Science.gov

Sample records for agulhas return current

  1. The Agulhas Current

    NASA Astrophysics Data System (ADS)

    de Ruijter, Will P. M.

    2008-03-01

    Many people in the United States know about the Gulf Stream, the impressive boundary current along the eastern U.S. coast that carries large amounts of heat poleward and, after separation from the coast, across the North Atlantic. Its impact on warming the eastern United States and the North Atlantic region including western Europe is also well known to the general public. But who in the United States knows about the Agulhas Current? This warm, western boundary current of the southern Indian Ocean flows southward along the continental slope of the African continent and is about as large as the Gulf Stream. It brings heat and moisture to the coastal regions of southeastern Africa. Variations in its transport lead to significant rainfall anomalies over this region. On a larger scale, its influence may even extend as far as the North Atlantic.

  2. Satellite observations of the Agulhas Current system.

    PubMed

    Quartly, Graham D; Srokosz, Meric A

    2003-01-15

    The Agulhas Current system is a complex interplay of currents and eddies with the bathymetry. Components such as the East Madagascar Retroflection and the Agulhas Return Current evolve significantly over a month, and they are thus not adequately resolved by infrequent research-ship cruises. This paper contrasts the abilities of three different spaceborne sensors for monitoring these complex regimes. A key parameter is sea-surface temperature, measured by both infrared and microwave radiometers. Ocean colour observations of chlorophyll can also be used to distinguish between water masses. PMID:12626239

  3. Measuring Agulhas Current strength and leakage from satellite altimetry

    NASA Astrophysics Data System (ADS)

    Le Bars, Dewi; De Ruijter, Wilhelmus P. M.; Dijkstra, Henk A.

    2013-04-01

    The Agulhas leakage is a flux of relatively warm and salty water from the Indian Ocean to the South Atlantic Ocean. It occurs south of the African continent where the Agulhas Current retroflects and sheds large anticyclonic eddies that quickly break up and mix with the surrounding water. This is one of the most energetic regions of the world ocean and the Agulhas leakage is therefore very difficult to quantify. In recent years two independent studies (Biastoch et al. 2009, Rouault et al. 2009) using different ocean models pointed out the possibility that the strength of the Agulhas leakage could have increased over the last decades. Unfortunately several discrepancies exist between these two studies on the magnitude and the causes of this increase showing the limitations of numerical modelling in this area. In this work we use a combination of along-track and mapped satellite geostrophic velocities to compute the strength of the Agulhas Current and to follow Lagrangian particles released in its core. The results confirm a positive trend of the volume of Agulhas leakage over the last two decades. This allows us to investigate the dependence of the leakage to upstream conditions like the Agulhas Current transport, the pattern and strength of the westerly winds and to test previous theories on the relations between these factors. Biastoch, A., Böning, C. W., Schwarzkopf, F. U. and Lutjeharms, J. R. E.: Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies, Nature, 462(7272), 495-498, doi:10.1038/nature08519, 2009. Rouault, M., Penven, P. and Pohl, B.: Warming in the Agulhas Current system since the 1980's, Geophys. Res. Lett, 36(L12602), doi:10.1029/2009GL037987, 2009.

  4. Wind changes above warm Agulhas Current eddies

    NASA Astrophysics Data System (ADS)

    Rouault, M.; Verley, P.; Backeberg, B.

    2016-04-01

    Sea surface temperature (SST) estimated from the Advanced Microwave Scanning Radiometer E onboard the Aqua satellite and altimetry-derived sea level anomalies are used south of the Agulhas Current to identify warm-core mesoscale eddies presenting a distinct SST perturbation greater than to 1 °C to the surrounding ocean. The analysis of twice daily instantaneous charts of equivalent stability-neutral wind speed estimates from the SeaWinds scatterometer onboard the QuikScat satellite collocated with SST for six identified eddies shows stronger wind speed above the warm eddies than the surrounding water in all wind directions, if averaged over the lifespan of the eddies, as was found in previous studies. However, only half of the cases showed higher wind speeds above the eddies at the instantaneous scale; 20 % of cases had incomplete data due to partial global coverage by the scatterometer for one path. For cases where the wind is stronger above warm eddies, there is no relationship between the increase in surface wind speed and the SST perturbation, but we do find a linear relationship between the decrease in wind speed from the centre to the border of the eddy downstream and the SST perturbation. SST perturbations range from 1 to 6 °C for a mean eddy SST of 15.9 °C and mean SST perturbation of 2.65 °C. The diameter of the eddies range from 100 to 250 km. Mean background wind speed is about 12 m s-1 (mostly southwesterly to northwesterly) and ranging mainly from 4 to 16 m s-1. The mean wind increase is about 15 %, which corresponds to 1.8 m s-1. A wind speed increase of 4 to 7 m s-1 above warm eddies is not uncommon. Cases where the wind did not increase above the eddies or did not decrease downstream had higher wind speeds and occurred during a cold front associated with intense cyclonic low-pressure systems, suggesting certain synoptic conditions need to be met to allow for the development of wind speed anomalies over warm-core ocean eddies. In many cases

  5. Origins and impacts of mesoscale meanders in the Agulhas Current

    NASA Astrophysics Data System (ADS)

    Elipot, S.; Beal, L. M.

    2014-12-01

    The Agulhas Current (AC) is the western boundary current of the South Indian subtropical gyre and is also the pathway for the inter-basin exchange of water, heat and salt between the Indian Ocean and the Atlantic Ocean, and thus a crucial part of the global overturning circulation of the world ocean. The AC, which otherwise flows stably along the coast of South Africa, undergoes dramatic offshore excursions from its mean path, forming large mesoscale solitary meanders propagating downstream and potentially linked to the leakage of Indian Ocean waters to the South Atlantic. These irregular meander events have been referred to as Natal Pulses.Here we present new observations and analyses of Agulhas meanders using full-depth velocity mooring observations from the Agulhas Current Time series experiment (ACT). Detailed analyses of the in-situ velocity reveal important differences between the behavior of the flow during solitary meander events and during meander events of smaller amplitude. During solitary meanders, an onshore cyclonic circulation and an offshore anticyclonic circulation act in concert to displace the jet offshore, leading to sudden and strong positive conversion of kinetic energy of the mean flow to the meander. In contrast, smaller amplitude meanderings are principally represented by a single cyclonic circulation spanning the entire jet that acts to displace the jet without significantly extracting kinetic energy from the mean flow. Solitary meander events can be traced upstream using satellite altimetry and linked to either Mozambique Channel eddies or Madagascar dipoles, the latter possibly part of a basin-wide pattern of propagating sea level anomalies consistent with Rossby wave dynamics. However, only a small number of these anomalies lead to solitary meanders. Altimetric observations suggest 1.5 meanders per year and show that the two-year period during ACT when no events were observed is unprecedented in the 20-year satellite record.

  6. Improving Understanding of the Agulhas Current and Its Global Climate Impacts

    NASA Astrophysics Data System (ADS)

    Beal, Lisa; Biastoch, Arne

    2010-05-01

    Working Group on the Climatic Importance of the Greater Agulhas System; Portland, Oregon, 20-21 February 2010; The first meeting of the new Scientific Committee on Oceanic Research (SCOR) Working Group 136 was held to discuss recent developments in understanding the greater Agulhas Current system and future research directions. The overarching goal of the working group is to improve understanding and awareness of the regional and global climate impacts of the Agulhas Current, a major western boundary current that flows along the east coast of Africa, and its interocean leakage. In addition to studying modern circulation, the working group is motivated by recent paleodata that suggest that through the currents' southern influence on the Atlantic meridional overturning circulation (AMOC), changes in the leakage of warm and salty Agulhas waters into the Atlantic may have triggered the end of ice ages. In terms of global climate, this arguably puts the importance of the greater Agulhas system on a par with Heinrich (land-ice release) events and high-latitude deepwater formation.

  7. Observations of an early Agulhas current retroflection event in 2001: A temporary cessation of inter-ocean exchange south of Africa?

    NASA Astrophysics Data System (ADS)

    van Aken, H. M.; Lutjeharms, J. R. E.; Rouault, M.; Whittle, C.; de Ruijter, W. P. M.

    2013-02-01

    The exchange of heat and salt between the South Indian Ocean and South Atlantic Ocean, at the southern terminus of the Agulhas current, forms a crucial link in the global ocean circulation. It has been surmised that upstream retroflections in this current could produce temporary interruptions to the exchange, but that their impact would depend on the vertical extent of such retroflections and on their duration. The fortuitous presence at sea of a research vessel has now enabled us to investigate such an episode at subsurface levels in combination with remote sensing of the sea surface. We present here the first in situ evidence that an upstream or early retroflection can extend to a depth of well over 750 m and last for 5 months. This event was likely triggered upstream by the happenstance of two Natal Pulses, large cyclonic eddies inshore of the Agulhas current. These eddies short-circuited the Agulhas with its Return current, leading to the shedding of three large Agulhas rings in quick succession. The arrival of a third cyclonic eddy when the Retroflection was still quite retracted did not lead to another ring shedding event. The resulting early retroflection may have had the effect of stalling the shedding of Agulhas rings and their motion towards the Cape Basin. However, these early retroflections are too scarce to allow generic statements on their generation or consequences, and the relation with large-scale environmental factors. It is likely that the observed withdrawal of the retroflection into the Transkei Basin is a fortuitous result of a series of contingent interactions.

  8. Madagascar corals track sea surface temperature variability in the Agulhas Current core region over the past 334 years

    PubMed Central

    Zinke, J.; Loveday, B. R.; Reason, C. J. C.; Dullo, W.-C.; Kroon, D.

    2014-01-01

    The Agulhas Current (AC) is the strongest western boundary current in the Southern Hemisphere and is key for weather and climate patterns, both regionally and globally. Its heat transfer into both the midlatitude South Indian Ocean and South Atlantic is of global significance. A new composite coral record (Ifaty and Tulear massive Porites corals), is linked to historical AC sea surface temperature (SST) instrumental data, showing robust correlations. The composite coral SST data start in 1660 and comprise 200 years more than the AC instrumental record. Numerical modelling exhibits that this new coral derived SST record is representative for the wider core region of the AC. AC SSTs variabilities show distinct cooling through the Little Ice Age and warming during the late 18th, 19th and 20th century, with significant decadal variability superimposed. Furthermore, the AC SSTs are teleconnected with the broad southern Indian and Atlantic Oceans, showing that the AC system is pivotal for inter-ocean heat exchange south of Africa. PMID:24637665

  9. The spatial evolution of t he directional wave spectrum in the Southern Ocean: Its relation to extreme waves in Agulhas Current

    NASA Technical Reports Server (NTRS)

    Beal, R. C.; Goldfinger, A.; Irvine, D.; Monaldo, F.; Tilley, D.; Shuchman, R.; Lyzenga, D.; Lyden, J.; Deleonibus, P.; Rufenach, C.

    1984-01-01

    An experiment using the Shuttle Imaging Radar-B (SIR-B) to monitor certain properties of the ocean wave directional spectrum and to track the long swell systems as they propagate northward to encounter the Agulhas near the southeastern coast of Africa is discussed. The experiment is designed around the unique capability of SIR-B to overcome key limitations of the Seasat synthetic aperture radar data set, and to extend the existing Seasat results into new areas. Ocean wave systems will be tracked. The variable-incidence-angle capability to examine wave imaging quality will be utilized. Doppler current measurements will be attempted. An effort will be made to verify that the lower range-to-velocity ratio of SIR-B will lead to the improved response of azimuth-traveling wave systems.

  10. Sea surface temperatures from the southern Benguela region from the Pliocene and Pleistocene: tracking Agulhas Current input into the SE Atlantic

    NASA Astrophysics Data System (ADS)

    Petrick, B. F.; McClymont, E.; Felder, S.; Lloyd, J. M.; Leng, M. J.

    2011-12-01

    The Pliocene and-Pleistocene epochs provide a way to understand the effect of past climate changes on key ocean currents. Here, we show results from ODP Site1087 (31.28'S, 15.19'E, 1374m water depth) to investigate changes in ocean circulation over the period of the mid-Pliocene warm period 3.0-3.5 Ma and compare these to the time of the 100 kyr Pleistocene glacial cycles. ODP 1087 is located in the South-eastern Atlantic Ocean, outside of the Benguela upwelling region; reconstructing the temperature history of the site will therefore provide an important data set from a part of the ocean that has few orbital-scale and continuous Pliocene temperature reconstructions. ODP 1087 can be used to investigate the history of the heat and salt transfer to the Atlantic Ocean from the Indian Ocean via the Agulhas Retroflection, which plays an important part in the global thermohaline circulation (Lutjeharms, 2007). Climate models and reconstructions for the most recent glacial-interglacial cycles have shown that changes to the strength of the heat transfer may cause major climatic changes and may play a role in transitions from glacial to interglacial events (Knorr & Lohmann, 2003). It is unknown how this transfer reacted to generally warmer global temperatures during the mid-Pliocene. Because the mid-Pliocene is seen as a model for future climate change it might provide a model for ocean circulations in a warmer world. Our approach is to apply several organic geochemistry proxies and foraminiferal analyses to reconstruct the history of ODP 1087. The UK37' index records differences in the unsaturated bonds in the C37 alkenones to reconstruct sea surface temperatures (Brassell et al., 1986). We present SSTs generated for the mid-Pliocene Warm period with a resolution of 4000 years. We compare this data to the time of the 100 kyr glacial cycles during the late Pleistocene. Even though ODP 1087 is located outside the Benguela upwelling system, it has lower Pliocene temperatures

  11. The global return current in a pulsar's magnetosphere

    NASA Astrophysics Data System (ADS)

    Barzilay, Yudith

    2016-08-01

    An open issue in pulsar's models is the current adjustment between the gap current and the global current that depends on the global structure of the pulsar's magnetosphere. Here I propose a mechanism for the global return current in pulsars.

  12. Spatio-temporal characteristics of Agulhas leakage: a model inter-comparison study

    NASA Astrophysics Data System (ADS)

    Holton, L.; Deshayes, J.; Backeberg, B. C.; Loveday, B. R.; Hermes, J. C.; Reason, C. J. C.

    2016-05-01

    Investigating the variability of Agulhas leakage, the volume transport of water from the Indian Ocean to the South Atlantic Ocean, is highly relevant due to its potential contribution to the Atlantic Meridional Overturning Circulation as well as the global circulation of heat and salt and hence global climate. Quantifying Agulhas leakage is challenging due to the non-linear nature of this process; current observations are insufficient to estimate its variability and ocean models all have biases in this region, even at high resolution . An Eulerian threshold integration method is developed to examine the mechanisms of Agulhas leakage variability in six ocean model simulations of varying resolution. This intercomparison, based on the circulation and thermohaline structure at the Good Hope line, a transect to the south west of the southern tip of Africa , is used to identify features that are robust regardless of the model used and takes into account the thermohaline biases of each model. When determined by a passive tracer method, 60 % of the magnitude of Agulhas leakage is captured and more than 80 % of its temporal fluctuations, suggesting that the method is appropriate for investigating the variability of Agulhas leakage. In all simulations but one, the major driver of variability is associated with mesoscale features passing through the section. High resolution ({<} 1/10°) hindcast models agree on the temporal (2-4 cycles per year) and spatial (300-500 km) scales of these features corresponding to observed Agulhas Rings. Coarser resolution models ({<} 1/4°) reproduce similar time scale of variability of Agulhas leakage in spite of their difficulties in representing the Agulhas rings properties. A coarser resolution climate model (2°) does not resolve the spatio-temporal mechanism of variability of Agulhas leakage. Hence it is expected to underestimate the contribution of Agulhas Current System to climate variability.

  13. Return stroke current reflections in rocket-triggered lightning

    NASA Astrophysics Data System (ADS)

    Caicedo, J. A.; Biagi, C.; Uman, M. A.; Jordan, D. M.; Hare, B.

    2016-03-01

    Ten upward propagating return stroke currents in eight triggered lightning flashes have been observed to reflect downward from 140 to 300 m altitude by way of measurements of the channel base current, close electric field and electric field derivative, and high-speed video. The current reflections appear as dips in the measured channel base current and in the electric fields and as bipolar pulses in the electric field derivative waveforms. The current dips occur 2.7 to 13.9 μs after the initiation of the return stroke current at ground. The observed phenomenon results from a portion of the upward propagating return stroke current wave being reflected from a channel impedance discontinuity apparently associated with an isolated section of unexploded triggering wire, as inferred from high-speed video records. A transmission line model is used to model the close electric field and electric field derivative of the postulated initial and reflected current waves, starting with the measured channel base current, and the results are compared favorably with measurements made at 92 to 326 m. From the measured time between the return stroke current initiation at the ground and the time the current reflection reaches the channel base and produces the current dip, along with the reflection height inferred from the video records, we find the average of the upward and downward reflected return stroke current speed for each of the 10 strokes to be between 0.81 and 2.06 × 108 m s-1.

  14. The arrest of Agulhas retroflection during glaciations

    NASA Astrophysics Data System (ADS)

    Zharkov, V.; Nof, D.; Ortiz, J. D.; Paldor, N.; Chassignet, E.

    2011-12-01

    Paleoceanographic proxy data indicate that the Agulhas leakage into the South Atlantic was dramatically reduced during glacial times, thus probably resulting in the collapse of the Atlantic Meridional Overturning Circulation. In our former papers, we hypothesized that this was due to a northward shift of the zero wind stress curl that, in turn, forced the retroflection to occur farther north, where the slant of the coastline relative to the north is steep. Here we propose that strong westerlies (0.4 Pa implying a wind speed of ~ 12 m/s at zero degrees centigrade), which were supposedly common during glaciations, also could have arrested the leakage. This arrest occurs because the wind stress opposes the momentum flux associated with the retroflection and, therefore, the retroflection does not shift in latitude. We use a simple, nonlinear, "reduced gravity" model to show analytically and numerically that, under the above conditions, the eastward wind stress compensates for the zonal westward flow-force associated with the retroflection, thus avoiding the development and shedding of rings. For a nearly zonal wall, westerly winds, and small upper layer thickness along the wall, the arresting wind stress is found, theoretically, to be, τx~0.042α3/2ρf[(2fQ)3/g']1/4 where α is twice the retroflection eddy vorticity, ρ the water density, and Q the Agulhas Current volume flux; the remaining notation is conventional. According to this formula, wind typical for the Agulhas region during glacial times (0.4Pa) significantly affects the moderately strong Agulhas rings of large PV (α=0.1) but, with increasing α, the influence of wind quickly decreases, and becomes negligible for α>0.2. This theoretical result is in agreement with the results of the numerical simulations that we conducted. The numerics show that the wind tends to destroy the detached rings by squeezing them onto the wall, a result that is valid in both the straight and the kinked coast cases. In the

  15. Variational principles for the return current in encephalography

    SciTech Connect

    Heller, L.

    1989-01-01

    The total electric current within the brain has been written as a sum of two terms, of distinctly different nature. The first, /rvec J//sup /iota//, is the 'primary' or 'impressed' intracellular current that flows within the neurons, and is the quantity of interest in neuroscience. This current leaks across the cell membrane, however, and since the cells are embedded in an electrically conducting medium the extracellular ('return') current flows through a large volume of this medium before returning to the cell. With the return current written as the product of the conductivity /sigma/ and the electric field intensity /rvec E/ = /minus//del/V, at low frequencies the electric potential V is determined by the continuity equation. 9 refs.

  16. Differing current and optical return stroke speeds in lightning

    NASA Astrophysics Data System (ADS)

    Liang, C.; Carlson, B.; Lehtinen, N.; Cohen, M.; Marshall, R. A.; Inan, U.

    2014-04-01

    During the return stroke in downward negative cloud-to-ground lightning, a current wave propagates upward from the ground along the lightning channel. The current wave causes rapid heating of the channel and induces intense optical radiation. The optical radiation wave propagation speed along the channel has been measured to be between 1/5 and 2/3 of the speed of light. The current wave speed is commonly assumed to be the same but cannot be directly measured. Past modeling efforts treat either the thermodynamics or electrodynamics. We present the first model that simultaneously treats the coupled current and thermodynamic physics in the return stroke channel. We utilize numerical simulations using realistic high-temperature air plasma properties that self-consistently solve Maxwell's equations coupled with equations of air plasma thermodynamics. The predicted optical radiation wave speed, rise time, and attenuation agree well with observations. The model predicts significantly higher current return stroke speed.

  17. On remote measurements of lightning return stroke peak currents

    NASA Astrophysics Data System (ADS)

    Mallick, S.; Rakov, V. A.; Tsalikis, D.; Nag, A.; Biagi, C.; Hill, D.; Jordan, D. M.; Uman, M. A.; Cramer, J. A.

    2014-01-01

    Return-stroke peak current is one of the most important measures of lightning intensity needed in different areas of atmospheric electricity research. It can be estimated from the corresponding electric or magnetic radiation field peak. Electric fields of 89 strokes in lightning flashes triggered using the rocket-and-wire technique at Camp Blanding (CB), Florida, were recorded at the Lightning Observatory in Gainesville, about 45 km from the lightning channel. Lightning return-stroke peak currents were estimated from the measured electric field peaks using the empirical formula of Rakov et al. (1992) and the field-to-current conversion equation based on the transmission line model (Uman and McLain, 1969). These estimates, along with peak currents reported by the U.S. National Lightning Detection Network (NLDN), were compared with the ground-truth data, currents directly measured at the lightning channel base. The empirical formula, based on data for 28 triggered-lightning strokes acquired at the Kennedy Space Center (KSC), tends to overestimate peak currents, whereas the NLDN-reported peak currents are on average underestimates. The field-to-current conversion equation based on the transmission line model gives the best match with directly measured peak currents for return-stroke speeds between c/2 and 2c/3 (1.5 and 2 × 108 m/s, respectively). Possible reasons for the discrepancy in the peak current estimates from the empirical formula and the ground-truth data include an error in the field calibration factor, difference in the typical return-stroke speeds at CB and at the KSC (considered here to be the most likely reason), and limited sample sizes, particularly for the KSC data. A new empirical formula, I = - 0.66-0.028rE, based on data for 89 strokes in lightning flashes triggered at CB, is derived.

  18. Genesis of return stroke current evolution at the wavefront

    NASA Astrophysics Data System (ADS)

    Kumar, Udaya; Raysaha, Rosy Balaram

    2013-07-01

    The channel dynamics at the wavefront is complex and is primarily responsible for the evolution of return stroke current. The enhancement of channel conductance at the wavefront is necessary for the evolution of current and hence, return stroke. In this regard several questions arise like: (i) what causes the enhancement of conductance, (ii) as the channel core temperature and electrical conductance are closely related, does one support the other and (iii) is the increase in core temperature on the nascent section of the channel the result of free burning arc of the wavefront just below. The present work investigates on these issues with appropriate transient thermal analysis and a macroscopic physical model for the lightning return stroke. Results clearly indicate that the contribution from the thermal field of the wavefront region to the adjacent nascent channel section is negligible as compared to the field enhancement brought in by the same. In other words, the whole process of return stroke evolution is dependent on the local heat generation at the nascent section caused by the enhancement of electric field due to the arrival of the wavefront.

  19. Return Stroke Current Reflections in Rocket-Triggered Lightning

    NASA Astrophysics Data System (ADS)

    Caicedo, J.; Uman, M. A.; Jordan, D.; Biagi, C. J.; Hare, B.

    2015-12-01

    In the six years from 2009 to 2014, there have been eight triggered flashes at the ICLRT, from a total of 125, in which a total of ten return stroke channel-base currents exhibited a dip 3.0 to 16.6 μs after the initial current peak. Close range electric field measurements show a related dip following the initial electric field peak, and electric field derivative measurements show an associated bipolar pulse, confirming that this phenomenon is not an instrumentation effect in the current measurement. For six of the eight flashes, high-speed video frames show what appears to be suspended sections of unexploded triggering wire at heights of about 150 to 300 m that are illuminated when the upward current wave reaches them. The suspended wire can act as an impedance discontinuity, perhaps as it explodes, and cause a downward reflection of some portion of the upward-propagating current wave. This reflected wave travels down the channel and causes the dip in the measured channel-base current when it reaches ground and reflects upward. The modified transmission line model with exponential decay (MTLE) is used to model the close electric field and electric field derivatives of the postulated initial and reflected current waves, starting with the measured channel base current, and the results are compared favorably with measurements made at distances ranging from 92 to 444 m. From the measured time between current impulse initiation and the time the current reflection reaches the channel base and the current dip initiates, along with the reflection height from the video records, we find the average return stroke current speed for each of the ten strokes to be from 0.28 to 1.9×108 ms-1, with an error of ±0.01×108 ms-1 due to a ±0.1 μs uncertainty in the measurement. This represents the first direct measurement of return stroke current speed, all previous return stroke speed measurements being derived from the luminosity of the process.

  20. Agulhas Plateau and Mozambique Ridge: Two LIPS of a Kind?

    NASA Astrophysics Data System (ADS)

    Uenzelmann-Neben, G.; Gohl, K.; Parsiegla, N.

    2008-12-01

    The seaway south of South Africa represents a critical gateway within the global ocean circulation. Here, warm surface and cold deep and bottom water masses meet and lead to a transfer of heat and salt between the Indian and Atlantic Oceans. This transfer maintains the global thermohaline circulation. The paths of the oceanic currents are strongly influenced by the seafloor topography observed in this region. Thus, the tectonic evolution of the South African continental margin and the gateway starting in Cretaceous times are of major importance in order to understand the evolution of the current system and the transition from the Greenhouse to the Icehouse world. The gateway itself is characterized by the Agulhas Plateau, which has been postulated to originate in the interaction of the Bouvet Hotspot and a triple junction and thus to fall within the world-wide suite of Large Igneous Provinces [Gohl and Uenzelmann-Neben, 2001; Parsiegla, et al., 2008; Uenzelmann-Neben, et al., 1999]. A similar structure has been identified for the crust of the southern Mozambique Ridge [Gohl, et al., submitted]. This raises the question whether those two LIP events were related, whether their emplacement happened at the same time and how they tie in with other LIP events observed in Late Cretaceous times such as the formation or the Kerguelen LIP. Furthermore, we may speculate on the effect those magmatic events had on the evolution of both oceanic currents and the climate. Similarities as well as differences in crustal structure and evolution and later sedimentary development will be presented for those two structures based on seismic refraction and reflection data. References: Gohl, K. and G. Uenzelmann-Neben (2001), The crustal role of the Agulhas Plateau, southwest Indian Ocean: Evidence from seismic profiling, Geophysical Journal International, 144, 632-646. Gohl, K., et al. (submitted), Is the Mozambique Ridge related to the Agulhas Plateau Large Igneous Province?, Geophysical

  1. Submicrosecond characteristics of lightning return-stroke currents

    NASA Technical Reports Server (NTRS)

    Leteinturier, Christiane; Hamelin, Joel H.; Eybert-Berard, Andre

    1991-01-01

    The authors describe the experimental results obtained during 1987 and 1988 triggered-lightning experiments in Florida. Seventy-four simultaneous submicrosecond time-resolved measurements of triggered return-stroke current (I) and current derivative (dI/dt) were made in Florida in 1987 and 1988. Peak currents ranged from about 5 to 76 kA, peak dI/dt amplitude from 13 to 411 kA/microsec and rise time from 90 to 1000 ns. The mean peak dI/dt values of 110 kA/microsec were 2-3 times higher than data from instrumented towers and peak I and dI/dt appear to be positively correlated. These data confirm previous experiments and conclusions supported by forty measurements. They are important in order to define, for example, standards for lightning protection. Present standards give a dI/dt maximum of 140 kA/microsec.

  2. RETURN CURRENTS AND ENERGY TRANSPORT IN THE SOLAR FLARING ATMOSPHERE

    SciTech Connect

    Codispoti, Anna; Torre, Gabriele; Piana, Michele; Pinamonti, Nicola

    2013-08-20

    According to the standard Ohmic perspective, the injection of accelerated electrons into the flaring region violates local charge equilibrium and therefore, in response, return currents are driven by an electric field to equilibrate such charge violation. In this framework, the energy loss rate associated with these local currents has an Ohmic nature and significantly shortens the accelerated electron path. In the present paper, we adopt a different viewpoint and, specifically, we study the impact of the background drift velocity on the energy loss rate of accelerated electrons in solar flares. We first utilize the Rutherford cross-section to derive the formula of the energy loss rate when the collisional target has a finite temperature and the background instantaneously and coherently moves up to equilibrate the electron injection. We then use the continuity equation for electrons and imaging spectroscopy data provided by RHESSI to validate this model. We show that this new formula for the energy loss rate provides a better fit of the experimental data with respect to the model based on the effects of standard Ohmic return currents.

  3. Advanced Curation: Solving Current and Future Sample Return Problems

    NASA Technical Reports Server (NTRS)

    Fries, M.; Calaway, M.; Evans, C.; McCubbin, F.

    2015-01-01

    Advanced Curation is a wide-ranging and comprehensive research and development effort at NASA Johnson Space Center that identifies and remediates sample related issues. For current collections, Advanced Curation investigates new cleaning, verification, and analytical techniques to assess their suitability for improving curation processes. Specific needs are also assessed for future sample return missions. For each need, a written plan is drawn up to achieve the requirement. The plan draws while upon current Curation practices, input from Curators, the analytical expertise of the Astromaterials Research and Exploration Science (ARES) team, and suitable standards maintained by ISO, IEST, NIST and other institutions. Additionally, new technologies are adopted on the bases of need and availability. Implementation plans are tested using customized trial programs with statistically robust courses of measurement, and are iterated if necessary until an implementable protocol is established. Upcoming and potential NASA missions such as OSIRIS-REx, the Asteroid Retrieval Mission (ARM), sample return missions in the New Frontiers program, and Mars sample return (MSR) all feature new difficulties and specialized sample handling requirements. The Mars 2020 mission in particular poses a suite of challenges since the mission will cache martian samples for possible return to Earth. In anticipation of future MSR, the following problems are among those under investigation: What is the most efficient means to achieve the less than 1.0 ng/sq cm total organic carbon (TOC) cleanliness required for all sample handling hardware? How do we maintain and verify cleanliness at this level? The Mars 2020 Organic Contamination Panel (OCP) predicts that organic carbon, if present, will be present at the "one to tens" of ppb level in martian near-surface samples. The same samples will likely contain wt% perchlorate salts, or approximately 1,000,000x as much perchlorate oxidizer as organic carbon

  4. Lightning Return-Stroke Current Waveforms Aloft, from Measured Field Change, Current, and Channel Geometry

    NASA Technical Reports Server (NTRS)

    Willett, J. C.; LeVine, D. M.; Idone, V. P.

    2006-01-01

    Three-dimensional reconstructions of six rocket-triggered lightning channels are derived from stereo photographs. These reconstructed channels are used to infer the behavior of the current in return strokes above the ground from current waveforms measured at the channel base and electric-field-change waveforms measured at a range of 5.2 kilometers for 24 return strokes in these channels. Streak photographs of 14 of the same strokes are analyzed to determine the rise times, propagation speeds, and amplitudes of relative light intensity for comparison with the electrical inferences. Results include the following: 1) The fine structure of the field-change waveforms that were radiated by these subsequent return strokes can be explained, in large part, by channel geometry. 2) The average 10 - 90% rise time of the stroke current increased by about a factor of seven in our sample, from an observed 0.31 plus or minus 0.17 microseconds at the surface to an inferred 2.2 plus or minus 0.5 microcseconds at 1 kilometer path length above the surface. 3) The three-dimensional propagation speed of the current front averaged 1.80 plus or minus 0.24 X 10(exp 8) meters per second over channel lengths typically greater than 1 kilometer. 4) Assuming that the measured current was entirely due to the return stroke forced an unreasonably large and abrupt reduction in inferred current amplitude over the first few tens of meters above the surface, especially in cases when the leader was bright relative to its stroke. Therefore, a significant fraction of the current at the surface was probably due to the leader, at least in such cases. 5) Peak return-stroke currents decreased by approximately 37 plus or minus 12% from 100 meters to 1 kilometer of path length above the surface. Because of uncertainty about how to partition the measured current between leader and return stroke, we are unable to infer the variation of current amplitude near the ground.

  5. The life cycle of a coherent Lagrangian Agulhas ring

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Beron-Vera, F. J.; Olascoaga, M. J.

    2016-06-01

    We document the long-term evolution of an Agulhas ring detected from satellite altimetry using a technique from nonlinear dynamical systems that enables objective (i.e., observer-independent) eddy framing. Such objectively detected eddies have Lagrangian (material) boundaries that remain coherent (unfilamented) over the detection period. The ring preserves a quite compact material entity for a period of about 2 years even after most initial coherence is lost within 5 months after detection. We attribute this to the successive development of short-term coherent material boundaries around the ring. These boundaries provide effective short-term shielding for the ring, which prevents a large fraction of the ring's interior from being mixed with the ambient turbulent flow. We show that such coherence regain events cannot be inferred from Eulerian analysis. This process is terminated by a ring-splitting event which marks the ring demise, near the South American coast. The genesis of the ring is characterized by a ring-merging event away from the Agulhas retroflection, followed by a 4 month-long partial coherence stage, scenario that is quite different than a current occlusion and subsequent eddy pinch off.

  6. Agulhas salt-leakage oscillations during abrupt climate changes of the Late Pleistocene

    NASA Astrophysics Data System (ADS)

    Marino, Gianluca; Zahn, Rainer; Ziegler, Martin; Purcell, Conor; Knorr, Gregor; Hall, Ian R.; Ziveri, Patrizia; Elderfield, Henry

    2013-09-01

    An ensemble of new, high-resolution records of surface ocean hydrography from the Indian-Atlantic oceanic gateway, south of Africa, demonstrates recurrent and high-amplitude salinity oscillations in the Agulhas Leakage area during the penultimate glacial-interglacial cycle. A series of millennial-scale salinification events, indicating strengthened salt leakage into the South Atlantic, appear to correlate with abrupt changes in the North Atlantic climate and Atlantic Meridional Overturning Circulation (AMOC). This interhemispheric coupling, which plausibly involved changes in the Hadley Cell and midlatitude westerlies that impacted the interocean transport at the tip of Africa, suggests that the Agulhas Leakage acted as a source of negative buoyancy for the perturbed AMOC, possibly aiding its return to full strength. Our finding points to the Indian-to-Atlantic salt transport as a potentially important modulator of the AMOC during the abrupt climate changes of the Late Pleistocene.

  7. Return Current Electron Beams and Their Generation of "Raman" Scattering

    NASA Astrophysics Data System (ADS)

    Simon, A.

    1998-11-01

    For some years, we(A. Simon and R. W. Short, Phys. Rev. Lett. 53), 1912 (1984). have proposed that the only reasonable explanation for many of the observations of "Raman" scattering is the presence of an electron beam in the plasma. (The beam creates a bump-on-tail instability.) Two major objections to this picture have been observation of Raman when no n_c/4 surface was present, with no likely source for the electron beam, and the necessity for the initially outward directed beam to bounce once to create the proper waves. Now new observations on LLE's OMEGA(R. Petrasso et al), this conference. and at LULI(C. Labaune et al)., Phys. Plasma 5, 234 (1998). have suggested a new origin for the electron beam. This new scenario answers the previous objections, maintains electron beams as the explanation of the older experiments, and may clear up puzzling observations that have remained unexplained. The new scenario is based on two assumptions: (1) High positive potentials develop in target plasmas during their creation. (2) A high-intensity laser beam initiates spark discharges from nearby surfaces to the target plasma. The resulting return current of electrons should be much more delta-like, is initially inwardly directed, and no longer requires the continued presence of a n_c/4 surface. Scattering of the interaction beam from the BOT waves yields the observed Raman signal. Experimental observations that support this picture will be cited. ``Pulsation'' of the scattering and broadband ``flashes'' are a natural part of this scenario. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC03-92SF19460.

  8. Lightning Return-Stroke Current Waveforms Aloft, From Measured Field Change, Current, and Channel Geometry

    NASA Technical Reports Server (NTRS)

    Willett, J. C.; LeVine, D. M.

    2002-01-01

    Direct current measurements are available near the attachment point from both natural cloud-to-ground lightning and rocket-triggered lightning, but little is known about the rise time and peak amplitude of return-stroke currents aloft. We present, as functions of height, current amplitudes, rise times, and effective propagation velocities that have been estimated with a novel remote-sensing technique from data on 24 subsequent return strokes in six different lightning flashes that were triggering at the NASA Kennedy Space Center, FL, during 1987. The unique feature of this data set is the stereo pairs of still photographs, from which three-dimensional channel geometries were determined previously. This has permitted us to calculate the fine structure of the electric-field-change (E) waveforms produced by these strokes, using the current waveforms measured at the channel base together with physically reasonable assumptions about the current distributions aloft. The computed waveforms have been compared with observed E waveforms from the same strokes, and our assumptions have been adjusted to maximize agreement. In spite of the non-uniqueness of solutions derived by this technique, several conclusions seem inescapable: 1) The effective propagation speed of the current up the channel is usually significantly (but not unreasonably) faster than the two-dimensional velocity measured by a streak camera for 14 of these strokes. 2) Given the deduced propagation speed, the peak amplitude of the current waveform often must decrease dramatically with height to prevent the electric field from being over-predicted. 3) The rise time of the current wave front must always increase rapidly with height in order to keep the fine structure of the calculated field consistent with the observations.

  9. Current thinking: return to play and transient quadriplegia.

    PubMed

    Cantu, Robert V; Cantu, Robert C

    2005-02-01

    Athletes that participate in contact and collision sports assume risk of serious injury each time they take the field. For those athletes that have sustained an episode of transient quadriplegia, the decision of whether to return to competition can be a difficult one. Some athletes, realizing how close they may have come to permanent injury, may decide that further participation is not in their best interest. Others may be somewhat undecided, and some may want to return at all costs. As the treating physician, the goal is to identify those athletes who after a single episode of transient quadriplegia are at increased risk for further injury and consequently should discontinue participation in contact sports. Factors that may contribute to that determination include mechanism of injury, prior history of neurologic symptoms or injury, and anatomic features that may predispose to further injury such as disc herniation, fracture, or cervical stenosis.

  10. Atlantic multi-decadal oscillation covaries with Agulhas leakage

    PubMed Central

    Biastoch, Arne; Durgadoo, Jonathan V.; Morrison, Adele K.; van Sebille, Erik; Weijer, Wilbert; Griffies, Stephen M.

    2015-01-01

    The interoceanic transfer of seawater between the Indian Ocean and the Atlantic, ‘Agulhas leakage', forms a choke point for the overturning circulation in the global ocean. Here, by combining output from a series of high-resolution ocean and climate models with in situ and satellite observations, we construct a time series of Agulhas leakage for the period 1870–2014. The time series demonstrates the impact of Southern Hemisphere westerlies on decadal timescales. Agulhas leakage shows a correlation with the Atlantic Multi-decadal Oscillation on multi-decadal timescales; the former leading by 15 years. This is relevant for climate in the North Atlantic. PMID:26656850

  11. Atlantic multi-decadal oscillation covaries with Agulhas leakage

    DOE PAGES

    Biastoch, Arne; Durgadoo, Jonathan V.; Morrison, Adele K.; van Sebille, Erik; Weijer, Wilbert; Griffies, Stephen M.

    2015-12-10

    The interoceanic transfer of seawater between the Indian Ocean and the Atlantic, ‘Agulhas leakage’, forms a choke point for the overturning circulation in the global ocean. Here, by combining output from a series of high-resolution ocean and climate models with in situ and satellite observations, we construct a time series of Agulhas leakage for the period 1870–2014. The time series demonstrates the impact of Southern Hemisphere westerlies on decadal timescales. Agulhas leakage shows a correlation with the Atlantic Multi-decadal Oscillation on multi-decadal timescales; the former leading by 15 years. Lastly, this is relevant for climate in the North Atlantic.

  12. Return stroke velocities and currents using a solid state silicon detector system

    NASA Technical Reports Server (NTRS)

    Mach, Douglas M.; Rust, W. David

    1988-01-01

    A small, portable device has been developed to measure return stroke velocities. With the device, velocities from 135 strokes that consist of 92 natural return strokes and 43 triggered return strokes have been analyzed. The average return stroke velocity for longer channels, greater than 500 meters, is 1.2 + or - 0.3 x 10 to the 8th m/s for both natural and triggered return strokes. For shorter channel lengths, less than 500 m, natural lightning has a statistically higher average return stroke velocity of 1.9 + or - 0.7 x 10 to the 8th m/s than triggered lightning with an average return stroke velocity of 1.4 + or - 0.4 x 10 to the 8th m/s. Using the transmission line model of the return stroke, natural lightning has a peak current distribution that is log-normal with a median value of 19 kA. Return stroke velocities and currents were determined for two distant single stroke natural positive cloud-to-ground flashes. The velocities were 1.0 and 1.7 x 10 to the 8th ms/s while the estimated peak current for each positive flash was over 125 kA.

  13. Physical derivation of resistive hose instabilities in electron beams with return current

    SciTech Connect

    Brandenburg, J.E.

    1985-09-01

    The hose instability dispersion relation for electron beams with plasma return current is derived using simple physical models. The self-hose instability appears due to the repulsion between beam and plasma currents. The results of the derivation agree with those of more complicated models. The stabilizing effect of beam generated conductivity is examined using a simple model. Using this model, the stabilization of the effect of return currents at low frequency is demonstrated for the case of rapid conductivity generation.

  14. Bulk Current Injection Testing of Close Proximity Cable Current Return, 1kHz to 1 MHz

    NASA Technical Reports Server (NTRS)

    Bradley, Arthur T.; Lee, William M.; Singh, Vivek; Yavoich, Brian

    2010-01-01

    This paper presents the results of an experiment examining the percentage of current that returns on adjacent wires or through a surrounding cable shield rather than through a shared conducting chassis. Simulation and measurement data are compared from 1 kHz 1 MHz for seven common cable configurations. The phenomenon is important to understand, because minimizing the return current path is vital in developing systems with low radiated emissions.

  15. Mechanisms of nearshore retention and offshore export of mussel larvae over the Agulhas Bank

    NASA Astrophysics Data System (ADS)

    Weidberg, Nicolás; Porri, Francesca; Von der Meden, Charles E. O.; Jackson, Jennifer M.; Goschen, Wayne; McQuaid, Christopher D.

    2015-04-01

    Ecological connectivity is critical for population dynamics but in many benthic species it is complicated by a planktonic larval phase, whose dispersal remains poorly understood. Using a plankton pump, we examine the distribution of intertidal mussel larvae along three axes: alongshore, cross-shelf and by depth during a large scale (600 km) cruise over the Agulhas Bank off southern Africa in August/September 2010. As a general pattern, higher veliger abundances were found close to the coast. Our analyses of the nearshore flow, estimated from ADCP data and the vertical distribution of larvae, show that onshore larval retention may be mediated by active vertical swimming through the water column guided by light and wind-induced turbulence. A massive offshore export of larvae off St Francis Bay was, however, observed during an Agulhas Current meander which influenced inner shelf waters. We hypothesize that, by increasing and homogenizing flow, the Agulhas Current may erase the effects of larval vertical positioning on onshore retention and transport larvae offshore. Our study highlights the need to integrate the effects of complex, region-specific physical dynamics with the swimming behaviour of larvae in order to explain their spatial distribution, population connectivity and the consequences for population dynamics.

  16. Observations of A Young Agulhas Ring, During Mare

    NASA Astrophysics Data System (ADS)

    van Veldhoven, A. K.; van Aken, H. M.; Veth, C.

    The MARE (Mixing of Agulhas Rings Experiment) project studies the effects of inter- ocean exchange between the Indian and Atlantic Ocean, via Agulhas rings, on the Atlantic meridional overturning circulation. This presentation is about the field pro- gramme of MARE which concentrates on the study of the decay and modification of a single Agulhas ring named Astrid, formed in January 2000. The ring was first iden- tified by an analysis of satellite altimetry data. During a detailed survey of this two months old ring in March 2000 it appeared that the ring had a significant barotropic component, additional to the baroclinic flow around its warm centre. The influence of the present topography, the Agulhas Ridge, on this ring may therefore be important. The observed fine-structure near its boundary suggested that exchange of water with its surroundings already had started. During this presentation some highlights of the results will be presented.

  17. Influence of channel base current and varying return stroke speed on the calculated fields of three important return stroke models

    NASA Technical Reports Server (NTRS)

    Thottappillil, Rajeev; Uman, Martin A.; Diendorfer, Gerhard

    1991-01-01

    Compared here are the calculated fields of the Traveling Current Source (TCS), Modified Transmission Line (MTL), and the Diendorfer-Uman (DU) models with a channel base current assumed in Nucci et al. on the one hand and with the channel base current assumed in Diendorfer and Uman on the other hand. The characteristics of the field wave shapes are shown to be very sensitive to the channel base current, especially the field zero crossing at 100 km for the TCS and DU models, and the magnetic hump after the initial peak at close range for the TCS models. Also, the DU model is theoretically extended to include any arbitrarily varying return stroke speed with height. A brief discussion is presented on the effects of an exponentially decreasing speed with height on the calculated fields for the TCS, MTL, and DU models.

  18. Photoelectric return-stroke velocity and peak current estimates in natural and triggered lightning

    NASA Technical Reports Server (NTRS)

    Mach, Douglas M.; Rust, W. David

    1989-01-01

    Two-dimensional photoelectric return stroke velocities from 130 strokes are presented, including 86 negative natural, 41 negative triggered, one positive triggered, and two positive natural return strokes. For strokes starting near the ground and exceeding 500 m in length, the average velocity is 1.3 + or - 0.3 X 10 to the 8th m/s for natural return strokes and 1.2 + or - 0.3 X 10 to the 8th m/s for triggered return strokes. For strokes with lengths less than 500 m, the average velocities are slightly higher. Using the transmission line model (TLM), the shortest segment one-dimensional return stroke velocity, and either the maximum or plateau electric field, it is shown that natural strokes have a peak current distribution that is lognormal with a median value of 16 kA (maximum E) or 12 kA (plateau E). Triggered lightning has a medium peak current value of 21 kA (maximum E) or 15 kA (plateau E). Correlations are found between TLM peak currents and velocities for triggered and natural subsequent return strokes, but not between TLM peak currents and natural first return stroke velocities.

  19. Lightning current and luminosity at and above channel bottom for return strokes and M-components

    NASA Astrophysics Data System (ADS)

    Carvalho, F. L.; Uman, M. A.; Jordan, D. M.; Ngin, T.

    2015-10-01

    We measured current and luminosity at the channel bottom of 12 triggered lightning discharges including 44 return strokes, 23 M-components, and 1 initial continuous current pulse. Combined current and luminosity data for impulse currents span a 10-90% risetime range from 0.15 to 192 µs. Current risetime and luminosity risetime at the channel bottom are roughly linearly correlated (τr,I = 0.71τr,L1.08). We observed a time delay between current and the resultant luminosity at the channel bottom, both measured at 20% of peak amplitude, that is approximately linearly related to both the luminosity 10-90% risetime (Δt20,b = 0.24τr,L1.12) and the current 10-90% risetime (Δt20,b = 0.35τr,I1.03). At the channel bottom, the peak current is roughly proportional to the square root of the peak luminosity (IP = 21.89LP0.57) over the full range of current and luminosity risetimes. For two return strokes we provide measurements of stroke luminosity vs. time for 11 increasing heights to 115 m altitude. We assume that measurements above the channel bottom behave similarly to those at the bottom and find that (1) one return stroke current peak decayed at 115 m to about 47% of its peak value at channel bottom, while the luminosity peak at 115 m decayed to about 20%, and for the second stroke 38% and 12%, respectively; and (2) measured upward return stroke luminosity speeds of the two strokes of 1.10 × 108 and 9.7 × 107 ms-1 correspond to current speeds about 30% faster. These results represent the first determination of return stroke current speed and current peak value above ground derived from measured return stroke luminosity data.

  20. Fast initial continuous current pulses versus return stroke pulses in tower-initiated lightning

    NASA Astrophysics Data System (ADS)

    Azadifar, Mohammad; Rachidi, Farhad; Rubinstein, Marcos; Rakov, Vladimir A.; Paolone, Mario; Pavanello, Davide; Metz, Stefan

    2016-06-01

    We present a study focused on pulses superimposed on the initial continuous current of upward negative discharges. The study is based on experimental data consisting of correlated lightning current waveforms recorded at the instrumented Säntis Tower in Switzerland and electric fields recorded at a distance of 14.7 km from the tower. Two different types of pulses superimposed on the initial continuous current were identified: (1) M-component-type pulses, for which the microsecond-scale electric field pulse occurs significantly earlier than the onset of the current pulse, and (2) fast pulses, for which the onset of the field matches that of the current pulse. We analyze the currents and fields associated with these fast pulses (return-stroke type (RS-type) initial continuous current (ICC) pulses) and compare their characteristics with those of return strokes. A total of nine flashes containing 44 RS-type ICC pulses and 24 return strokes were analyzed. The median current peaks associated with RS-type ICC pulses and return strokes are, respectively, 3.4 kA and 8 kA. The associated median E-field peaks normalized to 100 km are 1.5 V/m and 4.4 V/m, respectively. On the other hand, the electric field peaks versus current peaks for the two data sets (RS-type ICC pulses and return strokes) are characterized by very similar linear regression slopes, namely, 3.67 V/(m kA) for the ICC pulses and 3.77 V/(m kA) for the return strokes. Assuming the field-current relation based on the transmission line model, we estimated the apparent speed of both the RS-type ICC pulses and return strokes to be about 1.4 × 108 m/s. A strong linear correlation is observed between the E-field risetime and the current risetime for the ICC pulses, similar to the relation observed between the E-field risetime and current risetime for return strokes. The similarity of the RS-type ICC pulses with return strokes suggests that these pulses are associated with the mixed mode of charge transfer to ground.

  1. Gas-puff liner implosion in the configuration with helical current return rods

    SciTech Connect

    Sorokin, S. A.

    2013-02-15

    Results of experiments with double-shell gas-puff liners carried out on a high-current MIG generator (2 MA, 80 ns) are presented. To stabilize the process of liner implosion and increase the efficiency of energy transfer from the generator to the liner plasma, a current return in the form of a multifilar helix was used. The effect of the configuration of the current return on the parameters of the generated pulses of argon and neon K-shell radiation (with photon energies of 3-5 and 0.9-1.5 keV, respectively) and the neutron yield from a deuterium liner were studied.

  2. Method for Estimating Low-Frequency Return Current of DC Electric Railcar

    NASA Astrophysics Data System (ADS)

    Hatsukade, Satoru

    The Estimation of the harmonic current of railcars is necessary for achieving compatibility between train signaling systems and railcar equipment. However, although several theoretical analyses methods for estimating the harmonic current of railcars using switching functions exist, there are no theoretical analysis methods estimating a low-frequency current at a frequency less than the power converter's carrier frequency. This paper describes a method for estimating the spectrum (frequency and amplitude) of the low-frequency return current of DC electric railcars. First, relationships between the return current and characteristics of the DC electric railcars, such as mass and acceleration, are determined. Then, the mathematical (not numerical) calculation results for low-frequency current are obtained from the time-current curve for a DC electric railcar by using Fourier series expansions. Finally, the measurement results clearly show the effectiveness of the estimation method development in this study.

  3. Dawn-dusk asymmetry in ionospheric return flows: relationship between flows and Birkeland currents

    NASA Astrophysics Data System (ADS)

    Larson, R.; Anderson, B. J.; Korth, H.; Bodurtha, K. E.; Wilson, G.

    2008-12-01

    Intense duskside ionospheric flows occurring equatorward of the discrete auroral precipitation zone have been attributed to large electric fields resulting from partial ring current injections. In this picture the driver is the ion injection that feeds the Region 2 currents which in turn cause the electric field. Alternatively, one may take the view that the return flow at dusk is favored energetically by the coupled magnetosphere-ionosphere system. In this energetics view, the upward Region 2 at dawn corresponds to discrete aurora and enhanced conductance on closed field lines on the dawn side, whereas the downward Region 2 at dusk does not contribute as substantially to enhancing the duskside conductance. The energy dissipation associated with a given flow is proportional to the conductance. Thus, it is energetically more favorable for the coupled system to send more return flow to the dayside at dusk than at dawn. In this paper we assess whether there is a persistent dawn dusk asymmetry in the return flow relative to the Birkeland current location and intensity. Birkeland currents derived from the Iridium Satellite constellation, augmented with DMSP F13 magnetic field data are used to place DMSP F13 drift meter data in the context of both the global and local Birkeland currents. Using events from the Iridium stable currents database of Anderson et al. (2008), we identified 59 events with high quality drift observations during southward IMF. The events are divided into two ranges of IMF intensity and five IMF clock angle bins. We order the data in latitude relative to the peak Region 1 current density. There is a persistent suppression of the dawn return flows relative to those at dusk regardless of IMF By or IMF intensity. This result indicates that the return flow predominantly occurs through the evening closed field line region, consistent with the above energetics picture of return flow in the coupled system.

  4. Indian-atlantic transfer of thermocline water at the agulhas retroflection.

    PubMed

    Gordon, A L

    1985-03-01

    During November and December 1983, two anticyclonic eddies were observed west of the Agulhas Retroflection, apparently spawned at the retroflection. The western eddy, centered 300 kilometers southwest of Cape Town, has a winter cooled core encircled by warm Indian Ocean water. Between Cape Town and the "Cape Town Eddy" is a net geostrophic transport of Indian Ocean thermocline water (14 x 10(6) cubic meters per second) into the South Atlantic Ocean. This circulation configuration, similar to that observed by earlier researchers, suggests that Indian-Atlantic thermocline exchange is a common occurrence. Such a warmwater link between the Atlantic and Indian oceans would strongly influence global climate patterns. The Indian Ocean water is warmer than the adjacent South Atlantic water and thus represents a heat input of 2.3 x 10(13) to 47 x 10(13) watts into the Atlantic. The large uncertainty arises from the unknown partition between two possible routes for the return flow from the Atlantic to the Indian Ocean: cooler South Atlantic thermocline water or much colder North Atlantic Deep Water. In either case, interocean mass and heat exchange of thermocline water at the Agulhas Retroflection is a distinct likelihood.

  5. Two-dimensional velocity, optical risetime, and peak current estimates for natural positive lightning return strokes

    NASA Technical Reports Server (NTRS)

    Mach, Douglas M.; Rust, W. D.

    1993-01-01

    Velocities, optical risetimes, and transmission line model peak currents for seven natural positive return strokes are reported. The average 2D positive return stroke velocity for channel segments of less than 500 m in length starting near the base of the channel is 0.8 +/- 0.3 x 10 exp 8 m/s, which is slower than the present corresponding average velocity for natural negative first return strokes of 1.7 +/- 0.7 x 10 exp 8/s. It is inferred that positive stroke peak currents in the literature, which assume the same velocity as negative strokes, are low by a factor of 2. The average 2D positive return stroke velocity for channel segments of greater than 500 m starting near the base of the channel is 0.9 +/- 0.4 x 10 exp 8 m/s. The corresponding average velocity for the present natural negative first strokes is 1.2 +/- 0.6 x 10 exp 8 m/s. No significant velocity change with height is found for positive return strokes.

  6. Reduction of Return Current Noise Using Double-Series Resonant Filter

    NASA Astrophysics Data System (ADS)

    Azuma, Satoshi; Itoh, Daisuke; Sugahara, Kengo

    A novel double-series resonant filter is implemented in order to reduce the high-frequency return current noise generated by AC-powered electric cars with AC/DC PWM converters and inverters. The double-series resonant filter is placed between a main transformer and a converter. The resonant filter is tuned so that the noise signal due to the return current is attenuated at the exact noise frequency; for example, the 105-kHz component of an ATS (Automatic Train Stop) signal is attenuated by this filter. The filter has two LCR resonant circuits, one of which is in parallel with a resistance. This filter design helps achieve good attenuation at the noise frequency and helps limit unnecessary amplification at other frequencies. First, a test filter is realized, and the inductance and capacitance of this filter are in good agreement with the corresponding values in the filter design. Then, the filter is included in a full-scale test system with a main transformer and a converter. Then it is confirmed that a 5-dB reduction in the return current noise is achieved by using the proposed filter. Finally, the return current noise in the test system is confirmed to be well below the desired regulation level. This is expected to help realize simple methods for dealing with the effects of impedance at high frequencies in the main transformer.

  7. Agulhas ring injection into the South Atlantic during glacials and interglacials

    NASA Astrophysics Data System (ADS)

    Zharkov, V.; Nof, D.

    2008-03-01

    Recent proxies analysis suggest that, at the end of the last glacial, there was a significant increase in the injection of Agulhas rings into the South Atlantic (SA). This brought about a dramatic increase in the salt-influx (from the Indian Ocean) into the SA helping re-start the then-collapsed meridional overturning cell (MOC), leading to the termination of the Younger Dryas (YD). Here, we propose a mechanism through which large variations in ring production take place. Using nonlinear analytical solutions for eddy shedding we show that there are restricted possibilities for ring detachment when the coast is oriented in the north-south direction. We define a critical coastline angle below which there is rings shedding and above which there is almost no shedding. In the case of the Agulhas region, the particular shape of the African continent implies that rings can be produced only when the retroflection occurs beyond a specific latitude where the angle is critical. During glaciation, the wind stress curl (WSC) vanished at a latitude lower than that of the critical angle, which prohibited the retroflection from producing rings. When the latitude at which the WSC vanishes migrated poleward towards its present day position, the corresponding coastline angle decreased below the critical angle and allowed for a vigorous production of rings. Simple process-oriented numerical simulations (using the Bleck and Boudra model) are in very good agreement with our results and enable us to affirm that, during the glacials, the behavior of the Agulhas Current (AC) was similar to that of the modern East Australian Current (EAC), for which the coastline slant is supercritical.

  8. Agulhas ring injection into the South Atlantic during glacials and interglacials

    NASA Astrophysics Data System (ADS)

    Zharkov, V.; Nof, D.

    2008-09-01

    Recent proxies suggest that, at the end of the last glacial, there was a significant increase in the injection of Agulhas rings into the South Atlantic (SA). This brought about a dramatic increase in the salt-influx (from the Indian Ocean) into the SA helping re-start the then-collapsed meridional overturning cell (MOC), leading to the termination of the Younger Dryas (YD). Here, we propose a mechanism through which large variations in ring production take place. Using nonlinear analytical solutions for eddy shedding, we show that there are restricted possibilities for ring detachment when the coast is oriented in the north-south direction. We define a critical coastline angle below which there is rings shedding and above which there is almost no shedding. In the case of the Agulhas region, the particular shape of the African continent implies that rings can be produced only when the retroflection occurs beyond a specific latitude where the angle is critical. During glaciation, the wind stress curl (WSC) vanished at a latitude lower than that of the critical angle, which prohibited the retroflection from producing rings. When the latitude at which the WSC vanishes migrated poleward towards its present day position, the corresponding coastline angle decreased below the critical angle and allowed for a vigorous production of rings. Simple process-oriented numerical simulations (using the Bleck and Boudra model) are in satisfactory agreement with our results and enable us to affirm that, during the glacials, the behavior of the Agulhas Current (AC) was similar to that of the modern East Australian Current (EAC), for which the coastline slant is supercritical.

  9. Seismic Reflections Within the Water Column South of South Africa: Indications for the Agulhas Retroflection

    NASA Astrophysics Data System (ADS)

    Uenzelmann-Neben, G.; Klaeschen, D.; Krahmann, G.; Reston, T.; Visbeck, M.

    2006-12-01

    With the publication of Holbrook et al. (2003) the field of seismic oceanography experienced a major momentum. Several authors since then (Nandi et al., 2004; Holbrook and Fer, 2005; Paramo and Holbrook, 2005) could show that those reflections within the water column correspond to thin layers with strong vertical temperature gradients. Those reflections hence represent a chance to trace those temperature gradients over large distances. Weak seismic reflections within the water column south of South Africa gave rise to the question whether here traces of the Agulhas Current or Agulhas Retroflection can be observed. A careful reprocessing of the data led to the imaging of fields of reflections pointing towards a 135 km broad and about 1000 m deep reaching well stratified area with strong reflection amplitudes and several weaker reflections extending down to at least 1500 m water depth over the whole area of investigation. To image both the boundaries between the water masses as reflections and the different properties of the long wavelength velocity variations in depth special imaging technigues like prestack depth migration analysis were performed. Further, the temperature gradients from the short wavelength properties as velocity and density contrasts were determind by a two step inversion of acoustic amplitude versus angle analysis to better quantify the variations of the water masses of the Agulhas Current. References: Holbrook, W.S., and I. Fer, Ocean internal wave spectra inferred from seismic reflection transects, 2005, Geophys. Res. Lett., 32, L15604, doi:10.1029/2005GL023733. Nandi, P., W.S. Holbrook, S. Pearse, P. Paramo, and R.W. Schmitt, 2004, Seismic reflection imaging of Norwegian Sea water mass boundaries, Geophys. Res. Lett., 31, L23311, doi:10.1029/2004GL021325. Paramo, P., and W. S. Holbrook, 2005, Temperature contrasts in the water column inferred from amplitude-versus-offset analysis of acoustic reflections, Geophys. Res. Lett., v. 32, L24611, doi

  10. Correlated peak relative light intensity and peak current in triggered lightning subsequent return strokes

    NASA Technical Reports Server (NTRS)

    Idone, V. P.; Orville, R. E.

    1985-01-01

    The correlation between peak relative light intensity L(R) and stroke peak current I(R) is examined for 39 subsequent return strokes in two triggered lightning flashes. One flash contained 19 strokes and the other 20 strokes for which direct measurements were available of the return stroke peak current at ground. Peak currents ranged from 1.6 to 21 kA. The measurements of peak relative light intensity were obtained from photographic streak recordings using calibrated film and microsecond resolution. Correlations, significant at better than the 0.1 percent level, were found for several functional relationships. Although a relation between L(R) and I(R) is evident in these data, none of the analytical relations considered is clearly favored. The correlation between L(R) and the maximum rate of current rise is also examined, but less correlation than between L(R) and I(R) is found. In addition, the peak relative intensity near ground is evaluated for 22 dart leaders, and a mean ratio of peak dart leader to peak return stroke relative light intensity was found to be 0.1 with a range of 0.02-0.23. Using two different methods, the peak current near ground in these dart leaders is estimated to range from 0.1 to 6 kA.

  11. JSC Advanced Curation: Research and Development for Current Collections and Future Sample Return Mission Demands

    NASA Technical Reports Server (NTRS)

    Fries, M. D.; Allen, C. C.; Calaway, M. J.; Evans, C. A.; Stansbery, E. K.

    2015-01-01

    Curation of NASA's astromaterials sample collections is a demanding and evolving activity that supports valuable science from NASA missions for generations, long after the samples are returned to Earth. For example, NASA continues to loan hundreds of Apollo program samples to investigators every year and those samples are often analyzed using instruments that did not exist at the time of the Apollo missions themselves. The samples are curated in a manner that minimizes overall contamination, enabling clean, new high-sensitivity measurements and new science results over 40 years after their return to Earth. As our exploration of the Solar System progresses, upcoming and future NASA sample return missions will return new samples with stringent contamination control, sample environmental control, and Planetary Protection requirements. Therefore, an essential element of a healthy astromaterials curation program is a research and development (R&D) effort that characterizes and employs new technologies to maintain current collections and enable new missions - an Advanced Curation effort. JSC's Astromaterials Acquisition & Curation Office is continually performing Advanced Curation research, identifying and defining knowledge gaps about research, development, and validation/verification topics that are critical to support current and future NASA astromaterials sample collections. The following are highlighted knowledge gaps and research opportunities.

  12. Return to sport after ACL reconstruction: how, when and why? A narrative review of current evidence.

    PubMed

    Zaffagnini, Stefano; Grassi, Alberto; Serra, Margherita; Marcacci, Maurilio

    2015-01-01

    Allowing a patient to return to sport and unrestricted physical activity after ACL injury and reconstruction is one of the most challenging and difficult decisions an orthopaedic surgeon has to make. Indeed, many factors have to be taken into account before it can be considered safe for a patients to load a reconstructed knee. The current literature contains plenty of studies aimed at evaluating return to sport, and the factors that may affect or predict this outcome, e.g. intrinsic factors like genetics, biology, type of lesion, anatomical features, motivation and psychology, and extrinsic factors such as graft type, surgical technique, rehabilitation protocols, and biological support. It is possible that awareness of these issues could help the clinician to optimise outcomes, and possibly avoid failures too, although as yet no universal criteria for resuming sport have been produced. PMID:26151036

  13. Return to sport after ACL reconstruction: how, when and why? A narrative review of current evidence

    PubMed Central

    ZAFFAGNINI, STEFANO; GRASSI, ALBERTO; SERRA, MARGHERITA; MARCACCI, MAURILIO

    2015-01-01

    Allowing a patient to return to sport and unrestricted physical activity after ACL injury and reconstruction is one of the most challenging and difficult decisions an orthopaedic surgeon has to make. Indeed, many factors have to be taken into account before it can be considered safe for a patients to load a reconstructed knee. The current literature contains plenty of studies aimed at evaluating return to sport, and the factors that may affect or predict this outcome, e.g. intrinsic factors like genetics, biology, type of lesion, anatomical features, motivation and psychology, and extrinsic factors such as graft type, surgical technique, rehabilitation protocols, and biological support. It is possible that awareness of these issues could help the clinician to optimise outcomes, and possibly avoid failures too, although as yet no universal criteria for resuming sport have been produced. PMID:26151036

  14. Temporal and Spatial Characteristics of Acceleration Structures in the Auroral Return Current Region

    NASA Astrophysics Data System (ADS)

    Marklund, G. T.; Karlsson, T.; Figueiredo, S.; Johansson, T.; Buchert, S.

    2003-12-01

    Temporal and spatial characteristics of high-altitude auroral electric fields, and, in particular, those which are related to quasi-static auroral electric potential structures, are discussed using Cluster multi-point observations from auroral field line crossings at geocentric distances of about 5 RE. Intense and narrow-structured diverging electric fields, associated with upward accelerated electrons, being fingerprints of quasi-static acceleration structures in the auroral return current region, appear more frequently at these altitudes than their counterpart, converging electric fields, on auroral field lines, for reasons not yet understood. The time needed for evacuating ionospheric electrons at the ionospheric end of the return current flux tube, which depend on the field-aligned current density, represent one characteristic time scale for the accelerating electric fields. We present results from four Cluster encounters with such acceleration structures and how these and their associated field-aligned current and electron distributions, evolve on the different time scales given by different inter-spacecraft separation distances.

  15. Return current and proton emission from wire targets interacting with an intense short pulse laser

    NASA Astrophysics Data System (ADS)

    Beg, Farhat

    2004-05-01

    One of the important characteristics of short pulse high intensity laser-solid interactions is the generation of energetic charged particles, which result from the very efficient conversion of laser energy into hot electrons. Since the electrons in the electric field of the laser have relativistic quiver motions, the temperature of the hot electron distribution of the plasma produced at such extreme intensities can become very high. A large number of hot electrons (1013-1014) having an average energy of the order of 1-2 MeV can be generated as intensities exceed 1019 Wcm-2. Since the resulting beam current exceeds the Alfvén limit, a neutralizing return current of cold plasma electrons moving in the opposite direction is produced. Another source of return current is that due to the escape of very energetic electrons from the target, which then creates a large electrostatic potential due to charge separation. These return currents can cause significant ohmic heating. In addition escaping electrons establish the large electrostatic fields, accelerating a large number of protons from the target with energies of 10's of MeV. The experiments reported here were performed at the Rutherford Appleton Laboratory with the VULCAN laser facility at intensity greater than 5 x1019 Wcm-2 on wire targets. In some shots an additional wire or foil was placed nearby. The laser was blocked by the main wire target so that no laser light reached the additional wire or foil. Three main observations were made: (i) a Z-pinch was driven in the wire due to the return current, (ii) optical transition radiation (OTR) at 2w was generated and (iii) energetic proton emission was observed. The wire targets were observed to be ohmically heated and were m=0 unstable. The OTR emission is likely due to electron bunches accelerated by the ponderomotive force of the laser. The proton emission was in a form of thin disk perpendicular to the wire and centered on the wire at the laser focus. Proton

  16. The effect of beam-driven return current instability on solar hard X-ray bursts

    NASA Technical Reports Server (NTRS)

    Cromwell, D.; Mcquillan, P.; Brown, J. C.

    1986-01-01

    The problem of electrostatic wave generation by a return current driven by a small area electron beam during solar hard X-ray bursts is discussed. The marginal stability method is used to solve numerically the electron and ion heating equations for a prescribed beam current evolution. When ion-acoustic waves are considered, the method appears satisfactory and, following an initial phase of Coulomb resistivity in which T sub e/T sub i rise, predicts a rapid heating of substantial plasma volumes by anomalous ohmic dissipation. This hot plasma emits so much thermal bremsstrahlung that, contrary to previous expectations, the unstable beam-plasma system actually emits more hard X-rays than does the beam in the purely collisional thick target regime relevant to larger injection areas. Inclusion of ion-cyclotron waves results in ion-acoustic wave onset at lower T sub e/T sub i and a marginal stability treatment yields unphysical results.

  17. Characteristics of quasi-static potential structures observed in the auroral return current region by Cluster

    NASA Astrophysics Data System (ADS)

    Marklund, G. T.; Karlsson, T.; Figueiredo, S.; Johansson, T.; Lindqvist, P.-A.; André, M.; Buchert, S.; Kistler, L. M.; Fazakerley, A.

    2004-12-01

    Temporal and spatial characteristics of intense quasi-static electric fields and associated electric potential structures in the return current region are discussed using Cluster observations at geocentric distances of about 5 Earth radii. Results are presented from four Cluster encounters with such acceleration structures to illustrate common as well as different features of such structures. The electric field structures are characterized by (all values are projected to 100 km altitude) peak amplitudes of ≍1V/m, bipolar or unipolar profiles, perpendicular scale sizes of ≍10km, occurrence at auroral plasma boundaries associated with plasma density gradients, downward field-aligned currents of ≍10µA/m2, and upward electron beams with characteristic energies of a few hundred eV to a fewkeV. Two events illustrate the temporal evolution of bipolar, diverging electric field structures, indicative of positive U-shaped potentials increasing in magnitude from less than 1kV to a few kV on a few 100s time scale. This is also the typical formation time for ionospheric plasma cavities, which are connected to the potential structure and suggested to evolve hand-in-hand with these. In one of these events an energy decay of inverted-V ions was observed in the upward field-aligned current region prior to the acceleration potential increase in the adjacent downward current region, possibly suggesting that a potential redistribution took place between the two current branches. The other two events were characterized by intense unipolar electric fields, indicative of S-shaped potential contours and were encountered at the polar cap boundary. The total observation time for these events was typically 10-20s, too short for monitoring the evolution of the structure, but yet of interest for revealing their short term stability. The locations of the two bipolar events at the poleward boundary of the central plasma sheet and of the two unipolar events at the polar cap boundary

  18. Characteristics of return stroke currents of classical and altitude triggered lightning in GCOELD in China

    NASA Astrophysics Data System (ADS)

    Zheng, Dong; Zhang, Yijun; Lu, Weitao; Zhang, Yang; Dong, Wansheng; Chen, Shaodong; Dan, Jianru

    2013-07-01

    The currents of 29 return strokes (RSs) involved in 10 classical triggered lightning flashes (TLFs) and an altitude TLF conducted in Guangdong, China from 2008 to 2011 are analyzed for the first time. They have relatively greater peak values (geometric mean (GM) of 16.07 kA), average rate of rise between 10 and 90% (S10-90%, GM of 29.16 kA μs- 1), charge transfer within 1 ms (Q1 ms, GM of 1.36 C) and action integral within 1 ms (AI1 ms, GM of 5.39 × 103 A2 s), compared with those reported in other studies. The current peak value exhibits pronounced exponential relation with S10-90% (determination coefficient (R2) = 0.43) and maximum rate of rise (R2 = 0.77), power relation with Q1 ms (R2 = 0.89), and logarithmic relation with AI1 ms (R2 = 0.93). Additionally, the discharges associated with the processes of initial-stage return strokes (ISRSs) involved in two altitude TLFs, with the peak currents of 10.09 kA and 9.03 kA, respectively, are investigated. Their peak, 10-90% risetime, average rate of rise between 10 and 90% and maximum rate of rise are comparable to those of the RSs. The chopped-shape pulses closely following the ISRSs and the pulses associated with the disintegration and reconnections of the wire's channel are also discussed.

  19. Continental crust beneath the Agulhas Plateau, Southwest Indian Ocean

    SciTech Connect

    Tucholke, B.E.; Houtz, R.E.; Barrett, D.M.

    1981-05-10

    The Agulhas Plateau lies 500 km off the Cape of Good Hope in the southwestern Indian Ocean. Acoustic basement beneath the northern one third of this large, aseismic structural high has rugged morphology, but basement in the south is anomalously smooth, excepting a 30- to 90-km-wide zone with irregular relief that trends south-southwest through the center of the plateau. Seismic refraction profiles across the southern plateau indicate that the zone of irregular acoustic basement overlies thickened oceanic crust and that continental crust, locally thinned and intruded by basalts, underlies several regions of smooth acoustic basement. Recovery of quartzo-feldspathic gneisses in dredge hauls confirms the presence of continental crust. The smoothness of acoustic basement probably results from erosion (perhaps initially subaerial) of topographic highs with depositions and cementation of debris in ponds to form high-velocity beds. Basalt flows and sills also may contribute locally to form smooth basement. The rugged basement of the northern plateau appears to be of oceanic origin. A plate reconstruction to the time of initial opening of the South Atlantic places the continental part of the southern plateau adjacent to the southern edge of the Falkland Plateau, and both abut the western Mozambique Ridge. Both the Agulhas and Falkland plateaus were displaced westward during initial rifting in the Early Cretaceous. Formation of an RRR triple junction at the northern edge of the Agulhas continental fragment during middle Cretaceous time may explain the origin of the rugged, thickened oceanic crust beneath plateau as well as the apparent extension of the continental crust and intrusion of basaltic magmas beneath the southern plateau.

  20. Coronal vs chromospheric heating through co-spatial return currents during the 19 and 20 Jan 2005 solar flare

    NASA Astrophysics Data System (ADS)

    Alaoui, Meriem; Holman, Gordon D.

    2016-05-01

    The high electron flux required to explain the bremsstrahlung X-ray emission observed from solar flares is expected to be accompanied by a neutralizing co-spatial return current. In addition to resupplying the acceleration region with electrons, this return current will both heat the coronal plasma and flatten the electron distribution at lower energies. This flattening in the electron distribution in turn flattens the X-ray spectrum. We have found that return-current collisional thick-target model (RCCTTM) of Holman (2012) provides an acceptable fit to X-ray spectra with strong breaks for 18 flares observed with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI). This is a 1D model similar to the collisional thick-target model (CTTM) with two additional assumptions: (1) electrons lose some of their energy through return current losses along their path to the thick target, where they lose all their remaining energy through Coulomb collisions; (2) the non-thermal beam is streaming in a warm target, which means that electrons will be thermalized at a non-zero energy. We assume this energy to be equal to the analytical value derived by Kontar et al. 2015. We show that return-current heating in the corona is about an order of magnitude higher than the heating at the footpoints at times during the flare.

  1. Experiments on current-driven three-dimensional ion sound turbulence. I - Return-current limited electron beam injection. II - Wave dynamics

    NASA Technical Reports Server (NTRS)

    Stenzel, R. L.

    1978-01-01

    Pulsed electron beam injection into a weakly collisional magnetized background plasma is investigated experimentally; properties of the electron beam and background plasma, as well as the low-frequency instabilities and wave dynamics, are discussed. The current of the injected beam closes via a field-aligned return current of background electrons. Through study of the frequency and wavenumber distribution, together with the electron distribution function, the low-frequency instabilities associated with the pulsed injection are identified as ion acoustic waves driven unstable by the return current. The frequency cut-off of the instabilities predicted from renormalized plasma turbulence theory, has been verified experimentally.

  2. Understanding the Impact of Return-Current Losses on the X-Ray Emission from Solar Flares

    NASA Technical Reports Server (NTRS)

    Holman, Gordon D.

    2012-01-01

    I obtain and examine the implications of one-dimensional analytic solutions for return-current losses on an initially power-law distribution of energetic electrons with a sharp low-energy cutoff in flare plasma with classical (collisional) resistivity. These solutions show, for example, that return-current losses are not sensitive to plasma density, but are sensitive to plasma temperature and the low energy cutoff of the injected nonthermal electron distribution. A characteristic distance from the electron injection site, x(sub rc), is derived. At distances less than x(sub rc) the electron flux density is not reduced by return-current losses, but plasma heating can be substantial in this region, in the upper, coronal part of the flare loop. Before the electrons reach the collisional thick-target region of the flare loop, an injected power-law electron distribution with a low-energy cutoff maintains that structure, but with a flat energy distribution below the cutoff energy, which is now determined by the total potential drop experienced by the electrons. Modifications due to the presence of collisional losses are discussed. I compare these results with earlier analytical results and with more recent numerical simulations. Emslie's 1980 conjecture that there is a maximum integrated X-ray source brightness on the order of 10(exp -15) photons per square centimeter per second per square centimeter is examined. I find that this is not actually a maximum brightness and its value is parameter dependent, but it is nevertheless a valuable benchmark for identifying return-current losses in hard X-ray spectra. I discuss an observational approach to identifying return-current losses in flare data, including identification of a return-current "bump" in X-ray light curves at low photon energies.

  3. Factors affecting return to play after anterior cruciate ligament reconstruction: a review of the current literature.

    PubMed

    Bauer, Matthew; Feeley, Brian T; Wawrzyniak, John R; Pinkowsky, Gregory; Gallo, Robert A

    2014-11-01

    Anterior cruciate ligament reconstruction has been reported to produce normal or near-normal knee results in > 90% of patients. A recent meta-analysis suggested that, despite normal or near-normal knees, many athletes do not return to sports. Rates and timing of return to competitive athletics are quite variable depending on the graft type, the age of the patient, the sport, and the level of play. Even when athletes do return to play, often they do not return to their previous level. Graft failure, subjective physical factors, and psychological factors, including fear of reinjury and lack of motivation, appear to play a large role in patients' ability to return to sporting activities. PMID:25419890

  4. Inter-comparison studies between high-resolution HYCOM simulation and observational data: The South Atlantic and the Agulhas leakage system

    NASA Astrophysics Data System (ADS)

    Castellanos, P.; Campos, E. J. D.; Giddy, I.; Santis, W.

    2016-07-01

    Statistical analyses and model-data inter-comparisons are performed to evaluate the model's ability to reproduce the dynamics in the upper layers (< 2000 m) of the South Atlantic ocean. Outputs of an eddy-resolving Ocean General Circulation Model (OGCM) are analyzed and compared with observed data. The model, a 1/12-degree, 22-layer implementation of the Hybrid Coordinate Ocean Model (HYCOM) to the South Atlantic, was forced with monthly-mean products from the NCEP Reanalysis for the period 1960 to 2010. The numerical experiment was capable to reproduce the large scale and the mesoscale dynamic in the South Atlantic and in the Agulhas region. The vertical structure is in agreement with in situ data, the model has lower skill when compared with PIRATA lower temperatures, and is able to capture the seasonal and annual variability in the tropical Atlantic. Furthermore, sensitive change until 2007 is clear in the vertical structure, at 4°N-38°W; 0°-35°W and 10°S-10°W, suggesting an important change in the stratification. The primary results concern a significant change in the decadal anomalies of the temperatures and salinity, which exhibit a warmer and saltier water in the southeastern Atlantic. Furthermore, linear trends found in the transport time-series in the North Brazil Current, and the South Equatorial Current were seen to correspond with increasing trends of the warmer water from the Agulhas Current into South Atlantic. The integrated transport during the period 1960-2010, shows an increase in westward changes in the large-scale circulation south of Africa are show in the negative trends indicate a widening of the "Agulhas gap" and increase in westward volume transport since 1980. It is therefore suggested that variability in the Agulhas System on the last two decades is affecting the dynamic in the South Atlantic, namely the temperature and the volume transport, reach the tropical region of the Atlantic.

  5. Ocean plankton. Environmental characteristics of Agulhas rings affect interocean plankton transport.

    PubMed

    Villar, Emilie; Farrant, Gregory K; Follows, Michael; Garczarek, Laurence; Speich, Sabrina; Audic, Stéphane; Bittner, Lucie; Blanke, Bruno; Brum, Jennifer R; Brunet, Christophe; Casotti, Raffaella; Chase, Alison; Dolan, John R; d'Ortenzio, Fabrizio; Gattuso, Jean-Pierre; Grima, Nicolas; Guidi, Lionel; Hill, Christopher N; Jahn, Oliver; Jamet, Jean-Louis; Le Goff, Hervé; Lepoivre, Cyrille; Malviya, Shruti; Pelletier, Eric; Romagnan, Jean-Baptiste; Roux, Simon; Santini, Sébastien; Scalco, Eleonora; Schwenck, Sarah M; Tanaka, Atsuko; Testor, Pierre; Vannier, Thomas; Vincent, Flora; Zingone, Adriana; Dimier, Céline; Picheral, Marc; Searson, Sarah; Kandels-Lewis, Stefanie; Acinas, Silvia G; Bork, Peer; Boss, Emmanuel; de Vargas, Colomban; Gorsky, Gabriel; Ogata, Hiroyuki; Pesant, Stéphane; Sullivan, Matthew B; Sunagawa, Shinichi; Wincker, Patrick; Karsenti, Eric; Bowler, Chris; Not, Fabrice; Hingamp, Pascal; Iudicone, Daniele

    2015-05-22

    Agulhas rings provide the principal route for ocean waters to circulate from the Indo-Pacific to the Atlantic basin. Their influence on global ocean circulation is well known, but their role in plankton transport is largely unexplored. We show that, although the coarse taxonomic structure of plankton communities is continuous across the Agulhas choke point, South Atlantic plankton diversity is altered compared with Indian Ocean source populations. Modeling and in situ sampling of a young Agulhas ring indicate that strong vertical mixing drives complex nitrogen cycling, shaping community metabolism and biogeochemical signatures as the ring and associated plankton transit westward. The peculiar local environment inside Agulhas rings may provide a selective mechanism contributing to the limited dispersal of Indian Ocean plankton populations into the Atlantic.

  6. On the role of the Agulhas system in ocean circulation and climate.

    PubMed

    Beal, Lisa M; De Ruijter, Wilhelmus P M; Biastoch, Arne; Zahn, Rainer

    2011-04-28

    The Atlantic Ocean receives warm, saline water from the Indo-Pacific Ocean through Agulhas leakage around the southern tip of Africa. Recent findings suggest that Agulhas leakage is a crucial component of the climate system and that ongoing increases in leakage under anthropogenic warming could strengthen the Atlantic overturning circulation at a time when warming and accelerated meltwater input in the North Atlantic is predicted to weaken it. Yet in comparison with processes in the North Atlantic, the overall Agulhas system is largely overlooked as a potential climate trigger or feedback mechanism. Detailed modelling experiments--backed by palaeoceanographic and sustained modern observations--are required to establish firmly the role of the Agulhas system in a warming climate.

  7. Ocean plankton. Environmental characteristics of Agulhas rings affect interocean plankton transport.

    PubMed

    Villar, Emilie; Farrant, Gregory K; Follows, Michael; Garczarek, Laurence; Speich, Sabrina; Audic, Stéphane; Bittner, Lucie; Blanke, Bruno; Brum, Jennifer R; Brunet, Christophe; Casotti, Raffaella; Chase, Alison; Dolan, John R; d'Ortenzio, Fabrizio; Gattuso, Jean-Pierre; Grima, Nicolas; Guidi, Lionel; Hill, Christopher N; Jahn, Oliver; Jamet, Jean-Louis; Le Goff, Hervé; Lepoivre, Cyrille; Malviya, Shruti; Pelletier, Eric; Romagnan, Jean-Baptiste; Roux, Simon; Santini, Sébastien; Scalco, Eleonora; Schwenck, Sarah M; Tanaka, Atsuko; Testor, Pierre; Vannier, Thomas; Vincent, Flora; Zingone, Adriana; Dimier, Céline; Picheral, Marc; Searson, Sarah; Kandels-Lewis, Stefanie; Acinas, Silvia G; Bork, Peer; Boss, Emmanuel; de Vargas, Colomban; Gorsky, Gabriel; Ogata, Hiroyuki; Pesant, Stéphane; Sullivan, Matthew B; Sunagawa, Shinichi; Wincker, Patrick; Karsenti, Eric; Bowler, Chris; Not, Fabrice; Hingamp, Pascal; Iudicone, Daniele

    2015-05-22

    Agulhas rings provide the principal route for ocean waters to circulate from the Indo-Pacific to the Atlantic basin. Their influence on global ocean circulation is well known, but their role in plankton transport is largely unexplored. We show that, although the coarse taxonomic structure of plankton communities is continuous across the Agulhas choke point, South Atlantic plankton diversity is altered compared with Indian Ocean source populations. Modeling and in situ sampling of a young Agulhas ring indicate that strong vertical mixing drives complex nitrogen cycling, shaping community metabolism and biogeochemical signatures as the ring and associated plankton transit westward. The peculiar local environment inside Agulhas rings may provide a selective mechanism contributing to the limited dispersal of Indian Ocean plankton populations into the Atlantic. PMID:25999514

  8. THE n-DISTRIBUTION OF ELECTRONS AND DOUBLE LAYERS IN THE ELECTRON-BEAM-RETURN-CURRENT SYSTEM OF SOLAR FLARES

    SciTech Connect

    Karlicky, Marian

    2012-05-01

    We investigate processes in the electron-beam-return-current system in the impulsive phase of solar flares to answer a question about the formation of the n-electron distribution detected in this phase of solar flares. An evolution of the electron-beam-return-current system with an initial local density depression is studied using a three-dimensional electromagnetic particle-in-cell model. In the system the strong double layer is formed. Its electric field potential increases with the electron beam flux. In this electric field potential, the electrons of background plasma are strongly accelerated and propagate in the return-current direction. The high-energy part of their distribution at the high-potential side of the strong double layer resembles that of the n-distribution. Thus, the detection of the n-distributions, where a form of the high-energy part of the distribution is the most important, can indicate the presence of strong double layers in solar flares. The similarity between processes in solar flare loops and those in the downward current region of the terrestrial aurora, where the double layers were observed by FAST satellite, supports this idea.

  9. Soil surface potentials induced by ITAIPU HVDC ground return current. Part I - Theoretical evaluation

    SciTech Connect

    Kovarsky, D.; Pinto, L.J.; Caroli, C.E.; Santos, N. )

    1988-07-01

    The methodology for the theoretical evaluation of the soil surface potentials induced in ground return mode, is presented. For each electrode, soil resistivity data acquisition is discussed, giving rise to soil models amenable to mathematical analysis. For one electrode, the soil model considers a slanting interface between the first two layers, empirically considering the influence of a third deeper layer. For the other, the model consists of four different soil layers with horizontal interfaces, for which a special numerical approach is used, that can be extended to the case of AC induction between parallel wires over multilayer soils.

  10. Review of X-43A Return to Flight Activities and Current Status

    NASA Technical Reports Server (NTRS)

    Reubush, David E.; Nguyen, Luat T.; Rausch, Vincent L.

    2004-01-01

    This paper provides an overview and status of the return to flight activities for the X-43A scramjet flight demonstrator after the first flight mishap. The first flight was attempted on June 2, 2001 and resulted in vehicle destruction by range safety when the booster went out of control early in the flight. In the time since the mishap much work has been done to examine the causes of the failure and make modifications to the booster to insure that the boost for the second flight will be successful. In addition, all other aspects of the flight have been examined to maximize the probability of a successful flight.

  11. Agulhas leakage as a key process in the modes of Quaternary climate changes

    PubMed Central

    Caley, Thibaut; Giraudeau, Jacques; Malaizé, Bruno; Rossignol, Linda; Pierre, Catherine

    2012-01-01

    Heat and salt transfer from the Indian Ocean to the Atlantic Ocean (Agulhas leakage) has an important effect on the global thermohaline circulation and climate. The lack of long transfer record prevents elucidation of its role on climate changes throughout the Quaternary. Here, we present a 1,350-ka accumulation rate record of the planktic foraminiferal species Globorotalia menardii. We demonstrate that, according to previous assumptions, the presence and reseeding of this fauna in the subtropical southeast Atlantic was driven by interocean exchange south of Africa. The Agulhas transfer strengthened at glacial ice-volume maxima for every glacial-interglacial transition, with maximum reinforcements organized according to a 400-ka periodicity. The long-term dynamics of Agulhas leakage may have played a crucial role in regulating meridional overturning circulation and global climate changes during the Mid-Brunhes event and the Mid-Pleistocene transition, and could also play an important role in the near future. PMID:22508999

  12. Agulhas leakage as a key process in the modes of Quaternary climate changes.

    PubMed

    Caley, Thibaut; Giraudeau, Jacques; Malaizé, Bruno; Rossignol, Linda; Pierre, Catherine

    2012-05-01

    Heat and salt transfer from the Indian Ocean to the Atlantic Ocean (Agulhas leakage) has an important effect on the global thermohaline circulation and climate. The lack of long transfer record prevents elucidation of its role on climate changes throughout the Quaternary. Here, we present a 1,350-ka accumulation rate record of the planktic foraminiferal species Globorotalia menardii. We demonstrate that, according to previous assumptions, the presence and reseeding of this fauna in the subtropical southeast Atlantic was driven by interocean exchange south of Africa. The Agulhas transfer strengthened at glacial ice-volume maxima for every glacial-interglacial transition, with maximum reinforcements organized according to a 400-ka periodicity. The long-term dynamics of Agulhas leakage may have played a crucial role in regulating meridional overturning circulation and global climate changes during the Mid-Brunhes event and the Mid-Pleistocene transition, and could also play an important role in the near future.

  13. Agulhas leakage as a key process in the modes of Quaternary climate changes.

    PubMed

    Caley, Thibaut; Giraudeau, Jacques; Malaizé, Bruno; Rossignol, Linda; Pierre, Catherine

    2012-05-01

    Heat and salt transfer from the Indian Ocean to the Atlantic Ocean (Agulhas leakage) has an important effect on the global thermohaline circulation and climate. The lack of long transfer record prevents elucidation of its role on climate changes throughout the Quaternary. Here, we present a 1,350-ka accumulation rate record of the planktic foraminiferal species Globorotalia menardii. We demonstrate that, according to previous assumptions, the presence and reseeding of this fauna in the subtropical southeast Atlantic was driven by interocean exchange south of Africa. The Agulhas transfer strengthened at glacial ice-volume maxima for every glacial-interglacial transition, with maximum reinforcements organized according to a 400-ka periodicity. The long-term dynamics of Agulhas leakage may have played a crucial role in regulating meridional overturning circulation and global climate changes during the Mid-Brunhes event and the Mid-Pleistocene transition, and could also play an important role in the near future. PMID:22508999

  14. Cutaneous Leishmaniasis: Current Treatment Practices in the USA for Returning Travelers

    PubMed Central

    Eiras, Daniel P.; Kirkman, Laura A.; Murray, Henry W.

    2015-01-01

    Opinion statement Leishmaniasis, a protozoal infection transmitted by sandfly bite, produces a clinical spectrum of disease ranging from asymptomatic infection to ulcerative skin and mucosal lesions to visceral involvement. Leishmaniasis is endemic in regions of Africa, the Middle East, south Asia, southern Europe, northern South America, and Central America. There has been an increase in imported leishmaniasis into developed, non-endemic countries due to increasing global travel. While pentavalent antimonials have been the mainstay of antileishmanial treatment for decades, newer therapeutic options have become available for all forms of infection, including liposomal amphotericin B, miltefosine, fluconazole, and ketoconazole. For the returning traveler with cutaneous leishmaniasis in the USA, treatment approaches are determined based on infecting species, initial presentation, extent and progression of disease, the advantages and drawbacks of available parenteral and oral drugs, and clinician-consultant experience. PMID:25788870

  15. Ocean Virtual Laboratory: A New Way to Explore Multi-Sensor Synergy Demonstrated over the Agulhas Region

    NASA Astrophysics Data System (ADS)

    Collard, F.; Quartly, G. D.; Konik, M.; Johannessen, J. A.; Korosov, A.; Chapron, B.; Piolle, J.-F.; Herledan, S.; Darecki, M.; Isar, A.; Nafornita, C.

    2015-12-01

    Ocean Virtual Laboratory is an ESA-funded project to prototype the concept of a single point of access for all satellite remote-sensing data with ancillary model output and in situ measurements for a given region. The idea is to provide easy access for the non-specialist to both data and state-of-the-art processing techniques and enable their easy analysis and display. The project, led by OceanDataLab, is being trialled in the region of the Agulhas Current, as it contains signals of strong contrast (due to very energetic upper ocean dynamics) and special SAR data acquisitions have been recorded there. The project also encourages the take up of Earth Observation data by developing training material to help those not in large scientific or governmental organizations make the best use of what data are available. The website for access is: http://ovlproject.oceandatalab.com/

  16. The Role of Education in Economic Growth: Theory, History and Current Returns

    ERIC Educational Resources Information Center

    Breton, Theodore R.

    2013-01-01

    Background: This paper was prepared to address the issue of whether current levels of public expenditures on education are cost-effective in countries with widely differing average levels of education. Purpose: The paper examines the role of education in economic growth from a theoretical and historic perspective, addresses why education has been…

  17. Soil surface potentials induced by ITAIPU HVDC ground return current. Part II - Measurements

    SciTech Connect

    Caroli, C.E.; Santos, N.; Kovarsky, D.; Marques, M.A.M. )

    1988-07-01

    The method used for the measurement of the potential curves in the soil surface is presented, together with its results, obtained at different electrode current levels (100A, 600A, 1500A and 2300A). Circuits and instrumentation used are also presented, as well as notes on measurement noise and on the overall precision obtained. The results are finally also presented in the form of equipotential curves.

  18. Alumni of High School Internship Program Return for 25th Anniversary to Inspire Current Students | Poster

    Cancer.gov

    The Building 549 auditorium is often packed with high school interns eager to hear a scientific lecture. On April 22, however, the room swelled with interns spanning a wider age range. At the 25th Werner H. Kirsten Student Intern Program (WHK SIP) Anniversary Symposium, incoming, current, and former interns gathered to celebrate the program, which has provided biomedical research experience for local high school seniors.

  19. Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies.

    PubMed

    Biastoch, A; Böning, C W; Schwarzkopf, F U; Lutjeharms, J R E

    2009-11-26

    The transport of warm and salty Indian Ocean waters into the Atlantic Ocean-the Agulhas leakage-has a crucial role in the global oceanic circulation and thus the evolution of future climate. At present these waters provide the main source of heat and salt for the surface branch of the Atlantic meridional overturning circulation (MOC). There is evidence from past glacial-to-interglacial variations in foraminiferal assemblages and model studies that the amount of Agulhas leakage and its corresponding effect on the MOC has been subject to substantial change, potentially linked to latitudinal shifts in the Southern Hemisphere westerlies. A progressive poleward migration of the westerlies has been observed during the past two to three decades and linked to anthropogenic forcing, but because of the sparse observational records it has not been possible to determine whether there has been a concomitant response of Agulhas leakage. Here we present the results of a high-resolution ocean general circulation model to show that the transport of Indian Ocean waters into the South Atlantic via the Agulhas leakage has increased during the past decades in response to the change in wind forcing. The increased leakage has contributed to the observed salinification of South Atlantic thermocline waters. Both model and historic measurements off South America suggest that the additional Indian Ocean waters have begun to invade the North Atlantic, with potential implications for the future evolution of the MOC. PMID:19940923

  20. Agulhas Ridge, South Atlantic: the peculiar structure of a transform fault

    NASA Astrophysics Data System (ADS)

    Uenzelmann-Neben, G.; Gohl, K.

    2003-04-01

    Transform faults constitute conservative plate boundaries, where adjacent plates are in tangential contact. Transform faults in the ocean are marked by fracture zones, which are long, linear, bathymetric depressions. One of the largest transform offsets on Earth can be found in the South Atlantic. The 1200 km long Agulhas Falkland Fracture Zone (AFFZ), form by this, developed during the Early Cretaceous break-up of West Gondwana. Between approx. 41°S, 16°E and 43°S, 9°E the Agulhas Falkland Fracture Zone is characterised by a pronounced topographic anomaly, the Agulhas Ridge. The Agulhas Ridge rises more than 2 km above the surrounding seafloor. The only equivalent to this kind of topographic high, as part of the AFFZ, is found in form of marginal ridges along the continental parts of the fracture zone, namely the Falkland Escarpment at the South American continent and the Diaz Ridge adjacent to South Africa. But the Agulhas Ridge differs from both the Falkland Escarpment and the Diaz Ridge in the facts (1) that it was not formed during the early rift-drift phase, and (2) that it separates oceanic crust of different age and not continental from oceanic crust. A set of high-resolution seismic reflection data (total length 2000 km) and a seismic refraction line across the Agulhas Ridge give new information on the crustal and basement structure of this tectonic feature. We have observed that within the Cape Basin, to the North, the basement and sedimentary layers are in parts strongly deformed. We observe basement highs, which point towards intrusions. Both the basement and the sedimentary sequence show strong faulting. This points towards a combined tectono-magmatic activity, which led to the formation of basement ridges parallel to the Agulhas Ridge. Since at least the pre-Oligocene parts and, locally, the whole sedimentary column are affected we infer that the renewed activity began in the Middle Oligocene and may have lasted into the Quaternary. As an origin

  1. Two-stream stability properties of the return-current layer for intense ion beam propagation through background plasma

    SciTech Connect

    Startsev, Edward A.; Davidson, Ronald C.; Dorf, Mikhail

    2009-09-15

    When an ion beam with sharp edge propagates through a background plasma, its current is neutralized by the plasma return current everywhere except at the beam edge over a characteristic transverse distance {delta}x{sub perpendicular}{approx}{delta}{sub pe}, where {delta}{sub pe}=c/{omega}{sub pe} is the collisionless skin depth and {omega}{sub pe} is the electron plasma frequency. Because the background plasma electrons neutralizing the ion beam current inside the beam are streaming relative to the background plasma electrons outside the beam, the background plasma can support a two-stream surface-mode excitation. Such surface modes have been studied previously assuming complete charge and current neutralization, and have been shown to be strongly unstable. In this paper we study the detailed stability properties of this two-stream surface mode for an electron flow velocity profile self-consistently driven by the ion beam. In particular, it is shown that the self-magnetic field generated inside the unneutralized current layer, which has not been taken into account previously, completely eliminates the instability.

  2. PIG Ion Source with Permanent Magnets: Model Based Anode Current Return Circuit

    NASA Astrophysics Data System (ADS)

    Babapour Ghadikolaee, Mohammad Reza

    2012-12-01

    Ion sources are widely used in fusion technologies. A new high voltage pulsed power supply for use in penning ion gauge ion sources is proposed in this paper. To use discharge current, a diode-capacitor bank is included. The power supply is composed of 3 stages. A fast switching transistor is used as a single switch which is trigged by a pulse generator. A transformer is used to level up the voltage up to 2 kV without power loss. It is also used to isolate input and high voltage output. Also; the proposed high voltage power supply implementation uses a diode-capacitor bank whose capacitors are charged during plasma discharge. This system structure gives compactness and easiness to implement the total system which in combination with inexpensive commercially available components, makes the unit versatile and inexpensive.

  3. Return migration in Western Europe: current policy trends and their implications, in particular for the second generation.

    PubMed

    Entzinger, H

    1985-06-01

    Return migration in Western Europe is examined, with a focus on government policy trends and their implications. The need for international cooperation between sending and receiving countries is emphasized. The effects of migration policies on migrants now and in the future are analyzed. Particular attention is paid to the questions posed by the expressed desire of a significant percentage of second-generation migrants to return to the countries of their parents' origin. (summary in FRE, SPA)

  4. A study on the influence of corona on currents and electromagnetic fields predicted by a nonlinear lightning return-stroke model

    NASA Astrophysics Data System (ADS)

    De Conti, Alberto; Silveira, Fernando H.; Visacro, Silvério

    2014-05-01

    This paper investigates the influence of corona on currents and electromagnetic fields predicted by a return-stroke model that represents the lightning channel as a nonuniform transmission line with time-varying (nonlinear) resistance. The corona model used in this paper allows the calculation of corona currents as a function of the radial electric field in the vicinity of the channel. A parametric study is presented to investigate the influence of corona parameters, such as the breakdown electric field and the critical electric field for the stable propagation of streamers, on predicted currents and electromagnetic fields. The results show that, regardless of the assumed corona parameters, the incorporation of corona into the nonuniform and nonlinear transmission line model under investigation modifies the model predictions so that they consistently reproduce most of the typical features of experimentally observed lightning electromagnetic fields and return-stroke speed profiles. In particular, it is shown that the proposed model leads to close vertical electric fields presenting waveforms, amplitudes, and decay with distance in good agreement with dart leader electric field changes measured in triggered lightning experiments. A comparison with popular engineering return-stroke models further confirms the model's ability to predict consistent electric field waveforms in the close vicinity of the channel. Some differences observed in the field amplitudes calculated with the different models can be related to the fact that current distortion, while present in the proposed model, is ultimately neglected in the considered engineering return-stroke models.

  5. Multicentennial Agulhas leakage variability and links to North Atlantic climate during the past 80,000 years

    NASA Astrophysics Data System (ADS)

    Dyez, Kelsey A.; Zahn, Rainer; Hall, Ian R.

    2014-12-01

    New high-resolution sea surface temperature (SST) and sea surface salinity (SSS) estimates are presented from the Agulhas Bank slope in the Atlantic sector of the Agulhas Corridor using planktic foraminiferal (Globigerinoides ruber) δ18O and Mg/Ca-derived SST. By focusing on the last 80,000 years, this is the first fine-scale Agulhas leakage record that overlaps in time with much of the Greenland ice core record of abrupt climate changes in the North Atlantic region. The multicentennial profiles indicate instances of warm SST and/or increased SSS coincident with Northern Hemisphere cool periods, followed by Northern Hemisphere warming. These periods of enhanced SST and SSS in the Agulhas Corridor occur at the last glacial termination (T1) and during North Atlantic cold episodes associated with Heinrich (H) meltwater events. To a first-order approximation, the timing of maximal salinity events in relation to periods of North Atlantic freshwater perturbation is consistent with the concept suggested by climate models that enhanced Agulhas leakage provides for buoyancy compensation and can potentially trigger increased convective activity in the North Atlantic, thereby restoring Atlantic overturning circulation after relatively weak states.

  6. Paleo-Hydrography south of Africa: Assessing the role of the Subtropical Front in regulating Agulhas Leakage at the Last Glacial Termination

    NASA Astrophysics Data System (ADS)

    Skrivanek, A.; Franzese, A. M.

    2012-12-01

    While climate variability throughout the late Pleistocene and Holocene is linked to changes in insolation and atmospheric CO2, differences in the intensity of this variability indicate that other mechanisms are at work in the perturbation and stabilization of global climate. A proposed cause for glacial terminations - the rapid transition from glacial to warm interglacial climate - is the change in ocean circulation associated with a shift in westerly wind belts and corresponding oceanic fronts. Understanding the mechanisms behind such rapid events is critical to our prediction of future climate responses to anthropogenic global warming. This project reexamines the hypothesis that southward migrations of the Subtropical Front (STF) south of Africa allowed for increased Agulhas Leakage, which is recognized as a key component of the warm return route of Global Thermohaline Circulation, and is a possible prerequisite for North Atlantic overturning. We present new %CaCO3, Mg/Ca and stable oxygen isotope (δ18O) records using planktonic and benthic foraminifera for two sediment cores, VM34-158 (-41.25S) and VM34-155 (-42.17S), off the flank of the Agulhas Plateau. Benthic δ18O and %CaCO3 provide a framework for stratigraphy and the extent of dissolution throughout the cores. Planktonic Mg/Ca and δ18O of G.bulloides serve as proxies for sea surface temperature (SST) and salinity (SSS), and will be used to constrain the position of the STF with respect to changes in Agulhas Leakage. We observe a clear signal of the LGM and Holocene horizons and the Last Glacial termination ~18ka in all proxies. Higher δ18O and lower Mg/Ca ratios characterize the LGM, with the inverse situation for the early Holocene. Mg/Ca averages are 1.32±.21 and 1.04±.02 mmol/mol during the LGM, with δ18O averages of 3.17±.32‰ and 3.46±.28‰ for VM34-158 and VM34-155 respectively. The early Holocene features increased Mg/Ca averages of 1.52±.18 and 1.318±.12 mmol/mol, and reduced δ18O

  7. Return migration.

    PubMed

    Gmelch, G

    1980-01-01

    The author reviews the findings of the growing literature on return migration. Topics covered include typologies of return migrants, reasons for return, adaptation and readjustment of returnees, and the impact of return migration on the migrants' home societies. The focus of the study is on international return migration, migration to Northern Europe and northeastern North America, and return migration to the southern and eastern fringes of Europe and the Caribbean

  8. Studying an Agulhas ring's long-term pathway and decay with finite-time coherent sets

    NASA Astrophysics Data System (ADS)

    Froyland, Gary; Horenkamp, Christian; Rossi, Vincent; van Sebille, Erik

    2015-08-01

    Coherent sets in dynamical systems are regions in phase space that optimally "carry mass" with them under the system's evolution, so that these regions experience minimal leakage. The dominant tool for determining coherent sets is the transfer operator, which provides a complete description of Lagrangian mass transport. In this work, we combine existing transfer operator methods with a windowing scheme to study the spatial and temporal evolution of a so-called Agulhas ring: a large anticyclonic mesoscale eddy playing a key role in inter-ocean exchange of climate-relevant properties. Our focus is on ring decay over time and the windowing scheme enables us to study how the most coherent region (our estimate of the ring) varies in position and size over a period of more than two years. We compare the eddy-like structure and its spatio-temporal changes as revealed by our method and by a classical Eulerian approach.

  9. Why Current Doppler Ultrasound Methodology Is Inaccurate in Assessing Cerebral Venous Return: The Alternative of the Ultrasonic Jugular Venous Pulse

    PubMed Central

    2016-01-01

    Assessment of cerebral venous return is growing interest for potential application in clinical practice. Doppler ultrasound (DUS) was used as a screening tool. However, three meta-analyses of qualitative DUS protocol demonstrate a big heterogeneity among studies. In an attempt to improve accuracy, several authors alternatively measured the flow rate, based on the product of the time average velocity with the cross-sectional area (CSA). However, also the quantification protocols lacked of the necessary accuracy. The reasons are as follows: (a) automatic measurement of the CSA assimilates the jugular to a circle, while it is elliptical; (b) the use of just a single CSA value in a pulsatile vessel is inaccurate; (c) time average velocity assessment can be applied only in laminar flow. Finally, the tutorial describes alternative ultrasound calculation of flow based on the Womersley method, which takes into account the variation of the jugular CSA overtime. In the near future, it will be possible to synchronize the electrocardiogram with the brain inflow (carotid distension wave) and with the outflow (jugular venous pulse) in order to nicely have a noninvasive ultrasound picture of the brain-heart axis. US jugular venous pulse may have potential use in neurovascular, neurocognitive, neurosensorial, and neurodegenerative disorders. PMID:27006525

  10. A description of eddy-mean flow feedbacks in equatorial and boundary current systems of the South Indian Ocean

    NASA Astrophysics Data System (ADS)

    Aguiar-González, Borja; Ponsoni, Leandro; Maas, Leo R. M.; Ridderinkhof, Herman; van Aken, Hendrik

    2015-04-01

    While many observational and modeling efforts have addressed eddy-mean flow interactions acting over nearly idealized zonal jets, little is know about whether findings in those studies can be extended to current systems with different configurations in the real ocean. This topic is of special interest for ocean-climate models where eddy interactions with the mean flow may be unresolved, demanding further insight on the mechanism by which the eddy field and the mean circulation should feed back in a realistic representation of future climate change scenarios. Following this motivation, we investigate local exchange of momentum and kinetic energy operating in a variety of eddy-mean flow systems of the South Indian Ocean (SIO). To this aim we use 21 years (1993-2013) of newly processed satellite altimetry observations, and adopt a definition of the mean flow as a seasonally-dependent temporal mean where the eddy field encompasses the daily instantaneous deviation from the altimeter-derived velocities. This approach allows time-varying feedbacks to evolve throughout the year. We find that the eddy field feeds back on the mean circulation, contributing importantly to the overall seasonal strengthening and weakening of all current systems involved in the tropical and subtropical gyre of the SIO. Although significant contributions to the momentum and energy balances were also obtained along the Agulhas (Return) Current and the Antarctic Circumpolar Current (ACC), they exhibit a weak/absent seasonal cycle, suggesting that the strength of these dynamical processes is mostly persistent throughout the year. Spatial distribution of the eddy kinetic energy conversion rates and the convergence of horizontal eddy momentum fluxes indicate that over regions where the eddy field draws energy from the mean flow through barotropic instabilities, the current is importantly decelerated by alongstream eddy forces on its upstream side, while further downstream the situation reverses with

  11. Ocean circulation in the southern Benguela region from the Pliocene to the Pleistocene: tracking Agulhas leakage into the SE Atlantic

    NASA Astrophysics Data System (ADS)

    Petrick, Benjamin; McClymont, Erin; Felder, Sojna; Leng, Melanie

    2013-04-01

    The transition from the warmth of the middle Pliocene to the large amplitude, 100 kyr glacial-interglacial cycles of the late Pleistocene provides a way to understand the forcings and impacts of regional and global climate change. Here, we investigate changes in ocean circulation over the period from 3.5 Ma to present using a marine sediment core, ODP Site 1087 (31o28'S, 15o19'E, 1374m water depth). ODP 1087 is located in the South-east Atlantic Ocean, outside the Benguela upwelling region. Its location allows investigation of the history of the heat and salt transfer to the Atlantic Ocean from the Indian Ocean ("Agulhas leakage"), which plays an important part in the global thermohaline circulation. It is not known how this transfer reacted to generally warmer global temperatures during the mid-Pliocene, nor to the transition to a globally cooler climate in the early Pleistocene. Our approach is to apply several organic geochemistry proxies and foraminiferal analyses to reconstruct the history of ODP 1087. These include the U37K' index to reconstruct sea surface temperatures, pigment analysis for understanding productivity changes, and foraminifera assemblage analysis to detect the presence of different water masses at the site. We have identified changes in SSTs and biological productivity that we argue to reflect shifts in the position of the Benguela upwelling cells, and a changing influence of Agulhas leakage. Our new data reveal a different organization in the Southeast Atlantic. It shows that during the Pliocene ODP 1087 was dominated by Benguela upwelling which had shifted south. We find no evidence for Agulhas leakage during the mid Pliocene, which could mean that Agulhas Leakage was severely reduced during the mid Pliocene. The implications of these results for understanding Plio-Pleistocene climate changes will be explored here.

  12. The path of no return--Truncated protein N-termini and current ignorance of their genesis.

    PubMed

    Fortelny, Nikolaus; Pavlidis, Paul; Overall, Christopher M

    2015-07-01

    Almost all regulatory processes in biology ultimately lead to or originate from modifications of protein function. However, it is unclear to which extent each mechanism of regulation actually affects proteins and thus phenotypes. We assessed the extent of N-terminal protein truncation in a global analysis of N-terminomics data and find that most proteins have N-terminally truncated proteoforms. Because N-terminomics analyses do not identify the process generating the identified N-termini, we compared identified termini to the three N-termini generating events: protein cleavage, alternative translation, and alternative splicing. Of these, we sought to identify the most likely cause of N-terminal protein truncations in the human proteome. We found that protease cleavage and alternative protein translation are the likely cause for most shortened proteoforms. However, the vast majority (about 90%) of N-termini remain unexplained by any of these processes identified to date, so revealing large gaps in our knowledge of protein termini and their genesis. Further analysis and annotation of terminomics data is required, to which end we have created the TopFIND database, a major systematic annotation effort for protein termini. We outline the new features in version 3.0 of the updated database and the new bioinformatics tools available and encourage submission of generated data to fill current knowledge gaps.

  13. Application of the nonlinear antenna theory model to a tall tower struck by lightning for the evaluation of return stroke channel current and radiated electromagnetic fields

    NASA Astrophysics Data System (ADS)

    Moosavi, S. H. S.; Moini, R.; Sadeghi, S. H. H.; Kordi, B.

    2011-06-01

    In this paper an improved antenna theory (AT) model with nonlinearly varying resistive loading and fixed inductive loading is used to electromagnetically simulate lightning strikes to tall structures. Measurement data captured from Toronto's CN tower are used to verify the validity of the new model. Both the return stroke channel (RSC) and the tower are modeled by straight thin conducting wires. The wire model of the channel is assumed to have distributed nonlinear resistive elements as a function of current and time, adopted from the numerical models of a spark channel and consequent shockwave from a lightning discharge, yielding a varying value of the channel radius from the base to the cloud along the RSC. Such distributed elements are used to take into account the current attenuation while propagating along the channel and varying propagation speeds lower than the speed of light. RSC current distribution and radiated electromagnetic fields in near, intermediate, and far range distances predicted by the proposed model are compared with those obtained from the measurement data and with those of the original AT model and the AT with fixed inductive loading (ATIL-F) model. Current wave propagation speed profile in RSC and tower is investigated as a function of height as well. The effects of applying different tower geometry models are also studied. It is shown that the new model is able to reproduce one of the characteristic features of the electromagnetic fields radiated by lightning, namely, the far-field inversion of polarity with a zero crossing occurring in the tens of microseconds range. We have also investigated the effect of nonlinearity of the channel assumed in the new model. It is shown that among the electromagnetic models, distributed nonlinear resistance along the channel leads to a zero crossing in the tens of microseconds range even for large values of resistance. It is also shown that decreasing the nonlinearity results in the predictions

  14. Lightning return stroke models

    NASA Technical Reports Server (NTRS)

    Lin, Y. T.; Uman, M. A.; Standler, R. B.

    1980-01-01

    We test the two most commonly used lightning return stroke models, Bruce-Golde and transmission line, against subsequent stroke electric and magnetic field wave forms measured simultaneously at near and distant stations and show that these models are inadequate to describe the experimental data. We then propose a new return stroke model that is physically plausible and that yields good approximations to the measured two-station fields. Using the new model, we derive return stroke charge and current statistics for about 100 subsequent strokes.

  15. Return to Bangka Island.

    PubMed

    Spence, J

    2001-07-01

    This article is a return in a couple of ways to one of the most tragic events in the history of Australian military nursing. Firstly, it describes how the evacuation of nurses from Singapore in 1941 led to circumstances that resulted in the massacre or internment of many of those women. Then in 1993, a group of surviving World War II nurses and current serving Australian Army nurses returned to the site of their sorrow.

  16. Changing surface water conditions for the last 500 ka in the Southeast Atlantic: Implications for variable influences of Agulhas leakage and Benguela upwelling

    NASA Astrophysics Data System (ADS)

    Petrick, Benjamin F.; McClymont, Erin L.; Marret, Fabienne; Meer, Marcel T. J.

    2015-09-01

    The Southeast Atlantic Ocean is an important component of global ocean circulation, as it includes heat and salt transfer into the Atlantic through the Agulhas leakage as well as the highly productive Benguela upwelling system. Here we reconstruct sea surface temperatures (SSTs) from Ocean Drilling Program (ODP) Site 1087 in the Southeast Atlantic to investigate surface ocean circulation patterns during the late Pleistocene (0-500 ka). The UK'37 index and dinoflagellate cyst assemblages are used to reconstruct SSTs, δDalkenone is used to reconstruct changes in sea surface salinity, and mass accumulation rates of alkenones and chlorine pigments are quantified to detect changing marine export productivity. The greatest amplitude of SST warming precedes decreases in benthic δ18O and therefore occurs early in the transition from glacials to interglacials. The δDalkenone, as a salinity indicator, increases before SSTs, suggesting that the pattern of Agulhas leakage is more complex than suggested by SST proxies. Marine isotope stage (MIS) 10 shows an anomalous pattern: it is marked by a pronounced increase in chlorine concentration, which may be related to enhanced/expanded Benguela upwelling reaching the core site. We find no evidence of an absence of Agulhas leakage throughout the record, suggesting that there is no Agulhas cutoff even during MIS 10. Finally, the ODP Site 1087 record shows an increasing strength of Agulhas leakage towards the present day, which may have impacted the intensity of the Atlantic meridional overturning circulation. As a result, the new analyses from ODP Site 1087 demonstrate a complex interaction between influences of the Benguela upwelling and the Agulhas leakage through the late Pleistocene, which are inferred here to reflect changing circulation patterns in the Southern Ocean and in the atmosphere.

  17. Tatanka Returns.

    ERIC Educational Resources Information Center

    Simonelli, Richard

    1993-01-01

    Describes efforts of the InterTribal Bison Cooperative (Rapid City, SD) to reintroduce the buffalo for cultural purposes to American Indian reservations. Explains how the buffalo's return is contributing to community wellness. Discusses career opportunities for both Native and non-Native people in buffalo management. (LP)

  18. Exploiting multi-proxy analysis of marine sediments in the southeast Atlantic: Intensification of Agulhas leakage tied to the start of the 100ka cycles.

    NASA Astrophysics Data System (ADS)

    Petrick, Benjamin; McClymont, Erin; Marret, Fabienne

    2013-04-01

    The transition in orbital forcing from a 41 ka world to a 100 ka world was a major change in the climate regime over the last 1.5 Ma but its causes and its impacts are still being investigated. Here, we present reconstructions of sea-surface temperature (SST), salinity, and plankton assemblages obtained from a single core, ODP site 1087 (31°28'S, 15°19'E, 1374m water depth) spanning the last 1.5 Ma. Our hypothesis is that the response and position of the Agulhas leakage, which transfers heat and salt to the SE Atlantic region, has shifted as a result of changes in the dominant periodicity of orbital forcing. We draw on evidence from the alkenone (U37K') proxy for SST, dinoflagllate species analysis, and foraminifera oxygen isotopes for salinity and ice volume, to identify changes in the input of the Agulhas leakage to the SE Atlantic. We present the first continuous record of SE Atlantic SSTs reaching to 1.5 Ma which spans both the 41 kyr and 100 kyr glacial cycles. We identify large changes in SST and salinity on glacial-interglacial timescales, but show that there is a consistent pattern of SSTs leading salinity and then global ice volume change, so that deglaciation occurs some 5-10 kyr after the onset of rapid warming in the SE Atlantic during the recent glacials and interglacials. This early warming pattern, which characterizes the most recent cycles, began to develop as early at 900 ka, as the 100 kyr cycles became dominant. Before this time there is little evidence of Agulhas leakage in the ODP1087 record. We also show that over the last 600 ka there has been a strengthening of the Agulhas Leakage which has led to warmer interglacials over this time period. Overall the record shows that the strength and location of the Agulhas leakage is sensitive to changes in the dominant cycles in the climate.

  19. Changing surface water conditions for the last 500 ka in the Southeast Atlantic:Tracking Agulhas leakage using UK37' and δD

    NASA Astrophysics Data System (ADS)

    Petrick, Benjamin; McClymont, Erin; van der Meer, Marcel; Marret, Fabienne

    2015-04-01

    The Southeast Atlantic Ocean is an important component of global ocean circulation, as it includes heat and salt transfer into the Atlantic through Agulhas Leakage. Here, we reconstruct sea surface temperatures (SSTs) and sea surface salinity from Ocean Drilling Program (ODP) Site 1087 in the Southeast Atlantic to investigate surface ocean circulation patterns during the late Pleistocene (0-500 ka). The alkenone-derived U37K'index and assemblages of dinoflagellate cysts are used to reconstruct SSTs. The hydrogen isotope composition of the alkenones (δDalkenone) is used to reconstruct changes in sea-surface salinity. The greatest amplitude of SST warming precedes decreases in benthic δ18O and therefore occurs early in the transition from glacials to interglacials. The timing of the early warming is consistent with previously published foraminifera reconstructions from the same site (Caley et al., 2012). However, δDalkenone decreases at the start of interglacials, suggesting that sea surface salinity increased earlier than the deglacial warmings, and indicating that the pattern of Agulhas leakage is more complex than suggested by SST proxies alone. Furthermore, the δDalkenonevalues indicate a strong salinity increases occurred before both MIS 11 and MIS 1, which are both periods where there is evidence of connection between increased Agulhas Leakage and a stronger Atlantic meridional overturning circulation (AMOC). Finally, the ODP site 1087 record shows an overall trend of increasing SSTs and δDalkenone towards the present day, suggesting that Agulhas leakage has strengthened since 500 ka, which may have impacted the intensity of the AMOC. Caley, T., Giraudeau, J., Malaize, B., Rossignol, L., Pierre, C., 2012. Agulhas leakage as a key process in the modes of Quaternary climate changes. Proc. Natl. Acad. Sci. 109, 6835-6839. doi:10.1073/pnas.1115545109

  20. Effects of midlatitude westerlies on the paleoproductivity at the Agulhas Bank slope during the penultimate glacial cycle: Evidence from coccolith Sr/Ca ratios

    NASA Astrophysics Data System (ADS)

    Mejia, Luz Maria; Ziveri, Patrizia; Cagnetti, Marilisa; Bolton, Clara; Zahn, Rainer; Marino, Gianluca; Martinez Mendez, Gema; Stoll, Heather

    2015-04-01

    Because modern primary productivity on the Agulhas Bank, off South Africa, is linked to the mid-latitude westerlies, a paleoproductivity record from this area could be used to investigate past may changes in the westerlies dynamics. Coccolith Sr/Ca is a suitable productivity indicator to explore paleoproductivity from the penultimate glacial-interglacial cycle because it is independent of preservation changes that may accompany changes in deepwater circulation. In the Agulhas Bank slope core MD96-2080, the coccolith Sr/Ca record shows that phases of depressed productivity coincided with periods of stratification in the same core, indicated by high relative abundances of the coccolithophore Florisphaera profunda, and with low relative abundances of the upwelling indicator G. bulloides in the Cape Basin. This coherence suggests that upwelling regulated productivity throughout this region. As in the present, we infer that periods of low productivity result from northward positions of the westerlies which block the upwelling-promoting easterlies. Productivity minima also coincide with periods of increased ice-rafted detritus (IRD) deposition on the Agulhas Plateau, which also indicates extreme northward positions of the westerlies. The influence of the westerlies appears to be obliquity-conditioned, as productivity minima occur during low obliquity intervals. The dynamic connection between productivity and the westerlies is supported by coeval salinity changes in the South Indian Gyre that likewise respond sensitively to a poleward contraction of the westerlies.

  1. Investigating the role of capacitive coupling between the operating table and the return electrode of an electrosurgery unit in the modification of the current density distribution within the patients’ body

    PubMed Central

    2013-01-01

    Background Electrosurgery units are widely employed in modern surgery. Advances in technology have enhanced the safety of these devices, nevertheless, accidental burns are still regularly reported. This study focuses on possible causes of sacral burns as complication of the use of electrosurgery. Burns are caused by local densifications of the current, but the actual pathway of current within patient’s body is unknown. Numerical electromagnetic analysis can help in understanding the issue. Methods To this aim, an accurate heterogeneous model of human body (including seventy-seven different tissues), electrosurgery electrodes, operating table and mattress was build to resemble a typical surgery condition. The patient lays supine on the mattress with the active electrode placed onto the thorax and the return electrode on his back. Common operating frequencies of electrosurgery units were considered. Finite Difference Time Domain electromagnetic analysis was carried out to compute the spatial distribution of current density within the patient’s body. A differential analysis by changing the electrical properties of the operating table from a conductor to an insulator was also performed. Results Results revealed that distributed capacitive coupling between patient body and the conductive operating table offers an alternative path to the electrosurgery current. The patient’s anatomy, the positioning and the different electromagnetic properties of tissues promote a densification of the current at the head and sacral region. In particular, high values of current density were located behind the sacral bone and beneath the skin. This did not occur in the case of non-conductive operating table. Conclusion Results of the simulation highlight the role played from capacitive couplings between the return electrode and the conductive operating table. The concentration of current density may result in an undesired rise in temperature, originating burns in body region far from

  2. Phobos Sample Return mission

    NASA Astrophysics Data System (ADS)

    Zelenyi, Lev; Zakharov, A.; Martynov, M.; Polischuk, G.

    after the kickoff of the returned spacecraft. We plan to desribe the current status of the project and existing problems of its implementation. The main drive for Phobos investigation is strongly supported by the need to understand the basic scientific issues related to the Martian moons both as the representatives of the family of the small bodies in the Solar system and as principal components of the Martian environment: primordial matter of the Solar system (what, as many believe, they are). We plan to study the characteristics of the Martian satellites and hope to understand their origin. This may give a clue to the formation of satellite systems of the other planets.

  3. Effects of midlatitude westerlies on the paleoproductivity at the Agulhas Bank slope during the penultimate glacial cycle: Evidence from coccolith Sr/Ca ratios

    NASA Astrophysics Data System (ADS)

    Mejía, Luz María.; Ziveri, Patrizia; Cagnetti, Marilisa; Bolton, Clara; Zahn, Rainer; Marino, Gianluca; Martínez-Méndez, Gema; Stoll, Heather

    2014-07-01

    Modern primary productivity on the Agulhas Bank, off South Africa, has been proposed to be linked to the midlatitude westerlies. A paleoproductivity record from this area may therefore resolve temporal changes in the westerly dynamics. Accordingly, we produced a coccolith Sr/Ca-based paleoproductivity record from core MD96-2080 (Agulhas Bank slope) during the penultimate glacial-interglacial cycle. Deriving the productivity signal from Sr/Ca requires a correction for a temperature effect, here constrained using Mg/Ca sea surface temperatures from the foraminifer Globigerina bulloides from core MD96-2080. Phases of depressed productivity coincided with periods of stratification in the same core, indicated by high relative abundances of the coccolithophore Florisphaera profunda and with low relative abundances of the upwelling indicator G. bulloides in the nearby Cape Basin. These observations collectively suggest that productivity was regulated by upwelling throughout this region. We infer that, as in the present, periods of low productivity result from a more northerly position of the westerlies, potentially accompanied by subtropical front displacements, and blockage of upwelling promoting easterlies. Productivity minima also coincide with periods of increased ice-rafted detritus (IRD) deposition on the Agulhas Plateau, which also indicates extreme northward positions of the westerlies. The influence of the westerlies appears to be obliquity conditioned, as productivity minima (and IRD maxima) occur during low-obliquity intervals. The dynamic connection between productivity and the westerlies is supported by coeval salinity changes in the South Indian Gyre that likewise respond sensitively to a poleward contraction of the westerlies.

  4. Strontium isotope investigation of ungulate movement patterns on the Pleistocene Paleo-Agulhas Plain of the Greater Cape Floristic Region, South Africa

    NASA Astrophysics Data System (ADS)

    Copeland, Sandi R.; Cawthra, Hayley C.; Fisher, Erich C.; Lee-Thorp, Julia A.; Cowling, Richard M.; le Roux, Petrus J.; Hodgkins, Jamie; Marean, Curtis W.

    2016-06-01

    Middle Stone Age sites located within the Greater Cape Floristic Region on the South African southern coast have material culture with early evidence for key modern human behaviors such as projectile weaponry, large animal hunting, and symbolic behavior. In order to interpret how and why these changes evolved, it is necessary to understand their ecological context as it has direct relevance to foraging behavior. During periods of lowered sea level, a largely flat and vast expanse of land existed south of the modern coastline, but it is now submerged by higher sea levels. This exposed area, the Paleo-Agulhas Plain, likely created an ecological context unlike anything in the region today, as evidenced by fossil assemblages dominated by migratory ungulates. One hypothesis is that the Paleo-Agulhas Plain supported a migration ecosystem of large grazers driven by summer rainfall, producing palatable forage during summer in the east, and winter rainfall, producing palatable forage during winter in the west. Alternatively, ungulates may have been moving from the coastal plain in the south to the interior north of the Cape Fold Mountains, as observed for elephants in historic times. In this study, we assess ungulate movement patterns with inter- and intra-tooth enamel samples for strontium isotopes in fossil fauna from Pinnacle Point sites PP13B and PP30. To accomplish our goals we created a bioavailable 87Sr/86Sr isoscape for the region by collecting plants at 171 sampling sites and developing a geospatial model. The strontium isotope results indicate that ungulates spent most of their time on the Paleo-Agulhas Plain and avoided dissected plain, foothill, and mountain habitats located more than about 15 km north of the modern coastline. The results clearly exclude a north-south (coastal-interior) movement or migration pattern, and cannot falsify the east-west movements hypothesized in the south coast migration ecosystem hypothesis.

  5. Sample Return Science

    NASA Astrophysics Data System (ADS)

    Williford, K. H.; Allwood, A.; Beegle, L. W.; Bhartia, R.; Flannery, D.; Hoffmann, A.; Mora, M. F.; Orbay, J.; Petrizzo, D. A.; Tuite, M. L., Jr.; Willis, P. A.

    2014-12-01

    The first clear identification of an ancient habitable environment on Mars by the Mars Science Laboratory (MSL) rover mission relied on a synthetic analytical approach combining orbital and surface imagery and spectroscopy with sophisticated sample acquisition and handling technology including a rotary percussive drill that provided powdered rock for bulk geochemical analysis [1]. The recent announcement of the instrument package for the proposed NASA Mars2020 rover mission, including micro x-ray fluorescence (PIXL) for elemental mapping as well as scanning ultraviolet laser fluorescence and Raman (SHERLOC) suggests a shift in emphasis of Mars surface science towards spatially resolved geochemical analysis that will support the selection and acquisition of samples for coring, caching, and possible return to Earth for further analysis. During a recent field expedition to investigate Archean and Proterozoic biosignatures in the Pilbara region of Western Australia, we deployed a dry, rotary percussive coring drill with a bit assembly analogous to that being considered for Mars2020. Six targets of varying age and lithology were sampled with the coring drill, and surrounding and adjacent rock samples were collected simultaneously. These samples were subsequently prepared and subsampled for bulk and in situ, spatially resolved analysis using conventional laboratory methods as well as the existing PIXL and SHERLOC platforms currently in development. Here we present new approaches and data from this integrated and ongoing program of "sample return science" designed to simulate, and eventually reduce risk associated with a long-term effort towards Mars sample return. [1] Grotzinger, J.P. et al. 2014. Science 343 DOI: 10.1126/science.1242777.

  6. The Returns to Community College

    ERIC Educational Resources Information Center

    Agan, Amanda Yvonne

    2013-01-01

    Almost half of postsecondary students are currently enrolled in community colleges. These institutions imply that even amongst students with the same degree outcome there is considerable heterogeneity in the path taken to get there. I estimate the life-cycle private and social returns to the different postsecondary paths and sequential decisions…

  7. Returning to sports after a back injury

    MedlinePlus

    Back injury - returning to sports; Sciatica - returning to sports; Herniated disc - returning to sports; Herniated disk - returning to sports; Spinal stenosis - returning to sports; Back pain - returning ...

  8. Why Do Staff Return?

    ERIC Educational Resources Information Center

    Magnuson, Connie

    1992-01-01

    Surveyed 211 returning staff from 25 camps and interviewed 19 returning staff to study factors that influence a counselor's decision to return to camp. Examined the following dimensions of motivation and hygiene factors: (1) stimulation or inspiration; (2) personal; (3) job-related experience; (4) living conditions and camp life; (5) camp…

  9. Strontium isotope investigation of ungulate movement patterns on the Pleistocene Paleo-Agulhas Plain of the Greater Cape Floristic Region, South Africa

    DOE PAGES

    Copeland, Sandi R.; Cawthra, Hayley C.; Fisher, Erich C.; Lee-Thorp, Julia A.; Cowling, Richard M.; le Roux, Petrus J.; Hodgkins, Jamie; Marean, Curtis W.

    2016-04-16

    Middle Stone Age sites located within the Greater Cape Floristic Region on the South African southern coast have material culture with early evidence for key modern human behaviors such as projectile weaponry, large animal hunting, and symbolic behavior. In order to interpret how and why these changes evolved, it is necessary to understand their ecological context as it has direct relevance to foraging behavior. During periods of lowered sea level, a largely flat and vast expanse of land existed south of the modern coastline, but it is now submerged by higher sea levels. This exposed area, the Paleo-Agulhas Plain, likelymore » created an ecological context unlike anything in the region today, as evidenced by fossil assemblages dominated by migratory ungulates. One hypothesis is that the Paleo-Agulhas Plain supported a migration ecosystem of large grazers driven by summer rainfall, producing palatable forage during summer in the east, and winter rainfall, producing palatable forage during winter in the west. Furthermore, ungulates may have been moving from the coastal plain in the south to the interior north of the Cape Fold Mountains, as observed for elephants in historic times.« less

  10. Return flux experiment

    NASA Technical Reports Server (NTRS)

    Tveekrem, June L.

    1992-01-01

    All spacecraft emit molecules via outgassing, thruster plumes, vents, etc. The return flux is the portion of those molecules that scatter from the ambient atmosphere and return to the spacecraft. Return flux allows critical spacecraft surfaces to become contaminated even when there is no direct line of sight between the contamination source and the critical surface. Data from the Long Duration Exposure Facility (LDEF) show that contamination of LDEF surfaces could not have come entirely from direct flux. The data suggest significant return flux. Several computer models have been developed to simulate return flux, but the predictions have never been verified in orbit. Large uncertainties in predictions lead to overly conservative spacecraft designs. The purpose of the REturn FLux EXperiment (REFLEX) is to fly a controlled experiment that can be directly compared with predictions from several models.

  11. Return flux experiment

    NASA Astrophysics Data System (ADS)

    Tveekrem, June L.

    All spacecraft emit molecules via outgassing, thruster plumes, vents, etc. The return flux is the portion of those molecules that scatter from the ambient atmosphere and return to the spacecraft. Return flux allows critical spacecraft surfaces to become contaminated even when there is no direct line of sight between the contamination source and the critical surface. Data from the Long Duration Exposure Facility (LDEF) show that contamination of LDEF surfaces could not have come entirely from direct flux. The data suggest significant return flux. Several computer models have been developed to simulate return flux, but the predictions have never been verified in orbit. Large uncertainties in predictions lead to overly conservative spacecraft designs. The purpose of the REturn FLux EXperiment (REFLEX) is to fly a controlled experiment that can be directly compared with predictions from several models.

  12. Assured crew return vehicle

    NASA Technical Reports Server (NTRS)

    Cerimele, Christopher J. (Inventor); Ried, Robert C. (Inventor); Peterson, Wayne L. (Inventor); Zupp, George A., Jr. (Inventor); Stagnaro, Michael J. (Inventor); Ross, Brian P. (Inventor)

    1991-01-01

    A return vehicle is disclosed for use in returning a crew to Earth from low earth orbit in a safe and relatively cost effective manner. The return vehicle comprises a cylindrically-shaped crew compartment attached to the large diameter of a conical heat shield having a spherically rounded nose. On-board inertial navigation and cold gas control systems are used together with a de-orbit propulsion system to effect a landing near a preferred site on the surface of the Earth. State vectors and attitude data are loaded from the attached orbiting craft just prior to separation of the return vehicle.

  13. The Mars Sample Return Project.

    PubMed

    O'Neil, W J; Cazaux, C

    2000-01-01

    The Mars Sample Return (MSR) Project is underway. A 2003 mission to be launched on a Delta III Class vehicle and a 2005 mission launched on an Ariane 5 will culminate in carefully selected Mars samples arriving on Earth in 2008. NASA is the lead agency and will provide the Mars landed elements, namely, landers, rovers, and Mars ascent vehicles (MAVs). The French Space Agency CNES is the largest international partner and will provide for the joint NASA/CNES 2005 Mission the Ariane 5 launch and the Earth Return Mars Orbiter that will capture the sample canisters from the Mars parking orbits the MAVs place them in. The sample canisters will be returned to Earth aboard the CNES Orbiter in the Earth Entry Vehicles provided by NASA. Other national space agencies are also expected to participate in substantial roles. Italy is planning to provide a drill that will operate from the Landers to provide subsurface samples. Other experiments in addition to the MSR payload will also be carried on the Landers. This paper will present the current status of the design of the MSR missions and flight articles.

  14. The Mars Sample Return Project.

    PubMed

    O'Neil, W J; Cazaux, C

    2000-01-01

    The Mars Sample Return (MSR) Project is underway. A 2003 mission to be launched on a Delta III Class vehicle and a 2005 mission launched on an Ariane 5 will culminate in carefully selected Mars samples arriving on Earth in 2008. NASA is the lead agency and will provide the Mars landed elements, namely, landers, rovers, and Mars ascent vehicles (MAVs). The French Space Agency CNES is the largest international partner and will provide for the joint NASA/CNES 2005 Mission the Ariane 5 launch and the Earth Return Mars Orbiter that will capture the sample canisters from the Mars parking orbits the MAVs place them in. The sample canisters will be returned to Earth aboard the CNES Orbiter in the Earth Entry Vehicles provided by NASA. Other national space agencies are also expected to participate in substantial roles. Italy is planning to provide a drill that will operate from the Landers to provide subsurface samples. Other experiments in addition to the MSR payload will also be carried on the Landers. This paper will present the current status of the design of the MSR missions and flight articles. PMID:11708368

  15. Assured crew return capability Crew Emergency Return Vehicle (CERV) avionics

    NASA Technical Reports Server (NTRS)

    Myers, Harvey Dean

    1990-01-01

    The Crew Emergency Return Vehicle (CERV) is being defined to provide Assured Crew Return Capability (ACRC) for Space Station Freedom. The CERV, in providing the standby lifeboat capability, would remain in a dormat mode over long periods of time as would a lifeboat on a ship at sea. The vehicle must be simple, reliable, and constantly available to assure the crew's safety. The CERV must also provide this capability in a cost effective and affordable manner. The CERV Project philosophy of a simple vehicle is to maximize its useability by a physically deconditioned crew. The vehicle reliability goes unquestioned since, when needed, it is the vehicle of last resort. Therefore, its systems and subsystems must be simple, proven, state-of-the-art technology with sufficient redundancy to make it available for use as required for the life of the program. The CERV Project Phase 1'/2 Request for Proposal (RFP) is currently scheduled for release on October 2, 1989. The Phase 1'/2 effort will affirm the existing project requirements or amend and modify them based on a thorough evaluation of the contractor(s) recommendations. The system definition phase, Phase 2, will serve to define CERV systems and subsystems. The current CERV Project schedule has Phase 2 scheduled to begin October 1990. Since a firm CERV avionics design is not in place at this time, the treatment of the CERV avionics complement for the reference configuration is not intended to express a preference with regard to a system or subsystem.

  16. Optimization of return electrodes in neurostimulating arrays

    NASA Astrophysics Data System (ADS)

    Flores, Thomas; Goetz, Georges; Lei, Xin; Palanker, Daniel

    2016-06-01

    Objective. High resolution visual prostheses require dense stimulating arrays with localized inputs of individual electrodes. We study the electric field produced by multielectrode arrays in electrolyte to determine an optimal configuration of return electrodes and activation sequence. Approach. To determine the boundary conditions for computation of the electric field in electrolyte, we assessed current dynamics using an equivalent circuit of a multielectrode array with interleaved return electrodes. The electric field modeled with two different boundary conditions derived from the equivalent circuit was then compared to measurements of electric potential in electrolyte. To assess the effect of return electrode configuration on retinal stimulation, we transformed the computed electric fields into retinal response using a model of neural network-mediated stimulation. Main results. Electric currents at the capacitive electrode-electrolyte interface redistribute over time, so that boundary conditions transition from equipotential surfaces at the beginning of the pulse to uniform current density in steady state. Experimental measurements confirmed that, in steady state, the boundary condition corresponds to a uniform current density on electrode surfaces. Arrays with local return electrodes exhibit improved field confinement and can elicit stronger network-mediated retinal response compared to those with a common remote return. Connecting local return electrodes enhances the field penetration depth and allows reducing the return electrode area. Sequential activation of the pixels in large monopolar arrays reduces electrical cross-talk and improves the contrast in pattern stimulation. Significance. Accurate modeling of multielectrode arrays helps optimize the electrode configuration to maximize the spatial resolution, contrast and dynamic range of retinal prostheses.

  17. Electrostatic Return of Contaminants

    NASA Technical Reports Server (NTRS)

    Rantanen, R.; Gordon, T.

    2003-01-01

    A Model has been developed capable of calculating the electrostatic return of spacecraft-emitted molecules that are ionized and attracted back to the spacecraft by the spacecraft electric potential on its surfaces. The return of ionized contaminant molecules to charged spacecraft surfaces is very important to all altitudes. It is especially important at geosynchronous and interplanetary environments, since it may be the only mechanism by which contaminants can degrade a surface. This model is applicable to all altitudes and spacecraft geometries. In addition to results of the model will be completed to cover a wide range of potential space systems.

  18. Power and energy dissipation in subsequent return strokes as predicted by a new return stroke model

    NASA Technical Reports Server (NTRS)

    Cooray, Vernon

    1991-01-01

    Recently, Cooray introduced a new return stroke model which is capable of predicting the temporal behavior of the return stroke current and the return stroke velocity as a function of the height along the return stroke channel. The authors employed this model to calculate the power and energy dissipation in subsequent return strokes. The results of these calculations are presented here. It was concluded that a large fraction of the total energy available for the dart leader-subsequent stroke process is dissipated in the dart leader stage. The peak power per unit length dissipated in a subsequent stroke channel element decreases with increasing height of that channel element from ground level. For a given channel element, the peak power dissipation increases with increasing current in that channel element. The peak electrical power dissipation in a typical subsequent return stroke is about 1.5 times 10(exp 11) W. The energy dissipation in a subsequent stroke increases with increasing current in the return stroke channel, and for a typical subsequent stroke, the energy dissipation per unit length is about 5.0 times 10(exp 3) J/m.

  19. Fluctuation behaviors of financial return volatility duration

    NASA Astrophysics Data System (ADS)

    Niu, Hongli; Wang, Jun; Lu, Yunfan

    2016-04-01

    It is of significantly crucial to understand the return volatility of financial markets because it helps to quantify the investment risk, optimize the portfolio, and provide a key input of option pricing models. The characteristics of isolated high volatility events above certain threshold in price fluctuations and the distributions of return intervals between these events arouse great interest in financial research. In the present work, we introduce a new concept of daily return volatility duration, which is defined as the shortest passage time when the future volatility intensity is above or below the current volatility intensity (without predefining a threshold). The statistical properties of the daily return volatility durations for seven representative stock indices from the world financial markets are investigated. Some useful and interesting empirical results of these volatility duration series about the probability distributions, memory effects and multifractal properties are obtained. These results also show that the proposed stock volatility series analysis is a meaningful and beneficial trial.

  20. Higher Education Endowments Return

    ERIC Educational Resources Information Center

    Bahlmann, David; Walda, John D.; Sedlacek, Verne O.

    2012-01-01

    A new study of endowments by the National Association of College and University Business Officers (NACUBO) and the Commonfund Institute has brought good news to college and universities: While endowment returns dropped precipitously in fiscal year 2009 as a result of the financial crisis and accompanying slide in equity markets, they climbed to an…

  1. Columbia returns to Earth

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Columbia returns to Earth. Completing the first full test of the Space Transportation System (STS-1), the Orbiter Columbia is seen here on its final approach prior to landing on Rogers Drylake Runway 23 at NASA's Dryden Flight Research Center, Edwards AFB, Calif. For this first flight, the Columbia was flown by astronauts John Young, commander, and Robert Crippen, pilot.

  2. Sustainable Mars Sample Return

    NASA Technical Reports Server (NTRS)

    Alston, Christie; Hancock, Sean; Laub, Joshua; Perry, Christopher; Ash, Robert

    2011-01-01

    The proposed Mars sample return mission will be completed using natural Martian resources for the majority of its operations. The system uses the following technologies: In-Situ Propellant Production (ISPP), a methane-oxygen propelled Mars Ascent Vehicle (MAV), a carbon dioxide powered hopper, and a hydrogen fueled balloon system (large balloons and small weather balloons). The ISPP system will produce the hydrogen, methane, and oxygen using a Sabatier reactor. a water electrolysis cell, water extracted from the Martian surface, and carbon dioxide extracted from the Martian atmosphere. Indigenous hydrogen will fuel the balloon systems and locally-derived methane and oxygen will fuel the MAV for the return of a 50 kg sample to Earth. The ISPP system will have a production cycle of 800 days and the estimated overall mission length is 1355 days from Earth departure to return to low Earth orbit. Combining these advanced technologies will enable the proposed sample return mission to be executed with reduced initial launch mass and thus be more cost efficient. The successful completion of this mission will serve as the next step in the advancement of Mars exploration technology.

  3. Return to Play

    ERIC Educational Resources Information Center

    Mangan, Marianne

    2013-01-01

    Call it physical activity, call it games, or call it play. Whatever its name, it's a place we all need to return to. In the physical education, recreation, and dance professions, we need to redesign programs to address the need for and want of play that is inherent in all of us.

  4. Mars Earth Return Vehicle (MERV) Propulsion Options

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; McGuire, Melissa L.; Burke, Laura; Fincannon, James; Warner, Joe; Williams, Glenn; Parkey, Thomas; Colozza, Tony; Fittje, Jim; Martini, Mike; Packard, Tom; Hemminger, Joseph; Gyekenyesi, John

    2010-01-01

    The COMPASS Team was tasked with the design of a Mars Sample Return Vehicle. The current Mars sample return mission is a joint National Aeronautics and Space Administration (NASA) and European Space Agency (ESA) mission, with ESA contributing the launch vehicle for the Mars Sample Return Vehicle. The COMPASS Team ran a series of design trades for this Mars sample return vehicle. Four design options were investigated: Chemical Return /solar electric propulsion (SEP) stage outbound, all-SEP, all chemical and chemical with aerobraking. The all-SEP and Chemical with aerobraking were deemed the best choices for comparison. SEP can eliminate both the Earth flyby and the aerobraking maneuver (both considered high risk by the Mars Sample Return Project) required by the chemical propulsion option but also require long low thrust spiral times. However this is offset somewhat by the chemical/aerobrake missions use of an Earth flyby and aerobraking which also take many months. Cost and risk analyses are used to further differentiate the all-SEP and Chemical/Aerobrake options.

  5. Assured Crew Return Vehicle

    NASA Technical Reports Server (NTRS)

    Stone, D. A.; Craig, J. W.; Drone, B.; Gerlach, R. H.; Williams, R. J.

    1991-01-01

    The developmental status is discussed regarding the 'lifeboat' vehicle to enhance the safety of the crew on the Space Station Freedom (SSF). NASA's Assured Crew Return Vehicle (ACRV) is intended to provide a means for returning the SSF crew to earth at all times. The 'lifeboat' philosophy is the key to managing the development of the ACRV which further depends on matrixed support and total quality management for implementation. The risk of SSF mission scenarios are related to selected ACRV mission requirements, and the system and vehicle designs are related to these precepts. Four possible ACRV configurations are mentioned including the lifting-body, Apollo shape, Discoverer shape, and a new lift-to-drag concept. The SCRAM design concept is discussed in detail with attention to the 'lifeboat' philosophy and requirements for implementation.

  6. The Mechanism Underlying Inhibition of Saccadic Return

    ERIC Educational Resources Information Center

    Ludwig, Casimir J. H.; Farrell, Simon; Ellis, Lucy A.; Gilchrist, Iain D.

    2009-01-01

    Human observers take longer to re-direct gaze to a previously fixated location. Although there has been some exploration of the characteristics of inhibition of saccadic return (ISR), the exact mechanisms by which ISR operates are currently unknown. In the framework of accumulation models of response times, in which evidence is integrated over…

  7. Return to sport following amputation.

    PubMed

    Matthews, D; Sukeik, M; Haddad, F

    2014-08-01

    Amputation in athletes has a substantial impact on lifestyle and sporting activity, as well as self-perception and quality of life. The impact of limb loss on athletic ability will vary depending on the cause of amputation and the anatomical location of the amputation. The use of sporting activity for rehabilitation of amputees was first introduced in 1944 at Stoke Mandeville Hospital. The first international paralympic games were founded in 1960. Following these events the opportunity to participate in sport following limb loss has increased significantly. Sport participation has been aided by the development of sporting prostheses, however multiple factors will determine the exact prosthesis used. These include the nature of the sporting activity as well as the level of the amputation. The biomechanics involved in walking and running are altered following the loss of a limb or part thereof. This can cause subsequent degenerative changes within the remaining joints on the amputated limb as well as the contralateral limb. Factors affecting return to sporting activity are multivariate and inter-related, including patient factors, surgical factors, nature and level of the sporting activity and prosthetic factors. The authors review current literature, detail predictive factors of return to sport and the physical and psychosocial impact on patients following limb amputation.

  8. Return to sport following amputation.

    PubMed

    Matthews, D; Sukeik, M; Haddad, F

    2014-08-01

    Amputation in athletes has a substantial impact on lifestyle and sporting activity, as well as self-perception and quality of life. The impact of limb loss on athletic ability will vary depending on the cause of amputation and the anatomical location of the amputation. The use of sporting activity for rehabilitation of amputees was first introduced in 1944 at Stoke Mandeville Hospital. The first international paralympic games were founded in 1960. Following these events the opportunity to participate in sport following limb loss has increased significantly. Sport participation has been aided by the development of sporting prostheses, however multiple factors will determine the exact prosthesis used. These include the nature of the sporting activity as well as the level of the amputation. The biomechanics involved in walking and running are altered following the loss of a limb or part thereof. This can cause subsequent degenerative changes within the remaining joints on the amputated limb as well as the contralateral limb. Factors affecting return to sporting activity are multivariate and inter-related, including patient factors, surgical factors, nature and level of the sporting activity and prosthetic factors. The authors review current literature, detail predictive factors of return to sport and the physical and psychosocial impact on patients following limb amputation. PMID:25034549

  9. Returns to Education in Bangladesh

    ERIC Educational Resources Information Center

    Asadullah, Mohammad Niaz

    2006-01-01

    This paper reports labour market returns to education in Bangladesh using data from recent nationwide household survey. Returns are estimated separately for rural and urban samples, males, females and private-sector employees. Substantial heterogeneity in returns is observed; for example, estimates are higher for urban (than rural sample) and…

  10. A Look at Returning Teachers

    ERIC Educational Resources Information Center

    DeAngelis, Karen J.

    2013-01-01

    Research shows that one-quarter to one-third of teachers who leave the profession return, the majority after only a short absence. Though returning teachers can constitute a substantial share of newly hired teachers in schools each year, little is known about them, the factors associated with their decisions to return, or the schools to which…

  11. Energy Vs. Productivity: Diminishing Returns

    ERIC Educational Resources Information Center

    MOSAIC, 1975

    1975-01-01

    Energy invested in corn production is compared with food energy returned in calculations by David Pimentel at Cornell University. The rate of return is falling off sharply in this already energy-intensive agriculture. Increased energy input, in the form of fertilizer, would yield far greater returns where agriculture is less sophisticated.…

  12. Return to work.

    PubMed

    1999-10-29

    H.R. 3070, the "Work Incentives Improvement Act," was approved overwhelmingly by the House of Representatives. The bill would make it easier for people with disabilities to retain Medicaid and Medicare coverage if they return to work. The next step is for a committee to resolve the differences between the House and Senate versions of the bill. The House bill, which is weaker than the Senate version, would limit Medicare coverage to 10 years and make Medicaid "buy-in" optional, not mandatory, in each state. President Bill Clinton called the House bill "insufficient."

  13. Titan Science Return Quantification

    NASA Technical Reports Server (NTRS)

    Weisbin, Charles R.; Lincoln, William

    2014-01-01

    Each proposal for a NASA mission concept includes a Science Traceability Matrix (STM), intended to show that what is being proposed would contribute to satisfying one or more of the agency's top-level science goals. But the information traditionally provided cannot be used directly to quantitatively compare anticipated science return. We added numerical elements to NASA's STM and developed a software tool to process the data. We then applied this methodology to evaluate a group of competing concepts for a proposed mission to Saturn's moon, Titan.

  14. Planetary protection issues for sample return missions.

    PubMed

    DeVincenzi, D L; Klein, H P

    1989-01-01

    Sample return missions from a comet nucleus and the Mars surface are currently under study in the US, USSR, and by ESA. Guidance on Planetary Protection (PP) issues is needed by mission scientists and engineers for incorporation into various elements of mission design studies. Although COSPAR has promulgated international policy on PP for various classes of solar system exploration missions, the applicability of this policy to sample return missions, in particular, remains vague. In this paper, we propose a set of implementing procedures to maintain the scientific integrity of these samples. We also propose that these same procedures will automatically assure that COSPAR-derived PP guidelines are achieved. The recommendations discussed here are the first step toward development of official COSPAR implementation requirements for sample return missions. PMID:11537373

  15. 21 CFR 211.204 - Returned drug products.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Returned drug products. 211.204 Section 211.204 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR FINISHED PHARMACEUTICALS Returned and Salvaged...

  16. 21 CFR 211.204 - Returned drug products.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Returned drug products. 211.204 Section 211.204 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR FINISHED PHARMACEUTICALS Returned and Salvaged...

  17. 21 CFR 211.204 - Returned drug products.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Returned drug products. 211.204 Section 211.204 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR FINISHED PHARMACEUTICALS Returned and Salvaged...

  18. 21 CFR 211.204 - Returned drug products.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Returned drug products. 211.204 Section 211.204 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR FINISHED PHARMACEUTICALS Returned and Salvaged...

  19. 21 CFR 211.204 - Returned drug products.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Returned drug products. 211.204 Section 211.204 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR FINISHED PHARMACEUTICALS Returned and Salvaged...

  20. Returning Samples from Enceladus

    NASA Astrophysics Data System (ADS)

    Tsou, P.; Kanik, I.; Brownlee, D.; McKay, C.; Anbar, A.; Glavin, D.; Yano, H.

    2012-12-01

    From the first half century of space exploration, we have obtained samples only from the Moon, comet Wild 2, the Solar Wind and the asteroid Itokawa. The in-depth analyses of these samples in terrestrial laboratories have yielded profound knowledge that could not have been obtained without the returned samples. While obtaining samples from Solar System bodies is crucial science, it is rarely done due to cost and complexity. Cassini's discovery of geysers on Enceladus and organic materials, indicate that there is an exceptional opportunity and science rational to do a low-cost flyby sample return mission, similar to what was done by the Stardust. The earliest low cost possible flight opportunity is the next Discovery Mission [Tsou et al 2012]. Enceladus Plume Discovery - While Voyager provided evidence for young surfaces on Enceladus, the existence of Enceladus plumes was discovered by Cassini. Enceladus and comets are the only known solar system bodies that have jets enabling sample collection without landing or surface contact. Cassini in situ Findings -Cassini's made many discoveries at Saturn, including the break up of large organics in the plumes of Enceladus. Four prime criteria for habitability are liquid water, a heat source, organics and nitrogen [McKay et al. 2008, Waite et al. 2009, Postberg et al. 2011]. Out of all the NASA designated habitability targets, Enceladus is the single body that presents evidence for all four criteria. Significant advancement in the exploration of the biological potential of Enceladus can be made on returned samples in terrestrial laboratories where the full power of state-of-the-art laboratory instrumentation and procedures can be used. Without serious limits on power, mass or even cost, terrestrial laboratories provide the ultimate in analytical capability, adaptability, reproducibility and reliability. What Questions can Samples Address? - Samples collected from the Enceladus plume will enable a thorough and replicated

  1. Return to space

    NASA Astrophysics Data System (ADS)

    1989-08-01

    This video documents the preparations for Shuttle Flight STS-26 with Shuttle Discovery, NASA's return to manned space flight after the Challenger disaster. Footage and descriptions document such changes to the new Shuttle as new joints, improved insulation, and added O-rings to the solid rocket boosters; new safety hardware and procedures such as parachute and sidewire evacuations during liftoff, and new pressure suits; modified landing gear, brakes, and nose wheel steering, as well as a modified landing runway. Also profiled are the 5 member crew of all veteran Shuttle astronauts, the TDRS 3 Satellite to be released from the cargo bay in orbit, and 11 commercial and student experiments to be performed during the mission.

  2. Mars Sample Return from Meridiani Planum

    NASA Technical Reports Server (NTRS)

    Mittlefehldt, David W.

    2008-01-01

    The NASA Mars Exploration Program has four main goals: (i) determine if life ever arose there, (ii) understand the processes and history of its climate, (iii) determine the evolution of its surface and interior, and (iv) prepare for human exploration of Mars. These goals are embodied in the NASA Mars exploration strategy Follow the Water. Current Mars exploration tactics for lander missions build on knowledge gained by prior orbital investigations; the science rationale for choosing landing sites is based on the current best interpretation of the geology. A future Mars sample return mission will greatly exceed in cost typical lander missions because of the need to design for return to Earth and the infrastructure needed on Earth to curate and process the samples safely and cleanly. Because of this added cost burden, expectations for science return are higher. There must be some prospect that the returned samples will allow for testing higher level hypotheses relevant to NASA's goals. Site selection must be based on knowledge gained from prior in situ measurements to enhance the prospects for successfully meeting these goals. I will argue that Meridiani Planum should be that site.

  3. Analysis of Chinese Donors’ Return Behavior

    PubMed Central

    Guo, Nan; Wang, Jingxing; Ness, Paul; Yao, Fuzhu; Dong, Xiangdong; Bi, Xinhong; Mei, Heili; Li, Julin; He, Weilan; Lu, Yunlai; Ma, Hongli; Wen, Xiuqiong; Huang, Mei; Wright, David J.; King, Melissa; High, Patrick; Nelson, Kenrad; Shan, Hua

    2010-01-01

    Background It is important to understand donor return behavior. Converting first time donors to become repeat donors is essential for maintaining an adequate blood supply. Methods Characteristics of 241,552 whole blood (WB) donations from first time (FT) and repeat (RPT) donors who donated in 2008 at the 5 blood centers in China were compared. A subset of 54,394 WB donors who donated between January 1 and March 31, 2008 were analyzed for their return behavior in 2008 following the index donation using logistic regression. Results Of all donations, 64% was from FT donors. Donors with self-reported previous donations tended to be male, older, married, donated larger volume (≥300mL), and were heavier in weight. Among donors who donated from January to March, 2008, 14% returned for subsequent WB donations by the end of 2008. The number of previous donations and blood collection location were the two strongest predictors for making subsequent donations. Donors with 1, 2–3 and more than 3 previous donations were 3.7, 5.7, and 11.0 times more likely to return than FT donors. Those who donated in a blood collection vehicle were 4 times more likely to return than those who donated at a blood center. Being female, younger and of a lower education level (≤ middle school) were positively associated with subsequent return blood donation during the follow-up period observed in this study. Conclusion Most of the Chinese blood supply is from first time donors. Strategies aimed at encouraging current donors to become repeat donors are needed. PMID:20849408

  4. Homeward bound: Yemeni return migration.

    PubMed

    Colton, N A

    1993-01-01

    The author discusses the return migration of Yemenis from Saudi Arabia during the period 1970-1989. "Through the use of original, empirical data collected in Yemen, this article sheds light on who these returning migrants are, where they have come from, and what sort of future awaits them.... The survey conducted on return migration was administered in the winter and spring of 1989 in a region of North Yemen called al-Hujariyya."

  5. 11. VIEW OF A SITE RETURN WEAPONS COMPONENT. SITE RETURNS ...

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

    11. VIEW OF A SITE RETURN WEAPONS COMPONENT. SITE RETURNS WERE NUCLEAR WEAPONS SHIPPED TO THE ROCKY FLATS PLANT FROM THE NUCLEAR WEAPON STOCKPILE FOR RETIREMENT, TESTING, OR UPGRADING. FISSILE MATERIALS (PLUTONIUM, URANIUM, ETC.) AND RARE MATERIALS (BERYLLIUM) WERE RECOVERED FOR REUSE, AND THE REMAINDER WAS DISPOSED. (8/7/62) - Rocky Flats Plant, Plutonium Fabrication, Central section of Plant, Golden, Jefferson County, CO

  6. Return of the sheath.

    PubMed

    Felstein, I

    1980-10-01

    The history of the condom is reviewed with attention directed to the medical perspective that the return of the sheath to use is hopeful in terms of venereal disease control improvements. By 1950, condom manufacturers could claim that 1/2 of all the married couples using contraception included the sheath as a major or ancillary method in both the United States and the British Isles. The introduction of the oral contraceptive led to the sheath losing a large measure of its once universal popularity. Simultaneously there was a marked increase in venereal infections with a dramatic rise in gonorrhea and non-specific urethritis. Venereologists have been disturbed by the decline of sheath usage. The manufacturers of the sheath did not accept the reduction in sales. Taking advantage of the changed attitudes to sexuality and sex aids, manufacturers began to make colored sheaths and to vary textures in order to raise or lower sensitivity, increase or decrease friction, and add or diminish lubrication. Shapes have also been varied, and several attachments to the sheath have included clitoral stimulators and vulval stretchers. Improved marketing has seen retailing of condoms in open areas. PMID:6903257

  7. Christmas Island birds returning

    NASA Astrophysics Data System (ADS)

    Six months after their mass exodus, birds are beginning to return to Christmas Island. Roughly 17 million birds, almost the entire adult bird population, either perished or fled their mid-Pacific atoll home last autumn, leaving behind thousands of nestlings to starve (Eos, April 5, 1983, p. 131). It is believed that the strong El Niño altered the ecology of the surrounding waters and forced the birds to flee. Christmas Island is the world's largest coral atoll.“Ocean and atmosphere scientists are unsure of future directions for the El Niño conditions and cannot now predict what will happen to the birds in the coming months,” said Ralph W. Schreiber, curator of ornithology at the Natural History Museum of Los Angeles County in California. Heisthe ornithologist who discovered the disappearance. “The recovery of the bird populations depends on the food supply in the waters surrounding the island.” The island's birds feed exclusively on small fish and squid.

  8. The Point of No Return

    PubMed Central

    Logan, Gordon D.

    2015-01-01

    Bartlett (1958) described the point of no return as a point of irrevocable commitment to action, which was preceded by a period of gradually increasing commitment. As such, the point of no return reflects a fundamental limit on the ability to control thought and action. I review the literature on the point of no return, taking three perspectives. First, I consider the point of no return from the perspective of the controlled act, as a locus in the architecture and anatomy of the underlying processes. I review experiments from the stop-signal paradigm that suggest that the point of no return is located late in the response system. Then I consider the point of no return from the perspective of the act of control that tries to change the controlled act before it becomes irrevocable. From this perspective, the point of no return is a point in time that provides enough “lead time” for the act of control to take effect. I review experiments that measure the response time to the stop signal as the lead time required for response inhibition in the stop-signal paradigm. Finally, I consider the point of no return in hierarchically controlled tasks, in which there may be many points of no return at different levels of the hierarchy. I review experiments on skilled typing that suggest different points of no return for the commands that determine what is typed and the countermands that inhibit typing, with increasing commitment to action the lower the level in the hierarchy. I end by considering the point of no return in perception and thought as well as action. PMID:25633089

  9. Capital Structure and Stock Returns

    ERIC Educational Resources Information Center

    Welch, Ivo

    2004-01-01

    U.S. corporations do not issue and repurchase debt and equity to counteract the mechanistic effects of stock returns on their debt-equity ratios. Thus over one- to five-year horizons, stock returns can explain about 40 percent of debt ratio dynamics. Although corporate net issuing activity is lively and although it can explain 60 percent of debt…

  10. NEO Sample Return mission

    NASA Astrophysics Data System (ADS)

    Barucci, M. A.; Neo-Sr Team

    The NEOs are representative of the population of asteroids and dead comets thought to be the remnants of the ancient planetesimals that accreted to form the planets. The chemical investigation of NEOs having primitive characteristics is thus essential in the understanding the planet formation and evolution. They carry records of the solar system's birth/early phases and the geological evolution of small bodies in the interplanetary regions. Moreover, collisions of NEOs with Earth represent a serious hazard to life. For all these reasons the exploration and characterization of these objects are particularly interesting and urgent. NEOs are interesting and highly accessible targets for scientific research and robotic exploration. Within this framework, the mission LEONARD including an orbiter and a lander to the primitive double object (1996 FG3) has been studied by CNES, in collaboration with a number of European planetologists (France, Italy, Germany and United Kingdom) and related Space Agencies. A new Sample Return mission is under study within a large European community and possible collaboration with the Japanese Space Agency JAXA to reply to the ESA Cosmic Vision AO. The principal objectives are to investigate on 1) the properties of the building blocks of the terrestrial planets; 2) the major events (e.g. agglomeration, heating, ... . . ) which ruled the history of planetesimals; 3) the primitive asteroids which could contain presolar material unknown in meteoritic samples; 4) the organics in primitive materials; 5) the initial conditions and evolution history of the solar nebula; and 6) how they can shed light on the origin of molecules necessary for life. This type of mission appears clearly to have the potential to revolutionize our understanding of primitive materials.

  11. [Return to the family].

    PubMed

    Ouaidou, N G

    1993-08-01

    Sahelian countries occupy an inglorious place in the global list of human development. The human development index is superior to the gross national product (GNP) at measuring the progress of a country in terms of development, because it includes income, longevity, and educational level. The highest ranked Sahelian country holds the 114th position out of a 173 countries. The low human development index scores for the Sahel reflects the socioeconomic crisis which has overcome these countries. In 1991, only 3 of 9 Sahelian countries had a mean GP equal or superior to US$500. Just 2 countries had a life expectancy greater than 50 years. In fact, the Sahel had a lower life expectancy than all of Africa (50 years) and much lower than Asia (64 years) and Latin America (67 years). The economic crisis is worse than the cold statistics show. It destabilizes the most disadvantaged populations. The pressure it exerts often leads public authorities to adopt unpopular measures. It depreciates some sociocultural values and disintegrates traditional social structures. It is accentuated by the effects of war and drought. Internal and external migration increases even as urban hope is uncertain. For most people, the family (the traditional framework of individual development) is ready to break apart, leaving only a disincarnate nuclear entity to subsist. Yet, African history is built around the extended family: the place of reproduction, production, distribution, formation, management, perpetuation of demographic behavior, and social control. Senegal and Mali have created ministries which invest in families. The Third African Conference on Population, in 1992, chose its theme to be the relationship between family, population, and sustainable development. It is important to return to the natural or primordial framework--family--as a refuge against the economic crisis. PMID:12318645

  12. Return Stroke-Like Upward Illumination Occurring Immediately After Lightning Return Strokes

    NASA Astrophysics Data System (ADS)

    Stolzenburg, M.; Marshall, T.; Karunarathne, S.; Warner, T. A.; Orville, R. E.; Betz, H.

    2011-12-01

    In July 2010, correlated data for natural cloud-to-ground lightning flashes were obtained with a high-speed video camera, five flat-plate slow antennas, and a seven-station VLF/LF LIghtning NETwork, along with the four operational lightning and electric field networks at Kennedy Space Center (KSC), Florida. Optical images were obtained at 54000 frames per s, and fast electric field changes were sampled at 1 MHz. Four observed flashes had return-stroke-like upward illumination from the ground just after (within 1.9 ms of) a return stroke, but in a separate channel connection to ground. The upward illuminations were fast, of short duration (visible for less than 0.5 ms), and there were no apparent connections to the main return stroke channels. In one case, the main return stroke was no longer visible to the ground when the upward illumination began (1.30 ms later), although a section of channel was still distinct at mid-level. In another case, the main return stroke had dimmed over the 0.52 ms interval but was still visible to the ground. The remaining two cases had the entire length of the prior return stroke channel no longer luminous (for 40 and 240 us) before the upward illumination began (1.32 and 1.87 ms later). Slow antenna data for the upward illumination events resemble those of small return strokes. These events were not located by the operational ground strike detection systems, but three of four were detected by LINET as ground strokes with small peak current. This presentation will show the 2010 data for these events, along with additional examples of the same phenomenon from our 2011 field campaign at KSC.

  13. APOLLO 11: The heroes Return

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The crew of APOLLO 11 return as heroes after their succesfull landing on the lunar surface. From the film documentary 'APOLLO 11:'The Eagle Has Landed'', part of a documentary series on the APOLLO missions made in the early '70's and narrated by Burgess Meredith. APOLLO 11: First manned lunar landing and return to Earth with Neil A. Armstrong, Michael Collins, and Edwin E. Aldrin. Landed in the Sea of Tranquilityon July 20, 1969; deployed TV camera and EASEP experiments, performed lunar surface EVA, returned lunar soil samples. Mission Duration 195 hrs 18 min 35sec

  14. 27 CFR 53.151 - Returns.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... on TTB Form 5300.26. (3) Return periods prior to October 1, 1992. For return periods prior to October 1, 1992, every person required to make a return on TTB Form 5300.26 shall make a return for each... 27 Alcohol, Tobacco Products and Firearms 2 2014-04-01 2014-04-01 false Returns. 53.151 Section...

  15. Mars Sample Return Using Solar Sail Propulsion

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Macdonald, Malcolm; Mcinnes, Colin; Percy, Tom

    2012-01-01

    Many Mars Sample Return (MSR) architecture studies have been conducted over the years. A key element of them is the Earth Return Stage (ERS) whose objective is to obtain the sample from the Mars Ascent Vehicle (MAV) and return it safely to the surface of the Earth. ERS designs predominantly use chemical propulsion [1], incurring a significant launch mass penalty due to the low specific impulse of such systems coupled with the launch mass sensitivity to returned mass. It is proposed to use solar sail propulsion for the ERS, providing a high (effective) specific impulse propulsion system in the final stage of the multi-stage system. By doing so to the launch mass of the orbiter mission can be significantly reduced and hence potentially decreasing mission cost. Further, solar sailing offers a unique set of non-Keplerian low thrust trajectories that may enable modifications to the current approach to designing the Earth Entry Vehicle by potentially reducing the Earth arrival velocity. This modification will further decrease the mass of the orbiter system. Solar sail propulsion uses sunlight to propel vehicles through space by reflecting solar photons from a large, mirror-like surface made of a lightweight, reflective material. The continuous photonic pressure provides propellantless thrust to conduct orbital maneuvering and plane changes more efficiently than conventional chemical propulsion. Because the Sun supplies the necessary propulsive energy, solar sails require no onboard propellant, thus reducing system mass. This technology is currently at TRL 7/8 as demonstrated by the 2010 flight of the Japanese Aerospace Exploration Agency, JAXA, IKAROS mission. [2

  16. Return of the turboprops

    SciTech Connect

    Facey, J.R.; Whitlow, J.B. Jr.; Sievers, G.K.; Groeneweg, J.; Shepherd, K.; Henderson, W.

    1988-10-01

    Recent advances in propfan development for commercial aircraft cruising at high transonic speeds are discussed in a series of brief overviews and illustrated with photographs and diagrams. The efficiency and performance advantages and the problem of noise are examined; the history of turboprop design since the 1950s is recalled; NASA, DOT, FAA, and DOD turboprop projects are described; and the results of wind-tunnel and flight tests on particular propeller models are reviewed. Current trends in aircraft reconfiguration and acoustic redesign to reduce cabin noise levels are also surveyed.

  17. Total anomalous pulmonary venous return

    MedlinePlus

    ... the heart do not attach normally to the left atrium (left upper chamber of the heart). Instead, they attach ... returns through the pulmonary (lung) veins to the left side of the heart, which sends blood out ...

  18. Principles of rehabilitation and return to sports following injury.

    PubMed

    Fournier, Magali

    2015-04-01

    Rehabilitation of an athlete can present its own challenges. Few protocols are available to guide physicians in proper return to sport. Rehabilitation after foot and ankle sport injury can be categorized into 3 different stages but should also be individualized. The focus of this article is to help the treating physician in creating a protocol to safely return an injured athlete back to sport based on current literature and principles.

  19. Principles of rehabilitation and return to sports following injury.

    PubMed

    Fournier, Magali

    2015-04-01

    Rehabilitation of an athlete can present its own challenges. Few protocols are available to guide physicians in proper return to sport. Rehabilitation after foot and ankle sport injury can be categorized into 3 different stages but should also be individualized. The focus of this article is to help the treating physician in creating a protocol to safely return an injured athlete back to sport based on current literature and principles. PMID:25804715

  20. 28 CFR 540.24 - Returned mail.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... contraband all undelivered mail returned to an institution by the Post Office before returning it to the.... Any returned mail qualifying as “special mail” is opened and inspected for contraband in the...

  1. 28 CFR 540.24 - Returned mail.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... contraband all undelivered mail returned to an institution by the Post Office before returning it to the.... Any returned mail qualifying as “special mail” is opened and inspected for contraband in the...

  2. The Benguela Current: An ecosystem of four components

    NASA Astrophysics Data System (ADS)

    Hutchings, L.; van der Lingen, C. D.; Shannon, L. J.; Crawford, R. J. M.; Verheye, H. M. S.; Bartholomae, C. H.; van der Plas, A. K.; Louw, D.; Kreiner, A.; Ostrowski, M.; Fidel, Q.; Barlow, R. G.; Lamont, T.; Coetzee, J.; Shillington, F.; Veitch, J.; Currie, J. C.; Monteiro, P. M. S.

    2009-12-01

    sulphur eruptions result from local and remote forcing, restricting the habitat available for pelagic and demersal fish species. The Luderitz-Orange River Cone is an intensive perennial upwelling cell where strong winds, high turbulence and strong offshore transport constitute a partial barrier to epipelagic fish species. Upwelling source water alters in salinity and oxygen, across this boundary zone. A decline in upwelling-favourable winds occurred between 1990 and 2005. The southern Benguela region is characterised by a pulsed, seasonal, wind-driven upwelling at discrete centres and warm Agulhas water offshore. High primary productivity forms a belt of enrichment along the coast, constrained by a front. Low-oxygen water, which only occurs close inshore, may adversely affect some resources. The west coast is primarily a nursery ground for several fish species which spawn on the Agulhas Bank and are transported by alongshore jet currents to the west coast. The Agulhas Bank forms the southern boundary of the Benguela system and it displays characteristics of both an upwelling and a temperate shallow shelf system, with seasonal stratification and mixing, coastal, shelf-edge and dynamic upwelling, moderate productivity and a well oxygenated shelf. A large biomass of fish occupies the Bank during the summer season, with some evidence for tight coupling between trophic levels. A cool ridge of upwelled water, with links to coastal upwelling and to the Agulhas Current, appears to play an important but poorly understood role affecting the distribution and productivity of pelagic fish. A boom in sardine and anchovy populations was accompanied by an eastward shift, followed by 5 years of poor recruitment by sardine but successful recruitment of anchovy, indicating changes in the early life-history patterns of these two species.

  3. Boomerang Returns Unexpectedly

    NASA Astrophysics Data System (ADS)

    White, Martin; Scott, Douglas; Pierpaoli, Elena

    2000-12-01

    Experimental study of the anisotropy in the cosmic microwave background (CMB) is gathering momentum. The eagerly awaited Boomerang results have lived up to expectations. They provide convincing evidence in favor of the standard paradigm: the universe is close to flat and with primordial fluctuations that are redolent of inflation. Further scrutiny reveals something even more exciting, however-two hints that there may be some unforeseen physical effects. First, the primary acoustic peak appears at slightly larger scales than expected. Although this may be explicable through a combination of mundane effects, we suggest that it is also prudent to consider the possibility that the universe might be marginally closed. The other hint is provided by a second peak, which appears less prominent than expected. This may indicate one of a number of possibilities, including increased damping length or tilted initial conditions, but also breaking of coherence or features in the initial power spectrum. Further data should test whether the current concordance model needs only to be tweaked, or to be enhanced in some fundamental way. A paper about a boomerang by an Australian and his mates.

  4. 26 CFR 20.6075-1 - Returns; time for filing estate tax return.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false Returns; time for filing estate tax return. 20... Administration § 20.6075-1 Returns; time for filing estate tax return. The estate tax return required by section... tax return and tax payment must be made on or before April 30, 2001. When the due date falls...

  5. 12 CFR 210.12 - Return of cash items and handling of returned checks.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... the returned check, in paper or electronic form, for forward collection or return. (3) Warranties for all returned checks that are electronic items. A paying bank or returning bank that sends a returned check that is an electronic item makes the returning bank warranties set forth in and subject to...

  6. 12 CFR 210.12 - Return of cash items and handling of returned checks.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... the returned check, in paper or electronic form, for forward collection or return. (3) Warranties for all returned checks that are electronic items. A paying bank or returning bank that sends a returned check that is an electronic item makes the returning bank warranties set forth in and subject to...

  7. 12 CFR 210.12 - Return of cash items and handling of returned checks.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... the returned check, in paper or electronic form, for forward collection or return. (3) Warranties for all returned checks that are electronic items. A paying bank or returning bank that sends a returned check that is an electronic item makes the returning bank warranties set forth in and subject to...

  8. OSIRIS-REx, Returning the Asteroid Sample

    NASA Technical Reports Server (NTRS)

    Ajluni, Thomas, M.; Everett, David F.; Linn, Timothy; Mink, Ronald; Willcockson, William; Wood, Joshua

    2015-01-01

    This paper addresses the technical aspects of the sample return system for the upcoming Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) asteroid sample return mission. The overall mission design and current implementation are presented as an overview to establish a context for the technical description of the reentry and landing segment of the mission.The prime objective of the OSIRIS-REx mission is to sample a primitive, carbonaceous asteroid and to return that sample to Earth in pristine condition for detailed laboratory analysis. Targeting the near-Earth asteroid Bennu, the mission launches in September 2016 with an Earth reentry date of September 24, 2023.OSIRIS-REx will thoroughly characterize asteroid Bennu providing knowledge of the nature of near-Earth asteroids that is fundamental to understanding planet formation and the origin of life. The return to Earth of pristine samples with known geologic context will enable precise analyses that cannot be duplicated by spacecraft-based instruments, revolutionizing our understanding of the early Solar System. Bennu is both the most accessible carbonaceous asteroid and one of the most potentially Earth-hazardous asteroids known. Study of Bennu addresses multiple NASA objectives to understand the origin of the Solar System and the origin of life and will provide a greater understanding of both the hazards and resources in near-Earth space, serving as a precursor to future human missions to asteroids.This paper focuses on the technical aspects of the Sample Return Capsule (SRC) design and concept of operations, including trajectory design and reentry retrieval. Highlights of the mission are included below.The OSIRIS-REx spacecraft provides the essential functions for an asteroid characterization and sample return mission: attitude control propulsion power thermal control telecommunications command and data handling structural support to ensure successful

  9. Phobos Sample Return - a mission to return a sample from a Martian moon

    NASA Astrophysics Data System (ADS)

    Korablev, Oleg; Koschny, Detlef; Voirin, Thomas

    2016-07-01

    Phobos Sample Return is a mission currently studied by the European Space Agency (ESA), in collaboration with Russia. The main scientific goal is to return about 100 g of sample from the Martian moon Phobos. The current ESA Phase A study has identified a feasible mission with a launch in Sep 2024. It would arrive at Mars in Aug 2025, land on Phobos in April 2026, escape from Mars in September 2026 and bring back a sample to Earth in the summer of 2027. The spacecraft consists of a Propulsion Module (PM), a Lander Module (LM), an Earth Return Vehicle (ERV), and an Earth Reentry Capsule (ERC). A sampling Acquisition Transfer and Containment system (SATCS) composed of a robotic arm, sampling and sealing mechanism is responsible for the surface sampling operations. The PM is responsible for bringing the whole S/C composite into Mars orbit. The Lander/ERV/ERC composite would separate from the PM after Mars Orbit Insertion. After a phase of 1 month spent observing Deimos from a quasi-satellite orbit, the composite would be transferred to Phobos' vicinity for an extensive phase of detailed surface characterization which would allow the selection of the candidate landing site. The S/C would then land on Phobos and remain on the surface for a few weeks. After some initial characterization of the surroundings, the sample would be taken and transferred to the ERC. The ERV with the ERC would leave Phobos and return to Earth; the LM would continue performing surface science on Phobos until several weeks after ERV departure. Shortly before atmospheric entry, the ERC would separate from the ERV to enter the atmosphere safely. After recovery, the sample would be returned into an analysis lab. This presentation will give the latest status of the mission study, and outline future activities.

  10. Predictors of returning to work.

    PubMed

    Ash, P; Goldstein, S I

    1995-01-01

    An investigation of predictors of returning to work in a sample of physically injured persons who are receiving workers' compensation benefits and vocational rehabilitation is presented. One hundred fourteen injured subjects (86 with back injury; 28, other injury) undergoing vocational rehabilitation and receiving workers' compensation benefits were assessed on demographic, emotional, cognitive, financial incentive, and miscellaneous variables. Predictors for returning to work were identified using stepwise logistic regression. Patients with moderate or severe depression, defined as a score greater than 16 on the Beck Depression Inventory (BDI), were significantly less likely to return to work following vocational rehabilitation efforts than patients with less severe depression (for back-injured patients, odds ratio (OR) = 31, 95% CI [8.8, 108]). BDI scores correctly classified 84 percent of the back-injury and 86% of the other-injury groups with respect to their return to work. The level of workers' compensation benefit was the only variable that added (marginally) to the predictive power of the BDI. In a physically injured population receiving workers' compensation benefits, who are judged to be not clearly permanently disabled, level of depressive symptoms is a strong predictor of returning to work. Caution is warranted in using the BDI as the sole determinant in a forensic situation for making a real-world prediction, as BDI responses are easy to fake. Treatment of concurrent depression is an important component of helping physically injured workers resume gainful employment. PMID:8605404

  11. Radiation from lightning return strokes over a finitely conducting earth

    NASA Technical Reports Server (NTRS)

    Le Vine, D. M.; Gesell, L.; Kao, Michael

    1986-01-01

    The effects of the conductivity of the earth on radiation from lightning return strokes are examined theoretically using a piecewise linear transmission line model for the return stroke. First, calculations are made of the electric field radiated during the return stroke, and then this electric field is used to compute the response of conventional AM radio receivers and electric field change systems during the return stroke. The calculations apply to the entire transient waveform (they are not restricted to the initial portions of the return stroke) and yield fast field changes and RF radiation in agreement with measurements made during real lightning. This research was motivated by measurements indicating that a time delay exists between the time of arrival of the fast electric field change and the RF radiation from first return strokes. The time delay is on the order of 20 microsec for frequencies in the HF-UHF range for lightning in Florida. The time delay is obtained theoretically in this paper. It occurs when both the effects of attenuation due to conductivity of the earth, and the finite velocity of propagation of the current pulse up the return stroke channel, are taken into account in the model.

  12. Evaluation of the returned traveler.

    PubMed Central

    Hill, D. R.

    1992-01-01

    Recognition of clinical syndromes in returned travelers is an important part of providing care to international travelers. The first step is to take a history with attention to pre-travel preventive measures, the patient's itinerary, and potential exposure to infectious agents. The patient should then be examined to document physical signs, such as fever, rash, or hepatosplenomegaly, and to have basic laboratory data obtained. This evaluation will provide most physicians with the necessary information to generate a differential diagnosis. Each diagnosis should be matched against the incubation period of the disease, the geographic location of illness, the frequency of illness in returned travelers, and the pre-travel preventive measures. Careful attention to these aspects of patient care should result in the appropriate diagnosis and therapeutic intervention for the ill returned traveler. PMID:1290276

  13. Sample Return Primer and Handbook

    NASA Technical Reports Server (NTRS)

    Barrow, Kirk; Cheuvront, Allan; Faris, Grant; Hirst, Edward; Mainland, Nora; McGee, Michael; Szalai, Christine; Vellinga, Joseph; Wahl, Thomas; Williams, Kenneth; Lee, Gentry; Duxbury, Thomas

    2007-01-01

    This three-part Sample Return Primer and Handbook provides a road map for conducting the terminal phase of a sample return mission. The main chapters describe element-by-element analyses and trade studies, as well as required operations plans, procedures, contingencies, interfaces, and corresponding documentation. Based on the experiences of the lead Stardust engineers, the topics include systems engineering (in particular range safety compliance), mission design and navigation, spacecraft hardware and entry, descent, and landing certification, flight and recovery operations, mission assurance and system safety, test and training, and the very important interactions with external support organizations (non-NASA tracking assets, landing site support, and science curation).

  14. Prediction of Stock Returns Based on Cross-Sectional Multivariable Model

    NASA Astrophysics Data System (ADS)

    Yamada, Shinya; Takahashi, Shinsuke; Funabashi, Motohisa

    A new prediction method of stock returns was constructed from a cross-sectional multivariable model where explanatory variables are current financial indexes and an explained variable is a future stock return. To achieve precise prediction, explanatory variables were appropriately selected over time based on various test statistics and optimization of a performance index of expected portfolio return. A long-short portfolio, in which stocks with high predicted return were bought and stocks with low predicted return were sold short, was constructed to evaluate the proposed method. The simulation test showed that the proposed prediction method was effective to achieve high portfolio performance.

  15. Uncertain Educational Returns in a Developing Economy

    ERIC Educational Resources Information Center

    Mohapatra, Sandeep; Luckert, Martin K.

    2012-01-01

    This paper estimates the distribution of educational returns by gender for India. While previous studies focus on mean returns, the variance of educational returns has important implications for policy-making and micro-level decision making with respect to education. If the variance of educational returns is large, it can leave large sections of…

  16. Biological Sterilization of Returned Mars Samples

    NASA Technical Reports Server (NTRS)

    Allen, C. C.; Albert, F. G.; Combie, J.; Bodnar, R. J.; Hamilton, V. E.; Jolliff, B. L.; Kuebler, K.; Wang, A.; Lindstrom, D. J.; Morris, P. A.

    1999-01-01

    Martian rock and soil, collected by robotic spacecraft, will be returned to terrestrial laboratories early in the next century. Current plans call for the samples to be immediately placed into biological containment and tested for signs of present or past life and biological hazards. It is recommended that "Controlled distribution of unsterilized materials from Mars should occur only if rigorous analyses determine that the materials do not constitute a biological hazard. If any portion of the sample is removed from containment prior to completion of these analyses it should first be sterilized." While sterilization of Mars samples may not be required, an acceptable method must be available before the samples are returned to Earth. The sterilization method should be capable of destroying a wide range of organisms with minimal effects on the geologic samples. A variety of biological sterilization techniques and materials are currently in use, including dry heat, high pressure steam, gases, plasmas and ionizing radiation. Gamma radiation is routinely used to inactivate viruses and destroy bacteria in medical research. Many commercial sterilizers use Co-60 , which emits gamma photons of 1.17 and 1.33 MeV. Absorbed doses of approximately 1 Mrad (10(exp 8) ergs/g) destroy most bacteria. This study investigates the effects of lethal doses of Co-60 gamma radiation on materials similar to those anticipated to be returned from Mars. The goals are to determine the gamma dose required to kill microorganisms in rock and soil samples and to determine the effects of gamma sterilization on the samples' isotopic, chemical and physical properties. Additional information is contained in the original extended abstract.

  17. Return stroke speed of cloud-to-ground lightning estimated from elve hole radii

    NASA Astrophysics Data System (ADS)

    Blaes, P. R.; Marshall, R. A.; Inan, U. S.

    2014-12-01

    We present the first measurements of the lightning return stroke speed that directly relate to the current return stroke, as opposed to its optical manifestation. The shape of elves is determined by the electromagnetic pulse (EMP) radiation pattern at D region altitudes, which is in turn controlled by the geometry and current propagation properties of the return stroke channel. In particular, numerical simulation of the EMP-ionosphere interaction shows a strong relationship between the elve "hole" radius and the current return stroke speed. The hole radii are measured from a data set of 55 elves observed with the PIPER photometer. Using these radii observations in conjunction with numerical simulations of the EMP, we perform Bayesian inference to estimate the distribution of return stroke speeds. The results show a maximum a posteriori probability return stroke speed estimate of 0.64c for elve producing lightning.

  18. Comet coma sample return instrument

    NASA Technical Reports Server (NTRS)

    Albee, A. L.; Brownlee, Don E.; Burnett, Donald S.; Tsou, Peter; Uesugi, K. T.

    1994-01-01

    The sample collection technology and instrument concept for the Sample of Comet Coma Earth Return Mission (SOCCER) are described. The scientific goals of this Flyby Sample Return are to return to coma dust and volatile samples from a known comet source, which will permit accurate elemental and isotopic measurements for thousands of individual solid particles and volatiles, detailed analysis of the dust structure, morphology, and mineralogy of the intact samples, and identification of the biogenic elements or compounds in the solid and volatile samples. Having these intact samples, morphologic, petrographic, and phase structural features can be determined. Information on dust particle size, shape, and density can be ascertained by analyzing penetration holes and tracks in the capture medium. Time and spatial data of dust capture will provide understanding of the flux dynamics of the coma and the jets. Additional information will include the identification of cosmic ray tracks in the cometary grains, which can provide a particle's process history and perhaps even the age of the comet. The measurements will be made with the same equipment used for studying micrometeorites for decades past; hence, the results can be directly compared without extrapolation or modification. The data will provide a powerful and direct technique for comparing the cometary samples with all known types of meteorites and interplanetary dust. This sample collection system will provide the first sample return from a specifically identified primitive body and will allow, for the first time, a direct method of matching meteoritic materials captured on Earth with known parent bodies.

  19. Analysing Enterprise Returns on Training.

    ERIC Educational Resources Information Center

    Moy, Janelle; McDonald, Rod

    Recent Australian and overseas studies on evaluation of enterprises' return on training investment (ROTI) were reviewed to identify key issues in encouraging increased evaluation of training benefits by enterprises and successful approaches that may inform future "enterprise-friendly" studies of ROTI. It was concluded that more practical,…

  20. Skin lesions in returning travellers.

    PubMed

    Korzeniewski, Krzysztof; Juszczak, Dariusz; Jerzemowski, Janusz

    2015-01-01

    Skin lesions, apart from diarrhoeas, fever of unknown origin, and respiratory tract infections belong to the most frequent medical problems in travellers returned from tropical and subtropical destinations, accounting more than 10% of reported cases. Most dermatoses have their clinical onset during travel, although some of them can occur after return. Travel-related dermatological problems can have a wide spectrum of clinical picture, from macular, popular or nodular rash, linear and migratory lesions, to plaques, vesicles, bullae, erosions or ulcers. Skin conditions in returning travellers may be of infectious and non-infectious aetiologies. Infectious lesions may be originally tropical (e.g. dengue, chikungunya, schistosomiasis, leishmaniasis, myiasis, tungiasis, loiasis), although the majority are cosmopolitan (arthropod bites, sunburns, allergic rashes). The evaluation of skin lesions depends on many factors, including immune status of patients, use of medicines, exposure on health hazards (fauna, flora, risky behaviours), as well as the time, duration and location of travel. As the number of travellers to tropical and subtropical destinations has been continuously rising, the number of skin illnesses has also been increasing. This means that specialists in travel medicine need to extend their knowledge of epidemiology, clinical features and diagnosis of travel-related health problems including skin lesions in returning travellers. PMID:26394319

  1. Understanding Guyton's venous return curves

    PubMed Central

    Feigl, Eric O.

    2011-01-01

    Based on observations that as cardiac output (as determined by an artificial pump) was experimentally increased the right atrial pressure decreased, Arthur Guyton and coworkers proposed an interpretation that right atrial pressure represents a back pressure restricting venous return (equal to cardiac output in steady state). The idea that right atrial pressure is a back pressure limiting cardiac output and the associated idea that “venous recoil” does work to produce flow have confused physiologists and clinicians for decades because Guyton's interpretation interchanges independent and dependent variables. Here Guyton's model and data are reanalyzed to clarify the role of arterial and right atrial pressures and cardiac output and to clearly delineate that cardiac output is the independent (causal) variable in the experiments. Guyton's original mathematical model is used with his data to show that a simultaneous increase in arterial pressure and decrease in right atrial pressure with increasing cardiac output is due to a blood volume shift into the systemic arterial circulation from the systemic venous circulation. This is because Guyton's model assumes a constant blood volume in the systemic circulation. The increase in right atrial pressure observed when cardiac output decreases in a closed circulation with constant resistance and capacitance is due to the redistribution of blood volume and not because right atrial pressure limits venous return. Because Guyton's venous return curves have generated much confusion and little clarity, we suggest that the concept and previous interpretations of venous return be removed from educational materials. PMID:21666119

  2. Neurocognitive Performance: Returning to Competition

    ERIC Educational Resources Information Center

    McDaniel, Larry W.; McIntire, Kyle

    2010-01-01

    Athletes who suffer from concussions under report their symptoms in order to expedite their return to competition. Athletic trainers and coaches must be aware of what is going on with athletes, even if it means requiring them to refrain from competition. Ninety percent of concussions are minor and can be difficult to diagnosis. There is a lack of…

  3. Heat Pipe Blocks Return Flow

    NASA Technical Reports Server (NTRS)

    Eninger, J. E.

    1982-01-01

    Metal-foil reed valve in conventional slab-wick heat pipe limits heat flow to one direction only. With sink warmer than source, reed is forced closed and fluid returns to source side through annular transfer wick. When this occurs, wick slab on sink side of valve dries out and heat pipe ceases to conduct heat.

  4. Language Skills and Economic Returns

    ERIC Educational Resources Information Center

    Garrouste, Christelle

    2008-01-01

    This article focuses on the contributions from the emerging positivist epistemological approach, endorsed by the economics of language and the economics of education, to study the returns to language skills, assuming that language competencies constitute key components of human capital. It presents initial results from a study on economic returns…

  5. Skin lesions in returning travellers.

    PubMed

    Korzeniewski, Krzysztof; Juszczak, Dariusz; Jerzemowski, Janusz

    2015-01-01

    Skin lesions, apart from diarrhoeas, fever of unknown origin, and respiratory tract infections belong to the most frequent medical problems in travellers returned from tropical and subtropical destinations, accounting more than 10% of reported cases. Most dermatoses have their clinical onset during travel, although some of them can occur after return. Travel-related dermatological problems can have a wide spectrum of clinical picture, from macular, popular or nodular rash, linear and migratory lesions, to plaques, vesicles, bullae, erosions or ulcers. Skin conditions in returning travellers may be of infectious and non-infectious aetiologies. Infectious lesions may be originally tropical (e.g. dengue, chikungunya, schistosomiasis, leishmaniasis, myiasis, tungiasis, loiasis), although the majority are cosmopolitan (arthropod bites, sunburns, allergic rashes). The evaluation of skin lesions depends on many factors, including immune status of patients, use of medicines, exposure on health hazards (fauna, flora, risky behaviours), as well as the time, duration and location of travel. As the number of travellers to tropical and subtropical destinations has been continuously rising, the number of skin illnesses has also been increasing. This means that specialists in travel medicine need to extend their knowledge of epidemiology, clinical features and diagnosis of travel-related health problems including skin lesions in returning travellers.

  6. Return to sport after muscle injury.

    PubMed

    Wong, Stephanie; Ning, Anne; Lee, Carlin; Feeley, Brian T

    2015-06-01

    Skeletal muscle injuries are among the most common sports-related injuries that result in time lost from practice and competition. The cellular response to muscle injury can often result in changes made to the muscle fibers as well as the surrounding extracellular matrix during repair. This can negatively affect the force and range of the injured muscle even after the patient's return to play. Diagnosis of skeletal muscle injury involves both history and physical examinations; imaging modalities including ultrasound and magnetic resonance imaging (MRI) can also be used to assess the extent of injury. Current research is investigating potential methods, including clinical factors and MRI, by which to predict a patient's return to sports. Overall, function of acutely injured muscles seems to improve with time. Current treatment methods for skeletal muscle injuries include injections of steroids, anesthetics, and platelet-rich plasma (PRP). Other proposed methods involve inhibitors of key players in fibrotic pathways, such as transforming growth factor (TGF)-ß and angiotensin II, as well as muscle-derived stem cells.

  7. Phobos Sample Return: Next Approach

    NASA Astrophysics Data System (ADS)

    Zelenyi, Lev; Martynov, Maxim; Zakharov, Alexander; Korablev, Oleg; Ivanov, Alexey; Karabadzak, George

    The Martian moons still remain a mystery after numerous studies by Mars orbiting spacecraft. Their study cover three major topics related to (1) Solar system in general (formation and evolution, origin of planetary satellites, origin and evolution of life); (2) small bodies (captured asteroid, or remnants of Mars formation, or reaccreted Mars ejecta); (3) Mars (formation and evolution of Mars; Mars ejecta at the satellites). As reviewed by Galimov [2010] most of the above questions require the sample return from the Martian moon, while some (e.g. the characterization of the organic matter) could be also answered by in situ experiments. There is the possibility to obtain the sample of Mars material by sampling Phobos: following to Chappaz et al. [2012] a 200-g sample could contain 10-7 g of Mars surface material launched during the past 1 mln years, or 5*10-5 g of Mars material launched during the past 10 mln years, or 5*1010 individual particles from Mars, quantities suitable for accurate laboratory analyses. The studies of Phobos have been of high priority in the Russian program on planetary research for many years. Phobos-88 mission consisted of two spacecraft (Phobos-1, Phobos-2) and aimed the approach to Phobos at 50 m and remote studies, and also the release of small landers (long-living stations DAS). This mission implemented the program incompletely. It was returned information about the Martian environment and atmosphere. The next profect Phobos Sample Return (Phobos-Grunt) initially planned in early 2000 has been delayed several times owing to budget difficulties; the spacecraft failed to leave NEO in 2011. The recovery of the science goals of this mission and the delivery of the samples of Phobos to Earth remain of highest priority for Russian scientific community. The next Phobos SR mission named Boomerang was postponed following the ExoMars cooperation, but is considered the next in the line of planetary exploration, suitable for launch around 2022. A

  8. 78 FR 26506 - Disclosure of Returns and Return Information to Designee of Taxpayer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-07

    ... contents may become material in the administration of any internal revenue law. Generally, tax returns and... Internal Revenue Service 26 CFR Part 301 RIN 1545-BJ19 Disclosure of Returns and Return Information to... authorizations permitting disclosure of returns and return information to third-party designees....

  9. 26 CFR 20.6075-1 - Returns; time for filing estate tax return.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 14 2011-04-01 2010-04-01 true Returns; time for filing estate tax return. 20.6075-1 Section 20.6075-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... Administration § 20.6075-1 Returns; time for filing estate tax return. The estate tax return required by...

  10. Mars Sample Return Landed with Red Dragon

    NASA Technical Reports Server (NTRS)

    Stoker, Carol R.; Lemke, Lawrence G.

    2013-01-01

    A Mars Sample Return (MSR) mission is the highest priority science mission for the next decade as recommended by the recent Decadal Survey of Planetary Science. However, an affordable program to carry this out has not been defined. This paper describes a study that examined use of emerging commercial capabilities to land the sample return elements, with the goal of reducing mission cost. A team at NASA Ames examined the feasibility of the following scenario for MSR: A Falcon Heavy launcher injects a SpaceX Dragon crew capsule and trunk onto a Trans Mars Injection trajectory. The capsule is modified to carry all the hardware needed to return samples collected on Mars including a Mars Ascent Vehicle (MAV), an Earth Return Vehicle (ERV) and Sample Collection and Storage hardware. The Dragon descends to land on the surface of Mars using SuperSonic Retro Propulsion (SSRP) as described by Braun and Manning [IEEEAC paper 0076, 2005]. Samples are acquired and deliverd to the MAV by a prelanded asset, possibly the proposed 2020 rover. After samples are obtained and stored in the ERV, the MAV launches the sample-containing ERV from the surface of Mars. We examined cases where the ERV is delivered to either low Mars orbit (LMO), C3 = 0 (Mars escape), or an intermediate energy state. The ERV then provides the rest of the energy (delta V) required to perform trans-Earth injection (TEI), cruise, and insertion into a Moon-trailing Earth Orbit (MTEO). A later mission, possibly a crewed Dragon launched by a Falcon Heavy (not part of the current study) retrieves the sample container, packages the sample, and performs a controlled Earth re-entry to prevent Mars materials from accidentally contaminating Earth. The key analysis methods used in the study employed a set of parametric mass estimating relationships (MERs) and standard aerospace analysis software codes modified for the MAV class of launch vehicle to determine the range of performance parameters that produced converged

  11. Asteroid Return Mission Feasibility Study

    NASA Technical Reports Server (NTRS)

    Brophy, John R.; Gershman, Robert; Landau, Damon; Polk, James; Porter, Chris; Yeomans, Don; Allen, Carlton; Williams, Willie; Asphaug, Erik

    2011-01-01

    This paper describes an investigation into the technological feasibility of finding, characterizing, robotically capturing, and returning an entire Near-Earth Asteroid (NEA) to the International Space Station (ISS) for scientific investigation, evaluation of its resource potential, determination of its internal structure and other aspects important for planetary defense activities, and to serve as a testbed for human operations in the vicinity of an asteroid. Reasonable projections suggest that several dozen candidates NEAs in the size range of interest (approximately 2-m diameter) will be known before the end of the decade from which a suitable target could be selected. The conceptual mission objective is to return an approximately 10,000-kg asteroid to the ISS in a total flight time of approximately 5 years using a single Evolved Expendable Launch Vehicle. Preliminary calculations indicate that this could be accomplished using a solar electric propulsion (SEP) system with high-power Hall thrusters and a maximum power into the propulsion system of approximately 40 kW. The SEP system would be used to provide all of the post-launch delta V. The asteroid would have an unrestricted Earth return Planetary Protection categorization, and would be curated at the ISS where numerous scientific and resource utilization experiments would be conducted. Asteroid material brought to the ground would be curated at the NASA Johnson Space Center. This preliminary study identified several areas where additional work is required, but no show stoppers were identified for the approach that would return an entire 10,000-kg asteroid to the ISS in a mission that could be launched by the end of this decade.

  12. Comet nucleus sample return mission

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A comet nucleus sample return mission in terms of its relevant science objectives, candidate mission concepts, key design/technology requirements, and programmatic issues is discussed. The primary objective was to collect a sample of undisturbed comet material from beneath the surface of an active comet and to preserve its chemical and, if possible, its physical integrity and return it to Earth in a minimally altered state. The secondary objectives are to: (1) characterize the comet to a level consistent with a rendezvous mission; (2) monitor the comet dynamics through perihelion and aphelion with a long lived lander; and (3) determine the subsurface properties of the nucleus in an area local to the sampled core. A set of candidate comets is discussed. The hazards which the spacecraft would encounter in the vicinity of the comet are also discussed. The encounter strategy, the sampling hardware, the thermal control of the pristine comet material during the return to Earth, and the flight performance of various spacecraft systems and the cost estimates of such a mission are presented.

  13. Tick size and stock returns

    NASA Astrophysics Data System (ADS)

    Onnela, Jukka-Pekka; Töyli, Juuso; Kaski, Kimmo

    2009-02-01

    Tick size is an important aspect of the micro-structural level organization of financial markets. It is the smallest institutionally allowed price increment, has a direct bearing on the bid-ask spread, influences the strategy of trading order placement in electronic markets, affects the price formation mechanism, and appears to be related to the long-term memory of volatility clustering. In this paper we investigate the impact of tick size on stock returns. We start with a simple simulation to demonstrate how continuous returns become distorted after confining the price to a discrete grid governed by the tick size. We then move on to a novel experimental set-up that combines decimalization pilot programs and cross-listed stocks in New York and Toronto. This allows us to observe a set of stocks traded simultaneously under two different ticks while holding all security-specific characteristics fixed. We then study the normality of the return distributions and carry out fits to the chosen distribution models. Our empirical findings are somewhat mixed and in some cases appear to challenge the simulation results.

  14. CRPE: Cesium Return Program Experience FY 1995

    SciTech Connect

    Clements, E.P.

    1995-11-01

    Since 1945, the chemical reprocessing of irradiated nuclear fuels in the Hanford Chemical Separation areas has resulted in the generation of significant volumes of high-level, liquid, radioactive, by-product materials. However, because these materials were recognized to have beneficial uses, their disposal was delayed. To investigate the possibilities, the By-product Utilization Program (BUP) was initiated. The program mission was to develop a means for the application of radioactive-fission products for the benefit of society. Cs capsules were fabricated and distributed to private irradiation facilities for beneficial product sterilization. In June of 1988, a small leak developed in one of the Cs capsules at a private irradiator facility that is located in Decatur, Georgia. This leak prompted DOE to remove these capsules and to re-evaluate the BUP with the irradiator facilities that were currently using Cs capsules. As a result of this evaluation, a recall was issued to require that all remaining Cs capsules be returned to Hanford for safe management and storage pending final capsule disposition. The WHC completed the return of 309 capsules from a private irradiation facility, located in Northglenn, Colorado, to the Hanford Reservation. The DOE is also planning to remove 25 Cs capsules from a small, private irradiator facility located in Lynchburg, Virginia. This small irradiator facility is currently operational and uses the capsules for the underwater irradiation of wood-flooring products. This report discusses transportation-related activities that WHC has researched, developed, implemented, and is currently managing to ensure the safe and efficient movement of Cs-137 back to the Hanford Reservation.

  15. 49 CFR 1152.34 - Return on investment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... which the nominal return element shall apply shall be the sum of: (i) The allowable working capital... the subsidizer under 49 CFR 1152.32(m)(2), the investment base shall exclude the increment to the net... statement showing its current nominal cost of capital. The railroad's nominal cost of capital shall be...

  16. Mars Sample Return - Launch and Detection Strategies for Orbital Rendezvous

    NASA Technical Reports Server (NTRS)

    Woolley, Ryan C.; Mattingly, Richard L.; Riedel, Joseph E.; Sturm, Erick J.

    2011-01-01

    This study sets forth conceptual mission design strategies for the ascent and rendezvous phase of the proposed NASA/ESA joint Mars Sample Return Campaign. The current notional mission architecture calls for the launch of an acquisition/cache rover in 2018, an orbiter with an Earth return vehicle in 2022, and a fetch rover and ascent vehicle in 2024. Strategies are presented to launch the sample into a coplanar orbit with the Orbiter which facilitate robust optical detection, orbit determination, and rendezvous. Repeating ground track orbits exist at 457 and 572 km which provide multiple launch opportunities with similar geometries for detection and rendezvous.

  17. Heterogeneity in Schooling Rates of Return

    ERIC Educational Resources Information Center

    Henderson, Daniel J.; Polachek, Solomon W.; Wang, Le

    2011-01-01

    This paper relaxes the assumption of homogeneous rates of return to schooling by employing nonparametric kernel regression. This approach allows us to examine the differences in rates of return to education both across and within groups. Similar to previous studies we find that on average blacks have higher returns to education than whites,…

  18. 50 CFR 12.51 - Return procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Return procedure. 12.51 Section 12.51 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR TAKING... SEIZURE AND FORFEITURE PROCEDURES Return of Property § 12.51 Return procedure. If, at the conclusion...

  19. The Return of the Andromedids

    NASA Astrophysics Data System (ADS)

    Wiegert, Paul; Brown, P. G.; Weryk, R. J.; Wong, D. K.

    2012-10-01

    The Andromedid meteor shower, originating from comet 3D/Biela (which disintegrated in the mid-1800's) has been weak or absent since the late 19th Century. Here we report the return of this shower in Dec 2011 with a zenith hourly rate of approximately 50, the strongest return of the shower in a century. The outburst was detected by the Canadian Meteor Orbit Radar (CMOR). The shower outburst occurred during solar longitudes λ=250-252 ° in 2011 (Dec 3-5) and had a statistical significance of 30σ above the median background, one of only three single-day outbursts reaching this level of significance in CMOR's 10 years of operation. Of particular interest: orbital characteristics indicated that was old material, predating the debris released during the epoch of 3D/Biela's disintegration in the mid-19th century, and which produced the spectacular showers in 1872 and 1885. In total, 122 probable Andromedid radar orbits were recorded during the interval from λ=240 °-260 °, the majority (85) occurring between λ=250 °-253 ° from a radiant near α=18 °and δ=56 °. By way of comparison, between λ=250 °-253 ° the average number of radiants recorded by CMOR within 10 degrees of this location having similar speeds in the years 2001 - 2010 was 10 per year. The shower displays a slow geocentric speed (16 km/s) and an absence of large particles: mean measured mass from the radar is 5x10-7 kg corresponding to radii of 0.5mm. Numerical simulations of the parent comet indicate that the 2011 return of the Andromedids shower was produced by material released during Biela's 1649 perihelion passage. The orbital characteristics, radiant, timing as well as the absence of large particles in the streamlet are all confirmed by simulations. Simulations also predict appearances of this radiant in 2008 (seen in CMOR data at ZHR 30) and 2018.

  20. Potential of space-borne GNSS reflectometry to constrain simulations of the ocean circulation. A case study for the South African current system

    NASA Astrophysics Data System (ADS)

    Saynisch, Jan; Semmling, Maximilian; Wickert, Jens; Thomas, Maik

    2015-11-01

    The Agulhas current system transports warm and salty water masses from the Indian Ocean into the Southern Ocean and into the Atlantic. The transports impact past, present, and future climate on local and global scales. The size and variability, however, of the respective transports are still much debated. In this study, an idealized model based twin experiment is used to study whether sea surface height (SSH) anomalies estimated from reflected signals of the Global Navigation Satellite System reflectometry (GNSS-R) can be used to determine the internal water mass properties and transports of the Agulhas region. A space-borne GNSS-R detector on the International Space Station (ISS) is assumed and simulated. The detector is able to observe daily SSH fields with a spatial resolution of 1-5∘. Depending on reflection geometry, the precision of a single SSH observation is estimated to reach 3 cm (20 cm) when the carrier phase (code delay) information of the reflected GNSS signal is used. The average precision over the Agulhas region is 7 cm (42 cm). The proposed GNSS-R measurements surpass the radar-based satellite altimetry missions in temporal and spatial resolution but are less precise. Using the estimated GNSS-R characteristics, measurements of SSH are generated by sampling a regional nested general circulation model of the South African oceans. The artificial observations are subsequently assimilated with a 4DVAR adjoint data assimilation method into the same ocean model but with a different initial state and forcing. The assimilated and the original, i.e., the sampled model state, are compared to systematically identify improvements and degradations in the model variables that arise due to the assimilation of GNSS-R based SSH observations. We show that SSH and the independent, i.e., not assimilated model variables velocity, temperature, and salinity improve by the assimilation of GNSS-R based SSH observations. After the assimilation of 90 days of SSH observations

  1. Return to Flight Task Group

    NASA Technical Reports Server (NTRS)

    2005-01-01

    It has been 29 months since Columbia was lost over East Texas in February 2003. Seven months after the accident, the Columbia Accident Investigation Board (CAIB) released the first volume of its final report, citing a variety of technical, managerial, and cultural issues within NASA and the Space Shuttle Program. To their credit, NASA offered few excuses, embraced the report, and set about correcting the deficiencies noted by the accident board. Of the 29 recommendations issued by the CAIB, 15 were deemed critical enough that the accident board believed they should be implemented prior to returning the Space Shuttle to flight. Some of these recommendations were relatively easy, most were straightforward, a few bordered on the impossible, and others were largely overcome by events, particularly the decision by the President to retire the Space Shuttle by 2010. The Return to Flight Task Group (RTF TG, or simply, the Task Group) was chartered by the NASA Administrator in July 2003 to provide an independent assessment of the implementation of the 15 CAIB return-to-flight recommendations. An important observation must be stated up-front: neither the CAIB nor the RTF TG believes that all risk can be eliminated from Space Shuttle operations; nor do we believe that the Space Shuttle is inherently unsafe. What the CAIB and RTF TG do believe, however, is that NASA and the American public need to understand the risks associated with space travel, and that NASA must make every reasonable effort to minimize such risk. Since the release of the CAIB report, NASA and the Space Shuttle Program expended enormous effort and resources toward correcting the causes of the accident and preparing to fly again. Relative to the 15 specific recommendations that the CAIB indicated should be implemented prior to returning to flight, NASA has met or exceeded most of them the Task Group believes that NASA met the intent of the CAIB for 12 of these recommendations. The remaining three

  2. Mars 2005 Sample Return Workshop

    NASA Technical Reports Server (NTRS)

    Gulick, V. C. (Editor)

    1997-01-01

    Convened at the request of Dr. Jurgen Rahe of the NASA Office of Space Science, the purpose of this workshop was to reexamine the science issues that will determine how an optimum sample return mission would be carried out in 2005 given the new context that has emerged for Mars exploration since the last such workshop was held (in 1987). The results and summary of discussion that took place at the meeting are contained in this volume. The community was invited to participate in the preparation of the final written report by browsing through the agenda and reading the text and viewgraphs provided by workshop participants and submitting comments for that section.

  3. Data link and return link

    NASA Astrophysics Data System (ADS)

    Meuron, Bruce R.; Lyons, Joseph B., Jr.

    1991-05-01

    This invention relates to a data coder, code searching mechanism, data decoder, and range computer for a missile wherein the missile receiver is able to discriminate between the real signals and jamming signals. The system provides discrimination in aircraft receiver systems for the return synchronization signal. This is accomplished by utilizing a random code generator wherein the command data signals modulate the code train which in turn modulates the RF carrier. The missile contains a second code generator with a code searching mechanism which synchronizes the second code generator with the first generator. The comparison of the second code generator signal with the received signal produces the command signal as an output.

  4. Factors Influencing Return to Work

    PubMed Central

    Brewerton, D. A.; Daniel, J. W.

    1971-01-01

    Seventy-seven patients with severe brachial plexus injuries were interviewed two or more years later to determine their success in returning to work and the factors that had led to good or bad resettlement. For most of them these were crucial issues potentially influencing the rest of their lives. When interviewed virtually all had regular jobs in open industry, but many had endured long delays and most were working entirely one-handed. Failure of communication was regrettably common. Too often advice by doctors had been lacking, and there was evidence that the services for vocational resettlement could be improved. PMID:5123911

  5. Active inrush-current limiter

    NASA Technical Reports Server (NTRS)

    Kichak, R. A.

    1977-01-01

    By stretching turn-on time from approximately 1 to 200 ms, effects of inrush current (and of associated large current spikes) and current rate of rise (dl/dt) are made potentially less severe. Limiter arrangement consists of time-variable impedance connected in series between input dc power source return and power circuit of converter.

  6. Estimation of Lightning Return Stroke Speed Using Elve Observations

    NASA Astrophysics Data System (ADS)

    Blaes, P.; Marshall, R. A.; Inan, U.

    2014-12-01

    Elves are optical emissions in the D-region ionosphere that are a result of collisional heating from the intense lightning electromagnetic pulse (EMP). The shape of elves is determined by the EMP radiation pattern at D-region altitudes, which is in turn controlled by the geometry and current propagation properties of the return stroke channel. In particular, numerical simulation of the EMP-ionosphere interaction shows a strong relationship between the elve "hole" radius and the current return stroke speed. During the summer of 2013, hundreds of elves were observed from Langmuir Laboratory, in New Mexico, with the PIPER high-speed photometer. Of these, 55 had an appropriate viewing geometry in which the elve hole is observable and is not corrupted by cloud flashes or sprites. An "emission profile", characterizing the elve emissions versus radius and time, is fit to each of these events using a constrained least squares reconstruction, allowing easy extraction of the elve hole radius. Using these measured radii in conjunction with the numerical EMP model, we perform Bayesian inference to estimate the distribution of return stroke speeds. The MTLL engineering model is assumed for the current propagation with reasonable priors for the parameters. The results show a maximum a posteriori probability return stroke speed estimate of 0.64c for elve producing lightning.

  7. Submicrosecond risetimes in lightning return-stroke fields

    NASA Technical Reports Server (NTRS)

    Weidman, C. D.; Krider, E. P.

    1980-01-01

    Measurements of lightning electric field, E, and dE/dt signatures have been made near Tampa Bay, Florida, under conditions where the lightning locations were known and where the results were not significantly affected by the response time of the measuring system or groundwave propagation. The fast transitions found on the initial portion of return-stroke fields have 10-90% risetimes ranging from 40 to 200 nsec, with a mean of 90 nsec. The maximum field derivatives during return strokes range from 5 to 75 V/m per microsec with a mean of 29 V/m per microsec when normalized to a distance of 100 km. These field risetime and derivative values suggest that return-stroke currents contain large, submicrosecond components, and this in turn suggests that it may be necessary to reevaluate the possible effects of lightning and the performance of lightning-protection devices in many situations.

  8. Return to Play After Lumbar Spine Surgery.

    PubMed

    Cook, Ralph W; Hsu, Wellington K

    2016-10-01

    Surgical management of lumbar spine conditions can produce excellent outcomes in athletes. Microdiscectomy for lumbar disc herniation has favorable outcomes; most athletes return to play at preoperative performance levels. Direct pars repair is successful in younger athletes, with high rates of return to play for a variety of fixation techniques. Fusion in athletes with scoliosis is a negative predictor. There are few evidence-based return to play criteria. Athletes should demonstrate full resolution of symptoms and flexibility, endurance, and strength before returning to play. Deciding when to return an athlete to sport depends on particular injury sustained, sport, and individual factors. PMID:27543402

  9. The dynamics of health and return migration.

    PubMed

    Davies, Anita A; Borland, Rosilyne M; Blake, Carolyn; West, Haley E

    2011-06-01

    The increasing importance and complexity of migration globally also implies a global increase in return migration, and thus an increased interest in the health of returning migrants. The health of returning migrants is impacted by the cumulative exposure to social determinants and risk factors of health during the migration process, during the return movement, and following return. Circular migration often occurs among the diaspora, which can result in the transfer of knowledge and skills that contribute to development, including health system strengthening. Migrants with dual nationality often return to countries with better health services than their country of origin when they are sick and can not get care at home. To maintain and improve the health of returning migrants, multi-sectoral policies at global and national levels should facilitate access to appropriate and equitable health services, social services, and continuity of care across and within borders.

  10. THE RETURN OF THE ANDROMEDIDS METEOR SHOWER

    SciTech Connect

    Wiegert, Paul A.; Brown, Peter G.; Weryk, Robert J.; Wong, Daniel K.

    2013-03-15

    The Andromedid meteor shower underwent spectacular outbursts in 1872 and 1885, producing thousands of visual meteors per hour and described as ''stars fell like rain'' in Chinese records of the time. The shower originates from comet 3D/Biela whose disintegration in the mid-1800's is linked to the outbursts, but the shower has been weak or absent since the late 19th century. This shower returned in 2011 December with a zenithal hourly rate of approximately 50, the strongest return in over a hundred years. Some 122 probable Andromedid orbits were detected by the Canadian Meteor Orbit Radar while one possible brighter Andromedid member was detected by the Southern Ontario Meteor Network and several single station possible Andromedids by the Canadian Automated Meteor Observatory. The shower outburst occurred during 2011 December 3-5. The radiant at R.A. +18 Degree-Sign and decl. +56 Degree-Sign is typical of the ''classical'' Andromedids of the early 1800s, whose radiant was actually in Cassiopeia. Numerical simulations of the shower were necessary to identify it with the Andromedids, as the observed radiant differs markedly from the current radiant associated with that shower. The shower's orbital elements indicate that the material involved was released before 3D/Biela's breakup prior to 1846. The observed shower in 2011 had a slow geocentric speed (V{sub G} = 16 km s{sup -1}) and was comprised of small particles: the mean measured mass from the radar is {approx}5 Multiplication-Sign 10{sup -7} kg, corresponding to radii of 0.5 mm at a bulk density of 1000 kg m{sup -3}. Numerical simulations of the parent comet indicate that the meteoroids of the 2011 return of the Andromedids shower were primarily ejected during 3D/Biela's 1649 perihelion passage. The orbital characteristics, radiant, and timing as well as the absence of large particles in the streamlet are all broadly consistent with simulations. However, simulations of the 1649 perihelion passage necessitate going

  11. Risk analysis of earth return options for the Mars rover/sample return mission

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Four options for return of a Mars surface sample to Earth were studied to estimate the risk of mission failure and the risk of a sample container breach that might result in the release of Martian life forms, should such exist, in the Earth's biosphere. The probabilities calculated refer only to the time period from the last midcourse correction burn to possession of the sample on Earth. Two extreme views characterize this subject. In one view, there is no life on Mars, therefore there is no significant risk and no serious effort is required to deal with back contamination. In the other view, public safety overrides any desire to return Martian samples, and any risk of damaging contamination greater than zero is unacceptable. Zero risk requires great expense to achieve and may prevent the mission as currently envisioned from taking place. The major conclusion is that risk of sample container breach can be reduced to a very low number within the framework of the mission as now envisioned, but significant expense and effort, above that currently planned is needed. There are benefits to the public that warrant some risk. Martian life, if it exists, will be a major discovery. If it does not, there is no risk.

  12. Sepsis, venous return, and teleology.

    PubMed

    McNeilly, R G

    2014-11-01

    An understanding of heart-circulation interaction is crucial to our ability to guide our patients through an episode of septic shock. Our knowledge has advanced greatly in the last one hundred years. There are, however, certain empirical phenomena that may lead us to question the wisdom of our prevailing treatment algorithm. Three extreme but iatrogenically possible haemodynamic states exist. Firstly, inappropriately low venous return; secondly, overzealous arteriolar constriction; and finally, misguided inotropy and chronotropy. Following an unsuccessful fluid challenge, it would be logical to first set the venous tone, then set the cardiac rate and contractility, and finally set the peripheral vascular resistance. It is hypothesized that a combination of dihydroergotamine, milrinone and esmolol should be superior to a combination of noradrenaline and dobutamine for surviving sepsis. PMID:25245463

  13. Partial Return Yoke for MICE

    SciTech Connect

    Witte H.; Plate, S

    2013-05-03

    The international Muon Ionization Cooling Experiment (MICE) is a large scale experiment which is presently assembled at the Rutherford Appleton Laboratory in Didcot, UK. The purpose of MICE is to demonstrate the concept of ionization cooling experimentally. Ionization cooling is an important accelerator concept which will be essential for future HEP experiments such as a potential Muon Collider or a Neutrino Factory. The MICE experiment will house up to 18 superconducting solenoids, all of which produce a substantial amount of magnetic flux. Recently it was realized that this magnetic flux leads to a considerable stray magnetic field in the MICE hall. This is a concern as technical equipment in the MICE hall may may be compromised by this. In July 2012 a concept called partial return yoke was presented to the MICE community, which reduces the stray field in the MICE hall to a safe level. This report summarizes the general concept, engineering considerations and the expected shielding performance.

  14. Mars Sample Return mission utilizing in-situ propellant production

    NASA Technical Reports Server (NTRS)

    Zubrin, Robert; Price, Steve

    1995-01-01

    This report presents the results of a study examining the potential of in-situ propellant production (ISPP) on Mars to aid in achieving a low cost Mars Sample Return (MSR) mission. Two versions of such a mission were examined: a baseline version employing a dual string spacecraft, and a light weight version employing single string architecture with selective redundancy. Both systems employed light weight avionics currently being developed by Lockheed Martin, Jet Propulsion Lab and elsewhere in the aerospace community, both used a new concept for a simple, light weight parachuteless sample return capsule, both used a slightly modified version of the Mars Surveyor lander currently under development at Lockheed Martin for flight in 1998, and both used a combination of the Sabatier-electrolysis and reverse water gas shift ISPP systems to produce methane/oxygen propellant on Mars by combining a small quantity of imported hydrogen with the Martian CO2 atmosphere. It was found that the baseline mission could be launched on a Delta 7925 and return a 0.5 kg sample with 82 percent mission launch margin;over and beyond subsystem allocated contingency masses . The lightweight version could be launched on a Mid-Lite vehicle and return a 0.25 kg sample with 11 percent launch margin, over and above subsystem contingency mass allocations.

  15. Understanding Return Stroke Data with Time Domain Fractal Lightning Modeling

    NASA Astrophysics Data System (ADS)

    Liang, C.; Carlson, B. E.; Lehtinen, N. G.; Inan, U. S.

    2012-12-01

    Time domain fractal lightning (TDFL) modeling is an evolving technique for the study of lightning in the context of comprehensive existing experimental data. It incorporates the complex geometry of the lightning channel, keeps track of the time evolution of charge and current distribution along the lightning channel, and with both combined, simulates realistic electromagnetic radiation signals from lightning flashes. Recent development enhances the technique by bringing in various elements from the plasma physics aspect of lightning physics. For example, simple models are included to take account of effects due to corona sheath, channel heating and cooling, channel conductivity dependence on temperature etc. With future development, an even more sophisticated treatment of these elements is expected. With these features at hand, we present studies of return stroke related experimental data using TDFL. A wide variety of experimental data exists for the return stroke, including ground-base-current measurements, electric and magnetic field record, channel luminosity and estimations of various channel properties. We study these various aspects of lightning data under the single framework provided by TDFL. Emphasis is on exploring and explaining connections between the different types of data, e.g. dependence of the return stroke speed and electric field on channel properties, relation between ground-base-current peak current and charge transfer. Various other aspects such as effect of tortuous channel geometry, branches, and corona sheath are also explored.

  16. Sample Returns Missions in the Coming Decade

    NASA Technical Reports Server (NTRS)

    Desai, Prasun N.; Mitcheltree, Robert A.; Cheatwood, F. McNeil

    2000-01-01

    In the coming decade, several missions will attempt to return samples to Earth from varying parts of the solar system. These samples will provide invaluable insight into the conditions present during the early formation of the solar system, and possibly give clues to how life began on Earth. A description of five sample return missions is presented (Stardust, Genesis, Muses-C. Mars Sample Return, and Comet Nucleus Sample Return). An overview of each sample return mission is given, concentrating particularly on the technical challenges posed during the Earth entry, descent, and landing phase of the missions. Each mission faces unique challenges in the design of an Earth entry capsule. The design of the entry capsule must address the aerodynamic, heating, deceleration, landing, and recovery requirements for the safe return of samples to Earth.

  17. Return to Work After Diskogenic Fusion in Workers' Compensation Subjects.

    PubMed

    Anderson, Joshua T; Haas, Arnold R; Percy, Rick; Woods, Stephen T; Ahn, Uri M; Ahn, Nicholas U

    2015-12-01

    Lumbar fusion for degenerative disk disease (DDD) is associated with variable clinical outcomes. Patients with workers' compensation claims often have worse fusion outcomes than the general population. Few studies have evaluated the risk factors for poor outcomes within this clinically distinct population. The goal of this study was to identify preoperative predictors of return to work status after fusion for DDD in a workers' compensation setting. The authors used International Classification of Diseases, Ninth Revision (ICD-9), diagnosis and Current Procedural Terminology (CPT) procedural codes to identify 1037 subjects from the Ohio Bureau of Workers' Compensation database who underwent fusion for DDD between 1993 and 2013. Of these subjects, 23.2% (n=241) made a sustained return to work within 2 years after fusion. To identify preoperative predictors of postoperative return to work status, the authors used multivariate logistic regression analysis, adjusting for many important covariates. These included prolonged time out of work (P<.001; odds ratio [OR], 0.24), psychiatric history (P<.001; OR, 0.14), prolonged use of opioid analgesics (P<.001; OR, 0.46), male sex (P=.014; OR, 0.65), and legal representation (P=.042; OR, 0.67). The return to work rates associated with these risk factors were 10.4%, 2.0%, 11.9%, 21.1%, and 20.7%, respectively. Of the study subjects, 76.8% (n=796) did not return to work and had considerably worse postoperative outcomes, highlighted by chronic opioid dependence and high rates of failed back syndrome, additional surgery, and new psychiatric comorbidity. The low return to work rates and other generally poor outcomes reported in this study may indicate a more limited role for lumbar fusion among patients with DDD who have workers' compensation claims. More studies are needed to determine whether fusion for DDD can improve function and quality of life in these patients. PMID:26652326

  18. Irish return migration in the nineteenth century.

    PubMed

    Hart, M

    1985-01-01

    This study is concerned with return migration to Ireland from the United States during the nineteenth century. The author first notes that the rate of return migration was relatively low. Reasons for returning are then considered, including inheritance and poor health. Data on 671 Irish returnees from passenger lists of ships arriving in the United Kingdom from the United States between 1858 and 1867 are analyzed with regard to sex, marital status, age, occupations, and impact of returnees.

  19. Bulgarian Turkish emigration and return.

    PubMed

    Vasileva, D

    1992-01-01

    The main factors which determined the 1989 migration of Turks in Bulgaria back to Turkey are discussed. Background history is provided. After World War I, Turks in bulgaria comprised 10% of the total population. Bulgarian policy had been, up to the 1980s to send Rumelian Turks back, but the policy after 1980 was one of a national revival process to integrate Turks into the developed socialist society. Muslim traditions, customs, and Turkish language were interfered with. International disfavor resulted. In May 1989, the Communist Party declared, in an effort to show democratic ideals, open borders. Thus began the new emigration wave. 369,839 people fled to the Turkish border. 43% of the 9.47 ethnic Turks in bulgaria went to Turkey within 4 months. The numbers decreased in November, and soon after the communist regime ended. New laws were adopted allowing Turks to assume their original Turkish names. The huge migration was clearly political, and as such, the emigrant Turks should be determined as refugees and asylum seekers. The provocation of ethnic Turks was used by the communist regime to solve potential social conflicts. Not only did Turks flee to escape from violence or for religious, cultural, and moral reasons but also due to free market initiatives begun in Turkey in the early 1980s which improved Turkish quality of life. Food and consumer goods were cheaper and economic advantages were perceived. Emigrants were primarily peasants with lower levels of education, professional qualifications, and labor skills. 154,937 (42%) returned to bulgaria and 58% stayed in Turkey to comprise 25% of the former Turkish population. During this period, tensions between countries was high.l Bulgarians actively encouraged emigration and Turkey welcomed it. The emigrants to Turkey were seen as foreigners (muhacir or gocmen) but were received with good will and were readily accepted into menial positions. Emigrants were confronted with political, linguistic, and cultural

  20. 26 CFR 301.6103(i)-1 - Disclosure of returns and return information (including taxpayer return information) to and by...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... investigation, involving enforcement of Federal criminal statute not involving tax administration. 301.6103(i)-1... criminal statute not involving tax administration. (a) Disclosure of returns and return information... proceeding), pertaining to enforcement of a specifically designated Federal criminal statute not involving...

  1. The heat transfer characteristics of lightning return stroke channel

    NASA Astrophysics Data System (ADS)

    Dong, Caixia; Yuan, Ping; Cen, Jianyong; Wang, Xuejuan; Mu, Yali

    2016-09-01

    Based on the time-resolved spectra of lightning return stroke processes, the evolutional characteristics of thermal conductivity and thermal diffusivity of the discharge channels are discussed. The distribution of temperature along the radial direction of channels at the peak current stage of return stroke is also investigated, and then the heat transferring characteristics along radial direction of the channels are analyzed. The results show that a temperature gradient along radial direction of lightning channel is formed due to the outward heat transfer. The closer the distance is to the current core channel, the greater the temperature gradient is and the more heat is transferred along the radial direction of the channel. The heat transferring in per unit length of the channel and per unit time is in the order of 104 J/m ṡ s at the initial moment of lightning return stroke. After the peak current, the channel temperature decreases slowly and the heat transport coefficients vary as a monotonically decreasing function.

  2. The Returns to Quality in Graduate Education

    ERIC Educational Resources Information Center

    Stevenson, Adam

    2016-01-01

    This paper estimates the monetary return to quality in US graduate education, controlling for cognitive ability and self-selection across award level, program quality, and field-of-study. In most program types, I cannot reject the hypothesis of no returns to either degree completion or program quality. Important exceptions include master's…

  3. Recreation and the Returning Female Student.

    ERIC Educational Resources Information Center

    Bialeschki, M. Deborah; Henderson, Karla A.

    This study evaluated the leisure attitudes and recreation participation patterns of a sample of returning female college students. Interviews were conducted with 36 full-time women students who had returned to graduate school after a five-year lapse in their formal training. The women placed a high value on the cognitive and affective aspects of…

  4. The Stages of Mailed Questionnaire Returning Behavior.

    ERIC Educational Resources Information Center

    Lockhart, Daniel C.

    1984-01-01

    Six stages are hypothesized that define the behavior of returning mailed questionnaires: receiving the questionnaire, opening the mail, forming an overall impression, answering the questions, returning the questionnaire, and dealing with nonrespondents. The researcher must provide incentives at each stage if potential respondents are to complete a…

  5. 46 CFR 308.514 - Return premium.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Return premium. 308.514 Section 308.514 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Ii-Open Policy War Risk Cargo Insurance § 308.514 Return premium. No premium will...

  6. Returned Solar Max hardware degradation study results

    NASA Technical Reports Server (NTRS)

    Triolo, Jack J.; Ousley, Gilbert W.

    1989-01-01

    The Solar Maximum Repair Mission returned with the replaced hardware that had been in low Earth orbit for over four years. The materials of this returned hardware gave the aerospace community an opportunity to study the realtime effects of atomic oxygen, solar radiation, impact particles, charged particle radiation, and molecular contamination. The results of these studies are summarized.

  7. 27 CFR 41.112 - Tax return.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2013-04-01 2013-04-01 false Tax return. 41.112 Section 41.112 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF... States Deferred Payment of Tax in Puerto Rico on Tobacco Products § 41.112 Tax return. The...

  8. 27 CFR 41.112 - Tax return.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2014-04-01 2014-04-01 false Tax return. 41.112 Section 41.112 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF... States Deferred Payment of Tax in Puerto Rico on Tobacco Products § 41.112 Tax return. The...

  9. 27 CFR 41.112 - Tax return.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2012-04-01 2011-04-01 true Tax return. 41.112 Section 41.112 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF... States Deferred Payment of Tax in Puerto Rico on Tobacco Products § 41.112 Tax return. The...

  10. 27 CFR 41.112 - Tax return.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2011-04-01 2011-04-01 false Tax return. 41.112 Section 41.112 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF... States Deferred Payment of Tax in Puerto Rico on Tobacco Products § 41.112 Tax return. The...

  11. Aggregate Unemployment Decreases Individual Returns to Education

    ERIC Educational Resources Information Center

    Ammermueller, Andreas; Kuckulenz, Anja; Zwick, Thomas

    2009-01-01

    Aggregate unemployment may affect individual returns to education through qualification-specific responses in participation and wage bargaining. This paper shows that an increase in regional unemployment by 1% decreases returns to education by 0.005 percentage points. This implies that higher skilled employees are better sheltered from labour…

  12. Return migration to Italy and labour migration.

    PubMed

    Calvaruso, C

    1983-01-01

    The problems caused by large-scale return migration to Italy in recent years are considered. The importance of the additional skills and capital acquired by these migrants while abroad is stressed. Extensive data on the volume of return migration in the 1970s are included.

  13. Anxiety and the Newly Returned Adult Student

    ERIC Educational Resources Information Center

    Cleary, Michelle Navarre

    2012-01-01

    Based on interviews with students who had recently returned to school, this essay demonstrates the need for, challenges of, and ways to respond to the writing anxiety many adults bring with them back to school. Jessica and Sam were two of twenty-five newly returned adult students whom the author spent over sixty hours interviewing in the fall of…

  14. 7 CFR 356.8 - Return procedure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Return procedure. 356.8 Section 356.8 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE FORFEITURE PROCEDURES § 356.8 Return procedure. If, at the conclusion...

  15. 27 CFR 41.112 - Tax return.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Tax return. 41.112 Section 41.112 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF... States Deferred Payment of Tax in Puerto Rico on Tobacco Products § 41.112 Tax return. The...

  16. 21 CFR 203.23 - Returns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL PRESCRIPTION DRUG MARKETING Sales Restrictions § 203.23 Returns. The return of a prescription drug purchased by a hospital or health care entity or acquired at a reduced price by or donated to a...

  17. 46 CFR 308.514 - Return premium.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 8 2014-10-01 2014-10-01 false Return premium. 308.514 Section 308.514 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Open Policy War Risk Cargo Insurance § 308.514 Return premium. No premium will...

  18. 46 CFR 308.514 - Return premium.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 8 2013-10-01 2013-10-01 false Return premium. 308.514 Section 308.514 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Ii-Open Policy War Risk Cargo Insurance § 308.514 Return premium. No premium will...

  19. 46 CFR 308.514 - Return premium.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 8 2012-10-01 2012-10-01 false Return premium. 308.514 Section 308.514 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Ii-Open Policy War Risk Cargo Insurance § 308.514 Return premium. No premium will...

  20. 46 CFR 308.514 - Return premium.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 8 2011-10-01 2011-10-01 false Return premium. 308.514 Section 308.514 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Ii-Open Policy War Risk Cargo Insurance § 308.514 Return premium. No premium will...

  1. Managing Returns in a Catalog Distribution Center

    ERIC Educational Resources Information Center

    Gates, Joyce; Stuart, Julie Ann; Bonawi-tan, Winston; Loehr, Sarah

    2004-01-01

    The research team of the Purdue University in the United States developed an algorithm that considers several different factors, in addition to cost, to help catalog distribution centers process their returns more efficiently. A case study to teach the students important concepts involved in developing a solution to the returns disposition problem…

  2. Predictors of Return to Driving After Stroke

    PubMed Central

    Aufman, Elyse L.; Bland, Marghuretta D.; Barco, Peggy P.; Carr, David B.; Lang, Catherine E.

    2013-01-01

    Objective While returning to driving is a major concern for many stroke survivors, predicting who will return to driving after a stroke is often difficult for rehabilitation professionals. The primary aim of this study was to identify patient factors present at admission to an inpatient rehabilitation hospital that can be used to identify which patients with acute stroke will and will not return to driving. Design After comparing returners and non-returners on demographic and clinical characteristics, a logistic regression model with return to driving as the outcome variable was built using the backward stepwise method. Results Thirty-one percent (48/156) of patients who had been driving before their stroke had returned to driving six months post-stroke. The final regression model, using FIM cognition and lower extremity Motricity Index scores, predicted the driving outcome with an accuracy of 75% (107/143). Conclusions Patients with lower FIM cognition and lower extremity Motricity Index scores at admission to inpatient rehabilitation are less likely to return to driving at six months. This model could be used by rehabilitation professionals to help counsel patients and their families and focus treatment goals. PMID:23370577

  3. Maximizing your return on people.

    PubMed

    Bassi, Laurie; McMurrer, Daniel

    2007-03-01

    Though most traditional HR performance metrics don't predict organizational performance, alternatives simply have not existed--until now. During the past ten years, researchers Laurie Bassi and Daniel McMurrer have worked to develop a system that allows executives to assess human capital management (HCM) and to use those metrics both to predict organizational performance and to guide organizations' investments in people. The new framework is based on a core set of HCM drivers that fall into five major categories: leadership practices, employee engagement, knowledge accessibility, workforce optimization, and organizational learning capacity. By employing rigorously designed surveys to score a company on the range of HCM practices across the five categories, it's possible to benchmark organizational HCM capabilities, identify HCM strengths and weaknesses, and link improvements or back-sliding in specific HCM practices with improvements or shortcomings in organizational performance. The process requires determining a "maturity" score for each practice, based on a scale of 1 (low) to 5 (high). Over time, evolving maturity scores from multiple surveys can reveal progress in each of the HCM practices and help a company decide where to focus improvement efforts that will have a direct impact on performance. The authors draw from their work with American Standard, South Carolina's Beaufort County School District, and a bevy of financial firms to show how improving HCM scores led to increased sales, safety, academic test scores, and stock returns. Bassi and McMurrer urge HR departments to move beyond the usual metrics and begin using HCM measurement tools to gauge how well people are managed and developed throughout the organization. In this new role, according to the authors, HR can take on strategic responsibility and ensure that superior human capital management becomes central to the organization's culture.

  4. 76 FR 14827 - Disclosure of Returns and Return Information to Designee of Taxpayer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-18

    ... Internal Revenue Service 26 CFR Part 301 RIN 1545-BJ19 Disclosure of Returns and Return Information to Designee of Taxpayer AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Notice of proposed... the period for submission to the IRS of taxpayer authorizations permitting disclosure of returns...

  5. 26 CFR 1.6013-2 - Joint return after filing separate return.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) after the death of either spouse shall, with respect to the decedent, be made only by his executor or... return made under section 6013(b). (e) Additions to the tax and penalties. (1) Where the amount shown as... criminal penalties in the case of fraudulent returns), the term “return” includes a separate return...

  6. 26 CFR 1.6013-2 - Joint return after filing separate return.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the death of either spouse shall, with respect to the decedent, be made only by his executor or... return made under section 6013(b). (e) Additions to the tax and penalties. (1) Where the amount shown as... criminal penalties in the case of fraudulent returns), the term “return” includes a separate return...

  7. Trends in return migration to the South.

    PubMed

    Long, L H; Hansen, K A

    1975-11-01

    The rate of return migration to the South rose by nearly 19 percent between the late 1950's and the late 1960's and was an important factor in changing the South's overall migration pattern. But an increase in the rate of return migration was somewhat less important in changing Southern migration than (1) a decline in the rate of out-migration of native Southerners and (2) an increase in the rate at which non-Southern-born persons move to the South. The probability of former migrants returning to the South was over four times greater for whites than for blacks in the 1955-1960 period and three and one-fourth times greater in the 1965-1970 period. Since 1970 the rate of return migration has apparently continued to rise at a faster rate for blacks, but the black rate of return migration is still below the white rate.

  8. Upper Atmospheric Particulate Monitoring and Sample Return

    NASA Astrophysics Data System (ADS)

    Liddell, Alan; Sohl, John E.

    2010-10-01

    H.A.R.B.O.R. (High Altitude Reconnaissance Balloon for Outreach and Research) is a student-run program in which high-altitude balloon systems are designed, constructed, and flown by students conducting individual or group research projects. One area of interest is in the sampling of particles in the upper atmosphere. Collecting airborne particulates and studying them under an SEM can answer questions on the origins of airborne particulate matter. We could find explanations for climate change or directly measure pollution caused by smokestacks. The SEM has the capacity to capture images of particulates and determine their composition. I am building a system capable of sampling air up to 30km (100,000 ft). The system will contain a servo-controlled filter system for sampling air captured by the ascent of the balloon. Currently, filter types are being evaluated for capture rate and air flow resistance. A circuit has been built to test the mass throughput of the airflow as the balloon travels its course. A vacuum chamber is being built to simulate the nearspace environment. Testing and simulation should be complete in time to fly a finalized sample return mission in spring 2011.

  9. The return of the natural philosopher

    NASA Astrophysics Data System (ADS)

    Lehner, Ed

    2010-03-01

    John R. Staver's article calling for a constructivist epistemology to maneuver between the disparate ways of knowing between science and religion prompts this response. This paper acknowledges Staver's scholarly analysis of the issue. Scientific and religious conflicts do present prominent challenges because these are profound but often-monolithic ways of constructing knowledge. However, my response withholds fully embracing Staver's call for a constructivist epistemology chiefly because his work goes beyond the confines of constructivism. Conversely, Staver's call for constructivist epistemology does not go far enough to advance a resolution between science and religion. Why? Because both science and religion often employ hyper-rationality in understanding the world, a process that does little to clarify the world's complexities. Philosophically, I refrain from accepting a complete schism between the two because such a framing does little to heal a conflict between those who praise the seen and those who praise the unseen. My response explores how hyper-rationality has triumphed over both science and religion, leaving the believer in one, or both, to navigate the journey alone. This article calls for the return of the natural philosopher. Utilizing this nineteenth-century term for scientist, this paper calls for an inquirer, one who can rise above the ideologies of science and religion to observe the current concerns of each field anew. Finally, taking a cue from Staver, this response introduces a potential discourse between science and religion in ways that each may, without embracing a variant ideology, make space for dialogue and mutual respect.

  10. El Niño Returns

    NASA Astrophysics Data System (ADS)

    El Niño, a climatic disturbance that shifts much of the world's weather pattern every 2-7 years, has returned and is probably near the midpoint of its expected 18-month life cycle, according to an announcement by the National Weather Service (NWS) of the National Oceanic and Atmospheric Administration (NOAA). This El Niño appears to be much milder than its predecessor 4 years ago, from April 1982 to July 1983. That event, the worst in more than 100 years, caused floods and droughts that led to more than 1000 deaths and $2 billion to $8 billion in economic losses.The phenomenon comes about when equatorial winds that normally blow the Pacific Ocean's surface waters from east to west weaken or reverse themselves. The warm surface waters then flow from west to east. Results include a decrease in rainfall in the Philippines, Indonesia, Australia, New Guinea, and Southern Africa; increased rainfall in the South American coast, the southeastern United States, and eastern Africa; and milder than normal weather in the U.S. Pacific Northwest, western Canada, and Alaska. The current El Niño was successfully predicted by at least three different scientific models, according to The New York Times, although the event began somewhat later than expected.

  11. Characterization of avalanche photodiodes for lidar atmospheric return signal detectors

    NASA Technical Reports Server (NTRS)

    Antill, C. W., Jr.; Holloway, R. M.

    1988-01-01

    Results are presented from tests to characterize noise, dark current, overload, and gain versus bias, relationships of ten avalanche photodiodes. The advantages of avalanche photodiodes over photomultiplier tubes for given laser wavelengths and return signal amplitudes are outlined. The relationship between responsivity and temperature and dark current and temperature are examined. Also, measurements of the noise equivalent power, the excess noise factor, and linearity are given. The advantages of using avalanche photodiodes in the Lidar Atmospheric Sensing Experiment and the Lidar In-Space Technology Experiment are discussed.

  12. Mars Orbiter Sample Return Power Design

    NASA Technical Reports Server (NTRS)

    Mardesich, N.; Dawson, S.

    2005-01-01

    Mars has greatly intrigued scientists and the general public for many years because, of all the planets, its environment is most like Earth's. Many scientists believe that Mars once had running water, although surface water is gone today. The planet is very cold with a very thin atmosphere consisting mainly of CO2. Mariner 4, 6, and 7 explored the planet in flybys in the 1960s and by the orbiting Mariner 9 in 1971. NASA then mounted the ambitious Viking mission, which launched two orbiters and two landers to the planet in 1975. The landers found ambiguous evidence of life. Mars Pathfinder landed on the planet on July 4, 1997, delivering a mobile robot rover that demonstrated exploration of the local surface environment. Mars Global Surveyor is creating a highest-resolution map of the planet's surface. These prior and current missions to Mars have paved the way for a complex Mars Sample Return mission planned for 2003 and 2005. Returning surface samples from Mars will necessitate retrieval of material from Mars orbit. Sample mass and orbit are restricted to the launch capability of the Mars Ascent Vehicle. A small sample canister having a mass less than 4 kg and diameter of less than 16 cm will spend from three to seven years in a 600 km orbit waiting for retrieval by a second spacecraft consisting of an orbiter equipped with a sample canister retrieval system, and a Earth Entry Vehicle. To allow rapid detection of the on-orbit canister, rendezvous, and collection of the samples, the canister will have a tracking beacon powered by a surface mounted solar array. The canister must communicate using RF transmission with the recovery vehicle that will be coming in 2006 or 2009 to retrieve the canister. This paper considers the aspect and conclusion that went into the design of the power system that achieves the maximum power with the minimum risk. The power output for the spherical orbiting canister was modeled and plotted in various views of the orbit by the Satellite

  13. What stock market returns to expect for the future?

    PubMed

    Diamond, P A

    2000-01-01

    In evaluating proposals for reforming Social Security that involve stock investments, the Office of the Chief Actuary (OCACT) has generally used a 7.0 percent real return for stocks. The 1994-96 Advisory Council specified that OCACT should use that return in making its 75-year projections of investment-based reform proposals. The assumed ultimate real return on Treasury bonds of 3.0 percent implies a long-run equity premium of 4.0 percent. There are two equity-premium concepts: the realized equity premium, which is measured by the actual rates of return; and the required equity premium, which investors expect to receive for being willing to hold available stocks and bonds. Over the past two centuries, the realized premium was 3.5 percent on average, but 5.2 percent for 1926 to 1998. Some critics argue that the 7.0 percent projected stock returns are too high. They base their arguments on recent developments in the capital market, the current high value of the stock market, and the expectation of slower economic growth. Increased use of mutual funds and the decline in their costs suggest a lower required premium, as does the rising fraction of the American public investing in stocks. The size of the decrease is limited, however, because the largest cost savings do not apply to the very wealthy and to large institutional investors, who hold a much larger share of the stock market's total value than do new investors. These trends suggest a lower equity premium for projections than the 5.2 percent of the past 75 years. Also, a declining required premium is likely to imply a temporary increase in the realized premium because a rising willingness to hold stocks tends to increase their price. Therefore, it would be a mistake during a transition period to extrapolate what may be a temporarily high realized return. In the standard (Solow) economic growth model, an assumption of slower long-run growth lowers the marginal product of capital if the savings rate is constant

  14. What stock market returns to expect for the future?

    PubMed

    Diamond, P A

    2000-01-01

    In evaluating proposals for reforming Social Security that involve stock investments, the Office of the Chief Actuary (OCACT) has generally used a 7.0 percent real return for stocks. The 1994-96 Advisory Council specified that OCACT should use that return in making its 75-year projections of investment-based reform proposals. The assumed ultimate real return on Treasury bonds of 3.0 percent implies a long-run equity premium of 4.0 percent. There are two equity-premium concepts: the realized equity premium, which is measured by the actual rates of return; and the required equity premium, which investors expect to receive for being willing to hold available stocks and bonds. Over the past two centuries, the realized premium was 3.5 percent on average, but 5.2 percent for 1926 to 1998. Some critics argue that the 7.0 percent projected stock returns are too high. They base their arguments on recent developments in the capital market, the current high value of the stock market, and the expectation of slower economic growth. Increased use of mutual funds and the decline in their costs suggest a lower required premium, as does the rising fraction of the American public investing in stocks. The size of the decrease is limited, however, because the largest cost savings do not apply to the very wealthy and to large institutional investors, who hold a much larger share of the stock market's total value than do new investors. These trends suggest a lower equity premium for projections than the 5.2 percent of the past 75 years. Also, a declining required premium is likely to imply a temporary increase in the realized premium because a rising willingness to hold stocks tends to increase their price. Therefore, it would be a mistake during a transition period to extrapolate what may be a temporarily high realized return. In the standard (Solow) economic growth model, an assumption of slower long-run growth lowers the marginal product of capital if the savings rate is constant

  15. Integrating Public Perspectives in Sample Return Planning

    NASA Technical Reports Server (NTRS)

    Race, Margaret S.; MacGregor, G.

    2001-01-01

    Planning for extraterrestrial sample returns, whether from Mars or other solar system bodies, must be done in a way that integrates planetary protection concerns with the usual mission technical and scientific considerations. Understanding and addressing legitimate societal concerns about the possible risks of sample return will be a critical part of the public decision making process ahead. This paper presents the results of two studies, one with lay audiences, the other with expert microbiologists, designed to gather information, on attitudes and concerns about sample return risks and planetary protection. Focus group interviews with lay subjects, using generic information about Mars sample return and a preliminary environmental impact assessment, were designed to obtain an indication of how the factual content is perceived and understood by the public. A research survey of microbiologists gathered information on experts' views and attitudes about sample return, risk management approaches and space exploration risks. These findings, combined with earlier research results on risk perception, will be useful in identifying levels of concern and potential conflicts in understanding between experts and the public about sample return risks. The information will be helpful in guiding development of the environmental impact statement and also has applicability to proposals for sample return from other solar system bodies where scientific uncertainty about extraterrestrial life may persist at the time of mission planning.

  16. Mars sample return: The critical next step

    NASA Astrophysics Data System (ADS)

    Clark, Benton C.

    2007-06-01

    Before humans trek the mountains and canyons of Mars, a key event must happen. That vital undertaking will be to fly a roundtrip mission to Mars for acquiring representative surface materials and returning them to Earth. Mars sample return has also been a premier objective of planetary scientists for more than four decades. In the meantime, the Stardust mission has returned dust grains from a comet, and Genesis has collected and returned solar wind. Yet at this time, Mars sample return is no longer an official project in any space agency. Inestimable value would also accrue for engineering the systems needed for future human missions. Sample return from the surface will validate our collective ability to successfully accomplish such a roundtrip to Mars in absence of the ability for end-to-end testing on Earth. Embarking on a historic Mars surface sample return mission will provide the confirming signal that a space program is ready, willing, and capable to achieve the next major engineering challenge for exploration of our solar system. Beginning serious development of the missing critical link, the Mars Ascent Vehicle, will signal the beginning of this undertaking.

  17. Return to sports after shoulder arthroplasty

    PubMed Central

    Johnson, Christine C; Johnson, Daniel J; Liu, Joseph N; Dines, Joshua S; Dines, David M; Gulotta, Lawrence V; Garcia, Grant H

    2016-01-01

    Many patients prioritize the ability to return to sports following shoulder replacement surgeries, including total shoulder arthroplasty (TSA), reverse total shoulder arthroplasty (RTSA), and hemiarthroplasty (HA). While activity levels after hip and knee replacements have been well-established in the literature, studies on this topic in the field of shoulder arthroplasty are relatively limited. A review of the literature regarding athletic activity after shoulder arthroplasty was performed using the PubMed database. All studies relevant to shoulder arthroplasty and return to sport were included. The majority of patients returned to their prior level of activity within six months following TSA, RTSA, and shoulder HA. Noncontact, low demand activities are permitted by most surgeons postoperatively and generally have higher return rates than contact sports or high-demand activities. In some series, patients reported an improvement in their ability to participate in sports following the arthroplasty procedure. The rates of return to sports following TSA (75%-100%) are slightly higher than those reported for HA (67%-76%) and RTSA (75%-85%). Patients undergoing TSA, RTSA, and shoulder HA should be counseled that there is a high probability that they will be able to return to their preoperative activity level within six months postoperatively. TSA has been associated with higher rates of return to sports than RTSA and HA, although this may reflect differences in patient population or surgical indication.

  18. Return to sports after shoulder arthroplasty.

    PubMed

    Johnson, Christine C; Johnson, Daniel J; Liu, Joseph N; Dines, Joshua S; Dines, David M; Gulotta, Lawrence V; Garcia, Grant H

    2016-09-18

    Many patients prioritize the ability to return to sports following shoulder replacement surgeries, including total shoulder arthroplasty (TSA), reverse total shoulder arthroplasty (RTSA), and hemiarthroplasty (HA). While activity levels after hip and knee replacements have been well-established in the literature, studies on this topic in the field of shoulder arthroplasty are relatively limited. A review of the literature regarding athletic activity after shoulder arthroplasty was performed using the PubMed database. All studies relevant to shoulder arthroplasty and return to sport were included. The majority of patients returned to their prior level of activity within six months following TSA, RTSA, and shoulder HA. Noncontact, low demand activities are permitted by most surgeons postoperatively and generally have higher return rates than contact sports or high-demand activities. In some series, patients reported an improvement in their ability to participate in sports following the arthroplasty procedure. The rates of return to sports following TSA (75%-100%) are slightly higher than those reported for HA (67%-76%) and RTSA (75%-85%). Patients undergoing TSA, RTSA, and shoulder HA should be counseled that there is a high probability that they will be able to return to their preoperative activity level within six months postoperatively. TSA has been associated with higher rates of return to sports than RTSA and HA, although this may reflect differences in patient population or surgical indication. PMID:27672564

  19. Reliability, return periods, and risk under nonstationarity

    NASA Astrophysics Data System (ADS)

    Read, Laura K.; Vogel, Richard M.

    2015-08-01

    Water resources design has widely used the average return period as a concept to inform management and communication of the risk of experiencing an exceedance event within a planning horizon. Even though nonstationarity is often apparent, in practice hydrologic design often mistakenly assumes that the probability of exceedance, p, is constant from year to year which leads to an average return period To equal to 1/p; this expression is far more complex under nonstationarity. Even for stationary processes, the common application of an average return period is problematic: it does not account for planning horizon, is an average value that may not be representative of the time to the next flood, and is generally not applied in other areas of water planning. We combine existing theoretical and empirical results from the literature to provide the first general, comprehensive description of the probabilistic behavior of the return period and reliability under nonstationarity. We show that under nonstationarity, the underlying distribution of the return period exhibits a more complex shape than the exponential distribution under stationary conditions. Using a nonstationary lognormal model, we document the increased complexity and challenges associated with planning for future flood events over a planning horizon. We compare application of the average return period with the more common concept of reliability and recommend replacing the average return period with reliability as a more practical way to communicate event likelihood in both stationary and nonstationary contexts.

  20. Return to sports after shoulder arthroplasty

    PubMed Central

    Johnson, Christine C; Johnson, Daniel J; Liu, Joseph N; Dines, Joshua S; Dines, David M; Gulotta, Lawrence V; Garcia, Grant H

    2016-01-01

    Many patients prioritize the ability to return to sports following shoulder replacement surgeries, including total shoulder arthroplasty (TSA), reverse total shoulder arthroplasty (RTSA), and hemiarthroplasty (HA). While activity levels after hip and knee replacements have been well-established in the literature, studies on this topic in the field of shoulder arthroplasty are relatively limited. A review of the literature regarding athletic activity after shoulder arthroplasty was performed using the PubMed database. All studies relevant to shoulder arthroplasty and return to sport were included. The majority of patients returned to their prior level of activity within six months following TSA, RTSA, and shoulder HA. Noncontact, low demand activities are permitted by most surgeons postoperatively and generally have higher return rates than contact sports or high-demand activities. In some series, patients reported an improvement in their ability to participate in sports following the arthroplasty procedure. The rates of return to sports following TSA (75%-100%) are slightly higher than those reported for HA (67%-76%) and RTSA (75%-85%). Patients undergoing TSA, RTSA, and shoulder HA should be counseled that there is a high probability that they will be able to return to their preoperative activity level within six months postoperatively. TSA has been associated with higher rates of return to sports than RTSA and HA, although this may reflect differences in patient population or surgical indication. PMID:27672564

  1. Integrating public perspectives in sample return planning.

    PubMed

    Race, M S; MacGregor, D G

    2000-01-01

    Planning for extraterrestrial sample returns--whether from Mars or other solar system bodies--must be done in a way that integrates planetary protection concerns with the usual mission technical and scientific considerations. Understanding and addressing legitimate societal concerns about the possible risks of sample return will be a critical part of the public decision making process ahead. This paper presents the results of two studies, one with lay audiences, the other with expert microbiologists designed to gather information on attitudes and concerns about sample return risks and planetary protection. Focus group interviews with lay subjects, using generic information about Mars sample return and a preliminary environmental impact assessment, were designed to obtain an indication of how the factual content is perceived and understood by the public. A research survey of microbiologists gathered information on experts' views and attitudes about sample return, risk management approaches and space exploration risks. These findings, combined with earlier research results on risk perception, will be useful in identifying levels of concern and potential conflicts in understanding between experts and the public about sample return risks. The information will be helpful in guiding development of the environmental impact statement and also has applicability to proposals for sample return from other solar system bodies where scientific uncertainty about extraterrestrial life may persist at the time of mission planning. PMID:12038482

  2. Variables Associated With Return to Sport Following Anterior Cruciate Ligament Reconstruction: A Systematic Review

    PubMed Central

    Czuppon, Sylvia; Racette, Brad A.; Klein, Sandra E.; Harris-Hayes, Marcie

    2014-01-01

    Background As one of the purposes of anterior cruciate ligament reconstruction (ACLR) is to return athletes to their pre-injury activity level, it is critical to understand variables influencing return to sport. Associations between return to sport and variables representing knee impairment, function and psychological status have not been well studied in athletes following ACLR. Purpose The purpose of this review is to summarize the literature reporting on variables proposed to be associated with return to sport following anterior cruciate ligament reconstruction. Study Design Systematic Review Methods Medline, Embase, CINAHL and Cochrane databases were searched for articles published before November 2012. Articles included in this review met these criteria: 1) included patients with primary ACLR, 2) reported at least one knee impairment, function or psychological measure, 3) reported a return to sport measure and 4) analyzed the relationship between the measure and return to sport. Results Weak evidence existed in sixteen articles suggesting variables associated with return to sport included higher quadriceps strength, less effusion, less pain, greater tibial rotation, higher Marx Activity score, higher athletic confidence, higher pre-operative knee self-efficacy, lower kinesiophobia and higher pre-operative self-motivation. Conclusion Weak evidence supports an association between knee impairment, functional, and psychological variables and return to sport. Current return to sport guidelines should be updated to reflect all variables associated with return to sport. Utilizing evidence-based return to sport guidelines following ACLR may ensure athletes are physically and psychologically capable of sports participation, which may reduce re-injury rates and the need for subsequent surgery. PMID:24124040

  3. Return to work after knee replacement: a qualitative study of patient experiences

    PubMed Central

    Bardgett, Michelle; Lally, Joanne; Malviya, Ajay; Deehan, David

    2016-01-01

    Objective An increasing number of patients in the working population are undergoing total knee replacement (TKR) for end-stage osteoarthritis. The timing and success of return to work is becoming increasingly important for this group of patients with social and economic implications for patients, employers and society. There is limited understanding of the patient variables that determine the ability to return to work. Our objective was (from the patient's perspective) to gain an insight into the factors influencing return to work following knee replacement. Setting and participants This qualitative study was undertaken in a secondary-care setting in a large teaching hospital in the north of England. Semistructured interviews were carried out with 10 patients regarding their experiences of returning to work following TKR. Outcomes Interviews were transcribed and analysed using a qualitative thematic approach to identify the factors influencing return to work from the patient's perspective. Results Three themes were identified that influenced the process of return to work, from the patient's perspective. These were delays in surgical intervention, limited and often inconsistent advice from healthcare professionals regarding return to work, and finally the absence of rehabilitation to optimise patient's recovery and facilitate return to work. Conclusions There is currently no consistent process to optimise return to work for patients of working age after TKR. The impact of delayed surgical intervention, limited advice regarding return to work, and a lack of work-focused rehabilitation, all contribute to potential delays in successful return to work. There is a need to change the focus of healthcare provision for this cohort of patients, and provide a tailored healthcare intervention to optimise patient outcomes. PMID:26832426

  4. Return to Flying Duties Following Centrifuge or Vibration Exposures

    NASA Technical Reports Server (NTRS)

    Scheuring, Richard A.; Clarke, Jonathan; Jones, Jeffrey A.

    2009-01-01

    Introduction: In an effort to determine the human performance limits for vibration in spacecraft being developed by NASA, astronauts were evaluated during a simulated launch profile in a centrifuge/vibration environment and separate vibration-only simulation. Current USAF and Army standards for return to flight following centrifuge exposures require 12-24 hours to pass before a crewmember may return to flying duties. There are no standards on vibration exposures and return to flying duties. Based on direct observation and provocative neurological testing of the astronauts, a new standard for return to flying duties following centrifuge and/or vibration exposures was established. Methods: 13 astronaut participants were exposed to simulated launch profiles in a + 3.5 Gx bias centrifuge/vibration environment and separately on a vibration table at the NASA-Ames Research Center. Each subject had complete neurological evaluations pre- and post-exposure for the centrifuge/vibration runs with the NASA neurological function rating scale (NFRS). Subjects who participated in the vibration-only exposures had video oculography performed with provocative maneuvers in addition to the NFRS. NFRS evaluations occurred immediately following each exposure and at 1 hour post-run. Astronauts who remained symptomatic at 1 hour had repeat NFRS performed at 1 hour intervals until the crewmember was asymptomatic. Results: Astronauts in the centrifuge/vibration study averaged a 3-5 point increase in NFRS scores immediately following exposure but returned to baseline 3 hours post-run. Subjects exposed to the vibration-only simulation had a 1-3 point increase following exposure and returned to baseline within 1-2 hours. Pre- and post- vibration exposure video oculography did not reveal any persistent ocular findings with provocative testing 1 hour post-exposure. Discussion: Based on direct observations and objective measurement of neurological function in astronauts following simulated launch

  5. Return to Play Following Hip Arthroscopy.

    PubMed

    Lee, Simon; Kuhn, Andrew; Draovitch, Pete; Bedi, Asheesh

    2016-10-01

    Femoroacetabular impingement may be particularly disabling to the high-demand athlete, especially those with significant cutting and pivoting requirements. If nonoperative treatment fails to adequately alleviate symptoms or sufficiently restore function in the athlete, hip arthroscopy can lead to improved pain, improved range of motion, and high rates of return to play with proper postoperative rehabilitation. The rate of return to previous level of competition is also high with accurate diagnosis and well-executed correction of deformity. A clear understanding of the etiology, diagnosis, management, and outcomes is essential for clinicians to optimally help patients to return to play.

  6. Flexible Momentum Compaction Return Arcs for RLAs

    SciTech Connect

    Trbojevic, Dejan; Bogacz, Alex; Bogacz, Slawomir; Bogacz, Alex; Bogacz, Slawomir; Johnson, Rolland; Popovic, Milorad

    2008-07-01

    Neutrino Factories and Muon Colliders require rapid acceleration of short-lived muons to multi-GeV and TeV energies. A Recirculating Linear Accelerator (RLA) that uses a single Linac and teardrop return arcs can provide exceptionally fast and economical acceleration to the extent that the focusing range of the RLA quadrupoles allows each muon to pass several times through each high-gradient cavity and the cost of the return arcs is appropriate. Flexible Momentum Compaction (FMC) lattice designs for the teardrop return arcs provide sufficient momentum acceptance to allow multiple passes of each sign of muon in one string of magnets to improve cost-effectiveness.

  7. Return to Play Following Hip Arthroscopy.

    PubMed

    Lee, Simon; Kuhn, Andrew; Draovitch, Pete; Bedi, Asheesh

    2016-10-01

    Femoroacetabular impingement may be particularly disabling to the high-demand athlete, especially those with significant cutting and pivoting requirements. If nonoperative treatment fails to adequately alleviate symptoms or sufficiently restore function in the athlete, hip arthroscopy can lead to improved pain, improved range of motion, and high rates of return to play with proper postoperative rehabilitation. The rate of return to previous level of competition is also high with accurate diagnosis and well-executed correction of deformity. A clear understanding of the etiology, diagnosis, management, and outcomes is essential for clinicians to optimally help patients to return to play. PMID:27543404

  8. Technology for return of planetary samples

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Technological requirements of a planetary return sample mission were studied. The state-of-the-art for problems unique to this class of missions was assessed and technological gaps were identified. The problem areas where significant advancement of the state-of-the-art is required are: life support for the exobiota during the return trip and within the Planetary Receiving Laboratory (PRL); biohazard assessment and control technology; and quarantine qualified handling and experimentation methods and equipment for studying the returned sample in the PRL. Concepts for solving these problems are discussed.

  9. GEOS-1 laser pulse return shape analysis

    NASA Technical Reports Server (NTRS)

    Felsentreger, T. L.

    1972-01-01

    An attempt has been made to predict the shape of the laser return pulse from the corner cube retroreflectors on the GEOS-1 spacecraft. The study is geometrical only, and neglects factors such as optical interference, atmospheric perturbations, etc. A function giving the intensity of the return signal at any given time has been derived. In addition, figures are given which show the predicted return pulse shape as a function of time, the angle between the beam and the spin axis, and an in-plane angle (designating the orientation of the intersection of the planar waves with the plane of the corner cubes).

  10. FE Simulation of SMA Seal for Mars Sample Return

    NASA Technical Reports Server (NTRS)

    Bao, Xiaoqi; Younse, Paulo; Bhandari, Pradeep

    2013-01-01

    Several NASA rovers and landers have been on Mars and performed successful in-situ exploration. Returning Martian samples to Earth for extensive analysis is of great interest to the planetary science community. Current Mars sample return architecture would require leaving the acquired samples on Mars for years before being retrieved by subsequent mission. Each sample would be sealed securely to keep its integrity. A reliable seal technique that does not affect the integrity of the samples and uses a simple low-mass tool is required. The shape memory alloy (SMA) seal technique is a promising candidate. A study of the thermal performances of several primary designs of a SMA seal for sample tubes by finite element (FE) simulation are presented in this paper. The results show sealing the sample tube by SMA plugs and controlling the sample temperature below the allowed temperature level are feasible.

  11. An Integrated Tool for System Analysis of Sample Return Vehicles

    NASA Technical Reports Server (NTRS)

    Samareh, Jamshid A.; Maddock, Robert W.; Winski, Richard G.

    2012-01-01

    The next important step in space exploration is the return of sample materials from extraterrestrial locations to Earth for analysis. Most mission concepts that return sample material to Earth share one common element: an Earth entry vehicle. The analysis and design of entry vehicles is multidisciplinary in nature, requiring the application of mass sizing, flight mechanics, aerodynamics, aerothermodynamics, thermal analysis, structural analysis, and impact analysis tools. Integration of a multidisciplinary problem is a challenging task; the execution process and data transfer among disciplines should be automated and consistent. This paper describes an integrated analysis tool for the design and sizing of an Earth entry vehicle. The current tool includes the following disciplines: mass sizing, flight mechanics, aerodynamics, aerothermodynamics, and impact analysis tools. Python and Java languages are used for integration. Results are presented and compared with the results from previous studies.

  12. Canadian Return-for-Service Bursary Programs for Medical Trainees

    PubMed Central

    Neufeld, Shelley-May; Mathews, Maria

    2012-01-01

    Return-for-service (RFS) bursaries for physicians have been in use in Canada for many years, yet little is known about the programs that are currently available or the features of the RFS bursary that are particularly important to potential participants. Using document analysis, we found that RFS programs were available in nearly all provinces and territories. A survey of medical trainees from Memorial University showed that the most important factors in their decision to accept an RFS bursary were the location they would be required to work, the monetary value of the bursary and the return time required to repay the service commitment. RFS bursaries fund trainees who plan to remain in the province rather than attract new trainees to the province. These bursaries may nonetheless serve to reinforce the decisions of physicians who are predisposed to work in an underserved community. PMID:23634165

  13. Flight status of robotic asteroid sample return mission Hayabusa2

    NASA Astrophysics Data System (ADS)

    Tsuda, Yuichi; Nakazawa, Satoru; Kushiki, Kenichi; Yoshikawa, Makoto; Kuninaka, Hitoshi; Watanabe, Seiichiro

    2016-10-01

    The Japan Aerospace Exploration Agency launched the asteroid sample return spacecraft "Hayabusa2" on December 3, 2014. Hayabusa2 will reach the C-type asteroid 1999 JU3 in 2018, and return back to the Earth in 2020. Sample collections from three sites, four surface rovers deployment and a 4 MJ-class kinetic impact crater generation are planned in the 1.5 years of the asteroid-proximity operation. The mission objective of Hayabusa2 has three aspects, science, engineering and exploration, all of which would be expanded by the successful round-trip journey. This paper describes the outline of the Hayabusa2 mission and the current flight status after the seven month of the interplanetary cruise.

  14. 27 CFR 25.164 - Quarterly and semimonthly returns.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL BEER Tax on Beer Preparation and Remittance of Tax Returns... on beer (unless prepaid) by return on Form 5000.24. The brewer shall file Form 5000.24 as a return... file a return on Form 5000.24 for each return period even though no beer was removed for consumption...

  15. 27 CFR 25.164 - Quarterly and semimonthly returns.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL BEER Tax on Beer Preparation and Remittance of Tax Returns... on beer (unless prepaid) by return on Form 5000.24. The brewer shall file Form 5000.24 as a return... file a return on Form 5000.24 for each return period even though no beer was removed for consumption...

  16. 27 CFR 25.164 - Quarterly and semimonthly returns.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Tax on Beer Preparation and Remittance of Tax Returns... on beer (unless prepaid) by return on Form 5000.24. The brewer shall file Form 5000.24 as a return... file a return on Form 5000.24 for each return period even though no beer was removed for consumption...

  17. 26 CFR 301.6018-1 - Estate tax returns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Estate tax returns. 301.6018-1 Section 301.6018... ADMINISTRATION PROCEDURE AND ADMINISTRATION Information and Returns Returns and Records § 301.6018-1 Estate tax returns. For provisions relating to requirement of estate tax returns, see §§ 20.6018-1 to...

  18. 26 CFR 301.6019-1 - Gift tax returns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Gift tax returns. 301.6019-1 Section 301.6019-1... ADMINISTRATION PROCEDURE AND ADMINISTRATION Information and Returns Returns and Records § 301.6019-1 Gift tax returns. For provisions relating to requirement of gift tax returns, see §§ 25.6019-1 to...

  19. 26 CFR 301.7701-15 - Tax return preparer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... considered a tax return preparer of a partner's or a shareholder's return if the entry or entries on the partnership or small business corporation return reportable on the partner's or shareholder's return constitute a substantial portion of the partner's or shareholder's return. (iv) Examples. The provisions...

  20. Insulate Steam Distribution and Condensate Return Lines

    SciTech Connect

    Not Available

    2006-01-01

    This revised ITP tip sheet on insulating steam distribution and condensate return lines provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

  1. Mercury Sample Return using Solar Sails

    NASA Technical Reports Server (NTRS)

    Montgomery, Edward E.; Young, Roy M.; Adams, Charles L.

    2006-01-01

    A conventional Mercury sample return mission requires significant launch mass due to the large deltav required for the outbound and return trips, and the large mass of a planetary lander and ascent vehicle. Solar sailing can be used to reduce lander mass allocation by delivering the lander to a low, thermally safe orbit close to the terminator. Propellant mass is not an issue for solar sails so a sample can be returned relatively easily, without resorting to lengthy, multiple gravity assists. The initial Mercury sample return studies reported here were conducted under ESA contract ESTEC/16534/02/NL/NR, PI Colin McInnes, Technical Officer Peter Falkner. Updated solar sail capabilities were developed under the Ground System Demonstration program, funded by the NASA's In-Space Propulsion Technology (ISPT) Program.

  2. Spectral characteristics of the MST radar returns

    NASA Technical Reports Server (NTRS)

    Rastogi, P. K.

    1983-01-01

    The salient features of the spectra of atmospheric returns due to random refractivity fluctuations in the Mesosphere, Stratosphere, Troposphere MST region are reviewed. The nonhomogeneous layered structure of turbulence is often evident as multiple peaks in the spectra. The time evolution of the spectra observed with a fine Doppler resolution provides evidence for thin regions of turbulence associated with gravity waves and shear instabilities. Embedded in these regions are horizontally extended refractivity structures that produce enhanced returns due to specular reflections. It is conceivable that some enhanced returns arise due to anisotropy of small scale refractivity structures. Observed correlations of the strength of the returns with their Doppler spread, wind shears, and winds provide insights into the physical mechanisms that produce turbulence.

  3. STS-26: The return to flight

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The major activities leading up to the return to flight of the Space Shuttles are summarized. Major orbiter modifications and solid rocket motor redesign are described. Shuttle payloads are discussed briefly. Also provided are the biographies of the crew.

  4. African return migration: past, present, and future.

    PubMed

    Gregory, J W; Piche, V

    1983-01-01

    The various forms of return migration in Africa in the twentieth century are first examined, and the factors affecting them are discussed. The authors then consider the value of the household, rather than the individual, as the unit of analysis. Return migration is also analyzed in terms of the linking role it plays between Africa's capitalist and non-capitalist countries. Finally, alternative future trends in the circulatory flow of African labor are considered.

  5. Hayabusa: Navigation Challenges for Earth Return

    NASA Technical Reports Server (NTRS)

    Haw, Robert J.; Bhaskaran, S.; Strauss, W.; Sklyanskiy, E.; Graat, E. J.; Smith, J. J.; Menom, P.; Ardalan, S.; Ballard, C.; Williams, P.; Kawaguchi, J.; Makoto, Y.; Ohnishi, T.

    2011-01-01

    Hayabusa was a JAXA sample-return mission to Itokawa navigated, in part, by JPL personnel. Hayabusa survived several near mission-ending failures at Itokawa yet returned to Earth with an asteroid regolith sample on June 13, 2010. This paper describes NASA/JPL's participation in the Hayabusa mission during the last 100 days of its mission, wherein JPL provided tracking data and orbit determination, plus verification of maneuver design and entry, descent and landing.

  6. Comet nucleus and asteroid sample return missions

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Three Advanced Design Projects have been completed this academic year at Penn State. At the beginning of the fall semester the students were organized into eight groups and given their choice of either a comet nucleus or an asteroid sample return mission. Once a mission had been chosen, the students developed conceptual designs. These were evaluated at the end of the fall semester and combined into three separate mission plans, including a comet nucleus same return (CNSR), a single asteroid sample return (SASR), and a multiple asteroid sample return (MASR). To facilitate the work required for each mission, the class was reorganized in the spring semester by combining groups to form three mission teams. An integration team consisting of two members from each group was formed for each mission so that communication and information exchange would be easier among the groups. The types of projects designed by the students evolved from numerous discussions with Penn State faculty and mission planners at the Johnson Space Center Human/Robotic Spacecraft Office. Robotic sample return missions are widely considered valuable precursors to manned missions in that they can provide details about a site's environment and scientific value. For example, a sample return from an asteroid might reveal valuable resources that, once mined, could be utilized for propulsion. These missions are also more adaptable when considering the risk to humans visiting unknown and potentially dangerous locations, such as a comet nucleus.

  7. Integrating public perspectives in sample return planning

    NASA Astrophysics Data System (ADS)

    Race, Margaret S.; MacGregor, Donald G.

    Planning for extraterrestrial sample returns— whether from Mars or other solar system bodies— must be done in a way that integrates planetary protection concerns with the usual mission technical and scientific considerations. Understanding and addressing legitimate societal concerns about the possible risks of sample return will be a critical part of the public decision making process ahead. This paper presents the results of two studies, one with lay audiences, the other with expert microbiologists designed to gather information on attitudes and concerns about sample return risks and planetary protection. Focus group interviews with lay subjects, using generic information about Mars sample return and a preliminary environmental impact assessment, were designed to obtain an indication of how the factual content is perceived and understood by the public. A research survey of microbiologists gathered information on experts' views and attitudes about sample return, risk management approaches and space exploration risks. These findings, combined with earlier research results on risk perception, will be useful in identifying levels of concern and potential conflicts in understanding between experts and the public about sample return risks. The information will be helpful in guiding development of the environmental impact statement and also has applicability to proposals for sample return from other solar system bodies where scientific uncertainty about extraterrestrial life may persist at the time of mission planning.

  8. Comet nucleus and asteroid sample return missions

    NASA Astrophysics Data System (ADS)

    1992-06-01

    Three Advanced Design Projects have been completed this academic year at Penn State. At the beginning of the fall semester the students were organized into eight groups and given their choice of either a comet nucleus or an asteroid sample return mission. Once a mission had been chosen, the students developed conceptual designs. These were evaluated at the end of the fall semester and combined into three separate mission plans, including a comet nucleus same return (CNSR), a single asteroid sample return (SASR), and a multiple asteroid sample return (MASR). To facilitate the work required for each mission, the class was reorganized in the spring semester by combining groups to form three mission teams. An integration team consisting of two members from each group was formed for each mission so that communication and information exchange would be easier among the groups. The types of projects designed by the students evolved from numerous discussions with Penn State faculty and mission planners at the Johnson Space Center Human/Robotic Spacecraft Office. Robotic sample return missions are widely considered valuable precursors to manned missions in that they can provide details about a site's environment and scientific value. For example, a sample return from an asteroid might reveal valuable resources that, once mined, could be utilized for propulsion. These missions are also more adaptable when considering the risk to humans visiting unknown and potentially dangerous locations, such as a comet nucleus.

  9. 26 CFR 301.6103(h)(2)-1 - Disclosure of returns and return information (including taxpayer return information) to and by...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... administration. 301.6103(h)(2)-1 Section 301.6103(h)(2)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... Returns Returns and Records § 301.6103(h)(2)-1 Disclosure of returns and return information (including..., shall, to the extent provided by section 6103(h)(2) (A), (B), and (C) and subject to the requirements...

  10. 26 CFR 1.6033-4 - Required use of magnetic media for returns by organizations required to file returns under...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 13 2010-04-01 2010-04-01 false Required use of magnetic media for returns by... Returns § 1.6033-4 Required use of magnetic media for returns by organizations required to file returns under section 6033. The return of an organization that is required to be filed on magnetic media...

  11. 26 CFR 1.6033-4 - Required use of magnetic media for returns by organizations required to file returns under...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 13 2012-04-01 2012-04-01 false Required use of magnetic media for returns by...) Information Returns § 1.6033-4 Required use of magnetic media for returns by organizations required to file returns under section 6033. The return of an organization that is required to be filed on magnetic...

  12. 26 CFR 1.6033-4 - Required use of magnetic media for returns by organizations required to file returns under...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 13 2013-04-01 2013-04-01 false Required use of magnetic media for returns by...) Information Returns § 1.6033-4 Required use of magnetic media for returns by organizations required to file returns under section 6033. The return of an organization that is required to be filed on magnetic...

  13. 26 CFR 1.6033-4 - Required use of magnetic media for returns by organizations required to file returns under...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 13 2011-04-01 2011-04-01 false Required use of magnetic media for returns by...) Information Returns § 1.6033-4 Required use of magnetic media for returns by organizations required to file returns under section 6033. The return of an organization that is required to be filed on magnetic...

  14. 26 CFR 301.6011-7 - Specified tax return preparers required to file individual income tax returns using magnetic media.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... individual income tax returns using magnetic media. 301.6011-7 Section 301.6011-7 Internal Revenue INTERNAL... to file individual income tax returns using magnetic media. (a) Definitions. (1) Magnetic media. For...) Individual income tax return. The term individual income tax return means any return of tax imposed...

  15. 49 CFR 236.720 - Circuit, common return.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Circuit, common return. A term applied where one wire is used for the return of more than one electric circuit. ... 49 Transportation 4 2013-10-01 2013-10-01 false Circuit, common return. 236.720 Section...

  16. Natives, the Foreign-Born and High School Equivalents: New Evidence on the Returns to the GED. Discussion Paper.

    ERIC Educational Resources Information Center

    Clark, Melissa A.; Jaeger, David A.

    This paper explores the labor market returns to the General Education Development exam, or GED. Using new data from the Current Population Survey, it examines how the return to the GED varies between U.S. natives and the foreign-born. It finds that foreign-born men who hold a GED but received all of their formal schooling outside of the United…

  17. The propagation speed of a positive lightning return stroke

    NASA Technical Reports Server (NTRS)

    Idone, Vincent P.; Orville, Richard E.; Mach, Douglas M.; Rust, W. David

    1987-01-01

    The first direct determination of the propagation speed of a lightning return stroke lowering positive charge to ground has been made. This stroke was the third of eight otherwise negative strokes in a triggered lightning flash initiated at the Kennedy Space Center, FL. Two independent optical systems, one photographic and the other photoelectric, yielded common recordings for the third and fourth strokes; the respective two-dimensional return stroke propagation speeds were 1.0 vs 0.93 x 10 to the 8th m/s for the positive (third) stroke and 1.0 vs 1.0 x 10 to the 8th m/s for the fourth stroke. Using fast electric-field data, the positive stroke peak current was estimated to be 21 kA. Photoelectric data only yielded propagation speeds of 1.4, 1.6, 1.2, 1.3, 1.0 and 0.90 x 10 to the 8th m/s for the first, second and fifth through eighth return strokes, respectively.

  18. Sample return from the lunar South Pole-Aitken Basin

    NASA Astrophysics Data System (ADS)

    Duke, M. B.

    2003-06-01

    Automated sample return missions to the South Pole — Aitken Basin on the lunar far side are proposed as the best means of addressing major problems concerning the early impact history of the inner solar system, the nature of very large impact events, and the early differentiation of rocky planets. The opportunity to propose such missions has been opened by the recommendations of the U. S. National Research Council's Decadal Study of Solar System Exploration and the creation by NASA of the New Frontiers Program, which will support missions of intermediate cost, between the Discovery Program and large missions. A proposal for a South Pole — Aitken Basin Sample Return Mission was submitted to the Discovery Program in 2000, but not fimded. The New Frontiers Program, with a somewhat less stringent budget constraint, should allow several of the potential risks associated with the Discovery proposal to be addressed, including scientific and programmatic risks. A principal goal of current mission studies is to determine whether, within the New Frontiers Program's cost constraints, two separate samples could be collected from areas of different post-Basin geological history. If accepted by the New Frontiers Program, a South Pole — Aitken Basin sample return mission could be flown as early as 2008-2009.

  19. Groundbreaking Mars Sample Return for Science and Human Exploration

    NASA Technical Reports Server (NTRS)

    Cohen, Barbara; Draper, David; Eppler, Dean; Treiman, Allan

    2012-01-01

    Partnerships between science and human exploration have recent heritage for the Moon (Lunar Precursor Robotics Program, LPRP) and nearearth objects (Exploration Precursor Robotics Program, xPRP). Both programs spent appreciable time and effort determining measurements needed or desired before human missions to these destinations. These measurements may be crucial to human health or spacecraft design, or may be desired to better optimize systems designs such as spacesuits or operations. Both LPRP and xPRP recommended measurements from orbit, by landed missions and by sample return. LPRP conducted the Lunar Reconnaissance Orbiter (LRO) and Lunar Crater Observation and Sensing Satellite (LCROSS) missions, providing high-resolution visible imagery, surface and subsurface temperatures, global topography, mapping of possible water ice deposits, and the biological effects of radiation [1]. LPRP also initiated a landed mission to provide dust and regolith properties, local lighting conditions, assessment of resources, and demonstration of precision landing [2]. This mission was canceled in 2006 due to funding shortfalls. For the Moon, adequate samples of rocks and regolith were returned by the Apollo and Luna programs to conduct needed investigations. Many near-earth asteroids (NEAs) have been observed from the Earth and several have been more extensively characterized by close-flying missions and landings (NEAR, Hayabusa, Rosetta). The current Joint Robotic Precursor Activity program is considering activities such as partnering with the New Frontiers mission OSIRIS-Rex to visit a NEA and return a sample to the Earth. However, a strong consensus of the NEO User Team within xPRP was that a dedicated mission to the asteroid targeted by humans is required [3], ideally including regolith sample return for more extensive characterization and testing on the Earth.

  20. In-line beam current monitor

    DOEpatents

    Ekdahl, C.A. Jr.; Frost, C.A.

    1984-11-13

    An intense relativistic electron beam current monitor for a gas neutralized beam transport line includes a first foil for conducting plasma current to the wall where it is measured as it traverses an inductive loop formed by a cavity in the wall. An insulator foil separates the first foil from a second conducting foil which returns the current to the plasma environment.

  1. In-line beam current monitor

    DOEpatents

    Ekdahl, Jr., Carl A.; Frost, Charles A.

    1986-01-01

    An intense relativistic electron beam current monitor for a gas neutralized beam transport line includes a first foil for conducting plasma current to the wall where it is measured as it traverses an inductive loop formed by a cavity in the wall. An insulator foil separates the first foil from a second conducting foil which returns the current to the plasma environment.

  2. 26 CFR 301.6103(n)-1 - Disclosure of returns and return information in connection with written contracts or agreements...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... employees of a contractor for purposes of programming, maintaining, repairing, or testing computer equipment... reproduction of returns or return information, the programming, maintenance, repair, or testing of equipment...

  3. 26 CFR 301.6103(n)-1 - Disclosure of returns and return information in connection with written contracts or agreements...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... employees of a contractor for purposes of programming, maintaining, repairing, or testing computer equipment... reproduction of returns or return information, the programming, maintenance, repair, or testing of equipment...

  4. 26 CFR 301.6103(n)-1 - Disclosure of returns and return information in connection with written contracts or agreements...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... employees of a contractor for purposes of programming, maintaining, repairing, or testing computer equipment... reproduction of returns or return information, the programming, maintenance, repair, or testing of equipment...

  5. 26 CFR 301.6103(n)-1 - Disclosure of returns and return information in connection with written contracts or agreements...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... employees of a contractor for purposes of programming, maintaining, repairing, or testing computer equipment... reproduction of returns or return information, the programming, maintenance, repair, or testing of equipment...

  6. 76 FR 31543 - Disclosure of Returns and Return Information to Designee of Taxpayer; Hearing Cancellation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    ... Internal Revenue Service 26 CFR Part 301 RIN 1545-BJ19 Disclosure of Returns and Return Information to Designee of Taxpayer; Hearing Cancellation AGENCY: Internal Revenue Service (IRS), Treasury. ACTION... (76 FR 14827) announced that a public hearing was scheduled for June 9, 2011, at 10 a.m. in the...

  7. Where Are "Women Returners" Returning From? Deconstructing Domestication in the Context of Lifelong Learning.

    ERIC Educational Resources Information Center

    Clarke, Julia

    The question of where "women returners" to education are returning from was examined through an exploration of the life histories of 18 women in southern England. The study focused on the biographies of women who regarded themselves as primarily responsible for the care of others and yet whose aspirations involved some form of continuing…

  8. Return Migration: A Study of College Graduates Returning to Rural U.S. Homes

    ERIC Educational Resources Information Center

    Mahoney, Elizabeth D.

    2009-01-01

    The purpose of this study is to explore perceptions of return migration experiences and gain knowledge from rural residents who have left to obtain a college education and start careers in non-rural areas, and who then returned to their rural hometowns with the social and economic benefits of a college education, and other valuable resources. This…

  9. 27 CFR 479.151 - Failure to make returns: Substitute returns.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Failure to make returns: Substitute returns. 479.151 Section 479.151 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS,...

  10. 27 CFR 479.151 - Failure to make returns: Substitute returns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Failure to make returns: Substitute returns. 479.151 Section 479.151 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS,...

  11. 27 CFR 479.151 - Failure to make returns: Substitute returns.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Failure to make returns: Substitute returns. 479.151 Section 479.151 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS,...

  12. 27 CFR 479.151 - Failure to make returns: Substitute returns.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Failure to make returns: Substitute returns. 479.151 Section 479.151 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS,...

  13. 27 CFR 479.151 - Failure to make returns: Substitute returns.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Failure to make returns: Substitute returns. 479.151 Section 479.151 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS,...

  14. SOCCER: Comet Coma Sample Return Mission

    NASA Technical Reports Server (NTRS)

    Albee, A. L.; Uesugi, K. T.; Tsou, Peter

    1994-01-01

    Comets, being considered the most primitive bodies in the solar system, command the highest priority among solar system objects for studying solar nebula evolution and the evolution of life through biogenic elements and compounds. Sample Of Comet Coma Earth Return (SOCCER), a joint effort between NASA and the Institute of Space and Astronautical Science (ISAS) in Japan, has two primary science objectives: (1) the imaging of the comet nucleus and (2) the return to Earth of samples of volatile species and intact dust. This effort makes use of the unique strengths and capabilities of both countries in realizing this important quest for the return of samples from a comet. This paper presents an overview of SOCCER's science payloads, engineering flight system, and its mission operations.

  15. Ethnic return migration: an Estonian case.

    PubMed

    Kulu, H

    1998-01-01

    "This article examines return migration during the post World War 2 period of descendants of Estonians who emigrated to Russia at the end of the nineteenth and at the beginning of the twentieth century" The focus is on changing migration patterns over time. "The behavioural norm of Estonians born in the 1910s-1920s has been return migration to Estonia, while the migration behaviour of the 1930s-1940s and the 1950s-1960s generations can be characterized by urbanization in West Siberia. The results give reason to assume that ethnic return migration over a long period depends neither directly nor indirectly on momentary environmental changes, but rather on changes in people's values, habits, identity etc., which in the case of an ethnic minority living outside its historical homeland may be followed generation by generation." (EXCERPT)

  16. Earth Entry Vehicle for Mars Sample Return

    NASA Technical Reports Server (NTRS)

    Mitcheltree, R. A.; Braun, R. D.; Hughes. S. J.; Simonsen, L. C.

    2000-01-01

    The driving requirement for design of a Mars Sample return mission is assuring containment of the returned samples. The impact of this requirement on developmental costs, mass allocation, and design approach of the Earth Entry Vehicle is significant. A simple Earth entry vehicle is described which can meet these requirements and safely transport the Mars Sample Return mission's sample through the Earth's atmosphere to a recoverable location on the surface. Detailed analysis and test are combined with probabilistic risk assessment to design this entirely passive concept that circumvents the potential failure modes of a parachute terminal descent system. The design also possesses features that mitigate other risks during the entry, descent, landing and recovery phases. The results of a full-scale drop test are summarized.

  17. Stakeholder views on returning research results.

    PubMed

    Haga, Susanne B; Zhao, Jennifer Q

    2013-01-01

    While the disclosure of research findings is relevant to all types of biomedical research, it has garnered particular attention with respect to genetics and genomics research due to some of the unique aspects of the data and the high public profile of the field. In this chapter, we review the attitudes of stakeholders (research participants, policymakers, and researchers) to define areas of consensus regarding the issue of returning research results across and within groups. In addition to stakeholder attitudes about obligations and interest in research results, other major related issues related to returning research results, such as informed consent, communication of research results, and cost, are discussed. Given the consensus between stakeholders to return summary reports of a study's outcomes and individual research results of clinical significance, we conclude that the time has come to encourage, if not require, researchers to consider these issues in the developmental planning stages of a project and to plan and budget accordingly. PMID:24262096

  18. Simulating Line-Of-Sight Radar Returns

    NASA Technical Reports Server (NTRS)

    Moran, F. J.; Phillips, J. D.

    1988-01-01

    Computational method developed to model return signals of ground-mapping radar system for use in simulations where terrain is polygonal form commonly used with computer-generated imagery (CGI). Approach involves fast rejection of polygons not visible to radar return. Technique used to determine which objects in scene visible from specified vantage point and also to determine movements of robot arms avoiding obstacles. Test circles used in algorithm quickly rejects terrain features not traversed by radar line of sight. If circle does not cross line of sight, then all mountains in it rejected.

  19. Return-volatility correlation in financial dynamics

    NASA Astrophysics Data System (ADS)

    Qiu, T.; Zheng, B.; Ren, F.; Trimper, S.

    2006-06-01

    We investigate the return-volatility correlation both local and nonlocal in time with daily and minutely data of the German DAX and Chinese indices, and observe a leverage effect for the German DAX, while an antileverage effect for the Chinese indices. In the negative time direction, i.e., for the volatility-return correlation, an antileverage effect nonlocal in time is detected for both the German DAX and Chinese indices, although the duplicate local in time does not exist. A retarded volatility model may describe the asymmetric properties of the financial indices in the positive time direction.

  20. Horizontal fields generated by return strokes

    NASA Technical Reports Server (NTRS)

    Cooray, Vernon

    1991-01-01

    Horizontal fields generated by return strokes play an important role in the interaction of lightning generated electric fields with power lines. In many of the recent investigations on the interaction of lightning electromagnetic fields with power lines, the horizontal field was calculated by employing the expression for the tilt of the electric field of a plane wave propagating over finitely conducting earth. The method is suitable for calculating horizontal fields generated by return strokes at distances as close as 200m. At these close ranges, the use of the wavetilt expression can cause large errors.

  1. Geometrical compression of lidar return signals.

    PubMed

    Harms, J; Lahmann, W; Weitkamp, C

    1978-04-01

    The dynamic range of lidar return signals has been calculated for coaxial transmitter-receiver geometries via the spatial distribution of irradiance in the detector plane as a function of distance z. It is shown that the z(-2)dependence from the lidar equation can be converted to almost constant signal amplitude for distances up to 3 km by suitable and realistic choice of the geometric parameters. On the other hand, no signal degradation with respect to the lidar equation occurs at large distances. This geometrical compression of lidar return signal amplitudes is rated superior to electronic compression methods such as gain switching or logarithmic amplification. PMID:20197946

  2. Deciphering Martian climatic history using returned samples

    NASA Technical Reports Server (NTRS)

    Paige, D. A.; Krieger, D. B.; Brigham, C. A.

    1988-01-01

    By necessity, a Mars sample return mission must sample the upper few meters of the Martian surface. This material was subjected to a wide variety of physical processes. Presently, the most important processes are believed to be wind-driven erosion and deposition, and water ice accumulation at higher latitudes. A sample return mission represents an opportunity to better understand and quantify these important geological processes. By obtaining sample cores at key locations, it may be possible to interpret much of recent Martian climatic history.

  3. [The visit prior to returning home].

    PubMed

    Blond, Héléne

    2015-01-01

    Towards the end of a hospital stay, the question of the elderly person's future is raised. Depending on the situation, a return home, follow-up and rehabilitation care or admission to a nursing home may be envisaged. When a return home is considered, the preparatory home visit is important, both for the nursing team as well as for the patient and their family, as it enables the feasibility and suitability of the project to be assessed. Often coming down to an assessment regarding accessibility, it also makes the patient and their family think about the capacities of the hospitalised person and their future day-to-day reality.

  4. Multiple Approaches to Down Sizing of the Lunar Sample Return Collection

    NASA Technical Reports Server (NTRS)

    Lofgren, Gary E.; Horz, F.

    2010-01-01

    Future Lunar missions are planned for at least 7 days, significantly longer than the 3 days of the later Apollo missions. The last of those missions, A-17, returned 111 kg of samples plus another 20 kg of containers. The current Constellation program requirements for return weight for science is 100 kg with the hope of raising that limit to near 250 kg including containers and other non-geological materials. The estimated return weight for rock and soil samples will, at best, be about 175 kg. One method proposed to accomplish down-sizing of the collection is the use of a Geo-Lab in the lunar habitat to complete a preliminary examination of selected samples and facilitate prioritizing the return samples.

  5. 26 CFR 1.338-10 - Filing of returns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... otherwise included in consolidated return of selling group—(i) General rule. If the selling group files a... the selling group's consolidated return. A deemed sale return includes a combined deemed sale return... that old target's taxable year of the sale and the consolidated year of the selling group that...

  6. COSTS AND RETURNS OF TECHNICAL EDUCATION, A PILOT STUDY.

    ERIC Educational Resources Information Center

    CARROLL, ADGER B.; IHNEN, LOREN A.

    THE OBJECTIVES OF THIS STUDY WERE (1) TO OBTAIN ESTIMATES OF COSTS AND RETURNS OF TECHNICAL EDUCATION, (2) TO COMPUTE SOCIAL AND PRIVATE RATES OF RETURN ON INVESTMENTS IN TECHNICAL EDUCATION, AND (3) TO COMPARE THESE WITH ESTIMATES OF THE RATE OF RETURN ON GENERAL EDUCATION AND INVESTMENTS IN TANGIBLE CAPITAL. COSTS AND RETURNS WERE MEASURED BY…

  7. 26 CFR 1.6013-1 - Joint returns.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 13 2011-04-01 2011-04-01 false Joint returns. 1.6013-1 Section 1.6013-1...) INCOME TAXES (CONTINUED) Tax Returns Or Statements § 1.6013-1 Joint returns. (a) In general. (1) A husband and wife may elect to make a joint return under section 6013(a) even though one of the spouses...

  8. 26 CFR 1.6013-1 - Joint returns.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 13 2012-04-01 2012-04-01 false Joint returns. 1.6013-1 Section 1.6013-1...) INCOME TAXES (CONTINUED) Tax Returns Or Statements § 1.6013-1 Joint returns. (a) In general. (1) A husband and wife may elect to make a joint return under section 6013(a) even though one of the spouses...

  9. 26 CFR 1.6013-1 - Joint returns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 13 2010-04-01 2010-04-01 false Joint returns. 1.6013-1 Section 1.6013-1...) INCOME TAXES Tax Returns Or Statements § 1.6013-1 Joint returns. (a) In general. (1) A husband and wife may elect to make a joint return under section 6013(a) even though one of the spouses has no...

  10. 26 CFR 1.6013-1 - Joint returns.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 13 2013-04-01 2013-04-01 false Joint returns. 1.6013-1 Section 1.6013-1...) INCOME TAXES (CONTINUED) Tax Returns Or Statements § 1.6013-1 Joint returns. (a) In general. (1) A husband and wife may elect to make a joint return under section 6013(a) even though one of the spouses...

  11. 26 CFR 1.6013-1 - Joint returns.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 13 2014-04-01 2014-04-01 false Joint returns. 1.6013-1 Section 1.6013-1...) INCOME TAXES (CONTINUED) Tax Returns Or Statements § 1.6013-1 Joint returns. (a) In general. (1) A husband and wife may elect to make a joint return under section 6013(a) even though one of the spouses...

  12. 27 CFR 40.162 - Semimonthly tax return.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Semimonthly tax return. 40... Taxes on Tobacco Products § 40.162 Semimonthly tax return. Every manufacturer of tobacco products shall file, for each of his factories, a semimonthly tax return on Form 5000.24 for each return...

  13. 7 CFR 3560.305 - Return on investment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Return on investment. 3560.305 Section 3560.305... AGRICULTURE DIRECT MULTI-FAMILY HOUSING LOANS AND GRANTS Financial Management § 3560.305 Return on investment. (a) Borrower's return on investment. Borrowers may receive a return on their investment (ROI)...

  14. 7 CFR 3560.305 - Return on investment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false Return on investment. 3560.305 Section 3560.305... AGRICULTURE DIRECT MULTI-FAMILY HOUSING LOANS AND GRANTS Financial Management § 3560.305 Return on investment. (a) Borrower's return on investment. Borrowers may receive a return on their investment (ROI)...

  15. 7 CFR 3560.305 - Return on investment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Return on investment. 3560.305 Section 3560.305... AGRICULTURE DIRECT MULTI-FAMILY HOUSING LOANS AND GRANTS Financial Management § 3560.305 Return on investment. (a) Borrower's return on investment. Borrowers may receive a return on their investment (ROI)...

  16. The Economic Returns to Lifelong Learning in OECD Countries.

    ERIC Educational Resources Information Center

    Cohn, Elchanan; Addison, John T.

    1998-01-01

    Examines recent returns to schooling and vocational and occupational training in OECD countries. Provides estimates of short-cut, Mincer-type, and internal rates of return to schooling and alternative estimates of returns to formal and informal post-school training investments. High-return countries include Austria, Canada, France, Mexico,…

  17. Quantitative Planetary Protection for Sample Return from Ocean Worlds

    NASA Astrophysics Data System (ADS)

    Neveu, Marc; Takano, Yoshinori; Porco, Carolyn; McKay, Christopher P.; Glavin, Daniel; Anbar, Ariel; Sherwood, Brent; Yano, Hajime

    2016-07-01

    Volcanism on ocean worlds [1,2] facilitates ocean sample return missions, enabling uniquely flexible, sensitive, and specific laboratory analyses on Earth to study how far chemistry has evolved in presumably habitable oceans [3,4]. Such mission concepts have yet to quantitatively address planetary protection (PP) for ocean worlds [3,4]. These harbor liquid water [5,6], metabolically useful energy [7], and organic matter to support life [8]. Ocean temperatures may not exceed the limit for life as we know it [9,10], they are shielded from exogenic radiation by kilometers of ice, and their material has likely not been naturally exchanged with Earth [11]. The above factors would place sample return missions in Cat. V - Restricted Earth Return [12,13]. Forward PP requirements for Europa [13] and other ocean worlds [14] require that the probability of "introduction of a single viable terrestrial microorganism into a liquid-water environment" be lower than 10 ^{-4}. This probability should be estimated from (F1) "bioburden at launch," (F2) "cruise survival for contaminating organisms," (F3) "organism survival in the radiation environment adjacent to the target," (F4) "the probability of encountering […] the target," (F5) "the probability of surviving landing/impact on the target," (F6) "mechanisms and timescales of transport to the subsurface," and (F7) "survival […] after subsurface transfer" [13,14]. The compliance of specific designs of known cost could be evaluated from measurements of molecular contaminants as robust and universal proxies for microbial particulates [15] (F1); known microbial radiation tolerance [16] and planetary radiation budgets [17] (F2-F3); trajectory design (F4); projected impact velocities [18] (F5); ice transport timescales [19] (F6), and biomass growth rates in ice [20] (F7). In contrast, current backward PP requirements are only qualitative. Current policy [13,15] prohibits "destructive impact upon return," and requires that (B1) "unless

  18. Current sensor

    DOEpatents

    Yakymyshyn, Christopher Paul; Brubaker, Michael Allen; Yakymyshyn, Pamela Jane

    2007-01-16

    A current sensor is described that uses a plurality of magnetic field sensors positioned around a current carrying conductor. The sensor can be hinged to allow clamping to a conductor. The current sensor provides high measurement accuracy for both DC and AC currents, and is substantially immune to the effects of temperature, conductor position, nearby current carrying conductors and aging.

  19. Return Migration to Mexico: Does Health Matter?

    PubMed

    Arenas, Erika; Goldman, Noreen; Pebley, Anne R; Teruel, Graciela

    2015-12-01

    We use data from three rounds of the Mexican Family Life Survey to examine whether migrants in the United States returning to Mexico in the period 2005-2012 have worse health than those remaining in the United States. Despite extensive interest by demographers in health-related selection, this has been a neglected area of study in the literature on U.S.-Mexico migration, and the few results to date have been contradictory and inconclusive. Using five self-reported health variables collected while migrants resided in the United States and subsequent migration history, we find direct evidence of higher probabilities of return migration for Mexican migrants in poor health as well as lower probabilities of return for migrants with improving health. These findings are robust to the inclusion of potential confounders reflecting the migrants' demographic characteristics, economic situation, family ties, and origin and destination characteristics. We anticipate that in the coming decade, health may become an even more salient issue in migrants' decisions about returning to Mexico, given the recent expansion in access to health insurance in Mexico. PMID:26385111

  20. There's Little Return for Attentional Momentum

    ERIC Educational Resources Information Center

    Snyder, Janice J.; Schmidt, William C.; Kingstone, Alan

    2009-01-01

    Inhibition of return (IOR) refers to a delay in response time (RT) to targets appearing at a previously cued location. The prevailing view is that IOR reflects visual-motor inhibition. The "attentional momentum" account rejects this idea, and instead proposes that IOR reflects an automatic shift of attention away from the cued location resulting…

  1. Early Learning: Return on Investment. Annotated Bibliography

    ERIC Educational Resources Information Center

    Hite, Jenny

    2014-01-01

    Today's researchers seek to determine if contemporary pre-K programs provide the strong return on investment found by researchers in the 1960's High/Scope Perry Preschool Program and 1970's North Carolina Abecedarian Project. Research then showed that these two programs created positive academic effects that accompanied their students as they…

  2. How to maximize return on bond proceeds.

    PubMed

    Deluccia, D J

    1989-09-01

    Healthcare organizations issuing tax-exempt bonds to finance the acquisition, construction, or renovation of their facilities often neglect to invest bond proceeds to gain the maximum allowable return. Bond indentures--documents that contain all the terms and provisions of the financing plan--generally spell out a number of options for investing bond proceeds.

  3. Renewal, reform, and return to flight.

    PubMed

    Dorr, Robert F

    2005-06-01

    The Washington Watch column discusses budget issues on Capitol Hill relating to aerospace issues, including the shuttle's delayed return to flight and Michael Griffin becoming the new NASA administrator; the Transportation Security Administration becoming downsized; and new personnel at the Pentagon. PMID:16007744

  4. 75 FR 15610 - Consolidated Returns; Intercompany Obligations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE TREASURY Internal Revenue Service 26 CFR Part 1 Consolidated Returns; Intercompany Obligations CFR Correction In Title 26 of the Code of Federal Regulations, Part 1 (Sec. Sec. 1.1401 to 1.1550), revised as of April...

  5. Renewal, reform, and return to flight.

    PubMed

    Dorr, Robert F

    2005-06-01

    The Washington Watch column discusses budget issues on Capitol Hill relating to aerospace issues, including the shuttle's delayed return to flight and Michael Griffin becoming the new NASA administrator; the Transportation Security Administration becoming downsized; and new personnel at the Pentagon.

  6. Returns to Education in Bogota, Colombia.

    ERIC Educational Resources Information Center

    Schultz, T. P.

    This memorandum derives estimates of the private rate of return to schooling for men and women based on a 1965 labor force survey, past cross-sectional data, and the long-term educational public policy of Bogota, Colombia. Here resources may be viewed as an investment in the future productive capacity of people. Depending on the costs and benefits…

  7. Exploring Literate Lives: Returning to the Field

    ERIC Educational Resources Information Center

    Henderson, Robyn; Woods, Annette

    2016-01-01

    The challenges of conducting lengthy fieldwork in today's busy academic world have impacted the types of research that are able to be carried out. In particular, traditional educational ethnography has become problematic for research beyond initial doctoral research programs. This article analyzes data collected during a return to the field of a…

  8. A Sample Return Container with Hermetic Seal

    NASA Technical Reports Server (NTRS)

    Kong, Kin Yuen; Rafeek, Shaheed; Sadick, Shazad; Porter, Christopher C.

    2000-01-01

    A sample return container is being developed by Honeybee Robotics to receive samples from a derivative of the Champollion/ST4 Sample Acquisition and Transfer Mechanism or other samplers and then hermetically seal samples for a sample return mission. The container is enclosed in a phase change material (PCM) chamber to prevent phase change during return and re-entry to earth. This container is designed to operate passively with no motors and actuators. Using the sampler's featured drill tip for interfacing, transfer-ring and sealing samples, the container consumes no electrical power and therefore minimizes sample temperature change. The circular container houses a few isolated canisters, which will be sealed individually for samples acquired from different sites or depths. The drill based sampler indexes each canister to the sample transfer position, below the index interface for sample transfer. After sample transfer is completed, the sampler indexes a seal carrier, which lines up seals with the openings of the canisters. The sampler moves to the sealing interface and seals the sample canisters one by one. The sealing interface can be designed to work with C-seals, knife edge seals and cup seals. Again, the sampler provides all sealing actuation. This sample return container and co-engineered sample acquisition system are being developed by Honeybee Robotics in collaboration with the JPL Exploration Technology program.

  9. Near-Earth Asteroid Sample Return Missions

    NASA Technical Reports Server (NTRS)

    Sears, D. W. G.; Allen, C. C.; Britt, D. T.; Brownlee, D. E.; Cheng, A.; Chapman, C. R.; Clark, B. C.; Drake, B. G.; Franchi, I. A.; Gorevan, S.

    2001-01-01

    The rate of discovery of new Near Earth Asteroids (NEAs) and the success of D-S 1 and NEAR-Shoemaker, suggest that sample return from NEAs is now technically feasible. Here we present a summary of a recent workshop on the topic. Additional information is contained in the original extended abstract.

  10. Return Migration to Mexico: Does Health Matter?

    PubMed

    Arenas, Erika; Goldman, Noreen; Pebley, Anne R; Teruel, Graciela

    2015-12-01

    We use data from three rounds of the Mexican Family Life Survey to examine whether migrants in the United States returning to Mexico in the period 2005-2012 have worse health than those remaining in the United States. Despite extensive interest by demographers in health-related selection, this has been a neglected area of study in the literature on U.S.-Mexico migration, and the few results to date have been contradictory and inconclusive. Using five self-reported health variables collected while migrants resided in the United States and subsequent migration history, we find direct evidence of higher probabilities of return migration for Mexican migrants in poor health as well as lower probabilities of return for migrants with improving health. These findings are robust to the inclusion of potential confounders reflecting the migrants' demographic characteristics, economic situation, family ties, and origin and destination characteristics. We anticipate that in the coming decade, health may become an even more salient issue in migrants' decisions about returning to Mexico, given the recent expansion in access to health insurance in Mexico.

  11. Return migration from Canada to Britain.

    PubMed

    Richmond, A H

    1968-07-01

    Abstract Statistics of migrants returning from Canada to Britain and re-registering for national insurance purposes are compared with labour force immigrants entering Canada between 1956 and 1965. Short and long-term indices are calculated which suggest that return migration has been increasing since 1960. A sample survey carried out in 1962-63 distinguishes three types of returning migrant: (a) quasi-migrants who originally planned to return to Britain; (b) permanent repatriates who originally intended to settle in Canada but now expect to remain in Britain; (c) transilient migrants who exhibit a high propensity to move backwards and forwards between two or more countries without becoming permanently rooted in anyone. The demographic, economic and social characteristics of the three types are described. A further comparison is made between migrants who plan to settle in Britain, those who intend to come back again to Canada, and those who are uncertain of their future plans or who intend to move on to a third country.

  12. Reality Check: A Teacher Educator Returns Home

    ERIC Educational Resources Information Center

    Scherff, Lisa; Kaplan, Jeff

    2006-01-01

    This collaborative self-study, told through email excerpts and reflections, explores a teacher educator's return to high school teaching. In this study, we juxtapose our voices and alternate between past and present to develop insights that reveal how going back can lead to moving forward with respect to educating prospective teachers. While the…

  13. 27 CFR 479.51 - Fraudulent return.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Fraudulent return. 479.51 Section 479.51 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND...

  14. 27 CFR 479.51 - Fraudulent return.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Fraudulent return. 479.51 Section 479.51 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND...

  15. 27 CFR 479.51 - Fraudulent return.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Fraudulent return. 479.51 Section 479.51 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND...

  16. 27 CFR 479.51 - Fraudulent return.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Fraudulent return. 479.51 Section 479.51 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND...

  17. 27 CFR 479.51 - Fraudulent return.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Fraudulent return. 479.51 Section 479.51 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND...

  18. Returns to Education in Rural China

    ERIC Educational Resources Information Center

    Zhao, Litao

    2007-01-01

    Based on one of the most widely used datasets by foreign-based sociologists, this paper examines the rate of returns to education in rural China. Compared with the previous studies that showed rather low rates in rural areas throughout the 1980s, this study finds a considerably higher rate in 1996. A chief contributor is the rapid non-agricultural…

  19. Tortuosity of lightning return stroke channels

    NASA Technical Reports Server (NTRS)

    Levine, D. M.; Gilson, B.

    1984-01-01

    Data obtained from photographs of lightning are presented on the tortuosity of return stroke channels. The data were obtained by making piecewise linear fits to the channels, and recording the cartesian coordinates of the ends of each linear segment. The mean change between ends of the segments was nearly zero in the horizontal direction and was about eight meters in the vertical direction. Histograms of these changes are presented. These data were used to create model lightning channels and to predict the electric fields radiated during return strokes. This was done using a computer generated random walk in which linear segments were placed end-to-end to form a piecewise linear representation of the channel. The computer selected random numbers for the ends of the segments assuming a normal distribution with the measured statistics. Once the channels were simulated, the electric fields radiated during a return stroke were predicted using a transmission line model on each segment. It was found that realistic channels are obtained with this procedure, but only if the model includes two scales of tortuosity: fine scale irregularities corresponding to the local channel tortuosity which are superimposed on large scale horizontal drifts. The two scales of tortuosity are also necessary to obtain agreement between the electric fields computed mathematically from the simulated channels and the electric fields radiated from real return strokes. Without large scale drifts, the computed electric fields do not have the undulations characteristics of the data.

  20. Multivariate Models of Adult Pacific Salmon Returns

    PubMed Central

    Burke, Brian J.; Peterson, William T.; Beckman, Brian R.; Morgan, Cheryl; Daly, Elizabeth A.; Litz, Marisa

    2013-01-01

    Most modeling and statistical approaches encourage simplicity, yet ecological processes are often complex, as they are influenced by numerous dynamic environmental and biological factors. Pacific salmon abundance has been highly variable over the last few decades and most forecasting models have proven inadequate, primarily because of a lack of understanding of the processes affecting variability in survival. Better methods and data for predicting the abundance of returning adults are therefore required to effectively manage the species. We combined 31 distinct indicators of the marine environment collected over an 11-year period into a multivariate analysis to summarize and predict adult spring Chinook salmon returns to the Columbia River in 2012. In addition to forecasts, this tool quantifies the strength of the relationship between various ecological indicators and salmon returns, allowing interpretation of ecosystem processes. The relative importance of indicators varied, but a few trends emerged. Adult returns of spring Chinook salmon were best described using indicators of bottom-up ecological processes such as composition and abundance of zooplankton and fish prey as well as measures of individual fish, such as growth and condition. Local indicators of temperature or coastal upwelling did not contribute as much as large-scale indicators of temperature variability, matching the spatial scale over which salmon spend the majority of their ocean residence. Results suggest that effective management of Pacific salmon requires multiple types of data and that no single indicator can represent the complex early-ocean ecology of salmon. PMID:23326586

  1. Investment Return Calculations and Senior School Mathematics

    ERIC Educational Resources Information Center

    Fitzherbert, Richard M.; Pitt, David G. W.

    2010-01-01

    The methods for calculating returns on investments are taught to undergraduate level business students. In this paper, the authors demonstrate how such calculations are within the scope of senior school students of mathematics. In providing this demonstration the authors hope to give teachers and students alike an illustration of the power and the…

  2. An Editor's Journey: Return to Haiti

    ERIC Educational Resources Information Center

    Moy, Yvette

    2012-01-01

    This paper recounts the author's story as she returned to Haiti in February to join a building project near Port-Au-Prince and to document efforts by U.S. higher education institutions to help the country rebound from the devastating 2010 earthquake. The author describes how consortiums have been formed in order to support the development of the…

  3. NASA returns rocks from a comet.

    PubMed

    Burnett, Don S

    2006-12-15

    Cometary particles returned by the Stardust Discovery Mission are primarily silicate materials of solar system origin. Some of the grains were formed at high temperatures close to the Sun, but then transported far out to the Kuiper belt region of the solar system before being incorporated in the comet. PMID:17170288

  4. Return migration and occupational change: the case of Pakistani migrants returned from the Middle East.

    PubMed

    Arif, G M; Irfan, M

    1997-01-01

    This paper reports on the factors affecting occupational composition of Pakistani workers upon their return from Middle East employment locations as determined by using the 1986 ILO/ARTEP Survey of Return Migrant Households. Three issues related to post-migration occupation change of return migrants were explored: 1) the comparison of occupational composition in the pre-migration phase with the composition during migration; 2) the direction of occupational change; and 3) the factors affecting these changes after return. 44% of the total employed in the ILO sample changed their pre-migration occupations upon return from employment in production or service jobs to smallbusinessrelated employment; the highest level of occupational change was observed in nonirrigated areas. Occupational change was strongly related to migrants' duration of stay in the Middle East, their ages upon returning, and their level of educational attainment. Occupational mobility experienced by the returnees was mainly towards the business sectora direction approved by the Pakistan Government. The preference of the returnees to work independently might have enabled them to earn sufficient money to maintain their higher standard of living into the period following return migration. It is concluded that in order to achieve stability in the businesses established by the returnees, the Overseas Pakistanis' Foundation should provide services, including project-oriented training courses and loan plans, that will aid the returnees in managing their small businesses.

  5. 26 CFR 36.3121(l)(10)-3 - Returns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 15 2010-04-01 2010-04-01 false Returns. 36.3121(l)(10)-3 Section 36.3121(l)(10....3121(l)(10)-3 Returns. (a) The forms prescribed for use in making returns of the taxes imposed by the... returns of its liability under an agreement entered into as provided in § 36.3121(l)(1)-1. Returns of...

  6. 26 CFR 36.3121(l)(10)-3 - Returns.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 15 2011-04-01 2011-04-01 false Returns. 36.3121(l)(10)-3 Section 36.3121(l)(10....3121(l)(10)-3 Returns. (a) The forms prescribed for use in making returns of the taxes imposed by the... returns of its liability under an agreement entered into as provided in § 36.3121(l)(1)-1. Returns of...

  7. 26 CFR 36.3121(l)(10)-3 - Returns.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 15 2012-04-01 2012-04-01 false Returns. 36.3121(l)(10)-3 Section 36.3121(l)(10....3121(l)(10)-3 Returns. (a) The forms prescribed for use in making returns of the taxes imposed by the... returns of its liability under an agreement entered into as provided in § 36.3121(l)(1)-1. Returns of...

  8. 26 CFR 36.3121(l)(10)-3 - Returns.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 15 2014-04-01 2014-04-01 false Returns. 36.3121(l)(10)-3 Section 36.3121(l)(10....3121(l)(10)-3 Returns. (a) The forms prescribed for use in making returns of the taxes imposed by the... returns of its liability under an agreement entered into as provided in § 36.3121(l)(1)-1. Returns of...

  9. 26 CFR 36.3121(l)(10)-3 - Returns.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 15 2013-04-01 2013-04-01 false Returns. 36.3121(l)(10)-3 Section 36.3121(l)(10....3121(l)(10)-3 Returns. (a) The forms prescribed for use in making returns of the taxes imposed by the... returns of its liability under an agreement entered into as provided in § 36.3121(l)(1)-1. Returns of...

  10. 26 CFR 301.6103(n)-1 - Disclosure of returns and return information in connection with written contracts or agreements...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... administration purposes. 301.6103(n)-1 Section 301.6103(n)-1 Internal Revenue INTERNAL REVENUE SERVICE... and Returns Returns and Records § 301.6103(n)-1 Disclosure of returns and return information in... administration purposes. (a) General rule. (1) Pursuant to the provisions of section 6103(n) of the...

  11. 26 CFR 301.6033-4 - Required use of magnetic media for returns by organizations required to file returns under...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 18 2012-04-01 2012-04-01 false Required use of magnetic media for returns by... ADMINISTRATION Information and Returns Returns and Records § 301.6033-4 Required use of magnetic media for... required to file returns under section 6033 on magnetic media. An organization required to file a...

  12. 26 CFR 1.6011-7 - Specified tax return preparers required to file individual income tax returns using magnetic media.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... individual income tax returns using magnetic media. 1.6011-7 Section 1.6011-7 Internal Revenue INTERNAL... tax returns using magnetic media. Individual income tax returns that are required to be filed on magnetic media by tax return preparers under section 6011(e)(3) and § 301.6011-7 of this chapter must...

  13. 26 CFR 1.6011-7 - Specified tax return preparers required to file individual income tax returns using magnetic media.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... individual income tax returns using magnetic media. 1.6011-7 Section 1.6011-7 Internal Revenue INTERNAL... tax returns using magnetic media. Individual income tax returns that are required to be filed on magnetic media by tax return preparers under section 6011(e)(3) and § 301.6011-7 of this chapter must...

  14. 26 CFR 301.6033-4 - Required use of magnetic media for returns by organizations required to file returns under...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Required use of magnetic media for returns by... ADMINISTRATION Information and Returns Returns and Records § 301.6033-4 Required use of magnetic media for... required to file returns under section 6033 on magnetic media. An organization required to file a...

  15. 26 CFR 1.6011-7 - Specified tax return preparers required to file individual income tax returns using magnetic media.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... individual income tax returns using magnetic media. 1.6011-7 Section 1.6011-7 Internal Revenue INTERNAL... tax returns using magnetic media. Individual income tax returns that are required to be filed on magnetic media by tax return preparers under section 6011(e)(3) and § 301.6011-7 of this chapter must...

  16. 26 CFR 54.6109-1 - Tax return preparers furnishing identifying numbers for returns or claims for refund filed.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Tax return preparers furnishing identifying... EXCISE TAXES § 54.6109-1 Tax return preparers furnishing identifying numbers for returns or claims for refund filed. (a) In general. Each tax return or claim for refund of tax under Chapter 43 of subtitle...

  17. 26 CFR 53.6109-1 - Tax return preparers furnishing identifying numbers for returns or claims for refund filed.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Tax return preparers furnishing identifying... AND SIMILAR EXCISE TAXES Procedure and Administration § 53.6109-1 Tax return preparers furnishing identifying numbers for returns or claims for refund filed. (a) In general. Each tax return or claim...

  18. 26 CFR 301.6103(l)-1 - Disclosure of returns and return information for purposes other than tax administration.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... for purposes other than tax administration. 301.6103(l)-1 Section 301.6103(l)-1 Internal Revenue... ADMINISTRATION Information and Returns Returns and Records § 301.6103(l)-1 Disclosure of returns and return... provisions of section 6103(l) of the Internal Revenue Code, the term agent includes a contractor....

  19. 26 CFR 301.6103(p)(4)-1 - Procedures relating to safeguards for returns or return information.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... or return information. 301.6103(p)(4)-1 Section 301.6103(p)(4)-1 Internal Revenue INTERNAL REVENUE... Information and Returns Returns and Records § 301.6103(p)(4)-1 Procedures relating to safeguards for returns..., see § 301.6103(p)(7)-1....

  20. 26 CFR 301.6103(p)(4)-1 - Procedures relating to safeguards for returns or return information.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... or return information. 301.6103(p)(4)-1 Section 301.6103(p)(4)-1 Internal Revenue INTERNAL REVENUE... Information and Returns Returns and Records § 301.6103(p)(4)-1 Procedures relating to safeguards for returns..., see § 301.6103(p)(7)-1....

  1. 26 CFR 301.6103(p)(2)(B)-1 - Disclosure of returns and return information by other agencies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... other agencies. 301.6103(p)(2)(B)-1 Section 301.6103(p)(2)(B)-1 Internal Revenue INTERNAL REVENUE... Information and Returns Returns and Records § 301.6103(p)(2)(B)-1 Disclosure of returns and return information... regulations thereunder, including, if applicable, safeguards imposed by section 6103(p)(4). (d) Records...

  2. 26 CFR 301.6103(p)(2)(B)-1 - Disclosure of returns and return information by other agencies.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... other agencies. 301.6103(p)(2)(B)-1 Section 301.6103(p)(2)(B)-1 Internal Revenue INTERNAL REVENUE... Information and Returns Returns and Records § 301.6103(p)(2)(B)-1 Disclosure of returns and return information... regulations thereunder, including, if applicable, safeguards imposed by section 6103(p)(4). (d) Records...

  3. 26 CFR 301.6103(p)(2)(B)-1 - Disclosure of returns and return information by other agencies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... other agencies. 301.6103(p)(2)(B)-1 Section 301.6103(p)(2)(B)-1 Internal Revenue INTERNAL REVENUE... Information and Returns Returns and Records § 301.6103(p)(2)(B)-1 Disclosure of returns and return information... regulations thereunder, including, if applicable, safeguards imposed by section 6103(p)(4). (d) Records...

  4. 26 CFR 301.6103(p)(4)-1 - Procedures relating to safeguards for returns or return information.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... or return information. 301.6103(p)(4)-1 Section 301.6103(p)(4)-1 Internal Revenue INTERNAL REVENUE... Information and Returns Returns and Records § 301.6103(p)(4)-1 Procedures relating to safeguards for returns..., see § 301.6103(p)(7)-1....

  5. 26 CFR 301.6103(p)(2)(B)-1 - Disclosure of returns and return information by other agencies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... other agencies. 301.6103(p)(2)(B)-1 Section 301.6103(p)(2)(B)-1 Internal Revenue INTERNAL REVENUE... Information and Returns Returns and Records § 301.6103(p)(2)(B)-1 Disclosure of returns and return information... regulations thereunder, including, if applicable, safeguards imposed by section 6103(p)(4). (d) Records...

  6. 26 CFR 301.6103(p)(4)-1 - Procedures relating to safeguards for returns or return information.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... or return information. 301.6103(p)(4)-1 Section 301.6103(p)(4)-1 Internal Revenue INTERNAL REVENUE... Information and Returns Returns and Records § 301.6103(p)(4)-1 Procedures relating to safeguards for returns..., see § 301.6103(p)(7)-1....

  7. 26 CFR 301.6103(l)-1 - Disclosure of returns and return information for purposes other than tax administration.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... for purposes other than tax administration. 301.6103(l)-1 Section 301.6103(l)-1 Internal Revenue... ADMINISTRATION Information and Returns Returns and Records § 301.6103(l)-1 Disclosure of returns and return... provisions of section 6103(l) of the Internal Revenue Code, the term agent includes a contractor....

  8. 26 CFR 301.6103(l)-1 - Disclosure of returns and return information for purposes other than tax administration.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... for purposes other than tax administration. 301.6103(l)-1 Section 301.6103(l)-1 Internal Revenue... ADMINISTRATION Information and Returns Returns and Records § 301.6103(l)-1 Disclosure of returns and return... provisions of section 6103(l) of the Internal Revenue Code, the term agent includes a contractor....

  9. 26 CFR 301.6103(l)-1 - Disclosure of returns and return information for purposes other than tax administration.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... for purposes other than tax administration. 301.6103(l)-1 Section 301.6103(l)-1 Internal Revenue... ADMINISTRATION Information and Returns Returns and Records § 301.6103(l)-1 Disclosure of returns and return... provisions of section 6103(l) of the Internal Revenue Code, the term agent includes a contractor....

  10. 26 CFR 301.6103(l)-1 - Disclosure of returns and return information for purposes other than tax administration.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... for purposes other than tax administration. 301.6103(l)-1 Section 301.6103(l)-1 Internal Revenue... ADMINISTRATION Information and Returns Returns and Records § 301.6103(l)-1 Disclosure of returns and return... provisions of section 6103(l) of the Internal Revenue Code, the term agent includes a contractor....

  11. 26 CFR 301.6103(p)(2)(B)-1 - Disclosure of returns and return information by other agencies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Disclosure of returns and return information by other agencies. 301.6103(p)(2)(B)-1 Section 301.6103(p)(2)(B)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) PROCEDURE AND ADMINISTRATION PROCEDURE AND ADMINISTRATION Information and Returns Returns and Records...

  12. 26 CFR 301.6103(p)(4)-1 - Procedures relating to safeguards for returns or return information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Procedures relating to safeguards for returns or return information. 301.6103(p)(4)-1 Section 301.6103(p)(4)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) PROCEDURE AND ADMINISTRATION PROCEDURE AND ADMINISTRATION Information and Returns Returns and Records...

  13. Negotiating a successful return to work program.

    PubMed

    Di Guida, A W

    1995-02-01

    This article has examined selected reasons why companies resist implementation of return to work programs. The reasons include many fears that companies can readily justify. Nearly all the fears can be eliminated when the occupational health nurse applies both nursing and management principles. As a specialized line manager in the company, with a specialty in people and systems management, the occupational health nurse is the most likely person to plan and implement a successful program. To design, implement, and manage the plan to a successful end, the occupational health nurse must enhance skills in language, salesmanship, and quantifying results. Success must be measured in both people and dollar terms to have relevance to the company, its bottom line, and its employees. People results, the harder of the two to measure, have value in helping to establish positive attitudes of program participants toward the company. People results also help prevent the development of disability syndrome by ill or injured employees by keeping them connected to work and productivity. People results also can be measured by the change in culture the return to work program is likely to produce among managers and employees. The resulting culture will reflect a sense of caring by the company about employees, and expectation that manipulation of the company by opportunists will be reduced, as scarce company resources will be conserved. The early return to work program is managed within employee capabilities in a therapeutic environment during the recovery process. In the long term, financial success of the return to work program can be measured by reduced costs per claim annually. Using the nursing, management, financial, and marketing principles discussed in this article, the occupational health nurse can improve chances of negotiating implementation of a successful early return to work program.

  14. The effect that energy storage and return feet have on the propulsion of the body: a pilot study.

    PubMed

    Crimin, Anthony; McGarry, Anthony; Harris, Elena Jane; Solomonidis, Stephan Emanuel

    2014-09-01

    A variety of energy storage and return prosthetic feet are currently available for use within lower limb prostheses. Designs claim to provide a beneficial energy return during push-off, but the extent to which this occurs remains disputed. Techniques currently used to measure energy storage, dissipation and return within the structure of the prosthetic foot are debatable, with limited evidence to support substantial elastic energy storage and return from existing designs. The aim of this study was to evaluate the performance of energy storage and return foot designs through considering the ankle power during push-off and the effect on body centre of mass propulsion. To achieve this aim, the gait patterns of six trans-tibial prosthetic users wearing different designs of energy storage and return feet were analysed while ascending a ramp. Three examples of energy storage and return feet (suitable for moderate activity) were selected and randomly evaluated: the Blatchford's Epirus, Össur Assure and College Park Tribute feet. The power at the anatomical and mechanical ankle joints was integrated to evaluate the work done over the gait cycle. The direction of the inertial force, and therefore propulsion of the body centre of mass, was used to indicate the effect of the energy return by the energy storage and return feet. Results indicate that although energy storage and return feet may provide energy return, the work done around the prosthetic ankle indicates net power absorption. Therefore, the prosthetic limb is unable to contribute to the body centre of mass propulsion to the same extent as the biological limb.

  15. Planetary Protection for LIFE-Sample Return from Enceladus

    NASA Astrophysics Data System (ADS)

    Tsou, Peter; Yano, Hajime; Takano, Yoshinori; McKay, David; Takai, Ken; Anbar, Ariel; Baross, J.

    ]. Current Plan: At the 1st flyby of Enceladus at high plume altitude (~150 km), we would survey the status of the plume and jets by making in situ measurements of the gas and dust densities, compositions, and velocities. We would also collect solid ice/volatile samples based upon prior ground planning. The 2nd and final flyby (determined via optimal trajectory from the 1st flyby) will be conducted at low altitude (~20 km), and would perform in situ measurements and collect solid ice and volatile samples. During the 5 year return cruise, we would maintain the samples in their captured state (frozen) under desiccating conditions of low temperature and pressure. After a direct Earth reentry, we would transport the frozen samples from the sample return capsule into a sealed sample transport container, which would then be transported to a higher Biosafety Level (BSL) facility from JAMSTEC (Japan Agency for Marine-Earth Science and Technology) for sample return capsule de-integration and sample distribution. Planetary Protection: Several options for sample return have been conceived and some even demonstrated on previous flight missions (STARDUST, Genesis and Hayabusa). To date, a flight qualified sample containment system does not exist in the US, and it would be cost prohibitive to flight-qualify such a system for use by LIFE under a Discovery Program. Harsh sterilization of the samples would destroy valuable molecular information, defeating the very purpose of returning samples to assess the habitability of Enceladus. The LIFE team has found a viable approach by teaming with JAXA/ISAS. Their Hayabusa II sample containment is a third generation device that can be further improved to meet these NASA and COSPAR planetary protection requirements in an Integrated Sample Subsystem for LIFE. Another aspect of LIFE is the initial de-integration and certification of the returned samples in a higher BSL facility. JAMSTEC is the world’s leading oceanography organization. They are

  16. Planetary Protection for LIFE-Sample Return from Enceladus

    NASA Astrophysics Data System (ADS)

    Tsou, Peter; Yano, Hajime; Takano, Yoshinori; McKay, David; Takai, Ken; Anbar, Ariel; Baross, J.

    ]. Current Plan: At the 1st flyby of Enceladus at high plume altitude (~150 km), we would survey the status of the plume and jets by making in situ measurements of the gas and dust densities, compositions, and velocities. We would also collect solid ice/volatile samples based upon prior ground planning. The 2nd and final flyby (determined via optimal trajectory from the 1st flyby) will be conducted at low altitude (~20 km), and would perform in situ measurements and collect solid ice and volatile samples. During the 5 year return cruise, we would maintain the samples in their captured state (frozen) under desiccating conditions of low temperature and pressure. After a direct Earth reentry, we would transport the frozen samples from the sample return capsule into a sealed sample transport container, which would then be transported to a higher Biosafety Level (BSL) facility from JAMSTEC (Japan Agency for Marine-Earth Science and Technology) for sample return capsule de-integration and sample distribution. Planetary Protection: Several options for sample return have been conceived and some even demonstrated on previous flight missions (STARDUST, Genesis and Hayabusa). To date, a flight qualified sample containment system does not exist in the US, and it would be cost prohibitive to flight-qualify such a system for use by LIFE under a Discovery Program. Harsh sterilization of the samples would destroy valuable molecular information, defeating the very purpose of returning samples to assess the habitability of Enceladus. The LIFE team has found a viable approach by teaming with JAXA/ISAS. Their Hayabusa II sample containment is a third generation device that can be further improved to meet these NASA and COSPAR planetary protection requirements in an Integrated Sample Subsystem for LIFE. Another aspect of LIFE is the initial de-integration and certification of the returned samples in a higher BSL facility. JAMSTEC is the world’s leading oceanography organization. They are

  17. Does a Syrinx Matter for Return to Play in Contact Sports? A Case Report and Evidence-Based Review of Return-to-Play Criteria After Transient Quadriplegia

    PubMed Central

    Milles, Jeffrey L.; Gallizzi, Michael A.; Sherman, Seth L.; Smith, Patrick A.; Choma, Theodore J.

    2014-01-01

    Transient quadriplegia is a rare injury that can change the course of an athlete’s career if misdiagnosed or managed inappropriately. The clinician should be well versed in the return-to-play criteria for this type of injury. Unfortunately, when an unknown preexisting syrinx is present in the athlete, there is less guidance on their ability to return to play. This case report and review of the current literature illustrates a National Collegiate Athletic Association (NCAA) Division I football player who suffered a transient quadriplegic event during a kickoff return that subsequently was found to have an incidental cervical syrinx on magnetic resonance imaging. The player was able to have a full neurologic recovery, but ultimately he was withheld from football. PMID:25177422

  18. 12 CFR 229.31 - Returning bank's responsibility for return of checks.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... test, and the deadline for return under the U.C.C. and Regulation J (12 CFR part 210), are extended by... THE FEDERAL RESERVE SYSTEM AVAILABILITY OF FUNDS AND COLLECTION OF CHECKS (REGULATION CC)...

  19. 12 CFR 229.31 - Returning bank's responsibility for return of checks.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... test, and the deadline for return under the U.C.C. and Regulation J (12 CFR part 210), are extended by... THE FEDERAL RESERVE SYSTEM (CONTINUED) AVAILABILITY OF FUNDS AND COLLECTION OF CHECKS (REGULATION...

  20. 12 CFR 229.31 - Returning bank's responsibility for return of checks.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... test, and the deadline for return under the U.C.C. and Regulation J (12 CFR part 210), are extended by... THE FEDERAL RESERVE SYSTEM AVAILABILITY OF FUNDS AND COLLECTION OF CHECKS (REGULATION CC)...

  1. 12 CFR 229.31 - Returning bank's responsibility for return of checks.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... test, and the deadline for return under the U.C.C. and Regulation J (12 CFR part 210), are extended by... THE FEDERAL RESERVE SYSTEM (CONTINUED) AVAILABILITY OF FUNDS AND COLLECTION OF CHECKS (REGULATION...

  2. 12 CFR 229.31 - Returning bank's responsibility for return of checks.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... test, and the deadline for return under the U.C.C. and Regulation J (12 CFR part 210), are extended by... THE FEDERAL RESERVE SYSTEM AVAILABILITY OF FUNDS AND COLLECTION OF CHECKS (REGULATION CC)...

  3. OSIRIS-REx Asteroid Sample Return Mission

    NASA Astrophysics Data System (ADS)

    Drake, M. J.; Lauretta, D. S.; Team, O.

    2011-12-01

    OSIRIS-REx is an asteroid sample return mission to organic-rich asteroid (101955) 1999 RQ36. The mission seeks to address deep questions: where did we come from; what is our destiny? Earth sterilized itself during its formation, yet here we are today. Where did the organics come from? To do so, we will return at least 60g of pristine, uncontaminated, organic-rich regolith for study on Earth by advanced analytical equipment. Because it is relatively easy for us to get the RQ36, it is relatively easy for it to get to us, making I the most potentially hazardous asteroid know to humanity with a 1:1800 probability of impacting the Earth in 2180. We will study the Yarkovsky effect, thermal forces that cause small objects to deviate from keplerian orbits, with the goal of understanding how to mitigate against a civilization-ending or species-ending impact catastrophe. The mission launches in September, 2016, arrives at RQ36 in November of 2019, and spends about a year conducting detailed studies of RQ36 in order to select the best sampling site. Sampling is achieved by approaching the surface ay 10 cm/sec and agitating the regolith with nitrogen gas on contact. The agitated regolith is collected in a sample head, which is stowed in the Sample return capsule for return to Earth at the UTTR Test range in Utah in September 2023. Two years of funded studies are carried out by the U.S. and world community before end of mission in 2025, after which samples will still be available through the NASA-JSC Curation Facility. OSIRIS-REx will return samples never before available for study on Earth, probably using some instruments yet to be invented. In addition, OSIRIS-REx will provide "ground truth" for telescope observations of airless bodies by returning a pristine sample of the surface of RQ36. OSIRIS-REx will evaluate resources available to future human missions, both materials and technologies such as proximity operations. And we will learn how to mitigate against impact

  4. Future Applications Using Return-Pulse Correlation from Imaging Laser Altimeters

    NASA Technical Reports Server (NTRS)

    Blair, J. Bryan; Hofton, Michelle A.; Rabine, David L.

    2000-01-01

    The Laser Vegetation Imaging Sensor (LVIS) is an airborne, wide-swath, digitization-only laser altimeter capable of collecting full return waveforms (i.e. echoes) from laser footprints ranging in diameter from 1 to 80 m across up to a 1 km wide data swath. The return waveform can be used to enhance the accuracy of laser ranging and to provide information about the vertical structure of vegetation and topography within each laser footprint. Although extremely small laser footprints (< 1 0 cm diameter) generally return simple, impulse responses to their target surface, larger footprints typically exhibit complex returns representing the diverse vertical distributions of surfaces contained in each footprint. Only a handful of airborne and spaceborne laser altimeters record the return echo or return pulse that is reflected from the Earth's surface (i.e. NASA's LVIS, SLA, VCL, and GLAS laser altimeters). Waveforms are currently interpreted to extract a timing or ranging point or points to represent the mean ground elevation or the vertical height of vegetation. But, recent progress using pulse shape correlation techniques shows promise for a variety of science applications involving change detection of surface topography and vegetation as well as potential for improving data processing by correlating images or crossovers to solve systematic biases. We show example correlation images from LVIS and discuss instrument design implications and potential science applications.

  5. Return period adjustment for runoff coefficients based on analysis in undeveloped Texas watersheds

    USGS Publications Warehouse

    Dhakal, Nirajan; Fang, Xing; Asquith, William H.; Cleveland, Theodore G.; Thompson, David B.

    2013-01-01

    The rational method for peak discharge (Qp) estimation was introduced in the 1880s. The runoff coefficient (C) is a key parameter for the rational method that has an implicit meaning of rate proportionality, and the C has been declared a function of the annual return period by various researchers. Rate-based runoff coefficients as a function of the return period, C(T), were determined for 36 undeveloped watersheds in Texas using peak discharge frequency from previously published regional regression equations and rainfall intensity frequency for return periods T of 2, 5, 10, 25, 50, and 100 years. The C(T) values and return period adjustments C(T)/C(T=10  year) determined in this study are most applicable to undeveloped watersheds. The return period adjustments determined for the Texas watersheds in this study and those extracted from prior studies of non-Texas data exceed values from well-known literature such as design manuals and textbooks. Most importantly, the return period adjustments exceed values currently recognized in Texas Department of Transportation design guidance when T>10  years.

  6. Marco Polo: Near-Earth Object Sample Return Mission

    NASA Astrophysics Data System (ADS)

    Antonieta Barucci, Maria; Yoshikawa, M.; Koschny, D.; Boehnhardt, H.; Brucato, J. R.; Coradini, M.; Dotto, E.; Franchi, I. A.; Green, S. F.; Josset, J. L.; Kawagushi, J.; Michel, P.; Muinonen, K.; Oberst, J.; Yano, H.; Binzel, R. P.; Marco Polo Science Team

    2008-09-01

    MARCO POLO is a joint European-Japanese sample return mission to a Near-Earth Object (NEO), selected by ESA in the framework of COSMIC VISION 2015-2025 for an assessment study scheduled to last until October 2009. This Euro-Asian mission will go to a primitive Near-Earth Object (NEO), such as C or D-type, scientifically characterize it at multiple scales, and bring samples back to Earth for detailed scientific investigation. NEOs are part of the small body population in the Solar System, which are leftover building blocks of the Solar System formation process. They offer important clues to the chemical mixture from which planets formed about 4.6 billion years ago. The scientific objectives of Marco Polo will therefore contribute to a better understanding of the origin and evolution of the Solar System, the Earth, and the potential contribution of primitive material to the formation of Life. Marco Polo is based on a launch with a Soyuz Fregat and consists of a Mother Spacecraft (MSC), possibly carrying a lander. The MSC would approach the target asteroid and spend a few months for global characterization of the target to select a sampling site. Then, the MSC would then descend to retrieve several samples which will be transferred to a Sample Return Capsule (SRC). The MSC would return to Earth and release the SRC into the atmosphere for ground recovery. The sample of the NEO will then be available for detailed investigation in ground-based laboratories. In parallel to JAXA considering how to perform the mission, ESA has performed a Marco Polo study in their Concurrent Design Facility (CDF). Two parallel industrial studies will start in September 2008 to be conducted in Europe for one year. The scientific objectives addressed by the mission and the current status of the mission study (ESA-JAXA) will be presented and discussed.

  7. A Reliable Earth Return System for Safe Recovery of Mars Samples

    NASA Technical Reports Server (NTRS)

    Braun, R.; Killough, B.; Mitcheltree, R.; Carroll, C.

    2000-01-01

    The objective of a Mars sample return mission is to bring selected Mars surface materials to Earth. Numerous approaches for the Earth-return segment have been analyzed including propulsive or aerocapture return to low-Earth orbit followed by Space Shuttle rendezvous and direct entry. Of these approaches, ballistic entry of a small capsule terminating in a ground landing has been shown to be the lowest risk strategy. Over the past two years, significant work has been performed towards development of a robust direct entry vehicle for Mars sample return. In June 1999, the NASA Planetary Protection Officer provided initial guidance to the former Mars Sample Return Project. The sample return phase of the mission was assigned a restricted Earth return planetary protection classification. The draft mission requirement states that the total mean probability of release of unsterilized Mars material into the Earth;s biosphere must be less than 1.0E-06 (1 in a million). This strict requirement drives the approach and design of the Earth return system. To meet this requirement, selection of the Earth return strategy and development of the Earth return system must be guided by risk, not performance, based decisions. An initial Probabilistic Risk Assessment (PRA) was performed to address the direct entry Earth return system containment assurance reliability and to identify high-risk elements of this system. The results of this PRA identified risk elements that include thermal protection system performance during entry, spin-eject orientation and aerodynamic stability during entry, structural integrity under atmospheric deceleration and impact loads, and tracking/recovery of this system. This initial probabilistic risk quantification demonstrates that, with the proper development program, a prototypical direct entry design can satisfy the containment assurance reliability requirement. Through the current Mars Sample Return Advanced Technology Development effort, an extensive

  8. STARDUST: finessing expensive cometary sample returns.

    PubMed

    Brownlee, D E; Tsou, P; Atkins, K L; Yen, C W; Vellinga, J M; Price, S; Clark, B C

    1996-01-01

    The STARDUST Discovery mission will collect samples of cometary coma and interstellar dust and return them to Earth. Five years after launch in February 1999, coma dust in the 1- to 100-micrometers size range will be captured by impact into ultra-low-density silica aerogel during a 6 kms-1 flyby of Comet Wild 2. The returned samples will be investigated at laboratories where the most critical information on these primitive materials is retained. The Jet Propulsion Laboratory will provide project management with Lockheed Martin Astronauts as the spacecraft industrial partner. STARDUST management will aggressively and innovatively achieve cost control through the use of Total Quality Management principles, the chief of which will be organization in a Project Engineering and Integration Team that "flattens" the traditional hierarchical structure by including all project elements from the beginning, in a concurrent engineering framework focusing on evolving Integrated Mission Capability.

  9. Returners and explorers dichotomy in human mobility

    NASA Astrophysics Data System (ADS)

    Pappalardo, Luca; Simini, Filippo; Rinzivillo, Salvatore; Pedreschi, Dino; Giannotti, Fosca; Barabási, Albert-László

    2015-09-01

    The availability of massive digital traces of human whereabouts has offered a series of novel insights on the quantitative patterns characterizing human mobility. In particular, numerous recent studies have lead to an unexpected consensus: the considerable variability in the characteristic travelled distance of individuals coexists with a high degree of predictability of their future locations. Here we shed light on this surprising coexistence by systematically investigating the impact of recurrent mobility on the characteristic distance travelled by individuals. Using both mobile phone and GPS data, we discover the existence of two distinct classes of individuals: returners and explorers. As existing models of human mobility cannot explain the existence of these two classes, we develop more realistic models able to capture the empirical findings. Finally, we show that returners and explorers play a distinct quantifiable role in spreading phenomena and that a correlation exists between their mobility patterns and social interactions.

  10. Effective return, risk aversion and drawdowns

    NASA Astrophysics Data System (ADS)

    Dacorogna, Michel M.; Gençay, Ramazan; Müller, Ulrich A.; Pictet, Olivier V.

    2001-01-01

    We derive two risk-adjusted performance measures for investors with risk averse preferences. Maximizing these measures is equivalent to maximizing the expected utility of an investor. The first measure, Xeff, is derived assuming a constant risk aversion while the second measure, Reff, is based on a stronger risk aversion to clustering of losses than of gains. The clustering of returns is captured through a multi-horizon framework. The empirical properties of Xeff, Reff are studied within the context of real-time trading models for foreign exchange rates and their properties are compared to those of more traditional measures like the annualized return, the Sharpe Ratio and the maximum drawdown. Our measures are shown to be more robust against clustering of losses and have the ability to fully characterize the dynamic behaviour of investment strategies.

  11. Returners and explorers dichotomy in human mobility.

    PubMed

    Pappalardo, Luca; Simini, Filippo; Rinzivillo, Salvatore; Pedreschi, Dino; Giannotti, Fosca; Barabási, Albert-László

    2015-01-01

    The availability of massive digital traces of human whereabouts has offered a series of novel insights on the quantitative patterns characterizing human mobility. In particular, numerous recent studies have lead to an unexpected consensus: the considerable variability in the characteristic travelled distance of individuals coexists with a high degree of predictability of their future locations. Here we shed light on this surprising coexistence by systematically investigating the impact of recurrent mobility on the characteristic distance travelled by individuals. Using both mobile phone and GPS data, we discover the existence of two distinct classes of individuals: returners and explorers. As existing models of human mobility cannot explain the existence of these two classes, we develop more realistic models able to capture the empirical findings. Finally, we show that returners and explorers play a distinct quantifiable role in spreading phenomena and that a correlation exists between their mobility patterns and social interactions. PMID:26349016

  12. Near-Earth Asteroid Returned Sample (NEARS)

    NASA Technical Reports Server (NTRS)

    Shoemaker, Eugene M.; Cheng, Andrew F.

    1994-01-01

    The concept of the Near-Earth Asteroid Returned Sample (NEARS) mission is to return to Earth 10-100 g from each of four to six sites on a near-Earth asteroid and to perform global characterization of the asteroid and measure mass, volume, and density to ten percent. The target asteroid for the mission is 4660 Nereus, probably a primitive C-type asteroid, with the alternate target being 1989ML, an extremely accessible asteroid of unknown type. Launch dates will be 1998, 2000, 2002, and 2004 on the Delta II-7925 launch vehicle. The mission objectives are three-fold. (1) Provide first direct and detailed petrological, chemical, age, and isotopic characterization of a near-Earth asteroid and relate it to terrestrial, lunar, and meteoritic materials. (2) Sample the asteroid regolith and characterize any exotic fragments. (3) Identify heterogeneity in the asteroid's isotopic properties, age, and elemental chemistry.

  13. Mars Exploration Strategies: Forget About Sample Return

    NASA Astrophysics Data System (ADS)

    Paige, D. A.

    2000-07-01

    During the past months, loss of the Mars Climate Orbiter and Mars Polar Lander spacecraft have received considerable attention. In reality, NASA's toll of lost missions during this period has been much higher due to the cancellation of the Mars 2001 lander mission and the failure to plan a credible Mars sample return mission. NASA has commissioned a number of internal and independent investigations which have focused on the technical and management failures that were responsible for the failures of the '98 missions. However, the even more serious setbacks that the future missions in the Mars Surveyor Program are experiencing have not received the same degree of critical attention. In this paper, I attempt to identify some of the key science strategy issues relating to these problems, and suggest returning to a strategy for Mars exploration that is more closely aligned with reason, risk avoidance, and reality.

  14. Returners and explorers dichotomy in human mobility

    PubMed Central

    Pappalardo, Luca; Simini, Filippo; Rinzivillo, Salvatore; Pedreschi, Dino; Giannotti, Fosca; Barabási, Albert-László

    2015-01-01

    The availability of massive digital traces of human whereabouts has offered a series of novel insights on the quantitative patterns characterizing human mobility. In particular, numerous recent studies have lead to an unexpected consensus: the considerable variability in the characteristic travelled distance of individuals coexists with a high degree of predictability of their future locations. Here we shed light on this surprising coexistence by systematically investigating the impact of recurrent mobility on the characteristic distance travelled by individuals. Using both mobile phone and GPS data, we discover the existence of two distinct classes of individuals: returners and explorers. As existing models of human mobility cannot explain the existence of these two classes, we develop more realistic models able to capture the empirical findings. Finally, we show that returners and explorers play a distinct quantifiable role in spreading phenomena and that a correlation exists between their mobility patterns and social interactions. PMID:26349016

  15. Edward Teller Returns to LOS Alamos

    NASA Astrophysics Data System (ADS)

    Hecker, Siegfried S.

    2010-01-01

    I was asked to share some reflections of Edward Teller's return to Los Alamos during my directorship. I met Teller late in his life. My comments focus on that time and they will be mostly in the form of stories of my interactions and those of my colleagues with Teller. Although the focus of this symposium is on Teller's contributions to science, at Los Alamos it was never possible to separate Teller's science from policy and controversy ...

  16. Near-Earth Asteroid Sample Return Workshop

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This volume contains abstracts that have been accepted for presentation at the Near-Earth Asteroid Sample Return Workshop, 11-12 Dec 2000. The Steering Committee consisted of Derek Sears, Chair, Dan Britt, Don Brownlee, Andrew Cheng, Benton Clark, Leon Gefert, Steve Gorevan, Marilyn Lindstrom, Carle Pieters, Jeff Preble, Brian Wilcox, and Don Yeomans. Logistical, administrative, and publications support were provided by the Publications and Program Services Department of the Lunar and Planetary Institute.

  17. Mars Rover/Sample Return landing strategy

    NASA Technical Reports Server (NTRS)

    Friedlander, Alan L.; German, Darla J.

    1988-01-01

    This paper describes the analysis and results of an investigation of the Mars Rover/Sample Return mission's landing strategy, together with the trade-offs of different landing strategies. The percentile points and the descriptive statistics of the probability distribution of traverse distances are calculated using a simple model formulated on the basis of landing error characteristics. The results show that variations in the landing stratgegy can significantly affect the traverse distance requirements, which range from 20 to 200 km.

  18. Return migration to Scotland: some direct evidence.

    PubMed

    Gordon, I

    1982-04-01

    The author presents a critique of a paper by Bell and Kirwan in which they contend that the probability of return migration will tend to be equal for Scottish migrants to England and Wales and for English or Welsh migrants to Scotland. In the present article, comparable data for the United States and Scotland are evaluated, and comments are presented on the regression equations used. A reply by Bell and Kirwan is also included (pp. 135-6).

  19. Horizontal electric fields from lightning return strokes

    NASA Technical Reports Server (NTRS)

    Thomson, E. M.; Medelius, P. J.; Rubinstein, M.; Uman, M. A.; Johnson, J.

    1988-01-01

    An experiment to measure simultaneously the wideband horizontal and vertical electric fields from lightning return strokes is described. Typical wave shapes of the measured horizontal and vertical fields are presented, and the horizontal fields are characterized. The measured horizontal fields are compared with calculated horizontal fields obtained by applying the wavetilt formula to the vertical fields. The limitations and sources of error in the measurement technique are discussed.

  20. Isotopic studies in returned lunar samples

    NASA Technical Reports Server (NTRS)

    Alexander, E. C., Jr.

    1971-01-01

    Analysis of lunar soil samples returned by Apollo 11 and 12 flights are discussed. Isotopic studies of the rare gases from Apollo 11 flight lunar samples are presented. The lunar soil analyses indicated the following: (1) high concentrations of solar wind rare gases, (2) isotopic match between solar wind gases and gas components in gas-rich meteorites, and (3) rare gases attributable to spallation reactions induced in heavier nuclides by cosmic ray particles.

  1. Environmental water incentive policy and return flows

    NASA Astrophysics Data System (ADS)

    Qureshi, M. E.; Schwabe, K.; Connor, J.; Kirby, M.

    2010-04-01

    With increasing urban, industrial, and agricultural water demand and projected reduced supply under climate change, allocations to the environment are critically low in many arid and semiarid basins. Consequently, many governments are striving to augment environmental flows, often through market-oriented mechanisms that involve compensating irrigated agriculture, the largest water user in most basins, for reducing diversions. A widely documented challenge with policies to recover water for the environment arises because part of the water diversion reduction can form the basis for downstream consumptive water rights or environmental flows. This article gives an empirical comparison of two incentive policies to acquire water for environmental flows for a part of the Murray-Darling Basin (MDB), Australia. One policy consists of paying irrigators and water delivery firms to make capital and management investments that improve on-farm irrigation and water-conveyance; the other policy consists of having the government buy water from irrigators on the active MDB water market. The results show that the first option results in relatively larger return flow reduction, while the second option tends to induce significant irrigated land retirement with relatively large reductions in consumptive use and small reductions in return flow. In cases where irrigation losses result in little useful return flow (e.g., evaporative loss reduction or during drought in some instances), efficiency-improving investments may provide some cost-effective opportunities. Where a large portion of loss forms valuable return flow, it is difficult to make a case for the cost-effectiveness of policies involving payments for investments in irrigation and conveyance system upgrades.

  2. Mercury Sample Return using Solar Sails

    NASA Astrophysics Data System (ADS)

    Young, Roy; Montgomery, E.; Adams, C.

    2006-12-01

    Over the previous three years NASA’s In-Space Propulsion Technology (ISPT) Program has matured solar sail technology from laboratory components to full systems, demonstrated in as relevant a space environment as could be simulated on the ground. Solar sail propulsion uses sunlight to propel vehicles through space by reflecting solar photons from a large sails made of a lightweight, reflective material. With photonic pressure providing continuous thrust, sailcraft can conduct missions not available with conventional propulsion: • high-inclination plane changes • flyby or rendezvous missions to outer solar system objects • non-Keplarian orbits (e.g. above the pole of a planet) • hovering indefinitely near a Lagrange point in space To illustrate the capabilities of solar sails, the results of an European Space Agency Mercury Sample Return study using solar sails is described and compared with a mission using conventional propulsion. A conventional Mercury sample return mission requires significant launch mass due to the large Δv required for the outbound and return trips, and the large mass of a planetary lander and ascent vehicle. Solar sailing can reduce mass by delivering the lander to a low, orbit close to the terminator and providing the Δv for the return flight. The mission concept calls for a 275 m sail to deliver a lander, cruise stage and science payload to a Sun-synchronous orbit at Mercury in 2.85 years. The lander acquires samples, and conducts limited surface exploration. An ascent vehicle delivers a small vehicle containing the samples for transfer to the solar sail. The solar sail then spirals back to Earth in 1 year. Solar sailing reduces launch mass by 60% and trip time by 40%, relative to conventional mission concepts. Results of technology development activities sponsored by the ISPT Program will be provided to demonstrate the level of technology readiness for such missions.

  3. Earnings Quality Measures and Excess Returns

    PubMed Central

    Perotti, Pietro; Wagenhofer, Alfred

    2014-01-01

    This paper examines how commonly used earnings quality measures fulfill a key objective of financial reporting, i.e., improving decision usefulness for investors. We propose a stock-price-based measure for assessing the quality of earnings quality measures. We predict that firms with higher earnings quality will be less mispriced than other firms. Mispricing is measured by the difference of the mean absolute excess returns of portfolios formed on high and low values of a measure. We examine persistence, predictability, two measures of smoothness, abnormal accruals, accruals quality, earnings response coefficient and value relevance. For a large sample of US non-financial firms over the period 1988–2007, we show that all measures except for smoothness are negatively associated with absolute excess returns, suggesting that smoothness is generally a favorable attribute of earnings. Accruals measures generate the largest spread in absolute excess returns, followed by smoothness and market-based measures. These results lend support to the widespread use of accruals measures as overall measures of earnings quality in the literature. PMID:26300582

  4. Planetary protection for Mars sample return

    NASA Astrophysics Data System (ADS)

    Gershman, R.; Adams, M.; Mattingly, R.; Rohatgi, N.; Corliss, J.; Dillman, R.; Fragola, J.; Minarick, J.

    2004-01-01

    A Mars sample return (MSR) mission must deal with two new categories of planetary protection requirements: (1) assuring a very low probability of inadvertent release of the sample in order to provide extra protection against the extremely unlikely possibility of biological hazards in the returned material and (2) keeping the samples free of round-trip Earth organisms to facilitate confirmation of safety after return to Earth. This paper describes the planetary-protection-related technical challenges awaiting an MSR mission as well as the range of capabilities being developed to meet these challenges. Containment assurance requires breaking the chain of contact with Mars: the exterior of the sample container must not be contaminated with Mars material. The sample container and its seals must be designed to survive Earth impacts corresponding to the candidate mission profiles, and the Earth entry vehicle must be designed to withstand the thermal and structural rigors of Earth atmosphere entry (all with an unprecedented degree of confidence). Sample contamination must be avoided by sterilizing the entire spacecraft, a challenge with modern avionics, or by sterilizing the sample collection and containment gear and then isolating it from other parts of the spacecraft.

  5. Taking aims seriously: repository research and limits on the duty to return individual research findings

    PubMed Central

    Ossorio, Pilar

    2013-01-01

    Most discussions of researchers’ duties to return incidental findings or research results to research participants or repository contributors fail to provide an adequate theoretical grounding for such duties. Returning findings is a positive duty, a duty to help somebody. Typically, such duties are specified narrowly such that helping is only a duty when it poses little or no risk or burden to the helper and does not interfere with her legitimate aims. Under current budgetary and personnel constraints, and with currently available information technology, routine return of individual findings from research using repository materials would constitute a substantial burden on the scientific enterprise and would seriously frustrate the aims of both scientists and specimen/data contributors. In most cases, researchers’ limited duties to help repository contributors probably can be fulfilled by some action less demanding than returning individual findings. Furthermore, the duty-to-return issue should be analyzed as a conflict between (possibly) helping some contributors now and (possibly) helping a greater number of people who would benefit in the future from the knowledge produced by research. PMID:22402758

  6. School Leadership Preparation and Development in Kenya: Evaluating Performance Impact and Return on Leadership Development Investment

    ERIC Educational Resources Information Center

    Asuga, Gladys; Eacott, Scott; Scevak, Jill

    2015-01-01

    Purpose: The purpose of this paper is to evaluate the quality of the current provision for school leadership in Kenya, the extent to which they have an impact on student outcomes and the return on school leadership preparation and development investment. Design/Methodology/Approach: The paper draws from educational leadership, management and…

  7. Malaria is an important differential diagnosis in visitors returning from Sri Lankan National Safari Parks.

    PubMed

    Fernando, Sumadhya D; Paranavitane, Sarath; Galappaththy, Gawrie N L

    2011-01-01

    Diagnostic confusion may occur between dengue and malaria when febrile patients with thrombocytopenia return from travel to previous malaria endemic areas. Laboratory tests should include blood smear examination for malaria parasites even though current malaria endemicity in Sri Lanka is low.

  8. Is It Ever Too Late to Study? The Economic Returns on Late Tertiary Degrees in Sweden

    ERIC Educational Resources Information Center

    Hallsten, Martin

    2012-01-01

    This paper addresses the economic returns on tertiary degrees obtained in ages above 30 for individuals with upper-secondary schooling in light of current ideas on lifelong learning. Sweden is a case in point: Swedish tertiary education is open to older students, and labor market legislation supports employees who take a leave to study. The…

  9. Severe malaria not responsive to artemisinin derivatives in man returning from Angola to Vietnam.

    PubMed

    Van Hong, Nguyen; Amambua-Ngwa, Alfred; Tuan, Nguyen Quang; Cuong, Do Duy; Giang, Nguyen Thi Huong; Van Dung, Nguyen; Tinh, Ta Thi; Van Tien, Nguyen; Phuc, Bui Quang; Duong, Tran Thanh; Rosanas-Urgell, Anna; D'Alessandro, Umberto; Van Geertruyden, Jean-Pierre; Erhart, Annette

    2014-07-01

    Resistance to artemisinin derivatives, the most potent antimalarial drugs currently used, has emerged in Southeast Asia and threatens to spread to Africa. We report a case of malaria in a man who returned to Vietnam after 3 years in Angola that did not respond to intravenous artesunate and clindamycin or an oral artemisinin-based combination.

  10. Brain Gain or Brain Circulation? U.S. Doctoral Recipients Returning to South Korea

    ERIC Educational Resources Information Center

    Lee, Jenny J.; Kim, Dongbin

    2010-01-01

    This study explored the reasons for current reverse mobility patterns in South Korea and how the country benefits from returning U.S. doctoral recipients in the forms of brain gain and brain circulation. Based on interviews of Korean faculty who studied in the U.S., this study found that while the political economy might help to explain why Korean…

  11. A Four Year Follow-Up of Non-Returning Students at Montgomery College.

    ERIC Educational Resources Information Center

    Gell, Robert L.; And Others

    An annual survey of non-returning Montgomery College students from the years 1971 to 1973 was conducted in order to examine reasons for choosing to leave the college, identify trends, determine the status of students at the time of the survey, and assess the impact of their college experience on current activities. The 454 usable responses (20…

  12. Energy Return On Investment of Engineered Geothermal Systems Data

    DOE Data Explorer

    Mansure, Chip

    2012-01-01

    The project provides an updated Energy Return on Investment (EROI) for Enhanced Geothermal Systems (EGS). Results incorporate Argonne National Laboratory's Life Cycle Assessment and base case assumptions consistent with other projects in the Analysis subprogram. EROI is a ratio of the energy delivered to the consumer to the energy consumed to build, operate, and decommission the facility. EROI is important in assessing the viability of energy alternatives. Currently EROI analyses of geothermal energy are either out-of-date, of uncertain methodology, or presented online with little supporting documentation. This data set is a collection of files documenting data used to calculate the Energy Return On Investment (EROI) of Engineered Geothermal Systems (EGS) and erratum to publications prior to the final report. Final report is available from the OSTI web site (http://www.osti.gov/geothermal/). Data in this collections includes the well designs used, input parameters for GETEM, a discussion of the energy needed to haul materials to the drill site, the baseline mud program, and a summary of the energy needed to drill each of the well designs. EROI is the ratio of the energy delivered to the customer to the energy consumed to construct, operate, and decommission the facility. Whereas efficiency is the ratio of the energy delivered to the customer to the energy extracted from the reservoir.

  13. Zika without symptoms in returning travellers: What are the implications?

    PubMed

    Ginier, Mylène; Neumayr, Andreas; Günther, Stephan; Schmidt-Chanasit, Jonas; Blum, Johannes

    2016-01-01

    Against the background of the emergence and rapid spread of Zika virus (ZIKV) in the Americas, we report the case of an afebrile ZIKV infection in a traveller returning from Central America to highlight relevant clinical and diagnostic aspects. ZIKV should be considered in the differential diagnosis of patients with clinical symptoms suggestive of dengue or chikungunya fever. Given the frequent subfebril and afebrile manifestations of ZIKV infections, we propose abstaining from the term "Zika fever (ZF)" in favour of "Zika virus disease (ZVD)". Owing to its unspecific clinical presentation and cross-reactivity in serological assays, ZVD may easily be missed or misdiagnosed as dengue fever. Until conclusive data on the currently suspected link between ZIKV infection in pregnancy and foetal microcephaly become available, pregnant women and women who are trying to become pregnant should be advised against travelling to regions with ongoing ZIKV transmission. In addition, male travellers returning from regions with ongoing transmission should be informed of the potential risk of sexual transmission until conclusive data on the significance of this mode of transmission become available. Although probably low and seasonally restricted, there is a risk of ZIKV importation to Aedes mosquito-infested regions in temperate climates (including regions of North America and Europe) with consecutive autochthonous transmission.

  14. Scientific Collaborations: How Do We Measure the Return on Relationships?

    PubMed Central

    Fair, Jeanne M.; Stokes, Martha Mangum; Pennington, Deana; Mendenhall, Ian H.

    2016-01-01

    Emerging infectious diseases (EIDs), the majority of which are zoonotic, represent a tremendous challenge for public health and biosurveillance infrastructure across the globe. Due to the complexity of zoonotic pathogens, it is essential that research and response to EIDs be a transdisciplinary effort. And while crisis and circumstance may be the initial catalyst for responding to an outbreak, we provide examples of how transdisciplinary scientific collectives, which are organized and solidified in advance of crises, can transform the way the world responds to outbreaks and in some cases could even prevent one from occurring (1). Current methods for assessing whether a cooperative engagement between countries is producing measurable and sustainable value is based on the ideas of return on investment and do not consider the inherent importance of relationships. In this article, we apply the idea of return on relationships (ROR) and propose a method for measuring ROR, using a system dynamics modeling framework commonly used in epidemiology. Tracking the numerous and diverse scientific collaborations that emerged from a training workshop for biosurveillance of bats held in Singapore in 2014, we apply a methodology for visualizing and measuring the relationship networks and outcomes that result. Additionally, the collaborative, multidisciplinary network that coalesced in response to the Hantavirus outbreak in New Mexico is 1993 is discussed as an example of the long-term benefits of ROR. PMID:26913278

  15. 2016 Consensus statement on return to sport from the First World Congress in Sports Physical Therapy, Bern.

    PubMed

    Ardern, Clare L; Glasgow, Philip; Schneiders, Anthony; Witvrouw, Erik; Clarsen, Benjamin; Cools, Ann; Gojanovic, Boris; Griffin, Steffan; Khan, Karim M; Moksnes, Håvard; Mutch, Stephen A; Phillips, Nicola; Reurink, Gustaaf; Sadler, Robin; Silbernagel, Karin Grävare; Thorborg, Kristian; Wangensteen, Arnlaug; Wilk, Kevin E; Bizzini, Mario

    2016-07-01

    Deciding when to return to sport after injury is complex and multifactorial-an exercise in risk management. Return to sport decisions are made every day by clinicians, athletes and coaches, ideally in a collaborative way. The purpose of this consensus statement was to present and synthesise current evidence to make recommendations for return to sport decision-making, clinical practice and future research directions related to returning athletes to sport. A half day meeting was held in Bern, Switzerland, after the First World Congress in Sports Physical Therapy. 17 expert clinicians participated. 4 main sections were initially agreed upon, then participants elected to join 1 of the 4 groups-each group focused on 1 section of the consensus statement. Participants in each group discussed and summarised the key issues for their section before the 17-member group met again for discussion to reach consensus on the content of the 4 sections. Return to sport is not a decision taken in isolation at the end of the recovery and rehabilitation process. Instead, return to sport should be viewed as a continuum, paralleled with recovery and rehabilitation. Biopsychosocial models may help the clinician make sense of individual factors that may influence the athlete's return to sport, and the Strategic Assessment of Risk and Risk Tolerance framework may help decision-makers synthesise information to make an optimal return to sport decision. Research evidence to support return to sport decisions in clinical practice is scarce. Future research should focus on a standardised approach to defining, measuring and reporting return to sport outcomes, and identifying valuable prognostic factors for returning to sport. PMID:27226389

  16. 2016 Consensus statement on return to sport from the First World Congress in Sports Physical Therapy, Bern.

    PubMed

    Ardern, Clare L; Glasgow, Philip; Schneiders, Anthony; Witvrouw, Erik; Clarsen, Benjamin; Cools, Ann; Gojanovic, Boris; Griffin, Steffan; Khan, Karim M; Moksnes, Håvard; Mutch, Stephen A; Phillips, Nicola; Reurink, Gustaaf; Sadler, Robin; Silbernagel, Karin Grävare; Thorborg, Kristian; Wangensteen, Arnlaug; Wilk, Kevin E; Bizzini, Mario

    2016-07-01

    Deciding when to return to sport after injury is complex and multifactorial-an exercise in risk management. Return to sport decisions are made every day by clinicians, athletes and coaches, ideally in a collaborative way. The purpose of this consensus statement was to present and synthesise current evidence to make recommendations for return to sport decision-making, clinical practice and future research directions related to returning athletes to sport. A half day meeting was held in Bern, Switzerland, after the First World Congress in Sports Physical Therapy. 17 expert clinicians participated. 4 main sections were initially agreed upon, then participants elected to join 1 of the 4 groups-each group focused on 1 section of the consensus statement. Participants in each group discussed and summarised the key issues for their section before the 17-member group met again for discussion to reach consensus on the content of the 4 sections. Return to sport is not a decision taken in isolation at the end of the recovery and rehabilitation process. Instead, return to sport should be viewed as a continuum, paralleled with recovery and rehabilitation. Biopsychosocial models may help the clinician make sense of individual factors that may influence the athlete's return to sport, and the Strategic Assessment of Risk and Risk Tolerance framework may help decision-makers synthesise information to make an optimal return to sport decision. Research evidence to support return to sport decisions in clinical practice is scarce. Future research should focus on a standardised approach to defining, measuring and reporting return to sport outcomes, and identifying valuable prognostic factors for returning to sport.

  17. Extreme Volcanic Eruptions: return periods, impact and implications (Invited)

    NASA Astrophysics Data System (ADS)

    Sparks, R. S.

    2010-12-01

    In the very short history of civilisation, a few thousand years, there have been comparably few very large volcanic events which global effects. Such events include very large lavas flow eruptions, such as Laki (Iceland) in 1783 and major caldera-forming explosive eruptions, such as Tambora in 1815 and Tianchi around 930 AD. Much larger magnitude eruptions have happened regularly when time scales of millions of years are considered. The modern globalised world is arguably uniquely vulnerable to very large volcanic events, making the study of their return periods, possible environmental effects and consequences a key goal of volcanology. A database of Quaternary large magnitude explosive eruptions (M ≥ 4) is under development as part of the VOGRIPA project on global volcanic hazards and risk. The database, currently consisting of 1929 entries from 481 Quaternary volcanoes, can be applied to constraining the magnitude-frequency relationship of global and regional explosive volcanism. Application of extreme value statistics to a Holocene subset of data, corrected for under-recording, enables construction of a magnitude-frequency relationship for global volcanism. Return periods based on maximum likelihood statistical analysis are 7.9 years for M ≥ 4, 35 years for M ≥ 5, and 370 years for M ≥ 7.0 with uncertainty increasing with magnitude. The return periods depend on the threshold chosen between the main part of the distribution and the extreme value tail and the results cited here are for a threshold of M = 4. For the largest magnitude eruptions (M > 7.5) the Holocene period is too short to obtain a meaningful result. The effects if an eruption like Tambora 1815 (M ~ 6.9) in the modern world is likely to be dramatic as the populations in SE Asia are now well over 20 time greater and the socio-economic vulnerability has also increased. Effects will include atmospheric pollution lasting a few years, major global climate perturbations and regional disruption

  18. 78 FR 49296 - Centennial Challenges 2014 Sample Return Robot Challenge

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-13

    ... SPACE ADMINISTRATION Centennial Challenges 2014 Sample Return Robot Challenge AGENCY: National Aeronautics and Space Administration (NASA). ACTION: Notice of Centennial Challenges 2014 Sample Return Robot... Robot Challenge is scheduled and teams that wish to compete may register. Centennial Challenges is...

  19. Brief Return of Concussion Symptoms Normal Part of Recovery

    MedlinePlus

    ... gov/news/fullstory_160281.html Brief Return of Concussion Symptoms Normal Part of Recovery: Study It's not ... common for children who've suffered a mild concussion to experience a return of symptoms when they ...

  20. 46 CFR 111.05-11 - Hull return.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... REQUIREMENTS Equipment Ground, Ground Detection, and Grounded Systems § 111.05-11 Hull return. (a) A vessel's... conditions. (4) Welding systems with hull return except vessels subject to 46 CFR Subchapter D....

  1. 46 CFR 111.05-11 - Hull return.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... REQUIREMENTS Equipment Ground, Ground Detection, and Grounded Systems § 111.05-11 Hull return. (a) A vessel's... conditions. (4) Welding systems with hull return except vessels subject to 46 CFR Subchapter D....

  2. 46 CFR 111.05-11 - Hull return.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... REQUIREMENTS Equipment Ground, Ground Detection, and Grounded Systems § 111.05-11 Hull return. (a) A vessel's... conditions. (4) Welding systems with hull return except vessels subject to 46 CFR Subchapter D....

  3. Take Me "Home": Return Migration among Germany's Older Immigrants.

    PubMed

    Yahirun, Jenjira J

    2014-08-01

    This paper examines the determinants of return migration as foreign-born men approach old age in Germany. Return migration in later life engages a different set of conditions than return migration earlier on, including the framing of return as a possible retirement strategy. Using 23 years of longitudinal data from the German Socioeconomic Panel, this paper investigates how social and economic resources of immigrant men influence decisions to return "home." Results suggest that immigrants from former guest worker recruitment countries within the European Union are more likely to return than non-E.U. immigrants. In addition, return migrants are "negatively selected" such that those with the least education and weakest attachments to the labor force are more likely to emigrate. However, findings vary greatly depending on the immigrant's age and country of origin. Results from this paper highlight the heterogeneity of older immigrants and the factors that motivate their return "home."

  4. NASA's Planned Return to the Moon: Global Access and Anytime Return Requirement Implications on the Lunar Orbit Insertion Burns

    NASA Technical Reports Server (NTRS)

    Garn, Michelle; Qu, Min; Chrone, Jonathan; Su, Philip; Karlgaard, Chris

    2008-01-01

    Lunar orbit insertion LOI is a critical maneuver for any mission going to the Moon. Optimizing the geometry of this maneuver is crucial to the success of the architecture designed to return humans to the Moon. LOI burns necessary to meet current NASA Exploration Constellation architecture requirements for the lunar sortie missions are driven mainly by the requirement for global access and "anytime" return from the lunar surface. This paper begins by describing the Earth-Moon geometry which creates the worst case (delta)V for both the LOI and the translunar injection (TLI) maneuvers over the full metonic cycle. The trajectory which optimizes the overall (delta)V performance of the mission is identified, trade studies results covering the entire lunar globe are mapped onto the contour plots, and the effects of loitering in low lunar orbit as a means of reducing the insertion (delta)V are described. Finally, the lighting conditions on the lunar surface are combined with the LOI and TLI analyses to identify geometries with ideal lighting conditions at sites of interest which minimize the mission (delta)V.

  5. Doppler radar having phase modulation of both transmitted and reflected return signals

    NASA Technical Reports Server (NTRS)

    Kobayashi, H. S.; Shores, P. W.; Rozas, P. (Inventor)

    1984-01-01

    A microwave radar signal is generated for transmission through an antenna. Before transmission, the signal is phase modulated by 0 deg or 90 deg amounts during each alternate half-cycles of an intermediate frequency (IF) clock signal. After transmission and return, the signal is again phase modulated the same amounts during each alternate half-cycles. The return phase modulated signal is mixed with a leakage signal component of the microwave signal, leaving an IF Doppler. The IF Doppler signal may then be amplified, removing any requirement that direct current level signals be amplified and also removing the effect of detector noise from the Doppler signal.

  6. Calculations of lightning return stroke electric and magnetic fields above ground

    NASA Technical Reports Server (NTRS)

    Master, M. J.; Uman, M. A.; Ling, Y. T.; Standler, R. B.

    1981-01-01

    Lin et al., (1980) presented a lightning return stroke model with which return stroke electric and magnetic fields measured at ground level could be reproduced. This model and a modified version of it, in which the initial current peak decays with height above ground, are used to compute waveforms for altitudes from 0-10 km and at ranges of 20 m to 10 km. Both the original and modified models gave accurate predictions of measured ground-based fields. The use of the calculated fields in calibrating airborne field measurements from simultaneous ground and airborne data is discussed.

  7. The changes on physical characteristics of lightning discharge plasma during individual return stroke process

    SciTech Connect

    Xu, He; Yuan, Ping; Cen, Jian-Yong; Zhang, Guang-Shu

    2014-03-15

    A cloud-to-ground lightning with six return strokes has been recorded with a slit-less spectrograph in Qinghai province. According to the spectra of return strokes without continuous current, the electron density, the channel temperature, and the gas pressure have been calculated. Then, the correlativity of these parameters has been analyzed. The results indicate that the total intensity of spectra is positive correlated to the intensity of spectral line, they both decrease with time rapidly; furthermore, the channel temperature and the gas pressure decrease with time slowly in the similar trends.

  8. Re-entry and reintegration: returning home after combat.

    PubMed

    Doyle, Michael E; Peterson, Kris A

    2005-01-01

    Soldier life exists on a continuum of readiness for deployment. Re-entry and reintegration-the return home and reunion with family and community-key the success of the deployment cycle. In current and projected future operations, the Army and society will both bear the burden of this re-entry and re-integration. Programs and procedures in place work towards improving communication, mitigating distress and resolving crises during reentry and reintegration. Key elements include: inclusion of families and communities early into the planning for reentry and reintegration; normalization (non-medicalization of distress); easy access to behavioral health professionals; and education of families on resources and benefits. Through broad collaboration, maximal benefit to the Soldier, family members and society be realized.

  9. Mars sample return mission: What level of complexity

    NASA Technical Reports Server (NTRS)

    Ciesla, Thomas M.

    1988-01-01

    The complexity of the U.S. Sample Return Mission is ultimately dependent on current mission funding and the projected direction of the U.S. space program. Despite these uncertainties, it is important to examine mission scenarios to address desired scientific objectives that can be summarized in the following list: (1) determine existence of climatic records in geologic records; (2) does Mars have a subpermafrost groundwater system; (3) fundamental questions on the existence of Mars biology; (4) what is the internal structure of Mars; (5) determine the systems for regolith formation; and (6) what is the contribution of meteorites to Martian geology and climate are presented. To address these objectives, the sample size, quantity and location must be established and whether this should be the only data searched for on the Martian surface. With this in mind, three mission scenarios are briefly discussed, in order of increasing complexity.

  10. Returning Physicians to the Workforce: History, Progress, and Challenges

    ERIC Educational Resources Information Center

    Varjavand, Nielufar; Novack, Dennis H.; Schindler, Barbara A.

    2012-01-01

    There is growing recognition of the need to reeducate clinically inactive physicians seeking to return to practice and in the facilitation of this return. Physicians seeking to return to practice face many challenges: maneuvering the various requirements of licensing, medical, and credentialing boards; finding an appropriate educational program to…

  11. Project Return and Babygram Hospital Outreach, 1993-94.

    ERIC Educational Resources Information Center

    Weiler, Jeanne

    Project Return, a dropout recovery program to assist pregnant and parenting teenagers and parents of elementary school children to return to school, was first implemented in 1989-90, and by 1993-94 had expanded to serve 19 sites in New York City. The Babygram Hospital Outreach program, an outgrowth of Project Return, operated in 12 hospitals and…

  12. 26 CFR 1.6012-3 - Returns by fiduciaries.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... trusts—(1) In general. Every fiduciary, or at least one of joint fiduciaries, must make a return of... taxable income by section 511(b)(1) shall make a return on Form 990-T for each taxable year if the trust... filing of a joint return after death of spouse, see paragraph (d) of § 1.6013-1. (2) Nonresident...

  13. 27 CFR 25.211 - Beer returned to brewery.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Beer returned to brewery..., DEPARTMENT OF THE TREASURY LIQUORS BEER Beer Returned to Brewery § 25.211 Beer returned to brewery. (a) General. Beer, produced in the United States, on which the brewer has paid or determined the tax may...

  14. 26 CFR 48.6416(f)-1 - Credit on returns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Credit on returns. 48.6416(f)-1 Section 48.6416... Special Application to Retailers and Manufacturers Taxes § 48.6416(f)-1 Credit on returns. Any person..., in lieu of claiming refund of the overpayment, claim credit for the overpayment on any return of...

  15. 27 CFR 25.211 - Beer returned to brewery.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Beer returned to brewery..., DEPARTMENT OF THE TREASURY ALCOHOL BEER Beer Returned to Brewery § 25.211 Beer returned to brewery. (a) General. Beer, produced in the United States, on which the brewer has paid or determined the tax may...

  16. 27 CFR 25.211 - Beer returned to brewery.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Beer returned to brewery..., DEPARTMENT OF THE TREASURY ALCOHOL BEER Beer Returned to Brewery § 25.211 Beer returned to brewery. (a) General. Beer, produced in the United States, on which the brewer has paid or determined the tax may...

  17. 27 CFR 25.211 - Beer returned to brewery.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Beer returned to brewery..., DEPARTMENT OF THE TREASURY LIQUORS BEER Beer Returned to Brewery § 25.211 Beer returned to brewery. (a) General. Beer, produced in the United States, on which the brewer has paid or determined the tax may...

  18. 26 CFR 1.857-10 - Information returns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 9 2010-04-01 2010-04-01 false Information returns. 1.857-10 Section 1.857-10...) INCOME TAXES Real Estate Investment Trusts § 1.857-10 Information returns. Nothing in §§ 1.857-8 and 1... of filing information returns required by regulations prescribed under the provisions of subchapter...

  19. 26 CFR 301.6063-1 - Signing of partnership returns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Signing of partnership returns. 301.6063-1 Section 301.6063-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED....6063-1 Signing of partnership returns. For provisions relating to the signing of returns of...

  20. 21 CFR 870.4420 - Cardiopulmonary bypass cardiotomy return sucker.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass cardiotomy return sucker... Cardiopulmonary bypass cardiotomy return sucker. (a) Identification. A cardiopulmonary bypass cardiotomy return... from the chest or heart during cardiopulmonary bypass surgery. (b) Classification. Class...

  1. 76 FR 56819 - Centennial Challenges 2012 Sample Return Robot Challenge

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-14

    ... SPACE ADMINISTRATION Centennial Challenges 2012 Sample Return Robot Challenge AGENCY: National... 42 U.S.C. 2451(314)(d). The 2012 Sample Return Robot Challenge is scheduled and teams that wish to... technologies of interest and value to NASA and the nation. The 2012 Sample Return Robot Challenge is a...

  2. 27 CFR 25.211 - Beer returned to brewery.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Beer returned to brewery..., DEPARTMENT OF THE TREASURY LIQUORS BEER Beer Returned to Brewery § 25.211 Beer returned to brewery. (a) General. Beer, produced in the United States, on which the brewer has paid or determined the tax may...

  3. 10 CFR 436.22 - Adjusted internal rate of return.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Methodology and Procedures for Life Cycle Cost Analyses § 436.22 Adjusted internal rate of return. The adjusted internal rate of return is the overall rate of return on an energy or water conservation measure... yearly net savings in energy or water and non-fuel or non-water operation and maintenance...

  4. 10 CFR 436.22 - Adjusted internal rate of return.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Methodology and Procedures for Life Cycle Cost Analyses § 436.22 Adjusted internal rate of return. The adjusted internal rate of return is the overall rate of return on an energy or water conservation measure... yearly net savings in energy or water and non-fuel or non-water operation and maintenance...

  5. Supporting Women Returning to Work: A European Perspective.

    ERIC Educational Resources Information Center

    Shepherd, Jan; Saxby-Smith, Sue

    A 2-year project examined the effectiveness of courses for returning workers in enabling women to make a sustained return to paid employment in the following countries: France; Spain; Ireland; and the United Kingdom. In each country, a short foundation-level program and a longer accredited return-to-work program were selected for evaluation.…

  6. 27 CFR 40.167 - Prepayment tax return.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Prepayment tax return. 40... Taxes on Tobacco Products § 40.167 Prepayment tax return. (a) To prepay the tax on tobacco products a manufacturer shall file a prepayment tax return on Form 5000.24 showing the tax to be paid on the...

  7. 26 CFR 26.7701-1 - Tax return preparer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false Tax return preparer. 26.7701-1 Section 26.7701... TAXES GENERATION-SKIPPING TRANSFER TAX REGULATIONS UNDER THE TAX REFORM ACT OF 1986 § 26.7701-1 Tax return preparer. (a) In general. For the definition of a tax return preparer, see § 301.7701-15 of...

  8. 26 CFR 20.7701-1 - Tax return preparer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false Tax return preparer. 20.7701-1 Section 20.7701... TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 General Actuarial Valuations § 20.7701-1 Tax return preparer. (a) In general. For the definition of a tax return preparer, see §...

  9. 26 CFR 25.7701-1 - Tax return preparer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false Tax return preparer. 25.7701-1 Section 25.7701... TAXES GIFT TAX; GIFTS MADE AFTER DECEMBER 31, 1954 General Actuarial Valuations § 25.7701-1 Tax return preparer. (a) In general. For the definition of a tax return preparer, see § 301.7701-15 of this...

  10. 27 CFR 40.163 - Semimonthly tax return periods.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Semimonthly tax return... Payment of Taxes on Tobacco Products § 40.163 Semimonthly tax return periods. Except as provided in section 40.164, the periods to be covered by semimonthly tax returns shall be from the 1st day of...

  11. 26 CFR 40.7701-1 - Tax return preparer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Tax return preparer. 40.7701-1 Section 40.7701-1... TAXES EXCISE TAX PROCEDURAL REGULATIONS § 40.7701-1 Tax return preparer. (a) In general. For the definition of a tax return preparer, see § 301.7701-15 of this chapter. (b) Effective/applicability...

  12. 27 CFR 24.323 - Excise Tax Return form.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Excise Tax Return form. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.323 Excise Tax Return form. A proprietor who removes wine subject to tax shall prepare an TTB F 5000.24, Excise Tax Return, unless exempted under...

  13. 26 CFR 41.7701-1 - Tax return preparer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Tax return preparer. 41.7701-1 Section 41.7701-1... Application to Tax On Use of Certain Highway Motor Vehicles § 41.7701-1 Tax return preparer. (a) In general. For the definition of a tax return preparer, see § 301.7701-15 of this chapter. (b)...

  14. 10 CFR 436.22 - Adjusted internal rate of return.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Adjusted internal rate of return. 436.22 Section 436.22 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION FEDERAL ENERGY MANAGEMENT AND PLANNING PROGRAMS... adjusted internal rate of return is the overall rate of return on an energy or water conservation...

  15. 10 CFR 436.22 - Adjusted internal rate of return.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Adjusted internal rate of return. 436.22 Section 436.22 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION FEDERAL ENERGY MANAGEMENT AND PLANNING PROGRAMS... adjusted internal rate of return is the overall rate of return on an energy or water conservation...

  16. 26 CFR 1.542-4 - Corporations filing consolidated returns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Corporations filing consolidated returns. 1.542-4... consolidated returns. (a) General rule. A consolidated return under section 1501 shall determine the... consolidated gross income and consolidated personal holding company income of the group, as determined...

  17. 26 CFR 1.542-4 - Corporations filing consolidated returns.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 7 2011-04-01 2009-04-01 true Corporations filing consolidated returns. 1.542-4... consolidated returns. (a) General rule. A consolidated return under section 1501 shall determine the... consolidated gross income and consolidated personal holding company income of the group, as determined...

  18. 26 CFR 1.1502-79 - Separate return years.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 12 2013-04-01 2013-04-01 false Separate return years. 1.1502-79 Section 1.1502... years. (a) Carryover and carryback of consolidated net operating losses to separate return years. For losses arising in consolidated return years beginning before January 1, 1997, see § 1.1502-79A(a)....

  19. 26 CFR 1.1502-79 - Separate return years.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 12 2012-04-01 2012-04-01 false Separate return years. 1.1502-79 Section 1.1502... years. (a) Carryover and carryback of consolidated net operating losses to separate return years. For losses arising in consolidated return years beginning before January 1, 1997, see § 1.1502-79A(a)....

  20. 26 CFR 1.1502-79 - Separate return years.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 12 2010-04-01 2010-04-01 false Separate return years. 1.1502-79 Section 1.1502... (CONTINUED) INCOME TAXES Administrative Provisions and Other Rules § 1.1502-79 Separate return years. (a) Carryover and carryback of consolidated net operating losses to separate return years. For losses arising...

  1. 26 CFR 1.1502-79 - Separate return years.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 12 2011-04-01 2011-04-01 false Separate return years. 1.1502-79 Section 1.1502... years. (a) Carryover and carryback of consolidated net operating losses to separate return years. For losses arising in consolidated return years beginning before January 1, 1997, see § 1.1502-79A(a)....

  2. 19 CFR 145.35 - United States products returned.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 2 2011-04-01 2011-04-01 false United States products returned. 145.35 Section... OF THE TREASURY (CONTINUED) MAIL IMPORTATIONS Special Classes of Merchandise § 145.35 United States products returned. Products of the United States returned after having been exported, which have not...

  3. 19 CFR 145.35 - United States products returned.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 2 2013-04-01 2013-04-01 false United States products returned. 145.35 Section... OF THE TREASURY (CONTINUED) MAIL IMPORTATIONS Special Classes of Merchandise § 145.35 United States products returned. Products of the United States returned after having been exported, which have not...

  4. 19 CFR 145.35 - United States products returned.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 2 2012-04-01 2012-04-01 false United States products returned. 145.35 Section... OF THE TREASURY (CONTINUED) MAIL IMPORTATIONS Special Classes of Merchandise § 145.35 United States products returned. Products of the United States returned after having been exported, which have not...

  5. 26 CFR 40.7701-1 - Tax return preparer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 16 2013-04-01 2013-04-01 false Tax return preparer. 40.7701-1 Section 40.7701... EXCISE TAXES EXCISE TAX PROCEDURAL REGULATIONS § 40.7701-1 Tax return preparer. (a) In general. For the definition of a tax return preparer, see § 301.7701-15 of this chapter. (b) Effective/applicability...

  6. 26 CFR 40.7701-1 - Tax return preparer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 16 2012-04-01 2012-04-01 false Tax return preparer. 40.7701-1 Section 40.7701... EXCISE TAXES EXCISE TAX PROCEDURAL REGULATIONS § 40.7701-1 Tax return preparer. (a) In general. For the definition of a tax return preparer, see § 301.7701-15 of this chapter. (b) Effective/applicability...

  7. 26 CFR 40.7701-1 - Tax return preparer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 16 2011-04-01 2011-04-01 false Tax return preparer. 40.7701-1 Section 40.7701... EXCISE TAXES EXCISE TAX PROCEDURAL REGULATIONS § 40.7701-1 Tax return preparer. (a) In general. For the definition of a tax return preparer, see § 301.7701-15 of this chapter. (b) Effective/applicability...

  8. 49 CFR 236.720 - Circuit, common return.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, common return. 236.720 Section 236.720... Circuit, common return. A term applied where one wire is used for the return of more than one electric circuit....

  9. 49 CFR 236.720 - Circuit, common return.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Circuit, common return. 236.720 Section 236.720... Circuit, common return. A term applied where one wire is used for the return of more than one electric circuit....

  10. 49 CFR 236.720 - Circuit, common return.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Circuit, common return. 236.720 Section 236.720... Circuit, common return. A term applied where one wire is used for the return of more than one electric circuit....

  11. Return to Play Following Anterior Cruciate Ligament Reconstruction.

    PubMed

    Morris, Ryan C; Hulstyn, Michael J; Fleming, Braden C; Owens, Brett D; Fadale, Paul D

    2016-10-01

    Anterior cruciate ligament reconstructions are commonly performed in an attempt to return an athlete to sports activities. Accelerated rehabilitation has made recovery for surgery more predictable and shortened the timeline for return to play. Despite success with and advancements in anterior cruciate ligament reconstructions, some athletes still fail to return to play. PMID:27543405

  12. 26 CFR 1.6012-6 - Returns by political organizations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 13 2011-04-01 2011-04-01 false Returns by political organizations. 1.6012-6... TAX (CONTINUED) INCOME TAXES (CONTINUED) Tax Returns Or Statements § 1.6012-6 Returns by political..., every political organization described in section 527(e)(1), and every fund described in section...

  13. 26 CFR 1.6012-6 - Returns by political organizations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 13 2010-04-01 2010-04-01 false Returns by political organizations. 1.6012-6... TAX (CONTINUED) INCOME TAXES Tax Returns Or Statements § 1.6012-6 Returns by political organizations... political organization described in section 527(e)(1), and every fund described in section 527(f)(3)...

  14. 26 CFR 1.6012-6 - Returns by political organizations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 13 2014-04-01 2014-04-01 false Returns by political organizations. 1.6012-6... TAX (CONTINUED) INCOME TAXES (CONTINUED) Tax Returns Or Statements § 1.6012-6 Returns by political..., every political organization described in section 527(e)(1), and every fund described in section...

  15. 75 FR 14539 - Furnishing Identifying Number of Tax Return Preparer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-26

    ... Internal Revenue Service 26 CFR Part 1 RIN 1545-BI28 Furnishing Identifying Number of Tax Return Preparer... guidance to tax return preparers on furnishing an identifying number on tax returns and claims for refund of tax that they prepare. These proposed regulations provide guidance on the identifying number of...

  16. 26 CFR 53.7701-1 - Tax return preparer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Tax return preparer. 53.7701-1 Section 53.7701... EXCISE TAXES (CONTINUED) FOUNDATION AND SIMILAR EXCISE TAXES Procedure and Administration § 53.7701-1 Tax return preparer. (a) In general. For the definition of a tax return preparer, see § 301.7701-15 of...

  17. 26 CFR 157.7701-1 - Tax return preparer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Tax return preparer. 157.7701-1 Section 157... EXCISE TAXES (CONTINUED) EXCISE TAX ON STRUCTURED SETTLEMENT FACTORING TRANSACTIONS Procedure and Administration § 157.7701-1 Tax return preparer. (a) In general. For the definition of a tax return preparer,...

  18. 26 CFR 56.7701-1 - Tax return preparer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Tax return preparer. 56.7701-1 Section 56.7701... EXCISE TAXES (CONTINUED) PUBLIC CHARITY EXCISE TAXES § 56.7701-1 Tax return preparer. (a) In general. For the definition of a tax return preparer, see § 301.7701-15 of this chapter. (b)...

  19. 26 CFR 156.7701-1 - Tax return preparer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Tax return preparer. 156.7701-1 Section 156... EXCISE TAXES (CONTINUED) EXCISE TAX ON GREENMAIL Procedure and Administration § 156.7701-1 Tax return preparer. (a) In general. For the definition of a tax return preparer, see § 301.7701-15 of this...

  20. 26 CFR 54.7701-1 - Tax return preparer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Tax return preparer. 54.7701-1 Section 54.7701... EXCISE TAXES (CONTINUED) PENSION EXCISE TAXES § 54.7701-1 Tax return preparer. (a) In general. For the definition of a tax return preparer, see § 301.7701-15 of this chapter. (b) Effective/applicability...