The Martian polar caps: Stability and water transport at low obliquities

Science.gov (United States)

Henderson, B. G.; Jakosky, B. M.

1992-01-01

The seasonal cycle of water on Mars is regulated by the two polar caps. In the winter hemisphere, the seasonal CO2 deposits at a temperature near 150 K acts as a cold trap to remove water vapor from the atmosphere. When summer returns, water is pumped back into the atmosphere by a number of mechanisms, including release from the receding CO2 frost, diffusion from the polar regolith, and sublimation from a water-ice residual cap. These processes drive an exchange of water vapor between the polar caps that helps shape the Martian climate. Thus, understanding the behavior of the polar caps is important for interpreting the Martian climate both now and at other epochs. Mars' obliquity undergoes large variations over large time scales. As the obliquity decreases, the poles receive less solar energy so that more CO2 condenses from the atmosphere onto the poles. It has been suggested that permanent CO2 condenses from the atmosphere onto the poles. It has been suggested that permanent CO2 caps might form at the poles in response to a feedback mechanism existing between the polar cap albedo, the CO2 pressure, and the dust storm frequency. The year-round presence of the CO2 deposits would effectively dry out the atmosphere, while diffusion of water from the regolith would be the only source of water vapor to the atmosphere. We have reviewed the CO2 balance at low obliquity taking into account the asymmetries which make the north and south hemispheres different. Our analysis linked with a numerical model of the polar caps leads us to believe that one summertime cap will always lose its CO2 cover during a Martian year, although we cannot predict which cap this will be. We conclude that significant amounts of water vapor will sublime from the exposed cap during summer, and the Martian atmosphere will support an active water cycle even at low obliquity.

The evolution of polar caps in magnetic cataclysmic variables

International Nuclear Information System (INIS)

Frank, J.; Chanmugam, G.

1986-01-01

A simple analysis of the evolution of the size of the magnetic polar cap in accreting white dwarfs is made on the basis of current theories of the secular evolution of magnetic cataclysmic variables. For white dwarfs with dipolar fields it is shown that the size of the polar cap in DQ Her binaries is larger than in AM Her binaries. The size of the former is, however, smaller than deduced from interpretation of their X-ray light curves, while that of the latter is in rough agreement. If the dwarf contains an aligned magnetic quadrupole the size of the polar caps of the DQ Her binaries is significantly increased. Magnetic field decay of the quadrupole moment in the older AM Her binaries implies that their fields are predominantly dipolar. (author)

Polar cap contraction and expansion during a period of substorms

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Aikio, Anita; Pitkänen, Timo; Honkonen, Ilja; Palmroth, Minna; Amm, Olaf

We have studied the variations in the polar cap area and related parameters during a period of four substorms on February 18, 2004, following an extended quiet period. The measurements were obtained by the EISCAT incoherent scatter radars, MIRACLE magnetometers, Geotail and solar wind satellites. In addition, the event is modeled by the GUMICS-4 MHD simulation. By using the measured and modeled data, the dayside and nightside reconnection voltages are calculated. The results show a good general agreement in the polar cap boundary (PCB) location as estimated by the EISCAT radars and the GUMICS simulation. Deviations are found, too, like shorter durations of expansion phases in the simulation. Geotail measurements of the inclination angle of the magnetic field in the tail (Xgsm= -22 Re) agree with the PCB latitude variations measured by EISCAT at a different MLT. We conclude that a large polar cap corresponds to a stretched tail configuration in the near-Earth tail and a small polar cap to a more dipolar configuration. The substorm onsets took place during southward IMF. A specific feature is that the substorm expansion phases were not associated with significant contractions of the polar cap. Even though nightside reconnection voltages started to increase during expansion phases, maximum closure of open flux took place in the recovery phases. We shortly discuss implications of the observation to the definition of the recovery phase.

Convection flow structure in the central polar cap

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Bristow, W. A.

2017-12-01

A previous study of spatially averaged flow velocity in the central polar cap [Bristow et al., 2015] observed under steady IMF conditions found that it was extremely rare for the average to exceed 850 m/s (less than 0.2 % of the time). Anecdotally, however it is not uncommon to observe line-of-sight velocities in excess of 100 m/s in the McMurdo radar field of view directly over the magnetic pole. This discrepancy motivated this study, which examines the conditions under which high-velocity flows are observed at latitudes greater than 80° magnetic latitude. It was found that highly structured flows are common in the central polar cap, which leads to the flow within regions to have significant deviation from the average. In addition, the high-speed flow regions are usually directed away from the earth-sun line. No specific set of driving conditions was identified to be associated with high-speed flows. The study did conclude that 1)Polar cap velocities are generally highly structured. 2)Flow patterns typically illustrate narrow channels, vortical flow regions, and propagating features. 3) Persistent waves are a regular occurrence. 3)Features are observed to propagate from day side to night side, and from night side to day side.. 4)Convection often exhibits significant difference between the two hemispheres. And 5)About 10% of the time the velocity somewhere in the cap exceeds 1 Km/s The presentation will conclude with a discussion of the physical reasons for the flow structure. Bristow, W. A., E. Amata, J. Spaleta, and M. F. Marcucci (2015), Observations of the relationship between ionospheric central polar cap and dayside throat convection velocities, and solar wind/IMF driving, J. Geophys. Res. Space Physics, 120, doi:10.1002/2015JA021199.

Pair Cascades and Deathlines in Magnetic Fields with Offset Polar Caps

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Harding, Alice K.; Muslimov, Alex G.

2012-01-01

We present results of electron-positron pair cascade simulations in a dipole magnetic field whose polar cap is offset from the dipole axis. In such a field geometry, the polar cap is displaced a small fraction of the neutron star radius from the star symmetry axis and the field line radius of curvature is modified. Using the modified parallel electric field near the offset polar cap, we simulate pair cascades to determine the pair deathlines and pair multiplicities as a function of the offset. We find that the pair multiplicity can change dr;unatically with a modest offset, with a significant increase on one side of the polar cap. Lower pair deathlines allow a larger fraction of the pulsar population, that include old and millisecond pulsars, to produce cascades with high multiplicity. The results have some important implications for pulsar particle production, high-energy emission and cosmic-ray contribution.

Penetration of geomagnetic pulsations from one polar cao cap to the other one

International Nuclear Information System (INIS)

Mal'tsev, Yu.P.; Lyatskij, V.B.

1982-01-01

A theoretical study is made of penetration of geomagnetic pulsations, excited in one polar cap in the region of open field lines, into the other one. The geomagnetic pulsations excited in a polar cap in the region of open field lines are also observed in the opposite polar cap. This is connected with the flow of ionospheric perturbation currents from one hemisphere to another over the boundary of the region with closed magnetic lines. In case of long-period oscillations under symmetrical conditions, both in the north and south polar caps, the ionospheric effect of the opposite hemisphere results in the fact that the electrical currents flowing from a source to the polar cap boundary grow 1.5 times as high. In case of short-period oscillations a portion of longitudinal current flowing between the hemispheres is branched away for polarization currents. As a result, the electrical field and currents in the ionosphere of the opposite hemisphere can substantially decrease as compared to the long-period oscillations

DMSP optical and electron measurements in the vicinity of polar cap arcs

International Nuclear Information System (INIS)

Hardy, D.A.; Burke, W.J.; Gussenhoven, M.S.

1982-01-01

We have completed an extensive analysis of the electron and optical data from the DMSP satellites for an external period of polar cap arc occurrences on December 12, 1977. The polar cap arcs are observed in three distinct intervals in a period of quieting after a time of intense substorm activity. The observation of polar cap arcs is associated with the admittance of large and variable fluxes of low-energy electrons into a major portion of both the northern and southern hemisphere polar caps. These fluxes fall into the following categories: First, nearly Maxwellian distributions of electrons with temperatures between 50 eV and 200 eV and number densities varying from 0.03/cm 3 to 4/cm 3 . The highest densities are found at the poleward boundary of the diffuse aurorae and near the visible polar cap arcs. The lowest densities are associated with the polar rain. Second, distributions of electrons peaked between 50 eV and 200 eV. These distributions result from accelertion of the cold Maxwellian distribution through a potential of 50 to 200 V without any heating of the electrons. Third, distributions of electrons displaying two populations; an intense low-energy component with a temperature of approx.20 eV and a much weaker high-energy component with a temperature of 180 eV. We interpret such distributions as evidence of direct admittance of magnetosheath electrons into the polar cap. Fourth,, distributions of electrons peaked at approx.1 keV. These distributions produce the visible arcs. They result from the acceleration of a two-component electron population with temperatures of 100 and 350 eV through a potential drop of approx.750 V

Substorms and polar cap convection: the 10 January 2004 interplanetary CME case

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Y. Andalsvik

2012-01-01

Full Text Available The expansion-contraction model of Dungey cell plasma convection has two different convection sources, i.e. reconnections at the magnetopause and in the magnetotail. The spatial-temporal structure of the nightside source is not yet well understood. In this study we shall identify temporal variations in the winter polar cap convection structure during substorm activity under steady interplanetary conditions. Substorm activity (electrojets and particle precipitations is monitored by excellent ground-satellite DMSP F15 conjunctions in the dusk-premidnight sector. We take advantage of the wide latitudinal coverage of the IMAGE chain of ground magnetometers in Svalbard – Scandinavia – Russia for the purpose of monitoring magnetic deflections associated with polar cap convection and substorm electrojets. These are augmented by direct observations of polar cap convection derived from SuperDARN radars and cross-track ion drift observations during traversals of polar cap along the dusk-dawn meridian by spacecraft DMSP F13. The interval we study is characterized by moderate, stable forcing of the magnetosphere-ionosphere system (EKL = 4.0–4.5 mV m−1; cross polar cap potential (CPCP, Φ (Boyle = 115 kV during Earth passage of an interplanetary CME (ICME, choosing an 4-h interval where the magnetic field pointed continuously south-west (Bz By By polarity of the ICME magnetic field, a clear indication of a nightside source.

The thermospheric effects of a rapid polar cap expansion

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D. W. Idenden

Full Text Available In a previous publication we used results from a coupled thermosphere-ionosphere-plasmasphere model to illustrate a new mechanism for the formation of a large-scale patch of ionisation arising from a rapid polar cap expansion. Here we describe the thermospheric response to that polar cap expansion, and to the ionospheric structure produced. The response is dominated by the energy and momentum input at the dayside throat during the expansion phase itself. These inputs give rise to a large-scale travelling atmospheric disturbance (TAD that propagates both antisunward across the polar cap and equatorward at speeds much greater than both the ion drifts and the neutral winds. We concentrate only on the initially poleward travelling disturbance. The disturbance is manifested in the neutral temperature and wind fields, the height of the pressure level surfaces and in the neutral density at fixed heights. The thermospheric effects caused by the ionospheric structure produced during the expansion are hard to discern due to the dominating effects of the TAD.

Key words. Ionosphere (ionosphere · atmosphere interaction; modeling and forecasting; plasma convection.

Simultaneous observations of sun-aligned polar cap arcs in both hemispheres by EXOS-C and viking

International Nuclear Information System (INIS)

Obara, T.; Kitayama, M.; Mukai, T.; Kaya, N.; Murphree, J.S.; Cogger, L.L.

1988-01-01

On September 25, 1986, the EXOS-C satellite traversed an intense electron precipitation in the southern polar cap, while the Viking satellite simultaneously obtained image data of the polar cap arc in the northern hemisphere. The energy spectrum of the precipitation, measured by instrumentation aboard EXOS-C, was very similar to that of adjacent (typical) auroral arcs, and the precipitation in the southern polar cap was observed in the same local time sector in which the arc was found in the northern polar cap. Observations seem to support the view that the polar cap arc occurs on closed field lines and is conjugate in both hemispheres. copyright American Geophysical Union 1988

Polar cap particle precipitation and aurora: Review and commentary

Science.gov (United States)

Newell, Patrick T.; Liou, Kan; Wilson, Gordon R.

2009-02-01

Polar rain has a beautiful set of symmetry properties, individually established, but not previously discussed collectively, which can be organized by a single unifying principle. The key polar rain properties are favored hemisphere (controlled by the interplanetary magnetic field Bx), dawn/dusk gradient (IMF By), merging rate (IMF Bz or more generally d[Phi]MP/dt), nightside/dayside gradient, and seasonal effect. We argue that all five properties involve variants on a single theme: the further downstream a field line exits the magnetosphere (or less directly points toward the solar wind electron heat flux), the weaker the polar rain. This effect is the result of the requirements of charge quasi-neutrality, and because the ion thermal velocity declines and the tailward ion bulk flow velocity rises moving down tail from the frontside magnetopause. Polar cap arcs (or more properly, high-latitude sun-aligned arcs) are largely complementary to the polar rain, occurring most frequently when the dayside merging rate is low, and thus when polar rain is weak. Sun-aligned arcs are often considered as originating either in the polar rain or the expansion of the plasma sheet into the polar cap. In fact three quite distinct types of sun-aligned high-latitude arcs exist, two common, and one rare. One type of arc occurs as intensifications of the polar rain, and is common, but weak, typically 0.1 ergs/cm2 s usually occurs adjacent to the auroral oval, and includes ion precipitation. The plasma regime of these common, and at times intense, arcs is often distinct from the oval which they abut. Convection alone does not specify the open/closed nature of these arcs, because multiple narrow convection reversals are common around such arcs, and the arcs themselves can be embedded within flows that are either sunward or anti-sunward. These observational facts do not neatly fit into either a plasma sheet origin or a polar rain origin (e.g., the necessity to abut the auroral oval, and the

Variations in the polar cap area during two substorm cycles

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S. E. Milan

2003-05-01

Full Text Available This study employs observations from several sources to determine the location of the polar cap boundary, or open/closed field line boundary, at all local times, allowing the amount of open flux in the magnetosphere to be quantified. These data sources include global auroral images from the Ultraviolet Imager (UVI instrument on board the Polar spacecraft, SuperDARN HF radar measurements of the convection flow, and low altitude particle measurements from Defense Meteorological Satellite Program (DMSP and National Oceanographic and Atmospheric Administration (NOAA satellites, and the Fast Auroral SnapshoT (FAST spacecraft. Changes in the open flux content of the magnetosphere are related to the rate of magnetic reconnection occurring at the magnetopause and in the magnetotail, allowing us to estimate the day- and nightside reconnection voltages during two substorm cycles. Specifically, increases in the polar cap area are found to be consistent with open flux being created when the IMF is oriented southwards and low-latitude magnetopause reconnection is ongoing, and decreases in area correspond to open flux being destroyed at substorm breakup. The polar cap area can continue to decrease for 100 min following the onset of substorm breakup, continuing even after substorm-associated auroral features have died away. An estimate of the dayside reconnection voltage, determined from plasma drift measurements in the ionosphere, indicates that reconnection can take place at all local times along the dayside portion of the polar cap boundary, and hence presumably across the majority of the dayside magnetopause. The observation of ionospheric signatures of bursty reconnection over a wide extent of local times supports this finding.Key words. Ionosphere (plasma convection; polar ionosphere – Magnetospheric physics (magnetospheric configuration and dynamics

IR SPECTRAL MAPPING OF THE MARTIAN SOUTH POLAR RESIDUAL CAP USING CRISM

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J. Campbell

2016-06-01

Full Text Available Polycyclic aromatic hydrocarbons (PAHs are considered to be important in theories of abiogenesis (Allamandola, 2011 . There is evidence that PAHs have been detected on two icy Saturnian satellites using the Visual and Infrared Mapping Spectrometer (VIMS on the Cassini spacecraft (Cruikshank et al., 2007. The hypothesised presence of PAHs in Mars south polar cap has not been systematically examined even though the Mars south polar cap may allow the preservation of organic molecules that are typically destroyed at the Martian surface by UV radiation (Dartnell et al. 2012. This hypothesis is supported by recent analyses of South Polar Residual Cap (SPRC structural evolution (Thomas et al., 2009 that suggest the possibility that seasonal and long term sublimation may excavate dust particles from within the polar ice. Periodic sublimation is believed to be responsible for the formation of so-called “Swiss Cheese Terrain”, a unique surface feature found only in the Martian south polar residual cap consisting of flat floored, circular depressions (Byrne, 2009. We show the first examples of work towards the detection of PAHs in Swiss Cheese Terrain, using data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM, on board NASA’s Mars Reconnaissance Orbiter (MRO. CRISM is designed to search for mineralogical indications of past and present water, thus providing extensive coverage of the south polar cap. In this work, we discuss whether CRISM infrared spectra can be used to detect PAHs in Swiss Cheese Terrain and demonstrate a number of maps showing shifts in spectral profiles over the SPRC.

Inclined Pulsar Magnetospheres in General Relativity: Polar Caps for the Dipole, Quadrudipole, and Beyond

Science.gov (United States)

Gralla, Samuel E.; Lupsasca, Alexandru; Philippov, Alexander

2017-12-01

In the canonical model of a pulsar, rotational energy is transmitted through the surrounding plasma via two electrical circuits, each connecting to the star over a small region known as a “polar cap.” For a dipole-magnetized star, the polar caps coincide with the magnetic poles (hence the name), but in general, they can occur at any place and take any shape. In light of their crucial importance to most models of pulsar emission (from radio to X-ray to wind), we develop a general technique for determining polar cap properties. We consider a perfectly conducting star surrounded by a force-free magnetosphere and include the effects of general relativity. Using a combined numerical-analytical technique that leverages the rotation rate as a small parameter, we derive a general analytic formula for the polar cap shape and charge-current distribution as a function of the stellar mass, radius, rotation rate, moment of inertia, and magnetic field. We present results for dipole and quadrudipole fields (superposed dipole and quadrupole) inclined relative to the axis of rotation. The inclined dipole polar cap results are the first to include general relativity, and they confirm its essential role in the pulsar problem. The quadrudipole pulsar illustrates the phenomenon of thin annular polar caps. More generally, our method lays a foundation for detailed modeling of pulsar emission with realistic magnetic fields.

Characteristics of the polar cap at ionospheric levels and present understanding of the physical processes that give rise to these characteristics

International Nuclear Information System (INIS)

Brekke, A.

1983-01-01

This chapter discusses the relationship between the interplanetary magnetic field (IMF) and various polar cap current systems, such as the DP2-system and the S /SUB q/ P-system. The disagreements concerning these systems are examined. Topics considered include the polar cap (a result of an open magnetosphere); studies of the polar cap magnetic field variations; the DP2-current system and its relation to the IMF; the polar cap current system during a northward IMF; the azimuthal component of IMF and its influence on the polar cap magnetic field variations; the electric potential distribution on the polar cap; rocket observations of the polar cap electric field; the auroral arcs as a visible trace of the ionospheric convection; neutral wind measurements in the polar cap F-region; and further studies of polar cap dynamics. The focus is on the polar region inside the auroral oval. It is suggested that more research is needed of the polar cap current system in order to understand the magnetosphereionosphere coupling, with the polar cap ionospheric conductivity distribution being the most crucial parameter

Polar cap flow channel events: spontaneous and driven responses

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P. E. Sandholt

2010-11-01

Full Text Available We present two case studies of specific flow channel events appearing at the dusk and/or dawn polar cap boundary during passage at Earth of interplanetary (IP coronal mass ejections (ICMEs on 10 January and 25 July 2004. The channels of enhanced (>1 km/s antisunward convection are documented by SuperDARN radars and dawn-dusk crossings of the polar cap by the DMSP F13 satellite. The relationship with Birkeland currents (C1–C2 located poleward of the traditional R1–R2 currents is demonstrated. The convection events are manifest in ground magnetic deflections obtained from the IMAGE (International Monitor for Auroral Geomagnetic Effects Svalbard chain of ground magnetometer stations located within 71–76° MLAT. By combining the ionospheric convection data and the ground magnetograms we are able to study the temporal behaviour of the convection events. In the two ICME case studies the convection events belong to two different categories, i.e., directly driven and spontaneous events. In the 10 January case two sharp southward turnings of the ICME magnetic field excited corresponding convection events as detected by IMAGE and SuperDARN. We use this case to determine the ground magnetic signature of enhanced flow channel events (the NH-dusk/By<0 variant. In the 25 July case a several-hour-long interval of steady southwest ICME field (Bz<0; By<0 gave rise to a long series of spontaneous convection events as detected by IMAGE when the ground stations swept through the 12:00–18:00 MLT sector. From the ground-satellite conjunction on 25 July we infer the pulsed nature of the polar cap ionospheric flow channel events in this case. The typical duration of these convection enhancements in the polar cap is 10 min.

Polar cap ion beams during periods of northward IMF: Cluster statistical results

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R. Maggiolo

2011-05-01

Full Text Available Above the polar caps and during prolonged periods of northward IMF, the Cluster satellites detect upward accelerated ion beams with energies up to a few keV. They are associated with converging electric field structures indicating that the acceleration is caused by a quasi-static field-aligned electric field that can extend to altitudes higher than 7 RE (Maggiolo et al., 2006; Teste et al., 2007. Using the AMDA science analysis service provided by the Centre de Données de la Physique des Plasmas, we have been able to extract about 200 events of accelerated upgoing ion beams above the polar caps from the Cluster database. Most of these observations are taken at altitudes lower than 7 RE and in the Northern Hemisphere. We investigate the statistical properties of these ion beams. We analyze their geometry, the properties of the plasma populations and of the electric field inside and around the beams, as well as their dependence on solar wind and IMF conditions. We show that ~40 % of the ion beams are collocated with a relatively hot and isotropic plasma population. The density and temperature of the isotropic population are highly variable but suggest that this plasma originates from the plasma sheet. The ion beam properties do not change significantly when the isotropic, hot background population is present. Furthermore, during one single polar cap crossing by Cluster it is possible to detect upgoing ion beams both with and without an accompanying isotropic component. The analysis of the variation of the IMF BZ component prior to the detection of the beams indicates that the delay between a northward/southward turning of IMF and the appearance/disappearance of the beams is respectively ~2 h and 20 min. The observed electrodynamic characteristics of high altitude polar cap ion beams suggest that they are closely connected to polar cap auroral arcs. We discuss the implications of these Cluster observations above the polar cap on the magnetospheric

The instantaneous relationship between polar cap and oval auroras at times of northward interplanetary magnetic field

International Nuclear Information System (INIS)

Murphree, J.S.; Anger, C.D.; Cogger, L.L.

1982-01-01

Optical images of the polar cap region at both 5577 and 3914 A obtained from 1400 km above the earth have been used to study the relationship between polar cap and oval aurora during periods when the interplanetary magnetic field is strongly northward, i.e., B > 3.5 nT. When this rather rare condition occurs, distinction between the two types of aurora is no longer as clear as depicted on the basis of statistical definitions of the auroral oval. Diffuse, weak emission can fill in the region between the auroral oval and discrete auroral features in the polar cap. The polar cap discrete features can appear very similar to auroral oval arcs in intensity, intensity ratio, and structure. Even more striking are the situations where discrete polar cap features merge with oval auroras. From this study it is concluded that under conditions of large positive B the region of closed magnetic field lines can expand poleward to occupy much of the high latitude region

Modeling polar cap F-region patches using time varying convection

International Nuclear Information System (INIS)

Sojka, J.J.; Bowline, M.D.; Schunk, R.W.; Decker, D.T.; Valladares, C.E.; Sheehan, R.; Anderson, D.N.; Heelis, R.A.

1993-01-01

Here the authors present the results of computerized simulations of the polar cap regions which were able to model the formation of polar cap patches. They used the Utah State University Time-Dependent Ionospheric Model (TDIM) and the Phillips Laboratory (PL) F-region models in this work. By allowing a time varying magnetospheric electric field in the models, they were able to generate the patches. This time varying field generates a convection in the ionosphere. This convection is similar to convective changes observed in the ionosphere at times of southward pointing interplanetary magnetic field, due to changes in the B y component of the IMF

Pulsar Polar Cap and Slot Gap Models: Confronting Fermi Data

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Alice K. Harding

2013-09-01

Full Text Available Rotation-powered pulsars are excellent laboratories for studying particle acceleration as well as fundamental physics of strong gravity, strong magnetic fields and relativity. Particle acceleration and high-energy emission from the polar caps is expected to occur in connection with electron-positron pair cascades. I will review acceleration and gamma-ray emission from the pulsar polar cap and associated slot gap. Predictions of these models can be tested with the data set on pulsars collected by the Large Area Telescope on the Fermi Gamma-Ray Telescope over the last four years, using both detailed light curve fitting, population synthesis and phase-resolved spectroscopy.

Mars polar cap: a habitat for elementary life1

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Wallis, M. K.; Wickramasinghe, N. C.

2009-04-01

Ices in the Martian polar caps are potential habitats for various species of microorganisms. Salts in the ice and biological anti-freeze polymers maintain liquid in cracks in the ices far below 0°C, possibly down to the mean 220-240 K. Sub-surface microbial life is shielded from ultraviolet (UV) radiation, but could potentially be activated on south-facing slopes under the midday, midsummer Sun. Such life would be limited by low levels of vapour, little transport of nutrients, low light levels below a protective dirt-crust, frost accumulation at night and in shadows, and little if any active translocation of organisms. As in the Antarctic and in permafrost, movement to new habitats depends on geo-climatic changes, which for Mars's north polar cap occur on a 50 000 year scale, except for rare meteorite impacts.

Convection and field-aligned currents, related to polar cap arcs, during strongly northward IMF (11 January 1983)

International Nuclear Information System (INIS)

Israelevich, P.L.; Podgorny, I.M.; Kuzmin, A.K.; Nikolaeva, N.S.; Dubinin, E.M.

1988-01-01

Electric and magnetic fields and auroral emissions have been measured by the Intercosmos-Bulgaria-1300 satellite on 10-11 January 1983. The measured distributions of the plasma drift velocity show that viscous convection is diminished in the evening sector under IMF B y y > 0. A number of sun-aligned polar cap arcs were observed at the beginning of the period of strongly northward IMF and after a few hours a θ-aurora appeared. The intensity of ionized oxygen emission increased significantly reaching up to several kilo-Rayleighs in the polar cap arc. A complicated pattern of convection and field-aligned currents existed in the nightside polar cap which differed from the four-cell model of convection and NBZ field-aligned current system. This pattern was observed during 12 h and could be interpreted as six large scale field-aligned current sheets and three convective vortices inside the polar cap. Sun-aligned polar cap arcs may be located in regions both of sunward and anti-sunward convection. Structures of smaller spatial scale-correspond to the boundaries of hot plasma regions related to polar cap arcs. Obviously these structures are due to S-shaped distributions of electric potential. Parallel electric fields in these S-structures provide electron acceleration up to 1 keV at the boundaries of polar cap arcs. The pairs of field-aligned currents correspond to those S-structures: a downward current at the external side of the boundary and an upward current at the internal side of it. (author)

Comparison of S3-3 polar cap potential drops with the interplanetary magnetic field and models of magnetopause reconnection

International Nuclear Information System (INIS)

Wygant, J.R.; Torbert, R.B.; Mozer, F.S.

1983-01-01

Measurements of the cross polar cap electric potential, by the double probe electric field experiment aboard S3-3, from 55 orbits in the dawn-dusk plane are compared with the reconnection electric fields predicted by a variety of models, both theoretical and experimental. The purpose of these comparisons is to understand the extent to which nonreconnection contributes to the polar cap potential must be included, to determine the time response of the polar cap potential to time varying reconnection rates, and to determine the efficiency and saturation levels of the reconnection process. It is found that (1) After several hours of northward interplanetary magnetic field, the cross polar cap potential declines to progressively lower values than those after 1 hour of northward interplanetary magnetic field. This suggests that it requires several hours for the ionospheric polar cap potential to respond to the ''turning off'' of ''turning down'' of the reconnection process. (2) The decay of the polar cap potential is used to demonstrate that contirubtions to the polar cap potential not associated with the reconnection process can be limited to less than 20 kV. It is shown that contributions to the polar cap potential that scale with the dynamic pressure of the solar wind are limited to less than 1 kV. (3) The cross polar cap electric potential is best predicted by a weighted sum of contributions from interplanetary magnetic field parameter over the 4 hours previous to the measurement. The weighting functions have the form of an exponential decay 2--3 hours with the strongest weight on interplanetary parameters over the 1 hour previous to the measurement

The Mars water cycle at other epochs - Recent history of the polar caps and layered terrain

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Jakosky, Bruce M.; Henderson, Bradley G.; Mellon, Michael T.

1993-01-01

A numerical model is presented of the integrated role of seasonal water cycle on the evolution of polar deposits on Mars over the last 10 million years. From the model, it is concluded that the only major difference between the polar caps which affects their long-term behavior is ultimately the difference in their elevations. Because of that difference, there is a preference for CO2 frost to stay longer on the northern polar cap. The average difference in sublimation at the caps results in a net south-to-north transport of water ice over long time scales. Superimposed on any long-term behavior is a transfer of water ice between the caps on the 10 exp 5 - 10 exp 6 yr time scales. The amount of water exchanged is small compared to the total ice content of the polar deposits.

Characteristics of magnetospheric convective electric fields as mapped onto the polar caps

International Nuclear Information System (INIS)

Saunders, R.S.

1976-01-01

A study is made of the open connected magnetosphere using two numerical computer models: the Hones-Taylor (1965), with image and internal dipoles being the only sources, and the Mead-Williams (1965) with a current sheet added. The objectives of the study are to demonstrate that steady state field line connection across the magnetopause is a possible mechanism for producing the polar cap electric fields detected there, and to show the interesting characteristics of such fields. A review of the literature pertinent to the polar cap electric fields is included

IMF B(y) and day-night conductivity effects in the expanding polar cap convection model

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Moses, J. J.; Gorney, D. J.; Siscoe, G. L.; Crooker, N. U.

1987-01-01

During southward B(z) periods the open field line region in the ionosphere (polar cap) expands due to increased dayside merging. Ionospheric plasma flow patterns result which can be classified by the sign of the interplanetary magnetic field (IMF) B(y) component. In this paper, a time-dependent ionospheric convection model is constructed to simulate these flows. The model consists of a spiral boundary with a gap in it. The sign of the IMF B(y) component determines the geometry of the gap. A potential is applied across the gap and distributed around the boundary. A flow results which enters the polar cap through the gap and uniformly pushes the boundary outward. Results of the model show that B(y) effects are greatest near the gap and virtually unnoticeable on the nightside of the polar cap. Adding a day-night ionospheric conductivity gradient concentrates the polar cap electric field toward dawn. The resulting flow curvature gives a sunward component that is independent of B(y). These patterns are shown to be consistent with published observations.

Polar cap arcs from the magnetosphere to the ionosphere: kinetic modelling and observations by Cluster and TIMED

Directory of Open Access Journals (Sweden)

R. Maggiolo

2012-02-01

Full Text Available On 1 April 2004 the GUVI imager onboard the TIMED spacecraft spots an isolated and elongated polar cap arc. About 20 min later, the Cluster satellites detect an isolated upflowing ion beam above the polar cap. Cluster observations show that the ions are accelerated upward by a quasi-stationary electric field. The field-aligned potential drop is estimated to about 700 V and the upflowing ions are accompanied by a tenuous population of isotropic protons with a temperature of about 500 eV. The magnetic footpoints of the ion outflows observed by Cluster are situated in the prolongation of the polar cap arc observed by TIMED GUVI. The upflowing ion beam and the polar cap arc may be different signatures of the same phenomenon, as suggested by a recent statistical study of polar cap ion beams using Cluster data. We use Cluster observations at high altitude as input to a quasi-stationary magnetosphere-ionosphere (MI coupling model. Using a Knight-type current-voltage relationship and the current continuity at the topside ionosphere, the model computes the energy spectrum of precipitating electrons at the top of the ionosphere corresponding to the generator electric field observed by Cluster. The MI coupling model provides a field-aligned potential drop in agreement with Cluster observations of upflowing ions and a spatial scale of the polar cap arc consistent with the optical observations by TIMED. The computed energy spectrum of the precipitating electrons is used as input to the Trans4 ionospheric transport code. This 1-D model, based on Boltzmann's kinetic formalism, takes into account ionospheric processes such as photoionization and electron/proton precipitation, and computes the optical and UV emissions due to precipitating electrons. The emission rates provided by the Trans4 code are compared to the optical observations by TIMED. They are similar in size and intensity. Data and modelling results are consistent with the scenario of quasi

Estimation of the polar cap dimensions from photometric data

International Nuclear Information System (INIS)

Besprozvannaya, A.S.; Vorob'ev, V.G.; Ruga, G.N.; Shchuka, T.I.; Yagodkina, O.I.

1992-01-01

The moment of crossing near-polar boundary of auroral oval by the is. Heis station (Φ L =74,4 deg) according to simultaneous optical and ionospheric observations during the period, dated 25.12.83-10.01.84, is investigated. It is shown that time of the station appearance in the polar cap area, characterized by decrease in luminescence intensity of the basic auroral emissions by the background one and by appearance in the UT afternoon hours of flat layers, coincide. Correlation coefficient - r=0.95

The Mars water cycle at other epochs: History of the polar caps and layered terrain

Science.gov (United States)

Jakosky, Bruce M.; Henderson, Bradley G.; Mellon, Michael T.

1992-01-01

The atmospheric water cycle at the present epoch involves summertime sublimation of water from the north polar cap, transport of water through the atmosphere, and condensation on one or both winter CO2 caps. Exchange with the regolith is important seasonally, but the water content of the atmosphere appears to be controlled by the polar caps. The net annual transport through the atmosphere, integrated over long timescales, must be the driving force behind the long-term evolution of the polar caps; clearly, this feeds back into the evolution of the layered terrain. We have investigated the behavior of the seasonal water cycle and the net integrated behavior at the pole for the last 10 exp 7 years. Our model of the water cycle includes the solar input, CO2 condensation and sublimation, and summertime water sublimation through the seasonal cycles, and incorporates the long-term variations in the orbital elements describing the Martian orbit.

Sublimation and transport of water from the north residual polar cap on Mars

Science.gov (United States)

Haberle, Robert M.; Jakosky, Bruce M.

1990-01-01

The possible role of the north residual cap in the current Martian water cycle was examined using models to assess the ability of the cap to supply water to the atmosphere and the ability of the atmospheric circulation to transport it out of the polar regions to low northern latitudes. Results indicate that rather extreme circumstances would be required for the cap to provide all of the observed increase in atmospheric water, such as a combination of high surface winds, low cap emissivities, or substantial evaporation from dark material. But even if these conditions could be met, the high-latitude circulation is too localized in scale to move much water vapor out of the polar environment. Both the present calculations and the data from the Viking's Mars Atmospheric Water Detection Experiment show that about two thirds of the water appearing in the Martian northern hemisphere during summer must be supplied by other sources. It is suggested that the additional source is water desorbing from the nonpolar regolith.

Rocket measurements within a polar cap arc - Plasma, particle, and electric circuit parameters

Science.gov (United States)

Weber, E. J.; Ballenthin, J. O.; Basu, S.; Carlson, H. C.; Hardy, D. A.; Maynard, N. C.; Kelley, M. C.; Fleischman, J. R.; Pfaff, R. F.

1989-01-01

Results are presented from the Polar Ionospheric Irregularities Experiment (PIIE), conducted from Sondrestrom, Greenland, on March 15, 1985, designed for an investigation of processes which lead to the generation of small-scale (less than 1 km) ionospheric irregularities within polar-cap F-layer auroras. An instrumented rocket was launched into a polar cap F layer aurora to measure energetic electron flux, plasma, and electric circuit parameters of a sun-aligned arc, coordinated with simultaneous measurements from the Sondrestrom incoherent scatter radar and the AFGL Airborne Ionospheric Observatory. Results indicated the existence of two different generation mechanisms on the dawnside and duskside of the arc. On the duskside, parameters are suggestive of an interchange process, while on the dawnside, fluctuation parameters are consistent with a velocity shear instability.

Polar cap deflation during magnetospheric substorms

Science.gov (United States)

Moses, J. J.; Siscoe, G. L.; Heelis, R. A.; Winningham, J. D.

1989-01-01

The expanding/contracting polar cap model has been used to simulate DE-2 ion drift data during substorms as determined using the AL index. Of the 39 cases modeled, 57 percent required the opening of a nightside gap which maps to where reconnection occurs in the tail; 75 percent of the 16 recovery phase cases required a nightside gap, while only 29 percent of the 17 expansion phase cases required a nightside gap. On the basis of this result, it is concluded that if a nightside gap implies tail reconnection, then reconnection probably occurs after expansion phase onset and continues throughout most of the recovery phase of a substorm.

Mars seasonal polar caps as a test of the equivalence principle

International Nuclear Information System (INIS)

Rubincam, David Parry

2011-01-01

The seasonal polar caps of Mars can be used to test the equivalence principle in general relativity. The north and south caps, which are composed of carbon dioxide, wax and wane with the seasons. If the ratio of the inertial (passive) to gravitational (active) masses of the caps differs from the same ratio for the rest of Mars, then the equivalence principle fails, Newton's third law fails, and the caps will pull Mars one way and then the other with a force aligned with the planet's spin axis. This leads to a secular change in Mars's along-track position in its orbit about the Sun, and to a secular change in the orbit's semimajor axis. The caps are a poor Eoetvoes test of the equivalence principle, being 4 orders-of-magnitude weaker than laboratory tests and 7 orders-of-magnitude weaker than that found by lunar laser ranging; the reason is the small mass of the caps compared to Mars as a whole. The principal virtue of using Mars is that the caps contain carbon, an element not normally considered in such experiments. The Earth with its seasonal snow cover can also be used for a similar test.

Combined ESR and EISCAT observations of the dayside polar cap and auroral oval during the May 15, 1997 storm

Directory of Open Access Journals (Sweden)

H. Liu

Full Text Available The high-latitude ionospheric response to a major magnetic storm on May 15, 1997 is studied and different responses in the polar cap and the auroral oval are highlighted. Depletion of the F₂ region electron density occurred in both the polar cap and the auroral zone, but due to different physical processes. The increased recombination rate of O⁺ ions caused by a strong electric field played a crucial role in the auroral zone. The transport effect, however, especially the strong upward ion flow was also of great importance in the dayside polar cap. During the main phase and the beginning of the recovery phase soft particle precipitation in the polar cap showed a clear relation to the dynamic pressure of the solar wind, with a maximum cross-correlation coefficient of 0.63 at a time lag of 5 min.

Key words: Ionosphere (auroral ionosphere; polar ionosphere - Magnetospheric physics (storms and substorms

Combined ESR and EISCAT observations of the dayside polar cap and auroral oval during the May 15, 1997 storm

Directory of Open Access Journals (Sweden)

H. Liu

2000-09-01

Full Text Available The high-latitude ionospheric response to a major magnetic storm on May 15, 1997 is studied and different responses in the polar cap and the auroral oval are highlighted. Depletion of the F2 region electron density occurred in both the polar cap and the auroral zone, but due to different physical processes. The increased recombination rate of O+ ions caused by a strong electric field played a crucial role in the auroral zone. The transport effect, however, especially the strong upward ion flow was also of great importance in the dayside polar cap. During the main phase and the beginning of the recovery phase soft particle precipitation in the polar cap showed a clear relation to the dynamic pressure of the solar wind, with a maximum cross-correlation coefficient of 0.63 at a time lag of 5 min.Key words: Ionosphere (auroral ionosphere; polar ionosphere - Magnetospheric physics (storms and substorms

Variations in the polar cap area during intervals of substorm activity on 20-21 March 1990 deduced from AMIE convection patterns

Directory of Open Access Journals (Sweden)

J. R. Taylor

1996-09-01

Full Text Available The dynamic behaviour of the northern polar cap area is studied employing Northern Hemisphere electric potential patterns derived by the Assimilative Mapping of Ionospheric Electrodynamics (AMIE procedure. The rate of change in area of the polar cap, which can be defined as the region of magnetospheric field lines open to the interplanetary magnetic field (IMF, has been calculated during two intervals when the IMF had an approximately constant southward component (1100–2200 UT, 20 March 1990 and 1300–2100 UT, 21 March 1990. The estimates of the polar cap area are based on the approximation of the polar cap boundary by the flow reversal boundary. The change in the polar cap area is then compared to the predicted expansion rate based on a simple application of Faraday\\'s Law. Furthermore, timings of magnetospheric substorms are also related to changes in the polar cap area. Once the convection electric field reconfigures following a southward turning of the IMF, the growth rate of the observed polar cap boundary is consistent with that predicted by Faraday\\'s Law. A delay of typically 20 min to 50 min is observed between a substorm expansion phase onset and a reduction in the polar cap area. Such a delay is consistent with a synthesis between the near Earth neutral line and current disruption models of magnetospheric substorms in which the dipolarisation in the magnetotail may act as a trigger for reconnection. These delays may represent a propagation time between near geosynchronous orbit dipolarisation and subsequent reconnection further down tail. We estimate, from these delays, that the neutral X line occurs between ~35RE and ~75RE downstream in the tail.

Mars Seasonal Polar Caps as a Test of the Equivalence Principle

Science.gov (United States)

Rubincam, Daivd Parry

2011-01-01

The seasonal polar caps of Mars can be used to test the equivalence principle in general relativity. The north and south caps, which are composed of carbon dioxide, wax and wane with the seasons. If the ratio of the inertial to gravitational masses of the caps differs from the same ratio for the rest of Mars, then the equivalence principle fails, Newton's third law fails, and the caps will pull Mars one way and then the other with a force aligned with the planet's spin axis. This leads to a secular change in Mars's along-track position in its orbit about the Sun, and to a secular change in the orbit's semimajor axis. The caps are a poor E6tv6s test of the equivalence principle, being 4 orders-of-magnitude weaker than laboratory tests and 7 orders-of-magnitude weaker than that found by lunar laser ranging; the reason is the small mass of the caps compared to Mars as a whole. The principal virtue of using Mars is that the caps contain carbon, an element not normally considered in such experiments. The Earth with its seasonal snow cover can also be used for a similar test.

North-Polar Martian Cap as Habitat for Elementary Life

Science.gov (United States)

Wallis, M. K.; Wickramasinghe, J. T.; Wickramasinghe, N. C.

2008-09-01

North-polar cap over millenia Atmospheric water in Mars tends currently as for the past millenia to distil onto the polar caps and be buried under dust deposits. Diffusive release from ground-ice (and its excavation in meteorite impacts [1]) replenishes atmospheric water, allowing the gradual build up of polar ice-dust deposits. When sunlit, this warmed and sublimating ice-dust mix has interest as a potential habitat for micro-organisms. Modelling shows precipitable vapour at 10-50μm/yr, varying sensitively with small changes in orbitable obliquity around the present 25° [2]. The modelling applies to a globe with regionally uniform albedo, unlike the steep topography and dark layering of the north polar cap whose upper 300m have accumulated over the last 500 kyr [3]. The cliffs and ravines of the north-polar cap are thought to form through south-facing slopes sublimating and gaining a dirt-encrusted surface, while horizontal surfaces brighten through frost deposits. The two-phase surface derives from the dust and frost feedback on surface albedo [4] and the resulting terrain develops over diurnal cycles of frosting and sublimation, and over annual seasonal cycles. The steep south-facing sides of observed ravines when unshadowed would see for a few hours the full intensity of sunlight at near normal incidence, without the atmospheric dimming at similar inclinations on Earth. As exposed ice sublimates at T > 200K (partial pressure exceeds typical martian 0.1 Pa), a crust of dirt develops to maintain quasi-stability. The dirt crust's main function is to buffer the ice against diurnal temperature fluctuations, but it also slows down vapour diffusion - analogous to south polar ice sublimation [5] and the growth of ground-ice [6]. We envisage 1-10 mm/yr as the net sublimation rate, compatible with the 100 kyr life and scales of the north polar ravines. Modelling of icy-dirt crusts in the polar cap Plane-parallel layers have been used to model the changing temperature

Description of a multi-university education and collaborative care child psychiatry access program: New York State's CAP PC.

Science.gov (United States)

Kaye, D L; Fornari, V; Scharf, M; Fremont, W; Zuckerbrot, R; Foley, C; Hargrave, T; Smith, B A; Wallace, J; Blakeslee, G; Petras, J; Sengupta, S; Singarayer, J; Cogswell, A; Bhatia, I; Jensen, P

2017-09-01

Although, child mental health problems are widespread, few get adequate treatment, and there is a severe shortage of child psychiatrists. To address this public health need many states have adopted collaborative care programs to assist primary care to better assess and manage pediatric mental health concerns. This report adds to the small literature on collaborative care programs and describes one large program that covers most of New York state. CAP PC, a component program of New York State's Office of Mental Health (OMH) Project TEACH, has provided education and consultation support to primary care providers covering most of New York state since 2010. The program is uniquely a five medical school collaboration with hubs at each that share one toll free number and work together to provide education and consultation support services to PCPs. The program developed a clinical communications record to track information about all consultations which forms the basis of much of this report. 2-week surveys following consultations, annual surveys, and pre- and post-educational program evaluations have also been used to measure the success of the program. CAP PC has grown over the 6years of the program and has provided 8013 phone consultations to over 1500 PCPs. The program synergistically provided 17,523 CME credits of educational programming to 1200 PCPs. PCP users of the program report very high levels of satisfaction and self reported growth in confidence. CAP PC demonstrates that large-scale collaborative consultation models for primary care are feasible to implement, popular with PCPs, and can be sustained. The program supports increased access to child mental health services in primary care and provides child psychiatric expertise for patients who would otherwise have none. Copyright © 2017. Published by Elsevier Inc.

A multi-satellite study of accelerated ionospheric ion beams above the polar cap

Directory of Open Access Journals (Sweden)

R. Maggiolo

2006-07-01

Full Text Available This paper presents a study of nearly field-aligned outflowing ion beams observed on the Cluster satellites over the polar cap. Data are taken at geocentric radial distances of the order of 5–9 RE. The distinction is made between ion beams originating from the polar cusp/cleft and beams accelerated almost along the magnetic field line passing by the spacecraft. Polar cusp beams are characterized by nearly field-aligned proton and oxygen ions with an energy ratio EO+ / EH+, of the order of 3 to 4, due to the ion energy repartition inside the source and to the latitudinal extension of the source. Rapid variations in the outflowing ion energy are linked with pulses/modifications of the convection electric field. Cluster data allow one to show that these perturbations of the convection velocity and the associated ion structures propagate at the convection velocity. In contrast, polar cap local ion beams are characterized by field-aligned proton and oxygen ions with similar energies. These beams show the typical inverted V structures usually observed in the auroral zone and are associated with a quasi-static converging electric field indicative of a field-aligned electric field. The field-aligned potential drop fits well the ion energy profile. The simultaneous observation of precipitating electrons and upflowing ions of similar energies at the Cluster orbit indicates that the spacecraft are crossing the mid-altitude part of the acceleration region. In the polar cap, the parallel electric field can thus extend to altitudes higher than 5 Earth radii. A detailed analysis of the distribution functions shows that the ions are heated during their parallel acceleration and that energy is exchanged between H+ and O+. Furthermore, intense electrostatic waves are observed simultaneously. These observations could be due to an ion-ion two-stream instability.

Recession of the Northern polar cap from the PFS Mars Express observations

Science.gov (United States)

Zasova, L. V.; Formisano, V.; Moroz, V. I.; Giuranna, M.; Grassi, D.; Hansen, G.; Ignatiev, N. I.; Maturilli, A.; Pfs Team

Planetary Fourier Spectrometer (PFS) has two spectral channels, devoted to the thermal and solar reflected spectral range investigations. The first observations by PFS of the Northern hemisphere ,which includes the North pole, occurred at Ls= 342 (northern winter). Surface temperature alone the orbit shows that the CO2 ice polar cap, where the surface temperature is found around 150K and below, is extended down to about 62 N. The spectra at latitudes above 80 N are obtained at polar darkness and at latitudes below 80 at illumination by the low Sun. Retrieved temperature profiles of the atmosphere at darkness show that temperature of the atmosphere is low enough to allow the CO2 condensation up to about 25 km. Between 70 and 80 latitude the upper levels of the atmosphere are heated by the Sun, but condensation of the CO2 may occur in the near surface layer below 5 km. The water ice clouds exist at lower latitudes with maximum opacity at the edge of the polar cap. More detailed investigation of the data obtained in winter as well as of the measurements in the northern spring will be presented.

Parameterizing the Magnetopause Reconnection Rate from Observations of the Expanding Polar Cap

Science.gov (United States)

Milan, S. E.; Gosling, J. S.; Hubert, B.

2012-04-01

We determine an expression for the magnetopause reconnection rate in terms of upstream interplanetary parameters. We quantify the dayside reconnection rate from observations of the expanding polar cap when the nightside reconnection rate is assumed to be zero. The polar cap open flux is calculated from auroral images collected by the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) Far Ultraviolet camera (FUV), and its rate of increase is correlated with upstream solar wind and interplanetary magnetic field measurements from the OMNI data-set. We find that the reconnection rate is successfully reproduced by considering the magnetic flux transport within a 4 Re-wide channel within the solar wind (with an additional small correction for the solar wind velocity) and an IMF clock angle dependence with an exponent of 9/2. Contrary to several previous studies we do not find a dependence of the reconnection rate on solar wind density. We discuss our findings in the context of previous studies and solar wind-magnetosphere coupling models.

Modeling the Quiet Time Outflow Solution in the Polar Cap

Science.gov (United States)

Glocer, Alex

2011-01-01

We use the Polar Wind Outflow Model (PWOM) to study the geomagnetically quiet conditions in the polar cap during solar maximum, The PWOM solves the gyrotropic transport equations for O(+), H(+), and He(+) along several magnetic field lines in the polar region in order to reconstruct the full 3D solution. We directly compare our simulation results to the data based empirical model of Kitamura et al. [2011] of electron density, which is based on 63 months of Akebono satellite observations. The modeled ion and electron temperatures are also compared with a statistical compilation of quiet time data obtained by the EISCAT Svalbard Radar (ESR) and Intercosmos Satellites (Kitamura et al. [2011]). The data and model agree reasonably well. This study shows that photoelectrons play an important role in explaining the differences between sunlit and dark results, ion composition, as well as ion and electron temperatures of the quiet time polar wind solution. Moreover, these results provide validation of the PWOM's ability to model the quiet time ((background" solution.

A multi-satellite study of accelerated ionospheric ion beams above the polar cap

Directory of Open Access Journals (Sweden)

R. Maggiolo

2006-07-01

Full Text Available This paper presents a study of nearly field-aligned outflowing ion beams observed on the Cluster satellites over the polar cap. Data are taken at geocentric radial distances of the order of 5–9 R_E. The distinction is made between ion beams originating from the polar cusp/cleft and beams accelerated almost along the magnetic field line passing by the spacecraft. Polar cusp beams are characterized by nearly field-aligned proton and oxygen ions with an energy ratio E_O+ / E_H+, of the order of 3 to 4, due to the ion energy repartition inside the source and to the latitudinal extension of the source. Rapid variations in the outflowing ion energy are linked with pulses/modifications of the convection electric field. Cluster data allow one to show that these perturbations of the convection velocity and the associated ion structures propagate at the convection velocity.

In contrast, polar cap local ion beams are characterized by field-aligned proton and oxygen ions with similar energies. These beams show the typical inverted V structures usually observed in the auroral zone and are associated with a quasi-static converging electric field indicative of a field-aligned electric field. The field-aligned potential drop fits well the ion energy profile. The simultaneous observation of precipitating electrons and upflowing ions of similar energies at the Cluster orbit indicates that the spacecraft are crossing the mid-altitude part of the acceleration region. In the polar cap, the parallel electric field can thus extend to altitudes higher than 5 Earth radii. A detailed analysis of the distribution functions shows that the ions are heated during their parallel acceleration and that energy is exchanged between H⁺ and O⁺. Furthermore, intense electrostatic waves are observed simultaneously. These observations could be due to an ion-ion two-stream instability.

Phase Equilibrium Calculations for Multi-Component Polar Fluid Mixtures with tPC-PSAFT

DEFF Research Database (Denmark)

Karakatsani, Eirini; Economou, Ioannis

2007-01-01

The truncated Perturbed-Chain Polar Statistical Associating Fluid Theory (tPC-PSAFT) is applied to a number of different mixtures, including binary, ternary and quaternary mixtures of components that differ substantially in terms of intermolecular interactions and molecular size. In contrast to m...

A study of the relationship between interplanetary parameters and large displacements of the nightside polar cap boundary

International Nuclear Information System (INIS)

Lester, M.; Freeman, M.P.; Southwood, D.J.; Waldock, J.A.; Singer, H.J.

1990-01-01

On July 14, 1982 the Sweden and Britain Radar-Aurora Experiment (SABRE) observed the ionospheric flow reversal boundary at ∼ 0400 MLT to move equatorward across the radar field of view and then later to return poleward. The polar cap appeared to be considerably inflated at this time. Concurrent observations by ISEE-3 at the L1 libration point of the solar wind speed and density, and of the interplanetary magnetic field (IMF) indicated that the solar wind conditions were unusual throughout the interval under consideration. A mapping of the solar wind parameters from the L1 point to the subsolar magnetopause and thence to the SABRE local time sector indicates that the equatorward motion of the polar cap boundary was controlled by a southward turning of the IMF. The inference of a concomitant increase in open magnetic flux is supported by a comparison of the magnetopause location observed by ISEE-1 on an inbound pass in the 2,100 MLT sector with a magnetopause model based upon the solar wind measurements made by ISEE-3. Some 20 minutes after the expansion of the polar cap boundary was first seen by SABRE, there was a rapid contraction of the boundary, the casue of which was independent of the INF and solar wind parameters, and which had a poleward velocity component in excess of 1,900 m s -1 . the boundary as it moved across the radar field of view was highly structured and oriented at a large angle to the ionospheric footprints of the magnetic L shells. Observations in the premidnight sector by the Air Force Geophysics Laboratory (AFGL) magnetometer array indicate that the polar cap contraction is caused by substorm draining of the polar cap flux and occurs without a clearly associated trigger in the interplanetary medium. The response time in the early morning local time sector to the substorm onset switch is approximately 20 minutes, equivalent to an ionospheric azimuthal phase velocity of some 5 km s -1

Pulsar Polar Cap and Slot Gap Models: Confronting Fermi Data

Science.gov (United States)

Harding, Alice K.

2012-01-01

Rotation-powered pulsars are excellent laboratories for studying particle acceleration as well as fundamental physics of strong gravity, strong magnetic fields and relativity. I will review acceleration and gamma-ray emission from the pulsar polar cap and slot gap. Predictions of these models can be tested with the data set on pulsars collected by the Large Area Telescope on the Fermi Gamma-Ray Telescope over the last four years, using both detailed light curve fitting and population synthesis.

Relationship between interplanetary parameters and the magnetopause reconnection rate quantified from observations of the expanding polar cap

Science.gov (United States)

Milan, S. E.; Gosling, J. S.; Hubert, B.

2012-03-01

Many studies have attempted to quantify the coupling of energy from the solar wind into the magnetosphere. In this paper we parameterize the dependence of the magnetopause reconnection rate on interplanetary parameters from the OMNI data set. The reconnection rate is measured as the rate of expansion of the polar cap during periods when the nightside reconnection rate is thought to be low, determined from observations by the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) Far Ultraviolet (FUV) imager. Our fitting suggests that the reconnection rate is determined by the magnetic flux transport in the solar wind across a channel approximately 4 RE in width, with a small correction dependent on the solar wind speed, and a clock angle dependence. The reconnection rate is not found to be significantly dependent on the solar wind density. Comparison of the modeled reconnection rate with SuperDARN measurements of the cross-polar cap potential provides broad support for the magnitude of the predictions. In the course of the paper we discuss the relationship between the dayside reconnection rate and the cross-polar cap potential.

The Effect of an Offset Polar Cap Dipolar Magnetic Field on the Modeling of the Vela Pulsar's Gamma-Ray Light Curves

Science.gov (United States)

Barnard, M.; Venter, C.; Harding, A. K.

2016-01-01

We performed geometric pulsar light curve modeling using static, retarded vacuum, and offset polar cap (PC) dipole B-fields (the latter is characterized by a parameter epsilon), in conjunction with standard two-pole caustic (TPC) and outer gap (OG) emission geometries. The offset-PC dipole B-field mimics deviations from the static dipole (which corresponds to epsilon equals 0). In addition to constant-emissivity geometric models, we also considered a slot gap (SG) E-field associated with the offset-PC dipole B-field and found that its inclusion leads to qualitatively different light curves. Solving the particle transport equation shows that the particle energy only becomes large enough to yield significant curvature radiation at large altitudes above the stellar surface, given this relatively low E-field. Therefore, particles do not always attain the radiation-reaction limit. Our overall optimal light curve fit is for the retarded vacuum dipole field and OG model, at an inclination angle alpha equals 78 plus or minus 1 degree and observer angle zeta equals 69 plus 2 degrees or minus 1 degree. For this B-field, the TPC model is statistically disfavored compared to the OG model. For the static dipole field, neither model is significantly preferred. We found that smaller values of epsilon are favored for the offset-PC dipole field when assuming constant emissivity, and larger epsilon values favored for variable emissivity, but not significantly so. When multiplying the SG E-field by a factor of 100, we found improved light curve fits, with alpha and zeta being closer to best fits from independent studies, as well as curvature radiation reaction at lower altitudes.

The response of ionospheric convection in the polar cap to substorm activity

Directory of Open Access Journals (Sweden)

M. Lester

Full Text Available We report multi-instrument observations during an isolated substorm on 17 October 1989. The EISCAT radar operated in the SP-UK-POLI mode measuring ionospheric convection at latitudes 71°λ-78°λ. SAMNET and the EISCAT Magnetometer Cross provide information on the timing of substorm expansion phase onset and subsequent intensifications, as well as the location of the field aligned and ionospheric currents associated with the substorm current wedge. IMP-8 magnetic field data are also included. Evidence of a substorm growth phase is provided by the equatorward motion of a flow reversal boundary across the EISCAT radar field of view at 2130 MLT, following a southward turning of the interplanetary magnetic field (IMF. We infer that the polar cap expanded as a result of the addition of open magnetic flux to the tail lobes during this interval. The flow reversal boundary, which is a lower limit to the polar cap boundary, reached an invariant latitude equatorward of 71°λ by the time of the expansion phase onset. A westward electrojet, centred at 65.4°λ, occurred at the onset of the expansion phase. This electrojet subsequently moved poleward to a maximum of 68.1°λ at 2000 UT and also widened. During the expansion phase, there is evidence of bursts of plasma flow which are spatially localised at longitudes within the substorm current wedge and which occurred well poleward of the westward electrojet. We conclude that the substorm onset region in the ionosphere, defined by the westward electrojet, mapped to a part of the tail radially earthward of the boundary between open and closed magnetic flux, the "distant" neutral line. Thus the substorm was not initiated at the distant neutral line, although there is evidence that it remained active during the expansion phase. It is not obvious whether the electrojet mapped to a near-Earth neutral line, but at its most poleward, the expanded electrojet does not reach the estimated latitude of the polar cap

Method to locate the polar cap boundary in the nightside ionosphere and application to a substorm event

Directory of Open Access Journals (Sweden)

A. T. Aikio

2006-08-01

Full Text Available In this paper we describe a new method to be used for the polar cap boundary (PCB determination in the nightside ionosphere by using the EISCAT Svalbard radar (ESR field-aligned measurements by the 42-m antenna and southward directed low-elevation measurements by the ESR 32 m antenna or northward directed low-elevation measurements by the EISCAT VHF radar at Tromsø. The method is based on increased electron temperature (Te caused by precipitating particles on closed field lines. Since the Svalbard field-aligned measurement provides the reference polar cap Te height profile, the method can be utilised only when the PCB is located between Svalbard and the mainland. Comparison with the Polar UVI images shows that the radar-based method is generally in agreement with the PAE (poleward auroral emission boundary from Polar UVI. The new technique to map the polar cap boundary was applied to a substorm event on 6 November 2002. Simultaneous measurements by the MIRACLE magnetometers enabled us to put the PCB location in the framework of ionospheric electrojets. During the substorm growth phase, the polar cap expands and the region of the westward electrojet shifts gradually more apart from the PCB. The substorm onset takes place deep within the region of closed magnetic field region, separated by about 6–7° in latitude from the PCB in the ionosphere. We interpret the observations in the framework of the near-Earth neutral line (NENL model of substorms. After the substorm onset, the reconnection at the NENL reaches within 3 min the open-closed field line boundary and then the PCB moves poleward together with the poleward boundary of the substorm current wedge. The poleward expansion occurs in the form of individual bursts, which are separated by 2–10 min, indicating that the reconnection in the magnetotail neutral line is impulsive. The poleward expansions of the PCB are followed by latitude dispersed intensifications in the westward electrojet

A Novel Approach to Exploring the Mars Polar Caps

Science.gov (United States)

Brophy, John R.; Carsey, Frank D.; Rodgers, David H.; Soderblom, L. A.; Wilcox, Brian H.

2000-01-01

The Martian polar caps contain some of the most important scientific sites on the planet. There is much interest in exploring them with a view to understanding their role in the Mars climate system. By gaining access to the stratigraphy of the polar terrain, it is probable that one can access the climate history of the planet. Additionally, investigations aimed at localizing subsurface water--liquid or solid--are not only of great scientific interest but are also germane to the long-term interests of the manned space flight program. A major difficulty with polar exploration is access. Current techniques using chemical propulsion, Holman transfers, and direct-entry landers with aeroshells have limited capability to access the polar terrain. For the near term the authors propose a new approach to solving this transportation issue by using Solar Electric Propulsion (SEP), recently flight demonstrated on NASA's DS1 Mission to an asteroid and a comet. For a longer-term approach there are additional ways in which access to Mars, as well as other planets, can be significantly improved. These include the use of Chaos orbit theory to enable transportation between LaGrange points in the solar system, gossamer structures enabling very low-mass mobility, and advanced ascent vehicles. In this paper the authors describe how a 1000-kG payload can be transported to the surface of Mars and a polar sample obtained and returned to Earth in less than five years using SEP. A vision of how this approach can be integrated into a long-term Mars exploration strategy building toward the future is also discussed.

A Novel Approach to Exploring the Mars Polar Caps

Science.gov (United States)

Brophy, John R.; Carsey, Frank D.; Rodgers, David H.; Soderblom, L. A.; Wilcox, Brian H.

2000-08-01

The Martian polar caps contain some of the most important scientific sites on the planet. There is much interest in exploring them with a view to understanding their role in the Mars climate system. By gaining access to the stratigraphy of the polar terrain, it is probable that one can access the climate history of the planet. Additionally, investigations aimed at localizing subsurface water--liquid or solid--are not only of great scientific interest but are also germane to the long-term interests of the manned space flight program. A major difficulty with polar exploration is access. Current techniques using chemical propulsion, Holman transfers, and direct-entry landers with aeroshells have limited capability to access the polar terrain. For the near term the authors propose a new approach to solving this transportation issue by using Solar Electric Propulsion (SEP), recently flight demonstrated on NASA's DS1 Mission to an asteroid and a comet. For a longer-term approach there are additional ways in which access to Mars, as well as other planets, can be significantly improved. These include the use of Chaos orbit theory to enable transportation between LaGrange points in the solar system, gossamer structures enabling very low-mass mobility, and advanced ascent vehicles. In this paper the authors describe how a 1000-kG payload can be transported to the surface of Mars and a polar sample obtained and returned to Earth in less than five years using SEP. A vision of how this approach can be integrated into a long-term Mars exploration strategy building toward the future is also discussed.

The Mars water cycle at other epochs: Recent history of the polar caps and layered terrain

Science.gov (United States)

Jakosky, Bruce M.; Henderson, Bradley G.; Mellon, Michael T.

1992-01-01

The Martian polar caps and layered terrain presumably evolves by the deposition and removal of small amounts of water and dust each year, the current cap attributes therefore represent the incremental transport during a single year as integrated over long periods of time. The role was studied of condensation and sublimation of water ice in this process by examining the seasonal water cycle during the last 10(exp 7) yr. In the model, axial obliquity, eccentricity, and L sub s of perihelion vary according to dynamical models. At each epoch, the seasonal variations in temperature are calculated at the two poles, keeping track of the seasonal CO2 cap and the summertime sublimation of water vapor into the atmosphere; net exchange of water between the two caps is calculated based on the difference in the summertime sublimation between the two caps (or on the sublimation from one cap if the other is covered with CO2 frost all year). Results from the model can help to explain (1) the apparent inconsistency between the timescales inferred for layer formation and the much older crater retention age of the cap and (2) the difference in sizes of the two residual caps, with the south being smaller than the north.

Interannual observations and quantification of summertime H2O ice deposition on the Martian CO2 ice south polar cap

Science.gov (United States)

Brown, Adrian J.; Piqueux, Sylvain; Titus, Timothy N.

2014-01-01

The spectral signature of water ice was observed on Martian south polar cap in 2004 by the Observatoire pour l'Mineralogie, l'Eau les Glaces et l'Activite (OMEGA) ( Bibring et al., 2004). Three years later, the OMEGA instrument was used to discover water ice deposited during southern summer on the polar cap ( Langevin et al., 2007). However, temporal and spatial variations of these water ice signatures have remained unexplored, and the origins of these water deposits remains an important scientific question. To investigate this question, we have used observations from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument on the Mars Reconnaissance Orbiter (MRO) spacecraft of the southern cap during austral summer over four Martian years to search for variations in the amount of water ice. We report below that for each year we have observed the cap, the magnitude of the H2O ice signature on the southern cap has risen steadily throughout summer, particularly on the west end of the cap. The spatial extent of deposition is in disagreement with the current best simulations of deposition of water ice on the south polar cap (Montmessin et al., 2007). This increase in water ice signatures is most likely caused by deposition of atmospheric H2O ice and a set of unusual conditions makes the quantification of this transport flux using CRISM close to ideal. We calculate a ‘minimum apparent‘ amount of deposition corresponding to a thin H2O ice layer of 0.2 mm (with 70% porosity). This amount of H2O ice deposition is 0.6–6% of the total Martian atmospheric water budget. We compare our ‘minimum apparent’ quantification with previous estimates. This deposition process may also have implications for the formation and stability of the southern CO2 ice cap, and therefore play a significant role in the climate budget of modern day Mars.

O+ trough zones in the polar cap ionosphere-magnetosphere coupling region

Science.gov (United States)

Horwitz, James; Zeng, Wen; Jaafari, Fajer

Regions of low-density troughs in O+ have been observed at 1 RE altitude in the polar cap ionosphere-magnetosphere region by the Thermal Ion Dynamics Experiment(TIDE) on the POLAR spacecraft. In this presentation, the UT Arlington Dynamic Fluid-Kinetic (DyFK) code is employed to investigate the formation of such O+ density troughs. We utilize convection paths of flux tubes in the high-latitude region as prescribed by an empirical convection model with solar wind inputs to track the evolution of ionospheric plasma transport and in particular O+ densities along these tubes with time/space. The flux tubes are subjected to auroral processes of precipitation and wave-driven ion heating when they pass through the auroral oval, which tends to elevate the plasma densities in these tubes. When the F-regions of such tubes traverse locations where the F-region is in darkness, recombination there causes the higher-altitude regions to drain and the densities to decline throughout. Owing to the varying effects of these processes, significant and low trough-like densities at higher altitudes developed along these flux tubes. The modeled densities near 6000 km altitudes will be compared with multiple POLAR passes featuring POLAR/TIDE-measured O+ densities for inside and outside of such trough regions.

Drifting field-aligned density structures in the night-side polar cap

Czech Academy of Sciences Publication Activity Database

Santolík, Ondřej; Persoon, A. M.; Gurnett, D. A.; Décréau, P. M. E.; Pickett, J. S.; Maršálek, O.; Maksimovic, M.; Cornilleau-Wehrlin, N.

2005-01-01

Roč. 32, - (2005), L06106-1 ISSN 0094-8276 R&D Projects: GA ČR(CZ) GA202/03/0832; GA MŠk ME 650; GA MŠk 1P05ME811 Grant - others: NASA (US) NAG5-9974; NASA (US) NNG04GB98G; NSF(US) 0307319; ESA PECS(XE) 98025 Institutional research plan: CEZ:AV0Z30420517 Keywords : Magnetospheric Physics * Plasma convection * Plasma waves and instabilities * Polar cap phenomena * Magnetospheric configuration and dynamics Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.491, year: 2005

Mapping of the solar wind electric field to the Earth's polar caps

International Nuclear Information System (INIS)

Toffoletto, F.R.; Hill, T.W.

1989-01-01

In this paper we describe a quantitative model of a magnetically interconnected (open) magnetosphere, developed as a perturbation to Voigt's closed magnetosphere model with a given magnetopause shape. The ''interconnection'' (perturbation) field is obtained as a solution to a Neumann boundary value problem, with the magnetopause normal component distribution as a boundary condition. The normal component at the magnetopause is required to be time independent and is specified in accordance with one of two hypotheses: the subsolar point merging hypothesis and Crooker's antiparallel merging hypothesis. The resulting open magnetospheric configuration is used to map the magnetopause electric field down to the polar cap ionosphere. We present ionospheric convection patterns derived from three representative interplanetary magnetic field (IMF) orientations for each of the two dayside merging geometries. Both merging geometries reproduce the observed convergence of convection streamlines near noon in a convection ''throat,'' and the east-west deflection of these streamlines in response to the east-west IMF component. The major difference between the two dayside merging geometries occurs for nonsouthward IMF, and consists of a Sun-aligned convection gap that bifurcates the polar cap in the case of the antiparallel merging geometry but not in the subsolar point merging geometry. This convection gap may plausibly be associated with the ''theta aurora'' structure observed when the IMF has a northward component. copyright American Geophysical Union 1989

Identifications of the polar cap boundary and the auroral belt in the high-altitude magnetosphere: a model for field-aligned currents

International Nuclear Information System (INIS)

Sugiura, M.

1975-01-01

By means of the Ogo 5 Goddard Space Flight Center fluxgate magnetometer data the polar cap boundary is identified in the high-altitude magnetosphere by a sudden transition from a dipolar field to a more taillike configuration. It is inferred that there exists a field-aligned-current layer at the polar cap boundary. In the night side magnetosphere the polar cap boundary is identified as the high-latitude boundary of the plasma sheet. The field-aligned current flows downward to the ionosphere on the morning side of the magnetosphere and upward from the ionosphere on the afternoon side. The basic pattern of the magnetic field variations observed during the satellite's traversal of the auroral belt is presented. Currents flow in opposite directions in the two field-aligned-current layers. The current directions in these layers as observed by Ogo 5 in the high-altitude magnetosphere are the same as those observed at low altitudes by the polar-orbiting Triad satellite (Armstrong and Zmuda, 1973). The magnetic field in the region where the lower-latitude field-aligned-current layer is situated is essentially meridional. A model is presented in which two field-aligned-current systems, one at the polar cap boundary and the other on the low-latitude part of the auroral belt, are main []y connected by ionospheric currents flowing across the auroral belt. The existence of field-aligned currents deduced from the Ogo 5 observations is a permanent feature of the magnetosphere. Intensifications of the field-aligned currents and occurrences of multiple pairs of field-aligned-current layers characterize the disturbed conditions of these regions

Edge of polar cap patches

Science.gov (United States)

Hosokawa, K.; Taguchi, S.; Ogawa, Y.

2016-04-01

On the night of 4 December 2013, a sequence of polar cap patches was captured by an all-sky airglow imager (ASI) in Longyearbyen, Norway (78.1°N, 15.5°E). The 630.0 nm airglow images from the ASI of 4 second exposure time, oversampled the emission of natural lifetime (with quenching) of at least ˜30 sec, introduce no observational blurring effects. By using such high-quality ASI images, we succeeded in visualizing an asymmetry in the gradients between the leading/trailing edges of the patches in a 2-D fashion. The gradient in the leading edge was found to be 2-3 times steeper than that in the trailing edge. We also identified fingerlike structures, appearing only along the trailing edge of the patches, whose horizontal scale size ranged from 55 to 210 km. These fingers are considered to be manifestations of plasma structuring through the gradient-drift instability (GDI), which is known to occur only along the trailing edge of patches. That is, the current 2-D observations visualized, for the first time, how GDI stirs the patch plasma and such a mixing process makes the trailing edge more gradual. This result strongly implies a close connection between the GDI-driven plasma stirring and the asymmetry in the large-scale shape of patches and then suggests that the fingerlike structures can be used as markers to estimate the fine-scale structure in the plasma flow within patches.

Automated identification and tracking of polar-cap plasma patches at solar minimum

Directory of Open Access Journals (Sweden)

R. Burston

2014-03-01

Full Text Available A method of automatically identifying and tracking polar-cap plasma patches, utilising data inversion and feature-tracking methods, is presented. A well-established and widely used 4-D ionospheric imaging algorithm, the Multi-Instrument Data Assimilation System (MIDAS, inverts slant total electron content (TEC data from ground-based Global Navigation Satellite System (GNSS receivers to produce images of the free electron distribution in the polar-cap ionosphere. These are integrated to form vertical TEC maps. A flexible feature-tracking algorithm, TRACK, previously used extensively in meteorological storm-tracking studies is used to identify and track maxima in the resulting 2-D data fields. Various criteria are used to discriminate between genuine patches and "false-positive" maxima such as the continuously moving day-side maximum, which results from the Earth's rotation rather than plasma motion. Results for a 12-month period at solar minimum, when extensive validation data are available, are presented. The method identifies 71 separate structures consistent with patch motion during this time. The limitations of solar minimum and the consequent small number of patches make climatological inferences difficult, but the feasibility of the method for patches larger than approximately 500 km in scale is demonstrated and a larger study incorporating other parts of the solar cycle is warranted. Possible further optimisation of discrimination criteria, particularly regarding the definition of a patch in terms of its plasma concentration enhancement over the surrounding background, may improve results.

Pulsar bi-drifting: implications for polar cap geometry

Science.gov (United States)

Wright, Geoff; Weltevrede, Patrick

2017-01-01

For many years it has been considered puzzling how pulsar radio emission, supposedly created by a circulating carousel of sub-beams, can produce the drift bands demonstrated by PSR J0815+0939, and more recently PSR B1839-04, which simultaneously drifts in opposing directions. Here, we suggest that the carousels of these pulsars, and hence their beams, are not circular but elliptical with axes tilted with respect to the fiducial plane. We show that certain relatively unusual lines of sight can cause bi-drifting to be observed, and a simulation of the two known exemplars is presented. Although bi-drifting is rare, non-circular beams may be common among pulsars and reveal themselves by having profile centroids displaced from the fiducial plane identified by polarization position angle swings. They may also result in profiles with asymmetric- and frequency-dependent component evolution. It is further suggested that the carousels may change their tilt by specific amounts and later reverse them. This may occur suddenly, accompanying a mode change (e.g. PSR B0943+10), or more gradually and short lived as in `flare' pulsars (e.g. PSR B1859+07). A range of pulsar behaviour (e.g. the shifting drift patterns of PSRs B0818-41 and B0826-34) may also be the result of non-circular carousels with varying orientation. The underlying nature of these carousels - whether they are exclusively generated by polar cap physics or driven by magnetospheric effects - is briefly discussed.

Solar Cycle Variations in Polar Cap Area Measured by the SuperDARN Radars

Science.gov (United States)

Imber, S. M.; Milan, S. E.; Lester, M.

2013-12-01

We present a long term study, from January 1996 - August 2012, of the latitude of the Heppner-Maynard Boundary (HMB) measured at midnight using the northern hemisphere SuperDARN radars. The HMB represents the equatorward extent of ionospheric convection, and is used in this study as a measure of the global magnetospheric dynamics and activity. We find that the yearly distribution of HMB latitudes is single-peaked at 64° magnetic latitude for the majority of the 17-year interval. During 2003 the envelope of the distribution shifts to lower latitudes and a second peak in the distribution is observed at 61°. The solar wind-magnetosphere coupling function derived by Milan et al. (2012) suggests that the solar wind driving during this year was significantly higher than during the rest of the 17-year interval. In contrast, during the period 2008-2011 HMB distribution shifts to higher latitudes, and a second peak in the distribution is again observed, this time at 68° magnetic latitude. This time interval corresponds to a period of extremely low solar wind driving during the recent extreme solar minimum. This is the first statistical study of the polar cap area over an entire solar cycle, and the results demonstrate that there is a close relationship between the phase of the solar cycle and the area of the polar cap on a large scale statistical basis.

Motion of the dayside polar cap boundary during substorm cycles: II. Generation of poleward-moving events and polar cap patches by pulses in the magnetopause reconnection rate

Directory of Open Access Journals (Sweden)

M. Lockwood

2005-12-01

Full Text Available Using data from the EISCAT (European Incoherent Scatter VHF and CUTLASS (Co-operative UK Twin-Located Auroral Sounding System HF radars, we study the formation of ionospheric polar cap patches and their relationship to the magnetopause reconnection pulses identified in the companion paper by Lockwood et al. (2005. It is shown that the poleward-moving, high-concentration plasma patches observed in the ionosphere by EISCAT on 23 November 1999, as reported by Davies et al. (2002, were often associated with corresponding reconnection rate pulses. However, not all such pulses generated a patch and only within a limited MLT range (11:00-12:00 MLT did a patch result from a reconnection pulse. Three proposed mechanisms for the production of patches, and of the concentration minima that separate them, are analysed and evaluated: (1 concentration enhancement within the patches by cusp/cleft precipitation; (2 plasma depletion in the minima between the patches by fast plasma flows; and (3 intermittent injection of photoionisation-enhanced plasma into the polar cap. We devise a test to distinguish between the effects of these mechanisms. Some of the events repeat too frequently to apply the test. Others have sufficiently long repeat periods and mechanism (3 is shown to be the only explanation of three of the longer-lived patches seen on this day. However, effect (2 also appears to contribute to some events. We conclude that plasma concentration gradients on the edges of the larger patches arise mainly from local time variations in the subauroral plasma, via the mechanism proposed by Lockwood et al. (2000.

Magnetospheric convection and current system in the dayside polar cap

International Nuclear Information System (INIS)

Nishida, A.; Mukai, T.; Tsuruda, K.; Hayakawa, H.

1992-01-01

Field and particle observations on EXOS-D (Akebono) have yielded new information on convection and current system in the dayside polar cap. Convection patterns are distinctly different depending upon whether IMF B z is northward or southward. The number of convection cells is two when B z is southward but four when B z is northward. Lobe cells in which plasma flows sunward in the region of open field lines are observed as a pair (of which one is in the dawn and the other in the dusk sector) for any polarity of IMF B y and B z . Ions in the keV range precipitate not only in the dayside cusp region but also along the sunward directed streamlines of the dawn and dusk lobe cells. These observations require reconsideration on the position and the extent of the reconnection region on the magnetopause. They also suggest that the magnetotail plays a vital role in some phenomena which have been ascribed to dayside magnetopause processes. We have not been able to find evidence to prove the presence of the viscous cell under southward IMF

Relationships between the solar wind and the polar cap magnetic activity

International Nuclear Information System (INIS)

Berthelier, A.

1981-01-01

The influence of solar wind conditions on magnetic activity is described in order to delineate the differences in the response of the magnetic activity to the arrival on the magnetopause of different typical solar wind variations. By determining a new index of local magnetic activity free from seasonal and diurnal effects we put in evidence the dependence of the various effects upon the invariant latitude. Most important results are: (1) the main increase of the magnetic activity does not occur at the same invariant latitude for different interplanetary variations, e.g. peaks of Bz tend to increase magnetic activity mainly in the auroral zones while peaks of B correspond to a uniform increase in magnetic activity over the polar cap and auroral zone; (2) there is a two steps response of magnetic activity to the high speed plasma streams; (3) an increase of magnetic activity is observed for large and northward Bz, which probably indicates that the solar wind-magnetosphere coupling is efficient under these circumstances. The specific influences of the IMF polarity are also briefly reviewed. (orig.)

Mass balance of Mars' residual south polar cap from CTX images and other data

Science.gov (United States)

Thomas, P. C.; Calvin, W.; Cantor, B.; Haberle, R.; James, P. B.; Lee, S. W.

2016-04-01

Erosion of pits in the residual south polar cap (RSPC) of Mars concurrent with deposition and fluctuating cap boundaries raises questions about the mass balance and long term stability of the cap. Determining a mass balance by measurement of a net gain or loss of atmospheric CO2 by direct pressure measurements (Haberle, R.M. et al. [2014]. Secular climate change on Mars: An update using one Mars year of MSL pressure data. American Geophysical Union (Fall). Abstract 3947), although perhaps the most direct method, has so far given ambiguous results. Estimating volume changes from imaging data faces challenges, and has previously been attempted only in isolated areas of the cap. In this study we use 6 m/pixel Context Imager (CTX) data from Mars year 31 to map all the morphologic units of the RSPC, expand the measurement record of pit erosion rates, and use high resolution images to place limits on vertical changes in the surface of the residual cap. We find the mass balance in Mars years 9-31 to be -6 to +4 km3/♂y, or roughly -0.039% to +0.026% of the mean atmospheric CO2 mass/♂y. The indeterminate sign results chiefly from uncertainty in the amounts of deposition or erosion on the upper surfaces of deposits (as opposed to scarp retreat). Erosion and net deposition in this period appear to be controlled by summertime planetary scale dust events, the largest occurring in MY 9, another, smaller one in MY 28. The rates of erosion and the deposition observed since MY 9 appear to be consistent with the types of deposits and erosional behavior found in most of the residual cap. However, small areas (100 ♂y) of depositional and/or erosional conditions different from those occurring in the period since MY 9, although these environmental differences could be subtle.

Palmer Quest: A Feasible Nuclear Fission "Vision Mission" to the Mars Polar Caps

Science.gov (United States)

Carsey, F. D.; Beegle, L. W.; Nakagawa, R.; Elliott, J. O.; Matthews, J. B.; Coleman, M. L.; Hecht, M. H.; Ivaniov, A. B.; Head, J. W.; Milkovich, S.

2005-01-01

We are engaged in a NASA Vision Mission study, called Palmer Quest after the American Antarctic explorer Nathaniel Palmer, to assess the presence of life and evaluate the habitability of the basal domain of the Mars polar caps. We address this goal through four objectives: 1. Determine the presence of amino acids, nutrients, and geochemical heterogeneity in the ice sheet. 2. Quantify and characterize the provenance of the amino acids in Mars ice. 3. Assess the stratification of outcropped units for indications of habitable zones. 4. Determine the accumulation of ice, mineralogic material, and amino acids in Mars ice caps over the present epoch. Because of the defined scientific goal for the vision mission, the Palmer Quest focus is astrobiological; however, the results of the study make us optimistic that aggressive multi-platform in-situ missions that address a wide range of objectives, such as climate change, can be supported by variations of the approach used on this mission. Mission Overview: The Palmer Quest baseline

EISCAT and Cluster observations in the vicinity of the dynamical polar cap boundary

Directory of Open Access Journals (Sweden)

A. T. Aikio

2008-02-01

Full Text Available The dynamics of the polar cap boundary and auroral oval in the nightside ionosphere are studied during late expansion and recovery of a substorm from the region between Tromsø (66.6° cgmLat and Longyearbyen (75.2° cgmLat on 27 February 2004 by using the coordinated EISCAT incoherent scatter radar, MIRACLE magnetometer and Cluster satellite measurements. During the late substorm expansion/early recovery phase, the polar cap boundary (PCB made zig-zag-type motion with amplitude of 2.5° cgmLat and period of about 30 min near magnetic midnight. We suggest that the poleward motions of the PCB were produced by bursts of enhanced reconnection at the near-Earth neutral line (NENL. The subsequent equatorward motions of the PCB would then represent the recovery of the merging line towards the equilibrium state (Cowley and Lockwood, 1992. The observed bursts of enhanced westward electrojet just equatorward of the polar cap boundary during poleward expansions were produced plausibly by particles accelerated in the vicinity of the neutral line and thus lend evidence to the Cowley-Lockwood paradigm.

During the substorm recovery phase, the footpoints of the Cluster satellites at a geocentric distance of 4.4 R_E mapped in the vicinity of EISCAT measurements. Cluster data indicate that outflow of H⁺ and O⁺ ions took place within the plasma sheet boundary layer (PSBL as noted in some earlier studies as well. We show that in this case the PSBL corresponded to a region of enhanced electron temperature in the ionospheric F region. It is suggested that the ion outflow originates from the F region as a result of increased ambipolar diffusion. At higher altitudes, the ions could be further energized by waves, which at Cluster altitudes were observed as BBELF (broad band extra low frequency fluctuations.

The four-satellite configuration of Cluster revealed a sudden poleward expansion of the PSBL by 2° during

H2O grain size and the amount of dust in Mars' residual North polar cap

Science.gov (United States)

Kieffer, H.H.

1990-01-01

In Mars' north polar cap the probable composition of material residual from the annual condensation cycle is a mixture of fine dust and H2O grains of comparable size and abundance. However, metamorphism of such material will gradually lower its albedo by increasing the size of the H2O grains only. If the cap is undergoing net annual sublimation (as inferred from water vapor observations), late summer observations should be of old ice with H2O grain sizes of 100 ??m or more. Ice of this granularity containing 30% fine dust has a reflectivity similar to that of dust alone; the observed albedo and computed ice grain size imply dust concentrations of 1 part per 1000 or less. The brightness of the icy areas conflicts with what would be expected for a residual cap deposited by an annual cycle similar to that observed by Viking and aged for thousands of years. The residual cap surface cannot be "old dirty' ice. It could be old, coarse, and clean; or it could be young, fine, and dirty. This brings into question both the source of the late summer water vapor and the formation rate of laminated terrain. -Author

ST5 Observations of the Imbalance of Region 1 and 2 Field-Aligned Currents and Its Implication to the Cross-Polar Cap Pedersen Currents

Science.gov (United States)

Le, Guan; Slavin, J. A.; Strangeway, Robert

2011-01-01

In this study, we use the in-situ magnetic field observations from Space Technology 5 mission to quantify the imbalance of Region 1 (R1) and Region 2 (R2) currents. During the three-month duration of the ST5 mission, geomagnetic conditions range from quiet to moderately active. We find that the R1 current intensity is consistently stronger than the R2 current intensity both for the dawnside and the duskside large-scale field-aligned current system. The net currents flowing into (out of) the ionosphere in the dawnside (duskside) are in the order of 5% of the total R1 currents. We also find that the net currents flowing into or out of the ionosphere are controlled by the solar wind-magnetosphere interaction in the same way as the field-aligned currents themselves are. Since the net currents due to the imbalance of the R1 and R2 currents require that their closure currents flow across the polar cap from dawn to dusk as Pedersen currents, our results indicate that the total amount of the cross-polar cap Pedersen currents is in the order of 0.1 MA. This study, although with a very limited dataset, is one of the first attempts to quantify the cross-polar cap Pedersen currents. Given the importance of the Joule heating due to Pedersen currents to the high-latitude ionospheric electrodynamics, quantifying the cross-polar cap Pedersen currents and associated Joule heating is needed for developing models of the magnetosphere-ionosphere coupling.

PC12 polarity on biopolymer nanogratings

International Nuclear Information System (INIS)

Cecchini, M; Ferrari, A; Beltram, F

2008-01-01

Cell differentiation properties are strongly entangled with the morphology and physical properties of the extracellular environment. A complete understanding of this interaction needs artificial scaffolds with controlled nano-/micro-topography. We induced specific topographies by nanoimprint lithography (NIL) on tissue culture polystyrene (TCPS) dishes substrates and, using light microscopy and high-magnification scanning-electron-microscopy, quantitatively compared the changes in PC12 differentiation phenotype induced by the periodicity of the nanopatterns. This analysis revealed that nanogratings reduce the number of neurites produced by PC12 cells upon treatment with NGF and that neuronal bipolarity correlated with an increased stretching of the cell body and a reduced length of the cell neuronal protrusions

CAPS Activity in Priming Vesicle Exocytosis Requires CK2 Phosphorylation*

OpenAIRE

Nojiri, Mari; Loyet, Kelly M.; Klenchin, Vadim A.; Kabachinski, Gregory; Martin, Thomas F. J.

2009-01-01

CAPS (Ca2+-dependent activator protein for secretion) functions in priming Ca2+-dependent vesicle exocytosis, but the regulation of CAPS activity has not been characterized. Here we show that phosphorylation by protein kinase CK2 is required for CAPS activity. Dephosphorylation eliminated CAPS activity in reconstituting Ca2+-dependent vesicle exocytosis in permeable and intact PC12 cells. Ser-5, -6, and -7 and Ser-1281 were identified by mass spectrometry as the major phosphorylation sites in...

Azimuthal Structure of the Sand Erg that Encircles the North Polar Water-Ice Cap

Science.gov (United States)

Teodoro, L. A.; Elphic, R. C.; Eke, V. R.; Feldman, W. C.; Maurice, S.; Pathare, A.

2011-12-01

The sand erg that completely encircles the perennial water-ice cap that covers the Martian north geographic pole displays considerable azimuthal structure as seen in visible and near-IR images. Much of this structure is associated with the terminations of the many steep troughs that cut spiral the approximately 3 km thick polar ice cap. Other contributions come from the katabatic winds that spill over steep-sided edges of the cap, such as what bounds the largest set of dunes that comprise Olympia Undae. During the spring and summer months when these winds initiate from the higher altitudes that contain sublimating CO2 ice, which is very cold and dry, heat adiabatically when they compress as they lose altitude. These winds should then remove H2O moisture from the uppermost layer of the sand dunes that are directly in their path. Two likely locations where this desiccation may occur preferentially is at the termination of Chasma Boreale and the ice cap at Olympia Undae. We will search for this effect by sharpening the spatial structure of the epithermal neutron counting rates measured at northern high latitudes using the Mars Odyssey Neutron Spectrometer (MONS). The epithermal range of neutron energies is nearly uniquely sensitive to the hydrogen content of surface soils, which should likely be in the form of H2O/OH molecules/radicals. We therefore convert epithermal counting rates in terms of Water-Equivalent-Hydrogen, WEH. However, MONS counting-rate data have a FWHM of ~550 km., which is sufficiently broad to prevent a close association of WEH variability with images of geological features. In this study, we reduce spurious features in the instrument smeared neutron counting rates through deconvolution. We choose the PIXON numerical deconvolution technique for this purpose. This technique uses a statistical approach (Pina 2001, Eke 2001), which is capable of removing spurious features in the data in the presence of noise. We have previously carried out a detailed

Dependence of the cross polar cap potential saturation on the type of solar wind streams

OpenAIRE

Nikolaeva, N. S.; Yermolaev, Yu. I.; Lodkina, I. G.

2013-01-01

We compare of the cross polar cap potential (CPCP) saturation during magnetic storms induced by various types of the solar wind drivers. By using the model of Siscoe-Hill \\citep{Hilletal1976,Siscoeetal2002a,Siscoeetal2002b,Siscoeetal2004,Siscoe2011} we evaluate criteria of the CPCP saturation during the main phases of 257 magnetic storms ($Dst_{min} \\le -50$ nT) induced by the following types of the solar wind streams: magnetic clouds (MC), Ejecta, the compress region Sheath before MC ($Sh_{M...

PC index as a proxy of the solar wind energy that entered into the magnetosphere: Development of magnetic substorms

Science.gov (United States)

Troshichev, O. A.; Podorozhkina, N. A.; Sormakov, D. A.; Janzhura, A. S.

2014-08-01

The Polar Cap (PC) index has been approved by the International Association of Geomagnetism and Aeronomy (IAGA XXII Assembly, Merida, Mexico, 2013) as a new index of magnetic activity. The PC index can be considered to be a proxy of the solar wind energy that enters the magnetosphere. This distinguishes PC from AL and Dst indices that are more related to the dissipation of energy through auroral currents or storage of energy in the ring current during magnetic substorms or storms. The association of the PC index with the direct coupling of the solar wind energy into the magnetosphere is based upon analysis of the relationship of PC with parameters in the solar wind, on the one hand, and correlation between the time series of PC and the AL index (substorm development), on the other hand. This paper (the first of a series) provides the results of statistical investigations that demonstrate a strong correlation between the behavior of PC and the development of magnetic substorms. Substorms are classified as isolated and expanded. We found that (1) substorms are preceded by growth in the RS index, (2) sudden substorm expansion onsets are related to "leap" or "reverse" signatures in the PC index which are indicative of a sharp increase in the PC growth rate, (3) substorms start to develop when PC exceeds a threshold level 1.5 ± 0.5 mV/m irrespective of the length of the substorm growth phase, and (4) there is a linear relation between the intensity of substorms and PC for all substorm events.

Ferroelectric capped magnetization in multiferroic PZT/LSMO tunnel junctions

Energy Technology Data Exchange (ETDEWEB)

Kumar, Ashok, E-mail: ashok553@nplindia.org; Shukla, A. K. [National Physical Laboratory (CSIR), Dr. K. S. Krishnan Road, New Delhi-110012 (India); Barrionuevo, D.; Ortega, N.; Katiyar, Ram S. [Department of Physics and Institute of Functional Nanomaterials, University of Puerto Rico, San Juan, Puerto Rico 00931-3343 (United States); Shannigrahi, Santiranjan [Institute of Materials Research and Engineering - IMRE, Agency for Science Technology and Research (A-STAR), 3 Research Link, Singapore 117602 (Singapore); Scott, J. F. [Department of Chemistry and Department of Physics, University of St. Andrews, St. Andrews KY16 ST (United Kingdom)

2015-03-30

Self-poled ultra-thin ferroelectric PbZr{sub 0.52}Ti{sub 0.48}O{sub 3} (PZT) (5 and 7 nm) films have been grown by pulsed laser deposition technique on ferromagnetic La{sub 0.67}Sr{sub 0.33}MnO{sub 3} (LSMO) (30 nm) to check the effect of polar capping on magnetization for ferroelectric tunnel junction devices. PZT/LSMO heterostructures with thick polar PZT (7 nm) capping show nearly 100% enhancement in magnetization compared with thin polar PZT (5 nm) films, probably due to excess hole transfer from the ferroelectric to the ferromagnetic layers. Core-level x-ray photoelectron spectroscopy studies revealed the presence of larger Mn 3s exchange splitting and higher Mn{sup 3+}/Mn{sup 4+} ion ratio in the LSMO with 7 nm polar capping.

Ion Outflow and Convection in the Polar Cap and Cleft as Measured by Tide, EFI, MFE and Timas

Science.gov (United States)

Elliott, H. A.; Craven, P. D.; Chandler, M. O.; Moore, T. E.; Maynard, N. C.; Peterson, W. K.; Lennartsson, O. W.; Shelley, E. G.; Mozer, F. S.; Russell, C. T.

1997-01-01

This study examines high-latitude ion outflows and velocities perpendicular to the magnetic field derived from moments of ion distributions measured by the TIDE (Thermal Ion Dynamics Experiment) instrument on the Polar satellite. Hydrogen and oxygen ions are shown to be E X B drifting in the polar cap and cleft regions with a speed of about 5-20 km/s at apogee (approximately 9 Re) and a speed of 1-2 km/s at perigee (approximately 1. 8 Re). E X B drifts are calculated from electric fields measured by EFI (Electric Field Instrument) and magnetic fields measured by MFE (Magnetic Field Experiment) both of which are also on Polar. How convection at Polar's perigee relates to potential patterns of the ionosphere will be discussed. In the cusp/cleft the distribution of hydrogen extends over a large enough range of energy to be measured by both TIDE and the Toroidal Imaging Mass-Angle Spectrograph (TIMAS). Such comparisons will be also be presented.

Response of the polar cap boundary and the current system to changes in IMF observed from the MAGSAT satellite in the southern hemisphere during summer

International Nuclear Information System (INIS)

Bhatnagar, V.P.; Burrows, J.R.

1987-01-01

The magnetic field vector residuals observed from the Magsat satellite have been used to obtain the dependence of the polar cap boundary and the current system on IMF for quiet and mildly disturbed conditions. The study has been carried out for the summer months in the Southern Hemisphere. ''Shear reversals'' (SRs) in vector residuals indicative of the infinite current sheet approximation of the field-aligned currents (FACs) indicate roughly the polar cap boundary or the poleward boundary of the plasma sheet. This is also the poleward edge of the region 1 FACs. The SR is defined to occur at the latitude where the vector goes to minimum and changes direction by approximately 180 0 . It is found that SRs mainly occur when the interplanetary magnetic field (IMF) has a southward-directed Bsub(z) component and in the latitude range of about 70 0 -80 0 . SRs in the dusk sector occur predominantly when the azimuthal component Bsub(y) is positive and in the dawn sector when Bsub(y) is negative, irrespective of the sign of Bsub(z). These results agree with the known merging process of IMF with magnetopause field lines. When SRs occur on both dawn and dusk sectors, the residuals over the entire polar cap are nearly uniform in direction and magnitude, indicating negligible polar currents. Similar behaviour is observed during highly disturbed conditions usually associated with large negative values of Bsub(z). Forty-one Magsat orbits with such SRs are quantitatively modelled for preliminary case studies of the resulting current distribution. It is found that SRs, in the plane perpendicular to the geomagnetic field, for the current vectors and the magnetic vector residuals (perturbations relative to the unperturbed field) occur at almost the same latitudes. The electrojet intensities range from 1.2 x 10 4 to 6.5 x 10 5 A (amperes). A preliminary classification of polar cap boundary crossings characterized by vector rotations rather than SRs also shows that they tend to

Polar Ice Caps: a Canary for the Greenland Ice Sheet

Science.gov (United States)

Honsaker, W.; Lowell, T. V.; Sagredo, E.; Kelly, M. A.; Hall, B. L.

2010-12-01

Ice caps are glacier masses that are highly sensitive to climate change. Because of their hypsometry they can have a binary state. When relatively slight changes in the equilibrium line altitude (ELA) either intersect or rise above the land the ice can become established or disappear. Thus these upland ice masses have a fast response time. Here we consider a way to extract the ELA signal from independent ice caps adjacent to the Greenland Ice Sheet margin. It may be that these ice caps are sensitive trackers of climate change that also impact the ice sheet margin. One example is the Istorvet Ice Cap located in Liverpool Land, East Greenland (70.881°N, 22.156°W). The ice cap topography and the underlying bedrock surface dips to the north, with peak elevation of the current ice ranging in elevation from 1050 to 745 m.a.s.l. On the eastern side of the ice mass the outlet glaciers extending down to sea level. The western margin has several small lobes in topographic depressions, with the margin reaching down to 300 m.a.s.l. Topographic highs separate the ice cap into at least 5 main catchments, each having a pair of outlet lobes toward either side of the ice cap. Because of the regional bedrock slope each catchment has its own elevation range. Therefore, as the ELA changes it is possible for some catchments of the ice cap to experience positive mass balance while others have a negative balance. Based on weather observations we estimate the present day ELA to be ~1000 m.a.s.l, meaning mass balance is negative for the majority of the ice cap. By tracking glacier presence/absence in these different catchments, we can reconstruct small changes in the ELA. Another example is the High Ice Cap (informal name) in Milne Land (70.903°N, 25.626°W, 1080 m), East Greenland. Here at least 4 unconformities in ice layers found near the southern margin of the ice cap record changing intervals of accumulation and ablation. Therefore, this location may also be sensitive to slight

CoPc and CoPcF16 on gold: Site-specific charge-transfer processes

Directory of Open Access Journals (Sweden)

Fotini Petraki

2014-04-01

Full Text Available Interface properties of cobalt(II phthalocyanine (CoPc and cobalt(II hexadecafluoro-phthalocyanine (CoPcF16 to gold are investigated by photo-excited electron spectroscopies (X-ray photoemission spectroscopy (XPS, ultraviolet photoemission spectroscopy (UPS and X-ray excited Auger electron spectroscopy (XAES. It is shown that a bidirectional charge transfer determines the interface energetics for CoPc and CoPcF16 on Au. Combined XPS and XAES measurements allow for the separation of chemical shifts based on different local charges at the considered atom caused by polarization effects. This facilitates a detailed discussion of energetic shifts of core level spectra. The data allow the discussion of site-specific charge-transfer processes.

Reactions of human dental pulp cells to capping agents in the presence or absence of bacterial exposure.

Science.gov (United States)

Cai, Shiwei; Zhang, Wenjian; Tribble, Gena; Chen, Wei

2017-01-01

An ideal pulp-capping agent needs to have good biocompatibility and promote reparative dentinogenesis. Although the effects of capping agents on healthy pulp are known, limited data regarding their effects on bacterial contaminated pulp are available. This study aimed to evaluate the reaction of contaminated pulps to various capping agents to assist clinicians in making informed decisions. Human dental pulp (HDP) cell cultures were developed from extracted human molars. The cells were exposed to a bacterial cocktail comprising Porphyromonas gingivalis, Prevotella intermedia, and Streptococcus gordonii before being cocultured with capping agents such as mineral trioxide aggregate (MTA) Portland cement (PC), and Dycal. HDP cell proliferation was assayed by MTS colorimetric cell proliferation assay, and its differentiation was evaluated by real-time PCR for detecting alkaline phosphatase, dentin sialophosphoprotein, and osteocalcin expressions. MTA and PC had no apparent effect, whereas Dycal inhibited HDP cell proliferation. PC stimulated HDP cell differentiation, particularly when they were exposed to bacteria. MTA and Dycal inhibited differentiation, regardless of bacterial infection. In conclusion, PC was the most favorable agent, followed by MTA, and Dycal was the least favorable agent for supporting the functions of bacterial compromised pulp cells.

ON THE POLAR CAP CASCADE PAIR MULTIPLICITY OF YOUNG PULSARS

Energy Technology Data Exchange (ETDEWEB)

Timokhin, A. N.; Harding, A. K., E-mail: andrey.timokhin@nasa.gov [Astrophysics Science Division, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2015-09-10

We study the efficiency of pair production in polar caps of young pulsars under a variety of conditions to estimate the maximum possible multiplicity of pair plasma in pulsar magnetospheres. We develop a semi-analytic model for calculation of cascade multiplicity which allows efficient exploration of the parameter space and corroborate it with direct numerical simulations. Pair creation processes are considered separately from particle acceleration in order to assess different factors affecting cascade efficiency, with acceleration of primary particles described by recent self-consistent non-stationary model of pair cascades. We argue that the most efficient cascades operate in the curvature radiation/synchrotron regime, the maximum multiplicity of pair plasma in pulsar magnetospheres is ∼few × 10{sup 5}. The multiplicity of pair plasma in magnetospheres of young energetic pulsars weakly depends on the strength of the magnetic field and the radius of curvature of magnetic field lines and has a stronger dependence on pulsar inclination angle. This result questions assumptions about very high pair plasma multiplicity in theories of pulsar wind nebulae.

Extended period of polar cap auroral display: auroral dynamics and relation to the IMF and the ionospheric convection

Directory of Open Access Journals (Sweden)

V. G. Vorobjev

1995-08-01

Full Text Available An unusually extended period (5 h of polar cap auroral display on 3 August 1986 is examined. Auroras have been investigated using ground-based data as well as measurements from the IMP-8 spacecraft in interplanetary space and simultaneous observations from the polar-orbiting satellites Viking and DE-1 in the northern and southern hemispheres, respectively. It is found that visible Sun-aligned arcs are located inside the transpolar band of the θ-aurora observed from the satellite in ultraviolet wavelengths. The transpolar band can contain several Sun-aligned arcs that move inside the band toward the morning or evening side of the auroral oval independent of the direction of the band movement. Intensifications of polar cap auroras with durations of up to about 30 min are observed. No change has been found in either IMF parameters or substorm activity that can be related to these intensifications. The θ-aurora occurred during a 2-h period when the B z-component of the IMF was negative. A tendency is noted for dawnward (duskward displacement of the transpolar band when By>0 (By<0 in the southern hemisphere. Simultaneous observations of auroral ovals during interplanetary Bz<0, By<0 and Bx>0 in both hemispheres and convection patterns for Bz<0 and By<0 have been displayed using satellite and ground-based measurements. It was found that the transpolar band of the -aurora in the sunlit hemisphere was situated in the region of large-scale downward Birkeland currents.

Plasma drifts associated with a system of sun-aligned arcs in the polar cap

International Nuclear Information System (INIS)

Mende, S.B.; Doolittle, J.H.; Robinson, R.M.; Vondrak, R.R.; Rich, F.J.

1988-01-01

A series of four sun-aligned arcs passed over Sondre Stromfjord, Greenland, on the night of the 17th and 18th of February, 1985. Observations of these arcs were made using the Sondrestrom incoherent scatter radar and an intensified all-sky imaging TV system that was operated at the radar site. The first of the four arcs crossed the Sondre Stromfjord meridian just before local midnight moving westward, and the other three arcs followed at approximately half-hour intervals. When we account for the earth's rotation, the arc drift in an inertial frame was eastward, or dusk to dawn. The half-hour interval between meridian crossings of the arcs implies that the mean spacing between the arcs was 180 km. A Defense Meteorological Satellite Program (DMSP) F6 satellite pass at 0110 UT revealed the presence of highly structured electron and ion precipitation throughout the polar cap. The DMSP visible imager detected a single, sun-aligned arc associated with the largest peak in precipitating electron flux. This arc was also observed at Thule, Greenland, with an intensified film camera. These observations suggest that at least one of the arcs that were observed at Sondre Stromfjord extended across a large part of the polar cap. The radar at Sondre Stromfjord measured electron density and ion drift velocities associated with the four arcs. The radar drift measurements were superimposed on the all-sky video images to determine the location of the measurements relative to the arcs. Plasma drifts outside the arcs were found to be both sunward and antisunward, while within the arcs the drifts were predominantly antisunward. The variability of the drifts in the direction parallel to the arcs indicates that the electric fields were highly structured even though the configuration and motion of the arcs were well behaved

/sup 15/N(p,. cap alpha. )/sup 12/C reaction with polarized protons from 0. 34 to 1. 21 MeV

Energy Technology Data Exchange (ETDEWEB)

Pepper, G H; Brown, L [Carnegie Institution of Washington, D.C. (USA). Dept. of Terrestrial Magnetism

1976-03-29

A polarized beam was used to measure angular distributions of the analyzing power of the /sup 15/N(p,..cap alpha..)/sup 12/C reaction at 0.34 MeV and at five energies from 0.92 to 1.21 MeV. The analyzing power can be fitted with associated Legendre polynomials, P/sub 1//sup 1/ and P/sub 2//sup 1/ sufficing to describe the results except near 1.2 MeV where P/sub 3//sup 1/ is also required. Polarization excitation functions were measured throughout the entire energy range at angles where the polynomials P/sub 2//sup 1/ and P/sub 3//sup 1/ are zero. A polarization contour map is given.

Dielectric and Energy Storage Properties of the Heterogeneous P(VDF-HFP)/PC Composite Films

Science.gov (United States)

Zhao, Xiaojia; Peng, Guirong; Zhan, Zaiji

2017-12-01

Polymer-based materials with a high discharge energy and low energy loss have attracted considerable attention for energy storage applications. A new class of polymer-based composite films composed of amorphous polycarbonate (PC) and poly(vinylidene fluoride-hexafluoropropylene) [P(VDF-HFP)] has been fabricated by simply solution blending followed by thermal treatment under vacuum. The results show that the diameter of the spherical phase for PC and the melting temperature of P(VDF-HFP) increase, and the crystallinity and crystallization temperature of P(VDF-HFP) decrease with increasing PC content. The phase transition from the polar β phase to weak polarity γ phase is induced by PC addition. Moreover, the Curie temperature of the P(VDF-HFP)/PC composite films shifts to a lower temperature. With the addition of PC, the permittivity, polarization and discharge energy of the P(VDF-HFP)/PC composite films slightly decrease. However, the energy loss is significantly reduced.

On a distribution of electric fields caused by the northern component of the interplanetary magnetic field in the absence of longitudinal currents in the winter polar cap

International Nuclear Information System (INIS)

Uvarov, V.M.

1984-01-01

Data on the distribution of electric fields, conditioned by the northern component of the interplanetary magnetic field Bsub(z), have been discussed. The problem of electric field excitation is reduced to the solution of equations of continuity for the current in three regions: northern and southern polar caps and region beyond the caps. At the values Bsub(z)>0 in the ranqe of latitudes phi >= 80 deg the localization of convection conversion effect is obtained in calculations for summer cap and it agrees with the data of direct measurements

NESHAP Area-Specific Dose-Release Factors for Potential Onsite Member-of-the-Public Locations at SRS using CAP88-PC Version 4.0

Energy Technology Data Exchange (ETDEWEB)

Trimor, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-08-09

The Environmental Protection Agency (EPA) requires the use of the computer model CAP88-PC to estimate the total effective doses (TED) for demonstrating compliance with 40 CFR 61, Subpart H (EPA 2006), the National Emission Standards for Hazardous Air Pollutants (NESHAP) regulations. As such, CAP88 Version 4.0 was used to calculate the receptor dose due to routine atmospheric releases at the Savannah River Site (SRS). For estimation, NESHAP dose-release factors (DRFs) have been supplied to Environmental Compliance and Area Closure Projects (EC&ACP) for many years. DRFs represent the dose to a maximum receptor exposed to 1 Ci of a specified radionuclide being released into the atmosphere. They are periodically updated to include changes in the CAP88 version, input parameter values, site meteorology, and location of the maximally exposed individual (MEI). In this report, the DRFs were calculated for potential radionuclide atmospheric releases from 13 SRS release points. The three potential onsite MEI locations to be evaluated are B-Area, Three Rivers Landfill (TRL), and Savannah River Ecology Lab Conference Center (SRELCC) with TRL’s onsite workers considered as members-of-the-public, and the potential future constructions of dormitories at SRELCC and Barracks at B-Area. Each MEI location was evaluated at a specified compass sector with different area to receptor distances and was conducted for both ground-level and elevated release points. The analysis makes use of area-specific meteorological data (Viner 2014). The resulting DRFs are compared to the 2014 NESHAP offsite MEI DRFs for three operational areas; A-Area, H-Area, and COS for a release rate of 1 Ci of tritium oxide at 0 ft. elevation. CAP88 was executed again using the 2016 NESHAP MEI release rates for 0 and 61 m stack heights to determine the radionuclide dose at TRL from the center-of-site (COS).

Comparisons of CAP88PC version 2.0 default parameters to site specific inputs

International Nuclear Information System (INIS)

Lehto, M. A.; Courtney, J. C.; Charter, N.; Egan, T.

2000-01-01

The effects of varying the input for the CAP88PC Version 2.0 program on the total effective dose equivalents (TEDEs) were determined for hypothetical releases from the Hot Fuel Examination Facility (HFEF) located at the Argonne National Laboratory site on the Idaho National Engineering and Environmental Laboratory (INEEL). Values for site specific meteorological conditions and agricultural production parameters were determined for the 80 km radius surrounding the HFEF. Four nuclides, 3 H, 85 Kr, 129 I, and 137 Cs (with its short lived progeny, 137m Ba) were selected for this study; these are the radioactive materials most likely to be released from HFEF under normal or abnormal operating conditions. Use of site specific meteorological parameters of annual precipitation, average temperature, and the height of the inversion layer decreased the TEDE from 137 Cs- 137m Ba up to 36%; reductions for other nuclides were less than 3%. Use of the site specific agricultural parameters reduced TEDE values between 7% and 49%, depending on the nuclide. Reductions are associated with decreased committed effective dose equivalents (CEDEs) from the ingestion pathway. This is not surprising since the HFEF is located well within the INEEL exclusion area, and the surrounding area closest to the release point is a high desert with limited agricultural diversity. Livestock and milk production are important in some counties at distances greater than 30 km from the HFEF

Extended period of polar cap auroral display: auroral dynamics and relation to the IMF and the ionospheric convection

Directory of Open Access Journals (Sweden)

V. G. Vorobjev

Full Text Available An unusually extended period (5 h of polar cap auroral display on 3 August 1986 is examined. Auroras have been investigated using ground-based data as well as measurements from the IMP-8 spacecraft in interplanetary space and simultaneous observations from the polar-orbiting satellites Viking and DE-1 in the northern and southern hemispheres, respectively. It is found that visible Sun-aligned arcs are located inside the transpolar band of the θ-aurora observed from the satellite in ultraviolet wavelengths. The transpolar band can contain several Sun-aligned arcs that move inside the band toward the morning or evening side of the auroral oval independent of the direction of the band movement. Intensifications of polar cap auroras with durations of up to about 30 min are observed. No change has been found in either IMF parameters or substorm activity that can be related to these intensifications. The θ-aurora occurred during a 2-h period when the B _z-component of the IMF was negative. A tendency is noted for dawnward (duskward displacement of the transpolar band when B_y>0 (B_y<0 in the southern hemisphere. Simultaneous observations of auroral ovals during interplanetary B_z<0, B_y<0 and B_x>0 in both hemispheres and convection patterns for B_z<0 and B_y<0 have been displayed using satellite and ground-based measurements. It was found that the transpolar band of the -aurora in the sunlit hemisphere was situated in the region of large-scale downward Birkeland currents.

VISIONS: Remote Observations of a Spatially-Structured Filamentary Source of Energetic Neutral Atoms near the Polar Cap Boundary During an Auroral Substorm

Science.gov (United States)

Collier, Michael R.; Chornay, D.; Clemmons, J.; Keller, J. W.; Klenzing, J.; Kujawski, J.; McLain, J.; Pfaff, R.; Rowland, D.; Zettergren, M.

2015-01-01

We report initial results from the VISualizing Ion Outflow via Neutral atom imaging during a Substorm (VISIONS) rocket that flew through and near several regions of enhanced auroral activity and also sensed regions of ion outflow both remotely and directly. The observed neutral atom fluxes were largest at the lower energies and generally higher in the auroral zone than in the polar cap. In this paper, we focus on data from the latter half of the VISIONS trajectory when the rocket traversed the polar cap region. During this period, many of the energetic neutral atom spectra show a peak at 100 electronvolts. Spectra with peaks around 100 electronvolts are also observed in the Electrostatic Ion Analyzer (EIA) data consistent with these ions comprising the source population for the energetic neutral atoms. The EIA observations of this low energy population extend only over a few tens of kilometers. Furthermore, the directionality of the arriving energetic neutral atoms is consistent with either this spatially localized source of energetic ions extending from as low as about 300 kilometers up to above 600 kilometers or a larger source of energetic ions to the southwest.

Distribution of convection potential around the polar cap boundary as a function of the interplanetary magnetic field

International Nuclear Information System (INIS)

Lu, G.; Reiff, P.H.; Karty, J.L.; Hairston, M.R.; Heelis, R.A.

1989-01-01

Plasma flow data from the AE-C, AE-D and DE 2 satellites have been used to systematically study the distribution of the convection potential around the polar cap boundary under a variety of different interplanetary magnetic field (IMF) conditions. For either a garden hose (B x B y x B y >0) orientation of the IMF, the potential distribution is mainly affected by the sign of B y . In the northern hemisphere, the zero potential line (which separates the dusk convection cell from the dawn cell) on the dayside shifts duskward as B y changes from positive to negative. But in the southern hemisphere, a dawnward shift has been found, although the uncertainties are large. The typical range of displacement is about ±1.5 hours MLT. Note that this shift is in the opposite direction from most simple schematic models of ionospheric flow; this reflects the fact that the polar cap boundary is typically more poleward than the flow reversal associated with the region 1 current system, which shifts in the opposite direction. Thus the enhanced flow region typically crosses noon. In most cases a sine wave is an adequate representation of the distribution of potential around the boundary. However, in a few cases the data favors (at the 80% confidence level) a steeper gradient near noon, more indicative of a throat. The potential drop at the duskside boundary is almost greater than at the dawnside boundary. A slight duskward shift of the patterns observed as the IMF changes from garden hose to ortho-garden hose conditions. Analytic equipotential contours, given the potential function as a boundary condition, are constructed for several IMF conditions

On the polarization of Herbig Ae/Be star radiation

Energy Technology Data Exchange (ETDEWEB)

Petrova, N I; Shevchenko, V S

1987-08-01

Results of multicolor UBVRI polarimetry of 14 Herbig Ae/Be stars including 7 stars for which observations of polarization have been made for the first time are presented. 6 bright Herbig Ae/Be stars (As 441, AS 442, LK H..cap alpha..134, LK H..cap alpha..135, Lk H..cap alpha..169 and V517 Cyg) which belong to star formation region connected with IC 5070 show the polarization from 1 to 4.5. per cent with similar theta (approx. 180 deg) (basically of interstellar nature). The polarimetrical variability of BD+46 deg 3471, BD+65 deg 1637, HD 200775 and Lk H..cap alpha..234 is confirmed. Mechanismes of polarization in Herbig Ae/Be stars in circumstellar formations are discussed.

IDENTIFYING SURFACE CHANGES ON HRSC IMAGES OF THE MARS SOUTH POLAR RESIDUAL CAP (SPRC

Directory of Open Access Journals (Sweden)

A. R. D. Putri

2016-06-01

Full Text Available The surface of Mars has been an object of interest for planetary research since the launch of Mariner 4 in 1964. Since then different cameras such as the Viking Visual Imaging Subsystem (VIS, Mars Global Surveyor (MGS Mars Orbiter Camera (MOC, and Mars Reconnaissance Orbiter (MRO Context Camera (CTX and High Resolution Imaging Science Experiment (HiRISE have been imaging its surface at ever higher resolution. The High Resolution Stereo Camera (HRSC on board of the European Space Agency (ESA Mars Express, has been imaging the Martian surface, since 25th December 2003 until the present-day. HRSC has covered 100 % of the surface of Mars, about 70 % of the surface with panchromatic images at 10-20 m/pixel, and about 98 % at better than 100 m/pixel (Neukum et. al., 2004, including the polar regions of Mars. The Mars polar regions have been studied intensively recently by analysing images taken by the Mars Express and MRO missions (Plaut et al., 2007. The South Polar Residual Cap (SPRC does not change very much in volume overall but there are numerous examples of dynamic phenomena associated with seasonal changes in the atmosphere. In particular, we can examine the time variation of layers of solid carbon dioxide and water ice with dust deposition (Bibring, 2004, spider-like channels (Piqueux et al., 2003 and so-called Swiss Cheese Terrain (Titus et al., 2004. Because of seasonal changes each Martian year, due to the sublimation and deposition of water and CO2 ice on the Martian south polar region, clearly identifiable surface changes occur in otherwise permanently icy region. In this research, good quality HRSC images of the Mars South Polar region are processed based on previous identification as the optimal coverage of clear surfaces (Campbell et al., 2015. HRSC images of the Martian South Pole are categorized in terms of quality, time, and location to find overlapping areas, processed into high quality Digital Terrain Models (DTMs and

Chronological changes in the eighth cranial nerve compound action potential (CAP) in experimental endolymphatic hydrops: the effects of altering the polarity of click sounds.

Science.gov (United States)

Morizono, Tetsuo; Kondo, Tsuyoshi; Yamano, Takafumi; Miyagi, Morimichi; Shiraishi, Kimio

2009-02-01

Using a guinea pig model of experimental endolymphatic hydrops, click sounds of altered polarity showed different latencies and amplitudes in hydropic compared with normal cochleae. Latency changes appeared as early as 1 week after endolymphatic obstruction. This method can help diagnose endolymphatic hydrops. The goal of the study was to develop an objective electrophysiological diagnosis of endolymphatic hydrops. Endolymphatic hydrops were created surgically in guinea pigs. The latency and the amplitude of the eighth cranial nerve compound action potential (CAP) for click sounds of altered polarity were measured up to 8 weeks after the surgery. At early stages after surgery, the latency for condensation clicks became longer, and at later stages the latencies for both condensation and rarefaction became longer. The discrepancy in the latencies for rarefaction and condensation click sounds (rarefaction minus condensation) became larger by the first week after surgery, but no further discrepancy occurred thereafter. Compared with latency changes, amplitude changes in the CAP were rapid and progressive following surgery, suggesting ongoing damage to hair cells.

Hyperspectral characterisation of the Martian south polar residual cap using CRISM

Science.gov (United States)

Campbell, J. D.; Sidiropoulos, P.; Muller, J.-P.

2017-09-01

We present our research on hyperspectral characterization of the Martian South Polar Residual Cap (SPRC), with a focus on the detection of organic signatures within the dust content of the ice. The SPRC exhibits unique CO2 ice sublimation features known colloquially as 'Swiss Cheese Terrain' (SCT). These flat floored, circular depressions are highly dynamic, and may expose dust particles previously trapped within the ice in the depression walls and partially on the floors. Here we identify suitable regions for potential dust exposure on the SPRC, and utilise data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on board NASA's Mars Reconnaissance Orbiter (MRO) satellite to examine infrared spectra of dark regions to establish their mineral composition, to eliminate the effects of ices on sub-pixel dusty features, and to assess whether ther might be signatures indicative of Polycyclic Aromatic Hydrocarbons (PAHs). Spectral mapping has identified compositional differences between depression rims and the majority of the SPRC and CRISM spectra have been corrected to minimise the influence of CO2 and H2O ice. Whilst no conclusive evidence for PAHs has been found, depression rims are shown to have higher water content than regions of featureless ice, and there are indications of magnesium carbonate within the dark, dusty regions.

Martian North Polar Water-Ice Clouds During the Viking Era

Science.gov (United States)

Tamppari, L. K.; Bass, D. S.

2000-01-01

The Viking Orbiters determined that the surface of Mars' northern residual cap consists of water ice. Observed atmospheric water vapor abundances in the equatorial regions have been related to seasonal exchange between reservoirs such as the polar caps, the regolith and between different phases in the atmosphere. Kahn modeled the physical characteristics of ice hazes seen in Viking Orbiter imaging limb data, hypothesizing that ice hazes provide a method for scavenging water vapor from the atmosphere and accumulating it into ice particles. Given that Jakosky found that these particles had sizes such that fallout times were of order one Martian sol, these water-ice hazes provided a method for returning more water to the regolith than that provided by adsorption alone. These hazes could also explain the rapid hemispheric decrease in atmospheric water in late northern summer as well as the increase during the following early spring. A similar comparison of water vapor abundance versus polar cap brightness has been done for the north polar region. They have shown that water vapor decreases steadily between L(sub s) = 100-150 deg while polar cap albedo increases during the same time frame. As a result, they suggested that late summer water-ice deposition onto the ice cap may be the cause of the cap brightening. This deposition could be due to adsorption directly onto the cap surface or to snowfall. Thus, an examination of north polar waterice clouds could lend insight into the fate of the water vapor during this time period. Additional information is contained in the original extended abstract.

Polar cap mesosphere wind observations: comparisons of simultaneous measurements with a Fabry-Perot interferometer and a field-widened Michelson interferometer.

Science.gov (United States)

Fisher, G M; Killeen, T L; Wu, Q; Reeves, J M; Hays, P B; Gault, W A; Brown, S; Shepherd, G G

2000-08-20

Polar cap mesospheric winds observed with a Fabry-Perot interferometer with a circle-to-line interferometer optical (FPI/CLIO) system have been compared with measurements from a field-widened Michelson interferometer optimized for E-region winds (ERWIN). Both instruments observed the Meinel OH emission emanating from the mesopause region (approximately 86 km) at Resolute Bay, Canada (74.9 degrees N, 94.9 degrees W). This is the first time, to our knowledge, that winds measured simultaneously from a ground-based Fabry-Perot interferometer and a ground-based Michelson interferometer have been compared at the same location. The FPI/CLIO and ERWIN instruments both have a capability for high temporal resolution (less than 10 min for a full scan in the four cardinal directions and the zenith). Statistical comparisons of hourly mean winds for both instruments by scatterplots show excellent agreement, indicating that the two optical techniques provide equivalent observations of mesopause winds. Small deviations in the measured wind can be ascribed to the different zenith angles used by the two instruments. The combined measurements illustrate the dominance of the 12-h wave in the mesopause winds at Resolute Bay, with additional evidence for strong gravity wave activity with much shorter periods (tens of minutes). Future operations of the two instruments will focus on observation of complementary emissions, providing a unique passive optical capability for the determination of neutral winds in the geomagnetic polar cap at various altitudes near the mesopause.

Three-dimensional polarization characteristics of magnetic variations in the Pc 5 frequency range at conjugate areas near L=4

International Nuclear Information System (INIS)

Fukunishi, H.; Lanzerotti, L.J.; MaClennan, C.G.

1975-01-01

By using magnetic data measured at a network of stations extending from L approx. 3.2 to L approx. 4.4 and at a station in the conjugate area, ellipticities in the three orthogonal planes (H-D, H-Z, and D-Z) for the frequency range 2-5 mHz were computed continuously by the cross-spectral matrix method over 10 days with various levels of magnetic activity. The ellipticity diagrams in the H-D plane show that, except for the time interval during the main phase of a major magnetic storm, the sense of polarization reverses every day across local noon, with a left-hand polarization observed during local morning hours and a right-hand polarization observed during local evening hours, regardless of the level of magnetic activity. The second reversal of the sense of polarization occurs generally around approx. 2000 LT. The ellipticity diagrams in the H-Z plane show a predominantly clockwise polarization throughout the day, while the diurnal variation of the ellipticity in the D-Z plane tends to be confused. As to the latitude dependence of the wave phase, it is found that the D component oscillations are almost in phase at all latitudes, while the H component oscillations have advanced phase shifts at the lower-latitude stations. As to the conjugate dependence of wave phase, it is found that the D component oscillations are almost out of phase, while the H component oscillations are almost in phase atthe conjugate pair stations. These polarization characteristics are discussed in terms of external driving sources coupling to the shear Alfven waves of the local resonant field lines. Possible energy sources of Pc 5 waves are also discussed on the basis of the local time dependence of the sense of polarization

NESHAP Dose-Release Factor Isopleths for Five Source-to-Receptor Distances from the Center of Site and H-Area for all Compass Sectors at SRS using CAP88-PC Version 4.0

Energy Technology Data Exchange (ETDEWEB)

Trimor, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-08-09

The Environmental Protection Agency (EPA) requires the use of the computer model CAP88-PC to estimate the total effective doses (TED) for demonstrating compliance with 40 CFR 61, Subpart H (EPA 2006), the National Emission Standards for Hazardous Air Pollutants (NESHAP) regulations. As such, CAP88 Version 4.0 was used to calculate the receptor dose due to routine atmospheric releases at the Savannah River Site (SRS). For estimation, NESHAP dose-release factors (DRFs) have been supplied to Environmental Compliance and Area Closure Projects (EC&ACP) for many years. DRFs represent the dose to a maximum receptor exposed to 1 Ci of a specified radionuclide being released into the atmosphere. They are periodically updated to include changes in the CAP88 version, input parameter values, site meteorology, and location of the maximally exposed individual (MEI). This report presents the DRFs of tritium oxide released at two onsite locations, center-of-site (COS) and H-Area, at 0 ft. elevation to maximally exposed individuals (MEIs) located 1000, 3000, 6000, 9000, and 12000 meters from the release areas for 16 compass sectors. The analysis makes use of area-specific meteorological data (Viner 2014).

Surface-type nonvolatile electric memory elements based on organic-on-organic CuPc-H2Pc heterojunction

International Nuclear Information System (INIS)

Karimov, Khasan S.; Muqeet Rehman, M.; Zameer Abbas, S.; Ahmad, Zubair; Touati, Farid; Mahroof-Tahir, M.

2015-01-01

A novel surface-type nonvolatile electric memory elements based on organic semiconductors CuPc and H 2 Pc are fabricated by vacuum deposition of the CuPc and H 2 Pc films on preliminary deposited metallic (Ag and Cu) electrodes. The gap between Ag and Cu electrodes is 30–40 μm. For the current–voltage (I–V) characteristics the memory effect, switching effect, and negative differential resistance regions are observed. The switching mechanism is attributed to the electric-field-induced charge transfer. As a result the device switches from a low to a high-conductivity state and then back to a low conductivity state if the opposite polarity voltage is applied. The ratio of resistance at the high resistance state to that at the low resistance state is equal to 120–150. Under the switching condition, the electric current increases ∼ 80–100 times. A comparison between the forward and reverse I–V characteristics shows the presence of rectifying behavior. (paper)

Field-aligned currents and convection patterns in the Southern Polar Cap during stable northward, southward, and azimuthal IMF

International Nuclear Information System (INIS)

Papitashvili, V.O.; Belov, B.A.; Gromova, L.I.

1989-01-01

Equivalent ionospheric current patterns are derived from ground-based geomagnetic observations for events on 11-12 November 1979 (B/sub z/ >> 0), 24 November 1981 (B/sub z/ > 0) (B/sub y/ >> 0), and 25-26 November 1979 (B/sub y/ 0 . Due to stable external conditions, it is possible to calculate the field-aligned current (FAC) density within cells formed by two adjacent stations by taking into account the uniform conductivity of the summer polar ionosphere. These results completely correspond to regressional analysis of interplanetary magnetic fields (IMF) and ground-based geomagnetic data, and also to satellite observations of the NBZ current system. During stable southward IMF a new result was obtained, a reversal of antisunward convection flow is identified, and an NBZ-like FAC system is restored in the central part of the southern polar cap. The authors conclude that there may be an additional NBZ-like FAC system poleward of -85 0 , which is independent of the IMF and is generated by the quasi-viscous interaction between solar-wind plasma and high-latitude lobes of the magnetospheric tail

Effects of Long-term exposure of Gelatinated and Non-gelatinated Cadmium Telluride Quantum Dots on Differentiated PC12 cells

LENUS (Irish Health Repository)

Prasad, Babu R

2012-01-20

Abstract Background The inherent toxicity of unmodified Quantum Dots (QDs) is a major hindrance to their use in biological applications. To make them more potent as neuroprosthetic and neurotherapeutic agents, thioglycolic acid (TGA) capped CdTe QDs, were coated with a gelatine layer and investigated in this study with differentiated pheochromocytoma 12 (PC12) cells. The QD - cell interactions were investigated after incubation periods of up to 17 days by MTT and APOTOX-Glo Triplex assays along with using confocal microscopy. Results Long term exposure (up to 17 days) to gelatinated TGA-capped CdTe QDs of PC12 cells in the course of differentiation and after neurites were grown resulted in dramatically reduced cytotoxicity compared to non-gelatinated TGA-capped CdTe QDs. Conclusion The toxicity mechanism of QDs was identified as caspase-mediated apoptosis as a result of cadmium leaking from the core of QDs. It was therefore concluded that the gelatine capping on the surface of QDs acts as a barrier towards the leaking of toxic ions from the core QDs in the long term (up to 17 days).

Long-period polar rain variations, solar wind and hemispherically symmetric polar rain

International Nuclear Information System (INIS)

Makita, K.; Meng, C.

1987-01-01

On the basic of electron data obtained by the Defense Meteorological Satellite Program (DMSP) F2 satellite the long-period variations of the polar rain flux are examined for four consecutive solar rotations. It is clearly demonstrated that the asymmetric enhancement of the polar rain flux is strongly controlled by the sector structure of the interplanetary magnetic field (IMF). However, the orbit-to-orbit and day-to-day variations of the polar rain flux are detected even during a very stable sector period, and the polar rain flux does not have any clear relationship to the magnitude of the IMF B/sub x/ or B/sub y/. Thus the polarity of B/sub x/ controls only the accessibility of a polar region. It is also noticed that the intensity of polar rain fluxes does not show any relationship to the density of the solar wind, suggesting that the origin of the polar rain electrons is different from the commonly observed part of the solar wind electron distribution function. In addition to the asymmetric polar rain distribution, increasing polar rain fluxes of similar high intensity are sometimes detected over both polar caps. An examination of more than 1 year's data from the DMSP F2 and F4 satellites shows that simultaneous intense uniform precipitations (>10 7 electrons/cm 2 s sr) over both polar caps are not coincidental; it also shows that the spectra are similar. The occurrence of hemispherically symmetric events is not common. They generally are observed after an IMF sector transition period, during unstable periods in the sector structure, and while the solar wind density is high. copyright American Geophysical Union 1987

High resolution spectroscopy of the Martian atmosphere - Study of seasonal variations of CO, O3, H2O, and T on the north polar cap and a search for SO2, H2O2, and H2CO

Science.gov (United States)

Krasnopolsky, V. A.; Chakrabarti, S.; Larson, H.; Sandel, B. R.

1992-01-01

An overview is presented of an observational campaign which will measure (1) the seasonal variations of the CO mixing ratio on the Martian polar cap due to accumulation and depletion of CO during the condensation and evaporation of CO2, as well as (2) the early spring ozone and water vapor of the Martian north polar cap, and (3) the presence of H2CO, H2O2, and SO2. The lines of these compounds will be measured by a combined 4-m telescope and Fourier-transform spectrometer 27097.

Performance of predictive models in phase equilibria of complex associating systems: PC-SAFT and CEOS/GE

Directory of Open Access Journals (Sweden)

N. Bender

2013-03-01

Full Text Available Cubic equations of state combined with excess Gibbs energy predictive models (like UNIFAC and equations of state based on applied statistical mechanics are among the main alternatives for phase equilibria prediction involving polar substances in wide temperature and pressure ranges. In this work, the predictive performances of the PC-SAFT with association contribution and Peng-Robinson (PR combined with UNIFAC (Do through mixing rules are compared. Binary and multi-component systems involving polar and non-polar substances were analyzed. Results were also compared to experimental data available in the literature. Results show a similar predictive performance for PC-SAFT with association and cubic equations combined with UNIFAC (Do through mixing rules. Although PC-SAFT with association requires less parameters, it is more complex and requires more computation time.

Photonic Crystal Polarizing and Non-Polarizing Beam Splitters

International Nuclear Information System (INIS)

Chun-Ying, Guan; Jin-Hui, Shi; Li-Boo, Yuan

2008-01-01

A polarizing beam splitter (PBS) and a non-polarizing beam splitter (NPBS) based on a photonic crystal (PC) directional coupler are demonstrated. The photonic crystal directional coupler consists of a hexagonal lattice of dielectric pillars in air and has a complete photonic band gap. The photonic band structure and the band gap map are calculated using the plane wave expansion (PWE) method. The splitting properties of the splitter are investigated numerically using the finite difference time domain (FDTD) method

Interannual and seasonal changes in the south seasonal polar cap of Mars: Observations from MY 28-31 using MARCI

Science.gov (United States)

Calvin, W. M.; Cantor, B. A.; James, P. B.

2017-08-01

The Mars Color Imager (MARCI) camera on the Mars Reconnaissance Orbiter provides daily synoptic coverage that allows monitoring of seasonal cap retreat and interannual changes that occur between Mars Years (MY) and over the southern summer. We present the first analysis of this data for the southern seasonal cap evolution observed in MY 28, 29, 30 and 31 (2/2007 to 07/2013). Observation over multiple Mars years allows us to compare changes between years as well as longer-term evolution of the high albedo deposits at the poles. Seasonal cap retreat is similar in all years and to retreats observed in other years by both optical and thermal instruments. The cryptic terrain has a fairly consistent boundary in each year, but numerous small-scale variations occur in each MY observed. Additionally, numerous small dark deposits are identified outside the classically identified cyptic region, including Inca City and other locations not previously noted. The large water ice outlier is observed to retain seasonal frost the longest (outside the polar dome) and is also highly variable in each MY. The development of the cryptic/anti-cryptic hemispheres is inferred to occur due to albedo variations that develop after dust venting starts and may be caused by recondensation of CO2 ice on the brightest and coldest regions controlled by topographic winds. Ground ice may play a role in which regions develop cryptic terrain, as there is no elevation control on either cryptic terrain or the late season brightest deposits.

Evaluation of the truncated perturbed chain-polar statistical associating fluid theory for complex mixture fluid phase equilibria

DEFF Research Database (Denmark)

Karakatsani, Eirini; Kontogeorgis, Georgios; Economou, Ioannis

2006-01-01

Perturbed chain-statistical associating fluid theory (PC-SAFT) was extended rigorously to polar fluids based on the theory of Stell and co-workers [Mol. Phys. 1977, 33, 987]. The new PC-PSAFT was simplified to truncated PC-PSAFT (tPC-PSAFT) so that it can be practical for real polar fluid...

Electric Charge Accumulation in Polar and Non-Polar Polymers under Electron Beam Irradiation

Science.gov (United States)

Nagasawa, Kenichiro; Honjoh, Masato; Takada, Tatsuo; Miyake, Hiroaki; Tanaka, Yasuhiro

The electric charge accumulation under an electron beam irradiation (40 keV and 60 keV) was measured by using the pressure wave propagation (PWP) method in the dielectric insulation materials, such as polar polymeric films (polycarbonate (PC), polyethylene-naphthalate (PEN), polyimide (PI), and polyethylene-terephthalate (PET)) and non-polar polymeric films (polystyrene (PS), polypropylene (PP), polyethylene (PE) and polytetrafluoroethylene (PTFE)). The PE and PTFE (non-polar polymers) showed the properties of large amount of electric charge accumulation over 50 C/m3 and long saturation time over 80 minutes. The PP and PS (non-polar polymer) showed the properties of middle amount of charge accumulation about 20 C/m3 and middle saturation time about 1 to 20 minutes. The PC, PEN, PI and PET (polar polymers) showed the properties of small amount of charge accumulation about 5 to 20 C/m3 and within short saturation time about 1.0 minutes. This paper summarizes the relationship between the properties of charge accumulation and chemical structural formula, and compares between the electro static potential distribution with negative charged polymer and its chemical structural formula.

Electric charge accumulation in polar and non-polar polymers under electron beam irradiation

International Nuclear Information System (INIS)

Nagasawa, Kenichiro; Honjoh, Masato; Takada, Tatsuo; Miyake, Hiroaki; Tanaka, Yasuhiro

2010-01-01

The electric charge accumulation under an electron beam irradiation (40 keV and 60 keV) was measured by using the pressure wave propagation (PWP) method in the dielectric insulation materials, such as polar polymeric films (polycarbonate (PC), polyethylene-naphthalate (PEN), polyimide (PI), and polyethylene-terephthalate (PET)) and non-polar polymeric films (polystyrene (PS), polypropylene (PP), polyethylene (PE) and polytetrafluoroethylene (PTFE)). The PE and PTFE (non-polar polymers) showed the properties of large amount of electric charge accumulation over 50 C/m 3 and long saturation time over 80 minutes. The PP and PS (non-polar polymer) showed the properties of middle amount of charge accumulation about 20 C/m 3 and middle saturation time about 1 to 20 minutes. The PC, PEN, PI and PET (polar polymers) showed the properties of small amount of charge accumulation about 5 to 20 C/m 3 and within short saturation time about 1.0 minutes. This paper summarizes the relationship between the properties of charge accumulation and chemical structural formula, and compares between the electro static potential distribution with negative charged polymer and its chemical structural formula. (author)

Polar cap absorption events of November 2001 at Terra Nova Bay, Antarctica

Directory of Open Access Journals (Sweden)

L. Perrone

2004-04-01

Full Text Available Polar cap absorption (PCA events recorded during November 2001 are investigated by observations of ionospheric absorption of a 30MHz riometer installed at Terra Nova Bay (Antarctica, and of solar proton flux, monitored by the NOAA-GOES8 satellite in geo-synchronous orbit. During this period three solar proton events (SPE on 4, 19 and 23 November occurred. Two of these are among the dozen most intense events since 1954 and during the current solar cycle (23rd, the event of 4 November shows the greatest proton flux at energies >10MeV. Many factors contribute to the peak intensity of the two SPE biggest events, one is the Coronal Mass Ejection (CME speed, other factors are the ambient population of SPE and the shock front due to the CME. During these events absorption peaks of several dB (~20dB are observed at Terra Nova Bay, tens of minutes after the impact of fast halo CMEs on the geomagnetic field.

Results of a cross-correlation analysis show that the first hour of absorption is mainly produced by 84–500MeV protons in the case of the 4 November event and by 15–44MeV protons for the event of 23 November, whereas in the entire event the contribution to the absorption is due chiefly to 4.2–82MeV (4 November and by 4.2–14.5MeV (23 November. Good agreement is generally obtained between observed and calculated absorption by the empirical flux-absorption relationship for threshold energy E₀=10MeV. From the residuals one can argue that other factors (e.g. X-ray increases and geomagnetic disturbances can contribute to the ionospheric absorption.

Key words. Ionosphere (Polar Ionosphere, Particle precipitation – Solar physics (Flares and mass ejections

PC index as a proxy of the solar wind energy that entered into the magnetosphere and energy accumulated in the magnetosphere

Science.gov (United States)

Troshichev, Oleg; Sormakov, Dmitry

The PC index has been approved by the International Association of Geomagnetism and Aeronomy (Merida, Mexico, 2013) as a new international index of magnetic activity. Application of the PC index as a proxy of a solar wind energy that entered into the magnetosphere determines a principal distinction of the PC index from AL and Dst indices, which are regarded as characteristics of the energy that realized in magnetosphere in form of substorms and magnetic storms. This conclusion is based on results of analysis of relationships between the polar cap magnetic activity (PC-index) and parameters of the solar wind, on the one hand, relationships between changes of PC and development of magnetospheric substorms (AL-index) and magnetic storms (Dst-index), on the other hand. In this study the relationships between the PC and Dst indices in course of more than 200 magnetic storms observed in epoch of solar maximum (1998-2004) have been examined for different classes of storms separated by their kind and intensity. Results of statistical analysis demonstrate that depression of geomagnetic field starts to develop as soon as PC index steadily excess the threshold level ~1.5 mV/m; the storm intensity (DstMIN) follows, with delay ~ 1 hour, the maximum of PC in course of the storm. Main features of magnetic storms are determined, irrespective of their class and intensity, by the accumulated-mean PC value (PCAM): storm is developed as long as PCAM increases, comes to maximal intensity when PCAM attains the maximum, and starts to decay as soon as PCAM value displays decline. The run of “anomalous” magnetic storm on January 21-22, 2005, lasting many hours (with intensity of ≈ -100 nT) under conditions of northward or close to zero BZ component, is perfectly governed by behavior of the accumulated-mean PCAM index and, therefore, this storm should be regarded as an ordinary phenomenon. The conclusion is made that the PC index provides the unique on-line information on solar wind

Diurnal and seasonal occurrence of polar patches

Directory of Open Access Journals (Sweden)

A. S. Rodger

1996-05-01

Full Text Available Analysis of the diurnal and seasonal variation of polar patches, as identified in two years of HF-radar data from Halley, Antarctica during a period near sunspot maximum, shows that there is a broad maximum in occurrence centred about magnetic noon, not local noon. There are minima in occurrence near midsummer and midwinter, with maxima in occurrence between equinox and winter. There are no significant correlations between the occurrence of polar patches and the corresponding hourly averages of the solar wind and IMF parameters, except that patches usually occur when the interplanetary magnetic field has a southward component. The results can be understood in terms of UT and seasonal differences in the plasma concentration being convected from the dayside ionosphere into the polar cap. In summer and winter the electron concentrations in the polar cap are high and low, respectively, but relatively unstructured. About equinox, a tongue of enhanced ionisation is convected into the polar cap; this tongue is then structured by the effects of the interplanetary magnetic field, but these Halley data cannot be used to separate the various competing mechanisms for patch formation. The observed diurnal and seasonal variation in the occurrence of polar patches are largely consistent with predictions of Sojka et al. (1994 when their results are translated into the southern hemisphere. However, the ionospheric effects of flux transfer events are still considered essential in their formation, a feature not yet included in the Sojka et al. model.

Investigation on Surface Polarization of Al2O3-capped GaN/AlGaN/GaN Heterostructure by Angle-Resolved X-ray Photoelectron Spectroscopy.

Science.gov (United States)

Duan, Tian Li; Pan, Ji Sheng; Wang, Ning; Cheng, Kai; Yu, Hong Yu

2017-08-17

The surface polarization of Ga-face gallium nitride (GaN) (2 nm)/AlGaN (22 nm)/GaN channel (150 nm)/buffer/Si with Al 2 O 3 capping layer is investigated by angle-resolved X-ray photoelectron spectroscopy (ARXPS). It is found that the energy band varies from upward bending to downward bending in the interface region, which is believed to be corresponding to the polarization variation. An interfacial layer is formed between top GaN and Al 2 O 3 due to the occurrence of Ga-N bond break and Ga-O bond forming during Al 2 O 3 deposition via the atomic layer deposition (ALD). This interfacial layer is believed to eliminate the GaN polarization, thus reducing the polarization-induced negative charges. Furthermore, this interfacial layer plays a key role for the introduction of the positive charges which lead the energy band downward. Finally, a N 2 annealing at 400 °C is observed to enhance the interfacial layer growth thus increasing the density of positive charges.

Comparison of Mars Northern Cap Edge Advance and Recession Rates over the Last 6 Mars Years

Science.gov (United States)

Titus, T. N.; Cushing, G. E.; Langevin, Y.; Brown, A. J.; Themis Science Team; CRISM Science Team

2011-12-01

The most observable parameter that describes the Mars polar seasonal caps is their size, which has been measured since the days of Herschel. The advance and retreat of the polar cap from year to year may exhibit many clues to help elucidate little understood physical processes. For example, summertime heat storage in the regolith could delay the onset of seasonal CO2 cap formation. The evolution of the seasonal cap could also be directly affected by the thermal inertia of the near-surface regolith and place constraints on the depth of the ice table. Parameterizations of the seasonal cap edges provide useful constraints on atmospheric GCMs and mesoscale models. Longitudinally resolving the cap edges as they advance and retreat constrains the times when zonal means are appropriate and when longitudinal asymmetries make zonal means invalid. These same kinds of parameterizations can also be used when modeling other data that have low spatial resolutions, such as Gamma Ray Spectrometer (GRS )and Neutron Spectrometer (NS) data. By knowing where the cap edge should be, coarse spatial data can correct for subpixel mixing caused by large point-spread functions including both frosted and frost-free areas. The northern cap exhibits a near symmetric retreat, which has been well characterized at visible wavelengths by both telescopic and spacecraft observations. However, the advance of the cap has not been well characterized until the 21st century. Kieffer and Titus (2001) have used zonal means to observe surface temperature and visible bolometric albedo variations with season using MGS/TES. The TES thermal observations show an almost perfectly symmetrical advance; i.e., condensation at consistent latitude across all longitudes, with the most northern edge of the seasonal cap occurring between longitudes 245°E to 265°E and the most southern edge of the seasonal cap occurring between 280°E and 30°E. The advance of the northern cap typically leads the advance of the edge of

Polar Stratigraphy

Science.gov (United States)

1999-01-01

These three images were taken on three different orbits over the north polar cap in April 1999. Each shows a different part of the same ice-free trough. The left and right images are separated by a distance of more than 100 kilometers (62 miles). Note the similar layers in each image.

Substrate analysis of the Pneumocystis carinii protein kinases PcCbk1 and PcSte20 using yeast proteome microarrays provides a novel method for Pneumocystis signalling biology.

Science.gov (United States)

Kottom, Theodore J; Limper, Andrew H

2011-10-01

Pneumocystis carinii (Pc) undergoes morphological transitions between cysts and trophic forms. We have previously described two Pc serine/threonine kinases, termed PcCbk1 and PcSte20, with PcSte20 belonging to a family of kinases involved in yeast mating, while PcCbk1 is a member of a group of protein kinases involved in regulation of cell cycle, shape, and proliferation. As Pc remains genetically intractable, knowledge on specific substrates phosphorylated by these kinases remains limited. Utilizing the phylogenetic relatedness of Pc to Saccharomyces cerevisiae, we interrogated a yeast proteome microarray containing >4000 purified protein based peptides, leading to the identification of 18 potential PcCbk1 and 15 PcSte20 substrates (Z-score > 3.0). A number of these potential protein substrates are involved in bud site selection, polarized growth, and response to mating α factor and pseudohyphal and invasive growth. Full-length open reading frames suggested by the PcCbk1 and PcSte20 protoarrays were amplified and expressed. These five proteins were used as substrates for PcCbk1 or PcSte20, with each being highly phosphorylated by the respective kinase. Finally, to demonstrate the utility of this method to identify novel PcCbk1 and PcSte20 substrates, we analysed DNA sequence data from the partially complete Pc genome database and detected partial sequence information of potential PcCbk1 kinase substrates PcPxl1 and PcInt1. We additionally identified the potential PcSte20 kinase substrate PcBdf2. Full-length Pc substrates were cloned and expressed in yeast, and shown to be phosphorylated by the respective Pc kinases. In conclusion, the yeast protein microarray represents a novel crossover technique for identifying unique potential Pc kinase substrates. Copyright © 2011 John Wiley & Sons, Ltd.

ORPLOT.PC: a graphic utility for ORMGEN.PC and ORVIRT.PC

International Nuclear Information System (INIS)

Inversini, C.; Bryson, J.W.

1986-06-01

ORPLOT.PC is an interactive graphic utility for ORMGEN.PC and ORVIRT.PC. It executes on an IBM PC/XT or PC/AT equipped with hard disk, graphic card, and 512K minimum memory. The program is capable of: (1) displaying finite-element meshes generated by ORMGEN.PC complete with node numbers, element numbers, and boundary conditions; and (2) generating deformed mesh plots, contour plots, line (X-Y) plots, and developed surface plots of ORVIRT.PC output. A zooming feature allows detailed inspection of any subregion. Because simplicity and ease of use were important objectives during program development, all commands are entered interactively using free format. The option of automatic or user-defined scaling for most plots is another convenience. Plot files may be created and written to hard disk for subsequent hardcopy to printer or plotter. 2 refs., 7 figs

Magnetic-field fluctuations from 0 to 26 Hz observed from a polar-orbiting satellite

International Nuclear Information System (INIS)

Erlandson, R.E.; Zanetti, L.J.; Potemra, T.A.

1989-01-01

The polar orbit of the Viking satellite provides a unique opportunity to obtain observations of magnetic fluctuations at mid-altitudes on the dayside of the magnetosphere and in the polar-cusp region. One type of magnetic-field fluctuation, observed in the dayside magnetosphere, was Pc 1 waves. Pc 1 waves are in the electromagnetic ion-cyclotron mode and are generated by anisotropies in energetic ion distributions. The waves are thought to be generated near the equator and to propagate large distances along magnetic-field lines. Most observations of Pc 1 waves have been obtained near the equator using geosynchronous satellites and on the surface of the earth. The Viking observations provide an opportunity to observe Pc 1 waves at mid-latitudes above the ionosphere and to determine the spectral structure and polarization of the waves. ULF/ELF broadband noise represents a second type of magnetic fluctuation acquired by Viking. This type of magnetic fluctuation was observed at high latitudes near the polar cusp and may be useful in the identification of polar-cusp boundaries. Thirdly, electromagnetic ion-cyclotron waves have also been observed in the polar-cusp region. These waves occur only during an unusually high level of magnetic activity and appear to be generated locally

On an effect of interplanetary magnetic field on a distribution electric fields in the polar ionosphere

International Nuclear Information System (INIS)

Uvarov, V.M.; Barashkov, P.D.

1985-01-01

The problem on the effect of the interplanetary magnetic field (IMF) on the distribution of electric fields in polar ionosphere is discussed. The problem on excitation of electric fields is reduced to the solution of the system of continuity equations for the current in three regions-northern polar cap, southern cap and the region outside the caps. It is shown that one succeeds in reproducing the observed types of distributions of electric fields

Novel function of lecithin-cholesterol acyltransferase. Hydrolysis of oxidized polar phospholipids generated during lipoprotein oxidation.

Science.gov (United States)

Goyal, J; Wang, K; Liu, M; Subbaiah, P V

1997-06-27

Although the major function of lecithin-cholesterol acyltransferase (LCAT) is cholesterol esterification, our previous studies showed that it can also hydrolyze platelet-activating factor (PAF). Because of the structural similarities between PAF and the truncated phosphatidylcholines (polar PCs) generated during lipoprotein oxidation, we investigated the possibility that LCAT may also hydrolyze polar PCs to lyso-PC during the oxidation of plasma. PAF acetylhydrolase (PAF-AH), which is known to hydrolyze polar PCs in human plasma, was completely inhibited by 0.2 mM p-aminoethyl benzenesulfonyl fluoride (Pefabloc), a new serine esterase inhibitor, which had no effect on LCAT at this concentration. On the other hand, 1 mM diisopropylfluorophosphate (DFP) completely inhibited LCAT but had no effect on PAF-AH. Polar PC accumulation during the oxidation of plasma increased by 44% in the presence of 0.2 mM Pefabloc and by 30% in the presence of 1 mM DFP. The formation of lyso-PC was concomitantly inhibited by both of the inhibitors. The combination of the two inhibitors resulted in the maximum accumulation of polar PCs, suggesting that both PAF-AH and LCAT are involved in their breakdown. Oxidation of chicken plasma, which has no PAF-AH activity, also resulted in the formation of lyso-PC from the hydrolysis of polar PC, which was inhibited by DFP. Polar PCs, either isolated from oxidized plasma or by oxidation of labeled synthetic PCs, were hydrolyzed by purified LCAT, which had no detectable PAF-AH activity. These results demonstrate a novel function for LCAT in the detoxification of polar PCs generated during lipoprotein oxidation, especially when the PAF-AH is absent or inactivated.

Evaluation of ZnSe(S) Quantum Dots on the Cell Viability of Prostate Cancer Cell (PC3)

Science.gov (United States)

Calderón-Ortiz, E. R.; Bailón-Ruiz, S.; Martínez-Ferrer, M.; Rodríguez-Orengo, J. F.; Perales-Pérez, O.

2018-05-01

Nanomedicine is described as the process of diagnosing, treating, and preventing disease using nanostructured materials to improve human health. Quantum dots (QDs) host suitable optical properties for light-driven therapies, e.g., photo-dynamic therapy (PDT), for cancer treatment. The efficacy of QDs-assisted PDT relies on the capability of QDs to generate reactive oxygen species, which can be enhanced by inducing structural defects at the atomic level. Furthermore, data concerning the applicability of QDs-PDT in medicine is scarce, particularly for prostate cancer cells (PC3). On this basis, and as a first step in this research, the present report focused on the direct aqueous-synthesis of water-stable ZnSe(S) QDs via a microwave-assisted synthesis approach in the presence of thioglycolic acid (TGA) and mercaptopropionic acid (MPA). XRD analysis confirmed the face centered cubic structure in host ZnS; the average crystallite size was estimated at 10 nm. The photoluminescence of MPA-capped ZnSe(S) showed a strong main emission peak around 363 nm and a trap emission, attributed to structural defects, centered on 450 nm. The photoluminescence spectrum for TGA-capped ZnSe(S) QDs exhibited only the band gap peak around 390 nm, suggesting the absence of major structural defects. In turn, cell viability assays TGA-capped ZnSe(S) were not toxic at concentrations up to 100 ppm, whereas MPA-capped ZnSe(S) evidenced cytotoxicity at a concentration of 10 ppm. The lethal dose (LD50) for the MPA-capped ZnSe(S) in the PC3 cell line was 36 ppm and 35 ppm for 24 h and 48 h, respectively.

Polar observations of electron density distribution in the Earth’s magnetosphere. 2. Density profiles

Directory of Open Access Journals (Sweden)

H. Laakso

2002-11-01

Full Text Available Using spacecraft potential measurements of the Polar electric field experiment, we investigate electron density variations of key plasma regions within the magnetosphere, including the polar cap, cusp, trough, plasmapause, and auroral zone. The statistical results were presented in the first part of this study, and the present paper reports detailed structures revealed by individual satellite passes. The high-altitude (> 3 RE polar cap is generally one of the most tenuous regions in the magnetosphere, but surprisingly, the polar cap boundary does not appear as a steep density decline. At low altitudes (1 RE in summer, the polar densities are very high, several 100 cm-3 , and interestingly, the density peaks at the central polar cap. On the noonside of the polar cap, the cusp appears as a dense, 1–3° wide region. A typical cusp density above 4 RE distance is between several 10 cm-3 and a few 100 cm-3 . On some occasions the cusp is crossed multiple times in a single pass, simultaneously with the occurrence of IMF excursions, as the cusp can instantly shift its position under varying solar wind conditions, similar to the magnetopause. On the nightside, the auroral zone is not always detected as a simple density cavity. Cavities are observed but their locations, strengths, and sizes vary. Also, the electric field perturbations do not necessarily overlap with the cavities: there are cavities with no field disturbances, as well as electric field disturbances observed with no clear cavitation. In the inner magnetosphere, the density distributions clearly show that the plasmapause and trough densities are well correlated with geomagnetic activity. Data from individual orbits near noon and midnight demonstrate that at the beginning of geomagnetic disturbances, the retreat speed of the plasmapause can be one L-shell per hour, while during quiet intervals the plasmapause can expand anti-earthward at the same speed. For the trough region, it is found

The electrodynamic, thermal, and energetic character of intense sun-aligned arcs in the polar cap

International Nuclear Information System (INIS)

Valladares, C.E.; Carlson, H.C. Jr.

1991-01-01

The authors report here measurements of two intense Sun-aligned arcs. The two arcs were diagnosed on two different nights (February 26 and March 1, 1987) using the Sondre Stromfjord radar as a stand-alone diagnostic. Repeatable patterns are found in mesoscale area (order 10 3 km by 10 3 km) maps of altitude profiles for observed electron and ion gas number densities, temperatures and line-of-sight velocities, and projected mesoscale area maps of derived electric fields, Pedersen and Hall conductivities (N e , T e , T i , V, E, Σ p , Σ H ), horizontal and field-aligned currents, joule heating rate, and Poynting flux. They confirm, for the first time with continuous mesoscale area maps, that the arcs have the anticipated simple arc electrodynamics. That is, the visual and enhanced ionization signatures of the arc are produced by incoming energetic electrons carrying the outgoing current from the electric field convergence in the arc. Strong electron temperature enhancements (>2,000 K) are found as expected within the sheets of ionizing particle precipitation. Dawn to dusk decreases in the antisunward plasma flow of order 1 km s -1 , across order 100 km, correspond to peak electron densities of order 10 5 cm -3 down to altitudes as low as 120 km, and upward currents of order 1 μA m -2 . These data also lead to important implications for the physics of polar cap arcs. The high-velocity (antisunward flow on the dawnside) edge of the arc marks the location of strong persistent Joule heating driven by downward Poynting flux. The deposition rate into the atmosphere of the net electromagnetic energy well exceeds the net particle energy deposited by the ionizing energetic electron flux. This heating is a substantial source of heat into the polar thermosphere

Electrically Rotatable Polarizer Using One-Dimensional Photonic Crystal with a Nematic Liquid Crystal Defect Layer

Directory of Open Access Journals (Sweden)

Ryotaro Ozaki

2015-09-01

Full Text Available Polarization characteristics of defect mode peaks in a one-dimensional (1D photonic crystal (PC with a nematic liquid crystal (NLC defect layer have been investigated. Two different polarized defect modes are observed in a stop band. One group of defect modes is polarized along the long molecular axis of the NLC, whereas another group is polarized along its short axis. Polarizations of the defect modes can be tuned by field-induced in-plane reorientation of the NLC in the defect layer. The polarization properties of the 1D PC with the NLC defect layer is also investigated by the finite difference time domain (FDTD simulation.

Rocket measurements within a polar cap arc: Plasma, particle, and electric circuit parameters

International Nuclear Information System (INIS)

Weber, E.J.; Ballenthin, J.O.; Basu, S.; Carlson, H.C.; Hardy, D.A.; Maynard, N.C.; Smiddy, M.; Kelley, M.C.; Fleischman, J.R.; Sheehan, R.E.; Pfaff, R.F.; Rodriguez, P.

1989-01-01

An instrumented rocket payload was launched into a polar cap F layer aurora to investigate the energetic particle, plasma, and electric circuit parameters of a Sun-aligned arc. On-board instruments measured energetic electron flux, ion composition and density fluctuations, electron density and temperature, electron density fluctuations, and ac and dc electric fields. Real-time all-sky imaging photometer measurements of the location and motion of the aurora, were used to determine the proper geophysical situation for launch. Comparison of the in situ measurements with remote optical measurements shows that the arc was produced by fluxes of low-energy (< 1 keV) electrons. Field-aligned potentials in the arc inferred from the electron spectra had a maximum value of approximately 300 V, and from the spectral shape a parent population of preaccelerated electrons characteristic of the boundary plasma sheet or magnetosheath was inferred. Electric field components along and across the arc show sunward flow within the arc and duskward drift of the arc consistent with the drift direction and speed determined from optical imaging. Thus this arc is drifting duskward under the influence of the convection electric field. Three possible explanations for this (field-aligned currents, chemistry, and transport) are considered. Finally, ionospheric irregularity and electric field fluctuations indicate two different generation mechanisms on the dawnside and duskside of the arc. On the duskside, parameters are suggestive of an interchange process, while on the dawnside, fluctuation parameters are consistent with a velocity shear instability

Local time asymmetry of Pc 4--5 pulsations and associated particle modulations at synchronous orbit

International Nuclear Information System (INIS)

Kokubun, S.; Erickson, K.N.; Fritz, T.A.; McPherron, R.L.

1989-01-01

Magnetic field and particle flux observations on board ATS 6 at synchronous altitude are used to examine the dawn-dusk asymmetry of characteristics of Pc 4--5 waves and associated particle flux modulation. Most waves at synchronous orbit having ground correlations are polarized in the azimuthal direction (A class) and are usually detected in the dawn sector. Waves with a radially oriented polarization ellipse (R-class) are almost never observed near the subsatellite point on the ground, except for the regular pulsations known as giant pulsation Pg, observed in the early morning. R class Pc 4 waves occur at all local times and have an occurrence peak in the afternoon

''Electron Conic'' Signatures observed in the nightside auroral zone and over the polar cap

International Nuclear Information System (INIS)

Menietti, J.D.; Burch, J.L.

1985-01-01

A preliminary search of the Dynamics Explorer 1 high-altitude plasma instrument data base has yielded examples of ''electron conic'' signatures. The three example passes show an association with regions of downward electron acceleration and upward ion beams, but this is not true of all the electron conic events. The electron conic signatures are clearly discernible on energy-flux-versus-time color spectrograms as pairs of discrete vertical bands which are symmetric about a pitch angle of approximately 180 0 . One of the examples is a polar cap pass with electron conic signatures observed at invariant latitudes from 84 0 to 75 0 . The other two cases are nightside auroral zone passes in which the regions of detectable electron conics are spatially more confined, covering only about 1 0 in invariant latitude. The conic signatures have been found at energies that range from 50 eV 0 is larger than expected for a loss cone feature. If the electrons conserve the first adiabatic invariant in a dipole magnetic field, and in some cases a parallel electric field, the mirroring altitude varies between about 500 km and 8000 km, which is above the atmospheric loss region. For this reason, and in analogy with the formation of ion conics, we suggest that the conic signatures are produced by heating of the electrons perpendicular to the magnetic field

On the spatial relationship between auroral emissions and magnetic signatures of plasma convection in the midday polar cusp and cap ionospheres during negative and positive IMF Bsub(z)

International Nuclear Information System (INIS)

Sandholt, P.E.; Egeland, A.; Lybekk, B.

1986-03-01

The dynamics of midday auroras, including polar cusp and cap emissions, and their relation to the interplanetary magnetic field (IMF) have been investigated with optical ground-based observations from Svalbard, Norway and IMF data from spacecraft ISEE-2. One case is presented showing the spatial relationship, along the magnetic meridian in the midday sector, between the cusp aurora and IMF Bγ-related convection currets (the DPY signature) for negative and positive values of IMF Bsub(z)

Model of the polar ionosphere with account for the interplanetary medium

International Nuclear Information System (INIS)

Uvarov, V.M.; Barashkov, P.D.; Zakharova, A.P.

1992-01-01

The effect of IMR B y -component on F-region structure is simulated numerically. An additional convective vortex is reflected in the structure of F2 electronic density isolines in the form of vortex-live depression on the day half of the polar cap when B y y >0), the ionization is more profound on the night (daytime) side of the polar cap; plasma cavity is centered for after (before) midnight hours; F2 electron density increases (decreases) in the auroral peak and vortex-like depression is localized at p.m (a.m) hours

Ice Caps and Ice Belts: The Effects of Obliquity on Ice−Albedo Feedback

Energy Technology Data Exchange (ETDEWEB)

Rose, Brian E. J. [Department of Atmospheric and Environmental Sciences, University at Albany (State University of New York), 1400 Washington Avenue, Albany, NY 12222 (United States); Cronin, Timothy W. [Program in Atmospheres, Oceans, and Climate, Massachusetts Institute of Technology 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Bitz, Cecilia M., E-mail: brose@albany.edu [Department of Atmospheric Sciences, MS 351640, University of Washington, Seattle, WA 98195-1640 (United States)

2017-09-01

Planetary obliquity determines the meridional distribution of the annual mean insolation. For obliquity exceeding 55°, the weakest insolation occurs at the equator. Stable partial snow and ice cover on such a planet would be in the form of a belt about the equator rather than polar caps. An analytical model of planetary climate is used to investigate the stability of ice caps and ice belts over the widest possible range of parameters. The model is a non-dimensional diffusive Energy Balance Model, representing insolation, heat transport, and ice−albedo feedback on a spherical planet. A complete analytical solution for any obliquity is given and validated against numerical solutions of a seasonal model in the “deep-water” regime of weak seasonal ice line migration. Multiple equilibria and unstable transitions between climate states (ice-free, Snowball, or ice cap/belt) are found over wide swaths of parameter space, including a “Large Ice-Belt Instability” and “Small Ice-Belt Instability” at high obliquity. The Snowball catastrophe is avoided at weak radiative forcing in two different scenarios: weak albedo feedback and inefficient heat transport (favoring stable partial ice cover), or efficient transport at high obliquity (favoring ice-free conditions). From speculative assumptions about distributions of planetary parameters, three-fourths to four-fifths of all planets with stable partial ice cover should be in the form of Earth-like polar caps.

Large plasma density enhancements occurring in the northern polar region during the 6 April 2000 superstorm

Science.gov (United States)

Horvath, Ildiko; Lovell, Brian C.

2014-06-01

We focus on the ionospheric response of northern high-latitude region to the 6 April 2000 superstorm and aim to investigate how the storm-enhanced density (SED) plume plasma became distributed in the regions of auroral zone and polar cap plus to study the resultant ionospheric features and their development. Multi-instrument observational results combined with model-generated, two-cell convection maps permitted identifying the high-density plasma's origin and the underlying plasma transportation processes. Results show the plasma density feature of polar cap enhancement (PCE; 600 × 103 i+/cm3) appearing for 7 h during the main phase and characterized by increases reaching up to 6 times of the quiet time values. Meanwhile, strong westward convections ( 17,500 m/s) created low plasma densities in a wider region of the dusk cell. Oppositely, small ( 750 m/s) but rigorous westward drifts drove the SED plume plasma through the auroral zone, wherein plasma densities doubled. As the SED plume plasma traveled along the convection streamlines and entered the polar cap, a continuous enhancement of the tongue of ionization (TOI) developed under steady convection conditions. However, convection changes caused slow convections and flow stagnations and thus segmented the TOI feature by locally depleting the plasma in the affected regions of the auroral zone and polar cap. From the strong correspondence of polar cap potential drop and subauroral polarization stream (SAPS), we conclude that the SAPS E-field strength remained strong, and under its prolonged influence, the SED plume provided a continuous supply of downward flowing high-density plasma for the development and maintenance of PCEs.

Dynamics of the polar ionosphere structure disturbance in the Svalgaard-Mansurov effect

International Nuclear Information System (INIS)

Osipov, N.K.; Mozhaev, A.M.; Larina, T.N.; Ponomarev, Yu.N.

1988-01-01

Nonstationary disturbance model of the ionsphere of polar caps caused by change of B y component sign of interplanetary magnetic field is considered. It is shown that nonstationary convection transfer of ionospheric plasma represents the main and the most fast mechanism regulating reconstruction of ionosphere structure in polar caps during magnetosphere substorms, caused by the change of B y sign. Calculations show that characteristic time of sufficient change of ionosphere structure at ∼1500 km distances is on the order of 10-25 min

Cervical Cap

Science.gov (United States)

... Videos for Educators Search English Español The Cervical Cap KidsHealth / For Teens / The Cervical Cap What's in ... Call the Doctor? Print What Is a Cervical Cap? A cervical cap is a small cup made ...

PC communication

International Nuclear Information System (INIS)

Oh, Jae Cheol

1992-03-01

This text book is comprised of five charters, which is about PC communication for beginners who need to learn manners and how to use Ketel and PC serve. So it introduces first, conception of PC and precautions on using PC communication, second, preparation for PC communication with Modem, its program, install, kinds of protocol and how to use protocol, third directions of emulator of PC communication and super session, fourth, instruction of Ketel with join and access, basic command of Ketel, list of Ketel's menu, Ketel editor, service guide, directions of News service, Stock and bond service business and economic figures, exchange rate and interest rate, tax culture and leisure, Ketel BBS service and posting. The last part has a instruction of PC-serve about join, basic command of PC-serve, service guide and practical guideline.

PC communication

Energy Technology Data Exchange (ETDEWEB)

Oh, Jae Cheol

1992-03-15

This text book is comprised of five charters, which is about PC communication for beginners who need to learn manners and how to use Ketel and PC serve. So it introduces first, conception of PC and precautions on using PC communication, second, preparation for PC communication with Modem, its program, install, kinds of protocol and how to use protocol, third directions of emulator of PC communication and super session, fourth, instruction of Ketel with join and access, basic command of Ketel, list of Ketel's menu, Ketel editor, service guide, directions of News service, Stock and bond service business and economic figures, exchange rate and interest rate, tax culture and leisure, Ketel BBS service and posting. The last part has a instruction of PC-serve about join, basic command of PC-serve, service guide and practical guideline.

Integration of a photonic crystal polarization beam splitter and waveguide bend.

Science.gov (United States)

Zheng, Wanhua; Xing, Mingxin; Ren, Gang; Johnson, Steven G; Zhou, Wenjun; Chen, Wei; Chen, Lianghui

2009-05-11

In this work, we present the design of an integrated photonic-crystal polarization beam splitter (PC-PBS) and a low-loss photonic-crystal 60 degrees waveguide bend. Firstly, the modal properties of the PC-PBS and the mechanism of the low-loss waveguide bend are investigated by the two-dimensional finite-difference time-domain (FDTD) method, and then the integration of the two devices is studied. It shows that, although the individual devices perform well separately, the performance of the integrated circuit is poor due to the multi-mode property of the PC-PBS. By introducing deformed airhole structures, a single-mode PC-PBS is proposed, which significantly enhance the performance of the circuit with the extinction ratios remaining above 20 dB for both transverse-electric (TE) and transverse-magnetic (TM) polarizations. Both the specific result and the general idea of integration design are promising in the photonic crystal integrated circuits in the future.

Simulations of the general circulation of the Martian atmosphere. I - Polar processes

Science.gov (United States)

Pollack, James B.; Haberle, Robert M.; Schaeffer, James; Lee, Hilda

1990-01-01

Numerical simulations of the Martian atmosphere general circulation are carried out for 50 simulated days, using a three-dimensional model, based on the primitive equations of meteorology, which incorporated the radiative effects of atmospheric dust on solar and thermal radiation. A large number of numerical experiments were conducted for alternative choices of seasonal date and dust optical depth. It was found that, as the dust content of the winter polar region increased, the rate of atmospheric CO2 condensation increased sharply. It is shown that the strong seasonal variation in the atmospheric dust content observed might cause a number of hemispheric asymmetries. These asymmetries include the greater prevalence of polar hoods in the northern polar region during winter, the lower albedo of the northern polar cap during spring, and the total dissipation of the northern CO2 ice cap during the warmer seasons.

Additions and corrections to the absorption coefficients of CO2 ice: Applications to the Martian south polar cap

International Nuclear Information System (INIS)

Calvin, W.M.

1990-01-01

Reflectance spectra of carbon dioxide frosts were calculated using the optical constants provided by Warren (1986) for the wavelength region 2-6 μm. In comparing these calculated spectra to spectra of frosts observed in the laboratory and on the surface of Mars, problems in the optical constants presented by Warren (1986) became apparent. Absorption coefficients for CO 2 ice have been derived using laboratory reflectance measurements and the Hapke (1981) model for calculating diffuse reflectance. This provides approximate values in regions where no data were previously available and indicates where corrections to the compilation by Warren (1986) are required. Using these coefficients to calculate the reflectance of CO 2 ice at varying grain sizes indicates that a typical Mariner polar cap spectrum is dominated by absorptions due to CO 2 frost or ice at grain sizes that are quite large, probably of the order of millimeters to centimeters. There are indications of contamination of water frost or dust, but confirmation will require more precise absorption coefficients for solid CO 2 than can be obtained from the method used here

Generation of coordinates in PC for graphics of polar figure

International Nuclear Information System (INIS)

Macias B, L.R.

1991-10-01

The preferential orientation, not alone it exists in metals, but also in minerals or in general in crystalline materials, notwithstanding in the metals it can be transformed by means of those processes of having mechanical worked such as laminate, wrapping, etc. To the preferable orientation of the crystals is also known as texture and since the properties of the crystalline materials lens depend on the orientation that present its glasses, it is important to know its texture. The difficulty for to represent and to describe the grade of preferential orientation in textured materials take to F. Weber to adapt the stereo graphic projection of a monocrystal to a poles figure. Later on, its appeared but methods to obtain the polar figure, among them, that of reflection of L. G. Schultz, but again a technique appears it specifies for its obtaining. In all the cases, the methodology is the following one: a) It is obtained by means of the diffraction process, the correspondent spectra in digitized form. b) it is applied process of having softened mathematician of the spectrum. c) there are determined the fi coordinates, beta and intensity for graph nts of the polar figure. d) Its are graph the points generated in c obtaining the polar figures. The objective of this work, is leaving of a softened spectra, to generate the coordinated fi, beta and corresponding intensity to proceed to their graph and generation of the polar figure. In this specific work, the methodology of Philips is used that consists in making a sweeping in hairspring form with the radiation to detect in these points the execution of the Bragg law. (Author)

A snapshot of the polar ionosphere

International Nuclear Information System (INIS)

Whitteker, J.H.

1976-01-01

This paper presents a picture of the north polar F layer and topside ionosphere obtained primarily from three satellites (Alouette 2, ISIS 1, ISIS 2), that passed over the region within a time interval of ca. 50 min on 25 April 1971, a magnetically quiet day. The horizontal distribution of electron densities at the peak of the F layer is found to be similar to synoptic results from the IGY. Energetic particle and ionospheric plasma data are also presented, and the F layer data are discussed in terms of these measurements, and also in terms of electric field and neutral N 2 density measurements made by other satellites on other occasions. The major features observed are as follows: A tongue of F region ionization extends from the dayside across the polar cap, which is accounted for by antisunward drift due to magnetospheric convection. In the F layer and topside ionosphere, the main effect of auroral precipitation appears to be heating and expansion of the topside. A region of low F layer density appears on the morning side of the polar cap, which may be due to convection and possibly also to enhanced N 2 densities. (author)

Single NdPc2 molecules on surfaces. Adsorption, interaction, and molecular magnetism

International Nuclear Information System (INIS)

Fahrendorf, Sarah

2013-01-01

They have huge potential for application in molecular-spin-transistors, molecular-spinvalves, and molecular quantum computing. SMMs are characterized by high spin ground states with zero-field splitting leading to high relaxation barriers and long relaxation times. A relevant class of molecules are the lanthanide double-decker phthalocyanines (LaPc 2 ) with only one metal atom sandwiched between two organic phthalocyanine (Pc) ligands. For envisaged spintronic applications it is important to understand the interaction between the molecules and the substrate and its influence on the electronic and magnetic properties. The subject of this thesis is the investigation of the adsorbed neodymium double-decker phthalocyanine (NdPc 2 ) by means of low temperature scanning tunneling microscopy and spectroscopy (STM and STS). The molecules are deposited by sublimation onto different substrates. It is observed that a large fraction of the double-decker molecules decomposes during deposition. The decomposition probability strongly depends on the chosen substrate. Therefore it is concluded that the substrate modifies the electronic structure of the molecule leading to a stabilization or destabilization of the molecular entity. Charge transfer from the surface to the molecule is identified as a potential stabilizing mechanism. The electronic and magnetic properties are investigated in detail for adsorbed NdPc 2 molecules on Cu(100). The results of the experimental study are compared to state-of-the-art density functional theory calculations performed by our colleagues from the Peter Gruenberg Institute (PGI-1) at the Forschungszentrum Juelich. Interestingly, the lower Pc ring of the molecule hybridizes intensely with the substrate leading to strong chemisorption of the molecule, while the upper Pc ring keeps its molecular type electronic states, which can be energetically shifted by an external electric field. Importantly, it is possible to get direct access to the spin-polarized

Experimental investigation of insolation-driven dust ejection from Mars' CO2 ice caps

Science.gov (United States)

Kaufmann, E.; Hagermann, A.

2017-01-01

Mars' polar caps are - depending on hemisphere and season - partially or totally covered with CO2 ice. Icy surfaces such as the polar caps of Mars behave differently from surfaces covered with rock and soil when they are irradiated by solar light. The latter absorb and reflect incoming solar radiation within a thin layer beneath the surface. In contrast, ices are partially transparent in the visible spectral range and opaque in the infrared. Due to this fact, the solar radiation can penetrate to a certain depth and raise the temperature of the ice or dust below the surface. This may play an important role in the energy balance of icy surfaces in the solar system, as already noted in previous investigations. We investigated the temperature profiles inside CO2 ice samples including a dust layer under Martian conditions. We have been able to trigger dust eruptions, but also demonstrated that these require a very narrow range of temperature and ambient pressure. We discuss possible implications for the understanding of phenomena such as arachneiform patterns or fan shaped deposits as observed in Mars' southern polar region.

South Polar Polygons

Science.gov (United States)

2005-01-01

4 July 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a polgyon-cracked surface, into which deep, somewhat kidney-bean-shaped pits have formed. These are landscapes of the martian south polar residual cap. This view was captured during May 2005. Location near: 86.9oS, 5.1oW Image width: 1.5 km (0.9 mi) Illumination from: upper left Season Southern Spring

Polarity control and growth mode of InN on yttria-stabilized zirconia (111) surfaces

International Nuclear Information System (INIS)

Kobayashi, Atsushi; Okubo, Kana; Ohta, Jitsuo; Oshima, Masaharu; Fujioka, Hiroshi

2012-01-01

We have found that polarity of epitaxial InN layers has been controlled by choice of a capping material during high-temperature annealing of yttria-stabilized zirconia (YSZ) (111) substrates in air. Angle-resolved X-ray photoelectron spectroscopy has revealed that the amount of segregation of Y atoms to the YSZ surface depended on the capping material of the substrates. In-polar and N-polar InN have been reproducibly grown on Y-segregated and Y-segregation-free YSZ surfaces, respectively. We have also found that the growth of the first monolayer (ML) of N-polar InN proceeds in a step-flow mode which then switches to layer-by-layer mode after the coverage by 1-ML-thick InN. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Simultaneously improving optical absorption of both transverse-electric polarized and transverse-magnetic polarized light for organic solar cells with Ag grating used as transparent electrode

Directory of Open Access Journals (Sweden)

Yongbing Long

2014-08-01

Full Text Available Theoretical simulations are performed to investigate optical performance of organic solar cells with Ag grating electrode. It is demonstrated that optical absorption for both transverse-electric (TE polarized and transverse-magnetic(TM polarized light is simultaneously improved when compared with that for the device without the Ag grating. The improvement is respectively attributed to the resonance and the surface plasmon polaritons within the device. After an additional WO3 layer is capped on the Ag grating, absorption of TE-polarized light is further improved due to resonance of double microcavities within the device, and absorption of TM-polarized light is improved by the combined effects of the microcavity resonance and the surface plasmon polaritons. Correspondingly, the short current density for randomly polarized light is improved by 18.1% from that of the device without the Ag grating. Finally, it is demonstrated that high transmission may not be an essential prerequisite for metallic gratings when they are used as transparent electrode since absorption loss caused by low transmission can be compensated by using a capping layer to optimize optical resonance of the WMC structure within the device.

On determining the noon polar cap boundary from SuperDARN HF radar backscatter characteristics

Directory of Open Access Journals (Sweden)

M. Pinnock

Full Text Available Previous work has shown that ionospheric HF radar backscatter in the noon sector can be used to locate the footprint of the magnetospheric cusp particle precipitation. This has enabled the radar data to be used as a proxy for the location of the polar cap boundary, and hence measure the flow of plasma across it to derive the reconnection electric field in the ionosphere. This work used only single radar data sets with a field of view limited to ~2 h of local time. In this case study using four of the SuperDARN radars, we examine the boundary determined over 6 h of magnetic local time around the noon sector and its relationship to the convection pattern. The variation with longitude of the latitude of the radar scatter with cusp characteristics shows a bay-like feature. It is shown that this feature is shaped by the variation with longitude of the poleward flow component of the ionospheric plasma and may be understood in terms of cusp ion time-of-flight effects. Using this interpretation, we derive the time-of-flight of the cusp ions and find that it is consistent with approximately 1 keV ions injected from a subsolar reconnection site. A method for deriving a more accurate estimate of the location of the open-closed field line boundary from HF radar data is described.

Key words: Ionosphere (ionosphere–magnetosphere interactions; plasma convection · Magnetospheric physics (magnetopause · cusp · and boundary layers

Cervical Cap

Science.gov (United States)

... giving birth vaginally, which means the cervical cap may not fit as well. Inconsistent or incorrect use of the cervical cap increases your risk of pregnancy. For example, you may get pregnant when using the cervical cap if: ...

Parabolic heavy ion flow in the polar magnetosphere

International Nuclear Information System (INIS)

Horwitz, J.L.

1987-01-01

Recent observations by the Dynamics Explorer 1 satellite over the dayside polar cap magnetosphere have indicated downward flows of heavy ions (O + , O ++ , N + , N ++ ) with flow velocities of the order 1 km/s (Lockwood et al., 1985b). These downward flows were interpreted as the result of parabolic flow of these heavy ionospheric ions from a source region associated with the polar cleft topside ionosphere. Here the author utilizes a two-dimensional kinetic model to elicit features of the transport of very low energy O + ions from the cleft ionosphere. Bulk parameter (density, flux, thermal energies, etc.) distributions in the noon-midnight meridian plane illustrate the effects of varying convection electric fields and source energies. The results illustrate that particularly under conditions of weak convection electric fields and weak ion heating in the cleft region, much of the intermediate altitude polar cap magnetosphere may be populated by downward flowing heavy ions. It is further shown how two-dimensional transport effects may alter the characteristic vertical profiles of densities and fluxes from ordinary profiles computed in one-dimensional steady state models

Variations of the electron concentration in the polar ionosphere

International Nuclear Information System (INIS)

Chasovitin, Yu.K.; Shushkova, V.B.

1980-01-01

The possibility of constructing an empirical model of electron concentration in the polar ionosphere is considered. The results of rocket measurements carried out at Fort Churchill and on the Hays island at 70-210 km heights are used to analyse the distribution of electron concentration in the non-illuminated sector of the auroral oval, in the subauroral ionosphere and in the polar cap. Taking account of magnetospheric-ionospheric relationships and the geomagnetic environment, certain regularities in the distribution of electron concentration in the polar field, which may serve as a basis for constructing an empirical model of the polar ionosphere have been identified

Single NdPc{sub 2} molecules on surfaces. Adsorption, interaction, and molecular magnetism

Energy Technology Data Exchange (ETDEWEB)

Fahrendorf, Sarah

2013-01-24

spin-polarized 4f-states of the central Nd ion by means of STM and STS. This important and unique characteristic absent for late lanthanide double-decker phthalocyanine molecules opens the door for direct reading and writing of the molecular spin-state by purely electrical means. In view of the intended investigations of the magnetic properties of the NdPc2 molecule coupled to ferromagnetic surfaces, spin-polarized STM investigations of the second atomic layer of Fe on W(110) are performed. Here, bulk Cr-tips are used, which were ex-situ electrochemically etched from a Cr rod. Further in-situ treatment is shown to have no essential influence on the magnetic properties of the tips. The reproducible and reliable preparation of the ferromagnetic substrate and the Cr-tips is the basis for further investigations of the NdPc{sub 2} molecule adsorbed on the second atomic layer of Fe on W(110). Preliminary STM and STS results give strong evidence, that the direct access to the spin-polarized 4f-states is also feasible after adsorption of the double-decker molecule on a ferromagnetic substrate.

Evaluation of thermodynamic properties of fluid mixtures by PC-SAFT model

International Nuclear Information System (INIS)

Almasi, Mohammad

2014-01-01

Experimental and calculated partial molar volumes (V ¯ m,1 ) of MIK with (♦) 2-PrOH, (♢) 2-BuOH, (●) 2-PenOH at T = 298.15 K. (—) PC-SAFT model. - Highlights: • Densities and viscosities of the mixtures (MIK + 2-alkanols) were measured. • PC-SAFT model was applied to correlate the volumetric properties of binary mixtures. • Agreement between experimental data and calculated values by PC-SAFT model is good. - Abstract: Densities and viscosities of binary mixtures of methyl isobutyl ketone (MIK) with polar solvents namely, 2-propanol, 2-butanol and 2-pentanol, were measured at 7 temperatures (293.15–323.15 K) over the entire range of composition. Using the experimental data, excess molar volumes V m E , isobaric thermal expansivity α p , partial molar volumes V ¯ m,i and viscosity deviations Δη, have been calculated due to their importance in the study of specific molecular interactions. The observed negative and positive values of deviation/excess parameters were explained on the basis of the intermolecular interactions occur in these mixtures. The Perturbed Chain Statistical Association Fluid Theory (PC-SAFT) has been used to correlate the volumetric behavior of the mixtures

Anti-pp,. cap alpha cap alpha. and p. cap alpha. elastic scattering at high energies and Chou-Yang conjecture

Energy Technology Data Exchange (ETDEWEB)

Saleem, M.; Fazal-e-Aleem; Rifique, M.

1987-03-01

The recent experimental measurements for anti-pp and ..cap alpha cap alpha.. elastic scattering at high energies have shown that the Chou-Yang conjecture regarding the relationship between the electromagnetic and the hadronic form factor of a particle is only an approximation. A new ansatz has been proposed to obtain hadronic form factors of proton and the ..cap alpha..-particle. These form factors have been used to explain the various characteristics of anti-pp, ..cap alpha cap alpha.. and p..cap alpha.. elastic scattering at high energies.

Carrier and polarization dynamics in monolayer MoS2: temperature and power dependence

Science.gov (United States)

Urbaszek, Bernhard; Lagarde, D.; Bouet, L.; Amand, T.; Marie, X.; Zhu, C. R.; Liu, B. L.; Tan, P. H.

2014-03-01

In monolayer (ML) MoS2 optical transitions across the direct bandgap are governed by chiral selection rules, allowing optical k-valley initialization. Here we present the first time resolved photoluminescence (PL) polarization measurements in MoS2 MLs, providing vital information on the electron valley dynamics. Using quasi-resonant excitation of the A-exciton transitions, we can infer that the PL decays within τ ~= 4ps. The PL polarization of Pc ~ 60 % remains nearly constant in time for experiments from 4K - 300K, a necessary condition for the success of future Valley Hall experiments. τ does not vary significantly over this temperature range. This is surprising when considering the decrease of Pc in continuous wave experiments when going from 4K to 300K reported in the literature. By tuning the laser following the shift of the A-exciton resonance with temperature we are able to recover at 300K ~ 80 % of the polarization observed at 4K. For pulsed laser excitation, we observe a decrease of Pc with increasing laser power at all temperatures.

76 FR 5467 - Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350...

Science.gov (United States)

2011-02-01

...;Prices of new books are listed in the first FEDERAL REGISTER issue of each #0;week. #0; #0; #0; #0;#0..., Fairchild Heli Porter PC-6 airplanes, or Fairchild-Hiller Corporation PC-6 airplanes. Discussion Section... [[Page 5469

Analysis of RNA binding by the dengue virus NS5 RNA capping enzyme.

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Brittney R Henderson

Full Text Available Flaviviruses are small, capped positive sense RNA viruses that replicate in the cytoplasm of infected cells. Dengue virus and other related flaviviruses have evolved RNA capping enzymes to form the viral RNA cap structure that protects the viral genome and directs efficient viral polyprotein translation. The N-terminal domain of NS5 possesses the methyltransferase and guanylyltransferase activities necessary for forming mature RNA cap structures. The mechanism for flavivirus guanylyltransferase activity is currently unknown, and how the capping enzyme binds its diphosphorylated RNA substrate is important for deciphering how the flavivirus guanylyltransferase functions. In this report we examine how flavivirus NS5 N-terminal capping enzymes bind to the 5' end of the viral RNA using a fluorescence polarization-based RNA binding assay. We observed that the K(D for RNA binding is approximately 200 nM Dengue, Yellow Fever, and West Nile virus capping enzymes. Removal of one or both of the 5' phosphates reduces binding affinity, indicating that the terminal phosphates contribute significantly to binding. RNA binding affinity is negatively affected by the presence of GTP or ATP and positively affected by S-adensyl methoninine (SAM. Structural superpositioning of the dengue virus capping enzyme with the Vaccinia virus VP39 protein bound to RNA suggests how the flavivirus capping enzyme may bind RNA, and mutagenesis analysis of residues in the putative RNA binding site demonstrate that several basic residues are critical for RNA binding. Several mutants show differential binding to 5' di-, mono-, and un-phosphorylated RNAs. The mode of RNA binding appears similar to that found with other methyltransferase enzymes, and a discussion of diphosphorylated RNA binding is presented.

Cradle Cap (For Parents)

Science.gov (United States)

... Safe Videos for Educators Search English Español Cradle Cap (Infantile Seborrheic Dermatitis) KidsHealth / For Parents / Cradle Cap ( ... many babies develop called cradle cap. About Cradle Cap Cradle cap is the common term for seborrheic ...

Effect of the interplanetary magnetic field on the distribution of electric fields in the polar ionosphere

Science.gov (United States)

Uvarov, V. M.; Barashkov, P. D.

1985-08-01

Heppner (1972), in an analysis of satellite data, observed 12 types of electric-field distributions in the polar ionosphere along the morning-evening meridian. In the present paper it is shown that these distribution types can be described by the analytical model of Uvarov and Barashkov (1984). In this model the excitation of the electric fields is investigated by solving the set of continuity equations for current in three regions (the north and south polar caps and a region outside the caps) with allowance for the magnetic conjugacy of the ionosphere in the two hemispheres.

Evaluation of thermodynamic properties of fluid mixtures by PC-SAFT model

Energy Technology Data Exchange (ETDEWEB)

Almasi, Mohammad, E-mail: m.almasi@khouzestan.srbiau.ac.ir

2014-09-10

Experimental and calculated partial molar volumes (V{sup ¯}{sub m,1}) of MIK with (♦) 2-PrOH, (♢) 2-BuOH, (●) 2-PenOH at T = 298.15 K. (—) PC-SAFT model. - Highlights: • Densities and viscosities of the mixtures (MIK + 2-alkanols) were measured. • PC-SAFT model was applied to correlate the volumetric properties of binary mixtures. • Agreement between experimental data and calculated values by PC-SAFT model is good. - Abstract: Densities and viscosities of binary mixtures of methyl isobutyl ketone (MIK) with polar solvents namely, 2-propanol, 2-butanol and 2-pentanol, were measured at 7 temperatures (293.15–323.15 K) over the entire range of composition. Using the experimental data, excess molar volumes V{sub m}{sup E}, isobaric thermal expansivity α{sub p}, partial molar volumes V{sup ¯}{sub m,i} and viscosity deviations Δη, have been calculated due to their importance in the study of specific molecular interactions. The observed negative and positive values of deviation/excess parameters were explained on the basis of the intermolecular interactions occur in these mixtures. The Perturbed Chain Statistical Association Fluid Theory (PC-SAFT) has been used to correlate the volumetric behavior of the mixtures.

Glycosaminoglycan composition of PC12 pheochromocytoma cells: a comparison with PC12D cells, a new subline of PC12 cells

Energy Technology Data Exchange (ETDEWEB)

Katoh-Semba, R.; Oohira, A.; Sano, M.; Watanabe, K.; Kitajima, S.; Kashiwamata, S.

1989-03-01

PC12D cells, a new subline of conventional PC12 cells, respond not only to nerve growth factor but also to cyclic AMP by extending their neurites. These cells are flat in shape and are similar in appearance to PC12 cells that have been treated with nerve growth factor for a few days. In both cell lines, we have characterized the glycosaminoglycans, the polysaccharide moieties of proteoglycans, which are believed to play an important role in cell adhesion and in cell morphology. Under the present culture conditions, only chondroitin sulfate was detected in the media from PC12 and PC12D cells, whereas both chondroitin sulfate and heparan sulfate were found in the cell layers. The levels of cell-associated heparan sulfate and chondroitin sulfate were about twofold and fourfold higher in PC12D cells than in PC12 cells, respectively. Compared to PC12 cells, the amounts of (/sup 35/S)sulfate incorporated for 48 h into chondroitin sulfate were twofold lower but those into heparan sulfate were 35% higher in PC12D cells. The amount of chondroitin sulfate released by PC12D cells into the medium was about a half of that released by PC12 cells. The ratio of (/sup 35/S)sulfate-labeled heparan sulfate to chondroitin sulfate was 6.2 in PC12D cells and 2.2 in PC12 cells. These results suggest that there may be some correlation between the increase in content of glycosaminoglycans and the change in cell morphology, which is followed by neurite outgrowth.

First Experimental Demonstration of Coherent CAP for 300-Gb/s Metropolitan Optical Networks

DEFF Research Database (Denmark)

Estaran Tolosa, Jose Manuel; Iglesias Olmedo, Miguel; Zibar, Darko

2014-01-01

We report on high - capacity coherent links employing dual polarization 2D - CAP modulation, allowing for signal design in 8 - dimensional space. Successful demodulation of 221 Gb/s (7.5 b/s/Hz) and 336 Gb/s (7.8 b/s/Hz) after 225 km and 451 km of standard single - mode fiber (SSMF) is achieved....

VIDEO-PC, SVGA Routines for FORTRAN on PC

International Nuclear Information System (INIS)

1994-01-01

1 - Description of program or function: These primitives are the lowest level routines needed to perform super VGA graphics on a PC. A sample main program is included that exercises the primitives. Both Lahey and Microsoft FORTRAN's have graphics libraries. However, the libraries do not support 256 color graphics at resolutions greater than 320x200. The primitives bypass these libraries while still conforming to standard usage of BIOS. The supported graphics modes depend upon the PC graphics card and its memory. Super VGA resolutions of 640x480 and 800x600 have been tested on an ATI VGA Wonder card with 512 K memory and on several 80486 PC's (unknown manufacturers) at retail stores. 2 - Method of solution: Both Lahey and Microsoft primitives depend upon sending the correct parameters to the PC BIOS (basic input output system) as discussed in the references. 3 - Restrictions on the complexity of the problem: The primitives were developed for 256 color VGA applications. It is known, for instance, that some CGA and 16 color VGA video modes will not operate correctly using these primitives. Potential users should try the test program on their PC/video card combination to determine applicability

Biomimicry 1: PC.

Science.gov (United States)

Cumberland, D C; Gunn, J; Malik, N; Holt, C M

1998-01-01

The surface properties of stents can be modified by coating them, for example with a polymer. Phosphorylcoline (PC) is the major component of the outer layer of the cell membrane. The haemo- and biocompatibility of a PC-containing polymer is thus based on biomimicry, and has been confirmed by several experiments showing much reduced thrombogenicity of PC-coated surfaces, and porcine coronary artery implants showing no sign of adverse effect. Clinical experience with the PC-coated BiodivYsio appears favourable. The PC coating can be tailored for take up and controlled elution of various drugs for stent-based local delivery, a property which is being actively explored.

Scattering Fields Control by Metamaterial Device Based on Ultra-Broadband Polarization Converters

Directory of Open Access Journals (Sweden)

Si-Jia Li

2016-12-01

Full Text Available We proposed a novel ultra-broadband meta¬material screen with controlling the electromagnetic scat¬tering fields based on the three layers wideband polariza¬tion converter (TLW-PC. The unit cell of TLW-PC was composed of a three layers substrate loaded with double metallic split-rings structure and a metal ground plane. We observed that the polarization converter primarily per¬formed ultra-broadband cross polarization conversion from 5.71 GHz to 14.91 GHz. Furthermore, a metamaterial screen, which contributed to the low scattering charac¬teristics, had been exploited with the orthogonal array based on TLW-PC. The near scattering electronic fields are controlled due to the change of phase and amplitude for incident wave. The metamaterial screen significantly exhibited low scattering characteristics from 5.81 GHz to 15.06 GHz. To demonstrate design, a metamaterial device easily implemented by the common printed circuit board method has been fabricated and measured. Experimental results agreed well with the simulated results.

An unusual giant spiral arc in the polar cap region during the northward phase of a Coronal Mass Ejection

Directory of Open Access Journals (Sweden)

L. Rosenqvist

2007-03-01

Full Text Available The shock arrival of an Interplanetary Coronal Mass Ejection (ICME at ~09:50 UT on 22 November 1997 resulted in the development of an intense (D_st<−100 nT geomagnetic storm at Earth. In the early, quiet phase of the storm, in the sheath region of the ICME, an unusual large spiral structure (diameter of ~1000 km was observed at very high latitudes by the Polar UVI instrument. The evolution of this structure started as a polewardly displaced auroral bulge which further developed into the spiral structure spreading across a large part of the polar cap. This study attempts to examine the cause of the chain of events that resulted in the giant auroral spiral. During this period the interplanetary magnetic field (IMF was dominantly northward (B_z>25 nT with a strong duskward component (B_y>15 nT resulting in a highly twisted tail plasma sheet. Geotail was located at the equatorial dawnside magnetotail flank and observed accelerated plasma flows exceeding the solar wind bulk velocity by almost 60%. These flows are observed on the magnetosheath side of the magnetopause and the acceleration mechanism is proposed to be typical for strongly northward IMF. Identified candidates to the cause of the spiral structure include a B_y induced twisted magnetotail configuration, the development of magnetopause surface waves due to the enhanced pressure related to the accelerated magnetosheath flows aswell as the formation of additional magnetopause deformations due to external solar wind pressure changes. The uniqeness of the event indicate that most probably a combination of the above effects resulted in a very extreme tail topology. However, the data coverage is insufficient to fully investigate the physical mechanism behind the observations.

Cradle Cap: Treatment

Science.gov (United States)

Cradle cap Treatment Cradle cap usually doesn't require medical treatment. It clears up on its own within a few months. In the meantime, wash ... tips can help you control and manage cradle cap. Gently rub your baby's scalp with your fingers ...

Optical Polarization as a Probe of the Local Interstellar Medium

Science.gov (United States)

Tinbergen, J.

1984-01-01

The use of interstellar polarization as a tool for measuring interstellar dust is discussed. Problems resulting from dust and magnetic field configurations becoming mixed up are discussed, as is the availability of sufficiently bright stars to obtain the photons needed for precision measurements. It is proposed that: (1) on the scale of several hundred parsec, there is a preferential magnetic field direction, as evidenced by observations at the Galactic poles and selected longitudes in the Galactic plane; (2) the local (r 50 pc) region is devoid of dust, as evidenced by the mean square degree of polarization as a function of distance; and, less certainly, that (3) at a distance of less than 5 pc, there is a patch of dust which may be of interest in connection with cloud models.

Plasma Irregularity Production in the Polar Cap F-Region Ionosphere

Science.gov (United States)

Lamarche, Leslie

Plasma in the Earth's ionosphere is highly irregular on scales ranging between a few centimeters and hundreds of kilometers. Small-scale irregularities or plasma waves can scatter radio waves resulting in a loss of signal for navigation and communication networks. The polar region is particularly susceptible to strong disturbances due to its direct connection with the Sun's magnetic field and energetic particles. In this thesis, factors that contribute to the production of decameter-scale plasma irregularities in the polar F region ionosphere are investigated. Both global and local control of irregularity production are studied, i.e. we consider global solar control through solar illumination and solar wind as well as much more local control by plasma density gradients and convection electric field. In the first experimental study, solar control of irregularity production is investigated using the Super Dual Auroral Radar Network (SuperDARN) radar at McMurdo, Antarctica. The occurrence trends for irregularities are analyzed statistically and a model is developed that describes the location of radar echoes within the radar's field-of-view. The trends are explained through variations in background plasma density with solar illumination affecting radar beam propagation. However, it is found that the irregularity occurrence during the night is higher than expected from ray tracing simulations based on a standard ionospheric density model. The high occurrence at night implies an additional source of plasma density and it is proposed that large-scale density enhancements called polar patches may be the source of this density. Additionally, occurrence maximizes around the terminator due to different competing irregularity production processes that favor a more or less sunlit ionosphere. The second study is concerned with modeling irregularity characteristics near a large-scale density gradient reversal, such as those expected near polar patches, with a particular focus on

Beta-decay asymmetries in polarized /sup 12/B and /sup 12/N and the G-parity non-conservation

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, K [Osaka Univ., Toyonaka (Japan). Dept. of Physics

1976-07-01

The decay asymmetries (A) in polarized /sup 12/B and /sup 12/N have been measured as a function of ..beta..-ray energies (E). The coefficients ..cap alpha..sub(-+) in A = -+ P(p/E) (1 + ..cap alpha..sub(-+)E)) have been determined to be ..cap alpha..sub(-) (/sup 12/B) = +(0.31+-0.06)%/MeV and ..cap alpha..sub(+) (/sup 12/N) = -(0.21+-0.07)%/MeV. The experimental value, ..cap alpha..sub(-) - ..cap alpha..sub (+) = (0.52+-0.09)%/MeV, is larger than the prediction according to conservation of vector current which includes no second-class current, (..cap alpha..sub(-) - ..cap alpha..sub(+) CVC approximately equal to 0.27%/MeV, and indicates the existence of the second-class induced-tensor current.

Propagation of low frequency geomagnetic field fluctuations in Antarctica: comparison between two polar cap stations

Directory of Open Access Journals (Sweden)

L. Santarelli

2007-11-01

Full Text Available We conduct a statistical analysis of the coherence and phase difference of low frequency geomagnetic fluctuations between two Antarctic stations, Mario Zucchelli Station (geographic coordinates: 74.7° S, 164.1° E; corrected geomagnetic coordinates: 80.0° S, 307.7° E and Scott Base (geographic coordinates: 77.8° S 166.8° E; corrected geomagnetic coordinates: 80.0° S 326.5° E, both located in the polar cap. Due to the relative position of the stations, whose displacement is essentially along a geomagnetic parallel, the phase difference analysis allows to determine the direction of azimuthal propagation of geomagnetic fluctuations. The results show that coherent fluctuations are essentially detectable around local geomagnetic midnight and, in a minor extent, around noon; moreover, the phase difference reverses in the night time hours, indicating a propagation direction away from midnight, and also around local geomagnetic noon, indicating a propagation direction away from the subsolar point. The nigh time phase reversal is more clear for southward interplanetary magnetic field conditions, suggesting a relation with substorm activity. The introduction, in this analysis, of the Interplanetary Magnetic Field conditions, gave interesting results, indicating a relation with substorm activity during nighttime hours. We also conducted a study of three individual pulsation events in order to find a correspondence with the statistical behaviour. In particular, a peculiar event, characterized by quiet magnetospheric and northward interplanetary magnetic field conditions, shows a clear example of waves propagating away from the local geomagnetic noon; two more events, occurring during southward interplanetary magnetic field conditions, in one case even during a moderate storm, show waves propagating away from the local geomagnetic midnight.

Polarization measurements of the Bok globule B361

Energy Technology Data Exchange (ETDEWEB)

Williams, I P; Vedi, K [Queen Mary Coll., London (UK); Griffiths, W K [Leeds Univ. (UK); Bhatt, H C; Kulkarni, P V; Ashok, N M [Physical Research Lab., Ahmedabad (India); Wallis, R E [Royal Greenwich Observatory, Hailsham (UK)

1985-01-01

The results of the first measurements of the polarization of light from background stars passing through B361 are described. Nearly all the stars show that the direction of the polarized light is approximately north-south. If the polarization is caused by aligned grains within the globule then a magnetic field of the order of 50-100 ..mu..G is required. Both polarimetry and photometry confirm that two of the stars studied are very distant background stars while three of these stars were found to be foreground stars. The analysis indicates that the globule is not further away than 650 pc, but can only establish an approximate upper limit.

Efecto sobre la viabilidad celular de una nueva serie de espirosteroides sintéticos en células PC12 Effect of a new series of synthetic spiroteroids on the PC12 cell line viability

Directory of Open Access Journals (Sweden)

Laura García-Pupo

2013-03-01

Full Text Available Introducción: la diosgenina y sus derivados se han descrito como potentes inhibidores de la proliferación en varias líneas tumorales. Sin embargo otras moléculas relacionadas estructuralmente con dichos derivados, se han reportado como candidatos terapéuticos y otras de ellas se incluyen en alimentos de consumo humano. Objetivo: el presente trabajo evalúa el efecto sobre la viabilidad celular de una nueva serie de espiroesteroides sintéticos derivados de la diosgenina, en células tipo neurales PC12. Métodos: la viabilidad de los cultivos de PC12 se determinó mediante el ensayo de MTT y se calcularon descriptores moleculares teóricos como la lipofilicidad (logP virtual y la superficie de área polar (SAP, con el objetivo de establecer relaciones estructura-actividad. Resultados: nuestros resultados demuestran que solo el acido taurodesoxicólico disminuye de manera significativa la viabilidad celular. Más aun, dicha molécula presenta valores menores y mayores de logP virtual y SAP, respectivamente, respecto al resto de los esteroides de la serie. Conclusiones: los resultados anteriores avalan el estudio del acido taurodesoxicólico como potencial inhibidor de la proliferación celular y al resto de las moléculas de la serie como candidatos neuroprotectores a evaluar en esta misma línea celular y dosis de tratamiento.Introduction: diosgenin and its derivatives have been described as potent anti-proliferative compounds in several tumor cell lines. However, other structurally-related compounds are reported to exert neuroprotective activity and are also included in food for human consumption. Objective: to evaluate the effect of a novel series of diogesin-derived synthetic spirosteroids on cellular viability of neuron-like PC12 cell line. Methods: cellular viability was determined by the MTT assay along with some theorical molecular descriptors, such as lipophilicity and polar surface area, in order to establish the structure

Observations of polar patches generated by solar wind Alfvén wave coupling to the dayside magnetosphere

Directory of Open Access Journals (Sweden)

P. Prikryl

1999-04-01

Full Text Available A long series of polar patches was observed by ionosondes and an all-sky imager during a disturbed period (Kp = 7- and IMF Bz < 0. The ionosondes measured electron densities of up to 9 × 1011 m-3 in the patch center, an increase above the density minimum between patches by a factor of \\sim4.5. Bands of F-region irregularities generated at the equatorward edge of the patches were tracked by HF radars. The backscatter bands were swept northward and eastward across the polar cap in a fan-like formation as the afternoon convection cell expanded due to the IMF By > 0. Near the north magnetic pole, an all-sky imager observed the 630-nm emission patches of a distinctly band-like shape drifting northeastward to eastward. The 630-nm emission patches were associated with the density patches and backscatter bands. The patches originated in, or near, the cusp footprint where they were formed by convection bursts (flow channel events, FCEs structuring the solar EUV-produced photoionization and the particle-produced auroral/cusp ionization by segmenting it into elongated patches. Just equatorward of the cusp footprint Pc5 field line resonances (FLRs were observed by magnetometers, riometers and VHF/HF radars. The AC electric field associated with the FLRs resulted in a poleward-progressing zonal flow pattern and backscatter bands. The VHF radar Doppler spectra indicated the presence of steep electron density gradients which, through the gradient drift instability, can lead to the generation of the ionospheric irregularities found in patches. The FLRs and FCEs were associated with poleward-progressing DPY currents (Hall currents modulated by the IMF By and riometer absorption enhancements. The temporal and spatial characteristics of the VHF backscatter and associated riometer absorptions closely resembled those of poleward moving auroral forms (PMAFs. In the solar wind, IMP 8 observed large amplitude Alfvén waves that were correlated with Pc5 pulsations

Real-time multi-target ranging based on chaotic polarization laser radars in the drive-response VCSELs.

Science.gov (United States)

Zhong, Dongzhou; Xu, Geliang; Luo, Wei; Xiao, Zhenzhen

2017-09-04

According to the principle of complete chaos synchronization and the theory of Hilbert phase transformation, we propose a novel real-time multi-target ranging scheme by using chaotic polarization laser radar in the drive-response vertical-cavity surface-emitting lasers (VCSELs). In the scheme, to ensure each polarization component (PC) of the master VCSEL (MVCSEL) to be synchronized steadily with that of the slave VCSEL, the output x-PC and y-PC from the MVCSEL in the drive system and those in the response system are modulated by the linear electro-optic effect simultaneously. Under this condition, by simulating the influences of some key parameters of the system on the synchronization quality and the relative errors of the two-target ranging, related operating parameters can be optimized. The x-PC and the y-PC, as two chaotic radar sources, are used to implement the real-time ranging for two targets. It is found that the measured distances of the two targets at arbitrary position exhibit strong real-time stability and only slight jitter. Their resolutions are up to millimeters, and their relative errors are very small and less than 2.7%.

What can stimulus polarity and interphase gap tell us about auditory nerve function in cochlear-implant recipients?

Science.gov (United States)

Hughes, Michelle L; Choi, Sangsook; Glickman, Erin

2018-03-01

Modeling studies suggest that differences in neural responses between polarities might reflect underlying neural health. Specifically, large differences in electrically evoked compound action potential (eCAP) amplitudes and amplitude-growth-function (AGF) slopes between polarities might reflect poorer peripheral neural health, whereas more similar eCAP responses between polarities might reflect better neural health. The interphase gap (IPG) has also been shown to relate to neural survival in animal studies. Specifically, healthy neurons exhibit larger eCAP amplitudes, lower thresholds, and steeper AGF slopes for increasing IPGs. In ears with poorer neural survival, these changes in neural responses are generally less apparent with increasing IPG. The primary goal of this study was to examine the combined effects of stimulus polarity and IPG within and across subjects to determine whether both measures represent similar underlying mechanisms related to neural health. With the exception of one measure in one group of subjects, results showed that polarity and IPG effects were generally not correlated in a systematic or predictable way. This suggests that these two effects might represent somewhat different aspects of neural health, such as differences in site of excitation versus integrative membrane characteristics, for example. Overall, the results from this study suggest that the underlying mechanisms that contribute to polarity and IPG effects in human CI recipients might be difficult to determine from animal models that do not exhibit the same anatomy, variance in etiology, electrode placement, and duration of deafness as humans. Copyright © 2017 Elsevier B.V. All rights reserved.

Micromagnetism in (001) magnetite by spin-polarized low-energy electron microscopy

International Nuclear Information System (INIS)

Figuera, Juan de la; Vergara, Lucía; N'Diaye, Alpha T.; Quesada, Adrian; Schmid, Andreas K.

2013-01-01

Spin-polarized low-energy electron microscopy was used to image a magnetite crystal with (001) surface orientation. Sets of spin-dependent images of magnetic domain patterns observed in this surface were used to map the direction of the magnetization vector with high spatial and angular resolution. We find that domains are magnetized along the surface directions, and domain wall structures include 90° and 180° walls. A type of unusually curved domain walls are interpreted as Néel-capped surface terminations of 180° Bloch walls. - Highlights: ► The (001) surface of magnetite is imaged by spin-polarized low-energy electron microscopy. ► The magnetic domain microstructure is resolved. ► Magnetic easy axes in this surface are found to be along directions. ► Magnetic domain wall structures include wide Néel-caps

Micromagnetism in (001) magnetite by spin-polarized low-energy electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Figuera, Juan de la, E-mail: juan.delafiguera@iqfr.csic.es [Instituto de Química-Física “Rocasolano”, CSIC, Madrid 28006 (Spain); Vergara, Lucía [Instituto de Química-Física “Rocasolano”, CSIC, Madrid 28006 (Spain); N' Diaye, Alpha T. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Quesada, Adrian [Instituto de Cerámica y Vidrio, CSIC, Calle Kelsen 5, 28049, Madrid (Spain); Schmid, Andreas K. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

2013-07-15

Spin-polarized low-energy electron microscopy was used to image a magnetite crystal with (001) surface orientation. Sets of spin-dependent images of magnetic domain patterns observed in this surface were used to map the direction of the magnetization vector with high spatial and angular resolution. We find that domains are magnetized along the surface <110> directions, and domain wall structures include 90° and 180° walls. A type of unusually curved domain walls are interpreted as Néel-capped surface terminations of 180° Bloch walls. - Highlights: ► The (001) surface of magnetite is imaged by spin-polarized low-energy electron microscopy. ► The magnetic domain microstructure is resolved. ► Magnetic easy axes in this surface are found to be along <110> directions. ► Magnetic domain wall structures include wide Néel-caps.

The Contribution of Water Ice Clouds to the Water Cycle in the North Polar Region of Mars: Preliminary Analysis

Science.gov (United States)

Bass, D. S.; Tamppari, L. K.

2000-01-01

While it has long been known that Mars' north residual polar cap and the Martian regolith are significant sources of atmospheric water vapor, the amount of water vapor observed in the northern spring season by the Viking Mars Atmospheric Water Detector instrument (MAWD) cannot be attributed to cap and regolith sources alone. Kahn suggested that ice hazes may be the mechanism by which additional water is supplied to the Martian atmosphere. Additionally, a significant decrease in atmospheric water vapor was observed in the late northern summer that could not be correlated with the return of the cold seasonal C02 ice. While the detection of water ice clouds on Mars indicate that water exists in Mars' atmosphere in several different phases, the extent to which water ice clouds play a role in moving water through the Martian atmosphere remains uncertain. Work by Bass et. al. suggested that the time dependence of water ice cap seasonal variability and the increase in atmospheric water vapor depended on the polar cap center reaching 200K, the night time saturation temperature. Additionally, they demonstrated that a decrease in atmospheric water vapor may be attributed to deposition of water ice onto the surface of the polar cap; temperatures were still too warm at this time in the summer for the deposition of carbon dioxide. However, whether water ice clouds contribute significantly to this variability is unknown. Additional information is contained in original extended abstract.

Propagation of low frequency geomagnetic field fluctuations in Antarctica: comparison between two polar cap stations

Directory of Open Access Journals (Sweden)

L. Santarelli

2007-11-01

Full Text Available We conduct a statistical analysis of the coherence and phase difference of low frequency geomagnetic fluctuations between two Antarctic stations, Mario Zucchelli Station (geographic coordinates: 74.7° S, 164.1° E; corrected geomagnetic coordinates: 80.0° S, 307.7° E and Scott Base (geographic coordinates: 77.8° S 166.8° E; corrected geomagnetic coordinates: 80.0° S 326.5° E, both located in the polar cap. Due to the relative position of the stations, whose displacement is essentially along a geomagnetic parallel, the phase difference analysis allows to determine the direction of azimuthal propagation of geomagnetic fluctuations. The results show that coherent fluctuations are essentially detectable around local geomagnetic midnight and, in a minor extent, around noon; moreover, the phase difference reverses in the night time hours, indicating a propagation direction away from midnight, and also around local geomagnetic noon, indicating a propagation direction away from the subsolar point. The nigh time phase reversal is more clear for southward interplanetary magnetic field conditions, suggesting a relation with substorm activity.

The introduction, in this analysis, of the Interplanetary Magnetic Field conditions, gave interesting results, indicating a relation with substorm activity during nighttime hours.

We also conducted a study of three individual pulsation events in order to find a correspondence with the statistical behaviour. In particular, a peculiar event, characterized by quiet magnetospheric and northward interplanetary magnetic field conditions, shows a clear example of waves propagating away from the local geomagnetic noon; two more events, occurring during southward interplanetary magnetic field conditions, in one case even during a moderate storm, show waves propagating away from the local geomagnetic midnight.

On the relations between proton influx and D-region electron densities during the polar-cap absorption event of 28-29 October 2003

Directory of Open Access Journals (Sweden)

J. K. Hargreaves

2005-11-01

Full Text Available Observations by incoherent-scatter radar have been applied to explore relationships between the fluxes of incident protons and the resulting D-region electron densities during a polar-cap radio-absorption event. Using proton flux data from a GOES geosynchronous satellite, the energy band having the greatest influence at a selected height is estimated by a process of trial and error, and empirical relationships are defined. The height profiles of the effective recombination coefficient are determined for day and night, and the transition over the evening twilight is investigated for the height range 60-70 km.

The results show that the day-night change is confined to heights below 80 km, night-time values at the lower levels being consistent with a balance between negative ions and electrons controlled by 3-body attachment and collisional detachment. The daytime results confirm that, contrary to the prediction of some chemical models, a square-law continuity equation may be strictly applied. It is confirmed that, as previously reported, the timing of the sunset change varies with altitude.

On the relations between proton influx and D-region electron densities during the polar-cap absorption event of 28-29 October 2003

Directory of Open Access Journals (Sweden)

J. K. Hargreaves

2005-11-01

Full Text Available Observations by incoherent-scatter radar have been applied to explore relationships between the fluxes of incident protons and the resulting D-region electron densities during a polar-cap radio-absorption event. Using proton flux data from a GOES geosynchronous satellite, the energy band having the greatest influence at a selected height is estimated by a process of trial and error, and empirical relationships are defined. The height profiles of the effective recombination coefficient are determined for day and night, and the transition over the evening twilight is investigated for the height range 60-70 km. The results show that the day-night change is confined to heights below 80 km, night-time values at the lower levels being consistent with a balance between negative ions and electrons controlled by 3-body attachment and collisional detachment. The daytime results confirm that, contrary to the prediction of some chemical models, a square-law continuity equation may be strictly applied. It is confirmed that, as previously reported, the timing of the sunset change varies with altitude.

Polar cap geomagnetic field responses to solar sector changes

International Nuclear Information System (INIS)

Campbell, W.H.

1976-01-01

I made a computerized analysis of digitized magnetograms from Alert, Thule, Resolute Bay, Mould Bay, and Godhavn for 1965 and from Thule and Vostok for 1967 to determine the characteristic features of the day-to-day geomagnetic field variations related to the interplanetary solar sector field direction. Higher invariant latitude stations showed the sector effects most clearly. A sector-related phase shift in the characteristic diurnal variation of the field occurred principally for the dayside vertical geomagnetic component. The amplitude of this diurnal variation was related to Ap and could not be used to identify the sector direction. The quiet nighttime level of field Z component rose and fell on days when the interplanetary magnetic field was directed toward or away from the sun, respectively. When a station's base level field was determined from quiet magnetospheric conditions by using days with low values of Dst and AE indices, the mean field level of the Z component for the whole day increased or decreased (often over 100 γ) from this level as the solar sector direction was toward or away, respectively. With respect to the earth's main field direction the souther polar station field level changes were opposite those at the northern stations. This level shift corresponded with the two solar field directions during the summer months at polar stations for about 70% of the days in 1965 and 88% of the days in 1967. In 1967 the standoff locations of the magnetopause and magnetoshock boundaries were abotu 1 R/sub E/ more distant from the earth for the average toward sector days than for the away sector days

Towards 400GBASE 4-lane Solution Using Direct Detection of MultiCAP Signal in 14 GHz Bandwidth per Lane

DEFF Research Database (Denmark)

Iglesias Olmedo, Miguel; Tianjian, Zuo; Jensen, Jesper Bevensee

2013-01-01

We report on an experimental demonstration of 102 Gbit/s transmission over a 15km single wavelength and polarization fiber link with 14GHz 3dB bandwidth. Novel multiband CAP signaling allows for a 4-lane 400GBASE long reach solution....

Analysis of Strain and Intermixing in a Single Layer Ge/Si dots using polarized Raman Spectroscopy

OpenAIRE

PEROVA, TANIA; MOORE, ROBERT

2006-01-01

PUBLISHED The built-in strain and composition of as-grown and Si-capped single layers of Ge?Si dots grown at various temperatures (460?800 ?C) are studied by a comparative analysis of the Ge-Ge and Si-Ge modes in the polarized Raman spectra of the dots. A pronounced reduction of the strain and Ge content in the dots after deposition of the cap layer at low temperatures is observed, indicating that strain-induced Si diffusion from the cap layer is occurring. For large dots grown at 700?800...

A nanobody targeting the F-actin capping protein CapG restrains breast cancer metastasis.

Science.gov (United States)

Van Impe, Katrien; Bethuyne, Jonas; Cool, Steven; Impens, Francis; Ruano-Gallego, David; De Wever, Olivier; Vanloo, Berlinda; Van Troys, Marleen; Lambein, Kathleen; Boucherie, Ciska; Martens, Evelien; Zwaenepoel, Olivier; Hassanzadeh-Ghassabeh, Gholamreza; Vandekerckhove, Joël; Gevaert, Kris; Fernández, Luis Ángel; Sanders, Niek N; Gettemans, Jan

2013-12-13

Aberrant turnover of the actin cytoskeleton is intimately associated with cancer cell migration and invasion. Frequently however, evidence is circumstantial, and a reliable assessment of the therapeutic significance of a gene product is offset by lack of inhibitors that target biologic properties of a protein, as most conventional drugs do, instead of the corresponding gene. Proteomic studies have demonstrated overexpression of CapG, a constituent of the actin cytoskeleton, in breast cancer. Indirect evidence suggests that CapG is involved in tumor cell dissemination and metastasis. In this study, we used llama-derived CapG single-domain antibodies or nanobodies in a breast cancer metastasis model to address whether inhibition of CapG activity holds therapeutic merit. We raised single-domain antibodies (nanobodies) against human CapG and used these as intrabodies (immunomodulation) after lentiviral transduction of breast cancer cells. Functional characterization of nanobodies was performed to identify which biochemical properties of CapG are perturbed. Orthotopic and tail vein in vivo models of metastasis in nude mice were used to assess cancer cell spreading. With G-actin and F-actin binding assays, we identified a CapG nanobody that binds with nanomolar affinity to the first CapG domain. Consequently, CapG interaction with actin monomers or actin filaments is blocked. Intracellular delocalization experiments demonstrated that the nanobody interacts with CapG in the cytoplasmic environment. Expression of the nanobody in breast cancer cells restrained cell migration and Matrigel invasion. Notably, the nanobody prevented formation of lung metastatic lesions in orthotopic xenograft and tail-vein models of metastasis in immunodeficient mice. We showed that CapG nanobodies can be delivered into cancer cells by using bacteria harboring a type III protein secretion system (T3SS). CapG inhibition strongly reduces breast cancer metastasis. A nanobody-based approach offers

Dependence of distribution parameters of large-scale electric fields on Kp and AE indices of geomagnetic disturbance

International Nuclear Information System (INIS)

Uvarov, V.M.; Kandibolotskaya, M.A.; Moskvin, I.V.

1989-01-01

Regression equations, which link potential drop ΔΦ PC , kV with K P in polar cap and which are generalized in the form of ΔΦ PC =20+15K P , are obtained on the basis of three groups of published data on measurements conducted using cosmic vehicles and incoherent scattering facility. Regression equation for ΔΦ PC and AE is obtained using data of DE-2 CV: ΔΦ PC =31.65±12.50 (AE/100). Usage of the large file-mean initial data of ΔΦ RS values realized filtration and determined high, no lower, than 0.9, coefficients of correlation. Regression equations, which link P index of precipitation and invariant latitudes of convection lower boundary in the night and morning sectors with K P -index, are presented

/sup 58,60,62/Ni (. cap alpha. ,p) three--nucleon transfer reactions and. cap alpha. optical potential ambiguities

Energy Technology Data Exchange (ETDEWEB)

Yuanda, Wang; Xiuming, Bao; Zhiqiang, Mao; Rongfang, Yuan; Keling, Wen; Binyin, Huang; Zhifu, Wang; Shuming, Li; Jianan, Wang; Zuxun, Sun; others, and

1985-11-01

The differential cross sections are measured using 26.0 MeV ..cap alpha.. particle for /sup 58,62/Ni(..cap alpha.., ..cap alpha..) /sup 58,62/Ni and /sup 58,62/Ni(..cap alpha..,p) /sup 61,65/Cu reactions as well as 25.4 MeV ..cap alpha.. particle for /sup 60/Ni(..cap alpha.., ..cap alpha..)/sup 69/Ni and /sup 60/Ni(..cap alpha.., p)/sup 63/Cu reactions. Consistent calculations with optical model and ZR DWBA are made for (..cap alpha.., ..cap alpha..) and (..cap alpha.., p) reactions by using of single, two, three and four nucleon optical potential parameters. For elastic scattering due to the ..cap alpha.. optical potential ambiguities, all the above optical potential can reproduce the experimental angular distributions. However, the single, two and three nucleon potential, including the Baird's mass systematics and the Chang's energy systematics of ..cap alpha.. potentials, obviously can not provide a reasonable fitting with the (..cap alpha..,p) reaction experimental data. Only the results from the four nucleon potential is in good agreement with the (..cap alpha..,p) reaction experimental data. This reveals that in the ..cap alpha..-particle induced transfer reactions, the real depth of the ..cap alpha..-nucleus optical potential should be rather deep.

How does the antagonism between capping and anti-capping proteins affect actin network dynamics?

International Nuclear Information System (INIS)

Hu Longhua; Papoian, Garegin A

2011-01-01

Actin-based cell motility is essential to many biological processes. We built a simplified, three-dimensional computational model and subsequently performed stochastic simulations to study the growth dynamics of lamellipodia-like branched networks. In this work, we shed light on the antagonism between capping and anti-capping proteins in regulating actin dynamics in the filamentous network. We discuss detailed mechanisms by which capping and anti-capping proteins affect the protrusion speed of the actin network and the rate of nucleation of filaments. We computed a phase diagram showing the regimes of motility enhancement and inhibition by these proteins. Our work shows that the effects of capping and anti-capping proteins are mainly transmitted by modulation of the filamentous network density and local availability of monomeric actin. We discovered that the combination of the capping/anti-capping regulatory network with nucleation-promoting proteins introduces robustness and redundancy in cell motility machinery, allowing the cell to easily achieve maximal protrusion speeds under a broader set of conditions. Finally, we discuss distributions of filament lengths under various conditions and speculate on their potential implication for the emergence of filopodia from the lamellipodial network.

47 CFR 54.623 - Cap.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Cap. 54.623 Section 54.623 Telecommunication... Universal Service Support for Health Care Providers § 54.623 Cap. (a) Amount of the annual cap. The annual cap on federal universal service support for health care providers shall be $400 million per funding...

47 CFR 54.507 - Cap.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Cap. 54.507 Section 54.507 Telecommunication... Universal Service Support for Schools and Libraries § 54.507 Cap. (a) Amount of the annual cap. The annual funding cap on federal universal service support for schools and libraries shall be $2.25 billion per...

Space weather monitoring by groundbased means

CERN Document Server

Troshichev, Oleg

2012-01-01

This book demonstrates that the method, based on the ground polar cap magnetic observations is a reliable diagnosis of the solar wind energy coming into the magnetosphere Method for the uninterruptive monitoring of the magnetosphere state (i.e. space weather). It shows that the solar wind energy pumping power, can be described by the PC growth rate, thus, the magnetospheric substorms features are predetermined by the PC dynamics. Furthermore, it goes on to show that the beginning and ending of magnetic storms is predictable. The magnetic storm start only if the solar energy input into the magn

Principal State Analysis for a Compact in-Line Fiber Polarization Controller

International Nuclear Information System (INIS)

Li Zheng-Yong; Wu Chong-Qing; Wang Zhi-Hao; Qin Tao; Wang Yi-Xu

2013-01-01

A compact in-line fiber-based polarization controller (FPC) made of a rotatable fiber squeezer is investigated in detail with the Mueller matrix model established based on the generalized principal state of polarization (PSP). The PSP caused by the fiber squeezing is in the equator plane, which turns around S 3 axis on the Poincaré sphere when rotating the squeezer. Subsequently, a programmable polarization control method is proposed to realize the polarization conversion between arbitrary polarization states, in which only two parameters of phase shift and rotation angle need to be controlled. This type of FPC, which has a highly compact structure, lower insertion loss, and can be directly embedded into any fiber devices without any extra delay, will be an ideal PC for high-speed optical communication and all-optical signal processing

An eastward propagating compressional Pc 5 wave observed by AMPTE/CCE in the postmidnight sector

International Nuclear Information System (INIS)

Takahashi, K.; McEntire, R.W.; Zanetti, L.J.; Lopez, R.E.; Kistler, L.M.; Ipavich, R.M.

1987-01-01

Data from three instruments, the magnetometer, the charge-energy-mass spectrometer, and the medium-energy particle analyzer onboard the Active Magnetospheric Particle Tracer Explorers/Charge Composition Explorer (CCE) spacecraft have been used to study a compressional Pc 5 wave observed at 1925-2200 UT on day 202 (July 21) of 1986 at a radial distance of ≅ 8 R E in the postmidnight sector near the beginning of minor geomagnetic activity. The wave exhibited harmonically related transverse and compressional magnetic oscillations, modulation of the flux of medium energy protons (E approx-gt 10 keV), and a large azimuthal wave number (m ∼ 65). These properties are similar to those of compressional Pc 5 waves observed previously at geostationary orbit. The unique observations associated with the CCE event are the occurrence in the postmidnight sector, the eastward (or sunward) propagation with respect to the spacecraft, and the left-handed polarization of the perturbed magnetic field. These are opposite to previous geostationary observations. The authors propose that the unique propagation and polarization are propagating westward in the plasma rest frame, appears to propagate eastward to the observer because the electric field drift velocity is larger than the wave phase velocity

The pharmaceutical vial capping process: Container closure systems, capping equipment, regulatory framework, and seal quality tests.

Science.gov (United States)

Mathaes, Roman; Mahler, Hanns-Christian; Buettiker, Jean-Pierre; Roehl, Holger; Lam, Philippe; Brown, Helen; Luemkemann, Joerg; Adler, Michael; Huwyler, Joerg; Streubel, Alexander; Mohl, Silke

2016-02-01

Parenteral drug products are protected by appropriate primary packaging to protect against environmental factors, including potential microbial contamination during shelf life duration. The most commonly used CCS configuration for parenteral drug products is the glass vial, sealed with a rubber stopper and an aluminum crimp cap. In combination with an adequately designed and controlled aseptic fill/finish processes, a well-designed and characterized capping process is indispensable to ensure product quality and integrity and to minimize rejections during the manufacturing process. In this review, the health authority requirements and expectations related to container closure system quality and container closure integrity are summarized. The pharmaceutical vial, the rubber stopper, and the crimp cap are described. Different capping techniques are critically compared: The most common capping equipment with a rotating capping plate produces the lowest amount of particle. The strength and challenges of methods to control the capping process are discussed. The residual seal force method can characterize the capping process independent of the used capping equipment or CCS. We analyze the root causes of several cosmetic defects associated with the vial capping process. Copyright © 2015 Elsevier B.V. All rights reserved.

Modeling of Jovian Auroral Polar Ion and Proton Precipitation

Science.gov (United States)

Houston, S. J.; Ozak, N. O.; Cravens, T.; Schultz, D. R.; Mauk, B.; Haggerty, D. K.; Young, J. T.

2017-12-01

Auroral particle precipitation dominates the chemical and physical environment of the upper atmospheres and ionospheres of the outer planets. Precipitation of energetic electrons from the middle magnetosphere is responsible for the main auroral oval at Jupiter, but energetic electron, proton, and ion precipitation take place in the polar caps. At least some of the ion precipitation is associated with soft X-ray emission with about 1 GW of power. Theoretical modeling has demonstrated that the incident sulfur and oxygen ion energies must exceed about 0.5 MeV/nucleon (u) in order to produce the measured X-ray emission. In this work we present a model of the transport of magnetospheric oxygen ions as they precipitate into Jupiter's polar atmosphere. We have revised and updated the hybrid Monte Carlo model originally developed by Ozak et al., 2010 to model the Jovian X-ray aurora. We now simulate a wider range of incident oxygen ion energies (10 keV/u - 5 MeV/u) and update the collision cross-sections to model the ionization of the atmospheric neutrals. The polar cap location of the emission and magnetosphere-ionosphere coupling both indicate the associated field-aligned currents must originate near the magnetopause or perhaps the distant tail. Secondary electrons produced in the upper atmosphere by ion precipitation could be accelerated upward to relativistic energies due to the same field-aligned potentials responsible for the downward ion acceleration. To further explore this, we simulate the effect of the secondary electrons generated from the heavy ion precipitation. We use a two-stream transport model that computes the secondary electron fluxes, their escape from the atmosphere, and characterization of the H2 Lyman-Werner band emission, including a predicted observable spectrum with the associated color ratio. Our model predicts that escaping electrons have an energy range from 1 eV to 6 keV, H2 band emission rates produced are on the order of 75 kR for an input

Catastrophic antiphospholipid syndrome (CAPS): Descriptive analysis of 500 patients from the International CAPS Registry.

Science.gov (United States)

Rodríguez-Pintó, Ignasi; Moitinho, Marta; Santacreu, Irene; Shoenfeld, Yehuda; Erkan, Doruk; Espinosa, Gerard; Cervera, Ricard

2016-12-01

To analyze the clinical and immunologic manifestations of patients with catastrophic antiphospholipid syndrome (CAPS) from the "CAPS Registry". The demographic, clinical and serological features of 500 patients included in the website-based "CAPS Registry" were analyzed. Frequency distribution and measures of central tendency were used to describe the cohort. Comparison between groups regarding qualitative variables was undertaken by chi-square or Fisher exact test while T-test for independent variables was used to compare groups regarding continuous variables. 500 patients (female: 343 [69%]; mean age 38±17) accounting for 522 episodes of CAPS were included in the analysis. Forty percent of patients had an associated autoimmune disease, mainly systemic lupus erythematosus (SLE) (75%). The majority of CAPS episodes were triggered by a precipitating factor (65%), mostly infections (49%). Clinically, CAPS was characterized by several organ involvement affecting kidneys (73%), lungs (60%), brain (56%), heart (50%), and skin (47%). Lupus anticoagulant, IgG anticardiolipin and IgG anti-β2-glycprotein antibodies were the most often implicated antiphospholipid antibodies (83%, 81% and 78% respectively). Mortality accounted for 37% of episodes of CAPS. Several clinical differences could be observed based on the age of presentation and its association to SLE. Those cases triggered by a malignancy tended to occur in older patients, while CAPS episodes in young patients were associated with an infectious trigger and peripheral vessels involvement. Additionally, CAPS associated with SLE were more likely to have severe cardiac and brain involvement leading to a higher mortality (48%). Although the presentation of CAPS is characterized by multiorgan thrombosis and failure, clinical differences among patients exist based on age and underlying chronic diseases, e.g. malignancy and SLE. Copyright © 2016 Elsevier B.V. All rights reserved.

Dispersion relation of linearly polarized strong electromagnetic waves

Energy Technology Data Exchange (ETDEWEB)

Ferrari, A; Massaglia, S [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Dobrowolny, M [Comitato Nazionale per l' Energia Nucleaire, Frascati (Italy). Lab. Plasma Spazio

1975-12-15

A numerical study is presented of the dispersion relation of linearly polarized strong electromagnetic waves in a cold electron plasma. The nonlinear effects introduced by the relativistic motion of electrons are: (1) the dispersion relation depends explicitly on the field strength ..cap alpha..=eE/sub 0//mc..omega../sub 0/, and (2) the propagation of modes with frequencies below the formal electron plasma frequency is allowed.

Observations of polar patches generated by solar wind Alfvén wave coupling to the dayside magnetosphere

Directory of Open Access Journals (Sweden)

P. Prikryl

Full Text Available A long series of polar patches was observed by ionosondes and an all-sky imager during a disturbed period (K_p = 7- and IMF B_z < 0. The ionosondes measured electron densities of up to 9 × 10¹¹ m^-3 in the patch center, an increase above the density minimum between patches by a factor of sim4.5. Bands of F-region irregularities generated at the equatorward edge of the patches were tracked by HF radars. The backscatter bands were swept northward and eastward across the polar cap in a fan-like formation as the afternoon convection cell expanded due to the IMF B_y > 0. Near the north magnetic pole, an all-sky imager observed the 630-nm emission patches of a distinctly band-like shape drifting northeastward to eastward. The 630-nm emission patches were associated with the density patches and backscatter bands. The patches originated in, or near, the cusp footprint where they were formed by convection bursts (flow channel events, FCEs structuring the solar EUV-produced photoionization and the particle-produced auroral/cusp ionization by segmenting it into elongated patches. Just equatorward of the cusp footprint Pc5 field line resonances (FLRs were observed by magnetometers, riometers and VHF/HF radars. The AC electric field associated with the FLRs resulted in a poleward-progressing zonal flow pattern and backscatter bands. The VHF radar Doppler spectra indicated the presence of steep electron density gradients which, through the gradient drift instability, can lead to the generation of the ionospheric irregularities found in patches. The FLRs and FCEs were associated with poleward-progressing DPY currents (Hall currents modulated by the IMF B_y and riometer absorption enhancements. The temporal and spatial characteristics of the VHF backscatter and associated riometer absorptions closely resembled those of poleward moving auroral forms (PMAFs. In the solar

SeaWinds - Oceans, Land, Polar Regions

Science.gov (United States)

1999-01-01

The SeaWinds scatterometer on the QuikScat satellite makes global radar measurements -- day and night, in clear sky and through clouds. The radar data over the oceans provide scientists and weather forecasters with information on surface wind speed and direction. Scientists also use the radar measurements directly to learn about changes in vegetation and ice extent over land and polar regions.This false-color image is based entirely on SeaWinds measurements obtained over oceans, land, and polar regions. Over the ocean, colors indicate wind speed with orange as the fastest wind speeds and blue as the slowest. White streamlines indicate the wind direction. The ocean winds in this image were measured by SeaWinds on September 20, 1999. The large storm in the Atlantic off the coast of Florida is Hurricane Gert. Tropical storm Harvey is evident as a high wind region in the Gulf of Mexico, while farther west in the Pacific is tropical storm Hilary. An extensive storm is also present in the South Atlantic Ocean near Antarctica.The land image was made from four days of SeaWinds data with the aid of a resolution enhancement algorithm developed by Dr. David Long at Brigham Young University. The lightest green areas correspond to the highest radar backscatter. Note the bright Amazon and Congo rainforests compared to the dark Sahara desert. The Amazon River is visible as a dark line running horizontally though the bright South American rain forest. Cities appear as bright spots on the images, especially in the U.S. and Europe.The image of Greenland and the north polar ice cap was generated from data acquired by SeaWinds on a single day. In the polar region portion of the image, white corresponds to the largest radar return, while purple is the lowest. The variations in color in Greenland and the polar ice cap reveal information about the ice and snow conditions present.NASA's Earth Science Enterprise is a long-term research and technology program designed to examine Earth

Pc5 waves generated by substorm injection: a case study

Directory of Open Access Journals (Sweden)

N. A. Zolotukhina

2008-07-01

Full Text Available We analyzed the spectral-polarized characteristics of Pc5 ULF waves observed on 17 September 2000 after the 03:20:25 UT substorm onset with the satellites GOES 8 and 10 located east and west of the onset location. In the course of the event, the wave polarization changed from mixed (between toroidal and poloidal to poloidal, and then to mixed again. The hodogram of magnetic field oscillations rotated counterclockwise at GOES 8, and clockwise at GOES 10. It is suggested that the satellites detected the waves generated by the substorm injected clouds of the charged particles drifting in the magnetosphere in the opposite azimuthal directions: GOES 8 (located east of the substorm onset detected the wave generated by an electron cloud, and GOES 10 (west of the onset detected the wave generated by a positive ion cloud. This interpretation is confirmed by the energetic particles data recorded by LANL satellites.

ELIPGRID-PC: Upgraded version

International Nuclear Information System (INIS)

Davidson, J.R.

1995-12-01

Evaluating the need for and the effectiveness of remedial cleanup at waste sites often includes finding average contaminant concentrations and identifying pockets of contamination called hot spots. The standard tool for calculating the probability of detecting pockets of contamination called hot spots has been the ELIPGRID code of singer and Wickman. The ELIPGRID-PC program has recently made this algorithm available for an IBM reg-sign personal computer (PC) or compatible. A new version of ELIPGRID-PC, incorporating Monte Carlo test results and simple graphics, is herein described. Various examples of how to use the program for both single and multiple hot spot cases are given. The code for an American National Standards Institute C version of the ELIPGRID algorithm is provided, and limitations and further work are noted. This version of ELIPGRID-PC reliably meets the goal of moving Singer's ELIPGRID algorithm to the PC

Dice and Pulsars

International Nuclear Information System (INIS)

Kontorovich, V.M.

2007-01-01

The pulses sequence is interpreted as a realization of a random electron discharge process in a vacuum gap over the polar cap (PC) - the open magnetic force line region on the neutron star surface. This point of view is illustrated by an example based on the dice. The generators of the random numbers are a cube and a coin. Throwing of dice and coin tossing determine the discharge places on the 'light' and 'dark' sides of PC, and correspondingly - the 'shape' of the individual pulses and their statistical properties. The physical mechanism giving such discharge scheme is shortly discussed. It may be a charge drained down from a sharp top of surface waves in a parallel electric field on the liquid PC surface of a neutron star

Generation of coordinates in PC for graphics of polar figure; Generacion de coordenadas en microcomputadora para graficado de figura polar

Energy Technology Data Exchange (ETDEWEB)

Macias B, L.R

1991-10-15

The preferential orientation, not alone it exists in metals, but also in minerals or in general in crystalline materials, notwithstanding in the metals it can be transformed by means of those processes of having mechanical worked such as laminate, wrapping, etc. To the preferable orientation of the crystals is also known as texture and since the properties of the crystalline materials lens depend on the orientation that present its glasses, it is important to know its texture. The difficulty for to represent and to describe the grade of preferential orientation in textured materials take to F. Weber to adapt the stereo graphic projection of a monocrystal to a poles figure. Later on, its appeared but methods to obtain the polar figure, among them, that of reflection of L. G. Schultz, but again a technique appears it specifies for its obtaining. In all the cases, the methodology is the following one: a) It is obtained by means of the diffraction process, the correspondent spectra in digitized form. b) it is applied process of having softened mathematician of the spectrum. c) there are determined the fi coordinates, beta and intensity for graph nts of the polar figure. d) Its are graph the points generated in c obtaining the polar figures. The objective of this work, is leaving of a softened spectra, to generate the coordinated fi, beta and corresponding intensity to proceed to their graph and generation of the polar figure. In this specific work, the methodology of Philips is used that consists in making a sweeping in hairspring form with the radiation to detect in these points the execution of the Bragg law. (Author)

The rebirth of the cervical cap.

Science.gov (United States)

Cappiello, J D; Grainger-Harrison, M

1981-01-01

In an effort to dispel myths surrounding the cervical cap, the historical and political factors affecting the cap's use in the U.S. are described. Clinical aspects of cap fitting are also included. The cervical cap has found only limited acceptance in the U.S. Skepticisms on the part of physicians may be the result of 2 factors: confusion of the cervical cap with intracervical devices used for artificial insemination and confusion with stem pessaries; and the lack of clinical research and statistical evaluation of efficacy rates. The latter factor prompted Tietze et al. to conduct the only U.S. statistical study of the cap in 1953. Of the 143 women studied, the pregnancy rate was 7.6/100 years of use. Of the 28 unplanned pregnancies, 6 were related to faulty technique or omission of a spermicide and 10 were instances of admittedly irregular use. When these failures are omitted, the theoretical effectiveness rate is about 98%. Some practitioners are concerned about an increased incidence of cervical erosion with cap use. Possibly currently conducted studies will show that cap and spermicide users have a lower incidence of cervical erosion than women using no contraceptive method. Study findings suggest that the cervical cap may afford protection without any spermicidal supplement, but the use of spermicides continues to be recommended to clients. Advantages of the cervical cap include the following: it can be left in place longer than a diaphragm without additional applications of spermicide in the vagina; and the insertion of the cap is unrelated to the time of intercourse. Despite research on toleration of the cap for 3 weeks at a time, it is recommended that the cap be worn for only a few days at a time. At this time there are no manufacturers of cervical caps for contraceptive use in the U.S. The cap is now being imported from England and it costs $6.00. A factor that has made the cap unpopular with many physicians is the lengthy time required for fitting. An

PC-BLAS, PC Linear Algebra Subroutines

International Nuclear Information System (INIS)

Hanson, R.J.

1989-01-01

1 - Description of program or function: PC-BLAS is a highly optimized version of the Basic Linear Algebra Subprograms (BLAS), a standardized set of 38 routines that perform low-level operations on vectors of numbers in single- and double-precision real and complex arithmetic. Routines are included to find the index of the largest component of a vector, apply a Givens or modified Givens rotation, multiply a vector by a constant, determine the Euclidean length, perform a dot product, swap and copy vectors, and find the norm of a vector. 2 - Restrictions on the complexity of the problem: The number of components in any vector and the spacing or stride between their entries must not exceed 32,767 (2 15 -1). PC-BLAS will not work with an 80286 CPU operating in 'protected' mode

Microtubule's conformational cap

DEFF Research Database (Denmark)

Flyvbjerg, H.

1999-01-01

The molecular mechanisms that allow elongation of the unstable microtubule lattice remain unclear. It is usually thought that the GDP-liganded tubulin lattice is capped by a small layer of GTP- or GDP-P(i)-liganded molecules, the so called "GTP-cap". Here, we point-out that the elastic properties...

Double-chain phospholipid end-capped polyurethanes: Synthesis, characterization and platelet adhesion study

International Nuclear Information System (INIS)

Tan Dongsheng; Zhang Xiaoqing; Li Jiehua; Tan Hong; Fu Qiang

2012-01-01

A novel phospholipid containing double chains and phosphotidylcholine polar head groups, 2-(10-(2-aminoethylamino)-10-oxodecanamido)-3-(decyloxy)-3-oxopropyl phosphorylcholine (ADDPC), was synthesized and characterized. Two kinds of double-chain phospholipid end-capped polyurethanes with different soft segments were prepared. The structure of prepared polyurethanes was characterized by X-ray photoelectron spectroscopic (XPS), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectrometry and atomic force microscope (AFM), which indicated that the double-chain phospholipids enriched onto the top surface of the prepared polyurethane films. The preliminary evaluation of blood compatibility showed that these novel phospholipid end-capped polyurethanes could suppress platelet adhesion and activation effectively. This property did not depend on the chemical structure of polyurethanes. In addition, according to tensile test results, the phospholipid polyurethanes kept good mechanical properties in comparison with original polyurethanes. It is suggested that double-chain phospholipid end-caption has good potential for achieving both hemocompatibility and good mechanical properties simultaneously for polyurethanes.

Cluster observations of EMIC triggered emissions in association with Pc1 waves near Earth's plasmapause

Science.gov (United States)

Pickett, J. S.; Grison, B.; Omura, Y.; Engebretson, M. J.; Dandouras, I.; Masson, A.; Adrian, M. L.; Santolík, O.; Décréau, P. M. E.; Cornilleau-Wehrlin, N.; Constantinescu, D.

2010-05-01

The Cluster spacecraft were favorably positioned on the nightside near the equatorial plasmapause of Earth at L ˜ 4.3 on 30 March 2002 to observe electromagnetic ion cyclotron (EMIC) rising tone emissions in association with Pc1 waves at 1.5 Hz. The EMIC rising tone emissions were found to be left-hand, circularly polarized, dispersive, and propagating away from the equator. Their burstiness and dispersion of ˜30s/Hz rising out of the 1.5 Hz Pc1 waves are consistent with their identification as EMIC triggered chorus emissions, the first to be reported through in situ observations near the plasmapause. Along with the expected H+ ring current ions seen at higher energies (>300 eV), lower energy ions (300 eV and less) were observed during the most intense EMIC triggered emission events. Nonlinear wave-particle interactions via cyclotron resonance between the ˜2-10 keV H+ ions with temperature anisotropy and the linearly-amplified Pc1 waves are suggested as a possible generation mechanism for the EMIC triggered emissions.

Peak Pc Prediction in Conjunction Analysis: Conjunction Assessment Risk Analysis. Pc Behavior Prediction Models

Science.gov (United States)

Vallejo, J.J.; Hejduk, M.D.; Stamey, J. D.

2015-01-01

Satellite conjunction risk typically evaluated through the probability of collision (Pc). Considers both conjunction geometry and uncertainties in both state estimates. Conjunction events initially discovered through Joint Space Operations Center (JSpOC) screenings, usually seven days before Time of Closest Approach (TCA). However, JSpOC continues to track objects and issue conjunction updates. Changes in state estimate and reduced propagation time cause Pc to change as event develops. These changes a combination of potentially predictable development and unpredictable changes in state estimate covariance. Operationally useful datum: the peak Pc. If it can reasonably be inferred that the peak Pc value has passed, then risk assessment can be conducted against this peak value. If this value is below remediation level, then event intensity can be relaxed. Can the peak Pc location be reasonably predicted?

75 FR 49527 - Caps Visual Communications, LLC; Black Dot Group; Formerly Known as Caps Group Acquisition, LLC...

Science.gov (United States)

2010-08-13

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-74,195] Caps Visual Communications, LLC; Black Dot Group; Formerly Known as Caps Group Acquisition, LLC Chicago, IL; Amended... of Caps Visual Communications, LLC, Black Dot Group, formerly known as Caps Group Acquisition, LLC...

Macrophage Capping Protein CapG Is a Putative Oncogene Involved in Migration and Invasiveness in Ovarian Carcinoma

Directory of Open Access Journals (Sweden)

J. Glaser

2014-01-01

Full Text Available The actin binding protein CapG modulates cell motility by interacting with the cytoskeleton. CapG is associated with tumor progression in different nongynecologic tumor entities and overexpression in breast cancer cell lines correlates with a more invasive phenotype in vitro. Here, we report a significant CapG overexpression in 18/47 (38% of ovarian carcinomas (OC analyzed by qRealTime-PCR analyses. Functional analyses in OC cell lines through siRNA mediated CapG knockdown and CapG overexpression showed CapG-dependent cell migration and invasiveness. A single nucleotide polymorphism rs6886 inside the CapG gene was identified, affecting a CapG phosphorylation site and thus potentially modifying CapG function. The minor allele frequency (MAF of SNP rs6886 (c.1004A/G was higher and the homozygous (A/A, His335 genotype was significantly more prevalent in patients with fallopian tube carcinomas (50% as in controls (10%. With OC being one of the most lethal cancer diseases, the detection of novel biomarkers such as CapG could reveal new diagnostic and therapeutic targets. Moreover, in-depth analyses of SNP rs6886 related to FTC and OC will contribute to a better understanding of carcinogenesis and progression of OC.

Repairing and Upgrading Your PC

CERN Document Server

Thompson, Robert

2009-01-01

Repairing and Upgrading Your PC delivers start-to-finish instructions, simple enough for even the most inexperienced PC owner, for troubleshooting, repairing, and upgrading your computer. Written by hardware experts Robert Bruce Thompson and Barbara Fritchman Thompson, this book covers it all: how to troubleshoot a troublesome PC, how to identify which components make sense for an upgrade, and how to tear it all down and put it back together. This book shows how to repair and upgrade all of your PC's essential components.

The polarization of the far-infrared radiation from the Galactic center

Science.gov (United States)

Werner, M. W.; Davidson, J. A.; Morris, M.; Novak, G.; Platt, S. R.

1988-01-01

The first detection of linear polarization of the far-infrared (100-micron) radiation from the about 3-pc-diameter dust ring surrounding the galactic nucleus is reported. The percentage of polarization is between 1 and 2 percent at the three measured positions. It is argued that the polarized radiation is produced by thermal emission from elongated interstellar grains oriented by the local magnetic field. The dust ring is optically thin at 100 microns; therefore the observations sample dust through the entire depth of the cloud and are free of confusing effects due to embedded sources, scattering, or selective absorption. These data provide the first information about the configuration of the magnetic field in the dust ring.

The PC graphics handbook

CERN Document Server

Sanchez, Julio

2003-01-01

Part I - Graphics Fundamentals PC GRAPHICS OVERVIEW History and Evolution Short History of PC Video PS/2 Video Systems SuperVGA Graphics Coprocessors and Accelerators Graphics Applications State-of-the-Art in PC Graphics 3D Application Programming Interfaces POLYGONAL MODELING Vector and Raster Data Coordinate Systems Modeling with Polygons IMAGE TRANSFORMATIONS Matrix-based Representations Matrix Arithmetic 3D Transformations PROGRAMMING MATRIX TRANSFORMATIONS Numeric Data in Matrix Form Array Processing PROJECTIONS AND RENDERING Perspective The Rendering Pipeline LIGHTING AND SHADING Lightin

Designing Smart Charter School Caps

Science.gov (United States)

Dillon, Erin

2010-01-01

In 2007, Andrew J. Rotherham proposed a new approach to the contentious issue of charter school caps, the statutory limits on charter school growth in place in several states. Rotherham's proposal, termed "smart charter school caps," called for quality sensitive caps that allow the expansion of high-performing charter schools while also…

PcToll2 positively regulates the expression of antimicrobial peptides by promoting PcATF4 translocation into the nucleus.

Science.gov (United States)

Lan, Jiang-Feng; Zhao, Li-Juan; Wei, Shun; Wang, Yuan; Lin, Li; Li, Xin-Cang

2016-11-01

Drosophila Toll and mammalian Toll-like receptors (TLRs) are a family of evolutionarily conserved immune receptors that play a crucial role in the first-line defense against intruded pathogens. Activating transcription factor 4 (ATF4), a member of the ATF/CREB transcription factor family, is an important factor that participates in TLR signaling and other physiological processes. However, in crustaceans, whether ATF4 homologs were involved in TLR signaling remains unclear. In the current study, we identified a Toll homolog PcToll2 and a novel ATF4 homolog PcATF4 from Procambarus clarkii, and analyzed the likely regulatory activity of PcATF4 in PcToll2 signaling. The complete cDNA sequence of PcToll2 was 4175 bp long containing an open reading frame of 2820 bp encoding a 939-amino acid protein, and the cDNA sequence of PcATF4 was 2027 bp long with an open reading frame of 1296 bp encoding a 431-amino acid protein. PcToll2 and human TLR4 shared the high identity and they were grouped into a cluster. Furthermore, PcToll2 had a close relationship with other shrimp TLRs that possessed potential antibacterial activity. PcToll2 was highly expressed in the hemocytes, heart and gills, while PcATF4 mainly distributed in gills. Upon challenge with Vibrio parahemolyticus, PcToll2 and PcATF4 together with the antimicrobial peptides of ALF1 and ALF2 were significantly up-regulated in the hemocytes, and the PcATF4 was translocated into the nucleus. After PcToll2 silencing and challenge with Vibrio, the translocation of PcATF4 into the nucleus was inhibited and the expression of ALF1 and ALF2 was reduced, but the expression of PcDorsal and PcSTAT was not affected. Furthermore, after PcATF4 knockdown and challenge with or without Vibrio, the expression of ALF1 and ALF2 was also decreased while the expression of PcToll2 was upregulated. These results suggested that PcToll2 might regulate the expression of ALF1 and ALF2 by promoting the import of PcATF4, instead of the routine

Radar observations of density gradients, electric fields, and plasma irregularities near polar cap patches in the context of the gradient-drift instability

Science.gov (United States)

Lamarche, Leslie J.; Makarevich, Roman A.

2017-03-01

We present observations of plasma density gradients, electric fields, and small-scale plasma irregularities near a polar cap patch made by the Super Dual Auroral Radar Network radar at Rankin Inlet (RKN) and the northern face of Resolute Bay Incoherent Scatter Radar (RISR-N). RKN echo power and occurrence are analyzed in the context of gradient-drift instability (GDI) theory, with a particular focus on the previously uninvestigated 2-D dependencies on wave propagation, electric field, and gradient vectors, with the latter two quantities evaluated directly from RISR-N measurements. It is shown that higher gradient and electric field components along the wave vector generally lead to the higher observed echo occurrence, which is consistent with the expected higher GDI growth rate, but the relationship with echo power is far less straightforward. The RKN echo power increases monotonically as the predicted linear growth rate approaches zero from negative values but does not continue this trend into positive growth rate values, in contrast with GDI predictions. The observed greater consistency of echo occurrence with GDI predictions suggests that GDI operating in the linear regime can control basic plasma structuring, but measured echo strength may be affected by other processes and factors, such as multistep or nonlinear processes or a shear-driven instability.

Long-term exposure of CdTe quantum dots on PC12 cellular activity and the determination of optimum non-toxic concentrations for biological use

Directory of Open Access Journals (Sweden)

Gérard Valérie A

2010-03-01

Full Text Available Abstract Background The unique and tuneable photonic properties of Quantum Dots (QDs have made them potentially useful tools for imaging biological entities. However, QDs though attractive diagnostic and therapeutic tools, have a major disadvantage due to their inherent cytotoxic nature. The cellular interaction, uptake and resultant toxic influence of CdTe QDs (gelatinised and non-gelatinised Thioglycolic acid (TGA capped have been investigated with pheochromocytoma 12 (PC12 cells. In conjunction to their analysis by confocal microscopy, the QD - cell interplay was explored as the QD concentrations were varied over extended (up to 72 hours co-incubation times. Coupled to this investigation, cell viability, DNA quantification and cell proliferation assays were also performed to compare and contrast the various factors leading to cell stress and ultimately death. Results Thioglycolic acid (TGA stabilised CdTe QDs (gel and non - gel were co-incubated with PC12 cells and investigated as to how their presence influenced cell behaviour and function. Cell morphology was analysed as the QD concentrations were varied over co-incubations up to 72 hours. The QDs were found to be excellent fluorophores, illuminating the cytoplasm of the cells and no deleterious effects were witnessed at concentrations of ~10-9 M. Three assays were utilised to probe how individual cell functions (viability, DNA quantification and proliferation were affected by the presence of the QDs at various concentrations and incubation times. Cell response was found to not only be concentration dependant but also influenced by the surface environment of the QDs. Gelatine capping on the surface acts as a barrier towards the leaking of toxic atoms, thus reducing the negative impact of the QDs. Conclusion This study has shown that under the correct conditions, QDs can be routinely used for the imaging of PC12 cells with minimal adverse effects. We have found that PC12 cells are highly

Long-term exposure of CdTe quantum dots on PC12 cellular activity and the determination of optimum non-toxic concentrations for biological use

LENUS (Irish Health Repository)

Prasad, Babu R

2010-03-25

Abstract Background The unique and tuneable photonic properties of Quantum Dots (QDs) have made them potentially useful tools for imaging biological entities. However, QDs though attractive diagnostic and therapeutic tools, have a major disadvantage due to their inherent cytotoxic nature. The cellular interaction, uptake and resultant toxic influence of CdTe QDs (gelatinised and non-gelatinised Thioglycolic acid (TGA) capped) have been investigated with pheochromocytoma 12 (PC12) cells. In conjunction to their analysis by confocal microscopy, the QD - cell interplay was explored as the QD concentrations were varied over extended (up to 72 hours) co-incubation times. Coupled to this investigation, cell viability, DNA quantification and cell proliferation assays were also performed to compare and contrast the various factors leading to cell stress and ultimately death. Results Thioglycolic acid (TGA) stabilised CdTe QDs (gel and non - gel) were co-incubated with PC12 cells and investigated as to how their presence influenced cell behaviour and function. Cell morphology was analysed as the QD concentrations were varied over co-incubations up to 72 hours. The QDs were found to be excellent fluorophores, illuminating the cytoplasm of the cells and no deleterious effects were witnessed at concentrations of ~10-9 M. Three assays were utilised to probe how individual cell functions (viability, DNA quantification and proliferation) were affected by the presence of the QDs at various concentrations and incubation times. Cell response was found to not only be concentration dependant but also influenced by the surface environment of the QDs. Gelatine capping on the surface acts as a barrier towards the leaking of toxic atoms, thus reducing the negative impact of the QDs. Conclusion This study has shown that under the correct conditions, QDs can be routinely used for the imaging of PC12 cells with minimal adverse effects. We have found that PC12 cells are highly susceptible to

NATURE MANAGEMENT, LANDSCAPE AND THE CAP

OpenAIRE

Brouwer, Floor M.; Godeschalk, Frans E.

2004-01-01

The integration of nature management, landscape and environmental concerns into the Common Agricultural Policy (CAP) has gained momentum with the CAP reforms adopted in June 2003. The report explores instruments and approaches that contribute to the inte-gration of nature conservation and landscape concerns into the CAP. A broader use of the CAP instruments might help to achieve nature types in the Netherlands.

Constraints on the Within Season and Between Year Variability of the North Residual Cap from MGS-TES

Science.gov (United States)

Calvin, W. M.; Titus, T. N.; Mahoney, S. A.

2003-01-01

There is a long history of telescopic and spacecraft observations of the polar regions of Mars. The finely laminated ice deposits and surrounding layered terrains are commonly thought to contain a record of past climate conditions and change. Understanding the basic nature of the deposits and their mineral and ice constituents is a continued focus of current and future orbited missions. Unresolved issues in Martian polar science include a) the unusual nature of the CO2 ice deposits ("Swiss Cheese", "slab ice" etc.) b) the relationship of the ice deposits to underlying layered units (which differs from the north to the south), c) understanding the seasonal variations and their connections to the finely laminated units observed in high-resolution images and d) the relationship of dark materials in the wind-swept lanes and reentrant valleys to the surrounding dark dune and surface materials. Our work focuses on understanding these issues in relationship to the north residual ice cap. Recent work using Mars Global Surveyor (MGS) data sets have described evolution of the seasonal CO2 frost deposits. In addition, the north polar residual ice cap exhibits albedo variations between Mars years and within the summer season. The Thermal Emission Spectrometer (TES) data set can augment these observations providing additional constraints such as temperature evolution and spectral properties associated with ice and rocky materials. Exploration of these properties is the subject of our current study.

CAPS Simulation Environment Development

Science.gov (United States)

Murphy, Douglas G.; Hoffman, James A.

2005-01-01

The final design for an effective Comet/Asteroid Protection System (CAPS) will likely come after a number of competing designs have been simulated and evaluated. Because of the large number of design parameters involved in a system capable of detecting an object, accurately determining its orbit, and diverting the impact threat, a comprehensive simulation environment will be an extremely valuable tool for the CAPS designers. A successful simulation/design tool will aid the user in identifying the critical parameters in the system and eventually allow for automatic optimization of the design once the relationships of the key parameters are understood. A CAPS configuration will consist of space-based detectors whose purpose is to scan the celestial sphere in search of objects likely to make a close approach to Earth and to determine with the greatest possible accuracy the orbits of those objects. Other components of a CAPS configuration may include systems for modifying the orbits of approaching objects, either for the purpose of preventing a collision or for positioning the object into an orbit where it can be studied or used as a mineral resource. The Synergistic Engineering Environment (SEE) is a space-systems design, evaluation, and visualization software tool being leveraged to simulate these aspects of the CAPS study. The long-term goal of the SEE is to provide capabilities to allow the user to build and compare various CAPS designs by running end-to-end simulations that encompass the scanning phase, the orbit determination phase, and the orbit modification phase of a given scenario. Herein, a brief description of the expected simulation phases is provided, the current status and available features of the SEE software system is reported, and examples are shown of how the system is used to build and evaluate a CAPS detection design. Conclusions and the roadmap for future development of the SEE are also presented.

The cervical cap (image)

Science.gov (United States)

The cervical cap is a flexible rubber cup-like device that is filled with spermicide and self-inserted over the cervix ... left in place several hours after intercourse. The cap is a prescribed device fitted by a health ...

Does uncertainty justify intensity emission caps?

International Nuclear Information System (INIS)

Quirion, Philippe

2005-01-01

Environmental policies often set 'relative' or 'intensity' emission caps, i.e. emission limits proportional to the polluting firm's output. One of the arguments put forth in favour of relative caps is based on the uncertainty on business-as-usual output: if the firm's production level is higher than expected, so will be business-as-usual emissions, hence reaching a given level of emissions will be more costly than expected. As a consequence, it is argued, a higher emission level should be allowed if the production level is more important than expected. We assess this argument with a stochastic analytical model featuring two random variables: the business-as-usual emission level, proportional to output, and the slope of the marginal abatement cost curve. We compare the relative cap to an absolute cap and to a price instrument, in terms of welfare impact. It turns out that in most plausible cases, either a price instrument or an absolute cap yields a higher expected welfare than a relative cap. Quantitatively, the difference in expected welfare is typically very small between the absolute and the relative cap but may be significant between the relative cap and the price instrument. (author)

PC-based analog signal generator for simulated detector signals and arbitrary test waveforms for testing the nuclear instruments

International Nuclear Information System (INIS)

Catanescu, V.

1999-01-01

This work is performed in cooperation with IAEA-Vienna as a project, proposed as part of Agency's C o-ordinated Research Programme of Development of Computer-based Troubleshooting Tools and Instruments. A convenient way for testing and calibrating modern scientific equipment is to connect the test instruments to a personal computer to get additional feasibilities. This way, all settings for test, measurement and data acquisition functions are done by means of PC and are controlled by software drivers. This multifunctional spectrometric pulse generator is able to characterize different parts of high-resolution nuclear spectroscopy chain (preamplifier, amplifier, analog to digital converter, multichannel analyzer) as well as the whole chain. For this it generates periodic or random pulses with shape, time and amplitude specifications controlled by PC. Characteristics such as integral linearity, differential linearity, dead time, rate channel shifting and others will be easily determined. The block diagram of the multifunctional spectrometric generator is shown. The main sections are: PC-interface, control registers and command generation; PC-controlled periodic and random logic pulse oscillators; PC-controlled delay and width of periodic or random logic pulses; constant and ultra-linear ramp references for spectrometric pulse generation; generation of the tail and flat top pulses with PC-controlled amplitude and decay time; semi-gaussian pulse generation, polarity inverter and output amplifier. The specifications for generated signal correspond to: shape, time specifications and amplitude size. (author)

Cryopyrin-Associated Autoinflammatory Syndromes (CAPS) - Juvenile

Science.gov (United States)

... all ethnic groups can be affected. What are CAPS? Cryopyrin-associated autoinflammatory syndromes (CAPS) consist of three ... ears by magnetic resonance imaging (MRI). How is CAPS treated? Medications that target interleukin-1 are very ...

Evaluation of strain in GaN/AlN quantum dots by means of resonant Raman scattering: the effect of capping

Energy Technology Data Exchange (ETDEWEB)

Cros, A.; Budagosky, J.A.; Garro, N.; Cantarero, A. [Institut de Ciencia del Materials, Universitat de Valencia, 46071 Valencia (Spain); Coraux, J.; Renevier, H.; Favre-Nicolin, V. [CEA-CNRS Group, ' ' Nanophysique et Semiconducteurs' ' , DRFMC/SP2M/PSC, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble cedex 9 (France); Universite Joseph Fourier, BP 53, 38041 Grenoble Cedex 9 (France); Proietti, M.G. [Departamento de Fisica de la Materia Condensada, Instituto de Ciencia de Materiales de Aragon, CSIC-Universidad de Zaragoza, calle Pedro Cerbuna 12, 50009 Zaragoza (Spain); Daudin, B. [CEA-CNRS Group, ' ' Nanophysique et Semiconducteurs' ' , DRFMC/SP2M/PSC, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble cedex 9 (France)

2007-06-15

We have studied in detail changes in the strain state of GaN/AlN quantum dots during the capping process. {mu}-Raman scattering experiments allowed the detection of a resonant mode which provided information on the evolution of strain with capping. Simultaneously, Multiwavelength Anomalous Diffraction (MAD) and Diffraction Anomalous Fine Structure (DAFS) experiments were performed on the same samples, providing the independent determination of the wurtzite lattice parameters a and c. The remarkable agreement between Raman and X-ray data stands out the suitability of polar vibrational modes for the determination of strain in nanostructures. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

The North Zealand CAP Monitor

DEFF Research Database (Denmark)

Nielsen, Minna; Ravn, Pernille; Notander Clausen, Lise

with CAP. We started with 34 audit variables. Through repeated cycles of testing, feedback and discussions, we reduced the number of indicators to 22 and time per audit from 20 to 10 minutes. Strategy for change To link the monitoring system with our patient pathway for CAP we established an improvement...... Designing a database Designing and testing a dashboard to present indicators in a balanced way Messages for others Auditing patients with a common disease as CAP is useful to identify areas for improvement for a large group of patients. The baseline audit can serve as a basis for a monitoring system......Contect We describe how we developed a monitoring system for community acquired pneumonia (CAP) at North Zealand Regional hospital. We serve 310.000 inhabitants and annually around 3200 patients with CAP are admitted. As part of a program of clinical pathways for common conditions, a pathway...

PC/104 Embedded IOCs at Jefferson Lab

International Nuclear Information System (INIS)

Yan, Jianxun; Allison, Trent; Witherspoon, Sue; Cuffe, Anthony

2009-01-01

Jefferson Lab has developed embedded IOCs based on PC/104 single board computers (SBC) for low level control systems. The PC/104 IOCs run EPICS on top of the RTEMS operating system. Two types of control system configurations are used in different applications, PC/104 SBC with commercial PC/104 I/O cards and PC/104 SBC with custom designed FPGA-based boards. RTEMS was built with CEXP shell to run on the PC/104 SBC. CEXP shell provides the function of dynamic object loading, which is similar to the widely used VxWorks operating system. Standard software configurations were setup for PC/104 IOC application development to provide a familiar format for new projects as well as ease the conversion of applications from VME based IOCs to PC/104 IOCs. Many new projects at Jefferson Lab are going to employ PC/104 SBCs as IOCs and some applications have already been running them for accelerator operations. The PC/104 - RTEMS IOC provides a free open source Real-Time Operating System (RTOS), low cost/maintenance, easily installed/ configured, flexible, and reliable solution for accelerator control and 12GeV Upgrade projects.

Functional Analysis of Mouse G6pc1 Mutations Using a Novel In Situ Assay for Glucose-6-Phosphatase Activity and the Effect of Mutations in Conserved Human G6PC1/G6PC2 Amino Acids on G6PC2 Protein Expression.

Directory of Open Access Journals (Sweden)

Kayla A Boortz

Full Text Available Elevated fasting blood glucose (FBG has been associated with increased risk for development of type 2 diabetes. Single nucleotide polymorphisms (SNPs in G6PC2 are the most important common determinants of variations in FBG in humans. Studies using G6pc2 knockout mice suggest that G6pc2 regulates the glucose sensitivity of insulin secretion. G6PC2 and the related G6PC1 and G6PC3 genes encode glucose-6-phosphatase catalytic subunits. This study describes a functional analysis of 22 non-synonymous G6PC2 SNPs, that alter amino acids that are conserved in human G6PC1, mouse G6pc1 and mouse G6pc2, with the goal of identifying variants that potentially affect G6PC2 activity/expression. Published data suggest strong conservation of catalytically important amino acids between all four proteins and the related G6PC3 isoform. Because human G6PC2 has very low glucose-6-phosphatase activity we used an indirect approach, examining the effect of these SNPs on mouse G6pc1 activity. Using a novel in situ functional assay for glucose-6-phosphatase activity we demonstrate that the amino acid changes associated with the human G6PC2 rs144254880 (Arg79Gln, rs149663725 (Gly114Arg and rs2232326 (Ser324Pro SNPs reduce mouse G6pc1 enzyme activity without affecting protein expression. The Arg79Gln variant alters an amino acid mutation of which, in G6PC1, has previously been shown to cause glycogen storage disease type 1a. We also demonstrate that the rs368382511 (Gly8Glu, rs138726309 (His177Tyr, rs2232323 (Tyr207Ser rs374055555 (Arg293Trp, rs2232326 (Ser324Pro, rs137857125 (Pro313Leu and rs2232327 (Pro340Leu SNPs confer decreased G6PC2 protein expression. In summary, these studies identify multiple G6PC2 variants that have the potential to be associated with altered FBG in humans.

Dione and Rhea seasonal exospheres revealed by Cassini CAPS and INMS

Science.gov (United States)

Teolis, B. D.; Waite, J. H.

2016-07-01

A Dione O2 and CO2 exosphere of similar composition and density to Rhea's is confirmed by Cassini spacecraft Ion Neutral Mass Spectrometer (INMS) flyby data. INMS results from three Dione and two Rhea flybys show exospheric spatial and temporal variability indicative of seasonal exospheres, modulated by winter polar gas adsorption and desorption at the equinoxes. Cassini Plasma Spectrometer (CAPS) pickup ion fluxes also show exospheric structure and evolution at Rhea consistent with INMS, after taking into consideration the anticipated charge exchange, electron impact, and photo-ionization rates. Data-model comparisons show the exospheric evolution to be consistent with polar frost diffusion into the surface regolith, which limits surface exposure and loss of the winter frost cap by sputtering. Implied O2 source rates of ∼45(7) × 1021 s-1 at Dione(Rhea) are ∼50(300) times less than expected from known O2 radiolysis yields from ion-irradiated pure water ice measured in the laboratory, ruling out secondary sputtering as a major exospheric contributor, and implying a nanometer scale surface refractory lag layer consisting of concentrated carbonaceous impurities. We estimate ∼30:1(2:1) relative O2:CO2 source rates at Dione(Rhea), consistent with a stoichiometric bulk composition below the lag layer of 0.01(0.13) C atoms per H2O molecule, deriving from endogenic constituents, implanted micrometeoritic organics, and (in particular at Dione) exogenous H2O delivery by E-ring grains. Impact deposition, gardening and vaporization may thereby control the global O2 source rates by fresh H2O ice exposure to surface radiolysis and trapped oxidant ejection.

PC'eren på arbejde. 3. udgave

DEFF Research Database (Denmark)

Andersen, Povl Erik Rostgård

En generel og ikke-programspecifik introduktion til edb-området med speciel fokus på pc'er og pc-programmel.......En generel og ikke-programspecifik introduktion til edb-området med speciel fokus på pc'er og pc-programmel....

tPC-PSAFT modeling of gas solubility in imidazolium-based ionic liquids

DEFF Research Database (Denmark)

Karakatsani, Eirini; Economou, Ioannis; Kroon, M. C.

2007-01-01

The truncated perturbed chain-polar statistical associating fluid theory (tPC-PSAFT) is re-parametrized for imidazolium-based ionic liquids (ILs) by fitting IL density data over a wide temperature range and restricting the model to predict very low vapor pressure values, in agreement with recent...... experimental evidence. The new set of parameters is used for the correlation of carbon dioxide solubility in various ILs using a binary interaction parameter, k(ij). The correlated k(ij) values are much lower than the values used previously for the same mixtures (Kroon et al., J. Phys. Chem. B 2006, 110, 9262...

Manipulating the dipole layer of polar organic molecules on metal surfaces via different charge-transfer channels

Science.gov (United States)

Lin, Meng-Kai; Nakayama, Yasuo; Zhuang, Ying-Jie; Wang, Chin-Yung; Pi, Tun-Wen; Ishii, Hisao; Tang, S.-J.

The key properties of organic films such as energy level alignment (ELA), work functions, and injection barriers are closely linked to this dipole layer. Using angle resolved photoemission spectroscopy (ARPES), we systemically investigate the coverage-dependent work functions and spectra line shapes of occupied molecular orbital states of a polar molecule, chloroaluminium phthalocyanine (ClAlPc), grown on Ag(111) to show that the orientations of the first ClAlPc layer can be manipulated via the molecule deposition rate and post annealing, causing ELA at organic-metal interface to differ for about 0.3 eV between Cl-up and Cl-down configuration. Moreover, by comparing the experimental results with the calculations based on both gas-phase model and realistic model of ClAlPc on Ag(111) , we evidence that the different orientations of ClAlPc dipole layers lead to different charge-transfer channels between ClAlPc and Ag, a key factor that controls the ELA at organic-metal interface.

Estimated release from the saltstone landfill effect of landfill caps and landfill-cap/monolith-liner combinations

International Nuclear Information System (INIS)

Wilhite, E.L.

1985-01-01

The effect of capping the entire saltstone landfill is dependent on the effectiveness of the clay cap in preventing infiltration. A cap that is 99% effective will reduce releases from the saltstone landfill by a factor of 7.7. Several combinations of landfill design alterations will result in meeting ground water standards

Unusual strong quasi-monochromatic ground Pc5 geomagnetic pulsations in the recovery phase of November 2003 superstorm

Directory of Open Access Journals (Sweden)

N. G. Kleimenova

2005-10-01

Full Text Available Unusually large-amplitude morning Pc5 magnetic pulsations during the recovery phase of the huge magnetic storm in November 2003 have been studied by using ground-based multi-point observations. Two main spectral Pc5 enhancements were observed: at f≈2 mHz, which featured slowly increasing frequency with decreasing latitude, and at f≈3 mHz, which was latitude independent. The Pc5 pulsations were observed at wide range of latitudes (more than 10° with the same very strong amplitude (up to 500nT and with the same polarization. Only the 3-mHz peak was clearly seen in the spectra of pulsating auroral radio absorption, as observed by the Finnish riometer chain. Short and localized bursts of PiB (f~50–100 mHz magnetic pulsations and simultaneous short bursts of energetic electron precipitation were observed in the morning sector, as well. The beginning of the large-amplitude morning Pc5 activity occurred simultaneously with a substorm onset in the evening and midnight sectors. However, the spectra of pulsations in the morning and evening sectors were different. They were compared with spectra of IMF and solar wind parameters, measured by ACE spacecraft. The similarity between the spectra of morning Pc5 and IMF B_y was found, but the spectra of evening Pi3 pulsations were similar to the spectra of solar wind density variations. The Pc5 and PiB pulsations, as well as bursts of the auroral radio absorption, suddenly disappeared, when the solar wind density abruptly dropped. We suppose that the ~2-mHz Pc5 geomagnetic pulsations could be attributed to field line resonance (FLR, however, the 3-mHz oscillations were apparently non-resonance origin.

Keywords. Magnetospheric physics (MHD waves and instabilities; Solar wind-magnetosphere interaction; Storms and substorms

Unusual strong quasi-monochromatic ground Pc5 geomagnetic pulsations in the recovery phase of November 2003 superstorm

Directory of Open Access Journals (Sweden)

N. G. Kleimenova

2005-10-01

Full Text Available Unusually large-amplitude morning Pc5 magnetic pulsations during the recovery phase of the huge magnetic storm in November 2003 have been studied by using ground-based multi-point observations. Two main spectral Pc5 enhancements were observed: at f≈2 mHz, which featured slowly increasing frequency with decreasing latitude, and at f≈3 mHz, which was latitude independent. The Pc5 pulsations were observed at wide range of latitudes (more than 10° with the same very strong amplitude (up to 500nT and with the same polarization. Only the 3-mHz peak was clearly seen in the spectra of pulsating auroral radio absorption, as observed by the Finnish riometer chain. Short and localized bursts of PiB (f~50–100 mHz magnetic pulsations and simultaneous short bursts of energetic electron precipitation were observed in the morning sector, as well. The beginning of the large-amplitude morning Pc5 activity occurred simultaneously with a substorm onset in the evening and midnight sectors. However, the spectra of pulsations in the morning and evening sectors were different. They were compared with spectra of IMF and solar wind parameters, measured by ACE spacecraft. The similarity between the spectra of morning Pc5 and IMF By was found, but the spectra of evening Pi3 pulsations were similar to the spectra of solar wind density variations. The Pc5 and PiB pulsations, as well as bursts of the auroral radio absorption, suddenly disappeared, when the solar wind density abruptly dropped. We suppose that the ~2-mHz Pc5 geomagnetic pulsations could be attributed to field line resonance (FLR, however, the 3-mHz oscillations were apparently non-resonance origin. Keywords. Magnetospheric physics (MHD waves and instabilities; Solar wind-magnetosphere interaction; Storms and substorms

Adjustment of the ratio of Ca/P in the ceramic coating on Mg alloy by plasma electrolytic oxidation

International Nuclear Information System (INIS)

Yao Zhongping; Li Liangliang; Jiang Zhaohua

2009-01-01

The ceramic coatings containing Ca and P were prepared on AZ91D Mg alloy by plasma electrolytic oxidation technique in NaOH system and Na 2 SiO 3 system, respectively. The phase composition, morphology and the element distribution of the coatings was studied by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. The corrosion resistance of the coatings was examined by polarizing curve methods in a 0.9% NaCl solution. In NaOH system, there were a large number of micro-holes distributing evenly on the surface of the coating, and the coating was mainly composed of Mg, Al, P and Ca. In Na 2 SiO 3 system, the micro-holes in the coatings were reduced greatly in number and the distribution of the micro-holes was uneven, and the coating was mainly composed of Mg, Al, Si, P and Ca. The ratio of Ca/P in the coating can be controlled by the adjustment of the technique parameters to a certain extent. The adjustment of the concentration of Ca 2+ in the electrolyte was an effective method to change the ratio of Ca/P in the coating in both systems; the reaction time and the working voltage for the adjustment of the ratio of Ca/P in the coating was more suitable for the NaSi 2 O 3 system than the NaOH system. The polarizing curve tests showed the coatings improved the corrosion resistance of the AZ91D Mg alloy in 0.9% NaCl solution by nearly two orders of magnitude.

Spontaneous and trigger-associated substorms compared: Electrodynamic parameters in the polar ionosphere

Science.gov (United States)

Liu, Jun-Ming; Zhang, Bei-Chen; Kamide, Y.; Wu, Zhen-Sen; Hu, Ze-Jun; Yang, Hui-Gen

2011-01-01

An attempt is made to study the difference, if any, between the response of the polar ionosphere to spontaneous substorms and that to trigger-associated substorms in terms of electrodynamic parameters including ionospheric current vectors, the electric potential, and the current function. The results show that, in the first approximation, the ionospheric parameters for the two types of substorms are quite similar. It is therefore conceived that spontaneous substorms are not very different from trigger-associated substorms in the development of substorm processes in the magnetosphere-ionosphere system. We demonstrate, however, that spontaneous substorms seem to have a more clearly identifiable growth phase, whereas trigger-associated substorms have a more powerful unloading process. Changes in the current intensity and the electric potential drop across the polar cap in the recovery phase are also quite different from each other. Both the current intensity and the cross-polar cap potential drop show a larger decrease in the recovery phase of trigger-associated substorms, but the potential drop decreases only slightly and the currents in the late morning sector are still strong for spontaneous substorms. We interpret these findings as an indication of the relative importance of the unloading process and the directly driven process in conjunction with the north-south polarity of the interplanetary magnetic field. There still exists a strong directly driven process in the recovery phase of spontaneous substorms. For trigger-associated substorms, however, both the directly driven process and the unloading process become weak after the peak time.

Buried CO2 Ice traces in South Polar Layered Deposits of Mars detected by radar sounder

Science.gov (United States)

Castaldo, L.; Mège, D.; Orosei, R.; Séjourné, A.

2014-12-01

SHARAD (SHAllow RADar) is the subsurface sounding radar provided by the Italian Space Agency (ASI) as a facility instrument to NASA's 2005 Mars Reconnaissance Orbiter (MRO). The Reduced Data Record of SHARAD data covering the area of the South Polar Layered Deposits (SPLD), has been used. The elaboration and interpretation of the data, aimed to estimate electromagnetic properties of surface layers, has been performed in terms of permittivity. The theory of electromagnetic scattering from fractal surfaces, and the estimation of geometric parameters from topographic data by Mars Orbiter Laser Altimeter (MOLA) which was one of five instruments on board the Mars Global Surveyor (MGS) spacecraft, has been used. A deep analysis of inversion has been made on all Mars and extended to the South Polar Caps in order to extract the area with a permittivity constant of CO2 ice. Several corrections have been applied to the data, moreover the calibration of the signal requires the determination of a constant that takes into account the power gain due to the radar system and the surface in order to compensate the power losses due to the orbitographic phenomena. The determination of regions with high probability of buried CO2 ice in the first layer of the Martian surface, is obtained extracting the real part of the permittivity constant of the CO2 ice (~2), estimated by other means. The permittivity of CO2ice is extracted from the Global Permittivity Map of Mars using the global standard deviation of itself as following: ɛCO2ice=ɛCO2ice+ Σ (1)where Σ=±std(ɛMapMars)/2Figure 1(a) shows the south polar areas where the values of the permittivity point to the possibility of a CO2 ice layer. Figure 1(b) is the corresponding geologic map. The comparison between the two maps indicates that the area with probable buried CO2 overlaps Hesperian and Amazonian polar units (Hp, Hesperian plains-forming deposits marked by narrow sinuous, anabranching ridges and irregular depressions, and

Semi-analytical approach for guided mode resonance in high-index-contrast photonic crystal slab: TE polarization.

Science.gov (United States)

Yang, Yi; Peng, Chao; Li, Zhengbin

2013-09-09

In high-contrast (HC) photonic crystals (PC) slabs, the high-order coupling is so intense that it is indispensable for analyzing the guided mode resonance (GMR) effect. In this paper, a semi-analytical approach is proposed for analyzing GMR in HC PC slabs with TE-like polarization. The intense high-order coupling is included by using a convergent recursive procedure. The reflection of radiative waves at high-index-contrast interfaces is also considered by adopting a strict Green's function for multi-layer structures. Modal properties of interest like band structure, radiation constant, field profile are calculated, agreeing well with numerical finite-difference time-domain simulations. This analysis is promising for the design and optimization of various HC PC devices.

IBM PC/IX operating system evaluation plan

Science.gov (United States)

Dominick, Wayne D. (Editor); Granier, Martin; Hall, Philip P.; Triantafyllopoulos, Spiros

1984-01-01

An evaluation plan for the IBM PC/IX Operating System designed for IBM PC/XT computers is discussed. The evaluation plan covers the areas of performance measurement and evaluation, software facilities available, man-machine interface considerations, networking, and the suitability of PC/IX as a development environment within the University of Southwestern Louisiana NASA PC Research and Development project. In order to compare and evaluate the PC/IX system, comparisons with other available UNIX-based systems are also included.

ATLAS electromagnetic end-cap detector

CERN Multimedia

Maximilien Brice

2003-01-01

After the insertion of the first end-cap into this cryostat, the team proceed to the wiring operations. Millions of wires are connected to the electromagnetic calorimeter on this end-cap, whch must be carefully fed out from the detector so that data can be read out. The energy of photons, electrons and positrons will be measured as they pass through the end-cap having been created along the line of the beams in the proton-proton collisions.

ATLAS end-cap detector

CERN Multimedia

Maximilien Brice

2003-01-01

Three scientists from the Institute of Nuclear Phyiscs at Novossibirsk with one of the end-caps of the ATLAS detector. The end-caps will be used to detect particles produced in the proton-proton collisions at the heart of the ATLAS experiment that are travelling close to the axis of the two beams.

Polarization of seven MBM clouds at high Galactic latitude

Science.gov (United States)

Neha, S.; Maheswar, G.; Soam, A.; Lee, C. W.

2018-06-01

We made R-band polarization measurements of 234 stars towards the direction of the MBM 33-39 cloud complex. The distance of the MBM 33-39 complex was determined as 120 ± 10 pc using polarization results and near-infrared photometry from the 2MASS survey. The magnetic field geometry of the individual clouds inferred from our polarimetric results reveals that the field lines are in general consistent with the global magnetic field geometry of the region obtained from previous studies. This implies that the clouds in the complex are permeated by the interstellar magnetic field. Multi-wavelength polarization measurements of a few stars projected on to the complex suggest that the size of the dust grains in these clouds is similar to those found in the normal interstellar medium of the Milky Way. We studied a possible formation scenario of the MBM 33-39 complex by combining the polarization results from our study with those from the literature and by identifying the distribution of ionized, atomic and molecular (dust) components of material in the region.

21 CFR 884.5250 - Cervical cap.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cervical cap. 884.5250 Section 884.5250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... cap. (a) Identification. A cervical cap is a flexible cuplike receptacle that fits over the cervix to...

21 CFR 888.3000 - Bone cap.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bone cap. 888.3000 Section 888.3000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3000 Bone cap. (a) Identification. A bone cap is a mushroom...

Genetic ablation of root cap cells in Arabidopsis

OpenAIRE

Tsugeki, Ryuji; Fedoroff, Nina V.

1999-01-01

The root cap is increasingly appreciated as a complex and dynamic plant organ. Root caps sense and transmit environmental signals, synthesize and secrete small molecules and macromolecules, and in some species shed metabolically active cells. However, it is not known whether root caps are essential for normal shoot and root development. We report the identification of a root cap-specific promoter and describe its use to genetically ablate root caps by directing root cap-specific expression of...

Junior PC-Kørekort

DEFF Research Database (Denmark)

Hansbøl, Mikala; Mathiasen, Helle

udviklingsprojekt med forsøg med DANSK IT's Junior PC-kørekort® som metode og redskab til at evaluere og dokumentere elevernes IT-kompetencer. Projektet blev gennemført i perioden fra 2002-2003 og afsluttet i foråret 2003. Rapporten er baseret på kvalitative case studier af elever og læreres arbejde med Junior PC......-kørekort® prøverne. DANSK IT's Junior PC-kørekort® kan betragtes som et forsøg på at etablere en bestemt fælleskulturel tilgang til elevernes IT-kompetencer i folkeskolen. Ud fra et situeret læringsperspektiv problematiserer rapporten anvendelsen af de standardiserede prøver som metode til at dokumentere og evaluere...... elevernes IT-kompetencer. Rapporten (2MB) fylder 80 sider ekskl. bilag. Bemærk, at forskningsrapporten handler om Dansk IT's Junior PC-kørekort - ikke at forveksle med det IT-bevis for folkeskolens elever, som Undevisningsministeriet har udviklet. Dette IT-bevis koncept skiftede navn i januar 2004, hvor...

Phosphatidylcholine (PC) biosynthesis in pancreatic islets of Langerhans

International Nuclear Information System (INIS)

Hoffman, J.M.; Laychock, S.G.

1986-01-01

Islets of Langerhans isolated from rat pancreata were incubated with [ 14 C]choline to determine the biosynthesis of PC by the CDP choline to determine the biosynthesis of PC by the CDPcholine pathway. Recovery of [ 14 C]PC in islet membranes was time-related, and stimulated by glucose (17mM) during 60 min. The rate of PC synthesis was constant during 60 min with glucose stimulation. In contrast, the sulfonylurea tolbutamide (2 mM) reduced the recovery of [ 14 C]choline in PC, and 8-bromo-cyclic AMP (5 mM) did not significantly affect [ 14 C]PC recovery. Incubation of islets in Ca 2+ -free medium enhanced glucose-stimulated recovery of [ 14 C]choline-labeled PC due to the inhibition of phospholipase and phospholipid hydrolysis. Inhibition of CTP:phosphocholine cytidylyltransferase with 5-deoxy-5'-isobutylthioadenosine (SIBA) reduced [ 14 C]PC levels and insulin release in a concentration dependent manner. Treatment with SIBA also reduced Mg 2+ -dependent Ca 2+ -ATPase activity in islet microsomes. Quantitation of membrane PC showed that glucose stimulation did not alter islet P levels. Thus, islet PC biosynthesis is linked to glucose stimulation and contributes to the maintenance of PC levels in membranes undergoing exocytosis and phospholipid hydrolysis. Adequate PC levels support Ca 2+ pump activity and secretory mechanisms

CENTRIFUGE END CAP

Science.gov (United States)

Beams, J.W.; Snoddy, L.B.

1960-08-01

An end cap for ultra-gas centrifuges is designed to impart or remove angular momentum to or from the gas and to bring the entering gas to the temperature of the gas inside the centrifuge. The end cap is provided with slots or fins for adjusting the temperature and the angular momentum of the entering gas to the temperature and momentum of the gas in the centrifuge and is constructed to introduce both the inner and the peripheral stream into the centrifuge.

THE TURN OF THE MONTH EFFECT CONTINUED: A COMPARISON OF SMALL CAP STOCKS AND LARGE CAP STOCKS

OpenAIRE

Ramsundhar, Shamman

2010-01-01

The purpose of this paper is to investigate whether the turn of the month effect occurs in small cap and large cap stocks and if it occurs in both categories, to determine whether there is a difference in the magnitude. My research, for the period of 1963-2008, based on the CRSP value weighted index, shows that there is a significant turn of the month effect in small and large cap stocks, however the effect is larger in small cap stocks. Furthermore, this effect is not limited to a short time...

On the quiet-time Pc 5 pulsation events (spacequakes)

International Nuclear Information System (INIS)

Gupta, J.C.; Niblett, E.R.

1979-01-01

A quiet-time Pc 5 event (designated Spacequake) of March 18, 1974, first noted on the Fort Churchill magnetogram, was studied using global data. Its amplitude was found to be largest in the northern part of the auroral zone and its period seemed to increase with latitude. The clockwise polarization of the event noted at Baker Lake and higher latitudes changed to counterclockwise at Fort Churchill in X-Y, X-Z and Y-Z planes. The resonance of a field line (L approximately 10) excited due to an instability of the Kelvin-Helmholtz type may have given rise to the observed event. It is conjectured that the cause of instability at this altitude was internal convection of the magnetosphere. Similar quiet-time events from four Canadian observatories were selected from approximately 11 years of magnetograms and their statistical analysis revealed that (i) occurrences maximised near dawn and dusk (ii) the amplitude-latitude profile peaked at Great Whale River (L approximately 6.67), (iii) periods increased with increasing geomagnetic latitudes, (iv) a large number of events occurred in January, February and March every year, and (v) frequency of occurrence increased with increasing sunspot numbers. Comparison of these results with those available in the literature from analyses of satellite data clearly indicate that quiet-time Pc 5 events (Spacequakes) originate in the outer magnetosphere. (author)

Quality assessment of platelet concentrates prepared by platelet rich plasma-platelet concentrate, buffy coat poor-platelet concentrate (BC-PC and apheresis-PC methods

Directory of Open Access Journals (Sweden)

Singh Ravindra

2009-01-01

Full Text Available Background: Platelet rich plasma-platelet concentrate (PRP-PC, buffy coat poor-platelet concentrate (BC-PC, and apheresis-PC were prepared and their quality parameters were assessed. Study Design: In this study, the following platelet products were prepared: from random donor platelets (i platelet rich plasma - platelet concentrate (PRP-PC, and (ii buffy coat poor- platelet concentrate (BC-PC and (iii single donor platelets (apheresis-PC by different methods. Their quality was assessed using the following parameters: swirling, volume of the platelet concentrate, platelet count, WBC count and pH. Results: A total of 146 platelet concentrates (64 of PRP-PC, 62 of BC-PC and 20 of apheresis-PC were enrolled in this study. The mean volume of PRP-PC, BC-PC and apheresis-PC was 62.30±22.68 ml, 68.81±22.95 ml and 214.05±9.91 ml and ranged from 22-135 ml, 32-133 ml and 200-251 ml respectively. The mean platelet count of PRP-PC, BC-PC and apheresis-PC was 7.6±2.97 x 1010/unit, 7.3±2.98 x 1010/unit and 4.13±1.32 x 1011/unit and ranged from 3.2-16.2 x 1010/unit, 0.6-16.4 x 1010/unit and 1.22-8.9 x 1011/unit respectively. The mean WBC count in PRP-PC (n = 10, BC-PC (n = 10 and apheresis-PC (n = 6 units was 4.05±0.48 x 107/unit, 2.08±0.39 x 107/unit and 4.8±0.8 x 106/unit and ranged from 3.4 -4.77 x 107/unit, 1.6-2.7 x 107/unit and 3.2 - 5.2 x 106/unit respectively. A total of 26 units were analyzed for pH changes. Out of these units, 10 each were PRP-PC and BC-PC and 6 units were apheresis-PC. Their mean pH was 6.7±0.26 (mean±SD and ranged from 6.5 - 7.0 and no difference was observed among all three types of platelet concentrate. Conclusion: PRP-PC and BC-PC units were comparable in terms of swirling, platelet count per unit and pH. As expected, we found WBC contamination to be less in BC-PC than PRP-PC units. Variation in volume was more in BC-PC than PRP-PC units and this suggests that further standardization is required for preparation of BC-PC

Atmospheric Modeling of the Martian Polar Regions: One Mars Year of CRISM EPF Observations of the South Pole

Science.gov (United States)

Brown, A. J.; Wolff, M. J.

2009-03-01

We have used CRISM Emission Phase Function gimballed observations to investigate atmospheric dust/ice opacity and surface albedo in the south polar region for the first Mars year of MRO operations. This covers the MY28 "dust event" and cap recession.

FAINT LUMINESCENT RING OVER SATURN’S POLAR HEXAGON

Energy Technology Data Exchange (ETDEWEB)

Adriani, Alberto; D’Aversa, Emiliano; Oliva, Fabrizio; Filacchione, Gianrico [Institute of Space Astrophysics and Planetology of INAF, Via Fosso del Cavaliere 100, I-00133 Rome (Italy); Moriconi, Maria Luisa, E-mail: alberto.adriani@iaps.inaf.it [Institute of Atmospheric Sciences and Climate of CNR, Via Fosso del Cavaliere 100, I-00133 Rome (Italy)

2015-07-20

Springtime insolation is presently advancing across Saturn's north polar region. Early solar radiation scattered through the gaseous giant's atmosphere gives a unique opportunity to sound the atmospheric structure at its upper troposphere/lower stratosphere at high latitudes. Here, we report the detection of a tenuous bright structure in Saturn's northern polar cap corresponding to the hexagon equatorward boundary, observed by Cassini Visual and Infrared Mapping Spectrometer on 2013 June. The structure is spectrally characterized by an anomalously enhanced intensity in the 3610–3730 nm wavelength range and near 2500 nm, pertaining to relatively low opacity windows between strong methane absorption bands. Our first results suggest that a strong forward scattering by tropospheric clouds, higher in respect to the surrounding cloud deck, can be responsible for the enhanced intensity of the feature. This can be consistent with the atmospheric dynamics associated with the jet stream embedded in the polar hexagon. Further investigations at higher spectral resolution are needed to better assess the vertical distribution and microphysics of the clouds in this interesting region.

Effects of rooting and tree growth of selected woodland species on cap integrity in a mineral capped landfill site.

Science.gov (United States)

Hutchings, T R; Moffat, A J; Kemp, R A

2001-06-01

The above and below ground growth of three tree species (Alnus glutinosa, Pinus nigra var. maritima and Acer pseudoplatanus) was studied on a containment landfill site at Waterford, Hertfordshire, UK. Tree root architecture was studied using soil inspection pits excavated next to 12 trees of each species and mapped in detail. Tree height was related to soil thickness over the compacted mineral cap. No roots entered the cap where soil thickness was 1.3 m, but a few roots, especially of alder, were observed within it when the soil cover was 1.0 m or less. Micromorphological analysis of undisturbed samples of the mineral cap suggested that roots exploited weaknesses in the cap rather than actively causing penetration into it. Alder roots were more tolerant of anaerobic conditions within the cap than the other species examined. The results confirm that mineral caps should be covered by 1.5 m of soil or soil-forming material if tree establishment is intended over a restored landfill site, unless protected by other parts of a composite capping system.

Sodium, Iodine and Bromine in Polar Ice Cores

DEFF Research Database (Denmark)

Maffezzoli, Niccolo

Abstract: This research focuses on sodium, bromine and iodine in polar ice cores, with the aim of reviewing and advancing their current understanding with additional measurements and records, and investigating the connections of these tracers with sea ice and their feasibility as sea ice indicators...... with a description of the main analytic al techniques used to measure ionic and elemental species in ice cores. Chapter 4 introduces sodium, bromine and iodine with a theoretical perspective and a particular focus on their connections with sea ice. Some of the physical and chemical properties that are believed...... back trajectory analyses of the past 17 years. The results identify the aerosol source area influencing the Renland ice cap, a result necessary for the interpretation of impurity records obtained from the ice core. Chapter 6 reviews the published ice/snow measurements of bromine and iodine at polar...

PC clusters at CERN's PC farm

CERN Multimedia

Patrice Loïez

2001-01-01

These Linux-based PC clusters are mainly used for batch and interactive data processing. When the LHC starts operation in 2008, it will produce enough data every year to fill a stack of CDS 20 km tall, so high quality processing is required. To further facilitate this the LHC Computing Grid (LCG) has been set up to share processing power between facilities around the world.

Analyses of hydraulic performance of velocity caps

DEFF Research Database (Denmark)

Christensen, Erik Damgaard; Degn Eskesen, Mark Chr.; Buhrkall, Jeppe

2014-01-01

The hydraulic performance of a velocity cap has been investigated. Velocity caps are often used in connection with offshore intakes. CFD (computational fluid dynamics) examined the flow through the cap openings and further down into the intake pipes. This was combined with dimension analyses...

The origin of the mid-infrared nuclear polarization of active galactic nuclei

Science.gov (United States)

Lopez-Rodriguez, E.; Alonso-Herrero, A.; Diaz-Santos, T.; Gonzalez-Martin, O.; Ichikawa, K.; Levenson, N. A.; Martinez-Paredes, M.; Nikutta, R.; Packham, C.; Perlman, E.; Almeida, C. Ramos; Rodriguez-Espinosa, J. M.; Telesco, C. M.

2018-05-01

We combine new (NGC 1275, NGC 4151, and NGC 5506) and previously published (Cygnus A, Mrk 231, and NGC 1068) sub-arcsecond resolution mid-infrared (MIR; 8-13 μm) imaging- and spectro-polarimetric observations of six Seyfert galaxies using CanariCam on the 10.4-m Gran Telescopio CANARIAS. These observations reveal a diverse set of physical processes responsible for the nuclear polarization, and permit characterization of the origin of the MIR nuclear polarimetric signature of active galactic nuclei (AGN). For all radio quiet objects, we found that the nuclear polarization is low (sensitivity to detect such extended emission (i.e., NGC 1068 and NGC 4151). We suggest that the higher degree of polarization previously found in lower resolution data arises only on the larger-than-nuclear scales. Only the radio-loud Cygnus A exhibits significant nuclear polarization (˜11 per cent), attributable to synchrotron emission from the pc-scale jet close to the core. We present polarization models that suggest that the MIR nuclear polarization for highly obscured objects arises from a self-absorbed MIR polarized clumpy torus and/or dichroism from the host galaxy, while for unabsorbed cores, MIR polarization arises from dust scattering in the torus and/or surrounding nuclear dust.

49 CFR 230.41 - Flexible staybolts with caps.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Flexible staybolts with caps. 230.41 Section 230... Appurtenances Staybolts § 230.41 Flexible staybolts with caps. (a) General. Flexible staybolts with caps shall have their caps removed during every 5th annual inspection for the purpose of inspecting the bolts for...

Characterization of cap binding proteins associated with the nucleus

International Nuclear Information System (INIS)

Patzelt, E.

1986-04-01

Eucaryotic mRNAs a carry 7-methylguanosine triphosphate residue (called cap structure) at their 5' terminus. The cap plays an important role in RNA recognition. Cap binding proteins (CBP) of HeLa cells were identified by photoaffinity labelling using the cap analogue γ-( 32 P)-(4-(benzoyl-phenyl)methylamido)-7-methylguanosine-5'-triphosphate (BP-m 7 GTP). Photoreaction of this cap analogue with HeLa cell initiation factors resulted in specific labelling of two polypeptides of Msub(r) 37000 and 26000. The latter was also labelled in crude initiation factors prepared from reticulocytes and is identical to the cap binding protein CBP I previously identified. These cap binding proteins were also affinity labelled in poliovirus infected cell extracts. Photoaffinity reaction with BP-m 7 GTP of whole HeLa cell homogenate showed three additional polypeptides with Msub(r) 120000, 89000 and 80000. These cap binding proteins were found to be associated with the nucleus and are therefore referred to as nuclear cap binding proteins, i.e. NCBP 1, NCBP 2 and NCBP 3. They were also present in splicing extracts. Photoaffinity labelling in these nuclear extracts was differentially inhibited by various cap analogues and capped mRNAs. Affinity chromatography on immobilized globin mRNA led to a partial separation of the three nuclear cap binding proteins. Chromatography on m 7 GTP-Sepharose resulted in a specific binding of NCBP 3. The different behaviour of the cap binding proteins suggests that they are functionally distinct and that they might be involved in different processes requiring cap recognition. (Author)

Black carbon aerosols and the third polar ice cap

Energy Technology Data Exchange (ETDEWEB)

Menon, Surabi; Koch, Dorothy; Beig, Gufran; Sahu, Saroj; Fasullo, John; Orlikowski, Daniel

2010-04-15

Recent thinning of glaciers over the Himalayas (sometimes referred to as the third polar region) have raised concern on future water supplies since these glaciers supply water to large river systems that support millions of people inhabiting the surrounding areas. Black carbon (BC) aerosols, released from incomplete combustion, have been increasingly implicated as causing large changes in the hydrology and radiative forcing over Asia and its deposition on snow is thought to increase snow melt. In India BC emissions from biofuel combustion is highly prevalent and compared to other regions, BC aerosol amounts are high. Here, we quantify the impact of BC aerosols on snow cover and precipitation from 1990 to 2010 over the Indian subcontinental region using two different BC emission inventories. New estimates indicate that Indian BC emissions from coal and biofuel are large and transport is expected to expand rapidly in coming years. We show that over the Himalayas, from 1990 to 2000, simulated snow/ice cover decreases by {approx}0.9% due to aerosols. The contribution of the enhanced Indian BC to this decline is {approx}36%, similar to that simulated for 2000 to 2010. Spatial patterns of modeled changes in snow cover and precipitation are similar to observations (from 1990 to 2000), and are mainly obtained with the newer BC estimates.

Electromagnetic energy deposition rate in the polar upper thermosphere derived from the EISCAT Svalbard radar and CUTLASS Finland radar observations

Directory of Open Access Journals (Sweden)

H. Fujiwara

2007-11-01

Full Text Available From simultaneous observations of the European incoherent scatter Svalbard radar (ESR and the Cooperative UK Twin Located Auroral Sounding System (CUTLASS Finland radar on 9 March 1999, we have derived the height distributions of the thermospheric heating rate at the F region height in association with electromagnetic energy inputs into the dayside polar cap/cusp region. The ESR and CUTLASS radar observations provide the ionospheric parameters with fine time-resolutions of a few minutes. Although the geomagnetic activity was rather moderate (Kp=3⁺~4, the electric field obtained from the ESR data sometimes shows values exceeding 40 mV/m. The estimated passive energy deposition rates are also larger than 150 W/kg in the upper thermosphere over the ESR site during the period of the enhanced electric field. In addition, enhancements of the Pedersen conductivity also contribute to heating the upper thermosphere, while there is only a small contribution for thermospheric heating from the direct particle heating due to soft particle precipitation in the dayside polar cap/cusp region. In the same period, the CUTLASS observations of the ion drift show the signature of poleward moving pulsed ionospheric flows with a recurrence rate of about 10–20 min. The estimated electromagnetic energy deposition rate shows the existence of the strong heat source in the dayside polar cap/cusp region of the upper thermosphere in association with the dayside magnetospheric phenomena of reconnections and flux transfer events.

Electromagnetic energy deposition rate in the polar upper thermosphere derived from the EISCAT Svalbard radar and CUTLASS Finland radar observations

Directory of Open Access Journals (Sweden)

H. Fujiwara

2007-11-01

Full Text Available From simultaneous observations of the European incoherent scatter Svalbard radar (ESR and the Cooperative UK Twin Located Auroral Sounding System (CUTLASS Finland radar on 9 March 1999, we have derived the height distributions of the thermospheric heating rate at the F region height in association with electromagnetic energy inputs into the dayside polar cap/cusp region. The ESR and CUTLASS radar observations provide the ionospheric parameters with fine time-resolutions of a few minutes. Although the geomagnetic activity was rather moderate (Kp=3+~4, the electric field obtained from the ESR data sometimes shows values exceeding 40 mV/m. The estimated passive energy deposition rates are also larger than 150 W/kg in the upper thermosphere over the ESR site during the period of the enhanced electric field. In addition, enhancements of the Pedersen conductivity also contribute to heating the upper thermosphere, while there is only a small contribution for thermospheric heating from the direct particle heating due to soft particle precipitation in the dayside polar cap/cusp region. In the same period, the CUTLASS observations of the ion drift show the signature of poleward moving pulsed ionospheric flows with a recurrence rate of about 10–20 min. The estimated electromagnetic energy deposition rate shows the existence of the strong heat source in the dayside polar cap/cusp region of the upper thermosphere in association with the dayside magnetospheric phenomena of reconnections and flux transfer events.

PC Mobile Warrior with a built-in cellular phone; Keitai denwa naizogata PC 'Mobile warrior

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

A PC Mobile Warrior with a built-in cellular phone has been developed from PC Libretto through cooperation with the NTT DoCoMo. The new personal computer incorporates into itself some distinguished mobile PC features such as Wake On Radio and Wake On Ring which are defined by MCPC (Mobile Computing Promotion Consortium). Wake On Radio is a function that activates the PC upon entry into the zone from outside, and Wake On Ring is another function that does the same upon arrival of a phone call. Installed on these lower order functions are an application program for automatic transmission of stored e-mails making use of the former function and another for automatic reception of FAX messages making use of the latter function. (translated by NEDO)

Atomic-resolution structure of the CAP-Gly domain of dynactin on polymeric microtubules determined by magic angle spinning NMR spectroscopy.

Science.gov (United States)

Yan, Si; Guo, Changmiao; Hou, Guangjin; Zhang, Huilan; Lu, Xingyu; Williams, John Charles; Polenova, Tatyana

2015-11-24

Microtubules and their associated proteins perform a broad array of essential physiological functions, including mitosis, polarization and differentiation, cell migration, and vesicle and organelle transport. As such, they have been extensively studied at multiple levels of resolution (e.g., from structural biology to cell biology). Despite these efforts, there remain significant gaps in our knowledge concerning how microtubule-binding proteins bind to microtubules, how dynamics connect different conformational states, and how these interactions and dynamics affect cellular processes. Structures of microtubule-associated proteins assembled on polymeric microtubules are not known at atomic resolution. Here, we report a structure of the cytoskeleton-associated protein glycine-rich (CAP-Gly) domain of dynactin motor on polymeric microtubules, solved by magic angle spinning NMR spectroscopy. We present the intermolecular interface of CAP-Gly with microtubules, derived by recording direct dipolar contacts between CAP-Gly and tubulin using double rotational echo double resonance (dREDOR)-filtered experiments. Our results indicate that the structure adopted by CAP-Gly varies, particularly around its loop regions, permitting its interaction with multiple binding partners and with the microtubules. To our knowledge, this study reports the first atomic-resolution structure of a microtubule-associated protein on polymeric microtubules. Our approach lays the foundation for atomic-resolution structural analysis of other microtubule-associated motors.

Linear polarization measurements at H. beta. of early-type emission line stars

Energy Technology Data Exchange (ETDEWEB)

Clarke, D; McLean, I S [Glasgow Univ. (UK)

1976-02-01

Linear polarization measurements across the H..beta.. emission lines of the stars ..gamma.. Cas, zeta Tau and 48 Per are presented. For the first two stars there is a marked reduction of the polarization at the centre of the line and for ..gamma.. Cas, this varies from night to night. During the H..beta.. observations of zeta Tau, a change of polarization over tens of minutes was indicated in a monitor channel tuned to the continuum on the blue side of H..beta... For the fainter star, 48 Per, the uncertainties of the polarimetry were increased in relation to ..gamma.. Cas and zeta Tau by a factor of about two and at this precision, no differential effects across the line were recorded. Observations of ..cap alpha.. Cyg are also given to demonstrate the reliability of the polarimeter.

Long-term analysis of ionospheric polar patches based on CHAMP TEC data

DEFF Research Database (Denmark)

Noja, M.; Stolle, Claudia; Park, J.

2013-01-01

Total electron content (TEC) from LEO satellites offers great possibility to sound the upper ionosphere and plasmasphere. This paper describes a method to derive absolute TEC observations aboard CHAMP considering multipath effects and receiver differential code bias. The long-term data set of 9...... years GPS observations is used to investigate the climatological behavior of high-latitude plasma patches in both hemispheres. The occurrence of polar patches has a clear correlation with the solar cycle, which is less pronounced in the Southern Hemisphere (SH). Summed over all years, we observed...... a higher number of patches in the SH. The maximum occurrence rate of patches has been found at the dayside polar cusp during 12:00-18:00 MLT (magnetic local time) supporting the mechanisms for patch creation by local particle precipitation and by intrusion of subauroral plasma into the polar cap through...

PC Pricer

Data.gov (United States)

U.S. Department of Health & Human Services — The PC Pricer is a tool used to estimate Medicare PPS payments. The final payment may not be precise to how payments are determined in the Medicare claims processing...

The effect of capped layer thickness on switching behavior in perpendicular CoCrPt based coupled granular/continuous media

International Nuclear Information System (INIS)

Li, W.M.; Lim, W.K.; Shi, J.Z.; Ding, J.

2013-01-01

A systematic investigation of magnetic switching behavior of CoCrPt based capped media (perpendicularly coupled granular/continuous (CGC) media consisting of granular CoCrPt:SiO 2 TiO 2 Ta 2 O 5 /capped CoCrPt(B)) is performed by varying the thickness of the capped layer from 0 to 9 nm. The microscopic structures of CGC media with different thickness of capped layer are examined by transmission electron microscope. We find out that CoCrPt magnetic grains are separated by nonmagnetic oxide grain boundaries. Grain size and grain boundary are about 8.9 nm and 2 nm, respectively. The nonmagnetic oxide grain boundaries in the granular layer do not disappear immediately at the interface between the granular and capped layers. The amorphous grain boundary phase in the granular layer propagates to the top surface of the capped layer. After capping with the CoCrPt(B) layer, the grain size at the surface of CGC structure increases and the grain boundary decreases. Both coercivity and intergranular exchange coupling of the CGC media are investigated by Polar magneto-optic Kerr effect magnetometer and alternating gradient force magnetometer. Although H c apparently decreases at thicker capped layer, no obvious variation of macroscopic switching field distribution (SFD/H c ) is observed. We separate intrinsic switching field distribution from intergranular interactions. The investigation of reduced intrinsic SFD/H c and increased hysteresis loop slope at coercivity, suggests that improvement of absolute switching field distribution (SFD) is caused by both strong intergranular exchange coupling and uniform grain size. Micromagnetic simulation results further verify our conclusion that the capped layer in CGC media is not uniformly continuous but has some granular nature. However, grains in the CoCrPt(B) capped layer is not absolutely isolated, strong exchange coupling exists between grains. - Highlights: • In CGC media, CoCrPt magnetic grains are separated by nonmagnetic oxide

ELIPGRID-PC: A PC program for calculating hot spot probabilities

International Nuclear Information System (INIS)

Davidson, J.R.

1994-10-01

ELIPGRID-PC, a new personal computer program has been developed to provide easy access to Singer's 1972 ELIPGRID algorithm for hot-spot detection probabilities. Three features of the program are the ability to determine: (1) the grid size required for specified conditions, (2) the smallest hot spot that can be sampled with a given probability, and (3) the approximate grid size resulting from specified conditions and sampling cost. ELIPGRID-PC also provides probability of hit versus cost data for graphing with spread-sheets or graphics software. The program has been successfully tested using Singer's published ELIPGRID results. An apparent error in the original ELIPGRID code has been uncovered and an appropriate modification incorporated into the new program

Diagnostic criteria for cryopyrin-associated periodic syndrome (CAPS).

Science.gov (United States)

Kuemmerle-Deschner, Jasmin B; Ozen, Seza; Tyrrell, Pascal N; Kone-Paut, Isabelle; Goldbach-Mansky, Raphaela; Lachmann, Helen; Blank, Norbert; Hoffman, Hal M; Weissbarth-Riedel, Elisabeth; Hugle, Boris; Kallinich, Tilmann; Gattorno, Marco; Gul, Ahmet; Ter Haar, Nienke; Oswald, Marlen; Dedeoglu, Fatma; Cantarini, Luca; Benseler, Susanne M

2017-06-01

Cryopyrin-associated periodic syndrome (CAPS) is a rare, heterogeneous disease entity associated with NLRP3 gene mutations and increased interleukin-1 (IL-1) secretion. Early diagnosis and rapid initiation of IL-1 inhibition prevent organ damage. The aim of the study was to develop and validate diagnostic criteria for CAPS. An innovative process was followed including interdisciplinary team building, item generation: review of CAPS registries, systematic literature review, expert surveys, consensus conferences for item refinement, item reduction and weighting using 1000Minds decision software. Resulting CAPS criteria were tested in large cohorts of CAPS cases and controls using correspondence analysis. Diagnostic models were explored using sensitivity analyses. The international team included 16 experts. Systematic literature and registry review identified 33 CAPS-typical items; the consensus conferences reduced these to 14. 1000Minds exercises ranked variables based on importance for the diagnosis. Correspondence analysis determined variables consistently associated with the diagnosis of CAPS using 284 cases and 837 controls. Seven variables were significantly associated with CAPS (pCAPS-typical symptoms: urticaria-like rash, cold-triggered episodes, sensorineural hearing loss, musculoskeletal symptoms, chronic aseptic meningitis and skeletal abnormalities. Sensitivity was 81%, specificity 94%. It performed well for all CAPS subtypes and regardless of NLRP3 mutation. The novel approach integrated traditional methods of evidence synthesis with expert consensus, web-based decision tools and innovative statistical methods and may serve as model for other rare diseases. These criteria will enable a rapid diagnosis for children and adults with CAPS. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Enzymatic synthesis of RNAs capped with nucleotide analogues reveals the molecular basis for substrate selectivity of RNA capping enzyme: impacts on RNA metabolism.

Directory of Open Access Journals (Sweden)

Moheshwarnath Issur

Full Text Available RNA cap binding proteins have evolved to specifically bind to the N7-methyl guanosine cap structure found at the 5' ends of eukaryotic mRNAs. The specificity of RNA capping enzymes towards GTP for the synthesis of this structure is therefore crucial for mRNA metabolism. The fact that ribavirin triphosphate was described as a substrate of a viral RNA capping enzyme, raised the possibility that RNAs capped with nucleotide analogues could be generated in cellulo. Owing to the fact that this prospect potentially has wide pharmacological implications, we decided to investigate whether the active site of the model Paramecium bursaria Chlorella virus-1 RNA capping enzyme was flexible enough to accommodate various purine analogues. Using this approach, we identified several key structural determinants at each step of the RNA capping reaction and generated RNAs harboring various different cap analogues. Moreover, we monitored the binding affinity of these novel capped RNAs to the eIF4E protein and evaluated their translational properties in cellulo. Overall, this study establishes a molecular rationale for the specific selection of GTP over other NTPs by RNA capping enzyme It also demonstrates that RNAs can be enzymatically capped with certain purine nucleotide analogs, and it also describes the impacts of modified RNA caps on specific steps involved in mRNA metabolism. For instance, our results indicate that the N7-methyl group of the classical N7-methyl guanosine cap is not always indispensable for binding to eIF4E and subsequently for translation when compensatory modifications are present on the capped residue. Overall, these findings have important implications for our understanding of the molecular determinants involved in both RNA capping and RNA metabolism.

Morphological Response of a Mud Capped Dredge Pit in Western Louisiana After Sand Excavation for Barrier Island Restoration

Science.gov (United States)

Robichaux, P. A.; Xu, K.; Bentley, S. J.; Li, C.; Miner, M. D.

2017-12-01

Sand resources play a crucial role in supporting tourism, maintaining coastal ecosystems, and protecting property and infrastructure. Mud capped dredge pits (MCDPs) are created when paleochannel sand, covered by muddy shelf overburden, is excavated for restoration purposes; such paleochannels are one significant sand resource for coastal barrier protection. However, our knowledge of MCDPs is limited. To improve understanding of their morphological behavior, a dredge pit called Peveto Channel (PC) offshore of Holly Beach, LA, was studied in 2016. Our study consisted of a survey using multiple geophysical methods, including multibeam bathymetry, sidescan sonar, subbottom profiling, and magnetometry. Results indicate that PC has undergone 100% infilling since dredging occurred. Although the pit is filled up, analyses indicate the newly deposited material is unconsolidated and has yet to equilibrate to the ambient seafloor conditions. The surface of the pit area is pockmarked and uneven, likely caused by degassing processes and differential consolidation. Sidescan sonar images confirm that the pit walls have experienced little to no lateral erosion and are well preserved. The results from this survey and from historical surveys conducted in 2003 (a few months after dredging), 2004, 2006, and 2007 are compared to previously constructed numerical models used to predict the behavior of dredge pits. To our knowledge, PC is the only filled-up offshore dredge pit in coastal Louisiana. Thus the findings of this study provide new long-term information for regulatory policies and the feasibility of MCDPs as sand resources in the future.

PrPC from stem cells to cancer

Directory of Open Access Journals (Sweden)

Séverine eMartin-Lannerée

2014-09-01

Full Text Available The cellular prion protein PrPC was initially discovered as the normal counterpart of the pathological scrapie prion protein PrPSc, the main component of the infectious agent of Transmissible Spongiform Encephalopathies. While clues as to the physiological function of this ubiquitous protein were greatly anticipated from the development of knock-out animals, PrP-null mice turned out to be viable and to develop without major phenotypic abnormalities. Notwithstanding, the discovery that hematopoietic stem cells from PrP-null mice have impaired long-term repopulating potential has set the stage for investigating into the role of PrPC in stem cell biology. A wealth of data have now exemplified that PrPC is expressed in distinct types of stem cells and regulates their self-renewal as well as their differentiation potential. A role for PrPC in the fate restriction of embryonic stem cells has further been proposed. Paralleling these observations, an overexpression of PrPC has been documented in various types of tumours. In line with the contribution of PrPC to stemness and to the proliferation of cancer cells, PrPC was recently found to be enriched in subpopulations of tumour-initiating cells. In the present review, we summarize the current knowledge of the role played by PrPC in stem cell biology and discuss how the subversion of its function may contribute to cancer progression.

Synthesis of tritium or deuterium labelled 19-nor-3. cap alpha. -hydroxy-5. cap alpha. -androstan-17-one from nortestosterone

Energy Technology Data Exchange (ETDEWEB)

Protiva, J; Klinotova, E [Karlova Univ., Prague (Czechoslovakia). Prirodovedecka Fakulta; Filip, J [Ustav pro Vyzkum, Vyrobu a Vyuziti Radioisotopu, Prague (Czechoslovakia); Hampl, R [Research Inst. of Endocrinology, Praha (Czechoslovakia)

1982-10-20

Tritium and/or deuterium (5-H) labelled 19-nor-3..cap alpha..-hydroxy-5..cap alpha..-androstan-17-one (norandrosterone) was prepared from nortestosterone in view to use it as a radioligand for radioimmunoassay of the main nortestosterone metabolites. Based upon model experiments using testosterone and deuterium labelling, the following four step procedure was established: nortestosterone was oxidized with pyridine chlorochromate and the resulting 19-nor-4-androsten-3,17-dione was tritiated with tritium gas under catalysis with tris(triphenylphosphine)rhodium chloride to give (4,5..cap alpha..-/sup 3/H)19-nor-5..cap alpha..-androstan-3,17-dione. A selective reduction of the latter compound yielded (5-/sup 3/H)19-nor-3..cap alpha..-hydroxy-5..cap alpha..-androstan-17-one of the molar radioactivity 0.3 TBq (8.15 Ci)/mmol.

The readout performance evaluation of PowerPC

International Nuclear Information System (INIS)

Chu Yuanping; Zhang Hongyu; Zhao Jingwei; Ye Mei; Tao Ning; Zhu Kejun; Tang Suqiu; Guo Yanan

2003-01-01

PowerPC, as a powerful low-cost embedded computer, is one of the very important research objects in recent years in the project of BESIII data acquisition system. The researches on the embedded system and embedded computer have achieved many important results in the field of High Energy Physics especially in the data acquisition system. The one of the key points to design an acquisition system using PowerPC is to evaluate the readout ability of PowerPC correctly. The paper introduce some tests for the PowerPC readout performance. (authors)

7 CFR 1714.7 - Interest rate cap.

Science.gov (United States)

2010-01-01

... 7 Agriculture 11 2010-01-01 2010-01-01 false Interest rate cap. 1714.7 Section 1714.7 Agriculture... PRE-LOAN POLICIES AND PROCEDURES FOR INSURED ELECTRIC LOANS General § 1714.7 Interest rate cap. Except... section, or both the rate disparity test for the interest rate cap and the consumer income test set forth...

20 CFR 606.22 - Application for cap.

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Application for cap. 606.22 Section 606.22... Reduction § 606.22 Application for cap. (a) Application. (1) The Governor of the State shall make... a State requests a cap on tax credit reduction. The Governor is required to notify the Department on...

IAA transport in corn roots includes the root cap

International Nuclear Information System (INIS)

Hasenstein, K.H.

1989-01-01

In earlier reports we concluded that auxin is the growth regulator that controls gravicurvature in roots and that the redistribution of auxin occurs within the root cap. Since other reports did not detect auxin in the root cap, we attempted to confirm the IAA does move through the cap. Agar blocks containing 3 H-IAA were applied to the cut surface of 5 mm long apical segments of primary roots of corn (mo17xB73). After 30 to 120 min radioactivity (RA) of the cap and root tissue was determined. While segments suspended in water-saturated air accumulated very little RA in the cap, application of 0.5 μ1 of dist. water to the cap (=controls) increased RA of the cap dramatically. Application to the cap of 0.5 μ1 of sorbitol or the Ca 2+ chelator EGTA reduced cap RA to 46% and 70% respectively compared to water, without affecting uptake. Control root segments gravireacted faster than non-treated or osmoticum or EGTA treated segments. The data indicate that both the degree of hydration and calcium control the amount of auxin moving through the cap

Synthesis and luminescent properties of star-burst D-π-A compounds based on 1,3,5-triazine core and carbazole end-capped phenylene ethynylene arms

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zheng [Department of Applied Chemistry, Nanjing Tech University, Nanjing 210009 (China); Liu, Rui, E-mail: rui.liu@njtech.edu.cn [Department of Applied Chemistry, Nanjing Tech University, Nanjing 210009 (China); Zhu, Xiaolin [Department of Applied Chemistry, Nanjing Tech University, Nanjing 210009 (China); Li, Yuhao [Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433 (China); Chang, Jin [Queensland University of Technology, 2 George St., Brisbane 4000 (Australia); Zhu, Hongjun, E-mail: zhuhjnjut@hotmail.com [Department of Applied Chemistry, Nanjing Tech University, Nanjing 210009 (China); Ma, Liangwei; Lv, Wangjie; Guo, Jun [Department of Applied Chemistry, Nanjing Tech University, Nanjing 210009 (China)

2014-12-15

Two new star-burst compounds based on 1,3,5-triazine core and carbazole end-capped phenylene ethynylene arms (1a and 1b) were synthesized and characterized. Their photophysical properties were investigated systematically via spectroscopic and theoretical methods. Both compounds exhibit strong {sup 1}π–π{sup ⁎} transitions in the UV region and intense {sup 1}π–π{sup ⁎}/intramolecular charge transfer ({sup 1}ICT) absorption bands in the UV–vis region. Introducing the carbazole end-capped phenylene ethynylene arm on the 1,3,5-triazine core causes a slight bathochromic shift and enhanced molar extinction coefficient of the {sup 1}π–π{sup ⁎}/{sup 1}ICT transition band. Both compounds are emissive in solution at room temperature and 77 K, which exhibit pronounced positive solvatochromic effect. The emitting state could be ascribed to {sup 1}ICT state in more polar solvent, and {sup 1}π–π{sup ⁎} state in low-polarity solvent. The high emission quantum yields (Φ{sub em}=0.90∼1.0) of 1a and 1b (in hexane and toluene) make them potential candidates as efficient light-emitting materials. The spectroscopic studies and theoretical calculations indicate that the photophysical properties of these compounds can be tuned by the carbazole end-capped phenylene ethynylene arm, which would also be useful for rational design of photofunctional materials. - Highlights: • Star-burst compounds based on 1,3,5-triazine core and carbazole end-capped phenylene ethynylene arms. • Photophysical properties of target compounds were investigated systematically via spectroscopic and theoretical methods. • The relatively high fluorescence quantum yields make them potential candidates as light-emitting materials.

Ultracompact photonic crystal polarization beam splitter based on multimode interference.

Science.gov (United States)

Lu, Ming-Feng; Liao, Shan-Mei; Huang, Yang-Tung

2010-02-01

We propose a theoretical design for a compact photonic crystal (PC) polarization beam splitter (PBS) based on the multimode interference (MMI) effect. The size of a conventional MMI device designed by the self-imaging principle is not compact enough; therefore, we design a compact PC PBS based on the difference of the interference effect between TE and TM modes. Within the MMI coupler, the dependence of interference of modes on propagation distance is weak for a TE wave and strong for a TM wave; as a result, the length of the MMI section can be only seven lattice constants. Simulation results show that the insertion losses are 0.32 and 0.89 dB, and the extinction ratios are 14.4 and 17.5 dB for Port 1 (TE mode) and Port 2 (TM mode), respectively.

Cluster observations of band-limited Pc 1 waves associated with streaming H+ and O+ ions in the high-altitude plasma mantle

Czech Academy of Sciences Publication Activity Database

Engebretson, M. J.; Kahlstorf, C. R.G.; Murr, D. L.; Posch, J. L.; Keiling, A.; Lavraud, B.; Reme, H.; Lessard, M. R.; Kim, E. -H.; Johnson, J. R.; Dombeck, J.; Grison, Benjamin; Robert, P.; Glassmeier, K.; H.; Decreau, M. E.

2012-01-01

Roč. 117, A10 (2012), A10219/1-A10219/27 ISSN 0148-0227 R&D Projects: GA ČR(CZ) GPP209/11/P848 Institutional support: RVO:68378289 Keywords : Magnetotail boundary layers * MHD waves and instabilities * Plasma waves and instabilities * Polar cap phenomena Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.174, year: 2012 http://onlinelibrary.wiley.com/doi/10.1029/2012JA017982/abstract

Implementasi Penggunaan Smartphone Android untuk Control PC (Personal Computer

Directory of Open Access Journals (Sweden)

Imam Solikin

2018-05-01

Full Text Available The purpose of this research is to simplify the control of personal computer (PC such as control pointer, keyboard control and make it easier to do the presentation by controlling the slide remotely using smartphone through wifi connections facility. The smartphone is a multimedia phone that combines PC functionality with microprocessor, memory, and built-in modem to produce smart smartphone gadgets. Problems that occur when performing a presentation such as PC control, control pointer and keyboard control for input should be close to the PC so it is less than optimal in explaining the material. The model used in implementing the use of Android Smartphone for PC control is a conceptual model consisting of several stages: potential and problems, data collection, system testing, test results, and system implementation or implementation. From the results of PC control research can be done by connecting the Smartphone with a PC via wifi network so that PC can be controlled remotely. PC control application is an application that can control PC remotely connected via wifi network connection. Benefits derived from this research make it easy to mengedalikan PC remotely such as facilitate in the percentage and control pointer and control Keyboard for input process.

Distribution of irregularities in the northern polar region determined from Hilat observations

International Nuclear Information System (INIS)

Macdougall, J.W.

1990-01-01

Three years' observations of the Hilat satellite from stations Sondre, Churchill, and Tromso have been used to study the distributions of scintillations over the northern polar region. Two regions showed enhancement. Region (1) was an enhancement of phase scintillations when the line of sight to the satellite lay along an L shell and the observing station was under the auroral oval. Region (2) is revealed most clearly by amplitude scintillations and maximizes in an annular region several degrees poleward of the auroral oval. Region (1) is most likely associated with large-scale 'blobs' of ionization in the auroral zone; region (2) appears to be due to km-scale irregularities generated in the polar cap. 17 refs

Extraction of Polychlorinated Biphenyls (PCBs) and Dibenzyl Disulfide from Transformer Oils using Polar Aprotic Solvents andReductive Dehalogenation of Extracted PCBs

OpenAIRE

Kaštánek, P. (Petr); Kaštánek, F. (František); Maléterová, Y. (Ywetta); Matějková, M. (Martina); Spáčilová, L. (Lucie); Šolcová, O. (Olga)

2014-01-01

Extractions of PCBs from mineral oils with polar aprotic solvents (PAS) acrylonitrile AC, dimethyl sulfoxide DMSO, dimethyl formamide DMF, N-methyl pyrrolidone NMP and propylene carbonate PC were performed in order to compare the extraction efficiencies. In a single-stage extraction performed at room temperature, the efficiencies ranged from the highest to the lowest as follows: NMP → DMF → DMSO → PC → AC. NMP exhibited the highest efficiency, around 70%. . Pyridine N-oxide was also used a...

Installation and implementation of PC COSYMA; PC COSYMAn kaeyttoeoenotto ja soveltaminen

Energy Technology Data Exchange (ETDEWEB)

Rossi, J [VTT Energy, Espoo (Finland). Nuclear Energy

1995-12-01

COSYMA is a probabilistic reactor accident consequence assessment model developed in the 1980`s by the research institutes of the EC countries, primarily by NRPB and KfK. In 1993 a simplified version of the program was released to be implemented on a PC. In the study the PC COSYMA program was applied to calculate as the end points nuclide concentrations, doses received, numbers of health effects, areas affected by countermeasures and other results related to countermeasure strategies. Some results are compared with the results obtained by the ARANO program developed by VTT Energy (Technical Research Centre of Finland) to quarantee proper interpretation of the application. (15 refs.).

Increased 5. cap alpha. -reductase activity in idiopathic hirsutism

Energy Technology Data Exchange (ETDEWEB)

Serafini, P.; Lobo, R.A.

1985-01-01

In vitro, genital skin 5..cap alpha..-reductase activity (5..cap alpha..-RA) was measured in ten hirsute women with normal androgen levels (idiopathic hirsutism (IH)) and in ten hirsute women with elevated androgen levels (polycystic ovary syndrome (PCO)) in order to determine the influence of secreted androgens on 5..cap alpha..-RA. In vitro 5..cap alpha..-RA was assessed by incubations of skin with /sup 14/C-testosterone (T) for 2 hours, after which steroids were separated and the radioactivity of dihydrotestosterone (DHT) and 5..cap alpha..-androstane 3..cap alpha..-17..beta..-estradiol (3..cap alpha..-diol) in specific eluates were determined. All androgens were normal in IH with the exception of higher levels of 3..cap alpha..-diol glucuronide which were similar to the levels of PCO. The conversion ratio (CR) of T to DHT in IH and PCO were similar, yet significantly greater than the CR of control subjects. The CR of T to 3..cap alpha..-diol in IH and PCO were similar, yet higher than in control subjects. Serum androgens showed no correlation with 5..cap alpha..-RA, while the CR of T to DHT showed a significant positive correlation with the Ferriman and Gallwey score. The increased 5..cap alpha..-RA in IH appears to be independent of serum androgen levels and is, therefore, an inherent abnormality. The term idiopathic is a misnomer, because hirsutism in these patients may be explained on the basis of increased skin 5..cap alpha..-RA.

PC application in DIII-D neutral beam operation

International Nuclear Information System (INIS)

Gladd, A.S.

1986-01-01

An IBM PC/AT has been implemented to improve operation of the DIII-D neutral beams. The PC system provides centralization of all beam data with reasonable access for online shot-to-shot control and analysis. The PC hardware was configured to interface all four neutral beam host mini-computers, support multi-tasking, and provide storage for approximately one month's accumulation of beam data. The PC software is composed of commercial packages used for performance and statistical analysis (i.e. LOTUS 123, PC PLOT, etc.) host communications software (i.e. PCLINK, KERMIT, etc.) and applications developed software utilizing FORTRAN and BASIC. The objectives of this paper are to describe the implementation of the PC system, the methods of integrating the various software packages, and the scenario for online control and analysis

Inhibition of polar calcium movement and gravitropism in roots treated with auxin-transport inhibitors

Science.gov (United States)

Lee, J. S.; Mulkey, T. J.; Evans, M. L.

1984-01-01

Primary roots of maize (Zea mays L.) and pea (Pisum sativum L.) exhibit strong positive gravitropism. In both species, gravistimulation induces polar movement of calcium across the root tip from the upper side to the lower side. Roots of onion (Allium cepa L.) are not responsive to gravity and gravistimulation induces little or no polar movement of calcium across the root tip. Treatment of maize or pea roots with inhibitors of auxin transport (morphactin, naphthylphthalamic acid, 2,3,5-triiodobenzoic acid) prevents both gravitropism and gravity-induced polar movement of calcium across the root tip. The results indicate that calcium movement and auxin movement are closely linked in roots and that gravity-induced redistribution of calcium across the root cap may play an important role in the development of gravitropic curvature.

Cap-independent translation of plant viral RNAs.

Science.gov (United States)

Kneller, Elizabeth L Pettit; Rakotondrafara, Aurélie M; Miller, W Allen

2006-07-01

The RNAs of many plant viruses lack a 5' cap and must be translated by a cap-independent mechanism. Here, we discuss the remarkably diverse cap-independent translation elements that have been identified in members of the Potyviridae, Luteoviridae, and Tombusviridae families, and genus Tobamovirus. Many other plant viruses have uncapped RNAs but their translation control elements are uncharacterized. Cap-independent translation elements of plant viruses differ strikingly from those of animal viruses: they are smaller (translation factors, and speculate on their mechanism of action and their roles in the virus replication cycle. Much remains to be learned about how these elements enable plant viruses to usurp the host translational machinery.

Characterization of a mimivirus RNA cap guanine-N2 methyltransferase.

Science.gov (United States)

Benarroch, Delphine; Qiu, Zhicheng R; Schwer, Beate; Shuman, Stewart

2009-04-01

A 2,2,7-trimethylguanosine (TMG) cap is a signature feature of eukaryal snRNAs, telomerase RNAs, and trans-spliced nematode mRNAs. TMG and 2,7-dimethylguanosine (DMG) caps are also present on mRNAs of two species of alphaviruses (positive strand RNA viruses of the Togaviridae family). It is presently not known how viral mRNAs might acquire a hypermethylated cap. Mimivirus, a giant DNA virus that infects amoeba, encodes many putative enzymes and proteins implicated in RNA transactions, including the synthesis and capping of viral mRNAs and the promotion of cap-dependent translation. Here we report the identification, purification, and characterization of a mimivirus cap-specific guanine-N2 methyltransferase (MimiTgs), a monomeric enzyme that catalyzes a single round of methyl transfer from AdoMet to an m(7)G cap substrate to form a DMG cap product. MimiTgs, is apparently unable to convert a DMG cap to a TMG cap, and is thereby distinguished from the structurally homologous yeast and human Tgs1 enzymes. Nonetheless, we show genetically that MimiTgs is a true ortholog of Saccharomyces cerevisiae Tgs1. Our results hint that DMG caps can satisfy many of the functions of TMG caps in vivo. We speculate that DMG capping of mimivirus mRNAs might favor viral protein synthesis in the infected host.

Death cap

DEFF Research Database (Denmark)

Rudbæk, Torsten R; Kofoed, Pernille Bouteloup; Bove, Jeppe

2014-01-01

Death cap (Amanita phalloides) is commonly found and is one of the five most toxic fungi in Denmark. Toxicity is due to amatoxin, and poisoning is a serious medical condition, causing organ failure with potential fatal outcome. Acknowledgement and clarification of exposure, symptomatic and focused...

Feature of extradosed PC bridge and its design; Daihenshin keburu PC kyo no tokucho to sono sekkei

Energy Technology Data Exchange (ETDEWEB)

Komiya, M. [Japan Bridge and Structure Institute Inc., Tokyo (Japan)

1997-03-31

A PC bridge with the eccentricity of the external cable increased by protruding the deviated member to the outside of the beam for more effective use of the external cable is called a `PC bridge with tendons of large eccentricity.` The extradosed bridge of main beam/cable joint type is a PC bridge with the external cable arranged via a tower-shaped eccentric member provided at the intermediate support, and resembles morphologically a cable stayed bridge having a very low tower. There are two types of extradosed bridges, i.e. a type with concrete coated external cable (cable stayed slab bridge) and the other with non-coated external cable (external cable stayed bridge). Features, structural planning and designing of the general external cable stayed bridge are shown. The features are the possession of intermediate characteristics of those of the PC beam bridge and the PC cable stayed bridge from the viewpoints of structural property, workability, economic efficiency, and scenic property. Outline of the plan, selection of structural data, design of the external cable, and structural characteristics in the ultimate state are discussed. 19 refs., 18 figs., 15 tabs.

Polar ionospheric responses to solar wind IMF changes

Directory of Open Access Journals (Sweden)

Y. Zhang

2000-06-01

Full Text Available Auroral and airglow emissions over Eureka (89° CGM during the 1997-98 winter show striking variations in relation to solar wind IMF changes. The period January 19 to 22, 1998, was chosen for detailed study, as the IMF was particularly strong and variable. During most of the period, Bz was northward and polar arcs were observed. Several overpasses by DMSP satellites during the four day period provided a clear picture of the particle precipitation producing the polar arcs. The spectral character of these events indicated excitation by electrons of average energy 300 to 500 eV. Only occasionally were electrons of average energy up to ~1 keV observed and these appeared transitory from the ground optical data. It is noted that polar arcs appear after sudden changes in IMF By, suggesting IMF control over arc initiation. When By is positive there is arc motion from dawn to dusk, while By is negative the motion is consistently dusk to dawn. F-region (anti-sunward convections were monitored through the period from 630.0 nm emissions. The convection speed was low (100-150 m/s when Bz was northward but increased to 500 m/s after Bz turned southward on January 20.Key words: Atmospheric composition and structure (airglow and aurora - Ionosphere (particle precipitation - Magnetospheric Physics (polar cap phenomena

The structure of low-latitude Pc3 pulsations observed by CHAMP and on the ground

Directory of Open Access Journals (Sweden)

D. C. Ndiitwani

2009-03-01

Full Text Available The structure of low-latitude continuous pulsations termed Pc3, which are naturally occurring MHD waves in the Earth's magnetosphere, were studied by comparing ground and satellite magnetic field measurements. Data from two induction magnetometers, located at Hermanus and Sutherland in South Africa were used in conjunction with Challenging Minisatellite Payload (CHAMP satellite observations to study a Pc3 event observed on 15 February 2003, at a time when CHAMP was passing over the ground stations. We observed a number of discrete frequency oscillations for the fast mode wave, one of which drives a field line resonance (FLR at characteristic latitude as detected by both ground and satellite measurements. Consequently, our observations confirmed the compressional wave as being the driver of the field line resonance. The toroidal mode frequency observed on CHAMP experienced a Doppler frequency shift due to the rapid motion across the resonance region. Polarization hodograms in the resonance region clearly showed the expected 90° rotation of the field line resonant magnetic field components.

The structure of low-latitude Pc3 pulsations observed by CHAMP and on the ground

Directory of Open Access Journals (Sweden)

D. C. Ndiitwani

2009-03-01

Full Text Available The structure of low-latitude continuous pulsations termed Pc3, which are naturally occurring MHD waves in the Earth's magnetosphere, were studied by comparing ground and satellite magnetic field measurements. Data from two induction magnetometers, located at Hermanus and Sutherland in South Africa were used in conjunction with Challenging Minisatellite Payload (CHAMP satellite observations to study a Pc3 event observed on 15 February 2003, at a time when CHAMP was passing over the ground stations. We observed a number of discrete frequency oscillations for the fast mode wave, one of which drives a field line resonance (FLR at characteristic latitude as detected by both ground and satellite measurements. Consequently, our observations confirmed the compressional wave as being the driver of the field line resonance. The toroidal mode frequency observed on CHAMP experienced a Doppler frequency shift due to the rapid motion across the resonance region. Polarization hodograms in the resonance region clearly showed the expected 90° rotation of the field line resonant magnetic field components.

Characterization of interactions of eggPC lipid structures with different biomolecules.

Science.gov (United States)

Corrales Chahar, F; Díaz, S B; Ben Altabef, A; Gervasi, C; Alvarez, P E

2018-01-01

In this paper we study the interactions of two biomolecules (ascorbic acid and Annonacin) with a bilayer lipid membrane. Egg yolk phosphatidylcholine (eggPC) liposomes (in crystalline liquid state) were prepared in solutions of ascorbic acid (AA) at different concentration levels. On the other hand, liposomes were doped with Annonacin (Ann), a mono-tetrahydrofuran acetogenin (ACG), which is an effective citotoxic substance. While AA pharmacologic effect and action mechanisms are widely known, those of Ann's are only very recently being studied. Both Fourier Transformed Infrared (FTIR) and Raman spectroscopic techniques were used to study the participation of the main functional groups of the lipid bilayer involved in the membrane-solution interaction. The obtained spectra were comparatively analyzed, studying the spectral bands corresponding to both the hydrophobic and the hydrophilic regions in the lipid bilayer. Electrochemical experiments namely; impedance spectroscopy (EIS) and cyclic voltamperometry (CV) were used as the main characterization techniques to analyse stability and structural changes of a model system of supported EggPC bilayer in connection with its interactions with AA and Ann. At high molar ratios of AA, there is dehydration in both populations of the carbonyl group of the polar head of the lipid. On the other hand, Ann promotes the formation of hydrogen bonds with the carbonyl groups. No interaction between AA and phosphate groups is observed at low and intermediate molar ratios. Ann is expected to be able to induce the dehydration of the phosphate groups without the subsequent formation of H bonds with them. According to the electrochemical analysis, the interaction of AA with the supported lipid membrane does not alter its dielectric properties. This fact can be related to the conservation of structured water of the phosphate groups in the polar heads of the lipid. On the other hand, the incorporation of Ann into the lipid membrane generates

Enhancement of device performance by using quaternary capping over ternary capping in strain-coupled InAs/GaAs quantum dot infrared photodetectors

International Nuclear Information System (INIS)

Tongbram, B.; Shetty, S.; Ghadi, H.; Adhikary, S.; Chakrabarti, S.

2015-01-01

We investigate and compare the performance of 30 layers strain-coupled quantum dot (SCQD) infrared photodetectors capped with one of two different layers: a quaternary (In 0.21 Al 0.21 Ga 0.58 As) or ternary (In 0.15 Ga 0.85 As) alloy of 30 Aa and a GaAs layer with a thickness of 120-150 Aa. Measurements of optical properties, spectral responsivity, and cross-sectional transmission electron microscopy were conducted. Results showed that quaternary capping yielded more superior multilayer QD infrared photodetectors than ternary capping. Quaternary capping resulted in enhanced dot size, order, and uniformity of the QD array. The presence of Al in the capped layer helped in the reduction in dark current density and spectral linewidth as well as led to higher electron confinement of the QDs and enhanced device detectivity. The vertically ordered SCQD system with quaternary capping exhibited higher peak detectivity (∝10 10 cm Hz 1/2 /W) than that with ternary capping (∝10 7 cm Hz 1/2 /W). In addition, a very low noise current density of ∝10 -16 A/cm 2 Hz 1/2 at 77 K was achieved with quaternary-capped QDs. (orig.)

Building the perfect PC

CERN Document Server

Thompson, Robert Bruce

2006-01-01

This popular Build-It-Yourself (BIY) PC book covers everything you want to know about building your own system: Planning and picking out the right components, step-by-step instructions for assembling your perfect PC, and an insightful discussion of why you'd want to do it in the first place. Most big brand computers from HP, Dell and others use lower-quality components so they can meet their aggressive pricing targets. But component manufacturers also make high-quality parts that you can either purchase directly, or obtain through distributors and resellers. Consumers and corporations

Impact of GaN cap on charges in Al₂O₃/(GaN/)AlGaN/GaN metal-oxide-semiconductor heterostructures analyzed by means of capacitance measurements and simulations

Energy Technology Data Exchange (ETDEWEB)

Ťapajna, M., E-mail: milan.tapajna@savba.sk; Jurkovič, M.; Válik, L.; Haščík, Š.; Gregušová, D.; Kuzmík, J. [Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, 841 04 Bratislava (Slovakia); Brunner, F.; Cho, E.-M. [Ferdinand-Braun-Institut, Leibniz Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Strasse 4, 12489 Berlin (Germany); Hashizume, T. [Research Center for Integrated Quantum Electronics (RCIQE), Hokkaido University, 060-0814 Sapporo, Japan and JST-CREST, 102-0075 Tokyo (Japan)

2014-09-14

Oxide/semiconductor interface trap density (D{sub it}) and net charge of Al₂O₃/(GaN)/AlGaN/GaN metal-oxide-semiconductor high-electron mobility transistor (MOS-HEMT) structures with and without GaN cap were comparatively analyzed using comprehensive capacitance measurements and simulations. D{sub it} distribution was determined in full band gap of the barrier using combination of three complementary capacitance techniques. A remarkably higher D{sub it} (∼5–8 × 10¹²eV⁻¹ cm⁻²) was found at trap energies ranging from E_C-0.5 to 1 eV for structure with GaN cap compared to that (D{sub it} ∼ 2–3 × 10¹²eV⁻¹ cm⁻²) where the GaN cap was selectively etched away. D{sub it} distributions were then used for simulation of capacitance-voltage characteristics. A good agreement between experimental and simulated capacitance-voltage characteristics affected by interface traps suggests (i) that very high D{sub it} (>10¹³eV⁻¹ cm⁻²) close to the barrier conduction band edge hampers accumulation of free electron in the barrier layer and (ii) the higher D{sub it} centered about E_C-0.6 eV can solely account for the increased C-V hysteresis observed for MOS-HEMT structure with GaN cap. Analysis of the threshold voltage dependence on Al₂O₃ thickness for both MOS-HEMT structures suggests that (i) positive charge, which compensates the surface polarization, is not necessarily formed during the growth of III-N heterostructure, and (ii) its density is similar to the total surface polarization charge of the GaN/AlGaN barrier, rather than surface polarization of the top GaN layer only. Some constraints for the positive surface compensating charge are discussed.

Apical cap

International Nuclear Information System (INIS)

McLoud, T.C.; Isler, R.J.; Novelline, R.A.; Putman, C.E.; Simeone, J.; Stark, P.

1981-01-01

Apical caps, either unilateral or bilateral, are a common feature of advancing age and are usually the result of subpleural scarring unassociated with other diseases. Pancoast (superior sulcus) tumors are a well recognized cause of unilateral asymmetric apical density. Other lesions arising in the lung, pleura, or extrapleural space may produce unilateral or bilateral apical caps. These include: (1) inflammatory: tuberculosis and extrapleural abscesses extending from the neck; (2) post radiation fibrosis after mantle therapy for Hodgkin disease or supraclavicular radiation in the treatment of breast carcinoma; (3) neoplasm: lymphoma extending from the neck or mediastinum, superior sulcus bronchogenic carcinoma, and metastases; (4) traumatic: extrapleural dissection of blood from a ruptured aorta, fractures of the ribs or spine, or hemorrhage due to subclavian line placement; (5) vascular: coarctation of the aorta with dilated collaterals over the apex, fistula between the subclavian artery and vein; and (6) miscellaneous: mediastinal lipomatosis with subcostal fat extending over the apices

A nucleation theory of cell surface capping

International Nuclear Information System (INIS)

Coutsias, E.A.; Wester, M.J.; Perelson, A.S.

1997-01-01

We propose a new theory of cell surface capping based on the principles of nucleation. When antibody interacts with cell surface molecules, the molecules initially form small aggregates called patches that later coalesce into a large aggregate called a cap. While a cap can form by patches being pulled together by action of the cell''s cytoskeleton, in the case of some molecules, disruption of the cytoskeleton does not prevent cap formation. Diffusion of large aggregates on a cell surface is slow, and thus we propose that a cap can form solely through the diffusion of small aggregates containing just one or a few cell surface molecules. Here we consider the extreme case in which single molecules are mobile, but aggregates of all larger sizes are immobile. We show that a set of patches in equilibrium with a open-quotes seaclose quotes of free cell surface molecules can undergo a nucleation-type phase transition in which the largest patch will bind free cell surface molecules, deplete the concentration of such molecules in the open-quotes seaclose quotes and thus cause the other patches to shrink in size. We therefore show that a cap can form without patches having to move, collide with each other, and aggregate

47 CFR 61.41 - Price cap requirements generally.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Price cap requirements generally. 61.41 Section... (CONTINUED) TARIFFS General Rules for Dominant Carriers § 61.41 Price cap requirements generally. (a... companies shall not bar a carrier from electing price cap regulation provided the carrier is otherwise...

30 CFR 250.1157 - How do I receive approval to produce gas-cap gas from an oil reservoir with an associated gas cap?

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How do I receive approval to produce gas-cap gas from an oil reservoir with an associated gas cap? 250.1157 Section 250.1157 Mineral Resources... do I receive approval to produce gas-cap gas from an oil reservoir with an associated gas cap? (a...

Organic photovoltaic effects depending on CuPc layer thickness

International Nuclear Information System (INIS)

Hur, Sung Woo; Kim, Tae Wan; Chung, Dong Hoe; Oh, Hyun Seok; Kim, Chung Hyeok; Lee, Joon Ung; Park, Jong Wook

2004-01-01

Organic photovoltaic effects were studied in device structures of ITO/CuPc/Al and ITO/CuPc/C 60 /BCP/Al by varying the CuPc layer thickness. Since the exciton diffusion length is relatively short in organic semiconductors, a study on the thickness-dependent photovoltaic effects is important. The thickness of the CuPc layer was varied from 10 nm to 50 nm. We found that the optimum CuPc layer thickness was around 40 nm from the analysis of the current density-voltage characteristics in an ITO/CuPc/Al photovoltaic cell. The efficiency of the device shows that the multi-layered heterojunction structure is more appropriate for photovoltaic cells.

Devon island ice cap: core stratigraphy and paleoclimate.

Science.gov (United States)

Koerner, R M

1977-04-01

Valuable paleoclimatic information can be gained by studying the distribution of melt layers in deep ice cores. A profile representing the percentage of ice in melt layers in a core drilled from the Devon Island ice cap plotted against both time and depth shows that the ice cap has experienced a period of very warm summers since 1925, following a period of colder summers between about 1600 and 1925. The earlier period was coldest between 1680 and 1730. There is a high correlation between the melt-layer ice percentage and the mass balance of the ice cap. The relation between them suggests that the ice cap mass balance was zero (accumulation equaled ablation) during the colder period but is negative in the present warmer one. There is no firm evidence of a present cooling trend in the summer conditions on the ice cap. A comparison with the melt-layer ice percentage in cores from the other major Canadian Arctic ice caps shows that the variation of summer conditions found for the Devon Island ice cap is representative for all the large ice caps for about 90 percent of the time. There is also a good correlation between melt-layer percentage and summer sea-ice conditions in the archipelago. This suggests that the search for the northwest passage was influenced by changing climate, with the 19th-century peak of the often tragic exploration coinciding with a period of very cold summers.

Ion Transport across Biological Membranes by Carborane-Capped Gold Nanoparticles.

Science.gov (United States)

Grzelczak, Marcin P; Danks, Stephen P; Klipp, Robert C; Belic, Domagoj; Zaulet, Adnana; Kunstmann-Olsen, Casper; Bradley, Dan F; Tsukuda, Tatsuya; Viñas, Clara; Teixidor, Francesc; Abramson, Jonathan J; Brust, Mathias

2017-12-26

Carborane-capped gold nanoparticles (Au/carborane NPs, 2-3 nm) can act as artificial ion transporters across biological membranes. The particles themselves are large hydrophobic anions that have the ability to disperse in aqueous media and to partition over both sides of a phospholipid bilayer membrane. Their presence therefore causes a membrane potential that is determined by the relative concentrations of particles on each side of the membrane according to the Nernst equation. The particles tend to adsorb to both sides of the membrane and can flip across if changes in membrane potential require their repartitioning. Such changes can be made either with a potentiostat in an electrochemical cell or by competition with another partitioning ion, for example, potassium in the presence of its specific transporter valinomycin. Carborane-capped gold nanoparticles have a ligand shell full of voids, which stem from the packing of near spherical ligands on a near spherical metal core. These voids are normally filled with sodium or potassium ions, and the charge is overcompensated by excess electrons in the metal core. The anionic particles are therefore able to take up and release a certain payload of cations and to adjust their net charge accordingly. It is demonstrated by potential-dependent fluorescence spectroscopy that polarized phospholipid membranes of vesicles can be depolarized by ion transport mediated by the particles. It is also shown that the particles act as alkali-ion-specific transporters across free-standing membranes under potentiostatic control. Magnesium ions are not transported.

NEAR-INFRARED LINEAR POLARIZATION OF ULTRACOOL DWARFS

International Nuclear Information System (INIS)

Zapatero Osorio, M. R.; Bejar, V. J. S.; Rebolo, R.; Acosta-Pulido, J. A.; Manchado, A.; Pena Ramirez, K.; Goldman, B.; Caballero, J. A.

2011-01-01

We report on near-infrared J- and H-band linear polarimetric photometry of eight ultracool dwarfs (two late-M, five L0-L7.5, and one T2.5) with known evidence for photometric variability due to dust clouds, anomalous red infrared colors, or low-gravity atmospheres. The polarimetric data were acquired with the LIRIS instrument on the William Herschel Telescope. We also provide mid-infrared photometry in the interval 3.4-24 μm for some targets obtained with Spitzer and WISE, which has allowed us to confirm the peculiar red colors of five sources in the sample. We can impose modest upper limits of 0.9% and 1.8% on the linear polarization degree for seven targets with a confidence of 99%. Only one source, 2MASS J02411151-0326587 (L0), appears to be strongly polarized (P ∼ 3%) in the J band with a significance level of P/σ P ∼ 10. The likely origin of its linearly polarized light and rather red infrared colors may reside in a surrounding disk with an asymmetric distribution of grains. Given its proximity (66 ± 8 pc), this object becomes an excellent target for the direct detection of the disk.

Leo II PC

Data.gov (United States)

Kansas Data Access and Support Center — LEO II is a second-generation software system developed for use on the PC, which is designed to convert location references accurately between legal descriptions and...

Photoactivable caps for reactive metal nanoparticles

Science.gov (United States)

Patel, Ashish

The synthesis and stabilization of reactive metal nanoparticles is often challenging under normal atmospheric conditions. This problem can be alleviated by capping and passivation. Our lab has focused on forming polymer coatings on the surface of reactive metal nanoparticles. We discovered a convenient and effective route for stabilization of aluminum nanoparticles (Al NPs), which uses the nascent metal core as a polymerization initiator for various organic monomers. In our previous work, we used this method to passivate the Al NPs using variety of epoxides and copolymers of epoxides and alkenes. These products have demonstrated air stability for weeks to months with little to no degradation in the active Al content. Since our previously synthesized Al NP's were not beneficial for rapid and efficient thermodynamic access to the active Al core, our goal was find polymers that could easily be photochemically activated to enhance such access. Since poly(methyl methacrylate) (PMMA) has photodegrading properties, we used PMMA as a capping agent to passivate Al NPs. In this work, we present capping and stabilization of Al NPs with PMMA, and also with 1,2-epoxyhexane/ PMMA. In our previous work, we increased the stability of Al NP capped with 1,2-epoxy-9-decene by adding 1,13-tetradecadiene as a cross-linker. Here, we used the methyl methacrylate (MMA) monomer as cross-linker for Al NP capped with 1,2-epoxy-9-decene. We have also used the MMA as capping agent. We use powder x-ray diffractametry (PXRD), differential scanning calorimetry (DSC), and thermogravity analysis (TGA) to confirm the presence of elemental Al and ATR-FTIR to confirm the presence of polymers.

CAP FUTURE: WHAT DO STAKEHOLDERS WANT?

Directory of Open Access Journals (Sweden)

Petr BLIZKOVSKY

2018-03-01

Full Text Available The Common Agricultural Policy (CAP is at the crossroads of several policy interests. It is scrutinised by farming and environmental communities as well as by the food industry, regional authorities, research and public sector. The paper analyses the recent consultation process undertaken by the European Commission. The paper concludes that among the key reform issues are: the level of the financial support to the CAP; the continued environmental and other public goods orientation of the CAP and generational renewal. In addition, the focus on result orientation and reduction of the administrative burden can be expected. The relevant European Commission proposals are foreseen around summer 2018.

Empiric penicillin monotherapy of CAP is not associated with increased mortality; experiences from the retrospective CAP-North cohort

DEFF Research Database (Denmark)

Baunbæk-Knudsen, Getrud; Vestergaard Jensen, Andreas; Andersen, Stine

2016-01-01

Background: Community-acquired pneumonia (CAP) is a severe infection, with high morbidity and mortality. The antibiotic strategies for CAP differ across Europe. Objective: To assess the usage of Penicillin monotherapy in a real-life cohort and to evaluate predictors of treatment duration and the ......Background: Community-acquired pneumonia (CAP) is a severe infection, with high morbidity and mortality. The antibiotic strategies for CAP differ across Europe. Objective: To assess the usage of Penicillin monotherapy in a real-life cohort and to evaluate predictors of treatment duration......, and evaluated predictors of treatment duration by linear regression. Mortality of patients receiving empiric penicillin-G/V was compared to others by logistic regression analysis. The CAPNETZ database technology was used for data-capture. Results: We included 1320 patients. The incidence of hospitalized CAP...... was 3.1 per 1000 inhabitants. The median age was 71 years (IQR; 58.81). In-hospital mortality was 8%. Patients treated with penicillin-G/V as empiric monotherapy (45%) did not have a higher mortality than those treated with broader spectrum antibiotics (OR 1.30, CI 95% 0.84-2-02). The median duration...

Prognostic significance of platelet count changes during hospitalization for community-acquired pneumonia.

Science.gov (United States)

Gorelik, Oleg; Izhakian, Shimon; Barchel, Dana; Almoznino-Sarafian, Dorit; Tzur, Irma; Swarka, Muhareb; Beberashvili, Ilia; Feldman, Leonid; Cohen, Natan; Shteinshnaider, Miriam

2017-06-01

The prognostic significance of platelet count (PC) changes during hospitalization for community-acquired pneumonia (CAP) has not been investigated. For 976 adults, clinical data during hospitalization for CAP and all-cause mortality following discharge were compared according to ΔPC (PC on discharge minus PC on admission): groups A (declining PC, ΔPC 50 × 10 9 /l), and according to the presence of thrombocytopenia, normal PC, and thrombocytosis on admission/discharge. Groups A, B, and C comprised 7.9%, 46.5%, and 45.6% of patients, respectively. On hospital admission/discharge, thrombocytopenia, normal PC, and thrombocytosis were observed in 12.8%/6.4%, 84.1%/84.4%, and 3.1%/9.2% of patients, respectively. The respective 90-day, 3-year, and total (median follow-up of 54 months) mortality rates were significantly higher: in group A (40.3%, 63.6%, and 72.7%), compared to groups B (12.3%, 31.5%, and 39.0%) and C (4.9%, 17.3%, and 25.4%), p < 0.001; and in patients with thrombocytopenia at discharge (27.4%, 48.4%, and 51.6%), compared to those with normal PC (10.2%, 26.9%, and 35.4%) and thrombocytosis (8.9%, 17.8%, and 24.4%) at discharge (p < 0.001). Mortality rates were comparable among groups with thrombocytopenia, normal PC, and thrombocytosis at admission (p = 0.6). In the entire sample, each 100 × 10 9 /l increment of ΔPC strongly predicted lower mortality (p < 0.001, relative risk 0.73, 95% confidence interval 0.64-0.83). In conclusion, PC changes are common among CAP inpatients. Rising PC throughout hospitalization is a powerful predictor of better survival, while declining PC predicts poor outcome. Evaluation of PC changes during hospitalization for CAP may provide useful prognostic information.

Progress in LAr EndCap Calorimetry: News from the Hadronic EndCap Group.

CERN Multimedia

Oram, C.J.

With module production and testing completed for the Hadronic EndCap calorimeter, the attention of the HEC group is heavily directed towards wheel assembly in building 180. Three of the four HEC wheels are now assembled and rotated, and work is progressing on assembling the final wheel. This year has been a busy year for the installation of components in the EndCap C cryostat: the signal feedthrough installation was completed April 22nd, the pre-sampler shortly thereafter and the Electro-Magnetic EndCap August 13th. This allowed the HEC group to start transferring the HEC wheels from the T6A storage cradle into the cryostat. The operation started in mid-September and has progressed, on or ahead of schedule, since then with the major milestones being: Insertion of 67 ton front HEC wheel October 3rd Insertion of 90 ton rear HEC wheel October 22nd. The wheel alignment has proved to be excellent, with the position of the centre of the front(rear) wheel with respect to the nominal position being displaced b...

A thermoelectric cap for seafloor hydrothermal vents

International Nuclear Information System (INIS)

Xie, Yu; Wu, Shi-jun; Yang, Can-jun

2016-01-01

Highlights: • We developed a thermoelectric cap (TC) to harvest hydrothermal energy. • The TC was deployed at a hydrothermal vent site near Kueishantao islet, Taiwan. • The TC monitored the temperature of the hydrothermal fluids during the field test. • The TC could make the thermal energy of hydrothermal fluids a viable power source. - Abstract: Long-term in situ monitoring is crucial to seafloor scientific investigations. One of the challenges of operating sensors in seabed is the lifespan of the sensors. Such sensors are commonly powered by batteries when other alternatives, such as tidal or solar energy, are unavailable. However, the batteries have a limited lifespan and must be recharged or replaced periodically, which is costly and impractical. A thermoelectric cap, which harvests the thermal energy of hydrothermal fluids through a conduction pipe and converts the heat to electrical energy by using thermoelectric generators, was developed to avoid these inconveniences. The thermoelectric cap was combined with a power and temperature measurement system that enables the thermoelectric cap to power a light-emitting diode lamp, an electronic load (60 Ω), and 16 thermocouples continuously. The thermoelectric cap was field tested at a shallow hydrothermal vent site near Kueishantao islet, which is located offshore of northeastern Taiwan. By using the thermal gradient between hydrothermal fluids and seawater, the thermoelectric cap obtained a sustained power of 0.2–0.5 W during the field test. The thermoelectric cap successfully powered the 16 thermocouples and recorded the temperature of the hydrothermal fluids during the entire field test. Our results show that the thermal energy of hydrothermal fluids can be an alternative renewable power source for oceanographic research.

Density functional study of condensation in capped capillaries.

Science.gov (United States)

Yatsyshin, P; Savva, N; Kalliadasis, S

2015-07-15

We study liquid adsorption in narrow rectangular capped capillaries formed by capping two parallel planar walls (a slit pore) with a third wall orthogonal to the two planar walls. The most important transition in confined fluids is arguably condensation, where the pore becomes filled with the liquid phase which is metastable in the bulk. Depending on the temperature T, the condensation in capped capillaries can be first-order (at T≤Tcw) or continuous (at T>Tcw), where Tcw is the capillary wetting temperature. At T>Tcw, the capping wall can adsorb mesoscopic amounts of metastable under-condensed liquid. The onset of condensation is then manifested by the continuous unbinding of the interface between the liquid adsorbed on the capping wall and the gas filling the rest of the capillary volume. In wide capped capillaries there may be a remnant of wedge filling transition, which is manifested by the adsorption of liquid drops in the corners. Our classical statistical mechanical treatment predicts a possibility of three-phase coexistence between gas, corner drops and liquid slabs adsorbed on the capping wall. In sufficiently wide capillaries we find that thick prewetting films of finite length may be nucleated at the capping wall below the boundary of the prewetting transition. Prewetting then proceeds in a continuous manner manifested by the unbinding interface between the thick and thin films adsorbed on the side walls. Our analysis is based on a detailed numerical investigation of the density functional theory for the fluid equilibria for a number of illustrative case studies.

Durability of Capped Wood Plastic Composites

Science.gov (United States)

Mark Mankowski; Mark J. Manning; Damien P. Slowik

2015-01-01

Manufacturers of wood plastic composites (WPCs) have recently introduced capped decking to their product lines. These new materials have begun to take market share from the previous generation of uncapped products that possessed a homogenous composition throughout the thickness of their cross-section. These capped offerings have been introduced with claims that the...

ImmunoCAP assays: Pros and cons in allergology.

Science.gov (United States)

van Hage, Marianne; Hamsten, Carl; Valenta, Rudolf

2017-10-01

Allergen-specific IgE measurements and the clinical history are the cornerstones of allergy diagnosis. During the past decades, both characterization and standardization of allergen extracts and assay technology have improved. Here we discuss the uses, advantages, misinterpretations, and limitations of ImmunoCAP IgE assays (Thermo Fisher Scientific/Phadia, Uppsala, Sweden) in the field of allergology. They can be performed as singleplex (ImmunoCAP) and, for the last decade, as multiplex (Immuno Solid-phase Allergen Chip [ISAC]). The major benefit of ImmunoCAP is the obtained quantified allergen-specific IgE antibody level and the lack of interference from allergen-specific IgG antibodies. However, ImmunoCAP allergen extracts are limited to the composition of the extract. The introduction of allergen molecules has had a major effect on analytic specificity and allergy diagnosis. They are used in both singleplex ImmunoCAP and multiplex ImmunoCAP ISAC assays. The major advantage of ISAC is the comprehensive IgE pattern obtained with a minute amount of serum. The shortcomings are its semiquantitative measurements, lower linear range, and cost per assay. With respect to assay performance, ImmunoCAP allergen extracts are good screening tools, but allergen molecules dissect the IgE response on a molecular level and put allergy research on the map of precision medicine. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Electronic transitions and band offsets in C60:SubPc and C60:MgPc on MoO3 studied by modulated surface photovoltage spectroscopy

International Nuclear Information System (INIS)

Fengler, S.; Dittrich, Th.; Rusu, M.

2015-01-01

Electronic transitions at interfaces between MoO 3 layers and organic layers of C 60 , SubPc, MgPc, and nano-composite layers of SubPc:C 60 and MgPc:C 60 have been studied by modulated surface photovoltage (SPV) spectroscopy. For all systems, time dependent and modulated SPV signals pointed to dissociation of excitons at the MoO 3 /organic layer interfaces with a separation of holes towards MoO 3 . The highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gaps (E HL ) of C 60 , SubPc, and MgPc and the effective E HL of SubPc:C 60 and MgPc:C 60 were measured. The offsets between the LUMO (ΔE L ) or HOMO (ΔE H ) bands were obtained with high precision and amounted to 0.33 or 0.73 eV for SubPc:C 60 , respectively, and to −0.33 or 0.67 eV for MgPc:C 60 , respectively. Exponential tails below E HL and most pronounced sub-bandgap transitions were characterized and ascribed to disorder and transitions from HOMO bands to unoccupied defect states

Cryogenic control system of the large COMPASS polarized target

CERN Document Server

Gautheron, F; Baum, G; Berglund, P; Doshita, N; Görtz, S; Gustafsson, K K; Horikawa, N; Kisselev, Yu V; Koivuniemi, J H; Kondo, K; Meyer, Werner T; Reicherz, G

2004-01-01

The dilution refrigerator used to cool the large COMPASS polarized target is monitored through a PC running LabVIEW trademark 6.1 under Windows 2000 trademark . About 60 parameters of the target (temperatures, pressures, flow rates) are continuously plotted and checked. They are periodically recorded in an Oracle trademark database and in a data file. An alarm for every parameter can be individually activated and optionally connected to a GSM (Global System for Mobile Communication) delivery message system. A web server receives and publishes the online status of the target with online tables and graphics on a dedicated COMPASS polarized target information web site. A Siemens programmable logic controller (PLC) powered by an uninterruptable source keeps the cryogenic system safe and stable during the long beam periods by controlling valves and interlocks. This safety feature protects the dilution refrigerator against potential damages in case of power failure.

The Influence of Company Size on Accounting Information: Evidence in Large Caps and Small Caps Companies Listed on BM&FBovespa

Directory of Open Access Journals (Sweden)

Karen Yukari Yokoyama

2015-09-01

Full Text Available In this study, the relation between accounting information aspects and the capitalization level o companies listed on the São Paulo Stock Exchange was investigated, classified as Large Caps or Small Caps, companies with larger and smaller capitalization, respectively, between 2010 and 2012. Three accounting information measures were addressed: informativeness, conservatism and relevance, through the application of Easton and Harris’ (1991 models of earnings informativeness, Basu’s (1997 model of conditional conservatism and the value relevance model, based on Ohlson (1995. The results appointed that, although the Large Caps present a higher level of conservatism, their accounting figures were less informative and more relevant when compared to the Large Caps companies. Due to the greater production of private information (predisclosure surrounding larger companies, the market would tend to respond less strongly or surprised to the publication of these companies’ accounting information, while the lack of anticipated information would make the effect of disclosing these figures more preponderant for the Small Caps companies.

Contabilidad de Costos II. - Capítulo 4. Respuestas

OpenAIRE

Morillo Moreno, Marysela C.

2008-01-01

ÍNDICE Presentación Orientaciones para el usuario Capítulo 1: Contabilidad de costos por procesos Sistemas de Contabilidad de Costos por Proceso Costos de Producción Conjunta. Productos Principales y Secundarios Capítulo 2: Contabilidad de costos predeterminados Presupuesto Estático y Presupuesto Flexible Sistema de Costos Estándar Capítulo 3: Sistema de costos variables Capítulo 4: Respuestas Bibliografía recomendada Pr...

Experience using EPICS on PC platforms

International Nuclear Information System (INIS)

Hill, J.O.; Kasemire, K.U.

1997-03-01

The Experimental Physics and Industrial Control System (EPICS) has been widely adopted in the accelerator community. Although EPICS is available on many platforms, the majority of implementations have used UNIX workstations as clients, and VME- or VXI-based processors for distributed input output controllers. Recently, a significant portion of EPICS has been ported to personal computer (PC) hardware platforms running Microsoft's operating systems, and also Wind River System's real time vxWorks operating system. This development should significantly reduce the cost of deploying EPICS systems, and the prospect of using EPICS together with the many high quality commercial components available for PC platforms is also encouraging. A hybrid system using both PC and traditional platforms is currently being implemented at LANL for LEDA, the low energy demonstration accelerator under construction as part of the Accelerator Production of Tritium (APT) project. To illustrate these developments the authors compare their recent experience deploying a PC-based EPICS system with experience deploying similar systems based on traditional (UNIX-hosted) EPICS hardware and software platforms

22 CFR 121.11 - Military demolition blocks and blasting caps.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Military demolition blocks and blasting caps... blasting caps. Military demolition blocks and blasting caps referred to in Category IV(a) do not include the following articles: (a) Electric squibs. (b) No. 6 and No. 8 blasting caps, including electric...

Ion and solvent diffusion and ion conduction of PC-DEC and PC-DME binary solvent electrolytes of LiN(SO2CF3)2

International Nuclear Information System (INIS)

Hayamizu, Kikuko; Aihara, Yuichi

2004-01-01

Two binary mixed solvent systems typically used for lithium batteries were studied by measuring the self-diffusion coefficients of the solvent, lithium ion and anion, independently by using the multi-nuclear pulsed field-gradient spin-echo (PGSE) 1 H, 7 Li and 19 F NMR method. One system was propylene carbonate (PC) and diethyl carbonate (DEC) system and the other binary system was PC and 1,2-dimethoxyethane (DME), and the lithium salt used was LiN(SO 2 CF 3 ) 2 (LiTFSI). The relative ratio of the PC was changed from zero (pure DME and DEC) to 100% (pure PC) in the DME-PC and the DEC-PC systems, respectively. The self-diffusion coefficients of the solvents were measured with and without the lithium salt, and the two solvents had almost the same diffusion coefficient in the DEC-PC system, while DME diffused faster than PC in the DME-PC system. In the electrolytes the solvents diffused the fastest, followed by the anion with the lithium ion diffusing the slowest. The degree of ion dissociation was estimated for each electrolyte by comparing the ionic conductivities estimated from the ion diffusion and those measured directly by the electrochemical method

Salinomycin Exerts Anticancer Effects on PC-3 Cells and PC-3-Derived Cancer Stem Cells In Vitro and In Vivo

Directory of Open Access Journals (Sweden)

Yunsheng Zhang

2017-01-01

Full Text Available Salinomycin is an antibiotic isolated from Streptomyces albus that selectively kills cancer stem cells (CSCs. However, the antitumor mechanism of salinomycin is unclear. This study investigated the chemotherapeutic efficacy of salinomycin in human prostate cancer PC-3 cells. We found that cytotoxicity of salinomycin to PC-3 cells was stronger than to nonmalignant prostate cell RWPE-1, and exposure to salinomycin induced G2/M phage arrest and apoptosis of PC-3 cells. A mechanistic study found salinomycin suppressed Wnt/β-catenin pathway to induce apoptosis of PC-3 cells. An in vivo experiment confirmed that salinomycin suppressed tumorigenesis in a NOD/SCID mice xenograft model generated from implanted PC-3 cells by inhibiting the Wnt/β-catenin pathway, since the total β-catenin protein level was reduced and the downstream target c-Myc level was significantly downregulated. We also showed that salinomycin, but not paclitaxel, triggered more apoptosis in aldehyde dehydrogenase- (ALDH- positive PC-3 cells, which were considered as the prostate cancer stem cells, suggesting that salinomycin may be a promising chemotherapeutic to target CSCs. In conclusion, this study suggests that salinomycin reduces resistance and relapse of prostate tumor by killing cancer cells as well as CSCs.

Prices regulation in price-cap: the lessons of the british gas industry; Reglementations tarifaires en price-cap: les lecons de l'industrie gaziere anglaise

Energy Technology Data Exchange (ETDEWEB)

David, L.

2003-07-01

This article examines the problem of the price-cap regulation applied to the british gas transport. The RPI-X cap is a particular form of the price cap. This cap seems to be more remunerative for the regulatory firm than a cap calculated on the Laspeyres index because it authorizes a greater freedom of prices choice, to the prejudice of the consumers. Facing these perverse effects, Cowan proposed in 1997 a new system, not more satisfying. Another equation is analyzed in this article, proposed by Ofgem. Meanwhile this system presents no improvement of the consumers surplus facing the RPI-X cap. (A.L.B.)

PC based 8-parameter data acquisition system

International Nuclear Information System (INIS)

Gupta, J.D.; Naik, K.V.; Jain, S.K.; Pathak, R.V.; Suman, B.

1989-01-01

Multiparameter data acquisition (MPA) systems which analyse nuclear events with respect to more than one property of the event are essential tools for the study of some complex nuclear phenomena requiring analysis of time coincident spectra. For better throughput and accuracy each parameter is digitized by its own ADC. A stand alone low cost IBM PC based 8-parameter data acquisition system developed by the authors makes use of Address Recording technique for acquiring data from eight 12 bit ADC's in the PC Memory. Two memory buffers in the PC memory are used in ping-pong fashion so that data acquisition in one bank and dumping of data onto PC disk from the other bank can proceed simultaneously. Data is acquired in the PC memory through DMA mode for realising high throughput and hardware interrupt is used for switching banks for data acquisition. A comprehensive software package developed in Turbo-Pascal offers a set of menu-driven interactive commands to the user for setting-up system parameters and control of the system. The system is to be used with pelletron accelerator. (author). 5 figs

IN SITU REMEDIATION OF CONTAMINATED SEDIMENTS - ACTIVE CAPPING TECHNOLOGY

Energy Technology Data Exchange (ETDEWEB)

Knox, A.; Roberts, J.; Paller, M.; Reible, D.

2010-09-02

Active capping is a relatively new approach for treating contaminated sediments. It involves applying chemically reactive amendments to the sediment surface. The main role of active caps is to stabilize contaminants in contaminated sediments, lower the bioavailable pool of contaminants, and reduce the release of contaminants to the water column. Metals are common contaminants in many marine and fresh water environments as a result of industrial and military activities. The mobile, soluble forms of metals are generally considered toxic. Induced chemical precipitation of these metals can shift toxic metals from the aqueous phase to a solid, precipitated phase which is often less bioavailable. This approach can be achieved through application of sequestering agents such as rock phosphates, organoclays, zeolites, clay minerals, and biopolymers (e.g., chitosan) in active capping technology. Active capping holds great potential for a more permanent solution that avoids residual risks resulting from contaminant migration through the cap or breaching of the cap. In addition to identifying superior active capping agents, research is needed to optimize application techniques, application rates, and amendment combinations that maximize sequestration of contaminants. A selected set of active capping treatment technologies has been demonstrated at a few sites, including a field demonstration at the Savannah River Site, Aiken, SC. This demonstration has provided useful information on the effects of sequestering agents on metal immobilization, bioavailability, toxicity, and resistance to mechanical disturbance.

In Situ Remediation Of Contaminated Sediments - Active Capping Technology

International Nuclear Information System (INIS)

Knox, A.; Roberts, J.; Paller, M.; Reible, D.

2010-01-01

Active capping is a relatively new approach for treating contaminated sediments. It involves applying chemically reactive amendments to the sediment surface. The main role of active caps is to stabilize contaminants in contaminated sediments, lower the bioavailable pool of contaminants, and reduce the release of contaminants to the water column. Metals are common contaminants in many marine and fresh water environments as a result of industrial and military activities. The mobile, soluble forms of metals are generally considered toxic. Induced chemical precipitation of these metals can shift toxic metals from the aqueous phase to a solid, precipitated phase which is often less bioavailable. This approach can be achieved through application of sequestering agents such as rock phosphates, organoclays, zeolites, clay minerals, and biopolymers (e.g., chitosan) in active capping technology. Active capping holds great potential for a more permanent solution that avoids residual risks resulting from contaminant migration through the cap or breaching of the cap. In addition to identifying superior active capping agents, research is needed to optimize application techniques, application rates, and amendment combinations that maximize sequestration of contaminants. A selected set of active capping treatment technologies has been demonstrated at a few sites, including a field demonstration at the Savannah River Site, Aiken, SC. This demonstration has provided useful information on the effects of sequestering agents on metal immobilization, bioavailability, toxicity, and resistance to mechanical disturbance.

Monte Carlo tests of the ELIPGRID-PC algorithm

International Nuclear Information System (INIS)

Davidson, J.R.

1995-04-01

The standard tool for calculating the probability of detecting pockets of contamination called hot spots has been the ELIPGRID computer code of Singer and Wickman. The ELIPGRID-PC program has recently made this algorithm available for an IBM reg-sign PC. However, no known independent validation of the ELIPGRID algorithm exists. This document describes a Monte Carlo simulation-based validation of a modified version of the ELIPGRID-PC code. The modified ELIPGRID-PC code is shown to match Monte Carlo-calculated hot-spot detection probabilities to within ±0.5% for 319 out of 320 test cases. The one exception, a very thin elliptical hot spot located within a rectangular sampling grid, differed from the Monte Carlo-calculated probability by about 1%. These results provide confidence in the ability of the modified ELIPGRID-PC code to accurately predict hot-spot detection probabilities within an acceptable range of error

Kinetic Framework for the Magnetosphere-Ionosphere-Plasmasphere-Polar Wind System: Modeling Ion Outflow

Science.gov (United States)

Schunk, R. W.; Barakat, A. R.; Eccles, V.; Karimabadi, H.; Omelchenko, Y.; Khazanov, G. V.; Glocer, A.; Kistler, L. M.

2014-12-01

A Kinetic Framework for the Magnetosphere-Ionosphere-Plasmasphere-Polar Wind System is being developed in order to provide a rigorous approach to modeling the interaction of hot and cold particle interactions. The framework will include ion and electron kinetic species in the ionosphere, plasmasphere and polar wind, and kinetic ion, super-thermal electron and fluid electron species in the magnetosphere. The framework is ideally suited to modeling ion outflow from the ionosphere and plasmasphere, where a wide range for fluid and kinetic processes are important. These include escaping ion interactions with (1) photoelectrons, (2) cusp/auroral waves, double layers, and field-aligned currents, (3) double layers in the polar cap due to the interaction of cold ionospheric and hot magnetospheric electrons, (4) counter-streaming ions, and (5) electromagnetic wave turbulence. The kinetic ion interactions are particularly strong during geomagnetic storms and substorms. The presentation will provide a brief description of the models involved and discuss the effect that kinetic processes have on the ion outflow.

A stable wavelength-tunable single frequency and single polarization linear cavity erbium-doped fiber laser

International Nuclear Information System (INIS)

Feng, T; Yan, F P; Li, Q; Peng, W J; Tan, S Y; Feng, S C; Wen, X D; Liu, P

2013-01-01

We report the configuration and operation of a wavelength-tunable single frequency and single polarization erbium-doped fiber laser (EDFL) with a stable and high optical signal to noise ratio (OSNR) laser output. A narrow-band fiber Bragg grating (NBFBG), a FBG-based Fabry–Perot (FP) filter, a polarization controller (PC) and an unpumped erbium-doped fiber (EDF) as a saturable absorber (SA) are employed to realize stable single frequency lasing operation. An all-fiber polarizer (AFP) is introduced to suppress mode hopping and ensure the single polarization mode operation. By adjusting the length of the NBFBG using a stress adjustment module (SAM), four stable single frequency and single polarization laser outputs at wavelengths of 1544.946, 1545.038, 1545.118 and 1545.182 nm are obtained. At room temperature, performance with an OSNR of larger than 60 dB, power fluctuation of less than 0.04 dB, wavelength variation of less than 0.01 nm for about 5 h measurement, and degree of polarization (DOP) of close to 100% has been experimentally demonstrated for the fiber laser operating at these four wavelengths. (paper)

The SUrvey for Pulsars and Extragalactic Radio Bursts III: Polarization properties of FRBs 160102 & 151230

Science.gov (United States)

Caleb, M.; Keane, E. F.; van Straten, W.; Kramer, M.; Macquart, J. P.; Bailes, M.; Barr, E. D.; Bhat, N. D. R.; Bhandari, S.; Burgay, M.; Farah, W.; Jameson, A.; Jankowski, F.; Johnston, S.; Petroff, E.; Possenti, A.; Stappers, B.; Tiburzi, C.; Krishnan, V. Venkatraman

2018-05-01

We report on the polarization properties of two fast radio bursts (FRBs): 151230 and 160102 discovered in the SUrvey for Pulsars and Extragalactic Radio Bursts (SUPERB) at the Parkes radio telescope. FRB 151230 is observed to be 6 ± 11% circularly polarized and 35 ± 13 % linearly polarized with a rotation measure (RM) consistent with zero. Conversely, FRB 160102 is observed to have a circular polarization fraction of 30 ± 11 %, linear polarization fraction of 84 ± 15 % for RM =-221(6) rad m-2 and the highest measured DM (2596.1 ± 0.3 pc cm-3) for an FRB to date. We examine possible progenitor models for FRB 160102 in extragalactic, non-cosmological and cosmological scenarios. After accounting for the Galactic foreground contribution, we estimate the intrinsic RM to be -256(9) rad m-2 in the low-redshift case and ˜-2.4 × 102 rad m-2 in the high-redshift case. We assess the relative likeliness of these scenarios and how each can be tested. We also place constraints on the scattering measure and study the impact of scattering on the signal's polarization position angle.

Water on Mars: Inventory, distribution, and possible sources of polar ice

Science.gov (United States)

Clifford, S. M.

1992-01-01

Theoretical considerations and various lines of morphologic evidence suggest that, in addition to the normal seasonal and climatic exchange of H2O that occurs between the Martian polar caps, atmosphere, and mid to high latitude regolith, large volumes of water have been introduced into the planet's long term hydrologic cycle by the sublimation of equatorial ground ice, impacts, catastrophic flooding, and volcanism. Under the climatic conditions that are thought to have prevailed on Mars throughout the past 3 to 4 b.y., much of this water is expected to have been cold trapped at the poles. The amount of polar ice contributed by each of the planet's potential crustal sources is discussed and estimated. The final analysis suggests that only 5 to 15 pct. of this potential inventory is now in residence at the poles.

Lowering the YE+1 end-cap for CMS

CERN Multimedia

Maximilien Brice

2007-01-01

On 9 January 2007, the massive YE+1 end-cap was lowered into the CMS cavern. This is a very precise process as the crane must lower the end-cap through minimal clearance without tilt or sway. Once in the cavern, the end-cap is then positioned over the end of the barrel to detect particles produced in collisions that travel close to the axis of the beams.

Microtubule dynamics: Caps, catastrophes, and coupled hydrolysis

DEFF Research Database (Denmark)

Flyvbjerg, H.; Holy, T.E.; Leibler, S.

1996-01-01

An effective theory is formulated for the dynamics of the guanosine triphosphate (GTP) cap believed to stabilize growing microtubules. The theory provides a ''coarse-grained'' description of the cap's dynamics. ''Microscopic'' details, such as the microtubule lattice structure and the fate of its...

Who's (Still) Above the Social Security Payroll Tax Cap?

OpenAIRE

Nicole Woo; Janelle Jones; John Schmitt

2012-01-01

The Social Security payroll tax cap is the earnings level above which no further Social Security taxes are collected. The cap is currently at $110,100, though legislation has been introduced in Congress to apply the Social Security payroll tax to earnings above $250,000 (but not between the current cap and this level). This issue brief updates earlier work, finding that 5.8 percent of workers would be affected if the Social Security cap were eliminated entirely and 1.4 percent would be affect...

/sup 56/Fe (. gamma. ,. cap alpha. /sub 0/) reaction

Energy Technology Data Exchange (ETDEWEB)

Tamae, T; Sugawara, M [Tohoku Univ., Sendai (Japan). Lab. of Nuclear Science; Tsubota, H

1974-12-01

The reaction cross section of /sup 56/Fe (..gamma.., ..cap alpha../sub 0/) was measured from the electron energy of 15 to 25 MeV. The measured data were compared with the calculated ones based on statistic theory. Both agreed with each other. Therefore, the affirmative result was obtained for the presumption that the reaction of (..gamma.., ..cap alpha../sub 0/) of the nuclei around these energy levels can be explained by the statistical theory. The angular distribution of /sup 56/Fe (..gamma.., ..cap alpha../sub 0/) with 17 MeV electron energy was also measured, and the E2/E1 ratio was obtained. In the measurement of the /sup 56/Fe ( Gamma , ..cap alpha../sub 0/) reaction cross section, a natural target of 2.69 mg/cm/sup 2/ was irradiated with an electron beam with energy from 15 MeV to 25 MeV at intervals of 0.5 MeV, and the emitted ..cap alpha.. particles were detected by a broad band magnetic distribution meter. The measured cross section of the (..gamma.., ..cap alpha../sub 0/) reaction agreed with the calculated one based on statistical theory. If this fact is recognized in many nuclei, the cross section of the (..gamma.., ..cap alpha../sub 0/) reaction on those nuclei has the following characteristics. When the increasing rate of the product of a complex nucleus formation cross section and ..cap alpha../sub 0/ penetration factor is larger than that of the sum of all penetration factors of possible channels, the cross section of the (..gamma.., ..cap alpha../sub 0/) reaction increases, and takes a peak value when the above two increasing rates agree with each other.

A decision tool for selecting trench cap designs

Energy Technology Data Exchange (ETDEWEB)

Paige, G.B.; Stone, J.J.; Lane, L.J. [USDA-ARS, Tucson, AZ (United States)] [and others

1995-12-31

A computer based prototype decision support system (PDSS) is being developed to assist the risk manager in selecting an appropriate trench cap design for waste disposal sites. The selection of the {open_quote}best{close_quote} design among feasible alternatives requires consideration of multiple and often conflicting objectives. The methodology used in the selection process consists of: selecting and parameterizing decision variables using data, simulation models, or expert opinion; selecting feasible trench cap design alternatives; ordering the decision variables and ranking the design alternatives. The decision model is based on multi-objective decision theory and uses a unique approach to order the decision variables and rank the design alternatives. Trench cap designs are evaluated based on federal regulations, hydrologic performance, cover stability and cost. Four trench cap designs, which were monitored for a four year period at Hill Air Force Base in Utah, are used to demonstrate the application of the PDSS and evaluate the results of the decision model. The results of the PDSS, using both data and simulations, illustrate the relative advantages of each of the cap designs and which cap is the {open_quotes}best{close_quotes} alternative for a given set of criteria and a particular importance order of those decision criteria.

Immunoprecipitation of Tri-methylated Capped RNA.

Science.gov (United States)

Hayes, Karen E; Barr, Jamie A; Xie, Mingyi; Steitz, Joan A; Martinez, Ivan

2018-02-05

Cellular quiescence (also known as G 0 arrest) is characterized by reduced DNA replication, increased autophagy, and increased expression of cyclin-dependent kinase p27 Kip1 . Quiescence is essential for wound healing, organ regeneration, and preventing neoplasia. Previous findings indicate that microRNAs (miRNAs) play an important role in regulating cellular quiescence. Our recent publication demonstrated the existence of an alternative miRNA biogenesis pathway in primary human foreskin fibroblast (HFF) cells during quiescence. Indeed, we have identified a group of pri-miRNAs (whose mature miRNAs were found induced during quiescence) modified with a 2,2,7-trimethylguanosine (TMG)-cap by the trimethylguanosine synthase 1 (TGS1) protein and transported to the cytoplasm by the Exportin-1 (XPO1) protein. We used an antibody against (TMG)-caps (which does not cross-react with the (m 7 G)-caps that most pri-miRNAs or mRNAs contain [Luhrmann et al ., 1982]) to perform RNA immunoprecipitations from total RNA extracts of proliferating or quiescent HFFs. The novelty of this assay is the specific isolation of pri-miRNAs as well as other non-coding RNAs containing a TMG-cap modification.

Poster session ELIPGRID-PC

International Nuclear Information System (INIS)

Davidson, J.R.

1995-01-01

ELIPGRID-PC, a new personal computer program, has been developed to provide easy access to Singer's ELIPGRID algorithm for hot-spot detection probabilities. Three features of the program are the ability to determine: (1) the grid size required for specified conditions, (2) the smallest hot spot that can be sampled with a given probability, and (3) the approximate grid size resulting from specified conditions and sampling cost. ELIPGRID-PC also provides probability of detection versus cost data for graphing with spreadsheets or graphics software. The program has been successfully tested using Singer's published ELIPGRID results. An apparent error in the published ELIPGRID code has been uncovered and an appropriate modification incorporated into the new program

The evolution of the englacial temperature distribution in the superimposed ice zone of a polar ice cap during a summer season

NARCIS (Netherlands)

Greuell, W.; Oerlemans, J.

1989-01-01

The aim of the present investigation was to provide more insight into the processes affecting the evolution of the englacial temperature distribution at a non-temperate location on a glacier. Measurements were made in the top 10 m of the ice at the summit of Laika Ice Cap (Canadian Arctic)

Mapping of p140Cap phosphorylation sites

DEFF Research Database (Denmark)

Repetto, Daniele; Aramu, Simona; Boeri Erba, Elisabetta

2013-01-01

phosphorylation and tunes its interactions with other regulatory molecules via post-translation modification. In this work, using mass spectrometry, we found that p140Cap is in vivo phosphorylated on tyrosine (Y) within the peptide GEGLpYADPYGLLHEGR (from now on referred to as EGLYA) as well as on three serine...... residues. Consistently, EGLYA has the highest score of in silico prediction of p140Cap phosphorylation. To further investigate the p140Cap function, we performed site specific mutagenesis on tyrosines inserted in EGLYA and EPLYA, a second sequence with the same highest score of phosphorylation. The mutant...

Psychrophilic and Psychrotolerant Microbial Extremophiles in Polar Environments

Science.gov (United States)

Hoover, Richard B.; Pikuta, Elena V.

2010-01-01

The microbial extremophiles that inhabit the polar regions of our planet are of tremendous significance. The psychrophilic and psychrotolerant microorganisms, which inhabit all of the cold environments on Earth have important applications to Bioremediation, Medicine, Pharmaceuticals, and many other areas of Biotechnology. Until recently, most of the research on polar microorganisms was confined to studies of polar diatoms, yeast, fungi and cyanobacteria. However, within the past three decades, extensive studies have been conducted to understand the bacteria and archaea that inhabit the Arctic and Antarctic sea-ice, glaciers, ice sheets, permafrost and the cryptoendolithic, cryoconite and ice-bubble environments. These investigations have resulted in the discovery of many new genera and species of anaerobic and aerobic microbial extremophiles. Exotic enzymes, cold-shock proteins and pigments produced by some of the extremophiles from polar environments have the potential to be of great benefit to Mankind. Knowledge about microbial life in the polar regions is crucial to understanding the limitations and biodiversity of life on Earth and may provide valuable clues to the Origin of Life on Earth. The discovery of viable microorganisms in ancient ice from the Fox Tunnel, Alaska and the deep Vostok Ice has shown that microorganisms can remain alive while cryopreserved in ancient ice. The psychrophilic lithoautotrophic homoacetogen isolated from the deep anoxic trough of Lake Untersee is an ideal candidate for life that might inhabit comets or the polar caps of Mars. The spontaneous release of gas from within the Anuchin Glacier above Lake Untersee may provide clues to the ice geysers that erupt from the tiger stripe regions of Saturn s moon Enceladus. The methane productivity in the lower regimes of Lake Untersee may also provide insights into possible mechanisms for the recently discovered methane releases on Mars. Since most of the other water bearing bodies of our

PC-Reactor-core transient simulation code

International Nuclear Information System (INIS)

Nakata, H.

1989-10-01

PC-REATOR, a reactor core transient simulation code has been developed for the real-time operator training on a IBM-PC microcomputer. The program presents capabilities for on-line exchange of the operating parameters during the transient simulation, by friendly keyboard instructions. The model is based on the point-kinetics approximation, with 2 delayed neutron percursors and up to 11 decay power generating groups. (author) [pt

ATLAS end-caps 
on the move

CERN Multimedia

2007-01-01

Two delicate and spectacular transport operations have been performed for ATLAS in recent weeks: the first end-cap tracker was installed in its final position, and one of the huge end-caps of the toroid magnet was moved to the top of the experiment’s shaft.

CAPS OpenACC Compilers: Performance and Portability

CERN Multimedia

CERN. Geneva

2013-01-01

The announcement late 2011 of the new OpenACC directive-based programming standard supported by CAPS, CRAY and PGI compilers has open up the door to more scientific applications that can be ported on many-core systems. Following a porting methodology, this talk will first review the principles of programming with OpenACC and then the advanced features available in the CAPS compilers to further optimize OpenACC applications: library integration, tuning directives with auto-tune mechanisms to build applications adaptive to different GPUs. CAPS compilers use hardware vendors' backends such as NVIDIA CUDA and OpenCL making them the only OpenACC compilers supporting various many-core architectures. About the speaker Stéphane Bihan is co-funder and currently Director of Sales and Marketing at CAPS enterprise. He has held several R&D positions in companies such as ARC international plc in London, Canon Research Center France, ACE compiler experts in Amsterdam and the INRIA r...

In vitro antibacterial activity of a novel resin-based pulp capping material containing the quaternary ammonium salt MAE-DB and Portland cement.

Science.gov (United States)

Yang, Yanwei; Huang, Li; Dong, Yan; Zhang, Hongchen; Zhou, Wei; Ban, Jinghao; Wei, Jingjing; Liu, Yan; Gao, Jing; Chen, Jihua

2014-01-01

Vital pulp preservation in the treatment of deep caries is challenging due to bacterial infection. The objectives of this study were to synthesize a novel, light-cured composite material containing bioactive calcium-silicate (Portland cement, PC) and the antimicrobial quaternary ammonium salt monomer 2-methacryloxylethyl dodecyl methyl ammonium bromide (MAE-DB) and to evaluate its effects on Streptococcus mutans growth in vitro. The experimental material was prepared from a 2 : 1 ratio of PC mixed with a resin of 2-hydroxyethylmethacrylate, bisphenol glycerolate dimethacrylate, and triethylene glycol dimethacrylate (4 : 3 : 1) containing 5 wt% MAE-DB. Cured resin containing 5% MAE-DB without PC served as the positive control material, and resin without MAE-DB or PC served as the negative control material. Mineral trioxide aggregate (MTA) and calcium hydroxide (Dycal) served as commercial controls. S. mutans biofilm formation on material surfaces and growth in the culture medium were tested according to colony-forming units (CFUs) and metabolic activity after 24 h incubation over freshly prepared samples or samples aged in water for 6 months. Biofilm formation was also assessed by Live/Dead staining and scanning electron microscopy. S. mutans biofilm formation on the experimental material was significantly inhibited, with CFU counts, metabolic activity, viability staining, and morphology similar to those of biofilms on the positive control material. None of the materials affected bacterial growth in solution. Contact-inhibition of biofilm formation was retained by the aged experimental material. Significant biofilm formation was observed on MTA and Dycal. The synthesized material containing HEMA-BisGMA-TEGDMA resin with MAE-DB as the antimicrobial agent and PC to support mineralized tissue formation inhibited S. mutans biofilm formation even after aging in water for 6 months, but had no inhibitory effect on bacteria in solution. Therefore, this material shows

Effects of the strain relaxation of an AlGaN barrier layer induced by various cap layers on the transport properties in AlGaN/GaN heterostructures

International Nuclear Information System (INIS)

Liu Zi-Yang; Zhang Jin-Cheng; Duan Huan-Tao; Xue Jun-Shuai; Lin Zhi-Yu; Ma Jun-Cai; Xue Xiao-Yong; Hao Yue

2011-01-01

The strain relaxation of an AlGaN barrier layer may be influenced by a thin cap layer above, and affects the transport properties of AlGaN/GaN heterostructures. Compared with the slight strain relaxation found in AlGaN barrier layer without cap layer, it is found that a thin cap layer can induce considerable changes of strain state in the AlGaN barrier layer. The degree of relaxation of the AlGaN layer significantly influences the transport properties of the two-dimensional electron gas (2DEG) in AlGaN/GaN heterostructures. It is observed that electron mobility decreases with the increasing degree of relaxation of the AlGaN barrier, which is believed to be the main cause of the deterioration of crystalline quality and morphology on the AlGaN/GaN interface. On the other hand, both GaN and AlN cap layers lead to a decrease in 2DEG density. The reduction of 2DEG caused by the GaN cap layer may be attributed to the additional negative polarization charges formed at the interface between GaN and AlGaN, while the reduction of the piezoelectric effect in the AlGaN layer results in the decrease of 2DEG density in the case of AlN cap layer. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Wind blade spar cap and method of making

Science.gov (United States)

Mohamed, Mansour H [Raleigh, NC

2008-05-27

A wind blade spar cap for strengthening a wind blade including an integral, unitary three-dimensional woven material having a first end and a second end, corresponding to a root end of the blade and a tip end of the blade, wherein the material tapers in width from the first to the second end while maintaining a constant thickness and decreasing weight therebetween, the cap being capable of being affixed to the blade for providing increased strength with controlled variation in weight from the root end to the tip end based upon the tapered width of the material thereof. The present inventions also include the method of making the wind blade spar cap and a wind blade including the wind blade spar cap.

State-of-the-art synthetic membrane for capping landfills

International Nuclear Information System (INIS)

Kriofske, K.P.; Gagle, D.W.

1991-01-01

Very Low Density Polyethylene (VLDPE) has emerged as a superior capping material for landfill closures. Landfills must be capped by a material which will undergo substantial deformation in areas of localized settlement prior to rupture. Methane and hydrogen sulfide gases must be contained and directed to collection points without permeating the landfill cap. Vegetative growth in the cover sods will be protected by the gas impermeability of the geosynthetic membrane. VLDPE compounded with carbon black is minimally affected by radiation and is inert to ultraviolet rays. This property sustains VLDPE's ability to retard gas permeation at levels superior to other geosynthetics. Cover soil stability on long cap slopes in all weather conditions is crucial. It has been demonstrated in the laboratory and in full-scale, on-site test conditions that VLDPE exhibits friction characteristics equaling or exceeding other synthetics used for this purpose without diminishing physical and chemical properties. Large-scale, multiaxial stress tests have demonstrated the ability of VLDPE to deflect substantially in all directions of a potential settlement area. Only PVC can equal the elastic deformation properties of VLDPE, but PVC is more gas-permeable susceptible to degradation due to natural soil radiation or ultraviolet light and heat. Test results are presented to illustrate these points. The geosynthetic cap membrane must prevent water percolation into the landfill to prevent the formation of hazardous leachates. The use of a VLDPE cap reduces the depth of cap soils, thus increasing landfill volume. The economics and reduction in long-term liabilities of closure costs are enhanced by the use of VLDPE in the cap system. Since the expected half-life of polyethylene exceeds hundreds of years, the inclusion of VLDPE in the cap system will provide pollution security for many generations

IBM-PC-based reactor neutronics analysis package

International Nuclear Information System (INIS)

Nigg, D.W.; Wessol, D.E.; Grimesey, R.A.; Parsons, D.K.; Wheeler, F.J.; Yoon, W.Y.; Lake, J.A.

1985-01-01

Technical advances over the past few years have led to a situation where a wide range of complex scientific computations can now be done on properly configured microcomputers such as the IBM-PC (personal computer). For a number of reasons, including security, economy, and user convenience, the development of a comprehensive system of reactor neutronics codes suitable for operation on the IBM-PC has been undertaken at the Idaho National Engineering Laboratory (INEL). It is anticipated that a PC-based code system could also have wide applicability in the nuclear engineering education community since conversion of software generated by national laboratories and others to college and university mainframe hardware has historically been a time-consuming process that has sometimes met with only limited success. This paper discusses the philosophy behind the INEL reactor neutronics PC code system and describes those parts of the system that are currently complete, those that are now under development, and those that are still in the planning stage

Truncated Dual-Cap Nucleation Site Development

Science.gov (United States)

Matson, Douglas M.; Sander, Paul J.

2012-01-01

During heterogeneous nucleation within a metastable mushy-zone, several geometries for nucleation site development must be considered. Traditional spherical dual cap and crevice models are compared to a truncated dual cap to determine the activation energy and critical cluster growth kinetics in ternary Fe-Cr-Ni steel alloys. Results of activation energy results indicate that nucleation is more probable at grain boundaries within the solid than at the solid-liquid interface.

Standard and alternative landfill capping design in Germany

International Nuclear Information System (INIS)

Simon, Franz-Georg; Mueller, Werner W.

2004-01-01

Engineered capping systems are in most cases an indispensable and often the only efficient component required by the long-term safety concept for landfills, mine tailings tips and contaminated land. In Germany the composite liner is the main component of standard landfill cappings for municipal and hazardous waste landfills and the compacted clay liner (CCL) for landfills for inert or low-contamination waste. The composite liner is a technically highly effective but very expensive system. Research and experience has given rise to concern about the proper long-term performance of a conventional single CCL as a landfill capping. Therefore, alternative capping systems are discussed and applied for landfills and for the containment of contaminated sites. This paper gives an overview on various alternative engineered cappings and suitable systems for capping reflecting the state of the art and the expert view in Germany. According to the European Council Directive on the landfill of waste an impermeable mineral layer is recommended for the surface sealing of non-hazardous landfills and a composition of artificial sealing liner and impermeable mineral layer for hazardous landfills. In both cases a drainage layer thickness of at least 0.5 m is suggested. These recommendations should be interpreted flexibly and to some extent modified in the light of the experience and results presented in this paper

Following the south polar cap recession as viewed by OMEGA/MEX using automatic detection of H2O and CO2 ices.

Science.gov (United States)

Schmidt, F.; Doute, S.; Schmitt, B.

In order to understand Mars' current climate it is necessary to detect, characterize and monitor CO2 and H2O at the surface (permanent and seasonal icy deposits) and in the atmosphere (vapor and clouds). Here we will focus on the South Seasonal Polar Cap (SSPC) whose recession was previously observed with different techniques : from earth in the visible range with HST [James 1996], or from MGS spacecraft with MOC images [Benson 2005], in the thermal IR range by the TES [Kieffer 2000], in the near infrared by OMEGA/MEX [Langevin submitted]. The time and space evolutions of the SSPC is a major annual climatic signal both at the global and the regional scales. In particular the measurement of the temporal and spatial distributions of CO2 constrains exchange processes between both surface and atmosphere. This exchange may involve preponderant species : H2O, CO2 and dust. In this work we will apply a new detection technique : "wavanglet" in order to follow the recession of the SSPC thanks to OMEGA/MEX observations. This method was especially developed in the goal to classify a huge dataset, such OMEGA ones. We propose to use "wavanglet" as a supervised automatic classification method that identifies spectral features and classifies the image in spectrally homogeneous units. Additionally we will evaluate quantitative detection limits of "wavanglet" based on synthetic dataset simulating OMEGA spectra in typical situation of the SSPC. This detection limit will be discussed in terms of abundance for H2O and CO2 ices in order to improve the interpretation of the classification. Finally we will present the recession of the SSPC using "wavanglet" and we will compare the results with those of earlier investigation. An interpretation of the similarities and disagreements between those maps will be done.

Temperature Distribution within a Cold Cap during Nuclear Waste Vitrification.

Science.gov (United States)

Dixon, Derek R; Schweiger, Michael J; Riley, Brian J; Pokorny, Richard; Hrma, Pavel

2015-07-21

The kinetics of the feed-to-glass conversion affects the waste vitrification rate in an electric glass melter. The primary area of interest in this conversion process is the cold cap, a layer of reacting feed on top of the molten glass. The work presented here provides an experimental determination of the temperature distribution within the cold cap. Because direct measurement of the temperature field within the cold cap is impracticable, an indirect method was developed in which the textural features in a laboratory-made cold cap with a simulated high-level waste feed were mapped as a function of position using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. The temperature distribution within the cold cap was established by correlating microstructures of cold-cap regions with heat-treated feed samples of nearly identical structures at known temperatures. This temperature profile was compared with a mathematically simulated profile generated by a cold-cap model that has been developed to assess the rate of glass production in a melter.

20 CFR 606.21 - Criteria for cap.

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Criteria for cap. 606.21 Section 606.21 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TAX CREDITS UNDER THE... Reduction § 606.21 Criteria for cap. (a) Reduction in unemployment tax effort. (1) For purposes of paragraph...

Prostate carcinoma (PC) - an organ-related specific pathological neoplasm; Prostatakarzinom (PC) - eine organspezifische Neoplasie aus der Sicht der Pathologie

Energy Technology Data Exchange (ETDEWEB)

Massmann, J.; Funk, A. [Gemeinschaftspraxis Pathologie Massmann-Funk-Dettmar, Muenchen (Germany); Altwein, J. [Krankenhaus der Barmherzigen Brueder, Muenchen (Germany); Praetorius, M.

2003-06-01

The organ- and tumour-related specific characteristics of prostate carcinoma (PC) are presented in an overview under various aspects. It is the key for understanding pathological changes, including PC, to consider the subdivision of the prostate into anatomically and functionally distinguishable zones, especially the transitional zone (TZ) and the peripheral zone (PZ). The pseudoneoplastic hyperplasia of the TZ, combined with inflammatory consequences and age-related changes, forms a differential diagnostic challenge to both clinico-radiological diagnosis and macroscopic and microscopic examination. High-degree prostatic intra-epithelial neoplasia (PIN III) and atypical adenomatous hyperplasia (AAH) are presented as precursor lesions of PC with varying significance and assessment. Moreover, there are discussed the following characteristic features of PC: localisation types, focality, volume, progression, double-graduation according to Gleason, tumour stage, and prognosis. The most important prognosis factors of PC (category I) include the categories of the TNM system, such as stage, surgical marginal situation, degree and also the preoperative PSA level as a (poor) substitute for the tumour volume. Potential prognosis parameters (category II) show the tumour volume and the DNS ploidy, while there continues to exist a large number of non-established parameters (category III). The prognostic validity of the pathological examinations depends, on the one hand, on the tissue extent (needle biopsy, transurethral resection (TURP), so-called simple prostatectomy, radical prostatectomy (RPE)) and the prostate zones covered. On the other hand, the prognostic certainty also depends on the tumour-adequate macroscopic and microscopic assessment of an RPE that can only be a partial or complete handling in transversal large-area sections. (orig.) [German] Die organ- und tumorspezifischen Besonderheiten des Prostatakarzinoms (PC) werden in einer Uebersicht unter verschiedenen

Development of CAP code for nuclear power plant containment: Lumped model

Energy Technology Data Exchange (ETDEWEB)

Hong, Soon Joon, E-mail: sjhong90@fnctech.com [FNC Tech. Co. Ltd., Heungdeok 1 ro 13, Giheung-gu, Yongin-si, Gyeonggi-do 446-908 (Korea, Republic of); Choo, Yeon Joon; Hwang, Su Hyun; Lee, Byung Chul [FNC Tech. Co. Ltd., Heungdeok 1 ro 13, Giheung-gu, Yongin-si, Gyeonggi-do 446-908 (Korea, Republic of); Ha, Sang Jun [Central Research Institute, Korea Hydro & Nuclear Power Company, Ltd., 70, 1312-gil, Yuseong-daero, Yuseong-gu, Daejeon 305-343 (Korea, Republic of)

2015-09-15

Highlights: • State-of-art containment analysis code, CAP, has been developed. • CAP uses 3-field equations, water level oriented upwind scheme, local head model. • CAP has a function of linked calculation with reactor coolant system code. • CAP code assessments showed appropriate prediction capabilities. - Abstract: CAP (nuclear Containment Analysis Package) code has been developed in Korean nuclear society for the analysis of nuclear containment thermal hydraulic behaviors including pressure and temperature trends and hydrogen concentration. Lumped model of CAP code uses 2-phase, 3-field equations for fluid behaviors, and has appropriate constitutive equations, 1-dimensional heat conductor model, component models, trip and control models, and special process models. CAP can run in a standalone mode or a linked mode with a reactor coolant system analysis code. The linked mode enables the more realistic calculation of a containment response and is expected to be applicable to a more complicated advanced plant design calculation. CAP code assessments were carried out by gradual approaches: conceptual problems, fundamental phenomena, component and principal phenomena, experimental validation, and finally comparison with other code calculations on the base of important phenomena identifications. The assessments showed appropriate prediction capabilities of CAP.

Development of CAP code for nuclear power plant containment: Lumped model

International Nuclear Information System (INIS)

Hong, Soon Joon; Choo, Yeon Joon; Hwang, Su Hyun; Lee, Byung Chul; Ha, Sang Jun

2015-01-01

Highlights: • State-of-art containment analysis code, CAP, has been developed. • CAP uses 3-field equations, water level oriented upwind scheme, local head model. • CAP has a function of linked calculation with reactor coolant system code. • CAP code assessments showed appropriate prediction capabilities. - Abstract: CAP (nuclear Containment Analysis Package) code has been developed in Korean nuclear society for the analysis of nuclear containment thermal hydraulic behaviors including pressure and temperature trends and hydrogen concentration. Lumped model of CAP code uses 2-phase, 3-field equations for fluid behaviors, and has appropriate constitutive equations, 1-dimensional heat conductor model, component models, trip and control models, and special process models. CAP can run in a standalone mode or a linked mode with a reactor coolant system analysis code. The linked mode enables the more realistic calculation of a containment response and is expected to be applicable to a more complicated advanced plant design calculation. CAP code assessments were carried out by gradual approaches: conceptual problems, fundamental phenomena, component and principal phenomena, experimental validation, and finally comparison with other code calculations on the base of important phenomena identifications. The assessments showed appropriate prediction capabilities of CAP

Polar ionospheric responses to solar wind IMF changes

Directory of Open Access Journals (Sweden)

Y. Zhang

Full Text Available Auroral and airglow emissions over Eureka (89^° CGM during the 1997-98 winter show striking variations in relation to solar wind IMF changes. The period January 19 to 22, 1998, was chosen for detailed study, as the IMF was particularly strong and variable. During most of the period, B_z was northward and polar arcs were observed. Several overpasses by DMSP satellites during the four day period provided a clear picture of the particle precipitation producing the polar arcs. The spectral character of these events indicated excitation by electrons of average energy 300 to 500 eV. Only occasionally were electrons of average energy up to ~1 keV observed and these appeared transitory from the ground optical data. It is noted that polar arcs appear after sudden changes in IMF B_y, suggesting IMF control over arc initiation. When B_y is positive there is arc motion from dawn to dusk, while B_y is negative the motion is consistently dusk to dawn. F-region (anti-sunward convections were monitored through the period from 630.0 nm emissions. The convection speed was low (100-150 m/s when B_z was northward but increased to 500 m/s after B_z turned southward on January 20.

Key words: Atmospheric composition and structure (airglow and aurora - Ionosphere (particle precipitation - Magnetospheric Physics (polar cap phenomena

Survey of Enabling Technologies for CAPS

Science.gov (United States)

Antol, Jeffrey; Mazanek, Daniel D.; Koons, Robert H.

2005-01-01

The enabling technologies required for the development of a viable Comet/Asteroid Protection System (CAPS) can be divided into two principal areas: detection and deflection/orbit modification. With the proper funding levels, many of the technologies needed to support a CAPS architecture could be achievable within the next 15 to 20 years. In fact, many advanced detection technologies are currently in development for future in-space telescope systems such as the James Webb Space Telescope (JWST), formerly known as the Next Generation Space Telescope. It is anticipated that many of the JWST technologies would be available for application for CAPS detection concepts. Deflection/orbit modification technologies are also currently being studied as part of advanced power and propulsion research. However, many of these technologies, such as extremely high-output power systems, advanced propulsion, heat rejection, and directed energy systems, would likely be farther term in availability than many of the detection technologies. Discussed subsequently is a preliminary examination of the main technologies that have been identified as being essential to providing the element functionality defined during the CAPS conceptual study. The detailed requirements for many of the technology areas are still unknown, and many additional technologies will be identified as future in-depth studies are conducted in this area.

Study of MPI based on parallel MOM on PC clusters for EM-beam scattering by 2-D PEC rough surfaces

International Nuclear Information System (INIS)

Jun, Ma; Li-Xin, Guo; An-Qi, Wang

2009-01-01

This paper firstly applies the finite impulse response filter (FIR) theory combined with the fast Fourier transform (FFT) method to generate two-dimensional Gaussian rough surface. Using the electric field integral equation (EFIE), it introduces the method of moment (MOM) with RWG vector basis function and Galerkin's method to investigate the electromagnetic beam scattering by a two-dimensional PEC Gaussian rough surface on personal computer (PC) clusters. The details of the parallel conjugate gradient method (CGM) for solving the matrix equation are also presented and the numerical simulations are obtained through the message passing interface (MPI) platform on the PC clusters. It finds significantly that the parallel MOM supplies a novel technique for solving a two-dimensional rough surface electromagnetic-scattering problem. The influences of the root-mean-square height, the correlation length and the polarization on the beam scattering characteristics by two-dimensional PEC Gaussian rough surfaces are finally discussed. (classical areas of phenomenology)

Investigasi Serangan Malware Njrat Pada PC

Directory of Open Access Journals (Sweden)

Devi Rizky Septiani

2016-12-01

Full Text Available Malware merupakan salah satu bentuk dari kejahatan komputer yang terjadi pada sebuah sistem jaringan komputer, malware Njrat termasuk jenis Trojan horse. Trojan adalah salah satu jenis malware yang ikut berkembang di dalamnya, yang memungkinkan attacker masuk ke dalam sistem tanpa diketahui oleh pemilik. Penggunaan trojan saat ini lebih ke arah kejahatan dunia maya (cyber crime, salah satu dari malware yang sangat berbahaya karena besarnya dampak kerugian yang ditimbulkan, mulai dari pencurian data penting sampai mengubah hak akses pada PC korban. Sasaran terbanyak penybaran trojan adalah pengguna sistem operasi windows. Penyebaran trojan ini dilakukan dengan metode social engineering, yaitu teknik yang menggunakan kelemahan manusia, sehingga user tanpa curiga langsung mengeksekusi sebuah program yang tidak dikenal.  Aktivitas malware berkaitan erat dengan  performa PC dan juga aktifitas network pada system computer. Penelitian ini bertujuan untuk mengetahui cara kerja malware Njrat dan melakukan investigasi terhadap performa pada system computer. Metodologi yang digunakan dynamic analysis dengan melakukan analisa malware pada suatu sistem dan melihat aktivitas atau proses yang diaktifkan oleh malware tersebut. Dampak perubahan yang terjadi pada PC Target terlihat pada performa masing-masing PC yang telah disisipkan malware. Kata kunci            Malware, Njrat, System computer

CMS end-cap yoke at the detector's assembly site.

CERN Multimedia

Patrice Loïez

2002-01-01

The magnetic flux generated by the superconducting coil in the CMS detector is returned via an iron yoke comprising three end-cap discs at each end (end-cap yoke) and five concentric cylinders (barrel yoke). This picture shows the first of three end-cap discs (red) seen through the outer cylinder of the vacuum tank which will house the superconducting coil.

Multi-satellite study of the excitation of Pc3 and Pc4-5 ULF waves and their penetration across the plasmapause during the 2003 Halloween superstorm

Science.gov (United States)

Balasis, G.; Daglis, I. A.; Mann, I. R.; Papadimitriou, C.; Zesta, E.; Georgiou, M.; Haagmans, R.; Tsinganos, K.

2015-10-01

We use multi-satellite and ground-based magnetic data to investigate the concurrent characteristics of Pc3 (22-100 mHz) and Pc4-5 (1-22 mHz) ultra-low-frequency (ULF) waves on the 31 October 2003 during the Halloween magnetic superstorm. ULF waves are seen in the Earth's magnetosphere, topside ionosphere, and Earth's surface, enabling an examination of their propagation characteristics. We employ a time-frequency analysis technique and examine data from when the Cluster and CHAMP spacecraft were in good local time (LT) conjunction near the dayside noon-midnight meridian. We find clear evidence of the excitation of both Pc3 and Pc4-5 waves, but more significantly we find a clear separation in the L shell of occurrence of the Pc4-5 and Pc3 waves in the equatorial inner magnetosphere, separated by the density gradients at the plasmapause boundary layer. A key finding of the wavelet spectral analysis of data collected from the Geotail, Cluster, and CHAMP spacecraft and the CARISMA and GIMA magnetometer networks was a remarkably clear transition of the waves' frequency into dominance in a higher-frequency regime within the Pc3 range. Analysis of the local field line resonance frequency suggests that the separation of the Pc4-5 and Pc3 emissions across the plasmapause is consistent with the structure of the inhomogeneous field line resonance Alfvén continuum. The Pc4-5 waves are consistent with direct excitation by the solar wind in the plasma trough, as well as Pc3 wave absorption in the plasmasphere following excitation by upstream waves originating at the bow shock in the local noon sector. However, despite good solar wind coverage, our study was not able to unambiguously identify a clear explanation for the sharp universal time (UT) onset of the discrete frequency and large-amplitude Pc3 wave power.

Extended high circular polarization in the Orion massive star forming region: implications for the origin of homochirality in the solar system.

Science.gov (United States)

Fukue, Tsubasa; Tamura, Motohide; Kandori, Ryo; Kusakabe, Nobuhiko; Hough, James H; Bailey, Jeremy; Whittet, Douglas C B; Lucas, Philip W; Nakajima, Yasushi; Hashimoto, Jun

2010-06-01

We present a wide-field (approximately 6' x 6') and deep near-infrared (K(s) band: 2.14 mum) circular polarization image in the Orion nebula, where massive stars and many low-mass stars are forming. Our results reveal that a high circular polarization region is spatially extended (approximately 0.4 pc) around the massive star-forming region, the BN/KL nebula. However, other regions, including the linearly polarized Orion bar, show no significant circular polarization. Most of the low-mass young stars do not show detectable extended structure in either linear or circular polarization, in contrast to the BN/KL nebula. If our solar system formed in a massive star-forming region and was irradiated by net circularly polarized radiation, then enantiomeric excesses could have been induced, through asymmetric photochemistry, in the parent bodies of the meteorites and subsequently delivered to Earth. These could then have played a role in the development of biological homochirality on Earth.

Impact Response Study on Covering Cap of Aircraft Big-Size Integral Fuel Tank

Science.gov (United States)

Wang, Fusheng; Jia, Senqing; Wang, Yi; Yue, Zhufeng

2016-10-01

In order to assess various design concepts and choose a kind of covering cap design scheme which can meet the requirements of airworthiness standard and ensure the safety of fuel tank. Using finite element software ANSYS/LS- DYNA, the impact process of covering cap of aircraft fuel tank by projectile were simulated, in which dynamical characteristics of simple single covering cap and gland double-layer covering cap impacted by titanium alloy projectile and rubber projectile were studied, as well as factor effects on simple single covering cap and gland double-layer covering cap under impact region, impact angle and impact energy were also studied. Though the comparison of critical damage velocity and element deleted number of the covering caps, it shows that the external covering cap has a good protection effect on internal covering cap. The regions close to boundary are vulnerable to appear impact damage with titanium alloy projectile while the regions close to center is vulnerable to occur damage with rubber projectile. Equivalent strain in covering cap is very little when impact angle is less than 15°. Element deleted number in covering cap reaches the maximum when impact angle is between 60°and 65°by titanium alloy projectile. While the bigger the impact angle and the more serious damage of the covering cap will be when rubber projectile impact composite covering cap. The energy needed for occurring damage on external covering cap and internal covering cap is less than and higher than that when single covering cap occur damage, respectively. The energy needed for complete breakdown of double-layer covering cap is much higher than that of single covering cap.

Radio-continuum study of the supernova remnants in the large Magellanic Cloud: An SNR with a highly polarized breakout region: SNR J0455-6838

Directory of Open Access Journals (Sweden)

Crawford E.J.

2008-01-01

Full Text Available We present the results of new moderate resolution ATCA observations of SNR J0455-6838. We found that this SNR exhibits a mostly typical appearance with rather steep and curved α=-0.81±0.18 and D=43×31±1 pc. Regions of high polarization were detected, including unusually strong (~70% region corresponding to the northern breakout. Such a strong polarization in breakout regions has not been observed in any other SNR.

Facially amphiphilic thiol capped gold and silver nanoparticles

Indian Academy of Sciences (India)

Abstract. A series of bile acid-derived facially amphiphilic thiols have been used to cap sliver and gold nanoparticles. The self-assembling properties of these steroid-capped nanoparticles have been investigated and reported in this article.

Port virtual addressing for PC

International Nuclear Information System (INIS)

Bolanos, L.; Arista, E.; Osorio Deliz, J.F.

1997-01-01

Instruments for nuclear signal measurements based on add-on card for a personal computer (PC) are designed often. Then one faces the problem of the addressing of data input/output devices which show an integration level or intelligence that makes the use of several port address indispensable, and these are limited in the PC. The virtual addressing offers the advantage of the occupation of few addresses to accede to many of these devices. The principles of this technique and the appliances of a solution in radiometric in a radiometric card based on programmed logic are discussed in this paper

Sediment Capping and Natural Recovery, Contaminant Transport Fundamentals With Applications to Sediment Caps

National Research Council Canada - National Science Library

Petrovski, David M; Corcoran, Maureen K; May, James H; Patrick, David M

2005-01-01

Engineered sediment caps and natural recovery are in situ remedial alternatives for contaminated sediments, which consist of the artificial or natural placement of a layer of material over a sediment...

Landscape Evolution and the Reincarnation of the Southern Residual Ice Cap

Science.gov (United States)

Byrne, S.; Zuber, M. T.

2006-10-01

Given the present rate of erosion on the southern residual ice cap, it is unlikely that any part of the cap is older than a few centuries. Unless we're lucky, why is there a residual cap present today for us to observe? We propose a solution involving constant destruction and renewal of the cap.

Analyses of Current And Wave Forces on Velocity Caps

DEFF Research Database (Denmark)

Christensen, Erik Damgaard; Buhrkall, Jeppe; Eskesen, Mark C. D.

2015-01-01

Velocity caps are often used in connection with for instance offshore intake sea water for the use of for cooling water for power plants or as a source for desalinization plants. The intakes can also be used for river intakes. The velocity cap is placed on top of a vertical pipe. The vertical pipe......) this paper investigates the current and wave forces on the velocity cap and the vertical cylinder. The Morison’s force model was used in the analyses of the extracted force time series in from the CFD model. Further the distribution of the inlet velocities around the velocity cap was also analyzed in detail...

Development, genetic mapping and QTL association of cotton PHYA, PHYB, and HY5-specific CAPS and dCAPS markers

Science.gov (United States)

Among SNP markers that become increasingly valuable in molecular breeding of crop plants are the CAP and dCAP markers derived from the genes of interest. To date, the number of such gene-based markers is small in polyploid crop plants such as tetraploid cotton that has A and D subgenomes. The obje...

Preventing Thin Film Dewetting via Graphene Capping.

Science.gov (United States)

Cao, Peigen; Bai, Peter; Omrani, Arash A; Xiao, Yihan; Meaker, Kacey L; Tsai, Hsin-Zon; Yan, Aiming; Jung, Han Sae; Khajeh, Ramin; Rodgers, Griffin F; Kim, Youngkyou; Aikawa, Andrew S; Kolaczkowski, Mattew A; Liu, Yi; Zettl, Alex; Xu, Ke; Crommie, Michael F; Xu, Ting

2017-09-01

A monolayer 2D capping layer with high Young's modulus is shown to be able to effectively suppress the dewetting of underlying thin films of small organic semiconductor molecule, polymer, and polycrystalline metal, respectively. To verify the universality of this capping layer approach, the dewetting experiments are performed for single-layer graphene transferred onto polystyrene (PS), semiconducting thienoazacoronene (EH-TAC), gold, and also MoS 2 on PS. Thermodynamic modeling indicates that the exceptionally high Young's modulus and surface conformity of 2D capping layers such as graphene and MoS 2 substantially suppress surface fluctuations and thus dewetting. As long as the uncovered area is smaller than the fluctuation wavelength of the thin film in a dewetting process via spinodal decomposition, the dewetting should be suppressed. The 2D monolayer-capping approach opens up exciting new possibilities to enhance the thermal stability and expands the processing parameters for thin film materials without significantly altering their physical properties. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preform spar cap for a wind turbine rotor blade

Science.gov (United States)

Livingston, Jamie T [Simpsonville, SC; Driver, Howard D [Greer, SC; van Breugel, Sjef [Enschede, NL; Jenkins, Thomas B [Cantonment, FL; Bakhuis, Jan Willem [Nijverdal, NL; Billen, Andrew J [Daarlerveen, NL; Riahi, Amir [Pensacola, FL

2011-07-12

A spar cap for a wind turbine rotor blade. The spar cap may include multiple preform components. The multiple preform components may be planar sheets having a swept shape with a first end and a second end. The multiple preform components may be joined by mating the first end of a first preform component to the second end of a next preform component, forming the spar cap.

PC based 8K multichannel analyser for nuclear spectroscopy

International Nuclear Information System (INIS)

Jain, S.K.; Gupta, J.D.; Suman Kumari, B.

1989-01-01

An IBM-PC based 8K multichannel analyser(MCA) has been developed which incorporates all the features of an advanced system like very high throughput for data acquisition in PHA as well as MCS modes, fast real-time display, extensive display manipulation facilities, various present controls and concurrent data processing. The compact system hardware consists of a 2 bit wide NIM module and a PC add-on card. Because of external acquisition hardware, the system after initial programming by PC can acquire data independently allowing the PC to be switched off. To attain very high throughput, the most desirable feature of an MCA, a dual-port memory architecture has been used. The asymmetric dual-port RAM, housed in the NIM module offers 24 bit parallel access to the ADC and 8 bit wide access to PC which results in fast real-time histogramic display on the monitor. PC emulation software is menu driven and user friendly. It integrates a comprehensive set of commonly required application routines for concurrent data processing. After the transfer of know-how to the Electronic Corporation of India Ltd. (ECIL), this system is bein g produced at ECIL. (author). 5 refs., 4 figs

Numerical estimates of the maximum sustainable pore pressure in anticline formations using the tensor based concept of pore pressure-stress coupling

Directory of Open Access Journals (Sweden)

Andreas Eckert

2015-02-01

Full Text Available The advanced tensor based concept of pore pressure-stress coupling is used to provide pre-injection analytical estimates of the maximum sustainable pore pressure change, ΔPc, for fluid injection scenarios into generic anticline geometries. The heterogeneous stress distribution for different prevailing stress regimes in combination with the Young's modulus (E contrast between the injection layer and the cap rock and the interbedding friction coefficient, μ, may result in large spatial and directional differences of ΔPc. A single value characterizing the cap rock as for horizontal layered injection scenarios is not obtained. It is observed that a higher Young's modulus in the cap rock and/or a weak mechanical coupling between layers amplifies the maximum and minimum ΔPc values in the valley and limb, respectively. These differences in ΔPc imposed by E and μ are further amplified by different stress regimes. The more compressional the stress regime is, the larger the differences between the maximum and minimum ΔPc values become. The results of this study show that, in general compressional stress regimes yield the largest magnitudes of ΔPc and extensional stress regimes provide the lowest values of ΔPc for anticline formations. Yet this conclusion has to be considered with care when folded anticline layers are characterized by flexural slip and the friction coefficient between layers is low, i.e. μ = 0.1. For such cases of weak mechanical coupling, ΔPc magnitudes may range from 0 MPa to 27 MPa, indicating imminent risk of fault reactivation in the cap rock.

Chemical synthesis of highly size-confined triethylamine-capped ...

Indian Academy of Sciences (India)

2018-03-23

Mar 23, 2018 ... TiO2 nanoparticles and its dye-sensitized solar cell performance .... Figure 5. Formation mechanism of TEA-capped and uncapped TiO2 nanoparticles. ... this research work, synthesized TEA-capped TiO2 nanopar- ticles were ...

Physical and Mechanical Characteristics of Kevlar Fiber-Reinforced PC/ABS Composites

Directory of Open Access Journals (Sweden)

Kuljira Sujirote

2012-01-01

Full Text Available In this research, the composites between polycarbonate (PC and acrylonitrile-butadiene-styrene (ABS alloy and Kevlar fiber were prepared. The flexural and tensile properties of PC/ABS alloy and its composites were determined using a universal testing machine. The synergistic behavior of flexural modulus was observed for all regions of PC contents, while the synergism of flexural strength and tensile strength were found in some PC contents. It was found that the optimum weight ratio of PC:ABS was 60:40. In the Kevlar Fiber-reinforced PC/ABS composite system at PC:ABS of 60:40, both flexural modulus and strength were increased with matrix contents. Additionally, the flexural strength drastically increased with the matrix content and then reached the maximum value of 167 MPa at the matrix content of 33.4 wt%. The results from peel test, water contact measurement, and scanning electron microscopy (SEM reveal that the interfacial adhesion between the Kevlar fiber and the polymer matrix could be improved by increasing the PC content in the matrix.

Analysis of Dynamic Stiffness of Bridge Cap-Pile System

Directory of Open Access Journals (Sweden)

Jinhui Chu

2018-01-01

Full Text Available In order to investigate the applicability of dynamic stiffness for bridge cap-pile system, a laboratory test was performed. A numerical model was also built for this type of system. The impact load was applied on the cap top and the dynamic stiffness was analysed. Then, the effect of the effective friction area between pile and soil was also considered. Finally, the dynamic stiffness relationship between the single pile and the cap-pile system was also compared. The results show that the dynamic stiffness is a sensitive index and can well reflect the static characteristics of the pile at the elastic stage. There is a significant positive correlation between the vertical dynamic stiffness index and bearing capacity of the cap-pile system in the similar formation environment. For the cap-pile system with four piles, the dynamic stiffness is about four times as large as the single pile between 10 and 20 Hz.

Design of multichannel counting system for IBM PC and compatibles

International Nuclear Information System (INIS)

Majeed, B.; Ahmad, Z.; Osman, A.; Ysain, M.M.

1995-07-01

A Multichannel Counting System (MCCS), based on IBM-PC and compatible computer systems have been designed. The MCCS consists of a Multichannel Counting System plug-in interface card (MCCS-PC) for IBM PC and compatibles and a NIM-BIN module (MCCS-NB). The MCCS-PC provides simultaneous monitoring of upto seven independent SCA type inputs. An on board programmable timer provides elapsed time measurement. A menu-driven program for data acquisition and timer control has also been developed. (author) 8 figs

Multi-satellite study of the excitation of Pc3 and Pc4-5 ULF waves and their penetration across the plasmapause during the 2003 Halloween superstorm

Directory of Open Access Journals (Sweden)

G. Balasis

2015-10-01

Full Text Available We use multi-satellite and ground-based magnetic data to investigate the concurrent characteristics of Pc3 (22–100 mHz and Pc4-5 (1–22 mHz ultra-low-frequency (ULF waves on the 31 October 2003 during the Halloween magnetic superstorm. ULF waves are seen in the Earth's magnetosphere, topside ionosphere, and Earth's surface, enabling an examination of their propagation characteristics. We employ a time–frequency analysis technique and examine data from when the Cluster and CHAMP spacecraft were in good local time (LT conjunction near the dayside noon–midnight meridian. We find clear evidence of the excitation of both Pc3 and Pc4-5 waves, but more significantly we find a clear separation in the L shell of occurrence of the Pc4-5 and Pc3 waves in the equatorial inner magnetosphere, separated by the density gradients at the plasmapause boundary layer. A key finding of the wavelet spectral analysis of data collected from the Geotail, Cluster, and CHAMP spacecraft and the CARISMA and GIMA magnetometer networks was a remarkably clear transition of the waves' frequency into dominance in a higher-frequency regime within the Pc3 range. Analysis of the local field line resonance frequency suggests that the separation of the Pc4-5 and Pc3 emissions across the plasmapause is consistent with the structure of the inhomogeneous field line resonance Alfvén continuum. The Pc4-5 waves are consistent with direct excitation by the solar wind in the plasma trough, as well as Pc3 wave absorption in the plasmasphere following excitation by upstream waves originating at the bow shock in the local noon sector. However, despite good solar wind coverage, our study was not able to unambiguously identify a clear explanation for the sharp universal time (UT onset of the discrete frequency and large-amplitude Pc3 wave power.

El blindaje de una PC

Directory of Open Access Journals (Sweden)

Revista Chasqui

2015-01-01

Full Text Available La navegación en Internet y la consiguiente conexión a una red expone a una computadora a un sinfín de riesgos y peligros. Una PC que no sea utilizada para navegar en Internet o que no esté conectada a una red puede,incluso, ser también afectada por virus, por la utilización de disquetes contaminados que la contaminen con un virus. Para enfrentar esos problemas, la industria informática ha previsto una serie de protecciones y recaudos, de cuyo uso y utilización deben estar plenamente informados los usuarios de una PC.

THE MAGNETIC FIELD IN TAURUS PROBED BY INFRARED POLARIZATION

International Nuclear Information System (INIS)

Chapman, Nicholas L.; Goldsmith, Paul F.; Pineda, Jorge L.; Li Di; Clemens, D. P.; Krco, Marko

2011-01-01

We present maps of the plane-of-sky magnetic field within two regions of the Taurus molecular cloud: one in the dense core L1495/B213 filament and the other in a diffuse region to the west. The field is measured from the polarization of background starlight seen through the cloud. In total, we measured 287 high-quality near-infrared polarization vectors in these regions. In L1495/B213, the percent polarization increases with column density up to A V ∼ 9 mag, the limits of our data. The radiative torques model for grain alignment can explain this behavior, but models that invoke turbulence are inconsistent with the data. We also combine our data with published optical and near-infrared polarization measurements in Taurus. Using this large sample, we estimate the strength of the plane-of-sky component of the magnetic field in nine subregions. This estimation is done with two different techniques that use the observed dispersion in polarization angles. Our values range from 5 to 82 μG and tend to be higher in denser regions. In all subregions, the critical index of the mass-to-magnetic flux ratio is sub-unity, implying that Taurus is magnetically supported on large scales (∼2 pc). Within the region observed, the B213 filament takes a sharp turn to the north and the direction of the magnetic field also takes a sharp turn, switching from being perpendicular to the filament to becoming parallel. This behavior can be understood if we are observing the rim of a bubble. We argue that it has resulted from a supernova remnant associated with a recently discovered nearby gamma-ray pulsar.

Integration of the End Cap TEC+ of the CMS Silicon Strip Tracker

CERN Document Server

Adler, Volker; Ageron, Michel; Agram, Jean-Laurent; Atz, Bernd; Barvich, Tobias; Baulieu, Guillaume; Beaumont, Willem; Beissel, Franz; Bergauer, Thomas; Berst, Jean-Daniel; Blüm, Peter; Bock, E; Bogelsbacher, F; de Boer, Wim; Bonnet, Jean-Luc; Bonnevaux, Alain; Boudoul, Gaelle; Bouhali, Othmane; Braunschweig, Wolfgang; Bremer, R; Brom, Jean-Marie; Butz, Erik; Chabanat, Eric; Chabert, Eric Christian; Clerbaux, Barbara; Contardo, Didier; De Callatay, Bernard; Dehm, Philip; Delaere, Christophe; Della Negra, Rodolphe; Dewulf, Jean-Paul; D'Hondt, Jorgen; Didierjean, Francois; Dierlamm, Alexander; Dirkes, Guido; Dragicevic, Marko; Drouhin, Frédéric; Ernenwein, Jean-Pierre; Esser, Hans; Estre, Nicolas; Fahrer, Manuel; Feld, Lutz; Fernández, J; Florins, Benoit; Flossdorf, Alexander; Flucke, Gero; Flügge, Günter; Fontaine, Jean-Charles; Freudenreich, Klaus; Frey, Martin; Friedl, Markus; Furgeri, Alexander; Giraud, Noël; Goerlach, Ulrich; Goorens, Robert; Graehling, Philippe; Grégoire, Ghislain; Gregoriev, E; Gross, Laurent; Hansel, S; Haroutunian, Roger; Hartmann, Frank; Heier, Stefan; Hermanns, Thomas; Heydhausen, Dirk; Heyninck, Jan; Hosselet, J; Hrubec, Josef; Jahn, Dieter; Juillot, Pierre; Kaminski, Jochen; Karpinski, Waclaw; Kaussen, Gordon; Keutgen, Thomas; Klanner, Robert; Klein, Katja; König, Stefan; Kosbow, M; Krammer, Manfred; Ledermann, Bernhard; Lemaître, Vincent; De Lentdecker, Gilles; Linn, Alexander; Lounis, Abdenour; Lübelsmeyer, Klaus; Lumb, Nicholas; Maazouzi, Chaker; Mahmoud, Tariq; Michotte, Daniel; Militaru, Otilia; Mirabito, Laurent; Müller, Thomas; Neukermans, Lionel; Ollivetto, C; Olzem, Jan; Ostapchuk, Andrey; Pandoulas, Demetrios; Pein, Uwe; Pernicka, Manfred; Perriès, Stephane; Piaseki, C; Pierschel, Gerhard; Piotrzkowski, Krzysztof; Poettgens, Michael; Pooth, Oliver; Rouby, Xavier; Sabellek, Andreas; Schael, Stefan; Schirm, Norbert; Schleper, Peter; Schmitz, Stefan Antonius; Schultz von Dratzig, Arndt; Siedling, Rolf; Simonis, Hans-Jürgen; Stahl, Achim; Steck, Pia; Steinbruck, G; Stoye, Markus; Strub, Roger; Tavernier, Stefaan; Teyssier, Daniel; Theel, Andreas; Trocmé, Benjamin; Udo, Fred; Van der Donckt, M; Van der Velde, C; Van Hove, Pierre; Vanlaer, Pascal; Van Lancker, Luc; Van Staa, Rolf; Vanzetto, Sylvain; Weber, Markus; Weiler, Thomas; Weseler, Siegfried; Wickens, John; Wittmer, Bruno; Wlochal, Michael; De Wolf, Eddi A; Zhukov, Valery; Zoeller, Marc Henning

2009-01-01

The silicon strip tracker of the CMS experiment has been completed and inserted into the CMS detector in late 2007. The largest sub-system of the tracker is its end cap system, comprising two large end caps (TEC) each containing 3200 silicon strip modules. To ease construction, the end caps feature a modular design: groups of about 20 silicon modules are placed on sub-assemblies called petals and these self-contained elements are then mounted into the TEC support structures. Each end cap consists of 144 petals, and the insertion of these petals into the end cap structure is referred to as TEC integration. The two end caps were integrated independently in Aachen (TEC+) and at CERN (TEC--). This note deals with the integration of TEC+, describing procedures for end cap integration and for quality control during testing of integrated sections of the end cap and presenting results from the testing.

Polarization due to dust scattering in the planetary nebula Cn1-1

International Nuclear Information System (INIS)

Bhatt, H.C.

1989-01-01

The peculiar emission-line object Cn1-1 (=HDE330036=PK330+4 degrees 1), classified both as a symbiotic star and as a planetary nebula, was detected by the Infrared Astronomical Satellite (IRAS) as a strong source of far-infrared dust in the system. Bhatt and Mallik (1986) discussed the nature of the dust in Cn1-1 and argued that the object is a Type I protoplanetary nebula in a binary system. The argument presented here is that the polarization is intrinsic to Cn1-1 and is due to scattering by large (compared to interstellar) dust grains in the protoplanetary nebula that are asymmetrically distributed around the central star. The large degree of polarization (approximately 3 percent for the Cn1-1 distance of approximately 450 pc) with a large lambda(sub max) is naturally explained if it is caused by scattering by large dust grains in the Cn1-1 nebula. Since the H(sub alpha) line is also polarized at the same level and position angle as the continuum, the dust must be asymmetrically distributed around the central star. The morphology of the protoplanetary nebula in Cn1-1 may be bipolar. Thus, the polarization observations support the suggestion that Cn1-1 is a bipolar Type I planetary nebula

High Frequency Backscatter from the Polar and Auroral E-Region Ionosphere

Science.gov (United States)

Forsythe, Victoriya V.

The Earth's ionosphere contains collisional and partially-ionized plasma. The electric field, produced by the interaction between the Earth's magnetosphere and the solar wind, drives the plasma bulk motion, also known as convection, in the F-region of the ionosphere. It can also destabilize the plasma in the E-region, producing irregularities or waves. Intermediate-scale waves with wavelengths of hundreds of meters can cause scintillation and fading of the Global Navigation Satellite System (GNSS) signals, whereas the small-scale waves (lambda Network (SuperDARN). The theoretical part of this work focuses on symmetry properties of the general dispersion relation that describes wave propagation in the collisional plasma in the two-stream and gradient-drift instability regimes. The instability growth rate and phase velocity are examined under the presence of a background parallel electric field, whose influence is demonstrated to break the spatial symmetry of the wave propagation patterns. In the observational part of this thesis, a novel dual radar setup is used to examine E-region irregularities in the magnetic polar cap by probing the E-region along the same line from opposite directions. The phase velocity analysis together with raytracing simulations demonstrated that, in the polar cap, the radar backscatter is primarily controlled by the plasma density conditions. In particular, when the E-region layer is strong and stratified, the radar backscatter properties are controlled by the convection velocity, whereas for a tilted E-layer, the height and aspect angle conditions are more important. Finally, the fundamental dependence of the E-region irregularity phase velocity on the component of the plasma convection is investigated using two new SuperDARN radars at high southern latitudes where plasma convection estimates are accurately deduced from all SuperDARN radars in the southern hemisphere. Statistical analysis is presented showing that the predominance of the

Ultralow nonalloyed Ohmic contact resistance to self aligned N-polar GaN high electron mobility transistors by In(Ga)N regrowth

International Nuclear Information System (INIS)

Dasgupta, Sansaptak; Nidhi,; Brown, David F.; Wu, Feng; Keller, Stacia; Speck, James S.; Mishra, Umesh K.

2010-01-01

Ultralow Ohmic contact resistance and a self-aligned device structure are necessary to reduce the effect of parasitic elements and obtain higher f t and f max in high electron mobility transistors (HEMTs). N-polar (0001) GaN HEMTs, offer a natural advantage over Ga-polar HEMTs, in terms of contact resistance since the contact is not made through a high band gap material [Al(Ga)N]. In this work, we extend the advantage by making use of polarization induced three-dimensional electron-gas through regrowth of graded InGaN and thin InN cap in the contact regions by plasma (molecular beam epitaxy), to obtain an ultralow Ohmic contact resistance of 27 Ω μm to a GaN 2DEG.

Neutron transition multipole moment for /sup 88/Sr(. cap alpha. ,. cap alpha. ')/sup 88/Sr (2/sup +/, 1. 84 MeV)

Energy Technology Data Exchange (ETDEWEB)

Datta, S.K.; Ray, S.; Majumdar, H.; Ghosh, S.K.; Samanta, C.; Dasgupta, P.; Chintalapudi, S.N.; Banerjee, S.R.

1989-04-01

The neutron transition multipole moment, M/sub n/, for (0/sup +/..-->..2/sup +/, 1.84 MeV) transition is inferred by measuring the (..cap alpha..,..cap alpha..') angular distribution at E/sub ..cap alpha../ = 50 MeV and comparing it with a microscopic distorted-wave Born approximation calculation. Proton transition densities are taken from electron scattering data. M/sub n//M/sub p/ is found to be substantially less than N/Z in agreement with the (p,p') result.

Cap Bubble Drift Velocity in a Confined Test Section

International Nuclear Information System (INIS)

Xiaodong Sun; Seungjin Kim; Mamoru Ishii; Lincoln, Frank W.; Beus, Stephen G.

2002-01-01

In the two-group interfacial area transport equation, bubbles are categorized into two groups, i.e., spherical/distorted bubbles as group 1 and cap/slug/churn-turbulent bubbles as group 2. The bubble rise velocities for both groups of bubbles may be estimated by the drift flux model by applying different distribution parameters and drift velocities for both groups. However, the drift velocity for group 2 bubbles is not always applicable (when the wall effect becomes important) as in the current test loop of interest where the flow channel is confined by two parallel flat walls, with a dimension of 200-mm in width and 10-mm in gap. The previous experiments indicated that no stable slug flow existed in this test section, which was designed to permit visualization of the flow patterns and bubble characteristics without the distortion associated with curved surfaces. In fact, distorted cap bubbly and churn-turbulent flow was observed. Therefore, it is essential to developed a correlation for cap bubble drift velocity in this confined flow channel. Since the rise velocity of a cap bubble depends on its size, a high-speed movie camera is used to capture images of cap bubbles to obtain the bubble size information. Meanwhile, the rise velocity of cap and elongated bubbles (called cap bubbles hereafter) is investigated by examining the captured images frame by frame. As a result, the conventional correlation of drift velocity for slug bubbles is modified and acceptable agreements between the measurements and correlation estimation are achieved

Influence of thiol capping on the photoluminescence properties of L-cysteine-, mercaptoethanol- and mercaptopropionic acid-capped ZnS nanoparticles.

Science.gov (United States)

Tiwari, A; Dhoble, S J; Kher, R S

2015-11-01

Mercaptoethanol (ME), mercaptopropionic acid (MPA) and L-cysteine (L-Cys) having -SH functional groups were used as surface passivating agents for the wet chemical synthesis of ZnS nanoparticles. The effect of the thiol group on the optical and photoluminescence (PL) properties of ZnS nanoparticles was studied. L-Cysteine-capped ZnS nanoparticles showed the highest PL intensity among the studied capping agents, with a PL emission peak at 455 nm. The PL intensity was found to be dependent on the concentration of Zn(2+) and S(2-) precursors. The effect of buffer on the PL intensity of L-Cys-capped ZnS nanoparticles was also studied. UV/Vis spectra showed blue shifting of the absorption edge. Copyright © 2015 John Wiley & Sons, Ltd.

Application of simplified PC-SAFT to glycol ethers

DEFF Research Database (Denmark)

Avlund, Ane Søgaard; Kontogeorgis, Georgios; Michelsen, Michael Locht

2012-01-01

The simplified PC-SAFT (sPC-SAFT) equation of state is applied for binary glycol ether-containing mixtures, and it is investigated how the results are influenced by inclusion of intramolecular association in the association theory. Three different glycol ethers are examined: 2-methoxyethanol, 2...

PC Farms for Offline Event Reconstruction at Fermilab

International Nuclear Information System (INIS)

Beretvas, A.

1997-03-01

Fermilab is investigating the use of PC's for HEP computing. As a first step we have built a full offline environment under Linux on a set of Pentium (P5) and Pentium Pro (P6) machines (the ''PC Farm''). The Pythia simulation has been ported to run serially and in parallel (using CPS) on the PC Farm. Fermilab software products and CDF offline packages have also been ported to Linux. Run 1 CDF data has been analyzed on both Linux and SGI (Irix) with essentially identical results. The performance of the system is compared to results with commercial UNIX systems

ACTIVE CAPPING TECHNOLOGY - NEW APPROACHES FOR IN SITU REMEDIATION OF CONTAMINATED SEDIMENTS

Energy Technology Data Exchange (ETDEWEB)

Knox, A.; Paller, M.; Roberts, J.

2012-02-13

This study evaluated pilot-scale active caps composed of apatite, organoclay, biopolymers, and sand for the remediation of metal-contaminated sediments. The active caps were constructed in Steel Creek, at the Savannah River Site near Aiken, South Carolina. Monitoring was conducted for 12 months. Effectiveness of the caps was based on an evaluation of contaminant bioavailability, resistance to erosion, and impacts on benthic organisms. Active caps lowered metal bioavailability in the sediment during the one-year test period. Biopolymers reduced sediment suspension during cap construction, increased the pool of carbon, and lowered the release of metals. This field validation showed that active caps can effectively treat contaminants by changing their speciation, and that caps can be constructed to include more than one type of amendment to achieve multiple goals.

Test of radiation hardness of pcCVD detectors

Energy Technology Data Exchange (ETDEWEB)

Schlemme, Steffen [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Technische Universitaet Darmstadt (Germany); Enders, Joachim [Technische Universitaet Darmstadt (Germany); Figuera, P.; Salamone, S. [LNS-INFN Catania (Italy); Fruehauf, J.; Kis, Mladen; Kratz, A.; Kurz, N.; Loechner, S.; Nociforo, Chiara; Schirru, Fabio; Szczepanczyk, B.; Traeger, M.; Visinka, R. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Musumarra, A. [LNS-INFN Catania (Italy); University of Catania (Italy)

2016-07-01

The new in-flight separator Super-FRS is under construction at the Facility for Antiproton and Ion Research (FAIR, Darmstadt). Ion rates up to 3 x 10{sup 11} {sup 238}U/spill demand an adaption of detectors to a high radiation environment. A test experiment to investigate the radiation hardness of polycrystalline diamond detectors (pcCVD) was performed at the LNS-INFN in Catania using a {sup 12}C beam at 62 MeV/u and intensities of up to 1.5 pnA. The setup consisted of pcCVD strip detectors to measure the beam profile, a single crystal diamond detector to calibrate the ionisation chamber working in current mode as a beam intensity monitor and a pcCVD sample to be irradiated. The IC used was designed for FAIR and showed a stable counting rate allowing us to calibrate and perform beam intensity measurements with it. The total measured counts on the sample were 8.25 x 10{sup 11} counts/mm{sup 2} over a period of 60 hours. Digital waveforms of the pcCVD signals were taken with an oscilloscope and analysed. The results showed no change of the pcCVD signal properties during the entire irradiation.

Corrective action program (CAP) in United States

International Nuclear Information System (INIS)

Okamoto, Koji; Kobayashi, Masahide

2008-01-01

The Corrective Action Process (CAP) is one of the most important key issues on the Nuclear Reactor Safety. The experiences on the nuclear power plant operations, including safety culture, maintenance, and so on, should be continuously evaluated and influenced to the KAIZEN (improvement) of the NPP operations. The review of the CAP system in US will be useful for the NPP safety in Japan. (author)

Radioimmunological determination of. cap alpha. -MSH and ACTH in the rat

Energy Technology Data Exchange (ETDEWEB)

Usategui Echeverria, R; Oliver, C; Vaudry, H; Lombardi, G; Rozenberg, I; Vague, J [Centre Hospitalier Universitaire de la Timone, 13 - Marseille (France)

1975-09-01

Specific and sensitive radioimmunoassay methods for ..cap alpha..-MSH and ACTH are reported. They make possible specific measurements of each hormone in rat plasma or pituitary extracts. Endogenous ..cap alpha..-MSH and ACTH extracted from plasma or pituitary show the same immunoreactivity than synthetic ..cap alpha..-MSH and ACTH. ..cap alpha..-MSH and ACTH levels vary independently from each other in the following conditions: circadian rythm, corticoid treatment, adrenalectomy, ether stress, haloperidol injection.

PC data station for Hitachi F-2000 spectrofluorimeter

International Nuclear Information System (INIS)

Yakub Ali, Mohd; Dhoble, A.R.; Jadhav, R.T.; Godbole, S.V.

2004-01-01

The paper describes the PC based data station for stand-alone HIT ACHI F-2000 Spectrofluorimeter, for data acquisition, storage and analysis. The hardware link between the instrument and PC is made through RS232 serial port. The state of art software for control and data management is designed, developed and implemented in Visual Basic (Version 6). The software features on-screen editing of all operation parameters of the instrument and the operational control is achieved by Visual Basic command words communicated through serial port. Using this system, in addition to acquiring and storage of spectral data, it was possible to obtain the normalized absorption spectra of the samples. PC adapted Hitachi F-2000 Spectrofluorimeter can be successfully used for various operations such as photometric detection of UO22+ ions, recording of emission and excitation spectra and time evolution of fluorescence intensity on continuous UV irradiation. The data storage achieved through PC adaptation has also enabled recording of absorption spectra. (author)

Interfacial and Wall Transport Models for SPACE-CAP Code

International Nuclear Information System (INIS)

Hong, Soon Joon; Choo, Yeon Joon; Han, Tae Young; Hwang, Su Hyun; Lee, Byung Chul; Choi, Hoon; Ha, Sang Jun

2009-01-01

The development project for the domestic design code was launched to be used for the safety and performance analysis of pressurized light water reactors. And CAP (Containment Analysis Package) code has been also developed for the containment safety and performance analysis side by side with SPACE. The CAP code treats three fields (gas, continuous liquid, and dispersed drop) for the assessment of containment specific phenomena, and is featured by its multidimensional assessment capabilities. Thermal hydraulics solver was already developed and now under testing of its stability and soundness. As a next step, interfacial and wall transport models was setup. In order to develop the best model and correlation package for the CAP code, various models currently used in major containment analysis codes, which are GOTHIC, CONTAIN2.0, and CONTEMPT-LT, have been reviewed. The origins of the selected models used in these codes have also been examined to find out if the models have not conflict with a proprietary right. In addition, a literature survey of the recent studies has been performed in order to incorporate the better models for the CAP code. The models and correlations of SPACE were also reviewed. CAP models and correlations are composed of interfacial heat/mass, and momentum transport models, and wall heat/mass, and momentum transport models. This paper discusses on those transport models in the CAP code

Interfacial and Wall Transport Models for SPACE-CAP Code

Energy Technology Data Exchange (ETDEWEB)

Hong, Soon Joon; Choo, Yeon Joon; Han, Tae Young; Hwang, Su Hyun; Lee, Byung Chul [FNC Tech., Seoul (Korea, Republic of); Choi, Hoon; Ha, Sang Jun [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

2009-10-15

The development project for the domestic design code was launched to be used for the safety and performance analysis of pressurized light water reactors. And CAP (Containment Analysis Package) code has been also developed for the containment safety and performance analysis side by side with SPACE. The CAP code treats three fields (gas, continuous liquid, and dispersed drop) for the assessment of containment specific phenomena, and is featured by its multidimensional assessment capabilities. Thermal hydraulics solver was already developed and now under testing of its stability and soundness. As a next step, interfacial and wall transport models was setup. In order to develop the best model and correlation package for the CAP code, various models currently used in major containment analysis codes, which are GOTHIC, CONTAIN2.0, and CONTEMPT-LT, have been reviewed. The origins of the selected models used in these codes have also been examined to find out if the models have not conflict with a proprietary right. In addition, a literature survey of the recent studies has been performed in order to incorporate the better models for the CAP code. The models and correlations of SPACE were also reviewed. CAP models and correlations are composed of interfacial heat/mass, and momentum transport models, and wall heat/mass, and momentum transport models. This paper discusses on those transport models in the CAP code.

CAPS--pathogenesis, presentation and treatment of an autoinflammatory disease.

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