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Sample records for directe ou photostimulee

  1. Direct method for measuring and witnessing quantum entanglement of arbitrary two-qubit states through Hong-Ou-Mandel interference

    NASA Astrophysics Data System (ADS)

    Bartkiewicz, Karol; Chimczak, Grzegorz; Lemr, Karel

    2017-02-01

    We describe a direct method for experimental determination of the negativity of an arbitrary two-qubit state with 11 measurements performed on multiple copies of the two-qubit system. Our method is based on the experimentally accessible sequences of singlet projections performed on up to four qubit pairs. In particular, our method permits the application of the Peres-Horodecki separability criterion to an arbitrary two-qubit state. We explicitly demonstrate that measuring entanglement in terms of negativity requires three measurements more than detecting two-qubit entanglement. The reported minimal set of interferometric measurements provides a complete description of bipartite quantum entanglement in terms of two-photon interference. This set is smaller than the set of 15 measurements needed to perform a complete quantum state tomography of an arbitrary two-qubit system. Finally, we demonstrate that the set of nine Makhlin's invariants needed to express the negativity can be measured by performing 13 multicopy projections. We demonstrate both that these invariants are a useful theoretical concept for designing specialized quantum interferometers and that their direct measurement within the framework of linear optics does not require performing complete quantum state tomography.

  2. Tunable, nonlinear Hong-Ou-Mandel interferometer

    NASA Astrophysics Data System (ADS)

    Oehri, D.; Pletyukhov, M.; Gritsev, V.; Blatter, G.; Schmidt, S.

    2015-03-01

    We investigate the two-photon scattering properties of a Jaynes-Cummings (JC) nonlinearity consisting of a two-level system (qubit) interacting with a single-mode cavity, which is coupled to two waveguides, each containing a single incident photon wave packet initially. In this scattering setup, we study the interplay between the Hong-Ou-Mandel (HOM) effect arising due to quantum interference and effective photon-photon interactions induced by the presence of the qubit. We calculate the two-photon scattering matrix of this system analytically and identify signatures of interference and interaction in the second-order auto- and cross-correlation functions of the scattered photons. In the dispersive regime, when qubit and cavity are far detuned from each other, we find that the JC nonlinearity can be used as an almost linear, in situ tunable beam splitter giving rise to ideal Hong-Ou-Mandel interference, generating a highly path-entangled two-photon NOON state of the scattered photons. The latter manifests itself in strongly suppressed waveguide cross-correlations and Poissonian photon number statistics in each waveguide. If the two-level system and the cavity are on resonance, the JC nonlinearity strongly modifies the ideal HOM conditions leading to a smaller degree of path entanglement and sub-Poissonian photon number statistics. In the latter regime, we find that photon blockade is associated with bunched autocorrelations in both waveguides, while a two-polariton resonance can lead to bunched as well as antibunched correlations.

  3. Atomic Hong-Ou-Mandel experiment

    NASA Astrophysics Data System (ADS)

    Lopes, R.; Imanaliev, A.; Aspect, A.; Cheneau, M.; Boiron, D.; Westbrook, C. I.

    2015-04-01

    Two-particle interference is a fundamental feature of quantum mechanics, and is even less intuitive than wave-particle duality for a single particle. In this duality, classical concepts--wave or particle--are still referred to, and interference happens in ordinary space-time. On the other hand, two-particle interference takes place in a mathematical space that has no classical counterpart. Entanglement lies at the heart of this interference, as it does in the fundamental tests of quantum mechanics involving the violation of Bell's inequalities. The Hong, Ou and Mandel experiment is a conceptually simpler situation, in which the interference between two-photon amplitudes also leads to behaviour impossible to describe using a simple classical model. Here we report the realization of the Hong, Ou and Mandel experiment using atoms instead of photons. We create a source that emits pairs of atoms, and cause one atom of each pair to enter one of the two input channels of a beam-splitter, and the other atom to enter the other input channel. When the atoms are spatially overlapped so that the two inputs are indistinguishable, the atoms always emerge together in one of the output channels. This result opens the way to testing Bell's inequalities involving mechanical observables of massive particles, such as momentum, using methods inspired by quantum optics, and to testing theories of the quantum-to-classical transition. Our work also demonstrates a new way to benchmark non-classical atom sources that may be of interest for quantum information processing and quantum simulation.

  4. Atomic Hong-Ou-Mandel experiment.

    PubMed

    Lopes, R; Imanaliev, A; Aspect, A; Cheneau, M; Boiron, D; Westbrook, C I

    2015-04-02

    Two-particle interference is a fundamental feature of quantum mechanics, and is even less intuitive than wave-particle duality for a single particle. In this duality, classical concepts--wave or particle--are still referred to, and interference happens in ordinary space-time. On the other hand, two-particle interference takes place in a mathematical space that has no classical counterpart. Entanglement lies at the heart of this interference, as it does in the fundamental tests of quantum mechanics involving the violation of Bell's inequalities. The Hong, Ou and Mandel experiment is a conceptually simpler situation, in which the interference between two-photon amplitudes also leads to behaviour impossible to describe using a simple classical model. Here we report the realization of the Hong, Ou and Mandel experiment using atoms instead of photons. We create a source that emits pairs of atoms, and cause one atom of each pair to enter one of the two input channels of a beam-splitter, and the other atom to enter the other input channel. When the atoms are spatially overlapped so that the two inputs are indistinguishable, the atoms always emerge together in one of the output channels. This result opens the way to testing Bell's inequalities involving mechanical observables of massive particles, such as momentum, using methods inspired by quantum optics, and to testing theories of the quantum-to-classical transition. Our work also demonstrates a new way to benchmark non-classical atom sources that may be of interest for quantum information processing and quantum simulation.

  5. Spatial and temporal variation of the water quality of an intermittent river - Oued Fez (Morrocco)

    NASA Astrophysics Data System (ADS)

    Perrin, Jean-Louis; Bellarbi, Meriem; Lombard-Latune, Rémi; Rais, Naoual; Chahinian, Nanée.; Ijjaali, Mustafa

    2010-05-01

    In the South of the Mediterranean basin, many rivers are characterized by an alternation of very long dry periods only cut by short flood events. Currently, the socio-economical development of these zones is limited by the water scarcity but also by the poor quality of the water resources. In fact, human activities, generally concentrated in overpopulated cities, generate large quantity of domestic and industrial effluents which are directly rejected in the environment without any treatment. In Morocco, the well known city of Fez illustrates perfectly this situation observed in all the Maghreb countries. During the dry period, the Oued Fez which crosses the city, is only fed by non-treated anthropogenic inputs. Accumulation of pollutants is observed in the river bed sediments. Domestic and industrial effluents (200 000 m3/day) pollute all the down stream water bodies some of which are used for irrigation and other for fresh water supply. During floods, mainly generated by urban runoff, river bed sediments could be remobilized and a significant flush effect could occur. This study aims at characterising and quantifying the pollutant concentrations and fluxes in various points of the Oued Fez hydrological network and assessing its impact on the Sebou River; water resources of this river being considered as national priority in Morocco. Due to the peculiar Mediterranean hydrological regime, specific observation networks are set up to assess the temporal and spatial variability of pollutant fluxes in the river and to rank water and pollutant sources. The sampling sites on the Fez and Sebou oueds are selected based these criteria. A reference station is chosen upstream of the Oued Fez less than 300 metres from the direct anthropic inputs. Water quality is evaluated through nutrients (Total nitrogen, and total phosphorus essentially), heavy metals (essentially chromium) and suspended solids. The results of 4 sampling campaigns indicate that: in terms of nitrogen

  6. Hong-Ou-Mandel interferometer with one and two photon pairs

    NASA Astrophysics Data System (ADS)

    Cosme, Olavo; Pádua, S.; Bovino, Fabio A.; Mazzei, A.; Sciarrino, Fabio; de Martini, Francesco

    2008-05-01

    We study the Hong-Ou-Mandel interferometer in the regime of spontaneous parametric down-conversion with high pump beam power at the crystal. In this regime one and two photons from a pump pulsed laser beam generate one and two pairs of photons, respectively. These photons are then directed to the beam splitter of the interferometer and detected at its exit in coincidence. An interesting phenomenon is observed: The reduction of the visibility of the Hong-Ou-Mandel coincidence peak (or dip) with the increase of pump power. We study the relation between the visibility of the fourth-order interference pattern and the power of the pumping laser beam for type I and type II phase-matching crystals. Our theoretical calculations are in good agreement with the experimental results.

  7. Sidi Ali Ou Azza (L4): A New Moroccan Fall

    NASA Astrophysics Data System (ADS)

    Chennaoui Aoudjehane, H.; Agee, C. B.; Aaranson, A.; Bouragaa, A.

    2016-08-01

    Sidi Ali Ou Azza is the latest meteorite fall in Morocco, it occurred on 28 July 2015 very close (about 40 km) to Tissint martian shergottite fall that occurred on 18 July 2011. It's one of the small group of 23 L4 ordinary chondrite falls.

  8. Eielson Air Force Base OU-1 baseline risk assessment

    SciTech Connect

    Jarvis, M.T.; Jarvis, T.T.; Van Houten, N.C.; Lewis, R.E.

    1993-09-01

    This Baseline Risk Assessment report is the second volume in a set of three volumes for operable Unit 1 (OU-1). The companion documents contain the Remedial Investigation and the Feasibility Study. Operable Unit 1 (OU-1) is one of several groups of hazardous waste sites located at Eielson Air Force Base (AFB) near Fairbanks, Alaska. The operable units at Eielson are typically characterized by petroleum, oil, lubricant/solvent contamination, and by the presence of organics floating at the water table. In 1989 and 1990, firms under contract to the Air Force conducted field studies to gather information about the extent of chemical contamination in soil, groundwater, and soil air pore space (soil gas) at the site. This report documents the results of a baseline risk assessment, which uses the 1989 and 1991 site characterization database to quantify the potential human health risk associated with past Base industrial activities in the vicinity of OU-1. Background data collected in 1992 were also used in the preparation of this report.

  9. Hong-Ou-Mandel Interference with a Single Atom

    PubMed Central

    Ralley, K. A.; Lerner, I. V.; Yurkevich, I. V.

    2015-01-01

    The Hong-Ou-Mandel (HOM) effect is widely regarded as the quintessential quantum interference phenomenon in optics. In this work we examine how nonlinearity can smear statistical photon bunching in the HOM interferometer. We model both the nonlinearity and a balanced beam splitter with a single two-level system and calculate a finite probability of anti-bunching arising in this geometry. We thus argue that the presence of such nonlinearity would reduce the visibility in the standard HOM setup, offering some explanation for the diminution of the HOM visibility observed in many experiments. We use the same model to show that the nonlinearity affects a resonant two-photon propagation through a two-level impurity in a waveguide due to a “weak photon blockade” caused by the impossibility of double-occupancy and argue that this effect might be stronger for multi-photon propagation. PMID:26365761

  10. Hong-Ou-Mandel Interference with a Single Atom

    NASA Astrophysics Data System (ADS)

    Ralley, K. A.; Lerner, I. V.; Yurkevich, I. V.

    2015-09-01

    The Hong-Ou-Mandel (HOM) effect is widely regarded as the quintessential quantum interference phenomenon in optics. In this work we examine how nonlinearity can smear statistical photon bunching in the HOM interferometer. We model both the nonlinearity and a balanced beam splitter with a single two-level system and calculate a finite probability of anti-bunching arising in this geometry. We thus argue that the presence of such nonlinearity would reduce the visibility in the standard HOM setup, offering some explanation for the diminution of the HOM visibility observed in many experiments. We use the same model to show that the nonlinearity affects a resonant two-photon propagation through a two-level impurity in a waveguide due to a “weak photon blockade” caused by the impossibility of double-occupancy and argue that this effect might be stronger for multi-photon propagation.

  11. Geology and hydrocarbon potential of the Oued Mya basin, Algeria

    SciTech Connect

    Benamrane, O.; Messaoudi, M.; Messelles, H. )

    1993-09-01

    The Oued Mya hydrocarbon system is located in the Sahara basin. It is one of the best producing basins in Algeria, along with the Ghadames and Illizi basins. The stratigraphic section consists of Paleozoic and Mesozoic, and is about 5000 m thick. This intracratonic basin is limited to the north by the Toughourt saddle, and to the west and east it is flanked by regional arches, Allal-Tilghemt and Amguid-Hassi Messaoud, which culminate in the super giant Hassi Messaoud and Hassi R'mel hydrocarbon accumulations, respectively, producing oil from the Cambrian sands and gas from the Trissic sands. The primary source rock in this basin is lower Silurian shale, with an average thickness of 50 m and a total organic carbon of 6% (14% in some cases). Results of maturation modeling indicate that the lower Silurian source is in the oil window. The Ordovician shales are also source rocks, but in a second order. Clastic reservoirs are in the Trissic sequence, which is mainly fluvial deposits with complex alluvial channels, and the main target in the basin. Clastic reservoirs in the lower Devonian section have a good hydrocarbon potential east of the basin through a southwest-northwest orientation. The Late Trissic-Early Jurassic evaporites that overlie the Triassic clastic interval and extend over the entire Oued Mya basin, are considered to be a super-seal evaporite package, which consists predominantly of anhydrite and halite. For paleozoic targets, a large number of potential seals exist within the stratigraphic column. This super seal does not present oil dismigration possibilities. We can infer that a large amount of the oil generated by the Silurian source rock from the beginning of Cretaceous until now still is not discovered and significantly greater volumes could be trapped within structure closures and mixed or stratigraphic traps related to the fluvial Triassic sandstones, marine Devonian sands, and Cambrian-Ordovician reservoirs.

  12. Water quality assessment of a highly polluted Mediterranean River - Oued Fez (Morocco)

    NASA Astrophysics Data System (ADS)

    Perrin, J.-L.; Bellarbi, M.; Raïs, N.; Chahinian, N.; Moulin, P.; Ijjaali, M.

    2012-04-01

    In the South of the Mediterranean basin, many rivers are characterized by an alternation of very long dry periods only cut by short flood events. Currently, the socio-economical development of these zones is limited by water scarcity and poor quality of the water resources. Indeed human activities, generally concentrated in overpopulated cities, generate large quantity of domestic and industrial effluents which are directly rejected in the environment without any treatment. In Morocco, the well known city of Fez illustrates perfectly this situation, observed in most developing countries. The oued Fez receives continuously the non-treated domestic and industrial effluents (90.000 m3/day) of the city and pollutes all the downstream water bodies. Indeed, it is a tributary of the Sebou River, a major body of great economical importance used for irrigation and freshwater supply. This study aims at characterising and quantifying the pollutant concentrations and fluxes in various points of oued Fez's hydrological network and assessing its impact on the Sebou River; this river's preservation being considered a national priority in Morocco. A coupled water quality-water quantity monitoring scheme has been implemented on oued Fez since 2008. In addition to basic hydrological data, water quality samples are collected at regular intervals at 8 locations where discharge is simultaneously measured using an Acoustic Doppler Current Profiler (ADCP). Water samples are analysed for different forms of nitrogen (nitrates, nitrites, ammonium and total nitrogen), phosphorus (soluble reactive phosphorus and total phosphorus) but also total chromium which is used in the leather tanning processes, one of the most important industrial production of the city of Fez, using a photospectrometer (Hach Lange DR 2800 VIS-photometer (Germany). The results of 17 sampling campaigns, carried out over 3 hydrological years, indicate that the rural areas contribute mostly to baseflow during the wet

  13. Hong Ou Mandel interferometer: A quantum measurement tool

    NASA Astrophysics Data System (ADS)

    Borjemscaia, Natalia

    Quantum computing research has been around for several decades, since it was first proposed by Richard Feynman. Many efforts have been made to utilize quantum systems in creation of new computing devices in the recent years. One of the essential tools used for characterization and manipulation of optical quantum systems is a Hong Ou Mandel (HOM) Interferometer. It is used in this work to provide information about propagation, distortion and degree of indistinguishability of single photons. This work provides complete characterization of an optical tunneling effect in dielectric Bragg gratings. Samples with different thin film configurations are examined and their corresponding propagation delay times are calculated with sub-femtosecond precision. It is determined that for specific configurations for dielectric stacks, propagation delays can exhibit superluminal behavior. The distortion due to this effect is also calculated using HOM profiles. HOM interferometer is also used to calculate the degree of coalescence between two dissimilar sources. Single photons generated by quantum dot emission and parametric down conversion are tailored through aggressive filtering techniques to be identical in their spectral, temporal and polarization profiles. The degree of their coalescence is then calculated in an attempt to create quantum interference. This work attempts to provide better understanding of single photon interactions through use of an HOM interferometer.

  14. Interactions between the hydrology and hydrochemistry of an intermittent southern Mediterranean River- Oued Fez (Morocco)

    NASA Astrophysics Data System (ADS)

    Perrin, J.-L.; Bellarbi, M.; Chahinian, N.; Raïs, N.; Moulin, P.; Ijjaali, M.

    2012-04-01

    Mediterranean catchments are often characterized by highly variable rainfall inputs and intermittent flows. In comparison to the existing knowledge on their hydrological behaviour, the interactions between flow conditions and pollution levels remain less documented. This study aims at filling that gap through a case study on Oued Fez (Morocco). Oued Fez is an intermittent river located in central-eastern Morocco. It has a 615 km2 catchment 10% of which corresponds to the city of Fez, the 3rd biggest in the kingdom (1.2 M inhabitants). Oued Fes is a tributary of the Sebou River, a major body of great economical importance used for irrigation and freshwater supply. A coupled water quality-water quantity monitoring scheme has been implemented on Oued Fez since 2008. In addition to basic hydrological data, water quality samples are collected at regular intervals at 8 locations where discharge is simultaneously measured using an Acoustic Doppler Current Profiler (ADCP). Water samples are analysed for different forms of nitrogen (nitrates, nitrites, ammonium and total nitrogen) and phosphorus (soluble reactive phosphorus and total phosphorus) using a photospectrometer (Hach Lange DR 2800 VIS-photometer (Germany). The results of the study indicate that, despite variations in annual rainfall, the catchment's hydrological response is controlled by the urban impervious zones during floods. The rural areas contribute mostly to baseflow during the wet period while non-treated anthropogenic inputs constitute most of the flow during the dry period. This in turn affects the water quality results. Indeed: - during low flow conditions the pollution levels are very high and total nitrogen and total phosphorus concentrations reach 45 mg/l N and 6.5 mg/l P respectively at the most polluted sites. - during average and high flow conditions the pollution levels decrease due to dilution. Total nitrogen and total phosphorus concentrations reach 32 mg/l N and 3.5 mg/l P respectively with

  15. Do Advance Directives Direct?

    PubMed

    Shapiro, Susan P

    2015-06-01

    Resolution of long-standing debates about the role and impact of advance directives - living wills and powers of attorney for health care - has been hampered by a dearth of appropriate data, in particular data that compare the process and outcomes of end-of-life decision making on behalf of patients with and without advance directives. Drawing on a large ethnographic study of patients in two intensive care units in a large urban teaching hospital, this article compares aspects of the medical decision-making process and outcomes by advance-directive status. Controlling for demographic characteristics and severity of illness, the study finds few significant differences between patients without advance directives and those who claim to have them. Surprisingly, these few differences hold only for those whose directives are in their hospital chart. There are no significant differences between those with no directive and those claiming to have a copy at home or elsewhere. The article considers the implications if directives seemingly must be in hand to show even modest effects. Do advance directives direct? The intensive care unit data provide far more support for the growing body of literature that casts doubt on their impact than studies that promote the use of them.

  16. Water quality assessment of highly polluted rivers in a semi-arid Mediterranean zone Oued Fez and Sebou River (Morocco)

    NASA Astrophysics Data System (ADS)

    Perrin, J. L.; Raïs, N.; Chahinian, N.; Moulin, P.; Ijjaali, M.

    2014-03-01

    Oued Fez (one of the Sebou River tributaries - Morocco) allowed us to study and quantify the effect of the lack of wastewater treatment on surface water quality in semi-arid hydrological context. The analysis is based on field data collected from June 2009 to December 2011. Concentration and load patterns of nitrogen, phosphorus and chromium (used in the processing of leather) are compared in stable hydrological conditions during low flow and high flow periods in an eight-location sampling network. The Oued Fez and the Sebou River are characterised by severe pollution downstream from the city of Fez, particularly TN (mainly NH4 and Norg), TP (mainly Ppart) and TCr. The most polluted sites are those directly under the influence of domestic and industrial waste water inputs, particularly tannery effluents. Obviously, the concentrations measured at these locations are above all environmental quality standards. Pollutant loads are very heavy in the Sebou River and can contaminate the river course for kilometres. Moreover, as the water of the Sebou River is used for the irrigation of vegetables, serious problems of public health could arise. A better understanding of contaminant dynamics and self-purifying processes in these rivers will help implement actions and steps aimed at improving water quality in the Sebou River, which is the primary water supply source in Morocco and is used for agricultural and industrials purposes as well as for drinking water.

  17. Dynamique sédimentaire comparative dans les bassins stéphano-permiens des Ida Ou Zal et Ida Ou Ziki, haut Atlas Occidental, MarocDynamic sedimentology of two Upper Stephano-Lower Permian basins: Ida Ou Zal and Ida Ou Ziki, western High Atlas, Morocco

    NASA Astrophysics Data System (ADS)

    Saber, H.; El-Wartiti, M.; Broutin, J.

    2001-05-01

    The intra-mountainous Ida Ou Zal Basin developed as a graben during the Stephanian (Carboniferous) and Lower Permian. Along its borders from east to west are the remnants of basal conglomerates. Passing laterally towards the centre of the basin are fine-grained fluvial-lacustrine sediments or flood-plain deposits. The important accumulation (1800 m) of sediments, associated with climatic and tectonic changes, caused substantial subsidence in a late orogenic setting. The remnants of sporadic volcanic products (shards) found in the Ida Ou Zal and the Ida Ou Zika Basins suggest nearby simultaneous magmatic activity. A comparison between the basins of Ida Ou Zal and Ida Ou Ziki suggest that the two basins formed a single unit, called the Souss Basin, ultimately terminated between the Lower Permian and Upper Permian times by a sinistral movement of the N70-80° Agadir Ou Anzizen Fault (west branch of the Tizi N'Test Fault) at the very end of the Hercynian Orogeny in Morocco.

  18. Intercomparison of Groundwater Flow Monitoring Technologies at Site OU 1, Former Fort Ord, California

    SciTech Connect

    Daley, P F; Jantos, J; Pedler, W H; Mandell, W A

    2005-09-20

    This report presents an intercomparison of three groundwater flow monitoring technologies at a trichloroethylene (TCE) groundwater plume at Operational Unit 1 (OU 1) adjacent to the former Fritzsche Army Airfield at the former Fort Ord Army Base, located on Monterey Bay in northern Monterey County, California. Soil and groundwater at this site became contaminated by fuels and solvents that were burned on a portion of OU 1 called the Fire Drill Area (FDA) as part of firefighter training from 1962 and 1985. Cont Contamination is believed to be restricted to the unconfined A-aquifer, where water is reached at a depth of approximately 60 to 80 feet below the ground surface; the aquifer is from 15 to 20 feet in thickness, and is bounded below by a dense clay layer, the Salinas Valley Aquitard. Soil excavation and bioremediation were initiated at the site of fire training activities in the late 1980s. Since that time a pump-and-treat operation has been operated close to the original area of contamination, and this system has been largely successful at reducing groundwater contamination in this source area. However, a trichloroethylene (TCE) groundwater plume extends approximately 3000 ft (900 m) to the northwest away from the FDA. In this report, we have augmented flow monitoring equipment permanently installed in an earlier project (Oldenburg et al., 2002) with two additional flow monitoring devices that could be deployed in existing monitoring wells, in an effort to better understand their performance in a nearly ideal, homogeneous sand aquifer, that we expected would exhibit laminar groundwater flow owing to the site's relatively simple hydrogeology. The three flow monitoring tools were the Hydrotechnics{reg_sign} In In-Situ Permeable Flow Sensor (ISPFS), the RAS Integrated Subsurface Evaluation Hydrophysical Logging tool (HPL), and the Lawrence Livermore National Laboratory Scanning Colloidal Borescope Flow Meter (SCBFM). All three devices produce groundwater flow

  19. FIELD SCALE EVALUATION OF TREATMENT OF TCE IN A BIOWALL AT THE OU-1 SITE

    EPA Science Inventory

    A passive reactive barrier (Biowall) was installed at the OU-1 site at Altus Air Force Base, Oklahoma to treat TCE contamination in ground water from a landfill. Depth to ground water varies from 1.8 to 2.4 meters below land surface. To intercept and treat the plume of contamin...

  20. Gas physical conditions and kinematics of the giant outflow Ou4

    NASA Astrophysics Data System (ADS)

    Corradi, Romano L. M.; Grosso, Nicolas; Acker, Agnès; Greimel, Robert; Guillout, Patrick

    2014-10-01

    Context. The recently discovered bipolar outflow Ou4 has a projected size of more than one degree in the plane of the sky. It is apparently centred on the young stellar cluster - whose most massive representative is the triple system HR 8119 - inside the H ii region Sh 2-129. The driving source, the nature, and the distance of Ou4 are not known. Aims: The basic properties of Ou4 and its environment are investigated to shed light on the origin of this remarkable outflow. Methods: Deep narrow-band imagery of the whole nebula at arcsecond resolution was obtained to study the details of its morphology. Long-slit spectroscopy of the bipolar lobe tips was secured to determine the gas ionisation mechanism, physical conditions, and line-of-sight velocities. An estimate of the proper motions at the tip of the south lobe using archival plate images was attempted. The existing multi-wavelength data for Sh 2-129 and HR 8119 were also comprehensively reviewed. Results: The observed morphology of Ou4, its emission-line spatial distribution, line flux ratios, and the kinematic modelling developed adopting a bow-shock parabolic geometry, illustrate the expansion of a shock-excited fast collimated outflow. The observed radial velocities of Ou4 and its reddening are consistent with those of Sh 2-129 and HR 8119. The improved determination of the distance to HR 8119 (composed of two B0 V and one B0.5 V stars) and Sh 2-129 is 712 pc. We identify in WISE images at 22 μm an emission bubble of 5' radius (1 pc at the distance above) emitted by hot (107 K) dust grains, located inside the central part of Ou4 and corresponding to several [O iii] emission features of Ou4. Conclusions: The apparent position of Ou4 and the properties studied in this work are consistent with the hypothesis that Ou4 is located inside the Sh 2-129 H ii region, suggesting that it was launched some 90 000 yr ago by HR 8119. The outflow total kinetic energy is estimated to be ≈4 × 1047 ergs. However, we cannot

  1. Lait humain provenant d’une banque de dons ou acheté en ligne?

    PubMed Central

    St-Onge, Maude; Chaudhry, Shahnaz; Koren, Gideon

    2015-01-01

    Résumé Question Une de mes patientes m’a demandé si elle pourrait se procurer du lait humain par Internet pour allaiter son nourrisson s’il le fallait. L’usage de lait humain provenant d’une banque de dons est-il plus sécuritaire que son achat en ligne? Réponse L’Organisation mondiale de la Santé et l’American Academy of Pediatrics recommandent d’utiliser des dons de lait humain comme choix à privilégier lorsque le lait maternel n’est pas disponible. Cependant, la Société canadienne de pédiatrie n’approuve pas le partage de lait humain non traité. Le lait humain entreposé dans les banques de lait diffère de celui qu’on peut se procurer par Internet en raison du processus rigoureux de sélection des donneuses, des fréquentes inspections de la qualité, des procédés de transport règlementés et du processus de pasteurisation conforme aux directives établies par l’Agence canadienne d’inspection des aliments. La plupart des échantillons achetés en ligne contiennent des bactéries à gram négatif ou comptent au total plus de 104 unités formant colonies de bactéries aérobiques par millilitre; ils renferment aussi en moyenne au décompte total plus de bactéries aérobiques, de bactéries à gram négatif, de coliformes et de Staphylococcus spp que les échantillons des banques de lait. La croissance de la plupart des espèces de bactéries est associée au nombre de jours en transit, ce qui porte à croire que les conditions de collecte, d’entreposage et de transport sont médiocres pour le lait acheté en ligne.

  2. Hong-Ou-Mandel Interference between Two Deterministic Collective Excitations in an Atomic Ensemble.

    PubMed

    Li, Jun; Zhou, Ming-Ti; Jing, Bo; Wang, Xu-Jie; Yang, Sheng-Jun; Jiang, Xiao; Mølmer, Klaus; Bao, Xiao-Hui; Pan, Jian-Wei

    2016-10-28

    We demonstrate deterministic generation of two distinct collective excitations in one atomic ensemble, and we realize the Hong-Ou-Mandel interference between them. Using Rydberg blockade we create single collective excitations in two different Zeeman levels, and we use stimulated Raman transitions to perform a beam-splitter operation between the excited atomic modes. By converting the atomic excitations into photons, the two-excitation interference is measured by photon coincidence detection with a visibility of 0.89(6). The Hong-Ou-Mandel interference witnesses an entangled NOON state of the collective atomic excitations, and we demonstrate its two times enhanced sensitivity to a magnetic field compared with a single excitation. Our work implements a minimal instance of boson sampling and paves the way for further multimode and multiexcitation studies with collective excitations of atomic ensembles.

  3. Complete three photon Hong-Ou-Mandel interference at a three port device.

    PubMed

    Mährlein, Simon; von Zanthier, Joachim; Agarwal, Girish S

    2015-06-15

    We report the possibility of completely destructive interference of three indistinguishable photons on a three port device providing a generalisation of the well known Hong-Ou-Mandel interference of two indistinguishable photons on a two port device. Our analysis is based on the underlying mathematical framework of SU(3) transformations rather than SU(2) transformations. We show the completely destructive three photon interference for a large range of parameters of the three port device and point out the physical origin of such interference in terms of the contributions from different quantum paths. As each output port can deliver zero to three photons the device generates higher dimensional entanglement. In particular, different forms of entangled states of qudits can be generated depending on the device parameters. Our system is different from a symmetric three port beam splitter which does not exhibit a three photon Hong-Ou-Mandel interference.

  4. Hong-Ou-Mandel Interference between Two Deterministic Collective Excitations in an Atomic Ensemble

    NASA Astrophysics Data System (ADS)

    Li, Jun; Zhou, Ming-Ti; Jing, Bo; Wang, Xu-Jie; Yang, Sheng-Jun; Jiang, Xiao; Mølmer, Klaus; Bao, Xiao-Hui; Pan, Jian-Wei

    2016-10-01

    We demonstrate deterministic generation of two distinct collective excitations in one atomic ensemble, and we realize the Hong-Ou-Mandel interference between them. Using Rydberg blockade we create single collective excitations in two different Zeeman levels, and we use stimulated Raman transitions to perform a beam-splitter operation between the excited atomic modes. By converting the atomic excitations into photons, the two-excitation interference is measured by photon coincidence detection with a visibility of 0.89(6). The Hong-Ou-Mandel interference witnesses an entangled NOON state of the collective atomic excitations, and we demonstrate its two times enhanced sensitivity to a magnetic field compared with a single excitation. Our work implements a minimal instance of boson sampling and paves the way for further multimode and multiexcitation studies with collective excitations of atomic ensembles.

  5. Caracterisation des proprietes acoustiques des materiaux poreux a cellules ouvertes et a matrice rigide ou souple

    NASA Astrophysics Data System (ADS)

    Salissou, Yacoubou

    L'objectif global vise par les travaux de cette these est d'ameliorer la caracterisation des proprietes macroscopiques des materiaux poreux a structure rigide ou souple par des approches inverses et indirectes basees sur des mesures acoustiques faites en tube d'impedance. La precision des approches inverses et indirectes utilisees aujourd'hui est principalement limitee par la qualite des mesures acoustiques obtenues en tube d'impedance. En consequence, cette these se penche sur quatre problemes qui aideront a l'atteinte de l'objectif global precite. Le premier probleme porte sur une caracterisation precise de la porosite ouverte des materiaux poreux. Cette propriete en est une de passage permettant de lier la mesure des proprietes dynamiques acoustiques d'un materiau poreux aux proprietes effectives de sa phase fluide decrite par les modeles semi-phenomenologiques. Le deuxieme probleme traite de l'hypothese de symetrie des materiaux poreux selon leur epaisseur ou un index et un critere sont proposes pour quantifier l'asymetrie d'un materiau. Cette hypothese est souvent source d'imprecision des methodes de caracterisation inverses et indirectes en tube d'impedance. Le critere d'asymetrie propose permet ainsi de s'assurer de l'applicabilite et de la precision de ces methodes pour un materiau donne. Le troisieme probleme vise a mieux comprendre le probleme de transmission sonore en tube d'impedance en presentant pour la premiere fois un developpement exact du probleme par decomposition d'ondes. Ce developpement permet d'etablir clairement les limites des nombreuses methodes existantes basees sur des tubes de transmission a 2, 3 ou 4 microphones. La meilleure comprehension de ce probleme de transmission est importante puisque c'est par ce type de mesures que des methodes permettent d'extraire successivement la matrice de transfert d'un materiau poreux et ses proprietes dynamiques intrinseques comme son impedance caracteristique et son nombre d'onde complexe. Enfin, le

  6. Stratigraphic and structural characterization of the OU-1 area at the former George Air Force Base, Adelanto, Southern California

    USGS Publications Warehouse

    Catchings, R.D.; Gandhok, G.; Goldman, M.R.

    2001-01-01

    The former George Air Force Base (GAFB), now known as the Southern California Logistics Airport (SCLA), is located in the town of Adelanto, approximately 100 km northeast of Los Angeles, California (Fig. 1). In this report, we present acquisition parameters, data, and interpretations of seismic images that were acquired in the OU-1 area of GAFB during July 1999 (Fig. 2). GAFB is scheduled for conversion to civilian use, however, during its years as an Air Force base, trichlorethylene (TCE) was apparently introduced into the subsurface as a result of spills during normal aircraft maintenance operations. To comply with congressional directives, TCE contaminant removal has been ongoing since the early-tomid 1990s. However, only a small percentage of the TCE believed to have been introduced into the subsurface has been recovered, due largely to difficulty in locating the TCE within the subsurface. Because TCE migrates within the subsurface by ground water movement, attempts to locate the TCE contaminants in the subsurface have employed an array of ground-water monitoring and extraction wells. These wells primarily sample within a shallow-depth (~40 m) aquifer system. Cores obtained from the monitoring and extraction wells indicate that the aquifer, which is composed of sand and gravel channels, is bounded by aquitards composed largely of clay and other fine-grained sediments. Based on well logs, the aquifer is about 3 to 5 m thick along the seismic profiles. A more thorough understanding of the lateral variations in the depth and thickness of the aquifer system may be a key to finding and removing the remaining TCE. However, due to its complex depositional and tectonic history, the structural and stratigraphic sequences are not easily characterized. An indication of the complex nature of the structure and stratigraphy is the appreciable variation in stratigraphic sequences observed in some monitoring wells that are only a few tens of meters apart. To better

  7. Directing 101.

    ERIC Educational Resources Information Center

    Pintoff, Ernest

    Providing an introduction to anyone considering directing as a field of study or career, this book takes a broad look at the process of directing and encourages students and professionals alike to look outside of the movie industry for inspiration. Chapters in the book discuss selecting and acquiring material; budgeting and financing; casting and…

  8. How nonlinear optical effects degrade Hong-Ou-Mandel like interference

    NASA Astrophysics Data System (ADS)

    Mirza, Imran M.; van Enk, S. J.

    2015-05-01

    Two-photon interference effects, such as the Hong-Ou-Mandel (HOM) effect, can be used to characterize to what extent two photons are identical [20]. Furthermore, these interference effects underly linear optics quantum computation. We show here how nonlinear optical effects, such as those mediated by atoms or quantum dots in a cavity, degrade the interference. This implies that, on the one hand, nonlinearities are to be avoided if one wishes to utilize the interference, but on the other hand, one may be able to measure or detect nonlinearities by observing the disappearance of the interference.

  9. Hong-Ou-Mandel interference between triggered and heralded single photons from separate atomic systems

    NASA Astrophysics Data System (ADS)

    Leong, Victor; Kosen, Sandoko; Srivathsan, Bharath; Gulati, Gurpreet Kaur; Cerè, Alessandro; Kurtsiefer, Christian

    2015-06-01

    We present Hong-Ou-Mandel interference of single photons generated via two different physical processes by two independent atomic systems: scattering by a single atom, and parametric generation via four-wave mixing in a cloud of cold atoms. Without any spectral filtering, we observe a visibility of V =62 ±4 % . After correcting for accidental coincidences, we obtain V =93 ±6 % . The observed interference demonstrates the compatibility of the two sources, forming the basis for an efficient quantum interface between different physical systems.

  10. Tolerance and biomarkers as useful tools for assessing environmental quality in the Oued Souss estuary (Bay of Agadir, Morocco).

    PubMed

    Ait Alla, A; Mouneyrac, C; Durou, C; Moukrim, A; Pellerin, J

    2006-05-01

    The aim of this study was to assess aquatic environmental quality of Oued Souss (Agadir, Morocco). This estuary has been subjected for a long time to large amounts of sewage discharges and industrial effluents. Since November 2002, no waste outlets have been discharged in this site due to their connection to a wastewater purification plant. Firstly, we have compared metal tolerance of the annelid polychaete (Nereis diversicolor) originating from Oued Souss and a relatively clean site (Oualidia, Morocco). Secondly, we have evaluated with a multi-marker approach (acetylcholinesterase [AChE], glutathione-S-transferases [GSTs], catalase, thiobarbituric acid reactive substances [TBARs]) responses of worms to the pollution gradient. Results have shown that worms from Oued Souss have acquired tolerance to copper and zinc due to a long-term sub-lethal metal exposure and this metal tolerance was maintained in spite of the end of wastewater discharges in this site. Higher catalase, GSTs and TBARs values have been observed in worms from Oued Souss sampled before implantation of wastewater treatment. The multi-marker approach confirms that these worms have been submitted to various contaminants. In contrast, high inhibition in AChE activities measured in worms from Oued Souss could be explained by the continuous agricultural influence of nearest areas. The level of contamination was probably maintained since biomarker values were generally higher in worms from Oued Souss when compared to Oualidia.

  11. Nonlinear optical effects and Hong-Ou-Mandel interference in cavity quantum electrodynamics

    NASA Astrophysics Data System (ADS)

    Mirza, Imran M.; van Enk, Steven J.

    Pure quantum interference among single photons is one of the key ingredients to perform linear optics quantum computation (LOQC). The Hong-Ou-Mandel interference (HOMI) [C. K. Hong, Z. Y. Ou and L. Mandel, Phys. Rev. Lett. 59, (18), 2044-2046 (1987)] i.e. complete destructive interference between two identical and indistinguishable photons simultaneously entering input ports of a 50/50 beam splitter, is a well-known example in this context. In this talk, I'll present our theoretical study of HOMI in a coupled Jaynes-Cummings array. In particular and by applying quantum jump/trajectory formalism, I'll focus on how partial quantum interference between two photons survive both non-linearities produced by two-level emitter and spectral filtering due to optical cavities in our coupled cavity array setup [Imran M. Mirza and Steven J. van Enk, Opt. Comm. 343, 172-177 (2015)]. Along with LOQC, this work is crucial from the perspective of exploiting coupled cavity arrays to store single photons reliably (without altering their temporal and spectral traits) [Imran M. Mirza, Steven J. van Enk and Jeff Kimble, JOSA B, 10, 2640-2649, (2013)].

  12. Sur les anomalies structurales de l'anticlinal de l'oued Bahloul de Tunisie : héritage tectonique et plissement cisaillant de couverture

    NASA Astrophysics Data System (ADS)

    Saadi, Ahmed; Boukadi, Noureddine; Gaaya, Ali

    2006-07-01

    The Oued Bahloul structure exists in the central Atlas of Tunisia. This structure is oriented N70 and it shows a very particular geometry characterized by: ( i) an important disharmony between the northern and the southern flanks; ( ii) a dissymmetry between the east and the west parts of the structure; ( iii) several gaps and progressive unconformities present in the Cretaceous and Eocene series. Three major tectonic directions characterize this structure: ( i) the N120 appears in the western part of the anticline; ( ii) some north-south faults distinguish the oriental part; ( iii) the strike fault, which is confirmed by seismic data, affects the central part of this anticline. To cite this article: A. Saadi et al., C. R. Geoscience 338 (2006).

  13. Hong-Ou-Mandel experiment for temporal investigation of single-electron fractionalization.

    PubMed

    Freulon, V; Marguerite, A; Berroir, J-M; Plaçais, B; Cavanna, A; Jin, Y; Fève, G

    2015-04-21

    Coulomb interaction has a striking effect on electronic propagation in one-dimensional conductors. The interaction of an elementary excitation with neighbouring conductors favours the emergence of collective modes, which eventually leads to the destruction of the Landau quasiparticle. In this process, an injected electron tends to fractionalize into separated pulses carrying a fraction of the electron charge. Here we use two-particle interferences in the electronic analogue of the Hong-Ou-Mandel experiment in a quantum Hall conductor at filling factor 2 to probe the fate of a single electron emitted in the outer edge channel and interacting with the inner one. By studying both channels, we analyse the propagation of the single electron and the generation of interaction-induced collective excitations in the inner channel. These complementary pieces of information reveal the fractionalization process in the time domain and establish its relevance for the destruction of the quasiparticle, which degrades into the collective modes.

  14. Laser cooling atoms to indistinguishability: Atomic Hong-Ou-Mandel interference and entanglement through spin exchange

    NASA Astrophysics Data System (ADS)

    Kaufman, Adam

    2016-05-01

    Motional control of neutral atoms has a rich history and increasingly interest has turned to single-atom control. In my thesis work, we created a platform to individually prepare single bosonic atoms in highly pure quantum states, by developing methods to laser cool single atoms to the vibrational ground state of optical tweezer traps. Applying this toolset, we observe the atomic Hong-Ou-Mandel effect when we arrange for atom tunneling to play the role of a balanced beam splitter between two optical tweezers. In another experiment, we utilize spin exchange to create entanglement, which we then verify after spatially separating the atoms to observe their non-local correlations. Merging these results with our recent demonstration of deterministic loading of atomic arrays, our results establish the concept of quantum gas assembly, which could be applied to a variety of systems ranging from the production of single dipolar molecules to the assembly of low-entropy arrays of atoms.

  15. Multiparticle Correlations in Mesoscopic Scattering: Boson Sampling, Birthday Paradox, and Hong-Ou-Mandel Profiles

    NASA Astrophysics Data System (ADS)

    Urbina, Juan-Diego; Kuipers, Jack; Matsumoto, Sho; Hummel, Quirin; Richter, Klaus

    2016-03-01

    The interplay between single-particle interference and quantum indistinguishability leads to signature correlations in many-body scattering. We uncover these with a semiclassical calculation of the transmission probabilities through mesoscopic cavities for systems of noninteracting particles. For chaotic cavities we provide the universal form of the first two moments of the transmission probabilities over ensembles of random unitary matrices, including weak localization and dephasing effects. If the incoming many-body state consists of two macroscopically occupied wave packets, their time delay drives a quantum-classical transition along a boundary determined by the bosonic birthday paradox. Mesoscopic chaotic scattering of Bose-Einstein condensates is, then, a realistic candidate to build a boson sampler and to observe the macroscopic Hong-Ou-Mandel effect.

  16. Two-dimensional fermionic Hong-Ou-Mandel interference with massless Dirac fermions

    NASA Astrophysics Data System (ADS)

    Khan, M. A.; Leuenberger, Michael N.

    2014-08-01

    We propose a two-dimensional Hong-Ou-Mandel (HOM) type interference experiment for massless Dirac fermions in graphene and 3D topological insulators. Since massless Dirac fermions exhibit linear dispersion, similar to photons in vacuum, they can be used to obtain the HOM interference intensity pattern as a function of the delay time between two massless Dirac fermions. We show that while the Coulomb interaction leads to a significant change in the angle dependence of the tunneling of two identical massless Dirac fermions incident from opposite sides of a potential barrier, it does not affect the HOM interference pattern. We apply our formalism to develop a massless Dirac fermion beam splitter (BS) for controlling the transmission and reflection coefficients. We calculate the resulting time-resolved correlation function for two identical massless Dirac fermions scattering off the BS.

  17. Effects of interactions on the generalized Hong-Ou-Mandel effect

    NASA Astrophysics Data System (ADS)

    Gertjerenken, B.; Kevrekidis, P. G.

    2015-09-01

    We numerically investigate the influence of interactions on the generalized Hong-Ou-Mandel (HOM) effect for bosonic particles in a (quasi-)one-dimensional set-up with weak harmonic confinement and show results for the cases of N = 2, N = 3 and N = 4 bosons interacting with a beam splitter, whose role is played by a δ-barrier. In particular, we focus on the effect of attractive interactions and compare the results with the repulsive case, as well as with the analytically available results for the non-interacting case (that we use as a benchmark). We observe a fermionization effect both for growing repulsive and attractive interactions, i.e., the dip in the HOM coincidence count is progressively smeared out, for increasing interaction strengths. The role of input asymmetries is also explored.

  18. Hong-Ou-Mandel interference of entangled Hermite-Gauss modes

    NASA Astrophysics Data System (ADS)

    Zhang, Yingwen; Prabhakar, Shashi; Rosales-Guzmán, Carmelo; Roux, Filippus S.; Karimi, Ebrahim; Forbes, Andrew

    2016-09-01

    Hong-Ou-Mandel (HOM) interference is demonstrated experimentally for entangled photon pairs in the Hermite-Gauss (HG) basis. We use two Dove prisms in one of the paths of the photons to manipulate the entangled quantum state that enters the HOM interferometer. It is demonstrated that, when entangled photon pairs are in a symmetric Bell state in the Laguerre-Gauss (LG) basis, they will remain symmetric after decomposing them into the HG basis, thereby resulting in no coincidence events after the HOM interference. On the other hand, if the photon pairs are in an antisymmetric Bell state in the LG basis, then they will also be antisymmetric in the HG basis, thereby producing only coincidence events as a result of the HOM interference.

  19. Measurement of photon indistinguishability to a quantifiable uncertainty using a Hong-Ou-Mandel interferometer

    SciTech Connect

    Thomas, Peter J.; Cheung, Jessica Y.; Chunnilall, Christopher J.; Dunn, Malcolm H.

    2010-04-10

    We present a method for using the Hong-Ou-Mandel (HOM) interference technique to quantify photon indistinguishability within an associated uncertainty. The method allows the relative importance of various experimental factors affecting the HOM visibility to be identified, and enables the actual indistinguishability, with an associated uncertainty, to be estimated from experimentally measured quantities. A measurement equation has been derived that accounts for the non-ideal performance of the interferometer. The origin of each term of the equation is explained, along with procedures for their experimental evaluation and uncertainty estimation. These uncertainties are combined to give an overall uncertainty for the derived photon indistinguishability. The analysis was applied to measurements from an interferometer sourced with photon pairs from a parametric downconversion process. The measured photon indistinguishably was found to be 0.954+/-0.036 by using the prescribed method.

  20. Hong-Ou-Mandel experiment for temporal investigation of single-electron fractionalization

    PubMed Central

    Freulon, V.; Marguerite, A.; Berroir, J.-M.; Plaçais, B.; Cavanna, A.; Jin, Y.; Fève, G.

    2015-01-01

    Coulomb interaction has a striking effect on electronic propagation in one-dimensional conductors. The interaction of an elementary excitation with neighbouring conductors favours the emergence of collective modes, which eventually leads to the destruction of the Landau quasiparticle. In this process, an injected electron tends to fractionalize into separated pulses carrying a fraction of the electron charge. Here we use two-particle interferences in the electronic analogue of the Hong-Ou-Mandel experiment in a quantum Hall conductor at filling factor 2 to probe the fate of a single electron emitted in the outer edge channel and interacting with the inner one. By studying both channels, we analyse the propagation of the single electron and the generation of interaction-induced collective excitations in the inner channel. These complementary pieces of information reveal the fractionalization process in the time domain and establish its relevance for the destruction of the quasiparticle, which degrades into the collective modes. PMID:25896625

  1. Interactions and Charge Fractionalization in an Electronic Hong-Ou-Mandel Interferometer

    NASA Astrophysics Data System (ADS)

    Wahl, Claire; Rech, Jérôme; Jonckheere, Thibaut; Martin, Thierry

    2014-01-01

    We consider an electronic analog of the Hong-Ou-Mandel (HOM) interferometer, where two single electrons travel along opposite chiral edge states and collide at a quantum point contact. Studying the current noise, we show that because of interactions between copropagating edge states, the degree of indistinguishability between the two electron wave packets is dramatically reduced, leading to reduced contrast for the HOM signal. This decoherence phenomenon strongly depends on the energy resolution of the packets. Insofar as interactions cause charge fractionalization, we show that charge and neutral modes interfere with each other, leading to satellite dips or peaks in the current noise. Our calculations explain recent experimental results [E. Bocquillon, et al., Science 339, 1054 (2013)] where an electronic HOM signal with reduced contrast was observed.

  2. Spectrally resolved Hong-Ou-Mandel interference between independent photon sources

    NASA Astrophysics Data System (ADS)

    Jin, Rui-Bo; Gerrits, Thomas; Fujiwara, Mikio; Wakabayashi, Ryota; Yamashita, Taro; Miki, Shigehito; Terai, Hirotaka; Shimizu, Ryosuke; Takeoka, Masahiro; Sasaki, Masahide

    2015-11-01

    Hong-Ou-Mandel (HOM) interference between independent photon sources (HOMI-IPS) is the fundamental block for quantum information processing, such as quantum gate, Shor's algorithm, Boson sampling, etc. All the previous HOMI-IPS experiments were carried out in time-domain, however, the spectral information during the interference was lost, due to technical difficulties. Here, we investigate the HOMI-IPS in spectral domain using the recently developed fast fiber spectrometer, and demonstrate the spectral distribution during the HOM interference between two heralded single-photon sources, and two thermal sources. This experiment can not only deepen our understanding of HOMI-IPS in the spectral domain, but also be utilized to improve the visibility by post-processing spectral filtering.

  3. Direct Instruction.

    ERIC Educational Resources Information Center

    Education Commission of the States, Denver, CO.

    This paper provides an overview of Direct Instruction, an intensive instructional method for grades K-6 based on the theory that learning can be greatly accelerated if instructional presentations are clear, rule out likely misinterpretations and facilitate generalizations. Over 50 instructional programs have been developed based on this…

  4. Hong-Ou-Mandel interference of two phonons in trapped ions

    NASA Astrophysics Data System (ADS)

    Toyoda, Kenji; Hiji, Ryoto; Noguchi, Atsushi; Urabe, Shinji

    2015-11-01

    The quantum statistics of bosons and fermions manifest themselves in the manner in which two indistinguishable particles interfere quantum mechanically. When two photons, which are bosonic particles, enter a beam-splitter with one photon in each input port, they bunch together at either of the two output ports. The corresponding disappearance of the coincidence count is the Hong-Ou-Mandel effect. Here we show the phonon counterpart of this effect in a system of trapped-ion phonons, which are collective excitations derived by quantizing vibrational motions that obey Bose-Einstein statistics. We realize a beam-splitter transformation of the phonons by employing the mutual Coulomb repulsion between ions, and perform a two-phonon quantum interference experiment using that transformation. We observe an almost perfect disappearance of the phonon coincidence between two ion sites, confirming that phonons can be considered indistinguishable bosonic particles. The two-particle interference demonstrated here is purely a quantum effect, without a classical counterpart, hence it should be possible to demonstrate the existence of entanglement on this basis. We attempt to generate an entangled state of phonons at the centre of the Hong-Ou-Mandel dip in the coincidence temporal profile, under the assumption that the entangled phonon state is successfully generated if the fidelity of the analysis pulses is taken into account adequately. Two-phonon interference, as demonstrated here, proves the bosonic nature of phonons in a trapped-ion system. It opens the way to establishing phonon modes as carriers of quantum information in their own right, and could have implications for the quantum simulation of bosonic particles and analogue quantum computation via boson sampling.

  5. Hong-Ou-Mandel interference of two phonons in trapped ions.

    PubMed

    Toyoda, Kenji; Hiji, Ryoto; Noguchi, Atsushi; Urabe, Shinji

    2015-11-05

    The quantum statistics of bosons and fermions manifest themselves in the manner in which two indistinguishable particles interfere quantum mechanically. When two photons, which are bosonic particles, enter a beam-splitter with one photon in each input port, they bunch together at either of the two output ports. The corresponding disappearance of the coincidence count is the Hong-Ou-Mandel effect. Here we show the phonon counterpart of this effect in a system of trapped-ion phonons, which are collective excitations derived by quantizing vibrational motions that obey Bose-Einstein statistics. We realize a beam-splitter transformation of the phonons by employing the mutual Coulomb repulsion between ions, and perform a two-phonon quantum interference experiment using that transformation. We observe an almost perfect disappearance of the phonon coincidence between two ion sites, confirming that phonons can be considered indistinguishable bosonic particles. The two-particle interference demonstrated here is purely a quantum effect, without a classical counterpart, hence it should be possible to demonstrate the existence of entanglement on this basis. We attempt to generate an entangled state of phonons at the centre of the Hong-Ou-Mandel dip in the coincidence temporal profile, under the assumption that the entangled phonon state is successfully generated if the fidelity of the analysis pulses is taken into account adequately. Two-phonon interference, as demonstrated here, proves the bosonic nature of phonons in a trapped-ion system. It opens the way to establishing phonon modes as carriers of quantum information in their own right, and could have implications for the quantum simulation of bosonic particles and analogue quantum computation via boson sampling.

  6. Direct ELISA.

    PubMed

    Lin, Alice V

    2015-01-01

    First described by Engvall and Perlmann, the enzyme-linked immunosorbent assay (ELISA) is a rapid and sensitive method for detection and quantitation of an antigen using an enzyme-labeled antibody. Besides routine laboratory usage, ELISA has been utilized in medical field and food industry as diagnostic and quality control tools. Traditionally performed in 96-well or 384-well polystyrene plates, the technology has expanded to other platforms with increase in automation. Depending on the antigen epitope and availability of specific antibody, there are variations in ELISA setup. The four basic formats are direct, indirect, sandwich, and competitive ELISAs. Direct ELISA is the simplest format requiring an antigen and an enzyme-conjugated antibody specific to the antigen. This chapter describes the individual steps for detection of a plate-bound antigen using a horseradish peroxidase (HRP)-conjugated antibody and luminol-based enhanced chemiluminescence (ECL) substrate. The methodological approach to optimize the assay by chessboard titration is also provided.

  7. DIRECTIONAL COUPLERS

    DOEpatents

    Nigg, D.J.

    1961-12-01

    A directional coupler of small size is designed. Stripline conductors of non-rectilinear configuration, and separated from each other by a thin dielectric spacer. cross each other at least at two locations at right angles, thus providing practically pure capacitive coupling which substantially eliminates undesirable inductive coupling. The conductors are sandwiched between a pair of ground planes. The coupling factor is dependent only on the thickness and dielectric constant of the dielectric spacer at the point of conductor crossover. (AEC)

  8. DIRECTIONAL ANTENNA

    DOEpatents

    Bittner, B.J.

    1958-05-20

    A high-frequency directional antenna of the 360 d scaring type is described. The antenna has for its desirable features the reduction in both size and complexity of the mechanism for rotating the antenna through its scanning movement. These advantages result from the rotation of only the driven element, the reflector remaining stationary. The particular antenna structure comprises a refiector formed by a plurality of metallic slats arranged in the configuration of an annular cage having the shape of a zone of revolution. The slats are parallel to each other and are disposed at an angle of 45 d to the axis of the cage. A directional radiator is disposed inside the cage at an angle of 45 d to the axis of the cage in the same direction as the reflecting slats which it faces. As the radiator is rotated, the electromagnetic wave is reflected from the slats facing the radiator and thereafter passes through the cage on the opposite side, since these slats are not parallel with the E vector of the wave.

  9. The different origins of magnetic fields and activity in the Hertzsprung gap stars, OU Andromedae and 31 Comae

    NASA Astrophysics Data System (ADS)

    Borisova, A.; Aurière, M.; Petit, P.; Konstantinova-Antova, R.; Charbonnel, C.; Drake, N. A.

    2016-06-01

    Context. When crossing the Hertzsprung gap, intermediate-mass stars develop a convective envelope. Fast rotators on the main sequence, or Ap star descendants, are expected to become magnetic active subgiants during this evolutionary phase. Aims: We compare the surface magnetic fields and activity indicators of two active, fast rotating red giants with similar masses and spectral class but different rotation rates - OU And (Prot = 24.2 d) and 31 Com (Prot = 6.8 d) - to address the question of the origin of their magnetism and high activity. Methods: Observations were carried out with the Narval spectropolarimeter in 2008 and 2013. We used the least-squares deconvolution (LSD) technique to extract Stokes V and I profiles with high signal-to-noise ratio to detect Zeeman signatures of the magnetic field of the stars. We then provide Zeeman-Doppler imaging (ZDI), activity indicators monitoring, and a precise estimation of stellar parameters. We use state-of-the-art stellar evolutionary models, including rotation, to infer the evolutionary status of our giants, as well as their initial rotation velocity on the main sequence, and we interpret our observational results in the light of the theoretical Rossby numbers. Results: The detected magnetic field of OU Andromedae (OU And) is a strong one. Its longitudinal component Bl reaches 40 G and presents an about sinusoidal variation with reversal of the polarity. The magnetic topology of OU And is dominated by large-scale elements and is mainly poloidal with an important dipole component, as well as a significant toroidal component. The detected magnetic field of 31 Comae (31 Com) is weaker, with a magnetic map showing a more complex field geometry, and poloidal and toroidal components of equal contributions. The evolutionary models show that the progenitors of OU And and 31 Com must have been rotating at velocities that correspond to 30 and 53%, respectively, of their critical rotation velocity on the zero age main sequence

  10. Future direction of direct writing

    NASA Astrophysics Data System (ADS)

    Kim, Nam-Soo; Han, Kenneth N.

    2010-11-01

    Direct write technology using special inks consisting of finely dispersed metal nanoparticles in liquid is receiving an undivided attention in recent years for its wide range of applicability in modern electronic industry. The application of this technology covers radio frequency identification-tag (RFID-tag), flexible-electronics, organic light emitting diodes (OLED) display, e-paper, antenna, bumpers used in flip-chip, underfilling, frit, miniresistance applications and biological uses, artificial dental applications and many more. In this paper, the authors have reviewed various direct write technologies on the market and discussed their advantages and shortfalls. Emphasis has given on microdispensing deposition write (MDDW), maskless mesoscale materials deposition (M3D), and ink-jet technologies. All of these technologies allow printing various patterns without employing a mask or a resist with an enhanced speed with the aid of computer. MDDW and M3D are capable of drawing patterns in three-dimension and MDDW, in particular, is capable of writing nanoinks with high viscosity. However, it is still far away for direct write to be fully implemented in the commercial arena. One of the hurdles to overcome is in manufacturing conductive inks which are chemically and physically stable, capable of drawing patterns with acceptable conductivity, and also capable of drawing patterns with acceptable adhesiveness with the substrates. The authors have briefly discussed problems involved in manufacturing nanometal inks to be used in various writing devices. There are numerous factors to be considered in manufacturing such inks. They are reducing agents, concentrations, oxidation, compact ability allowing good conductivity, and stability in suspension.

  11. Prise en Charge du Syndrome de Lyell ou Necrolyse Epidermique Toxique

    PubMed Central

    Siah, S.; Baite, A.; Bakkali, H.; Atmani, M.; Ababou, K.; Ihrai, H.

    2009-01-01

    Summary Le syndrome de Lyell ou nécrolyse épidermique toxique (NET) est une pathologie très grave des dermatoses bulleuses d'étiologie médicamenteuse. Il se caractérise par une nécrose aiguë de l'épiderme sur toute la hauteur du corps muqueux. L'aspect clinique de la NET est celui d'une brûlure étendue du deuxième degré profond. A ce tableau s'associent constamment des lésions muqueuses et une atteinte multiviscérale qui aggrave le pronostic. Nous rapportons deux cas de NET qui illustrent l'importance d'une prise en charge précoce et multidisciplinaire de ces patients atteints au sein d'un service de réanimation des brûlés, dont les fondements reposent sur l'asepsie rigoureuse, l'apport hydroélectrolytique et nutritionnel, la prévention de l'infection et son traitement par une antibiothérapie adaptée, et un nursing et des soins locaux. L'efficacité supposée des immunoglobulines intraveineuses ne repose que sur des cas isolés et il n'y a pas encore d'études randomisées. PMID:21991170

  12. The 'ouR-HOPE' approach for ethics and communication about neonatal neurological injury.

    PubMed

    Racine, Eric; Bell, Emily; Farlow, Barbara; Miller, Steven; Payot, Antoine; Rasmussen, Lisa Anne; Shevell, Michael I; Thomson, Donna; Wintermark, Pia

    2017-02-01

    Predicting neurological outcomes of neonates with acute brain injury is an essential component of shared decision-making, in order to guide the development of treatment goals and appropriate care plans. It can aid parents in imagining the child's future, and guide timely and ongoing treatment decisions, including shifting treatment goals and focusing on comfort care. However, numerous challenges have been reported with respect to evidence-based practices for prognostication such as biases about prognosis among clinicians. Additionally, the evaluation or appreciation of living with disability can differ, including the well-known disability paradox where patients self-report a good quality of life in spite of severe disability. Herein, we put forward a set of five practice principles captured in the "ouR-HOPE" approach (Reflection, Humility, Open-mindedness, Partnership, and Engagement) and related questions to encourage clinicians to self-assess their practice and engage with others in responding to these challenges. We hope that this proposal paves the way to greater discussion and attention to ethical aspects of communicating prognosis in the context of neonatal brain injury.

  13. Hong-Ou-Mandel Interference with Atomic Many-Body States

    NASA Astrophysics Data System (ADS)

    Islam, Rajibul; Lukin, Alexander; Ma, Ruichao; Preiss, Philipp; Rispoli, Matthew; Tai, M. Eric; Greiner, Markus

    2015-05-01

    Hong-Ou-Mandel (HOM) interference experiments are a powerful probe for the indistinguishability and underlying quantum statistics of particles. In the classic HOM experiment, a pair of identical photons incident on different input ports of a beamsplitter exits via the same output port. Using the precise control and readout afforded by our quantum gas microscope, we present an implementation of this classic experiment using massive bosons in a doublewell optical potential. Identical states are prepared on each site of the doublewell and by lowering the tunnel coupling between the sites for specific times, we drive a beam splitter operation between the sites. For single-atom Fock input states, we have realized a high fidelity beamsplitter operation and observed an HOM interference contrast of >90%. By generalizing to more complex initial states on the input ports, we have been able to establish HOM experiment protocols as a robust approach towards studying the indistinguishability of many-body states as well as probe interaction-induced effects. These techniques open a path towards the measurement of purity in a quantum system and entanglement entropy in many-body states.

  14. Hong-Ou-Mandel Interference Between Triggered And Heralded Single Photons From Separate Atomic Systems

    NASA Astrophysics Data System (ADS)

    Cere, Alessandro; Leong, Victor; Kaur Gulati, Gurpreet; Srivathsan, Bharath; Kosen, Sandoko; Kurtsiefer, Christian

    2015-05-01

    The realization of quantum networks and long distance quantum communication rely on the capability of generating entanglement between separated nodes. We demonstrate the compatibility of two different sources of single photons: a single atom and four-wave mixing in a cold cloud of atoms. The four-wave mixing process in a cloud of cold 87Rb generates photon pairs. The cascade level scheme used ensures the generation of heralded single photons with exponentially decaying temporal envelope. The temporal shape of the heralding photons matches the shape of photons emitted by spontaneous decay but for the shorter coherence time A single 87Rb atom is trapped in an far-off-resonance optical dipole trap and can be excited with high probability using a short (~3 ns) intense pulse of resonant light, emitting a single photon by spontaneous decay. A large numerical aperture lens collects ~4% of the total fluorescence. The heralded and the triggered photons are launched into a Houng-Ou-Mandel interferometer: a symmetrical beam-splitter with outputs connected to single photon detectors. Scanning the relative delay between the two sources we observe the HOM dip with a maximum visibility of 70 +/-4%.

  15. Hong-Ou-Mandel interference with two independent weak coherent states

    NASA Astrophysics Data System (ADS)

    Hua, Chen; Xue-Bi, An; Juan, Wu; Zhen-Qiang, Yin; Shuang, Wang; Wei, Chen; Zhen-Fu, Han

    2016-02-01

    Recently, the Hong-Ou-Mandel (HOM) interference between two independent weak coherent pulses (WCPs) has been paid much attention due to the measurement-device-independent (MDI) quantum key distribution (QKD). Using classical wave theory, articles reported before show that the visibility of this kind of HOM-type interference is ≤ 50%. In this work, we analyze this kind of interference using quantum optics, which reveals more details compared to the wave theory. Analyses confirm the maximum visibility of 50%. And we conclude that the maximum visibility of 50% comes from the two single-photon states in WCPs, without considering the noise. In the experiment, we successfully approach the visibility of 50% by using WCPs splitting from the single pico-second laser source and phase scanning. Since this kind of HOM interference is immune to slow phase fluctuations, both the realized and proposed experiment designs can provide stable ways of high-resolution optical distance detection. Project supported by the National Basic Research Program of China (Grants Nos. 2011CBA00200 and 2011CB921200), the National Natural Science Foundation of China (Grant Nos. 61201239, 61205118, 11304397, and 61475148) and the “Strategic Priority Research Program (B)” of the Chinese Academy of Sciences (Grant No. XDB01030100 and XDB01030300).

  16. Future directions.

    PubMed

    Erickson, David L; Kress, W John

    2012-01-01

    It is a risky task to attempt to predict the direction that DNA barcoding and its applications may take in the future. In a very short time, the endeavor of DNA barcoding has gone from being a tool to facilitate taxonomy in difficult to identify species, to an ambitious, global initiative that seeks to tackle such pertinent and challenging issues as quantifying global biodiversity, revolutionizing the forensic identifications of species, advancing the study of interactions among species, and promoting the reconstruction of evolutionary relationships within communities. The core element of DNA barcoding will always remain the same: the generation of a set of well-identified samples collected and genotyped at one or more genetic barcode markers and assembled into a properly curated database. But the application of this body of data will depend on the creativity and need of the research community in using a "gold standard" of annotated DNA sequence data at the species level. We foresee several areas where the application of DNA barcode data is likely to yield important evolutionary, ecological, and societal insights, and while far from exclusive, provide examples of how DNA barcode data will continue to empower scientists to address hypothesis-driven research. Three areas of immediate and obvious concern are (1) biodiversity inventories, (2) phylogenetic applications, and (3) species interactions.

  17. 200-DV-1OU Sediment and Pore Water Analysis and Report for Samples at Borehole C8096

    SciTech Connect

    Lindberg, Michael J.

    2011-10-01

    This is an analytical data report for sediment samples received at 200-DV-1 OU. On August 30, 2011 sediment samples were received from 200-DV-1 OU Borehole C8096 for geochemical studies. The analyses for this project were performed at the 331 building located in the 300 Area of the Hanford Site. The analyses were performed according to Pacific Northwest National Laboratory (PNNL) approved procedures and/or nationally recognized test procedures. The data sets include the sample identification numbers, analytical results, estimated quantification limits (EQL), and quality control data. The preparatory and analytical quality control requirements, calibration requirements, acceptance criteria, and failure actions are defined in the on-line QA plan 'Conducting Analytical Work in Support of Regulatory Programs' (CAW). This QA plan implements the Hanford Analytical Services Quality Assurance Requirements Documents (HASQARD) for PNNL.

  18. Implementation of Enhanced Attenuation at the DOE Mound Site OU-1 Landfill: Accelerating Progress and Reducing Costs

    SciTech Connect

    Hooten, Gwendolyn; Cato, Rebecca; Looney, Brian

    2016-03-06

    At the US Department of Energy (DOE), Office of Legacy Management, Mound, Ohio, Site, chlorinated organic contaminants (cVOCs) originating from the former solid-waste landfill have impacted groundwater in Operable Unit 1 (OU-1). The baseline groundwater remedy was groundwater pump and treat (P&T). Since the source materials have been removed from the landfill, the Mound core team, which consists of DOE, US Environmental Protection Agency (US EPA), Ohio EPA, and other stakeholders, is assessing the feasibility of switching from the active P&T remedy to a passive attenuation-based remedy. Toward this end, an enhanced attenuation (EA) strategy based on the creation of structured geochemical zones was developed. This EA strategy addresses the residual areas of elevated cVOCs in soil and groundwater while minimizing the rebound of groundwater concentrations above regulatory targets (e.g., maximum contaminant levels [MCLs]) and avoiding plume expansion while the P&T system is turned off. The EA strategy has improved confidence and reduced risk on the OU-1 groundwater transition path to monitored natural attenuation (MNA). To better evaluate the EA strategy, DOE is conducting a field demonstration to evaluate the use of edible oils to enhance the natural attenuation processes. The field demonstration is designed to determine whether structured geochemical zones can be established that expedite the attenuation of cVOCs in the OU-1 groundwater. The EA approach at OU-1 was designed based on “structured geochemical zones” and relies on groundwater flow through a succession of anaerobic and aerobic zones. The anaerobic zones stimulate relatively rapid degradation of the original solvent source compounds (e.g., cVOCs such as tetrachloroethene [PCE] and trichloroethene [TCE]). The surrounding aerobic areas encourage relatively rapid degradation of daughter products (such as dichloroethene [DCE] and vinyl chloride [VC]) as well as enhanced cometabolism of TCE resulting from

  19. Demonstration/Validation of Long-Term Monitoring Using Wells Installed by Direct-Push Technologies

    DTIC Science & Technology

    2008-04-01

    conditions as well as a cross-section of regulatory domains (e.g., EPA regions and states ). Direct- push wells have been installed adjacent to, in...compliance monitoring including chemical concentrations, oxidation - reduction potential (ORP), pH, temperature, conductivity, turbidity , and dissolved...Engineering Service Center NRCS Natural Resources Conservation Service NTU Nephelometric Turbidity Unit ORP Oxidation /Reduction Potential OU Operational

  20. Market memory and fat tail consequences in option pricing on the expOU stochastic volatility model

    NASA Astrophysics Data System (ADS)

    Perelló, Josep

    2007-08-01

    The expOU stochastic volatility model is capable of reproducing fairly well most important statistical properties of financial markets daily data. Among them, the presence of multiple time scales in the volatility autocorrelation is perhaps the most relevant which makes appear fat tails in the return distributions. This paper wants to go further on with the expOU model we have studied in Ref. [J. Masoliver, J. Perelló, Quant. Finance 6 (2006) 423] by exploring an aspect of practical interest. Having as a benchmark the parameters estimated from the Dow Jones daily data, we want to compute the price for the European option. This is actually done by Monte Carlo, running a large number of simulations. Our main interest is to “see” the effects of a long-range market memory from our expOU model in its subsequent European call option. We pay attention to the effects of the existence of a broad range of time scales in the volatility. We find that a richer set of time scales brings the price of the option higher. This appears in clear contrast to the presence of memory in the price itself which makes the price of the option cheaper.

  1. Analysis of Aquifer Response, Groundwater Flow, and PlumeEvolution at Site OU 1, Former Fort Ord, California

    SciTech Connect

    Jordan, Preston D.; Oldenburg, Curtis M.; Su, Grace W.

    2005-02-24

    This report presents a continuation from Oldenburg et al. (2002) of analysis of the hydrogeology, In-Situ Permeable Flow Sensor (ISPFS) results, aquifer response, and changes in the trichloroethylene (TCE) groundwater plume at Operational Unit 1 (OU 1) adjacent to the former Fritzsche Army Airfield at the former Fort Ord Army Base, located on Monterey Bay in northern Monterey County. Fuels and solvents were burned on a portion of OU 1 called the Fire Drill Area (FDA) during airport fire suppression training between 1962 and 1985. This activity resulted in soil and groundwater contamination in the unconfined A-aquifer. In the late 1980's, soil excavation and bioremediation were successful in remediating soil contamination at the site. Shortly thereafter, a groundwater pump, treat, and recharge system commenced operation. This system has been largely successful at remediating groundwater contamination at the head of the groundwater plume. However, a trichloroethylene (TCE) groundwater plume extends approximately 3000 ft (900 m) to the northwest away from the FDA. In the analyses presented here, we augment our prior work (Oldenburg et al., 2002) with new information including treatment-system totalizer data, recent water-level and chemistry data, and data collected from new wells to discern trends in contaminant migration and groundwater flow that may be useful for ongoing remediation efforts. Some conclusions from the prior study have been modified based on these new analyses, and these are pointed out clearly in this report.

  2. Predicting link directions using local directed path

    NASA Astrophysics Data System (ADS)

    Wang, Xiaojie; Zhang, Xue; Zhao, Chengli; Xie, Zheng; Zhang, Shengjun; Yi, Dongyun

    2015-02-01

    Link prediction in directed network is attracting growing interest among many network scientists. Compared with predicting the existence of a link, determining its direction is more complicated. In this paper, we propose an efficient solution named Local Directed Path to predict link direction. By adding an extra ground node to the network, we solve the information loss problem in sparse network, which makes our method effective and robust. As a quasi-local method, our method can deal with large-scale networks in a reasonable time. Empirical analysis on real networks shows that our method can correctly predict link directions, which outperforms some local and global methods.

  3. Direct Antiglobulin Test

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Direct Antiglobulin Test Share this page: Was this page helpful? Also known as: DAT; Direct Coombs Test; Direct Anti-human Globulin Test Formal ...

  4. Performing Hong-Ou-Mandel-type numerical experiments with repulsive condensates: The case of dark and dark-bright solitons

    NASA Astrophysics Data System (ADS)

    Sun, Zhi-Yuan; Kevrekidis, Panayotis G.; Krüger, Peter

    2016-12-01

    The Hong-Ou-Mandel experiment leads indistinguishable photons simultaneously reaching a 50:50 beam splitter to emerge on the same port through a two-photon interference. Motivated by this phenomenon, we consider numerical experiments of the same flavor for classical wave objects in the setting of repulsive condensates. We examine dark solitons interacting with a repulsive barrier, a case in which we find no significant asymmetries in the emerging waves after the collision, presumably due to their topological nature. We also consider case examples of two-component systems, where the dark solitons trap a bright structure in the second component (dark-bright solitary waves). For these, pronounced asymmetries upon collision are possible for the nontopological bright component. We also show an example of a similar phenomenology for ring dark-bright structures in two dimensions.

  5. Hong-Ou-Mandel interference mediated by the magnetic plasmon waves in a three-dimensional optical metamaterial.

    PubMed

    Wang, S M; Mu, S Y; Zhu, C; Gong, Y X; Xu, P; Liu, H; Li, T; Zhu, S N; Zhang, X

    2012-02-27

    We studied the quantum properties of magnetic plasmon waves in a three-dimensional coupled metamaterial. A Hong-Ou-Mandel dip of two-photon interference with a visibility of 86 ± 6.0% was explicitly observed, when the sample was inserted into one of the two arms of the interferometer. This meant that the quantum interference property survived in such a magnetic plasmon wave-mediated transmission process, thus testifying the magnetic plasmon waves owned a quantum nature. A full quantum model was utilized to describe our experimental results. The results showed that the metamaterials could not only steer the classical light but also the non-classical light and they might have potential application in the future quantum information.

  6. Loss-tolerant state engineering for quantum-enhanced metrology via the reverse Hong-Ou-Mandel effect.

    PubMed

    Ulanov, Alexander E; Fedorov, Ilya A; Sychev, Demid; Grangier, Philippe; Lvovsky, A I

    2016-06-21

    Highly entangled quantum states, shared by remote parties, are vital for quantum communications and metrology. Particularly promising are the N00N states-entangled N-photon wavepackets delocalized between two different locations-which outperform coherent states in measurement sensitivity. However, these states are notoriously vulnerable to losses, making them difficult to both share them between remote locations and recombine in order to exploit interference effects. Here we address this challenge by utilizing the reverse Hong-Ou-Mandel effect to prepare a high-fidelity two-photon N00N state shared between two parties connected by a lossy optical medium. We measure the prepared state by two-mode homodyne tomography, thereby demonstrating that the enhanced phase sensitivity can be exploited without recombining the two parts of the N00N state. Finally, we demonstrate the application of our method to remotely prepare superpositions of coherent states, known as Schrödinger's cat states.

  7. Loss-tolerant state engineering for quantum-enhanced metrology via the reverse Hong-Ou-Mandel effect

    NASA Astrophysics Data System (ADS)

    Ulanov, Alexander E.; Fedorov, Ilya A.; Sychev, Demid; Grangier, Philippe; Lvovsky, A. I.

    2016-06-01

    Highly entangled quantum states, shared by remote parties, are vital for quantum communications and metrology. Particularly promising are the N00N states--entangled N-photon wavepackets delocalized between two different locations--which outperform coherent states in measurement sensitivity. However, these states are notoriously vulnerable to losses, making them difficult to both share them between remote locations and recombine in order to exploit interference effects. Here we address this challenge by utilizing the reverse Hong-Ou-Mandel effect to prepare a high-fidelity two-photon N00N state shared between two parties connected by a lossy optical medium. We measure the prepared state by two-mode homodyne tomography, thereby demonstrating that the enhanced phase sensitivity can be exploited without recombining the two parts of the N00N state. Finally, we demonstrate the application of our method to remotely prepare superpositions of coherent states, known as Schrödinger's cat states.

  8. Contribution to the study of pollution of soil and water in Oued El Maleh area (Mohammedia, Morocco)

    NASA Astrophysics Data System (ADS)

    El hajjaji, Souad; Dahchour, Abdelmalek; Belhsaien, Kamal; Zouahri, Abdelmjid; Moussadek, Rachid; Douaik, Ahmed

    2016-04-01

    In Morocco, diffuse ground and surface water pollution in irrigated areas has caused an increase in the risk of water and soil quality deterioration. This has generated a health and environmental risks. The present study was carried out in the Oued El Maleh region located 65 Km to the south of Rabat on the Moroccan Atlantic coast. It covers a surface area of 310 km2 where agriculture constitutes the main activity of the population. This region is considered as a very important agricultural area, known nationally for its high potential for market gardening. This intensification has been accompanied by an excessive use of agrochemical inputs and poor control of irrigation and drainage. Consequently, salinization phenomena and deterioration of soil structure as well as water are about to create an alarming situation. In order to assess the state of pollution of waters and soil in the region, our study focuses on the determination of physicochemical parameters for the quality of water and soil. The obtained results from sampled wells and surface water show relatively higher values of nitrate and conductivity exceeding Moroccan national standards and revealing net degradation of water quality; therefore the water can be considered not suitable for human consumption and can induce a degradation of soil. The results of the studied soil show that the pH of these soils is weakly to moderately basic; they are usually non-saline with organic matter content moderately filled. Moreover, very high concentrations of nutrients (potassium, phosphorus and nitrogen) were recorded, highlighting poor management fertilizing vegetable crops in the region of Oued El Maleh.

  9. L’administration postnatale de corticoïdes pour traiter ou prévenir les affections pulmonaires chroniques chez les prématurés

    PubMed Central

    2002-01-01

    Le présent énoncé est conçu à l’intention des professionnels de la santé qui soignent des nouveau-nés et de jeunes nourrissons. Il vise à examiner les effets à court et à long terme de l’administration postnatale de corticoïdes systémiques et par inhalation pour prévenir ou traiter une affection pulmonaire chronique évolutive ou établie et à faire des recommandations quant à l’usage de corticoïdes chez les nourrissons à très faible poids de naissance. Le recours systématique à la dexaméthasone systémique pour prévenir ou traiter une affection pulmonaire chronique n’est pas recommandé chez les nourrissons à très faible poids de naissance.

  10. Homeland Security Presidential Directives

    EPA Pesticide Factsheets

    Three of these directives directly affect EPA's role in the national emergency response system: HSPD-5 Management of Domestic Incidents; HSPD-7 Critical Infrastructure Identification, Prioritization, and Protection; and HSPD-8 National Preparedness.

  11. The planetary nebula IPHASXJ211420.0+434136 (Ou5): insights into common-envelope dynamical and chemical evolution

    NASA Astrophysics Data System (ADS)

    Corradi, R. L. M.; Rodríguez-Gil, P.; Jones, D.; García-Rojas, J.; Mampaso, A.; García-Alvarez, D.; Pursimo, T.; Eenmäe, T.; Liimets, T.; Miszalski, B.

    2014-07-01

    While analysing the images of the IPHAS (INT/WFC Photometric Hα Survey of the northern Galactic plane) survey, we noticed that the central star of the candidate planetary nebula IPHASXJ211420.0+434136 (also named Ou5) was clearly variable. This is generally considered as an indication of binarity. To confirm it, we performed a photometric monitoring of the central star, and obtained images and spectra of the nebula. The nebular spectrum confirms that IPHASXJ211420.0+434136 is a planetary nebula of moderately high excitation. It has a remarkable morphology with two nested pairs of bipolar lobes and other unusual features. The light curve of the central star reveals that it is an eclipsing binary system with an orbital period of 8.74 h. It also displays a strong irradiation effect with an amplitude of 1.5 mag. The presence of multiple bipolar outflows adds constraints to the formation of these nebulae, suggesting the occurrence of discrete ejection events during, or immediately before, the common-envelope phase. IPHASXJ211420.0+434136 also adds evidence to the hypothesis that a significant fraction of planetary nebulae with close binary central stars have a peculiar nebular chemistry and a relatively low nebular mass. This may point to low-mass, low-metallicity progenitors, with additional effects related to the binary evolution. We also suggest that these objects may be relevant to understand the abundance discrepancy problem in planetary nebulae.

  12. Geo-environmental risk in the upper valley of the Oued Sebou (Fès, Central Morocco): a preliminary approach

    NASA Astrophysics Data System (ADS)

    De Waele, J.; Di Gregorio, F.; El Wartiti, M.; Fadli, D.; Follesa, R.; Marini, A.; Melis, M. T.

    2004-06-01

    In the framework of several projects sustained by the Regional Sardinian Government Laws no. 43 (28/09/1990) and no. 19 (11/04/1996), research groups of the University of Cagliari (Sardinia, Italy) and of the University Mohamed V-Agdal of Rabat (Morocco) have started a series of preliminary geo-environmental studies in the basin of the Oued Sebou. An area of almost 1000 square km around the famous city of Fès has been studied, using satellite images and two ground surveying campaigns. These surveys aim to define the geological and structural settings, the vegetation and land use, in order to define the landscape units and to select the areas of major hydrogeological and geo-environmental risk. The satellite data used are the LANDSAT TM5 images taken on the 9th of October 1997. These images have been analysed to obtain the different bases for further thematic mapping, resulting in the geo-environmental map of the area around Fès that constitutes an up-to-date representation of the geological and environmental state of the territory and a useful instrument for further risk assessment and urban and territorial planning.

  13. Ou (Psittirostra psittacea)

    USGS Publications Warehouse

    Snetsinger, Thomas J.; Reynolds, Michelle H.; Herrmann, Christina M.

    1998-01-01

    The ‘Ö‘ü and the Läna‘i Hookbill are plump, predominantly olive green, thick-billed Hawaiian honeycreepers. The ‘Ö‘ü is now very rare and restricted to remote, high-elevation native forest, and the Läna‘i Hookbill is extinct. They are closely related species, belonging to a specialized tribe, Psittirostrini, consisting of nine historically known Hawaiian species with heavy, finchlike to parrotlike bills. Because of their taxonomic affinity and the paucity of information on the Läna‘i Hookbill, we are treating the two species in a single account.

  14. Risk factors for falls in older adults with lower extremity arthritis: a conceptual framework of current knowledge and future directions.

    PubMed

    Arnold, Cathy M; Gyurcsik, Nancy C

    2012-01-01

    Objectif : Le nombre de Canadiens de 65 ans et plus augmentera au cours des 20 prochaines années et la prévalence des maladies chroniques, dont l'arthrite, sera en hausse, tout comme le nombre de chutes. Bien que des facteurs de risques de chute connus soient associés à l'arthrose du genou ou de la hanche, une somme minimale de recherches a évalué les risques ou les taux de chutes et de fractures chez ce segment de la population. En conséquence, l'objectif de cette étude était de dresser un résumé des recherches réalisées sur les risques de chute ou de fracture chez les adultes plus âgés aux prises avec de l'arthrose au genou ou à la hanche, et d'élaborer un cadre conceptuel pour le dépistage et l'évaluation des risques de chute. Méthode : La Classification internationale du fonctionnement, du handicap et de la santé (CIF), qui forme les directives cliniques pour le dépistage des risques de chute, et une revue documentaire sélective ont été utilisées. Résultats : Il existe des lacunes dans nos connaissances relatives aux risques de chute et de fracture au sein de ce segment de la population. La dégradation de la performance musculaire, de l'équilibre et de la mobilité a été établie, mais on sait peu de choses en ce qui a trait aux répercussions possibles de facteurs contextuels personnels ou environnementaux sur les risques de chute ou de fracture. L'activité physique peut aider à prévenir les chutes, mais la non-adhésion des patients à un programme d'activité physique pose problème. Conclusion : Une évaluation des risques de chute chez les adultes plus âgés souffrant d'arthrose du genou ou de la hanche est nécessaire. La promotion de l'activité physique régulière, en se concentrant sur les facteurs contextuels personnels propres à la maladie ou à l'activité, pourrait aider directement la planification du traitement.

  15. Colposcopy - directed biopsy

    MedlinePlus

    ... squamous cells - colposcopy; Pap smear - colposcopy; HPV - colposcopy; Human papilloma virus - colposcopy; Cervix - colposcopy; Colposcopy Images Female reproductive anatomy Colposcopy-directed biopsy Uterus References American College of ...

  16. Rubber friction directional asymmetry

    NASA Astrophysics Data System (ADS)

    Tiwari, A.; Dorogin, L.; Steenwyk, B.; Warhadpande, A.; Motamedi, M.; Fortunato, G.; Ciaravola, V.; Persson, B. N. J.

    2016-12-01

    In rubber friction studies it is usually assumed that the friction force does not depend on the sliding direction, unless the substrate has anisotropic properties, like a steel surface grinded in one direction. Here we will present experimental results for rubber friction, where we observe a strong asymmetry between forward and backward sliding, where forward and backward refer to the run-in direction of the rubber block. The observed effect could be very important in tire applications, where directional properties of the rubber friction could be induced during braking.

  17. Direct current transformer

    NASA Technical Reports Server (NTRS)

    Khanna, S. M.; Urban, E. W. (Inventor)

    1979-01-01

    A direct current transformer in which the primary consists of an elongated strip of superconductive material, across the ends of which is direct current potential is described. Parallel and closely spaced to the primary is positioned a transformer secondary consisting of a thin strip of magnetoresistive material.

  18. Direct Conversion of Energy.

    ERIC Educational Resources Information Center

    Corliss, William R.

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. Direct energy conversion involves energy transformation without moving parts. The concepts of direct and dynamic energy conversion plus the laws governing energy conversion are investigated. Among the topics…

  19. Direct Instruction News, 2001.

    ERIC Educational Resources Information Center

    Tarver, Sara, Ed.

    2001-01-01

    These three issues of a newsletter offer diverse kinds of information deemed to be of interest to Association for Direct Instruction (ADI) members--stories of successful implementations in different settings, write-ups of ADI awards, tips on "how to" deliver direct instruction (DI) more effectively, topical articles focused on particular…

  20. Modelling directional solidification

    NASA Technical Reports Server (NTRS)

    Wilcox, William R.

    1991-01-01

    The long range goal of this program is to develop an improved understanding of phenomena of importance to directional solidification and to enable explanation and prediction of differences in behavior between solidification on Earth and in space. Current emphasis is on determining the influence of perturbations on directional solidification.

  1. Decisions Concerning Directional Dependence

    ERIC Educational Resources Information Center

    von Eye, Alexander; DeShon, Richard P.

    2012-01-01

    In this rejoinder, von Eye and DeShon discuss the decision strategies proposed in their original article ("Directional Dependence in Developmental Research," this issue), as well as the ones proposed by the authors of the commentary (Pornprasertmanit and Little, "Determining Directional Dependency in Causal Associations," this issue). In addition,…

  2. Modelling Directional Solidification

    NASA Technical Reports Server (NTRS)

    Wilcox, William R.; Regel, Liya L.; Zhou, Jian; Yuan, Weijun

    1992-01-01

    The long range goal of this program has been to develop an improved understanding of phenomena of importance to directional solidification, in order to enable explanation and prediction of differences in behavior between solidification on Earth and in space. Current emphasis is on determining the influence of perturbations on directional solidification.

  3. Direct Support Workforce Development.

    ERIC Educational Resources Information Center

    Impact, 1998

    1998-01-01

    The fourteen brief articles in this theme issue all examine challenges in the development of direct support staff working with people who have developmental disabilities. The articles also include the views of direct support providers and people with developmental disabilities themselves, as well as examples of strategies used by provider agencies…

  4. Direct peroral cholangioscopy

    PubMed Central

    Parsi, Mansour A

    2014-01-01

    Peroral cholangioscopy is an important tool for diagnosis and treatment of various biliary disorders. Peroral cholangioscopy can be performed by using a dedicated cholangioscope that is advanced through the accessory channel of a duodenoscope, or by direct insertion of a small-diameter endoscope into the bile duct. Direct peroral cholangioscopy refers to insertion of an ultraslim endoscope directly into the bile duct for visualization of the biliary mucosa and lumen. This approach provides a valuable and economic solution for diagnostic and therapeutic applications in the biliary tree. Compared to ductoscopy using a dedicated cholangioscope, the direct approach has several advantages and disadvantages. In this editorial, I discuss the advantages, disadvantages, and possible future developments pertaining to direct peroral cholangioscopy. PMID:24527174

  5. Antibody Production, Anaphylactic Signs, and T-Cell Responses Induced by Oral Sensitization With Ovalbumin in BALB/c and C3H/HeOuJ Mice

    PubMed Central

    Pablos-Tanarro, Alba; López-Expósito, Ivan; Lozano-Ojalvo, Daniel; López-Fandiño, Rosina

    2016-01-01

    Purpose Two mouse strains, BALB/c and C3H/HeOuJ, broadly used in the field of food allergy, were compared for the evaluation of the allergenic potential of ovalbumin (OVA). Methods Sensitization was made by administering 2 different OVA doses (1 and 5 mg), with cholera toxin as Th2-polarizing adjuvant. Antibody levels, severity of anaphylaxis, and Th1 and Th2 responses induced by the allergen were assessed. In addition, because the mice selected had functional toll-like receptor 4, the influence of contamination with lipopolysaccharide (LPS) on the immunostimulating capacity of OVA on spleen cells was also evaluated. Results Both strains exhibited similar susceptibility to OVA sensitization. The 2 protein doses generated similar OVA-specific IgE and IgG1 levels in both strains, whereas C3H/HeOuJ mice produced significantly more IgG2a. Oral challenge provoked more severe manifestations in C3H/HeOuJ mice as indicated by the drop in body temperature and the severity of the anaphylactic scores. Stimulation of splenocytes with OVA led to significantly higher levels of Th2 and Th1 cytokines in BALB/c, and these were less affected by protein contamination with LPS. Conclusions The antibody and cytokine levels induced by OVA in BALB/c mice and the observation that BALB/c spleen cell cultures were more resistant than those of C3H/HeOuJ mice to the stimulus of LPS make this strain prone to exhibit Th2-mediated food allergic reactions and very adequate for the study of the features of OVA that make it allergenic. PMID:26922934

  6. Le syndrome du canal d’Alcock ou névralgie pudendale : un diagnostic à ne pas méconnaître

    PubMed Central

    Ziouziou, Imad; Bennani, Hassan; Zizi, Mohamed; Karmouni, Tarik; Khader, Khalid El; Koutani, Abdellatif; Andaloussi, Ahmed Iben Attya

    2013-01-01

    Résumé Le syndrome du canal d’Alcock – ou névralgie pudendale – est lié à la compression chronique du nerf pudendal dans la fossette ischiorectale ou au niveau du ligament sacroépineux. Le diagnostic du syndrome d’Alcock est surtout clinique. Les examens complémentaires sont dominés par les explorations électrophysiologiques et le test de bloc anesthésique. Le diagnostic repose sur des critères bien précis, soit les critères de Nantes. La prise en charge doit être globale, comprenant un traitement médicamenteux, des infiltrations, des techniques de neuromodulation, et dans les cas graves ou résistants, un traitement chirurgical qui consiste à libérer le nerf pudendal. Les névralgies pudendales peuvent être rencontrées après traitement d’une incontinence urinaire d’effort par bande-lettes sous-urétrales (TVT). Ce syndrome motive des consultations en urologie, car la douleur intéresse le territoire du périnée et des organes génitaux. Des signes urinaires peuvent aussi accompagner cette douleur. Il est donc judicieux de connaître cette pathologie. PMID:23914265

  7. Directionality of dog vocalizations

    NASA Astrophysics Data System (ADS)

    Frommolt, Karl-Heinz; Gebler, Alban

    2004-07-01

    The directionality patterns of sound emission in domestic dogs were measured in an anechoic environment using a microphone array. Mainly long-distance signals from four dogs were investigated. The radiation pattern of the signals differed clearly from an omnidirectional one with average differences in sound-pressure level between the frontal and rear position of 3-7 dB depending from the individual. Frequency dependence of directionality was shown for the range from 250 to 3200 Hz. The results indicate that when studying acoustic communication in mammals, more attention should be paid to the directionality pattern of sound emission.

  8. L’administration postnatale de corticoïdes pour traiter ou prévenir la maladie pulmonaire chronique chez les prématurés

    PubMed Central

    Jefferies, Ann L

    2012-01-01

    RÉSUMÉ Les corticoïdes sont administrés pendant la période postnatale pour prévenir et traiter la maladie pulmonaire chronique néonatale (MPC) (qu’on appelle aussi dysplasie bronchopulmonaire), une cause importante de mortalité et de morbidité chez les nourrissons prématurés. Puisque l’administration de dexaméthasone ou d’hydrocortisone pendant les sept premiers jours de vie s’associe à un plus grand risque d’infirmité motrice cérébrale, il n’est pas recommandé d’amorcer rapidement une corticothérapie pour prévenir la MPC pendant la période postnatale. Après sept jours de vie, il a été établi que la dexaméthasone réduit le taux de MPC à 36 semaines d’âge postmenstruel et a moins de répercussions sur les issues neurodéveloppementales. Aucun essai n’a évalué si les bienfaits des corticoïdes sont supérieurs à leurs effets indésirables chez les nourrissons à haut risque de MPC ou atteints d’une grave MPC. Il n’est pas recommandé d’administrer systématiquement de la dexaméthasone à tous les enfants sous respirateur, mais les cliniciens peuvent envisager un court traitement à l’aide de faibles doses de dexaméthasone à des nourrissons sélectionnés à haut risque de MPC ou atteints d’une grave MPC. Aucune donnée probante n’indique que l’hydrocortisone est une solution efficace ou sécuritaire pour remplacer la dexaméthasone, et peu de données probantes appuient l’utilisation systématique de corticoïdes en aérosol dans le cadre de la prévention ou du traitement. On peut envisager la corticothérapie en aérosol pour remplacer la dexaméthasone dans le traitement de nourrissons sélectionnés atteints d’une grave MPC. La présente révision remplace le document de principes publié conjointement avec l’American Academy of Pediatrics en 2002.

  9. Direct interval volume visualization.

    PubMed

    Ament, Marco; Weiskopf, Daniel; Carr, Hamish

    2010-01-01

    We extend direct volume rendering with a unified model for generalized isosurfaces, also called interval volumes, allowing a wider spectrum of visual classification. We generalize the concept of scale-invariant opacity—typical for isosurface rendering—to semi-transparent interval volumes. Scale-invariant rendering is independent of physical space dimensions and therefore directly facilitates the analysis of data characteristics. Our model represents sharp isosurfaces as limits of interval volumes and combines them with features of direct volume rendering. Our objective is accurate rendering, guaranteeing that all isosurfaces and interval volumes are visualized in a crack-free way with correct spatial ordering. We achieve simultaneous direct and interval volume rendering by extending preintegration and explicit peak finding with data-driven splitting of ray integration and hybrid computation in physical and data domains. Our algorithm is suitable for efficient parallel processing for interactive applications as demonstrated by our CUDA implementation.

  10. Advanced care directives

    MedlinePlus

    ... you want no matter how ill you are. Writing an advance care directive may be hard. You ... wishes usually replace those you made previously in writing. Additional Information Write your living will or health ...

  11. Direct nuclear pumped laser

    DOEpatents

    Miley, George H.; Wells, William E.; DeYoung, Russell J.

    1978-01-01

    There is provided a direct nuclear pumped gas laser in which the lasing mechanism is collisional radiated recombination of ions. The gas laser active medium is a mixture of the gases, with one example being neon and nitrogen.

  12. Refrigerant directly cooled capacitors

    DOEpatents

    Hsu, John S.; Seiber, Larry E.; Marlino, Laura D.; Ayers, Curtis W.

    2007-09-11

    The invention is a direct contact refrigerant cooling system using a refrigerant floating loop having a refrigerant and refrigeration devices. The cooling system has at least one hermetic container disposed in the refrigerant floating loop. The hermetic container has at least one electronic component selected from the group consisting of capacitors, power electronic switches and gating signal module. The refrigerant is in direct contact with the electronic component.

  13. Directed Energy Weapons

    DTIC Science & Technology

    2007-12-01

    negative side is a reduction in serious competition for defense contracts and a large number of 2nd and 3r’ tier companies out of work or turning to...the USD (I) staff to be afocalpointfor advocating improvement in all dimensions of directed energy intelligence. - The Director, Defense Inteligence ...staff to be afocalpoint for advocating iprovement in all dimensions of directed energy intelligence. The Director, Defense Inteligence Ageng7 should

  14. Electrohydrodynamic direct-writing

    NASA Astrophysics Data System (ADS)

    Huang, Yongan; Bu, Ningbin; Duan, Yongqing; Pan, Yanqiao; Liu, Huimin; Yin, Zhouping; Xiong, Youlun

    2013-11-01

    The electrohydrodynamic (EHD) direct-writing technique can be used to print solid/liquid straight/serpentine nanofibers onto a large-area substrate, in a direct, continuous, and controllable manner. It is a high-efficiency and cost-effective solution-processable technique to satisfy increasing demands of large-area micro/nano-manufacturing. It is ground-breaking to direct-write sub-100 nm fibers on a rigid/flexible substrate using organic materials. A comprehensive review is presented on the research and developments related to the EHD direct-writing technique and print heads. Many developments have been presented to improve the controllability of the electrospun fibers to form high-resolution patterns and devices. EHD direct-writing is characterized by its non-contact, additive and reproducible processing, high resolution, and compatibility with organic materials. It combines dip-pen, inkjet, and electrospinning by providing the feasibility of controllable electrospinning for sub-100 nm nanofabrication, and overcomes the drawbacks of conventional electron-beam lithography, which is relatively slow, complicated and expensive.

  15. Electrohydrodynamic direct-writing.

    PubMed

    Huang, YongAn; Bu, Ningbin; Duan, Yongqing; Pan, Yanqiao; Liu, Huimin; Yin, Zhouping; Xiong, Youlun

    2013-12-21

    The electrohydrodynamic (EHD) direct-writing technique can be used to print solid/liquid straight/serpentine nanofibers onto a large-area substrate, in a direct, continuous, and controllable manner. It is a high-efficiency and cost-effective solution-processable technique to satisfy increasing demands of large-area micro/nano-manufacturing. It is ground-breaking to direct-write sub-100 nm fibers on a rigid/flexible substrate using organic materials. A comprehensive review is presented on the research and developments related to the EHD direct-writing technique and print heads. Many developments have been presented to improve the controllability of the electrospun fibers to form high-resolution patterns and devices. EHD direct-writing is characterized by its non-contact, additive and reproducible processing, high resolution, and compatibility with organic materials. It combines dip-pen, inkjet, and electrospinning by providing the feasibility of controllable electrospinning for sub-100 nm nanofabrication, and overcomes the drawbacks of conventional electron-beam lithography, which is relatively slow, complicated and expensive.

  16. Estimating directional epistasis

    PubMed Central

    Le Rouzic, Arnaud

    2014-01-01

    Epistasis, i.e., the fact that gene effects depend on the genetic background, is a direct consequence of the complexity of genetic architectures. Despite this, most of the models used in evolutionary and quantitative genetics pay scant attention to genetic interactions. For instance, the traditional decomposition of genetic effects models epistasis as noise around the evolutionarily-relevant additive effects. Such an approach is only valid if it is assumed that there is no general pattern among interactions—a highly speculative scenario. Systematic interactions generate directional epistasis, which has major evolutionary consequences. In spite of its importance, directional epistasis is rarely measured or reported by quantitative geneticists, not only because its relevance is generally ignored, but also due to the lack of simple, operational, and accessible methods for its estimation. This paper describes conceptual and statistical tools that can be used to estimate directional epistasis from various kinds of data, including QTL mapping results, phenotype measurements in mutants, and artificial selection responses. As an illustration, I measured directional epistasis from a real-life example. I then discuss the interpretation of the estimates, showing how they can be used to draw meaningful biological inferences. PMID:25071828

  17. Direct Photons at RHIC

    SciTech Connect

    Gabor,D.

    2008-07-29

    Direct photons are ideal tools to investigate kinematical and thermodynamical conditions of heavy ion collisions since they are emitted from all stages of the collision and once produced they leave the interaction region without further modification by the medium. The PHENIX experiment at RHIC has measured direct photon production in p+p and Au+Au collisions at 200 GeV over a wide transverse momentum (p{sub T}) range. The p+p measurements allow a fundamental test of QCD, and serve as a baseline when we try to disentangle more complex mechanisms producing high p{sub T} direct photons in Au+Au. As for thermal photons in Au+Au we overcome the difficulties due to the large background from hadronic decays by measuring 'almost real' virtual photons which appear as low invariant mass e{sup +}e{sup -} pairs: a significant excess of direct photons is measured above the above next-to-leading order perturbative quantum chromodynamics calculations. Additional insights on the origin of direct photons can be gained with the study of the azimuthal anisotropy which benefits from the increased statistics and reaction plane resolution achieved in RHIC Year-7 data.

  18. Highly directional thermal emitter

    SciTech Connect

    Ribaudo, Troy; Shaner, Eric A; Davids, Paul; Peters, David W

    2015-03-24

    A highly directional thermal emitter device comprises a two-dimensional periodic array of heavily doped semiconductor structures on a surface of a substrate. The array provides a highly directional thermal emission at a peak wavelength between 3 and 15 microns when the array is heated. For example, highly doped silicon (HDSi) with a plasma frequency in the mid-wave infrared was used to fabricate nearly perfect absorbing two-dimensional gratings structures that function as highly directional thermal radiators. The absorption and emission characteristics of the HDSi devices possessed a high degree of angular dependence for infrared absorption in the 10-12 micron range, while maintaining high reflectivity of solar radiation (.about.64%) at large incidence angles.

  19. Fermilab Library directions

    SciTech Connect

    Garrett, P.; Ritchie, D.

    1990-05-04

    In this document, we indicate our current thinking about the directions of the Fermilab Library. The ideas relate to the preprint management issue in a number of ways. The ideas are subject to revision as we come to understand what is possible as well as what is needed by the Laboratory community. This document should therefore be regarded as our personal view--the availability of off-the-shelf technology, of funding as well as feedback from the laboratory community about their needs will all affect how far we actually proceed in any of these directions.

  20. Directed flux motor

    NASA Technical Reports Server (NTRS)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2011-01-01

    A directed flux motor described utilizes the directed magnetic flux of at least one magnet through ferrous material to drive different planetary gear sets to achieve capabilities in six actuated shafts that are grouped three to a side of the motor. The flux motor also utilizes an interwoven magnet configuration which reduces the overall size of the motor. The motor allows for simple changes to modify the torque to speed ratio of the gearing contained within the motor as well as simple configurations for any number of output shafts up to six. The changes allow for improved manufacturability and reliability within the design.

  1. Directly Executed Languages.

    DTIC Science & Technology

    2014-09-26

    Architecture 2 1.1 An Evaluation of Adept-A Pascal Based Architecture 2 1.2 A Microprocessor Implementation of a DCA 2 1.3 The Instruction Bandwidth of...Direct Correspondence Architectures 3 1.4 Memory Hierarchies for Directly Executed Language Microprocessors 3 2 Architectural Analysis 4 3 Concurrent...reduction: 3.46 I data read reduction (in bytes): 5.42 "-data write reduction (in bytes): 14.72 A microprocessor based implementation of a Pascal-based DCA

  2. Microsegregation during directional solidification

    NASA Technical Reports Server (NTRS)

    Coriell, S. R.; Mcfadden, G. B.

    1984-01-01

    During the directional solidification of alloys, solute inhomogeneities transverse to the growth direction arise due to morphological instabilities (leading to cellular or dendritic growth) and/or due to convection in the melt. In the absence of convection, the conditions for the onset of morphological instability are given by the linear stability analysis of Mullins and Sekerka. For ordinary solidification rates, the predictions of linear stability analysis are similar to the constitutional supercooling criterion. However, at very rapid solidification rates, linear stability analysis predicts a vast increase in stabilization in comparison to constitutional supercooling.

  3. Optimizing WIMP directional detectors

    NASA Astrophysics Data System (ADS)

    Green, Anne M.; Morgan, Ben

    2007-03-01

    We study the dependence of the exposure required to directly detect a WIMP directional recoil signal on the capabilities of a directional detector. Specifically we consider variations in the nuclear recoil energy threshold, the background rate, whether the detector measures the recoil momentum vector in two or three dimensions and whether or not the sense of the momentum vector can be determined. We find that the property with the biggest effect on the required exposure is the measurement of the momentum vector sense. If the detector cannot determine the recoil sense, the exposure required is increased by an order of magnitude for 3-d read-out and two orders of magnitude for 2-d read-out. For 2-d read-out the required exposure, in particular if the senses cannot be measured, can be significantly reduced by analyzing the reduced angles with the, time dependent, projected direction of solar motion subtracted. The background rate effectively places a lower limit on the WIMP cross-section to which the detector is sensitive; it will be very difficult to detect WIMPs with a signal rate more than an order of magnitude below the background rate. Lowering the energy threshold also reduces the required exposure, but only for thresholds above 20 keV.

  4. Optimizing WIMP Directional Detectors

    NASA Astrophysics Data System (ADS)

    Green, A. M.; Morgan, B.

    2007-08-01

    We study the dependence of the number of events required to directly detect a WIMP directional recoil signal on the capabilities of a directional detector. We consider variations in the nuclear recoil energy threshold, the background rate, whether the detector measures the recoil momentum vector in 2 or 3 dimensions and whether or not the sense of the momentum vector can be determined. The property with the biggest effect on the required exposure is the measurement of the momentum vector sense. If the detector cannot determine the recoil sense, the exposure required is increased by an order of magnitude for 3-d read-out and two orders of magnitude for 2-d read-out. For 2-d read-out the required exposure, in particular if the senses can not be measured, can be significantly reduced by analyzing the reduced angles with the, time dependent, projected direction of solar motion subtracted. The background rate effectively places a lower limit on the WIMP cross-section to which the detector is sensitive; it will be very difficult to detect WIMPs with a signal rate more than an order of magnitude below the background rate. Lowering the energy threshold also reduces the required exposure, but only for thresholds above 20 keV.

  5. Direct Multizone System.

    ERIC Educational Resources Information Center

    Lennox Industries, Inc., Marshalltown, IA.

    Describes Lennox indoor direct multizone equipment and controls. The following areas are covered--(1) unit features, (2) controls and operations, (3) approvals, (4) air patterns, (5) typical applications, (6) specifications and ratings, (7) dimensioned drawings of a typical unit, (8) mixing boxes, (9) blower data, (10) water valve selection and…

  6. The Directed Case Method.

    ERIC Educational Resources Information Center

    Cliff, William H.; Curtin, Leslie Nesbitt

    2000-01-01

    Provides an example of a directed case on human anatomy and physiology. Uses brief real life newspaper articles and clinical descriptions of medical reference texts to describe an actual, fictitious, or composite event. Includes interrelated human anatomy and physiology topics in the scenario. (YDS)

  7. Conclusions and Future Directions

    ERIC Educational Resources Information Center

    Lillibridge, Fred

    2012-01-01

    Benchmarking, when done properly, offers a lot of promise for higher education units that want to improve how they do business. It is clear that much is known, but still more needs to be learned before it reaches its full potential as a useful tool. Readers of this issue of "New Directions for Institutional Research" have been treated to useful…

  8. Statewide Direct Writing Assessment.

    ERIC Educational Resources Information Center

    Peckham, Irvin

    1987-01-01

    Criticizes the California Assessment Program (CAP) prior to l987 for testing writing skills objectively. Describes the specific improvements in the new CAP Directed Writing Assessment which focuses on the most important characteristics necessary to a particular type of writing rather than those that are common to all types.(NH)

  9. Direct fired heat exchanger

    DOEpatents

    Reimann, Robert C.; Root, Richard A.

    1986-01-01

    A gas-to-liquid heat exchanger system which transfers heat from a gas, generally the combustion gas of a direct-fired generator of an absorption machine, to a liquid, generally an absorbent solution. The heat exchanger system is in a counterflow fluid arrangement which creates a more efficient heat transfer.

  10. Core Directions in HRD.

    ERIC Educational Resources Information Center

    1996

    This document consists of four papers presented at a symposium on core directions in human resource development (HRD) moderated by Verna Willis at the 1996 conference of the Academy of Human Resource Development. "Reengineering the Organizational HRD Function: Two Case Studies" (Neal Chalofsky) reports an action research study in which…

  11. Developing Ethical Direction

    ERIC Educational Resources Information Center

    Ribble, Mike S.; Bailey,Gerald D.

    2005-01-01

    When you read or hear an unethical suggestion, such as "Steal this article and sell it to another magazine," we're guessing that your internal compass indicates "wrong direction." In other words, your internal voice says, "No, that would be wrong!" Your internal compass tells you when something is right and something is wrong. In our example, your…

  12. Direction sensitive neutron detector

    DOEpatents

    Ahlen, Steven; Fisher, Peter; Dujmic, Denis; Wellenstein, Hermann F.; Inglis, Andrew

    2017-01-31

    A neutron detector includes a pressure vessel, an electrically conductive field cage assembly within the pressure vessel and an imaging subsystem. A pressurized gas mixture of CF.sub.4, .sup.3He and .sup.4He at respective partial pressures is used. The field cage establishes a relatively large drift region of low field strength, in which ionization electrons generated by neutron-He interactions are directed toward a substantially smaller amplification region of substantially higher field strength in which the ionization electrons undergo avalanche multiplication resulting in scintillation of the CF.sub.4 along scintillation tracks. The imaging system generates two-dimensional images of the scintillation patterns and employs track-finding to identify tracks and deduce the rate and direction of incident neutrons. One or more photo-multiplier tubes record the time-profile of the scintillation tracks permitting the determination of the third coordinate.

  13. Modelling directional solidification

    NASA Technical Reports Server (NTRS)

    Wilcox, William R.

    1987-01-01

    An improved understanding of the phenomena of importance to directional solidification is attempted to enable explanation and prediction of differences in behavior between solidification on Earth and in space. Emphasis is now on experimentally determining the influence of convection and freezing rate fluctuations on compositional homogeneity and crystalline perfection. A correlation is sought between heater temperature profiles, buoyancy-driven convection, and doping inhomogeneities using naphthalene doped with anthracene. The influence of spin-up/spin-down is determined on compositional homogeneity and microstructure of indium gallium antimonide. The effect is determined of imposed melting - freezing cycles on indium gallium antimonide. The mechanism behind the increase of grain size caused by using spin-up/spin-down in directional solidification of mercury cadimum telluride is sought.

  14. Propulsion by directional adhesion

    NASA Astrophysics Data System (ADS)

    Bush, John; Prakash, Manu

    2008-03-01

    The rough, hairy integument of water-walking arthropods is well known to be responsible for their water-repellency; we here consider its additional propulsive role. We demonstrate that the tilted flexible leg hairs of water-walking arthropods render the leg cuticle directionally anisotropic: contact lines advance most readily towards the leg tips. The dynamical role of the resulting unidirectional adhesion is explored, and yields new insight into the manner in which water-walking arthropods generate thrust, glide and leap from the free surface. We thus provide new rationale for the fundamental topological difference in the roughness on plants and insects, and suggest novel directions for biomimetic design of smart, hydrophobic surfaces.

  15. Modelling direction solidification

    NASA Technical Reports Server (NTRS)

    Wilcox, W. R.

    1986-01-01

    The overall objective of this program is to develop an improved understanding of some phenomena of importance to directional solidification. The aim of this research is also to help predict differences in behavior between solidification on Earth and solidification in space. In this report, the validity of the Burton-Primslichter equation is explored. The influence of operating variables on grain and twin generation and propagation in single crystals of In sub (x) Ga sub (1-x) Sb is also investigated.

  16. Direct hydrocarbon fuel cells

    DOEpatents

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  17. Directional Spherical Cherenkov Detector

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D.; Fralick, Gustave C.; Wrbanek, Susan Y.

    2010-01-01

    A proposed radiation-detecting apparatus would provide information on the kinetic energies, directions, and electric charges of highly energetic incident subatomic particles. The apparatus was originally intended for use in measuring properties of cosmic rays in outer space, but could also be adapted to terrestrial uses -- for example, radiation dosimetry aboard high-altitude aircraft and in proton radiation therapy for treatment of tumors.

  18. Directionally Solidified Multifunctional Ceramics

    DTIC Science & Technology

    2006-12-01

    properties (creep, high temperature strength and toughness) and formulate in-situ composite mechanics for multiphase structures. The research efforts on...naturally occurring in-situ composite. The mechanical properties of two phase eutectic are superior to that of either constituent alone due to the strong...directional solidification and can produce strong and stable reinforcing phase/matrix bonding [5]. The phases compromising a eutectic are thermodynamically

  19. Direct drive wind turbine

    DOEpatents

    Bywaters, Garrett; Danforth, William; Bevington, Christopher; Stowell, Jesse; Costin, Daniel

    2006-07-11

    A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

  20. Direct drive wind turbine

    DOEpatents

    Bywaters, Garrett; Danforth, William; Bevington, Christopher; Jesse, Stowell; Costin, Daniel

    2007-02-27

    A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

  1. Direct drive wind turbine

    DOEpatents

    Bywaters, Garrett Lee; Danforth, William; Bevington, Christopher; Stowell, Jesse; Costin, Daniel

    2006-09-19

    A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

  2. Direct drive wind turbine

    DOEpatents

    Bywaters, Garrett; Danforth, William; Bevington, Christopher; Jesse, Stowell; Costin, Daniel

    2006-10-10

    A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

  3. Topologies on directed graphs

    NASA Technical Reports Server (NTRS)

    Lieberman, R. N.

    1972-01-01

    Given a directed graph, a natural topology is defined and relationships between standard topological properties and graph theoretical concepts are studied. In particular, the properties of connectivity and separatedness are investigated. A metric is introduced which is shown to be related to separatedness. The topological notions of continuity and homeomorphism. A class of maps is studied which preserve both graph and topological properties. Applications involving strong maps and contractions are also presented.

  4. Directional Hearing Aid

    NASA Technical Reports Server (NTRS)

    Jhabvala, M.; Lin, H. C.

    1989-01-01

    Hearing-aid device indicates visually whether sound is coming from left, right, back, or front. Device intended to assist individuals who are deaf in at least one ear and unable to discern naturally directions to sources of sound. Device promotes safety in street traffic, on loading docks, and in presence of sirens, alarms, and other warning sounds. Quadraphonic version of device built into pair of eyeglasses and binaural version built into visor.

  5. Direct observation detonator operation

    NASA Astrophysics Data System (ADS)

    Hall, Charles R.

    2001-11-01

    The analysis of detonator-timing performance has involved the use of rotating-mirror cameras (RMC) used in the streak mode and high-speed film. Fiducial timing marks are applied to the film to provide temporal references. The use of a RMC for detonator analysis requires aligning the camera, performing an exposure test, capturing light from the detonation and then processing the film. This procedure can take up to an hour for two technicians. After the film is possessed another technician compares each light streak on the film with the fiducial timing marks also recorded on the film. Capturing light from a detonator and recording it directly to a digitizer can improve detonator-timing measurement in several ways. The digitized signals can then be directly analyzed with software. The direct recording method reduces the need for expensive rotating mirror cameras, film processing and subjective optical measurement comparison. Furthermore, an extensive support facility requiring several specialized technicians is reduced to a single technician in a modest laboratory. This technician is then capable of performing several tests an hour. Tests were preformed to measure light intensity at detonation. An optical method of capturing the light was designed using a remote microscope coupled to optical fiber to bring the light to an optical/electrical converter and a digitizer then records the signal. This system is presently used in parallel with a RMC. The results are compared for accuracy.

  6. Direct somatic lineage conversion

    PubMed Central

    Tanabe, Koji; Haag, Daniel; Wernig, Marius

    2015-01-01

    The predominant view of embryonic development and cell differentiation has been that rigid and even irreversible epigenetic marks are laid down along the path of cell specialization ensuring the proper silencing of unrelated lineage programmes. This model made the prediction that specialized cell types are stable and cannot be redirected into other lineages. Accordingly, early attempts to change the identity of somatic cells had little success and was limited to conversions between closely related cell types. Nuclear transplantation experiments demonstrated, however, that specialized cells even from adult mammals can be reprogrammed into a totipotent state. The discovery that a small combination of transcription factors can reprogramme cells to pluripotency without the need of oocytes further supported the view that these epigenetic barriers can be overcome much easier than assumed, but the extent of this flexibility was still unclear. When we showed that a differentiated mesodermal cell can be directly converted to a differentiated ectodermal cell without a pluripotent intermediate, it was suggested that in principle any cell type could be converted into any other cell type. Indeed, the work of several groups in recent years has provided many more examples of direct somatic lineage conversions. Today, the question is not anymore whether a specific cell type can be generated by direct reprogramming but how it can be induced. PMID:26416679

  7. Direct conversion technology

    NASA Technical Reports Server (NTRS)

    Massier, P. F.; Bankston, C. P.; Fabris, G.; Kirol, L. D.

    1988-01-01

    The overall objective of the Direct Conversion Technology task is to develop an experimentally verified technology base for promising direct thermal-to-electric energy conversion systems that have potential application for energy conservation in the end-use sectors. This report contains progress of research on the Alkali Metal Thermal-to-Electric Converter (AMTEC), and on the Two-Phase Liquid-Metal MHD Electrical Generator (LMMHD) for the period January 1988 through December 1988. Research on these concepts was initiated during October 1987. In addition, status reviews and assessments are presented for thermomagnetic converter concepts and for thermoelastic converters (Nitinol heat engines). Reports prepared on previous occasions contain discussions on the following other direct conversion concepts: thermoelectric, pyroelectric, thermionic thermophotovoltaic and thermoacoustic; and also, more complete discussions of AMTEC and LMMHD systems. A tabulated summary of the various systems which have been reviewed thus far has been prepared. Some of the important technical research needs are listed and a schematic of each system is shown.

  8. Direct imaging of exoplanets.

    PubMed

    Lagrange, Anne-Marie

    2014-04-28

    Most of the exoplanets known today have been discovered by indirect techniques, based on the study of the host star radial velocity or photometric temporal variations. These detections allowed the study of the planet populations in the first 5-8 AU from the central stars and have provided precious information on the way planets form and evolve at such separations. Direct imaging on 8-10 m class telescopes allows the detection of giant planets at larger separations (currently typically more than 5-10 AU) complementing the indirect techniques. So far, only a few planets have been imaged around young stars, but each of them provides an opportunity for unique dedicated studies of their orbital, physical and atmospheric properties and sometimes also on the interaction with the 'second-generation', debris discs. These few detections already challenge formation theories. In this paper, I present the results of direct imaging surveys obtained so far, and what they already tell us about giant planet (GP) formation and evolution. Individual and emblematic cases are detailed; they illustrate what future instruments will routinely deliver for a much larger number of stars. I also point out the limitations of this approach, as well as the needs for further work in terms of planet formation modelling. I finally present the progress expected in direct imaging in the near future, thanks in particular to forthcoming planet imagers on 8-10 m class telescopes.

  9. Total petroleum systems of the Trias/Ghadames Province, Algeria, Tunisia, and Libya; the Tanezzuft-Oued Mya, Tanezzuft-Melrhir, and Tanezzuft-Ghadames

    USGS Publications Warehouse

    Klett, T.R.

    2000-01-01

    Undiscovered conventional oil and gas resources were assessed within total petroleum systems of the Trias/Ghadames Province (2054) as part of the U.S. Geological Survey World Petroleum Assessment 2000. The Trias/Ghadames Province is in eastern Algeria, southern Tunisia, and westernmost Libya. The province and its total petroleum systems generally coincide with the Triassic Basin. The province includes the Oued Mya Basin, Melrhir Basin, and Ghadames (Berkine) Basin. Although several total petroleum systems may exist within each of these basins, only three ?composite? total petroleum systems were identified. Each total petroleum system occurs in a separate basin, and each comprises a single assessment unit. The main source rocks are the Silurian Tanezzuft Formation (or lateral equivalents) and Middle to Upper Devonian mudstone. Maturation history and the major migration pathways from source to reservoir are unique to each basin. The total petroleum systems were named after the oldest major source rock and the basin in which it resides. The estimated means of the undiscovered conventional petroleum volumes in total petroleum systems of the Trias/Ghadames Province are as follows: [MMBO, million barrels of oil; BCFG, billion cubic feet of gas; MMBNGL, million barrels of natural gas liquids] Total Petroleum System MMBO BCFG MMBNGL Tanezzuft-Oued Mya 830 2,341 110 Tanezzuft-Melrhir 1,875 4,887 269 Tanezzuft-Ghadames 4,461 12,035 908

  10. Calcification and silicification: fossilization potential of cyanobacteria from stromatolites of Niuafo'ou's Caldera Lakes (Tonga) and implications for the early fossil record.

    PubMed

    Kremer, Barbara; Kazmierczak, Józef; Lukomska-Kowalczyk, Maja; Kempe, Stephan

    2012-06-01

    Calcification and silicification processes of cyanobacterial mats that form stromatolites in two caldera lakes of Niuafo'ou Island (Vai Lahi and Vai Si'i) were evaluated, and their importance as analogues for interpreting the early fossil record are discussed. It has been shown that the potential for morphological preservation of Niuafo'ou cyanobacteria is highly dependent on the timing and type of mineral phase involved in the fossilization process. Four main modes of mineralization of cyanobacteria organic parts have been recognized: (i) primary early postmortem calcification by aragonite nanograins that transform quickly into larger needle-like crystals and almost totally destroy the cellular structures, (ii) primary early postmortem silicification of almost intact cyanobacterial cells that leave a record of spectacularly well-preserved cellular structures, (iii) replacement by silica of primary aragonite that has already recrystallized and obliterated the cellular structures, (iv) occasional replacement of primary aragonite precipitated in the mucopolysaccharide sheaths and extracellular polymeric substances by Al-Mg-Fe silicates. These observations suggest that the extremely scarce earliest fossil record may, in part, be the result of (a) secondary replacement by silica of primary carbonate minerals (aragonite, calcite, siderite), which, due to recrystallization, had already annihilated the cellular morphology of the mineralized microbiota or (b) relatively late primary silicification of already highly degraded and no longer morphologically identifiable microbial remains.

  11. Visual direction finding by fishes

    NASA Technical Reports Server (NTRS)

    Waterman, T. H.

    1972-01-01

    The use of visual orientation, in the absence of landmarks, for underwater direction finding exercises by fishes is reviewed. Celestial directional clues observed directly near the water surface or indirectly at an asymptatic depth are suggested as possible orientation aids.

  12. Directional control of radiant heat

    NASA Technical Reports Server (NTRS)

    Howell, J. R.; Perlmutter, M.

    1970-01-01

    Surface with grooves having flat bases gives directional emissivities and absorptivities that can be made to approximate a perfect directional surface. Radiant energy can then be transferred in desired directions.

  13. Exploring Dephasing of a Solid-State Quantum Emitter via Time- and Temperature-Dependent Hong-Ou-Mandel Experiments

    NASA Astrophysics Data System (ADS)

    Thoma, A.; Schnauber, P.; Gschrey, M.; Seifried, M.; Wolters, J.; Schulze, J.-H.; Strittmatter, A.; Rodt, S.; Carmele, A.; Knorr, A.; Heindel, T.; Reitzenstein, S.

    2016-01-01

    We probe the indistinguishability of photons emitted by a semiconductor quantum dot (QD) via time- and temperature-dependent two-photon interference (TPI) experiments. An increase in temporal separation between consecutive photon emission events reveals a decrease in TPI visibility on a nanosecond time scale, theoretically described by a non-Markovian noise process in agreement with fluctuating charge traps in the QD's vicinity. Phonon-induced pure dephasing results in a decrease in TPI visibility from (96 ±4 )% at 10 K to a vanishing visibility at 40 K. In contrast to Michelson-type measurements, our experiments provide direct access to the time-dependent coherence of a quantum emitter on a nanosecond time scale.

  14. Directional Antineutrino Detection

    NASA Astrophysics Data System (ADS)

    Safdi, B. R.; Suerfu, J.

    2014-12-01

    We propose the first truly directional antineutrino detector for antineutrinos near the threshold for the inverse beta decay (IBD) of hydrogen, with potential applications including the spatial mapping of geo-neutrinos, searches for stellar antineutrinos, and the monitoring of nuclear reactors. The detector consists of adjacent and separated target and neutron-capture layers. The IBD events, which result in a neutron and a positron, take place in the target layers. These layers are thin enough so that the neutrons escape without scattering elastically. The neutrons are detected in the thicker neutron-capture layers. The location of the IBD event is determined from the energy deposited by the positron as it slows in the medium and from the two gamma rays that come from the positron annihilation. Since the neutron recoils in the direction of the antineutrino's motion, a line may then be drawn between the IBD event location and the neutron-capture location to approximate the antineutrino's velocity. In some events, we may even measure the positron's velocity, which further increases our ability to reconstruct the antineutrino's direction of motion. Our method significantly improves upon previous methods by allowing the neutron to freely travel a long distance before diffusing and being captured. Moreover, our design is a straightforward modification of existing antineutrino detectors; a prototype could easily be built with existing technology. We verify our design through Monte Carlo simulations in Geant4, using commercially-available boron-loaded plastic scintillators for the target and neutron-capture layer materials. We are able to discriminate from background using multiple coincidence signatures within a short, ~microsecond time interval. We conclude that the detector could likely operate above ground with minimal shielding.

  15. Direct effects protection

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Protection of an aircraft and each of its various systems against the direct effects of lightning were analyzed. Components located in different sections of the aircraft were individually examined since they are likely to experience different degrees of susceptibility to lightning, and may be vulnerable to different components of the lightning flash. The basic steps to be followed in establishing lightning protection were presented by discussing the varieties of arc entry and current flow-through damage. The lightning-strike zones and lightning current environments are established, since environmental conditions in the zones are those under which specific protective measures must perform. Airworthiness regulations which apply to lightning protection are cited.

  16. Omni-directional railguns

    DOEpatents

    Shahinpoor, M.

    1995-07-25

    A device is disclosed for electromagnetically accelerating projectiles. The invention features two parallel conducting circular plates, a plurality of electrode connections to both upper and lower plates, a support base, and a projectile magazine. A projectile is spring-loaded into a firing position concentrically located between the parallel plates. A voltage source is applied to the plates to cause current to flow in directions defined by selectable, discrete electrode connections on both upper and lower plates. Repulsive Lorentz forces are generated to eject the projectile in a 360 degree range of fire. 4 figs.

  17. Omni-directional railguns

    DOEpatents

    Shahinpoor, Mohsen

    1995-01-01

    A device for electromagnetically accelerating projectiles. The invention features two parallel conducting circular plates, a plurality of electrode connections to both upper and lower plates, a support base, and a projectile magazine. A projectile is spring-loaded into a firing position concentrically located between the parallel plates. A voltage source is applied to the plates to cause current to flow in directions defined by selectable, discrete electrode connections on both upper and lower plates. Repulsive Lorentz forces are generated to eject the projectile in a 360 degree range of fire.

  18. Direct reading inductance meter

    NASA Technical Reports Server (NTRS)

    Kolby, R. B. (Inventor)

    1977-01-01

    A direct reading inductance meter comprised of a crystal oscillator and an LC tuned oscillator is presented. The oscillators function respectively to generate a reference frequency, f(r), and to generate an initial frequency, f(0), which when mixed produce a difference equal to zero. Upon connecting an inductor of small unknown value in the LC circuit to change its resonant frequency to f(x), a difference frequency (f(r)-f(x)) is produced that is very nearly a linear function of the inductance of the inductor. The difference frequency is measured and displayed on a linear scale in units of inductance.

  19. Direct to Digital Holography

    SciTech Connect

    Bingham, P.R.; Tobin, K.W.

    2007-09-30

    In this Cooperative Research and Development Agreement (CRADA), Oak Ridge National Laboratory (ORNL) assisted nLine Corporation of Austin, TX in the development of prototype semiconductor wafer inspection tools based on the direct-to-digital holographic (DDH) techniques invented at ORNL. Key components of this work included, testing of DDH for detection of defects in High Aspect Ratio (HAR) structures, development of image processing techniques to enhance detection capabilities through the use of both phase and intensity, and development of methods for autofocus on the DDH tools.

  20. Direct to Digital Holography

    SciTech Connect

    Bingham, P.R.; Tobin, K.W.

    2002-06-15

    In this CRADA, Oak Ridge National Laboratory (ORNL) assisted nLine Corporation of Austin, TX in the development of prototype semiconductor wafer inspection tools based on the direct-to-digital holographic (DDH) techniques invented at ORNL. Key components of this work included, testing of DDH for detection of defects in High Aspect Ratio (HAR) structures, development of image processing techniques to enhance detection capabilities through the use of both phase and intensity, and development of methods for autofocus on the DDH tools.

  1. Goal directed fluid therapy.

    PubMed

    Marik, Paul E; Desai, Himanshu

    2012-01-01

    The cornerstone of treating patients with shock remains as it has for decades, intravenous fluids. Surprisingly, dosing intravenous fluid during resuscitation of shock remains largely empirical. Recent data suggests that early aggressive resuscitation of critically ill patients may limit and/or reverse tissue hypoxia, progression to organ failure and improve outcome. However, overzealous fluid resuscitation has been associated with increased complications, increased length of intensive care unit (ICU) and hospital stay and increased mortality. This review focuses on methods to assess fluid responsiveness and the application of these methods for goal directed fluid therapy in critically ill and peri-operative patients.

  2. Reciprocity in directed networks

    NASA Astrophysics Data System (ADS)

    Yin, Mei; Zhu, Lingjiong

    2016-04-01

    Reciprocity is an important characteristic of directed networks and has been widely used in the modeling of World Wide Web, email, social, and other complex networks. In this paper, we take a statistical physics point of view and study the limiting entropy and free energy densities from the microcanonical ensemble, the canonical ensemble, and the grand canonical ensemble whose sufficient statistics are given by edge and reciprocal densities. The sparse case is also studied for the grand canonical ensemble. Extensions to more general reciprocal models including reciprocal triangle and star densities will likewise be discussed.

  3. DISE: directed sphere exclusion.

    PubMed

    Gobbi, Alberto; Lee, Man-Ling

    2003-01-01

    The Sphere Exclusion algorithm is a well-known algorithm used to select diverse subsets from chemical-compound libraries or collections. It can be applied with any given distance measure between two structures. It is popular because of the intuitive geometrical interpretation of the method and its good performance on large data sets. This paper describes Directed Sphere Exclusion (DISE), a modification of the Sphere Exclusion algorithm, which retains all positive properties of the Sphere Exclusion algorithm but generates a more even distribution of the selected compounds in the chemical space. In addition, the computational requirement is significantly reduced, thus it can be applied to very large data sets.

  4. Psychiatric Advance Directives: Getting Started

    MedlinePlus

    ... More... Home Getting Started National Resource Center on Psychiatric Advance Directives - Getting Started Getting Started Psychiatric advance directives (PADs) are relatively new legal instruments ...

  5. NON-DIRECTIVE PSYCHOTHERAPY

    PubMed Central

    Smith, Lloyd F.

    1950-01-01

    Psychotherapy is a word to describe an age-old process. It would be better not to speak of psychotherapy, but of psychotherapies. Specialists are not the only ones who act as psychotherapists, since every human being fills this role at one time or another. Besides this, no two persons follow an identical approach. Finally, all therapists change technique constantly. The kinds of psychotherapy must therefore approach infinity. Some physicians appear to assume that only one type of psychotherapy may claim a scientific basis. Although Freud first put psychotherapy on a scientific path, there is no reason to say that Freud must be the last in this field. Over the past few years a new trend has started in psychotherapy which deserves close study. This new trend challenges some old beliefs and gives a new tool to help patients of some types. It is called non-directive or client-centered psychotherapy. This therapy does not try to solve the patient's problems for him, but rather establishes the conditions under which a patient can work out his own salvation. Each year non-directive psychotherapy grows in importance. Much can be learned from the method. PMID:14778014

  6. Direct Aerosol Forcing Uncertainty

    DOE Data Explorer

    Mccomiskey, Allison

    2008-01-15

    Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

  7. Direct thermal dyes

    NASA Astrophysics Data System (ADS)

    Ehlinger, Edward

    1990-07-01

    Direct thermal dyes are members of a class of compounds referred to in the imaging industry as color formers or leuco dyes. The oldest members of that class have simple triarylmethane structures, and have been employed for years in various dyeing applications. More complex triarylmethane compounds, such as phthalides and fluorans, are now used in various imaging systems to produce color. Color is derived from all of these compounds via the same mechanism, on a molecular level. That is, an event of activation produces a highly resonating cationic system whose interaction with incident light produces reflected light of a specific color. The activation event in the case of a direct thermal system is the creation of a melt on the paper involving dye and an acidic developer. The three major performance parameters in a thermal system are background color, image density, and image stability. The three major dye physical parameters affecting thermal performance are chemical constituency, purity, and particle size. Those dyes having the best combination of characteristics which can also be manufactured economically dominate the marketplace. Manufacturing high performance dyes for the thermal market involves multi-step, convergent reaction sequences performed on large scale. Intermediates must be manufactured at the right time, and at the right quality to be useful.

  8. Remote direct memory access

    DOEpatents

    Archer, Charles J.; Blocksome, Michael A.

    2012-12-11

    Methods, parallel computers, and computer program products are disclosed for remote direct memory access. Embodiments include transmitting, from an origin DMA engine on an origin compute node to a plurality target DMA engines on target compute nodes, a request to send message, the request to send message specifying a data to be transferred from the origin DMA engine to data storage on each target compute node; receiving, by each target DMA engine on each target compute node, the request to send message; preparing, by each target DMA engine, to store data according to the data storage reference and the data length, including assigning a base storage address for the data storage reference; sending, by one or more of the target DMA engines, an acknowledgment message acknowledging that all the target DMA engines are prepared to receive a data transmission from the origin DMA engine; receiving, by the origin DMA engine, the acknowledgement message from the one or more of the target DMA engines; and transferring, by the origin DMA engine, data to data storage on each of the target compute nodes according to the data storage reference using a single direct put operation.

  9. Detecting Extrasolar Planets Directly

    NASA Astrophysics Data System (ADS)

    Guenther, E. W.; Neuhäuser, R.; Huélamo, N.; Ott, T.; Brandner, W.; Alves, J.; Comerón, F.; Eckart, A.; Hatzes, A.

    Up to now, all extrasolar planets have been found by means of indirect methods. Direct detection of planets orbiting even the nearest stars seems at first glance to be impossible with present day equipment, because of the enormous difference in brightness between the star and the planet, and the small angular separation between them. However, young planets which are still in the contraction phase of evolution are comparatively bright in the infrared, and since many of the extrasolar planets detected have excentric orbits, where they are most of the time at a relatively large distance from the stars, the prospect of detecting young planets directly is much better. In fact, it is principle be possible to detect an extrasolar giant planet, if the planet is younger than 100 millon years, and if the distance is less than 100 pc. Three years ago we thus have embarked on a survey to observe more than one-hundred young, nearby stars in the near infrared. In this talk, we will review the status of the survey. In order to find out whether these stars have additionally a planet at a small distance from the star, we also carried out sensitive radial velocity observation of a subsample using an iodine-cell and the Echelle spectrograph of the Alfred-Jensch Telescope in Tautenburg.

  10. La prévention et le traitement des infections bactériennes chez les enfants aspléniques ou hypospléniques

    PubMed Central

    1999-01-01

    L’asplénie, qu’elle soit fonctionnelle ou anatomique, s’associe à un accroissement du risque d’infection potentiellement fatale ou constituant un danger de septicémie postsplénectomie (SPS). En raison du risque accru de bactériémie par des bactéries encapsulées chez les enfants aspléniques, la vaccination visant à prévenir une infection au Streptococcus pneumoniae, à l’Haemophilus influenzae de type b (Hib) et au Neiserria meningitidis est recommandée. Malgré la prévalence croissante de S pneumoniae pénicillinorésistant, on recommande aussi l’usage de pénicilline prophylactique chez les enfants aspléniques de moins de cinq ans, et pendant au moins un an après une splénectomie. La poursuite de la prophylaxie antibiotique après cette période dépend de la situation clinique de chaque enfant et de la prévalence de S pneumoniae pénicillinorésistant au sein de la collectivité. Lorsque des enfants aspléniques font de la fièvre ou présentent des symptômes non spécifiques, ils devraient faire l’objet d’une évaluation immédiate. Si on présume la présence de septicémie bactérienne, il faut procéder à une analyse du sang et des autres liquides organiques pertinents et entreprendre sur-le-champ une antibiothérapie à large spectre par voie parentérale, laquelle doit agir également contre les souches de S pneumoniae présentes dans la collectivité. Chez les enfants aspléniques souffrant d’une septicémie foudroyante à S pneumoniae, le taux de mortalité est élevé, malgré l’utilisation rapide d’une antibiothérapie convenable, d’où l’importance des mesures préventives.

  11. Directed light fabrication

    SciTech Connect

    Lewis, G.K.; Nemec, R.; Milewski, J.; Thoma, D.J.; Cremers, D.; Barbe, M.

    1994-09-01

    Directed Light Fabrication (DLF) is a rapid prototyping process being developed at Los Alamos National Laboratory to fabricate metal components. This is done by fusing gas delivered metal powder particles in the focal zone of a laser beam that is, programmed to move along or across the part cross section. Fully dense metal is built up a layer at a time to form the desired part represented by a 3 dimensional solid model from CAD software. Machine ``tool paths`` are created from the solid model that command the movement and processing parameters specific to the DLF process so that the part can be built one layer at a time. The result is a fully dense, near net shape metal part that solidifies under rapid solidification conditions.

  12. Task directed sensing

    NASA Technical Reports Server (NTRS)

    Firby, R. James

    1990-01-01

    High-level robot control research must confront the limitations imposed by real sensors if robots are to be controlled effectively in the real world. In particular, sensor limitations make it impossible to maintain a complete, detailed world model of the situation surrounding the robot. To address the problems involved in planning with the resulting incomplete and uncertain world models, traditional robot control architectures must be altered significantly. Task-directed sensing and control is suggested as a way of coping with world model limitations by focusing sensing and analysis resources on only those parts of the world relevant to the robot's active goals. The RAP adaptive execution system is used as an example of a control architecture designed to deploy sensing resources in this way to accomplish both action and knowledge goals.

  13. Modelling directional solidification

    NASA Technical Reports Server (NTRS)

    Wilcox, William R.

    1990-01-01

    The long range goal is to develop an improved understanding of phenomena of importance to directional solidification, to enable explanation and prediction of differences in behavior between solidification on Earth and in space. Emphasis during the period of this grant was on experimentally determining the influence of convection and freezing rate fluctuations on compositional homogeneity and crystalline perfection in the vertical Bridgman-Stockbarger technique. Heater temperature profiles, buoyancy-driven convection, and doping inhomogeneties were correlated using naphthalene doped with azulene. In addition the influence of spin-up/spin-down on compositional homogeneity and microstructure of indium gallium antimonide and the effect of imposed melting-freezing cycles on indium gallium antimonide are discussed.

  14. Mutanome directed cancer immunotherapy.

    PubMed

    Vormehr, Mathias; Diken, Mustafa; Boegel, Sebastian; Kreiter, Sebastian; Türeci, Özlem; Sahin, Ugur

    2016-04-01

    Somatic mutations are important drivers of cancer development. Accumulating evidence suggests that a significant subset of mutations result in neo-epitopes recognized by autologous T cells and thus may constitute the Achilles' heel of tumor cells. T cells directed against mutations have been shown to have a key role in clinical efficacy of potent cancer immunotherapy modalities, such as adoptive transfer of autologous tumor infiltrating lymphocytes and immune checkpoint inhibitors. Whereas these findings strengthen the idea of a prominent role of neo-epitopes in tumor rejection, the systematic therapeutic exploitation of mutations was hampered until recently by the uniqueness of the repertoire of mutations ('the mutanome') in every patient's tumor. This review highlights insights into immune recognition of neo-epitopes and novel concepts for comprehensive identification and immunotherapeutic exploitation of individual mutations.

  15. Site directed recombination

    DOEpatents

    Jurka, Jerzy W.

    1997-01-01

    Enhanced homologous recombination is obtained by employing a consensus sequence which has been found to be associated with integration of repeat sequences, such as Alu and ID. The consensus sequence or sequence having a single transition mutation determines one site of a double break which allows for high efficiency of integration at the site. By introducing single or double stranded DNA having the consensus sequence flanking region joined to a sequence of interest, one can reproducibly direct integration of the sequence of interest at one or a limited number of sites. In this way, specific sites can be identified and homologous recombination achieved at the site by employing a second flanking sequence associated with a sequence proximal to the 3'-nick.

  16. DIRECT CURRENT ELECTROMAGNETIC PUMP

    DOEpatents

    Barnes, A.H.

    1957-11-01

    An improved d-c electromagnetic pump is presented in which the poles, and consequently the magetic gap at the poles, are tapered to be wider at the upstream end. In addition, the cross section of the tube carryiQ the liquid metal is tapered so that the velocity of the pumped liquid increases in the downstream direction at a rate such that the counter-induced voltage in the liquid metal remains constant as it traverses the region between the poles. This configuration compensates for the distortion of the magnetic field caused by the induced voltage that would otherwise result in the lowering of the pumping capacity. This improved electromagnetic pump as practical application in the pumping of liquid metal coolants for nuclear reactors where conventional positive displacement pumps have proved unsatisfactory due to the high temperatures and the corrosive properties of the liquid metals involved.

  17. Nanoparticles and direct immunosuppression

    PubMed Central

    Ngobili, Terrika A

    2016-01-01

    Targeting the immune system with nanomaterials is an intensely active area of research. Specifically, the capability to induce immunosuppression is a promising complement for drug delivery and regenerative medicine therapies. Many novel strategies for immunosuppression rely on nanoparticles as delivery vehicles for small-molecule immunosuppressive compounds. As a consequence, efforts in understanding the mechanisms in which nanoparticles directly interact with the immune system have been overshadowed. The immunological activity of nanoparticles is dependent on the physiochemical properties of the nanoparticles and its subsequent cellular internalization. As the underlying factors for these reactions are elucidated, more nanoparticles may be engineered and evaluated for inducing immunosuppression and complementing immunosuppressive drugs. This review will briefly summarize the state-of-the-art and developments in understanding how nanoparticles induce immunosuppressive responses, compare the inherent properties of nanomaterials which induce these immunological reactions, and comment on the potential for using nanomaterials to modulate and control the immune system. PMID:27229901

  18. Magnetostrictive direct drive motors

    NASA Technical Reports Server (NTRS)

    Naik, Dipak; Dehoff, P. H.

    1990-01-01

    Developing magnetostrictive direct drive research motors to power robot joints is discussed. These type motors are expected to produce extraordinary torque density, to be able to perform microradian incremental steps and to be self-braking and safe with the power off. Several types of motor designs have been attempted using magnetostrictive materials. One of the candidate approaches (the magnetostrictive roller drive) is described. The method in which the design will function is described as is the reason why this approach is inherently superior to the other approaches. Following this, the design will be modelled and its expected performance predicted. This particular candidate design is currently undergoing detailed engineering with prototype construction and testing scheduled for mid 1991.

  19. Direct Field Acoustic Testing

    NASA Technical Reports Server (NTRS)

    Larkin, Paul; Goldstein, Bob

    2008-01-01

    This paper presents an update to the methods and procedures used in Direct Field Acoustic Testing (DFAT). The paper will discuss some of the recent techniques and developments that are currently being used and the future publication of a reference standard. Acoustic testing using commercial sound system components is becoming a popular and cost effective way of generating a required acoustic test environment both in and out of a reverberant chamber. This paper will present the DFAT test method, the usual setup and procedure and the development and use of a closed-loop, narrow-band control system. Narrow-band control of the acoustic PSD allows all standard techniques and procedures currently used in random control to be applied to acoustics and some examples are given. The paper will conclude with a summary of the development of a standard practice guideline that is hoped to be available in the first quarter of next year.

  20. Fiber optic TV direct

    NASA Technical Reports Server (NTRS)

    Kassak, John E.

    1991-01-01

    The objective of the operational television (OTV) technology was to develop a multiple camera system (up to 256 cameras) for NASA Kennedy installations where camera video, synchronization, control, and status data are transmitted bidirectionally via a single fiber cable at distances in excess of five miles. It is shown that the benefits (such as improved video performance, immunity from electromagnetic interference and radio frequency interference, elimination of repeater stations, and more system configuration flexibility) can be realized if application of the proven fiber optic transmission concept is used. The control system will marry the lens, pan and tilt, and camera control functions into a modular based Local Area Network (LAN) control network. Such a system does not exist commercially at present since the Television Broadcast Industry's current practice is to divorce the positional controls from the camera control system. The application software developed for this system will have direct applicability to similar systems in industry using LAN based control systems.

  1. Directed Polymerase Evolution

    PubMed Central

    Chen, Tingjian; Romesberg, Floyd E.

    2014-01-01

    Polymerases evolved in nature to synthesize DNA and RNA, and they underlie the storage and flow of genetic information in all cells. The availability of these enzymes for use at the bench has driven a revolution in biotechnology and medicinal research; however, polymerases did not evolve to function efficiently under the conditions required for some applications and their high substrate fidelity precludes their use for most applications that involve modified substrates. To circumvent these limitations, researchers have turned to directed evolution to tailor the properties and/or substrate repertoire of polymerases for different applications, and several systems have been developed for this purpose. These systems draw on different methods of creating a pool of randomly mutated polymerases and are differentiated by the process used to isolate the most fit members. A variety of polymerases have been evolved, providing new or improved functionality, as well as interesting new insight into the factors governing activity. PMID:24211837

  2. Directed light fabrication

    NASA Astrophysics Data System (ADS)

    Lewis, G. K.; Nemec, R.; Milewski, J.; Thoma, D. J.; Cremers, D.; Barbe, M.

    1994-09-01

    Directed Light Fabrication (DLF) is a rapid prototyping process being developed at Los Alamos National Laboratory to fabricate metal components. This is done by fusing gas delivered metal powder particles in the focal zone of a laser beam that is programmed to move along or across the part cross section. Fully dense metal is built up a layer at a time to form the desired part represented by a 3 dimensional solid model from CAD software. Machine 'tool paths' are created from the solid model that command the movement and processing parameters specific to the DLF process so that the part can be built one layer at a time. The result is a fully dense, near net shape metal part that solidifies under rapid solidification conditions.

  3. New directions in mechanics

    SciTech Connect

    Kassner, Michael E.; Nemat-Nasser, Sia; Suo, Zhigang; Bao, Gang; Barbour, J. Charles; Brinson, L. Catherine; Espinosa, Horacio; Gao, Huajian; Granick, Steve; Gumbsch, Peter; Kim, Kyung -Suk; Knauss, Wolfgang; Kubin, Ladislas; Larson, Ben C.; Mahadevan, L.; Majumdar, Arun; Torquato, Salvatore; van Swol, Frank

    2004-09-15

    The Division of Materials Sciences and Engineering of the US Department of Energy (DOE) sponsored a workshop to identify cutting-edge research needs and opportunities, enabled by the application of theoretical and applied mechanics. The workshop also included input from biochemical, surface science, and computational disciplines, on approaching scientific issues at the nanoscale, and the linkage of atomistic-scale with nano-, meso-, and continuum-scale mechanics. This paper is a summary of the outcome of the workshop, consisting of three main sections, each put together by a team of workshop participants. Section 1 addresses research opportunities that can be realized by the application of mechanics fundamentals to the general area of self-assembly, directed self-assembly, and fluidics. Section 2 examines the role of mechanics in biological, bioinspired, and biohybrid material systems, closely relating to and complementing the material covered in Section 1. In this manner, it was made clear that mechanics plays a fundamental role in understanding the biological functions at all scales, in seeking to utilize biology and biological techniques to develop new materials and devices, and in the general area of bionanotechnology. While direct observational investigations are an essential ingredient of new discoveries and will continue to open new exciting research doors, it is the basic need for controlled experimentation and fundamentally- based modeling and computational simulations that will be truly empowered by a systematic use of the fundamentals of mechanics. Section 3 brings into focus new challenging issues in inelastic deformation and fracturing of materials that have emerged as a result of the development of nanodevices, biopolymers, and hybrid bio–abio systems. As a result, each section begins with some introductory overview comments, and then provides illustrative examples that were presented at the workshop and which are believed to highlight the enabling

  4. Conclusions and Policy Directions,

    SciTech Connect

    Wilbanks, Thomas J; Romero-Lankao, Paty; Gnatz, P

    2011-01-01

    This chapter briefly revisits the constraints and opportunities of mitigation and adaptation, and highlights and the multiple linkages, synergies and trade-offs between mitigation, adaptation and urban development. The chapter then presents future policy directions, focusing on local, national and international principles and policies for supporting and enhancing urban responses to climate change. In summary, policy directions for linking climate change responses with urban development offer abundant opportunities; but they call for new philosophies about how to think about the future and how to connect different roles of different levels of government and different parts of the urban community. In many cases, this implies changes in how urban areas operate - fostering closer coordination between local governments and local economic institutions, and building new connections between central power structures and parts of the population who have often been kept outside of the circle of consultation and discourse. The difficulties involved in changing deeply set patterns of interaction and decision-making in urban areas should not be underestimated. Because it is so difficult, successful experiences need to be identified, described and widely publicized as models for others. However, where this challenge is met, it is likely not only to increase opportunities and reduce threats to urban development in profoundly important ways, but to make the urban area a more effective socio-political entity, in general - a better city in how it works day to day and how it solves a myriad of problems as they emerge - far beyond climate change connections alone. It is in this sense that climate change responses can be catalysts for socially inclusive, economically productive and environmentally friendly urban development, helping to pioneer new patterns of stakeholder communication and participation.

  5. New directions in mechanics

    DOE PAGES

    Kassner, Michael E.; Nemat-Nasser, Sia; Suo, Zhigang; ...

    2004-09-15

    The Division of Materials Sciences and Engineering of the US Department of Energy (DOE) sponsored a workshop to identify cutting-edge research needs and opportunities, enabled by the application of theoretical and applied mechanics. The workshop also included input from biochemical, surface science, and computational disciplines, on approaching scientific issues at the nanoscale, and the linkage of atomistic-scale with nano-, meso-, and continuum-scale mechanics. This paper is a summary of the outcome of the workshop, consisting of three main sections, each put together by a team of workshop participants. Section 1 addresses research opportunities that can be realized by the applicationmore » of mechanics fundamentals to the general area of self-assembly, directed self-assembly, and fluidics. Section 2 examines the role of mechanics in biological, bioinspired, and biohybrid material systems, closely relating to and complementing the material covered in Section 1. In this manner, it was made clear that mechanics plays a fundamental role in understanding the biological functions at all scales, in seeking to utilize biology and biological techniques to develop new materials and devices, and in the general area of bionanotechnology. While direct observational investigations are an essential ingredient of new discoveries and will continue to open new exciting research doors, it is the basic need for controlled experimentation and fundamentally- based modeling and computational simulations that will be truly empowered by a systematic use of the fundamentals of mechanics. Section 3 brings into focus new challenging issues in inelastic deformation and fracturing of materials that have emerged as a result of the development of nanodevices, biopolymers, and hybrid bio–abio systems. As a result, each section begins with some introductory overview comments, and then provides illustrative examples that were presented at the workshop and which are believed to highlight the

  6. Growth directions of microstructures in directional solidification of crystalline materials.

    PubMed

    Deschamps, J; Georgelin, M; Pocheau, A

    2008-07-01

    In directional solidification, as the solidification velocity increases, the growth direction of cells or dendrites rotates from the direction of the thermal gradient to that of a preferred cristalline orientation. Meanwhile, their morphology varies with important implications for microsegregation. Here, we experimentally document the growth directions of these microstructures in a succinonitrile alloy in the whole accessible range of directions, velocities, and spacings. For this, we use a thin sample made of a single crystal on which the direction of the thermal gradient can be changed. This allows a fine monitoring of the misorientation angle between thermal gradient and preferred crystalline orientation. Data analysis shows evidence of an internal symmetry which traces back to a scale invariance of growth directions with respect to a Péclet number. This enables the identification of the relationship between growth directions and relevant variables, in fair agreement with experiment. Noticeable variations of growth directions with misorientation angles are evidenced and linked to a single parameter.

  7. Determination of heavy metals in suspended waste water collected from Oued El Harrach Algiers River by Energy Dispersive X-Ray Fluorescence

    NASA Astrophysics Data System (ADS)

    Ouziane, S.; Amokrane, A.; Toumert, I.

    2013-12-01

    A preliminary study of the atmospheric pollution in the centre of Algiers is one of the important fields of applications in the environmental science. Nowadays, we need to evaluate the level of the contamination which has an unfavourable effect on physicochemical properties of soils and plants and namely also on human health. In the present work, water samples collected from Oued El-Harrach Algiers River, have been filtered in 0.45 μm Millipore filters to be analysed by Energy Dispersive X-Ray Fluorescence technique using 109Cd radioisotope source. Concentrations of the toxic elements like heavy metals are determined and compared with the published ones values by Yoshida [1] and those obtained using PIXE and NAA techniques [6].

  8. Le fibromatosis colli ou torticolis congénital: son diagnostic et sa prise en charge à propos de deux cas

    PubMed Central

    Tchaou, Mazamaesso; Pegbessou, Plaodezina Essobozou; Sonhaye, Lantam; Ahouanssou, Patricia Yékpé; Amadou, Abdoulatif; Kolou, Beresa; Kama, Lidi Bessi; Garba, Nouhou Mahamadou; Koussema, Lama Kegdigoma Agoda; N'dakéna, Koffi

    2015-01-01

    Le fibromatosis colli (FC) est pseudotumeur rare du muscle sterno-cléido-mastoïdien (SCM), à l'origine d'un torticolis dit congénital chez le nouveau-né ou le nourrisson. Le mécanisme étio-pathogénique de sa survenue est sujet à controverse. Son diagnostic fait appel à l’échographie qui permet de mettre en évidence un épaississement caractéristique du muscle. Nous rapportons deux cas diagnostiqués par l’échographie avec pour un cas une notion de malposition intra-utérine et pour l'autre cas une absence totale de malposition et de traumatisme obstétrical qui pourtant est évoqué comme élément du mécanisme de survenue du FC. PMID:26834927

  9. What Feynman could not yet use: the generalised Hong-Ou-Mandel experiment to improve the QED explanation of the Pauli exclusion principle

    NASA Astrophysics Data System (ADS)

    Malgieri, Massimiliano; Tenni, Antonio; Onorato, Pasquale; De Ambrosis, Anna

    2016-09-01

    In this paper we present a reasoning line for introducing the Pauli exclusion principle in the context of an introductory course on quantum theory based on the sum over paths approach. We start from the argument originally introduced by Feynman in ‘QED: The Strange Theory of Light and Matter’ and improve it by discussing with students modern experimental evidence from the famous Hong-Ou-Mandel experiment with indistinguishable photons and its generalised version using electrons. The experiments can be analysed in a rather simple way using Feynman’s method of ‘arrow multiplication’ for treating processes involving more than one quantum object. The approach described is especially relevant in the formation of high school physics teachers to the basics of modern physics.

  10. Link direction for link prediction

    NASA Astrophysics Data System (ADS)

    Shang, Ke-ke; Small, Michael; Yan, Wei-sheng

    2017-03-01

    Almost all previous studies on link prediction have focused on using the properties of the network to predict the existence of links between pairs of nodes. Unfortunately, previous methods rarely consider the role of link direction for link prediction. In fact, many real-world complex networks are directed and ignoring the link direction will mean overlooking important information. In this study, we propose a phase-dynamic algorithm of the directed network nodes to analyse the role of link directions and demonstrate that the bi-directional links and the one-directional links have different roles in link prediction and network structure formation. From this, we propose new directional prediction methods and use six real networks to test our algorithms. In real networks, we find that compared to a pair of nodes which are connected by a one-directional link, a pair of nodes which are connected by a bi-directional link always have higher probabilities to connect to the common neighbours with only bi-directional links (or conversely by one-directional links). We suggest that, in the real networks, the bi-directional links will generally be more informative for link prediction and network structure formation. In addition, we propose a new directional randomized algorithm to demonstrate that the direction of the links plays a significant role in link prediction and network structure formation.

  11. Response of Nereis diversicolor (Polychaeta, Nereidae) populations to reduced wastewater discharge in the polluted estuary of Oued Souss, Bay of Agadir, Morocco

    NASA Astrophysics Data System (ADS)

    Ait Alla, A.; Gillet, P.; Deutsch, B.; Moukrim, A.; Bergayou, H.

    2006-12-01

    Field investigations on the population dynamics of Nereis diversicolor were carried out from January 2002 to December 2003 in the estuary of Oued Souss (southwestern Morocco) to determine the changes caused by setting up of a domestic and industrial wastewater purification plant (M'zar) before and after by the end of wastewater discharges in November 2002 on the structure of the ecosystem. Samples of N. diversicolor were collected monthly in the intertidal zone at low tide before (during 2002) and after (during 2003) the end of wastewater discharges. Separation of cohorts using the Algorithm EM method (McLachlan, G.J., Krishnan, T., 1997. The EM algorithm and extensions. Wiley Series in Probability and Statistics. Wiley, New York, 274 pp.) allowed determination of the growth rate (mm day -1) by cohort and the annual production. The data showed significant differences between populations of Nereis diversicolor before and after the end of wastewater discharges. During the wastewater discharge period (2002), the population had a mean annual density of 1992 ind m -2, a mean annual biomass of 75.52 g DW m -2 and an annual secondary production of 141.3 g DW m -2 with a P/ B ratio of 1.87. After the end of discharges (2003), density, biomass and secondary production decreased significantly. The annual averages for these parameters were 740 ind m -2, 14.16 g DW m -2 and 23.83 g DW m -2, respectively, with a P/ B ratio of 1.68. The important decrease observed in density, biomass and secondary production of Nereis diversicolor may be attributed (a) to the environmental changes observed after the end of wastewater discharges in the estuary of Oued Souss, namely the increase of salinity and the decrease of organic matter content, and (b) to the migration of this species towards other areas.

  12. Ore deposits and epithermal evidences associated with intra-magmatic faults at Aïn El Araâr-Oued Belif ring structure (NW of Tunisia)

    NASA Astrophysics Data System (ADS)

    Aissa, Wiem Ben; Aissa, Lassaâd Ben; Amara, Abdesslem Ben Haj; Tlig, Said; Alouani, Rabah

    2017-03-01

    Hydrothermal ore deposits at Aïn El Araâr-Oued Belif location are classified as epithermal deposits type. The ore bodies are hosted by upper Turonian (8-9 M.y) volcanic rhyodacitic complex. Polymetallic sulfide orebodies are mainly concentrated within intra-magmatic faults. Petrographic, XRD, and TEM-STEM investigations revealed that ore minerals are essentially, arsenopyrite, pyrite, chalcopyrite, pyrrhotite, hematite, goethite and magnetite with Au, Ag and Pt trace metals. Gangue minerals are mainly adularia, quartz, sericite, alunite, tridymite, chlorite, phlogopite and smectite. Epithermal alteration is well zoned with four successive characteristic zones: (1) zone of quartz-adularia-sericite and rare alunite; (2) zone of kaolinite and plagioclase albitization; (3) intermediate zone of illite-sericite; (4) sapropelic alteration type zone of chlorite-smectite and rare illite. This can be interpreted as a telescoping of two different acidity epithermal phases; low sulfidation (adularia-sericite) and high sulfidation (quartz-alunite), separated in time or due to a gradual increase of fluids acidity and oxicity within the same mineralization phase. Brecciated macroscopic facies with fragments hosting quartz-adularia-sericite minerals (low-sulfidation phase) without alunite, support the last hypothesis. Geodynamic context and mineral alteration patterns are closely similar to those of Maria Josefa gold mine at SE of Spain which exhibit a volcanic-hosted epithermal ore deposit in a similar vein system, within rhyolitic ignimbrites, altered to an argillic assemblage (illite-sericite abundant and subordinate kaolinite) that grades outwards into propylitic alteration (Sanger-von Oepen et al. (1990)). Mineralogical and lithologic study undertaken in the volcanic host rock at Aïn El Araâr-Oued Belif reveals a typical epithermal low-sulfidation and high-sulfidation ore deposits with dominance of low-sulfidation. Host rocks in these systems range from silicic to

  13. Simulation d'un systeme de stockage saisonnier de glace pour la climatisation d'un batiment commercial ou institutionnel

    NASA Astrophysics Data System (ADS)

    Giraldo, Raul Alberto

    The principal goal of this study was to evaluate, using numerical simulation, the feasibility of an air conditioning system, supported by a seasonal ice storage system, installed in a commercial or institutional building. In this regard, the effects of changing several elements around the design of two possible scenarios were modeled in TRNSYS using Matlab® as a programming tool. In the first scenario, the air demanded inside the building passes directly through the ice storage system. In a second scenario, a closed loop pipe full of glycol transports the heat between the ice reservoir and an air cooling coil. First of all, the literature review shows some studies and earlier relevant applications, as well as different solving methods for moving boundary problems in a biphasic medium (waterice). Next, the heat load profile for a typical institutional building in Montreal is determined as a reference point using EE4 and three different methods of solving the boundary motion problem are compared for both, ice training and ice melting. Subsequently, the design parameters are presented for each scenario. This is followed by a description of the programming codes in Matlab® and the components that have been implemented in TRNSYS. Finally, the results involving the heat exchanged and the waterice boundary movements, among others, are collected for one year and for three years. The simulations of both scenarios have also included the experimental variation of some parameters such as the construction area for the ice reservoir, the duration of the ice melting period and other related physical variables. A final analysis of results was followed by an economic study, which considered the changes in initial investment and the potential energy savings for each scenario, compared with a traditional air conditioning unit. This showed that, although research is still needed on many improvements in the design of scenarios and whether its application is limited by several

  14. New Directions in Biotechnology

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The macromolecule crystallization program within NASA is undergoing considerable pressure, particularly budgetary pressure. While it has shown some successes, they have not lived up to the expectations of others, and technological advances may rapidly overtake the natural advantages offered by crystallization in microgravity. Concomitant with the microgravity effort has been a research program to study the macromolecule crystallization process. It was believed that a better understanding of the process would lead to growth of improved crystals for X-ray diffraction studies. The results of the various research efforts have been impressive in improving our understanding of macromolecule crystallization, but have not led to any improved structures. Macromolecule crystallization for structure determination is "one of", the job being unique for every protein and finished once a structure is obtained. However, the knowledge gained is not lost, but instead lays the foundation for developments in new areas of biotechnology and nanotechnology. In this it is highly analogous to studies into small molecule crystallization, the results of which have led to our present day microelectronics-based society. We are conducting preliminary experiments into areas such as designed macromolecule crystals, macromolecule-inorganic hybrid structures, and macromolecule-based nanotechnology. In addition, our protein crystallization studies are now being directed more towards industrial and new approaches to membrane protein crystallization.

  15. Multiple direction vibration fixture

    DOEpatents

    Cericola, Fred; Doggett, James W.; Ernest, Terry L.; Priddy, Tommy G.

    1991-01-01

    An apparatus for simulating a rocket launch environment on a test item undergoing centrifuge testing by subjecting the item simultaneously or separately to vibration along an axis of centripetal force and along an axis perpendicular to the centripetal force axis. The apparatus includes a shaker motor supported by centrifuge arms and a right angle fixture pivotally connected to one of the shaker motor mounts. When the shaker motor vibrates along the centripetal force axis, the vibrations are imparted to a first side of the right angle fixture. The vibrations are transmitted 90 degrees around the pivot and are directed to a second side of the right angle fixture which imparts vibrations perpendicular to the centripetal force axis. The test item is in contact with a third side of the right angle fixture and receives both centripetal-force-axis vibrations and perpendicular axis vibrations simultaneously. A test item can be attached to the third side near the flexible coupling or near the air bag to obtain vibrations along the centripetal force axis or transverse to the centripetal force axis.

  16. Magnetostrictive direct drive motor

    NASA Technical Reports Server (NTRS)

    Naik, Dipak; Dehoff, P. H.

    1991-01-01

    Highly magnetostrictive materials such as Tb.3Dy.7Fe2, commercially known as TERFENOL-D, have been used to date in a variety of devices such as high power actuators and linear motors. The larger magnetostriction available in twinned single crystal TERFENOL-D, approx. 2000 ppm at moderate magnetic field strengths, makes possible a new generation of magnetomechanical devices. NASA researchers are studying the potential of this material as the basis for a direct microstepping rotary motor with torque densities on the order of industrial hydraulics and five times greater than that of the most efficient, high power electric motors. Such a motor would be a micro-radian stepper, capable of precision movements and self-braking in the power-off state. Innovative mechanical engineering techniques are juxtaposed on proper magnetic circuit design to reduce losses in structural flexures, inertias, thermal expansions, eddy currents, and magneto-mechanical coupling, thus optimizing motor performance and efficiency. Mathematical models are presented, including magnetic, structural, and both linear and nonlinear dynamic calculations and simulations. In addition, test results on prototypes are presented.

  17. Coatings for directional eutectics

    NASA Technical Reports Server (NTRS)

    Rairden, J. R.; Jackson, M. R.

    1976-01-01

    Significant advances have been made in the development of an environmentally stable coating for a very high strength, directionally solidified eutectic alloy designated NiTaC-13. Three duplex (two-layer) coatings survived 3,000 hours on a cyclic oxidation test (1,100 C to 90 C). These coatings were fabricated by first depositing a layer of NiCrAl(Y) by vacuum evaporation from an electron beam heated source, followed by depositing an aluminizing overlayer. The alloy after exposure with these coatings was denuded of carbide fibers at the substrate/coating interface. It was demonstrated that TaC fiber denudation can be greatly retarded by applying a carbon-bearing coating. The coating was applied by thermal spraying followed by aluminization. Specimens coated with NiCrAlCY+Al survived over 2,000 hours in the cyclic oxidation test with essentially no TaC denudation. Coating ductility was studied for coated and heat-treated bars, and stress rupture life at 871 C and 1,100 C was determined for coated and cycled bars.

  18. Directed Incremental Symbolic Execution

    NASA Technical Reports Server (NTRS)

    Person, Suzette; Yang, Guowei; Rungta, Neha; Khurshid, Sarfraz

    2011-01-01

    The last few years have seen a resurgence of interest in the use of symbolic execution -- a program analysis technique developed more than three decades ago to analyze program execution paths. Scaling symbolic execution and other path-sensitive analysis techniques to large systems remains challenging despite recent algorithmic and technological advances. An alternative to solving the problem of scalability is to reduce the scope of the analysis. One approach that is widely studied in the context of regression analysis is to analyze the differences between two related program versions. While such an approach is intuitive in theory, finding efficient and precise ways to identify program differences, and characterize their effects on how the program executes has proved challenging in practice. In this paper, we present Directed Incremental Symbolic Execution (DiSE), a novel technique for detecting and characterizing the effects of program changes. The novelty of DiSE is to combine the efficiencies of static analysis techniques to compute program difference information with the precision of symbolic execution to explore program execution paths and generate path conditions affected by the differences. DiSE is a complementary technique to other reduction or bounding techniques developed to improve symbolic execution. Furthermore, DiSE does not require analysis results to be carried forward as the software evolves -- only the source code for two related program versions is required. A case-study of our implementation of DiSE illustrates its effectiveness at detecting and characterizing the effects of program changes.

  19. Microfluidic Compartmentalized Directed Evolution

    PubMed Central

    Paegel, Brian M.; Joyce, Gerald F.

    2010-01-01

    Summary Directed evolution studies often make use of water-in-oil compartments, which conventionally are prepared by bulk emulsification, a crude process that generates non-uniform droplets and can damage biochemical reagents. A microfluidic emulsification circuit was devised that generates uniform water-in-oil droplets (21.9 ± 0.8 μm radius) with high throughput (107–108 droplets per hour). The circuit contains a radial array of aqueous flow nozzles that intersect a surrounding oil flow channel. This device was used to evolve RNA enzymes with RNA ligase activity, selecting enzymes that could resist inhibition by neomycin. Each molecule in the population had the opportunity to undergo 108-fold selective amplification within its respective compartment. Then the progeny RNAs were harvested and used to seed new compartments. During five rounds of this procedure, the enzymes acquired mutations that conferred resistance to neomycin and caused some enzymes to become dependent on neomycin for optimal activity. PMID:20659684

  20. Coatings for directional eutectics

    NASA Technical Reports Server (NTRS)

    Rairden, J. R.; Jackson, M. R.

    1976-01-01

    Coatings developed to provide oxidation protection for the directionally-solidified eutectic alloy NiTaC-B (4.4 weight percent Cr) were evaluated. Of seven Co-, Fe- and Ni-base coatings that were initially investigated, best resistance to cyclic oxidation was demonstrated by duplex coatings fabricated by depositing a layer of NiCrAl(Y) by vacuum evaporation from an electron beam source followed by deposition of an Al overlayer using the pack cementation process. It was found that addition of carbon to the coating alloy substantially eliminated the problem of fiber denudation in TaC-type eutectic alloys. Burner rig cycled NiTaC-B samples coated with Ni-20Cr-5Al-0.1C-0.1Y+Al and rupture-tested at 1100 deg C performed as well as or better than uncoated, vacuum cycled and air-tested NiTaC-13; however, a slight degradation with respect to uncoated material was noted in air-stress rupture tests at 870 deg C for both cycled and uncycled samples.

  1. Directed HK propagator.

    PubMed

    Kocia, Lucas; Heller, Eric J

    2015-09-28

    We offer a more formal justification for the successes of our recently communicated "directed Heller-Herman-Kluk-Kay" (DHK) time propagator by examining its performance in one-dimensional bound systems which exhibit at least quasi-periodic motion. DHK is distinguished by its single one-dimensional integral--a vast simplification over the usual 2N-dimensional integral in full Heller-Herman-Kluk-Kay (for an N-dimensional system). We find that DHK accurately captures particular coherent state autocorrelations when its single integral is chosen to lie along these states' fastest growing manifold, as long as it is not perpendicular to their action gradient. Moreover, the larger the action gradient, the better DHK will perform. We numerically examine DHK's accuracy in a one-dimensional quartic oscillator and illustrate that these conditions are frequently satisfied such that the method performs well. This lends some explanation for why DHK frequently seems to work so well and suggests that it may be applicable to systems exhibiting quite strong anharmonicity.

  2. Directed HK propagator

    NASA Astrophysics Data System (ADS)

    Kocia, Lucas; Heller, Eric J.

    2015-09-01

    We offer a more formal justification for the successes of our recently communicated "directed Heller-Herman-Kluk-Kay" (DHK) time propagator by examining its performance in one-dimensional bound systems which exhibit at least quasi-periodic motion. DHK is distinguished by its single one-dimensional integral—a vast simplification over the usual 2N-dimensional integral in full Heller-Herman-Kluk-Kay (for an N-dimensional system). We find that DHK accurately captures particular coherent state autocorrelations when its single integral is chosen to lie along these states' fastest growing manifold, as long as it is not perpendicular to their action gradient. Moreover, the larger the action gradient, the better DHK will perform. We numerically examine DHK's accuracy in a one-dimensional quartic oscillator and illustrate that these conditions are frequently satisfied such that the method performs well. This lends some explanation for why DHK frequently seems to work so well and suggests that it may be applicable to systems exhibiting quite strong anharmonicity.

  3. Direct spark ignition system

    SciTech Connect

    Gann, R.A.

    1986-12-02

    This patent describes a direct spark ignition system having a gas burner, an electrically operable valve connected to the burner to admit fuel thereto, a gated oscillator having a timing circuit for timing a trial ignition, a spark generator responsive to the oscillator for igniting fuel emanating from the burner, and a flame sensor for sustaining oscillations of the oscillator while a flame exists at the burner. The spark generator has an inverter connected to a low voltage dc source and responsive to the oscillator for converting the dc voltage to a high ac voltage, a means for rectifying the high ac voltage, a capacitor connected to the rectifying means for storing the rectified high voltage, an ignition coil in series between the storage capacitor and a switch, and a means for periodically turning on the switch to produce ignition pulses through the coil. The ignition system is powered from the dc source but controlled by the oscillator. An improvement described here is wherein the inverter is comprised of a step-up transformer having its primary winding connected in series with the dc source and a common emitter transistor having its collector connected to the primary winding. The transistor has its base connected to be controlled by the oscillator to chop the dc into ac in the primary winding, and a diode connected between the storage capacitor and the collector of the transistor, the diode being poled to couple into the capacitor back EMF energy when the transistor is turned off.

  4. Parsec's astrometry direct approaches .

    NASA Astrophysics Data System (ADS)

    Andrei, A. H.

    Parallaxes - and hence the fundamental establishment of stellar distances - rank among the oldest, keyest, and hardest of astronomical determinations. Arguably amongst the most essential too. The direct approach to obtain trigonometric parallaxes, using a constrained set of equations to derive positions, proper motions, and parallaxes, has been labeled as risky. Properly so, because the axis of the parallactic apparent ellipse is smaller than one arcsec even for the nearest stars, and just a fraction of its perimeter can be followed. Thus the classical approach is of linearizing the description by locking the solution to a set of precise positions of the Earth at the instants of observation, rather than to the dynamics of its orbit, and of adopting a close examination of the never many points available. In the PARSEC program the parallaxes of 143 brown dwarfs were aimed at. Five years of observation of the fields were taken with the WIFI camera at the ESO 2.2m telescope, in Chile. The goal is to provide a statistically significant number of trigonometric parallaxes to BD sub-classes from L0 to T7. Taking advantage of the large, regularly spaced, quantity of observations, here we take the risky approach to fit an ellipse in ecliptical observed coordinates and derive the parallaxes. We also combine the solutions from different centroiding methods, widely proven in prior astrometric investigations. As each of those methods assess diverse properties of the PSFs, they are taken as independent measurements, and combined into a weighted least-square general solution.

  5. Slug Test Characterization Results for Multi-Test/Depth Intervals Conducted During the Drilling of CERCLA Operable Unit OU UP-1 Wells 299-W19-48, 699-30-66, and 699-36-70B

    SciTech Connect

    Spane, Frank A.; Newcomer, Darrell R.

    2010-06-15

    This report presents test descriptions and analysis results for multiple, stress-level slug tests that were performed at selected test/depth intervals within three Operable Unit (OU) UP-1 wells: 299-W19-48 (C4300/Well K), 699-30-66 (C4298/Well R), and 699-36-70B (C4299/Well P). These wells are located within, adjacent to, and to the southeast of the Hanford Site 200-West Area. The test intervals were characterized as the individual boreholes were advanced to their final drill depths. The primary objective of the hydrologic tests was to provide information pertaining to the areal variability and vertical distribution of hydraulic conductivity with depth at these locations within the OU UP-1 area. This type of characterization information is important for predicting/simulating contaminant migration (i.e., numerical flow/transport modeling) and designing proper monitor well strategies for OU and Waste Management Area locations.

  6. Slug Test Characterization Results for Multi-Test/Depth Intervals Conducted During the Drilling of CERCLA Operable Unit OU ZP-1 Wells 299-W11-43, 299-W15-50, and 299-W18-16

    SciTech Connect

    Spane, Frank A.; Newcomer, Darrell R.

    2010-06-21

    The following report presents test descriptions and analysis results for multiple, stress level slug tests that were performed at selected test/depth intervals within three Operable Unit (OU) ZP-1 wells: 299-W11-43 (C4694/Well H), 299-W15-50 (C4302/Well E), and 299-W18-16 (C4303/Well D). These wells are located within south-central region of the Hanford Site 200-West Area (Figure 1.1). The test intervals were characterized as the individual boreholes were advanced to their final drill depths. The primary objective of the hydrologic tests was to provide information pertaining to the areal variability and vertical distribution of hydraulic conductivity with depth at these locations within the OU ZP-1 area. This type of characterization information is important for predicting/simulating contaminant migration (i.e., numerical flow/transport modeling) and designing proper monitor well strategies for OU and Waste Management Area locations.

  7. Interface dynamics and anisotropy effects in directional solidification

    NASA Astrophysics Data System (ADS)

    de Cheveigné, S.; Guthmann, C.

    1992-02-01

    A study of the dynamics of the cellular solid-liquid interface in directional solidification of dilute CBr{4} alloy has allowed us to observe a number of secondary instabilities (travelling states, optical modes, anomalous cells, etc.) some of which were well known and traditionally attributed to the effect of crystalline anisotropy. However, most of these instabilities are also observed in a hydrodynamic analog of directional solidification, directional viscous fingering (M. Rabaud, S. Michalland and Y. Couder, Phys. Rev. Lett. 64 (1990) 184). This analogy enables us to discuss the interplay of crystalline anisotropy and of the dynamics generic to one-dimensional systems in directional solidification. Une étude de la dynamique de l'interface cellulaire en solidification directionnelle d'un alliage binaire dilué de CBr4 nous a permis d'observer un certain nombre d'instabilités secondaires (propagation de cellules inclinées, modes optiques, cellules anormales, etc.) dont certaines étaient bien connues et traditionnellement attribuées à des effets de l'anisotropie cristalline. Cependant, la plupart de ces instabilités sont observables dans une expérience qui est l'analogue hydrodynamique de la solidification directionnelle, la digitation visqueuse dirigée ou instabilité de l'imprimeur (M. Rabaud, S. Michalland and Y. Couder, Phys. Rev. Lett. 64 (1990) 184). Cette analogie va nous permettre de discuter les rôles respectifs de l'anisotropie cristalline et de la dynamique propre aux systèmes uni-dimentionnels.

  8. Directly Driven Ion Outflow

    NASA Technical Reports Server (NTRS)

    Elliott, H. A.; Comfort, R. H.; Craven, P. D.; Moore, T. E.; Russell, C. T.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    We examine ionospheric outflows in the high altitude magnetospheric polar cap during the POLAR satellite's apogee on April 19, 1996 using the Thermal Ion Dynamics Experiment (TIDE) instrument. The elevated levels of O(+) observed in this pass may be due to the geophysical conditions during and prior to the apogee pass. In addition to the high abundance of O(+) relative to H(+), several other aspects of this data are noteworthy. We observe relationships between the density, velocity, and temperature which appear to be associated with perpendicular heating and the mirror force, rather than adiabatic expansion. The H(+) outflow is at a fairly constant flux which is consistent with being source limited by charge exchange at lower altitudes. Local centrifugal acceleration in the polar cap is found to be insufficient to account for the main variations we observe in the outflow velocity. The solar wind speed is high during this pass approximately 700 kilometers per second, and there are Alfve'n waves present in the solar wind such that the solar wind speed and IMF Bx are correlated. In this pass both the H(+) and O(+) outflow velocities correlate with both the solar wind speed and IMF fluctuations. Polar cap magnetometer and Hydra electron data show the same long period wave structure as found in the solar wind and polar cap ion outflow. In addition, the polar cap Poynting flux along the magnetic field direction correlates well with the H(+) temperature (R=0.84). We conclude that the solar wind can drive polar cap ion outflow particularly during polar squalls by setting up a parallel drop that is tens of eV which then causes the ion outflow velocity of O(+) and H(+), the electrons, and magnetic perturbations to vary in a similar fashion.

  9. Utilisation de la post-décharge d'un plasma micro-ondes d'air ou d'azote pour valoriser le méthane

    NASA Astrophysics Data System (ADS)

    Oumghar, A.; Legrand, J. C.; Diamy, A. M.; Turillon, N.; Ben-Aïm, R. I.

    1994-01-01

    Valorization of methane is obtained by means of the reaction with a plasma. The plasma is produced in a quartz tube (30 mm in diameter) crossing a wave guide. The energy is supplied by a generator (Thomson CSF, 2 450 MHz, 15 to 1 500 W). Directional couplers followed by an attenuator and thermistor detectors enable forward Pi_i and reflected Pi_r power to be measured. Methane is introduced in the post-discharge zone through five tubes symmetrically arranged around the reactor. Methane consumption α, selectivity SX and yield RX are measured as a function of the following parameters : β methane/air ratio, F gaz flow, d distance where methane is introduced in the plasma, P pressure, Pi microwave power absorbed by air or nitrogen. It appears that acetylene is the major hydrocarbon obtained. The corresponding selectivity is increased when Pi and P are increased or when d and F are decreased. The optimum value of β is 4/5. If the best experimental conditions are selected, selectivity of total C2 reaches 44 % with a conversion ratio of 80 %. By decreasing methane/air ratio, carbon monoxide yield is increased. The ratio acetylene/ethylene can by varied without changing the conversion ratio, by introducing a catalyst in the post reaction zone. La valorisation du méthane est réalisée dans la post-décharge d'un plasma microondes (2 450 MHz) d'air ou d'azote. Lorsque la décharge est produite dans l'azote, les principaux produits dosés sont l'acétylène, l'éthylène, l'éthane et l'hydrogène. Lorsque la décharge est produite dans l'air, on dose en outre le monoxyde de carbone. Le taux de conversion du méthane ainsi que la sélectivité des produits ont été déterminés en fonction des paramètres expérimentaux suivants : proportion méthane/gaz plasmagène, flux gazeux, distance d'introduction du méthane dans la post-décharge, pression et puissance micro-ondes. Le procédé expérimenté permet d'obtenir des rendements chimiques importants et d'éviter la

  10. A reference region for the Ordovician-Silurian boundary: the Oued In Djerane, Algerian SaharaUne région de référence pour la limite Ordovicien-Silurien : l'Oued In Djerane, Sahara algérien

    NASA Astrophysics Data System (ADS)

    Legrand, Philippe

    2000-01-01

    The melting chronology of the Latest Ordovician inlandsis takes on a particular importance in northern Gondwana. A continuous sequence of Diplograptid range zones has been defined from outcrops in the Oued In Djerane, but its comparison with the sequence observed in the stratotype of the Silurian-Ordovician boundary is problematic because of the endemic character of the Saharan species. Moreover, some difficulties are linked to the definition of the Ordovician-Silurian boundary, which, in the Algerian Sahara, probably lies in the Pseudorthograptus (?) kiliani zone. A definite regional diachronism in the melting of the ice-cap has also been confirmed.

  11. New directions at NSF

    NASA Astrophysics Data System (ADS)

    Harvey, Albert B.

    1995-10-01

    The mission and scope of the National Science Foundation (NSF) and lightwave technology will be very briefly discussed. The focus of the presentation will be directed toward changes in research support that are taking place and the opportunities we have for aiming our research to meet the challenges and needs that face the nation. In the USA it is very clear that defense oriented research is downsizing and is being redirected into economy driven aresas, such as manufacturing, business, and industry. For those researchers who are willing to move into these areas and find a niche, the rewards may be very great. Industrial research partners should also seize these opportunities to enhance their resources in an otherwise bleak future for industrial support of basic research in lightwave technology and many other reserach disciplines. These activities of bringing together industry and academia will have the value added benefit of providing increased job opportunities for students. An outline of some of these opportunities and incentives will be presented. On the international front, there has never been a better time for the encouragement of joint research and collaboration across borders. The economic potential for involvement in Eastern Europe and Asia are enormous. Agencies like ourselves are open to help support of visiting scientist/engineer exchange, international conferences and forums and support of innovative ideas to help further enhance economic developemnt of the world and hence the quality of life. The presence of the Russian delegation here at these SPIE meetings in in part the result of NSF support. Concomitant with these changes is a growing interest in education. Academia is gradually realizing that education includes training for students to acquire jobs and hence we complete the cycle of the importance of interacting with industry. At the NSF a major new initiative is being introduced in Optical Science and Engineering (OSE). This effort has been

  12. A Change of Direction

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released July 21, 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth.

    Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms.

    In this image we can clearly see a major change in wind regimes. The classic yardang form occupies the top of the image. These older yardangs were formed by a NW/SE wind regime. The younger, smaller yardangs are forming in the rest of the image from a NE/SW wind. The age relationship is readily visible at the intersection area, where the large yardangs are being cut crosswise into NE/SW aligned forms. The top framelet of this image has vertical black/white lines caused by charge on the camera CCD.

    Image information: VIS instrument. Latitude -6.3, Longitude 183.8 East (176.2 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal

  13. Dark matter directional detection: comparison of the track direction determination

    NASA Astrophysics Data System (ADS)

    Couturier, C.; Zopounidis, J. P.; Sauzet, N.; Naraghi, F.; Santos, D.

    2017-01-01

    Several directional techniques have been proposed for a directional detection of Dark matter, among others anisotropic crystal detectors, nuclear emulsion plates, and low-pressure gaseous TPCs. The key point is to get access to the initial direction of the nucleus recoiling due to the elastic scattering by a WIMP. In this article, we aim at estimating, for each method, how the information of the recoil track initial direction is preserved in different detector materials. We use the SRIM simulation code to emulate the motion of the first recoiling nucleus in each material. We propose the use of a new observable, D, to quantify the preservation of the initial direction of the recoiling nucleus in the detector. We show that in an emulsion mix and an anisotropic crystal, the initial direction is lost very early, while in a typical TPC gas mix, the direction is well preserved.

  14. Directional detector of gamma rays

    DOEpatents

    Cox, Samson A.; Levert, Francis E.

    1979-01-01

    A directional detector of gamma rays comprises a strip of an electrical cuctor of high atomic number backed with a strip of a second electrical conductor of low atomic number. These elements are enclosed within an electrical conductor that establishes an electrical ground, maintains a vacuum enclosure and screens out low-energy gamma rays. The detector exhibits a directional sensitivity marked by an increased output in the favored direction by a factor of ten over the output in the unfavored direction.

  15. Self-Directed Workplace Learning.

    ERIC Educational Resources Information Center

    1998

    This document contains four papers from a symposium on self-directed workplace learning. "Self-Directed Work Teams: Implementation and Performance" (Marcel van der Klink, Hilde ter Horst) discusses the results of a study examining the implementation and effects of self-directed work teams in a land register office and the role of the…

  16. Applications of Payload Directed Flight

    NASA Technical Reports Server (NTRS)

    Ippolito, Corey; Fladeland, Matthew M.; Yeh, Yoo Hsiu

    2009-01-01

    Next generation aviation flight control concepts require autonomous and intelligent control system architectures that close control loops directly around payload sensors in manner more integrated and cohesive that in traditional autopilot designs. Research into payload directed flight control at NASA Ames Research Center is investigating new and novel architectures that can satisfy the requirements for next generation control and automation concepts for aviation. Tighter integration between sensor and machine requires definition of specific sensor-directed control modes to tie the sensor data directly into a vehicle control structures throughout the entire control architecture, from low-level stability- and control loops, to higher level mission planning and scheduling reasoning systems. Payload directed flight systems can thus provide guidance, navigation, and control for vehicle platforms hosting a suite of onboard payload sensors. This paper outlines related research into the field of payload directed flight; and outlines requirements and operating concepts for payload directed flight systems based on identified needs from the scientific literature.'

  17. Détention provisoire des jeunes femmes accusées d'avortement clandestin ou d'infanticide au Sénégal

    PubMed Central

    Soumah, Mohamed Maniboliot; Pemba, Liliane Flore

    2012-01-01

    Introduction L'activité sexuelle chez les jeunes les expose à un accroissement du risque de contracter des grossesses non désirées. Le recours à l'avortement clandestin avec son corollaire de complications peut entrainer le décès de la jeune femme. Avortement et infanticide sont interdits et sanctionnés par la loi sénégalaise. Comment ces jeunes femmes vivent-elles leur détention? Existe-il des alternatives à la détention pour éviter leur désocialisation? Méthodes Cette étude rétrospective portait sur la maison d'arrêt des femmes de Dakar située à Liberté 6, un quartier de Dakar. Nous avons procédé à des entretiens avec des femmes détenues à la maison d'arrêt des femmes de Dakar et suspectées d'infanticide ou d'avortement clandestin. Résultats Les femmes de notre échantillon ont une moyenne d’âge inférieure à 25 ans avec parmi elles une fille mineure de 16 ans. Nous avons trouvé 18,51% de femmes suspectées d'infanticide ou d'avortement. Dans notre étude 50% des femmes sont originaires de la périphérie et de la banlieue de Dakar et presque 44% proviennent des autres régions du pays. La durée moyenne de détention provisoire est de neuf mois. Conclusion Malgré leur qualification distincte dans le code pénal: l'infanticide est un crime et l'avortement un délit, les femmes suspectées d'avoir commis ces actes sont soumises à de longues détentions préventives. PMID:22937189

  18. Direction Finding Using an Antenna with Direction Dependent Impulse Response

    NASA Technical Reports Server (NTRS)

    Foltz, Heinrich; Kegege, Obadiah

    2016-01-01

    Wideband antennas may be designed to have an impulse response that is direction dependent, not only in amplitude but also in waveform shape. This property can be used to perform direction finding using a single fixed antenna, without the need for an array or antenna rotation. In this paper direction finding is demonstrated using a simple candelabra-shaped monopole operating in the 1-3 GHz range. The method requires a known transmitted pulse shape and high signal-to-noise ratio, and is not as accurate or robust as conventional methods. However, it can add direction finding capability to a wideband communication system without the addition of any hardware.

  19. Fiabilité des structures mécaniques adaptatives: effet de la panne des actionneurs ou des capteurs sur la stabilité

    NASA Astrophysics Data System (ADS)

    Fall, H.; Charon, W.; Kouta, R.

    2002-12-01

    Ces dernières décennies, des activités significatives dans le monde étaient dirigées autour du contrôle actif. Le but de ces recherches était essentiellement d'améliorer les performances, la fiabilité et la sécurité des systèmes. Notamment dans le cas des structures soumises à des vibrations aléatoires. D'importants travaux ont été consacré à l'utilisation des “matériaux intelligents” comme capteurs et actionneurs. Cette article propose l'analyse de la fiabilité des systèmes mécaniques en étudiant les pannes des actionneurs ou des capteurs. L'effet de ces pannes sur la stabilité et la performance du système y est démontré. Les méthodologies de conception y sont rappelées. Des exemples numériques sont fournis à travers le contrôle d'un panneau sous chargement dynamique pour illustrer la méthode proposée.

  20. Coupling of spin and orbital degrees of freedom in tunable Hong-Ou-Mandel interference involving photons in hybrid spin-orbit modes

    NASA Astrophysics Data System (ADS)

    Leary, Cody C.; Lankford, Maggie; Sundarraman, Deepika

    2015-05-01

    We investigate the connection between biphoton states involving photons in product modes of their spin and orbital degrees of freedom and those involving photons in hybrid spin-orbit modes, as mediated by Hong-Ou-Mandel interference (HOMI) in an asymmetric Mach-Zehnder interferometer. We predict that two input photons in balanced superposition states of both their spin and orbital degrees of freedom will exhibit HOMI while undergoing a simultaneous mode conversion from product spin-orbit input modes to hybrid output modes bearing orbital angular momentum. These hybrid outputs contain a spatially varying polarization structure which may be controllably rotated about the photonic beam axis by varying the relative phase between the vertical and horizontal components of each input photon's polarization. Additionally, a type of coupling of the spin and orbital degrees of freedom is exhibited in this system: the transverse spatial profile of the output photons may be continuously manipulated by tuning the polarization parameters of the input photons, in such a way that the HOMI between the photons remains stable. An interesting corollary to this work is the possibility of demonstrating in a simple experimental system that HOMI may occur between distinguishable input modes.

  1. Soil Organic Carbon Pool and Its Chemical Composition in Phyllostachy pubescens Forests at Two Altitudes in Jian-ou City, China

    PubMed Central

    Ji, Haibao; Zhuang, Shunyao; Zhu, Zhaoliang; Zhong, Zheke

    2015-01-01

    Phyllostachys pubescens forests play an important role in soil organic carbon (SOC) sequestration in terrestrial ecosystems. However, the estimation and mechanism of SOC sequestration by P. pubescens forests remain unclear. In this study, the effect of P. pubescens forest distribution with elevation was investigated at two altitude sites in Jian-ou City, Southeast China. SOC storage was estimated and its chemical composition was obtained via 13C-nuclear magnetic resonance (NMR), chemical classification, and spectral analysis. Results showed that the SOC contents and stocks were significantly higher at the high-altitude site than at the low-altitude site in the entire soil profile (0–60 cm). The C contents of the three combined humus forms exhibited similar responses to the elevation change, and all of these forms were higher at the high-altitude site than at the low-altitude site regardless of soil layer. However, the proportions of the three combined humus C showed no significant differences between the two altitudes. The results of 13C-NMR showed that the SOC chemical composition did not significantly vary with elevation as well. This finding was consistent with the E465/E665 of the loosely combined humus. Overall, the results suggested that altitude should be considered during regional SOC estimation and that altitude affected the quantity rather than the quality of the SOC under the same P. pubescens vegetation. PMID:26716688

  2. Soil Organic Carbon Pool and Its Chemical Composition in Phyllostachy pubescens Forests at Two Altitudes in Jian-ou City, China.

    PubMed

    Ji, Haibao; Zhuang, Shunyao; Zhu, Zhaoliang; Zhong, Zheke

    2015-01-01

    Phyllostachys pubescens forests play an important role in soil organic carbon (SOC) sequestration in terrestrial ecosystems. However, the estimation and mechanism of SOC sequestration by P. pubescens forests remain unclear. In this study, the effect of P. pubescens forest distribution with elevation was investigated at two altitude sites in Jian-ou City, Southeast China. SOC storage was estimated and its chemical composition was obtained via 13C-nuclear magnetic resonance (NMR), chemical classification, and spectral analysis. Results showed that the SOC contents and stocks were significantly higher at the high-altitude site than at the low-altitude site in the entire soil profile (0-60 cm). The C contents of the three combined humus forms exhibited similar responses to the elevation change, and all of these forms were higher at the high-altitude site than at the low-altitude site regardless of soil layer. However, the proportions of the three combined humus C showed no significant differences between the two altitudes. The results of 13C-NMR showed that the SOC chemical composition did not significantly vary with elevation as well. This finding was consistent with the E465/E665 of the loosely combined humus. Overall, the results suggested that altitude should be considered during regional SOC estimation and that altitude affected the quantity rather than the quality of the SOC under the same P. pubescens vegetation.

  3. Improvement and Comparative Assessment of a New Hydrological Modelling Approach for the Ouémé River Basin (Bénin), West Africa

    NASA Astrophysics Data System (ADS)

    GABA, C. O. U.

    2015-12-01

    Assessing water resources is still an important issue especially in the context of climatic changes. Although numerous hydrological models exist, new approaches are still under investigation. In this context, we propose a new modelling approach based on the Physics Principle of Least Action. A first version of a Least Action based model, in its deterministic version has already given very good results on simulating the Bétérou catchment in the Ouémé basin, Benin. The paper presents new hypotheses to go further in the model development with a view of widening its application. The improved version of the model MODYPMA was applied on 22 subcatchments in Africa, in Bénin, Côte d'Ivoire, Ethiopia; in Europe, and in the USA. Its performance was compared to two well known lumped conceptual models, the GR4J and HBV models. The model could be successfully calibrated and validated; it shows a good performance for a range of scales but a limited applicability to catchments smaller than 500 km2 . The analysis revealed that the three models have similar performance and timing errors. The parameter uncertainty was analysed using the GLUE methodology. It is concluded that model uncertainty is higher during high flows and that uncertainty analysis should include the uncertainty of the discharge data. Finally, some aspects that further research must address are brought out.

  4. Formes hémorragiques de Dengue observées dans le service des maladies infectieuses du CHU Yalgado Ouédraogo, Burkina Faso

    PubMed Central

    Mamoudou, Savadogo; Boushab, Boushab Mohamed

    2016-01-01

    La dengue est une arbovirose ré émergente dans les pays tropicaux. Sa forme hémorragique peut s'accompagner d'une défaillance circulatoire pouvant conduire à un choc hypovolémique, souvent fatal. Nous rapportons une série de trois cas de formes hémorragiques de dengue observées dans le service des maladies infectieuses du CHU Yalgado Ouédraogo de Ouagadougou dont l'objectif est de décrire les caractéristiques épidémiologiques cliniques et évolutives. Les cas étaient des jeunes de sexe féminin dont l’âge variait entre 27 ans et 43 ans, résidant dans la ville de Ouagadougou. Malgré de multiples transfusions de concentrées plaquettaires et un traitement symptomatique, nous déplorons un cas de décès. Le développement d'antiviraux et la mise au point de nouveaux vaccins constituent une lueur d'espoir pour prévenir la létalité due à cette maladie. PMID:27303584

  5. 78 FR 32533 - Proposed Collection of Information: Direct Deposit, Go Direct, and Direct Express Sign-Up Forms

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-30

    ... Bureau of the Fiscal Service Proposed Collection of Information: Direct Deposit, Go Direct, and Direct...'', Form 1200 ``Go Direct Sign-Up Form for Direct Deposit of Federal Benefit Payments'', Form 1200VADE... below: Title: Direct Deposit Sign-Up Form, and Go Direct Sign-Up Form, and Direct Express Form...

  6. The Influence of Directional Associations on Directed Forgetting and Interference

    ERIC Educational Resources Information Center

    Sahakyan, Lili; Goodmon, Leilani B.

    2007-01-01

    Two experiments examined how cross-list directional associations influenced list-method directed forgetting and the degree of interference observed on each list. Each List 1 item had a (a) bidirectionally related item on List 2 (chip ?? potato), (b) forward association with an item on List 2 (chip ? wood), (c) backward association from an item on…

  7. Directionality Time - New Analytical Treatment of Directionally Biased, Crawling Motility

    NASA Astrophysics Data System (ADS)

    Tang, Jay; Loosley, Alexander

    Insights on crucial biological functions often emerge from measuring how animal cells crawl on surfaces, particularly in response to gradients of external cues that cause directionally biased motion. Most existing metrics commonly used to characterize directional migration, such as straightness index (or chemotactic index), persistence time, and turning angle distribution, tend to be sensitive to relatively large errors at short sampling times. In contrast, we recently introduced a new metric, called directionality time, to define the onset time by which a seemingly random motion becomes directionally biased (O'Brien et al., J Leukocyte Biol, 2014, 95:993-1004 Loosley et al., PLOS ONE, 2015, 10.1371). Directionality time is obtained by fitting the mean squared displacement as a function of time interval, in log-log coordinates, to a fit function based on biased and persistent random walk processes. We show that the fit function is approximately model invariant and is applicable to a variety of directionally biased motions. Simulations are performed to show the robustness of the directionality time model and its decoupling from measurement errors. Finally, we demonstrate as an example how to usefully apply the directionality time fit to trajectories of chemotactic neutrophils.

  8. Relativistic solutions to directed energy

    NASA Astrophysics Data System (ADS)

    Kulkarni, Neeraj; Lubin, Philip M.; Zhang, Qicheng

    2016-09-01

    This paper analyses the nature and feasibility of using directed energy to propel probes through space at relativistic speeds. Possible mission scenarios are considered by varying the spacecraft mass, thickness of the sail and power of the directed energy array. We calculate that gram-scaled probes are capable of achieving relativistic speeds and reaching Alpha Centauri well within a human lifetime. A major drawback is the diffraction of the beam which reduces the incident power on the sail resulting in a terminal velocity for the probes. Various notions of efficiency are discussed and we conclude that directed energy propulsion provides a viable direction for future space exploration.

  9. Directional excitation without breaking reciprocity

    NASA Astrophysics Data System (ADS)

    Ramezani, Hamidreza; Dubois, Marc; Wang, Yuan; Shen, Y. Ron; Zhang, Xiang

    2016-09-01

    We propose a mechanism for directional excitation without breaking reciprocity. This is achieved by embedding an impedance matched parity-time symmetric potential in a three-port system. The amplitude distribution within the gain and loss regions is strongly influenced by the direction of the incoming field. Consequently, the excitation of the third port is contingent on the direction of incidence while transmission in the main channel is immune. Our design improves the four-port directional coupler scheme, as there is no need to implement an anechoic termination to one of the ports.

  10. Direct cooled power electronics substrate

    DOEpatents

    Wiles, Randy H [Powell, TN; Wereszczak, Andrew A [Oak Ridge, TN; Ayers, Curtis W [Kingston, TN; Lowe, Kirk T [Knoxville, TN

    2010-09-14

    The disclosure describes directly cooling a three-dimensional, direct metallization (DM) layer in a power electronics device. To enable sufficient cooling, coolant flow channels are formed within the ceramic substrate. The direct metallization layer (typically copper) may be bonded to the ceramic substrate, and semiconductor chips (such as IGBT and diodes) may be soldered or sintered onto the direct metallization layer to form a power electronics module. Multiple modules may be attached to cooling headers that provide in-flow and out-flow of coolant through the channels in the ceramic substrate. The modules and cooling header assembly are preferably sized to fit inside the core of a toroidal shaped capacitor.

  11. Directivity of linear microstrip arrays

    NASA Astrophysics Data System (ADS)

    Daniel, J. P.

    1987-08-01

    An analytical expression for the directivity is derived for uniformly excited linear arrays of rectangular printed antennas. Each antenna is assumed to radiate as two identical slots with a spacing which depends on the dielectric substrate. The directivity is plotted against distance between printed elements for two dielectric substrates, PTFE and alumina.

  12. Optically broadcasting wind direction indicator

    NASA Technical Reports Server (NTRS)

    Zysko, Jan A. (Inventor)

    1994-01-01

    An optically broadcasting wind direction indicator generates flashes of light which are separated by a time interval that is directly proportional to the angle of the wind direction relative to a fixed direction, such as north. An angle/voltage transducer generates a voltage that is proportional to the wind direction relative to the fixed direction, and this voltage is employed by timing circuitry or a microprocessor that generates pulses for actuating a light source trigger circuit first at the start of the time interval, and then at the end of the time interval. To aid an observer in distinguishing between the beginning and end of the interval, two stop flashes can be provided in quick succession. The time scale is preferably chosen so that each second of the time interval corresponds to 30 deg of direction relative to north. In this manner, an observer can easily correlate the measured time interval to the wind direction by visualizing the numbers on a conventional clock face, each of which correspond to one second of time and 30 deg of angle.

  13. Discordance gradient-surface dans le rétrécissement mitral: le gradient moyen transmitral est-il un critère de sévérité ou un indice de tolérance du rétrécissement mitral serré?

    PubMed Central

    Najih, Hayat; Arous, Salim; Laarje, Aziza; Baghdadi, Dalila; Benouna, Mohamed Ghali; Azzouzi, Leila; Habbal, Rachida

    2016-01-01

    Le rétrécissement mitral (RM) rhumatismal demeure une valvulopathie fréquente dans les pays en voie de développement. Cependant, les pays industrialisés ont vu l'émergence ces dernières années de nouvelles étiologies de RM; notamment l'origine médicamenteuse et/ou toxique responsable de valvulopathies restrictives aussi bien sténosantes que régurgitantes. Pour cette raison, l'évaluation échocardiographique du RM et surtout, la définition de critères objectifs pour conclure au caractère serré du RM reste toujours d'actualité. Les objectifs du travail sont: évaluer l'existence ou non d'une corrélation directe entre le gradient moyen transmitral (GMT) et la sévérité du RM chez les patients porteurs d'un RM serré ou très serré (critère primaire) et analyser les différents paramètres qui conditionnent le gradient moyen transmitral (GMT) (Critère secondaire). Il s'agit d'une étude transversale monocentrique incluant tous les patients admis au service de Cardiologie du CHU Ibn Rochd de Casablanca pour un RM serré ou très serré, sur une période d'une année (Janvier 2014 à Décembre 2014). Nous avons analysés séparément deux groupes de patients : ceux avec un gradient moyen transmitral<10 mmHg (groupe 1) et ceux avec un gradient>10mmHg (groupe2). 50 patients porteurs d'un RM serré ou très serré ont été inclus. L'âge moyen de nos patients est de 41,7 ans avec prédominance féminine (sex ratio: 0,25). 64% de nos patients avaient un RM serré et 36% avaient un RM très serré. 52% (26 patients) avaient un GMT <10mmHg et 48% (24 patients) avaient un gradient moyen >10mmHg, ce qui suggère l'absence de corrélation directe entre la sévérité du RM et le GMT (coefficient de Pearson R: -0,137). Pour la dyspnée, 80% des patients du groupe 1 étaient dyspnéiques stade II de la NYHA et 70% des patients du groupe 2 étaient dyspnéiques stade III (41%) ou IV (29%) de la NYHA, ce qui signifie l'existence d'une corr

  14. Chapter 1: Direct Normal Radiation

    SciTech Connect

    Myer, Daryl R.

    2016-04-15

    This chapter addresses the quantitative and qualitative aspects of the solar resource, the direct solar radiation. It discusses the total or integrated broadband direct beam extraterrestrial radiation (ETR). This total integrated irradiance is comprised of photons of electromagnetic radiation. The chapter also discusses the impact of the atmosphere and its effect upon the direct normal irradiance (DNI) beam radiation. The gases and particulates present in the atmosphere traversed by the direct beam reflect, absorb, and scatter differing spectral regions and proportions of the direct beam, and act as a variable filter. Knowledge of the available broadband DNI beam radiation resource data is essential in designing a concentrating photovoltaic (CPV) system. Spectral variations in the DNI beam radiation affect the performance of a CPV system depending on the solar cell technology used. The chapter describes propagation and scattering processes of circumsolar radiation (CSR), which includes the Mie scattering from large particles.

  15. Efficient Placement of Directional Antennas

    SciTech Connect

    Pan, Feng; Kasiviswanathan, Shiva

    2010-09-20

    Directional antenna is an technology for the proliferation of wireless networks. In centralized wireless network, wireless devices communicate through base stations. Directed antennas are placed on base stations and form a backbone of communication. The communication between base stations and wireless devices can be interfered due to a large number of wireless device. Methodically positioning and orienting directed antennas can help to reduce the interference while saving energy. An integer linear programming is developed for siting and directing antennas on multiple base stations, and this formulation can be extended to model non-overlapping channels. Through the integer programming formulation, optimal antenna positions can be used to analyze the performance of directed antennas with different parameters like the number base stations and the number of non-overlapping channels.

  16. Comparative study of microflora in Rhizospheric soils of Argania spinosa and Acacia raddiana of the arid zone from Oued El Ma (Tindouf)

    NASA Astrophysics Data System (ADS)

    Tissouras, Fatiha; Habib, Semira; Missoum, Malika; Louacini, Braim Kamel

    2016-04-01

    Desert soils occupy a large area in Algeria (80Moreover, exploitation of the Saharan soil microorganisms has several interests and especially in maintaining the ecological equilibrium of ecosystems. Unfortunately, few of microbiological studies have been conducted so far about the Saharan soil Algerian, with the exception of some work done on the desert soils in the region of Beni Ounif. This work falls within the framework of Project CNEPRU F02320100009. The study focuses on an evaluation of the main germs rhizosphere soils from Argania spinosa and Acacia raddiana of the region of Oued El-ma (wilaya of Tindouf), located in southwest Algeria, followed by physicochemical analysis of some parameters (soil texture, pH, moisture content, organic matter). The results reveal that both rhizosphere soils have a sandy silt texture of alkali pH, with very low water content slightly different. Organic material of the rate varies from 0.2 to 1The type of vegetation influences positively the quantity and the dynamics of microbial population. Indeed, the two soils have an interesting microbial diversity, with densities of azotobacters, fungi, aerobic bacteria and actinomycetes are very high, followed germs ammonifiants, nitrifying and denitrifying. In the presence of Argania spinosa the microbial growth is most important (6.53 × 107 germs /g soil), compared with Acacia raddiana (3.13 × 107 germs /g). This shows the stimulating effect of the vegetation on the increase in the rate of these microorganisms in the soil. Well as the strong Fitness of adaptation the microbial biomass to drought. Keywords: Argania spinoza; Acacia raddiana; rhizospheric soil; microbiology evaluation.

  17. Amorçage d'une décharge dans le vide entre deux electrodes d'argent ou des alliages argent-nickel

    NASA Astrophysics Data System (ADS)

    Zouache, N.; Lefort, A.

    1997-03-01

    Comparison of the characteristics of an electric are breakdown in vacuum between two silver or silver-nickel alloy electrodes prompted us to study the evolution of the breakdown voltage with electrode separation, with resistance value placed between the anode and the high voltage supply used for the breakdown, and with the effect of conditionning by heating in vacuum. The measurement of the commutation time and delay time, and the observations by a metallographic microscope of the electrodes surfaces after one breakdown, enabled us to evidence the origin of the electric arc for each of the studied materials. La comparaison des caractéristiques de l'amorçage d'un arc électrique dans le vide entre deux électrodes bombées de 8mm de diamètre et de rayon de courbure en surface de 16mm, constituées d'argent ou de son alliage avec le nickel, nous a amené à étudier l'évolution de la tension d'amorçage avec plusieurs paramètres : la distance inter-électrodes, les valeurs de la résistance intercalée entre la source haute tension servant au claquage et les électrodes et le conditionnement par chauffage sous vide des électrodes. La mesure du temps de commutation, du temps de retard et les observations au microscope métallographique de la surface des électrodes après un amorçage donnent des informations sur l'origine de l'arc électrique concernant chaque matériau étudié.

  18. [Effects of saline-alkali stress on electrical impedance spectroscopy parameters and ion contents in shoots of Ping'ou hybrid hazelnut].

    PubMed

    Zhang, Li; Jia, Zhi-Guo; Ma, Qing-Hua; Zhang, Gang; Wang, Gui-Xi

    2014-11-01

    To study the adaptability to salt-alkaline stress of Ping'ou hybrid hazelnut, 'Liaozhen 3' shoots which were treated with three types of stress neutral NaCl, alkaline Na2CO3, and mixed salt-alkali, and the changes in electrical impedance spectroscopy (EIS) parameters and mineral ion contents were subsequently determined. The correlations between the EIS parameters and mineral ion contents were analyzed. The results showed that with the increasing level of NaCl, specific high- frequency resistance (r), specific low-frequency resistance ( r(l)), specific intracellular resistance (r(i)) and specific extracellular resistance (r(e)) of shoots decreased firstly, then increased, and finally decreased again. However, these parameters increased gradually with the increasing level of Na2CO3, while r(l) and r(e) decreased slowly in the mixed salt-alkali treatments. The Na+ contents of shoots increased significantly under the three salt-alkali stresses with the order of NaCl stress > mixed salt-alkali stress > Na2CO3 stress. Furthermore, Na2CO3 stress resulted in the decreases in the contents of three elements Zn, B and Ca. The significant negative correlation was found between the sum of five cations and four EIS parameters r(l), r(e), relaxation time (τ) , and distribution coefficient of relaxation time (ψ). The shoots of 'Liaozhen 3' might be tolerant of Na2CO3 stress of 200 mmol · L(-1), while they could be resistant to NaCl stress of 100-150 mmol · L(-1).

  19. Les fractures de jambe à fibula intact: traitement orthopédique ou enclouage centromédullaire? (étude comparative à propos de 60 cas)

    PubMed Central

    Abouchane, Merouane; Fadili, Assia; Belmoubarik, Amine; EL Andaloussi, Yassir; Nechad, Mohammed

    2015-01-01

    La fracture de jambe à fibula intact (FJFI) est caractérisée par un potentiel de déplacement minime ainsi le pronostic semble bon, souvent associées à des difficultés de réduction de consolidation ou de cal vicieux. Notre but est de comparer les résultats du traitement orthopédique et de l'enclouage centromédullaire (ECM). Entre janvier 2006 et janvier 2011, on a traité 60 fractures de jambe à fibula intact. 31 patients ont bénéficié d'un ECM, dont 14 fois était statique, 16 fois dynamique et simple une fois, avec un appui compris entre le 2eme jour (pour la plupart des patients) et la sixième semaine. 29 patients ont bénéficiés d'un traitement orthopédique après réduction par plâtre cruro-pédieux avec libération du genou après 4 semaines avec appui total chez la plupart des patients. La durée de consolidation été de 4 mois en moyenne pour les patients traites par ECM et de 6 mois pour les patients traites orthopédiquement. On a noté 3 cas de pseudarthrose dans notre série d’étude soit 5%: 2 observées chez le groupe de l'ECM soit 6,4% et un cas pour le groupe du traitement orthopédique soit 3,8%. 6 cas de déplacement secondaires ont été note chez les patients traites orhtopédiquement à j15 du traitement, pour 5 patients le déplacement été jugé tolérable et pour un seul patient (trouble angulaire supérieur à 10°) ayant nécessité un ECM. 13 cas soit 54% de cal vicieux angulaire supérieur à 10 dans notre série tous traités orthopédiquement versus aucun cas de cal vicieux chez les patients du groupe du traitement par ECM. Cliniquement: tous les patients traités par ECM ont présenté une mobilité du genou et de la cheville normale. Les patients traités orthopédiquement ont tous bénéficié d'une rééducation du genou libération du genou et confection d'un plâtre type Sarmiento et celle de la cheville après son ablation définitive, ainsi aucun de nos patients n'a gardé une raideur après avoir termin

  20. Potential theory for directed networks.

    PubMed

    Zhang, Qian-Ming; Lü, Linyuan; Wang, Wen-Qiang; Zhu, Yu-Xiao; Zhou, Tao

    2013-01-01

    Uncovering factors underlying the network formation is a long-standing challenge for data mining and network analysis. In particular, the microscopic organizing principles of directed networks are less understood than those of undirected networks. This article proposes a hypothesis named potential theory, which assumes that every directed link corresponds to a decrease of a unit potential and subgraphs with definable potential values for all nodes are preferred. Combining the potential theory with the clustering and homophily mechanisms, it is deduced that the Bi-fan structure consisting of 4 nodes and 4 directed links is the most favored local structure in directed networks. Our hypothesis receives strongly positive supports from extensive experiments on 15 directed networks drawn from disparate fields, as indicated by the most accurate and robust performance of Bi-fan predictor within the link prediction framework. In summary, our main contribution is twofold: (i) We propose a new mechanism for the local organization of directed networks; (ii) We design the corresponding link prediction algorithm, which can not only testify our hypothesis, but also find out direct applications in missing link prediction and friendship recommendation.

  1. Direct Manipulation in Virtual Reality

    NASA Technical Reports Server (NTRS)

    Bryson, Steve

    2003-01-01

    Virtual Reality interfaces offer several advantages for scientific visualization such as the ability to perceive three-dimensional data structures in a natural way. The focus of this chapter is direct manipulation, the ability for a user in virtual reality to control objects in the virtual environment in a direct and natural way, much as objects are manipulated in the real world. Direct manipulation provides many advantages for the exploration of complex, multi-dimensional data sets, by allowing the investigator the ability to intuitively explore the data environment. Because direct manipulation is essentially a control interface, it is better suited for the exploration and analysis of a data set than for the publishing or communication of features found in that data set. Thus direct manipulation is most relevant to the analysis of complex data that fills a volume of three-dimensional space, such as a fluid flow data set. Direct manipulation allows the intuitive exploration of that data, which facilitates the discovery of data features that would be difficult to find using more conventional visualization methods. Using a direct manipulation interface in virtual reality, an investigator can, for example, move a data probe about in space, watching the results and getting a sense of how the data varies within its spatial volume.

  2. Directional Summation in Non-direction Selective Retinal Ganglion Cells

    PubMed Central

    Abbas, Syed Y.; Hamade, Khaldoun C.; Yang, Ellen J.; Nawy, Scott; Smith, Robert G.; Pettit, Diana L.

    2013-01-01

    Retinal ganglion cells receive inputs from multiple bipolar cells which must be integrated before a decision to fire is made. Theoretical studies have provided clues about how this integration is accomplished but have not directly determined the rules regulating summation of closely timed inputs along single or multiple dendrites. Here we have examined dendritic summation of multiple inputs along On ganglion cell dendrites in whole mount rat retina. We activated inputs at targeted locations by uncaging glutamate sequentially to generate apparent motion along On ganglion cell dendrites in whole mount retina. Summation was directional and dependent13 on input sequence. Input moving away from the soma (centrifugal) resulted in supralinear summation, while activation sequences moving toward the soma (centripetal) were linear. Enhanced summation for centrifugal activation was robust as it was also observed in cultured retinal ganglion cells. This directional summation was dependent on hyperpolarization activated cyclic nucleotide-gated (HCN) channels as blockade with ZD7288 eliminated directionality. A computational model confirms that activation of HCN channels can override a preference for centripetal summation expected from cell anatomy. This type of direction selectivity could play a role in coding movement similar to the axial selectivity seen in locust ganglion cells which detect looming stimuli. More generally, these results suggest that non-directional retinal ganglion cells can discriminate between input sequences independent of the retina network. PMID:23516351

  3. Direct optical to microwave conversion

    NASA Astrophysics Data System (ADS)

    Taylor, Henry F.

    1990-09-01

    Support of high frequency fiber optic links through development of innovative higher efficiency techniques to convert optical energy directly to RF Energy. Control of Phases Arrays by optical means in an area of expanding technology development. Fiber optics and other forms of optical waveguide can provide greater accuracy and true time delay in a phase delay network. Methods of improvement in transfer of optical energy to RF Energy are determined. Development of Direct Optical-to-RF-Direct Amplifiers will result in higher efficiency, low noise, optical receivers for fiber optic links with improved performance. This results in longer fiber optic links without repeaters and improved BER or shorter links.

  4. Module bay with directed flow

    DOEpatents

    Torczynski, John R.

    2001-02-27

    A module bay requires less cleanroom airflow. A shaped gas inlet passage can allow cleanroom air into the module bay with flow velocity preferentially directed toward contaminant rich portions of a processing module in the module bay. Preferential gas flow direction can more efficiently purge contaminants from appropriate portions of the module bay, allowing a reduced cleanroom air flow rate for contaminant removal. A shelf extending from an air inlet slit in one wall of a module bay can direct air flowing therethrough toward contaminant-rich portions of the module bay, such as a junction between a lid and base of a processing module.

  5. Nonimaging radiant energy direction device

    DOEpatents

    Winston, Roland

    1980-01-01

    A raidant energy nonimaging light direction device is provided. The device includes an energy transducer and a reflective wall whose contour is particularly determined with respect to the geometrical vector flux of a field associated with the transducer.

  6. Photon upconversion with directed emission

    NASA Astrophysics Data System (ADS)

    Börjesson, K.; Rudquist, P.; Gray, V.; Moth-Poulsen, K.

    2016-08-01

    Photon upconversion has the potential to increase the efficiency of single bandgap solar cells beyond the Shockley Queisser limit. Efficient light management is an important point in this context. Here we demonstrate that the direction of upconverted emission can be controlled in a reversible way, by embedding anthracene derivatives together with palladium porphyrin in a liquid crystalline matrix. The system is employed in a triplet-triplet annihilation photon upconversion scheme demonstrating controlled switching of directional anti Stokes emission. Using this approach an emission ratio of 0.37 between the axial and longitudinal emission directions and a directivity of 1.52 is achieved, reasonably close to the theoretical maximal value of 2 obtained from a perfectly oriented sample. The system can be switched for multiple cycles without any visible degradation and the speed of switching is only limited by the intrinsic rate of alignment of the liquid crystalline matrix.

  7. Direct Broadcast Satellite: Radio Program

    NASA Technical Reports Server (NTRS)

    Hollansworth, James E.

    1992-01-01

    NASA is committed to providing technology development that leads to the introduction of new commercial applications for communications satellites. The Direct Broadcast Satellite-Radio (DBS-R) Program is a joint effort between The National Aeronautics and Space Administration (NASA) and The United States Information Agency/Voice of America (USIA/VOA) directed at this objective. The purpose of this program is to define the service and develop the technology for a direct-to-listener satellite sound broadcasting system. The DBS-R Program, as structured by NASA and VOA, is now a three-phase program designed to help the U.S. commercial communications satellite and receiver industry bring about this new communications service. Major efforts are being directed towards frequency planning hardware and service development, service demonstration, and experimentation with new satellite and receiver technology.

  8. Photon upconversion with directed emission

    PubMed Central

    Börjesson, K.; Rudquist, P.; Gray, V.; Moth-Poulsen, K.

    2016-01-01

    Photon upconversion has the potential to increase the efficiency of single bandgap solar cells beyond the Shockley Queisser limit. Efficient light management is an important point in this context. Here we demonstrate that the direction of upconverted emission can be controlled in a reversible way, by embedding anthracene derivatives together with palladium porphyrin in a liquid crystalline matrix. The system is employed in a triplet-triplet annihilation photon upconversion scheme demonstrating controlled switching of directional anti Stokes emission. Using this approach an emission ratio of 0.37 between the axial and longitudinal emission directions and a directivity of 1.52 is achieved, reasonably close to the theoretical maximal value of 2 obtained from a perfectly oriented sample. The system can be switched for multiple cycles without any visible degradation and the speed of switching is only limited by the intrinsic rate of alignment of the liquid crystalline matrix. PMID:27573539

  9. Quantum direct communication with authentication

    SciTech Connect

    Lee, Hwayean; Lim, Jongin; Yang, HyungJin

    2006-04-15

    We propose two quantum direct communication (QDC) protocols with user authentication. Users can identify each other by checking the correlation of Greenberger-Horne-Zeilinger (GHZ) states. Alice can directly send a secret message to Bob without any previously shared secret using the remaining GHZ states after authentication. Our second QDC protocol can be used even though there is no quantum link between Alice and Bob. The security of the transmitted message is guaranteed by properties of entanglement of GHZ states.

  10. Direct nuclear-powered lasers

    NASA Technical Reports Server (NTRS)

    Jalufka, N. W.

    1983-01-01

    The development of direct nuclear pumped lasers is reviewed. Theoretical and experimental investigations of various methods of converting the energy of nuclear fission fragments to laser power are summarized. The development of direct nuclear pumped lasers was achieved. The basic processes involved in the production of a plasma by nuclear radiation were studied. Significant progress was accomplished in this area and a large amount of basic data on plasma formation and atomic and molecular processes leading to population inversions is available.

  11. Joint Direct Attack Munition (JDAM)

    DTIC Science & Technology

    2013-12-01

    2005 FEB 2005 Selective Availability Anti- Spoofing Module (SAASM)/ GPS Anti-Jam Production Award N/A MAR 2005 SEP 2005 MAR 2005 Change Explanations...Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-503 Joint Direct Attack Munition (JDAM) As of FY 2015 President’s Budget...2013 to 00-00-2013 4. TITLE AND SUBTITLE Joint Direct Attack Munition (JDAM) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

  12. Directional microwave applicator and methods

    NASA Technical Reports Server (NTRS)

    Fink, Patrick W. (Inventor); Lin, Greg Y. (Inventor); Chu, Andrew W. (Inventor); Dobbins, Justin A. (Inventor); Arndt, G. Dickey (Inventor); Ngo, Phong H. (Inventor)

    2008-01-01

    A miniature microwave antenna is disclosed which may be utilized for biomedical applications such as, for example, radiation induced hyperthermia through catheter systems. One feature of the antenna is that it possesses azimuthal directionality despite its small size. This directionality permits targeting of certain tissues while limiting thermal exposure of adjacent tissue. One embodiment has an outer diameter of about 0.095'' (2.4 mm) but the design permits for smaller diameters.

  13. Direct Measurement of Intracellular Pressure

    PubMed Central

    Petrie, Ryan J.; Koo, Hyun

    2014-01-01

    A method to directly measure the intracellular pressure of adherent, migrating cells is described in the Basic Protocol. This approach is based on the servo-null method where a microelectrode is introduced into the cell to directly measure the physical pressure of the cytoplasm. We also describe the initial calibration of the microelectrode as well as the application of the method to cells migrating inside three-dimensional (3D) extracellular matrix (ECM). PMID:24894836

  14. Presidentially Directed Relocation: Compliance Attitudes.

    DTIC Science & Technology

    1980-05-01

    presidential intervention. The primary target group for crisis relocation programs are those in- dividuals that reside in risk areas and are not likely to...qw.A 3. POTENTIAL RELOCATABLES The largest group of individuals (35.3%), and the principal target group for directed relocation are those people that...are likely to ’stay’ in risk areas (TR-82) in the pre-direction period. They are the principal target group in essentially three ways: 1. They are the

  15. Asymmetric Wettability Directs Leidenfrost Droplets

    SciTech Connect

    Agapov, Rebecca L; Boreyko, Jonathan B; Briggs, Dayrl P; Srijanto, Bernadeta R; Retterer, Scott T; Collier, Pat; Lavrik, Nickolay V

    2014-01-01

    Leidenfrost phenomena on nano- and microstructured surfaces are of great importance for increasing control over heat transfer in high power density systems utilizing boiling phenomena. They also provide an elegant means to direct droplet motion in a variety of recently emerging fluidic systems. Here, we report the fabrication and characterization of tilted nanopillar arrays (TNPAs) that exhibit directional Leidenfrost water droplets under dynamic conditions, namely on impact with Weber numbers 40 at T 325 C. The batch fabrication of the TNPAs was achieved by glancing-angle anisotropic reactive ion etching of a thermally dewet platinum mask, with mean pillar diameters of 100 nm and heights of 200-500 nm. In contrast to previously implemented macro- and microscopic Leidenfrost ratchets, our TNPAs induce no preferential directional movement of Leidenfrost droplets under conditions approaching steady-state film boiling, suggesting that the observed droplet directionality is not a result of asymmetric vapor flow. Using high-speed imaging, phase diagrams were constructed for the boiling behavior upon impact for droplets falling onto TNPAs, straight nanopillar arrays, and smooth silicon surfaces. The asymmetric impact and directional trajectory of droplets was exclusive to the TNPAs for impacts corresponding to the transition boiling regime, revealing that asymmetric wettability upon impact is the mechanism for the droplet directionality.

  16. Approche au diagnostic de la maladie cœliaque chez les patients ayant une faible densité minérale osseuse ou des fractures de fragilité

    PubMed Central

    Rios, Lorena P.; Khan, Aliya; Sultan, Muhammad; McAssey, Karen; Fouda, Mona A.; Armstrong, David

    2013-01-01

    Résumé Objectif Présenter aux cliniciens une mise à jour sur le diagnostic de la maladie cœliaque (MC), ainsi que des recommandations sur les indications de procéder au dépistage de la MC chez les patients présentant une faible densité minérale osseuse (DMO) ou des fractures de fragilité. Qualité des données Un groupe de travail multidisciplinaire a élaboré des questions cliniquement pertinentes relativement au diagnostic de la MC servant de fondement à une recherche documentaire dans les bases de données MEDLINE, EMBASE et CENTRAL (de janvier 2000 à janvier 2009) à l’aide des mots clés en anglais celiac disease, osteoporosis, osteopenia, low bone mass et fracture. Les ouvrages scientifiques existants comportent des études de niveaux I et II. Message principal La prévalence estimée de la MC asymptomatique est de 2 % à 3 % chez les personnes qui ont une faible DMO. Par ailleurs, un dépistage ciblé est recommandé pour les patients qui ont des T-scores de −1,0 ou moins à la colonne vertébrale ou aux hanches ou des antécédents de fractures de fragilité associées à des symptômes ou à des problèmes reliés à la MC, des antécédents familiaux de MC ou de bas niveaux de calcium urinaire, une insuffisance en vitamine D et des niveaux à la hausse d’hormones parathyroïdiennes en dépit d’un apport suffisant en calcium et en vitamine D. Le dépistage de la MC devrait se faire pendant que le sujet consomme un régime alimentaire contenant du gluten. On procède au dépistage initial par le dosage d’immunoglobuline (Ig) A antitransglutaminase en utilisant la transglutaminase tissulaire humaine recombinante ou une autre transglutaminase tissulaire, en association avec l’immunofluorescence des IgA anti-endomysium. Une biopsie du duodénum est nécessaire pour confirmer le diagnostic de la MC. Le typage des antigènes des leucocytes humains peut aider à confirmer ou à exclure le diagnostic de la MC dans les cas où la s

  17. Direct measurement of the biphoton Wigner function through two-photon interference

    PubMed Central

    Douce, T.; Eckstein, A.; Walborn, S. P.; Khoury, A. Z.; Ducci, S.; Keller, A.; Coudreau, T.; Milman, P.

    2013-01-01

    The Hong-Ou-Mandel (HOM) experiment was a benchmark in quantum optics, evidencing the non–classical nature of photon pairs, later generalized to quantum systems with either bosonic or fermionic statistics. We show that a simple modification in the well-known and widely used HOM experiment provides the direct measurement of the Wigner function. We apply our results to one of the most reliable quantum systems, consisting of biphotons generated by parametric down conversion. A consequence of our results is that a negative value of the Wigner function is a sufficient condition for non-gaussian entanglement between two photons. In the general case, the Wigner function provides all the required information to infer entanglement using well known necessary and sufficient criteria. The present work offers a new vision of the HOM experiment that further develops its possibilities to realize fundamental tests of quantum mechanics using simple optical set-ups. PMID:24346262

  18. Direction Selectivity in Drosophila Emerges from Preferred-Direction Enhancement and Null-Direction Suppression

    PubMed Central

    Leong, Jonathan Chit Sing; Esch, Jennifer Judson; Poole, Ben; Ganguli, Surya

    2016-01-01

    Across animal phyla, motion vision relies on neurons that respond preferentially to stimuli moving in one, preferred direction over the opposite, null direction. In the elementary motion detector of Drosophila, direction selectivity emerges in two neuron types, T4 and T5, but the computational algorithm underlying this selectivity remains unknown. We find that the receptive fields of both T4 and T5 exhibit spatiotemporally offset light-preferring and dark-preferring subfields, each obliquely oriented in spacetime. In a linear-nonlinear modeling framework, the spatiotemporal organization of the T5 receptive field predicts the activity of T5 in response to motion stimuli. These findings demonstrate that direction selectivity emerges from the enhancement of responses to motion in the preferred direction, as well as the suppression of responses to motion in the null direction. Thus, remarkably, T5 incorporates the essential algorithmic strategies used by the Hassenstein–Reichardt correlator and the Barlow–Levick detector. Our model for T5 also provides an algorithmic explanation for the selectivity of T5 for moving dark edges: our model captures all two- and three-point spacetime correlations relevant to motion in this stimulus class. More broadly, our findings reveal the contribution of input pathway visual processing, specifically center-surround, temporally biphasic receptive fields, to the generation of direction selectivity in T5. As the spatiotemporal receptive field of T5 in Drosophila is common to the simple cell in vertebrate visual cortex, our stimulus-response model of T5 will inform efforts in an experimentally tractable context to identify more detailed, mechanistic models of a prevalent computation. SIGNIFICANCE STATEMENT Feature selective neurons respond preferentially to astonishingly specific stimuli, providing the neurobiological basis for perception. Direction selectivity serves as a paradigmatic model of feature selectivity that has been

  19. Complications du diverticule de Meckel (DM) chez l'adulte: à propos de 11 cas au CHU-Yalgado Ouédraogo au Burkina Faso

    PubMed Central

    Ouangré, Edgar; Zida, Maurice; Bazongo, Moussa; Sanou, Adama; Bonkoungou, Gilbert Patindé; Doamba, Rodrigue Namékinsba; Sawadogo, Elie Yamba; Ouédraogo, Sidziguin; Zongo, Nayi; Traore, Si Simon

    2015-01-01

    Le diverticule de Meckel (DM) est la persistance partielle du canal omphalomésentérique. Ses complications sont rares. Le diagnostic est le plus souvent per opératoire. L'objectif a été de décrire les complications du diverticule de Meckel chez l'adulte dans le service de chirurgie générale et digestive du CHU Yalgado Ouédraogo. Il s'est agi d'une étude transversale descriptive sur 10 ans (janvier 2004-décembre 2013) portant sur les dossiers des patients âgés de plus de 15 ans ayant présenté un DM compliqué. Durant la période d’étude, 11 cas ont été colligés. L'incidence annuelle a été de 11 cas. Nous avons noté une prédominance masculine avec un sex-ratio de 4,5. L’âge moyen des patients était de 29,8 ans. Le diagnostic préopératoire a été dans huit cas une occlusion intestinale aiguë, une appendicite aiguë dans deux cas, une péritonite aiguë généralisée dans un cas. Il a été diagnostiqué en peropératoire une occlusion intestinale dans neuf cas; une diverticulite dans un cas et un cas de perforation du DM. Tous les DM avaient été réséqués dont huit résections segmentaires iléales emportant le DM et trois résections cunéiformes. Tous les DM étaient situés à moins d'un mètre de la jonction iléo-caecale. L'histologie réalisée dans deux cas avait conclu à une diverticulite. Les suites opératoires ont été simples dans neuf cas, compliquées dans deux cas dont une éventration et un décès. Les complications du diverticule de Meckel sont rares. Le diagnostic préopératoire est difficile. Le traitement est essentiellement chirurgical. PMID:26958137

  20. [New anticoagulants - direct thrombin inhibitors].

    PubMed

    Brand, B; Graf, L

    2012-11-01

    Direct thrombin-inhibitors inactivate not only free but also fibrin-bound thrombin. The group of parenteral direct thrombin-inhibitors includes the recombinant hirudins lepirudin and desirudin, the synthetic hirudin bivalirudin, and the small molecule argatroban. All these compounds do not interact with PF4/heparin-antibodies. Therefore, argatroban as well as bivalirudin are currently used to treat heparin-induced thrombocytopenia (HIT). The oral direct thrombin-inhibitor dabigatran etexilate is already licensed in many countries for the treatment of non-valvular atrial fibrillation. Dabigatran etexilate reveals a stable and predictable effect that allows a medication without dose adjustment or monitoring. The substance shows only few interactions with other drugs but strong inhibitors of p-glycoprotein can increase plasma levels of dabigatran substantially. After oral intake, the prodrug dabigatran etexilate is cleaved by esterase-mediated hydrolyses to the active compound dabigatran. Elimination of dabigatran is predominantly renal. Safety and efficacy of dabigatran etexilate were tested in an extensive clinical study program. Non-inferiority compared to current standard treatments was shown for prophylaxis of venous thromboembolic events after total knee and hip replacement, for stroke prevention in atrial fibrillation, and for treatment of acute venous thromboembolism. In daily practice, Dabigatran etexilate competes against the new direct factor Xa-inhibitors. In the absence of direct comparative clinical trials, it is not yet clear if one class of substances has distinct advantages over the other.

  1. Direct simulation of turbulent combustion

    NASA Technical Reports Server (NTRS)

    Poinsot, T. J.

    1990-01-01

    Understanding and modeling of turbulent combustion are key-problems in the computation of numerous practical systems. Because of the lack of analytical theories in this field and of the difficulty of performing precise experiments, direct simulation appears to be one of the most attractive tools to use in addressing this problem. The present work can be split into two parts: (1) Development and validation of a direct simulation method for turbulent combustion; (2) Applications of the method to premixed turbulent combustion problems. The goal of part 1 is to define and to test a numerical method for direct simulation of reacting flows. A high level of confidence should be attached to direct simulation results, and this can only be achieved through extensive validation tests. In part 2, direct simulation is used to address some of the many critical problems related to turbulent combustion. At the present time, I have limited this work to premixed combustion and considered only four basic issues: (1) The effect of pressure waves on flame propagation; (2) The interaction between flame fronts and vortices; (3) The influence of curvature on premixed flame fronts; and (4) The validation of flamelet models for premixed turbulent combustion.

  2. "Let Me Be Direct": Using Direct Assessments with Student Leaders

    ERIC Educational Resources Information Center

    Lindsay, Nathan; Hourigan, Aimee; Smist, Jennifer; Wray, Larry

    2013-01-01

    A primary goal of assessment is to deliver truthful and clear information that can be used to inform and improve outcomes. Although there are multiple ways to achieve this goal, common approaches can be broken down into two major categories: (1) direct assessment; and (2) indirect assessment. Indirect assessment typically relies on general…

  3. Direct Instruction? Don't I Instruct Directly?

    ERIC Educational Resources Information Center

    Peryon, Charleen D.

    A teaching method particularly effective with children who are hard to teach arithmetic and reading is described. Known as a direct instructional system for teaching arithmetic and reading, it is a set of materials in which everything the teacher says and does is specified. This technique is effective in small group instruction. Specific…

  4. Photoelectrochemical based direct conversion systems

    SciTech Connect

    Kocha, S.; Arent, D.; Peterson, M.

    1995-09-01

    The goal of this research is to develop a stable, cost effective, photoelectrochemical based system that will split water upon illumination, producing hydrogen and oxygen directly, using sunlight as the only energy input. This type of direct conversion system combines a photovoltaic material and an electrolyzer into a single monolithic device. We report on our studies of two multifunction multiphoton photoelectrochemical devices, one based on the ternary semiconductor gallium indium phosphide, (GaInP{sub 2}), and the other one based on amorphous silicon carbide. We also report on our studies of the solid state surface treatment of GaInP{sub 2} as well as our continuing effort to develop synthetic techniques for the attachment of transition metal complexes to the surface of semiconductor electrodes. All our surface studies are directed at controlling the interface energetics and forming stable catalytic surfaces.

  5. Mortality plateaus and directionality theory.

    PubMed

    Demetrius, L

    2001-10-07

    Recent large scale studies of senescence in animals and humans have revealed mortality rates that levelled off at advanced ages. These empirical findings are now known to be inconsistent with evolutionary theories of senescence based on the Malthusian parameter as a measure of fitness. This article analyses the incidence of mortality plateaus in terms of directionality theory, a new class of models based on evolutionary entropy as a measure of fitness. We show that the intensity of selection, in the context of directionality theory, is a convex function of age, and we invoke this property to predict that in populations evolving under bounded growth constraints, evolutionarily stable mortality patterns will be described by rates which abate with age at extreme ages. The explanatory power of directionality theory, in contrast with the limitations of the Malthusian model, accords with the claim that evolutionary entropy, rather than the Malthusian parameter, constitutes the operationally valid measure of Darwinian fitness.

  6. Direct vs. Indirect Moral Enhancement.

    PubMed

    Schaefer, G Owen

    2015-09-01

    Moral enhancement is an ostensibly laudable project. Who wouldn't want people to become more moral? Still, the project's approach is crucial. We can distinguish between two approaches for moral enhancement: direct and indirect. Direct moral enhancements aim at bringing about particular ideas, motives or behaviors. Indirect moral enhancements, by contrast, aim at making people more reliably produce the morally correct ideas, motives or behaviors without committing to the content of those ideas, motives and/or actions. I will argue, on Millian grounds, that the value of disagreement puts serious pressure on proposals for relatively widespread direct moral enhancement. A more acceptable path would be to focus instead on indirect moral enhancements while staying neutral, for the most part, on a wide range of substantive moral claims. I will outline what such indirect moral enhancement might look like, and why we should expect it to lead to general moral improvement.

  7. Multi-Directional Environmental Sensors

    NASA Technical Reports Server (NTRS)

    Manohara, Harish (Inventor); Del Castillo, Linda Y. (Inventor); Mojarradi, Mohammed M. (Inventor)

    2016-01-01

    Systems and methods in accordance with embodiments of the invention implement multi-directional environmental sensors. In one embodiment, a multi-directional environmental sensor includes: an inner conductive element that is substantially symmetrical about three orthogonal planes; an outer conductive element that is substantially symmetrical about three orthogonal planes; and a device that measures the electrical characteristics of the multi-directional environmental sensor, the device having a first terminal and a second terminal; where the inner conductive element is substantially enclosed within the outer conductive element; where the inner conductive element is electrically coupled to the first terminal of the device; and where the outer conductive element is electrically coupled to the second terminal of the device.

  8. Stereographic projections and direct products.

    PubMed

    Kettle, S F

    2001-09-01

    The concept of stereographic projections of point groups is reviewed. If the focus of attention is moved from the symmetry-equivalence of points to the symmetry operations inter-relating points, it is possible to give simple diagrams of irreducible representations, at least for many axial groups. This approach may be elaborated by the use of trigonometric basis functions, when these may be shown on similar stereographic-related diagrams. These two simple steps enable some insights into direct products; in particular, it is possible to give a diagrammatic representation of an antisymmetric direct product.

  9. Directional drilling and earth curvature

    SciTech Connect

    Williamson, H.S.; Wilson, H.F.

    2000-03-01

    This paper provides a review of current practices for calculating directional drilling placement in the light of modern extended-reach applications. The review highlights the potential for gross errors in the application of geodetic reference information and errors inherent in the calculation method. Both types of error are quantified theoretically and illustrated with a real example. The authors borrow established land surveying calculation methods to develop a revised best practice for directional drilling. For the elimination of gross errors they prescribe increased awareness and a more disciplined approach to the handling of positional data.

  10. Direct flow crystal growth system

    DOEpatents

    Montgomery, Kenneth E.; Milanovich, Fred P.

    1992-01-01

    A crystal is grown in a constantly filtered solution which is flowed directly into the growing face of a crystal. In a continuous flow system, solution at its saturation temperature is removed from a crystal growth tank, heated above its saturation temperature, filtered, cooled back to its saturation temperature, and returned to the tank.

  11. The Internet: Trends and Directions.

    ERIC Educational Resources Information Center

    Anderson, Byron

    1996-01-01

    Examines current trends and directions in information technology and telecommunications. Discusses legislation; mergers and acquisitions; Internet service providers; fiscal control in libraries and the pooling of electronic information access through consortiums; demand for more bandwidth; technology selection; Internet usage patterns; the…

  12. Laboratory-Directed Protein Evolution

    PubMed Central

    Yuan, Ling; Kurek, Itzhak; English, James; Keenan, Robert

    2005-01-01

    Systematic approaches to directed evolution of proteins have been documented since the 1970s. The ability to recruit new protein functions arises from the considerable substrate ambiguity of many proteins. The substrate ambiguity of a protein can be interpreted as the evolutionary potential that allows a protein to acquire new specificities through mutation or to regain function via mutations that differ from the original protein sequence. All organisms have evolutionarily exploited this substrate ambiguity. When exploited in a laboratory under controlled mutagenesis and selection, it enables a protein to “evolve” in desired directions. One of the most effective strategies in directed protein evolution is to gradually accumulate mutations, either sequentially or by recombination, while applying selective pressure. This is typically achieved by the generation of libraries of mutants followed by efficient screening of these libraries for targeted functions and subsequent repetition of the process using improved mutants from the previous screening. Here we review some of the successful strategies in creating protein diversity and the more recent progress in directed protein evolution in a wide range of scientific disciplines and its impacts in chemical, pharmaceutical, and agricultural sciences. PMID:16148303

  13. Direct Sum Decomposition of Groups

    ERIC Educational Resources Information Center

    Thaheem, A. B.

    2005-01-01

    Direct sum decomposition of Abelian groups appears in almost all textbooks on algebra for undergraduate students. This concept plays an important role in group theory. One simple example of this decomposition is obtained by using the kernel and range of a projection map on an Abelian group. The aim in this pedagogical note is to establish a direct…

  14. Direct Instruction Reading. Third Edition.

    ERIC Educational Resources Information Center

    Carnine, Douglas W.; And Others

    Creating a learning and instructional environment for teaching students in a "humane and efficient" manner, this book is designed to empower teachers by providing them with specific suggestions for problems they will encounter as they provide students with direct, explicit instruction in reading. As in earlier editions, the book devotes…

  15. Direct Loan Training Trainee Guide.

    ERIC Educational Resources Information Center

    Office of Student Financial Assistance (ED), Washington, DC.

    This training guide describes the provisions of the Federal Direct Student Loan Program, identifies the functions of the different partners in the program, and explains the responsibilities of participating schools. Topics covered include an overview of the participants and the program's operation; determining of eligibility and loan amount;…

  16. Training of Direct Service Staff.

    ERIC Educational Resources Information Center

    Wallace, Teri, Ed.; And Others

    1992-01-01

    This newsletter theme issue features articles on training of direct service staff working with persons with developmental disabilities in employment, education, and residential settings. The articles examine job training, delivery systems, training models, and implications of current approaches. The newsletter includes three articles presenting…

  17. Electromagnetic direct implicit PIC simulation

    SciTech Connect

    Langdon, A.B.

    1983-03-29

    Interesting modelling of intense electron flow has been done with implicit particle-in-cell simulation codes. In this report, the direct implicit PIC simulation approach is applied to simulations that include full electromagnetic fields. The resulting algorithm offers advantages relative to moment implicit electromagnetic algorithms and may help in our quest for robust and simpler implicit codes.

  18. Direction discriminating hearing aid system

    NASA Technical Reports Server (NTRS)

    Jhabvala, M.; Lin, H. C.; Ward, G.

    1991-01-01

    A visual display was developed for people with substantial hearing loss in either one or both ears. The system consists of three discreet units; an eyeglass assembly for the visual display of the origin or direction of sounds; a stationary general purpose noise alarm; and a noise seeker wand.

  19. The 1990 direct support infrastructure

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The airport and cargo terminal were individually analyzed in depth as the principal direct infrastructure components having cross impacts with aircraft carrying cargo. Containerization was also addressed in depth as an infrastructure component since it categorically is linked with and cross impacted by the aircraft, the cargo terminal, the surface transport system, the shipper and consignee, and the actual cargo being moved.

  20. The Direct Loan Reconciliation Game.

    ERIC Educational Resources Information Center

    Department of Education, Washington, DC.

    This training guide for a one-day workshop provides an introduction to the William D. Ford Federal Direct Loan Program for administrative personnel at higher education institutions. The six sections of the guide, each corresponding to a workshop session, include activity sheets, questions for participants to answer, and space for notes. Following…

  1. Sensing roughness and polish direction

    NASA Astrophysics Data System (ADS)

    Jakobsen, M. L.; Olesen, A. S.; Larsen, H. E.; Stubager, J.; Hanson, S. G.; Pedersen, T. F.; Pedersen, H. C.

    2016-04-01

    As a part of the work carried out on a project supported by the Danish council for technology and innovation, we have investigated the option of smoothing standard CNC machined surfaces. In the process of constructing optical prototypes, involving custom-designed optics, the development cost and time consumption can become relatively large numbers in a research budget. Machining the optical surfaces directly is expensive and time consuming. Alternatively, a more standardized and cheaper machining method can be used, but then the object needs to be manually polished. During the polishing process the operator needs information about the RMS-value of the surface roughness and the current direction of the scratches introduces by the polishing process. The RMS-value indicates to the operator how far he is from the final finish, and the scratch orientation is often specified by the customer in order to avoid complications during the casting process. In this work we present a method for measuring the RMS-values of the surface roughness while simultaneously determining the polishing direction. We are mainly interested in the RMS-values in the range from 0 - 100 nm, which corresponds to the finish categories of A1, A2 and A3. Based on simple intensity measurements we estimates the RMS-value of the surface roughness, and by using a sectioned annual photo-detector to collect the scattered light we can determine the direction of polishing and distinguish light scattered from random structures and light scattered from scratches.

  2. Teaching Ethics: A Direct Approach.

    ERIC Educational Resources Information Center

    Penn, William Y., Jr.

    1990-01-01

    Compares five designs of an undergraduate ethics course at Saint Edward's University (Texas) in a 5-year study involving 318 students. Reveals the effectiveness of directly targeting and teaching in tandem the elements of moral reasoning. Bases study on Lawrence Kohlberg's moral development theory. Argues that this approach best develops moral…

  3. Directing Performers for the Cameras.

    ERIC Educational Resources Information Center

    Wilson, George P., Jr.

    An excellent way for an undergraduate, novice director of television and film to pick up background experience in directing performers for cameras is by participating in nonbroadcast-film activities, such as theatre, dance, and variety acts, both as performer and as director. This document describes the varieties of activities, including creative,…

  4. Directions for Defense Digital Libraries.

    ERIC Educational Resources Information Center

    Larsen, Ronald L.

    1998-01-01

    Describes directions, challenges, and objectives of the information management program of the United States Defense Advanced Research Projects Agency (DARPA). The program envisions the rigor and organization normally associated with a research library to be virtually rendered and extended in the networked world of distributed information. (AEF)

  5. Patient safety: honoring advanced directives.

    PubMed

    Tice, Martha A

    2007-02-01

    Healthcare providers typically think of patient safety in the context of preventing iatrogenic injury. Prevention of falls and medication or treatment errors is the typical focus of adverse event analyses. If healthcare providers are committed to honoring the wishes of patients, then perhaps failures to honor advanced directives should be viewed as reportable medical errors.

  6. High-directivity acoustic antenna

    NASA Technical Reports Server (NTRS)

    El-Sum, H. M. A.

    1974-01-01

    Acoustic antenna with unique electronic steering control is used to identify and define aerodynamic noise sources in free field, particularly in wind tunnel which is quite reverberant. Provision is made for high directivity as well as improved discrimination against unwanted background noise such as reverberation or echoes.

  7. Underwater Multimode Directional Transducer Evaluation

    DTIC Science & Technology

    2003-12-01

    The work described in the present thesis is intended to establish a procedure for analyzing directional transducers for future underwater wireless...networks, as well as to carry out the performance evaluation of a multimode transducer prototype with respect to its main operational requirements

  8. Directional Dependence in Developmental Research

    ERIC Educational Resources Information Center

    von Eye, Alexander; DeShon, Richard P.

    2012-01-01

    In this article, we discuss and propose methods that may be of use to determine direction of dependence in non-normally distributed variables. First, it is shown that standard regression analysis is unable to distinguish between explanatory and response variables. Then, skewness and kurtosis are discussed as tools to assess deviation from…

  9. Duplex Direct Data Distribution System

    NASA Technical Reports Server (NTRS)

    Greenfield, Israel (Technical Monitor)

    2001-01-01

    The NASA Glenn Research Center (GRC) is developing and demonstrating communications and network technologies that are helping to enable the near-Earth space Internet. GRC envisions several service categories. The first of these categories is direct data distribution or D3 (pronounced "D-cubed"). Commercially provided D3 will make it possible to download a data set from a spacecraft, like the International Space Station. as easily as one can extract a file from a remote server today, using a file transfer protocol. In a second category, NASA spacecraft will make use of commercial satellite communication (SATCOM) systems. Some of those services will come from purchasing time on unused transponders that cover landmasses. While it is likely there will be gaps in service coverage, Internet services should be available using these systems. This report addresses alternative methods of implementing a full duplex enhancement of the GRC developed experimental Ka-Band Direct Data Distribution (D3) space-to-ground communication link. The resulting duplex version is called the Duplex Direct Data Distribution (D4) system. The D4 system is intended to provide high-data-rate commercial direct or internet-based communications service between the NASA spacecraft in low earth orbit (LEO) and the respective principal investigators associated with these spacecraft. Candidate commercial services were assessed regarding their near-term potential to meet NASA requirements. Candidates included Ka-band and V-band geostationary orbit and non-geostationary orbit satellite relay services and direct downlink ("LEO teleport") services. End-to-end systems concepts were examined and characterized in terms of alternative link layer architectures. Alternatives included a Direct Link, a Relay Link, a Hybrid Link, and a Dual Mode Link. The direct link assessment examined sample ground terminal placements and antenna angle issues. The SATCOM-based alternatives examined existing or proposed commercial

  10. Inferring directed climatic interactions with renormalized partial directed coherence and directed partial correlation

    NASA Astrophysics Data System (ADS)

    Tirabassi, Giulio; Sommerlade, Linda; Masoller, Cristina

    2017-03-01

    Inferring interactions between processes promises deeper insight into mechanisms underlying network phenomena. Renormalised partial directed coherence is a frequency-domain representation of the concept of Granger causality, while directed partial correlation is an alternative approach for quantifying Granger causality in the time domain. Both methodologies have been successfully applied to neurophysiological signals for detecting directed relationships. This paper introduces their application to climatological time series. We first discuss the application to El Niño-Southern Oscillation—Monsoon interaction and then apply the methodologies to the more challenging air-sea interaction in the South Atlantic Convergence Zone (SACZ). In the first case, the results obtained are fully consistent with the present knowledge in climate modeling, while in the second case, the results are, as expected, less clear, and to fully elucidate the SACZ air-sea interaction, further investigations on the specificity and sensitivity of these methodologies are needed.

  11. Breakdown of interdependent directed networks

    PubMed Central

    Liu, Xueming; Stanley, H. Eugene; Gao, Jianxi

    2016-01-01

    Increasing evidence shows that real-world systems interact with one another via dependency connectivities. Failing connectivities are the mechanism behind the breakdown of interacting complex systems, e.g., blackouts caused by the interdependence of power grids and communication networks. Previous research analyzing the robustness of interdependent networks has been limited to undirected networks. However, most real-world networks are directed, their in-degrees and out-degrees may be correlated, and they are often coupled to one another as interdependent directed networks. To understand the breakdown and robustness of interdependent directed networks, we develop a theoretical framework based on generating functions and percolation theory. We find that for interdependent Erdős–Rényi networks the directionality within each network increases their vulnerability and exhibits hybrid phase transitions. We also find that the percolation behavior of interdependent directed scale-free networks with and without degree correlations is so complex that two criteria are needed to quantify and compare their robustness: the percolation threshold and the integrated size of the giant component during an entire attack process. Interestingly, we find that the in-degree and out-degree correlations in each network layer increase the robustness of interdependent degree heterogeneous networks that most real networks are, but decrease the robustness of interdependent networks with homogeneous degree distribution and with strong coupling strengths. Moreover, by applying our theoretical analysis to real interdependent international trade networks, we find that the robustness of these real-world systems increases with the in-degree and out-degree correlations, confirming our theoretical analysis. PMID:26787907

  12. Direct Imaging of Giant Exoplanets

    NASA Astrophysics Data System (ADS)

    Tamura, Motohide

    Since the first detection of exoplanets around a Sun-like star 51 Peg in 1995, their detection and characterization are mainly led by indirect methods such as radial velocity and transit methods. However, recent progresses of observational techniques have finally enabled the direct imaging observations of giant planets of solar-system-scale orbit (with their semi-major axes less than about 50 AU) around A-type stars (e.g., Marois et al. 2008, 2010) and G-type stars (e.g., Kuzuhara et al. 2013). Direct imaging is useful to obtain the physical and atmospheric parameters of exoplanets. In fact not only colors but also a medium-resolution spectroscopy of such planets has been successfully obtained for their atmospheric characterization (Barman et al. 2013). Their masses are typically a few to ~10 Jupiter masses and they orbit at a Saturn- to-Pluto distance. Therefore, like hot-Jupiters and super-Earths they are unlike any solar-system planets, and called wide-orbit giant planets. A recent large search for planets and disk on the Subaru 8.2-m telescope (SEEDS project) has detected a 3-5 Jupiter-masses planet around a Sun-like star GJ 504 (Kuzuhara et al. 2013). It is the coolest planetary companion so far directly imaged and its near-infrared color is “bluer” than that of other directly imaged planets. In this contribution, I will review the recent progresses on direct imaging of exoplanets, highlight the results of the SEEDS project, and discuss the future developments.

  13. Sampling properties of directed networks

    NASA Astrophysics Data System (ADS)

    Son, S.-W.; Christensen, C.; Bizhani, G.; Foster, D. V.; Grassberger, P.; Paczuski, M.

    2012-10-01

    For many real-world networks only a small “sampled” version of the original network may be investigated; those results are then used to draw conclusions about the actual system. Variants of breadth-first search (BFS) sampling, which are based on epidemic processes, are widely used. Although it is well established that BFS sampling fails, in most cases, to capture the IN component(s) of directed networks, a description of the effects of BFS sampling on other topological properties is all but absent from the literature. To systematically study the effects of sampling biases on directed networks, we compare BFS sampling to random sampling on complete large-scale directed networks. We present new results and a thorough analysis of the topological properties of seven complete directed networks (prior to sampling), including three versions of Wikipedia, three different sources of sampled World Wide Web data, and an Internet-based social network. We detail the differences that sampling method and coverage can make to the structural properties of sampled versions of these seven networks. Most notably, we find that sampling method and coverage affect both the bow-tie structure and the number and structure of strongly connected components in sampled networks. In addition, at a low sampling coverage (i.e., less than 40%), the values of average degree, variance of out-degree, degree autocorrelation, and link reciprocity are overestimated by 30% or more in BFS-sampled networks and only attain values within 10% of the corresponding values in the complete networks when sampling coverage is in excess of 65%. These results may cause us to rethink what we know about the structure, function, and evolution of real-world directed networks.

  14. Direct Measurement of Directional Disorder for Ciliary Metachronal Wave

    DTIC Science & Technology

    2007-11-02

    subjects [6]-[8]. Ciliary disorientation alone can lead to the clinical syndrome of primary ciliary dyskinesia (PCD) [9]. The directions based on...Orientation of respiratory tract cilia in patients with primary ciliary dyskinesia , bronchiectasis, and in normal subjects,” J. Clin. Pathol., vol. 42, pp...ciliary dyskinesia syndrome,” Am. J. Respir. Crit. Care Med., vol. 153, pp. 1123-1129, 1996. [10] L. Gheber and Z. Priel, “Metachronal activity of

  15. Fault Branching and Rupture Directivity

    NASA Astrophysics Data System (ADS)

    Dmowska, R.; Rice, J. R.; Kame, N.

    2002-12-01

    Can the rupture directivity of past earthquakes be inferred from fault geometry? Nakata et al. [J. Geogr., 1998] propose to relate the observed surface branching of fault systems with directivity. Their work assumes that all branches are through acute angles in the direction of rupture propagation. However, in some observed cases rupture paths seem to branch through highly obtuse angles, as if to propagate ``backwards". Field examples of that are as follows: (1) Landers 1992. When crossing from the Johnson Valley to the Homestead Valley (HV) fault via the Kickapoo (Kp) fault, the rupture from Kp progressed not just forward onto the northern stretch of the HV fault, but also backwards, i.e., SSE along the HV [Sowers et al., 1994, Spotila and Sieh, 1995, Zachariasen and Sieh, 1995, Rockwell et al., 2000]. Measurements of surface slip along that backward branch, a prominent feature of 4 km length, show right-lateral slip, decreasing towards the SSE. (2) At a similar crossing from the HV to the Emerson (Em) fault, the rupture progressed backwards along different SSE splays of the Em fault [Zachariasen and Sieh, 1995]. (3). In crossing from the Em to Camp Rock (CR) fault, again, rupture went SSE on the CR fault. (4). Hector Mine 1999. The rupture originated on a buried fault without surface trace [Li et al., 2002; Hauksson et al., 2002] and progressed bilaterally south and north. In the south it met the Lavic Lake (LL) fault and progressed south on it, but also progressed backward, i.e. NNW, along the northern stretch of the LL fault. The angle between the buried fault and the northern LL fault is around -160o, and that NNW stretch extends around 15 km. The field examples with highly obtuse branch angles suggest that there may be no simple correlation between fault geometry and rupture directivity. We propose that an important distinction is whether those obtuse branches actually involved a rupture path which directly turned through the obtuse angle (while continuing

  16. The direct methanol fuel cell

    SciTech Connect

    Halpert, G.; Narayanan, S.R.; Frank, H.

    1995-08-01

    This presentation describes the approach and progress in the ARPA-sponsored effort to develop a Direct Methanol, Liquid-Feed Fuel Cell (DMLFFC) with a solid Polymer Electrolyte Membrane (PEM) for battery replacement in small portable applications. Using Membrane Electrode Assemblies (MEAs) developed by JPL and Giner, significant voltage was demonstrated at relatively high current densities. The DMLFFC utilizes a 3 percent aqueous solution of methanol that is oxidized directly in the anode (fuel) chamber and oxygen (air) in the cathode chamber to produce water and significant power. The only products are water and CO{sub 2}. The ARPA effort is aimed at replacing the battery in the BA 5590 military radio.

  17. Direct spinning of fiber supercapacitor

    NASA Astrophysics Data System (ADS)

    Xu, Tong; Ding, Xiaoteng; Liang, Yuan; Zhao, Yang; Chen, Nan; Qu, Liangti

    2016-06-01

    A direct wet spinning approach is demonstrated for facile and continuous fabrication of a whole fiber supercapacitor using a microfluidic spinneret. The resulting fiber supercapacitor shows good electrochemical properties and possesses high flexibility and mechanical stability. This strategy paves the way for large-scale continuous production of fiber supercapacitors for weavable electronics.A direct wet spinning approach is demonstrated for facile and continuous fabrication of a whole fiber supercapacitor using a microfluidic spinneret. The resulting fiber supercapacitor shows good electrochemical properties and possesses high flexibility and mechanical stability. This strategy paves the way for large-scale continuous production of fiber supercapacitors for weavable electronics. Electronic supplementary information (ESI) available: Design of the microfluidic spinneret and operation of the spinneret (movie). See DOI: 10.1039/c6nr03116a

  18. Human Promoters Are Intrinsically Directional

    PubMed Central

    Duttke, Sascha H.C.; Lacadie, Scott A.; Ibrahim, Mahmoud M.; Glass, Christopher K.; Corcoran, David L.; Benner, Christopher; Heinz, Sven; Kadonaga, James T.; Ohler, Uwe

    2015-01-01

    Divergent transcription, in which reverse-oriented transcripts occur upstream of eukaryotic promoters in regions devoid of annotated genes, has been suggested to be a general property of active promoters. Here we show that the human basal RNA polymerase II transcriptional machinery and core promoter are inherently unidirectional, and that reverse-oriented transcripts originate from their own cognate reverse-directed core promoters. In vitro transcription analysis and mapping of nascent transcripts in cells revealed that sequences at reverse start sites are similar to those of their forward counterparts. The use of DNase I accessibility to define proximal promoter borders revealed that up to half of promoters are unidirectional and that unidirectional promoters are depleted at their upstream edges of reverse core promoter sequences and their associated chromatin features. Divergent transcription is thus not an inherent property of the transcription process, but rather the consequence of the presence of both forward- and reverse-directed core promoters. PMID:25639469

  19. Directives préalables

    PubMed Central

    O’Sullivan, Rory; Mailo, Kevin; Angeles, Ricardo; Agarwal, Gina

    2015-01-01

    Résumé Objectif Établir la prévalence de patients dotés de directives préalables dans une pratique familiale et décrire les points de vue des patients quant au rôle du médecin de famille dans l’amorce de discussions à propos des directives préalables. Conception Un questionnaire auquel les patients ont répondu eux-mêmes. Contexte Une clinique d’enseignement en médecine familiale achalandée en milieu urbain, à Hamilton, en Ontario. Participants Un échantillon de commodité formé de patients adultes qui se sont présentés à la clinique durant une semaine de travail typique. Principaux paramètres à l’étude La prévalence des directives préalables dans une population de patients a été déterminée et les attentes à l’endroit du rôle de leur médecin de famille ont été sollicitées. Résultats Les répondants au sondage étaient au nombre de 800 (un taux de réponse de 72,5 %) et leurs groupes d’âges étaient bien répartis; 19,7 % d’entre eux avaient rédigé des directives préalables et 43,8 % avaient déjà discuté du sujet des directives préalables, mais seulement 4,3 % de ces discussions avaient eu lieu avec un médecin de famille. Dans 5,7 % des cas, un médecin de famille avait soulevé la question; 72,3 % des répondants croyaient que les patients devraient amorcer la discussion. Les patients qui considéraient les directives préalables d’une importance extrême étaient considérablement plus enclins à vouloir que leur médecin de famille commence la conversation (rapport de cotes de 3,98; p < ,05). Conclusion Les directives préalables n’étaient pas systématiquement abordées dans la pratique familiale. La plupart des patients préféraient amorcer la discussion des directives préalables. Toutefois, les patients qui considéraient le sujet d’une extrême importance voulaient que leur médecin de famille commence la discussion.

  20. Model transport directional solidification apparatus

    SciTech Connect

    Mason, J.T.; Eshelman, M.A.

    1986-07-01

    A model transport directional solidification apparatus is described. It has three functional components, each of which are described: the temperature gradient stage, the motor and drive mechanism, and the measuring systems. A small amount of sample is held between two glass slides on the temperature gradient stage so that the portion of sample in the hot chamber is molten and the portion in the cold chamber is solidified. Conditions are set so that the solid-liquid interface occurs in the gap between the chambers and can be observed through the microscope system. In-situ directional solidification is observed by driving the sample from the hot chamber to the cold chamber and observing the solidification process as it occurs. (LEW)

  1. Multimode waveguide based directional coupler

    NASA Astrophysics Data System (ADS)

    Ahmed, Rajib; Rifat, Ahmmed A.; Sabouri, Aydin; Al-Qattan, Bader; Essa, Khamis; Butt, Haider

    2016-07-01

    The Silicon-on-Insulator (SOI) based platform overcomes limitations of the previous copper and fiber based technologies. Due to its high index difference, SOI waveguide (WG) and directional couplers (DC) are widely used for high speed optical networks and hybrid Electro-Optical inter-connections; TE00-TE01, TE00-TE00 and TM00-TM00 SOI direction couplers are designed with symmetrical and asymmetrical configurations to couple with TE00, TE01 and TM00 in a multi-mode semi-triangular ring-resonator configuration which will be applicable for multi-analyte sensing. Couplers are designed with effective index method and their structural parameters are optimized with consideration to coupler length, wavelength and polarization dependence. Lastly, performance of the couplers are analyzed in terms of cross-talk, mode overlap factor, coupling length and coupling efficiency.

  2. OM300 Direction Drilling Module

    DOE Data Explorer

    MacGugan, Doug

    2013-08-22

    OM300 – Geothermal Direction Drilling Navigation Tool: Design and produce a prototype directional drilling navigation tool capable of high temperature operation in geothermal drilling Accuracies of 0.1° Inclination and Tool Face, 0.5° Azimuth Environmental Ruggedness typical of existing oil/gas drilling Multiple Selectable Sensor Ranges High accuracy for navigation, low bandwidth High G-range & bandwidth for Stick-Slip and Chirp detection Selectable serial data communications Reduce cost of drilling in high temperature Geothermal reservoirs Innovative aspects of project Honeywell MEMS* Vibrating Beam Accelerometers (VBA) APS Flux-gate Magnetometers Honeywell Silicon-On-Insulator (SOI) High-temperature electronics Rugged High-temperature capable package and assembly process

  3. Direct Fuel Injector Temporal Measurements

    DTIC Science & Technology

    2014-10-01

    type direct fuel injector. The manufacturing specification is listed in Table 1. An electromagnetic field is created in the air gap between the...signal stops. However, the current cannot increase or decrease instantaneously like a switch due to the inductance of the coil. Instead, a certain...voltage is limited, this unwanted delay due to the inductance becomes the main obstacle for fast switching. A Pulse-Width-Modulation (PWM) servo

  4. Direct search for dark matter

    SciTech Connect

    Yoo, Jonghee; /Fermilab

    2009-12-01

    Dark matter is hypothetical matter which does not interact with electromagnetic radiation. The existence of dark matter is only inferred from gravitational effects of astrophysical observations to explain the missing mass component of the Universe. Weakly Interacting Massive Particles are currently the most popular candidate to explain the missing mass component. I review the current status of experimental searches of dark matter through direct detection using terrestrial detectors.

  5. AUTOMATIC AIR BURST DIRECTION FINDER

    DOEpatents

    Allard, G.A.

    1952-01-31

    This patent application describes an atomic explosion direction indicator comprising a geometric heat-scorchable indicating surface symmetrical about an axis, elevation and azimuth markings on the heat scorchable surface, and an indicating rod at the axis of said surface arranged to cast a shadow hereon, whereby heat from an atomic explosion will scorch a pattern on said surface indicative of the azimuth and elevation of said explosion.

  6. Direct Energy Conversion Literature Abstracts

    DTIC Science & Technology

    1962-12-01

    3530-3533 4. Fusion ........................................................ 3534-3536 C. Solar Collection and Concentration...Cooley, W.C. SOLAR DIRECT-CONVERSION. 245p., New York, United Nations, 1961. POWER SYSTEMS. Inst. Radio Engra. Trans. MIL-6: 91-98, illus., Jan. j 1962...In ch.V entitled Fuel and Power Research, nuclear and solar energy are discussed, in A survey is made of the present status of general. technology of

  7. Direct broadcast satellite technical issues

    NASA Astrophysics Data System (ADS)

    McManamon, P. M.

    The satellites discussed here are those that have been proposed for operation in the 12.2-12.7 GHz band in the U.S. to provide domestic services. Technical issues are summarized which will influence policy, regulatory practices, and decisions bearing on domestic and international sharing. Technical approaches are presented for the efficient use of the orbit to be used by direct broadcast satellites for the Broadcasting-Satellite Service.

  8. Fault branching and rupture directivity

    NASA Astrophysics Data System (ADS)

    Fliss, Sonia; Bhat, Harsha S.; Dmowska, Renata; Rice, James R.

    2005-06-01

    Could the directivity of a complex earthquake be inferred from the ruptured fault branches it created? Typically, branches develop in forward orientation, making acute angles relative to the propagation direction. Direct backward branching of the same style as the main rupture (e.g., both right lateral) is disallowed by the stress field at the rupture front. Here we propose another mechanism of backward branching. In that mechanism, rupture stops along one fault strand, radiates stress to a neighboring strand, nucleates there, and develops bilaterally, generating a backward branch. Such makes diagnosing directivity of a past earthquake difficult without detailed knowledge of the branching process. As a field example, in the Landers 1992 earthquake, rupture stopped at the northern end of the Kickapoo fault, jumped onto the Homestead Valley fault, and developed bilaterally there, NNW to continue the main rupture but also SSE for 4 km forming a backward branch. We develop theoretical principles underlying such rupture transitions, partly from elastostatic stress analysis, and then simulate the Landers example numerically using a two-dimensional elastodynamic boundary integral equation formulation incorporating slip-weakening rupture. This reproduces the proposed backward branching mechanism based on realistic if simplified fault geometries, prestress orientation corresponding to the region, standard lab friction values for peak strength, and fracture energies characteristic of the Landers event. We also show that the seismic S ratio controls the jumpable distance and that curving of a fault toward its compressional side, like locally along the southeastern Homestead Valley fault, induces near-tip increase of compressive normal stress that slows rupture propagation.

  9. Volumetric direct nuclear pumped laser

    NASA Technical Reports Server (NTRS)

    Jalufka, N. W.; Hohl, F.; Deyoung, R. J.; Williams, M. D. (Inventor)

    1978-01-01

    A volumetric direct nuclear pumped laser was developed in which the gas is a mixture of He-3 and a minority gas from the group of argon, krypton, xenon, chlorine and fluorine. The mixture of He-3 and the minority gas produces lasing with a minority gas concentration of from 0.01 to 10 percent argon, 1 percent krypton, 0.01 to 5 percent xenon and small concentrations of chlorine or fluorine.

  10. A Syntax Directed Editor Environment.

    DTIC Science & Technology

    1983-12-05

    Much of his work was based on research by Bruce J. MacLennan of the Naval Postgraduate School (Ref 9) and two of Mister MacLennan’s former thesis...of Defense. Requirement for ADA Programming Suport | .:Environments - Stoneman. Washington, D.C. 1980. • .,6. Feiler , Peter H. and Raul Medina-Mora...1982. (AD-A053032). 9. MacLennan, Bruce J. The Automatic Generation of Syntax-Directed Editors. Naval Postgraduate School, Monterey, CA., 1981. 10

  11. WHEN TOBACCO TARGETS DIRECT DEMOCRACY

    PubMed Central

    Laposata, Elizabeth; Kennedy, Allison P.

    2013-01-01

    Tobacco control advocates began to use ballot initiatives to enact tobacco control policies in the late 1970s. In response, the tobacco industry worked for over two decades to change laws governing initiative and referendum processes to prevent passage of tobacco control measures. In 1981, the tobacco industry’s political lobbying arm, the Tobacco Institute, created a front group that presented itself as a neutral initiative research clearinghouse to affect changes in state initiative and referenda laws. In 1990, the Tobacco Institute began creating an in-house team, and worked with third party groups to try to change state initiative laws. While the industry ultimately abandoned both efforts when neither achieved immediate success, over time, the industry’s goals have penetrated legitimate discourse on the I&R process in the United States and many specific ideas it advocated have garnered mainstream support. Direct democracy advocates, as well as public health advocates and policymakers, need to understand the tobacco industry’s goals (which other industries adopted) of limiting the direct democracy process in order to ensure that any changes do not inadvertently increase the power of the special interests that direct democracy was developed to counterbalance. PMID:24603083

  12. Wellbore inertial directional surveying system

    DOEpatents

    Andreas, Ronald D.; Heck, G. Michael; Kohler, Stewart M.; Watts, Alfred C.

    1991-01-01

    A wellbore inertial directional surveying system for providing a complete directional survey of an oil or gas well borehole to determine the displacement in all three directions of the borehole path relative to the well head at the surface. The information generated by the present invention is especially useful when numerous wells are drilled to different geographical targets from a single off-shore platform. Accurate knowledge of the path of the borehole allows proper well spacing and provides assurance that target formations are reached. The tool is lowered down into a borehole on the electrical cable. A computer positioned on the surface communicates with the tool via the cable. The tool contains a sensor block which is supported on a single gimbal, the rotation axis of which is aligned with the cylinder axis of the tool and, correspondingly, the borehole. The gyroscope measurement of the sensor block rotation is used in a null-seeking servo loop which essentially prevents rotation of the sensor block aboutthe gimbal axis. Angular rates of the sensor block about axes which are perpendicular to the gimbal axis are measured by gyroscopes in a manner similar to a strapped-down arrangement. Three accelerometers provide acceleration information as the tool is lowered within the borehole. The uphole computer derives position information based upon acceleration information and anular rate information. Kalman estimation techniques are used to compensate for system errors.

  13. Direct reciprocity in structured populations

    PubMed Central

    van Veelen, Matthijs; García, Julián; Rand, David G.; Nowak, Martin A.

    2012-01-01

    Reciprocity and repeated games have been at the center of attention when studying the evolution of human cooperation. Direct reciprocity is considered to be a powerful mechanism for the evolution of cooperation, and it is generally assumed that it can lead to high levels of cooperation. Here we explore an open-ended, infinite strategy space, where every strategy that can be encoded by a finite state automaton is a possible mutant. Surprisingly, we find that direct reciprocity alone does not lead to high levels of cooperation. Instead we observe perpetual oscillations between cooperation and defection, with defection being substantially more frequent than cooperation. The reason for this is that “indirect invasions” remove equilibrium strategies: every strategy has neutral mutants, which in turn can be invaded by other strategies. However, reciprocity is not the only way to promote cooperation. Another mechanism for the evolution of cooperation, which has received as much attention, is assortment because of population structure. Here we develop a theory that allows us to study the synergistic interaction between direct reciprocity and assortment. This framework is particularly well suited for understanding human interactions, which are typically repeated and occur in relatively fluid but not unstructured populations. We show that if repeated games are combined with only a small amount of assortment, then natural selection favors the behavior typically observed among humans: high levels of cooperation implemented using conditional strategies. PMID:22665767

  14. Directional Darwinian Selection in proteins

    PubMed Central

    2013-01-01

    Background Molecular evolution is a very active field of research, with several complementary approaches, including dN/dS, HON90, MM01, and others. Each has documented strengths and weaknesses, and no one approach provides a clear picture of how natural selection works at the molecular level. The purpose of this work is to present a simple new method that uses quantitative amino acid properties to identify and characterize directional selection in proteins. Methods Inferred amino acid replacements are viewed through the prism of a single physicochemical property to determine the amount and direction of change caused by each replacement. This allows the calculation of the probability that the mean change in the single property associated with the amino acid replacements is equal to zero (H0: μ = 0; i.e., no net change) using a simple two-tailed t-test. Results Example data from calanoid and cyclopoid copepod cytochrome oxidase subunit I sequence pairs are presented to demonstrate how directional selection may be linked to major shifts in adaptive zones, and that convergent evolution at the whole organism level may be the result of convergent protein adaptations. Conclusions Rather than replace previous methods, this new method further complements existing methods to provide a holistic glimpse of how natural selection shapes protein structure and function over evolutionary time. PMID:24267049

  15. Direct detection with dark mediators

    NASA Astrophysics Data System (ADS)

    Curtin, David; Surujon, Ze'ev; Tsai, Yuhsin

    2014-11-01

    We introduce dark mediator Dark Matter (dmDM) where the dark and visible sectors are connected by at least one light mediator ϕ carrying the same dark charge that stabilizes DM. ϕ is coupled to the Standard Model via an operator q bar qϕϕ* / Λ, and to dark matter via a Yukawa coupling yχχc bar χϕ. Direct detection is realized as the 2 → 3 process χN → χ bar Nϕ at tree-level for mϕ ≲ 10 keV and small Yukawa coupling, or alternatively as a loop-induced 2 → 2 process χN → χN. We explore the direct-detection consequences of this scenario and find that a heavy O (100 GeV) dmDM candidate fakes different O (10 GeV) standard WIMPs in different experiments. Large portions of the dmDM parameter space are detectable above the irreducible neutrino background and not yet excluded by any bounds. Interestingly, for the mϕ range leading to novel direct detection phenomenology, dmDM is also a form of Self-Interacting Dark Matter (SIDM), which resolves inconsistencies between dwarf galaxy observations and numerical simulations.

  16. Wellbore inertial directional surveying system

    DOEpatents

    Andreas, R.D.; Heck, G.M.; Kohler, S.M.; Watts, A.C.

    1982-09-08

    A wellbore inertial directional surveying system for providing a complete directional survey of an oil or gas well borehole to determine the displacement in all three directions of the borehole path relative to the well head at the surface. The information generated by the present invention is especially useful when numerous wells are drilled to different geographical targets from a single offshore platform. Accurate knowledge of the path of the borehole allows proper well spacing and provides assurance that target formations are reached. The tool is lowered down into a borehole on an electrical cable. A computer positioned on the surface communicates with the tool via the cable. The tool contains a sensor block which is supported on a single gimbal, the rotation axis of which is aligned with the cylinder axis of the tool and, correspondingly, the borehole. The gyroscope measurement of the sensor block rotation is used in a null-seeking servo loop which essentially prevents rotation of the sensor block about the gimbal axis. Angular rates of the sensor block about axes which are perpendicular to te gimbal axis are measured by gyroscopes in a manner similar to a strapped-down arrangement. Three accelerometers provide acceleration information as the tool is lowered within the borehole. The uphole computer derives position information based upon acceleration information and angular rate information. Kalman estimation techniques are used to compensate for system errors. 25 figures.

  17. Protrusion Fluctuations Direct Cell Motion

    PubMed Central

    Caballero, David; Voituriez, Raphaël; Riveline, Daniel

    2014-01-01

    Many physiological phenomena involve directional cell migration. It is usually attributed to chemical gradients in vivo. Recently, other cues have been shown to guide cells in vitro, including stiffness/adhesion gradients or micropatterned adhesive motifs. However, the cellular mechanism leading to these biased migrations remains unknown, and, often, even the direction of motion is unpredictable. In this study, we show the key role of fluctuating protrusions on ratchet-like structures in driving NIH3T3 cell migration. We identified the concept of efficient protrusion and an associated direction index. Our analysis of the protrusion statistics facilitated the quantitative prediction of cell trajectories in all investigated conditions. We varied the external cues by changing the adhesive patterns. We also modified the internal cues using drug treatments, which modified the protrusion activity. Stochasticity affects the short- and long-term steps. We developed a theoretical model showing that an asymmetry in the protrusion fluctuations is sufficient for predicting all measures associated with the long-term motion, which can be described as a biased persistent random walk. PMID:24988339

  18. Graphlet characteristics in directed networks

    PubMed Central

    Trpevski, Igor; Dimitrova, Tamara; Boshkovski, Tommy; Stikov, Nikola; Kocarev, Ljupcho

    2016-01-01

    Graphlet analysis is part of network theory that does not depend on the choice of the network null model and can provide comprehensive description of the local network structure. Here, we propose a novel method for graphlet-based analysis of directed networks by computing first the signature vector for every vertex in the network and then the graphlet correlation matrix of the network. This analysis has been applied to brain effective connectivity networks by considering both direction and sign (inhibitory or excitatory) of the underlying directed (effective) connectivity. In particular, the signature vectors for brain regions and the graphlet correlation matrices of the brain effective network are computed for 40 healthy subjects and common dependencies are revealed. We found that the signature vectors (node, wedge, and triangle degrees) are dominant for the excitatory effective brain networks. Moreover, by considering only those correlations (or anti correlations) in the correlation matrix that are significant (>0.7 or <−0.7) and are presented in more than 60% of the subjects, we found that excitatory effective brain networks show stronger causal (measured with Granger causality) patterns (G-causes and G-effects) than inhibitory effective brain networks. PMID:27830769

  19. Graphlet characteristics in directed networks

    NASA Astrophysics Data System (ADS)

    Trpevski, Igor; Dimitrova, Tamara; Boshkovski, Tommy; Stikov, Nikola; Kocarev, Ljupcho

    2016-11-01

    Graphlet analysis is part of network theory that does not depend on the choice of the network null model and can provide comprehensive description of the local network structure. Here, we propose a novel method for graphlet-based analysis of directed networks by computing first the signature vector for every vertex in the network and then the graphlet correlation matrix of the network. This analysis has been applied to brain effective connectivity networks by considering both direction and sign (inhibitory or excitatory) of the underlying directed (effective) connectivity. In particular, the signature vectors for brain regions and the graphlet correlation matrices of the brain effective network are computed for 40 healthy subjects and common dependencies are revealed. We found that the signature vectors (node, wedge, and triangle degrees) are dominant for the excitatory effective brain networks. Moreover, by considering only those correlations (or anti correlations) in the correlation matrix that are significant (>0.7 or <‑0.7) and are presented in more than 60% of the subjects, we found that excitatory effective brain networks show stronger causal (measured with Granger causality) patterns (G-causes and G-effects) than inhibitory effective brain networks.

  20. Direct Thrombus Imaging in Stroke

    PubMed Central

    Kim, Jongseong; Park, Jung E.; Nahrendorf, Matthias; Kim, Dong-Eog

    2016-01-01

    There is an emergent need for imaging methods to better triage patients with acute stroke for tissue-plasminogen activator (tPA)-mediated thrombolysis or endovascular clot retrieval by directly visualizing the size and distribution of cerebral thromboemboli. Currently, magnetic resonance (MR) or computed tomography (CT) angiography visualizes the obstruction of blood flow within the vessel lumen rather than the thrombus itself. The present visualization method, which relies on observation of the dense artery sign (the appearance of cerebral thrombi on a non-enhanced CT), suffers from low sensitivity. When translated into the clinical setting, direct thrombus imaging is likely to enable individualized acute stroke therapy by allowing clinicians to detect the thrombus with high sensitivity, assess the size and nature of the thrombus more precisely, serially monitor the therapeutic effects of thrombolysis, and detect post-treatment recurrence. This review is intended to provide recent updates on stroke-related direct thrombus imaging using MR imaging, positron emission tomography, or CT. PMID:27733029

  1. BNL Direct Wind Superconducting Magnets

    SciTech Connect

    Parker, B.; Anerella, M.; Escallier, J.; Ghosh, A.; Jain, A.; Marone, A.; Muratore, A.; Wanderer, P.

    2011-09-12

    BNL developed Direct Wind magnet technology is used to create a variety of complex multi-functional multi-layer superconducting coil structures without the need for creating custom production tooling and fixturing for each new project. Our Direct Wind process naturally integrates prestress into the coil structure so external coil collars and yokes are not needed; the final coil package transverse size can then be very compact. Direct Wind magnets are produced with very good field quality via corrections applied during the course of coil winding. The HERA-II and BEPC-II Interaction Region (IR) magnet, J-PARC corrector and Alpha antihydrogen magnetic trap magnets and our BTeV corrector magnet design are discussed here along with a full length ILC IR prototype magnet presently in production and the coils that were wound for an ATF2 upgrade at KEK. A new IR septum magnet design concept for a 6.2 T combined-function IR magnet for eRHIC, a future RHIC upgrade, is introduced here.

  2. 31 CFR 357.26 - Direct Deposit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... AND BILLS HELD IN TREASURY/RESERVE AUTOMATED DEBT ENTRY SYSTEM (TRADES) AND LEGACY TREASURY DIRECT Legacy Treasury Direct Book-Entry Securities System (Legacy Treasury Direct) § 357.26 Direct Deposit. (a) General. A payment by the Department with respect to a security shall be by direct deposit unless it...

  3. Entrance Counseling Guide for Direct Loan Borrowers

    ERIC Educational Resources Information Center

    Federal Student Aid, US Department of Education, 2010

    2010-01-01

    This guide describes the four types of loans offered by the Direct Loan Program[SM]: (1) Direct Subsidized Loans; (2) Direct Unsubsidized Loans; (3) Direct PLUS Loans; and (4) Direct Consolidation Loans. Among the topics covered in the guide are: Use of Your Loan Money, The Master Promissory Note, How Your Loans Will Be Disbursed (Paid Out),…

  4. Direct detection of dark matter axions with directional sensitivity

    SciTech Connect

    Irastorza, Igor G.; García, Juan A. E-mail: jagarpas@unizar.es

    2012-10-01

    We study the directional effect of the expected axion dark matter signal in a resonant cavity of an axion haloscope detector, for cavity geometries not satisfying the condition that the axion de Broglie wavelength λ{sub a} is sufficiently larger than the cavity dimensions L for a fully coherent conversion, i.e. λ{sub a}∼>2πL. We focus on long thin cavities immersed in dipole magnets and find, for appropriately chosen cavity lengths, an O(1) modulation of the signal with the cavity orientation with respect the momentum distribution of the relic axion background predicted by the isothermal sphere model for the galactic dark matter halo. This effect can be exploited to design directional axion dark matter detectors, providing an unmistakable signature of the extraterrestrial origin of a possible positive detection. Moreover, the precise shape of the modulation may give information of the galactic halo distribution and, for specific halo models, give extra sensitivity for higher axion masses.

  5. Performances comparées des machines à aimants et à réluctance variable. Maximisation du couple massique ou volumique

    NASA Astrophysics Data System (ADS)

    Matt, D.; Llibre, J. F.

    1995-10-01

    The subject of this article is to compare the performances of electrical machines using three different principles of functioning which are recently exploited. We consider possibilities to realise actuators with high torque and power per unit of mass for direct drive applications. The three different machines involved in the comparison are: (i) the classical synchronous structure with permanent magnets in the inductor, (ii) the vernier reluctance structure, (iii) the vernier reluctance structure with permanent magnets. To allow a good comparison, the architecture of those three motors has to be identical, particularly the shape of the main elements. L'objet de cet article est de comparer directement, pour la première fois à notre connaissance, les performances de machines électriques mettant en oeuvre trois principes de fonctionnement différents, très récemment exploités. Nous examinons les possibilités de réalisation d'actionneurs à fort couple et puissance massique élevée, pour des applications d'entraînement direct, conçus à partir soit d'une structure synchrone classique utilisant des aimants pour l'inducteur, soit d'une structure à réluctance variable vernier soit, enfin, d'un dispositif combinant l'effet de réluctance variable à l'utilisation d'aimants. Pour permettre une comparaison réellement directe, l'architecture des trois moteurs exploitant les concepts évoqués, ainsi que la forme de leurs principales pièces, seront pratiquement identiques.

  6. Slug Test Characterization Results for Multi-Test/Depth Intervals Conducted During the Drilling of CERCLA Operable Unit OU ZP-1 Wells 299-W10-33 and 299-W11-48

    SciTech Connect

    Newcomer, Darrell R.

    2007-09-30

    Slug-test results obtained from single and multiple, stress-level slug tests conducted during drilling and borehole advancement provide detailed hydraulic conductivity information at two Hanford Site Operable Unit (OU) ZP-1 test well locations. The individual test/depth intervals were generally sited to provide hydraulic-property information within the upper ~10 m of the unconfined aquifer (i.e., Ringold Formation, Unit 5). These characterization results complement previous and ongoing drill-and-test characterization programs at surrounding 200-West and -East Area locations (see Figure S.1).

  7. Un exemple de volcanisme calco-alcalin de type orogénique mis en place en contexte de rifting (Cambrien de l'oued Rhebar, Meseta occidentale, Maroc)

    NASA Astrophysics Data System (ADS)

    El Hadi, Hassan; Tahiri, Abdelfatah; Simancas Cabrera, Fernando; González Lodeiro, Francisco; Azor Pérez, Antonio; Jesús Martínez Poyatos, David

    2006-03-01

    The Middle Cambrian calc-alkaline Oued Rhebar volcanic complex (western Meseta, Morocco) compares with rocks originated in orogenic contexts. The La/Nb ratios are relatively high (5.2), suggesting a lithospheric mantle origin. The La/Ta ratios, higher than 26, and the negative Nb anomaly indicate a lithospheric source contaminated by the continental crust. These rocks were generated in the Mesetian Mid-Cambrian rift and would have inherited their orogenic signature from the partial melting of a previously metasomatized mantle. To cite this article: H. El Hadi et al., C. R. Geoscience 338 (2006).

  8. Comparison of Identify-Friend-Foe and Blue-Force Tracking Decision Support for Combat Identification (Comparaison des Systemes d’aide a la Decision Identification ami ou Ennemi et Suivi des Forces Bleues pour l’Identification au Combat)

    DTIC Science & Technology

    2011-02-01

    disposition de chaque soldat à pied. Deux expériences ont permis d’examiner l’efficacité des systèmes d’aide à la décision Identification ami ou ennemi (IAE...chaque fois qu’ils sont ciblés par une transmission donnée (infrarouge, radar, etc.). Les soldats munis du générateur et récepteur de signaux...rapidement et pourraient éventuellement être mises à la disposition de chaque soldat à pied. Deux expériences ont permis d’examiner l’efficacité des

  9. Directed energy deflection laboratory measurements

    NASA Astrophysics Data System (ADS)

    Brashears, Travis; Lubin, Phillip; Hughes, Gary B.; Meinhold, Peter; Suen, Jonathan; Batliner, Payton; Motta, Caio; Griswold, Janelle; Kangas, Miikka; Johansson, Isbella; Alnawakhtha, Yusuf; Prater, Kenyon; Lang, Alex; Madajian, Jonathan

    2015-09-01

    We report on laboratory studies of the effectiveness of directed energy planetary defense as a part of the DESTAR (Directed Energy System for Targeting of Asteroids and exploRation) program. DE-STAR [1][5][6] and DE-STARLITE [2][5][6] are directed energy "stand-off" and "stand-on" programs, respectively. These systems consist of a modular array of kilowatt-class lasers powered by photovoltaics, and are capable of heating a spot on the surface of an asteroid to the point of vaporization. Mass ejection, as a plume of evaporated material, creates a reactionary thrust capable of diverting the asteroid's orbit. In a series of papers, we have developed a theoretical basis and described numerical simulations for determining the thrust produced by material evaporating from the surface of an asteroid [1][2][3][4][5][6]. In the DE-STAR concept, the asteroid itself is used as the deflection "propellant". This study presents results of experiments designed to measure the thrust created by evaporation from a laser directed energy spot. We constructed a vacuum chamber to simulate space conditions, and installed a torsion balance that holds an "asteroid" sample. The sample is illuminated with a fiber array laser with flux levels up to 60 MW/m2 which allows us to simulate a mission level flux but on a small scale. We use a separate laser as well as a position sensitive centroid detector to readout the angular motion of the torsion balance and can thus determine the thrust. We compare the measured thrust to the models. Our theoretical models indicate a coupling coefficient well in excess of 100 μN/Woptical, though we assume a more conservative value of 80 μN/Woptical and then degrade this with an optical "encircled energy" efficiency of 0.75 to 60 μN/Woptical in our deflection modeling. Our measurements discussed here yield about 45 μN/Wabsorbed as a reasonable lower limit to the thrust per optical watt absorbed.

  10. Joint Direct Attack Munition (JDAM)

    DTIC Science & Technology

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-503 Joint Direct Attack Munition (JDAM) As of FY 2017 President’s Budget Defense Acquisition...RDT&E - Research, Development, Test, and Evaluation SAR - Selected Acquisition Report SCP - Service Cost Position TBD - To Be Determined TY - Then Year...N/A Feb 2005 Feb 2005 Feb 2005 Selective Availability Anti-Spoofing Module (SAASM)/GPS Anti-Jam Production Award N/A Mar 2005 Mar 2005 Mar 2005

  11. Nerve lesioning with direct current

    NASA Astrophysics Data System (ADS)

    Ravid, E. Natalie; Shi Gan, Liu; Todd, Kathryn; Prochazka, Arthur

    2011-02-01

    Spastic hypertonus (muscle over-activity due to exaggerated stretch reflexes) often develops in people with stroke, cerebral palsy, multiple sclerosis and spinal cord injury. Lesioning of nerves, e.g. with phenol or botulinum toxin is widely performed to reduce spastic hypertonus. We have explored the use of direct electrical current (DC) to lesion peripheral nerves. In a series of animal experiments, DC reduced muscle force by controlled amounts and the reduction could last several months. We conclude that in some cases controlled DC lesioning may provide an effective alternative to the less controllable molecular treatments available today.

  12. Multi-directional local search.

    PubMed

    Tricoire, Fabien

    2012-12-01

    This paper introduces multi-directional local search, a metaheuristic for multi-objective optimization. We first motivate the method and present an algorithmic framework for it. We then apply it to several known multi-objective problems such as the multi-objective multi-dimensional knapsack problem, the bi-objective set packing problem and the bi-objective orienteering problem. Experimental results show that our method systematically provides solution sets of comparable quality with state-of-the-art methods applied to benchmark instances of these problems, within reasonable CPU effort. We conclude that the proposed algorithmic framework is a viable option when solving multi-objective optimization problems.

  13. Direct condensation by humid air

    NASA Astrophysics Data System (ADS)

    Schwab, S.; Schiebelsberger, B.

    1980-12-01

    The practicability of direct condensation with humid air (DKFL) for waste heat removal from thermal power plants was investigated with regard to technical, economical and environmental aspects. The adjustment of a uniform trickling-water film was examined. A vertical test tube was erected to study the phenomenon of a trickling-water film. A pilot plant with a vertical tube-bundle was installed to evaluate the main process parameters. The applicability of the cooling system is judged. A theoretical model was derived for the design of a DKFL apparatus. A vertical geometry for the test tube has essential operational and economical advantages in comparison with a horizontal one.

  14. Future direction in airline marketing

    NASA Technical Reports Server (NTRS)

    Colussy, D. A.

    1972-01-01

    The rapid growth and broadening of the air travel market, coupled with a more sophisticated consumer, will dramatically change airline marketing over the next decade. Discussed is the direction this change is likely to take and its implications for companies within the industry. New conceptualization approaches are required if the full potential of this expanding market is to be fully realized. Marketing strategies are developed that will enable various elements of the travel industry to compete not only against each other but also with other products that are competing for the consumer's discretionary income.

  15. Direct application of geothermal energy

    SciTech Connect

    Reistad, G.M.

    1980-01-01

    An overall treatment of direct geothermal applications is presented with an emphasis on the above-ground engineering. The types of geothermal resources and their general extent in the US are described. The potential market that may be served with geothermal energy is considered briefly. The evaluation considerations, special design aspects, and application approaches for geothermal energy use in each of the applications are considered. The present applications in the US are summarized and a bibliography of recent studies and applications is provided. (MHR)

  16. Future directions in aeropropulsion technology

    NASA Technical Reports Server (NTRS)

    Saunders, N. T.; Glassman, A. J.

    1985-01-01

    Future directions in aeropropulsion technology that have been identified in a series of studies recently sponsored by the U.S. Government are discussed. Advanced vehicle concepts that could become possible by the turn of the century are presented along with some of their projected capabilities. Key building-block propulsion technologies that will contribute to making these vehicle concepts a reality are discussed along with projections of their status by the year 2000. Some pertinent highlights of the NASA aeropropulsion program are included in the discussion.

  17. Surface passivation optimization using DIRECT

    NASA Astrophysics Data System (ADS)

    Graf, Peter A.; Kim, Kwiseon; Jones, Wesley B.; Wang, Lin-Wang

    2007-06-01

    We describe a systematic and efficient method of determining pseudo-atom positions and potentials for use in nanostructure calculations based on bulk empirical pseudopotentials (EPMs). Given a bulk EPM for binary semiconductor X, we produce parameters for pseudo-atoms necessary to passivate a nanostructure of X in preparation for quantum mechanical electronic structure calculations. These passivants are based on the quality of the wave functions of a set of small test structures that include the passivants. Our method is based on the global optimization method DIRECT. It enables and/or streamlines surface passivation for empirical pseudopotential calculations.

  18. 75 FR 76630 - Direct Investment Surveys: BE-577, Quarterly Survey of U.S. Direct Investment Abroad-Direct...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-09

    ... Bureau of Economic Analysis 15 CFR Part 806 RIN 0691--AA75 Direct Investment Surveys: BE-577, Quarterly Survey of U.S. Direct Investment Abroad--Direct Transactions of U.S. Reporter With Foreign Affiliate... requirements for BE-577 quarterly survey of U.S. direct investment abroad. BEA conducts the survey...

  19. 75 FR 53611 - Direct Investment Surveys: BE-577, Quarterly Survey of U.S. Direct Investment Abroad-Direct...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-01

    ... 15 CFR Part 806 [Docket No. 100202061-0063-01] RIN 0691-AA75 Direct Investment Surveys: BE-577, Quarterly Survey of U.S. Direct Investment Abroad--Direct Transactions of U.S. Reporter With Foreign.... Direct Investment Abroad--Transactions of U.S. Reporter With Foreign Affiliate.'' The exemption level...

  20. Plasma dark matter direct detection

    SciTech Connect

    Clarke, J.D.; Foot, R. E-mail: rfoot@unimelb.edu.au

    2016-01-01

    Dark matter in spiral galaxies like the Milky Way may take the form of a dark plasma. Hidden sector dark matter charged under an unbroken U(1)' gauge interaction provides a simple and well defined particle physics model realising this possibility. The assumed U(1)' neutrality of the Universe then implies (at least) two oppositely charged dark matter components with self-interactions mediated via a massless 'dark photon' (the U(1)' gauge boson). In addition to nuclear recoils such dark matter can give rise to keV electron recoils in direct detection experiments. In this context, the detailed physical properties of the dark matter plasma interacting with the Earth is required. This is a complex system, which is here modelled as a fluid governed by the magnetohydrodynamic equations. These equations are numerically solved for some illustrative examples, and implications for direct detection experiments discussed. In particular, the analysis presented here leaves open the intriguing possibility that the DAMA annual modulation signal is due primarily to electron recoils (or even a combination of electron recoils and nuclear recoils). The importance of diurnal modulation (in addition to annual modulation) as a means of probing this kind of dark matter is also emphasised.

  1. Radial lean direct injection burner

    DOEpatents

    Khan, Abdul Rafey; Kraemer, Gilbert Otto; Stevenson, Christian Xavier

    2012-09-04

    A burner for use in a gas turbine engine includes a burner tube having an inlet end and an outlet end; a plurality of air passages extending axially in the burner tube configured to convey air flows from the inlet end to the outlet end; a plurality of fuel passages extending axially along the burner tube and spaced around the plurality of air passage configured to convey fuel from the inlet end to the outlet end; and a radial air swirler provided at the outlet end configured to direct the air flows radially toward the outlet end and impart swirl to the air flows. The radial air swirler includes a plurality of vanes to direct and swirl the air flows and an end plate. The end plate includes a plurality of fuel injection holes to inject the fuel radially into the swirling air flows. A method of mixing air and fuel in a burner of a gas turbine is also provided. The burner includes a burner tube including an inlet end, an outlet end, a plurality of axial air passages, and a plurality of axial fuel passages. The method includes introducing an air flow into the air passages at the inlet end; introducing a fuel into fuel passages; swirling the air flow at the outlet end; and radially injecting the fuel into the swirling air flow.

  2. Direct observation of vinyl hydroperoxide.

    PubMed

    Liu, Fang; Fang, Yi; Kumar, Manoj; Thompson, Ward H; Lester, Marsha I

    2015-08-28

    Many alkyl-substituted Criegee intermediates are predicted to undergo an intramolecular 1,4-hydrogen transfer to form isomeric vinyl hydroperoxide species (C[double bond, length as m-dash]COOH moiety), which break apart to release OH and vinoxy radicals. We report direct detection of stabilized vinyl hydroperoxides formed via carboxylic acid-catalyzed tautomerization of Criegee intermediates. A doubly hydrogen-bonded interaction between the Criegee intermediate and carboxylic acid facilitates efficient hydrogen transfer through a double hydrogen shift. Deuteration of formic or acetic acid permits migration of a D atom to yield partially deuterated vinyl hydroperoxides, which are distinguished from the CH3CHOO, (CH3)2COO, and CH3CH2CHOO Criegee intermediates by mass. Using 10.5 eV photoionization, three prototypical vinyl hydroperoxides, CH2[double bond, length as m-dash]CHOOD, CH2[double bond, length as m-dash]C(CH3)OOD, and CH3CH[double bond, length as m-dash]CHOOD, are detected directly. Complementary electronic structure calculations reveal several reaction pathways, including the barrierless acid-catalyzed tautomerization reaction predicted previously and a barrierless addition reaction that yields hydroperoxy alkyl formate.

  3. Efficient goal-directed exploration

    SciTech Connect

    Smirnov, Y.; Koenig, S.; Veloso, M.M.; Simmons, R.G.

    1996-12-31

    If a state space is not completely known in advance, then search algorithms have to explore it sufficiently to locate a goal state and a path leading to it, performing therefore what we call goal-directed exploration. Two paradigms of this process are pure exploration and heuristic-driven exploitation: the former approaches explore the state space using only knowledge of the physically visited portion of the domain, whereas the latter approaches totally rely on heuristic knowledge to guide the search towards goal states. Both approaches have disadvantages: the first one does not utilize available knowledge to cut down the search effort, and the second one relies too much on the knowledge, even if it is misleading. We have therefore developed a framework for goal-directed exploration, called VECA, that combines the advantages of both approaches by automatically switching from exploitation to exploration on parts of the state space where exploitation does not perform well. VECA provides better performance guarantees than previously studied heuristic-driven exploitation algorithms, and experimental evidence suggests that this guarantee does not deteriorate its average-case performance.

  4. Direct cholangiography and biliary drainage.

    PubMed

    Burcharth, F; Kruse, A

    1996-01-01

    Direct cholangiography by percutaneous transhepatic cholangiography or endoscopic retrograde cholangiography has greatly improved diagnostic work-up of patients with known or suspected biliary obstruction. These diagnostic procedures were introduced in Denmark in the early 1970s, and technical refinements and clinical research of the methods were initiated. The Danish contribution led to definition of indications for direct cholangiography and general acceptance of the methods in daily clinical practice; nationally as well as internationally. The transhepatic cholangiography with selective catheterization of the biliary ducts permitted external drainage of obstructed ducts. The disadvantages of this technique inspired the innovation of internal biliary drainage and the invention of the biliary endoprosthesis. The endoscopic approach to the biliary tract and the technical improvements of accessory instruments led to the early introduction of therapeutic procedures, i.e. papillotomy, stone removal, biliary drainage and treatment of strictures and post-traumatic lesions. Experimental and clinical research with endoprostheses improved their function and prevented dislodgment. Clinical research documented that biliary drainage by endoprosthesis is a valuable alternative to surgical bypass in patients with inoperable biliary obstructions. Endoscopic therapeutic procedures for common bile duct stones have almost replaced conventional surgical treatment. Endoluminal imaging techniques are under evaluation and may contribute to future improvements.

  5. Direct dating of human fossils.

    PubMed

    Grün, Rainer

    2006-01-01

    The methods that can be used for the direct dating of human remains comprise of radiocarbon, U-series, electron spin resonance (ESR), and amino acid racemization (AAR). This review gives an introduction to these methods in the context of dating human bones and teeth. Recent advances in ultrafiltration techniques have expanded the dating range of radiocarbon. It now seems feasible to reliably date bones up to 55,000 years. New developments in laser ablation mass spectrometry permit the in situ analysis of U-series isotopes, thus providing a rapid and virtually non-destructive dating method back to about 300,000 years. This is of particular importance when used in conjunction with non-destructive ESR analysis. New approaches in AAR analysis may lead to a renaissance of this method. The potential and present limitations of these direct dating techniques are discussed for sites relevant to the reconstruction of modern human evolution, including Florisbad, Border Cave, Tabun, Skhul, Qafzeh, Vindija, Banyoles, and Lake Mungo.

  6. Semantics of directly manipulating spatializations.

    PubMed

    Hu, Xinran; Bradel, Lauren; Maiti, Dipayan; House, Leanna; North, Chris; Leman, Scotland

    2013-12-01

    When high-dimensional data is visualized in a 2D plane by using parametric projection algorithms, users may wish to manipulate the layout of the data points to better reflect their domain knowledge or to explore alternative structures. However, few users are well-versed in the algorithms behind the visualizations, making parameter tweaking more of a guessing game than a series of decisive interactions. Translating user interactions into algorithmic input is a key component of Visual to Parametric Interaction (V2PI) [13]. Instead of adjusting parameters, users directly move data points on the screen, which then updates the underlying statistical model. However, we have found that some data points that are not moved by the user are just as important in the interactions as the data points that are moved. Users frequently move some data points with respect to some other 'unmoved' data points that they consider as spatially contextual. However, in current V2PI interactions, these points are not explicitly identified when directly manipulating the moved points. We design a richer set of interactions that makes this context more explicit, and a new algorithm and sophisticated weighting scheme that incorporates the importance of these unmoved data points into V2PI.

  7. Staged direct injection diesel engine

    DOEpatents

    Baker, Quentin A.

    1985-01-01

    A diesel engine having staged injection for using lower cetane number fuels than No. 2 diesel fuel. The engine includes a main fuel injector and a pilot fuel injector. Pilot and main fuel may be the same fuel. The pilot injector injects from five to fifteen percent of the total fuel at timings from 20.degree. to 180.degree. BTDC depending upon the quantity of pilot fuel injected, the fuel cetane number and speed and load. The pilot fuel injector is directed toward the centerline of the diesel cylinder and at an angle toward the top of the piston, avoiding the walls of the cylinder. Stratification of the early injected pilot fuel is needed to reduce the fuel-air mixing rate, prevent loss of pilot fuel to quench zones, and keep the fuel-air mixture from becoming too fuel lean to become effective. In one embodiment, the pilot fuel injector includes a single hole for injection of the fuel and is directed at approximately 48.degree. below the head of the cylinder.

  8. UROLOGIC ROBOTS AND FUTURE DIRECTIONS

    PubMed Central

    Mozer, Pierre; Troccaz, Jocelyne; Stoianovici, Dan

    2009-01-01

    Purpose of review Robot-assisted laparoscopic surgery in urology has gained immense popularity with the Da Vinci system but a lot of research teams are working on new robots. The purpose of this paper is to review current urologic robots and present future developments directions. Recent findings Future systems are expected to advance in two directions: improvements of remote manipulation robots and developments of image-guided robots. Summary The final goal of robots is to allow safer and more homogeneous outcomes with less variability of surgeon performance, as well as new tools to perform tasks based on medical transcutaneous imaging, in a less invasive way, at lower costs. It is expected that improvements for remote system could be augmented reality, haptic feed back, size reduction and development of new tools for NOTES surgery. The paradigm of image-guided robots is close to a clinical availability and the most advanced robots are presented with end-user technical assessments. It is also notable that the potential of robots lies much further ahead than the accomplishments of the daVinci system. The integration of imaging with robotics holds a substantial promise, because this can accomplish tasks otherwise impossible. Image guided robots have the potential to offer a paradigm shift. PMID:19057227

  9. Boltzmann, Darwin and Directionality theory

    NASA Astrophysics Data System (ADS)

    Demetrius, Lloyd A.

    2013-09-01

    Boltzmann’s statistical thermodynamics is a mathematical theory which relates the macroscopic properties of aggregates of interacting molecules with the laws of their interaction. The theory is based on the concept thermodynamic entropy, a statistical measure of the extent to which energy is spread throughout macroscopic matter. Macroscopic evolution of material aggregates is quantitatively explained in terms of the principle: Thermodynamic entropy increases as the composition of the aggregate changes under molecular collision. Darwin’s theory of evolution is a qualitative theory of the origin of species and the adaptation of populations to their environment. A central concept in the theory is fitness, a qualitative measure of the capacity of an organism to contribute to the ancestry of future generations. Macroscopic evolution of populations of living organisms can be qualitatively explained in terms of a neo-Darwinian principle: Fitness increases as the composition of the population changes under variation and natural selection. Directionality theory is a quantitative model of the Darwinian argument of evolution by variation and selection. This mathematical theory is based on the concept evolutionary entropy, a statistical measure which describes the rate at which an organism appropriates energy from the environment and reinvests this energy into survivorship and reproduction. According to directionality theory, microevolutionary dynamics, that is evolution by mutation and natural selection, can be quantitatively explained in terms of a directionality principle: Evolutionary entropy increases when the resources are diverse and of constant abundance; but decreases when the resource is singular and of variable abundance. This report reviews the analytical and empirical support for directionality theory, and invokes the microevolutionary dynamics of variation and selection to delineate the principles which govern macroevolutionary dynamics of speciation and

  10. Multi-directional local search

    PubMed Central

    Tricoire, Fabien

    2012-01-01

    This paper introduces multi-directional local search, a metaheuristic for multi-objective optimization. We first motivate the method and present an algorithmic framework for it. We then apply it to several known multi-objective problems such as the multi-objective multi-dimensional knapsack problem, the bi-objective set packing problem and the bi-objective orienteering problem. Experimental results show that our method systematically provides solution sets of comparable quality with state-of-the-art methods applied to benchmark instances of these problems, within reasonable CPU effort. We conclude that the proposed algorithmic framework is a viable option when solving multi-objective optimization problems. PMID:25140071

  11. Direct reconstruction of dark energy.

    PubMed

    Clarkson, Chris; Zunckel, Caroline

    2010-05-28

    An important issue in cosmology is reconstructing the effective dark energy equation of state directly from observations. With so few physically motivated models, future dark energy studies cannot only be based on constraining a dark energy parameter space. We present a new nonparametric method which can accurately reconstruct a wide variety of dark energy behavior with no prior assumptions about it. It is simple, quick and relatively accurate, and involves no expensive explorations of parameter space. The technique uses principal component analysis and a combination of information criteria to identify real features in the data, and tailors the fitting functions to pick up trends and smooth over noise. We find that we can constrain a large variety of w(z) models to within 10%-20% at redshifts z≲1 using just SNAP-quality data.

  12. New Directions in RFID Security

    NASA Astrophysics Data System (ADS)

    Blass, Erik-Oliver; Molva, Refik

    Current research in RFID security focuses on basic authentication protocols between a tag and a reader. In this paper, we claim that, in future, different new RFID-based scenarios will play an increasing role. In particular, we propose two new research directions: 1. Multi-Tag Security, and 2. RFID-based Payment. In multi-tag security, multiple tags try to jointly compute an information while using the reader either as the focal point of all communication or as a relay for tag-to-tag communication. In this scenario, the security of the computation has to be guaranteed while also privacy of individual tags must be protected. In a payment scenario, tags are used as electronic wallets similar to the notions of traditional electronic cash. Payment must be secured against malicious spending, and the privacy of tags and their payments must be protected.

  13. Laboratory directed research and development

    SciTech Connect

    Not Available

    1991-11-15

    The purposes of Argonne's Laboratory Directed Research and Development (LDRD) Program are to encourage the development of novel concepts, enhance the Laboratory's R D capabilities, and further the development of its strategic initiatives. Among the aims of the projects supported by the Program are establishment of engineering proof-of-principle''; development of an instrumental prototype, method, or system; or discovery in fundamental science. Several of these project are closely associated with major strategic thrusts of the Laboratory as described in Argonne's Five Year Institutional Plan, although the scientific implications of the achieved results extend well beyond Laboratory plans and objectives. The projects supported by the Program are distributed across the major programmatic areas at Argonne. Areas of emphasis are (1) advanced accelerator and detector technology, (2) x-ray techniques in biological and physical sciences, (3) advanced reactor technology, (4) materials science, computational science, biological sciences and environmental sciences. Individual reports summarizing the purpose, approach, and results of projects are presented.

  14. Direct Reduction of Iron Ore

    NASA Astrophysics Data System (ADS)

    Small, M.

    1981-04-01

    In the search for a pure, available iron source, steelmakers are focusing their attention on Directly Reduced Iron (DRI). This material is produced by the reaction of a low gangue iron ore with a hydrocarbonaceous substance. Commercially, DRI is generated in four different reactors: shaft (moving-bed), rotary kiln, fluidized bed, and retort (fixed-bed). Annual worldwide production capacity approaches 33 million metric tons. Detailed assessments have been made of the uses of DRI, especially as a substitute for scrap in electric furnace (EF) steelmaking. DRI is generally of a quality superior to current grades of scrap, with steels produced more efficiently in the EF and containing lower levels of impurities. However, present economics favor EF steel production with scrap. But this situation could change within this decade because of a developing scarcity of good quality scrap.

  15. Direct writing of conducting polymers.

    PubMed

    Aydemir, Nihan; Parcell, James; Laslau, Cosmin; Nieuwoudt, Michel; Williams, David E; Travas-Sejdic, Jadranka

    2013-08-01

    Described herein is a new printing method-direct writing of conducting polymers (CPs)-based on pipette-tip localized continuous electrochemical growth. A single barrel micropipette containing a metal wire (Pt) is filled with a mixture of monomer, supporting electrolyte, and an appropriate solvent. A droplet at the tip of the pipette contacts the substrate, which becomes the working electrode of a micro-electrochemical cell confined to the tip droplet and the pipette. The metallic wire in the pipette acts as both counter and reference electrode. Electropolymerization forms the CP on the working electrode in a pattern controlled by the movement of the pipette. In this study, various width poly(pyrrole) 2D and 3D structures are extruded and characterized in terms of microcyclic voltammetry, Raman spectroscopy, and scanning electron microscopy.

  16. Direct synthesis of magnesium borohydride

    DOEpatents

    Ronnebro, Ewa Carin Ellinor [Kennewick, WA; Severa, Godwin [Honolulu, HI; Jensen, Craig M [Kailua, HI

    2012-04-03

    A method is disclosed for directly preparing an alkaline earth metal borohydride, i.e. Mg(BH.sub.4).sub.2, from the alkaline earth metal boride MgB.sub.2 by hydrogenating the MgB.sub.2 at an elevated temperature and pressure. The boride may also be doped with small amounts of a metal chloride catalyst such as TiCl.sub.3 and/or NiCl.sub.2. The process provides for charging MgB.sub.2 with high pressure hydrogen above at least 70 MPa while simultaneously heating the material to about 350.degree. C. to about 400.degree. C. The method is relatively simple and inexpensive and provides a reversible hydride compound having a hydrogen capacity of at least 11 wt %.

  17. Directed Therapy for Exfoliation Syndrome

    PubMed Central

    Angelilli, Allison; Ritch, Robert

    2009-01-01

    Exfoliation syndrome (XFS) is an age-related disorder of the extracellular matrix that leads the production of abnormal fibrillar material that leads to elevated intraocular pressure and a relatively severe glaucoma. Exfoliation material is deposited in numerous ocular tissues and extraocular organs. XFS is associated with ocular ischemia, cerebrovascular disease, neurodegenerative disease and cardiovascular disease. Current modalities of treatment include intraocular pressure lowering with topical antihypertensives, laser trabeculoplasty and filtration surgery. The disease paradigm for XFS should be expanded to include directed therapy designed specifically to target the underlying disease process. Potential targets include preventing the formation or promoting the depolymerization of exfoliation material. Novel therapies targeting trabecular meshwork may prove particularly useful in the care of exfoliative glaucoma. The systemic and ocular associations of XFS underscore the need for a comprehensive search for neuroprotective agents in its treatment. PMID:19888433

  18. Direct Approach to Quantum Tunneling

    NASA Astrophysics Data System (ADS)

    Andreassen, Anders; Farhi, David; Frost, William; Schwartz, Matthew D.

    2016-12-01

    The decay rates of quasistable states in quantum field theories are usually calculated using instanton methods. Standard derivations of these methods rely in a crucial way upon deformations and analytic continuations of the physical potential and on the saddle-point approximation. While the resulting procedure can be checked against other semiclassical approaches in some one-dimensional cases, it is challenging to trace the role of the relevant physical scales, and any intuitive handle on the precision of the approximations involved is at best obscure. In this Letter, we use a physical definition of the tunneling probability to derive a formula for the decay rate in both quantum mechanics and quantum field theory directly from the Minkowski path integral, without reference to unphysical deformations of the potential. There are numerous benefits to this approach, from nonperturbative applications to precision calculations and aesthetic simplicity.

  19. Method for directional hydraulic fracturing

    DOEpatents

    Swanson, David E.; Daly, Daniel W.

    1994-01-01

    A method for directional hydraulic fracturing using borehole seals to confine pressurized fluid in planar permeable regions, comprising: placing a sealant in the hole of a structure selected from geologic or cemented formations to fill the space between a permeable planar component and the geologic or cemented formation in the vicinity of the permeable planar component; making a hydraulic connection between the permeable planar component and a pump; permitting the sealant to cure and thereby provide both mechanical and hydraulic confinement to the permeable planar component; and pumping a fluid from the pump into the permeable planar component to internally pressurize the permeable planar component to initiate a fracture in the formation, the fracture being disposed in the same orientation as the permeable planar component.

  20. Direct synthesis of calcium borohydride

    DOEpatents

    Ronnebro, Ewa Carin Ellinor; Majzoub, Eric H.

    2009-10-27

    A method is disclosed for directly preparing an alkaline earth metal borohydride, i.e. Ca(BH.sub.4).sub.2, from the alkaline earth metal hydride and the alkaline earth metal boride. The borohydride thus prepared is doped with a small portion of a metal chloride catalyst compound, such as RuCl.sub.3, TiCl.sub.3, or a mixture of TiCl.sub.3 and palladium metal. The process provides for mechanically mixing the dry reagents under an inert atmosphere followed by charging the mixed materials with high pressure hydrogen at about 70 MPa while heating the mixture to about 400.degree. C. The method is relatively simple and inexpensive and provides reversible hydride compounds which are free of the usual contamination introduced by prior art wet chemical methods.

  1. Direct imaging of photonic nanojets.

    PubMed

    Ferrand, Patrick; Wenger, Jérôme; Devilez, Alexis; Pianta, Martina; Stout, Brian; Bonod, Nicolas; Popov, Evgueni; Rigneault, Hervé

    2008-05-12

    We report the direct experimental observation of photonic nanojets created by single latex microspheres illuminated by a plane wave at a wavelength of 520 nm. Measurements are performed with a fast scanning confocal microscope in detection mode, where the detection pinhole defines a diffraction-limited observation volume that is scanned in three dimensions over the microsphere vicinity. From the collected stack of images, we reconstruct the full 3 dimensional photonic nanojet beam. Observations are conducted for polystyrene spheres of 1, 3 and 5 microm diameter deposited on a glass substrate, the upper medium being air or water. Experimental results are compared to calculations performed using the Mie theory. We measure nanojet sizes as small as 270 nm FWHM for a 3 microm sphere at a wavelength lambda of 520 nm. The beam keeps a subwavelength FWHM over a propagation distance of more than 3 lambda, displaying all the specificities of a photonic nanojet.

  2. Directed actin assembly and motility.

    PubMed

    Boujemaa-Paterski, Rajaa; Galland, Rémi; Suarez, Cristian; Guérin, Christophe; Théry, Manuel; Blanchoin, Laurent

    2014-01-01

    The actin cytoskeleton is a key component of the cellular architecture. However, understanding actin organization and dynamics in vivo is a complex challenge. Reconstitution of actin structures in vitro, in simplified media, allows one to pinpoint the cellular biochemical components and their molecular interactions underlying the architecture and dynamics of the actin network. Previously, little was known about the extent to which geometrical constraints influence the dynamic ultrastructure of these networks. Therefore, in order to study the balance between biochemical and geometrical control of complex actin organization, we used the innovative methodologies of UV and laser patterning to design a wide repertoire of nucleation geometries from which we assembled branched actin networks. Using these methods, we were able to reconstitute complex actin network organizations, closely related to cellular architecture, to precisely direct and control their 3D connections. This methodology mimics the actin networks encountered in cells and can serve in the fabrication of innovative bioinspired systems.

  3. Surface passivation optimization using DIRECT

    NASA Astrophysics Data System (ADS)

    Kim, Kwiseon; Graf, Peter A.; Jones, Wesley B.; Wang, Lin-Wang

    2006-03-01

    The calculation of the electronic structure of a nanostructure must take into account surface effects. In experiments, the dangling bonds at the surface of a semiconductor nanostructure are passivated by other semiconductors or by organic ligands. In either case, photoluminescence measurements reveal that the emission comes from bulk-like, dot-interior states. These observations suggest that an approach to passivating a simulated nanostructure would be to attach “pseudo-atoms” to each dangling bond. Here we present an automated methodology for generating surface passivating pseudo potentials for bulk empirical pseudo potentials. Our method is based on the global optimization method DIRECT. We apply it to two materials, CdSe and InP. Incorporated into a larger computational nanoscience infrastructure, our work represents a much needed improvement in the usability of the empirical pseudo potential method.

  4. Probabilistic direct counterfactual quantum communication

    NASA Astrophysics Data System (ADS)

    Zhang, Sheng

    2017-02-01

    It is striking that the quantum Zeno effect can be used to launch a direct counterfactual communication between two spatially separated parties, Alice and Bob. So far, existing protocols of this type only provide a deterministic counterfactual communication service. However, this counterfactuality should be payed at a price. Firstly, the transmission time is much longer than a classical transmission costs. Secondly, the chained-cycle structure makes them more sensitive to channel noises. Here, we extend the idea of counterfactual communication, and present a probabilistic-counterfactual quantum communication protocol, which is proved to have advantages over the deterministic ones. Moreover, the presented protocol could evolve to a deterministic one solely by adjusting the parameters of the beam splitters. Project supported by the National Natural Science Foundation of China (Grant No. 61300203).

  5. Self-Directed Learning: Emerging Theory & Practice.

    ERIC Educational Resources Information Center

    Long, Huey B.; And Others

    This book contains the following collection of papers: "Self-Directed Learning: Emerging Theory and Practice" (Long); "Self-Directed Orientation toward Learning: A Learning Style" (Bonham); "Self-Direction and Problem Solving: Theory and Method" (Peters); "Facilitating Self-Directed Learning: Not a Contradiction…

  6. 31 CFR 357.26 - Direct Deposit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AND BILLS HELD IN LEGACY TREASURY DIRECT Legacy Treasury Direct Book-Entry Securities System (Legacy... security shall be by direct deposit unless it is deemed necessary by the Department to make payment by... account. Where the Legacy Treasury Direct ® securities account is in the name of individual(s) in...

  7. Expanding Horizons in Self-Directed Learning.

    ERIC Educational Resources Information Center

    Long, Huey B.; And Others

    The following papers are included: "Preface" (Huey B. Long); "Self-Directed Learning: Smoke and Mirrors?" (Huey B. Long); "From Self-Culture to Self-Direction: An Historical Analysis of Self-Directed Learning" (Amy D. Rose); "The Link between Self-Directed and Transformative Learning" (Jane Pilling-Cormick);…

  8. 40 CFR 73.72 - Direct sales.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Direct sales. 73.72 Section 73.72... ALLOWANCE SYSTEM Auctions, Direct Sales, and Independent Power Producers Written Guarantee § 73.72 Direct sales. Allowances that were formerly part of the direct sale program, which has been terminated...

  9. Direct lateral maneuvers in hawkmoths

    PubMed Central

    Greeter, Jeremy S. M.; Hedrick, Tyson L.

    2016-01-01

    ABSTRACT We used videography to investigate direct lateral maneuvers, i.e. ‘sideslips’, of the hawkmoth Manduca sexta. M. sexta sideslip by rolling their entire body and wings to reorient their net force vector. During sideslip they increase net aerodynamic force by flapping with greater amplitude, (in both wing elevation and sweep), allowing them to continue to support body weight while rolled. To execute the roll maneuver we observed in sideslips, they use an asymmetric wing stroke; increasing the pitch of the roll-contralateral wing pair, while decreasing that of the roll-ipsilateral pair. They also increase the wing sweep amplitude of, and decrease the elevation amplitude of, the contralateral wing pair relative to the ipsilateral pair. The roll maneuver unfolds in a stairstep manner, with orientation changing more during downstroke than upstroke. This is due to smaller upstroke wing pitch angle asymmetries as well as increased upstroke flapping counter-torque from left-right differences in global reference frame wing velocity about the moth's roll axis. Rolls are also opposed by stabilizing aerodynamic moments from lateral motion, such that rightward roll velocity will be opposed by rightward motion. Computational modeling using blade-element approaches confirm the plausibility of a causal linkage between the previously mentioned wing kinematics and roll/sideslip. Model results also predict high degrees of axial and lateral damping. On the time scale of whole and half wing strokes, left-right wing pair asymmetries directly relate to the first, but not second, derivative of roll. Collectively, these results strongly support a roll-based sideslip with a high degree of roll damping in M. sexta. PMID:26740573

  10. Directed Forgetting and Directed Remembering in Visual Working Memory

    PubMed Central

    Williams, Melonie; Woodman, Geoffrey F.

    2013-01-01

    A defining characteristic of visual working memory is its limited capacity. This means that it is crucial to maintain only the most relevant information in visual working memory. However, empirical research is mixed as to whether it is possible to selectively maintain a subset of the information previously encoded into visual working memory. Here we examined the ability of subjects to use cues to either forget or remember a subset of the information already stored in visual working memory. In Experiment 1, participants were cued to either forget or remember one of two groups of colored squares during a change-detection task. We found that both types of cues aided performance in the visual working memory task, but that observers benefited more from a cue to remember than a cue to forget a subset of the objects. In Experiment 2, we show that the previous findings, which indicated that directed-forgetting cues are ineffective, were likely due to the presence of invalid cues that appear to cause observers to disregard such cues as unreliable. In Experiment 3, we recorded event-related potentials (ERPs) and show that an electrophysiological index of focused maintenance is elicited by cues that indicate which subset of information in visual working memory needs to be remembered, ruling out alternative explanations of the behavioral effects of retention-interval cues. The present findings demonstrate that observers can focus maintenance mechanisms on specific objects in visual working memory based on cues indicating future task relevance. PMID:22409182

  11. Directional synthetic aperture flow imaging.

    PubMed

    Jensen, Jørgen Arendt; Nikolov, Svetoslav Ivanov

    2004-09-01

    A method for flow estimation using synthetic aperture imaging and focusing along the flow direction is presented. The method can find the correct velocity magnitude for any flow angle, and full color flow images can be measured using only 32 to 128 pulse emissions. The approach uses spherical wave emissions with a number of defocused elements and a linear frequency-modulated pulse (chirp) to improve the signal-to-noise ratio. The received signals are dynamically focused along the flow direction and these signals are used in a cross-correlation estimator for finding the velocity magnitude. The flow angle is manually determined from the B-mode image. The approach can be used for both tissue and blood velocity determination. The approach was investigated using both simulations and a flow system with a laminar flow. The flow profile was measured with a commercial 7.5 MHz linear array transducer. A plastic tube with an internal diameter of 17 mm was used with an EcoWatt 1 pump generating a laminar, stationary flow. The velocity profile was measured for flow angles of 90 and 60 degrees. The RASMUS research scanner was used for acquiring radio frequency (RF) data from 128 elements of the array, using 8 emissions with 11 elements in each emission. A 20-micros chirp was used during emission. The RF data were subsequently beamformed off-line and stationary echo canceling was performed. The 60-degree flow with a peak velocity of 0.15 m/s was determined using 16 groups of 8 emissions, and the relative standard deviation was 0.36% (0.65 mm/s). Using the same setup for purely transverse flow gave a standard deviation of 1.2% (2.1 mm/s). Variation of the different parameters revealed the sensitivity to number of lines, angle deviations, length of correlation interval, and sampling interval. An in vivo image of the carotid artery and jugular vein of a healthy 29-year-old volunteer was acquired. A full color flow image using only 128 emissions could be made with a high

  12. Direct observation of bosonic quantum interference of surface plasmon polaritons using photon-number-resolving detectors

    NASA Astrophysics Data System (ADS)

    Fujii, Go; Fukuda, Daiji; Inoue, Shuichiro

    2014-08-01

    Quantum plasmonics is a field of research combining plasmonics with quantum optics and investigates interactions between photons and metallic nanostructures. So far, it has been proven that quantum properties of single photons to excite single surface plasmon polaritons (SPPs) are preserved in the process of photon-SPP-photon mode conversion in plasmonic nanostructures, which suggests the potential application of SPPs to the quantum information processing (QIP). Recently the Hong-Ou-Mandel (HOM) interference of single SPPs was observed in a plasmonic circuitry. However, the visibility was below the classical limit (50%) due to the simultaneous excitation of distinguishable SPP modes. We employed a directional coupler based on long-range surface-plasmon-polariton waveguides (LRSPP-DC) and superconducting photon-number-resolving detectors to directly observe the bosonic quantum interference of single SPPs beyond the classical limit. In addition, we demonstrated the indistinguishability of photons that excite single SPPs is well preserved in the process of photon-SPP mode conversion.

  13. Efficiency of parallel direct optimization

    NASA Technical Reports Server (NTRS)

    Janies, D. A.; Wheeler, W. C.

    2001-01-01

    Tremendous progress has been made at the level of sequential computation in phylogenetics. However, little attention has been paid to parallel computation. Parallel computing is particularly suited to phylogenetics because of the many ways large computational problems can be broken into parts that can be analyzed concurrently. In this paper, we investigate the scaling factors and efficiency of random addition and tree refinement strategies using the direct optimization software, POY, on a small (10 slave processors) and a large (256 slave processors) cluster of networked PCs running LINUX. These algorithms were tested on several data sets composed of DNA and morphology ranging from 40 to 500 taxa. Various algorithms in POY show fundamentally different properties within and between clusters. All algorithms are efficient on the small cluster for the 40-taxon data set. On the large cluster, multibuilding exhibits excellent parallel efficiency, whereas parallel building is inefficient. These results are independent of data set size. Branch swapping in parallel shows excellent speed-up for 16 slave processors on the large cluster. However, there is no appreciable speed-up for branch swapping with the further addition of slave processors (>16). This result is independent of data set size. Ratcheting in parallel is efficient with the addition of up to 32 processors in the large cluster. This result is independent of data set size. c2001 The Willi Hennig Society.

  14. Direct detector for terahertz radiation

    DOEpatents

    Wanke, Michael C.; Lee, Mark; Shaner, Eric A.; Allen, S. James

    2008-09-02

    A direct detector for terahertz radiation comprises a grating-gated field-effect transistor with one or more quantum wells that provide a two-dimensional electron gas in the channel region. The grating gate can be a split-grating gate having at least one finger that can be individually biased. Biasing an individual finger of the split-grating gate to near pinch-off greatly increases the detector's resonant response magnitude over prior QW FET detectors while maintaining frequency selectivity. The split-grating-gated QW FET shows a tunable resonant plasmon response to FIR radiation that makes possible an electrically sweepable spectrometer-on-a-chip with no moving mechanical optical parts. Further, the narrow spectral response and signal-to-noise are adequate for use of the split-grating-gated QW FET in a passive, multispectral terahertz imaging system. The detector can be operated in a photoconductive or a photovoltaic mode. Other embodiments include uniform front and back gates to independently vary the carrier densities in the channel region, a thinned substrate to increase bolometric responsivity, and a resistive shunt to connect the fingers of the grating gate in parallel and provide a uniform gate-channel voltage along the length of the channel to increase the responsivity and improve the spectral resolution.

  15. Interface Reconstruction with Directional Walking

    SciTech Connect

    Yao, J

    2009-05-22

    Young's interface reconstruction with three-dimensional arbitrary mesh, in general, is rather tedious to implement compared to the case of a regular mesh. The main difficulty comes from the construction of a planar facet that bounds a certain volume inside a cell. Unlike the five basic configurations with a Cartesian mesh, there can be a great number of different configurations in the case of a general mesh. We represent a simple method that can derive the topology/geometry of the intersection of arbitrary planar objects in a uniform way. The method is based on a directional walking on the surface of objects, and links the intersection points with the paths of the walking naturally defining the intersection of objects. The method works in both two and three dimensions. The method does not take advantage of convexity, thus decomposition of an object is not necessary. Therefore, the solution with this method will have a reduced number of edges and less data storage, compared with methods that use shape decomposition. The treatment is general for arbitrary polyhedrons, and no look-up tables are needed. The same operation can easily be extended for curved geometry. The implementation of this new algorithm shall allow the interface reconstruction on an arbitrary mesh to be as simple as it is on a regular mesh. Furthermore, we exactly compute the integral of partial cell volume bounded by quadratic interface. Therefore, interface reconstruction with higher than second order accuracy can be achieved on an arbitrary mesh.

  16. Low backlash direct drive actuator

    DOEpatents

    Kuklo, T.C.

    1994-10-25

    A low backlash direct drive actuator is described which comprises a motor such as a stepper motor having at least 200 steps per revolution; a two part hub assembly comprising a drive hub coaxially attached to the shaft of the motor and having a plurality of drive pins; a driven hub having a plurality of bores in one end thereof in alignment with the drive pins in the drive hub and a threaded shaft coaxially mounted in an opposite end of the driven hub; and a housing having a central bore therein into which are fitted the drive hub and driven hub, the housing having a motor mount on one end thereof to which is mounted the stepper motor, and a closed end portion with a threaded opening therein coaxial with the central bore in the housing and receiving therein the threaded shaft attached to the driven hub. Limit switches mounted to the housing cooperate with an enlarged lip on the driven hub to limit the lateral travel of the driven hub in the housing, which also acts to limit the lateral travel of the threaded shaft which functions as a lead screw. 10 figs.

  17. Some directions in ecological theory.

    PubMed

    Kendall, Bruce E

    2015-12-01

    The role of theory within ecology has changed dramatically in recent decades. Once primarily a source of qualitative conceptual framing, ecological theories and models are now often used to develop quantitative explanations of empirical patterns and to project future dynamics of specific ecological systems. In this essay, I recount my own experience of this transformation, in which accelerating computing power and the widespread incorporation of stochastic processes into ecological theory combined to create some novel integration of mathematical and statistical models. This stronger integration drives theory towards incorporating more biological realism, and I explore ways in which we can grapple with that realism to generate new general theoretical insights. This enhanced realism, in turn, may lead to frameworks for projecting ecological responses to anthropogenic change, which is, arguably, the central challenge for 21st-century ecology. In an era of big data and synthesis, ecologists are increasingly seeking to infer causality from observational data; but conventional biometry provides few tools for this project. This is a realm where theorists can and should play an important role, and I close by pointing towards some analytical and philosophical approaches developed in our sister discipline of economics that address this very problem. While I make no grand prognostications about the likely discoveries of ecological theory over the coming century, you will find in this essay a scattering of more or less far-fetched ideas that I, at least, think are interesting and (possibly) fruitful directions for our field.

  18. Gravitational spectra from direct measurements

    NASA Technical Reports Server (NTRS)

    Wagner, C. A.; Colombo, O. L.

    1978-01-01

    A simple rapid method is described for determining the spectrum of a surface field from harmonic analysis of direct measurements along great circle arcs. The method is shown to give excellent overall trends to very high degree from even a few short arcs of satellite data. Three examples are taken with perfect measurements of satellite tracking over a planet made up of hundreds of point-masses using (1) altimetric heights from a low orbiting spacecraft, (2) velocity residuals between a low and a high satellite in circular orbits, and (3) range-rate data between a station at infinity and a satellite in highly eccentric orbit. In particular, the smoothed spectrum of the Earth's gravitational field is determined to about degree 400(50 km half wavelength) from 1 D x 1 D gravimetry and the equivalent of 11 revolutions of Geos 3 and Skylab altimetry. This measurement shows there is about 46 cm of geoid height remaining in the field beyond degree 180.

  19. Future Directions in Ultraviolet Spectroscopy

    NASA Technical Reports Server (NTRS)

    Sonneborn, George (Editor); Moos, Warren; VanSteenberg, Michael

    2009-01-01

    The 'Future Directions in Ultraviolet Spectroscopy' conference was inspired by the accomplishments of the Far Ultraviolet Spectroscopic Explorer (FUSE) Mission. The FUSE mission was launched in June 1999 and spent over eight years exploring the far-ultraviolet universe, gathering over 64 million seconds of high-resolution spectral data on nearly 3000 astronomical targets. The goal of this conference was not only to celebrate the accomplishments of FUSE, but to look toward the future and understand the major scientific drivers for the ultraviolet capabilities of the next generation fo space observatories. Invited speakers presented discussions based on measurements made by FUSE and other ultraviolet instruments, assessed their connection with measurements made with other techniques and, where appropriate, discussed the implications of low-z measurements for high-z phenomena. In addition to the oral presentations, many participants presented poster papers. The breadth of these presentation made it clear that much good science is still in progress with FUSE data and that these result will continue to have relevance in many scientific areas.

  20. Low backlash direct drive actuator

    DOEpatents

    Kuklo, Thomas C.

    1994-01-01

    A low backlash direct drive actuator is described which comprises a motor such as a stepper motor having at least 200 steps per revolution; a two part hub assembly comprising a drive hub coaxially attached to the shaft of the motor and having a plurality of drive pins; a driven hub having a plurality of bores in one end thereof in alignment with the drive pins in the drive hub and a threaded shaft coaxially mounted in an opposite end of the driven hub; and a housing having a central bore therein into which are fitted the drive hub and driven hub, the housing having a motor mount on one end thereof to which is mounted the stepper motor, and a closed end portion with a threaded opening therein coaxial with the central bore in the housing and receiving therein the threaded shaft attached to the driven hub. Limit switches mounted to the housing cooperate with an enlarged lip on the driven hub to limit the lateral travel of the driven hub in the housing, which also acts to limit the lateral travel of the threaded shaft which functions as a lead screw.

  1. Direct Plasmon-Driven Photoelectrocatalysis.

    PubMed

    Robatjazi, Hossein; Bahauddin, Shah Mohammad; Doiron, Chloe; Thomann, Isabell

    2015-09-09

    Harnessing the energy from hot charge carriers is an emerging research area with the potential to improve energy conversion technologies.1-3 Here we present a novel plasmonic photoelectrode architecture carefully designed to drive photocatalytic reactions by efficient, nonradiative plasmon decay into hot carriers. In contrast to past work, our architecture does not utilize a Schottky junction, the commonly used building block to collect hot carriers. Instead, we observed large photocurrents from a Schottky-free junction due to direct hot electron injection from plasmonic gold nanoparticles into the reactant species upon plasmon decay. The key ingredients of our approach are (i) an architecture for increased light absorption inspired by optical impedance matching concepts,4 (ii) carrier separation by a selective transport layer, and (iii) efficient hot-carrier generation and injection from small plasmonic Au nanoparticles to adsorbed water molecules. We also investigated the quantum efficiency of hot electron injection for different particle diameters to elucidate potential quantum effects while keeping the plasmon resonance frequency unchanged. Interestingly, our studies did not reveal differences in the hot-electron generation and injection efficiencies for the investigated particle dimensions and plasmon resonances.

  2. Cooperation for direct fitness benefits.

    PubMed

    Leimar, Olof; Hammerstein, Peter

    2010-09-12

    Studies of the evolution of helping have traditionally used the explanatory frameworks of reciprocity and altruism towards relatives, but recently there has been an increasing interest in other kinds of explanations. We review the success or otherwise of work investigating alternative processes and mechanisms, most of which fall under the heading of cooperation for direct benefits. We evaluate to what extent concepts such as by-product benefits, pseudo-reciprocity, sanctions and partner choice, markets and the build-up of cross-species spatial trait correlations have contributed to the study of the evolution of cooperation. We conclude that these alternative ideas are successful and show potential to further increase our understanding of cooperation. We also bring up the origin and role of common interest in the evolution of cooperation, including the appearance of organisms. We note that there are still unresolved questions about the main processes contributing to the evolution of common interest. Commenting on the broader significance of the recent developments, we argue that they represent a justified balancing of the importance given to different major hypotheses for the evolution of cooperation. This balancing is beneficial because it widens considerably the range of phenomena addressed and, crucially, encourages empirical testing of important theoretical alternatives.

  3. New directions for veterinary technology.

    PubMed

    Chadderdon, Linda M; Lloyd, James W; Pazak, Helene E

    2014-01-01

    Veterinary technology has generally established itself well in companion-animal and mixed-animal veterinary medical practice, but the career's growth trajectory is uncertain. Michigan State University (MSU) convened a national conference, "Creating the Future of Veterinary Technology-A National Dialogue," in November 2011 to explore ways to elevate the veterinary technician/technologist's role in the veterinary medical profession and to identify new directions in which the career could expand. Veterinary technicians/technologists might advance their place in private practice by not only improving their clinical skills, but by also focusing on areas such as practice management, leadership training, business training, conflict resolution, information technology, and marketing/communications. Some new employment settings for veterinary technicians/technologists include more participation within laboratory animal medicine and research, the rural farm industry, regulatory medicine, and shelter medicine. Achieving these ends would call for new training options beyond the current 2-year and 4-year degree programs. Participants suggested specialty training programs, hybrid programs of various types, online programs, veterinary technician residency programs of 12-18 months, and more integration of veterinary technician/technology students and veterinary medicine students at colleges of veterinary medicine.

  4. The direct aromatization of methane

    SciTech Connect

    Marcelin, G.; Oukaci, R.; Migone, R.A.; Kazi, A.M.

    1995-12-31

    The thermal decomposition of methane shows significant potential as a process for the production of higher unsaturated and aromatic hydrocarbons when the extent of the reaction is limited. Thermodynamic calculations have shown that when the reaction is limited to the formation of C{sub 2} to C{sub 10} products, yields of aromatics can exceed 40% at temperatures of 1200{degrees}C. Preliminary experiments have shown that when the reaction is limited to the formation of C{sub 2} to C{sub 10} products, yields of aromatics can exceed 40% at temperatures of 1200{degrees}C. Preliminary experiments have shown that cooling the product and reacting gases as the reaction proceeds can significantly reduce or eliminate the formation of solid carbon and heavier (C{sub 10+}) materials. Much work remains to be done in optimizing the quenching process and this is one of the goals of this program. Means to lower the temperature of the reaction are being studied as this result in a more feasible commercial process due to savings realized in energy and material of construction costs. The use of free-radical generators and catalysts will be investigated as a means of lowering the reaction temperature thus allowing faster quenching. It is highly likely that such studies will lead to a successful direct methane to higher hydrocarbon process.

  5. Efficiency of parallel direct optimization.

    PubMed

    Janies, D A; Wheeler, W C

    2001-03-01

    Tremendous progress has been made at the level of sequential computation in phylogenetics. However, little attention has been paid to parallel computation. Parallel computing is particularly suited to phylogenetics because of the many ways large computational problems can be broken into parts that can be analyzed concurrently. In this paper, we investigate the scaling factors and efficiency of random addition and tree refinement strategies using the direct optimization software, POY, on a small (10 slave processors) and a large (256 slave processors) cluster of networked PCs running LINUX. These algorithms were tested on several data sets composed of DNA and morphology ranging from 40 to 500 taxa. Various algorithms in POY show fundamentally different properties within and between clusters. All algorithms are efficient on the small cluster for the 40-taxon data set. On the large cluster, multibuilding exhibits excellent parallel efficiency, whereas parallel building is inefficient. These results are independent of data set size. Branch swapping in parallel shows excellent speed-up for 16 slave processors on the large cluster. However, there is no appreciable speed-up for branch swapping with the further addition of slave processors (>16). This result is independent of data set size. Ratcheting in parallel is efficient with the addition of up to 32 processors in the large cluster. This result is independent of data set size.

  6. Direct simulation of groundwater age

    USGS Publications Warehouse

    Goode, D.J.

    1996-01-01

    A new method is proposed to simulate groundwater age directly, by use of an advection-dispersion transport equation with a distributed zero-order source of unit (1) strength, corresponding to the rate of aging. The dependent variable in the governing equation is the mean age, a mass- weighted average age. The governing equation is derived from residence- time-distribution concepts for the case of steady flow. For the more general case of transient flow, a transient governing equation for age is derived from mass-conservation principles applied to conceptual 'age mass.' The age mass is the product of the water mass and its age, and age mass is assumed to be conserved during mixing. Boundary conditions include zero age mass flux across all noflow and inflow boundaries trod no age mass dispersive flux across outflow boundaries. For transient-flow conditions, the initial distribution of age must be known. The solution of the governing transport equation yields the spatial distribution of the mean groundwater age and includes diffusion, dispersion, mixing, and exchange processes that typically are considered only through tracer-specific solute transport simulation. Traditional methods have relied on advective transport to predict point values of groundwater travel time and age. The proposed method retains the simplicity and tracer-independence of advection-only models, but incorporates the effects of dispersion and mixing on volume- averaged age. Example simulations of age in two idealized regional aquifer systems, one homogeneous and the other layered, demonstrate the agreement between the proposed method and traditional particle-tracking approaches and illustrate use of the proposed method to determine the effects of diffusion, dispersion, and mixing on groundwater age.

  7. Time series geophysical monitoring of permanganate injections and in situ chemical oxidation of PCE, OU1 area, Savage Superfund Site, Milford, NH, USA

    USGS Publications Warehouse

    Harte, Philip T.; Smith, Thor E.; Williams, John H.; Degnan, James R.

    2012-01-01

    In situ chemical oxidation (ISCO) treatment with sodium permanganate, an electrically conductive oxidant, provides a strong electrical signal for tracking of injectate transport using time series geophysical surveys including direct current (DC) resistivity and electromagnetic (EM) methods. Effective remediation is dependent upon placing the oxidant in close contact with the contaminated aquifer. Therefore, monitoring tools that provide enhanced tracking capability of the injectate offer considerable benefit to guide subsequent ISCO injections. Time-series geophysical surveys were performed at a superfund site in New Hampshire, USA over a one-year period to identify temporal changes in the bulk electrical conductivity of a tetrachloroethylene (PCE; also called tetrachloroethene) contaminated, glacially deposited aquifer due to the injection of sodium permanganate. The ISCO treatment involved a series of pulse injections of sodium permanganate from multiple injection wells within a contained area of the aquifer. After the initial injection, the permanganate was allowed to disperse under ambient groundwater velocities. Time series geophysical surveys identified the downward sinking and pooling of the sodium permanganate atop of the underlying till or bedrock surface caused by density-driven flow, and the limited horizontal spread of the sodium permanganate in the shallow parts of the aquifer during this injection period. When coupled with conventional monitoring, the surveys allowed for an assessment of ISCO treatment effectiveness in targeting the PCE plume and helped target areas for subsequent treatment.

  8. Time series geophysical monitoring of permanganate injections and in situ chemical oxidation of PCE, OU1 area, Savage Superfund Site, Milford, NH, USA.

    PubMed

    Harte, Philip T; Smith, Thor E; Williams, John H; Degnan, James R

    2012-05-01

    In situ chemical oxidation (ISCO) treatment with sodium permanganate, an electrically conductive oxidant, provides a strong electrical signal for tracking of injectate transport using time series geophysical surveys including direct current (DC) resistivity and electromagnetic (EM) methods. Effective remediation is dependent upon placing the oxidant in close contact with the contaminated aquifer. Therefore, monitoring tools that provide enhanced tracking capability of the injectate offer considerable benefit to guide subsequent ISCO injections. Time-series geophysical surveys were performed at a superfund site in New Hampshire, USA over a one-year period to identify temporal changes in the bulk electrical conductivity of a tetrachloroethylene (PCE; also called tetrachloroethene) contaminated, glacially deposited aquifer due to the injection of sodium permanganate. The ISCO treatment involved a series of pulse injections of sodium permanganate from multiple injection wells within a contained area of the aquifer. After the initial injection, the permanganate was allowed to disperse under ambient groundwater velocities. Time series geophysical surveys identified the downward sinking and pooling of the sodium permanganate atop of the underlying till or bedrock surface caused by density-driven flow, and the limited horizontal spread of the sodium permanganate in the shallow parts of the aquifer during this injection period. When coupled with conventional monitoring, the surveys allowed for an assessment of ISCO treatment effectiveness in targeting the PCE plume and helped target areas for subsequent treatment.

  9. Time series geophysical monitoring of permanganate injections and in situ chemical oxidation of PCE, OU1 area, Savage Superfund Site, Milford, NH, USA

    NASA Astrophysics Data System (ADS)

    Harte, Philip T.; Smith, Thor E.; Williams, John H.; Degnan, James R.

    2012-05-01

    In situ chemical oxidation (ISCO) treatment with sodium permanganate, an electrically conductive oxidant, provides a strong electrical signal for tracking of injectate transport using time series geophysical surveys including direct current (DC) resistivity and electromagnetic (EM) methods. Effective remediation is dependent upon placing the oxidant in close contact with the contaminated aquifer. Therefore, monitoring tools that provide enhanced tracking capability of the injectate offer considerable benefit to guide subsequent ISCO injections. Time-series geophysical surveys were performed at a superfund site in New Hampshire, USA over a one-year period to identify temporal changes in the bulk electrical conductivity of a tetrachloroethylene (PCE; also called tetrachloroethene) contaminated, glacially deposited aquifer due to the injection of sodium permanganate. The ISCO treatment involved a series of pulse injections of sodium permanganate from multiple injection wells within a contained area of the aquifer. After the initial injection, the permanganate was allowed to disperse under ambient groundwater velocities. Time series geophysical surveys identified the downward sinking and pooling of the sodium permanganate atop of the underlying till or bedrock surface caused by density-driven flow, and the limited horizontal spread of the sodium permanganate in the shallow parts of the aquifer during this injection period. When coupled with conventional monitoring, the surveys allowed for an assessment of ISCO treatment effectiveness in targeting the PCE plume and helped target areas for subsequent treatment.

  10. Directional intercept factor of truncated CPCs

    SciTech Connect

    Minano, J.C.

    1983-09-01

    The fraction of power reaching the collector of a truncated cylindrical compound parabolic concentrator, out of the total power arriving at its entry aperture in a given direction, is calculated without ray tracing for all directions.

  11. Proposed amendments to the medical devices Directives.

    PubMed

    Donawa, Maria

    2006-01-01

    As 2005 came to a close, the European Commission issued its formal proposal for a Directive amending the medical devices Directives. This article discusses certain aspects of the proposed amendments and encourages readers to review them in their entirety.

  12. Outrunning Nature: Directed Evolution of Superior Biocatalysts

    ERIC Educational Resources Information Center

    Woodyer, Ryan; Chen, Wilfred; Zhao, Huimin

    2004-01-01

    The development of enzymes as biocatalysts for industrial use and the emergence of directed evolution in the invention of advanced biocatalysts are discussed and illustrated. Thus, directed evolution has bridged the functional gap between natural and specially designed biocatalysts.

  13. Etude de l'effet de la température de dépôt ou de recuit sur la formation de l'interface Au/GaSb(100) par diffraction d'électrons lents et spectroscopies d'électrons Auger ou de pertes d'énergies

    NASA Astrophysics Data System (ADS)

    Rouanet, M.; Oueini, W.; Nouaoura, M.; Bertru, N.; Bonnet, J.; Lassabatere, L.

    1995-05-01

    Auger electron spectroscopy (AES), energy electron loss spectroscopy (EELS) and low energy electron diffraction (LEED) are used to precise the interaction of gold with GaSb(100) surfaces grown on GaSb substrates by molecular beam epitaxy (MBE). After the growth, the GaSb layers, produced in the laboratory, were transferred by the mean of an ultra vacuum lock chamber, into an other ultra vacuum devoted to the deposit of gold and to the physical studies. Measurements were first performed on the clean surfaces and then on surfaces covered by increasing amounts of gold (6 × 10^{13} 1.8 × 10^{16} atoms cm^{-2}) deposited on substrates brought at room temperature or at low temperature (220 K). The samples were then studied during the annealing up to 520 K. The results show, at the beginning of the deposition, gold was adsorbed on the MBE GaSb(100) surface. When the gold coverage increases and becomes higher than 10^{15} atomes cm^{-2}, Au diffuses into the bulk and forms alloys. Nous étudions par spectroscopie d'électrons Auger (SEA), spectroscopie de pertes d'énergies d'électrons lents (SPEEL) et diffraction d'électrons lents (DEL), l'adsorption de l'or sur des surfaces (100) de couches de GaSb obtenues au laboratoire par épitaxie par jets moléculaires (EJM) sur des substrats de GaSb, puis transférées pour dépôt et étude dans l'enceinte à ultravvide de dépôt métallique par l'intermédiaire d'un sas sous ultravide. Les mesures sont effectuées avant et après dépôts d'or (6 × 10^{13} 1,8 × 10^{16} atomes cm^{-2}) réalisés sur un substrat à la température ambiante ou refroidi à 220 K. Les échantillons sont ensuite étudiés pendant lerecuit jusqu'à 520 K. Les résultats obtenues montrent que l'or, dans un premier temps s'adsorbe sur la surface, puis, lorsque le dépôt augmente, diffuse dans le volume du matériau. cette diffusion, qui peut s'acompagner de la formation d'alliages, n'est cependant notable dans la gamme de température utilis

  14. Future directions of ecosystem science

    USGS Publications Warehouse

    Baron, Jill; Galvin, Kathleen A.

    1990-01-01

    , and global--have not replaced one another (Clark and Holling 1985). Instead, the effects are superimposed, creating what some perceive as impending global environmental crisis (Clark 1989, MacNeill 1989, WCED 1987). Public demands are developing for economic, political, social, and environmental efforts directed toward creating a state of global sustainability.

  15. MAPPING DIRECTLY IMAGED GIANT EXOPLANETS

    SciTech Connect

    Kostov, Veselin; Apai, Daniel

    2013-01-01

    With the increasing number of directly imaged giant exoplanets, the current atmosphere models are often not capable of fully explaining the spectra and luminosity of the sources. A particularly challenging component of the atmosphere models is the formation and properties of condensate cloud layers, which fundamentally impact the energetics, opacity, and evolution of the planets. Here we present a suite of techniques that can be used to estimate the level of rotational modulations these planets may show. We propose that the time-resolved observations of such periodic photometric and spectroscopic variations of extrasolar planets due to their rotation can be used as a powerful tool to probe the heterogeneity of their optical surfaces. In this paper, we develop simulations to explore the capabilities of current and next-generation ground- and space-based instruments for this technique. We address and discuss the following questions: (1) what planet properties can be deduced from the light curve and/or spectra, and in particular can we determine rotation periods, spot coverage, spot colors, and spot spectra?; (2) what is the optimal configuration of instrument/wavelength/temporal sampling required for these measurements?; and (3) can principal component analysis be used to invert the light curve and deduce the surface map of the planet? Our simulations describe the expected spectral differences between homogeneous (clear or cloudy) and patchy atmospheres, outline the significance of the dominant absorption features of H{sub 2}O, CH{sub 4}, and CO, and provide a method to distinguish these two types of atmospheres. Assuming surfaces with and without clouds for most currently imaged planets the current models predict the largest variations in the J band. Simulated photometry from current and future instruments is used to estimate the level of detectable photometric variations. We conclude that future instruments will be able to recover not only the rotation periods

  16. Hydrothermal industrialization: direct heat development. Final report

    SciTech Connect

    Not Available

    1982-05-01

    A description of hydrothermal resources suitable for direct applications, their associated temperatures, geographic distribution and developable capacity are given. An overview of the hydrothermal direct-heat development infrastructure is presented. Development activity is highlighted by examining known and planned geothermal direct-use applications. Underlying assumptions and results for three studies conducted to determine direct-use market penetration of geothermal energy are discussed.

  17. Wavelet Characterizations of Multi-Directional Regularity

    NASA Astrophysics Data System (ADS)

    Slimane, Mourad Ben

    2011-05-01

    The study of d dimensional traces of functions of m several variables leads to directional behaviors. The purpose of this paper is two-fold. Firstly, we extend the notion of one direction pointwise Hölder regularity introduced by Jaffard to multi-directions. Secondly, we characterize multi-directional pointwise regularity by Triebel anisotropic wavelet coefficients (resp. leaders), and also by Calderón anisotropic continuous wavelet transform.

  18. NASA directives master list and index

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This Handbook sets forth in two parts the information for the guidance of users of the NASA Management Directives System. Complementary to this Handbook is the NASA Online Directives Information System (NODIS), an electronic computer text retrieval system. The first part contains the Master List of Management Directives in force as of 30 Sep. 1993. The second part contains an Index to NASA Management Directives in force as of 30 Sep. 1993.

  19. DRIFT: a directionally sensitive dark matter detector

    NASA Astrophysics Data System (ADS)

    Morgan, Ben; Drift; Uk Dark Matter Collaborations

    2003-11-01

    Directional Recoil Identification From Tracks-I (DRIFT) is the world's first WIMP dark matter detector with sensitivity to the directions of nuclear recoils. The distribution of WIMP induced nuclear recoil directions offers the most powerful way of positively identifying a WIMP signal. This paper discusses the DRIFT-I detector and considers future high spatial resolution readout schemes.

  20. New Ideas about Self-Directed Learning.

    ERIC Educational Resources Information Center

    Long, Huey B.; And Others

    These 16 papers provide as complete a picture as possible of the current efforts in self-directed learning (SDL) application and research. The papers are: "Challenging Some Myths about Self-Directed Learning Research" (Long); "Childhood Experiences as Origins of Self-Directed Learning Experiences" (Long, Stubblefield);…

  1. 48 CFR 31.202 - Direct costs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Direct costs. 31.202... REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Commercial Organizations 31.202 Direct costs. (a) No final cost objective shall have allocated to it as a direct cost any cost, if other...

  2. 48 CFR 31.202 - Direct costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Direct costs. 31.202... REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Commercial Organizations 31.202 Direct costs. (a) No final cost objective shall have allocated to it as a direct cost any cost, if other...

  3. Directed Forgetting of Recently Recalled Autobiographical Memories

    ERIC Educational Resources Information Center

    Barnier, Amanda J.; Conway, Martin A.; Mayoh, Lyndel; Speyer, Joanne; Avizmil, Orit; Harris, Celia B.

    2007-01-01

    In 6 experiments, the authors investigated list-method directed forgetting of recently recalled autobiographical memories. Reliable directed forgetting effects were observed across all experiments. In 4 experiments, the authors examined the impact of memory valence on directed forgetting. The forget instruction impaired recall of negative,…

  4. 47 CFR 101.115 - Directional antennas.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Directional antennas. 101.115 Section 101.115... SERVICES Technical Standards § 101.115 Directional antennas. Link to an amendment published at 76 FR 59572... authorized under the rules of this part must employ a directional antenna adjusted with the center of...

  5. 47 CFR 101.115 - Directional antennas.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Directional antennas. 101.115 Section 101.115... SERVICES Technical Standards § 101.115 Directional antennas. (a) Unless otherwise authorized upon specific... antenna adjusted with the center of the major lobe of radiation in the horizontal plane directed...

  6. 47 CFR 101.115 - Directional antennas.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Directional antennas. 101.115 Section 101.115... SERVICES Technical Standards § 101.115 Directional antennas. (a) Unless otherwise authorized upon specific... antenna adjusted with the center of the major lobe of radiation in the horizontal plane directed...

  7. 47 CFR 101.115 - Directional antennas.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Directional antennas. 101.115 Section 101.115... SERVICES Technical Standards § 101.115 Directional antennas. Link to an amendment published at 77 FR 54432... authorized under the rules of this part must employ a directional antenna adjusted with the center of...

  8. 47 CFR 101.115 - Directional antennas.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Directional antennas. 101.115 Section 101.115... SERVICES Technical Standards § 101.115 Directional antennas. (a) Unless otherwise authorized upon specific... antenna adjusted with the center of the major lobe of radiation in the horizontal plane directed...

  9. The Direct Satellite Connection: Definitions and Prospects.

    ERIC Educational Resources Information Center

    Wigand, Rolf T.

    1980-01-01

    Defines direct satellite broadcasting as the transmission of broadcast signals via high-powered satellites that permit direct reception of television or radio programs by means of small antennas. Outlines American, European, and Japanese plans for direct-to-home television reception and implications for the broadcasting industry. (JMF)

  10. 33 CFR 86.07 - Directional properties.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... NAVIGATION RULES ANNEX III: TECHNICAL DETAILS OF SOUND SIGNAL APPLIANCES Whistles § 86.07 Directional properties. The sound pressure level of a directional whistle shall be not more than 4 dB below the sound... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Directional properties....

  11. 33 CFR 86.07 - Directional properties.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... NAVIGATION RULES ANNEX III: TECHNICAL DETAILS OF SOUND SIGNAL APPLIANCES Whistles § 86.07 Directional properties. The sound pressure level of a directional whistle shall be not more than 4 dB below the sound... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Directional properties....

  12. 33 CFR 86.07 - Directional properties.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... NAVIGATION RULES ANNEX III: TECHNICAL DETAILS OF SOUND SIGNAL APPLIANCES Whistles § 86.07 Directional properties. The sound pressure level of a directional whistle shall be not more than 4 dB below the sound... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Directional properties....

  13. 33 CFR 86.07 - Directional properties.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... NAVIGATION RULES ANNEX III: TECHNICAL DETAILS OF SOUND SIGNAL APPLIANCES Whistles § 86.07 Directional properties. The sound pressure level of a directional whistle shall be not more than 4 dB below the sound... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Directional properties....

  14. 33 CFR 86.07 - Directional properties.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... NAVIGATION RULES ANNEX III: TECHNICAL DETAILS OF SOUND SIGNAL APPLIANCES Whistles § 86.07 Directional properties. The sound pressure level of a directional whistle shall be not more than 4 dB below the sound... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Directional properties....

  15. Air breathing direct methanol fuel cell

    DOEpatents

    Ren, Xiaoming

    2002-01-01

    An air breathing direct methanol fuel cell is provided with a membrane electrode assembly, a conductive anode assembly that is permeable to air and directly open to atmospheric air, and a conductive cathode assembly that is permeable to methanol and directly contacting a liquid methanol source.

  16. Emerging Perspectives of Self-Directed Learning.

    ERIC Educational Resources Information Center

    Long, Huey B.; And Others

    These 17 papers attest to the deepening and broadening interest in self-directed learning as one solution to the lifelong learning needs of men and women in an increasingly dynamic society. The papers include the following: "Self-Directed Learning Knowledge: Some Issues" (Long); "Development of Self-Directed Learning Readiness: A…

  17. 10 CFR 35.40 - Written directives.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Written directives. 35.40 Section 35.40 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL General Administrative Requirements § 35.40 Written directives. (a) A written directive must be dated and signed by an authorized user before the...

  18. 10 CFR 35.40 - Written directives.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Written directives. 35.40 Section 35.40 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL General Administrative Requirements § 35.40 Written directives. (a) A written directive must be dated and signed by an authorized user before the...

  19. 10 CFR 35.40 - Written directives.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Written directives. 35.40 Section 35.40 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL General Administrative Requirements § 35.40 Written directives. (a) A written directive must be dated and signed by an authorized user before the...

  20. 10 CFR 35.40 - Written directives.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Written directives. 35.40 Section 35.40 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL General Administrative Requirements § 35.40 Written directives. (a) A written directive must be dated and signed by an authorized user before the...

  1. 10 CFR 35.40 - Written directives.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Written directives. 35.40 Section 35.40 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL General Administrative Requirements § 35.40 Written directives. (a) A written directive must be dated and signed by an authorized user before the...

  2. Self Directed Learning and Self Management. Symposium.

    ERIC Educational Resources Information Center

    2002

    This document contains three papers from a symposium on self-directed learning and self-management. "Validating a More-Dimensional Conception of Self-Directed Learning" (Gerald A. Straka, Cornelia Schaefer) discusses the development and validation of a conception of self-directed learning as a dynamic interplay between behavior,…

  3. 18 CFR 381.107 - Direct billing.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Direct billing. 381.107... OF ENERGY REVISED GENERAL RULES FEES General Provisions § 381.107 Direct billing. (a) Applicability... billing procedure for the direct and indirect costs of processing that filing. The Commission will make...

  4. 18 CFR 381.107 - Direct billing.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Direct billing. 381.107... OF ENERGY REVISED GENERAL RULES FEES General Provisions § 381.107 Direct billing. (a) Applicability... billing procedure for the direct and indirect costs of processing that filing. The Commission will make...

  5. 7 CFR 1710.51 - Direct loans.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 11 2014-01-01 2014-01-01 false Direct loans. 1710.51 Section 1710.51 Agriculture... GENERAL AND PRE-LOAN POLICIES AND PROCEDURES COMMON TO ELECTRIC LOANS AND GUARANTEES Types of Loans and Loan Guarantees § 1710.51 Direct loans. RUS makes direct loans under section 4 of the RE Act....

  6. 7 CFR 1710.51 - Direct loans.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 11 2012-01-01 2012-01-01 false Direct loans. 1710.51 Section 1710.51 Agriculture... GENERAL AND PRE-LOAN POLICIES AND PROCEDURES COMMON TO ELECTRIC LOANS AND GUARANTEES Types of Loans and Loan Guarantees § 1710.51 Direct loans. RUS makes direct loans under section 4 of the RE Act....

  7. 7 CFR 1710.51 - Direct loans.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 11 2011-01-01 2011-01-01 false Direct loans. 1710.51 Section 1710.51 Agriculture... GENERAL AND PRE-LOAN POLICIES AND PROCEDURES COMMON TO ELECTRIC LOANS AND GUARANTEES Types of Loans and Loan Guarantees § 1710.51 Direct loans. RUS makes direct loans under section 4 of the RE Act....

  8. 7 CFR 1710.51 - Direct loans.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 11 2013-01-01 2013-01-01 false Direct loans. 1710.51 Section 1710.51 Agriculture... GENERAL AND PRE-LOAN POLICIES AND PROCEDURES COMMON TO ELECTRIC LOANS AND GUARANTEES Types of Loans and Loan Guarantees § 1710.51 Direct loans. RUS makes direct loans under section 4 of the RE Act....

  9. 12 CFR 619.9135 - Direct lender.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Direct lender. 619.9135 Section 619.9135 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM DEFINITIONS § 619.9135 Direct lender. The term direct lender refers to Farm Credit banks and associations (production credit...

  10. Empirical Evaluation of Directional-Dependence Tests

    ERIC Educational Resources Information Center

    Thoemmes, Felix

    2015-01-01

    Testing of directional dependence is a method to infer causal direction that recently has attracted some attention. Previous examples by e.g. von Eye and DeShon (2012a) and extensive simulation studies by Pornprasertmanit and Little (2012) have demonstrated that under specific assumptions, directional-dependence tests can recover the true causal…

  11. Understanding Direct Lending: Dispelling Misconceptions and Myths.

    ERIC Educational Resources Information Center

    Hicks, Elizabeth M.

    1993-01-01

    It is argued that direct lending by the federal government to the student, characterized by direct financing, delivery, and communication, is a form of financial aid more cost effective than current programs such as the federal Guaranteed Student Loans. Direct loans can be better administered by the federal government, and protection against fraud…

  12. 14 CFR 212.7 - Direct sales.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Direct sales. 212.7 Section 212.7... REGULATIONS CHARTER RULES FOR U.S. AND FOREIGN DIRECT AIR CARRIERS § 212.7 Direct sales. (a) Certificated and foreign air carriers may sell or offer for sale, and operate, as principal, Public Charter flights...

  13. AIRTV: Broadband Direct to Aircraft

    NASA Astrophysics Data System (ADS)

    Sorbello, R.; Stone, R.; Bennett, S. B.; Bertenyi, E.

    2002-01-01

    Airlines have been continuously upgrading their wide-body, long-haul aircraft with IFE (in-flight entertainment) systems that can support from 12 to 24 channels of video entertainment as well as provide the infrastructure to enable in-seat delivery of email and internet services. This is a direct consequence of increased passenger demands for improved in-flight services along with the expectations that broadband delivery systems capable of providing live entertainment (news, sports, financial information, etc.) and high speed data delivery will soon be available. The recent events of Sept. 11 have slowed the airline's upgrade of their IFE systems, but have also highlighted the compelling need for broadband aeronautical delivery systems to include operational and safety information. Despite the impact of these events, it is estimated that by 2005 more than 3000 long haul aircraft (servicing approximately 1 billion passengers annually) will be fully equipped with modern IFE systems. Current aircraft data delivery systems, which use either Inmarsat or NATS, are lacking in bandwidth and consequently are unsuitable to satisfy passenger demands for broadband email/internet services or the airlines' burgeoning data requirements. Present live video delivery services are limited to regional coverage and are not readily expandable to global or multiregional service. Faced with a compelling market demand for high data transport to aircraft, AirTV has been developing a broadband delivery system that will meet both passengers' and airlines' needs. AirTV is a global content delivery system designed to provide a range of video programming and data services to commercial airlines. When AirTV is operational in 2004, it will provide a broadband connection directly to the aircraft, delivering live video entertainment, internet/email service and essential operational and safety data. The system has been designed to provide seamless global service to all airline routes except for those

  14. What determines the direction of subliminal priming

    PubMed Central

    Jaśkowski, Piotr; Verleger, Rolf

    2008-01-01

    Masked stimuli (primes) can affect the preparation of a motor response to subsequently presented target stimuli. Reactions to the target can be facilitated (straight priming) or inhibited (inverse priming) when preceded by a compatible prime (calling for the same response) and also when preceded by an incompatible prime. Several hypotheses are currently under debate. These are the self-inhibition (SI) hypothesis, the object-updating (OU) hypothesis, and mask-triggered inhibition (MTI) hypothesis. All assume that the initial activation of the motor response is elicited by the prime according to its identity. This activation inevitably leads to straight priming in some cases and the mechanisms involved are undisputed. The hypotheses differ, however, as to why inverse priming occurs. The self-inhibition (SI) hypothesis assumes that the motor activation elicited by a prime is automatically followed by an inhibition phase, leading to inverse priming if three conditions are fulfilled: perceptual evidence for the prime has to be sufficiently strong, it has to be immediately removed by the mask, and the delay between the prime and target has to be long enough for inhibition to become effective. The object-updating (OU) hypothesis assumes that inverse priming is triggered by the mask, provided that it contains features calling for the alternative response (i.e. the one contrasting with the response induced by the prime). The MTI hypothesis assumes that the inhibitory phase is triggered by each successive stimulus which does not support the perceptual hypothesis provided by the prime. Based mostly on our own experiments, we argue that (1) attempts to manipulate the three factors required by the SI hypothesis imply changes of other variables and that (2) indeed, other variables seem to affect priming: prime-mask perceptual interaction and temporal position of the mask. These observations are in favor of the MTI hypothesis. A limiting factor for all three hypotheses is that

  15. Direct manipulation of virtual objects

    NASA Astrophysics Data System (ADS)

    Nguyen, Long K.

    Interacting with a Virtual Environment (VE) generally requires the user to correctly perceive the relative position and orientation of virtual objects. For applications requiring interaction in personal space, the user may also need to accurately judge the position of the virtual object relative to that of a real object, for example, a virtual button and the user's real hand. This is difficult since VEs generally only provide a subset of the cues experienced in the real world. Complicating matters further, VEs presented by currently available visual displays may be inaccurate or distorted due to technological limitations. Fundamental physiological and psychological aspects of vision as they pertain to the task of object manipulation were thoroughly reviewed. Other sensory modalities -- proprioception, haptics, and audition -- and their cross-interactions with each other and with vision are briefly discussed. Visual display technologies, the primary component of any VE, were canvassed and compared. Current applications and research were gathered and categorized by different VE types and object interaction techniques. While object interaction research abounds in the literature, pockets of research gaps remain. Direct, dexterous, manual interaction with virtual objects in Mixed Reality (MR), where the real, seen hand accurately and effectively interacts with virtual objects, has not yet been fully quantified. An experimental test bed was designed to provide the highest accuracy attainable for salient visual cues in personal space. Optical alignment and user calibration were carefully performed. The test bed accommodated the full continuum of VE types and sensory modalities for comprehensive comparison studies. Experimental designs included two sets, each measuring depth perception and object interaction. The first set addressed the extreme end points of the Reality-Virtuality (R-V) continuum -- Immersive Virtual Environment (IVE) and Reality Environment (RE). This

  16. Multipolar interference for directed light emission.

    PubMed

    Hancu, Ion M; Curto, Alberto G; Castro-López, Marta; Kuttge, Martin; van Hulst, Niek F

    2014-01-08

    By directing light, optical antennas can enhance light-matter interaction and improve the efficiency of nanophotonic devices. Here we exploit the interference among the electric dipole, quadrupole, and magnetic dipole moments of a split-ring resonator to experimentally realize a compact directional optical antenna. This single-element antenna design robustly directs emission even when covered with nanometric emitters at random positions, outperforming previously demonstrated nanoantennas with a bandwidth of 200 nm and a directivity of 10.1 dB from a subwavelength structure. The advantages of this approach bring directional optical antennas closer to practical applications.

  17. Graphlet-based Characterization of Directed Networks

    NASA Astrophysics Data System (ADS)

    Sarajlić, Anida; Malod-Dognin, Noël; Yaveroğlu, Ömer Nebil; Pržulj, Nataša

    2016-10-01

    We are flooded with large-scale, dynamic, directed, networked data. Analyses requiring exact comparisons between networks are computationally intractable, so new methodologies are sought. To analyse directed networks, we extend graphlets (small induced sub-graphs) and their degrees to directed data. Using these directed graphlets, we generalise state-of-the-art network distance measures (RGF, GDDA and GCD) to directed networks and show their superiority for comparing directed networks. Also, we extend the canonical correlation analysis framework that enables uncovering the relationships between the wiring patterns around nodes in a directed network and their expert annotations. On directed World Trade Networks (WTNs), our methodology allows uncovering the core-broker-periphery structure of the WTN, predicting the economic attributes of a country, such as its gross domestic product, from its wiring patterns in the WTN for up-to ten years in the future. It does so by enabling us to track the dynamics of a country’s positioning in the WTN over years. On directed metabolic networks, our framework yields insights into preservation of enzyme function from the network wiring patterns rather than from sequence data. Overall, our methodology enables advanced analyses of directed networked data from any area of science, allowing domain-specific interpretation of a directed network’s topology.

  18. Determining wave direction using curvature parameters.

    PubMed

    de Queiroz, Eduardo Vitarelli; de Carvalho, João Luiz Baptista

    2016-01-01

    The curvature of the sea wave was tested as a parameter for estimating wave direction in the search for better results in estimates of wave direction in shallow waters, where waves of different sizes, frequencies and directions intersect and it is difficult to characterize. We used numerical simulations of the sea surface to determine wave direction calculated from the curvature of the waves. Using 1000 numerical simulations, the statistical variability of the wave direction was determined. The results showed good performance by the curvature parameter for estimating wave direction. Accuracy in the estimates was improved by including wave slope parameters in addition to curvature. The results indicate that the curvature is a promising technique to estimate wave directions.•In this study, the accuracy and precision of curvature parameters to measure wave direction are analyzed using a model simulation that generates 1000 wave records with directional resolution.•The model allows the simultaneous simulation of time-series wave properties such as sea surface elevation, slope and curvature and they were used to analyze the variability of estimated directions.•The simultaneous acquisition of slope and curvature parameters can contribute to estimates wave direction, thus increasing accuracy and precision of results.

  19. Graphlet-based Characterization of Directed Networks

    PubMed Central

    Sarajlić, Anida; Malod-Dognin, Noël; Yaveroğlu, Ömer Nebil; Pržulj, Nataša

    2016-01-01

    We are flooded with large-scale, dynamic, directed, networked data. Analyses requiring exact comparisons between networks are computationally intractable, so new methodologies are sought. To analyse directed networks, we extend graphlets (small induced sub-graphs) and their degrees to directed data. Using these directed graphlets, we generalise state-of-the-art network distance measures (RGF, GDDA and GCD) to directed networks and show their superiority for comparing directed networks. Also, we extend the canonical correlation analysis framework that enables uncovering the relationships between the wiring patterns around nodes in a directed network and their expert annotations. On directed World Trade Networks (WTNs), our methodology allows uncovering the core-broker-periphery structure of the WTN, predicting the economic attributes of a country, such as its gross domestic product, from its wiring patterns in the WTN for up-to ten years in the future. It does so by enabling us to track the dynamics of a country’s positioning in the WTN over years. On directed metabolic networks, our framework yields insights into preservation of enzyme function from the network wiring patterns rather than from sequence data. Overall, our methodology enables advanced analyses of directed networked data from any area of science, allowing domain-specific interpretation of a directed network’s topology. PMID:27734973

  20. Fluctuations along supersymmetric flat directions during inflation

    NASA Astrophysics Data System (ADS)

    Enqvist, Kari; Figueroa, Daniel G.; Rigopoulos, Gerasimos

    2012-01-01

    We consider a set of scalar fields, consisting of a single flat direction and one or several non-flat directions. We take our cue from the MSSM, considering separately D-flat and F-flat directions, but our results apply to any supersymmetric scenario containing flat directions. We study the field fluctuations during pure de Sitter inflation, following the evolution of the infrared modes by numerically solving the appropriate Langevin equations. We demonstrate that for the Standard Model U(1)Y, SU(2)L or SU(3)c gauge couplings, as well as for large enough Yukawa couplings, the fluctuations along the non-flat directions effectively block the fluctuations along the flat directions. The usual expected behaviour langlephi2rangleproptoN, with N the number of e-folds, may be strongly violated, depending on the coupling strengths. As a consequence, those cosmological considerations, which are derived assuming that during inflation flat directions fluctuate freely, should be revised.

  1. The persistence of directivity in small earthquakes

    USGS Publications Warehouse

    Boatwright, J.

    2007-01-01

    We derive a simple inversion of peak ground acceleration (PGA) or peak ground velocity (PGV) for rupture direction and rupture velocity and then test this inversion on the peak motions obtained from seven 3.5 ??? M ??? 4.1 earthquakes that occurred in two clusters in November 2002 and February 2003 near San Ramon, California. These clusters were located on two orthogonal strike-slip faults so that the events share the same approximate focal mechanism but not the same fault plane. Three earthquakes exhibit strong directivity, but the other four earthquakes exhibit relatively weak directivity. We use the residual PGAs and PGVs from the other six events to determine station corrections for each earthquake. The inferred rupture directions unambiguously identify the fault plane for the three earthquakes with strong directivity and for three of the four earthquakes with weak directivity. The events with strong directivity have fast rupture velocities (0.63????? v ??? 0.87??); the events with weak directivity either rupture more slowly (0.17????? v ???0.35??) or bilaterally. The simple unilateral inversion cannot distinguish between slow and bilateral ruptures: adding a bilateral rupture component degrades the fit of the rupture directions to the fault planes. By comparing PGAs from the events with strong and weak directivity, we show how an up-dip rupture in small events can distort the attenuation of peak ground motion with distance. When we compare the rupture directions of the earthquakes to the location of aftershocks in the two clusters, we find than almost all the aftershocks of the three earthquakes with strong directivity occur within 70?? of the direction of rupture.

  2. Flow direction determination of lava flows.

    NASA Technical Reports Server (NTRS)

    Smith, E. I.; Rhodes, R. C.

    1972-01-01

    The flow direction technique, previously applied to ash-flow sheets, can be used to determine direction of movement and locate eruptive centers for lava flows. The method provides statistically stronger and more consistent flow direction data for lava than ash-flow tuff. The accuracy and reliability of the technique was established on the porphyritic basaltic andesite of Mount Taylor, New Mexico, which erupted from a known center, the Mount Taylor Amphitheater. The technique was then applied to volcanic units with unknown sources: the John Kerr Peak Quartz Latite and mid-Tertiary andesite flows in the Mogollon Mountains, both in southwestern New Mexico. The flow direction technique indicated flow patterns and suggested source areas for each rock unit. In the Mogollon Mountains flow direction measurements were supported by independent directional criteria such as dips of cross beds, stratigraphic thickening, facies changes, and megascopic textures.-

  3. Directional emittance surface measurement system and process

    NASA Technical Reports Server (NTRS)

    Puram, Chith K. (Inventor); Daryabeigi, Kamran (Inventor); Wright, Robert (Inventor); Alderfer, David W. (Inventor)

    1994-01-01

    Apparatus and process for measuring the variation of directional emittance of surfaces at various temperatures using a radiometric infrared imaging system. A surface test sample is coated onto a copper target plate provided with selective heating within the desired incremental temperature range to be tested and positioned onto a precision rotator to present selected inclination angles of the sample relative to the fixed positioned and optically aligned infrared imager. A thermal insulator holder maintains the target plate on the precision rotator. A screen display of the temperature obtained by the infrared imager, and inclination readings are provided with computer calculations of directional emittance being performed automatically according to equations provided to convert selected incremental target temperatures and inclination angles to relative target directional emittance values. The directional emittance of flat black lacquer and an epoxy resin measurements obtained are in agreement with the predictions of the electromagnetic theory and with directional emittance data inferred from directional reflectance measurements made on a spectrophotometer.

  4. Direct conversion of algal biomass to biofuel

    DOEpatents

    Deng, Shuguang; Patil, Prafulla D; Gude, Veera Gnaneswar

    2014-10-14

    A method and system for providing direct conversion of algal biomass. Optionally, the method and system can be used to directly convert dry algal biomass to biodiesels under microwave irradiation by combining the reaction and combining steps. Alternatively, wet algae can be directly processed and converted to fatty acid methyl esters, which have the major components of biodiesels, by reacting with methanol at predetermined pressure and temperature ranges.

  5. Air breathing direct methanol fuel cell

    DOEpatents

    Ren, Xiaoming; Gottesfeld, Shimshon

    2002-01-01

    An air breathing direct methanol fuel cell is provided with a membrane electrode assembly, a conductive anode assembly that is permeable to air and directly open to atmospheric air, and a conductive cathode assembly that is permeable to methanol and directly contacting a liquid methanol source. Water loss from the cell is minimized by making the conductive cathode assembly hydrophobic and the conductive anode assembly hydrophilic.

  6. Direct methanol fuel cell for portable applications

    SciTech Connect

    Valdez, T.I.; Narayanan, S.R.; Frank, H.; Chun, W.

    1997-12-01

    A five cell direct methanol fuel cell stack has been developed at the Jet Propulsion Laboratory. Presently direct methanol fuel cell technology is being incorporated into a system for portable applications. Electrochemical performance and its dependence on flow rate and temperature for a five cell stack are presented. Water transport data, and water transport mechanisms for direct methanol fuel cells are discussed. Stack response to pulse loads has been characterized. Implications of stack performance and operating conditions on system design have been addressed.

  7. The far future of exoplanet direct characterization.

    PubMed

    Schneider, Jean; Léger, Alain; Fridlund, Malcolm; White, Glenn J; Eiroa, Carlos; Henning, Thomas; Herbst, Tom; Lammer, Helmut; Liseau, René; Paresce, Francesco; Penny, Alan; Quirrenbach, Andreas; Röttgering, Huub; Selsis, Franck; Beichman, Charles; Danchi, William; Kaltenegger, Lisa; Lunine, Jonathan; Stam, Daphne; Tinetti, Giovanna

    2010-01-01

    We describe future steps in the direct characterization of habitable exoplanets subsequent to medium and large mission projects currently underway and investigate the benefits of spectroscopic and direct imaging approaches. We show that, after third- and fourth-generation missions have been conducted over the course of the next 100 years, a significant amount of time will lapse before we will have the capability to observe directly the morphology of extrasolar organisms.

  8. Cellular Mechanisms of Transcranial Direct Current Stimulation

    DTIC Science & Technology

    2016-07-14

    AFRL-AFOSR-VA-TR-2016-0252 Cellular Mechanisms of Transcranial Direct Current Stimulation Marom Bikson RFCUNY - CITY COLLEGE CONVENT AVE & 138TH ST...2. REPORT TYPE Final 3. DATES COVERED (From - To) March 15, 2013 to March 14, 2016 4. TITLE AND SUBTITLE Cellular Mechanisms of Transcranial Direct ...ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT 13. SUPPLEMENTARY NOTES 14. ABSTRACT During transcranial Direct

  9. Ionization based multi-directional flow sensor

    DOEpatents

    Chorpening, Benjamin T.; Casleton, Kent H.

    2009-04-28

    A method, system, and apparatus for conducting real-time monitoring of flow (airflow for example) in a system (a hybrid power generation system for example) is disclosed. The method, system and apparatus measure at least flow direction and velocity with minimal pressure drop and fast response. The apparatus comprises an ion source and a multi-directional collection device proximate the ion source. The ion source is configured to generate charged species (electrons and ions for example). The multi-directional collection source is configured to determine the direction and velocity of the flow in real-time.

  10. NASA directives master list and index

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This handbook sets forth in two parts, Master List of Management Directives and Index to NASA Management Directives, the following information for the guidance of users of the NASA Management Directives System. Chapter 1 contains introductory information material on how to use this handbook. Chapter 2 is a complete master list of agencywide management directives, describing each directive by type, number, effective date, expiration date, title, and organization code of the office responsible for the directive. Chapter 3 includes a consolidated numerical list of all delegations of authority and a breakdown of such delegation by the office or center to which special authority is assigned. Chapter 4 sets forth a consolidated list of all NASA handbooks (NHB's) and important footnotes covering the control and ordering of such documents. Chapter 5 is a consolidated list of NASA management directives applicable to the Jet Propulsion Laboratory. Chapter 6 is a consolidated list of NASA regulations published in the Code of Federal Regulations. Chapter 7 is a consolidated list of NASA regulations published in Title 14 of the Code of Federal Regulations. Complementary manuals to the NASA Management Directives System are described in Chapter 8. The second part contains an in depth alphabetical index to all NASA management directives other than handbooks, most of which are indexed by titles only.

  11. Master list and index to NASA directives

    NASA Technical Reports Server (NTRS)

    1982-01-01

    All NASA management directives in force as of August 1, 1982 are listed by major subject headings showing number, effective data, title, responsible office, and distribution code. Delegations of authority in print by that date are listed numerically as well as by the installation or office to which special authority is assigned. Other consolidated lists show all management handbooks, directives applicable to the Jet Propulsion Laboratory, directions published in the Code of Federal Regulations, complementary manuals, and NASA safety standards. Distribution policies and instructions for ordering directives are included.

  12. Master list and index to NASA directives

    NASA Technical Reports Server (NTRS)

    1984-01-01

    All NASA management directives in force as of August 1, 1984 are listed by major subject headings showing number, effective date, title, responsible office, and distribution code. Delegations of authority in print by that date are listed numerically as well as by the installation or office to which special authority is assigned. Other consolidated lists show all management handbooks, directives applicable to the Jet Propulsion Laboratory, directives published in the Code of Federal Regulations, complementary manuals, and NASA safety standards. Distribution policies and instructions for ordering directives are included.

  13. Attentional capture by change in direct gaze.

    PubMed

    Yokoyama, Takemasa; Ishibashi, Kazuya; Hongoh, Yuki; Kita, Shinichi

    2011-01-01

    In three experiments, we examined whether change in direct gaze was better at capturing visuospatial attention than non-direct gaze change. Also, change in direct gaze can be categorised into two types: 'look toward', which means gaze changing to look toward observers, and 'look away', which means gaze changing to look away from observers. Thus, we also investigated which type of change in direct gaze was more effective in capturing visuospatial attention. Each experiment employed a change-detection task, and we compared detection accuracy between 'look away', 'look toward', and non-direct gaze-change conditions. In experiment 1, we found detection advantage for change in direct gaze relative to non-direct gaze change, and for 'look toward' compared with 'look away'. In experiment 2, we conducted control experiments to exclude possibilities of simple motion detection and geometrical factors of eyes, and confirm detection advantage in experiment 1 only occurred when the stimuli were processed as faces and gazes. In experiment 3, we manipulated the head deviation, but the results in experiment 1 persisted despite changes in head orientation. The findings establish that individuals are sensitive to change in direct relative to non-direct gaze change, and 'look toward' compared with 'look away'.

  14. Random versus directionally persistent cell migration

    PubMed Central

    Petrie, Ryan J.; Doyle, Andrew D.; Yamada, Kenneth M.

    2009-01-01

    Directional migration is an important component of cell motility. Although the basic mechanisms of random cell movement are well characterized, no single model explains the complex regulation of directional migration. Multiple factors operate at each step of cell migration to stabilize lamellipodia and maintain directional migration. Factors such as topography of the extracellular matrix, the cellular polarity machinery, receptor signalling, integrin trafficking and co-receptors, and actin–myosin contraction converge on regulation of the Rho family of GTPases and control of lamellipodial protrusions to promote directional migration. PMID:19603038

  15. Adaptation to direction statistics modulates perceptual discrimination.

    PubMed

    Price, Nicholas S C; Prescott, Danielle L

    2012-06-22

    Perception depends on the relative activity of populations of sensory neurons with a range of tunings and response gains. Each neuron's tuning and gain are malleable and can be modified by sustained exposure to an adapting stimulus. Here, we used a combination of human psychophysical testing and models of neuronal population decoding to assess how rapid adaptation to moving stimuli might change neuronal tuning and thereby modulate direction perception. Using a novel motion stimulus in which the direction changed every 10 ms, we demonstrated that 1,500 ms of adaptation to a distribution of directions was capable of modifying human psychophysical direction discrimination performance. Consistent with previous reports, we found perceptual repulsion following adaptation to a single direction. Notably, compared with a uniform adaptation condition in which all motion directions were equiprobable, discrimination was impaired after adaptation to a stimulus comprising only directions ± 30-60° from the discrimination boundary and enhanced after adaptation to the complementary range of directions. Thus, stimulus distributions can be selectively chosen to either impair or improve discrimination performance through adaptation. A neuronal population decoding model incorporating adaptation-induced repulsive shifts in direction tuning curves can account for most aspects of our psychophysical data; however, changes in neuronal gain are sufficient to account for all aspects of our psychophysical data.

  16. Flight directions of passerine migrants in daylight and darkness: A radar and direct visual study

    NASA Technical Reports Server (NTRS)

    Gauthreaux, S. A., Jr.

    1972-01-01

    The application of radar and visual techniques to determine the migratory habits of passerine birds during daylight and darkness is discussed. The effects of wind on the direction of migration are examined. Scatter diagrams of daytime and nocturnal migration track directions correlated with wind direction are presented. It is concluded that migratory birds will fly at altitudes where wind direction and migratory direction are nearly the same. The effects of cloud cover and solar obscuration are considered negligible.

  17. Direct numerical simulation of turbulent flows over superhydrophobic surfaces with gas pockets using linearized boundary conditions

    NASA Astrophysics Data System (ADS)

    Seo, Jongmin; Bose, Sanjeeb; Garcia-Mayoral, Ricardo; Mani, Ali

    2012-11-01

    Superhydrophobic surfaces are shown to be effective for surface drag reduction under laminar regime by both experiments and simulations (see for example, Ou and Rothstein, Phys. Fluids 17:103606, 2005). However, such drag reduction for fully developed turbulent flow maintaining the Cassie-Baxter state remains an open problem due to high shear rates and flow unsteadiness of turbulent boundary layer. Our work aims to develop an understanding of mechanisms leading to interface breaking and loss of gas pockets due to interactions with turbulent boundary layers. We take advantage of direct numerical simulation of turbulence with slip and no-slip patterned boundary conditions mimicking the superhydrophobic surface. In addition, we capture the dynamics of gas-water interface, by deriving a proper linearized boundary condition taking into account the surface tension of the interface and kinematic matching of interface deformation and normal velocity conditions on the wall. We will show results from our simulations predicting the dynamical behavior of gas pocket interfaces over a wide range of dimensionless surface tensions. Supported by the Office of Naval Research and the Kwanjeong Educational Scholarship Foundation.

  18. Perceptual learning of motion direction discrimination transfers to an opposite direction with TPE training.

    PubMed

    Zhang, Jun-Yun; Yang, Yu-Xiang

    2014-06-01

    Motion direction learning is known to be specific to the trained direction. However, in this study we used our recently developed TPE (training-plus-exposure) method to demonstrate that motion direction learning can transfer to an opposite direction. Specifically, we first replicated the strict direction specificity of motion direction learning with a group of moving dots. However, when the participants were exposed to the opposite direction in an irrelevant dot number discrimination task, either simultaneously with motion direction training or at a later time, but not in a reversed order, motion direction learning transferred to the opposite direction significantly and sometimes completely. These results suggest that motion direction learning may be a high-level process in which the brain learns the potentially transferrable rules of reweighting the motion direction inputs. However, we speculate that high-level learning may not functionally connect to sensory neurons that are tuned to other directions but are not stimulated during training, which leads to direction specificity. It is the stimulus exposure in TPE training that connects high-level learning to the exposed opposite direction to enable learning transfer.

  19. Head direction is coded more strongly than movement direction in a population of entorhinal neurons

    PubMed Central

    Raudies, Florian; Brandon, Mark P.; Chapman, G. William; Hasselmo, Michael E.

    2014-01-01

    The spatial firing pattern of entorhinal grid cells may be important for navigation. Many different computational models of grid cell firing use path integration based on movement direction and the associated movement speed to drive grid cells. However, the response of neurons to movement direction has rarely been tested, in contrast to multiple studies showing responses of neurons to head direction. Here, we analyzed the difference between head direction and movement direction during rat movement and analyzed cells recorded from entorhinal cortex for their tuning to movement direction. During foraging behavior, movement direction differs significantly from head direction. The analysis of neuron responses shows that only 5 out of 758 medial entorhinal cells show significant coding for both movement direction and head direction when evaluating periods of rat behavior with speeds above 10 cm/sec and ±30° angular difference between movement and head direction. None of the cells coded movement direction alone. In contrast, 21 cells in this population coded only head direction during behavioral epochs with these constraints, indicating much stronger coding of head direction in this population. This suggests that the movement direction signal required by most grid cell models may arise from other brain structures than the medial entorhinal cortex. PMID:25451111

  20. Head direction is coded more strongly than movement direction in a population of entorhinal neurons.

    PubMed

    Raudies, Florian; Brandon, Mark P; Chapman, G William; Hasselmo, Michael E

    2015-09-24

    The spatial firing pattern of entorhinal grid cells may be important for navigation. Many different computational models of grid cell firing use path integration based on movement direction and the associated movement speed to drive grid cells. However, the response of neurons to movement direction has rarely been tested, in contrast to multiple studies showing responses of neurons to head direction. Here, we analyzed the difference between head direction and movement direction during rat movement and analyzed cells recorded from entorhinal cortex for their tuning to movement direction. During foraging behavior, movement direction differs significantly from head direction. The analysis of neuron responses shows that only 5 out of 758 medial entorhinal cells show significant coding for both movement direction and head direction when evaluating periods of rat behavior with speeds above 10 cm/s and ±30° angular difference between movement and head direction. None of the cells coded movement direction alone. In contrast, 21 cells in this population coded only head direction during behavioral epochs with these constraints, indicating much stronger coding of head direction in this population. This suggests that the movement direction signal required by most grid cell models may arise from other brain structures than the medial entorhinal cortex. This article is part of a Special Issue entitled SI: Brain and Memory.

  1. 75 FR 15387 - Veterinary Feed Directive

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-29

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Parts 510, 514, and 558 Veterinary Feed Directive... relating to veterinary feed directive (VFD) drugs. FDA's VFD regulation, which became effective on January... CONTACT: Neal Bataller, Center for Veterinary Medicine (HFV-230), Food and Drug Administration,...

  2. DIRECT AMMONIA-AIR FUEL CELL.

    DTIC Science & Technology

    Experimental runs were conducted on direct ammonia fuel cells . Effects of temperature, composition, as well as run effect and block effect were...cells and to electrode flooding are discussed. Data on performance of complete laboratory direct ammonia-oxygen fuel cells are presented and discussed. (Author)

  3. Learning Words from Labeling and Directive Speech

    ERIC Educational Resources Information Center

    Callanan, Maureen A.; Akhtar, Nameera; Sussman, Lisa

    2014-01-01

    Despite the common intuition that labeling may be the best way to teach a new word to a child, systematic testing is needed of the prediction that children learn words better from labeling utterances than from directive utterances. Two experiments compared toddlers' label learning in the context of hearing words used in directive versus labeling…

  4. 77 FR 55163 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-07

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes... directive (AD) for certain Airbus Model A330-200, A330-300, A340-200, and A340- 300 series airplanes; and Model A340-541 airplanes and Model A340-642 airplanes. That NPRM proposed to require performing...

  5. 78 FR 46543 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-01

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-300 series airplanes and Model A340-200 and -300 series airplanes. This proposed AD was prompted by reports of...

  6. 78 FR 28159 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-14

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A300 series airplanes; Model A300 B4-600, B4-600R, and F4-600R series airplanes, and Model A300 C4-605R Variant F...

  7. Spectroscopy and Direct Products: Simpler yet Deeper

    ERIC Educational Resources Information Center

    Kettle, Sidney F. A.

    2010-01-01

    When irreducible representations are given in diagrammatic form, it is possible to show direct products pictorially. By giving a similar description of the electric vector associated with a light wave, group-theoretical selection rules (the requirement of a totally symmetric direct product) can also be shown in pictorial form. The [upsilon](CO)…

  8. 32 CFR 2800.2 - Guiding directives.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Guiding directives. 2800.2 Section 2800.2 National Defense Other Regulations Relating to National Defense OFFICE OF THE VICE PRESIDENT OF THE UNITED STATES SECURITY PROCEDURES § 2800.2 Guiding directives. (a) Executive Order 12065, June 28, 1978,...

  9. 32 CFR 2800.2 - Guiding directives.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Guiding directives. 2800.2 Section 2800.2 National Defense Other Regulations Relating to National Defense OFFICE OF THE VICE PRESIDENT OF THE UNITED STATES SECURITY PROCEDURES § 2800.2 Guiding directives. (a) Executive Order 12065, June 28, 1978,...

  10. 32 CFR 2800.2 - Guiding directives.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Guiding directives. 2800.2 Section 2800.2 National Defense Other Regulations Relating to National Defense OFFICE OF THE VICE PRESIDENT OF THE UNITED STATES SECURITY PROCEDURES § 2800.2 Guiding directives. (a) Executive Order 12065, June 28, 1978,...

  11. 32 CFR 2800.2 - Guiding directives.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Guiding directives. 2800.2 Section 2800.2 National Defense Other Regulations Relating to National Defense OFFICE OF THE VICE PRESIDENT OF THE UNITED STATES SECURITY PROCEDURES § 2800.2 Guiding directives. (a) Executive Order 12065, June 28, 1978,...

  12. 32 CFR 2800.2 - Guiding directives.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Guiding directives. 2800.2 Section 2800.2 National Defense Other Regulations Relating to National Defense OFFICE OF THE VICE PRESIDENT OF THE UNITED STATES SECURITY PROCEDURES § 2800.2 Guiding directives. (a) Executive Order 12065, June 28, 1978,...

  13. Direct Reading Instruction and the NYS ELA

    ERIC Educational Resources Information Center

    Jones-Carey, Margaret H.

    2013-01-01

    This study analyzed the impact of classroom based reading instruction ("direct instruction") on the standardized test scores of 6th grade students as measured by the New York State English Language Arts assessment (NYS ELA). It was hypothesized that the implementation of direct instruction in reading in grade 6 would improve NYS ELA…

  14. Hydroxyl-directed stereoselective diboration of alkenes.

    PubMed

    Blaisdell, Thomas P; Caya, Thomas C; Zhang, Liang; Sanz-Marco, Amparo; Morken, James P

    2014-07-02

    An alkoxide-catalyzed directed diboration of alkenyl alcohols is described. This reaction occurs in a stereoselective fashion and is demonstrated with cyclic and acyclic homoallylic and bishomoallylic alcohol substrates. After oxidation, the reaction generates 1,2-diols such that the process represents a method for the stereoselective directed dihydroxylation of alkenes.

  15. 77 FR 37797 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-25

    ...-059-AD; Amendment 39-17092; AD 2012-12-12] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes.... SUMMARY: We are adopting a new airworthiness directive (AD) for all Airbus Model A330-200 series airplanes; Airbus Model A330-200 Freighter series airplanes; Airbus Model A330-300 series airplanes; Airbus...

  16. 78 FR 7261 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-01

    ...-070-AD; Amendment 39-17332; AD 2013-02-11] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes.... SUMMARY: We are adopting a new airworthiness directive (AD) for all Airbus Model A310-203 airplanes. This... Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, WA 98057-3356; telephone (425) 227-2125; fax...

  17. Circular Data Images for Directional Data

    NASA Technical Reports Server (NTRS)

    Morpet, William J.

    2004-01-01

    Directional data includes vectors, points on a unit sphere, axis orientation, angular direction, and circular or periodic data. The theoretical statistics for circular data (random points on a unit circle) or spherical data (random points on a unit sphere) are a recent development. An overview of existing graphical methods for the display of directional data is given. Cross-over occurs when periodic data are measured on a scale for the measurement of linear variables. For example, if angle is represented by a linear color gradient changing uniformly from dark blue at -180 degrees to bright red at +180 degrees, the color image will be discontinuous at +180 degrees and -180 degrees, which are the same location. The resultant color would depend on the direction of approach to the cross-over point. A new graphical method for imaging directional data is described, which affords high resolution without color discontinuity from "cross-over". It is called the circular data image. The circular data image uses a circular color scale in which colors repeat periodically. Some examples of the circular data image include direction of earth winds on a global scale, rocket motor internal flow, earth global magnetic field direction, and rocket motor nozzle vector direction vs. time.

  18. Stigma and Schizophrenia: Directions in Student Training

    ERIC Educational Resources Information Center

    Mason, Susan E.; Miller, Rachel

    2006-01-01

    The persistence of stigma related to schizophrenia is addressed as a continuing challenge for social work students working in mental health. Student education is best grounded in direct clinical work with clients in conjunction with field supervision and classroom education. Through direct practice in individual and group sessions, students learn…

  19. 47 CFR 216.1 - NCS Directives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false NCS Directives. 216.1 Section 216.1 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL NATIONAL COMMUNICATIONS... Directives, which establish and implement organizational responsibilities, authorities, policies...

  20. 47 CFR 216.1 - NCS Directives.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false NCS Directives. 216.1 Section 216.1 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL NATIONAL COMMUNICATIONS... Directives, which establish and implement organizational responsibilities, authorities, policies...

  1. 47 CFR 216.1 - NCS Directives.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false NCS Directives. 216.1 Section 216.1 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL NATIONAL COMMUNICATIONS... Directives, which establish and implement organizational responsibilities, authorities, policies...

  2. 47 CFR 216.1 - NCS Directives.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false NCS Directives. 216.1 Section 216.1 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL NATIONAL COMMUNICATIONS... Directives, which establish and implement organizational responsibilities, authorities, policies...

  3. 47 CFR 216.1 - NCS Directives.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false NCS Directives. 216.1 Section 216.1 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL NATIONAL COMMUNICATIONS... Directives, which establish and implement organizational responsibilities, authorities, policies...

  4. NASA directives: Master list and index

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This Handbook sets forth in two parts the following information for the guidance of users of the NASA Management Directives System. Chapter 1 contains introductory information material on how to use this Handbook. Chapter 2 is a complete master list of Agency-wide management directives, describing each directive by type, number, effective date, expiration date, title, and organization code of the office responsible for the directive. Chapter 3 includes a consolidated numerical list of all delegations of authority and a breakdown of such delegation by the office of Installation to which special authority is assigned. Chapter 4 sets forth a consolidated list of all NASA Handbooks (NHB's) and important footnotes covering the control and ordering of such documents. Chapter 5 is a consolidated list of NASA management directives applicable to the Jet Propulsion Laboratory. Chapter 6 is a consolidated list of NASA management directives published in the code of Federal Regulations. Complementary manuals to the NASA Management Directives System are described in Chapter 7. Part B contains an in-depth alphabetical index to all NASA management directives other than Handbooks.

  5. On the Strong Direct Summand Conjecture

    ERIC Educational Resources Information Center

    McCullough, Jason

    2009-01-01

    In this thesis, our aim is the study the Vanishing of Maps of Tor Conjecture of Hochster and Huneke. We mainly focus on an equivalent characterization called the Strong Direct Summand Conjecture, due to N. Ranganathan. Our results are separated into three chapters. In Chapter 3, we prove special cases of the Strong Direct Summand Conjecture in…

  6. 50 CFR 18.87 - Direct testimony.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Direct testimony. 18.87 Section 18.87 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED... PLANTS (CONTINUED) MARINE MAMMALS Notice and Hearing on Section 103 Regulations § 18.87 Direct...

  7. Replicating Direction Service: A Hand Book.

    ERIC Educational Resources Information Center

    Drake Univ., Des Moines, IA. Midwest Regional Resource Center.

    The handbook details planning and development of a direction service center (DSC), an agency which matches the needs of handicapped persons with appropriate services. A replication sequence, based upon practices of the Jackson County, Missouri, Direction Service Center, is discussed for the following six areas: development of a resource…

  8. 19 CFR 351.509 - Direct taxes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 3 2013-04-01 2013-04-01 false Direct taxes. 351.509 Section 351.509 Customs... Identification and Measurement of Countervailable Subsidies § 351.509 Direct taxes. (a) Benefit—(1) Exemption or remission of taxes. In the case of a program that provides for a full or partial exemption or remission of...

  9. 19 CFR 351.509 - Direct taxes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 3 2014-04-01 2014-04-01 false Direct taxes. 351.509 Section 351.509 Customs... Identification and Measurement of Countervailable Subsidies § 351.509 Direct taxes. (a) Benefit—(1) Exemption or remission of taxes. In the case of a program that provides for a full or partial exemption or remission of...

  10. 19 CFR 351.509 - Direct taxes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Direct taxes. 351.509 Section 351.509 Customs... Identification and Measurement of Countervailable Subsidies § 351.509 Direct taxes. (a) Benefit—(1) Exemption or remission of taxes. In the case of a program that provides for a full or partial exemption or remission of...

  11. 19 CFR 351.509 - Direct taxes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 3 2012-04-01 2012-04-01 false Direct taxes. 351.509 Section 351.509 Customs... Identification and Measurement of Countervailable Subsidies § 351.509 Direct taxes. (a) Benefit—(1) Exemption or remission of taxes. In the case of a program that provides for a full or partial exemption or remission of...

  12. 19 CFR 351.509 - Direct taxes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 3 2011-04-01 2011-04-01 false Direct taxes. 351.509 Section 351.509 Customs... Identification and Measurement of Countervailable Subsidies § 351.509 Direct taxes. (a) Benefit—(1) Exemption or remission of taxes. In the case of a program that provides for a full or partial exemption or remission of...

  13. Direct fired absorption machine flue gas recuperator

    DOEpatents

    Reimann, Robert C.; Root, Richard A.

    1985-01-01

    A recuperator which recovers heat from a gas, generally the combustion gas of a direct-fired generator of an absorption machine. The recuperator includes a housing with liquid flowing therethrough, the liquid being in direct contact with the combustion gas for increasing the effectiveness of the heat transfer between the gas and the liquid.

  14. SDR (Systems Directed Reading): An Overview.

    ERIC Educational Resources Information Center

    Baugo Community Schools, Elkhart, IN.

    The objective of this project for kindergarten through fifth grade is to interest public and private educational institutions in the systematization of elementary school reading programs. Facets of Systems Directed Reading (SDR) include the use of a differentiated staffing pattern; experienced language arts unit leaders guiding and directing all…

  15. 28 CFR 35.139 - Direct threat.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Direct threat. 35.139 Section 35.139 Judicial Administration DEPARTMENT OF JUSTICE NONDISCRIMINATION ON THE BASIS OF DISABILITY IN STATE AND LOCAL GOVERNMENT SERVICES General Requirements § 35.139 Direct threat. (a) This part does not require...

  16. 28 CFR 35.139 - Direct threat.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Direct threat. 35.139 Section 35.139 Judicial Administration DEPARTMENT OF JUSTICE NONDISCRIMINATION ON THE BASIS OF DISABILITY IN STATE AND LOCAL GOVERNMENT SERVICES General Requirements § 35.139 Direct threat. (a) This part does not require...

  17. 19 CFR 10.193 - Imported directly.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... control of the customs authority of the intermediate country; (2) Did not enter into the commerce of the... Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... directly. To qualify for treatment under the CBI, an article shall be imported directly from a...

  18. Self-Directed Thinking in the Curriculum.

    ERIC Educational Resources Information Center

    Dirkes, M. Ann

    1988-01-01

    Gifted students can learn to direct their thinking to maximize learning and creative production. They do this by stating what they intend to do, choosing strategies and appropriate conditions for thinking, and self-monitoring. The article describes techniques for developing self-directed thinking and applies these techniques to a class assignment.…

  19. Planar antenna system for direction finding

    NASA Astrophysics Data System (ADS)

    Mardale, Iulia-Cezara; Cocias, Gabriela; Dumitrascu, Ana; Tamas, Razvan; Berescu, Serban

    2015-02-01

    Applications of direction finding techniques include detection and localization of pulsed electromagnetic sources. This paper presents the design and analysis of a planar antenna system for direction finding. Our proposed system includes 4 hybrid couplers that generate 900 shifted signals, 2 crossover couplers also known as 0dB couplers, two 450 phase shifters, two 00 phase shifters and 4 patch antennas.

  20. Direct Instruction News: Effective School Practices, 2003.

    ERIC Educational Resources Information Center

    Tarver, Sara G., Ed.

    2003-01-01

    The mission of the Association for Direct Instruction is to promote the improvement of effective educational methods. This journal, "Direct Instruction News," is their publication. The Spring 2003 (Volume 3, Number 1) contains the following articles: "Implementing DI Successfully" (Sara G. Tarver); "Textbooks: What?"…

  1. Encoding Direction when Interpreting Proximal Terms

    ERIC Educational Resources Information Center

    Ashley, Aaron; Carlson, Laura A.

    2007-01-01

    The location of an object is often described by spatially relating it to a known landmark. The spatial terms used in such descriptions can provide various types of information. For example, projective terms such as "above" indicate direction but not distance, whereas proximal terms such as "near" indicate distance but not direction. Previous…

  2. Determining Directions of Ultrasound in Solids

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R.; Roth, Don J.

    1987-01-01

    Ultrasound shadows cast by grooves. Improved method for determining direction of ultrasound in materials is shadow method using Scanning laser acoustic microscopy (SLAM). Direction of ultrasound calculated from dimensions of groove and portion of surface groove shields from ultrasound. Method has variety of applications in nontraditional quality-control applications.

  3. Directional Communication in Evolved Multiagent Teams

    DTIC Science & Technology

    2013-06-10

    only a fraction of the observable state of the environment. In such tasks, communication facilitates sharing information among team members to...architecture is becoming increasingly important for evolving autonomous multiagent systems. Directional reception of signals, a design feature of communication ...Title ABSTRACT How to best design a communication architecture is becoming increasingly important for evolving autonomous multiagent systems. Directional

  4. Direct Job Creation: Potentials and Realities.

    ERIC Educational Resources Information Center

    Haveman, Robert H.

    Measures to directly create jobs have begun to occupy an important position in American economic policies. Most of these measures involve direct public service programs and employment subsidies. This paper explores the reasons for the emergence of such programs and notes that the economic rationale for these measures suggests a substantial…

  5. Statewide Direct Writing Assessment in California.

    ERIC Educational Resources Information Center

    Peckham, Irvin

    California has provided other states with an example of how not to assess student writing and has initiated a new direction in the statewide assessment of student writing achievement, a direction designed to influence writing instruction positively. Before 1987, the California Assessment Program (CAP) limited English skills assessment to multiple…

  6. Gaze Direction Detection in Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Forgeot d'Arc, Baudouin; Delorme, Richard; Zalla, Tiziana; Lefebvre, Aline; Amsellem, Frédérique; Moukawane, Sanaa; Letellier, Laurence; Leboyer, Marion; Mouren, Marie-Christine; Ramus, Franck

    2017-01-01

    Detecting where our partners direct their gaze is an important aspect of social interaction. An atypical gaze processing has been reported in autism. However, it remains controversial whether children and adults with autism spectrum disorder interpret indirect gaze direction with typical accuracy. This study investigated whether the detection of…

  7. A Response to "New Direction for CCBD?"

    ERIC Educational Resources Information Center

    Colvin, Geoff

    2011-01-01

    The author is pleased to see that the future directions of the Council for Children with Behavioral Disorders (CCBD) are being addressed. The celebration of the 50th birthday of the inception of CCBD has set the occasion to carefully examine the status quo of the organization and to set future directions, as appropriate. The authors of "New…

  8. 19 CFR 18.42 - Direct exportation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Direct exportation. 18.42 Section 18.42 Customs... TRANSPORTATION IN BOND AND MERCHANDISE IN TRANSIT Merchandise Not Otherwise Subject to Customs Control Exported Under Cover of A Tir Carnet § 18.42 Direct exportation. At the port of exportation, the container...

  9. Symbolic transfer entropy: inferring directionality in biosignals.

    PubMed

    Staniek, Matthäus; Lehnertz, Klaus

    2009-12-01

    Inferring directional interactions from biosignals is of crucial importance to improve understanding of dynamical interdependences underlying various physiological and pathophysiological conditions. We here present symbolic transfer entropy as a robust measure to infer the direction of interactions between multidimensional dynamical systems. We demonstrate its performance in quantifying driver-responder relationships in a network of coupled nonlinear oscillators and in the human epileptic brain.

  10. 30 CFR 556.71 - Directional drilling.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Directional drilling. 556.71 Section 556.71 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF... Directional drilling. In accordance with an approved exploration plan or development and production plan,...

  11. 30 CFR 556.71 - Directional drilling.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Directional drilling. 556.71 Section 556.71 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF... Directional drilling. In accordance with an approved exploration plan or development and production plan,...

  12. 30 CFR 556.71 - Directional drilling.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Directional drilling. 556.71 Section 556.71 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF... Directional drilling. In accordance with an approved exploration plan or development and production plan,...

  13. Direct reading of electrocardiograms and respiration rates

    NASA Technical Reports Server (NTRS)

    Wise, J. P.

    1969-01-01

    Technique for reading heart and respiration rates is more accurate and direct than the previous method. Index of a plastic calibrated card is aligned with a point on the electrocardiogram. Complexes are counted as indicated on the card and heart or respiration rate is read directly from the appropriate scale.

  14. 5 CFR 330.402 - Direct recruitment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Direct recruitment. 330.402 Section 330.402 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RECRUITMENT, SELECTION, AND PLACEMENT (GENERAL) Positions Restricted to Preference Eligibles § 330.402 Direct...

  15. 5 CFR 330.402 - Direct recruitment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Direct recruitment. 330.402 Section 330.402 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RECRUITMENT, SELECTION, AND PLACEMENT (GENERAL) Positions Restricted to Preference Eligibles § 330.402 Direct...

  16. Directional Excitatory Input to Direction-Selective Ganglion Cells in the Rabbit Retina.

    PubMed

    Percival, Kumiko A; Venkataramani, Sowmya; Smith, Robert G; Rowland Taylor, W

    2017-03-14

    Directional responses in retinal ganglion cells are generated in large part by direction-selective release of GABA from starburst amacrine cells onto direction-selective ganglion cells (DSGCs). The excitatory inputs to DSGCs are also widely reported to be direction-selective, however, recent evidence suggests that glutamate release from bipolar cells is not directional, and directional excitation seen in patch-clamp analyses may be an artifact resulting from incomplete voltage control. Here we test this voltage-clamp-artifact hypothesis in recordings from 62 On-Off DSGCs in the rabbit retina. The strength of the directional excitatory signal varies considerably across the sample of cells, but is not correlated with the strength of directional inhibition, as required for a voltage-clamp artifact. These results implicate additional mechanisms in generating directional excitatory inputs to DSGCs. This article is protected by copyright. All rights reserved.

  17. Deriving directions through procedural task analysis.

    PubMed

    Yuen, H K; D'Amico, M

    1998-01-01

    Task analysis is one of the essential components of activity analysis. Procedural task analysis involves breaking down an activity into a sequence of steps. Directions are the sequence of steps resulting from the task analysis (i.e., the product of the task analysis). Directions become a guide for caregivers or trainers use in teaching clients a specific skill. However, occupational therapy students often have difficulty in writing directions that are clear enough for caregivers or trainers to carry out. Books on activity analysis only provide examples of directions without giving guidelines on how to perform the writing process. The purposes of this paper are to describe the process of procedural task analysis and to provide a guideline for writing steps of directions.

  18. Physical limits on cellular directional mechanosensing

    NASA Astrophysics Data System (ADS)

    Bouffanais, Roland; Sun, Jianmin; Yue, Dick K. P.

    2013-05-01

    Many eukaryotic cells are able to perform directional mechanosensing by directly measuring minute spatial differences in the mechanical stress on their membranes. Here, we explore the limits of a single mechanosensitive channel activation using a two-state double-well model for the gating mechanism. We then focus on the physical limits of directional mechanosensing by a single cell having multiple mechanosensors and subjected to a shear flow inducing a nonuniform membrane tension. Our results demonstrate that the accuracy in sensing the mechanostimulus direction not only increases with cell size and exposure to a signal, but also grows for cells with a near-critical membrane prestress. Finally, the existence of a nonlinear threshold effect, fundamentally limiting the cell's ability to effectively perform directional mechanosensing at a low signal-to-noise ratio, is uncovered.

  19. Novel Random Mutagenesis Method for Directed Evolution.

    PubMed

    Feng, Hong; Wang, Hai-Yan; Zhao, Hong-Yan

    2017-01-01

    Directed evolution is a powerful strategy for gene mutagenesis, and has been used for protein engineering both in scientific research and in the biotechnology industry. The routine method for directed evolution was developed by Stemmer in 1994 (Stemmer, Proc Natl Acad Sci USA 91, 10747-10751, 1994; Stemmer, Nature 370, 389-391, 1994). Since then, various methods have been introduced, each of which has advantages and limitations depending upon the targeted genes and procedure. In this chapter, a novel alternative directed evolution method which combines mutagenesis PCR with dITP and fragmentation by endonuclease V is described. The kanamycin resistance gene is used as a reporter gene to verify the novel method for directed evolution. This method for directed evolution has been demonstrated to be efficient, reproducible, and easy to manipulate in practice.

  20. Direct-to-consumer advertising of pharmaceuticals.

    PubMed

    Gellad, Ziad F; Lyles, Kenneth W

    2007-06-01

    Since the US Food and Drug Administration (FDA) released new guidelines on broadcast direct-to-consumer advertising in 1997, the prevalence of direct-to-consumer advertising of prescription drugs has increased exponentially. The impact on providers, patients, and the health care system is varied and dynamic, and the rapid changes in the last several years have markedly altered the health care landscape. To continue providing optimal medical care, physicians and other health care providers must be able to manage this influence on their practice, and a more thorough understanding of this phenomenon is an integral step toward this goal. This review will summarize the history of direct-to-consumer drug advertisements and the current regulations governing them. It will summarize the evidence concerning the impact of direct-to-consumer advertising on the public, providers, and the health care system, and conclude with observations regarding the future of direct-to-consumer advertising.