the potential tsunamigenic threat by estimating the probability of exceeding specific levels of tsunami intensity metrics (e.g., run-up or maximum inundation heights) within a certain period of time (exposure time) at given locations (target sites); these estimates can be summarized in hazard maps or hazard curves. This discussion presents a broad overview of PTHA, including (i) sources and mechanisms of tsunami generation, emphasizing the variety and complexity of the tsunami sources and their generation mechanisms, (ii) developments in modeling the propagation and impact of tsunami waves, and (iii) statistical procedures for tsunami hazard estimates that include the associated epistemic and aleatoric uncertainties. Key elements in understanding the potential tsunami hazard are discussed, in light of the rapid development of PTHA methods during the last decade and the globally distributed applications, including the importance of considering multiple sources, their relative intensities, probabilities of occurrence, and uncertainties in an integrated and consistent probabilistic framework.

Probabilistic Tsunami Hazard Analysis: Multiple Sources and Global Applications

NASA Astrophysics Data System (ADS)

Grezio, Anita; Babeyko, Andrey; Baptista, Maria Ana; Behrens, Jörn; Costa, Antonio; Davies, Gareth; Geist, Eric L.; Glimsdal, Sylfest; González, Frank I.; Griffin, Jonathan; Harbitz, Carl B.; LeVeque, Randall J.; Lorito, Stefano; Løvholt, Finn; Omira, Rachid; Mueller, Christof; Paris, Raphaël.; Parsons, Tom; Polet, Jascha; Power, William; Selva, Jacopo; Sørensen, Mathilde B.; Thio, Hong Kie

2017-12-01

Applying probabilistic methods to infrequent but devastating natural events is intrinsically challenging. For tsunami analyses, a suite of geophysical assessments should be in principle evaluated because of the different causes generating tsunamis (earthquakes, landslides, volcanic activity, meteorological events, and asteroid impacts) with varying mean recurrence rates. Probabilistic Tsunami Hazard Analyses (PTHAs) are conducted in different areas of the world at global, regional, and local scales with the aim of understanding tsunami hazard to inform tsunami risk reduction activities. PTHAs enhance knowledge of the potential tsunamigenic threat by estimating the probability of exceeding specific levels of tsunami intensity metrics (e.g., run-up or maximum inundation heights) within a certain period of time (exposure time) at given locations (target sites); these estimates can be summarized in hazard maps or hazard curves. This discussion presents a broad overview of PTHA, including (i) sources and mechanisms of tsunami generation, emphasizing the variety and complexity of the tsunami sources and their generation mechanisms, (ii) developments in modeling the propagation and impact of tsunami waves, and (iii) statistical procedures for tsunami hazard estimates that include the associated epistemic and aleatoric uncertainties. Key elements in understanding the potential tsunami hazard are discussed, in light of the rapid development of PTHA methods during the last decade and the globally distributed applications, including the importance of considering multiple sources, their relative intensities, probabilities of occurrence, and uncertainties in an integrated and consistent probabilistic framework.

Step-induced deconstruction and step-height evolution of the Au(110) surface

NASA Astrophysics Data System (ADS)

Romahn, U.; von Blanckenhagen, P.; Kroll, C.; Göpel, W.

1993-05-01

We use temperature-dependent high-resolution low-energy electron diffraction and spot-profile analysis low-energy electron diffraction to study the Au(110) surface at room temperature up to 786 K. The experimental data were analyzed within the framework of the kinematic theory. Oscillations were determined of the positions of half order and fundamental Bragg peaks as well as of the full width at half maximum of the specular peak as a function of perpendicular momentum transfer. Evidence of mono- atomic steps occurring in the [001] direction was found below and around the (2×1)-->(1×1) transition at Tc. Above Tc, the surface gets smoother in the [001] direction; at the roughening temperature, TR, the evolution of multiple-height steps starts in both symmetry directions.

49 CFR 231.31 - Drawbars for freight cars; standard height.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Drawbars for freight cars; standard height. 231.31... cars; standard height. (a) Except on cars specified in paragraph (b) of this section— (1) On standard gage (561/2-inch gage) railroads, the maximum height of drawbars for freight cars (measured...

49 CFR 231.31 - Drawbars for freight cars; standard height.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Drawbars for freight cars; standard height. 231.31... cars; standard height. (a) Except on cars specified in paragraph (b) of this section— (1) On standard gage (561/2-inch gage) railroads, the maximum height of drawbars for freight cars (measured...

49 CFR 231.31 - Drawbars for freight cars; standard height.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Drawbars for freight cars; standard height. 231.31... cars; standard height. (a) Except on cars specified in paragraph (b) of this section— (1) On standard gage (561/2-inch gage) railroads, the maximum height of drawbars for freight cars (measured...

49 CFR 231.31 - Drawbars for freight cars; standard height.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Drawbars for freight cars; standard height. 231.31... cars; standard height. (a) Except on cars specified in paragraph (b) of this section— (1) On standard gage (561/2-inch gage) railroads, the maximum height of drawbars for freight cars (measured...

49 CFR 231.31 - Drawbars for freight cars; standard height.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Drawbars for freight cars; standard height. 231.31... cars; standard height. (a) Except on cars specified in paragraph (b) of this section— (1) On standard gage (561/2-inch gage) railroads, the maximum height of drawbars for freight cars (measured...

Secondary trauma from occlusion: three-dimensional analysis using the finite element method.

PubMed

Geramy, Allahyar; Faghihi, Sharieh

2004-01-01

Clinical effects of forces applied by dental occlusion on the periodontium have been evaluated for decades. Historically, trauma from occlusion has been considered as a major etiologic factor of inflammatory periodontal diseases, while some researchers have interpreted it to be of less importance or without any detectable importance in periodontics. In this study, five three-dimensional models of a maxillary central incisor were created using ANSYS 5.40. The only difference in each model was the height of the alveolar bone that showed from normal height (13 mm of alveolar bone height) to 8 mm of alveolar bone loss (5 mm of alveolar bone height). Five-point forces of 0.3 N summing up to 1.5 N were applied in a parallel line, 1 mm apical to the incisal edge on the palatal side in a palatolabial direction. The maximum (S1) and minimum (S3) principal stresses in the nodes of the labial side of the periodontal ligament (apical to the alveolar crest) were assessed. Analysis was done using the finite element method. An increase of S1 (up to 16 times in the cervical and 11.25 times in the apical area) and S3 (up to 17.13 times in the cervical and 9.9 times in the apical area) in comparison to the normal model was shown. The highest stress levels were traced in the subcervical area, except for the last model (8 mm of the alveolar bone loss). According to the results of this study, 2.5 mm of alveolar bone loss can be considered as a limit beyond which stress alterations were accelerated. Based on the FEM analysis, alveolar bone loss increases stress (S1 and S3) produced in the PDL, in spite of applying the same force vector.

Tibiofemoral contact forces during walking, running and sidestepping.

PubMed

Saxby, David J; Modenese, Luca; Bryant, Adam L; Gerus, Pauline; Killen, Bryce; Fortin, Karine; Wrigley, Tim V; Bennell, Kim L; Cicuttini, Flavia M; Lloyd, David G

2016-09-01

We explored the tibiofemoral contact forces and the relative contributions of muscles and external loads to those contact forces during various gait tasks. Second, we assessed the relationships between external gait measures and contact forces. A calibrated electromyography-driven neuromusculoskeletal model estimated the tibiofemoral contact forces during walking (1.44±0.22ms(-1)), running (4.38±0.42ms(-1)) and sidestepping (3.58±0.50ms(-1)) in healthy adults (n=60, 27.3±5.4years, 1.75±0.11m, and 69.8±14.0kg). Contact forces increased from walking (∼1-2.8 BW) to running (∼3-8 BW), sidestepping had largest maximum total (8.47±1.57 BW) and lateral contact forces (4.3±1.05 BW), while running had largest maximum medial contact forces (5.1±0.95 BW). Relative muscle contributions increased across gait tasks (up to 80-90% of medial contact forces), and peaked during running for lateral contact forces (∼90%). Knee adduction moment (KAM) had weak relationships with tibiofemoral contact forces (all R(2)<0.36) and the relationships were gait task-specific. Step-wise regression of multiple external gait measures strengthened relationships (0.20

Unipedal Postural Balance and Countermovement Jumps After a Warm-up and Plyometric Training Session: A Randomized Controlled Trial.

PubMed

Romero-Franco, Natalia; Jiménez-Reyes, Pedro

2015-11-01

The purpose of this study was to analyze the immediate effects of a plyometric training protocol on unipedal postural balance and countermovement jumps. In addition, we analyzed the effects of a warm-up on these parameters. Thirty-two amateur male sprinters (24.9 ± 4.1 years; 72.3 ± 10.7 kg; 1.78 ± 0.05 m; 22.6 ± 3.3 kg·m) were randomly sorted into a control group (n = 16) (they did not perform any physical activity) and a plyometric training group (n = 16) (they performed a 15-minute warm-up and a high-intensity plyometric protocol consisting of 10 sets of 15 vertical jumps). Before and after the warm-up, and immediately after and 5 minutes after the plyometric protocol, all athletes indicated the perceived exertion on calf and quad regions on a scale from 0 (no exertion) to 10 (maximum exertion). They also carried out a maximum countermovement jump and a unipedal postural balance test (athletes would remain as still as possible for 15 seconds in a left leg and right leg support stance). Results showed that, in the plyometric group, length and velocity of center-of-pressure movement in right leg support stance increased compared with baseline (p = 0.001 and p = 0.004, respectively) and to the control group (p = 0.035 and p = 0.029, respectively) immediately after the plyometric protocol. In addition, the countermovement jump height decreased right after the plyometric protocol (p < 0.001). The perceived exertion on calf and quad regions increased after the plyometry (p < 0.001). Five minutes later, these parameters remained deteriorated despite a slight recovery (length: p = 0.044; velocity: p = 0.05; countermovement jump height: p < 0.001; local exertion: p < 0.001). Data also showed that countermovement jump height improved after the warm-up (p = 0.021), but unipedal postural balance remained unaltered. As a conclusion, high-intensity plyometric exercises blunt unipedal postural balance and countermovement jump performance. The deterioration lasts at least 5 minutes, which may influence future exercises in the training session. Coaches should plan the training routine according to the immediate effects of plyometry on postural balance and vertical jumps, which play a role in injury prevention and sports performance.

Human vertical eye movement responses to earth horizontal pitch

NASA Technical Reports Server (NTRS)

Wall, C. 3rd; Petropoulos, A. E.

1993-01-01

The vertical eye movements in humans produced in response to head-over-heels constant velocity pitch rotation about a horizontal axis resemble those from other species. At 60 degrees/s these are persistent and tend to have non-reversing slow components that are compensatory to the direction of rotation. In most, but not all subjects, the slow component velocity was well characterized by a rapid build-up followed by an exponential decay to a non-zero baseline. Super-imposed was a cyclic or modulation component whose frequency corresponded to the time for one revolution and whose maximum amplitude occurred during a specific head orientation. All response components (exponential decay, baseline and modulation) were larger during pitch backward compared to pitch forward runs. Decay time constants were shorter during the backward runs, thus, unlike left to right yaw axis rotation, pitch responses display significant asymmetries between paired forward and backward runs.

Physiological effects of wearing graduated compression stockings during running.

PubMed

Ali, Ajmol; Creasy, Robert H; Edge, Johann A

2010-08-01

This study examined the effect of wearing different grades of graduated compression stockings (GCS) on physiological and perceptual measures during and following treadmill running in competitive runners. Nine males and one female performed three 40-min treadmill runs (80 +/- 5% maximal oxygen uptake) wearing either control (0 mmHg; CON), low (12-15 mmHg; LO-GCS), or high (23-32 mmHg; HI-GCS) grade GCS in a double-blind counterbalanced order. Oxygen uptake, heart rate and blood lactate were measured. Perceptual scales were used pre- and post-run to assess comfort, tightness and any pain associated with wearing GCS. Changes in muscle function, soreness and damage were determined pre-run, immediately after running and 24 and 48 h post-run by measuring creatine kinase and myoglobin, counter-movement jump height, perceived soreness diagrams, and pressure sensitivity. There were no significant differences between trials for oxygen uptake, heart rate or blood lactate during exercise. HI-GCS was perceived as tighter (P < 0.05) and more pain-inducing (P < 0.05) than the other interventions; CON and LO-GCS were rated more comfortable than HI-GCS (P < 0.05). Creatine kinase (P < 0.05), myoglobin (P < 0.05) and jump height (P < 0.05) were higher and pressure sensitivity was more pronounced (P < 0.05) immediately after running but not after 24 and 48 h. Only four participants reported muscle soreness during recovery from running and there were no differences in muscle function between trials. In conclusion, healthy runners wearing GCS did not experience any physiological benefits during or following treadmill running. However, athletes felt more comfortable wearing low-grade GCS whilst running.

Performance Testing of Twist Drills on AISI 4140 Alloy Steel

DTIC Science & Technology

1979-07-01

AISI 4140 Annealed, RPM: 110, Feed Rate: 0.005 Ipr 2^ vi 1 LIST OF FIGURES (cont.) Figure Page 20. Maximum Height of Built-up Edge at Various...period. This investigation was conducted using only one kind of work material, AISI 4140 steel, annealed. The drill used for this investigation was a...HSS (M7), 0.5 inch diameter regular point, taper shank. AISI 4140 steel, annealed, belongs to a group of high strength materials relatively hard to

High-intensity interval running is perceived to be more enjoyable than moderate-intensity continuous exercise: implications for exercise adherence.

PubMed

Bartlett, Jonathan D; Close, Graeme L; MacLaren, Don P M; Gregson, Warren; Drust, Barry; Morton, James P

2011-03-01

The aim of this study was to objectively quantify ratings of perceived enjoyment using the Physical Activity Enjoyment Scale following high-intensity interval running versus moderate-intensity continuous running. Eight recreationally active men performed two running protocols consisting of high-intensity interval running (6 × 3 min at 90% VO(2max) interspersed with 6 × 3 min active recovery at 50% VO(2max) with a 7-min warm-up and cool down at 70% VO(2max)) or 50 min moderate-intensity continuous running at 70% VO(2max). Ratings of perceived enjoyment after exercise were higher (P < 0.05) following interval running compared with continuous running (88 ± 6 vs. 61 ± 12) despite higher (P < 0.05) ratings of perceived exertion (14 ± 1 vs. 13 ± 1). There was no difference (P < 0.05) in average heart rate (88 ± 3 vs. 87 ± 3% maximum heart rate), average VO(2) (71 ± 6 vs. 73 ± 4%VO(2max)), total VO(2) (162 ± 16 vs. 166 ± 27 L) or energy expenditure (811 ± 83 vs. 832 ± 136 kcal) between protocols. The greater enjoyment associated with high-intensity interval running may be relevant for improving exercise adherence, since running is a low-cost exercise intervention requiring no exercise equipment and similar relative exercise intensities have previously induced health benefits in patient populations.

The General Circulation Model Response to a North Pacific SST Anomaly: Dependence on Time Scale and Pattern Polarity.

NASA Astrophysics Data System (ADS)

Kushnir, Yochanan; Lau, Ngar-Cheung

1992-04-01

A general circulation model was integrated with perpetual January conditions and prescribed sea surface temperature (SST) anomalies in the North Pacific. A characteristic pattern with a warm region centered northeast of Hawaii and a cold region along the western seaboard of North America was alternately added to and subtracted from the climatological SST field. Long 1350-day runs, as well as short 180-day runs, each starting from different initial conditions, were performed. The results were compared to a control integration with climatological SSTs.The model's quasi-stationary response does not exhibit a simple linear relationship with the polarity of the prescribed SST anomaly. In the short runs with a negative SST anomaly over the central ocean, a large negative height anomaly, with an equivalent barotropic vertical structure, occurs over the Gulf of Alaska. For the same SST forcing, the long run yields a different response pattern in which an anomalous high prevails over northern Canada and the Alaskan Peninsula. A significant reduction in the northward heat flux associated with baroclinic eddies and a concomitant reduction in convective heating occur along the model's Pacific storm track. In the runs with a positive SST anomaly over the central ocean, the average height response during the first 90-day period of the short runs is too weak to be significant. In the subsequent 90-day period and in the long run an equivalent barotropic low occurs downstream from the warm SST anomaly. All positive anomaly runs exhibit little change in baroclinic eddy activity or in the patterns of latent heat release. Horizontal momentum transports by baroclinic eddies appear to help sustain the quasi-stationary response in the height field regardless of the polarity of the SST anomaly. These results emphasize the important role played by baroclinic eddies in determining the quasi-stationary response to midlatitude SST anomalies. Differences between the response patterns of the short and long integrations may be relevant to future experimental design for studying air-sea interactions in the extratropies.

Key algorithms used in GR02: A computer simulation model for predicting tree and stand growth

Treesearch

Garrett A. Hughes; Paul E. Sendak; Paul E. Sendak

1985-01-01

GR02 is an individual tree, distance-independent simulation model for predicting tree and stand growth over time. It performs five major functions during each run: (1) updates diameter at breast height, (2) updates total height, (3) estimates mortality, (4) determines regeneration, and (5) updates crown class.

Jumping and hopping in elite and amateur orienteering athletes and correlations to sprinting and running.

PubMed

Hébert-Losier, Kim; Jensen, Kurt; Holmberg, Hans-Christer

2014-11-01

Jumping and hopping are used to measure lower-body muscle power, stiffness, and stretch-shortening-cycle utilization in sports, with several studies reporting correlations between such measures and sprinting and/or running abilities in athletes. Neither jumping and hopping nor correlations with sprinting and/or running have been examined in orienteering athletes. The authors investigated squat jump (SJ), countermovement jump (CMJ), standing long jump (SLJ), and hopping performed by 8 elite and 8 amateur male foot-orienteering athletes (29 ± 7 y, 183 ± 5 cm, 73 ± 7 kg) and possible correlations to road, path, and forest running and sprinting performance, as well as running economy, velocity at anaerobic threshold, and peak oxygen uptake (VO(2peak)) from treadmill assessments. During SJs and CMJs, elites demonstrated superior relative peak forces, times to peak force, and prestretch augmentation, albeit lower SJ heights and peak powers. Between-groups differences were unclear for CMJ heights, hopping stiffness, and most SLJ parameters. Large pairwise correlations were observed between relative peak and time to peak forces and sprinting velocities; time to peak forces and running velocities; and prestretch augmentation and forest-running velocities. Prestretch augmentation and time to peak forces were moderately correlated to VO(2peak). Correlations between running economy and jumping or hopping were small or trivial. Overall, the elites exhibited superior stretch-shortening-cycle utilization and rapid generation of high relative maximal forces, especially vertically. These functional measures were more closely related to sprinting and/or running abilities, indicating benefits of lower-body training in orienteering.

Humans running in place on water at simulated reduced gravity.

PubMed

Minetti, Alberto E; Ivanenko, Yuri P; Cappellini, Germana; Dominici, Nadia; Lacquaniti, Francesco

2012-01-01

On Earth only a few legged species, such as water strider insects, some aquatic birds and lizards, can run on water. For most other species, including humans, this is precluded by body size and proportions, lack of appropriate appendages, and limited muscle power. However, if gravity is reduced to less than Earth's gravity, running on water should require less muscle power. Here we use a hydrodynamic model to predict the gravity levels at which humans should be able to run on water. We test these predictions in the laboratory using a reduced gravity simulator. We adapted a model equation, previously used by Glasheen and McMahon to explain the dynamics of Basilisk lizard, to predict the body mass, stride frequency and gravity necessary for a person to run on water. Progressive body-weight unloading of a person running in place on a wading pool confirmed the theoretical predictions that a person could run on water, at lunar (or lower) gravity levels using relatively small rigid fins. Three-dimensional motion capture of reflective markers on major joint centers showed that humans, similarly to the Basilisk Lizard and to the Western Grebe, keep the head-trunk segment at a nearly constant height, despite the high stride frequency and the intensive locomotor effort. Trunk stabilization at a nearly constant height differentiates running on water from other, more usual human gaits. The results showed that a hydrodynamic model of lizards running on water can also be applied to humans, despite the enormous difference in body size and morphology.

The Mucosal Immune Function Is Not Compromised during a Period of High-Intensity Interval Training. Is It Time to Reconsider an Old Assumption?

PubMed

Born, Dennis-Peter; Zinner, Christoph; Sperlich, Billy

2017-01-01

Purpose: The aim of the study was to evaluate the mucosal immune function and circadian variation of salivary cortisol, Immunoglobin-A (sIgA) secretion rate and mood during a period of high-intensity interval training (HIIT) compared to long-slow distance training (LSD). Methods: Recreational male runners ( n = 28) completed nine sessions of either HIIT or LSD within 3 weeks. The HIIT involved 4 × 4 min of running at 90-95% of maximum heart rate interspersed with 3 min of active recovery while the LSD comprised of continuous running at 70-75% of maximum heart rate for 60-80 min. The psycho-immunological stress-response was investigated with a full daily profile of salivary cortisol and immunoglobin-A (sIgA) secretion rate along with the mood state on a baseline day, the first and last day of training and at follow-up 4 days after the last day of training. Before and after the training period, each athlete's running performance and peak oxygen uptake (V · O 2peak ) was determined with an incremental exercise test. Results: The HIIT resulted in a longer time-to-exhaustion ( P = 0.02) and increased V · O 2peak compared to LSD ( P = 0.01). The circadian variation of sIgA secretion rate showed highest values in the morning immediately after waking up followed by a decrease throughout the day in both groups ( P < 0.05). With HIIT, the wake-up response of sIgA secretion rate was higher on the last day of training ( P < 0.01) as well as the area under the curve (AUC G ) higher on the first and last day of training and follow-up compared to the LSD ( P = 0.01). Also the AUC G for the sIgA secretion rate correlated with the increase in V · O 2peak and running performance. The AUC G for cortisol remained unaffected on the first and last day of training but increased on the follow-up day with both, HIIT and LSD ( P < 0.01). Conclusion: The increased sIgA secretion rate with the HIIT indicates no compromised mucosal immune function compared to LSD and shows the functional adaptation of the mucosal immune system in response to the increased stress and training load of nine sessions of HIIT.

The Mucosal Immune Function Is Not Compromised during a Period of High-Intensity Interval Training. Is It Time to Reconsider an Old Assumption?

PubMed Central

Born, Dennis-Peter; Zinner, Christoph; Sperlich, Billy

2017-01-01

Purpose: The aim of the study was to evaluate the mucosal immune function and circadian variation of salivary cortisol, Immunoglobin-A (sIgA) secretion rate and mood during a period of high-intensity interval training (HIIT) compared to long-slow distance training (LSD). Methods: Recreational male runners (n = 28) completed nine sessions of either HIIT or LSD within 3 weeks. The HIIT involved 4 × 4 min of running at 90–95% of maximum heart rate interspersed with 3 min of active recovery while the LSD comprised of continuous running at 70–75% of maximum heart rate for 60–80 min. The psycho-immunological stress-response was investigated with a full daily profile of salivary cortisol and immunoglobin-A (sIgA) secretion rate along with the mood state on a baseline day, the first and last day of training and at follow-up 4 days after the last day of training. Before and after the training period, each athlete's running performance and peak oxygen uptake (V·O2peak) was determined with an incremental exercise test. Results: The HIIT resulted in a longer time-to-exhaustion (P = 0.02) and increased V·O2peak compared to LSD (P = 0.01). The circadian variation of sIgA secretion rate showed highest values in the morning immediately after waking up followed by a decrease throughout the day in both groups (P < 0.05). With HIIT, the wake-up response of sIgA secretion rate was higher on the last day of training (P < 0.01) as well as the area under the curve (AUCG) higher on the first and last day of training and follow-up compared to the LSD (P = 0.01). Also the AUCG for the sIgA secretion rate correlated with the increase in V·O2peak and running performance. The AUCG for cortisol remained unaffected on the first and last day of training but increased on the follow-up day with both, HIIT and LSD (P < 0.01). Conclusion: The increased sIgA secretion rate with the HIIT indicates no compromised mucosal immune function compared to LSD and shows the functional adaptation of the mucosal immune system in response to the increased stress and training load of nine sessions of HIIT. PMID:28744226

Twelve Weeks of Plyometric Training Improves Motor Performance of 7- to 9-Year-Old Boys Who Were Overweight/Obese: A Randomized Controlled Intervention.

PubMed

Nobre, Gabriela G; de Almeida, Marcelus B; Nobre, Isabele G; Dos Santos, Fernanda K; Brinco, Raphael A; Arruda-Lima, Thalison R; de-Vasconcelos, Kenya L; de-Lima, Jociellen G; Borba-Neto, Manoel E; Damasceno-Rodrigues, Emmanuel M; Santos-Silva, Steve M; Leandro, Carol G; Moura-Dos-Santos, Marcos A

2017-08-01

Nobre, GG, de Almeida, MB, Nobre, IG, dos Santos, FK, Brinco, RA, Arruda-Lima, TR, de-Vasconcelos, KL, de-Lima, JG, Borba-Neto, ME, Damasceno-Rodrigues, EM, Santos-Silva, SM, Leandro, CG, and Moura-dos-Santos, MA. Twelve weeks of plyometric training improves motor performance of 7- to 9-year-old boys who were overweight/obese: a randomized controlled intervention. J Strength Cond Res 31(8): 2091-2099, 2017-The prevalence of childhood overweight/obesity has increased, and physical training at school may to be effective to combat this scenario. We analyzed the effects of a protocol of plyometric training on body composition and motor performance of boys who were overweight/obese aged 7-9 years. The sample was randomly assigned into 2 groups: plyometric training group (T, n = 40) and control group (C, n = 19). Training consisted of 20 min·d (twice a week, during 12 weeks) of lower extremity plyometric exercise. Health-related physical fitness was measured by handgrip strength, standing long jump (SLJ), curl-ups, sit and reach, square test, running speed, and mile run test. Gross motor coordination was evaluated by means of the Körperkoordinations-test für Kinder (KTK) tests. Baseline and postintervention differences were investigated, and effect size was estimated through Cohen's d coefficient. Both groups showed increased body weight, height, and sitting height after intervention with a negligible effect size. Only T group showed increased fat-free mass (p = 0.011) compared with baseline values with small effect size. Plyometric training improved handgrip strength (d = 0.23), sit and reach (d = 0.18), curl-ups (d = 0.39), SLJ (d = 0.80), agility (d = 0.48), and time in the mile run test (d = 0.38). For gross motor coordination results, T group showed better performance in all tests after plyometric training with moderate/large effect size. Thus, 12 weeks of PT improved health-related physical fitness components and motor coordination acquisition of 7- to 9-year-old boys who were overweight/obese.

33 CFR 177.07 - Other unsafe conditions.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) The wave height within the Regulated Boating Area is 4 feet or greater; or (2) The wave height within the Regulated Boating Area is equal to or greater than the wave height determined by the formula L/10... from the lowest point along the upper strake edge to the surface of the water. W=Maximum wave height in...

33 CFR 177.07 - Other unsafe conditions.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) The wave height within the Regulated Boating Area is 4 feet or greater; or (2) The wave height within the Regulated Boating Area is equal to or greater than the wave height determined by the formula L/10... from the lowest point along the upper strake edge to the surface of the water. W=Maximum wave height in...

33 CFR 177.07 - Other unsafe conditions.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) The wave height within the Regulated Boating Area is 4 feet or greater; or (2) The wave height within the Regulated Boating Area is equal to or greater than the wave height determined by the formula L/10... from the lowest point along the upper strake edge to the surface of the water. W=Maximum wave height in...

Judgements about the relation between force and trajectory variables in verbally described ballistic projectile motion.

PubMed

White, Peter A

2013-01-01

How accurate are explicit judgements about familiar forms of object motion, and how are they made? Participants judged the relations between force exerted in kicking a soccer ball and variables that define the trajectory of the ball: launch angle, maximum height attained, and maximum distance reached. Judgements tended to conform to a simple heuristic that judged force tends to increase as maximum height and maximum distance increase, with launch angle not being influential. Support was also found for the converse prediction, that judged maximum height and distance tend to increase as the amount of force described in the kick increases. The observed judgemental tendencies did not resemble the objective relations, in which force is a function of interactions between the trajectory variables. This adds to a body of research indicating that practical knowledge based on experiences of actions on objects is not available to the processes that generate judgements in higher cognition and that such judgements are generated by simple rules that do not capture the objective interactions between the physical variables.

Effects of size, sex, and voluntary running speeds on costs of locomotion in lines of laboratory mice selectively bred for high wheel-running activity.

PubMed

Rezende, Enrico L; Kelly, Scott A; Gomes, Fernando R; Chappell, Mark A; Garland, Theodore

2006-01-01

Selective breeding for over 35 generations has led to four replicate (S) lines of laboratory house mice (Mus domesticus) that run voluntarily on wheels about 170% more than four random-bred control (C) lines. We tested whether S lines have evolved higher running performance by increasing running economy (i.e., decreasing energy spent per unit of distance) as a correlated response to selection, using a recently developed method that allows for nearly continuous measurements of oxygen consumption (VO2) and running speed in freely behaving animals. We estimated slope (incremental cost of transport [COT]) and intercept for regressions of power (the dependent variable, VO2/min) on speed for 49 males and 47 females, as well as their maximum VO2 and speeds during wheel running, under conditions mimicking those that these lines face during the selection protocol. For comparison, we also measured COT and maximum aerobic capacity (VO2max) during forced exercise on a motorized treadmill. As in previous studies, the increased wheel running of S lines was mainly attributable to increased average speed, with males also showing a tendency for increased time spent running. On a whole-animal basis, combined analysis of males and females indicated that COT during voluntary wheel running was significantly lower in the S lines (one-tailed P=0.015). However, mice from S lines are significantly smaller and attain higher maximum speeds on the wheels; with either body mass or maximum speed (or both) entered as a covariate, the statistical significance of the difference in COT is lost (one-tailed P> or =0.2). Thus, both body size and behavior are key components of the reduction in COT. Several statistically significant sex differences were observed, including lower COT and higher resting metabolic rate in females. In addition, maximum voluntary running speeds were negatively correlated with COT in females but not in males. Moreover, males (but not females) from the S lines exhibited significantly higher treadmill VO2max as compared to those from C lines. The sex-specific responses to selection may in part be consequences of sex differences in body mass and running style. Our results highlight how differences in size and running speed can account for lower COT in S lines and suggest that lower COT may have coadapted in response to selection for higher running distances in these lines.

Spontaneous running activity in male rats - Effect of age

NASA Technical Reports Server (NTRS)

Mondon, C. E.; Dolkas, C. B.; Sims, C.; Reaven, G. M.

1985-01-01

Variations in the intensity and the patterns of spontaneous running activity in wheel cages were studied in male rats aged 7 weeks to one year. Daily running records were obtained for periods of 12 mo, and 24-hour recordings were made for selected runners in order to study variations in running activity during the day. The data indicate that for rats running over two miles/day, the maximum running intensity can be divided into two groups: a group of high achievers running 8 miles/day; and a group of moderate achievers running 4.8 miles/day. For both groups spontaneous activity reached a maximum after 4-5 weeks. An hourly pattern of running activity during the day was identified in rats of increasing age who averaged 9.0, 4.5, 2.6, and 1.2 miles/day, respectively. Progressive losses were observed in both the speed and the duration of spontaneous running as the rats increased in age, with the intensity of exercise falling below 2 miles/day after 7-8 months of age.

Vertical Jump Height Estimation Algorithm Based on Takeoff and Landing Identification Via Foot-Worn Inertial Sensing.

PubMed

Wang, Jianren; Xu, Junkai; Shull, Peter B

2018-03-01

Vertical jump height is widely used for assessing motor development, functional ability, and motor capacity. Traditional methods for estimating vertical jump height rely on force plates or optical marker-based motion capture systems limiting assessment to people with access to specialized laboratories. Current wearable designs need to be attached to the skin or strapped to an appendage which can potentially be uncomfortable and inconvenient to use. This paper presents a novel algorithm for estimating vertical jump height based on foot-worn inertial sensors. Twenty healthy subjects performed countermovement jumping trials and maximum jump height was determined via inertial sensors located above the toe and under the heel and was compared with the gold standard maximum jump height estimation via optical marker-based motion capture. Average vertical jump height estimation errors from inertial sensing at the toe and heel were -2.2±2.1 cm and -0.4±3.8 cm, respectively. Vertical jump height estimation with the presented algorithm via inertial sensing showed excellent reliability at the toe (ICC(2,1)=0.98) and heel (ICC(2,1)=0.97). There was no significant bias in the inertial sensing at the toe, but proportional bias (b=1.22) and fixed bias (a=-10.23cm) were detected in inertial sensing at the heel. These results indicate that the presented algorithm could be applied to foot-worn inertial sensors to estimate maximum jump height enabling assessment outside of traditional laboratory settings, and to avoid bias errors, the toe may be a more suitable location for inertial sensor placement than the heel.

Catastrophic event recorded among Holocene eolianites (Sidi Salem Formation, SE Tunisia)

NASA Astrophysics Data System (ADS)

Frébourg, Gregory; Hasler, Claude-Alain; Davaud, Eric

2010-03-01

A high-energy deposit cuts through the early Holocene eolianites of the Sidi Salem Formation which forms a ridge along the southeastern coast of Tunisia. The sedimentary structures as well as the paleo-altitude and paleo-location of the outcrop state for a subaqueous deposition by an unusually large catastrophic event. Regarding its age and the related uncertainties, it could be either an exceptional storm, or a landslide or impact triggered tsunami. The mega-tsunami of the 8000 BP collapse of the Valle del Bove valley (Etna Volcano) could be this event, for its matching age and calculated run-up height.

Impact of an asteroid or comet in the ocean and extinction of terrestrial life

NASA Technical Reports Server (NTRS)

Ahrens, T. J.; Okeefe, J. D.

1982-01-01

Finite difference calculations describing the impact mechanics associated with a 10 to 30 km diameter silicate or water object impacting a 5 km deep ocean overlying a silicate solid planet demonstrate that from 12 to 15% of the bolide energy resides in the water. It is speculated that minimal global tsunami run-up heights on the continents would be 300-400 meters, and that such waves would inundate all low altitude continental areas, and strip and silt-over virtually all vegetation. As a result the terrestrial animal food chain would be seriously perturbed. This could in turn cause extinction of large terrestrial animals.

An investigation of ionospheric upper transition height variations at low and equatorial latitudes deduced from combined COSMIC and C/NOFS measurements

NASA Astrophysics Data System (ADS)

Yang, Changjun; Zhao, Biqiang; Zhu, Jie; Yue, Xinan; Wan, Weixing

2017-10-01

In this study we propose the combination of topside in-situ ion density data from the Communication/Navigation Outage Forecast System (C/NOFS) along with the electron density profile measurement from Constellation Observing System for Meteorology, Ionosphere & Climate (COSMIC) satellites Radio Occultation (RO) for studying the spatial and temporal variations of the ionospheric upper transition height (hT) and the oxygen ion (O+) density scale height. The latitudinal, local time and seasonal distributions of upper transition height show more consistency between hT re-calculated by the profile of the O+ using an α-Chapman function with linearly variable scale height and that determined from direct in-situ ion composition measurements, than with constant scale height and only the COSMIC data. The discrepancy in the values of hT between the C/NOFS measurement and that derived by the combination of COSMIC and C/NOFS satellites observations with variable scale height turns larger as the solar activity decreases, which suggests that the photochemistry and the electrodynamics of the equatorial ionosphere during the extreme solar minimum period produce abnormal structures in the vertical plasma distribution. The diurnal variation of scale heights (Hm) exhibits a minimum after sunrise and a maximum around noon near the geomagnetic equator. Further, the values of Hm exhibit a maximum in the summer hemisphere during daytime, whereas in the winter hemisphere the maximum is during night. Those features of Hm consistently indicate the prominent role of the vertical electromagnetic (E × B) drift in the equatorial ionosphere.

An investigation of ionospheric upper transition height variations at low and equatorial latitudes deduced from combined COSMIC and C/NOFS measurements

NASA Astrophysics Data System (ADS)

Zhao, Biqiang

2017-04-01

In this study we propose the combination of topside in-situ ion density data from the Communication/Navigation Outage Forecast System (C/NOFS) along with the electron density profile measurement from Constellation Observing System for Meteorology, Ionosphere & Climate (COSMIC) satellites Radio Occultation (RO) for studying the spatial and temporal variations of the ionospheric upper transition height (hT) and the oxygen ion (O+) density scale height. The latitudinal, local time and seasonal distributions of upper transition height show more consistency between hT re-calculated by the profile of the O+ using an a-Chapman function with linearly variable scale height and that determined from direct in-situ ion composition measurements, than with constant scale height and only the COSMIC data. The discrepancy in the values of hT between the C/NOFS measurement and that derived by the combination of COSMIC and C/NOFS satellites observations with variable scale height turns larger as the solar activity decreases, which suggests that the photochemistry and the electrodynamics of the equatorial ionosphere during the extreme solar minimum period produce abnormal structures in the vertical plasma distribution. The diurnal variation of scale heights (Hm) exhibits a minimum after sunrise and a maximum around noon near the geomagnetic equator. Further, the values of Hm exhibit a maximum in the summer hemisphere during daytime, whereas in the winter hemisphere the maximum is during night. Those features of Hm consistently indicate the prominent role of the vertical electromagnetic (E×B) drift in the equatorial ionosphere.

The Fatigue Behavior of Built-Up Welded Beams of Commercially Pure Titanium

NASA Astrophysics Data System (ADS)

Patnaik, Anil; Poondla, Narendra; Bathini, Udaykar; Srivatsan, T. S.

2011-10-01

In this article, the results of a recent study aimed at evaluating, understanding, and rationalizing the extrinsic influence of fatigue loading on the response characteristics of built-up welded beams made from commercially pure titanium (Grade 2) are presented and discussed. The beams were made from welding plates and sheets of titanium using the pulsed gas metal arc welding technique to form a structural beam having an I-shaped cross section. The welds made for the test beams of the chosen metal were fillet welds using a matching titanium filler metal wire. The maximum and minimum load values at which the built-up beams were cyclically deformed were chosen to be within the range of 22-45% of the maximum predicted flexural static load. The beams were deformed in fatigue at a stress ratio of 0.1 and constant frequency of 5 Hz. The influence of the ratio of maximum load with respect to the ultimate failure load on fatigue performance, quantified in terms of fatigue life, was examined. The percentage of maximum load to ultimate load that resulted in run-out of one million cycles was established. The overall fracture behavior of the failed beam sample was characterized by scanning electron microscopy observations to establish the conjoint influence of load severity, intrinsic microstructural effects, and intrinsic fracture surface features in governing failure by fracture.

Preliminary safety analysis of Pb-Bi cooled 800 MWt modified CANDLE burn-up scheme based fast reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su'ud, Zaki, E-mail: szaki@fi.itba.c.id; Sekimoto, H., E-mail: hsekimot@gmail.com

2014-09-30

Pb-Bi Cooled fast reactors with modified CANDLE burn-up scheme with 10 regions and 10 years cycle length has been investigated from neutronic aspects. In this study the safety aspect of such reactors have been investigated and discussed. Several condition of unprotected loss of flow (ULOF) and unprotected rod run-out transient over power (UTOP) have been simulated and the results show that the reactors excellent safety performance. At 80 seconds after unprotected loss of flow condition, the core flow rate drop to about 25% of its initial flow and slowly move toward its natural circulation level. The maximum fuel temperature canmore » be managed below 1000°C and the maximum cladding temperature can be managed below 700°C. The dominant reactivity feedback is radial core expansion and Doppler effect, followed by coolant density effect and fuel axial expansion effect.« less

Liquid inflow to initially empty cylindrical tanks in low gravity

NASA Technical Reports Server (NTRS)

Spuckler, C. M.

1972-01-01

An experimental investigation was performed to determine the characteristics of liquid inflow to initially empty cylindrical tanks in a low gravity environment. The acceleration was varied so that Bond numbers based on the inlet radius varied from 0.059 to 2.80. The liquid entered the tank as a jet that grew to a maximum height and then decreased in height with respect to the bottom of the tank, with the liquid from the jet collecting in the bottom of the tank. The maximum jet heights were correlated in terms of the Weber number and the Bond number.

Rail height effects on safety performance of Midwest Guardrail System.

PubMed

Asadollahi Pajouh, Mojdeh; Julin, Ramen D; Stolle, Cody S; Reid, John D; Faller, Ronald K

2018-02-17

Guardrail heights play a crucial role in the way that errant vehicles interact with roadside barriers. Low rail heights increase the propensity of vehicle rollover and override, whereas excessively tall rails promote underride. Further, rail mounting heights and post embedment depths may be altered by variations in roadside terrain. An increased guardrail height may be desirable to accommodate construction tolerances, soil erosion, frost heave, and future roadway overlays. This study aimed to investigate and identify a maximum safe installation height for the Midwest Guardrail System that would be robust and remain crashworthy before and after pavement overlays. A research investigation was performed to evaluate the safety performance of increased mounting heights for the standard 787-mm (31-in.)-tall Midwest Guardrail System (MGS) through crash testing and computer simulation. Two full-scale crash tests with small passenger cars were performed on the MGS with top-rail mounting heights of 864 and 914 mm (34 and 36 in.). Test results were then used to calibrate computer simulation models. In the first test, a small car impacted the MGS with 864-mm (34-in.) rail height at 102 km/h (63.6 mph) and 25.0° and was successfully redirected. In the second test, another small car impacted the MGS with a 914-mm (36-in.) rail height at 103 km/h (64.1 mph) and 25.6° and was successful. Both system heights satisfied the Manual for Assessing Safety Hardware (MASH) Test Level 3 (TL-3) evaluation criteria. Test results were then used to calibrate computer simulation models. A mounting height of 36 in. was determined to be the maximum guardrail height that would safely contain and redirect small car vehicles. Simulations confirmed that taller guardrail heights (i.e., 37 in.) would likely result in small car underride. In addition, simulation results indicated that passenger vehicle models were successfully contained by the 34- and 36-in.-tall MGS installed on approach slopes as steep as 6:1. A mounting height of 914 mm (36 in.) was determined to be the maximum guardrail height that would safely contain and redirect 1100C vehicles and not allow underride or excessive vehicle snag on support posts. Recommendations were also provided regarding the safety performance of the MGS with increased height.

Karl von Frisch lecture. Signals and flexibility in the dance communication of honeybees.

PubMed

Michelsen, Axel

2003-03-01

Progress in understanding dance communication in honeybees is reviewed. The behaviour of both dancers and follower bees contain flexible and stereotypic elements. The transfer of specific information about direction and distance probably involves more than one sensory modality. The follower bees need to stay behind the dancer (within the angle of wagging) during at least one waggle run in order to perceive the specific information. Within this zone, a small stationary air-flow receiver (like the antenna of a follower bee) experiences a well-defined maximum when the abdomen of the wagging dancer passes by. Within 1 mm from the tip of the abdomen, the maximum may be caused by oscillating flows generated by the wagging motion. At other positions and distances (up to several millimetres from the dancer) the maximum is due to a spatially narrow jet air flow generated by the vibrating wings. The time pattern of these maxima is a function of the angular position of the receiver relative to the axis of the waggle run and thus a potential cue for direction. In addition to the narrow jet air flows, the dancers can generate a broad jet. The jets are not automatic by-products of wing vibration, since they can be switched on and off when the dancer adjusts the position of her wings.

Planetary boundary layer height over the Indian subcontinent: Variability and controls with respect to monsoon

NASA Astrophysics Data System (ADS)

Sathyanadh, Anusha; Prabhakaran, Thara; Patil, Chetana; Karipot, Anandakumar

2017-10-01

Planetary boundary layer (PBL) height characteristics over the Indian sub-continent at diurnal to seasonal scales and its controlling factors in relation to monsoon are investigated. The reanalysis (Modern Era Retrospective analysis for Research and Applications, MERRA) PBL heights (PBLH) used for the study are validated against those derived from radiosonde observations and radio occultation air temperature and humidity profiles. The radiosonde observations include routine India Meteorological Department observations at two locations (coastal and an inland) for one full year and campaign based early afternoon radiosonde observations at six inland locations over the study region for selected days from May-September 2011. The temperature and humidity profiles from radio occultations spread over the sub-continent at irregular timings during the year 2011. The correlations and root mean square errors are in the range 0.74-0.83 and 407 m-643 m, respectively. Large pre-monsoon, monsoon and post-monsoon variations in PBL maximum height (1000 m-4000 m), time of occurrence of maximum height (11:00 LST-17:00 LST) and growth rate (100 to 400 m h- 1) are noted over the land, depending on geographical location and more significantly on the moisture availability which influences the surface sensible and latent heat fluxes. The PBLH variations associated with active-break intra-seasonal monsoon oscillations are up to 1000 m over central Indian locations. Inter relationship between the PBLH and the controlling factors, i.e. Evaporative Fraction, net radiation, friction velocity, surface Richardson number, and scalar diffusivity fraction, show significant variation between dry and wet PBL regimes, which also varies with geographical location. Evaporative fraction has dominant influence on the PBLH over the region. Enhanced entrainment during monsoon contributes to reduction in PBLH, whereas the opposite effect is noted during dry period. Linear regression, cross wavelet and Analysis of Variance (ANOVA) methods are used to elucidate the role of controlling factors and interactions on PBLH in relation to monsoon.

Changes in photosynthesis and leaf characteristics with tree height in five dipterocarp species in a tropical rain forest.

PubMed

Kenzo, Tanaka; Ichie, Tomoaki; Watanabe, Yoko; Yoneda, Reiji; Ninomiya, Ikuo; Koike, Takayoshi

2006-07-01

Variations in leaf photosynthetic, morphological and biochemical properties with increasing plant height from seedlings to emergent trees were investigated in five dipterocarp species in a Malaysian tropical rain forest. Canopy openness increased significantly with tree height. Photosynthetic properties, such as photosynthetic capacity at light saturation, light compensation point, maximum rate of carboxylation and maximum rate of photosynthetic electron transport, all increased significantly with tree height. Leaf morphological and biochemical traits, such as leaf mass per area, palisade layer thickness, nitrogen concentration per unit area, chlorophyll concentration per unit dry mass and chlorophyll to nitrogen ratio, also changed significantly with tree height. Leaf properties had simple and significant relationships with tree height, with few intra- and interspecies differences. Our results therefore suggest that the photosynthetic capacity of dipterocarp trees depends on tree height, and that the trees adapt to the light environment by adjusting their leaf morphological and biochemical properties. These results should aid in developing models that can accurately estimate carbon dioxide flux and biomass production in tropical rain forests.

An investigation of rugby scrimmaging posture and individual maximum pushing force.

PubMed

Wu, Wen-Lan; Chang, Jyh-Jong; Wu, Jia-Hroung; Guo, Lan-Yuen

2007-02-01

Although rugby is a popular contact sport and the isokinetic muscle torque assessment has recently found widespread application in the field of sports medicine, little research has examined the factors associated with the performance of game-specific skills directly by using the isokinetic-type rugby scrimmaging machine. This study is designed to (a) measure and observe the differences in the maximum individual pushing forward force produced by scrimmaging in different body postures (3 body heights x 2 foot positions) with a self-developed rugby scrimmaging machine and (b) observe the variations in hip, knee, and ankle angles at different body postures and explore the relationship between these angle values and the individual maximum pushing force. Ten national rugby players were invited to participate in the examination. The experimental equipment included a self-developed rugby scrimmaging machine and a 3-dimensional motion analysis system. Our results showed that the foot positions (parallel and nonparallel foot positions) do not affect the maximum pushing force; however, the maximum pushing force was significantly lower in posture I (36% body height) than in posture II (38%) and posture III (40%). The maximum forward force in posture III (40% body height) was also slightly greater than for the scrum in posture II (38% body height). In addition, it was determined that hip, knee, and ankle angles under parallel feet positioning are factors that are closely negatively related in terms of affecting maximum pushing force in scrimmaging. In cross-feet postures, there was a positive correlation between individual forward force and hip angle of the rear leg. From our results, we can conclude that if the player stands in an appropriate starting position at the early stage of scrimmaging, it will benefit the forward force production.

ATLAS@Home: Harnessing Volunteer Computing for HEP

NASA Astrophysics Data System (ADS)

Adam-Bourdarios, C.; Cameron, D.; Filipčič, A.; Lancon, E.; Wu, W.; ATLAS Collaboration

2015-12-01

A recent common theme among HEP computing is exploitation of opportunistic resources in order to provide the maximum statistics possible for Monte Carlo simulation. Volunteer computing has been used over the last few years in many other scientific fields and by CERN itself to run simulations of the LHC beams. The ATLAS@Home project was started to allow volunteers to run simulations of collisions in the ATLAS detector. So far many thousands of members of the public have signed up to contribute their spare CPU cycles for ATLAS, and there is potential for volunteer computing to provide a significant fraction of ATLAS computing resources. Here we describe the design of the project, the lessons learned so far and the future plans.

Deep slip distribution and rupture directivity enhance shaking during the 2017 Mw 8.2 Chiapas earthquake

NASA Astrophysics Data System (ADS)

Chen, K.; Feng, W.; Liu, Z.; Song, T.

2017-12-01

As the largest intraplate normal faulting event ever recorded, the 2017 Mw 8.2 Mexico Chiapas earthquake is strongly felt as far as Mexico City that is almost 720 km northwest of the epicenter, causing tsunami with a maximum wave height of about six feet. In this contribution, we model this event by joint inversion of static GPS offsets, 1-Hz GPS displacement waveforms, InSAR observations and teleseismic P waves. To validate the preferred model determined from this study, we run tsunami simulation based on the synthetic sea floor deformation and compare it with tsunami records. Our results show that this earthquake took place near the "bending point" of subduction interface in SLAB 1.0, where seismic energy was accumulated. It propagated mainly unilaterally towards to the northwest of the epicenter at a relatively high speed ( 2.8 km/s), and at least two asperities were identified. The dominant one is centered at depth from 40 to 60 km while the second patch is relatively shallow at about 20 km depth. The peak slip is approximately 12 meters and the total released energy is 2.7e+21 Nm, equal to Mw 8.2. Note that the peak ground acceleration (PGA) recorded along the propagation direction is tens of times larger than that recorded in the opposite direction with nearly identical epicentral distances (about 700 km), and clear co-seismic dynamic displacement waveforms (up to 5 cm) are observed at a GPS station with 1450 km epicentral distance. Based on these preliminary results, we suggest that the deep slip in the low attenuation mantle and rupture directivity may contribute to the nationwide ground shaking, and the shallow slip induces evident vertical surface displacements, which amplify local tsunami heights. Keywords: Chiapas earthquake, joint inversion, tsunami, rupture directivity

Physical modeling of long-wave run-up mitigation using submerged breakwaters

NASA Astrophysics Data System (ADS)

Lee, Yu-Ting; Wu, Yun-Ta; Hwung, Hwung-Hweng; Yang, Ray-Yeng

2016-04-01

Natural hazard due to tsunami inundation inland has been viewed as a crucial issue for coastal engineering community. The 2004 India Ocean tsunami and the 2011 Tohoku earthquake tsunami were caused by mega scale earthquakes that brought tremendous catastrophe in the disaster regions. It is thus of great importance to develop innovative approach to achieve the reduction and mitigation of tsunami hazards. In this study, new experiments have been carried out in a laboratory-scale to investigate the physical process of long-wave through submerged breakwaters built upon a mild slope. Solitary-wave is employed to represent the characteristic of long-wave with infinite wavelength and wave period. Our goal is twofold. First of all, through changing the positions of single breakwater and multiple breakwaters upon a mild slope, the optimal locations of breakwaters can be pointed out by means of maximum run-up reduction. Secondly, through using a state-of-the-art measuring technique Bubble Image Velocimetry, which features non-intrusive and image-based measurement, the wave kinematics in the highly aerated region due to solitary-wave shoaling, breaking and uprush can be quantitated. Therefore, the mitigation of long-wave due to the construction of submerged breakwaters built upon a mild slope can be evaluated not only for imaging run-up and run-down characteristics but also for measuring turbulent velocity fields due to breaking wave. Although we understand the most devastating tsunami hazards cannot be fully mitigated with impossibility, this study is to provide quantitated information on what kind of artificial coastal structure that can withstand which level of wave loads.

Kinematic classification of iliotibial band syndrome in runners.

PubMed

Grau, S; Krauss, I; Maiwald, C; Axmann, D; Horstmann, T; Best, R

2011-04-01

Several inconsistent causative biomechanical factors are considered to be crucial in the occurrence of iliotibial band syndrome (ITBS). The focus of this study was on assessing differences in the kinematic characteristics between healthy runners [control group (CO)] and runners with ITBS in order to recommend treatment strategies to deal with this injury. Three-dimensional kinematics of barefoot running was used in the biomechanical setup. Both groups were matched with respect to gender, height and weight. After determining drop outs, the final population comprised 36 subjects (26 male and 10 female): 18 CO and 18 ITBS (13 male and five female, each). Kinematic evaluations indicate less hip adduction and frontal range of motion at the hip joint in runners with ITBS. Furthermore, maximum hip flexion velocity and maximum knee flexion velocity were lower in runners with ITBS. Lack of joint coordination, expressed as earlier hip flexion and a tendency toward earlier knee flexion, was found to be another discriminating variable in subjects with ITBS compared with CO subjects. We assume that an increase in range of motion at the hip joint, stretching of the hip abductors, as well as stretching the hamstrings, calf muscles and hip flexors will help treat ITBS. © 2009 John Wiley & Sons A/S.

Physiological consequences of military high-speed boat transits.

PubMed

Myers, Stephen D; Dobbins, Trevor D; King, Stuart; Hall, Benjamin; Ayling, Ruth M; Holmes, Sharon R; Gunston, Tom; Dyson, Rosemary

2011-09-01

The purpose of this study was to investigate the consequences of a high-speed boat transit on physical performance. Twenty-four Royal Marines were randomly assigned to a control (CON) or transit (TRAN) group. The CON group sat onshore for 3 h whilst the TRAN group completed a 3-h transit in open-boats running side-by-side, at 40 knots in moderate-to-rough seas, with boat deck and seat-pan acceleration recorded. Performance tests (exhaustive shuttle-run, handgrip, vertical-jump, push-up) were completed pre- and immediately post-transit/sit, with peak heart rate (HRpeak) and rating of perceived exertion (RPE) recorded. Serial blood samples (pre, 24, 36, 48, 72 h) were analyzed for creatine kinase (CK) activity. The transit was typified by frequent high shock impacts, but moderate mean heart rates (<45% HRpeak). The TRAN group post-transit run distance (-219 m, P < 0.01) and vertical-jump height (5%, P < 0.05) were reduced, the CON group showed no change. The TRAN group post-transit test RPE increased (P < 0.05), however, HRpeak was similar for each group (98%). Post-transit CK activity increased in the TRAN group up to 72 h (P < 0.01) and also, but less markedly, in the CON group (24 and 48 h, P < 0.05). Post-transit run and jump performances were reduced despite mean transit heart rates indicating low energy expenditure. The greater TRAN CK activity suggests muscle damage may have been a contributory factor. These findings have operational implications for Special Forces/naval/police/rescue services carrying out demanding, high-risk physical tasks during and immediately after high-speed boat transits.

The effect of recovery duration on running speed and stroke quality during intermittent training drills in elite tennis players.

PubMed

Ferrauti, A; Pluim, B M; Weber, K

2001-04-01

The aim of this study was to assess the effect of the recovery duration in intermittent training drills on metabolism and coordination in sport games. Ten nationally ranked male tennis players (age 25.3+/-3.7 years, height 1.83+/-0.8 m, body mass 77.8+/-7.7 kg; mean +/- sx) participated in a passing-shot drill (baseline sprint with subsequent passing shot) that aimed to improve both starting speed and stroke quality (speed and precision). Time pressure for stroke preparation was individually adjusted by a ball-machine and corresponded to 80% of maximum running speed. In two trials (T10, T15) separated by 2 weeks, the players completed 30 strokes and sprints subdivided into 6 x 5 repetitions with a 1 min rest between series. The rest between each stroke-and-sprint lasted either 10 s (T10) or 15 s (T15). The sequence of both conditions was randomized between participants. Post-exercise blood lactate concentration was significantly elevated in T10 (9.04+/-3.06 vs 5.01+/-1.35 mmol x l(-1), P < 0.01). Running time for stroke preparation (1.405+/-0.044 vs 1.376+/-0.045 s, P < 0.05) and stroke speed (106+/-12 vs 114+/-8 km x h(-1), P < 0.05) were significantly decreased in T10, while stroke precision - that is, more target hits (P < 0.1) and fewer errors (P < 0.05) - tended to be higher. We conclude that running speed and stroke quality during intermittent tennis drills are highly dependent on the duration of recovery time. Optimization of training efficacy in sport games (e.g. combined improvement of conditional and technical skills) requires skilful fine-tuning of monitoring guidelines.

Strength and Conditioning Training by the Danish National Handball Team Before an Olympic Tournament.

PubMed

Kvorning, Thue; Hansen, Mikkel R B; Jensen, Kurt

2017-07-01

Kvorning, T, Hansen, MRB, and Jensen, K. Strength and conditioning training by the Danish national handball team before an Olympic tournament. J Strength Cond Res 31(7): 1759-1765, 2017-The physical demands imposed on national team handball teams during the Olympics imply significant physical preparation to improve performance and reduce incidence of injuries. The purpose of this case report was to describe and analyze the strength and conditioning (S&C) training performed by the Danish national handball team before the Beijing Olympic Games. Eight weeks of S&C was divided into 5 weeks emphasizing muscle hypertrophy and long-interval running followed by 3 weeks emphasizing strength, power, and short-interval running. Body mass increased by 1.6% (p < 0.05), whereas body fat decreased by 1.0% (p < 0.05). No differences were seen in countermovement jump or jump-and-reach height (p > 0.05). Agility performance was evaluated by a T-test and improved by 2.5% (p < 0.05). Changes by 6% and 22% were seen in 1 repetition maximum (1RM) bench press and 1RM back squat, respectively. However, only the 1RM bench press increased significantly (p < 0.05). Running performance was tested by the Yo-Yo intermittent recovery test, level 2, and improved by 25% (p < 0.05). In conclusion, during 8 weeks of S&C training before the Beijing Olympics, body composition changed toward more muscle mass, better upper-body strength, better interval running, and agility performance, whereas no changes were seen in jumping or lower-body muscle strength. This case report may be used as a handy script for handball teams preparing for competition. Detailed and periodized S&C training programs for 8 weeks are provided and can be used by teams ranging from moderately to highly trained.

Tuning in to Another Person's Action Capabilities: Perceiving Maximal Jumping-Reach Height from Walking Kinematics

ERIC Educational Resources Information Center

Ramenzoni, Veronica; Riley, Michael A.; Davis, Tehran; Shockley, Kevin; Armstrong, Rachel

2008-01-01

Three experiments investigated the ability to perceive the maximum height to which another actor could jump to reach an object. Experiment 1 determined the accuracy of estimates for another actor's maximal reach-with-jump height and compared these estimates to estimates of the actor's standing maximal reaching height and to estimates of the…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maurer, K. D.; Bohrer, G.; Kenny, W. T.

Surface roughness parameters, namely the roughness length and displacement height, are an integral input used to model surface fluxes. However, most models assume these parameters to be a fixed property of plant functional type and disregard the governing structural heterogeneity and dynamics. In this study, we use large-eddy simulations to explore, in silico, the effects of canopy-structure characteristics on surface roughness parameters. We performed a virtual experiment to test the sensitivity of resolved surface roughness to four axes of canopy structure: (1) leaf area index, (2) the vertical profile of leaf density, (3) canopy height, and (4) canopy gap fraction.more » We found roughness parameters to be highly variable, but uncovered positive relationships between displacement height and maximum canopy height, aerodynamic canopy height and maximum canopy height and leaf area index, and eddy-penetration depth and gap fraction. We also found negative relationships between aerodynamic canopy height and gap fraction, as well as between eddy-penetration depth and maximum canopy height and leaf area index. We generalized our model results into a virtual "biometric" parameterization that relates roughness length and displacement height to canopy height, leaf area index, and gap fraction. Using a decade of wind and canopy-structure observations in a site in Michigan, we tested the effectiveness of our model-driven biometric parameterization approach in predicting the friction velocity over heterogeneous and disturbed canopies. We compared the accuracy of these predictions with the friction-velocity predictions obtained from the common simple approximation related to canopy height, the values calculated with large-eddy simulations of the explicit canopy structure as measured by airborne and ground-based lidar, two other parameterization approaches that utilize varying canopy-structure inputs, and the annual and decadal means of the surface roughness parameters at the site from meteorological observations. We found that the classical representation of constant roughness parameters (in space and time) as a fraction of canopy height performed relatively well. Nonetheless, of the approaches we tested, most of the empirical approaches that incorporate seasonal and interannual variation of roughness length and displacement height as a function of the dynamics of canopy structure produced more precise and less biased estimates for friction velocity than models with temporally invariable parameters.« less

Kinematics and Kinetics of Maximum Running Speed in Youth Across Maturity.

PubMed

Rumpf, Michael C; Cronin, John B; Oliver, Jonathan; Hughes, Michael

2015-05-01

Sprinting is an important physical capacity and the development of sprint ability can take place throughout the athlete's growth. The purpose of this study therefore was to determine if the kinematics and kinetics associated with maximum sprint velocity differs in male youth participants of different maturity status (pre, mid- and postpeak height velocity (PHV)) and if maximum sprint velocity is determined by age, maturity or individual body size measurement. Participants (n = 74) sprinted over 30 meters on a nonmotorized treadmill and the fastest four consecutive steps were analyzed. Pre-PHV participants were found to differ significantly (p < .05) to mid- and post-PHV participants in speed, step length, step frequency, vertical and horizontal force, and horizontal power (~8-78%). However, only relative vertical force and speed differed significantly between mid and post-PHV groups. The greatest average percent change in kinetics and kinematics was observed from pre- to mid-PHV (37.8%) compared with mid- to post- PHV groups (11.6%). When maturity offset was entered as a covariate, there was no significant difference in velocity between the three groups. However, all groups were significantly different from each other when age was chosen as the covariate. The two best predictors of maximal velocity within each maturity group were power and horizontal force (R2 = 97-99%) indicating the importance of horizontal force application while sprinting. Finally, maturity explained 83% of maximal velocity across all groups.

New imaging of submarine landslides from the 1964 earthquake near Whittier, Alaska, and a comparison to failures in other Alaskan fjords

USGS Publications Warehouse

Haeussler, Peter J.; Parsons, Thomas E.; Finlayson, David P.; Hart, Patrick J.; Chaytor, Jason D.; Ryan, Holly F; Lee, Homa J.; Labay, Keith A.; Peterson, Andrew; Liberty, Lee

2014-01-01

The 1964 Alaska M w 9.2 earthquake triggered numerous submarine slope failures in fjords of southern Alaska. These failures generated local tsunamis, such as at Whittier, where they inundated the town within 4 min of the beginning of shaking. Run-up was up to 32 m, with 13 casualties. We collected new multibeam bathymetry and high-resolution sparker seismic data in Passage Canal, and we examined bathymetry changes before and after the earthquake. The data reveal the debris flow deposit from the 1964 landslides, which covers the western 5 km of the fjord bottom. Individual blocks in the flow are up to 145-m wide and 25-m tall. Bathymetry changes show the mass transfer deposits originated from the fjord head and Whittier Creek deltas and had a volume of about 42 million m3. The 1964 deposit has an average thickness of ∼5.4 m. Beyond the debris flow, the failures likely deposited a ∼4.6-m thick megaturbidite in a distal basin. We have studied the 1964 submarine landslides in three fjords. All involved failure of the fjord-head delta. All failures eroded basin-floor sediments and incorporated them as they travelled. All the failures deposited blocks, but their size and travel distances varied greatly. We find a correlation between maximum block size and maximum tsunami run-up regardless of the volume of the slides. Lastly, the fjord’s margins were influenced by increased supply of glacial sediments during the little ice age, which along with a long interseismic interval (∼900 years) may have caused the 1964 earthquake to produce particularly numerous and large submarine landslides.

Features of tropospheric and stratospheric dust.

PubMed

Elterman, L; Wexler, R; Chang, D T

1969-05-01

A series of 119 profiles obtained over New Mexico comprise aerosol attenuation coefficients vs altitude to about 35 km. These profiles show the existence of several features. A surface convective dust layer extending up to about 5 km is seasonally dependent. Also, a turbidity maximum exists below the tropopause. The altitude of an aerosol maximum in the lower stratosphere is located just below that of the minimum temperature. The colder the minimum temperature, the greater is the aerosol content of the layer. This relationship suggests that the 20-km dust layer is due to convection in tropical air and advection to higher latitudes. Computed averages of optical thickness show that abatement of stratospheric dust from the Mt. Agung eruption became evident in April 1964. Results based on seventy-nine profiles characterizing volcanic dust abatement indicate that above 26 km, the aerosol scale height averages 3.75 km. Extrapolating with this scale height, tabulations are developed for uv, visible, and ir attenuation to 50 km. Optical mixing ratios are used to examine the aerosol concentrations at various altitudes, including a layer at 26 km having an optical thickness 10(-3) for 0.55-micro wavelength.

Direct Methods for Predicting Movement Biomechanics Based Upon Optimal Control Theory with Implementation in OpenSim.

PubMed

Porsa, Sina; Lin, Yi-Chung; Pandy, Marcus G

2016-08-01

The aim of this study was to compare the computational performances of two direct methods for solving large-scale, nonlinear, optimal control problems in human movement. Direct shooting and direct collocation were implemented on an 8-segment, 48-muscle model of the body (24 muscles on each side) to compute the optimal control solution for maximum-height jumping. Both algorithms were executed on a freely-available musculoskeletal modeling platform called OpenSim. Direct collocation converged to essentially the same optimal solution up to 249 times faster than direct shooting when the same initial guess was assumed (3.4 h of CPU time for direct collocation vs. 35.3 days for direct shooting). The model predictions were in good agreement with the time histories of joint angles, ground reaction forces and muscle activation patterns measured for subjects jumping to their maximum achievable heights. Both methods converged to essentially the same solution when started from the same initial guess, but computation time was sensitive to the initial guess assumed. Direct collocation demonstrates exceptional computational performance and is well suited to performing predictive simulations of movement using large-scale musculoskeletal models.

Air pollution potential: Regional study in Argentina

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gassmann, M.I.; Mazzeo, N.A.

2000-04-01

Air pollution potential is a measure of the atmospheric conditions that are unable to transport and dilute pollutants into the air, independently of the existence of sources. This potential can be determined from two atmospheric parameters; mixing height and transport wind. In this paper a statistical analysis of the mixing height and transport wind, in order to determine the areas with high or poor atmospheric ventilation in Argentina, is presented. In order to achieve this, meteorological data registered during 1979--1982 at eight meteorological stations were used. Daily values of the maximum mixing height were calculated from observations of daily temperaturesmore » at different heights and maximum surface temperature. At the same time as the maximum mixing height, the values of the transport wind were determined from the surface windspeed and the characteristics of the ground in the surroundings of each meteorological station. The mean seasonal values for both parameters were obtained. Isopleths of the mean seasonal of the maximum mixing heights were drawn. The percentage of seasonal frequencies of poor ventilation conditions were calculated and the frequency isopleths were also drawn to determine areas with minor and major relative frequencies. It was found that the northeastern and central-eastern regions of Argentina had a high air pollution potential during the whole year. Unfavorable atmospheric ventilation conditions were also found in the central-western side of the country during the cold seasons (37.5% in autumn and 56.9% in winter). The region with the greatest atmospheric ventilation is located south of 40{degree}S, where the frequency of poor ventilation varies between 8.0% in summer and 10.8% in winter.« less

Projected changes, climate change signal, and uncertainties in the CMIP5-based projections of ocean surface wave heights

NASA Astrophysics Data System (ADS)

Wang, Xiaolan; Feng, Yang; Swail, Val R.

2016-04-01

Ocean surface waves can be major hazards in coastal and offshore activities. However, wave observations are available only at limited locations and cover only the recent few decades. Also, there exists very limited information on ocean wave behavior in response to climate change, because such information is not simulated in current global climate models. In a recent study, we used a multivariate regression model with lagged dependent variable to make statistical global projections of changes in significant wave heights (Hs) using mean sea level pressure (SLP) information from 20 CMIP5 climate models for the twenty-first century. The statistical model was calibrated and validated using the ERA-Interim reanalysis of Hs and SLP for the period 1981-2010. The results show Hs increases in the tropics (especially in the eastern tropical Pacific) and in southern hemisphere high-latitudes. Under the projected 2070-2099 climate condition of the RCP8.5 scenario, the occurrence frequency of the present-day one-in-10-year extreme wave heights is likely to double or triple in several coastal regions around the world (e.g., the Chilean coast, Gulf of Oman, Gulf of Bengal, Gulf of Mexico). More recently, we used the analysis of variance approaches to quantify the climate change signal and uncertainty in multi-model ensembles of statistical Hs simulations globally, which are based on the CMIP5 historical, RCP4.5 and RCP8.5 forcing scenario simulations of SLP. In a 4-model 3-run ensemble, the 4-model common signal of climate change is found to strengthen over time, as would be expected. For the historical followed by RCP8.5 scenario, the common signal in annual mean Hs is found to be significant over 16.6%, 55.0% and 82.2% of the area by year 2005, 2050 and 2099, respectively. For the annual maximum, the signal is much weaker. The signal is strongest in the eastern tropical Pacific, featuring significant increases in both the annual mean and maximum of Hs in this region. The climate model uncertainty (i.e., inter-model variability) is significant over 99.9% of the area; its magnitude is comparable to or greater than the climate change signal by 2099 over most areas, except in the eastern tropical Pacific where the signal is much larger. In a 20-model 2-scenario single-run ensemble of statistical Hs simulations for the period 2006-2099, the model uncertainty is found to be significant globally; it is about 10 times as large as the scenario uncertainty between RCP4.5 and RCP8.5 scenarios.

Hydrodynamic characteristics of a novel annular spouted bed with multiple air nozzles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gong, X.W.; Hu, G.X.; Li, Y.H.

A novel spouted bed, namely, an annular spouted bed with multiple air nozzles, has been proposed for drying, pyrolysis, and gasification of coal particulates. It consists of two homocentric upright cylinders with some annularly located spouting air nozzles between inner and outer cylinders. Experiments have been performed to study hydrodynamic characteristics of this device. The test materials studied are ash particle, soy bean, and black bean. Three distinct spouting stages have been examined and outlined with the hold-ups increase. In the fully developed spouting stage, three flow behaviors of particles have been observed and delimited. The effects of nozzle modemore » and spouting velocity on the maximum spouting height of the dense-phase region, spoutable static bed height, and spouting pressure drop in the bed have been investigated experimentally.« less

Probabilistic tsunami hazard assessment for Makran considering recently suggested larger maximum magnitudes and sensitivity analysis for GNSS-based early warning

NASA Astrophysics Data System (ADS)

Zamora, N.; Hoechner, A.; Babeyko, A. Y.

2014-12-01

Iran and Pakistan are countries frequently affected by destructive earthquakes, as for instance, the magnitude 6.6 Bam earthquake in 2003 in Iran with about 30 000 casualties, or the magnitude 7.6 Kashmir earthquake 2005 in Pakistan with about 80'000 casualties. Both events took place inland, but in terms of magnitude, even significantly larger events can be expected to happen offshore, at the Makran subduction zone. This small subduction zone is seismically rather quiescent, nevertheless a tsunami caused by a thrust event in 1945 (Balochistan earthquake) led to about 4000 casualties. Nowadays, the coastal regions are more densely populated and vulnerable to similar events. Furthermore, some recent publications discuss the possiblity of rather rare huge magnitude 9 events at the Makran subduction zone. We analyze the seismicity at the subduction plate interface and generate various synthetic earthquake catalogs spanning 100000 years. All the events are projected onto the plate interface using scaling relations and a tsunami model is run for every scenario. The tsunami hazard along the coast is computed and presented in the form of annual probability of exceedance, probabilistic tsunami height for different time periods and other measures. We show how the hazard reacts to variation of the Gutenberg-Richter parameters and maximum magnitudes.We model the historic Balochistan event and its effect in terms of coastal wave heights. Finally, we show how an effective tsunami early warning could be achieved by using an array of high-precision real-time GNSS (Global Navigation Satellite System) receivers along the coast by applying it to the 1945 event and by performing a sensitivity analysis.

Effects of Whole-body Vibration Training on Sprint Running Kinematics and Explosive Strength Performance

PubMed Central

Giorgos, Paradisis; Elias, Zacharogiannis

2007-01-01

The aim of this study was to investigate the effect of 6 wk of whole body vibration (WBV) training on sprint running kinematics and explosive strength performance. Twenty-four volunteers (12 women and 12 men) participated in the study and were randomised (n = 12) into the experimental and control groups. The WBV group performed a 6-wk program (16-30 min·d-1, 3 times a week) on a vibration platform. The amplitude of the vibration platform was 2.5 mm and the acceleration was 2.28 g. The control group did not participate in any training. Tests were performed Pre and post the training period. Sprint running performance was measured during a 60 m sprint where running time, running speed, step length and step rate were calculated. Explosive strength performance was measured during a counter movement jump (CMJ) test, where jump height and total number of jumps performed in a period of 30 s (30CVJT). Performance in 10 m, 20 m, 40 m, 50 m and 60 m improved significantly after 6 wk of WBV training with an overall improvement of 2.7%. The step length and running speed improved by 5.1% and 3.6%, and the step rate decreased by 3.4%. The countermovement jump height increased by 3.3%, and the explosive strength endurance improved overall by 7.8%. The WBV training period of 6 wk produced significant changes in sprint running kinematics and explosive strength performance. Key pointsWBV training.Sprint running kinematics.Explosive strength performance PMID:24149223

Exercise economy in skiing and running

PubMed Central

Losnegard, Thomas; Schäfer, Daniela; Hallén, Jostein

2014-01-01

Substantial inter-individual variations in exercise economy exist even in highly trained endurance athletes. The variation is believed to be determined partly by intrinsic factors. Therefore, in the present study, we compared exercise economy in V2-skating, double poling, and uphill running. Ten highly trained male cross-country skiers (23 ± 3 years, 180 ± 6 cm, 75 ± 8 kg, VO2peak running: 76.3 ± 5.6 mL·kg−1·min−1) participated in the study. Exercise economy and VO2peak during treadmill running, ski skating (V2 technique) and double poling were compared based on correlation analysis. There was a very large correlation in exercise economy between V2-skating and double poling (r = 0.81) and large correlations between V2-skating and running (r = 0.53) and double poling and running (r = 0.58). There were trivial to moderate correlations between exercise economy and the intrinsic factors VO2peak (r = 0.00–0.23), cycle rate (r = 0.03–0.46), body mass (r = −0.09–0.46) and body height (r = 0.11–0.36). In conclusion, the inter-individual variation in exercise economy could be explained only moderately by differences in VO2peak, body mass and body height. Apparently other intrinsic factors contribute to the variation in exercise economy between highly trained subjects. PMID:24478718

Optimum Drop Jump Height in Division III Athletes: Under 75% of Vertical Jump Height.

PubMed

Peng, Hsien-Te; Khuat, Cong Toai; Kernozek, Thomas W; Wallace, Brian J; Lo, Shin-Liang; Song, Chen-Yi

2017-10-01

Our purpose was to evaluate the vertical ground reaction force, impulse, moments and powers of hip, knee and ankle joints, contact time, and jump height when performing a drop jump from different drop heights based on the percentage of a performer's maximum vertical jump height (MVJH). Fifteen male Division III athletes participated voluntarily. Eleven synchronized cameras and two force platforms were used to collect data. One-way repeated-measures analysis of variance tests were used to examine the differences between drop heights. The maximum hip, knee and ankle power absorption during 125%MVJH and 150%MVJH were greater than those during 75%MVJH. The impulse during landing at 100%MVJH, 125%MVJH and 150%MVJH were greater than 75%MVJH. The vertical ground reaction force during 150%MVJH was greater than 50%MVJH, 75%MVJH and 100%MVJH. Drop height below 75%MVJH had the most merits for increasing joint power output while having a lower impact force, impulse and joint power absorption. Drop height of 150%MVJH may not be desirable as a high-intensity stimulus due to the much greater impact force, increasing the risk of injury, without increasing jump height performance. © Georg Thieme Verlag KG Stuttgart · New York.

Evaluation of the wave measurement in a stormy sea by the Along-Track interferometry SAR

NASA Astrophysics Data System (ADS)

Kojima, S.

2015-12-01

NICT developed the along-track interferometry SAR (AT-InSAR) system to detect the running cars and ships and measure sea surface velocity in 2011. The preliminary experiments for the running truck and ship were performed and it confirmed that the system performance was satisfactory to its specifications. In addition, a method to estimate the wave height from the sea surface velocity measured by the AT-InSAR was developed. The preliminary wave height observation was performed in a calm sea, and it was confirmed that the wave height could be estimated from the measured sea surface velocity. The purpose of this study is to check the capability of the ocean waves observation in a stormy sea by the AT-InSAR. Therefore, the ocean wave observation was performed under the low atmospheric pressure. The observation area is the sea surface at 10 km off the coast of Kushiro, south-east to Hokaido, JAPAN on the 4th of March 2015. The wind speed was 8〜10m/s during the observation, and the significant wave height and period were 1.5m and 6.0s. The observation was performed in 2 directions and the accuracy of the estimation results were checked. The significant wave height and period measured by the AT-InSAR agreed with it measured by the wave gage located close to this observation area. In addition, it was confirmed that there were no irregular wave heights in the distribution of the estimated wave height. As a result, it became clear that the AT-InSAR could observe the wave height in a stormy sea.

The behavior of the radar parameters of cumulonimbus clouds during cloud seeding with AgI

NASA Astrophysics Data System (ADS)

Vujović, D.; Protić, M.

2017-06-01

Deep convection yielding severe weather phenomena (hail, flash floods, thunder) is frequent in Serbia during the warmer part of the year, i.e. April to September. As an effort to mitigate any potential damage to material goods, agricultural crops and vegetation from larger hailstones, cloud seeding is performed. In this paper, we analyzed 29 severe hailstorms seeded by silver iodide. From these, we chose five intense summer thunderstorm cells to analyze in detail the influence of silver-iodide cloud seeding on the radar parameters. Four of them were seeded and one was not. We also used data from firing stations (hail fall occurrence, the size of the hailstones). The most sensitive radar parameter in seeding was the height where maximum reflectivity in the cloud was observed. Its cascade appeared in every case of seeding, but was absent from the non-seeded case. In the case of the supercell, increase and decrease of the height where maximum reflectivity in the cloud was observed occurred in almost regular intervals, 12 to 15 min. The most inert parameter in seeding was maximum radar reflectivity. It changed one to two dBz during one cycle. The height of the top of the cloud and the height of the zone exhibiting enhanced radar echo both had similar behavior. It seems that both increased after seeding due to a dynamic effect: upward currents increasing due to the release of latent heat during the freezing of supercooled droplets. Mean values of the height where maximum reflectivity in the cloud was observed, the height of the top of the cloud and the height of the zone exhibiting enhanced radar echo during seeded period were greater than during unseeded period in 75.9%, 72.4% and 79.3% cases, respectively. This is because the values of the chosen storm parameters were higher when the seeding started, and then those values decreased after the seeded was conducted.

Effect of Running Speed and Leg Prostheses on Mediolateral Foot Placement and Its Variability

PubMed Central

Arellano, Christopher J.; McDermott, William J.; Kram, Rodger; Grabowski, Alena M.

2015-01-01

This study examined the effects of speed and leg prostheses on mediolateral (ML) foot placement and its variability in sprinters with and without transtibial amputations. We hypothesized that ML foot placement variability would: 1. increase with running speed up to maximum speed and 2. be symmetrical between the legs of non-amputee sprinters but asymmetrically greater for the affected leg of sprinters with a unilateral transtibial amputation. We measured the midline of the body (kinematic data) and center of pressure (kinetic data) in the ML direction while 12 non-amputee sprinters and 7 Paralympic sprinters with transtibial amputations (6 unilateral, 1 bilateral) ran across a range of speeds up to maximum speed on a high-speed force measuring treadmill. We quantified ML foot placement relative to the body’s midline and its variability. We interpret our results with respect to a hypothesized relation between ML foot placement variability and lateral balance. We infer that greater ML foot placement variability indicates greater challenges with maintaining lateral balance. In non-amputee sprinters, ML foot placement variability for each leg increased substantially and symmetrically across speed. In sprinters with a unilateral amputation, ML foot placement variability for the affected and unaffected leg also increased substantially, but was asymmetric across speeds. In general, ML foot placement variability for sprinters with a unilateral amputation was within the range observed in non-amputee sprinters. For the sprinter with bilateral amputations, both affected legs exhibited the greatest increase in ML foot placement variability with speed. Overall, we find that maintaining lateral balance becomes increasingly challenging at faster speeds up to maximum speed but was equally challenging for sprinters with and without a unilateral transtibial amputation. Finally, when compared to all other sprinters in our subject pool, maintaining lateral balance appears to be the most challenging for the Paralympic sprinter with bilateral transtibial amputations. PMID:25590634

Exospheric temperature and composition from satellite beacon measurements

NASA Technical Reports Server (NTRS)

Titheridge, J. E.

1974-01-01

Routine measurements of the slab thickness of the ionosphere, from 1965 to 1971, are used to infer the changes in neutral temperature and ion composition at a mean latitude of 40 S. Values of neutral temperature at solar maximum are 5 to 10% above Northern Hemisphere backscatter results. The diurnal and seasonal changes agree closely with satellite drag and backscatter measurements, except that the maximum temperature occurs after sunset in winter. Winter night-time values of the O(+)/H(+) transition height were 500 km in 1965-1966, 800 km in 1968-1969, and 700 km in 1971. Changes in the transition height lag about six months behind the changes in solar flux. Diurnal variations have a minimum just before sunrise and a maximum 1 to 3 hr after noon. On winter nights the transition height descends to the level set by chemical equilibrium. On summer nights the transition height is always above this level, giving a continual production of H(+) which serves as an additional source for maintaining the night-time ionosphere in the winter hemisphere.

Modeling Caribbean tree stem diameters from tree height and crown width measurements

Treesearch

Thomas Brandeis; KaDonna Randolph; Mike Strub

2009-01-01

Regression models to predict diameter at breast height (DBH) as a function of tree height and maximum crown radius were developed for Caribbean forests based on data collected by the U.S. Forest Service in the Commonwealth of Puerto Rico and Territory of the U.S. Virgin Islands. The model predicting DBH from tree height fit reasonably well (R2 = 0.7110), with...

Sound-Intensity Feedback During Running Reduces Loading Rates and Impact Peak.

PubMed

Tate, Jeremiah J; Milner, Clare E

2017-08-01

Study Design Controlled laboratory study, within-session design. Background Gait retraining has been proposed as an effective intervention to reduce impact loading in runners at risk of stress fractures. Interventions that can be easily implemented in the clinic are needed. Objective To assess the immediate effects of sound-intensity feedback related to impact during running on vertical impact peak, peak vertical instantaneous loading rate, and vertical average loading rate. Methods Fourteen healthy, college-aged runners who ran at least 9.7 km/wk participated (4 male, 10 female; mean ± SD age, 23.7 ± 2.0 years; height, 1.67 ± 0.08 m; mass, 60.9 ± 8.7 kg). A decibel meter provided real-time sound-intensity feedback of treadmill running via an iPad application. Participants were asked to reduce the sound intensity of running while receiving continuous feedback for 15 minutes, while running at their self-selected preferred speed. Baseline and follow-up ground reaction force data were collected during overground running at participants' self-selected preferred running speed. Results Dependent t tests indicated a statistically significant reduction in vertical impact peak (1.56 BW to 1.13 BW, P≤.001), vertical instantaneous loading rate (95.48 BW/s to 62.79 BW/s, P = .001), and vertical average loading rate (69.09 BW/s to 43.91 BW/s, P≤.001) after gait retraining, compared to baseline. Conclusion The results of the current study support the use of sound-intensity feedback during treadmill running to immediately reduce loading rate and impact force. The transfer of within-session reductions in impact peak and loading rates to overground running was demonstrated. Decreases in loading were of comparable magnitude to those observed in other gait retraining methods. J Orthop Sports Phys Ther 2017;47(8):565-569. Epub 6 Jul 2017. doi:10.2519/jospt.2017.7275.

Task-level strategies for human sagittal-plane running maneuvers are consistent with robotic control policies.

PubMed

Qiao, Mu; Jindrich, Devin L

2012-01-01

The strategies that humans use to control unsteady locomotion are not well understood. A "spring-mass" template comprised of a point mass bouncing on a sprung leg can approximate both center of mass movements and ground reaction forces during running in humans and other animals. Legged robots that operate as bouncing, "spring-mass" systems can maintain stable motion using relatively simple, distributed feedback rules. We tested whether the changes to sagittal-plane movements during five running tasks involving active changes to running height, speed, and orientation were consistent with the rules used by bouncing robots to maintain stability. Changes to running height were associated with changes to leg force but not stance duration. To change speed, humans primarily used a "pogo stick" strategy, where speed changes were associated with adjustments to fore-aft foot placement, and not a "unicycle" strategy involving systematic changes to stance leg hip moment. However, hip moments were related to changes to body orientation and angular speed. Hip moments could be described with first order proportional-derivative relationship to trunk pitch. Overall, the task-level strategies used for body control in humans were consistent with the strategies employed by bouncing robots. Identification of these behavioral strategies could lead to a better understanding of the sensorimotor mechanisms that allow for effective unsteady locomotion.

National Program for Inspection of Non-Federal Dams, Wheeler Dam (NH 00028), Arlington Mill Reservoir, Merrimack River Basin, Salem, New Hampshire. Phase I Inspection Report.

DTIC Science & Technology

1978-08-01

dam is a concrete gravity dam with earth abutments. It is 730 ft. long and the maximum height of it is 54 ft. The dam is assessed to be in poor...concrete gravity dam with earth abutments constructed in 1920. Overall length is 730 feet and maximum height is 54 feet. The Spicket River flows 5...the Spillway Test flood is based on the estimated "Probable Maximum Flood" for the region ( greatest reasonably possible storm runoff), or fractions

Deck Wetness and Extreme Motions Experiments: An Investigation into Establishing Reliable Statistics for Rare Events

DTIC Science & Technology

1990-02-01

CAlA WACe Mns. b. Amalgamated for all tank runs: (1) Significant wave height and mdal period of achieved wave condition. (2) Mean And .S mortions...experimental conditions. It is impossible to set sa jndtrd run lengths for all experimental conditions and so a method should be developed to analyse the

Physical characteristics that predict involvement with the ball in recreational youth soccer.

PubMed

Ré, Alessandro H Nicolai; Cattuzzo, Maria Teresa; Henrique, Rafael Dos Santos; Stodden, David F

2016-09-01

This study examined the relative contribution of age, stage of puberty, anthropometric characteristics, health-related fitness, soccer-specific tests and match-related technical performance to variance in involvements with the ball during recreational 5-a-side small-sided (32 × 15 m) soccer matches. Using a cross-sectional design, 80 healthy male students (14.6 ± 0.5 years of age; range 13.6-15.4) who played soccer recreationally were randomly divided into 10 teams and played against each other. Measurements included height, body mass, pubertal status, health-related fitness (12-min walk/run test, standing long jump, 15-m sprint and sit-ups in 30 s), soccer-specific tests (kicking for speed, passing for accuracy and agility run with and without a ball), match-related technical performance (kicks, passes and dribbles) and involvements with the ball during matches. Forward multiple regression analysis revealed that cardiorespiratory fitness (12-min walk/run test) accounted for 36% of the variance in involvements with the ball. When agility with the ball (zigzag running) and power (standing long jump) were included among the predictors, the total explained variance increased to 62%. In conclusion, recreational adolescent players, regardless of their soccer-specific skills, may increase participation in soccer matches most through physical activities that promote improvement in cardiorespiratory fitness, muscle power and agility.

First Release of Gravimetric Geoid Model over Saudi Arabia Based on Terrestrial Gravity and GOCE Satellite Data: KSAG01

NASA Astrophysics Data System (ADS)

Alothman, A. O.; Elsaka, B.

2015-12-01

A new gravimetric quasi-geoid, known as KSAG0, has been developed recently by Remove-Compute-Restore techniques (RCR), provided by the GRAVSOFT software, using gravimetric free air anomalies. The terrestrial gravity data used in this computations are: 1145 gravity field anomalies observed by ARAMCO (Saudi Arabian Oil Company) and 2470 Gravity measurements from BGI (Bureau Gravimétrique International). The computations were carried out implementing the least squares collocation method through the RCR techniques. The KSAG01 is based on merging in addition to the terrestrial gravity observations, GOCE satellite model (Eigen-6C4) and global gravity model (EGM2008) have been utilized in the computations. The long, medium and short wavelength spectrum of the height anomalies were compensated from Eigen-6C4 and EGM2008 geoid models truncated up to Degree and order (d/o) up to 2190. KSAG01 geoid covers 100 per cent of the kingdom, with geoid heights range from - 37.513 m in the southeast to 23.183 m in the northwest of the country. The accuracy of the geoid is governed by the accuracy, distribution, and spacing of the observations. The standard deviation of the predicted geoid heights is 0.115 m, with maximum errors of about 0.612 m. The RMS of geoid noise ranges from 0.019 m to 0.04 m. Comparison of the predicted gravimetric geoid with EGM, GOCE, and GPS/Levelling geoids, reveals a considerable improvements of the quasi-geoid heights over Saudi Arabia.

First Release of Gravimetric Geoid Model over Saudi Arabia Based on Terrestrial Gravity and GOCE Satellite Data: KSAG01

NASA Astrophysics Data System (ADS)

Alothman, Abdulaziz; Elsaka, Basem

2016-04-01

A new gravimetric quasi-geoid, known as KSAG0, has been developed recently by Remove-Compute-Restore techniques (RCR), provided by the GRAVSOFT software, using gravimetric free air anomalies. The terrestrial gravity data used in this computations are: 1145 gravity field anomalies observed by ARAMCO (Saudi Arabian Oil Company) and 2470 Gravity measurements from BGI (Bureau Gravimétrique International). The computations were carried out implementing the least squares collocation method through the RCR techniques. The KSAG01 is based on merging in addition to the terrestrial gravity observations, GOCE satellite model (Eigen-6C4) and global gravity model (EGM2008) have been utilized in the computations. The long, medium and short wavelength spectrum of the height anomalies were compensated from Eigen-6C4 and EGM2008 geoid models truncated up to Degree and order (d/o) up to 2190. KSAG01 geoid covers 100 per cent of the kingdom, with geoid heights range from - 37.513 m in the southeast to 23.183 m in the northwest of the country. The accuracy of the geoid is governed by the accuracy, distribution, and spacing of the observations. The standard deviation of the predicted geoid heights is 0.115 m, with maximum errors of about 0.612 m. The RMS of geoid noise ranges from 0.019 m to 0.04 m. Comparison of the predicted gravimetric geoid with EGM, GOCE, and GPS/Levelling geoids, reveals a considerable improvements of the quasi-geoid heights over Saudi Arabia.

Effects of general, specific and combined warm-up on explosive muscular performance

PubMed Central

Henriquez–Olguín, C; Beltrán, AR; Ramírez, MA; Labarca, C; Cornejo, M; Álvarez, C; Ramírez-Campillo, R

2015-01-01

The purpose of this study was to compare the acute effects of general, specific and combined warm-up (WU) on explosive performance. Healthy male (n = 10) subjects participated in six WU protocols in a crossover randomized study design. Protocols were: passive rest (PR; 15 min of passive rest), running (Run; 5 min of running at 70% of maximum heart rate), stretching (STR; 5 min of static stretching exercise), jumping [Jump; 5 min of jumping exercises – 3x8 countermovement jumps (CMJ) and 3x8 drop jumps from 60 cm (DJ60)], and combined (COM; protocols Run+STR+Jump combined). Immediately before and after each WU, subjects were assessed for explosive concentric-only (i.e. squat jump – SJ), slow stretch-shortening cycle (i.e. CMJ), fast stretch-shortening cycle (i.e. DJ60) and contact time (CT) muscle performance. PR significantly reduced SJ performance (p =0.007). Run increased SJ (p =0.0001) and CMJ (p =0.002). STR increased CMJ (p =0.048). Specific WU (i.e. Jump) increased SJ (p =0.001), CMJ (p =0.028) and DJ60 (p =0.006) performance. COM increased CMJ performance (p =0.006). Jump was superior in SJ performance vs. PR (p =0.001). Jump reduced (p =0.03) CT in DJ60. In conclusion, general, specific and combined WU increase slow stretch-shortening cycle (SSC) muscle performance, but only specific WU increases fast SSC muscle performance. Therefore, to increase fast SSC performance, specific fast SSC muscle actions must be included during the WU. PMID:26060335

Morphological response of coastal dunes to a group of three typhoons on Pingtan Island, China

NASA Astrophysics Data System (ADS)

Yang, Lin; Dong, Yuxiang; Huang, Dequan

2018-06-01

Pingtan Island (Fujian, China) was severely impacted by a group of three typhoons in a sequence of Nepartak, Meranti, and Megi during the summer of 2016. Field investigations were conducted on the island before and after the typhoons using high-precision RTK GPS technology and surveying methods, and we analyzed the morphological responses of three types of coastal dunes (coastal foredunes, climbing dunes, and coastal sand sheets) to the typhoon group. The maximum height decrease among coastal foredunes was 2.89 m after the typhoon group landed; dune volume increased by 0.9%, and the windward side showed a slight height increase, whereas that of the slope crest and leeward slope were slightly lower than the values before the typhoon group landed. The maximum height decrease among climbing dunes was 1.43 m, and dune volume decreased slightly by 0.1%; the height change among climbing dunes differed in magnitude between sites. Among coastal sand sheets, the maximum height increase was 0.75 m, and dune volume increased by 1.5%; the height of frontal coastal sand sheets increased markedly as result of storm surge washover deposits, whereas the heights barely changed at the middle and trailing edges. The above results suggest that the typhoon group imposed significant morphological changes on coastal dunes. However, the features of morphological responses differed between the three types of coastal dunes studied, and also among dunes of the same type based on local characteristics. Furthermore, coastal dunes showed no cumulative effects in their responses to the typhoon group, despite the individual typhoon impacts on coastal dune morphology.

The Origin and Age of Scallop Floodplain Benches from Difficult Run, Fairfax County, Virginia.

NASA Astrophysics Data System (ADS)

Scamardo, J. E.; Pizzuto, J. E.; Skalak, K.; Benthem, A.

2015-12-01

Sediment is deposited within scallop-shaped erosional scarps that form between trees armoring the banks of Difficult Run, a suburban watershed with a forested riparian zone. These deposits create small (surface area 85 m2, volume 300 m3), low-lying floodplain landforms this group terms Scallop Floodplain Benches (SFB). It is hypothesized that SFB formed within the past couple decades initially forming as transversal accretion deposits and eventually gaining floodplain features dominated by vertical accretion. Stratigraphic data supports that SFB deposits begin laterally as sand and gravel bars approximately 100 cm thick, and continue to grow by vertical accretion of sand, silt, and clay. As a SFB reaches its maximum height, a distinctive levee develops adjacent to the channel, and fine-grained silt and clay are deposited behind the levee. Core samples to a depth of 118 cm and additional samples from an overbank event that occurred on June 20, 2015 were collected from one of two SFB on Difficult Run near Leesburg Pike. The grain size distribution was measured using a Coulter Counter and activities of Pb-210, Cs-137, and Be-7 were measured using High Purity Germanium Detectors. Cs-137 activities are relatively constant with depth without a well-defined peak, suggesting that the SFB was deposited after 1963. Be-7 is present in the recent flood deposits, but is absent below the surface, suggesting that the SFB deposits are at least several years old. Excess Pb-210 activities decrease exponentially with depth, and can be fit using the Constant Rate of Supply method to determine an average age of approximately 13.5 years for the SFB. The SFB is storing sediment at a rate of 27 tons/year, which is equal to 0.35% of the annual sediment load of Difficult Run, based on this average age. SFB appear to be a significant component of the sediment storage of Difficult Run and therefore should be considered in the sediment budget.

Current-wave spectra coupling project. Volume I. Hurricane fields and cross sections, surface winds and currents, significant waves and wave spectra for potential OTEC sites: (A) Keahole Point, Hawaii, 100 year hurricane; (B) Punta Tuna, Puerto Rico, 100 year hurricane; (C) New Orleans, Louisiana, 100 year hurricane; (D) West Coast of Florida, 100 year hurricane; and for (E) Hurricane Camille (1969) off Louisiana Coast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bretschneider, C.L.

1980-06-01

This volume is an extension of and consists of several modifications to the earlier report by Bretschneider (April 1979) on the subject of hurricane design wind, wave and current criteria for the four potential OTEC sites. The 100-year hurricane criteria for the design of OTEC plants is included. The criteria, in addition to the maximum conditions of winds, waves and surface current, include: hurricane fields for wind speed U/sub s/ and significant wave height H/sub s/; hurricane fields for modal wave period f/sub 0//sup -1/ and maximum energy density S/sub max/ of the wave spectrum; the corresponding Ekman wind-driven surfacemore » current V/sub s/; tabulated cross-sections for U/sub s/, H/sub s/, f/sub 0//sup -1/ and S/sub max/ through max U/sub s/ and through max H/sub s/ along traverses at right angles to and along traverses parallel to the forward movement of the hurricane; most probable maximum wave height and the expected corresponding wave period, based on statistical analysis of maximum wave heights from five hurricanes; design wave spectra for maximum U/sub s/ and also maximum H/sub s/, since maximum U/sub s/ and maximum H/sub s/ do not occur simultaneously; the envelope of wave spectra through maximum U/sub s/ and through maximum H/sub s/ along traverses parallel to the forward movement of the hurricane; the above same determinations for Hurricane Camille (1969) as for the four OTEC locations; and alternative methods (suggested) for obtaining design wave spectra from the joint probability distribution functions for wave height and period given by Longuet-Higgins (1975) and C.N.E.X.O. after Arhan, et al (1976).« less

Relationship between Aerobic Capacity and Yo-Yo IR1 Performance in Brazilian Professional Futsal Players.

PubMed

Boullosa, Daniel A; Tonello, Lais; Ramos, Isabela; Silva, Alessandro de Oliveira; Simoes, Herbert G; Nakamura, Fabio Y

2013-09-01

To evaluate the relationship between aerobic and intermittent capacities in a team of professional futsal players. FIFTEEN FUTSAL PLAYERS FROM BRAZILIAN FIRST DIVISION (AGE: 25.9±5.1 yrs; height: 1.77±0.04 m, body mass: 74.37±6.02 kg) performed in random order a ramp test and the Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) at the start of the season for determination of maximum oxygen consumption (VO2max), peak running speed (Speak), and intermittent running ability. Mean VO2max was of 57.25±6.35 ml·kg(-1)min(-1) with a Speak of 17.69±1.88 km·h(-1). Yo-Yo IR1 performance was of 1,226±282 m. There was no correlation between VO2max and Yo-Yo performance while Speak and Yo-Yo IR1 performance were correlated (r=0.641; P=0.007). From the current results, it may be suggested that both continuous and intermittent physical evaluations are necessary for obtaining a complete fitness profile of futsal players. The low Yo-Yo IR1 performance of Brazilian futsal players when compared to other elite team sport athletes warrants further investigation.

Relationship between Aerobic Capacity and Yo-Yo IR1 Performance in Brazilian Professional Futsal Players

PubMed Central

Boullosa, Daniel A.; Tonello, Lais; Ramos, Isabela; Silva, Alessandro de Oliveira; Simoes, Herbert G.; Nakamura, Fabio Y.

2013-01-01

Purpose To evaluate the relationship between aerobic and intermittent capacities in a team of professional futsal players. Methods Fifteen futsal players from Brazilian first division (age: 25.9±5.1 yrs; height: 1.77±0.04 m, body mass: 74.37±6.02 kg) performed in random order a ramp test and the Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) at the start of the season for determination of maximum oxygen consumption (VO2max), peak running speed (Speak), and intermittent running ability. Results Mean VO2max was of 57.25±6.35 ml·kg-1min-1 with a Speak of 17.69±1.88 km·h-1. Yo-Yo IR1 performance was of 1,226±282 m. There was no correlation between VO2max and Yo-Yo performance while Speak and Yo-Yo IR1 performance were correlated (r=0.641; P=0.007). Conclusion From the current results, it may be suggested that both continuous and intermittent physical evaluations are necessary for obtaining a complete fitness profile of futsal players. The low Yo-Yo IR1 performance of Brazilian futsal players when compared to other elite team sport athletes warrants further investigation. PMID:24427483

Acute Lower Extremity Running Kinematics After a Hamstring Stretch

PubMed Central

Davis Hammonds, Autumn L.; Laudner, Kevin G.; McCaw, Steve; McLoda, Todd A.

2012-01-01

Context: Limited passive hamstring flexibility might affect kinematics, performance, and injury risk during running. Pre-activity static straight-leg raise stretching often is used to gain passive hamstring flexibility. Objective: To investigate the acute effects of a single session of passive hamstring stretching on pelvic, hip, and knee kinematics during the swing phase of running. Design: Randomized controlled clinical trial. Setting: Biomechanics research laboratory. Patients or Other Participants: Thirty-four male (age = 21.2 ± 1.4 years) and female (age = 21.3±2.0 years) recreational athletes. Intervention(s): Participants performed treadmill running pretests and posttests at 70% of their age-predicted maximum heart rate. Pelvis, hip, and knee joint angles during the swing phase of 5 consecutive gait cycles were collected using a motion analysis system. Right and left hamstrings of the intervention group participants were passively stretched 3 times for 30 seconds in random order immediately after the pretest. Control group participants performed no stretching or movement between running sessions. Main Outcome Measure(s): Six 2-way analyses of variance to determine joint angle differences between groups at maximum hip flexion and maximum knee extension with an α level of .008. Results: Flexibility increased between pretest and post-test in all participants (F1,30 = 80.61, P<.001). Anterior pelvic tilt (F1,30 = 0.73, P=.40), hip flexion (F1,30 = 2.44, P=.13), and knee extension (F1,30 = 0.06, P=.80) at maximum hip flexion were similar between groups throughout testing. Anterior pelvic tilt (F1,30 = 0.69, P=.41), hip flexion (F1,30 = 0.23, P=.64), and knee extension (F1,30 = 3.38, P=.62) at maximum knee extension were similar between groups throughout testing. Men demonstrated greater anterior pelvic tilt than women at maximum knee extension (F1,30 = 13.62, P=.001). Conclusions: A single session of 3 straight-leg raise hamstring stretches did not change pelvis, hip, or knee running kinematics. PMID:22488225

Dynamic traversal of high bumps and large gaps by a small legged robot

NASA Astrophysics Data System (ADS)

Gart, Sean; Winey, Nastasia; de La Tijera Obert, Rafael; Li, Chen

Small animals encounter and negotiate diverse obstacles comparable in size or larger than themselves. In recent experiments, we found that cockroaches can dynamically traverse bumps up to 4 times hip height and gaps up to 1 body length. To better understand the physics that governs these locomotor transitions, we studied a small six-legged robot negotiating high bumps and large gaps and compared it to animal observations. We found that the robot was able to traverse bumps as large as 1 hip height and gaps as wide as 0.5 body length. For the bump, the robot often climbed over to traverse when initial body yaw was small, but was often deflected laterally and failed to traverse when initial body yaw was large. A simple locomotion energy landscape model explained these observations. For the gap, traversal probability decreased with gap width, which was well explained by a simple Lagrangian model of a forward-moving rigid body falling over the gap edge. For both the bump and the gap, animal performance far exceeded that of the robot, likely due to their relatively higher running speeds and larger rotational oscillations prior to and during obstacle traversal. Differences between animal and robot obstacle negotiation behaviors revealed that animals used active strategies to overcome potential energy barriers.

Roles of Urban Tree Canopy and Buildings in Urban Heat Island Effects: Parameterization and Preliminary Results

NASA Technical Reports Server (NTRS)

Loughner, Christopher P.; Allen, Dale J.; Zhang, Da-Lin; Pickering, Kenneth E.; Dickerson, Russell R.; Landry, Laura

2012-01-01

Urban heat island (UHI) effects can strengthen heat waves and air pollution episodes. In this study, the dampening impact of urban trees on the UHI during an extreme heat wave in the Washington, D.C., and Baltimore, Maryland, metropolitan area is examined by incorporating trees, soil, and grass into the coupled Weather Research and Forecasting model and an urban canopy model (WRF-UCM). By parameterizing the effects of these natural surfaces alongside roadways and buildings, the modified WRF-UCM is used to investigate how urban trees, soil, and grass dampen the UHI. The modified model was run with 50% tree cover over urban roads and a 10% decrease in the width of urban streets to make space for soil and grass alongside the roads and buildings. Results show that, averaged over all urban areas, the added vegetation decreases surface air temperature in urban street canyons by 4.1 K and road-surface and building-wall temperatures by 15.4 and 8.9 K, respectively, as a result of tree shading and evapotranspiration. These temperature changes propagate downwind and alter the temperature gradient associated with the Chesapeake Bay breeze and, therefore, alter the strength of the bay breeze. The impact of building height on the UHI shows that decreasing commercial building heights by 8 m and residential building heights by 2.5 m results in up to 0.4-K higher daytime surface and near-surface air temperatures because of less building shading and up to 1.2-K lower nighttime temperatures because of less longwave radiative trapping in urban street canyons.

Formation, distribution and variability in snow cover on the Asian territory of the USSR

NASA Technical Reports Server (NTRS)

Pupkov, V. N.

1985-01-01

A description is given of maps compiled for annual and average multiple-year water reserves. The annual and average multiple-year maximum snow cover height for winter, extreme values of maximum snow reserves, and the average height and snow reserves at the end of each decade are shown. These maps were made for the entire Asian territory of the USSR, excluding Central Asia, Kamchatka Peninsula, and the Sakhalin Islands.

Determination of contact angle from the maximum height of enlarged drops on solid surfaces

NASA Astrophysics Data System (ADS)

Behroozi, F.

2012-04-01

Measurement of the liquid/solid contact angle provides useful information on the wetting properties of fluids. In 1870, the German physicist Georg Hermann Quincke (1834-1924) published the functional relation between the maximum height of an enlarged drop and its contact angle. Quincke's relation offered an alternative to the direct measurement of contact angle, which in practice suffers from several experimental uncertainties. In this paper, we review Quincke's original derivation and show that it is based on a hidden assumption. We then present a new derivation that exposes this assumption and clarifies the conditions under which Quincke's relation is valid. To explore Quincke's relation experimentally, we measure the maximum height of enlarged water drops on several substrates and calculate the contact angle in each case. Our results are in good agreement with contact angles measured directly from droplet images.

Combined effects of total grain-size distribution and crosswind on the rise of eruptive volcanic columns

NASA Astrophysics Data System (ADS)

Girault, F.; Carazzo, G.; Tait, S.; Kaminski, E.

2016-10-01

The maximum height of an explosive volcanic column, H, depends on the 1/4th power of the eruptive mass flux, Q, and on the 3/4th power of the stratification of the atmosphere, N. Expressed as scaling laws, this relationship has made H a widely used proxy to estimate Q. Two additional effects are usually included to produce more accurate and robust estimates of Q based on H: particle sedimentation from the volcanic column, which depends on the total grain-size distribution (TGSD) and the atmospheric crosswind. Both coarse TGSD and strong crosswind have been shown to decrease strongly the maximum column height, and TGSD, which also controls the effective gas content in the column, influences the stability of the column. However, the impact of TGSD and of crosswind on the dynamics of the volcanic column are commonly considered independently. We propose here a steady-state 1D model of an explosive volcanic column rising in a windy atmosphere that explicitly accounts for particle sedimentation and wind together. We consider three typical wind profiles: uniform, linear, and complex, with the same maximum wind velocity of 15 m s- 1. Subject to a uniform wind profile, the calculations show that the maximum height of the plume strongly decreases for any TGSD. The effect of TGSD on maximum height is smaller for uniform and complex wind profiles than for a linear profile or without wind. The largest differences of maximum heights arising from different wind profiles are observed for the largest source mass fluxes (> 107 kg s- 1) for a given TGSD. Compared to no wind conditions, the field of column collapse is reduced for any wind profile and TGSD at the vent, an effect that is the strongest for small mass fluxes and coarse TGSD. Provided that the maximum plume height and the wind profile are known from real-time observations, the model predicts the mass discharge rate feeding the eruption for a given TGSD. We apply our model to a set of eight historical volcanic eruptions for which all the required information is known. Taking into account the measured wind profile and the actual TGSD at the vent substantially improves (by ≈ 30%) the agreement between the mass discharge rate calculated from the model based on plume height and the field observation of deposit mass divided by eruption duration, relative to a model taking into account TGSD only. This study contributes to the improvement of the characterization of volcanic source term required as input to larger scale models of ash and aerosol dispersion.

Aneurysm Morphology and Prediction of Rupture: An International Study of Unruptured Intracranial Aneurysms Analysis.

PubMed

Mocco, J; Brown, Robert D; Torner, James C; Capuano, Ana W; Fargen, Kyle M; Raghavan, Madhavan L; Piepgras, David G; Meissner, Irene; Huston, John

2018-04-01

There are conflicting data between natural history studies suggesting a very low risk of rupture for small, unruptured intracranial aneurysms and retrospective studies that have identified a much higher frequency of small, ruptured aneurysms than expected. To use the prospective International Study of Unruptured Intracranial Aneurysms cohort to identify morphological characteristics predictive of unruptured intracranial aneurysm rupture. A case-control design was used to analyze morphological characteristics associated with aneurysm rupture in the International Study of Unruptured Intracranial Aneurysms database. Fifty-seven patients with ruptured aneurysms during follow-up were matched (by size and location) with 198 patients with unruptured intracranial aneurysms without rupture during follow-up. Twelve morphological metrics were measured from cerebral angiograms in a blinded fashion. Perpendicular height (P = .008) and size ratio (ratio of maximum diameter to the parent vessel diameter; P = .01) were predictors of aneurysm rupture on univariate analysis. Aspect ratio, daughter sacs, multiple lobes, aneurysm angle, neck diameter, parent vessel diameter, and calculated aneurysm volume were not statistically significant predictors of rupture. On multivariate analysis, perpendicular height was the only significant predictor of rupture (Chi-square 7.1, P-value .008). This study underscores the importance of other morphological factors, such as perpendicular height and size ratio, that may influence unruptured intracranial aneurysm rupture risk in addition to greatest diameter and anterior vs posterior location.

Evaluation of WRF-Predicted Near-Hub-Height Winds and Ramp Events over a Pacific Northwest Site with Complex Terrain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Qing; Berg, Larry K.; Pekour, Mikhail

The WRF model version 3.3 is used to simulate near hub-height winds and power ramps utilizing three commonly used planetary boundary-layer (PBL) schemes: Mellor-Yamada-Janjic (MYJ), University of Washington (UW), and Yonsei University (YSU). The predicted winds have small mean biases compared with observations. Power ramps and step changes (changes within an hour) consistently show that the UW scheme performed better in predicting up ramps under stable conditions with higher prediction accuracy and capture rates. Both YSU and UW scheme show good performance predicting up- and down- ramps under unstable conditions with YSU being slightly better for ramp durations longer thanmore » an hour. MYJ is the most successful simulating down-ramps under stable conditions. The high wind speed and large shear associated with low-level jets are frequently associated with power ramps, and the biases in predicted low-level jet explain some of the shown differences in ramp predictions among different PBL schemes. Low-level jets were observed as low as ~200 m in altitude over the Columbia Basin Wind Energy Study (CBWES) site, located in an area of complex terrain. The shear, low-level peak wind speeds, as well as the height of maximum wind speed are not well predicted. Model simulations with 3 PBL schemes show the largest variability among them under stable conditions.« less

Periodic spring-mass running over uneven terrain through feedforward control of landing conditions.

PubMed

Palmer, Luther R; Eaton, Caitrin E

2014-09-01

This work pursues a feedforward control algorithm for high-speed legged locomotion over uneven terrain. Being able to rapidly negotiate uneven terrain without visual or a priori information about the terrain will allow legged systems to be used in time-critical applications and alongside fast-moving humans or vehicles. The algorithm is shown here implemented on a spring-loaded inverted pendulum model in simulation, and can be configured to approach fixed running height over uneven terrain or self-stable terrain following. Offline search identifies unique landing conditions that achieve a desired apex height with a constant stride period over varying ground levels. Because the time between the apex and touchdown events is directly related to ground height, the landing conditions can be computed in real time as continuous functions of this falling time. Enforcing a constant stride period reduces the need for inertial sensing of the apex event, which is nontrivial for physical systems, and allows for clocked feedfoward control of the swing leg.

47 CFR 73.811 - LPFM power and antenna height requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false LPFM power and antenna height requirements. 73... SERVICES RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.811 LPFM power and antenna... operate with maximum facilities of 100 watts effective radiated power (ERP) at 30 meters antenna height...

47 CFR 73.811 - LPFM power and antenna height requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 4 2012-10-01 2012-10-01 false LPFM power and antenna height requirements. 73... SERVICES RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.811 LPFM power and antenna... operate with maximum facilities of 100 watts effective radiated power (ERP) at 30 meters antenna height...

47 CFR 90.205 - Power and antenna height limits.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 5 2012-10-01 2012-10-01 false Power and antenna height limits. 90.205 Section... SERVICES PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.205 Power and antenna height.... (d) 150-174 MHz. (1) The maximum allowable station ERP is dependent upon the station's antenna HAAT...

47 CFR 73.811 - LPFM power and antenna height requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false LPFM power and antenna height requirements. 73... SERVICES RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.811 LPFM power and antenna... operate with maximum facilities of 100 watts effective radiated power (ERP) at 30 meters antenna height...

47 CFR 90.205 - Power and antenna height limits.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Power and antenna height limits. 90.205 Section... SERVICES PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.205 Power and antenna height.... (d) 150-174 MHz. (1) The maximum allowable station ERP is dependent upon the station's antenna HAAT...

47 CFR 90.205 - Power and antenna height limits.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Power and antenna height limits. 90.205 Section... SERVICES PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.205 Power and antenna height.... (d) 150-174 MHz. (1) The maximum allowable station ERP is dependent upon the station's antenna HAAT...

47 CFR 90.205 - Power and antenna height limits.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 5 2013-10-01 2013-10-01 false Power and antenna height limits. 90.205 Section... SERVICES PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.205 Power and antenna height.... (d) 150-174 MHz. (1) The maximum allowable station ERP is dependent upon the station's antenna HAAT...

47 CFR 90.205 - Power and antenna height limits.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 5 2014-10-01 2014-10-01 false Power and antenna height limits. 90.205 Section... SERVICES PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.205 Power and antenna height.... (d) 150-174 MHz. (1) The maximum allowable station ERP is dependent upon the station's antenna HAAT...

Method to Determine Appropriate Source Models of Large Earthquakes Including Tsunami Earthquakes for Tsunami Early Warning in Central America

NASA Astrophysics Data System (ADS)

Tanioka, Yuichiro; Miranda, Greyving Jose Arguello; Gusman, Aditya Riadi; Fujii, Yushiro

2017-08-01

Large earthquakes, such as the Mw 7.7 1992 Nicaragua earthquake, have occurred off the Pacific coasts of El Salvador and Nicaragua in Central America and have generated distractive tsunamis along these coasts. It is necessary to determine appropriate fault models before large tsunamis hit the coast. In this study, first, fault parameters were estimated from the W-phase inversion, and then an appropriate fault model was determined from the fault parameters and scaling relationships with a depth dependent rigidity. The method was tested for four large earthquakes, the 1992 Nicaragua tsunami earthquake (Mw7.7), the 2001 El Salvador earthquake (Mw7.7), the 2004 El Astillero earthquake (Mw7.0), and the 2012 El Salvador-Nicaragua earthquake (Mw7.3), which occurred off El Salvador and Nicaragua in Central America. The tsunami numerical simulations were carried out from the determined fault models. We found that the observed tsunami heights, run-up heights, and inundation areas were reasonably well explained by the computed ones. Therefore, our method for tsunami early warning purpose should work to estimate a fault model which reproduces tsunami heights near the coast of El Salvador and Nicaragua due to large earthquakes in the subduction zone.

Impact of NGO run mid day meal program on nutrition status and growth of primary school children.

PubMed

Sharma, A K; Singh, Samiksha; Meena, Sonali; Kannan, A T

2010-07-01

To study the impact of wholesome mid day meal (MDM) program run by an NGO on the growth of the primary school students in rural area of Mathura district. This intervention study involved children enrolled in Government run rural primary schools in Mathura district in Uttar Pradesh from March 06 through August 07. A wholesome, nutritionally balanced MDM provided by an NGO for the students in the 6 primary schools was selected as intervention group. Control group consisted of children in 8 schools which received locally prepared MDM by village panchayats. Height, weight, change in height/month, change in weight/month, prevalence of protein-energy malnutrition and prevalence of signs of vitamin deficiencies, were measured. Food was provided for 221 days in one year. Within group and between groups repetitive measures were compared using generalized estimating equation (GEE). Within both intervention and control groups height and weight had significantly increased (p < 0.05), while there was no significant difference between the groups. There was no change in prevalence of malnutrition within either of the groups. Reduction in vitamin A deficiency signs was 38% more in intervention group (p < 0.001). Prevalence of Vitamin D deficiency reduced by 50% more in intervention group. No such differences between groups were observed for vitamin B complex and vitamin C. MDM provided by the NGO has no better impact on growth of the primary school children, however, it reduced prevalence of vitamin deficiency significantly in comparison to the MDM run by Village Panchayats.

Digital terrestrial photogrammetric methods for tree stem analysis

Treesearch

Neil A. Clark; Randolph H. Wynne; Daniel L. Schmoldt; Matt Winn

2000-01-01

A digital camera was used to measure diameters at various heights along the stem on 20 red oak trees. Diameter at breast height ranged from 16 to over 60 cm, and height to a 10-cm top ranged from 12 to 20 m. The chi-square maximum anticipated error of geometric mean diameter estimates at the 95 percent confidence level was within ±4 cm for all heights when...

Athletic Performance at the National Basketball Association Combine After Anterior Cruciate Ligament Reconstruction

PubMed Central

Mehran, Nima; Williams, Phillip N.; Keller, Robert A.; Khalil, Lafi S.; Lombardo, Stephen J.; Kharrazi, F. Daniel

2016-01-01

Background: Anterior cruciate ligament (ACL) injuries are significant injuries in elite-level basketball players. In-game statistical performance after ACL reconstruction has been demonstrated; however, few studies have reviewed functional performance in National Basketball Association (NBA)–caliber athletes after ACL reconstruction. Purpose: To compare NBA Combine performance of athletes after ACL reconstruction with an age-, size-, and position-matched control group of players with no previous reported knee injury requiring surgery. We hypothesized that there is no difference between the 2 groups in functional performance. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 1092 NBA-caliber players who participated in the NBA Combine between 2000 and 2015 were reviewed. Twenty-one athletes were identified as having primary ACL reconstruction prior to participation in the combine. This study group was compared with an age-, size-, and position-matched control group in objective functional performance testing, including the shuttle run test, lane agility test, three-quarter court sprint, vertical jump (no step), and maximum vertical jump (running start). Results: With regard to quickness and agility, both ACL-reconstructed athletes and controls scored an average of 11.5 seconds in the lane agility test and 3.1 seconds in the shuttle run test (P = .745 and .346, respectively). Speed and acceleration was measured by the three-quarter court sprint, in which both the study group and the control group averaged 3.3 seconds (P = .516). In the maximum vertical jump, which demonstrates an athlete’s jumping ability with a running start, the ACL reconstruction group had an average height of 33.6 inches while the controls averaged 33.9 inches (P = .548). In the standing vertical jump, the ACL reconstruction group averaged 28.2 inches while the control group averaged 29.2 inches (P = .067). Conclusion: In athletes who are able to return to sport and compete at a high level such as the NBA Combine, there is no significant difference in any combine performance test between players who have had primary ACL reconstruction compared with an age-, size-, and position-matched control group. Clinical Relevance: Athletes with previous ACL reconstruction who are able to return to high-level professional basketball have equivalent performance measures with regard to speed, quickness, and jumping ability as those athletes who have not undergone knee surgery. PMID:27294169

Athletic Performance at the National Basketball Association Combine After Anterior Cruciate Ligament Reconstruction.

PubMed

Mehran, Nima; Williams, Phillip N; Keller, Robert A; Khalil, Lafi S; Lombardo, Stephen J; Kharrazi, F Daniel

2016-05-01

Anterior cruciate ligament (ACL) injuries are significant injuries in elite-level basketball players. In-game statistical performance after ACL reconstruction has been demonstrated; however, few studies have reviewed functional performance in National Basketball Association (NBA)-caliber athletes after ACL reconstruction. To compare NBA Combine performance of athletes after ACL reconstruction with an age-, size-, and position-matched control group of players with no previous reported knee injury requiring surgery. We hypothesized that there is no difference between the 2 groups in functional performance. Cross-sectional study; Level of evidence, 3. A total of 1092 NBA-caliber players who participated in the NBA Combine between 2000 and 2015 were reviewed. Twenty-one athletes were identified as having primary ACL reconstruction prior to participation in the combine. This study group was compared with an age-, size-, and position-matched control group in objective functional performance testing, including the shuttle run test, lane agility test, three-quarter court sprint, vertical jump (no step), and maximum vertical jump (running start). With regard to quickness and agility, both ACL-reconstructed athletes and controls scored an average of 11.5 seconds in the lane agility test and 3.1 seconds in the shuttle run test (P = .745 and .346, respectively). Speed and acceleration was measured by the three-quarter court sprint, in which both the study group and the control group averaged 3.3 seconds (P = .516). In the maximum vertical jump, which demonstrates an athlete's jumping ability with a running start, the ACL reconstruction group had an average height of 33.6 inches while the controls averaged 33.9 inches (P = .548). In the standing vertical jump, the ACL reconstruction group averaged 28.2 inches while the control group averaged 29.2 inches (P = .067). In athletes who are able to return to sport and compete at a high level such as the NBA Combine, there is no significant difference in any combine performance test between players who have had primary ACL reconstruction compared with an age-, size-, and position-matched control group. Athletes with previous ACL reconstruction who are able to return to high-level professional basketball have equivalent performance measures with regard to speed, quickness, and jumping ability as those athletes who have not undergone knee surgery.

14 CFR 31.27 - Strength.

Code of Federal Regulations, 2012 CFR

2012-01-01

... drop test height of 36 inches, or a drop test height that produces, upon impact, a velocity equal to the maximum vertical velocity determined in accordance with § 31.19, whichever is higher, must be used...

14 CFR 31.27 - Strength.

Code of Federal Regulations, 2013 CFR

2013-01-01

... drop test height of 36 inches, or a drop test height that produces, upon impact, a velocity equal to the maximum vertical velocity determined in accordance with § 31.19, whichever is higher, must be used...

14 CFR 31.27 - Strength.

Code of Federal Regulations, 2014 CFR

2014-01-01

... drop test height of 36 inches, or a drop test height that produces, upon impact, a velocity equal to the maximum vertical velocity determined in accordance with § 31.19, whichever is higher, must be used...

Long-term statistics of extreme tsunami height at Crescent City

NASA Astrophysics Data System (ADS)

Dong, Sheng; Zhai, Jinjin; Tao, Shanshan

2017-06-01

Historically, Crescent City is one of the most vulnerable communities impacted by tsunamis along the west coast of the United States, largely attributed to its offshore geography. Trans-ocean tsunamis usually produce large wave runup at Crescent Harbor resulting in catastrophic damages, property loss and human death. How to determine the return values of tsunami height using relatively short-term observation data is of great significance to assess the tsunami hazards and improve engineering design along the coast of Crescent City. In the present study, the extreme tsunami heights observed along the coast of Crescent City from 1938 to 2015 are fitted using six different probabilistic distributions, namely, the Gumbel distribution, the Weibull distribution, the maximum entropy distribution, the lognormal distribution, the generalized extreme value distribution and the generalized Pareto distribution. The maximum likelihood method is applied to estimate the parameters of all above distributions. Both Kolmogorov-Smirnov test and root mean square error method are utilized for goodness-of-fit test and the better fitting distribution is selected. Assuming that the occurrence frequency of tsunami in each year follows the Poisson distribution, the Poisson compound extreme value distribution can be used to fit the annual maximum tsunami amplitude, and then the point and interval estimations of return tsunami heights are calculated for structural design. The results show that the Poisson compound extreme value distribution fits tsunami heights very well and is suitable to determine the return tsunami heights for coastal disaster prevention.

Comparing Run-Out Efficiency of Fluidized Ejecta on Mars with Terrestrial and Martian Mass Movements

NASA Technical Reports Server (NTRS)

Barnouin-Jha, O. S.; Baloga, S.

2003-01-01

We broadly characterize the rheology of fluidized ejecta on Mars as it flows during its final stages of emplacement by using the concept of run-out efficiency. Run-out efficiency for ejecta can be obtained through an energy balance between the kinetic energy of the excavated ejecta, and the total work lost during its deposition. Such an efficiency is directly comparable to run-out efficiency (i.e., L/H analyzes where L is the run-out distance and H is onset height) of terrestrial and extraterrestrial mass movements. Determination of the L/H ratio is commonly used in terrestrial geology to broadly determine the type and rheology of mass movements

The association between motor skill competence and physical fitness in young adults.

PubMed

Stodden, David; Langendorfer, Stephen; Roberton, Mary Ann

2009-06-01

We examined the relationship between competence in three fundamental motor skills (throwing kicking, and jumping) and six measures of health-related physical fitness in young adults (ages 18-25). We assessed motor skill competence using product scores of maximum kicking and throwing speed and maximum jumping distance. A factor analysis indicated the 12-min run/walk, percent body fat, curl-ups, grip strength, and maximum leg press strength all loaded on one factor defining the construct of "overall fitness. "Multiple regression analyses indicated that the product scores for jumping (74%), kicking (58%), and throwing (59%) predicted 79% of the variance in overall fitness. Gender was not a significant predictor of fitness. Results suggest that developing motor skill competence may be fundamental in developing and maintaining adequate physical fitness into adulthood. These data represent the strongest to date on the relationship between motor skill competence and physical fitness.

New-style defect inspection system of film

NASA Astrophysics Data System (ADS)

Liang, Yan; Liu, Wenyao; Liu, Ming; Lee, Ronggang

2002-09-01

An inspection system has been developed for on-line detection of film defects, which bases on combination of photoelectric imaging and digital image processing. The system runs in high speed of maximum 60m/min. Moving film is illuminated by LED array which emits even infrared (peak wavelength λp=940nm), and infrared images are obtained with a high quality and high speed CCD camera. The application software based on Visual C++6.0 under Windows processes images in real time by means of such algorithms as median filter, edge detection and projection, etc. The system is made up of four modules, which are introduced in detail in the paper. On-line experiment results shows that the inspection system can recognize defects precisely in high speed and run reliably in practical application.

Variations of Scale Height at F-Region Peak Based on Ionosonde Measurements during Solar Maximum over the Crest of Equatorial Ionization Anomaly Region

PubMed Central

Chuo, Yu-Jung

2014-01-01

Scale height is an important parameter in characterizing the shape of the ionosphere and its physical processes. In this study, we attempt to examine and discuss the variation of scale height, H m, around the F-layer peak height during high solar activity at the northern crest of the equatorial ionization anomaly (EIA) region. H m exhibits day-to-day variation and seasonal variation, with a greater average daily variation during daytime in summer. Furthermore, the diurnal variation of H m exhibits an abnormal peak at presunrise during all the seasons, particularly in winter. This increase is also observed in the F2-layer peak height for the same duration with an upward movement associated with thermospheric wind toward the equator; this upward movement increases the N2/O ratio and H m, but it causes a decrease in the F2-layer maximum critical frequency during the presunrise period. PMID:25162048

Update on Simulating Ice-Cliff Failure

NASA Astrophysics Data System (ADS)

Parizek, B. R.; Christianson, K. A.; Alley, R. B.; Voytenko, D.; Vankova, I.; Dixon, T. H.; Walker, R. T.; Holland, D.

2017-12-01

Using a 2D full-Stokes diagnostic ice-flow model and engineering and glaciological failure criteria, we simulate the limiting physical conditions for rapid structural failure of subaerial ice cliffs. Previously, using a higher-order flowline model, we reported that the threshold height, in crevassed ice and/or under favorable conditions for hydrofracture or crack lubrication, may be only slightly above the 100-m maximum observed today and that under well-drained or low-melt conditions, mechanically-competent ice supports cliff heights up to 220 m (with a likely range of 180-275 m) before ultimately succumbing to tensional and compressive failure along a listric surface. However, proximal to calving fronts, bridging effects lead to variations in vertical normal stress from the background glaciostatic stress state that give rise to the along-flow gradients in vertical shear stress that are included within a full-Stokes momentum balance. When including all flowline stresses within the physics core, diagnostic solutions continue to support our earlier findings that slumping failure ultimately limits the upper bound for cliff heights. Shear failure still requires low cohesive strength, tensile failure leads to deeper dry-crevasse propagation (albeit, less than halfway through the cliff), and compressive failure drops the threshold height for triggering rapid ice-front retreat via slumping to 200 m (145-280 m).

An early warning system for marine storm hazard mitigation

NASA Astrophysics Data System (ADS)

Vousdoukas, M. I.; Almeida, L. P.; Pacheco, A.; Ferreira, O.

2012-04-01

The present contribution presents efforts towards the development of an operational Early Warning System for storm hazard prediction and mitigation. The system consists of a calibrated nested-model train which consists of specially calibrated Wave Watch III, SWAN and XBeach models. The numerical simulations provide daily forecasts of the hydrodynamic conditions, morphological change and overtopping risk at the area of interest. The model predictions are processed by a 'translation' module which is based on site-specific Storm Impact Indicators (SIIs) (Ciavola et al., 2011, Storm impacts along European coastlines. Part 2: lessons learned from the MICORE project, Environmental Science & Policy, Vol 14), and warnings are issued when pre-defined threshold values are exceeded. For the present site the selected SIIs were (i) the maximum wave run-up height during the simulations; and (ii) the dune-foot horizontal retreat at the end of the simulations. Both SIIs and pre-defined thresholds were carefully selected on the grounds of existing experience and field data. Four risk levels were considered, each associated with an intervention approach, recommended to the responsible coastal protection authority. Regular updating of the topography/bathymetry is critical for the performance of the storm impact forecasting, especially when there are significant morphological changes. The system can be extended to other critical problems, like implications of global warming and adaptive management strategies, while the approach presently followed, from model calibration to the early warning system for storm hazard mitigation, can be applied to other sites worldwide, with minor adaptations.

Acute Effects of Stretching on Leg and Vertical Stiffness During Treadmill Running.

PubMed

Pappas, Panagiotis T; Paradisis, Giorgos P; Exell, Timothy A; Smirniotou, Athanasia S; Tsolakis, Charilaos K; Arampatzis, Adamantios

2017-12-01

Pappas, PT, Paradisis, GP, Exell, TA, Smirniotou, AS, Tsolakis, CK, and Arampatzis, A. Acute effects of stretching on leg and vertical stiffness during treadmill running. J Strength Cond Res 31(12): 3417-3424, 2017-The implementation of static (SS) and dynamic (DS) stretching during warm-up routines produces significant changes in biological and functional properties of the human musculoskeletal system. These properties could affect the leg and vertical stiffness characteristics that are considered important factors for the success of athletic activities. The aim of this study was to investigate the influence of SS and DS on selected kinematic variables, and leg and vertical stiffness during treadmill running. Fourteen men (age: 22.58 ± 1.05 years, height: 1.77 ± 0.05 m, body mass: 72.74 ± 10.04 kg) performed 30-second running bouts at 4.44 m·s, under 3 different stretching conditions (SS, DS, and no stretching). The total duration in each stretching condition was 6 minutes, and each of the 4 muscle groups was stretched for 40 seconds. Leg and vertical stiffness values were calculated using the "sine wave" method, with no significant differences in stiffness found between stretching conditions. After DS, vertical ground reaction force increased by 1.7% (p < 0.05), which resulted in significant (p < 0.05) increases in flight time (5.8%), step length (2.2%), and vertical displacement of the center of mass (4.5%) and a decrease in step rate (2.2%). Practical durations of SS and DS stretching did not influence leg or vertical stiffness during treadmill running. However, DS seems to result in a small increase in lower-limb force production which may influence running mechanics.

Large-eddy simulations of surface roughness parameter sensitivity to canopy-structure characteristics

DOE PAGES

Maurer, K. D.; Bohrer, G.; Kenny, W. T.; ...

2015-04-30

Surface roughness parameters, namely the roughness length and displacement height, are an integral input used to model surface fluxes. However, most models assume these parameters to be a fixed property of plant functional type and disregard the governing structural heterogeneity and dynamics. In this study, we use large-eddy simulations to explore, in silico, the effects of canopy-structure characteristics on surface roughness parameters. We performed a virtual experiment to test the sensitivity of resolved surface roughness to four axes of canopy structure: (1) leaf area index, (2) the vertical profile of leaf density, (3) canopy height, and (4) canopy gap fraction.more » We found roughness parameters to be highly variable, but uncovered positive relationships between displacement height and maximum canopy height, aerodynamic canopy height and maximum canopy height and leaf area index, and eddy-penetration depth and gap fraction. We also found negative relationships between aerodynamic canopy height and gap fraction, as well as between eddy-penetration depth and maximum canopy height and leaf area index. We generalized our model results into a virtual "biometric" parameterization that relates roughness length and displacement height to canopy height, leaf area index, and gap fraction. Using a decade of wind and canopy-structure observations in a site in Michigan, we tested the effectiveness of our model-driven biometric parameterization approach in predicting the friction velocity over heterogeneous and disturbed canopies. We compared the accuracy of these predictions with the friction-velocity predictions obtained from the common simple approximation related to canopy height, the values calculated with large-eddy simulations of the explicit canopy structure as measured by airborne and ground-based lidar, two other parameterization approaches that utilize varying canopy-structure inputs, and the annual and decadal means of the surface roughness parameters at the site from meteorological observations. We found that the classical representation of constant roughness parameters (in space and time) as a fraction of canopy height performed relatively well. Nonetheless, of the approaches we tested, most of the empirical approaches that incorporate seasonal and interannual variation of roughness length and displacement height as a function of the dynamics of canopy structure produced more precise and less biased estimates for friction velocity than models with temporally invariable parameters.« less

Large-eddy simulations of surface roughness parameter sensitivity to canopy-structure characteristics

NASA Astrophysics Data System (ADS)

Maurer, K. D.; Bohrer, G.; Kenny, W. T.; Ivanov, V. Y.

2015-04-01

Surface roughness parameters, namely the roughness length and displacement height, are an integral input used to model surface fluxes. However, most models assume these parameters to be a fixed property of plant functional type and disregard the governing structural heterogeneity and dynamics. In this study, we use large-eddy simulations to explore, in silico, the effects of canopy-structure characteristics on surface roughness parameters. We performed a virtual experiment to test the sensitivity of resolved surface roughness to four axes of canopy structure: (1) leaf area index, (2) the vertical profile of leaf density, (3) canopy height, and (4) canopy gap fraction. We found roughness parameters to be highly variable, but uncovered positive relationships between displacement height and maximum canopy height, aerodynamic canopy height and maximum canopy height and leaf area index, and eddy-penetration depth and gap fraction. We also found negative relationships between aerodynamic canopy height and gap fraction, as well as between eddy-penetration depth and maximum canopy height and leaf area index. We generalized our model results into a virtual "biometric" parameterization that relates roughness length and displacement height to canopy height, leaf area index, and gap fraction. Using a decade of wind and canopy-structure observations in a site in Michigan, we tested the effectiveness of our model-driven biometric parameterization approach in predicting the friction velocity over heterogeneous and disturbed canopies. We compared the accuracy of these predictions with the friction-velocity predictions obtained from the common simple approximation related to canopy height, the values calculated with large-eddy simulations of the explicit canopy structure as measured by airborne and ground-based lidar, two other parameterization approaches that utilize varying canopy-structure inputs, and the annual and decadal means of the surface roughness parameters at the site from meteorological observations. We found that the classical representation of constant roughness parameters (in space and time) as a fraction of canopy height performed relatively well. Nonetheless, of the approaches we tested, most of the empirical approaches that incorporate seasonal and interannual variation of roughness length and displacement height as a function of the dynamics of canopy structure produced more precise and less biased estimates for friction velocity than models with temporally invariable parameters.

Power spectra of mesospheric velocities in polar regions

NASA Technical Reports Server (NTRS)

Czechowsky, P.; Ruster, R.

1985-01-01

The mobile SOUSY radar was operated on Andoya in Northern Norway during the MAP/WINE campaign from November 1983 to February 1984 and for about two weeks in June 1984 to study the seasonal dependence of mesospheric structures and dynamics at polar latitudes. During the winter period, measurements were carried out on 57 days, primarily in coordination with the schedule of the rocket experiments. Echoes were detected in the troposphere and stratosphere up to 30 km and at mesospheric heights from about 50 to 90 km with a distinct maximum around noon. In summer, the radar system was operated continuously from 19th to the 28th of June 1984. Echoes occurred almost for 24 hours in the height range from 70 to 95 km showing no recognizable diurnal variation. Similar observations in polar latitudes were carried out for several years with the Poker Flat Radar in Alaska.

Spherical Harmonic-based Random Fields Based on Real Particle 3D Data: Improved Numerical Algorithm and Quantitative Comparison to Real Particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

X Liu; E Garboczi; m Grigoriu

Many parameters affect the cyclone efficiency, and these parameters can have different effects in different flow regimes. Therefore the maximum-efficiency cyclone length is a function of the specific geometry and operating conditions in use. In this study, we obtained a relationship describing the minimum particle diameter or maximum cyclone efficiency by using a theoretical approach based on cyclone geometry and fluid properties. We have compared the empirical predictions with corresponding literature data and observed good agreement. The results address the importance of fluid properties. Inlet and vortex finder cross-sections, cone-apex diameter, inlet Reynolds number and surface roughness are found tomore » be the other important parameters affecting cyclone height. The surface friction coefficient, on the other hand, is difficult to employ in the calculations.We developed a theoretical approach to find the maximum-efficiency heights for cyclones with tangential inlet and we suggested a relation for this height as a function of cyclone geometry and operating parameters. In order to generalize use of the relation, two dimensionless parameters, namely for geometric and operational variables, we defined and results were presented in graphical form such that one can calculate and enter the values of these dimensionless parameters and then can find the maximum efficiency height of his own specific cyclone.« less

SCALE UP OF CERAMIC WASTE FORMS FOR THE EBR-II SPENT FUEL TREATMENT PROCESS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthew C. Morrison; Kenneth J. Bateman; Michael F. Simpson

2010-11-01

ABSTRACT SCALE UP OF CERAMIC WASTE FORMS FOR THE EBR-II SPENT FUEL TREATMENT PROCESS Matthew C. Morrison, Kenneth J. Bateman, Michael F. Simpson Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415 The ceramic waste process is the intended method for disposing of waste salt electrolyte, which contains fission products from the fuel-processing electrorefiners (ER) at the INL. When mixed and processed with other materials, the waste salt can be stored in a durable ceramic waste form (CWF). The development of the CWF has recently progressed from small-scale testing and characterization to full-scale implementation and experimentation using surrogate materialsmore » in lieu of the ER electrolyte. Two full-scale (378 kg and 383 kg) CWF test runs have been successfully completed with final densities of 2.2 g/cm3 and 2.1 g/cm3, respectively. The purpose of the first CWF was to establish material preparation parameters. The emphasis of the second pre-qualification test run was to evaluate a preliminary multi-section CWF container design. Other considerations were to finalize material preparation parameters, measure the material height as it consolidates in the furnace, and identify when cracking occurs during the CWF cooldown process.« less

Rogue waves in shallow water

NASA Astrophysics Data System (ADS)

Soomere, T.

2010-07-01

Most of the processes resulting in the formation of unexpectedly high surface waves in deep water (such as dispersive and geometrical focusing, interactions with currents and internal waves, reflection from caustic areas, etc.) are active also in shallow areas. Only the mechanism of modulational instability is not active in finite depth conditions. Instead, wave amplification along certain coastal profiles and the drastic dependence of the run-up height on the incident wave shape may substantially contribute to the formation of rogue waves in the nearshore. A unique source of long-living rogue waves (that has no analogues in the deep ocean) is the nonlinear interaction of obliquely propagating solitary shallow-water waves and an equivalent mechanism of Mach reflection of waves from the coast. The characteristic features of these processes are (i) extreme amplification of the steepness of the wave fronts, (ii) change in the orientation of the largest wave crests compared with that of the counterparts and (iii) rapid displacement of the location of the extreme wave humps along the crests of the interacting waves. The presence of coasts raises a number of related questions such as the possibility of conversion of rogue waves into sneaker waves with extremely high run-up. Also, the reaction of bottom sediments and the entire coastal zone to the rogue waves may be drastic.

Combining low-cost GPS receivers with upGPR to derive continuously liquid water content, snow height and snow water equivalent in Alpine snow covers

NASA Astrophysics Data System (ADS)

Koch, Franziska; Schmid, Lino; Prasch, Monika; Heilig, Achim; Eisen, Olaf; Schweizer, Jürg; Mauser, Wolfram

2015-04-01

The temporal evolution of Alpine snowpacks is important for assessing water supply, hydropower generation, flood predictions and avalanche forecasts. Especially in high mountain regions with an extremely varying topography, it is until now often difficult to derive continuous and non-destructive information on snow parameters. Since autumn 2012, we are running a new low-cost GPS (Global Positioning System) snow measurement experiment at the high alpine study site Weissfluhjoch (2450 m a.s.l.) in Switzerland. The globally and freely broadcasted GPS L1-band (1.57542 GHz) was continuously recorded with GPS antennas, which are installed at the ground surface underneath the snowpack. GPS raw data, containing carrier-to-noise power density ratio (C/N0) as well as elevation and azimuth angle information for each time step of 1 s, was stored and analyzed for all 32 GPS satellites. Since the dielectric permittivity of an overlying wet snowpack influences microwave radiation, the bulk volumetric liquid water content as well as daily melt-freeze cycles can be derived non-destructively from GPS signal strength losses and external snow height information. This liquid water content information is qualitatively in good accordance with meteorological and snow-hydrological data and quantitatively highly agrees with continuous data derived from an upward-looking ground-penetrating radar (upGPR) working in a similar frequency range. As a promising novelty, we combined the GPS signal strength data with upGPR travel-time information of active impulse radar rays to the snow surface and back from underneath the snow cover. This combination allows determining liquid water content, snow height and snow water equivalent from beneath the snow cover without using any other external information. The snow parameters derived by combining upGPR and GPS data are in good agreement with conventional sensors as e.g. laser distance gauges or snow pillows. As the GPS sensors are cheap, they can easily be installed in parallel with further upGPR systems or as sensor networks to monitor the snowpack evolution in avalanche paths or at a larger scale in an entire hydrological basin to derive distributed melt-water runoff information.

Design and characteristics of MRF-based actuators for torque transmission under influence of high shear rates up to 34,000s-1

NASA Astrophysics Data System (ADS)

Güth, Dirk; Erbis, Vadim; Schamoni, Markus; Maas, Jürgen

2014-04-01

High rotational speeds for brakes and clutches based on magnetorheological fluids represent a remaining challenge for the industrial or automotive application. Beside particle centrifugation effects and rotational speed-depending no-load losses, the torque characteristic is an important property that needs to considered in the design process of actuators. Due to missing experimental data for these operating conditions, in this paper the shear rate and flux depending yield stress behavior of magnetorheological uids is experimentally investigated for high rotational speeds or respectively high shear rates. Therefore a brake actuator with variable shear gap heights up to 4 mm is designed, realized and used for the experimental investigation, which are performed for a maximum shear rate of ƴ= 34; 000 s-1 under large magnetic elds. The measurement results point out a strong dependency between shear rate, magnetic ux density and resulting yield stress. For low shear gap heights, a significant reduction in the yield stress up to 10 % can be determined. Additionally the development of Taylor vortices is determined, which will not only occur in viscous case without an applied magnetic field. The measurement results are important for a reliable actuator design which should be used in application with high rotational speeds.

Characteristics of youth soccer players aged 13–15 years classified by skill level

PubMed Central

Malina, Robert M; Ribeiro, Basil; Aroso, João; Cumming, Sean P

2007-01-01

Objective To evaluate the growth, maturity status and functional capacity of youth soccer players grouped by level of skill. Subjects The sample included 69 male players aged 13.2–15.1 years from clubs that competed in the highest division for their age group. Methods Height and body mass of players were measured and stage of pubic hair (PH) was assessed at clinical examination. Years of experience in football were obtained at interview. Three tests of functional capacity were administered: dash, vertical jump and endurance shuttle run. Performances on six soccer‐specific tests were converted to a composite score which was used to classify players into quintiles of skill. Multiple analysis of covariance, controlling for age, was used to test differences among skill groups in experience, growth status and functional capacity, whereas multiple linear regression analysis was used to estimate the relative contributions of age, years of training in soccer, stage of PH, height, body mass, the height×weight interaction and functional capacities to the composite skill score. Results The skill groups differed significantly in the intermittent endurance run (p<0.05) but not in the other variables. Only the difference between the highest and lowest skill groups in the endurance shuttle run was significant. Most players in the highest (12 of 14) and high (11 of 14) skill groups were in stages PH 4 and PH 5. Pubertal status and height accounted for 21% of the variance in the skill score; adding aerobic resistance to the regression increased the variance in skill accounted for to 29%. In both regressions, the coefficient for height was negative. Conclusion Adolescent soccer players aged 13–15 years classified by skill do not differ in age, experience, body size, speed and power, but differ in aerobic endurance, specifically at the extremes of skill. Stage of puberty and aerobic resistance (positive coefficients) and height (negative coefficient) are significant predictors of soccer skill (29% of the total explained variance), highlighting the inter‐relationship of growth, maturity and functional characteristics of youth soccer players. PMID:17224444

Treadmill based reference running data for healthy subjects is dependent on speed and morphological parameters.

PubMed

Schulze, Stephan; Schwesig, René; Edel, Melanie; Fieseler, Georg; Delank, Karl-Stefan; Hermassi, Souhail; Laudner, Kevin G

2017-10-01

To obtain spatiotemporal and dynamic running parameters of healthy participants and to identify relationships between running parameters, speed, and physical characteristics. A dynamometric treadmill was used to collect running data among 417 asymptomatic subjects during speeds ranging from 10 to 24km/h. Spatiotemporal and dynamic running parameters were calculated and measured. Results of the analyses showed that assessing running parameters is dependent on running speed. Body height correlated with stride length (r=0.5), cadence (r=-0.5) and plantar forefoot force (r=0.6). Body mass also had a strong relationship to plantar forefoot forces at 14 and 24km/h and plantar midfoot forces at 14 and 24km/h. This reference data base can be used in the kinematic and kinetic evaluation of running under a wide range of speeds. Copyright © 2017 Elsevier B.V. All rights reserved.

Biomechanics and running economy.

PubMed

Anderson, T

1996-08-01

Running economy, which has traditionally been measured as the oxygen cost of running at a given velocity, has been accepted as the physiological criterion for 'efficient' performance and has been identified as a critical element of overall distance running performance. There is an intuitive link between running mechanics and energy cost of running, but research to date has not established a clear mechanical profile of an economic runner. It appears that through training, individuals are able to integrate and accommodate their own unique combination of dimensions and mechanical characteristics so that they arrive at a running motion which is most economical for them. Information in the literature suggests that biomechanical factors are likely to contribute to better economy in any runner. A variety of anthropometric dimensions could influence biomechanical effectiveness. These include: average or slightly smaller than average height for men and slightly greater than average height for women; high ponderal index and ectomorphic or ectomesomorphic physique; low percentage body fat; leg morphology which distributes mass closer to the hip joint; narrow pelvis and smaller than average feet. Gait patterns, kinematics and the kinetics of running may also be related to running economy. These factors include: stride length which is freely chosen over considerable running time; low vertical oscillation of body centre of mass; more acute knee angle during swing; less range of motion but greater angular velocity of plantar flexion during toe-off; arm motion of smaller amplitude; low peak ground reaction forces; faster rotation of shoulders in the transverse plane; greater angular excursion of the hips and shoulders about the polar axis in the transverse plane; and effective exploitation of stored elastic energy. Other factors which may improve running economy are: lightweight but well-cushioned shoes; more comprehensive training history; and the running surface of intermediate compliance. At the developmental level, this information might be useful in identifying athletes with favourable characteristics for economical distance running. At higher levels of competition, it is likely that 'natural selection' tends to eliminate athletes who failed to either inherit or develop characteristics which favour economy.

14 CFR 23.75 - Landing distance.

Code of Federal Regulations, 2012 CFR

2012-01-01

... to the 50 foot height and— (1) The steady approach must be at a gradient of descent not greater than 5.2 percent (3 degrees) down to the 50-foot height. (2) In addition, an applicant may demonstrate by tests that a maximum steady approach gradient steeper than 5.2 percent, down to the 50-foot height, is...

14 CFR 23.75 - Landing distance.

Code of Federal Regulations, 2014 CFR

2014-01-01

... to the 50 foot height and— (1) The steady approach must be at a gradient of descent not greater than 5.2 percent (3 degrees) down to the 50-foot height. (2) In addition, an applicant may demonstrate by tests that a maximum steady approach gradient steeper than 5.2 percent, down to the 50-foot height, is...

14 CFR 23.75 - Landing distance.

Code of Federal Regulations, 2013 CFR

2013-01-01

... to the 50 foot height and— (1) The steady approach must be at a gradient of descent not greater than 5.2 percent (3 degrees) down to the 50-foot height. (2) In addition, an applicant may demonstrate by tests that a maximum steady approach gradient steeper than 5.2 percent, down to the 50-foot height, is...

Consequence assessment of large rock slope failures in Norway

NASA Astrophysics Data System (ADS)

Oppikofer, Thierry; Hermanns, Reginald L.; Horton, Pascal; Sandøy, Gro; Roberts, Nicholas J.; Jaboyedoff, Michel; Böhme, Martina; Yugsi Molina, Freddy X.

2014-05-01

Steep glacially carved valleys and fjords in Norway are prone to many landslide types, including large rockslides, rockfalls, and debris flows. Large rockslides and their secondary effects (rockslide-triggered displacement waves, inundation behind landslide dams and outburst floods from failure of landslide dams) pose a significant hazard to the population living in the valleys and along the fjords shoreline. The Geological Survey of Norway performs systematic mapping of unstable rock slopes in Norway and has detected more than 230 unstable slopes with significant postglacial deformation. This large number necessitates prioritisation of follow-up activities, such as more detailed investigations, periodic displacement measurements, continuous monitoring and early-warning systems. Prioritisation is achieved through a hazard and risk classification system, which has been developed by a panel of international and Norwegian experts (www.ngu.no/en-gb/hm/Publications/Reports/2012/2012-029). The risk classification system combines a qualitative hazard assessment with a consequences assessment focusing on potential life losses. The hazard assessment is based on a series of nine geomorphological, engineering geological and structural criteria, as well as displacement rates, past events and other signs of activity. We present a method for consequence assessment comprising four main steps: 1. computation of the volume of the unstable rock slope; 2. run-out assessment based on the volume-dependent angle of reach (Fahrböschung) or detailed numerical run-out modelling; 3. assessment of possible displacement wave propagation and run-up based on empirical relations or modelling in 2D or 3D; and 4. estimation of the number of persons exposed to rock avalanches or displacement waves. Volume computation of an unstable rock slope is based on the sloping local base level technique, which uses a digital elevation model to create a second-order curved surface between the mapped extent of the unstable rock slope. This surface represents the possible basal sliding surface of an unstable rock slope. The elevation difference between this surface and the topographic surface estimates the volume of the unstable rock slope. A tool has been developed for the present study to adapt the curvature parameters of the computed surface to local geological and structural conditions. The obtained volume is then used to define the angle of reach of a possible rock avalanche from the unstable rock slope by using empirical derived values of angle of reach vs. volume relations. Run-out area is calculated using FlowR; the software is widely used for run-out assessment of debris flows and is adapted here for assessment of rock avalanches, including their potential to ascend opposing slopes. Under certain conditions, more sophisticated and complex numerical run-out models are also used. For rock avalanches with potential to reach a fjord or a lake the propagation and run-up area of triggered displacement waves is assessed. Empirical relations of wave run-up height as a function of rock avalanche volume and distance from impact location are derived from a national and international inventory of landslide-triggered displacement waves. These empirical relations are used in first-level hazard assessment and where necessary, followed by 2D or 3D displacement wave modelling. Finally, the population exposed in the rock avalanche run-out area and in the run-up area of a possible displacement wave is assessed taking into account different population groups: inhabitants, persons in critical infrastructure (hospitals and other emergency services), persons in schools and kindergartens, persons at work or in shops, tourists, persons on ferries and so on. Exposure levels are defined for each population group and vulnerability values are set for the rock avalanche run-out area (100%) and the run-up area of a possible displacement wave (70%). Finally, the total number of persons within the hazard area is calculated taking into account exposure and vulnerability. The method for consequence assessment is currently tested through several case studies in Norway and, thereafter, applied to all unstable rock slopes in the country to assess their risk level. Follow-up activities (detailed investigations, periodic displacement measurements or continuous monitoring and early-warning systems) can then be prioritized based on the risk level and with a standard approach for whole Norway.

Investigation of internally finned LED heat sinks

NASA Astrophysics Data System (ADS)

Li, Bin; Xiong, Lun; Lai, Chuan; Tang, Yumei

2018-03-01

A novel heat sink is proposed, which is composed of a perforated cylinder and internally arranged fins. Numerical studies are performed on the natural convection heat transfer from internally finned heat sinks; experimental studies are carried out to validate the numerical results. To compare the thermal performances of internally finned heat sinks and externally finned heat sinks, the effects of the overall diameter, overall height, and installation direction on maximum temperature, air flow and heat transfer coefficient are investigated. The results demonstrate that internally finned heat sinks show better thermal performance than externally finned heat sinks; the maximum temperature of internally finned heat sinks decreases by up to 20% compared with the externally finned heat sinks. The existence of a perforated cylinder and the installation direction of the heat sink affect the thermal performance significantly; it is shown that the heat transfer coefficient of the heat sink with the perforated cylinder is improved greater than that with the imperforated cylinder by up to 34%, while reducing the mass of the heat sink by up to 13%. Project supported by the Scientific Research Fund of Sichuan Provincial Education Department (No. 18ZB0516) and the Sichuan University of Arts and Science (No. 2016KZ009Y).

Using leg muscles as shock absorbers: theoretical predictions and experimental results of drop landing performance.

PubMed

Minetti, A E; Ardigò, L P; Susta, D; Cotelli, F

1998-12-01

The use of muscles as power dissipators is investigated in this study, both from the modellistic and the experimental points of view. Theoretical predictions of the drop landing manoeuvre for a range of initial conditions have been obtained by accounting for the mechanical characteristics of knee extensor muscles, the limb geometry and assuming maximum neural activation. Resulting dynamics have been represented in the phase plane (vertical displacement versus speed) to better classify the damping performance. Predictions of safe landing in sedentary subjects were associated to dropping from a maximum (feet) height of 1.6-2.0 m (about 11 m on the moon). Athletes can extend up to 2.6-3.0 m, while for obese males (m = 100 kg, standard stature) the limit should reduce to 0.9-1.3 m. These results have been calculated by including in the model the estimated stiffness of the 'global elastic elements' acting below the squat position. Experimental landings from a height of 0.4, 0.7, 1.1 m (sedentary males (SM) and male (AM) and female (AF) athletes from the alpine ski national team) showed dynamics similar to the model predictions. While the peak power (for a drop height of about 0.7 m) was similar in SM and AF (AM shows a +40% increase, about 33 W/kg), AF stopped the downward movement after a time interval (0.219 +/- 0.030 s) from touch-down 20% significantly shorter than SM. Landing strategy and the effect of anatomical constraints are discussed in the paper.

Height unification using GOCE

NASA Astrophysics Data System (ADS)

Rummel, R.

2012-12-01

With the gravity field and steady-state ocean circulation explorer (GOCE) (preferably combined with the gravity field and climate experiment (GRACE)) a new generation of geoid models will become available for use in height determination. These models will be globally consistent, accurate (<3 cm) and with a spatial resolution up to degree and order 200, when expressed in terms of a spherical harmonic expansion. GOCE is a mission of the European Space Agency (ESA). It is the first satellite equipped with a gravitational gradiometer, in the case of GOCE it measures the gradient components Vxx , Vyy, Vzzand Vxz. The GOCE gravitational sensor system comprises also a geodetic global positioning system (GPS)-receiver, three star sensors and ion-thrusters for drag compensation in flight direction. GOCE was launched in March 2009 and will fly till the end of 2013. Several gravity models have been derived from its data, their maximum degree is typically between 240 and 250. In summer 2012 a first re-processing of all level-1b data took place. One of the science objectives of GOCE is the unification of height systems. The existing height offsets among the datum zones can be determined by least-squares adjustment. This requires several precise geodetic reference points available in each height datum zone, physical heights from spirit levelling (plus gravimetry), the GOCE geoid and, in addition, short wavelength geoid refinement from terrestrial gravity anomalies. GOCE allows for important simplifications of the functional and stochastic part of the adjustment model. The future trend will be the direct determination of physical heights (orthometric as well as normal) from precise global navigation satellite system (GNSS)-positioning in combination with a next generation combined satellite-terrestrial high-resolution geoid model.

Megatsunami of the World Ocean: Did They Occur in the Recent Past?

NASA Astrophysics Data System (ADS)

Abbott, D.; Bryant, T.; Gusiakov, V.; Masse, W.

2007-05-01

The comprehensive historical tsunami database collected at the Novosibirsk Tsunami Laboratory, contains data on more than 2250 historical tsunamis in the World Ocean from 1628 BC to present. Even if the historical data set is incomplete for many areas, especially for older times, the world catalog contains enough data to estimate average run-up heights for the largest seismically-induced tsunamis that caused wide-spread damage and many fatalities (1755 Lisbon, 1868 and 1877 Chile, 1952 Kamchatka, 1957 Aleutians, 1960 Chile, 1964 Alaska, 2005 Sumatra). This average run-up does not exceed 30-35 meters on the nearest coast with 10-12 meters at the distances of more than 5000 km. Somewhat larger waves (up to 40-45 m) can be generated by volcanic explosions followed by volcanic cone collapse (Santorini 1628 BC, Kuwae 1453, Unzen 1792, Tambora 1815, Krakatau 1883). Landslide-generated tsunamis have the largest recorded heights (up to 525 m) but normally these events are very local with a width of inundated area from hundreds of meters to several kilometers (1958, 1936, 1853 Lituya Bay, 1936 Norway, 2000 Greenland). Meanwhile, many parts of the World Ocean coastline contain prominent features of catastrophic impact of water currents and waves that came from the ocean. They are large boulders, weighing well above one hundred tons, lying on the top of vertical cliffs at the height up to 60 m and large vortexes cut-down in rather resistive coastal rocks. On a smaller scale, these features include sculptured bedrocks, grooves, canyons, cavettos and flutes, found in areas where hurricanes and severe tropical storms are not common. Sedimentary features of water impacts include mega-ripples found in the north-western Australia and so-called chevrons (parabolic and blade- like sand dunes) that are common along many parts of the Indian Ocean coast. In southern Madagascar, chevrons reach an altitude of 205 m with 30-45 km of in-land penetration. A high energy water flux of that scale could be generated by Storegga-class submarine landslides or Santorini-class volcanic explosions, but for this area does not have nearby active volcanoes or large sedimentary basins with the potential for large-volume submarine sliding. Not widely acknowledged presently, but still a real possibility is the creation of these coastal features by catastrophic oceanic waves generated by deep-water impacts of large comets or asteroids. In the Indian Ocean, several crater candidates (Burckle, Mahuika, Kukla, Christie) have been found recently by geomorphological analysis of detailed bathymetric maps. They are geologically young and analysis of nearby deep-sea cores shows the presence of some elements and minerals typical of oceanic impact structures. This paper discusses the consistency of these data with spatial and azimuthal distribution of the large-scale erosional and sedimentary features found at the Australian and Madagascar coast.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sommer, C. M., E-mail: christof.sommer@med.uni-heidelberg.de; Grenacher, L.; Stampfl, U.

The purpose of this study was to evaluate the impact of stent design on in-stent stenosis in rabbit iliac arteries. Four different types of stent were implanted in rabbit iliac arteries, being different in stent design (crown or wave) and strut thickness (50 or 100 {mu}m). Ten stents of each type were implanted. Each animal received one crown and one wave stent with the same strut thickness. Follow-up was either 12 weeks (n = 10 rabbits) or 24 weeks (n = 10 rabbits). Primary study end points were angiographic and microscopic in-stent stenosis. Secondary study end points were vessel injury,more » vascular inflammation, and stent endothelialization. Average stent diameter, relative stent overdilation, average and minimal luminal diameter, and relative average and maximum luminal loss were not significantly different. However, a trend to higher relative stent overdilation was recognized in crown stents compared to wave stents. A trend toward higher average and minimal luminal diameter and lower relative average and maximum luminal loss was recognized in crown stents compared to wave stents with a strut thickness of 100 {mu}m. Neointimal height, relative luminal area stenosis, injury score, inflammation score, and endothelialization score were not significantly different. However, a trend toward higher neointimal height was recognized in crown stents compared to wave stents with a strut thickness of 50 {mu}m and a follow-up of 24 weeks. In conclusion, in this study, crown stents seem to trigger neointima. However, the optimized radial force might equalize the theoretically higher tendency for restenosis in crown stents. In this context, also more favorable positive remodeling in crown stents could be important.« less

Mid-latitude empirical model of the height distribution of atomic oxygen in the MLT region for different solar and geophysical conditions

NASA Astrophysics Data System (ADS)

Semenov, A.; Shefov, N.; Fadel, Kh.

The model of altitude distributions of atomic oxygen in the region of the mesopause and lower thermosphere (MLT) is constructed on the basis of empirical models of variations of the intensities, temperatures and altitudes of maximum of the layers of the emissions of atomic oxygen at 557.7 nm, hydroxyl and Atmospheric system of molecular oxygen. An altitude concentration distribution of neutral components is determined on the basis of systematization of the long-term data of temperature of the middle atmosphere from rocket, nightglow and ionospheric measurements at heights of 30-110 km in middle latitudes. They include dependence on a season, solar activity and a long-term trend. Examples of results of calculation for different months of year for conditions of the lower and higher solar activity are presented. With increasing of solar activity, the height of a layer of a maximum of atomic oxygen becomes lower, and the thickness of the layer increases. There is a high correlation between characteristics of a layer of atomic oxygen and a maximum of temperature at heights of the mesopause and lower thermosphere. This work is supported by grant of ISTC No. 2274.

The relationship between tree height and leaf area: sapwood area ratio.

PubMed

McDowell, N; Barnard, H; Bond, B; Hinckley, T; Hubbard, R; Ishii, H; Köstner, B; Magnani, F; Marshall, J; Meinzer, F; Phillips, N; Ryan, M; Whitehead, D

2002-06-01

The leaf area to sapwood area ratio (A l :A s ) of trees has been hypothesized to decrease as trees become older and taller. Theory suggests that A l :A s must decrease to maintain leaf-specific hydraulic sufficiency as path length, gravity, and tortuosity constrain whole-plant hydraulic conductance. We tested the hypothesis that A l :A s declines with tree height. Whole-tree A l :A s was measured on 15 individuals of Douglas-fir (Pseudotsuga menziesii var. menziesii) ranging in height from 13 to 62 m (aged 20-450 years). A l :A s declined substantially as height increased (P=0.02). Our test of the hypothesis that A l :A s declines with tree height was extended using a combination of original and published data on nine species across a range of maximum heights and climates. Meta-analysis of 13 whole-tree studies revealed a consistent and significant reduction in A l :A s with increasing height (P<0.05). However, two species (Picea abies and Abies balsamea) exhibited an increase in A l :A s with height, although the reason for this is not clear. The slope of the relationship between A l :A s and tree height (ΔA l :A s /Δh) was unrelated to mean annual precipitation. Maximum potential height was positively correlated with ΔA l :A s /Δh. The decrease in A l :A s with increasing tree size that we observed in the majority of species may be a homeostatic mechanism that partially compensates for decreased hydraulic conductance as trees grow in height.

Impacts of tides on tsunami propagation due to potential Nankai Trough earthquakes in the Seto Inland Sea, Japan

NASA Astrophysics Data System (ADS)

Lee, Han Soo; Shimoyama, Tomohisa; Popinet, Stéphane

2015-10-01

The impacts of tides on extreme tsunami propagation due to potential Nankai Trough earthquakes in the Seto Inland Sea (SIS), Japan, are investigated through numerical experiments. Tsunami experiments are conducted based on five scenarios that consider tides at four different phases, such as flood, high, ebb, and low tides. The probes that were selected arbitrarily in the Bungo and Kii Channels show less significant effects of tides on tsunami heights and the arrival times of the first waves than those that experience large tidal ranges in inner basins and bays of the SIS. For instance, the maximum tsunami height and the arrival time at Toyomaesi differ by more than 0.5 m and nearly 1 h, respectively, depending on the tidal phase. The uncertainties defined in terms of calculated maximum tsunami heights due to tides illustrate that the calculated maximum tsunami heights in the inner SIS with standing tides have much larger uncertainties than those of two channels with propagating tides. Particularly in Harima Nada, the uncertainties due to the impacts of tides are greater than 50% of the tsunami heights without tidal interaction. The results recommend simulate tsunamis together with tides in shallow water environments to reduce the uncertainties involved with tsunami modeling and predictions for tsunami hazards preparedness. This article was corrected on 26 OCT 2015. See the end of the full text for details.

Predicting forest height using the GOST, Landsat 7 ETM+, and airborne LiDAR for sloping terrains in the Greater Khingan Mountains of China

NASA Astrophysics Data System (ADS)

Gu, Chengyan; Clevers, Jan G. P. W.; Liu, Xiao; Tian, Xin; Li, Zhouyuan; Li, Zengyuan

2018-03-01

Sloping terrain of forests is an overlooked factor in many models simulating the canopy bidirectional reflectance distribution function, which limits the estimation accuracy of forest vertical structure parameters (e.g., forest height). The primary objective of this study was to predict forest height on sloping terrain over large areas with the Geometric-Optical Model for Sloping Terrains (GOST) using airborne Light Detection and Ranging (LiDAR) data and Landsat 7 imagery in the western Greater Khingan Mountains of China. The Sequential Maximum Angle Convex Cone (SMACC) algorithm was used to generate image endmembers and corresponding abundances in Landsat imagery. Then, LiDAR-derived forest metrics, topographical factors and SMACC abundances were used to calibrate and validate the GOST, which aimed to accurately decompose the SMACC mixed forest pixels into sunlit crown, sunlit background and shade components. Finally, the forest height of the study area was retrieved based on a back-propagation neural network and a look-up table. Results showed good performance for coniferous forests on all slopes and at all aspects, with significant coefficients of determination above 0.70 and root mean square errors (RMSEs) between 0.50 m and 1.00 m based on ground observed validation data. Higher RMSEs were found in areas with forest heights below 5 m and above 17 m. For 90% of the forested area, the average RMSE was 3.58 m. Our study demonstrates the tremendous potential of the GOST for quantitative mapping of forest height on sloping terrains with multispectral and LiDAR inputs.

RAxML-VI-HPC: maximum likelihood-based phylogenetic analyses with thousands of taxa and mixed models.

PubMed

Stamatakis, Alexandros

2006-11-01

RAxML-VI-HPC (randomized axelerated maximum likelihood for high performance computing) is a sequential and parallel program for inference of large phylogenies with maximum likelihood (ML). Low-level technical optimizations, a modification of the search algorithm, and the use of the GTR+CAT approximation as replacement for GTR+Gamma yield a program that is between 2.7 and 52 times faster than the previous version of RAxML. A large-scale performance comparison with GARLI, PHYML, IQPNNI and MrBayes on real data containing 1000 up to 6722 taxa shows that RAxML requires at least 5.6 times less main memory and yields better trees in similar times than the best competing program (GARLI) on datasets up to 2500 taxa. On datasets > or =4000 taxa it also runs 2-3 times faster than GARLI. RAxML has been parallelized with MPI to conduct parallel multiple bootstraps and inferences on distinct starting trees. The program has been used to compute ML trees on two of the largest alignments to date containing 25,057 (1463 bp) and 2182 (51,089 bp) taxa, respectively. icwww.epfl.ch/~stamatak

33 CFR 156.320 - Maximum operating conditions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... wave height is 3 meters (10 feet) or more. (b) Cargo transfer operations shall cease and transfer hoses shall be drained when— (1) The wind velocity exceeds 82 km/hr (44 knots); or (2) Wave heights exceed 5...

33 CFR 156.320 - Maximum operating conditions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... wave height is 3 meters (10 feet) or more. (b) Cargo transfer operations shall cease and transfer hoses shall be drained when— (1) The wind velocity exceeds 82 km/hr (44 knots); or (2) Wave heights exceed 5...

33 CFR 156.320 - Maximum operating conditions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... wave height is 3 meters (10 feet) or more. (b) Cargo transfer operations shall cease and transfer hoses shall be drained when— (1) The wind velocity exceeds 82 km/hr (44 knots); or (2) Wave heights exceed 5...

Task-Level Strategies for Human Sagittal-Plane Running Maneuvers Are Consistent with Robotic Control Policies

PubMed Central

Qiao, Mu; Jindrich, Devin L.

2012-01-01

The strategies that humans use to control unsteady locomotion are not well understood. A “spring-mass” template comprised of a point mass bouncing on a sprung leg can approximate both center of mass movements and ground reaction forces during running in humans and other animals. Legged robots that operate as bouncing, “spring-mass” systems can maintain stable motion using relatively simple, distributed feedback rules. We tested whether the changes to sagittal-plane movements during five running tasks involving active changes to running height, speed, and orientation were consistent with the rules used by bouncing robots to maintain stability. Changes to running height were associated with changes to leg force but not stance duration. To change speed, humans primarily used a “pogo stick” strategy, where speed changes were associated with adjustments to fore-aft foot placement, and not a “unicycle” strategy involving systematic changes to stance leg hip moment. However, hip moments were related to changes to body orientation and angular speed. Hip moments could be described with first order proportional-derivative relationship to trunk pitch. Overall, the task-level strategies used for body control in humans were consistent with the strategies employed by bouncing robots. Identification of these behavioral strategies could lead to a better understanding of the sensorimotor mechanisms that allow for effective unsteady locomotion. PMID:23284804

Students Learning Physics While Lifting Themselves: A Simple Analysis of a Scissors Jack

NASA Astrophysics Data System (ADS)

Haugland, Ole Anton

2017-02-01

Every time I have to jack up my car, I am a bit surprised by how slowly the scissors jack works the higher I raise it, and close to maximum height I need very little force to turn the crank. This agrees well with the principle of simple machines. Since I have to jack up my car at least twice a year to change between winter tires and summer tires, I thought it was time to take a closer look at the physics behind the process. And like most physics teachers, I am always looking for new ideas for my teaching. In this note I will present a few ideas on how a jack can be a topic in physics teaching.

Feeding height stratification among the herbivorous dinosaurs from the Dinosaur Park Formation (upper Campanian) of Alberta, Canada

PubMed Central

2013-01-01

Background Herbivore coexistence on the Late Cretaceous island continent of Laramidia has been a topic of great interest, stemming from the paradoxically high diversity and biomass of these animals in relation to the relatively small landmass available to them. Various hypotheses have been advanced to account for these facts, of which niche partitioning is among the most frequently invoked. However, despite its wide acceptance, this hypothesis has not been rigorously tested. This study uses the fossil assemblage from the Dinosaur Park Formation of Alberta as a model to investigate whether niche partitioning facilitated herbivorous dinosaur coexistence on Laramidia. Specifically, the question of feeding height stratification is examined in light of the role it plays in facilitating modern ungulate coexistence. Results Most herbivorous dinosaur species from the Dinosaur Park Formation were restricted to feeding no higher than approximately 1 m above the ground. There is minimal evidence for feeding height partitioning at this level, with ceratopsids capable of feeding slightly higher than ankylosaurs, but the ecological significance of this is ambiguous. Hadrosaurids were uniquely capable of feeding up to 2 m quadrupedally, or up to 5 m bipedally. There is no evidence for either feeding height stratification within any of these clades, or for change in these ecological relationships through the approximately 1.5 Ma record of the Dinosaur Park Formation. Conclusions Although we cannot reject the possibility, we find no good evidence that feeding height stratification, as revealed by reconstructed maximum feeding heights, played an important role in facilitating niche partitioning among the herbivorous dinosaurs of Laramidia. Most browsing pressure was concentrated in the herb layer, although hadrosaurids were capable of reaching shrubs and low-growing trees that were out of reach from ceratopsids, ankylosaurs, and other small herbivores, effectively dividing the herbivores in terms of relative abundance. Sympatric hadrosaurids may have avoided competing with one another by feeding differentially using bipedal and quadrupedal postures. These ecological relationships evidently proved to be evolutionarily stable because they characterize the herbivore assemblage of the Dinosaur Park Formation through time. If niche partitioning served to facilitate the rich diversity of these animals, it may have been achieved by other means in addition to feeding height stratification. Consideration of other feeding height proxies, including dental microwear and skull morphology, may help to alleviate problems of underdetermination identified here. PMID:23557203

Feeding height stratification among the herbivorous dinosaurs from the Dinosaur Park Formation (upper Campanian) of Alberta, Canada.

PubMed

Mallon, Jordan C; Evans, David C; Ryan, Michael J; Anderson, Jason S

2013-04-04

Herbivore coexistence on the Late Cretaceous island continent of Laramidia has been a topic of great interest, stemming from the paradoxically high diversity and biomass of these animals in relation to the relatively small landmass available to them. Various hypotheses have been advanced to account for these facts, of which niche partitioning is among the most frequently invoked. However, despite its wide acceptance, this hypothesis has not been rigorously tested. This study uses the fossil assemblage from the Dinosaur Park Formation of Alberta as a model to investigate whether niche partitioning facilitated herbivorous dinosaur coexistence on Laramidia. Specifically, the question of feeding height stratification is examined in light of the role it plays in facilitating modern ungulate coexistence. Most herbivorous dinosaur species from the Dinosaur Park Formation were restricted to feeding no higher than approximately 1 m above the ground. There is minimal evidence for feeding height partitioning at this level, with ceratopsids capable of feeding slightly higher than ankylosaurs, but the ecological significance of this is ambiguous. Hadrosaurids were uniquely capable of feeding up to 2 m quadrupedally, or up to 5 m bipedally. There is no evidence for either feeding height stratification within any of these clades, or for change in these ecological relationships through the approximately 1.5 Ma record of the Dinosaur Park Formation. Although we cannot reject the possibility, we find no good evidence that feeding height stratification, as revealed by reconstructed maximum feeding heights, played an important role in facilitating niche partitioning among the herbivorous dinosaurs of Laramidia. Most browsing pressure was concentrated in the herb layer, although hadrosaurids were capable of reaching shrubs and low-growing trees that were out of reach from ceratopsids, ankylosaurs, and other small herbivores, effectively dividing the herbivores in terms of relative abundance. Sympatric hadrosaurids may have avoided competing with one another by feeding differentially using bipedal and quadrupedal postures. These ecological relationships evidently proved to be evolutionarily stable because they characterize the herbivore assemblage of the Dinosaur Park Formation through time. If niche partitioning served to facilitate the rich diversity of these animals, it may have been achieved by other means in addition to feeding height stratification. Consideration of other feeding height proxies, including dental microwear and skull morphology, may help to alleviate problems of underdetermination identified here.

Scaling exponents for ordered maxima

DOE PAGES

Ben-Naim, E.; Krapivsky, P. L.; Lemons, N. W.

2015-12-22

We study extreme value statistics of multiple sequences of random variables. For each sequence with N variables, independently drawn from the same distribution, the running maximum is defined as the largest variable to date. We compare the running maxima of m independent sequences and investigate the probability S N that the maxima are perfectly ordered, that is, the running maximum of the first sequence is always larger than that of the second sequence, which is always larger than the running maximum of the third sequence, and so on. The probability S N is universal: it does not depend on themore » distribution from which the random variables are drawn. For two sequences, S N~N –1/2, and in general, the decay is algebraic, S N~N –σm, for large N. We analytically obtain the exponent σ 3≅1.302931 as root of a transcendental equation. Moreover, the exponents σ m grow with m, and we show that σ m~m for large m.« less

Modeling and relationship of respiratory exchange ratio to athletic performance.

PubMed

Bellar, David; Judge, Lawrence W

2012-09-01

Previous research has related the results of tests of maximum aerobic capacity to performance for endurance athletes. These results are often only able to predict the running velocity of races such as the marathon. This investigation sought to determine the absolute V[Combining Dot Above]O2 at various respiratory exchange ratio (RER) values (0.85, 0.90, 0.95, 1.0, 1.05, and 1.10) by using a third-order polynomial regression to model the physiological responses for V[Combining Dot Above]O2 and RER obtained from an assessment of maximum aerobic capacity. The V[Combining Dot Above]O2 determined was subsequently correlated to race performance. The participants in the study were selected from a population of National Collegiate Athletic Association Division 1 crosscountry runners (male n = 7, female n = 7, age 20.5 ± 0.9 years; height 170.3 ± 8.2 cm; weight 59.7 ± 8.7 kg; V[Combining Dot Above]O2max 57.0 ± 7.8 ml O2·kg·min). Third-order regression analysis resulted in strong curve fitting between the variables (r = 0.949 ± 0.03). Partial correlations (controlled for weight) were used to assess the relationship between oxygen consumption at the desired points of RER and race performance. The partial correlations revealed that the absolute oxygen consumptions at all RER points of interest were significantly correlated to race performance (r > 0.740, p < 0.01). There was a significant difference in the strength of the correlations for the points RER 0.95 (t = 2.68957, p = 0.01), 1.0 (t = 2.18516, p = 0.03), and 1.05 (t = 1.85668, p = 0.04) and the correlations found for RER 0.85. After converting the oxygen consumption at the RER points to estimated horizontal running speeds, only the estimate at RER 1.05 was not statistically different from the actual speed achieved in the culminating XC race. It can be suggested based upon these results that coaches of collegiate crosscountry runners who engage in metabolic testing of athletes examine the estimated running pace at RER 1.05 to gain an insight into a runner's potential.

A Comparison of Variable Selection Criteria for Multiple Linear Regression: A Second Simulation Study

DTIC Science & Technology

1993-03-01

statistical mathe- matics, began in the late 1800’s when Sir Francis Galton first attempted to use practical mathematical techniques to investigate the...randomly collected (sampled) many pairs of parent/child height mea- surements (data), Galton observed that for a given parent- height average, the...ty only Maximum Adjusted R2 will be discussed. However, Maximum Adjusted R’ and Minimum MSE test exactly the same 2.thing. Adjusted R is related to R

Past and future drivers of increased erosion risk in the northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Wahl, T.; Plant, N. G.

2014-12-01

We use hourly observations of water levels from two tide gauges and wave data from three buoys to assess their relative contribution to past and potential future changes in the erosion risk for Dauphin Island, a barrier island located off the coastline of Alabama. Topographic information (i.e. beach slopes and dune toe and crest heights) is obtained from the most recent lidar survey conducted in the area in July 2013. Water levels and wave parameters (i.e. significant wave height and peak period) from the two tide gauges and three wave buoys are merged into single records spanning the period from 1981 to 2013. The Stockdon et al. (2006) run-up model is used to estimate the 2% exceedance values of wave run-up maxima, which are then combined with the observed water levels at the representative tide gauge site to obtain total water levels (TWLs). With this information we assess the relative contribution of geocentric sea level rise, vertical land-movement, and long-term changes in the wave parameters to the observed increase in erosion risk. The latter is approximated using the concept of impact hours per year (IHPY; Ruggiero 2013) at dune toe and dune crest elevation thresholds derived from the lidar data. Wahl et al. (2014) recently discovered a significant increase in the amplitude of the seasonal sea level cycle in the Gulf of Mexico. Here, we explore the potential of these changes, and similar developments in the seasonal cycle of the wave data and corresponding IHPY, to affect coastal erosion. Such intra-annual signals with longer-term variations have not been included in most earlier studies in favour of analysing the effects of annually averaged long-term trends. Finally, scenarios of potential future changes of all relevant parameters are used to explore their relative contribution to further increase in the coastal erosion risk over the next few decades.

Physical Limits on Hmax, the Maximum Height of Glaciers and Ice Sheets

NASA Astrophysics Data System (ADS)

Lipovsky, B. P.

2017-12-01

The longest glaciers and ice sheets on Earth never achieve a topographic relief, or height, greater than about Hmax = 4 km. What laws govern this apparent maximum height to which a glacier or ice sheet may rise? Two types of answer appear possible: one relating to geological process and the other to ice dynamics. In the first type of answer, one might suppose that if Earth had 100 km tall mountains then there would be many 20 km tall glaciers. The counterpoint to this argument is that recent evidence suggests that glaciers themselves limit the maximum height of mountain ranges. We turn, then, to ice dynamical explanations for Hmax. The classical ice dynamical theory of Nye (1951), however, does not predict any break in scaling to give rise to a maximum height, Hmax. I present a simple model for the height of glaciers and ice sheets. The expression is derived from a simplified representation of a thermomechanically coupled ice sheet that experiences a basal shear stress governed by Coulomb friction (i.e., a stress proportional to the overburden pressure minus the water pressure). I compare this model to satellite-derived digital elevation map measurements of glacier surface height profiles for the 200,000 glaciers in the Randolph Glacier Inventory (Pfeffer et al., 2014) as well as flowlines from the Greenland and Antarctic Ice Sheets. The simplified model provides a surprisingly good fit to these global observations. Small glaciers less than 1 km in length are characterized by having negligible influence of basal melt water, cold ( -15C) beds, and high surface slopes ( 30 deg). Glaciers longer than a critical distance 30km are characterized by having an ice-bed interface that is weakened by the presence of meltwater and is therefore not capable of supporting steep surface slopes. The simplified model makes predictions of ice volume change as a function of surface temperature, accumulation rate, and geothermal heat flux. For this reason, it provides insights into both past and future global ice volume changes.

Impact reduction through long-term intervention in recreational runners: midfoot strike pattern versus low-drop/low-heel height footwear.

PubMed

Giandolini, Marlène; Horvais, Nicolas; Farges, Yohann; Samozino, Pierre; Morin, Jean-Benoît

2013-08-01

Impact reduction has become a factor of interest in the prevention of running-related injuries such as stress fractures. Currently, the midfoot strike pattern (MFS) is thought as a potential way to decrease impact. The purpose was to test the effects of two long-term interventions aiming to reduce impact during running via a transition to an MFS: a foot strike retraining versus a low-drop/low-heel height footwear. Thirty rearfoot strikers were randomly assigned to two experimental groups (SHOES and TRAIN). SHOES progressively wore low-drop/low-heel height shoes and TRAIN progressively adopted an MFS, over a 3-month period with three 30-min running sessions per week. Measurement sessions (pre-training, 1, 2 and 3 months) were performed during which subjects were equipped with three accelerometers on the shin, heel and metatarsals, and ran for 15 min on an instrumented treadmill. Synchronized acceleration and vertical ground reaction force signals were recorded. Peak heel acceleration was significantly lower as compared to pre-training for SHOES (-33.5 ± 12.8 % at 2 months and -25.3 ± 18.8 % at 3 months, p < 0.001), and so was shock propagation velocity (-12.1 ± 9.3 %, p < 0.001 at 2 months and -11.3 ± 4.6 %, p < 0.05 at 3 months). No change was observed for TRAIN. Important inter-individual variations were noted in both groups and reported pains were mainly located at the shin and calf. Although it induced reversible pains, low-drop/low-heel height footwear seemed to be more effective than foot strike retraining to attenuate heel impact in the long term.

Body Mass and Circumference of Upper Arm Are Associated with Race Performance in Ultraendurance Runners in a Multistage Race--The Isarrun 2006

ERIC Educational Resources Information Center

Knechtle, Beat; Duff, Brida; Welzel, Ulrich; Kohler, Gotz

2009-01-01

In the present study, we investigated the association of anthropometric parameters with race performance in ultraendurance runners in a multistage ultraendurance run, in which athletes had to run 338 km within 5 consecutive days. In 17 male successful finishers, calculations of body mass, body height, skinfold thicknesses, extremity circumference,…

Probabilistic storm surge inundation maps for Metro Manila based on Philippine public storm warning signals

NASA Astrophysics Data System (ADS)

Tablazon, J.; Caro, C. V.; Lagmay, A. M. F.; Briones, J. B. L.; Dasallas, L.; Lapidez, J. P.; Santiago, J.; Suarez, J. K.; Ladiero, C.; Gonzalo, L. A.; Mungcal, M. T. F.; Malano, V.

2015-03-01

A storm surge is the sudden rise of sea water over the astronomical tides, generated by an approaching storm. This event poses a major threat to the Philippine coastal areas, as manifested by Typhoon Haiyan on 8 November 2013. This hydro-meteorological hazard is one of the main reasons for the high number of casualties due to the typhoon, with 6300 deaths. It became evident that the need to develop a storm surge inundation map is of utmost importance. To develop these maps, the Nationwide Operational Assessment of Hazards under the Department of Science and Technology (DOST-Project NOAH) simulated historical tropical cyclones that entered the Philippine Area of Responsibility. The Japan Meteorological Agency storm surge model was used to simulate storm surge heights. The frequency distribution of the maximum storm surge heights was calculated using simulation results of tropical cyclones under a specific public storm warning signal (PSWS) that passed through a particular coastal area. This determines the storm surge height corresponding to a given probability of occurrence. The storm surge heights from the model were added to the maximum astronomical tide data from WXTide software. The team then created maps of inundation for a specific PSWS using the probability of exceedance derived from the frequency distribution. Buildings and other structures were assigned a probability of exceedance depending on their occupancy category, i.e., 1% probability of exceedance for critical facilities, 10% probability of exceedance for special occupancy structures, and 25% for standard occupancy and miscellaneous structures. The maps produced show the storm-surge-vulnerable areas in Metro Manila, illustrated by the flood depth of up to 4 m and extent of up to 6.5 km from the coastline. This information can help local government units in developing early warning systems, disaster preparedness and mitigation plans, vulnerability assessments, risk-sensitive land use plans, shoreline defense efforts, and coastal protection measures. These maps can also determine the best areas to build critical structures, or at least determine the level of protection of these structures should they be built in hazard areas. Moreover, these will support the local government units' mandate to raise public awareness, disseminate information about storm surge hazards, and implement appropriate countermeasures for a given PSWS.

Growth hormone (GH) dosing during catch-up growth guided by individual responsiveness decreases growth response variability in prepubertal children with GH deficiency or idiopathic short stature.

PubMed

Kriström, Berit; Aronson, A Stefan; Dahlgren, Jovanna; Gustafsson, Jan; Halldin, Maria; Ivarsson, Sten A; Nilsson, Nils-Osten; Svensson, Johan; Tuvemo, Torsten; Albertsson-Wikland, Kerstin

2009-02-01

Weight-based GH dosing results in a wide variation in growth response in children with GH deficiency (GHD) or idiopathic short stature (ISS). The hypothesis tested was whether individualized GH doses, based on variation in GH responsiveness estimated by a prediction model, reduced variability in growth response around a set height target compared with a standardized weight-based dose. A total of 153 short prepubertal children diagnosed with isolated GHD or ISS (n = 43) and at least 1 SD score (SDS) below midparental height SDS (MPH(SDS)) were included in this 2-yr multicenter study. The children were randomized to either a standard (43 microg/kg.d) or individualized (17-100 microg/kg.d) GH dose. We measured the deviation of height(SDS) from individual MPH(SDS) (diffMPH(SDS)). The primary endpoint was the difference in the range of diffMPH(SDS) between the two groups. The diffMPH(SDS) range was reduced by 32% in the individualized-dose group relative to the standard-dose group (P < 0.003), whereas the mean diffMPH(SDS) was equal: -0.42 +/- 0.46 and -0.48 +/- 0.67, respectively. Gain in height(SDS) 0-2 yr was equal for the GH-deficient and ISS groups: 1.31 +/- 0.47 and 1.36 +/- 0.47, respectively, when ISS was classified on the basis of maximum GH peak on the arginine-insulin tolerance test or 24-h profile. Individualized GH doses during catch-up growth significantly reduce the proportion of unexpectedly good and poor responders around a predefined individual growth target and result in equal growth responses in children with GHD and ISS.

Changes in Lower Facial Height and Facial Esthetics with Incremental Increases in Occlusal Vertical Dimension in Dentate Subjects.

PubMed

Orenstein, Noah P; Bidra, Avinash S; Agar, John R; Taylor, Thomas D; Uribe, Flavio; Litt, Mark D; Little, Mark D

2015-01-01

To determine if there are objective changes in lower facial height and subjective changes in facial esthetics with incremental increases in occlusal vertical dimension in dentate subjects. Twenty subjects of four different races and both sexes with a Class I dental occlusion had custom diagnostic occlusal prostheses (mandibular overlays) fabricated on casts mounted on a semi-adjustable articulator. The overlays were fabricated at 2-mm, 3-mm, 4-mm, and 5-mm openings of the anterior guide pin of a semi-adjustable articulator. Direct facial measurements were made between pronasale and menton on each subject while wearing the four different overlays. Thereafter, two digital photographs (frontal and profile) were taken for each subject at maximum intercuspation (baseline) and wearing each of the four mandibular overlays. The photographs of eight subjects were standardized and displayed in a random order to 60 judges comprising 30 laypeople, 15 general dentists, and 15 prosthodontists. Using a visual analog scale, each judge was asked to rate the facial esthetics twice for each of the 80 images. For objective changes, although an anterior guide pin-lower facial height relationship of 1:0.63 mm was observed, the findings were not correlated (P>.20). For subjective changes, the visual analog scale ratings of judges were uncorrelated with increases in anterior guide pin opening up to 5 mm, irrespective of the judge's background status or the sexes of the judges or the subjects (P>.80). Incremental increases in anterior guide pin opening up to 5 mm did not correlate to similar increases in lower facial height. Additionally, it made no difference in a judge's evaluation of facial esthetics irrespective of the judge's background status (layperson, general dentist, or prosthodontist) or sex.

High-speed GPU-based finite element simulations for NDT

NASA Astrophysics Data System (ADS)

Huthwaite, P.; Shi, F.; Van Pamel, A.; Lowe, M. J. S.

2015-03-01

The finite element method solved with explicit time increments is a general approach which can be applied to many ultrasound problems. It is widely used as a powerful tool within NDE for developing and testing inspection techniques, and can also be used in inversion processes. However, the solution technique is computationally intensive, requiring many calculations to be performed for each simulation, so traditionally speed has been an issue. For maximum speed, an implementation of the method, called Pogo [Huthwaite, J. Comp. Phys. 2014, doi: 10.1016/j.jcp.2013.10.017], has been developed to run on graphics cards, exploiting the highly parallelisable nature of the algorithm. Pogo typically demonstrates speed improvements of 60-90x over commercial CPU alternatives. Pogo is applied to three NDE examples, where the speed improvements are important: guided wave tomography, where a full 3D simulation must be run for each source transducer and every different defect size; scattering from rough cracks, where many simulations need to be run to build up a statistical model of the behaviour; and ultrasound propagation within coarse-grained materials where the mesh must be highly refined and many different cases run.

Control strategy of maximum vertical jumps: The preferred countermovement depth may not be fully optimized for jump height.

PubMed

Mandic, Radivoj; Knezevic, Olivera M; Mirkov, Dragan M; Jaric, Slobodan

2016-09-01

The aim of the present study was to explore the control strategy of maximum countermovement jumps regarding the preferred countermovement depth preceding the concentric jump phase. Elite basketball players and physically active non-athletes were tested on the jumps performed with and without an arm swing, while the countermovement depth was varied within the interval of almost 30 cm around its preferred value. The results consistently revealed 5.1-11.2 cm smaller countermovement depth than the optimum one, but the same difference was more prominent in non-athletes. In addition, although the same differences revealed a marked effect on the recorded force and power output, they reduced jump height for only 0.1-1.2 cm. Therefore, the studied control strategy may not be based solely on the countermovement depth that maximizes jump height. In addition, the comparison of the two groups does not support the concept of a dual-task strategy based on the trade-off between maximizing jump height and minimizing the jumping quickness that should be more prominent in the athletes that routinely need to jump quickly. Further research could explore whether the observed phenomenon is based on other optimization principles, such as the minimization of effort and energy expenditure. Nevertheless, future routine testing procedures should take into account that the control strategy of maximum countermovement jumps is not fully based on maximizing the jump height, while the countermovement depth markedly confound the relationship between the jump height and the assessed force and power output of leg muscles.

Feasibility of Wave Energy in Hong Kong

NASA Astrophysics Data System (ADS)

Lu, M.; Hodgson, P.

2014-12-01

Kinetic energy produced by the movement of ocean waves can be harnessed by wave energy converter equipment such as wave turbines to power onshore electricity generators, creating a valuable source of renewable energy. This experiment measures the potential of wave energy in Hoi Ha Wan Marine Park, Hong Kong using a data buoy programmed to send data through wireless internet every five minutes. Wave power (known as 'wave energy flux') is proportional to wave energy periodicity and to the square of wave height, and can be calculated using the equation: P = 0.5 kW/(m3)(s) x Hs2 x Tp P = wave energy flux (wave energy per unit of wave crest length in kW/m) Hs = significant wave height (m) Tp = wave period (seconds) Acoustic Doppler Current Profilers (ADCPs), or ultrasonic sensors, were installed on the seabed at three monitoring locations to measure Significant Wave Heights (Hs), Significant Wave Periods (Tp) and Significant Wave Direction (Wd). Over a twelve month monitoring period, Significant Wave Heights ranged from 0 ~ 8.63m. Yearly averages were 1.051m. Significant Wave Period ranged from 0 ~ 14.9s. Yearly averages were 6.846s. The maximum wave energy amount recorded was 487.824 kW/m. These results implied that electricity sufficient to power a small marine research center could be supplied by a generator running at 30% efficiency or greater. A wave piston driven generator prototype was designed that could meet output objectives without using complex hydraulics, expensive mechanical linkages, or heavy floating buoys that might have an adverse impact on marine life. The result was a design comprising a water piston connected by an air pipe to a rotary turbine powered generator. A specially designed air valve allowed oscillating bidirectional airflow generated in the piston to be converted into unidirectional flow through the turbine, minimizing kinetic energy loss. A 35cm wave with a one second period could generate 139.430W of electricity, with an efficiency of 37.6%.

Physical Mechanisms of Glaze Ice Scallop Formations on Swept Wings

NASA Technical Reports Server (NTRS)

Vargas, Mario; Reshotko, Eli

1998-01-01

An experiment was conducted to understand the physical mechanisms that lead to the formation of scallops on swept wings. Icing runs were performed on a NACA 0012 swept wing tip at 45 deg, 30 deg, and 15 deg sweep angles. A baseline case was chosen and direct measurements of scallop height and spacing, castings, video data and close-up photographic data were obtained. The results showed the scallops are made of glaze ice feathers that grow from roughness elements that have reached a minimum height and are located beyond a given distance from the attachment line. This distance depends on tunnel conditions and sweep angle, and is the critical parameter in the formation of scallops. It determines if complete scallops, incomplete scallops or no scallops are going to be formed. The mechanisms of growth for complete and incomplete scallops were identified. The effect of velocity, temperature and LWC on scallop formation was studied. The possibility that cross flow instability may be the physical mechanism that triggers the growth of roughness elements into glaze ice feathers is examined.

Effects of height on treetop transpiration and stomatal conductance in coast redwood (Sequoia sempervirens).

PubMed

Ambrose, Anthony R; Sillett, Stephen C; Koch, George W; Van Pelt, Robert; Antoine, Marie E; Dawson, Todd E

2010-10-01

Treetops become increasingly constrained by gravity-induced water stress as they approach maximum height. Here we examine the effects of height on seasonal and diurnal sap flow dynamics at the tops of 12 unsuppressed Sequoia sempervirens (D. Don) Endl. (coast redwood) trees 68-113 m tall during one growing season. Average treetop sap velocity (V(S)), transpiration per unit leaf area (E(L)) and stomatal conductance per unit leaf area (G(S)) significantly decreased with increasing height. These differences in sap flow were associated with an unexpected decrease in treetop sapwood area-to-leaf area ratios (A(S):A(L)) in the tallest trees. Both E(L) and G(S) declined as soil moisture decreased and vapor pressure deficit (D) increased throughout the growing season with a greater decline in shorter trees. Under high soil moisture and light conditions, reference G(S) (G(Sref); G(S) at D = 1 kPa) and sensitivity of G(S) to D (-δ; dG(S)/dlnD) significantly decreased with increasing height. The close relationship we observed between G(Sref) and -δ is consistent with the role of stomata in regulating E(L) and leaf water potential (Ψ(L)). Our results confirm that increasing tree height reduces gas exchange of treetop foliage and thereby contributes to lower carbon assimilation and height growth rates as S. sempervirens approaches maximum height.

Comparison of maximum runup through analytical and numerical approaches for different fault parameters estimates

NASA Astrophysics Data System (ADS)

Kanoglu, U.; Wronna, M.; Baptista, M. A.; Miranda, J. M. A.

2017-12-01

The one-dimensional analytical runup theory in combination with near shore synthetic waveforms is a promising tool for tsunami rapid early warning systems. Its application in realistic cases with complex bathymetry and initial wave condition from inverse modelling have shown that maximum runup values can be estimated reasonably well. In this study we generate a simplistic bathymetry domains which resemble realistic near-shore features. We investigate the accuracy of the analytical runup formulae to the variation of fault source parameters and near-shore bathymetric features. To do this we systematically vary the fault plane parameters to compute the initial tsunami wave condition. Subsequently, we use the initial conditions to run the numerical tsunami model using coupled system of four nested grids and compare the results to the analytical estimates. Variation of the dip angle of the fault plane showed that analytical estimates have less than 10% difference for angles 5-45 degrees in a simple bathymetric domain. These results shows that the use of analytical formulae for fast run up estimates constitutes a very promising approach in a simple bathymetric domain and might be implemented in Hazard Mapping and Early Warning.

Estimation procedures for understory biomass and fuel loads in sagebrush steppe invaded by woodlands

Treesearch

Alicia L. Reiner; Robin J. Tausch; Roger F. Walker

2010-01-01

Regression equations were developed to predict biomass for 9 shrubs, 9 grasses, and 10 forbs that generally dominate sagebrush ecosystems in central Nevada. Independent variables included percent cover, average height, and plant volume. We explored 2 ellipsoid volumes: one with maximum plant height and 2 crown diameters and another with live crown height and 2 crown...

Airborne plutonium-239 and americium-241 concentrations measured from the 125-meter Hanford Meteorological Tower

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sehmel, G.A.

1978-01-01

Airborne plutonium-239 and americium-241 concentrations and fluxes were measured at six heights from 1.9 to 122 m on the Hanford meteorological tower. The data show that plutonium-239 was transported on nonrespirable and small particles at all heights. Airborne americium-241 concentrations on small particles were maximum at the 91 m height.

Dwell time, Hartman effect and transport properties in a ferromagnetic phosphorene monolayer

NASA Astrophysics Data System (ADS)

Hedayati Kh, Hamed; Faizabadi, Edris

2018-02-01

In this paper, spin-dependent dwell time, spin Hartman effect and spin-dependent conductance were theoretically investigated through a rectangular barrier in the presence of an exchange field by depositing a ferromagnetic insulator on the phosphorene layer in the barrier region. The existence of the spin Hartman effect was shown for all energies (energies lower than barrier height) and all incident angles in phosphorene. We also compared our results of the dwell time in the phosphorene structure with similar research performed on graphene. We reported a significant difference between the tunneling time values of incident quasiparticles with spin-up and spin-down. We found that the barrier was almost transparent for incident quasiparticles with a wide range of incident angles and energies higher than the barrier height in phosphorene. We also found that the maximum spin-dependent transmission probability for energies higher than barrier height does not necessarily occur in the zero incident angle. In addition, we showed that the spin conductance for energies higher (lower) than barrier height fluctuates (decays) in terms of barrier thickness. We discovered that, in contrast to graphene, the Klein paradox does not occur in the normal incident in the phosphorene structure. Furthermore, the results demonstrated the achievement of good total conductance at certain thicknesses of the barrier for energies higher than the barrier height. This study could serve as a basis for investigations of the basic physics of tunneling mechanisms and also for using phosphorene as a spin polarizer in designing nanoelectronic devices.

Dwell time, Hartman effect and transport properties in a ferromagnetic phosphorene monolayer.

PubMed

Hedayati Kh, Hamed; Faizabadi, Edris

2018-02-28

In this paper, spin-dependent dwell time, spin Hartman effect and spin-dependent conductance were theoretically investigated through a rectangular barrier in the presence of an exchange field by depositing a ferromagnetic insulator on the phosphorene layer in the barrier region. The existence of the spin Hartman effect was shown for all energies (energies lower than barrier height) and all incident angles in phosphorene. We also compared our results of the dwell time in the phosphorene structure with similar research performed on graphene. We reported a significant difference between the tunneling time values of incident quasiparticles with spin-up and spin-down. We found that the barrier was almost transparent for incident quasiparticles with a wide range of incident angles and energies higher than the barrier height in phosphorene. We also found that the maximum spin-dependent transmission probability for energies higher than barrier height does not necessarily occur in the zero incident angle. In addition, we showed that the spin conductance for energies higher (lower) than barrier height fluctuates (decays) in terms of barrier thickness. We discovered that, in contrast to graphene, the Klein paradox does not occur in the normal incident in the phosphorene structure. Furthermore, the results demonstrated the achievement of good total conductance at certain thicknesses of the barrier for energies higher than the barrier height. This study could serve as a basis for investigations of the basic physics of tunneling mechanisms and also for using phosphorene as a spin polarizer in designing nanoelectronic devices.

Determination of the maximum MGS mounting height : phase I crash testing.

DOT National Transportation Integrated Search

2012-03-09

Post-and-rail guardrail systems encounter environmental conditions, such as severe frost heave or erosion, which : may drastically affect the post embedment depth and rail mounting height. In addition, guardrail systems may be designed : to accommoda...

Evaluation of starter dietary digestible lysine level on broilers raised under a sex-separated or straight-run housing regime, part 2: Economics of sex separation and digestible lysine level for maximum returns.

PubMed

Da Costa, M J; Colson, G; Frost, T J; Halley, J; Pesti, G M

2017-09-01

The objective of this experiment was to determine the maximum net returns digestible lysine (dLys) levels (MNRL) when maintaining the ideal amino acid ratio for starter diets of broilers raised sex separate or comingled (straight-run). A total of 3,240 Ross 708 chicks was separated by sex and placed in 90 pens by 2 rearing types: sex separate (36 males or 36 females) or straight-run (18 males + 18 females). Each rearing type was fed 6 starter diets (25 d) formulated to have dLys levels between 1.05 and 1.80%. A common grower diet with 1.02% of dLys was fed from 25 to 32 days. Body weight gain (BWG) and feed intake were assessed at 25 and 32 d for performance evaluation. Additionally, at 26 and 33 d, 4 birds per pen were sampled for carcass yield evaluation. Data were modeled using response surface methodology in order to estimate feed intake and whole carcass weight at 1,600 g live BW. Returns over feed cost were estimated for a 1.8-million-broiler complex of each rearing system under 9 feed/meat price scenarios. Results indicated that females needed more feed to reach market weight, followed by straight-run birds, and then males. At medium meat and feed prices, female birds had MNRL at 1.07% dLys, whereas straight-run and males had MNRL at 1.05%. As feed and meat prices increased, females had MNRL increased up to 1.15% dLys. Sex separation resulted in increased revenue under certain feed and meat prices, and before sex separation cost was deducted. When the sexing cost was subtracted from the returns, sex separation was not shown to be economically viable when targeting birds for light market BW. © 2017 Poultry Science Association Inc.

Hydrostatic constraints on morphological exploitation of light in tall Sequoia sempervirens trees.

PubMed

Ishii, Hiroaki T; Jennings, Gregory M; Sillett, Stephen C; Koch, George W

2008-07-01

We studied changes in morphological and physiological characteristics of leaves and shoots along a height gradient in Sequoia sempervirens, the tallest tree species on Earth, to investigate whether morphological and physiological acclimation to the vertical light gradient was constrained by hydrostatic limitation in the upper crown. Bulk leaf water potential (Psi) decreased linearly and light availability increased exponentially with increasing height in the crown. During the wet season, Psi was lower in the outer than inner crown. C isotope composition of leaves (delta(13)C) increased with increasing height indicating greater photosynthetic water use efficiency in the upper crown. Leaf and shoot morphology changed continuously with height. In contrast, their relationships with light availability were discontinuous: morphological characteristics did not correspond to increasing light availability above 55-85 m. Mass-based chlorophyll concentration (chl) decreased with increasing height and increasing light availability. In contrast, area-based chl remained constant or increased with increasing height. Mass-based maximum rate of net photosynthesis (P (max)) decreased with increasing height, whereas area-based P (max) reached maximum at 78.4 m and decreased with increasing height thereafter. Mass-based P (max) increased with increasing shoot mass per area (SMA), whereas area-based P (max) was not correlated with SMA in the upper crown. Our results suggest that hydrostatic limitation of morphological development constrains exploitation of light in the upper crown and contributes to reduced photosynthetic rates and, ultimately, reduced height growth at the tops of tall S. sempervirens trees.

The implications of basalt in the formation and evolution of mountains on Venus

NASA Astrophysics Data System (ADS)

Jull, Matthew G.; Arkani-Hamed, Jafar

1995-06-01

The highland region of Ishtar Terra on Venus has mountains that reach up to 11 km in height and are thought to be basaltic in composition. Assuming that dynamic uplift of crust to this height is unlikely, we examine the topography produced by an isostatically supported thickening basaltic crust. It is found that regardless of whether the crust thickens by crustal shortening or by volcanic construction, the high-density basalt-eclogite phase transition is the limiting factor for producing significant elevation of the mountains. The maximum height attained by basaltic mountains depends on the nature of the basalt-eclogite phase transition. Without a phase transition, a basaltic crust must thicken to greater than 100 km to reach heights over 10 km. An instantaneous phase transition of basalt to eclogite allows a maximum topographic height of less than about 2 km. However, with a time lag of 100 Ma owing to slow rates of solid-state diffusion, our calculations show that the mountains can reach elevations greater than 10 km only if they are less than 25 Ma old. Higher temperatures within the Venusian crust may decrease the extent of the stability fields of high-density basalt phases and allow high topography if the thickening crust melts. This can occur if the radioactive element concentrations measured on the surface of Venus are uniformly distributed throughout the crust, the crust thickens to greater than 65 km, and the thickened crust is older than about 400 Ma. The conflicting results of a young age predicted for high basaltic mountains and an almost uniform surface age of 500 Ma from crater populations, coupled with similarities in bulk physical properties of Venus and Earth, suggest that the basaltic surface composition found at several landing sites on the planet may not be representative of the entire crust. We suggest that Ishtar Terra formed from the collision of continent-like highly silicic cratons over a region of mantle downwelling. Lakshmi Planum resulted from the thickening of a basaltic crust and the peripheral mountain belts formed from the collision of granitic cratons that were pulled toward a downwelling region of mantle.

Morphology and shallow structure of seafloor mounds in the Canary Basin (Eastern Central Atlantic Ocean)

NASA Astrophysics Data System (ADS)

Sanchez-Guillamón, O.; Vázquez, J. T.; Palomino, D.; Medialdea, T.; Fernández-Salas, L. M.; León, R.; Somoza, L.

2018-07-01

The increasing volume of high-resolution multibeam bathymetry data collected along continental margins and adjacent deep seafloor regions is providing further opportunities to study new morphological seafloor features in deep water environments. In this paper, seafloor mounds have been imaged in detail with multibeam echosounders and parametric sub-bottom profilers in the deep central area of the Canary Basin ( 350-550 km west off El Hierro Island) between 4800 and 5200 mbsl. These features have circular to elongated shapes with heights of 10 to 250 m, diameters of 2-24 km and with flank slopes of 2-50°. Based on their morphological features and the subsurface structures these mounds have been classified into five different types of mounds that follow a linear correlation between height and slope but not between height and size. The first, second (Subgroup A), and third mound-types show heights lower than 80 m and maximum slopes of 35° with extension ranging from 2 to 400 km2 and correspond to domes formed at the surface created by intrusions located at depth that have not outcropped yet. The second (Subgroup B), fourth, and fifth mound-types show higher heights up to 250 m high, maximum slopes of 47° and sizes between 10 and 20 km2 and are related to the expulsion of hot and hydrothermal fluids and/or volcanics from extrusive deep-seated systems. Based on the constraints on their morphological and structural analyses, we suggest that morphostructural types of mounds are intimately linked to a specific origin that leaves its footprint in the morphology of the mounds. We propose a growth model for the five morphostructural types of mounds where different intrusive and extrusive phenomena represent the dominant mechanisms for mound growth evolution. These structures are also affected by tectonics (bulge-like structures clearly deformed by faulting) and mass movements (slide scars and mass transport deposits). In this work, we report how intrusive and extrusive processes may affect the seafloor morphology, identifying a new type of geomorphological feature as 'intrusive' domes that have, to date, only been reported in fossil environments but might extend to other oceanic areas.

How tall can gelatin towers be? An introduction to elasticity and buckling

NASA Astrophysics Data System (ADS)

Taberlet, Nicolas; Ferrand, Jérémy; Camus, Élise; Lachaud, Léa; Plihon, Nicolas

2017-12-01

The stability of elastic towers is studied through simple hands-on experiments. Using gelatin-based stackable bricks, one can investigate the maximum height a simple structure can reach before collapsing. We show through experiments and by using the classical linear elastic theory that the main limitation to the height of such towers is the buckling of the elastic structures under their own weight. Moreover, the design and architecture of the towers can be optimized to greatly improve their resistance to self-buckling. To this aim, the maximum height of hollow and tapered towers is investigated. The experimental and theoretical developments presented in this paper can help students grasp the fundamental concepts in elasticity and mechanical stability.

Effects of a Low-Load Gluteal Warm-Up on Explosive Jump Performance

PubMed Central

Comyns, Thomas; Kenny, Ian; Scales, Gerard

2015-01-01

The purpose of this study was to investigate the effects of a low-load gluteal warm-up protocol on countermovement and squat jump performance. Research by Crow et al. (2012) found that a low-load gluteal warm-up could be effective in enhancing peak power output during a countermovement jump. Eleven subjects performed countermovement and squat jumps before and after the gluteal warm-up protocol. Both jumps were examined in separate testing sessions and performed 30 seconds, and 2, 4, 6 & 8 minutes post warm-up. Height jumped and peak ground reaction force were the dependent variables examined in both jumps, with 6 additional variables related to fast force production being examined in the squat jump only. All jumps were performed on a force platform (AMTI OR6-5). Repeated measures analysis of variance found a number of significant differences (p ≤ 0.05) between baseline and post warm-up scores. Height jumped decreased significantly in both jumps at all rest intervals excluding 8 minutes. Improvement was seen in 7 of the 8 recorded SJ variables at the 8 minute interval. Five of these improvements were deemed statistically significant, namely time to peak GRF (43.0%), and time to the maximum rate of force development (65.7%) significantly decreased, while starting strength (63.4%), change of force in first 100 ms of contraction (49.1%) and speed strength (43.6%) significantly increased. The results indicate that a gluteal warm-up can enhance force production in squat jumps performed after 8 minutes recovery. Future research in this area should include additional warm-up intervention groups for comparative reasons. PMID:26240661

Probabilistic Tsunami Hazard Assessment along Nankai Trough (1) An assessment based on the information of the forthcoming earthquake that Earthquake Research Committee(2013) evaluated

NASA Astrophysics Data System (ADS)

Hirata, K.; Fujiwara, H.; Nakamura, H.; Osada, M.; Morikawa, N.; Kawai, S.; Ohsumi, T.; Aoi, S.; Yamamoto, N.; Matsuyama, H.; Toyama, N.; Kito, T.; Murashima, Y.; Murata, Y.; Inoue, T.; Saito, R.; Takayama, J.; Akiyama, S.; Korenaga, M.; Abe, Y.; Hashimoto, N.

2015-12-01

The Earthquake Research Committee(ERC)/HERP, Government of Japan (2013) revised their long-term evaluation of the forthcoming large earthquake along the Nankai Trough; the next earthquake is estimated M8 to 9 class, and the probability (P30) that the next earthquake will occur within the next 30 years (from Jan. 1, 2013) is 60% to 70%. In this study, we assess tsunami hazards (maximum coastal tsunami heights) in the near future, in terms of a probabilistic approach, from the next earthquake along Nankai Trough, on the basis of ERC(2013)'s report. The probabilistic tsunami hazard assessment that we applied is as follows; (1) Characterized earthquake fault models (CEFMs) are constructed on each of the 15 hypothetical source areas (HSA) that ERC(2013) showed. The characterization rule follows Toyama et al.(2015, JpGU). As results, we obtained total of 1441 CEFMs. (2) We calculate tsunamis due to CEFMs by solving nonlinear, finite-amplitude, long-wave equations with advection and bottom friction terms by finite-difference method. Run-up computation on land is included. (3) A time predictable model predicts the recurrent interval of the present seismic cycle is T=88.2 years (ERC,2013). We fix P30 = 67% by applying the renewal process based on BPT distribution with T and alpha=0.24 as its aperiodicity. (4) We divide the probability P30 into P30(i) for i-th subgroup consisting of the earthquakes occurring in each of 15 HSA by following a probability re-distribution concept (ERC,2014). Then each earthquake (CEFM) in i-th subgroup is assigned a probability P30(i)/N where N is the number of CEFMs in each sub-group. Note that such re-distribution concept of the probability is nothing but tentative because the present seismology cannot give deep knowledge enough to do it. Epistemic logic-tree approach may be required in future. (5) We synthesize a number of tsunami hazard curves at every evaluation points on coasts by integrating the information about 30 years occurrence probabilities P30(i) for all earthquakes (CEFMs) and calculated maximum coastal tsunami heights. In the synthesis, aleatory uncertainties relating to incompleteness of governing equations, CEFM modeling, bathymetry and topography data, etc, are modeled assuming a log-normal probabilistic distribution. Examples of tsunami hazard curves will be presented.

Reversible uptake of water on NaCl nanoparticles at relative humidity below deliquescence point observed by noncontact environmental atomic force microscopy

NASA Astrophysics Data System (ADS)

Bruzewicz, Derek A.; Checco, Antonio; Ocko, Benjamin M.; Lewis, Ernie R.; McGraw, Robert L.; Schwartz, Stephen E.

2011-01-01

The behavior of NaCl nanoparticles as a function of relative humidity (RH) has been characterized using non-contact environmental atomic force microscopy (e-AFM) to measure the heights of particles deposited on a prepared hydrophobic surface. Cubic NaCl nanoparticles with sides of 35 and 80 nm were found to take up water reversibly with increasing RH well below the bulk deliquescence relative humidity (DRH) of 75% at 23° C, and to form a liquid-like surface layer of thickness 2 to 5 nm, with measurable uptake ( >2 nm increase in particle height) beginning at 70% RH. The maximum thickness of the layer increased with increasing RH and increasing particle size over the range studied. The liquid-like behavior of the layer was indicated by a reversible rounding at the upper surface of the particles, fit to a parabolic cross-section, where the ratio of particle height to maximum radius of curvature increases from zero (flat top) at 68% RH to 0.7 ± 0.3 at 74% RH. These observations, which are consistent with a reorganization of mass on the solid NaCl nanocrystal at RH below the DRH, suggest that the deliquescence of NaCl nanoparticles is more complex than an abrupt first-order phase transition. The height measurements are consistent with a phenomenological model that assumes favorable contributions to the free energy of formation of a liquid layer on solid NaCl due both to van der Waals interactions, which depend partly upon the Hamaker constant, A_{{film}}, of the interaction between the thin liquid film and the solid NaCl, and to a longer-range electrostatic interaction over a characteristic length of persistence, ξ; the best fit to the data corresponded to A_{{film}} = 1 kT and ξ = 2.33 nm.

47 CFR 73.525 - TV Channel 6 protection.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... (4) The maximum permissible effective radiated power (ERP) and antenna height may be adjusted for..., the maximum permissible vertically polarized ERP will be the maximum horizontally polarized ERP... it does not. (ii) If the applicant chooses to use mixed polarity, the permissible ERP is as follows...

Ballistic stretching increases flexibility and acute vertical jump height when combined with basketball activity.

PubMed

Woolstenhulme, Mandy T; Griffiths, Christine M; Woolstenhulme, Emily M; Parcell, Allen C

2006-11-01

Stretching is often included as part of a warm-up procedure for basketball activity. However, the efficacy of stretching with respect to sport performance has come into question. We determined the effects of 4 different warm-up protocols followed by 20 minutes of basketball activity on flexibility and vertical jump height. Subjects participated in 6 weeks (2 times per week) of warm-up and basketball activity. The warm-up groups participated in ballistic stretching, static stretching, sprinting, or basketball shooting (control group). We asked 3 questions. First, what effect does 6 weeks of warm-up exercise and basketball play have on both flexibility and vertical jump height? We measured sit and reach and vertical jump height before (week -1) and after (week 7) the 6 weeks. Flexibility increased for the ballistic, static, and sprint groups compared to the control group (p < 0.0001), while vertical jump height did not change for any of the groups. Our second question was what is the acute effect of each warm-up on vertical jump height? We measured vertical jump immediately after the warm-up on 4 separate occasions during the 6 weeks (at weeks 0, 2, 4, and 6). Vertical jump height was not different for any group. Finally, our third question was what is the acute effect of each warm-up on vertical jump height following 20 minutes of basketball play? We measured vertical jump height immediately following 20 minutes of basketball play at weeks 0, 2, 4, and 6. Only the ballistic stretching group demonstrated an acute increase in vertical jump 20 minutes after basketball play (p < 0.05). Coaches should consider using ballistic stretching as a warm-up for basketball play, as it is beneficial to vertical jump performance.

Water availability predicts forest canopy height at the global scale.

PubMed

Klein, Tamir; Randin, Christophe; Körner, Christian

2015-12-01

The tendency of trees to grow taller with increasing water availability is common knowledge. Yet a robust, universal relationship between the spatial distribution of water availability and forest canopy height (H) is lacking. Here, we created a global water availability map by calculating an annual budget as the difference between precipitation (P) and potential evapotranspiration (PET) at a 1-km spatial resolution, and in turn correlated it with a global H map of the same resolution. Across forested areas over the globe, Hmean increased with P-PET, roughly: Hmean (m) = 19.3 + 0.077*(P-PET). Maximum forest canopy height also increased gradually from ~ 5 to ~ 50 m, saturating at ~ 45 m for P-PET > 500 mm. Forests were far from their maximum height potential in cold, boreal regions and in disturbed areas. The strong association between forest height and P-PET provides a useful tool when studying future forest dynamics under climate change, and in quantifying anthropogenic forest disturbance. © 2015 John Wiley & Sons Ltd/CNRS.

Predictability of Zonal Means During Boreal Summer

NASA Technical Reports Server (NTRS)

Schubert, Siegfried; Suarez, Max J.; Pegion, Philip J.; Kistler, Michael A.; Kumar, Arun; Einaudi, Franco (Technical Monitor)

2001-01-01

This study examines the predictability of seasonal means during boreal summer. The results are based on ensembles of June-July-August (JJA) simulations (started in mid May) carried out with the NASA Seasonal-to-Interannual Prediction Project (NSIPP-1) atmospheric general circulation model (AGCM) forced with observed sea surface temperatures (SSTS) and sea ice for the years 1980-1999. We find that the predictability of the JJA extra-tropical height field is primarily in the zonal mean component of the response to the SST anomalies. This contrasts with the cold season (January-February-March) when the predictability of seasonal means in the boreal extratropics is primarily in the wave component of the El Nino/Southern Oscillation (ENSO) response. Two patterns dominate the interannual variability of the ensemble mean JJA zonal mean height field. One has maximum variance in the tropical/subtropical upper troposphere, while the other has substantial variance in middle latitudes of both hemispheres. Both are symmetric with respect to the equator. A regression analysis suggests that the tropical/subtropical pattern is associated with SST anomalies in the far eastern tropical Pacific and the Indian Ocean, while the middle latitude pattern is forced by SST anomalies in the tropical Pacific just east of the dateline. The two leading zonal height patterns are reproduced in model runs forced with the two leading JJA SST patterns of variability. A comparison with observations shows a signature of the middle latitude pattern that is consistent with the occurrence of dry and wet summers over the United States. We hypothesize that both patterns, while imposing only weak constraints on extratropical warm season continental-scale climates, may play a role in the predilection for drought or pluvial conditions.

Maximizing Total QoS-Provisioning of Image Streams with Limited Energy Budget

NASA Astrophysics Data System (ADS)

Lee, Wan Yeon; Kim, Kyong Hoon; Ko, Young Woong

To fully utilize the limited battery energy of mobile electronic devices, we propose an adaptive adjustment method of processing quality for multiple image stream tasks running with widely varying execution times. This adjustment method completes the worst-case executions of the tasks with a given budget of energy, and maximizes the total reward value of processing quality obtained during their executions by exploiting the probability distribution of task execution times. The proposed method derives the maximum reward value for the tasks being executable with arbitrary processing quality, and near maximum value for the tasks being executable with a finite number of processing qualities. Our evaluation on a prototype system shows that the proposed method achieves larger reward values, by up to 57%, than the previous method.

Effects on run-off water quantity and quality of urban organic wastes applied in a degraded semi-arid ecosystem.

PubMed

Martínez, F; Casermeiro, M A; Morales, D; Cuevas, G; Walter, Ingrid

2003-04-15

Biosolids and composted municipal solid wastes were surface-applied (0 and 80 Mg ha(-1)) to a degraded soil in a semi-arid environment to determine their effects on the quantity and quality of run-off water. Three and 4 years after application, a simulated rainfall was performed (intensity=942.5 ml min(-1) and kinetic energy=3.92 J m(-2)) on 0.078 m(2) plots using a portable rainfall simulator. The run-off from the different treatment plots was collected and analysed. The type of treatment was highly related to infiltration, run-off and sediment production. The biosolid-treated plots showed the minimum value of total run-off, maximum time to the beginning of run-off and maximum run-off ratio (the relationship between total rainfall and run-off). The MSW-treated plots showed values intermediate between biosolid-treated plots and control plots. Soil losses were also closely related to treatment type. Control plots showed the maximum sediment yield, MSW-treated plots showed intermediate values, and biosolid plots the minimum values for washout. The concentrations of NH(4)-N and PO(4)-P in the run-off water were significantly higher in the treated plots than in control plots. The highest PO(4)-P value, 0.73 mg l(-1), was obtained in the soil treated with biosolids; NO(3)-N concentration also increased significantly with respect to the control and MSW treatments. NH(4)-N concentrations of 15.6 and 15.0 mg l(-1) were recorded in the soils treated with biosolids and MSW, respectively, values approximately five times higher than those obtained in run-off water from untreated soil. However, the concentrations of all these constituents were lower than threshold limits cited in water quality standards for agricultural use. With the exception of Cu, all trace metals analysed in the run-off water were below detection limits.

In-field High Throughput Phenotyping and Cotton Plant Growth Analysis Using LiDAR.

PubMed

Sun, Shangpeng; Li, Changying; Paterson, Andrew H; Jiang, Yu; Xu, Rui; Robertson, Jon S; Snider, John L; Chee, Peng W

2018-01-01

Plant breeding programs and a wide range of plant science applications would greatly benefit from the development of in-field high throughput phenotyping technologies. In this study, a terrestrial LiDAR-based high throughput phenotyping system was developed. A 2D LiDAR was applied to scan plants from overhead in the field, and an RTK-GPS was used to provide spatial coordinates. Precise 3D models of scanned plants were reconstructed based on the LiDAR and RTK-GPS data. The ground plane of the 3D model was separated by RANSAC algorithm and a Euclidean clustering algorithm was applied to remove noise generated by weeds. After that, clean 3D surface models of cotton plants were obtained, from which three plot-level morphologic traits including canopy height, projected canopy area, and plant volume were derived. Canopy height ranging from 85th percentile to the maximum height were computed based on the histogram of the z coordinate for all measured points; projected canopy area was derived by projecting all points on a ground plane; and a Trapezoidal rule based algorithm was proposed to estimate plant volume. Results of validation experiments showed good agreement between LiDAR measurements and manual measurements for maximum canopy height, projected canopy area, and plant volume, with R 2 -values of 0.97, 0.97, and 0.98, respectively. The developed system was used to scan the whole field repeatedly over the period from 43 to 109 days after planting. Growth trends and growth rate curves for all three derived morphologic traits were established over the monitoring period for each cultivar. Overall, four different cultivars showed similar growth trends and growth rate patterns. Each cultivar continued to grow until ~88 days after planting, and from then on varied little. However, the actual values were cultivar specific. Correlation analysis between morphologic traits and final yield was conducted over the monitoring period. When considering each cultivar individually, the three traits showed the best correlations with final yield during the period between around 67 and 109 days after planting, with maximum R 2 -values of up to 0.84, 0.88, and 0.85, respectively. The developed system demonstrated relatively high throughput data collection and analysis.

Final height in survivors of childhood cancer compared with Height Standard Deviation Scores at diagnosis.

PubMed

Knijnenburg, S L; Raemaekers, S; van den Berg, H; van Dijk, I W E M; Lieverst, J A; van der Pal, H J; Jaspers, M W M; Caron, H N; Kremer, L C; van Santen, H M

2013-04-01

Our study aimed to evaluate final height in a cohort of Dutch childhood cancer survivors (CCS) and assess possible determinants of final height, including height at diagnosis. We calculated standard deviation scores (SDS) for height at initial cancer diagnosis and height in adulthood in a cohort of 573 CCS. Multivariable regression analyses were carried out to estimate the influence of different determinants on height SDS at follow-up. Overall, survivors had a normal height SDS at cancer diagnosis. However, at follow-up in adulthood, 8.9% had a height ≤-2 SDS. Height SDS at diagnosis was an important determinant for adult height SDS. Children treated with (higher doses of) radiotherapy showed significantly reduced final height SDS. Survivors treated with total body irradiation (TBI) and craniospinal radiation had the greatest loss in height (-1.56 and -1.37 SDS, respectively). Younger age at diagnosis contributed negatively to final height. Height at diagnosis was an important determinant for height SDS at follow-up. Survivors treated with TBI, cranial and craniospinal irradiation should be monitored periodically for adequate linear growth, to enable treatment on time if necessary. For correct interpretation of treatment-related late effects studies in CCS, pre-treatment data should always be included.

Variation in Foot Strike Patterns among Habitually Barefoot and Shod Runners in Kenya.

PubMed

Lieberman, Daniel E; Castillo, Eric R; Otarola-Castillo, Erik; Sang, Meshack K; Sigei, Timothy K; Ojiambo, Robert; Okutoyi, Paul; Pitsiladis, Yannis

2015-01-01

Runners are often categorized as forefoot, midfoot or rearfoot strikers, but how much and why do individuals vary in foot strike patterns when running on level terrain? This study used general linear mixed-effects models to explore both intra- and inter-individual variations in foot strike pattern among 48 Kalenjin-speaking participants from Kenya who varied in age, sex, body mass, height, running history, and habitual use of footwear. High speed video was used to measure lower extremity kinematics at ground contact in the sagittal plane while participants ran down 13 meter-long tracks with three variables independently controlled: speed, track stiffness, and step frequency. 72% of the habitually barefoot and 32% of the habitually shod participants used multiple strike types, with significantly higher levels of foot strike variation among individuals who ran less frequently and who used lower step frequencies. There was no effect of sex, age, height or weight on foot strike angle, but individuals were more likely to midfoot or forefoot strike when they ran on a stiff surface, had a high preferred stride frequency, were habitually barefoot, and had more experience running. It is hypothesized that strike type variation during running, including a more frequent use of forefoot and midfoot strikes, used to be greater before the introduction of cushioned shoes and paved surfaces.

Effects of a capacitive-resistive electric transfer therapy on physiological and biomechanical parameters in recreational runners: A randomized controlled crossover trial.

PubMed

Duñabeitia, Iratxe; Arrieta, Haritz; Torres-Unda, Jon; Gil, Javier; Santos-Concejero, Jordan; Gil, Susana M; Irazusta, Jon; Bidaurrazaga-Letona, Iraia

2018-05-26

This study compared the effects of a capacitive-resistive electric transfer therapy (Tecar) and passive rest on physiological and biomechanical parameters in recreational runners when performed shortly after an exhausting training session. Randomized controlled crossover trial. University biomechanical research laboratory. Fourteen trained male runners MAIN OUTCOME MEASURES: Physiological (running economy, oxygen uptake, respiratory exchange ratio, ventilation, heart rate, blood lactate concentration) and biomechanical (step length; stride angle, height, frequency, and contact time; swing time; contact phase; support phase; push-off phase) parameters were measured during two incremental treadmill running tests performed two days apart after an exhaustive training session. When running at 14 km/h and 16 km/h, the Tecar treatment group presented greater increases in stride length (p < 0.001), angle (p < 0.05) and height (p < 0.001) between the first and second tests than the control group and, accordingly, greater decreases in stride frequency (p < 0.05). Physiological parameters were similar between groups. The present study suggests that a Tecar therapy intervention enhances biomechanical parameters in recreational runners after an exhaustive training session more than passive rest, generating a more efficient running pattern without affecting selected physiological parameters. Copyright © 2018 Elsevier Ltd. All rights reserved.

Numerical simulations of inductive-heated float-zone growth

NASA Technical Reports Server (NTRS)

Chan, Y. T.; Choi, S. K.

1992-01-01

The present work provides an improved fluid flow and heat-transfer modeling of float-zone growth by introducing a RF heating model so that an ad hoc heating temperature profile is not necessary. Numerical simulations were carried out to study the high-temperature float-zone growth of titanium carbide single crystal. The numerical results showed that the thermocapillary convection occurring inside the molten zone tends to increase the convexity of the melt-crystal interface and decrease the maximum temperature of the molten zone, while the natural convection tends to reduce the stability of the molten zone by increasing its height. It was found that the increase of induced heating due to the increase of applied RF voltage is reduced by the decrease of zone diameter. Surface tension plays an important role in controlling the amount of induced heating. Finally, a comparison of the computed shape of the free surface with a digital image obtained during a growth run showed adequate agreement.

Wind power as an electrical energy source in Illinois

NASA Astrophysics Data System (ADS)

Wendland, W. M.

1982-03-01

A preliminary estimate of the total wind power available in Illinois was made using available historical data, and projections of cost savings due to the presence of wind-generated electricity were attempted. Wind data at 10 m height were considered from nine different sites in the state, with three years data nominally being included. Wind-speed frequency histograms were developed for day and night periods, using a power law function to extrapolate the 10 m readings to 20 m. Wind speeds over the whole state were found to average over 8 mph, the cut-in point for most wind turbines, for from 40-63% of the time. A maximum of 75% run-time was determined for daylight hours in April-May. A reference 1.8 kW windpowered generator was used in annual demand projections for a reference one family home, using the frequency histograms. The small generator was projected to fulfill from 25-53% of the annual load, and, based on various cost assumptions, exhibited paybacks taking from 14-27 yr.

Snow precipitation in Adelie Land, Antarctica. MAR validation using data from a meteorological radar

NASA Astrophysics Data System (ADS)

Gallée, Hubert; Grazioli, Jacopo; Berne, Alexis; Christophe, Genthon

2017-04-01

The regional climate model MAR (Modèle Atmosphérique Régional) has been run over Adélie Land in the frame of the APRES3 project, in order to understand the different physical mechanisms affecting precipitation in this region. An horizontal resolution of 5 km is used. Several case studies have been considered during the period between december 2015 and may 2016. MAR snow precipitation flux is compared to observations made with a meteorological radar operating at Dumont d'Urville during this period. It is found that MAR sometimes simulates a maximum in the precipitation flux which is situated well above the ground, as in the observations. Possible causes may the found in the influence of the dry katabatic airflow often observed in Adélie Land. Our work indicates that the retreive of a precipitation climatology from satellite observations must be done with caution, when these observations are possible only for a significant height above the ground.

Updraft Model for Development of Autonomous Soaring Uninhabited Air Vehicles

NASA Technical Reports Server (NTRS)

Allen, Michael J.

2006-01-01

Large birds and glider pilots commonly use updrafts caused by convection in the lower atmosphere to extend flight duration, increase cross-country speed, improve range, or simply to conserve energy. Uninhabited air vehicles may also have the ability to exploit updrafts to improve performance. An updraft model was developed at NASA Dryden Flight Research Center (Edwards, California) to investigate the use of convective lift for uninhabited air vehicles in desert regions. Balloon and surface measurements obtained at the National Oceanic and Atmospheric Administration Surface Radiation station (Desert Rock, Nevada) enabled the model development. The data were used to create a statistical representation of the convective velocity scale, w*, and the convective mixing-layer thickness, zi. These parameters were then used to determine updraft size, vertical velocity profile, spacing, and maximum height. This paper gives a complete description of the updraft model and its derivation. Computer code for running the model is also given in conjunction with a check case for model verification.

Postnatal craniofacial skeleton development following a pushback operation of patients with cleft palate.

PubMed

Viteporn, S; Enemark, H; Melsen, B

1991-10-01

A longitudinal growth study of the craniofacial skeleton in 52 (19 males, 33 females) Danish individuals with cleft palates was performed. Thirty (13 males, 17 females) had clefts of the soft palate only or clefts extending into the posterior third of the hard palate. Twenty-two (6 males, 16 females) had more extensive clefts including up to two-thirds of the hard palate. The cleft was closed with a pushback operation at 22 months of age. Orthodontic treatment was included in the early mixed dentition. Lateral cephalometries were obtained at 5, 8, 12, 16, and 21 years of age. Twenty-four variables were digitized and analyzed. The results indicated that patients with more extensive clefts demonstrated significantly smaller anterior cranial base length (N-S), total cranial base length (N-Ba), maxillary dentoalveolar base length (A-PMP), mandibular length (Cd-Pgn), upper anterior and posterior facial heights (N-ANS and P-PMP), and total facial height (N-Gn). Patients with the more extensive clefts reached maximum growth spurt later than patients with less extensive clefts in all dimensions except the A-PMP and the lower and total facial heights.

Evaluation of GOCE-based Global Geoid Models in Finnish Territory

NASA Astrophysics Data System (ADS)

Saari, Timo; Bilker-Koivula, Mirjam

2015-04-01

The gravity satellite mission GOCE made its final observations in the fall of 2013. By then it had exceeded its expected lifespan of one year with more than three additional years. Thus, the mission collected more data from the Earth's gravitational field than expected, and more comprehensive global geoid models have been derived ever since. The GOCE High-level Processing Facility (HPF) by ESA has published GOCE global gravity field models annually. We compared all of the 12 HPF-models as well as 3 additional GOCE, 11 GRACE and 6 combined GOCE+GRACE models with GPS-levelling data and gravity observations in Finland. The most accurate models were compared against high resolution global geoid models EGM96 and EGM2008. The models were evaluated up to three different degrees and order: 150 (the common maximum for the GRACE models), 240 (the common maximum for the GOCE models) and maximum. When coefficients up to degree and order 150 are used, the results of the GOCE models are comparable with the results of the latest GRACE models. Generally, all of the latest GOCE and GOCE+GRACE models give standard deviations of the height anomaly differences of around 15 cm and of gravity anomaly differences of around 10 mgal over Finland. The best solutions were not always achieved with the highest maximum degree and order of the satellite gravity field models, since the highest coefficients (above 240) may be less accurately determined. Over Finland, the latest GOCE and GOCE+GRACE models give similar results as the high resolution models EGM96 and EGM2008 when coefficients up to degree and order 240 are used. This is mainly due to the high resolution terrestrial data available in the area of Finland, which was used in the high resolution models.

Comparison of VO[subscript 2] Maximum Obtained from 20 m Shuttle Run and Cycle Ergometer in Children with and without Developmental Coordination Disorder

ERIC Educational Resources Information Center

Cairney, John; Hay, John; Veldhuizen, Scott; Faught, Brent

2010-01-01

Oxygen consumption at peak physical exertion (VO[subscript 2] maximum) is the most widely used indicator of cardiorespiratory fitness. The purpose of this study was to compare two protocols for its estimation, cycle ergometer testing and the 20 m shuttle run, among children with and without probable developmental coordination disorder (pDCD). The…

Assimilation of GOES-Derived Cloud Fields Into MM5

NASA Astrophysics Data System (ADS)

Biazar, A. P.; Doty, K. G.; McNider, R.

2007-12-01

This approach for the assimilation of GOES-derived cloud data into an atmospheric model (the Fifth-Generation Pennsylvania State University-National Center for Atmospheric Research Mesoscale Model, or MM5) was performed in two steps. In the first step, multiple linear regression equations were developed using a control MM5 simulation to develop relationships for several dependent variables in model columns that had one or more layers of clouds. In the second step, the regression equations were applied during an MM5 simulation with assimilation in which the hourly GOES satellite data were used to determine the cloud locations and some of the cloud properties, but with all the other variables being determined by the model data. The satellite-derived fields used were shortwave cloud albedo and cloud top pressure. Ten multiple linear regression equations were developed for the following dependent variables: total cloud depth, number of cloud layers, depth of the layer that contains the maximum vertical velocity, the maximum vertical velocity, the height of the maximum vertical velocity, the estimated 1-h stable (i.e., grid scale) precipitation rate, the estimated 1-h convective precipitation rate, the height of the level with the maximum positive diabatic heating, the magnitude of the maximum positive diabatic heating, and the largest continuous layer of upward motion. The horizontal components of the divergent wind were adjusted to be consistent with the regression estimate of the maximum vertical velocity. The new total horizontal wind field with these new divergent components was then used to nudge an ongoing MM5 model simulation towards the target vertical velocity. Other adjustments included diabatic heating and moistening at specified levels. Where the model simulation had clouds when the satellite data indicated clear conditions, procedures were taken to remove or diminish the errant clouds. The results for the period of 0000 UTC 28 June - 0000 UTC 16 July 1999 for both a continental 32-km grid and an 8-km grid over the Southeastern United States indicate a significant improvement in the cloud bias statistics. The main improvement was the reduction of high bias values that indicated times and locations in the control run when there were model clouds but when the satellite indicated clear conditions. The importance of this technique is that it has been able to assimilate the observed clouds in the model in a dynamically sustainable manner. Acknowledgments. This work was partially funded by the following grants: a GEWEX grant from NASA , the Cooperative Agreement between the University of Alabama in Huntsville and the Minerals Management Service on Gulf of Mexico Issues, a NASA applications grant, and a NSF grant.

Posture-related distribution of hyperbaric bupivacaine in cerebro-spinal fluid is influenced by spinal needle characteristics.

PubMed

Mardirosoff, C; Dumont, L; Deyaert, M; Leconte, M

2001-07-01

No studies have evaluated the relationship between duration of time sitting and spinal needle type on the maximal spread of local anaesthetics. The few trials available have studied the influence of time spent sitting on the spread of anaesthesia without standardising spinal needle types, and have not found any effect. In this randomised, blinded study, 60 patients scheduled for elective orthopaedic surgery of the lower limbs were divided into 4 groups. With the patient sitting erect, 15 mg hyperbaric bupivacaine were injected in a standard manner through a 24G Sprotte or a 27G Whitacre needle and patients were placed supine after 1 min (24G/1 group and 27G/1 group) or 4 min (24G/4 group and 27G/4 group). Time to achieve maximum block height after injection was similar in all groups. Block height levels were significantly lower at all time points for the 24G/4 group. Maximum block heights were Th4 in the 24G/1, 27G/1 and 27G/4 groups, and Th6 in the 24G/4 group (P<0.0001). In a standard spinal anaesthesia procedure, when different lengths of time spent sitting are compared, spinal needle characteristics influence the maximum spread of hyperbaric bupivacaine. However, within the limits of our study, a two-segment difference in block height is too small to consider using spinal needles as valuable tools to control block height during spinal anaesthesia in our daily practice.

Projections of wind-waves in South China Sea for the 21st century

NASA Astrophysics Data System (ADS)

Mohammed, Aboobacker; Dykyi, Pavlo; Zheleznyak, Mark; Tkalich, Pavel

2013-04-01

IPCC-coordinated work has been completed within Fourth Assessment Report (AR4) to project climate and ocean variables for the 21st century using coupled atmospheric-ocean General Circulation Models (GCMs). GCMs are not having a wind-wave variable due to a poor grid resolution; therefore, dynamical downscaling of wind-waves to the regional scale is advisable using well established models, such as Wave Watch III (WWIII) and SWAN. Rectilinear-coordinates WWIII model is adapted for the far field comprising the part of Pacific and Indian Oceans centered at the South China Sea and Sunda Shelf (90 °E-130 °E, 10 °S - 26.83 °N) with a resolution of 10' (about 18 km). Near-field unstructured-mesh SWAN model covers Sunda Shelf and centered on Singapore Strait, while reading lateral boundary values from WWIII model. The unstructured grid has the coarsest resolution in the South China Sea (6 to 10 km), medium resolution in the Malacca Strait (1 to 2 km), and the finest resolution in the Singapore Strait (400 m) and along the Singapore coastline (up to 100 m). Following IPCC methodology, the model chain is validated climatologically for the past period 1961-1990 against Voluntary Observing Ship (VOS) data; additionally, the models are validated using recent high-resolution satellite data. The calibrated model chain is used to project waves to 21st century using WRF-downscaled wind speed output of CCSM GCM run for A1FI climate change scenario. To comply with IPCC methodology the entire modeling period is split into three 30-years periods for which statistical parameters are computed individually. Time series of significant wave height at key points near Singapore and on ship sea routes in the SCS are statistically analysed to get probability distribution functions (PDFs) of extreme values. Climatological maps of mean and maximum significant wave height (SWH) values, and mean wave period are built for Singapore region for each 30-yrs period. Linear trends of mean SWH values for northeast (NE) and southwest (SW) monsoons have been derived. The maximum values of predicted 100 year return period (YRP) SWH are obtained for the 1st 30-yrs period (2011-2040). In the deep eastern part of the Singapore, 100yrp SWH are 2.4 - 2.8 m, whereas those at the shallow nearshore areas are 1.7-2.3 m. On the ship routes at Sunda Shelf the 100 YRP SWHs are 1.1 - 3.2 m, and those at the SCS routes are 3.6 - 10.4 m. The biggest changes in future against hindcasted SWH is in first 30-yrs, where extreme 100 YRP SWH will grow up in the range from 36%-120% at points near Singapore and to 39%-108% at ship sea routes.

Simulation-Based Height of Burst Map for Asteroid Airburst Damage Prediction

NASA Technical Reports Server (NTRS)

Aftosmis, Michael J.; Mathias, Donovan L.; Tarano, Ana M.

2017-01-01

Entry and breakup models predict that airburst in the Earth's atmosphere is likely for asteroids up to approximately 200 meters in diameter. Objects of this size can deposit over 250 megatons of energy into the atmosphere. Fast-running ground damage prediction codes for such events rely heavily upon methods developed from nuclear weapons research to estimate the damage potential for an airburst at altitude. (Collins, 2005; Mathias, 2017; Hills and Goda, 1993). In particular, these tools rely upon the powerful yield scaling laws developed for point-source blasts that are used in conjunction with a Height of Burst (HOB) map to predict ground damage for an airburst of a specific energy at a given altitude. While this approach works extremely well for yields as large as tens of megatons, it becomes less accurate as yields increase to the hundreds of megatons potentially released by larger airburst events. This study revisits the assumptions underlying this approach and shows how atmospheric buoyancy becomes important as yield increases beyond a few megatons. We then use large-scale three-dimensional simulations to construct numerically generated height of burst maps that are appropriate at the higher energy levels associated with the entry of asteroids with diameters of hundreds of meters. These numerically generated HOB maps can then be incorporated into engineering methods for damage prediction, significantly improving their accuracy for asteroids with diameters greater than 80-100 m.

Particulate matter emission by a vehicle running on unpaved road

NASA Astrophysics Data System (ADS)

Williams, David Scott; Shukla, Manoj K.; Ross, Jim

2008-05-01

The particulate matter (PM) emission from unpaved roads starts with the pulverization of surface material by the force of the vehicle, uplifting and subsequent exposure of road to strong air currents behind the wheels. The objectives of the project were to: demonstrate the utility of a simple technique for collecting suspended airborne PM emitted by vehicle running on an unpaved road, determine the mass balance of airborne PM at different heights, and determine the particle size and elemental composition of PM. We collected dust samples on sticky tapes using a rotorod sampler mounted on a tower across an unpaved road located at the Leyendecker Plant Sciences Research Center, Las Cruces, NM, USA. Dust samples were collected at 1.5, 4.5 and 6 m height above the ground surface on the east and west side of the road. One rotorod sampler was also installed at the centre of the road at 6 m height. Dust samples from unpaved road were mostly (70%) silt and clay-sized particles and were collected at all heights. The height and width of the PM plume and the amount of clay-sized particles captured on both sides of the road increased with speed and particle captured ranged from 0.05 to 159 μm. Dust particles between PM10 and PM2.5 did not correlate with vehicle speed but particles ⩽PM2.5 did. Emission factors estimated for the total suspended PM were 10147 g km-1 at 48 km h-1 and 11062 g km-1 at 64 km h-1 speed, respectively. The predominant elements detected in PM were carbon, aluminum and silica at all heights. Overall, sticky tape method coupled with electron microscopy was a useful technique for a rapid particle size and elemental characterization of airborne PM.

Maximum Power Training and Plyometrics for Cross-Country Running.

ERIC Educational Resources Information Center

Ebben, William P.

2001-01-01

Provides a rationale for maximum power training and plyometrics as conditioning strategies for cross-country runners, examining: an evaluation of training methods (strength training and maximum power training and plyometrics); biomechanic and velocity specificity (role in preventing injury); and practical application of maximum power training and…

47 CFR 90.693 - Grandfathering provisions for incumbent licensees.

Code of Federal Regulations, 2010 CFR

2010-10-01

... shall be calculated using the maximum ERP and the actual height of the antenna above average terrain... using the maximum ERP and the actual HAAT along each radial. Incumbent licensees seeking to utilize an...

47 CFR 90.693 - Grandfathering provisions for incumbent licensees.

Code of Federal Regulations, 2011 CFR

2011-10-01

... shall be calculated using the maximum ERP and the actual height of the antenna above average terrain... using the maximum ERP and the actual HAAT along each radial. Incumbent licensees seeking to utilize an...

Kinetic Space Towers and Launchers

NASA Astrophysics Data System (ADS)

Bolonkin, A.

The paper discusses a new revolutionary method for access to outer space. A cable stands up vertically and pulls up its payload to space with a maximum force determined by its strength. From the ground the cable is allowed to rise up to the required altitude. After this, one can climb to an altitude by this cable or deliver to altitude a required load. The paper shows this is possible and does not infringe on the law of gravity. The article contains the theory of the method and the computations for four projects for towers that are 4, 75, 225 and 160,000 km in height. The first three projects use conventional artificial fiber widely produced by current industry, while the fourth project uses nanotubes made in scientific laboratories. The paper also shows in a fifth project how this idea can be used to launch a load at high altitude.

Match running performance and skill execution improves with age but not the number of disposals in young Australian footballers.

PubMed

Gastin, Paul B; Tangalos, Christie; Torres, Lorena; Robertson, Sam

2017-12-01

This study investigated age-related differences in maturity, physical and functional characteristics and playing performance in youth Australian Football (AF). Young male players (n = 156) were recruited from 12 teams across 6 age groups (U10-U15) of a recreational AF club. All players were tested for body size, maturity and fitness. Player performance was assessed during a match in which disposals (kicks and handballs) and their effectiveness were coded from a video recording and match running performance measured using Global Positioning System. Significant main effects (P < 0.01) for age group were observed for age, years to peak height velocity, body mass, height, 20 m sprint, maximal speed over 20 m, vertical jump, 20 m multistage shuttle run, match distance, high-speed running distance, peak speed, number of effective disposals and percentage of effective disposals. Age-related differences in fitness characteristics (speed, lower body power and endurance) appeared to transfer to match running performance. The frequency in which players disposed of the football did not differ between age groups, however the effectiveness of each disposal (i.e., % effective disposals) improved with age. Match statistics, particularly those that evaluate skill execution outcome (i.e., effectiveness), are useful to assess performance and to track player development over time. Differences between age groups, and probably variability within age groups, are strongly associated with chronological age and maturity.