Rare earth-transition metal scrap treatment method

DOEpatents

Schmidt, F.A.; Peterson, D.T.; Wheelock, J.T.; Jones, L.L.; Lincoln, L.P.

1992-02-11

Rare earth-transition metal (e.g. iron) scrap (e.g. Nd-Fe-B scrap) is melted to reduce the levels of tramp oxygen and nitrogen impurities therein. The tramp impurities are reduced in the melt by virtue of the reaction of the tramp impurities and the rare earth to form dross on the melt. The purified melt is separated from the dross for reuse. The oxygen and nitrogen of the melt are reduced to levels acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets. 3 figs.

A super-Earth transiting a nearby low-mass star.

PubMed

Charbonneau, David; Berta, Zachory K; Irwin, Jonathan; Burke, Christopher J; Nutzman, Philip; Buchhave, Lars A; Lovis, Christophe; Bonfils, Xavier; Latham, David W; Udry, Stéphane; Murray-Clay, Ruth A; Holman, Matthew J; Falco, Emilio E; Winn, Joshua N; Queloz, Didier; Pepe, Francesco; Mayor, Michel; Delfosse, Xavier; Forveille, Thierry

2009-12-17

A decade ago, the detection of the first transiting extrasolar planet provided a direct constraint on its composition and opened the door to spectroscopic investigations of extrasolar planetary atmospheres. Because such characterization studies are feasible only for transiting systems that are both nearby and for which the planet-to-star radius ratio is relatively large, nearby small stars have been surveyed intensively. Doppler studies and microlensing have uncovered a population of planets with minimum masses of 1.9-10 times the Earth's mass (M[symbol:see text]), called super-Earths. The first constraint on the bulk composition of this novel class of planets was afforded by CoRoT-7b (refs 8, 9), but the distance and size of its star preclude atmospheric studies in the foreseeable future. Here we report observations of the transiting planet GJ 1214b, which has a mass of 6.55M[symbol:see text]), and a radius 2.68 times Earth's radius (R[symbol:see text]), indicating that it is intermediate in stature between Earth and the ice giants of the Solar System. We find that the planetary mass and radius are consistent with a composition of primarily water enshrouded by a hydrogen-helium envelope that is only 0.05% of the mass of the planet. The atmosphere is probably escaping hydrodynamically, indicating that it has undergone significant evolution during its history. The star is small and only 13 parsecs away, so the planetary atmosphere is amenable to study with current observatories.

Three Transits for the Price of One: Super-Earth Transits of the Nearest Planetary System Discovered By Kepler/K2

NASA Astrophysics Data System (ADS)

Redfield, Seth; Niraula, Prajwal; Hedges, Christina; Crossfield, Ian; Kreidberg, Laura; Greene, Tom; Rodriguez, Joey; Vanderburg, Andrew; Laughlin, Gregory; Millholland, Sarah; Wang, Songhu; Cochran, William; Livingston, John; Gandolfi, Davide; Guenther, Eike; Fridlund, Malcolm; Korth, Judith

2018-05-01

We propose primary transit observations of three Super-Earth planets in the newly discovered planetary system around a bright, nearby star, GJ 9827. We recently announced the detection of three super-Earth planets in 1:3:5 commensurability, the inner planet, GJ 9827 b having a period of 1.2 days. This is the nearest planetary system that Kepler or K2 has found, at 30 pc, and given its brightness is one of the top systems for follow-up characterization. This system presents a unique opportunity to acquire three planetary transits for the price of one. There are several opportunities in the Spitzer visibility windows to obtain all three transits in a short period of time. We propose 3.6 micron observations of all three Super-Earth transits in a single 18-hour observation window. The proximity to a 1:3:5 resonance is intriguing from a dynamical standpoint as well. Indeed, anomalous transit timing offsets have been measured for planet d in Hubble observations that suffer from partial phase coverage. The short cadence and extended coverage of Spitzer is essential to provide a firm determination of the ephemerides and characterize any transit timing variations. Constraining these orbital parameters is critical for follow-up observations from space and ground-based telescopes. Due to the brightness of the host star, this planetary system is likely to be extensively observed in the years to come. Indeed, our team has acquired observations of the planets orbiting GJ9827 with Hubble in the ultraviolet and infrared. The proposed observations will provide infrared atmospheric measurements and firm orbital characterization which is critical for planning and designing future observations, in particular atmospheric characterization with JWST.

Dynamical Generation of the Transition Zone in the Earth's Mantle

NASA Astrophysics Data System (ADS)

Hansen, U.; Stemmer, K.

2005-12-01

The internal structure of the Earth is made up by a series of layers, though it is unclear how many layers exist and if there are layers invisible to remote sensing techniques. The transition zone is likely to be a boundary layer separating the convective systems in the lower and upper mantle. It seems likely that currently there is some mass exchange across this boundary, rather than the two systems beeing strictly separated.a Double-diffusive convection(d.d.c) is a vital mechanism which can generate layered structure and may thus be an important mmical machinery behind the formation of the transition zone. Double-diffusive convection determines the dynamics of systems whose density is influenced by at least two components with different molecular diffusivities.In the mantle, composition and temperature play the role of those two components. By means of numerical experiments we demonstrate that under mantle relevant conditions d.d.c typically leads to the formation of a transition zone. The calculations encompass two- and three dimensional Cartesian geometries as well as fully 3D spherical domains. We have further included strongly temperature dependent viscosity and find that this leads to even more pronounced layering. In most cases a layered flow pattern emerges, where two layers with a transition zone in between resembles a quasistationary state. Thus, the transition zone can be the result of a self organization process of the convective flow in the mantle. The presence of a phase transition further helps to stabilize the boundary against overturning, even on a time scale on the order of the age of the Earth.

The effects of refraction on transit transmission spectroscopy: application to Earth-like exoplanets

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

Misra, Amit; Meadows, Victoria; Crisp, Dave, E-mail: amit0@astro.washington.edu

2014-09-01

We quantify the effects of refraction in transit transmission spectroscopy on spectral absorption features and on temporal variations that could be used to obtain altitude-dependent spectra for planets orbiting stars of different stellar types. We validate our model against altitude-dependent transmission spectra of the Earth from ATMOS and against lunar eclipse spectra from Pallé et al. We perform detectability studies to show the potential effects of refraction on hypothetical observations of Earth analogs with the James Webb Space Telescope NIRSPEC. Due to refraction, there will be a maximum tangent pressure level that can be probed during transit for each givenmore » planet-star system. We show that because of refraction, for an Earth-analog planet orbiting in the habitable zone of a Sun-like star only the top 0.3 bars of the atmosphere can be probed, leading to a decrease in the signal-to-noise ratio (S/N) of absorption features by 60%, while for an Earth-analog planet orbiting in the habitable zone of an M5V star it is possible to probe almost the entire atmosphere with minimal decreases in S/N. We also show that refraction can result in temporal variations in the transit transmission spectrum which may provide a way to obtain altitude-dependent spectra of exoplanet atmospheres. Additionally, the variations prior to ingress and subsequent to egress provide a way to probe pressures greater than the maximum tangent pressure that can be probed during transit. Therefore, probing the maximum range of atmospheric altitudes, and in particular the near-surface environment of an Earth-analog exoplanet, will require looking at out-of-transit refracted light in addition to the in-transit spectrum.« less

Lunar Flight Study Series: Volume 6. A Study of Geometrical and Terminal Characteristics of Earth-Moon Transits Embedded in the Earth-Moon Plane

NASA Technical Reports Server (NTRS)

Lisle, B. J.

1963-01-01

This report represents the results of a study of coplanar earth-moon transits. The study was initiated to provide information concerning coplanar geometrical characteristics of earth-moon trnasits. The geometrical aspects of transit behavior are related to variations injection conditions. The model of the earth-moon system used in this investigation is the Jacobian model of the restricted three body problem. All transits considered in this study are restricted to the moon-earth plane (MEP).

Recent Transits of the Super-Earth Exoplanet GJ 1214b

NASA Astrophysics Data System (ADS)

Sada, Pedro V.; Deming, Drake; Jackson, Brian; Jennings, Donald E.; Peterson, Steven W.; Haase, Flynn; Bays, Kevin; O'Gorman, Eamon; Lundsford, Alan

2010-09-01

We report recent ground-based photometry of the transiting super-Earth exoplanet GJ 1214b at several wavelengths, including the infrared near 1.25 μm (J band). We observed a J-band transit with the FLAMINGOS infrared imager and the 2.1 m telescope on Kitt Peak, and we observed several optical transits using a 0.5 m telescope on Kitt Peak and the 0.36 m Universidad de Monterrey Observatory telescope. Our high-precision J-band observations exploit the brightness of the M dwarf host star at this infrared wavelength as compared with the optical and are significantly less affected by stellar activity and limb darkening. We fit the J-band transit to obtain an independent determination of the planetary and stellar radii. Our radius for the planet (2.61+0.30 -0.11 R ⊕) is in excellent agreement with the discovery value reported by Charbonneau et al. based on optical data. We demonstrate that the planetary radius is insensitive to degeneracies in the fitting process. We use all of our observations to improve the transit ephemeris, finding P = 1.5804043 ± 0.0000005 days and T 0 = 2454964.94390 ± 0.00006 BJD.

Water-induced convection in the Earth's mantle transition zone

NASA Astrophysics Data System (ADS)

Richard, Guillaume C.; Bercovici, David

2009-01-01

Water enters the Earth's mantle by subduction of oceanic lithosphere. Most of this water immediately returns to the atmosphere through arc volcanism, but a part of it is expected as deep as the mantle transition zone (410-660 km depth). There, slabs can be deflected and linger before sinking into the lower mantle. Because it lowers the density and viscosity of the transition zone minerals (i.e., wadsleyite and ringwoodite), water is likely to affect the dynamics of the transition zone mantle overlying stagnant slabs. The consequences of water exchange between a floating slab and the transition zone are investigated. In particular, we focus on the possible onset of small-scale convection despite the adverse thermal gradient (i.e., mantle is cooled from below by the slab). The competition between thermal and hydrous effects on the density and thus on the convective stability of the top layer of the slab is examined numerically, including water-dependent density and viscosity and temperature-dependent water solubility. For plausible initial water content in a slab (≥0.5 wt %), an episode of convection is likely to occur after a relatively short time delay (5-20 Ma) after the slab enters the transition zone. However, water induced rheological weakening is seen to be a controlling parameter for the onset time of convection. Moreover, small-scale convection above a stagnant slab greatly enhances the rate of slab dehydration. Small-scale convection also facilitates heating of the slab, which in itself may prolong the residence time of the slab in the transition zone.

Method for treating rare earth-transition metal scrap

DOEpatents

Schmidt, Frederick A.; Peterson, David T.; Wheelock, John T.; Jones, Lawrence L.

1992-12-29

Rare earth-transition metal (e.g., iron) scrap (e.g., Nd-Fe-B scrap) is flux (slag) remelted to reduce tramp non-metallic impurities, such as oxygen and nitrogen, and metallic impurities, such as Li, Na, Al, etc., picked up by the scrap from previous fabrication operations. The tramp impurities are reduced to concentrations acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets. The scrap is electroslag or inductoslag melted using a prefused, rare earth fluoride-bearing flux of CaF.sub.2, CaCl.sub.2 or mixtures thereof or the slag resulting from practice of the thermite reduction process to make a rare earth-iron alloy.

Method for treating rare earth-transition metal scrap

DOEpatents

Schmidt, F.A.; Peterson, D.T.; Wheelock, J.T.; Jones, L.L.

1992-12-29

Rare earth-transition metal (e.g., iron) scrap (e.g., Nd-Fe-B scrap) is flux (slag) remelted to reduce tramp non-metallic impurities, such as oxygen and nitrogen, and metallic impurities, such as Li, Na, Al, etc., picked up by the scrap from previous fabrication operations. The tramp impurities are reduced to concentrations acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets. The scrap is electroslag or inductoslag melted using a rare earth fluoride-bearing flux of CaF[sub 2], CaCl[sub 2] or mixtures thereof or the slag resulting from practice of the thermite reduction process to make a rare earth-iron alloy. 3 figs.

THEORETICAL TRANSIT SPECTRA FOR GJ 1214b AND OTHER 'SUPER-EARTHS'

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

Howe, Alex R.; Burrows, Adam S., E-mail: arhowe@astro.princeton.edu, E-mail: burrows@astro.princeton.edu

2012-09-10

We present new calculations of transit spectra of super-Earths that allow for atmospheres with arbitrary proportions of common molecular species and haze. We test this method with generic spectra, reproducing the expected systematics and absorption features, then apply it to the nearby super-Earth GJ 1214b, which has produced conflicting observational data, leaving the questions of a hydrogen-rich versus hydrogen-poor atmosphere and the water content of the atmosphere ambiguous. We present representative transit spectra for a range of classes of atmosphere models for GJ 1214b. Our analysis supports a hydrogen-rich atmosphere with a cloud or haze layer, although a hydrogen-poor modelmore » with {approx}<10% water is not ruled out. Several classes of models are ruled out, however, including hydrogen-rich atmospheres with no haze, hydrogen-rich atmospheres with a haze of {approx}0.01 {mu}m tholin particles, and hydrogen-poor atmospheres with major sources of absorption other than water. We propose an observational test to distinguish hydrogen-rich from hydrogen-poor atmospheres. Finally, we provide a library of theoretical transit spectra for super-Earths with a broad range of parameters to facilitate future comparison with anticipated data.« less

Post-16 and Post-18 Transitions of Young People with Visual Impairment in Wales

ERIC Educational Resources Information Center

Keil, Sue; Crews, Nicola

2008-01-01

This article gives an overview of a three-year qualitative study following the transition pathways of one blind and four partially sighted young people in Wales, beginning with the transition from compulsory to post-compulsory education at the age of 16. The study highlighted the inequity in provision for young people who remain in school sixth…

Geomagnetic polarity transitions

NASA Astrophysics Data System (ADS)

Merrill, Ronald T.; McFadden, Phillip L.

1999-05-01

The top of Earth's liquid outer core is nearly 2900 km beneath Earth's surface, so we will never be able to observe it directly. This hot, dense, molten iron-rich body is continuously in motion and is the source of Earth's magnetic field. One of the most dynamic manifestations at Earth's surface of this fluid body is, perhaps, a reversal of the geomagnetic field. Unfortunately, the most recent polarity transition occurred at about 780 ka, so we have never observed a transition directly. It seems that a polarity transition spans many human lifetimes, so no human will ever witness the phenomenon in its entirety. Thus we are left with the tantalizing prospect that paleomagnetic records of polarity transitions may betray some of the secrets of the deep Earth. Certainly, if there are systematics in the reversal process and they can be documented, then this will reveal substantial information about the nature of the lowermost mantle and of the outer core. Despite their slowness on a human timescale, polarity transitions occur almost instantaneously on a geological timescale. This rapidity, together with limitations in the paleomagnetic recording process, prohibits a comprehensive description of any reversal transition both now and into the foreseeable future, which limits the questions that may at this stage be sensibly asked. The natural model for the geomagnetic field is a set of spherical harmonic components, and we are not able to obtain a reliable model for even the first few harmonic terms during a transition. Nevertheless, it is possible, in principle, to make statements about the harmonic character of a geomagnetic polarity transition without having a rigorous spherical harmonic description of one. For example, harmonic descriptions of recent geomagnetic polarity transitions that are purely zonal can be ruled out (a zonal harmonic does not change along a line of latitude). Gleaning information about transitions has proven to be difficult, but it does seem

Venus Transit

NASA Image and Video Library

2012-06-05

It appeared that New Yorkers were not going to be able to see the transit of the planet Venus across the Sun, but just before the transit was over the sun broke through the clouds and Yvette Lee Kang was able to catch a glimpse of the transit on Tuesday, June 5, 2012 in New York. A transit of Venus occurs when the planet passes directly between the sun and earth. This alignment is rare, coming in pairs that are eight years apart but separated by over a century. The next Venus transit will be in December 2117. Photo Credit: (NASA/Bill Ingalls)

Saudi Deaf Students Post-Secondary Transitioning Experience: A Grounded Theory Study

ERIC Educational Resources Information Center

Almotiri, Abdullah

2017-01-01

Understanding how deaf and hard-of-hearing (DHH) international students transition to post-secondary institutions is important for ensuring their academic and personal success. In this grounded theory study, five Saudi Arabian students who are DHH and enrolled at Gallaudet University were interviewed about their transition experience. Participants…

Improving the Transition of Earth Satellite Observations from Research to Operations

NASA Technical Reports Server (NTRS)

Goodman, Steven J.; Lapenta, William M.; Jedlovec, Gary J.

2004-01-01

There are significant gaps between the observations, models, and decision support tools that make use of new data. These challenges include: 1) Decreasing the time to incorporate new satellite data into operational forecast assimilation systems, 2) Blending in-situ and satellite observing systems to produce the most accurate and comprehensive data products and assessments, 3) Accelerating the transition from research to applications through national test beds, field campaigns, and pilot demonstrations, and 4) Developing the partnerships and organizational structures to effectively transition new technology into operations. At the Short-term Prediction Research and Transition (SPORT) Center in Huntsville, Alabama, a NASA-NOAA-University collaboration has been developed to accelerate the infusion of NASA Earth science observations, data assimilation and modeling research into NWS forecast operations and decision-making. The SPoRT Center research focus is to improve forecasts through new observation capability and the regional prediction objectives of the US Weather Research Program dealing with 0-1 day forecast issues such as convective initiation and 24-hr quantitative precipitation forecasting. The near real-time availability of high-resolution experimental products of the atmosphere, land, and ocean from the Moderate Resolution Imaging Spectroradiometer (MODIS), the Advanced Infrared Spectroradiometer (AIRS), and lightning mapping systems provide an opportunity for science and algorithm risk reduction, and for application assessment prior to planned observations from the next generation of operational low Earth orbiting and geostationary Earth orbiting satellites. This paper describes the process for the transition of experimental products into forecast operations, current products undergoing assessment by forecasters, and plans for the future. The SPoRT Web page is at (http://www.ghcc.msfc.nasa.gov/sport).

GROUND-BASED TRANSIT OBSERVATIONS OF THE SUPER-EARTH 55 Cnc e

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

De Mooij, E. J. W.; López-Morales, M.; Karjalainen, R.

2014-12-20

We report the first ground-based detections of the shallow transit of the super-Earth exoplanet 55 Cnc e using a 2 m class telescope. Using differential spectrophotometry, we observed one transit in 2013 and another in 2014, with average spectral resolutions of ∼700 and ∼250, spanning the Johnson BVR photometric bands. We find a white light planet-to-star radius ratio of 0.0190{sub −0.0027}{sup +0.0023} from the 2013 observations and 0.0200{sub −0.0018}{sup +0.0017} from the 2014 observations. The two data sets combined result in a radius ratio of 0.0198{sub −0.0014}{sup +0.0013}. These values are all in agreement with previous space-based results. Scintillation noise in themore » data prevents us from placing strong constraints on the presence of an extended hydrogen-rich atmosphere. Nevertheless, our detections of 55 Cnc e in transit demonstrate that moderate-sized telescopes on the ground will be capable of routine follow-up observations of super-Earth candidates discovered by the Transiting Exoplanet Survey Satellite around bright stars. We expect it also will be possible to place constraints on the atmospheric characteristics of those planets by devising observational strategies to minimize scintillation noise.« less

RECENT TRANSITS OF THE SUPER-EARTH EXOPLANET GJ 1214b

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

Sada, Pedro V.; Deming, Drake; Jackson, Brian

We report recent ground-based photometry of the transiting super-Earth exoplanet GJ 1214b at several wavelengths, including the infrared near 1.25 {mu}m (J band). We observed a J-band transit with the FLAMINGOS infrared imager and the 2.1 m telescope on Kitt Peak, and we observed several optical transits using a 0.5 m telescope on Kitt Peak and the 0.36 m Universidad de Monterrey Observatory telescope. Our high-precision J-band observations exploit the brightness of the M dwarf host star at this infrared wavelength as compared with the optical and are significantly less affected by stellar activity and limb darkening. We fit themore » J-band transit to obtain an independent determination of the planetary and stellar radii. Our radius for the planet (2.61{sup +0.30} {sub -0.11} R {sub +}) is in excellent agreement with the discovery value reported by Charbonneau et al. based on optical data. We demonstrate that the planetary radius is insensitive to degeneracies in the fitting process. We use all of our observations to improve the transit ephemeris, finding P = 1.5804043 {+-} 0.0000005 days and T {sub 0} = 2454964.94390 {+-} 0.00006 BJD.« less

Caregiver Perspectives during the Post Inpatient Hospital Transition: A Mixed Methods Approach

ERIC Educational Resources Information Center

Blizzard, Angela M.; Weiss, Catherine L.; Wideman, Rukiya; Stephan, Sharon H.

2016-01-01

Background: Knowledge of caregiver perspectives of their psychosocial resources and needs during the post inpatient psychiatric hospitalization is limited. Examining caregivers' perspectives of the transition period may be a critical step in improving the transition success of children with emotional and behavioral disorders. Using quantitative…

MOST Detects Transits of HD 97658b, a Warm, Likely Volatile-rich Super-Earth

NASA Astrophysics Data System (ADS)

Dragomir, Diana; Matthews, Jaymie M.; Eastman, Jason D.; Cameron, Chris; Howard, Andrew W.; Guenther, David B.; Kuschnig, Rainer; Moffat, Anthony F. J.; Rowe, Jason F.; Rucinski, Slavek M.; Sasselov, Dimitar; Weiss, Werner W.

2013-07-01

Through photometric monitoring of the extended transit window of HD 97658b with the MOST space telescope, we have found that this exoplanet transits with an ephemeris consistent with that predicted from radial velocity measurements. The mid-transit times are 5.6σ earlier than those of the unverified transit-like signals reported in 2011, and we find no connection between the two sets of events. The transit depth together with our determined stellar radius (R_\\star = 0.703^{+0.039}_{-0.034}\\ R_\\odot) indicates a 2.34^{+0.18}_{-0.15} R ⊕ super-Earth. When combined with the radial velocity determined mass of 7.86 ± 0.73 M ⊕, our radius measure allows us to derive a planet density of 3.44^{+0.91}_{-0.82} g cm-3. Models suggest that a planet with our measured density has a rocky core that is enveloped in an atmosphere composed of lighter elements. The star of the HD 97658 system is the second brightest known to host a transiting super-Earth, facilitating follow-up studies of this not easily daunted, warm and likely volatile-rich exoplanet. Based on data from the MOST satellite, a Canadian Space Agency mission operated by Microsatellite Systems Canada Inc. (MSCI; former Dynacon Inc.) and the Universities of Toronto and British Columbia, with the assistance of the University of Vienna.

The Avahan Transition: Effects of Transition Readiness on Program Institutionalization and Sustained Outcomes

PubMed Central

Singh, Suneeta; Singh, Kriti; Chhabra, Vibha; Bennett, Sara

2016-01-01

Background With declines in development assistance for health and growing interest in country ownership, donors are increasingly faced with the task of transitioning health programs to local actors towards a path to sustainability. Yet there is little available guidance on how to measure and evaluate the success of a transition and its subsequent effects. This study assesses the transition of the Avahan HIV/AIDS prevention program in India to investigate how preparations for transition affected continuation of program activities post-transition. Methods Two rounds of two surveys were conducted and supplemented by data from government and Avahan Computerized Management Information Systems (CMIS). Exploratory factor analysis was used to develop two measures: 1) transition readiness pre-transition, and 2) institutionalization (i.e. integration of initial program systems into organizational procedures and behaviors) post-transition. A fixed effects model was built to examine changes in key program delivery outcomes over time. An ordinary least square regression was used to assess the relationship between transition readiness and sustainability of service outcomes both directly, and indirectly through institutionalization. Results Transition readiness data revealed 3 factors (capacity, alignment and communication), on a 15-item scale with adequate internal consistency (alpha 0.73). Institutionalization was modeled as a unidimensional construct, and a 12-item scale demonstrated moderate internal consistency (alpha 0.60). Coverage of key populations and condom distribution were sustained compared to pre-transition levels (p<0.01). Transition readiness, but not institutionalization, predicted sustained outcomes post-transition. Transition readiness did not necessarily lead to institutionalization of key program elements one year after transition. Conclusion Greater preparedness prior to transition is important to achieve better service delivery outcomes post-transition

Temperate Earth-sized planets transiting a nearby ultracool dwarf star

PubMed Central

Gillon, Michaël; Jehin, Emmanuël; Lederer, Susan M.; Delrez, Laetitia; de Wit, Julien; Burdanov, Artem; Van Grootel, Valérie; Burgasser, Adam; Triaud, Amaury H. M. J.; Opitom, Cyrielle; Demory, Brice-Olivier; Sahu, Devendra K.; Bardalez Gagliuffi, Daniella; Magain, Pierre; Queloz, Didier

2017-01-01

Stellar-like objects with effective temperatures of 2700K and below are referred to as “ultracool dwarfs”1. This heterogeneous group includes both extremely low-mass stars and brown dwarfs (substellar objects not massive enough to sustain hydrogen fusion), and represents about 15% of the stellar-like objects in the vicinity of the Sun2. Based on the small masses and sizes of their protoplanetary disks3,4, core-accretion theory for ultracool dwarfs predicts a large, but heretofore undetected population of close-in terrestrial planets5, ranging from metal-rich Mercury-sized planets6 to more hospitable volatile-rich Earth-sized planets7. Here we report the discovery of three short-period Earth-sized planets transiting an ultracool dwarf star 12 parsecs away using data collected by the TRAPPIST8 telescope as part of an ongoing prototype transit survey9. The inner two planets receive four and two times the irradiation of Earth, respectively, placing them close to the inner edge of the habitable zone of the star10. Eleven orbits remain possible for the third planet based on our data, the most likely resulting in an irradiation significantly smaller than Earth's. The infrared brightness of the host star combined with its Jupiter-like size offer the possibility of thoroughly characterizing the components of this nearby planetary system. PMID:27135924

Glass transition temperature of hard chairside reline materials after post-polymerisation treatments.

PubMed

Urban, Vanessa M; Machado, Ana L; Alves, Marinês O; Maciel, Adeilton P; Vergani, Carlos E; Leite, Edson R

2010-09-01

This study evaluated the effect of post-polymerisation treatments on the glass transition temperature (T(g)) of five hard chairside reline materials (Duraliner II-D, Kooliner-K, New Truliner-N, Ufi Gel hard-U and Tokuso Rebase Fast-T). Specimens (10 x 10 x 1 mm) were made following the manufacturers' instructions and divided into three groups (n = 5). Control group specimens were left untreated. Specimens from the microwave group were irradiated with pre-determined power/time combinations, and specimens from the water-bath group were immersed in hot water at 55 degrees C for 10 min. Glass transition ( degrees C) was performed by differential scanning calorimetry. Data were analysed using anova, followed by post hoc Tukey's test (alpha = 0.05). Both post-polymerisation treatments promoted a significant (p < 0.05) increase in the T(g) of reline material K. Materials K, D and N showed the lowest T(g) (p < 0.05). No significant difference between T and U specimens was observed. Post-polymerisation treatments improved the glass transition of material Kooliner, with the effect being more pronounced for microwave irradiation.

Stable isotopes of transition and post-transition metals as tracers in environmental studies

USGS Publications Warehouse

Bullen, Thomas D.; Baskaran, Mark

2011-01-01

The transition and post-transition metals, which include the elements in Groups 3–12 of the Periodic Table, have a broad range of geological and biological roles as well as industrial applications and thus are widespread in the environment. Interdisciplinary research over the past decade has resulted in a broad understanding of the isotope systematics of this important group of elements and revealed largely unexpected variability in isotope composition for natural materials. Significant kinetic and equilibrium isotope fractionation has been observed for redox sensitive metals such as iron, chromium, copper, molybdenum and mercury, and for metals that are not redox sensitive in nature such as cadmium and zinc. In the environmental sciences, the isotopes are increasingly being used to understand important issues such as tracing of metal contaminant sources and fates, unraveling metal redox cycles, deciphering metal nutrient pathways and cycles, and developing isotope biosignatures that can indicate the role of biological activity in ancient and modern planetary systems.

Highlights from the Student Transitions Project: Post-Secondary Student Mobility

ERIC Educational Resources Information Center

Heslop, Joanne

2017-01-01

The Student Transitions Project (STP) newsletter focuses exclusively on student mobility within the B.C. public post-secondary system. In this context, student mobility includes the sequential or simultaneous enrollment of academic credit registrants attending one or more B.C. public post-secondary institutions throughout their academic studies.…

A Transiting Jupiter Analog

NASA Astrophysics Data System (ADS)

Kipping, D. M.; Torres, G.; Henze, C.; Teachey, A.; Isaacson, H.; Petigura, E.; Marcy, G. W.; Buchhave, L. A.; Chen, J.; Bryson, S. T.; Sandford, E.

2016-04-01

Decadal-long radial velocity surveys have recently started to discover analogs to the most influential planet of our solar system, Jupiter. Detecting and characterizing these worlds is expected to shape our understanding of our uniqueness in the cosmos. Despite the great successes of recent transit surveys, Jupiter analogs represent a terra incognita, owing to the strong intrinsic bias of this method against long orbital periods. We here report on the first validated transiting Jupiter analog, Kepler-167e (KOI-490.02), discovered using Kepler archival photometry orbiting the K4-dwarf KIC-3239945. With a radius of (0.91+/- 0.02) {R}{{J}}, a low orbital eccentricity ({0.06}-0.04+0.10), and an equilibrium temperature of (131+/- 3) K, Kepler-167e bears many of the basic hallmarks of Jupiter. Kepler-167e is accompanied by three Super-Earths on compact orbits, which we also validate, leaving a large cavity of transiting worlds around the habitable-zone. With two transits and continuous photometric coverage, we are able to uniquely and precisely measure the orbital period of this post snow-line planet (1071.2323 ± 0.0006d), paving the way for follow-up of this K = 11.8 mag target.

Discovery of Temperate Earth-Sized Planets Transiting a Nearby Ultracool Dwarf Star

NASA Technical Reports Server (NTRS)

Jehin, Emmanuel; Gillon, Michael; Lederer, Susan M.; Delrez, Laetitia; De Wit, Julien; Burdanov, Artem; Van Grootel, Valerie; Burgasser, Adam; Triaud, Amaury; Demory, Brice-Olivier;

There will be some changes made: A survivor perspective on post-acquired brain injury residential transition.

PubMed

O'Neil-Pirozzi, Therese M; Lorenz, Laura S; Demore-Taber, Michelle; Samayoa, Sindi

2015-01-01

Brain injury survivors experience many transitions post-injury and it is important that they experience these in the most supportive and integrative ways possible. This study provided a group of chronic brain injury survivors the opportunity to share their insights and experience of residential transition and to suggest strategies to help maximize the transition experience and outcomes. This study used a qualitative design that consisted of semi-structured interviews. Twenty-one adults with chronic acquired brain injury residing in community-based supported group houses answered a series of scripted questions. Interviews were recorded and participant statements were transcribed and coded according to prospectively developed transition themes. Participants discussed positive and negative insights and experiences regarding residential transitions. Themes of balance between support and independence, life purpose and transition to more or less structure were frequently addressed. Participants suggested caregiver-targeted strategies to facilitate successful transitions before, during and after a move. The insights and suggestions shared by this group of chronic acquired brain injury survivors add to already existing knowledge of post-injury residential transitions and strategies professional caregivers may use to maximize the ease and success of the survivor's transitional experience.

Earth Science Markup Language: Transitioning From Design to Application

NASA Technical Reports Server (NTRS)

Moe, Karen; Graves, Sara; Ramachandran, Rahul

2002-01-01

The primary objective of the proposed Earth Science Markup Language (ESML) research is to transition from design to application. The resulting schema and prototype software will foster community acceptance for the "define once, use anywhere" concept central to ESML. Supporting goals include: 1. Refinement of the ESML schema and software libraries in cooperation with the user community. 2. Application of the ESML schema and software libraries to a variety of Earth science data sets and analysis tools. 3. Development of supporting prototype software for enhanced ease of use. 4. Cooperation with standards bodies in order to assure ESML is aligned with related metadata standards as appropriate. 5. Widespread publication of the ESML approach, schema, and software.

Understanding Student Mobility in the B.C. Public Post-Secondary System. Highlights from the Student Transitions Project: Post-Secondary Student Mobility

ERIC Educational Resources Information Center

British Columbia Council on Admissions and Transfer, 2013

2013-01-01

This annual newsletter summarizes the work of the Post-secondary Student Mobility (PSM) Subcommittee of the Student Transitions Project (STP) . In an effort to better understand student mobility in the B.C. public post-secondary system, the Student Transitions Project continues to describe and quantify the numerous education pathways of students…

Transitioning a Large Scale HIV/AIDS Prevention Program to Local Stakeholders: Findings from the Avahan Transition Evaluation

PubMed Central

Bennett, Sara; Singh, Suneeta; Rodriguez, Daniela; Ozawa, Sachiko; Singh, Kriti; Chhabra, Vibha; Dhingra, Neeraj

2015-01-01

Background Between 2009–2013 the Bill and Melinda Gates Foundation transitioned its HIV/AIDS prevention initiative in India from being a stand-alone program outside of government, to being fully government funded and implemented. We present an independent prospective evaluation of the transition. Methods The evaluation drew upon (1) a structured survey of transition readiness in a sample of 80 targeted HIV prevention programs prior to transition; (2) a structured survey assessing institutionalization of program features in a sample of 70 targeted intervention (TI) programs, one year post-transition; and (3) case studies of 15 TI programs. Findings Transition was conducted in 3 rounds. While the 2009 transition round was problematic, subsequent rounds were implemented more smoothly. In the 2011 and 2012 transition rounds, Avahan programs were well prepared for transition with the large majority of TI program staff trained for transition, high alignment with government clinical, financial and managerial norms, and strong government commitment to the program. One year post transition there were significant program changes, but these were largely perceived positively. Notable negative changes were: limited flexibility in program management, delays in funding, commodity stock outs, and community member perceptions of a narrowing in program focus. Service coverage outcomes were sustained at least six months post-transition. Interpretation The study suggests that significant investments in transition preparation contributed to a smooth transition and sustained service coverage. Notwithstanding, there were substantive program changes post-transition. Five key lessons for transition design and implementation are identified. PMID:26327591

Ground-based Search of Earth-mass Exoplanets using Transit-Timing Variations

NASA Astrophysics Data System (ADS)

Fernandez, J. M.

2010-10-01

This work presents recent results from a ground-based transit follow-up program of the extrasolar planet XO-2b in order to find Earth-mass companions. It also introduces the future use of the MONET 1m-class robotic telescopes as part of the effort to overcome the difficulties of this kind of project.

Mercury Solar Transit

NASA Image and Video Library

2016-05-09

The planet Mercury is seen in silhouette, lower left, as it transits across the face of the sun Monday, May 9, 2016, as viewed from Boyertown, Pennsylvania. Mercury passes between Earth and the sun only about 13 times a century, with the previous transit taking place in 2006. Photo Credit: (NASA/Bill Ingalls)

Mercury Solar Transit

NASA Image and Video Library

2016-05-09

The planet Mercury is seen in silhouette, lower left of image, as it transits across the face of the sun, Monday, May 9, 2016, as viewed from Boyertown, Pennsylvania. Mercury passes between Earth and the sun only about 13 times a century, with the previous transit taking place in 2006. Photo Credit: (NASA/Bill Ingalls)

Mercury Solar Transit

NASA Image and Video Library

2016-05-09

The planet Mercury is seen in silhouette, lower center of image, as it transits across the face of the sun, Monday, May 9, 2016, as viewed from Boyertown, Pennsylvania. Mercury passes between Earth and the sun only about 13 times a century, with the previous transit taking place in 2006. Photo Credit: (NASA/Bill Ingalls)

Mercury Solar Transit

NASA Image and Video Library

2016-05-09

The planet Mercury is seen in silhouette, lower third of image, as it transits across the face of the sun Monday, May 9, 2016, as viewed from Boyertown, Pennsylvania. Mercury passes between Earth and the sun only about 13 times a century, with the previous transit taking place in 2006. Photo Credit: (NASA/Bill Ingalls)

High-pressure phase transitions in rare earth metal thulium to 195 GPa.

PubMed

Montgomery, Jeffrey M; Samudrala, Gopi K; Tsoi, Georgiy M; Vohra, Yogesh K

2011-04-20

We have performed image plate x-ray diffraction studies on a heavy rare earth metal, thulium (Tm), in a diamond anvil cell to a pressure of 195 GPa and volume compression V/V₀ = 0.38 at room temperature. The rare earth crystal structure sequence, hcp →Sm-type→ dhcp →fcc → distorted fcc, is observed in Tm below 70 GPa with the exception of a pure fcc phase. The focus of our study is on the ultrahigh-pressure phase transition and Rietveld refinement of crystal structures in the pressure range between 70 and 195 GPa. The hexagonal hR-24 phase is seen to describe the distorted fcc phase between 70 and 124 GPa. Above 124 ± 4 GPa, a structural transformation from hR 24 phase to a monoclinic C 2/m phase is observed with a volume change of -1.5%. The equation of state data shows rapid stiffening above the phase transition at 124 GPa and is indicative of participation of f-electrons in bonding. We compare the behavior of Tm to other heavy rare-earths and heavy actinide metals under extreme conditions of pressure.

High-pressure phase transitions in rare earth metal thulium to 195 GPa

NASA Astrophysics Data System (ADS)

Montgomery, Jeffrey M.; Samudrala, Gopi K.; Tsoi, Georgiy M.; Vohra, Yogesh K.

2011-04-01

We have performed image plate x-ray diffraction studies on a heavy rare earth metal, thulium (Tm), in a diamond anvil cell to a pressure of 195 GPa and volume compression V/Vo = 0.38 at room temperature. The rare earth crystal structure sequence, {hcp}\\to {Sm {-}type} \\to {dhcp} \\to {fcc} \\to distorted fcc, is observed in Tm below 70 GPa with the exception of a pure fcc phase. The focus of our study is on the ultrahigh-pressure phase transition and Rietveld refinement of crystal structures in the pressure range between 70 and 195 GPa. The hexagonal hR- 24 phase is seen to describe the distorted fcc phase between 70 and 124 GPa. Above 124 ± 4 GPa, a structural transformation from hR 24 phase to a monoclinic C 2/m phase is observed with a volume change of - 1.5%. The equation of state data shows rapid stiffening above the phase transition at 124 GPa and is indicative of participation of f-electrons in bonding. We compare the behavior of Tm to other heavy rare-earths and heavy actinide metals under extreme conditions of pressure.

Dual Credit: Secondary to Post-Secondary Transitions--Dual Credit Policy and Practice in BC and Elsewhere

ERIC Educational Resources Information Center

FitzGibbon, John

2015-01-01

There has been considerable interest in British Columbia in improving secondary to post-secondary transitions, and the provincial government and secondary and post-secondary institutions have adopted a number of strategies intended to aid in successful student transition from one system to the other. This paper looks specifically at the policy and…

Transition and Post-School Outcomes for Youth with Disabilities: Closing the Gaps to Post-Secondary Education and Employment.

ERIC Educational Resources Information Center

National Council on Disability, Washington, DC.

This report presents an analysis of research on the state of transition, post-secondary education, and employment outcomes for youth and young adults with disabilities over the past 25 years. It identifies what has worked in the areas of transition planning, services, and supports. It also considers what should work in light of unmet needs and…

Venus transit 2004: An international education program

NASA Astrophysics Data System (ADS)

Mayo, L.; Odenwald, S.

2003-04-01

December 6th, 1882 was the last transit of the planet Venus across the disk of the sun. It was heralded as an event of immense interest and importance to the astronomical community as well as the public at large. There have been only six such occurrences since Galileo first trained his telescope on the heavens in 1609 and on Venus in 1610 where he concluded that Venus had phases like the moon and appeared to get larger and smaller over time. Many historians consider this the final nail in the coffin of the Ptolemaic, Earth centered solar system. In addition, each transit has provided unique opportunities for discovery such as measurement and refinement of the detection of Venus' atmosphere, calculation of longitudes, and calculation of the astronomical unit (and therefore the scale of the solar system). The NASA Sun Earth Connection Education Forum (SECEF) in partnership with the Solar System Exploration (SSE) and Structure and Evolution of the Universe (SEU) Forums, AAS Division for Planetary Sciences (DPS), and a number of NASA space missions and science centers are developing plans for an international education program centered around the June 8, 2004 Venus transit. The transit will be visible in its entirety from Europe and partially from the East Coast of the United States. We will use a series of robotic observatories including the Telescopes In Education (TIE) network distributed in latitude to provide observations of the transit that will allow middle and high school students to calculate the A.U. through application of parallax. We will compare the terrestrial planets in terms of the evolutionary processes that define their magnetic fields, their widely differing interactions with the solar wind, and the implications this has for life on Earth and elsewhere in the universe. We will also use Venus transit as a probe of episodes in American history (e.g. 1769: revolutionary era, 1882: post civil war era, and 2004: modern era). Museums and planetariums in

Neutron Diffraction Studies of Some Rare Earth-Transition Metal Deuterides.

DTIC Science & Technology

1986-05-01

RD-A168 M NEUTRON DIFFRACTION STUDIES OF SONE RARE EARTH-TRANSITION METAL DEUTERIDES(U) MISSOURI UNIV-ROLLR MATERIALS RESEARCH CENTER N J JAMES MY 86...REPORT William J. James OTtO -il May 1986 ZLECTEJU U. S. Army Research Office DAAG29-83-K-01 59 ".;’ Graduate Center for Materials Research ...9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT, PROJECT. TASK AREA & WORK UNIT NUMBERS 2* Graduate Center for Materials Research

NASA's SDO Captures Mercury Transit Time-lapses SDO Captures Mercury Transit Time-lapse

NASA Image and Video Library

2017-12-08

Less than once per decade, Mercury passes between the Earth and the sun in a rare astronomical event known as a planetary transit. The 2016 Mercury transit occurred on May 9th, between roughly 7:12 a.m. and 2:42 p.m. EDT. The images in this video are from NASA’s Solar Dynamics Observatory Music: Encompass by Mark Petrie For more info on the Mercury transit go to: www.nasa.gov/transit This video is public domain and may be downloaded at: svs.gsfc.nasa.gov/12235 NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Two planetary systems with transiting Earth-size and super-Earth planets orbiting late-type dwarf stars

NASA Astrophysics Data System (ADS)

Alonso, E. Díez; Hernández, J. I. González; Suárez Gómez, S. L.; Aguado, D. S.; González Gutiérrez, C.; Suárez Mascareño, A.; Cabrera-Lavers, A.; González-Nuevo, J.; Toledo-Padrón, B.; Gracia, J.; de Cos Juez, F. J.; Rebolo, R.

2018-06-01

We present two new planetary systems found around cool dwarf stars with data from the K2 mission. The first system was found in K2-XX1 (EPIC 248545986), characterized in this work as M3.0V and observed in the 14th campaign of K2. It consists of three Earth-size transiting planets with radii of 1.1, 1.0 and 1.1 R⊕, showing a compact configuration with orbital periods of 5.24, 7.78 and 10.1 days, close to 2:3:4 resonance. The second was found in K2-XX2 (EPIC 249801827), characterized in this work as M0.5V and observed in the 15th campaign. It consists of two transiting super-Earths with radii 2.0 and 1.8 R⊕ and orbital periods of 6.03 and 20.5 days. The equilibrium temperatures of the atmospheres of these planets are estimated to be in the range of 380-600 K and the amplitudes of signals in transmission spectroscopy are estimated at ˜ 10 ppm.

Three 2012 Transits of Venus: From Earth, Jupiter, and Saturn

NASA Astrophysics Data System (ADS)

Pasachoff, Jay M.; Schneider, G.; Babcock, B. A.; Lu, M.; Edelman, E.; Reardon, K.; Widemann, T.; Tanga, P.; Dantowitz, R.; Silverstone, M. D.; Ehrenreich, D.; Vidal-Madjar, A.; Nicholson, P. D.; Willson, R. C.; Kopp, G. A.; Yurchyshyn, V. B.; Sterling, A. C.; Scherrer, P. H.; Schou, J.; Golub, L.; McCauley, P.; Reeves, K.

2013-01-01

We observed the 2012 June 6/5 transit seen from Earth (E/ToV), simultaneously with Venus Express and several other spacecraft not only to study the Cytherean atmosphere but also to provide an exoplanet-transit analog. From Haleakala, the whole transit was visible in coronal skies; among our instruments was one of the world-wide Venus Twilight Experiment's nine coronagraphs. Venus's atmosphere became visible before first contact. SacPeak/IBIS provided high-resolution images at Hα/carbon-dioxide. Big Bear's NST also provided high-resolution observations of the Cytherean atmosphere and black-drop evolution. Our liaison with UH's Mees Solar Observatory scientists provided magneto-optical imaging at calcium and potassium. Solar Dynamics Observatory's AIA and HMI, and the Solar Optical Telescope (SOT) and X-ray Telescope (XRT) on Hinode, and total-solar-irradiance measurements with ACRIMSAT and SORCE/TIM, were used to observe the event as an exoplanet-transit analog. On September 20, we imaged Jupiter for 14 Hubble Space Telescope orbits, centered on a 10-hour ToV visible from Jupiter (J/ToV), as an exoplanet-transit analog in our own solar system, using Jupiter as an integrating sphere. Imaging was good, although much work remains to determine if we can detect the expected 0.01% solar irradiance decrease at Jupiter and the even slighter differential effect between our violet and near-infrared filters caused by Venus's atmosphere. We also give a first report on our currently planned December 21 Cassini UVIS observations of a transit of Venus from Saturn (S/ToV). Our E/ToV expedition was sponsored by the Committee for Research and Exploration/National Geographic Society; supplemented: NASA/AAS's Small Research Grant Program. We thank Rob Ratkowski, Stan Truitt, Rob Lucas, Aram Friedman, and Eric Pilger '82 at Haleakala, and Joseph Gangestad '06 at Big Bear for assistance, and Lockheed Martin Solar and Astrophysics Lab and Hinode science and operations teams for support

Factors in Successful Post-School Transitions. Research Brief. Winter 2013

ERIC Educational Resources Information Center

LoBianco, Tony; Kleinert, Harold L.

2013-01-01

Young adults with disabilities face multiple challenges in obtaining successful post-school outcomes. In a National Longitudinal Transition Study-2 report, Wagner, Newman, Cameto, Garza, and Levine (2005) found that for former students with disabilities, 70% had engaged in paid employment since leaving high school, though only 40% were employed at…

Major evolutionary transitions in individuality

PubMed Central

West, Stuart A.; Fisher, Roberta M.; Gardner, Andy; Kiers, E. Toby

2015-01-01

The evolution of life on earth has been driven by a small number of major evolutionary transitions. These transitions have been characterized by individuals that could previously replicate independently, cooperating to form a new, more complex life form. For example, archaea and eubacteria formed eukaryotic cells, and cells formed multicellular organisms. However, not all cooperative groups are en route to major transitions. How can we explain why major evolutionary transitions have or haven’t taken place on different branches of the tree of life? We break down major transitions into two steps: the formation of a cooperative group and the transformation of that group into an integrated entity. We show how these steps require cooperation, division of labor, communication, mutual dependence, and negligible within-group conflict. We find that certain ecological conditions and the ways in which groups form have played recurrent roles in driving multiple transitions. In contrast, we find that other factors have played relatively minor roles at many key points, such as within-group kin discrimination and mechanisms to actively repress competition. More generally, by identifying the small number of factors that have driven major transitions, we provide a simpler and more unified description of how life on earth has evolved. PMID:25964342

Chain Breakage in the Supercooled Liquid - Liquid Transition and Re-entry of the λ-transition in Sulfur.

PubMed

Zhang, Linji; Ren, Yang; Liu, Xiuru; Han, Fei; Evans-Lutterodt, Kenneth; Wang, Hongyan; He, Yali; Wang, Junlong; Zhao, Yong; Yang, Wenge

2018-03-14

Amorphous sulfur was prepared by rapid compression of liquid sulfur at temperatures above the λ-transition for to preserve the high-temperature liquid structure. We conducted synchrotron high-energy X-ray diffraction and Raman spectroscopy to diagnose the structural evolution of amorphous sulfur from room temperature to post-λ-transition temperature. Discontinuous changes of the first and second peaks in atomic pair-distribution-function, g(r), were observed during the transition from amorphous to liquid sulfur. The average first-neighbor coordination numbers showed an abrupt drop from 1.92 to 1.81. The evolution of the chain length clearly shows that the transition was accompanied by polymeric chains breaking. Furthermore, a re-entry of the λ-transition structure was involved in the heating process. The amorphous sulfur, which inherits the post-λ-transition structure from its parent melts, transformed to the pre-λ-transition liquid structure at around 391 K. Upon further heating, the pre-λ-transition liquid transformed to a post-λ-transition structure through the well-known λ-transition process. This discovery offers a new perspective on amorphous sulfur's structural inheritance from its parent liquid and has implications for understanding the structure, evolution and properties of amorphous sulfur and its liquids.

47 CFR 73.616 - Post-transition DTV station interference protection.

Code of Federal Regulations, 2013 CFR

2013-10-01

... RADIO SERVICES RADIO BROADCAST SERVICES Television Broadcast Stations § 73.616 Post-transition DTV... land mobile protection requirements of § 73.623(e); and the FM radio protection requirement of § 73.623... through the Internet at http://www.fcc.gov/oet/info/documents/bulletins/#69. Note to § 73.616: When this...

47 CFR 73.616 - Post-transition DTV station interference protection.

Code of Federal Regulations, 2014 CFR

2014-10-01

... RADIO SERVICES RADIO BROADCAST SERVICES Television Broadcast Stations § 73.616 Post-transition DTV... land mobile protection requirements of § 73.623(e); and the FM radio protection requirement of § 73.623... through the Internet at http://www.fcc.gov/oet/info/documents/bulletins/#69. Note to § 73.616: When this...

Dynamics of Mantle Plume Controlled by both Post-spinel and Post-garnet Phase Transitions

NASA Astrophysics Data System (ADS)

Liu, H.; Leng, W.

2017-12-01

Mineralogical studies indicate that two major phase transitions occur near 660 km depth in the Earth's pyrolitic mantle: the ringwoodite (Rw) to perovskite (Pv) + magnesiowüstite (Mw) and majorite (Mj) to perovskite (Pv) phase transitions. Seismological results also show a complicated phase boundary structure for plume regions at this depth, including broad pulse, double reflections and depressed 660 km discontinuity beneath hot regions etc… These observations have been attributed to the co-existence of these two phase transformations. However, previous geodynamical modeling mainly focused on the effects of Rw-Pv+Mw phase transition on the plume dynamics and largely neglected the effects of Mj-Pv phase transition. Here we develop a 3-D regional spherical geodynamic model to study the influence of the combination of Rw - Pv+Mw and Mj - Pv phase transitions on plume dynamics, including the topography fluctuation of 660 km discontinuity, plume shape and penetration capability of plume. Our results show that (1) a double phase boundary occurs at the hot center area of plume while for other regions with relatively lower temperature the phase boundary is single and flat, which respectively corresponds to the double reflections in the seismic observations and a high velocity prism-like structure at the top of 660 km discontinuity; (2) a large amount of low temperature plume materials could be trapped to form a complex trapezoid overlying the 660 km depth; (3) Mj - Pv phase change strongly enhances the plume penetration capability at 660 km depth, which significantly increases the plume mass flux due to the increased plume radius, but significantly reduces plume heat flux due to the decreased plume temperature in the upper mantle. Our model results provide new enlightenments for better constraining seismic structure and mineral reactions at 660 km phase boundaries.

Transit of Venus 2004 [detail

NASA Image and Video Library

2017-12-08

To read more about the 2012 Venus Transit go to: sunearthday.nasa.gov/transitofvenus Add your photos of the Transit of Venus to our Flickr Group here: www.flickr.com/groups/venustransit/ NASA FILE PHOTO Date: 8 Jun 2004 NASA's TRACE satellite captured this image of Venus crossing the face of the Sun as seen from Earth orbit. The last event occurred in 1882. The next Venus transit will be visible in 2012. This image also is a good example of the scale of Earth to the Sun since Venus and Earth are similar in size. Credit: NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Perspectives of Post-Acute Transition of Care for Cardiac Surgery Patients

PubMed Central

Stoicea, Nicoleta; You, Tian; Eiterman, Andrew; Hartwell, Clifton; Davila, Victor; Marjoribanks, Stephen; Florescu, Cristina; Bergese, Sergio Daniel; Rogers, Barbara

2017-01-01

Post-acute care (PAC) facilities improve patient recovery, as measured by activities of daily living, rehabilitation, hospital readmission, and survival rates. Seamless transitions between discharge and PAC settings continue to be challenges that hamper patient outcomes, specifically problems with effective communication and coordination between hospitals and PAC facilities at patient discharge, patient adherence and access to cardiac rehabilitation (CR) services, caregiver burden, and the financial impact of care. The objective of this review is to examine existing models of cardiac transitional care, identify major challenges and social factors that affect PAC, and analyze the impact of current transitional care efforts and strategies implemented to improve health outcomes in this patient population. We intend to discuss successful methods to address the following aspects: hospital-PAC linkages, improved discharge planning, caregiver burden, and CR access and utilization through patient-centered programs. Regular home visits by healthcare providers result in decreased hospital readmission rates for patients utilizing home healthcare while improved hospital-PAC linkages reduced hospital readmissions by 25%. We conclude that widespread adoption of improvements in transitional care will play a key role in patient recovery and decrease hospital readmission, morbidity, and mortality. PMID:29230400

Perspectives of Post-Acute Transition of Care for Cardiac Surgery Patients.

PubMed

Stoicea, Nicoleta; You, Tian; Eiterman, Andrew; Hartwell, Clifton; Davila, Victor; Marjoribanks, Stephen; Florescu, Cristina; Bergese, Sergio Daniel; Rogers, Barbara

2017-01-01

Post-acute care (PAC) facilities improve patient recovery, as measured by activities of daily living, rehabilitation, hospital readmission, and survival rates. Seamless transitions between discharge and PAC settings continue to be challenges that hamper patient outcomes, specifically problems with effective communication and coordination between hospitals and PAC facilities at patient discharge, patient adherence and access to cardiac rehabilitation (CR) services, caregiver burden, and the financial impact of care. The objective of this review is to examine existing models of cardiac transitional care, identify major challenges and social factors that affect PAC, and analyze the impact of current transitional care efforts and strategies implemented to improve health outcomes in this patient population. We intend to discuss successful methods to address the following aspects: hospital-PAC linkages, improved discharge planning, caregiver burden, and CR access and utilization through patient-centered programs. Regular home visits by healthcare providers result in decreased hospital readmission rates for patients utilizing home healthcare while improved hospital-PAC linkages reduced hospital readmissions by 25%. We conclude that widespread adoption of improvements in transitional care will play a key role in patient recovery and decrease hospital readmission, morbidity, and mortality.

Mercury Transit Across the Sun

NASA Image and Video Library

2016-05-09

On May 9, 2016, Mercury passed directly between the Sun and Earth, making a transit of the Sun. Mercury transits happen about 13 times each century. NASA SDO studies the Sun 24/7 and captured the eight-hour event.

Mercury Solar Transit

NASA Image and Video Library

2016-05-09

Boyertown Area High School astronomy teacher Peter Detterline prepares high powered binoculars with a solar filter so that his students may view the planet Mercury as it transits across the face of the sun , Monday, May 9, 2016, Boyertown Area High School, Boyertown, Pennsylvania. Mercury passes between Earth and the sun only about 13 times a century, with the previous transit taking place in 2006. Photo Credit: (NASA/Bill Ingalls)

Mercury Solar Transit

NASA Image and Video Library

2016-05-09

Boyertown Area High School 12th grade student Jay Hallman looks through a photographers lens and solar filter to see the planet Mercury as it transits across the face of the sun , Monday, May 9, 2016, Boyertown area High School, Boyertown, Pennsylvania. Mercury passes between Earth and the sun only about 13 times a century, with the previous transit taking place in 2006. Photo Credit: (NASA/Bill Ingalls)

Mercury Solar Transit

NASA Image and Video Library

2016-05-09

Boyertown Area High School 12th grade student Ben Maurer uses his smartphone and a photographers lens with a solar filter to make a photograph of the planet Mercury transitting the sun, Monday, May 9, 2016, Boyertown area High School, Boyertown, Pennsylvania. Mercury passes between Earth and the sun only about 13 times a century, with the previous transit taking place in 2006. Photo Credit: (NASA/Bill Ingalls)

Mercury Solar Transit

NASA Image and Video Library

2016-05-09

Boyertown Area High School students, 12th grader Bransen Mackey, left, and 11th grader Nick Cioppi wear solar safety glasses and attempt to see the planet Mercury as it transits across the face of the sun, Monday, May 9, 2016, Boyertown, Pennsylvania. Mercury passes between Earth and the sun only about 13 times a century, with the previous transit taking place in 2006. Photo Credit: (NASA/Bill Ingalls)

K2-155: A Bright Metal-poor M Dwarf with Three Transiting Super-Earths

NASA Astrophysics Data System (ADS)

Hirano, Teruyuki; Dai, Fei; Livingston, John H.; Fujii, Yuka; Cochran, William D.; Endl, Michael; Gandolfi, Davide; Redfield, Seth; Winn, Joshua N.; Guenther, Eike W.; Prieto-Arranz, Jorge; Albrecht, Simon; Barragan, Oscar; Cabrera, Juan; Cauley, P. Wilson; Csizmadia, Szilard; Deeg, Hans; Eigmüller, Philipp; Erikson, Anders; Fridlund, Malcolm; Fukui, Akihiko; Grziwa, Sascha; Hatzes, Artie P.; Korth, Judith; Narita, Norio; Nespral, David; Niraula, Prajwal; Nowak, Grzegorz; Pätzold, Martin; Palle, Enric; Persson, Carina M.; Rauer, Heike; Ribas, Ignasi; Smith, Alexis M. S.; Van Eylen, Vincent

2018-03-01

We report on the discovery of three transiting super-Earths around K2-155 (EPIC 210897587), a relatively bright early M dwarf (V = 12.81 mag) observed during Campaign 13 of the NASA K2 mission. To characterize the system and validate the planet candidates, we conducted speckle imaging and high-dispersion optical spectroscopy, including radial velocity measurements. Based on the K2 light curve and the spectroscopic characterization of the host star, the planet sizes and orbital periods are {1.55}-0.17+0.20 {R}\\oplus and 6.34365 ± 0.00028 days for the inner planet; {1.95}-0.22+0.27 {R}\\oplus and 13.85402 ± 0.00088 days for the middle planet; and {1.64}-0.17+0.18 {R}\\oplus and 40.6835 ± 0.0031 days for the outer planet. The outer planet (K2-155d) is near the habitable zone, with an insolation 1.67 ± 0.38 times that of the Earth. The planet’s radius falls within the range between that of smaller rocky planets and larger gas-rich planets. To assess the habitability of this planet, we present a series of three-dimensional global climate simulations, assuming that K2-155d is tidally locked and has an Earth-like composition and atmosphere. We find that the planet can maintain a moderate surface temperature if the insolation proves to be smaller than ∼1.5 times that of the Earth. Doppler mass measurements, transit spectroscopy, and other follow-up observations should be rewarding, as K2-155 is one of the optically brightest M dwarfs known to harbor transiting planets.

Separation of rare earths from transition metals by liquid-liquid extraction from a molten salt hydrate to an ionic liquid phase.

PubMed

Rout, Alok; Binnemans, Koen

2014-02-28

The solvent extraction of trivalent rare-earth ions and their separation from divalent transition metal ions using molten salt hydrates as the feed phase and an undiluted fluorine-free ionic liquid as the extracting phase were investigated in detail. The extractant was tricaprylmethylammonium nitrate, [A336][NO3], and the hydrated melt was calcium nitrate tetrahydrate, Ca(NO3)2·4H2O. The extraction behavior of rare-earth ions was studied for solutions of individual elements, as well as for mixtures of rare earths in the hydrated melt. The influence of different extraction parameters was investigated: the initial metal loading in the feed phase, percentage of water in the feed solution, equilibration time, and the type of hydrated melt. The extraction of rare earths from Ca(NO3)2·4H2O was compared with extraction from CaCl2·4H2O by [A336][Cl] (Aliquat 336). The nitrate system was found to be the better one. The extraction and separation of rare earths from the transition metals nickel, cobalt and zinc were also investigated. Remarkably high separation factors of rare-earth ions over transition metal ions were observed for extraction from Ca(NO3)2·4H2O by the [A336][NO3] extracting phase. Furthermore, rare-earth ions could be separated efficiently from transition metal ions, even in melts with very high concentrations of transition metal ions. Rare-earth oxides could be directly dissolved in the Ca(NO3)2·4H2O phase in the presence of small amounts of Al(NO3)3·9H2O or concentrated nitric acid. The efficiency of extraction after dissolving the rare-earth oxides in the hydrated nitrate melt was identical to extraction from solutions with rare-earth nitrates dissolved in the molten phase. The stripping of the rare-earth ions from the loaded ionic liquid phase and the reuse of the recycled ionic liquid were also investigated in detail.

Lattice vibrations and electronic transitions in the rare-earth metals: yttrium, gadolinium and lutetium.

PubMed

Olijnyk, Helmut

2005-01-12

Lattice vibrations in high-pressure phases of Y, Gd and Lu were studied by Raman spectroscopy. The observed phonon frequencies decrease towards the transitions to the dhcp and fcc phases. There is evidence that the entire structural sequence [Formula: see text] under pressure for the individual regular rare-earth metals and along the lanthanide series at ambient pressure involve softening of certain acoustic and optical phonon modes and of the elastic shear modulus C(44). Comparison is made to transitions between close-packed lattices in other metals, and possible correlations to s-d electron transfer are discussed.

Lost in Transition: HIV Prevalence and Correlates of Infection among Young People Living in Post-Emergency Phase Transit Camps in Gulu District, Northern Uganda

PubMed Central

Patel, Sheetal; Schechter, Martin T.; Sewankambo, Nelson K.; Atim, Stella; Kiwanuka, Noah; Spittal, Patricia M.

2014-01-01

Objective Little is known about HIV infection and the related vulnerabilities of young people living in resource-scarce, post-emergency transit camps that are now home to thousands of Internally Displaced Persons (IDPs) following two decades of war in northern Uganda. The objective of this analysis was to assess the prevalence and correlates of HIV infection among young people living in post-conflict transition in Gulu District, northern Uganda. Methods In 2010, a cross-sectional demographic and behavioural survey was conducted in two of Gulu District’s sub-counties with 384 purposively selected transit camp residents aged 15 to 29 years. Biological specimens were collected for rapid HIV testing in the field and confirmatory laboratory testing. Multivariable logistic regression identified independent determinants of HIV infection. Results HIV prevalence was alarmingly high at 12.8% (95% CI: 9.6%, 16.5%). The strongest determinant of HIV infection among young people was a non-consensual sexual debut (adjusted odds ratio [AOR], 9.88; 95% CI: 1.70–18.06). Residing in Awach sub-county (AOR, 2.93; 95% CI: 1.28–6.68), experiencing STI symptoms in the previous 12 months (AOR, 2.36; 95% CI: 1.43–6.17), and practicing dry sex (AOR, 2.31; 95% CI: 1.04–5.13) were other key determinants of HIV infection. Conclusions Study findings contribute to filling an important gap in epidemiological evidence and are useful for planning public health interventions in northern Uganda that effectively target young people in post-conflict transition and support them in the resettlement process. Findings serve to recommend reaching beyond traditional prevention programming in a way more effectively beneficial to young people in post-conflict settings by developing population-specific responses sensitive to local contexts and sufficient to address the underlying causes of the complex risk factors influencing the spread of HIV. PMID:24587034

Public Pedagogy via PostSecret: A Transitional Space Where Private and Public Coincide

ERIC Educational Resources Information Center

Motter, Jennifer L.

2011-01-01

PostSecret (www.postsecret.com) is a transitional space where the in-betweenness of public and private exists. Within this space, peer public pedagogy occurs through critical participatory democratic interactions of community participants. Integrating PostSecret into the art education curriculum can offer the potential for generative knowledge…

An Educational Transition: Post-Secondary Correctional Education--A Qualitative Case Study

ERIC Educational Resources Information Center

Bartholomew, Greg

2013-01-01

Administration of post-secondary correctional education (PSCE) programs within state was vastly changed through legislation enacted in 2009. This study examined the transition of a PSCE system formerly facilitated by higher education to the current system administered by the State Department of Corrections (SDC). This qualitative case study…

Reconstructing Transition Knowledge in Taiwan

ERIC Educational Resources Information Center

Cheng, Chen-chen

2012-01-01

Taking a post-colonial stand and using school to work transition as an example, the author re-examines the special education discourses in Taiwan and attempts to construct alternate understandings of transition from sociological and cultural perspectives. A review of past transition literature and a survey of the educational background of the…

The reduced transition probabilities for excited states of rare-earths and actinide even-even nuclei

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

Ghumman, S. S.

The theoretical B(E2) ratios have been calculated on DF, DR and Krutov models. A simple method based on the work of Arima and Iachello is used to calculate the reduced transition probabilities within SU(3) limit of IBA-I framework. The reduced E2 transition probabilities from second excited states of rare-earths and actinide even–even nuclei calculated from experimental energies and intensities from recent data, have been found to compare better with those calculated on the Krutov model and the SU(3) limit of IBA than the DR and DF models.

A liquid-liquid transition can exist in monatomic transition metals with a positive melting slope

PubMed Central

Lee, Byeongchan; Lee, Geun Woo

2016-01-01

Liquid-liquid transitions under high pressure are found in many elemental materials, but the transitions are known to be associated with either sp-valent materials or f-valent rare-earth elements, in which the maximum or a negative slope in the melting line is readily suggestive of the transition. Here we find a liquid-liquid transition with a positive melting slope in transition metal Ti from structural, electronic, and thermodynamic studies using ab-initio molecular dynamics calculations, showing diffusion anomaly, but no density anomaly. The origin of the transition in liquid Ti is a pressure-induced increase of local structures containing very short bonds with directionality in electronic configurations. This behavior appears to be characteristic of the early transition metals. In contrast, the late transition metal liquid Ni does not show the L-L transition with pressure. This result suggests that the possibility of the L-L transition decreases from early to late transition metals as electronic structures of late transition metals barely have a Jahn-Teller effect and bond directionality. Our results generalize that a phase transition in disordered materials is found with any valence band regardless of the sign of the melting slope, but related to the symmetry of electronic structures of constituent elements. PMID:27762334

Does What You Study at Age 14-16 Matter for Educational Transitions Post-16?

ERIC Educational Resources Information Center

Moulton, Vanessa; Sullivan, Alice; Henderson, Morag; Anders, Jake

2018-01-01

This paper considers whether subject choice at 14-16 influences post-16 transitions, taking into account prior academic attainment and school characteristics, and if so, whether this accounts for socioeconomic, gender, and ethnic differences in access to post-16 education. We consider post-16 progression to full-time education, A-levels, and…

Parents' and Students' Perspectives of Transition Planning and Post-Secondary Outcomes

ERIC Educational Resources Information Center

Morgan, Valda R. Beasley

2010-01-01

One of many responsibilities for public schools concerning students with mental retardation is to assist students with the development of their individual transition plans. The purpose of this study was to evaluate if post-secondary outcomes identified for students with mental retardation while in public school were the actual outcomes in which…

Lattice vibrations and electronic transitions in the rare-earth metals: yttrium, gadolinium and lutetium

NASA Astrophysics Data System (ADS)

Olijnyk, Helmut

2005-01-01

Lattice vibrations in high-pressure phases of Y, Gd and Lu were studied by Raman spectroscopy. The observed phonon frequencies decrease towards the transitions to the dhcp and fcc phases. There is evidence that the entire structural sequence {\\mathrm {hcp \\to Sm\\mbox {-}type \\to dhcp \\to fcc}} under pressure for the individual regular rare-earth metals and along the lanthanide series at ambient pressure involve softening of certain acoustic and optical phonon modes and of the elastic shear modulus C44. Comparison is made to transitions between close-packed lattices in other metals, and possible correlations to s-d electron transfer are discussed.

Physiological consequences of military high-speed boat transits.

PubMed

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

2011-09-01

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

Applying an ecological framework to understand transition pathways to post-secondary education for youth with physical disabilities.

PubMed

Lindsay, Sally; Duncanson, Michelle; Niles-Campbell, Nadia; McDougall, Carolyn; Diederichs, Sara; Menna-Dack, Dolly

2018-02-01

The purpose of this study was to explore the experiences of youth with physical disabilities and clinicians who support them in their transition to post-secondary education (PSE). Most research on transition to PSE has focused on youth with intellectual disabilities while there is a lack of research on youth with physical disabilities. This study drew on 30 interviews with 20 youth with disabilities and 10 clinicians. We used Bronfrenbrenner's ecological framework to inform our analysis. Our results showed that there are several important individual skills that youth need to be successful in transitioning to PSE. Youth with disabilities experienced supports from peers and family that influence their transition to PSE. Several disability-specific issues (e.g., coping, self-care, disclosure, and accommodations) were often a barrier to transitioning to PSE. Clinicians and youth both reported that improved inter-professional collaboration and inter-agency partnerships were needed to enhance the transition experience. Societal attitudes (stigma and discrimination), policies, and the timing of transitions also influence youth's transition. Applying an ecological approach helped to provide a more holistic perspective of the PSE transitions and emphasizes the need to consider more than just preparing individuals but also where they are transitioned. Implications for rehabilitation Clinicians and educators should continue to promote the development of relevant life skills (e.g., self-advocacy, disclosure, and navigating public transportation) that youth need to succeed in post-secondary education. Clinicians should continue to educate and support youth regarding the process for disclosing their condition and how to request and set up accommodations in PSE. Clinicians should connect youth with disabilities to appropriate resources that can support them and continue to help them to set career goals and develop career plans. There is a critical need for improved inter

A key phase in the recruitment dynamics of coral reef fishes: post-settlement transition

USGS Publications Warehouse

Kaufman, L.; Ebersole, J.L.; Beets, Jim; McIvor, Carole

1992-01-01

Recent studies of recruitment dynamics in demersal fishes have placed major emphasis on presettlement mortality, and little on events bridging late larval and early juvenile periods. Observations on 68 taxa of Caribbean coral reef fishes before and during settlement revealed the existence of a distinct post-settlement life phase called the transition juvenile, associated with the act of recruitment. Transition juveniles were found as solitary individuals, in conspecific groups, or in heterospecific groups. The groups were either uniform or heterogenous in appearance. The complexity of the transition phase and its apparently widespread occurrence in coral reef fishes suggests that important aspects of population structure may be determined between settlement and first appearance as a full-fledged juvenile.

Lesions Responsible for Delayed Oral Transit Time in Post-stroke Dysphagia.

PubMed

Moon, Hyun Im; Yoon, Seo Yeon; Yi, Tae Im; Jeong, Yoon Jeong; Cho, Tae Hwan

2018-06-01

Some stroke patients show oral phase dysphagia, characterized by a markedly prolonged oral transit time that hinders oral feeding. The aim of this study was to clarify the clinical characteristics and lesions responsible for delayed swallowing. We reviewed 90 patients with stroke. The oral processing time plus the postfaucial aggregation time required to swallow semisolid food was assessed. The patients were divided into two groups according to oral transit time, and we analyzed the differences in characteristics such as demographic factors, lesion factors, and cognitive function. Logistic regression analyses were performed to examine the predictors of delayed oral transit time. Lesion location and volume were measured on brain magnetic resonance images. We generated statistic maps of lesions related to delayed oral phase in swallowing using voxel-based lesion symptom mapping (VLSM). The group of patients who showed delayed oral transit time had significantly low cognitive function. Also, in a regression model, delayed oral phase was predicted with low K-MMSE (Korean version of the Mini Mental Status Exam). Using VLSM, we found the lesion location to be associated with delayed oral phase after adjusting for K-MMSE score. Although these results did not reach statistical significance, they showed the lesion pattern with predominant distribution in the left frontal lobe. Delayed oral phase in post-stroke patients was not negligible clinically. Patients' cognitive impairments affect the oral transit time. When adjusting it, we found a trend that the lesion responsible for delayed oral phase was located in the left frontal lobe, though the association did not reach significance. The delay might be related to praxis function.

Calculating Absolute Transition Probabilities for Deformed Nuclei in the Rare-Earth Region

NASA Astrophysics Data System (ADS)

Stratman, Anne; Casarella, Clark; Aprahamian, Ani

2017-09-01

Absolute transition probabilities are the cornerstone of understanding nuclear structure physics in comparison to nuclear models. We have developed a code to calculate absolute transition probabilities from measured lifetimes, using a Python script and a Mathematica notebook. Both of these methods take pertinent quantities such as the lifetime of a given state, the energy and intensity of the emitted gamma ray, and the multipolarities of the transitions to calculate the appropriate B(E1), B(E2), B(M1) or in general, any B(σλ) values. The program allows for the inclusion of mixing ratios of different multipolarities and the electron conversion of gamma-rays to correct for their intensities, and yields results in absolute units or results normalized to Weisskopf units. The code has been tested against available data in a wide range of nuclei from the rare earth region (28 in total), including 146-154Sm, 154-160Gd, 158-164Dy, 162-170Er, 168-176Yb, and 174-182Hf. It will be available from the Notre Dame Nuclear Science Laboratory webpage for use by the community. This work was supported by the University of Notre Dame College of Science, and by the National Science Foundation, under Contract PHY-1419765.

Effects of spin transition on diffusion of Fe2+ in ferropericlase in Earth's lower mantle

NASA Astrophysics Data System (ADS)

Saha, Saumitra; Bengtson, Amelia; Crispin, Katherine L.; van Orman, James A.; Morgan, Dane

2011-11-01

Knowledge of Fe composition in lower-mantle minerals (primarily perovskite and ferropericlase) is essential to a complete understanding of the Earth's interior. Fe cation diffusion potentially controls many aspects of the distribution of Fe in the Earth's lower mantle, including mixing of chemical heterogeneities, element partitioning, and the extent of core-mantle communications. Fe in ferropericlase has been shown to undergo a spin transition starting at about 40 GPa and exists in a mixture of high-spin and low-spin states over a wide range of pressures. Present experimental data on Fe transport in ferropericlase is limited to pressures below 35 GPa and provides little information on the pressure dependence of the activation volume and none on the impact of the spin transition on diffusion. Therefore, known experimental data on Fe diffusion cannot be reliably extrapolated to predict diffusion throughout the lower mantle. Here, first-principles and statistical modeling are combined to predict diffusion of Fe in ferropericlase over the entire lower mantle, including the effects of the Fe spin transition. A thorough statistical thermodynamic treatment is given to fully incorporate the coexistence of high- and low-spin Fe in the model of overall Fe diffusion in the lower mantle. Pure low-spin Fe diffuses approximately 104 times slower than high-spin Fe in ferropericlase but Fe diffusion of the mixed-spin state is only about 10 times slower than that of high-spin Fe. The predicted Fe diffusivities demonstrate that ferropericlase is unlikely to be rate limiting in transporting Fe in deep earth since much slower Fe diffusion in perovskite is predicted.

Detection of Terrestrial Planets Using Transit Photometry

NASA Technical Reports Server (NTRS)

Koch, David; Witteborn, Fred; Jenkins, Jon; Dunham, Edward; Boruci, William; DeVincenzi, Donald (Technical Monitor)

2001-01-01

Transit photometry detection of planets offers many advantages: an ability to detect terrestrial size planets, direct determination of the planet's size, applicability to all main-sequence stars, and a differential brightness change of the periodic signature being independent of stellar distance or planetary orbital semi-major axis. Ground and space based photometry have already been successful in detecting transits of the giant planet HD209458b. However, photometry 100 times better is required to detect terrestrial planets. We present results of laboratory measurements of an end-to-end photometric system incorporating all of the important confounding noise features of both the sky and a space based photometer including spacecraft jitter. In addition to demonstrating an instrumental noise of less than 10 ppm (an Earth transit of a solar-like star is 80 ppm), the brightnesses of individual stars were dimmed to simulate Earth-size transit signals. These 'transits' were reliably detected as part of the tests.

Electrochemical study of pre- and post-transition corrosion of Zr alloys in PWR coolant

NASA Astrophysics Data System (ADS)

Macák, Jan; Novotný, Radek; Sajdl, Petr; Renčiuková, Veronika; Vrtílková, Věra

Corrosion properties of Zr-Sn and Zr-Nb zirconium alloys were studied under simulated PWR conditions (or, more exactly, VVER conditions — boric acid, potassium hydroxide, lithium hydroxide) at temperatures up to 340°C and 15MPa using in-situ electrochemical impedance spectroscopy (EIS) and polarization measurements. EIS spectra were obtained in a wide range of frequencies (typically 100kHz — 100μHz). It enabled to gain information of both dielectric properties of oxide layers developing on the Zr-alloys surface and of the kinetics of the corrosion process and the associated charge and mass transfer phenomena. Experiments were run for more than 380 days; thus, the study of all the corrosion stages (pre-transition, transition, post-transition) was possible.

Abnormal Elasticity of Single-Crystal Magnesiosiderite across the Spin Transition in Earth's Lower Mantle

NASA Astrophysics Data System (ADS)

Fu, Suyu; Yang, Jing; Lin, Jung-Fu

2017-01-01

Brillouin light scattering and impulsive stimulated light scattering have been used to determine the full elastic constants of magnesiosiderite [(Mg0.35Fe0.65)CO3 ] up to 70 GPa at room temperature in a diamond-anvil cell. Drastic softening in C11 , C33 , C12 , and C13 elastic moduli associated with the compressive stress component and stiffening in C44 and C14 moduli associated with the shear stress component are observed to occur within the spin transition between ˜42.4 and ˜46.5 GPa . Negative values of C12 and C13 are also observed within the spin transition region. The Born criteria constants for the crystal remain positive within the spin transition, indicating that the mixed-spin state remains mechanically stable. Significant auxeticity can be related to the electronic spin transition-induced elastic anomalies based on the analysis of Poisson's ratio. These elastic anomalies are explained using a thermoelastic model for the rhombohedral system. Finally, we conclude that mixed-spin state ferromagnesite, which is potentially a major deep-carbon carrier, is expected to exhibit abnormal elasticity, including a negative Poisson's ratio of -0.6 and drastically reduced VP by 10%, in Earth's midlower mantle.

Skill Formation and Utilisation in the Post-Soviet Transition: Higher Education Planning in Post-Soviet Georgia

ERIC Educational Resources Information Center

Gvaramadze, Irakli

2010-01-01

Changes in the former Soviet system had a dramatic influence on higher education in Georgia. The main objective of the current article is to analyse implications of the post-Soviet transition for the skill formation and skill utilisation system in Georgia. In particular, the study analyses recent trends in Georgian higher education including…

Parental Involvement and Adolescents' Career Goal Pursuit during the Post-School Transition

ERIC Educational Resources Information Center

Dietrich, Julia; Salmela-Aro, Katariina

2013-01-01

This study investigated adolescents' and parents' co-regulation of career-related goals during the post-school transition. Finnish adolescents (N = 807, 49% female) were assessed twice in high school and once after graduation. It was examined how their career goal motivation (autonomous vs. controlled) and appraisals (goal attainability, effort,…

The Post-School Outcomes Transition Survey: A Tool for Effective Decision Making?

ERIC Educational Resources Information Center

Eaves, Ronald C.; Rabren, Karen; Hall, George

2012-01-01

This study investigated the validity of the "Post-School Outcomes Transition Survey" (PSOTS). The PSOTS was designed to ascertain whether individuals who received special education services in secondary school have obtained postschool employment or have enrolled in postsecondary education or training within 1 to 2 years of exiting high school. The…

Transiting Exoplanet Observations at Grinnell College

NASA Astrophysics Data System (ADS)

Sauerhaft, Julia; Slough, P.; Cale, B.; Kempton, E.

2014-01-01

Grinnell College, a small liberal arts college in Grinnell, Iowa with 1600 undergraduate students, is home to the Grant O. Gale Observatory. Over the past year, we have successfully detected extrasolar planets using the transit method with our 24-inch Cassegrain reflecting telescope equipped with a CCD camera. With little light pollution and an easily accessible observatory, Grinnell College is an optimal location for transiting exoplanet observations. With the current telescope set-up and CCD camera, we have taken time series data and created image calibration and post-processing programs that detect exoplanet transits at high photometric precision. In the future, we will continue to use these observation and data reduction procedures to conduct transiting exoplanet research. Goals for our research program include performing follow-up observations of transiting exoplanet candidates to confirm their planetary nature, searching for additional exoplanets in known planetary systems using the transit timing detection method, tracking long period transiting planets, and refining properties of exoplanets and their host stars. Ground-based transiting planet science is especially important in the post-Kepler era, and our dedicated mid-sized telescope with plenty of access to dark clear nights provides an ideal resource for a variety of follow up and exoplanet detection efforts.

Temperate Earth-sized planets transiting a nearby ultracool dwarf star

NASA Astrophysics Data System (ADS)

Gillon, Michaël; Jehin, Emmanuël; Lederer, Susan M.; Delrez, Laetitia; de Wit, Julien; Burdanov, Artem; Van Grootel, Valérie; Burgasser, Adam J.; Triaud, Amaury H. M. J.; Opitom, Cyrielle; Demory, Brice-Olivier; Sahu, Devendra K.; Bardalez Gagliuffi, Daniella; Magain, Pierre; Queloz, Didier

2016-05-01

Star-like objects with effective temperatures of less than 2,700 kelvin are referred to as ‘ultracool dwarfs’. This heterogeneous group includes stars of extremely low mass as well as brown dwarfs (substellar objects not massive enough to sustain hydrogen fusion), and represents about 15 per cent of the population of astronomical objects near the Sun. Core-accretion theory predicts that, given the small masses of these ultracool dwarfs, and the small sizes of their protoplanetary disks, there should be a large but hitherto undetected population of terrestrial planets orbiting them—ranging from metal-rich Mercury-sized planets to more hospitable volatile-rich Earth-sized planets. Here we report observations of three short-period Earth-sized planets transiting an ultracool dwarf star only 12 parsecs away. The inner two planets receive four times and two times the irradiation of Earth, respectively, placing them close to the inner edge of the habitable zone of the star. Our data suggest that 11 orbits remain possible for the third planet, the most likely resulting in irradiation significantly less than that received by Earth. The infrared brightness of the host star, combined with its Jupiter-like size, offers the possibility of thoroughly characterizing the components of this nearby planetary system.

Temperate Earth-sized planets transiting a nearby ultracool dwarf star.

PubMed

Gillon, Michaël; Jehin, Emmanuël; Lederer, Susan M; Delrez, Laetitia; de Wit, Julien; Burdanov, Artem; Van Grootel, Valérie; Burgasser, Adam J; Triaud, Amaury H M J; Opitom, Cyrielle; Demory, Brice-Olivier; Sahu, Devendra K; Bardalez Gagliuffi, Daniella; Magain, Pierre; Queloz, Didier

2016-05-12

Star-like objects with effective temperatures of less than 2,700 kelvin are referred to as 'ultracool dwarfs'. This heterogeneous group includes stars of extremely low mass as well as brown dwarfs (substellar objects not massive enough to sustain hydrogen fusion), and represents about 15 per cent of the population of astronomical objects near the Sun. Core-accretion theory predicts that, given the small masses of these ultracool dwarfs, and the small sizes of their protoplanetary disks, there should be a large but hitherto undetected population of terrestrial planets orbiting them--ranging from metal-rich Mercury-sized planets to more hospitable volatile-rich Earth-sized planets. Here we report observations of three short-period Earth-sized planets transiting an ultracool dwarf star only 12 parsecs away. The inner two planets receive four times and two times the irradiation of Earth, respectively, placing them close to the inner edge of the habitable zone of the star. Our data suggest that 11 orbits remain possible for the third planet, the most likely resulting in irradiation significantly less than that received by Earth. The infrared brightness of the host star, combined with its Jupiter-like size, offers the possibility of thoroughly characterizing the components of this nearby planetary system.

The effect of fluorine on the stability of wadsleyite: Implications for the nature and depths of the transition zone in the Earth's mantle

NASA Astrophysics Data System (ADS)

Grützner, Tobias; Klemme, Stephan; Rohrbach, Arno; Gervasoni, Fernanda; Berndt, Jasper

2018-01-01

The Earth's mantle contains significant amounts of volatile elements, such as hydrogen (H), carbon (C) and the halogens fluorine (F), chlorine (Cl) and bromine (Br) and iodine (I). There is a wealth of knowledge about the global cycling of H and C, but there is only scant data on the concentrations of halogens in different Earth reservoirs and on the behavior of halogens during recycling in subduction zones. Here we focus on the storage potential of F in deeper parts of the Earth's mantle. The transition zone is a region in the Earth's mantle (410-660 km) known for its high water storage capacity, as the high pressure polymorphs of olivine, wadsleyite and ringwoodite are known to be able to incorporate several per-cent of water. In order to assess potential fractionation between water and F in the transition zone of the Earth's mantle, we set out to investigate the storage capacity of the halogen F in wadsleyite and olivine at transition zone conditions. Experiments were performed in a simplified mantle composition at temperatures from 1400 °C to 1900 °C and pressures from 17 up to 21 GPa in a multi anvil apparatus. The results show that F can shift the olivine-wadsleyite transition towards higher pressure. We find that F has an opposing effect to water, the latter of which extends the transition zone towards lower pressure. Moreover, the F storage capacity of wadsleyite is significantly lower than previously anticipated. F concentrations in wadsleyite range from 1470 ± 60 μg/g to 2110 ± 600 μg/g independent of temperature or pressure. The F storage capacity in wadsleyite is even lower than the F storage capacity of forsterite under transition zone conditions, and the latter can incorporate 3930 ± 140 μg/g F under these conditions. Based on our data we find that the transition zone cannot be a reservoir for F as it is assumed to be for water. Furthermore, we argue that during subduction of a volatile-bearing slab, fractionation of water from F will occur

A review of visible, near-IR, and mid-IR transitions in rare-earth doped glass waveguides for remote sensing and LIDAR

NASA Astrophysics Data System (ADS)

Jha, Animesh

2006-12-01

In the review article we explain the recent investigations on rare-earth doped glass and optical fibres for designing lasers which may be suitable for remote sensing and LIDAR applications. The paper explains the importance of engineering efficient lasing transitions in visible (480-650 nm) for generating UV lasers via one-stage harmonic generation. Besides visible transitions, we also demonstrate the transitions in near- and mid-IR via near-IR pumping scheme.

A Transition to Metallic Hydrogen: Evidence of the Plasma Phase Transition

NASA Astrophysics Data System (ADS)

Silvera, Isaac; Zaghoo, Mohamed; Salamat, Ashkan

The insulator-metal transition in hydrogen is one of the most outstanding problems in condensed matter physics. The high-pressure metallic phase is now predicted to be liquid atomic from T =0 K to very high temperatures. We have conducted measurements of optical properties of hot dense hydrogen in the region of 1.1-1.7 Mbar and up to 2200 K in a diamond anvil cell using pulsed laser heating of the sample. We present evidence in two forms: a plateau in the heating curves (average laser power vs temperature) characteristic of a first-order phase transition with latent heat, and changes in transmittance and reflectance characteristic of a metal for temperatures above the plateau temperature. For thick films the reflectance saturates at ~0.5. The phase line of this transition has a negative slope in agreement with theories of the so-called plasma phase transition. The NSF, Grant DMR-1308641, the DOE Stockpile Stewardship Academic Alliance Program, Grant DE-FG52-10NA29656, and NASA Earth and Space Science Fellowship Program, Award NNX14AP17H supported this research.

THE GJ1214 SUPER-EARTH SYSTEM: STELLAR VARIABILITY, NEW TRANSITS, AND A SEARCH FOR ADDITIONAL PLANETS

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

Berta, Zachory K.; Charbonneau, David; Bean, Jacob

2011-07-20

The super-Earth GJ1214b transits a nearby M dwarf that exhibits a 1% intrinsic variability in the near-infrared. Here, we analyze new observations to refine the physical properties of both the star and planet. We present three years of out-of-transit photometric monitoring of the stellar host GJ1214 from the MEarth Observatory and find the rotation period to be long, most likely an integer multiple of 53 days, suggesting low levels of magnetic activity and an old age for the system. We show that such variability will not pose significant problems to ongoing studies of the planet's atmosphere with transmission spectroscopy. Wemore » analyze two high-precision transit light curves from ESO's Very Large Telescope (VLT) along with seven others from the MEarth and Fred Lawrence Whipple Observatory 1.2 m telescopes, finding physical parameters for the planet that are consistent with previous work. The VLT light curves show tentative evidence for spot occultations during transit. Using two years of MEarth light curves, we place limits on additional transiting planets around GJ1214 with periods out to the habitable zone of the system. We also improve upon the previous photographic V-band estimate for the star, finding V = 14.71 {+-} 0.03.« less

Transit visibility zones of the Solar system planets

NASA Astrophysics Data System (ADS)

Wells, R.; Poppenhaeger, K.; Watson, C. A.; Heller, R.

2018-01-01

The detection of thousands of extrasolar planets by the transit method naturally raises the question of whether potential extrasolar observers could detect the transits of the Solar system planets. We present a comprehensive analysis of the regions in the sky from where transit events of the Solar system planets can be detected. We specify how many different Solar system planets can be observed from any given point in the sky, and find the maximum number to be three. We report the probabilities of a randomly positioned external observer to be able to observe single and multiple Solar system planet transits; specifically, we find a probability of 2.518 per cent to be able to observe at least one transiting planet, 0.229 per cent for at least two transiting planets, and 0.027 per cent for three transiting planets. We identify 68 known exoplanets that have a favourable geometric perspective to allow transit detections in the Solar system and we show how the ongoing K2 mission will extend this list. We use occurrence rates of exoplanets to estimate that there are 3.2 ± 1.2 and 6.6^{+1.3}_{-0.8} temperate Earth-sized planets orbiting GK and M dwarf stars brighter than V = 13 and 16, respectively, that are located in the Earth's transit zone.

Transitional justice as social control: political transitions, human rights norms and the reclassification of the past.

PubMed

Dudai, Ron

2017-09-12

This article offers an interpretation of transitional justice policies - the efforts of post-conflict and post-dictatorship societies to address the legacy of past abuses - as a form of social control. While transitional justice is commonly conceptualized as responding to a core problem of impunity, this article argues that such formulation is too narrow and leads to lack of coherence in the analysis of the diverse array of transitional mechanisms, which include among others trials, truth commissions, reparations for victims and apologies. Building on the work of Stanley Cohen, the article contends that the core transitional problem is the denial of human rights violations, and consequently that the common purpose of all transitional justice mechanisms is to reclassify the past: redefining as deviant some acts and individuals which prior to the transition were considered 'normal'. The article identifies and analyses three themes in the application of a social control framework to transitional justice: (1) truth, memory and retroactive social control, pertains to the way truth-seeking transitional justice mechanisms reclassify past events by engaging in social control of and through memory; (2) censure, celebration and transitional social control refers to the reclassification of categories of individuals through expressions of both social disapproval and praise; and (3) civil society and social control from below concerns the role of social movements, organizations and groups as informal agents of social control during transitions. The concluding section recaps and briefly explores the concept of 'good moral panic' in the context of political transitions. While the concept of social control tends to have negative connotations for critical sociologists, this work suggests that efforts to categorize, punish and disapprove certain behaviours as deviant may not only be viewed as supporting a conservative status-quo, but also as promoting fledging human rights norms. �

SDO Transit, September 2015

NASA Image and Video Library

2015-09-13

On Sept. 13, 2015, as NASA's Solar Dynamics Observatory, or SDO, kept up its constant watch on the sun, its view was photobombed not once, but twice. Just as the moon came into SDO's field of view on a path to cross the sun, Earth entered the picture, blocking SDO's view completely. When SDO's orbit finally emerged from behind Earth, the moon was just completing its journey across the sun's face. Though SDO sees dozens of Earth eclipses and several lunar transits each year, this is the first time ever that the two have coincided. SDO's orbit usually gives us unobstructed views of the sun, but Earth's revolution around the sun means that SDO's orbit passes behind Earth twice each year, for two to three weeks at a time. During these phases, Earth blocks SDO's view of the sun for anywhere from a few minutes to over an hour once each day. Earth's outline looks fuzzy, while the moon's is crystal-clear. This is because-while the planet itself completely blocks the sun's light-Earth's atmosphere is an incomplete barrier, blocking different amounts of light at different altitudes. However, the moon has no atmosphere, so during the transit we can see the crisp edges of the moon's horizon. http://photojournal.jpl.nasa.gov/catalog/PIA19949

First Results of Exoplanet Observations with the Gran Telescopio Canarias: Narrow-Band Transit Photometry Capable of Detecting Super-Earth-size Planets

NASA Astrophysics Data System (ADS)

Ford, Eric B.; Colon, K. D.; Blake, C.; Lee, B.; Mahadevan, S.

2010-01-01

We present the first exoplanet observations from the Gran Telescopio Canarias (GTC) using the OSIRIS tunable filter imager. Our narrow-band transit follow-up observations set a new record for ground-based, narrow-band photometric precision of an exoplanet transit. The demonstrated precision would allow the detection of a transiting super-Earth-sized planet at near-infrared wavelengths. Such high-precision follow-up observations could significantly improve measurements of the size and orbit of transiting super-Earth and Earth-like planets to be discovered by the CoRoT and Kepler space missions (Colon & Ford 2009). OSIRIS is one of two first light instruments for the GTC and features a tunable filter imaging mode. We observed the planet's host star along with several nearby reference stars during each transit, rapidly alternating observations between multiple narrow band-passes. The GTC's large aperture results in small photon noise and minimal scintillation noise, so care must be taken to minimize other potential systematic noise sources. The use of a narrow bandpass (2nm) reduces the effects of differential extinction, and we chose bandpasses that minimize atmospheric absorption and variability. We measure the flux of the target star relative to an ensemble of reference stars, using an aperture photometry algorithm adapted to allow for: 1) the center of the band-pass varying across the field and resulting in sky rings, and 2) a significant defocus to reduce flat fielding uncertainties and increase observing efficiency. We present results from the first tunable filter observations of an exoplanet transit and outline the exciting prospects for future GTC/OSIRIS observations to study super-Earth planets and the atmospheres of giant planets via occultation photometry. Based on observations made with the Gran Telescopio Canarias (GTC), installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, in the island of La Palma.

Transits in our Solar System for educational activities: Mercury Transit 2016 and Total Solar Eclipse 2017

NASA Astrophysics Data System (ADS)

Pérez-Ayúcar, M.; Breitfelner, M.

2017-09-01

Solar transits are rare astronomical event of profound historical importance and with an enormous potential to engage nowadays students and general public into Planetary Sciences and Space. Mercury transits occur only about every 13-14 times per century. Total solar eclipses occur around 18 months apart somewhere on Earth, but they recur only every 3-4 centuries on the same location. Although its historic scientific importance (examples, to measure the distances in the solar system, to observe the solar corona) has diminished since humanity roams our solar system with robotic spacecrafts, transits remain a spectacular astronomical event that is used very effectively to engage general public and students to Science and Space in general. The educational project CESAR (Cooperation through Education in Science and Astronomy Research) has been covering since 2012 such events (Venus transit 2012, live Sun transmissions, solar eclipses, ISS transits ...). We report the outstanding outcome of the two public educational and outreach events since last year: the May 2016 Mercury Transit, and the recent August 2017 Total Eclipse. And the follow up activities expected for future transits.

Gender identity disorder: treatment and post-transition care in transsexual adults.

PubMed

Jain, A; Bradbeer, C

2007-03-01

As sex reassignment surgeries become more common and advanced, health professionals are more likely to see patients with gender identity disorders (GID) in their clinics. This can be challenging in many ways, and the challenges continue even after gender reassignment surgery as each case may present with unique anatomy. This article reviews the definition and treatment of GID, service provision in National Health Service and post-transition care of such patients.

Characterizing K2 Planet Discoveries: A Super-Earth Transiting the Bright K Dwarf HIP 116454

NASA Astrophysics Data System (ADS)

Vanderburg, Andrew; Montet, Benjamin T.; Johnson, John Asher; Buchhave, Lars A.; Zeng, Li; Pepe, Francesco; Collier Cameron, Andrew; Latham, David W.; Molinari, Emilio; Udry, Stéphane; Lovis, Christophe; Matthews, Jaymie M.; Cameron, Chris; Law, Nicholas; Bowler, Brendan P.; Angus, Ruth; Baranec, Christoph; Bieryla, Allyson; Boschin, Walter; Charbonneau, David; Cosentino, Rosario; Dumusque, Xavier; Figueira, Pedro; Guenther, David B.; Harutyunyan, Avet; Hellier, Coel; Kuschnig, Rainer; Lopez-Morales, Mercedes; Mayor, Michel; Micela, Giusi; Moffat, Anthony F. J.; Pedani, Marco; Phillips, David F.; Piotto, Giampaolo; Pollacco, Don; Queloz, Didier; Rice, Ken; Riddle, Reed; Rowe, Jason F.; Rucinski, Slavek M.; Sasselov, Dimitar; Ségransan, Damien; Sozzetti, Alessandro; Szentgyorgyi, Andrew; Watson, Chris; Weiss, Werner W.

2015-02-01

We report the first planet discovery from the two-wheeled Kepler (K2) mission: HIP 116454 b. The host star HIP 116454 is a bright (V = 10.1, K = 8.0) K1 dwarf with high proper motion and a parallax-based distance of 55.2 ± 5.4 pc. Based on high-resolution optical spectroscopy, we find that the host star is metal-poor with [Fe/H] =-0.16 ± 0.08 and has a radius R sstarf = 0.716 ± 0.024 R ⊙ and mass M sstarf = 0.775 ± 0.027 M ⊙. The star was observed by the Kepler spacecraft during its Two-Wheeled Concept Engineering Test in 2014 February. During the 9 days of observations, K2 observed a single transit event. Using a new K2 photometric analysis technique, we are able to correct small telescope drifts and recover the observed transit at high confidence, corresponding to a planetary radius of Rp = 2.53 ± 0.18 R ⊕. Radial velocity observations with the HARPS-N spectrograph reveal a 11.82 ± 1.33 M ⊕ planet in a 9.1 day orbit, consistent with the transit depth, duration, and ephemeris. Follow-up photometric measurements from the MOST satellite confirm the transit observed in the K2 photometry and provide a refined ephemeris, making HIP 116454 b amenable for future follow-up observations of this latest addition to the growing population of transiting super-Earths around nearby, bright stars.

Phase-Adequate Engagement at the Post-School Transition

ERIC Educational Resources Information Center

Dietrich, Julia; Parker, Philip; Salmela-Aro, Katariina

2012-01-01

The transition from general education (e.g., high school) to vocational and tertiary education (e.g., college, vocational school) or to the labor market presents a number of developmental challenges. These challenges include making career choices and, more broadly, managing the transition. Coping with these challenges depends on the individual,…

Lunar Flight Study Series: Volume 4. Preliminary Investigation of the Astronautics of Earth - Moon Transits

NASA Technical Reports Server (NTRS)

Braud, Nolan J.

1963-01-01

Preliminary information on flight profiles, velocity budgets and launch windows for Apollo and Support Vehicle flights is presented in this report. A newly conceived method of establishing a flight mechanical classification of the earth-moon transits is discussed. The results are empirical and are designed to contribute to the mission mode selection.

The role of upper mantle mineral phase transitions on the current structure of large-scale Earth's mantle convection.

NASA Astrophysics Data System (ADS)

Thoraval, C.

2017-12-01

Describing the large-scale structures of mantle convection and quantifying the mass transfer between upper and lower mantle request to account for the role played by mineral phase transitions in the transition zone. We build a density distribution within the Earth mantle from velocity anomalies described by global seismic tomographic models. The density distribution includes thermal anomalies and topographies of the phase transitions at depths of 410 and 660 km. We compute the flow driven by this density distribution using a 3D spherical circulation model, which account for depth-dependent viscosity. The dynamic topographies at the surface and at the CMB and the geoid are calculated as well. Within the range of viscosity profiles allowing for a satisfying restitution of the long wavelength geoid, we perform a parametric study to decipher the role of the characteristics of phase diagrams - mainly the Clapeyron's slopes - and of the kinetics of phase transitions, which may modify phase transition topographies. Indeed, when a phase transition is delayed, the boundary between two mineral phases is both dragged by the flow and interfere with it. The results are compared to recent estimations of surface dynamic topography and to the phase transition topographies as revealed by seismic studies. The consequences are then discussed in terms of structure of mantle flow. Comparisons between various tomographic models allow us to enlighten the most robust features. At last, the role played by the phase transitions on the lateral variations of mass transfer between upper and lower mantle are quantified by comparison to cases with no phase transitions and confronted to regional tomographic models, which reflect the variability of the behaviors of the descending slabs in the transition zone.

Hybridization wave as the cause of the metal-insulator transition in rare earth nickelates

NASA Astrophysics Data System (ADS)

Park, Hyowon; Marianetti, Chris A.; Millis, Andrew J.

2012-02-01

The metal-insulator transition driven by varying rare earth (Re) ion in ReNiO3 has been a longstanding challenge to materials theory. Experimental evidence suggesting charge order is seemingly incompatible with the strong Mott-Hubbard correlations characteristic of transition metals. We present density functional, Hartree-Fock and Dynamical Mean field calculations showing that the origin of the insulating phase is a hybridization wave, in which a two sublattice ordering of the oxygen breathing mode produces two Ni sites with almost identical Ni d-charge densities but very different magnetic moments and other properties. The high temperature crystal structure associated with smaller Re ions such as Lu is shown to be more susceptible to the distortion than the high temperature structure associated with larger Re ions such as La.

Unambiguously identifying spin states of transition-metal ions in the Earth (Invited)

NASA Astrophysics Data System (ADS)

Hsu, H.

2010-12-01

The spin state of a transition-metal ion in crystalline solids, defined by the number of unpaired electrons in the ion’s incomplete 3d shell, may vary with many factors, such as temperature, pressure, strain, and the local atomic configuration, to name a few. Such a phenomenon, known as spin-state crossover, plays a crucial role in spintronic materials. Recently, the pressure-induced spin-state crossover in iron-bearing minerals has been recognized to affect the minerals’ structural and elastic properties. However, the detailed mechanism of such crossover in iron-bearing magnesium silicate perovskite, the most abundant mineral in the Earth, remains unclear. A significant part of this confusion arises from the difficulty in reliably extracting the spin state from experiments. For the same reason, the thermally-induced spin-state crossover in lanthanum cobaltite (LaCoO3) has been controversial for more than four decades. In this talk, I will discuss how first-principle calculations can help clarifying these long-standing controversies. In addition to the total energy, equation of state, and elastic properties of each spin state, first-principle calculations also predict the electric field gradient (EFG) at the nucleus of each transition-metal ion. Our calculations showed that the nuclear EFG, a quantity that can be measured via Mössbauer or nuclear magnetic resonance (NMR) spectroscopy, depends primarily on the spin state, irrespective of the concentration or configuration of transition-metal ions. Such robustness makes EFG a unique fingerprint to identify the spin state. The combination of first-principle calculations and Mössbauer/NMR spectroscopy can therefore be a reliable and efficient approach in tackling spin-state crossover problems in the Earth. This work was primarily supported by the MRSEC Program of NSF under Awards Number DMR-0212302 and DMR-0819885, and partially supported by NSF under ATM-0428774 (V-Lab), EAR-1019853, and EAR-0810272. The

Small Effect of Hydration on Elastic Wave Velocities of Ringwoodite in Earth's Transition Zone

NASA Astrophysics Data System (ADS)

Schulze, K.; Marquardt, H.; Boffa Ballaran, T.; Kurnosov, A.; Kawazoe, T.; Koch-Müller, M.

2017-12-01

Ringwoodite can incorporate significant amounts of hydrogen as OH-defects into its crystal structure. The measurement of 1.4 wt.% H20 in a natural ringwoodite diamond inclusion (Pearson et al. 2014) showed that hydrous ringwoodite can exist in the Earth's mantle. Since ringwoodite is considered to be the major phase in the mantle between 520 and 660 km depth it likely plays an important role for Earth's deep water cycle and the mantle water budget. Previous experimental work has shown that hydration reduces seismic wave velocities in ringwoodite, motivating attempts to map the hydration state of the mantle using seismic wave speed variations as depicted by seismic tomography. However, large uncertainties on the actual effects at transition zone pressures and temperatures remain. A major difficulty is the comparability of studies with different experimental setups and pressure- and temperature conditions. Here, we present results from a comparative elasticity study designed to quantify the effects of hydration on the seismic wave velocities of ringwoodite in Earth's transition zone. Focused ion beam cut single-crystals of four samples of either Fo90 or Fo100 ringwoodite with hydration states between 0.21 - 1.71 wt.% H2O were loaded in the pressure chamber of one diamond-anvil cell to ensure identical experimental conditions. Single-crystal Brillouin Spectroscopy and X-ray diffraction measurements were performed at room temperature to a pressure of 22 GPa. Additional experiments at high pressure and temperatures up to 500 K were performed. Our data collected at low pressures show a significant reduction of elastic wave velocities with hydration, consistent with previous work. However, in contrast to previous inferences, our results indicate that pressure significantly reduces the effect of hydration. Based on the outcome of our work, the redution in aggregate velocities caused by 1 wt.% H2O becomes smaller than 1% in ringwoodite at pressures equivalent to the Earth

Assessment to Guide Individualized Transition Plans from School to Post-School for Children Ages 14+ with Moderate Disabilities

ERIC Educational Resources Information Center

Skidmore, Kevin

2014-01-01

As a part of the Individualized Education Plan (IEP), special education teachers work along with their student with special needs and their parent(s)/guardian(s) to create and implement Individualized Transition Plans (ITP) to assist the student with their transition to the post-school environment. As mandated by Individuals with Disabilities…

Tradeoffs in Chemical and Thermal Variations in the Post-perovskite Phase Transition: Mixed Phase Regions in the Deep Lower Mantle?

NASA Astrophysics Data System (ADS)

Giles, G. F.; Spera, F. J.; Yuen, D. A.

2005-12-01

The recent discovery of a phase-transition in Mg-rich perovskite (Pv) to a post-perovskite (pPv) phase at lower mantle depths and its relationship to D", lower mantle heterogeneity and iron content prompted an investigation of the relative importance of lower mantle (LM) compositional and temperature fluctuations in creating topographic undulations on mixed phase regions. Above the transition, Mg-rich Pv makes up ~70 percent by mass of the LM. Using results from experimental phase equilibria, first-principles computations and thermodynamic relations for Fe2+-Mg mixing in silicates, a preliminary thermodynamic model for the perovskite to post-perovskite phase transition in the divariant system MgSiO3-FeSiO3 is developed. Complexities associated with components Fe2O3 and Al2O3 and other phases (Ca-Pv, magnesiowustite) are neglected. The model predicts phase transition pressures are sensitive to the FeSiO3 content of perovskite (~-1.5 GPa per one mole percent FeSiO3). This leads to considerable topography along the top boundary of the mixed phase region. The Clapeyron slope for the Pv to pPv transition at XFeSiO3=0.1 is +11 MPa/K about 20% higher than for pure Mg-Pv. Increasing bulk concentration of iron elevates the mixed (two-phase) layer above the core-mantle boundary (CMB); increasing temperature acts to push the mixed layer deeper into the LM into the D" thermal boundary layer resting upon the (CMB). For various LM geotherms and CMB temperatures, a single mixed layer of thickness ~300 km lies within the bottom 40% of the lower mantle. For low iron contents (XFeSiO3 ~5 mole percent or less), two perched layers are found. This is the divariant analog to the univariant double-crosser. The hotter the mantle, the deeper the mixed phase layer; the more iron-rich the LM, the higher the mixed phase layer. In a hotter Hadean Earth with interior temperatures everywhere 200-500 K warmer pPv is not stable unless the LM bulk composition is Fe-enriched compared to the present

Sexual Preferences and Partnerships of Transgender Persons Mid- or Post-Transition.

PubMed

Fein, Lydia A; Salgado, Christopher J; Sputova, Klara; Estes, Christopher M; Medina, Carlos A

2018-01-01

The process of gender transition has varying effects on various aspects of sexuality. The purpose of this study was to investigate the effects of transitioning on transgender persons' sexual preferences and partnerships. Data were collected through an anonymous online survey. Questions focused on timing of gender transition in relation to change in sexual preference. Transgender individuals have a variety of sexual partners, predominantly cisgender, and may change sexual preference when they transition. Transitioning can be associated with having no primary sexual partner, despite past sexual partnerships. Length of time between identifying as transgender and starting the transition might be associated with changing sexual partner preference, particularly in transgender women. The emerging trends of sexual partnerships and changing sexual preferences related to the transition in this study warrant further investigation. These data provide more understanding of the relationship between transitioning and sexual preferences and partnerships.

The School-to-Work Transition of Canadian Post-Secondary Graduates: A Dynamic Analysis

ERIC Educational Resources Information Center

Finnie, Ross

2004-01-01

This paper reports the results of an empirical analysis of the school-to-work transition of Canadian post-secondary graduates based on three waves of the National Graduates Surveys, representing those who successfully completed their programmes at Canadian colleges and universities in 1982, 1986, and 1990. Information was gathered during…

Negative refraction using Raman transitions and chirality

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

Sikes, D. E.; Yavuz, D. D.

2011-11-15

We present a scheme that achieves negative refraction with low absorption in far-off resonant atomic systems. The scheme utilizes Raman resonances and does not require the simultaneous presence of an electric-dipole transition and a magnetic-dipole transition near the same wavelength. We show that two interfering Raman tran-sitions coupled to a magnetic-dipole transition can achieve a negative index of refraction with low absorption through magnetoelectric cross-coupling. We confirm the validity of the analytical results with exact numerical simulations of the density matrix. We also discuss possible experimental implementations of the scheme in rare-earth metal atomic systems.

Radiative and Nonradiative Transitions of the Rare-Earth Ions Tm(3+) and Ho(3+) in Y3AI5O12 and LiYF4

NASA Technical Reports Server (NTRS)

Walsh, Brian M.; Armagan, Guzin; Dibartolo, Baldassare; Modlin, Edward A.

1995-01-01

The optical spectra of rare earth ions in solids arise primarily from electric and magnetic dipole transitions between stark split multiplets of the 4f(sup N) electronic configuration. Electric dipole transitions are parity forbidden between levels of the 4f(sup N) configuration, while those of magnetic dipole origin are allowed. It is known from experiment, however, that the significant contributions to the intensities of most transitions are electric dipole in nature. Judd and Ofelt developed the theory of forced electric dipole transitions of rare-earth ions. This study is devoted to determining electric dipole transition probabilities and branching ratios for Tm(3+) and Ho(3+) ions in Yttrium Aluminum Garnet (YAG) and Yttrium Lithium Fluoride (YLF) using the theory of Judd and Ofelt. The radiative rates determined from the Judd-Ofelt analysis are used with measured lifetimes to find nonradiative rates of relaxation.

Factors influencing job satisfaction in post-transition economies: the case of the Czech Republic.

PubMed

Čábelková, Inna; Abrhám, Josef; Strielkowski, Wadim

2015-01-01

This paper presents an analysis of factors influencing job satisfaction in post-transition economies on the example of the Czech Republic. Our research shows that women reported higher levels of job satisfaction compared to men. Education proved to be statistically significant in one of three indicators of job satisfaction. Personal income and workplace relationships proved to be positively and significantly related to all the three indicators of job satisfaction. Most of the occupational dummies were significantly related to two out of three indicators of job satisfaction. In addition, we found that Czech entrepreneurs enjoy and value their job, which indicates strong self-selection for doing business in post-transition economies. However, human capital expressed by the level of education was significant factor for job satisfaction, meaning that well-educated people might not be satisfied with their jobs or feel that their education and experience are wasted in the market economy.

Detection of Terrestrial Planets Using Transit Photometry

NASA Astrophysics Data System (ADS)

Koch, D.; Witteborn, F.; Jenkins, J.; Dunham, E.; Borucki, W.

2000-12-01

Transit photometry detection of planets offers many advantages: an ability to detect terrestrial-size planets, direct determination of the planet's size, applicability to all main-sequence stars, and a periodic signature (differential brightness change) being independent of stellar distance or planetary orbital semi-major axis. Ground and space based photometry have already been successful in detecting transits of the giant planet HD209458b (Charbonneau, et al. 2000, Castellano et al. 2000 and references therein). However, photometry 100 times better is required to detect terrestrial planets. We present results of measurements of an end-to-end photometric system incorporating all of the important confounding noise features of both the sky and a spacebased photometer including spacecraft jitter. In addition to demonstrating an instrumental noise of less than 10 ppm per transit (an Earth transit of a solar-like star is 80 ppm), the brightnesses of individual stars were dimmed to simulate Earth-size transit signals. These "transits" were reliably detected as part of the tests. Funding for this work was provided by NASA's Discovery and Origins programs and by NASA Ames. Charbonneau, D.; Brown, T.M.; Latham, D.W.; Mayor, M., ApJ, 529, L45, 2000. Castellano, T., Jenkins, J., Trilling, D. E., Doyle, L., and Koch, D., ApJ Let. 532, L51-L53 (2000)

Cluster synthesis and direct ordering of rare-earth transition-metal nanomagnets.

PubMed

Balasubramanian, Balamurugan; Skomski, Ralph; Li, Xingzhong; Valloppilly, Shah R; Shield, Jeffrey E; Hadjipanayis, George C; Sellmyer, David J

2011-04-13

Rare-earth transition-metal (R-TM) alloys show superior permanent magnetic properties in the bulk, but the synthesis and application of R-TM nanoparticles remains a challenge due to the requirement of high-temperature annealing above about 800 °C for alloy formation and subsequent crystalline ordering. Here we report a single-step method to produce highly ordered R-TM nanoparticles such as YCo(5) and Y(2)Co(17), without high-temperature thermal annealing by employing a cluster-deposition system and investigate their structural and magnetic properties. The direct ordering is highly desirable to create and assemble R-TM nanoparticle building blocks for future permanent-magnet and other significant applications.

Spatially quantifying and attributing 17 years of land cover change to examine post-agricultural forest transition in Hawai`i

NASA Astrophysics Data System (ADS)

Lucas, M.; Trauernicht, C.; Carlson, K. M.; Miura, T.; Giambelluca, T. W.; Chen, Q.

2017-12-01

The past decades in Hawaii have seen large scale land use change and land cover shifts. However, much these dynamics are only described anecdotally or studied at a single locale, with little information on the extent, rate, or direction of change. This lack of data hinders any effort to assess, plan, and prioritize land management. To improve assessments of statewide vegetation and land cover change, this project developed high resolution, sub-pixel, percent cover maps of forest, grassland and bare earth at annual time steps from 1999 to 2016. Vegetation cover was quantified using archived LANDSAT imagery and a custom remote-sensing algorithm developed in the Google Earth Engine platform. A statistical trend analysis of annual maps of the these three proportional land covers were then used to detect land cover transitions across the archipelago. The aim of this work focused on quantifying the total area of change, annual rates of change and final vegetation cover outcomes statewide. Additionally these findings were attributed to past and current land uses and management history by compiling spatial datasets of development, agriculture, forest restoration sites and burned areas statewide. Results indicated that nearly 10% of the state's land surfaces are suspected to have transitioned between the three cover classes during the study period. Total statewide net change resulted in a gain in forest cover with largest areas of change occurring in unmanaged areas, current and past pastoral land, commercial forestry and abandoned cultivated land. The fastest annual rates of change were forest increases that occurred in restoration areas and commercial forestry. These findings indicate that Hawaii is going through a forest transition, primarily driven by agricultural abandonment with likely feedbacks from invasive species, but also influenced by the establishment of forestry production on former agricultural lands that show potential for native forest restoration. These

RTGs on Transit

NASA Astrophysics Data System (ADS)

Dassoulas, John; McNutt, Ralph L.

2007-01-01

Transit, the US Navy's Navigation Satellite System was conceived at the Applied Physics Laboratory in 1957 by observing the Doppler shift while tracking Sputnik I. As spacecraft development proceeded there was concern about the ability of batteries to maintain the hermetic seal over a 5-year operational life requirement; therefore, alternate energy sources were investigated. The radioisotope thermoelectric generator (RTG) concept was pursued and resulted in the launch of SNAP 3s, providing partial power on both Transit 4A and 4B. SNAP 9s provided full power on three Transit 5BNs. All launches occurred in the early 1960s. When the U.S. conducted the high altitude nuclear test from Johnson Island, several spacecraft were lost due to artificial enhancement of charged particles in the Earth's magnetosphere resulting in rapid degradation of solar cell power production. This led to the decision to have both an RTG and Solar cell/battery design for Transit power systems; hence, a new RTG design, with a separable heat source and radiative coupling to the thermoelectric elements, was flown on TRIAD. This pioneering effort provided the impetus for future RTGs on interplanetary spacecraft. This paper describes the origin and purpose of the Transit program and provides details on the five satellites in that program that were powered by the first American RTGs used in space. The rationale and some of the challenges inherent in that use are also described.

Analysis of flight test transition and turbulent heating data. Part 1: Boundary layer transition results

NASA Technical Reports Server (NTRS)

Martellucci, A.; Maguire, B. L.; Neff, R. S.

1972-01-01

The objective of the study was to provide a detailed post flight evaluation of ballistic vehicle flight test boundary layer transition data. A total of fifty-five vehicles were selected for analysis. These vehicles were chosen from a data sampling of roughly two hundred flights and the criteria for vehicle selection is delineated herein. The results of the analysis indicate that frustum transition of re-entry vehicles appears to be nose tip dominated. Frustum related parameters and materials apparently have a second order effect on transition. This implies that local viscous parameters on the frustum should not correlate flight test transition data, and in fact they do not. Specific parameters relative to the nose tip have been identified as the apparent dominant factors that characterize the transition phenomena and a correlation of flight test data is presented.

Light Scattering in Exoplanet Transits

NASA Astrophysics Data System (ADS)

Robinson, Tyler D.; Fortney, Jonathan J.

2016-10-01

Transit spectroscopy is currently the leading technique for studying exoplanet atmospheric composition, and has led to the detection of molecular species, clouds, and/or hazes for numerous worlds outside the Solar System. The field of exoplanet transit spectroscopy will be revolutionized with the anticipated launch of NASA's James Webb Space Telescope (JWST) in 2018. Over the course of the design five year mission for JWST, the observatory is expected to provide in-depth observations of many tens of transiting exoplanets, including some worlds in the poorly understood 2-4 Earth-mass regime. As the quality of transit spectrum observations continues to improve, so should models of exoplanet transits. Thus, certain processes initially thought to be of second-order importance should be revisited and possibly added to modeling tools. For example, atmospheric refraction, which was commonly omitted from early transit spectrum models, has recently been shown to be of critical importance in some terrestrial exoplanet transits. Beyond refraction, another process that has seen little study with regards to exoplanet transits is light multiple scattering. In most cases, scattering opacity in exoplanet transits has been treated as equivalent to absorption opacity. However, this equivalence cannot always hold, such as in the case of a strongly forward scattering, weakly absorbing aerosol. In this presentation, we outline a theory of exoplanet transit spectroscopy that spans the geometric limit (used in most modern models) to a fully multiple scattering approach. We discuss a new technique for improving model efficiency that effectively separates photon paths, which tend to vary slowly in wavelength, from photon absorption, which can vary rapidly in wavelength. Using this newly developed approach, we explore situations where cloud or haze scattering may be important to JWST observations of gas giants, and comment on the conditions necessary for scattering to become a major

Ground-based transit observations of the super-Earth GJ 1214 b

NASA Astrophysics Data System (ADS)

Cáceres, C.; Kabath, P.; Hoyer, S.; Ivanov, V. D.; Rojo, P.; Girard, J. H.; Miller-Ricci Kempton, E.; Fortney, J. J.; Minniti, D.

2014-05-01

Context. GJ 1214 b is one of the few known transiting super-Earth-sized exoplanets with a measured mass and radius. It orbits an M-dwarf, only 14.55 pc away, making it a favorable candidate for follow-up studies. However, the composition of GJ 1214 b's mysterious atmosphere has yet to be fully unveiled. Aims: Our goal is to distinguish between the various proposed atmospheric models to explain the properties of GJ 1214 b: hydrogen-rich or hydrogen-He mix, or a heavy molecular weight atmosphere with reflecting high clouds, as latest studies have suggested. Methods: Wavelength-dependent planetary radii measurements from the transit depths in the optical/NIR are the best tool to investigate the atmosphere of GJ 1214 b. We present here (i) photometric transit observations with a narrow-band filter centered on 2.14 μm and a broad-band I-Bessel filter centered on 0.8665 μm, and (ii) transmission spectroscopy in the H and K atmospheric windows that cover three transits. The photometric and spectrophotometric time series obtained were analyzed with MCMC simulations to measure the planetary radii as a function of wavelength. We determined radii ratios of 0.1173-0.0024+0.0022 for I-Bessel and 0.11735-0.00076+0.00072 at 2.14 μm. Results: Our measurements indicate a flat transmission spectrum, in agreement with the last atmospheric models that favor featureless spectra with clouds and high molecular weight compositions. Based on observations obtained at the Southern Astrophysical Research (SOAR) Telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the US National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). SofI results are based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 087.C-0509.Tables of the lightcurve data are only available at the CDS via anonymous

Global Transition Zone Anisotropy and Consequences for Mantle Flow and Earth's Deep Water Cycle

NASA Astrophysics Data System (ADS)

Beghein, C.; Yuan, K.

2011-12-01

The transition zone has long been at the center of the debate between multi- and single-layered convection models that directly relate to heat transport and chemical mixing throughout the mantle. It has also been suggested that the transition zone is a reservoir that collects water transported by subduction of the lithosphere into the mantle. Since water lowers mantle minerals density and viscosity, thereby modifying their rheology and melting behavior, it likely affects global mantle dynamics and the history of plate tectonics. Constraining mantle flow is therefore important for our understanding of Earth's thermochemical evolution and deep water cycle. Because it can result from deformation by dislocation creep during convection, seismic anisotropy can help us model mantle flow. It is relatively well constrained in the uppermost mantle, but its presence in the transition zone is still debated. Its detection below 250 km depth has been challenging to date because of the poor vertical resolution of commonly used datasets. In this study, we used global Love wave overtone phase velocity maps, which are sensitive to structure down to much larger depths than fundamental modes alone, and have greater depth resolution than shear wave-splitting data. This enabled us to obtain a first 3-D model of azimuthal anisotropy for the upper 800km of the mantle. We inverted the 2Ψ terms of anisotropic phase velocity maps [Visser, et al., 2008] for the first five Love wave overtones between 35s and 174s period. The resulting model shows that the average anisotropy amplitude for vertically polarized shear waves displays two main stable peaks: one in the uppermost mantle and, most remarkably, one in the lower transition zone. F-tests showed that the presence of 2Ψ anisotropy in the transition zone is required to improve the third, fourth, and fifth overtones fit. Because of parameter trade-offs, however, we cannot exclude that the anisotropy is located in the upper transition zone as

CHARACTERIZING K2 PLANET DISCOVERIES: A SUPER-EARTH TRANSITING THE BRIGHT K DWARF HIP 116454

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

Vanderburg, Andrew; Montet, Benjamin T.; Johnson, John Asher

We report the first planet discovery from the two-wheeled Kepler (K2) mission: HIP 116454 b. The host star HIP 116454 is a bright (V = 10.1, K = 8.0) K1 dwarf with high proper motion and a parallax-based distance of 55.2 ± 5.4 pc. Based on high-resolution optical spectroscopy, we find that the host star is metal-poor with [Fe/H] =–0.16 ± 0.08 and has a radius R {sub *} = 0.716 ± 0.024 R {sub ☉} and mass M {sub *} = 0.775 ± 0.027 M {sub ☉}. The star was observed by the Kepler spacecraft during its Two-Wheeled Concept Engineering Test in 2014more » February. During the 9 days of observations, K2 observed a single transit event. Using a new K2 photometric analysis technique, we are able to correct small telescope drifts and recover the observed transit at high confidence, corresponding to a planetary radius of R{sub p} = 2.53 ± 0.18 R {sub ⊕}. Radial velocity observations with the HARPS-N spectrograph reveal a 11.82 ± 1.33 M {sub ⊕} planet in a 9.1 day orbit, consistent with the transit depth, duration, and ephemeris. Follow-up photometric measurements from the MOST satellite confirm the transit observed in the K2 photometry and provide a refined ephemeris, making HIP 116454 b amenable for future follow-up observations of this latest addition to the growing population of transiting super-Earths around nearby, bright stars.« less

Abrupt Upper-Plate Tilting Upon Slab-Transition-Zone Collision

NASA Astrophysics Data System (ADS)

Crameri, F.; Lithgow-Bertelloni, C. R.

2017-12-01

During its sinking, the remnant of a surface plate crosses and interacts with multiple boundaries in Earth's interior. The most-prominent dynamic interaction arises at the upper-mantle transition zone where the sinking plate is strongly affected by the higher-viscosity lower mantle. Within our numerical model, we unravel, for the first time, that this very collision of the sinking slab with the transition zone induces a sudden, dramatic downward tilt of the upper plate towards the subduction trench. The slab-transition zone collision sets parts of the higher-viscosity lower mantle in motion. Naturally, this then induces an overall larger return flow cell that, at its onset, tilts the upper plate abruptly by around 0.05 degrees and over around 10 Millions of years. Such a significant and abrupt variation in surface topography should be clearly visible in temporal geologic records of large-scale surface elevation and might explain continental-wide tilting as observed in Australia since the Eocene or North America during the Phanerozoic. Unravelling this crucial mantle-lithosphere interaction was possible thanks to state-of-the-art numerical modelling (powered by StagYY; Tackley 2008, PEPI) and post-processing (powered by StagLab; www.fabiocrameri.ch/software). The new model that is introduced here to study the dynamically self-consistent temporal evolution of subduction features accurate subduction-zone topography, robust single-sided plate sinking, stronger plates close to laboratory values, an upper-mantle phase transition and, crucially, simple continents at a free surface. A novel, fully-automated post-processing includes physical model diagnostics like slab geometry, mantle flow pattern, upper-plate tilt angle and trench location.

Plasmonics and SERS activity of post-transition metal nanoparticles

NASA Astrophysics Data System (ADS)

Bezerra, A. G.; Machado, T. N.; Woiski, T. D.; Turchetti, D. A.; Lenz, J. A.; Akcelrud, L.; Schreiner, W. H.

2018-05-01

Nanoparticles of the post-transition metals, In, Sn, Pb, and Bi, and of the metalloid Sb were produced by laser ablation synthesis in solution (LASiS) and tested for localized surface plasmon resonances (LSPR) and surface-enhanced Raman scattering (SERS). The nanoparticles were characterized by UV-Vis optical absorption, dynamic light scattering (DLS), and transmission electron microscopy (TEM). Several organic and biological molecules were tested, and SERS activity was demonstrated for all tested nanoparticles and molecules. The Raman enhancement factor for each nanoparticle class and molecule was experimentally determined. The search for new plasmonic nanostructures is important mainly for life sciences-related applications and this study expands the range of SERS active systems.

Investigating Transitional Care to Decrease Post-pancreatectomy 30-Day Hospital Readmissions for Dehydration or Failure to Thrive.

PubMed

Xourafas, Dimitrios; Ablorh, Akweley; Clancy, Thomas E; Swanson, Richard S; Ashley, Stanley W

2016-06-01

Current literature emphasizes post-operative complications as a leading cause of post-pancreatectomy readmissions. Transitional care factors associated with potentially preventable conditions such as dehydration and failure to thrive (FTT) may play a significant role in readmission after pancreatectomy and have not been studied. Thirty-one post-pancreatectomy patients, who were readmitted for dehydration or FTT between 2009 and 2014, were compared to 141 nonreadmitted patients. Medical record review and a questionnaire-based survey, specifically designed to assess transitional care, were used to identify predictors of readmissions for dehydration or FTT. Logistic regression models were used to evaluate outcomes. On multivariable analysis, the strongest predictors of readmission for dehydration and FTT were the patient's lower educational level (P = 0.0233), the absence of family during the delivery of discharge instructions (P = 0.0098), episodic intermittent nausea at discharge (P = 0.0019), uncertainty about quantity, quality, or frequency of fluid intake (P = 0.0137), and the inability or failure to adhere to the clinician's instructions in the outpatient setting (P = 0.0048). Transitional-care-related factors are found to be associated with post-pancreatectomy readmission for dehydration and FTT. Using these results to identify high-risk patients and implement focused preventive measures combining efficient communication and optimal inpatient and outpatient management could potentially decrease readmission rates.

Ground-state oxygen holes and the metal–insulator transition in the negative charge-transfer rare-earth nickelates

PubMed Central

Bisogni, Valentina; Catalano, Sara; Green, Robert J.; Gibert, Marta; Scherwitzl, Raoul; Huang, Yaobo; Strocov, Vladimir N.; Zubko, Pavlo; Balandeh, Shadi; Triscone, Jean-Marc; Sawatzky, George; Schmitt, Thorsten

2016-01-01

The metal–insulator transition and the intriguing physical properties of rare-earth perovskite nickelates have attracted considerable attention in recent years. Nonetheless, a complete understanding of these materials remains elusive. Here we combine X-ray absorption and resonant inelastic X-ray scattering (RIXS) spectroscopies to resolve important aspects of the complex electronic structure of rare-earth nickelates, taking NdNiO3 thin film as representative example. The unusual coexistence of bound and continuum excitations observed in the RIXS spectra provides strong evidence for abundant oxygen holes in the ground state of these materials. Using cluster calculations and Anderson impurity model interpretation, we show that distinct spectral signatures arise from a Ni 3d8 configuration along with holes in the oxygen 2p valence band, confirming suggestions that these materials do not obey a conventional positive charge-transfer picture, but instead exhibit a negative charge-transfer energy in line with recent models interpreting the metal–insulator transition in terms of bond disproportionation. PMID:27725665

Making the Transition to Post-Secondary Education: Opportunities and Challenges Experienced by Students with ASD in the Republic of Ireland

ERIC Educational Resources Information Center

Bell, Sheena; Devecchi, Cristina; Mc Guckin, Conor; Shevlin, Michael

2017-01-01

Internationally there are increasing numbers of young people on the ASD spectrum attending higher education. Early transition planning is essential and students with ASD often require support to articulate their post-school educational goals and actively participate in transition planning meetings. Services within higher education are primarily…

Breeding Super-Earths and Birthing Super-puffs in Transitional Disks

NASA Astrophysics Data System (ADS)

Lee, Eve J.; Chiang, Eugene

2016-02-01

The riddle posed by super-Earths (1-4R⊕, 2-20M⊕) is that they are not Jupiters: their core masses are large enough to trigger runaway gas accretion, yet somehow super-Earths accreted atmospheres that weigh only a few percent of their total mass. We show that this puzzle is solved if super-Earths formed late, as the last vestiges of their parent gas disks were about to clear. This scenario would seem to present fine-tuning problems, but we show that there are none. Ambient gas densities can span many (in one case up to 9) orders of magnitude, and super-Earths can still robustly emerge after ˜0.1-1 Myr with percent-by-weight atmospheres. Super-Earth cores are naturally bred in gas-poor environments where gas dynamical friction has weakened sufficiently to allow constituent protocores to gravitationally stir one another and merge. So little gas is present at the time of core assembly that cores hardly migrate by disk torques: formation of super-Earths can be in situ. The basic picture—that close-in super-Earths form in a gas-poor (but not gas-empty) inner disk, fed continuously by gas that bleeds inward from a more massive outer disk—recalls the largely evacuated but still accreting inner cavities of transitional protoplanetary disks. We also address the inverse problem presented by super-puffs: an uncommon class of short-period planets seemingly too voluminous for their small masses (4-10R⊕, 2-6M⊕). Super-puffs most easily acquire their thick atmospheres as dust-free, rapidly cooling worlds outside ˜1 AU where nebular gas is colder, less dense, and therefore less opaque. Unlike super-Earths, which can form in situ, super-puffs probably migrated in to their current orbits; they are expected to form the outer links of mean-motion resonant chains, and to exhibit greater water content. We close by confronting observations and itemizing remaining questions.

BREEDING SUPER-EARTHS AND BIRTHING SUPER-PUFFS IN TRANSITIONAL DISKS

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

Lee, Eve J.; Chiang, Eugene, E-mail: evelee@berkeley.edu, E-mail: echiang@astro.berkeley.edu

The riddle posed by super-Earths (1–4R{sub ⊕}, 2–20M{sub ⊕}) is that they are not Jupiters: their core masses are large enough to trigger runaway gas accretion, yet somehow super-Earths accreted atmospheres that weigh only a few percent of their total mass. We show that this puzzle is solved if super-Earths formed late, as the last vestiges of their parent gas disks were about to clear. This scenario would seem to present fine-tuning problems, but we show that there are none. Ambient gas densities can span many (in one case up to 9) orders of magnitude, and super-Earths can still robustlymore » emerge after ∼0.1–1 Myr with percent-by-weight atmospheres. Super-Earth cores are naturally bred in gas-poor environments where gas dynamical friction has weakened sufficiently to allow constituent protocores to gravitationally stir one another and merge. So little gas is present at the time of core assembly that cores hardly migrate by disk torques: formation of super-Earths can be in situ. The basic picture—that close-in super-Earths form in a gas-poor (but not gas-empty) inner disk, fed continuously by gas that bleeds inward from a more massive outer disk—recalls the largely evacuated but still accreting inner cavities of transitional protoplanetary disks. We also address the inverse problem presented by super-puffs: an uncommon class of short-period planets seemingly too voluminous for their small masses (4–10R{sub ⊕}, 2–6M{sub ⊕}). Super-puffs most easily acquire their thick atmospheres as dust-free, rapidly cooling worlds outside ∼1 AU where nebular gas is colder, less dense, and therefore less opaque. Unlike super-Earths, which can form in situ, super-puffs probably migrated in to their current orbits; they are expected to form the outer links of mean-motion resonant chains, and to exhibit greater water content. We close by confronting observations and itemizing remaining questions.« less

Spin crossover and Mott—Hubbard transition under high pressure and high temperature in the low mantle of the Earth

NASA Astrophysics Data System (ADS)

Ovchinnikov, S. G.; Ovchinnikova, T. M.; Plotkin, V. V.; Dyad'kov, P. G.

2015-11-01

Effect of high pressure induced spin crossover on the magnetic, electronic and structural properties of the minerals forming the Earth's low mantle is discussed. The low temperature P, T phase diagram of ferropericlase has the quantum phase transition point Pc = 56 GPa at T = 0 confirmed recently by the synchrotron Mössbauer spectroscopy. The LDA+GTB calculated phase diagram describes the experimental data. Its extension to the high temperature resulted earlier in prediction of the metallic properties of the Earth's mantle at the depth 1400 km < h < 1800 km. Estimation of the electrical conductivity based on the percolation theory is given. We discuss also the thermodynamic properties and structural anomalies resulting from the spin crossover and metal-insulator transition and compare them with the experimental seismic and geomagnetic field data.

Pressure driven spin transition in siderite and magnesiosiderite single crystals.

PubMed

Weis, Christopher; Sternemann, Christian; Cerantola, Valerio; Sahle, Christoph J; Spiekermann, Georg; Harder, Manuel; Forov, Yury; Kononov, Alexander; Sakrowski, Robin; Yavaş, Hasan; Tolan, Metin; Wilke, Max

2017-11-28

Iron-bearing carbonates are candidate phases for carbon storage in the deep Earth and may play an important role for the Earth's carbon cycle. To elucidate the properties of carbonates at conditions of the deep Earth, we investigated the pressure driven magnetic high spin to low spin transition of synthetic siderite FeCO 3 and magnesiosiderite (Mg 0.74 Fe 0.26 )CO 3 single crystals for pressures up to 57 GPa using diamond anvil cells and x-ray Raman scattering spectroscopy to directly probe the iron 3d electron configuration. An extremely sharp transition for siderite single crystal occurs at a notably low pressure of 40.4 ± 0.1 GPa with a transition width of 0.7 GPa when using the very soft pressure medium helium. In contrast, we observe a broadening of the transition width to 4.4 GPa for siderite with a surprising additional shift of the transition pressure to 44.3 ± 0.4 GPa when argon is used as pressure medium. The difference is assigned to larger pressure gradients in case of argon. For magnesiosiderite loaded with argon, the transition occurs at 44.8 ± 0.8 GPa showing similar width as siderite. Hence, no compositional effect on the spin transition pressure is observed. The spectra measured within the spin crossover regime indicate coexistence of regions of pure high- and low-spin configuration within the single crystal.

Transmission electron microscopic study of pyrochlore to defect-fluorite transition in rare-earth pyrohafnates

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

Karthik, Chinnathambi, E-mail: Karthikchinnathambi@boisestate.edu; Center for Advanced Energy Studies, 995 University Blvd, Idaho Falls, ID 83415; Anderson, Thomas J.

2012-10-15

A structural transition in rare earth pyrohafnates, Ln{sub 2}Hf{sub 2}O{sub 7} (Ln=Y, La, Pr, Nd, Tb, Dy, Yb and Lu), has been identified. Neutron diffraction showed that the structure transforms from well-ordered pyrochloric to fully fluoritic through the lanthanide series from La to Lu with a corresponding increase in the position parameter x of the 48f (Fd3{sup Macron }m) oxygen site from 0.330 to 0.375. As evidenced by the selected area electron diffraction, La{sub 2}Hf{sub 2}O{sub 7}, Pr{sub 2}Hf{sub 2}O{sub 7} and Nd{sub 2}Hf{sub 2}O{sub 7} exhibited a well-ordered pyrocholoric structure with the presence of intense superlattice spots, which becamemore » weak and diffuse (in Dy{sub 2}Hf{sub 2}O{sub 7} and Tb{sub 2}Hf{sub 2}O{sub 7}) before disappearing completely as the series progressed towards the Lu end. High resolution electron microscopic studies showed the breakdown of the pyrochlore ordering in the form of antiphase domains resulting in diffused smoke-like superlattice spots in the case of Dy{sub 2}Hf{sub 2}O{sub 7} and Tb{sub 2}Hf{sub 2}O{sub 7}. - Graphical abstract: Transmission electron microscopic studies showed the ordered pyrochlore to defect fluorite transition in rare-earth pyrohafnates to occur via the formation of anti-phase domains to start with. Highlights: Black-Right-Pointing-Pointer Pyrochlore to fluorite structural transition in rare earth pyrohafnates. Black-Right-Pointing-Pointer La{sub 2}Hf{sub 2}O{sub 7}, Pr{sub 2}Hf{sub 2}O{sub 7} and Nd{sub 2}Hf{sub 2}O{sub 7} showed well ordered pyrochlore structure. Black-Right-Pointing-Pointer Short range ordering in Dy{sub 2}Hf{sub 2}O{sub 7} and Tb{sub 2}Hf{sub 2}O{sub 7}. Black-Right-Pointing-Pointer Break down of pyrochlore ordering due to antiphase boundaries. Black-Right-Pointing-Pointer Rest of the series showed fluoritic structure.« less

Steady Stream of High School Graduates Enter B.C. Public Post-Secondary Education for the First Time Each Year. Research Results from the Student Transitions Project

ERIC Educational Resources Information Center

Student Transitions Project, 2014

2014-01-01

The Student Transition project (STP) has collected eleven years of grade 12 and post-secondary enrollment data, since it's inception in 2003. This information is used to track student transitions from grade 12 graduation into post-secondary education, student mobility between post-secondary institutions and post-secondary credential completions.…

Method of determining lanthanidies in a transition element host

DOEpatents

De Kalb, Edward L.; Fassel, Velmer A.

1976-02-03

A phosphor composition contains a lanthanide activator element within a host matrix having a transition element as a major component. The host matrix is composed of certain rare earth phosphates or vanadates such as YPO.sub.4 with a portion of the rare earth replaced with one or more of the transition elements. On X-ray or other electromagnetic excitation, trace lanthanide impurities or additives within the phosphor are spectrometrically determined from their characteristic luminescence.

Transitions.

ERIC Educational Resources Information Center

Nathanson, Jeanne H., Ed.

1993-01-01

This theme issue on transitions for individuals with disabilities contains nine papers discussing transition programs and issues. "Transition Issues for the 1990s," by Michael J. Ward and William D. Halloran, discusses self-determination, school responsibility for transition, continued educational engagement of at-risk students, and service…

Transition from School to Post-School Life for Individuals with Disabilities

ERIC Educational Resources Information Center

Levinson, Edward M.

2004-01-01

This book is designed to assist professionals in developing and implementing transition services for students with disabilities. Specifically, this book focuses on the importance of assessment in transition planning and targets the various domains that should be included in any school-to-work transition assessment. The book advocates a…

BOOK REVIEW: June 8, 2004: Venus in Transit

NASA Astrophysics Data System (ADS)

Maor, Eli

2000-09-01

A transit of Venus is a relatively rare astronomical event in which the silhouette of Venus is seen to move across the face of the Sun. The phenomenon typically lasts several hours, during which Venus is seen as a small dot against the half-degree angular diameter of the solar disc. The last transit of Venus occurred in 1882; the next will be 8 June 2004. Such transits were once of great importance in astronomy. By observing a transit simultaneously from well separated points on the Earth's surface, astronomers were able to measure, with some degree of accuracy, the crucially important separation of the Earth and the Sun. Knowing this enabled them to convert the relative spacings of the planets indicated by Kepler's laws into absolute interplanetary distances expressed in miles or kilometres. Eli Maor's book presents the general reader with a full account of Venusian transits that covers the history of their observation as well as their significance and the reasons for their rarity. The book is a light and enjoyable read that opens well with an imaginative description of observing the 2004 transit from the hills outside Jerusalem. Following an account of Kepler's prediction of a transit of Mercury in 1631 and its observation by Gassendi, the book moves on to describe the transit of Venus in 1639, giving particular emphasis to the prescient work of Jeremiah Horrocks, the extraordinary young English curate and astronomer who died just two years later at the age of 21. The story, however, really takes off with Edmond Halley's realization, in 1677, that transits of Venus might provide the key to determining distances within the solar system. The details of Halley's method are confined to an appendix, but the central chapters of the book detail the increasingly elaborate efforts that astronomers made to observe transits of Venus up to the time of the 1882 transit, when, due to the impact of new photographic methods, interest in transit observations was waning. By that

Energy harvesting from localized dynamic transitions in post-buckled elastic beams under quasi-static loading

NASA Astrophysics Data System (ADS)

Borchani, Wassim

The deployability of structural health monitoring self-powered sensors relies on their capability to harvest energy from signals being monitored. Many of the signals required to assess the structure condition are quasi-static events which limits the levels of power that can be extracted. Several vibration-based techniques have been proposed to increase the transferred level of power and broaden the harvester operating bandwidth. However, these techniques require vibration input excitations at frequencies higher than dominant structural response frequencies which makes them inefficient and not suitable for ambient quasi-static excitations. This research proposes a novel sensing and energy harvesting technique at low frequencies using mechanical energy concentrators and triggers. These mechanisms consist of axially-loaded bilaterally-constrained beams with attached piezoelectric energy harvesters. When the quasi-static axial load reaches a certain mechanical threshold, a sudden snap-through mode-switching occurs. These transitions excite the attached piezoelectric scavengers with high-rate input accelerations, generating then electric power. The main objectives are to understand and model the post-buckling behavior of bilaterally-constrained beams, control it by tailoring geometry and material properties of the buckled elements or stacking them into system assemblies, and finally characterize the energy harvesting and sensing capability of the system under quasi-static excitations. The fundamental principle relies on the following concept. Under axial load, a straight slender beam buckles in the first buckling mode. The increased transverse deformations from a buckled shape lead to contact interaction with the lateral boundaries. The contact interaction generates transverse forces that induce the development of higher order buckling configurations. Transitions between the buckled configurations occur not only during loading, but also unloading. In this work, the post

High-latitude ocean ventilation and its role in Earth's climate transitions

PubMed Central

MacGilchrist, Graeme A. ; Brown, Peter J.; Evans, D. Gwyn; Meijers, Andrew J. S.; Zika, Jan D.

2017-01-01

The processes regulating ocean ventilation at high latitudes are re-examined based on a range of observations spanning all scales of ocean circulation, from the centimetre scales of turbulence to the basin scales of gyres. It is argued that high-latitude ocean ventilation is controlled by mechanisms that differ in fundamental ways from those that set the overturning circulation. This is contrary to the assumption of broad equivalence between the two that is commonly adopted in interpreting the role of the high-latitude oceans in Earth's climate transitions. Illustrations of how recognizing this distinction may change our view of the ocean's role in the climate system are offered. This article is part of the themed issue ‘Ocean ventilation and deoxygenation in a warming world’. PMID:28784714

[Importation and transit of products of animal origin at the border inspection post of Hamburg as an example].

PubMed

Mielmann, P

2001-08-01

The EU conditions for the approval of border inspection posts are explained, just as the modalities of checking (documentary check, identity check, physical examination) and the information and communication systems (ANIMO, Rapid Alerts, EU Internet). The differences in procedure between import, transit and some specials are outlined. An overview is given of the volume, kinds of products, origins and the import figures relating to the transit figures. The results of the checks are commented.

Influence of Disability and Gender on Transition Assessment and Goal Generator (TAGG) Scores

ERIC Educational Resources Information Center

El-Kazimi, Nidal

2012-01-01

Legislators mandated transition education for students with disabilities to improve their post-school outcomes. Each student with an IEP should have an annual transition plan at or before his or her 16th birthday. IDEA mandated the utilization of age appropriate transition assessment to develop students' post-secondary transition goals based on…

The Role of Educational Psychologists in Supporting Post-16 Transition: Findings from the Literature

ERIC Educational Resources Information Center

Morris, Rachel; Atkinson, Cathy

2018-01-01

The Children and Families Act (2014) has seen the extension of the role of educational psychologists (EPs) to cover the age range from birth to 25 years. EPs have had to develop and extend their practice to meet the needs of post-16 young people with special educational needs and disabilities. Research on transition from compulsory education to…

Transition and post-transition metal ions in borate glasses: Borate ligand speciation, cluster formation, and their effect on glass transition and mechanical properties.

PubMed

Möncke, D; Kamitsos, E I; Palles, D; Limbach, R; Winterstein-Beckmann, A; Honma, T; Yao, Z; Rouxel, T; Wondraczek, L

2016-09-28

A series of transition and post-transition metal ion (Mn, Cu, Zn, Pb, Bi) binary borate glasses was studied with special consideration of the cations impact on the borate structure, the cations cross-linking capacity, and more generally, structure-property correlations. Infrared (IR) and Raman spectroscopies were used for the structural characterization. These complementary techniques are sensitive to the short-range order as in the differentiation of tetrahedral and trigonal borate units or regarding the number of non-bridging oxygen ions per unit. Moreover, vibrational spectroscopy is also sensitive to the intermediate-range order and to the presence of superstructural units, such as rings and chains, or the combination of rings. In order to clarify band assignments for the various borate entities, examples are given from pure vitreous B 2 O 3 to meta-, pyro-, ortho-, and even overmodified borate glass compositions. For binary metaborate glasses, the impact of the modifier cation on the borate speciation is shown. High field strength cations such as Zn 2+ enhance the disproportionation of metaborate to polyborate and pyroborate units. Pb 2+ and Bi 3+ induce cluster formation, resulting in PbO n - and BiO n -pseudophases. Both lead and bismuth borate glasses show also a tendency to stabilize very large superstructural units in the form of diborate polyanions. Far-IR spectra reflect on the bonding states of modifier cations in glasses. The frequency of the measured cation-site vibration band was used to obtain the average force constant for the metal-oxygen bonding, F M-O . A linear correlation between glass transition temperature (T g ) and F M-O was shown for the metaborate glass series. The mechanical properties of the glasses also correlate with the force constant F M-O , though for cations of similar force constant the fraction of tetrahedral borate units (N 4 ) strongly affects the thermal and mechanical properties. For paramagnetic Cu- and Mn-borate glasses

Ground-state oxygen holes and the metal–insulator transition in the negative charge-transfer rare-earth nickelates

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

Bisogni, Valentina; Catalano, Sara; Green, Robert J.

The metal-insulator transitions and the intriguing physical properties of rare-earth perovskite nickelates have attracted considerable attention in recent years. However, a complete understanding of these materials remains elusive. Here, taking a NdNiO 3 thin film as a representative example, we utilize a combination of x-ray absorption (XAS) and resonant inelastic x-ray scattering (RIXS) spectroscopies to resolve important aspects of the complex electronic structure of the rare-earth nickelates. The unusual coexistence of bound and continuum excitations observed in the RIXS spectra provides strong evidence for the abundance of oxygen 2p holes in the ground state of these materials. Using cluster calculationsmore » and Anderson impurity model interpretation, we show that these distinct spectral signatures arise from a Ni 3d 8 configuration along with holes in the oxygen 2p valence band, confirming suggestions that these materials do not obey a “conventional” positive charge-transfer picture, but instead exhibit a negative charge-transfer energy, in line with recent models interpreting the metal to insulator transition in terms of bond disproportionation.« less

Ground-state oxygen holes and the metal–insulator transition in the negative charge-transfer rare-earth nickelates

DOE PAGES

Bisogni, Valentina; Catalano, Sara; Green, Robert J.; ...

2016-10-11

The metal-insulator transitions and the intriguing physical properties of rare-earth perovskite nickelates have attracted considerable attention in recent years. However, a complete understanding of these materials remains elusive. Here, taking a NdNiO 3 thin film as a representative example, we utilize a combination of x-ray absorption (XAS) and resonant inelastic x-ray scattering (RIXS) spectroscopies to resolve important aspects of the complex electronic structure of the rare-earth nickelates. The unusual coexistence of bound and continuum excitations observed in the RIXS spectra provides strong evidence for the abundance of oxygen 2p holes in the ground state of these materials. Using cluster calculationsmore » and Anderson impurity model interpretation, we show that these distinct spectral signatures arise from a Ni 3d 8 configuration along with holes in the oxygen 2p valence band, confirming suggestions that these materials do not obey a “conventional” positive charge-transfer picture, but instead exhibit a negative charge-transfer energy, in line with recent models interpreting the metal to insulator transition in terms of bond disproportionation.« less

Blending Non-Group-3 Transition Metal and Rare-Earth Metal into a C80 Fullerene Cage with D5h Symmetry.

PubMed

Wei, Tao; Jin, Fei; Guan, Runnan; Huang, Jing; Chen, Muqing; Li, Qunxiang; Yang, Shangfeng

2018-02-11

Rare-earth metals have been mostly entrapped into fullerene cages to form endohedral clusterfullerenes, whereas non-Group-3 transition metals that can form clusterfullerenes are limited to titanium (Ti) and vanadium (V), and both are exclusively entrapped within an I h -C 80 cage. Non-Group-3 transition-metal-containing endohedral fullerenes based on a C 80 cage with D 5h symmetry, V x Sc 3-x N@D 5h -C 80 (x=1, 2), have now been synthesized, which exhibit two variable cluster compositions. The molecular structure of VSc 2 N@D 5h -C 80 was unambiguously determined by X-ray crystallography. According to a comparative study with the reported Ti- and V-containing clusterfullerenes based on a I h -C 80 cage and the analogous D 5h -C 80 -based metal nitride clusterfullerenes containing rare-earth metals only, the decisive role of the non-Group-3 transition metal on the formation of the corresponding D 5h -C 80 -based clusterfullerenes is unraveled. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Transit light curves with finite integration time: Fisher information analysis

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

Price, Ellen M.; Rogers, Leslie A.

2014-10-10

Kepler has revolutionized the study of transiting planets with its unprecedented photometric precision on more than 150,000 target stars. Most of the transiting planet candidates detected by Kepler have been observed as long-cadence targets with 30 minute integration times, and the upcoming Transiting Exoplanet Survey Satellite will record full frame images with a similar integration time. Integrations of 30 minutes affect the transit shape, particularly for small planets and in cases of low signal to noise. Using the Fisher information matrix technique, we derive analytic approximations for the variances and covariances on the transit parameters obtained from fitting light curvemore » photometry collected with a finite integration time. We find that binning the light curve can significantly increase the uncertainties and covariances on the inferred parameters when comparing scenarios with constant total signal to noise (constant total integration time in the absence of read noise). Uncertainties on the transit ingress/egress time increase by a factor of 34 for Earth-size planets and 3.4 for Jupiter-size planets around Sun-like stars for integration times of 30 minutes compared to instantaneously sampled light curves. Similarly, uncertainties on the mid-transit time for Earth and Jupiter-size planets increase by factors of 3.9 and 1.4. Uncertainties on the transit depth are largely unaffected by finite integration times. While correlations among the transit depth, ingress duration, and transit duration all increase in magnitude with longer integration times, the mid-transit time remains uncorrelated with the other parameters. We provide code in Python and Mathematica for predicting the variances and covariances at www.its.caltech.edu/∼eprice.« less

Activated phosphors having matrices of yttrium-transition metal compound

DOEpatents

De Kalb, E.L.; Fassel, V.A.

1975-07-01

A method is described for preparing a phosphor composition containing a lanthanide activator element with a host matrix having a transition element as a major component. The host matrix is composed of certain rare earth phosphates or vanadates such as YPO$sub 4$ with a portion of the rare earth replaced with one or more of the transition elements. On x-ray or other electromagnetic excitation, trace lanthanide impurities or additives within the phosphor are spectrometrically determined from their characteristic luminescence. (auth)

Magnetic and Structural Phase Transitions in Thulium under High Pressures and Low Temperatures

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

Vohra, Yogesh K.; Tsoi, Georgiy M.; Samudrala, Gopi K.

2017-10-01

The nature of 4f electrons in many rare earth metals and compounds may be broadly characterized as being either "localized" or "itinerant", and is held responsible for a wide range of physical and chemical properties. The pressure variable has a very dramatic effect on the electronic structure of rare earth metals which in turn drives a sequence of structural and magnetic transitions. We have carried out four-probe electrical resistance measurements on rare earth metal Thulium (Tm) under high pressures to 33 GPa and low temperatures to 10 K to monitor the magnetic ordering transition. These studies are complemented by anglemore » dispersive x-ray diffraction studies to monitor crystallographic phase transitions at high pressures and low temperatures. We observe an abrupt increase in magnetic ordering temperature in Tm at a pressure of 17 GPa on phase transition from ambient pressure hcp-phase to α-Sm phase transition. In addition, measured equation of state (EOS) at low temperatures show anomalously low thermal expansion coefficients likely linked to magnetic transitions.« less

Magnetic coupling at rare earth ferromagnet/transition metal ferromagnet interfaces: A comprehensive study of Gd/Ni.

PubMed

Higgs, T D C; Bonetti, S; Ohldag, H; Banerjee, N; Wang, X L; Rosenberg, A J; Cai, Z; Zhao, J H; Moler, K A; Robinson, J W A

2016-07-22

Thin film magnetic heterostructures with competing interfacial coupling and Zeeman energy provide a fertile ground to study phase transition between different equilibrium states as a function of external magnetic field and temperature. A rare-earth (RE)/transition metal (TM) ferromagnetic multilayer is a classic example where the magnetic state is determined by a competition between the Zeeman energy and antiferromagnetic interfacial exchange coupling energy. Technologically, such structures offer the possibility to engineer the macroscopic magnetic response by tuning the microscopic interactions between the layers. We have performed an exhaustive study of nickel/gadolinium as a model system for understanding RE/TM multilayers using the element-specific measurement technique x-ray magnetic circular dichroism, and determined the full magnetic state diagrams as a function of temperature and magnetic layer thickness. We compare our results to a modified Stoner-Wohlfarth-based model and provide evidence of a thickness-dependent transition to a magnetic fan state which is critical in understanding magnetoresistance effects in RE/TM systems. The results provide important insight for spintronics and superconducting spintronics where engineering tunable magnetic inhomogeneity is key for certain applications.

Magnetic coupling at rare earth ferromagnet/transition metal ferromagnet interfaces: A comprehensive study of Gd/Ni

DOE PAGES

Higgs, T. D. C.; Bonetti, S.; Ohldag, H.; ...

2016-07-22

Thin film magnetic heterostructures with competing interfacial coupling and Zeeman energy provide a fertile ground to study phase transition between different equilibrium states as a function of external magnetic field and temperature. A rare-earth (RE)/transition metal (TM) ferromagnetic multilayer is a classic example where the magnetic state is determined by a competition between the Zeeman energy and antiferromagnetic interfacial exchange coupling energy. Technologically, such structures offer the possibility to engineer the macroscopic magnetic response by tuning the microscopic interactions between the layers. We have performed an exhaustive study of nickel/gadolinium as a model system for understanding RE/TM multilayers using themore » element-specific measurement technique x-ray magnetic circular dichroism, and determined the full magnetic state diagrams as a function of temperature and magnetic layer thickness. We compare our results to a modified Stoner-Wohlfarth-based model and provide evidence of a thickness-dependent transition to a magnetic fan state which is critical in understanding magnetoresistance effects in RE/TM systems. In conclusion, the results provide important insight for spintronics and superconducting spintronics where engineering tunable magnetic inhomogeneity is key for certain applications.« less

Magnetic coupling at rare earth ferromagnet/transition metal ferromagnet interfaces: A comprehensive study of Gd/Ni

NASA Astrophysics Data System (ADS)

Higgs, T. D. C.; Bonetti, S.; Ohldag, H.; Banerjee, N.; Wang, X. L.; Rosenberg, A. J.; Cai, Z.; Zhao, J. H.; Moler, K. A.; Robinson, J. W. A.

2016-07-01

Thin film magnetic heterostructures with competing interfacial coupling and Zeeman energy provide a fertile ground to study phase transition between different equilibrium states as a function of external magnetic field and temperature. A rare-earth (RE)/transition metal (TM) ferromagnetic multilayer is a classic example where the magnetic state is determined by a competition between the Zeeman energy and antiferromagnetic interfacial exchange coupling energy. Technologically, such structures offer the possibility to engineer the macroscopic magnetic response by tuning the microscopic interactions between the layers. We have performed an exhaustive study of nickel/gadolinium as a model system for understanding RE/TM multilayers using the element-specific measurement technique x-ray magnetic circular dichroism, and determined the full magnetic state diagrams as a function of temperature and magnetic layer thickness. We compare our results to a modified Stoner-Wohlfarth-based model and provide evidence of a thickness-dependent transition to a magnetic fan state which is critical in understanding magnetoresistance effects in RE/TM systems. The results provide important insight for spintronics and superconducting spintronics where engineering tunable magnetic inhomogeneity is key for certain applications.

Reaction between hydrous wadsleyite and iron: Implication for water distribution in Earth's transition zone

NASA Astrophysics Data System (ADS)

Zhu, F.; Li, J.; Liu, J.; Dong, J.

2017-12-01

The mantle transition zone (TZ) is considered as a potential water reservoir due to large capacities of wadsleyite and ringwoodite to store water in the structures. Whether it is a hydrous layer or an empty reservoir, however, is still under debate. Because the TZ may contain metallic iron1, 2 and water is an oxidizing agent at > 5 GPa, the stability of coexisting iron and TZ hydrous phases needs to be examined. In this study, we conducted multi-anvil experiments on iron with synthetic hydrous wadsleyite or forsterite and water under TZ pressure-temperature conditions. Similar rapid reactions were observed for both types of starting materials, producing ferropericlase, iron-bearing wadsleyite or ringwoodite, and iron hydride. The results imply that a hydrous TZ is incompatible with a reduced state, and that water distribution of TZ is confined to subducting slabs and slab-mantle boundaries, where water or hydrous phases in slab must oxidize the adjacent mantle before they can hydrate the silicates. In contrast, the bulk transition zone may be mostly dry. The iron hydride produced from this slab-mantle interaction may sink to greater depths due to their low melting temperature3, thus providing a pathway for hydrogen to enter the lower mantle and core. References 1. O'Neill HSC, McCammon C, Canil D, Rubie D, Ross C, Seifert F. Mossbauer spectroscopy of mantle transition zone phases and determination of minimum Fe3+ content. American Mineralogist 1993, 78(3-4): 456-460. 2. Rohrbach A, Ballhaus C, Golla-Schindler U, Ulmer P, Kamenetsky VS, Kuzmin DV. Metal saturation in the upper mantle. Nature 2007, 449(7161): 456-458. 3. Sakamaki K, Takahashi E, Nakajima Y, Nishihara Y, Funakoshi K, Suzuki T, et al. Melting phase relation of FeH x up to 20GPa: Implication for the temperature of the Earth's core. Physics of the Earth and Planetary Interiors 2009, 174(1): 192-201.

Young adults with intellectual disability transitioning from school to post-school: a literature review framed within the ICF.

PubMed

Foley, K-R; Dyke, P; Girdler, S; Bourke, J; Leonard, H

2012-01-01

The purpose of this review was to describe literature relating to transition for young people with an intellectual disability and identify gaps within the current knowledge base. A narrative literature review was undertaken. Searches of databases Medline, CINAHL, PsycINFO, ERIC, ISI Web of Science and ProQuest 500 International provided relevant research articles. The search terms used were intellectual disability, transition, employment, and ICF as well as other terms derived from the ICF. Manual searches of reference lists identified additional studies. Furthermore, government websites were searched for relevant reports and policies. Transition literature was explored by ICF domains; body functions and structures, activity and participation and contextual factors. Studies were identified in some but not all areas and included literature describing self-determination and participation in leisure activities for those with mild intellectual disability. However, significant gaps were found particularly for those with severe intellectual disability. The ICF is a useful tool in framing a review of transition literature for young people with intellectual disability due to the complexity and multi-faceted nature of transition. The important influence of environmental factors including family systems, post-school services and access to transport were highlighted as having considerable impacts on transition outcomes.

Alarming weight gain in women of a post-transitional country.

PubMed

Garmendia, Maria L; Alonso, Faustino T; Kain, Juliana; Uauy, Ricardo; Corvalan, Camila

2014-03-01

In post-transitional countries, obesity disproportionally affects women. Longitudinal studies can detect high-risk groups in whom to target actions. We investigated the magnitude and velocity of BMI changes in Chilean women of reproductive age and evaluated whether these trends vary in specific groups. Longitudinal study. We measured weight and height in 2007 (baseline) and again in 2010 (follow-up); we estimated change in BMI (weight/height2) within the 3-year period and assessed its relationship with age, years of education and parity, collected at baseline and follow-up using a questionnaire. Population-based cohort of low- to middle-income Chilean women. Seven hundred and sixty-one women of reproductive age (mean 32·0 (sd 7·0) years), mothers of children who participate in the Growth and Obesity Cohort Study (GOCS). At baseline, 61 % of women had BMI ≥ 25·0 kg/m2. After 3 years, women gained on average 2·6 kg and obesity (BMI ≥ 30·0 kg/m2) increased by 23 % (12 % new obesity cases). Women with normal nutritional status gained more BMI than obese women (1·4 v. 0·6 kg/m2, P < 0·001). An increase in parity was positively associated with BMI change, independently of age, nutritional status and education (P < 0·05). Age and education were not associated with BMI change after controlling for other factors (P > 0·05). In Chile, a post-transitional country, we observed an alarming increase in obesity among women of reproductive age. Our results indicate that in this population actions need to be targeted at all women irrespective of their nutritional status. A key component of these policies should be avoiding excessive weight gain during pregnancy.

Calculating the Magnetic Anisotropy of Rare-Earth-Transition-Metal Ferrimagnets

NASA Astrophysics Data System (ADS)

Patrick, Christopher E.; Kumar, Santosh; Balakrishnan, Geetha; Edwards, Rachel S.; Lees, Martin R.; Petit, Leon; Staunton, Julie B.

2018-03-01

Magnetocrystalline anisotropy, the microscopic origin of permanent magnetism, is often explained in terms of ferromagnets. However, the best performing permanent magnets based on rare earths and transition metals (RE-TM) are in fact ferrimagnets, consisting of a number of magnetic sublattices. Here we show how a naive calculation of the magnetocrystalline anisotropy of the classic RE-TM ferrimagnet GdCo5 gives numbers that are too large at 0 K and exhibit the wrong temperature dependence. We solve this problem by introducing a first-principles approach to calculate temperature-dependent magnetization versus field (FPMVB) curves, mirroring the experiments actually used to determine the anisotropy. We pair our calculations with measurements on a recently grown single crystal of GdCo5 , and find excellent agreement. The FPMVB approach demonstrates a new level of sophistication in the use of first-principles calculations to understand RE-TM magnets.

Calculating the Magnetic Anisotropy of Rare-Earth-Transition-Metal Ferrimagnets.

PubMed

Patrick, Christopher E; Kumar, Santosh; Balakrishnan, Geetha; Edwards, Rachel S; Lees, Martin R; Petit, Leon; Staunton, Julie B

2018-03-02

Magnetocrystalline anisotropy, the microscopic origin of permanent magnetism, is often explained in terms of ferromagnets. However, the best performing permanent magnets based on rare earths and transition metals (RE-TM) are in fact ferrimagnets, consisting of a number of magnetic sublattices. Here we show how a naive calculation of the magnetocrystalline anisotropy of the classic RE-TM ferrimagnet GdCo_{5} gives numbers that are too large at 0 K and exhibit the wrong temperature dependence. We solve this problem by introducing a first-principles approach to calculate temperature-dependent magnetization versus field (FPMVB) curves, mirroring the experiments actually used to determine the anisotropy. We pair our calculations with measurements on a recently grown single crystal of GdCo_{5}, and find excellent agreement. The FPMVB approach demonstrates a new level of sophistication in the use of first-principles calculations to understand RE-TM magnets.

Scatterometer Observes Extratropical Transition of Pacific Typhoons

NASA Technical Reports Server (NTRS)

Liu, W. Timothy; Tang, Wen-Qing; Dunbar, R. Scott

1997-01-01

From September 15 to 25, 1996, NASA's scatterometer (NSCAT) monitored the evolution of twin typhoons-Violet and Tom-as they moved north from the western tropical Pacific, acquiring features of mid-latitude storms. The typhoons developed frontal structures, increased asymmetry, and dry air was introduced into their cores. Violet hit Japan, causing death and destruction, and Tom merged with a mid-latitude trough and evolved into a large extratropical storm with gale-force winds. We understand relatively little about the extratropical transition of tropical cyclones because of the complex thermodynamics involved, but we do know that the mid-latitude storms resulting from tropical cyclones usually generate strong winds and heavy precipitation. Since the transition usually occurs over the ocean, few measurements have been made. The transition is a fascinating science problem, but it also has important economic consequences. The transition occurs over the busiest trans-ocean shipping lanes, and when the resulting storms hit land, they usually devastate populated areas. NSCAT was successfully launched into a near-polar, sunsynchronous orbit on the Japanese Advanced Earth Observing Satellite (ADEOS) in August 1996 from Tanegashima Space Center in Japan. NSCAT's six antennas send microwave pulses at a frequency of 14 GHz to the Earth's surface and measure the backscatter.

Transition States and transition state analogue interactions with enzymes.

PubMed

Schramm, Vern L

2015-04-21

Enzymatic transition states have lifetimes of a few femtoseconds (fs). Computational analysis of enzyme motions leading to transition state formation suggests that local catalytic site motions on the fs time scale provide the mechanism to locate transition states. An experimental test of protein fs motion and its relation to transition state formation can be provided by isotopically heavy proteins. Heavy enzymes have predictable mass-altered bond vibration states without altered electrostatic properties, according to the Born-Oppenheimer approximation. On-enzyme chemistry is slowed in most heavy proteins, consistent with altered protein bond frequencies slowing the search for the transition state. In other heavy enzymes, structural changes involved in reactant binding and release are also influenced. Slow protein motions associated with substrate binding and catalytic site preorganization are essential to allow the subsequent fs motions to locate the transition state and to facilitate the efficient release of products. In the catalytically competent geometry, local groups move in stochastic atomic motion on the fs time scale, within transition state-accessible conformations created by slower protein motions. The fs time scale for the transition state motions does not permit thermodynamic equilibrium between the transition state and stable enzyme states. Isotopically heavy enzymes provide a diagnostic tool for fast coupled protein motions to transition state formation and mass-dependent conformational changes. The binding of transition state analogue inhibitors is the opposite in catalytic time scale to formation of the transition state but is related by similar geometries of the enzyme-transition state and enzyme-inhibitor interactions. While enzymatic transition states have lifetimes as short as 10(-15) s, transition state analogues can bind tightly to enzymes with release rates greater than 10(3) s. Tight-binding transition state analogues stabilize the rare but

High-latitude ocean ventilation and its role in Earth's climate transitions.

PubMed

Naveira Garabato, Alberto C; MacGilchrist, Graeme A; Brown, Peter J; Evans, D Gwyn; Meijers, Andrew J S; Zika, Jan D

2017-09-13

The processes regulating ocean ventilation at high latitudes are re-examined based on a range of observations spanning all scales of ocean circulation, from the centimetre scales of turbulence to the basin scales of gyres. It is argued that high-latitude ocean ventilation is controlled by mechanisms that differ in fundamental ways from those that set the overturning circulation. This is contrary to the assumption of broad equivalence between the two that is commonly adopted in interpreting the role of the high-latitude oceans in Earth's climate transitions. Illustrations of how recognizing this distinction may change our view of the ocean's role in the climate system are offered.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'. © 2017 The Authors.

The role of solid-solid phase transitions in mantle convection

NASA Astrophysics Data System (ADS)

Faccenda, Manuele; Dal Zilio, Luca

2017-01-01

With changing pressure and temperature conditions, downwelling and upwelling crustal and mantle rocks experience several solid-solid phase transitions that affect the mineral physical properties owing to structural changes in the crystal lattice and to the absorption or release of latent heat. Variations in density, together with phase boundary deflections related to the non-null reaction slope, generate important buoyancy forces that add to those induced by thermal perturbations. These buoyancy forces are proportional to the density contrast between reactant and product phases, their volume fraction, the slope and the sharpness of the reaction, and affect the style of mantle convection depending on the system composition. In a homogeneous pyrolitic mantle there is little tendency for layered convection, with slabs that may stagnate in the transition zone because of the positive buoyancy caused by post-spinel and post-ilmenite reactions, and hot plumes that are accelerated by phase transformations in the 600-800 km depth range. By adding chemical and mineralogical heterogeneities as on Earth, phase transitions introduce bulk rock and volatiles filtering effects that generate a compositional gradient throughout the entire mantle, with levels that are enriched or depleted in one or more of these components. Phase transitions often lead to mechanical softening or hardening that can be related to a different intrinsic mechanical behaviour and volatile solubility of the product phases, the heating or cooling associated with latent heat, and the transient grain size reduction in downwelling cold material. Strong variations in viscosity would enhance layered mantle convection, causing slab stagnation and plume ponding. At low temperatures and relatively dry conditions, reactions are delayed due to the sluggish kinetics, so that non-equilibrium phase aggregates can persist metastably beyond the equilibrium phase boundary. Survival of low-density metastable olivine

The pyrohealth transition: how combustion emissions have shaped health through human history.

PubMed

Johnston, Fay H; Melody, Shannon; Bowman, David M J S

2016-06-05

Air pollution from landscape fires, domestic fires and fossil fuel combustion is recognized as the single most important global environmental risk factor for human mortality and is associated with a global burden of disease almost as large as that of tobacco smoking. The shift from a reliance on biomass to fossil fuels for powering economies, broadly described as the pyric transition, frames key patterns in human fire usage and landscape fire activity. These have produced distinct patters of human exposure to air pollution associated with the Agricultural and Industrial Revolutions and post-industrial the Earth global system-wide changes increasingly known as the Anthropocene. Changes in patterns of human fertility, mortality and morbidity associated with economic development have been previously described in terms of demographic, epidemiological and nutrition transitions, yet these frameworks have not explicitly considered the direct consequences of combustion emissions for human health. To address this gap, we propose a pyrohealth transition and use data from the Global Burden of Disease (GBD) collaboration to compare direct mortality impacts of emissions from landscape fires, domestic fires, fossil fuel combustion and the global epidemic of tobacco smoking. Improving human health and reducing the environmental impacts on the Earth system will require a considerable reduction in biomass and fossil fuel combustion.This article is part of the themed issue 'The interaction of fire and mankind'. © 2016 The Author(s).

The pyrohealth transition: how combustion emissions have shaped health through human history

PubMed Central

Johnston, Fay H.; Melody, Shannon

2016-01-01

Air pollution from landscape fires, domestic fires and fossil fuel combustion is recognized as the single most important global environmental risk factor for human mortality and is associated with a global burden of disease almost as large as that of tobacco smoking. The shift from a reliance on biomass to fossil fuels for powering economies, broadly described as the pyric transition, frames key patterns in human fire usage and landscape fire activity. These have produced distinct patters of human exposure to air pollution associated with the Agricultural and Industrial Revolutions and post-industrial the Earth global system-wide changes increasingly known as the Anthropocene. Changes in patterns of human fertility, mortality and morbidity associated with economic development have been previously described in terms of demographic, epidemiological and nutrition transitions, yet these frameworks have not explicitly considered the direct consequences of combustion emissions for human health. To address this gap, we propose a pyrohealth transition and use data from the Global Burden of Disease (GBD) collaboration to compare direct mortality impacts of emissions from landscape fires, domestic fires, fossil fuel combustion and the global epidemic of tobacco smoking. Improving human health and reducing the environmental impacts on the Earth system will require a considerable reduction in biomass and fossil fuel combustion. This article is part of the themed issue ‘The interaction of fire and mankind’. PMID:27216506

Enzymatic Transition States, Transition-State Analogs, Dynamics, Thermodynamics, and Lifetimes

PubMed Central

Schramm, Vern L.

2017-01-01

Experimental analysis of enzymatic transition-state structures uses kinetic isotope effects (KIEs) to report on bonding and geometry differences between reactants and the transition state. Computational correlation of experimental values with chemical models permits three-dimensional geometric and electrostatic assignment of transition states formed at enzymatic catalytic sites. The combination of experimental and computational access to transition-state information permits (a) the design of transition-state analogs as powerful enzymatic inhibitors, (b) exploration of protein features linked to transition-state structure, (c) analysis of ensemble atomic motions involved in achieving the transition state, (d) transition-state lifetimes, and (e) separation of ground-state (Michaelis complexes) from transition-state effects. Transition-state analogs with picomolar dissociation constants have been achieved for several enzymatic targets. Transition states of closely related isozymes indicate that the protein’s dynamic architecture is linked to transition-state structure. Fast dynamic motions in catalytic sites are linked to transition-state generation. Enzymatic transition states have lifetimes of femtoseconds, the lifetime of bond vibrations. Binding isotope effects (BIEs) reveal relative reactant and transition-state analog binding distortion for comparison with actual transition states. PMID:21675920

Studies on phase transition temperature of rare earth niobates Ln3NbO7 (Ln = Pr, Sm, Eu) with orthorhombic fluorite-related structure

NASA Astrophysics Data System (ADS)

Hinatsu, Yukio; Doi, Yoshihiro

2017-06-01

The phase transition of ternary rare earth niobates Ln3NbO7 (Ln = Pr, Sm, Eu) was investigated by the measurements of high-temperature and low-temperature X-ray diffraction, differential scanning calorimetry (DSC) and differential thermal analysis (DTA). These compounds crystallize in an orthorhombic superstructure derived from the structure of cubic fluorite (space group Pnma for Ln = Pr; C2221 for Ln = Sm, Eu). Sm3NbO7 undergoes the phase transition when the temperature is increased through ca. 1080 K and above the transition temperature, its structure is well described with space group Pnma. For Eu3NbO7, the phase transition was not observed up to 1273 K Pr3NbO7 indicates the phase transition when the temperature is increased through ca. 370 K. The change of the phase transition temperature against the Ln ionic radius for Ln3NbO7 is quite different from those for Ln3MO7 (M = Mo, Ru, Re, Os, or Ir), i.e., no systematic relationship between the phase transition temperature and the Ln ionic radius has been observed for Ln3NbO7 compounds.

Transits of Venus and Mercury: Exoplanet Analogs in Our Solar System

NASA Astrophysics Data System (ADS)

Pasachoff, Jay M.

2012-05-01

Since Johannes Kepler's predictions of transits of Mercury and Venus in 1631, and observations by Jeremiah Horrocks and William Crabtree of the 1639 transit of Venus, only 5 other transits of Venus have been observed: in 1761 and 1769, 1874 and 1882, and 2004. Expeditions were sent all over the world for the 18th and 19th century transits to follow the methods of Halley and others to determine the Astronomical Unit, giving the size and scale of the solar system, arguably the most important problem in astronomy for centuries. I will discuss how the infamous black-drop effect bedeviled astronomers in that quest for an accurate A.U., and how Glenn Schneider and I explained the effect through satellite observations of transits of Mercury, showing that it was not simply caused by the Cytherean atmosphere. During the 2004 transit, we worked with Richard Willson of ACRIMsat to detect the 0.1% drop in the Total Solar Irradiance, showing the effect of solar limb darkening, positioning such observations of transits of Venus and of Mercury as analogs to exoplanet transits. Our observations of the atmosphere of Venus with NASA's Transition Region and Coronal Explorer in 2004 led us to plan extensive observations of Venus's atmosphere and other phenomena during the June 5, 2012, transit of Venus, the last to be visible from Earth until 2117. We will have used NASA's Solar Dynamics Observatory, Hinode, ACRIMsat, and other spacecraft, and ground-based solar telescopes at Sacramento Peak, Kitt Peak, Big Bear, and Haleakala to observe the transit; I hope to give preliminary reports on these observations during this talk. Further, I will discuss the plans of Ehrenreich and colleagues for Hubble observations of this transit and our hopes of detecting transits of Venus and Earth as seen from Jupiter and Saturn over the next few years.

Primary to Post-Primary Transition for Students with Special Educational Needs from an Irish Context

ERIC Educational Resources Information Center

Foley, Tom; Foley, Shane; Curtin, Alicia

2016-01-01

This paper explores primary to post-primary transitions for students with Special Educational Needs (SEN) within mainstream schooling in an Irish context. A questionnaire was distributed to a cohort of sixth class students (n = 58) from four different primary schools in advance of their transfer and results were then compared with a similar cohort…

Transit Illustration of TRAPPIST-1

NASA Image and Video Library

2017-02-22

This illustration shows the seven TRAPPIST-1 planets as they might look as viewed from Earth using a fictional, incredibly powerful telescope. The sizes and relative positions are correctly to scale: This is such a tiny planetary system that its sun, TRAPPIST-1, is not much bigger than our planet Jupiter, and all the planets are very close to the size of Earth. Their orbits all fall well within what, in our solar system, would be the orbital distance of our innermost planet, Mercury. With such small orbits, the TRAPPIST-1 planets complete a "year" in a matter of a few Earth days: 1.5 for the innermost planet, TRAPPIST-1b, and 20 for the outermost, TRAPPIST-1h. This particular arrangement of planets with a double-transit reflect an actual configuration of the system during the 21 days of observations made by NASA's Spitzer Space Telescope in late 2016. The system has been revealed through observations from NASA's Spitzer Space Telescope and the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope, as well as other ground-based observatories. The system was named for the TRAPPIST telescope. http://photojournal.jpl.nasa.gov/catalog/PIA21429

Surgical weight loss as a life-changing transition: The impact of interpersonal relationships on post bariatric women.

PubMed

Ficaro, Irene

2018-04-01

Surgical Weight Loss as A Life-changing Transition: The Impact of Interpersonal Relationships on Post-Bariatric Women BACKGROUND: Although women account for 80% of patients having bariatric surgery (BS), the complex psychosocial mechanisms that accompany this transformation process have not been well established. The purpose of this study is to explore the lived experience of women transitioning in their interpersonal relationships post BS. A semi-structured interview with four questions was used. Six women, from six to 12 months post BS, were interviewed. The interviews were recorded, transcribed and analyzed using thematic analysis. By seeking support systems prior to undergoing BS, adequate social support was received during their recovery period. Attending bariatric support group meetings and using social media were significant to these women's satisfactory recovery. Relationship adjustments were sometimes needed, but overall these women established fulfilling social lives. Within the first year post bariatric surgery, women began to gain emotional strength and inspire others to lose weight as well. By inquiring about the psychosocial concerns of women who have undergone BS, healthcare providers can provide a more practical wellness plan. Copyright © 2017. Published by Elsevier Inc.

Photometric Analysis and Transit Times of TRAPPIST-1 B and C

NASA Astrophysics Data System (ADS)

Morris, Brett M.; Agol, Eric; Hawley, Suzanne L.

2018-01-01

TRAPPIST-1 hosts seven Earth-sized planets transiting an M8 star. We observed mid-transit times of each of the inner two planets with the Astrophysical Research Consortium (ARC) 3.5 m Telescope at Apache Point Observatory (APO) to help constrain the planet masses with transit timing variations, and we outline a procedure for analyzing transit observations of late-M stars with APO. The transit times of TRAPPIST-1 b and c are $\\mathrm{BJD}_{\\mathrm{TDB}} = 2457580.87634^{+0.00034}_{-0.00034}$ and $2457558.89477^{+0.00080}_{-0.00085}$, respectively, which will help constrain the planet masses.

A system of three transiting super-Earths in a cool dwarf star

NASA Astrophysics Data System (ADS)

Díez Alonso, E.; Suárez& Gómez, S. L.; González Hernández, J. I.; Suárez Mascareño, A.; González Gutiérrez, C.; Velasco, S.; Toledo-Padrón, B.; de Cos Juez, F. J.; Rebolo, R.

2018-05-01

We present the detection of three super-Earths transiting the cool star LP415-17, monitored by K2 mission in its 13th campaign. High-resolution spectra obtained with High Accuracy Radial velocity Planet Searcher-North/Telescopio Nazionale Galileo (HARPS-N/TNG) showed that the star is a mid-late K dwarf. Using spectral synthesis models, we infer its effective temperature, surface gravity, and metallicity, and subsequently determined from evolutionary models a stellar radius of 0.58 R⊙. The planets have radii of 1.8, 2.6, and 1.9 R⊕ and orbital periods of 6.34, 13.85, and 40.72 d. High-resolution images discard any significant contamination by an intervening star in the line of sight. The orbit of the furthest planet has radius of 0.18 au, close to the inner edge of the habitable zone. The system is suitable to improve our understanding of formation and dynamical evolution of super-Earth systems in the rocky-gaseous threshold, their atmospheres, internal structure, composition, and interactions with host stars.

Post-Secondary Pathways of Non-Graduates from B.C. Grade 12. Research Results from the Student Transitions Project

ERIC Educational Resources Information Center

Beatty-Guenter, Patricia; Cowin, Bob

2013-01-01

The Student Transitions Project (STP) has focused its research since 2005 on the achievements of British Columbia (B.C.) grade 12 graduates who enrolled in post-secondary education. Some students who do not graduate from Grade 12 also enroll at post-secondary institutions in a variety of programs, but little has been reported on these…

Cost-effectiveness of a health-social partnership transitional program for post-discharge medical patients.

PubMed

Wong, Frances Kam Yuet; Chau, June; So, Ching; Tam, Stanley Ku Fu; McGhee, Sarah

2012-12-24

Readmissions are costly and have implications for quality of care. Studies have been reported to support effects of transitional care programs in reducing hospital readmissions and enhancing clinical outcomes. However, there is a paucity of studies executing full economic evaluation to assess the cost-effectiveness of these transitional care programs. This study is therefore launched to fill this knowledge gap. Cost-effectiveness analysis was conducted alongside a randomized controlled trial that examined the effects of a Health-Social Transitional Care Management Program (HSTCMP) for medical patients discharged from an acute regional hospital in Hong Kong. The cost and health outcomes were compared between the patients receiving the HSTCMP and usual care. The total costs comprised the pre-program, program, and healthcare utilization costs. Quality of life was measured with SF-36 and transformed to utility values between 0 and 1. The readmission rates within 28 (control 10.2%, study 4.0%) and 84 days (control 19.4%, study 8.1%) were significantly higher in the control group. Utility values showed no difference between the control and study groups at baseline (p = 0.308). Utility values for the study group were significantly higher than in the control group at 28 (p < 0.001) and 84 days (p = 0.002). The study group also had a significantly higher QALYs gain (p < 0.001) over time at 28 and 84 days when compared with the control group. The intervention had an 89% chance of being cost-effective at the threshold of £20000/QALY. Previous studies on transitional care focused mainly on clinical outcomes and not too many included cost as an outcome measure. Studies examining the cost-effectiveness of the post-discharge support services are scanty. This study is the first to examine the cost-effectiveness of a transitional care program that used nurse-led services participated by volunteers. Results have shown that a health-social partnership transitional

K2-111 b - a short period super-Earth transiting a metal poor, evolved old star

NASA Astrophysics Data System (ADS)

Fridlund, Malcolm; Gaidos, Eric; Barragán, Oscar; Persson, Carina M.; Gandolfi, Davide; Cabrera, Juan; Hirano, Teruyuki; Kuzuhara, Masayuki; Csizmadia, Sz.; Nowak, Grzegorz; Endl, Michael; Grziwa, Sascha; Korth, Judith; Pfaff, Jeremias; Bitsch, Bertram; Johansen, Anders; Mustill, Alexander J.; Davies, Melvyn B.; Deeg, Hans J.; Palle, Enric; Cochran, William D.; Eigmüller, Philipp; Erikson, Anders; Guenther, Eike; Hatzes, Artie P.; Kiilerich, Amanda; Kudo, Tomoyuki; MacQueen, Phillip; Narita, Norio; Nespral, David; Pätzold, Martin; Prieto-Arranz, Jorge; Rauer, Heike; Van Eylen, Vincent

2017-07-01

Context. From a light curve acquired through the K2 space mission, the star K2-111(EPIC 210894022) has been identified as possibly orbited by a transiting planet. Aims: Our aim is to confirm the planetary nature of the object and derive its fundamental parameters. Methods: We analyse the light curve variations during the planetary transit using packages developed specifically for exoplanetary transits. Reconnaissance spectroscopy and radial velocity observations have been obtained using three separate telescope and spectrograph combinations. The spectroscopic synthesis package SME has been used to derive the stellar photospheric parameters that were used as input to various stellar evolutionary tracks in order to derive the parameters of the system. The planetary transit was also validated to occur on the assumed host star through adaptive imaging and statistical analysis. Results: The star is found to be located in the background of the Hyades cluster at a distance at least 4 times further away from Earth than the cluster itself. The spectrum and the space velocities of K2-111 strongly suggest it to be a member of the thick disk population. The co-added high-resolution spectra show that that it is a metal poor ([Fe/H] = - 0.53 ± 0.05 dex) and α-rich somewhat evolved solar-like star of spectral type G3. We find Teff = 5730 ± 50 K, log g⋆ = 4.15 ± 0.1 cgs, and derive a radius of R⋆ = 1.3 ± 0.1 R⊙ and a mass of M⋆ = 0.88 ± 0.02 M⊙. The currently available radial velocity data confirms a super-Earth class planet with a mass of 8.6 ± 3.9 M⊕ and a radius of 1.9 ± 0.2 R⊕. A second more massive object with a period longer than about 120 days is indicated by a long-term radial velocity drift. Conclusions: The radial velocity detection together with the imaging confirms with a high level of significance that the transit signature is caused by a planet orbiting the star K2-111. This planet is also confirmed in the radial velocity data. A second more

A miniature single element effusion cell for the vacuum deposition of transition-metal and rare-earth elements

NASA Astrophysics Data System (ADS)

Harris, V. G.; Koon, N. C.

1997-08-01

A miniature single element effusion cell has been fabricated and tested that allows for the high-vacuum deposition of a variety of transition-metal and rare-earth elements. The cell is designed to operate under high-vacuum conditions, ≈10-9 Torr, with low power demands, <200 W. The virtues of this evaporator are the simplicity of design and ease of fabrication, assembly, maintenance, and operation.

Post-transcriptional regulatory network of epithelial-to-mesenchymal and mesenchymal-to-epithelial transitions

PubMed Central

2014-01-01

Epithelial-to-mesenchymal transition (EMT) and its reverse process, mesenchymal-to-epithelial transition (MET), play important roles in embryogenesis, stem cell biology, and cancer progression. EMT can be regulated by many signaling pathways and regulatory transcriptional networks. Furthermore, post-transcriptional regulatory networks regulate EMT; these networks include the long non-coding RNA (lncRNA) and microRNA (miRNA) families. Specifically, the miR-200 family, miR-101, miR-506, and several lncRNAs have been found to regulate EMT. Recent studies have illustrated that several lncRNAs are overexpressed in various cancers and that they can promote tumor metastasis by inducing EMT. MiRNA controls EMT by regulating EMT transcription factors or other EMT regulators, suggesting that lncRNAs and miRNA are novel therapeutic targets for the treatment of cancer. Further efforts have shown that non-coding-mediated EMT regulation is closely associated with epigenetic regulation through promoter methylation (e.g., miR-200 or miR-506) and protein regulation (e.g., SET8 via miR-502). The formation of gene fusions has also been found to promote EMT in prostate cancer. In this review, we discuss the post-transcriptional regulatory network that is involved in EMT and MET and how targeting EMT and MET may provide effective therapeutics for human disease. PMID:24598126

Stripline/Microstrip Transition in Multilayer Circuit Board

NASA Technical Reports Server (NTRS)

Epp, Larry; Khan, Abdur

2005-01-01

A stripline-to-microstrip transition has been incorporated into a multilayer circuit board that supports a distributed solid-state microwave power amplifier, for the purpose of coupling the microwave signal from a buried-layer stripline to a top-layer microstrip. The design of the transition could be adapted to multilayer circuit boards in such products as cellular telephones (for connecting between circuit-board signal lines and antennas), transmitters for Earth/satellite communication systems, and computer mother boards (if processor speeds increase into the range of tens of gigahertz). The transition is designed to satisfy the following requirements in addition to the basic coupling requirement described above: (1) The transition must traverse multiple layers, including intermediate layers that contain DC circuitry. (2) The transition must work at a frequency of 32 GHz with low loss and low reflection. (3) The power delivered by the transition to top-layer microstrip must be split equally in opposite directions along the microstrip. Referring to the figure, this amounts to a requirement that when power is supplied to input port 1, equal amounts of power flow through output ports 2 and 3. (4) The signal-line via that is necessarily a part of such a transition must not be what is known in the art as a blind via; that is, it must span the entire thickness of the circuit board.

Development and Application of the Transit Timing Planet Detection Technique

NASA Astrophysics Data System (ADS)

Steffen, J. H.; Agol, E.

2005-12-01

We present the development and application of a new planet detection technique that uses the transit timing of a known, transiting planet. The transits of a solitary planet orbiting a star occur at equally spaced intervals in time. If a second planet is present, then dynamical interactions within the system will cause the time interval between transits to vary. These transit time variations (TTV) can be used to infer the orbital elements and mass of the unseen, perturbing planet. In some cases, particularly near mean-motion resonances, this technique could detect planets with masses less than the mass of the Earth---a capability not yet achieved by other planet detection schemes. We present an analysis of the set of transit times of the TrES-1 system given by Charbonneau et al. (2005). While no convincing evidence for a second planet in the TrES-1 system was found from that data, we constrain the mass that a perturbing planet could have as a function of the semi-major axis ratio of the two planets and the eccentricity of the perturbing planet. Near low-order, mean-motion resonances (within about 1% fractional deviation), we find that a secondary planet must generally have a mass comparable to or less than the mass of the Earth--showing that this data is the first to have sensitivity to sub Earth-mass planets. We present results from our studies that use simulated data and from an ongoing analysis of the HD209458 system. These results show that TTV will be an important tool in the detection and characterization of extrasolar planetary systems.

Radiative, nonradiative, and mixed-decay transitions of rare-earth ions in dielectric media

NASA Astrophysics Data System (ADS)

Burshtein, Zeev

2010-09-01

We present and discuss in a comprehensive, deductive, and simplified manner, issues of nonradiative transitions involvement in fluorescence of ions embedded in dielectric solid matrices. The semiclassical approach is favored over a full quantum description, and empiric quantities are introduced from the start. One issue is nonradiative single-phonon transitions when the energy gap between the adjacent electronic ion states is smaller than the cutoff matrix phonon energy. Another issue is transitions in a complex energy scheme, where some visible and near-visible transitions are radiative and others are nonradiative. A refined Füchtbauer-Ladenburg recipe for calculation of the stimulated emission spectrum on the basis of measurable absorption and fluorescence emission spectra is worked out. The last issue is multiphonon nonradiative transitions occurring when the energy gap between adjacent electronic ion states is larger than the cutoff matrix phonon energy. Transition probabilities were calculated on the basis of anharmonicity of the effective potential supporting the internal atomic basis vibrations. An expression in a closed form is obtained, similar to the empiric ``energy gap'' law, however, with parameters related to specific host material properties and the actual transition in the ion. Comparison to existing experimental evidence is presented and discussed in detail.

Agreement between pre-post measures of change and transition ratings as well as then-tests.

PubMed

Meyer, Thorsten; Richter, Susanne; Raspe, Heiner

2013-03-27

recall bias. Pre-test variation accounted for a substantial amount of variance in transition ratings in addition to the post-test scores, indicating a low level of present-state bias. Indirect and quasi-indirect measurements of change yielded comparable results indicating that recall bias does not necessarily affect quasi-indirect measurement of change. Quasi-indirect measurement might serve as a substitute for pre-post measurement under conditions still to be specified. Transition ratings reflect different aspects of change than indirect and quasi-indirect methods do, but are not necessarily biased by patients' present states.

APOSTLE: 11 TRANSIT OBSERVATIONS OF TrES-3b

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

Kundurthy, P.; Becker, A. C.; Agol, E.

2013-02-10

The Apache Point Survey of Transit Lightcurves of Exoplanets (APOSTLE) observed 11 transits of TrES-3b over two years in order to constrain system parameters and look for transit timing and depth variations. We describe an updated analysis protocol for APOSTLE data, including the reduction pipeline, transit model, and Markov Chain Monte Carlo analyzer. Our estimates of the system parameters for TrES-3b are consistent with previous estimates to within the 2{sigma} confidence level. We improved the errors (by 10%-30%) on system parameters such as the orbital inclination (i {sub orb}), impact parameter (b), and stellar density ({rho}{sub *}) compared to previousmore » measurements. The near-grazing nature of the system, and incomplete sampling of some transits, limited our ability to place reliable uncertainties on individual transit depths and hence we do not report strong evidence for variability. Our analysis of the transit timing data shows no evidence for transit timing variations and our timing measurements are able to rule out super-Earth and gas giant companions in low-order mean motion resonance with TrES-3b.« less

Magnetic properties and structural transitions of fluorite-related rare earth osmates Ln3OsO7 (Ln=Pr, Tb)

NASA Astrophysics Data System (ADS)

Hinatsu, Yukio; Doi, Yoshihiro

2013-02-01

Ternary rare-earth osmates Ln3OsO7 (Ln=Pr, Tb) have been prepared. They crystallize in an ortho-rhombic superstructure of cubic fluorite with space group Cmcm. Both of these compounds undergo a structural phase transition at 130 K (Ln=Pr) and 580 K (Ln=Tb). These compounds show complex magnetic behavior at low temperatures. Pr3OsO7 exhibits magnetic transitions at 8 and 73 K, and Tb3OsO7 magnetically orders at 8 and 60 K. The Os moments become one-dimensionally ordered, and when the temperature is furthermore decreased, it provokes the ordering in the Ln3+ sublattice that simultaneously becomes three-dimensionally ordered with the Os sublattice.

Management practices to support donor transition: lessons from Avahan, the India AIDS Initiative.

PubMed

Bennett, Sara; Rodriguez, Daniela; Ozawa, Sachiko; Singh, Kriti; Bohren, Meghan; Chhabra, Vibha; Singh, Suneeta

2015-06-13

During 2009-2012, Avahan, a large donor funded HIV/AIDS prevention program in India was transferred from donor support and operation to government. This transition of approximately 200 targeted interventions (TIs), occurred in three tranches in 2009, 2011 and 2012. This paper reports on the management practices pursued in support of a smooth transition of the program, and addresses the extent to which standard change management practices were employed, and were useful in supporting transition. We conducted structured surveys of a sample of 80 TIs from the 2011 and 2012 rounds of transition. One survey was administered directly before transition and the second survey 12 month after transition. These surveys assessed readiness for transition and practices post-transition. We also conducted 15 case studies of transitioning TIs from all three rounds, and re-visited 4 of these 1-3 years later. Considerable evolution in the nature of relationships between key actors was observed between transition rounds, moving from considerable mistrust and lack of collaboration in 2009 toward a shared vision of transition and mutually respectful relationships between Avahan and government in later transition rounds. Management practices also evolved with the gradual development of clear implementation plans, establishment of the post of "transition manager" at state and national levels, identified budgets to support transition, and a common minimum programme for transition. Staff engagement was important, and was carried out relatively effectively in later rounds. While the change management literature suggests short-term wins are important, this did not appear to be the case for Avahan, instead a difficult first round of transition seemed to signal the seriousness of intentions regarding transition. In the Avahan case a number of management practices supported a smooth transition these included: an extended and sequenced time frame for transition; co-ownership and planning of

NASA's SDO Satellite Captures 2012 Venus Transit

NASA Image and Video Library

2017-12-08

NASA image captured June 5, 2012. On June 5-6 2012, SDO is collecting images of one of the rarest predictable solar events: the transit of Venus across the face of the sun. This event happens in pairs eight years apart that are separated from each other by 105 or 121 years. The last transit was in 2004 and the next will not happen until 2117. Credit: NASA/SDO, HMI To read more about the 2012 Venus Transit go to: sunearthday.nasa.gov/transitofvenus Add your photos of the Transit of Venus to our Flickr Group here: www.flickr.com/groups/venustransit/ NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Interagency Transition Team Development and Facilitation. Essential Tools.

ERIC Educational Resources Information Center

Stodden, Robert A.; Brown, Steven E.; Galloway, L. M.; Mrazek, Susan; Noy, Liora

2005-01-01

The purpose of this Essential Tool is to assist state-level transition coordinators and others responsible for forming, conducting, and evaluating the performance of interagency transition teams that are focused upon the school and post-school needs of youth with disabilities. This Essential Tool is designed to guide the coordination efforts of…

Determination of calcium carbonate and sodium carbonate melting curves up to Earth's transition zone pressures with implications for the deep carbon cycle

NASA Astrophysics Data System (ADS)

Li, Zeyu; Li, Jie; Lange, Rebecca; Liu, Jiachao; Militzer, Burkhard

2017-01-01

Melting of carbonated eclogite or peridotite in the mantle influences the Earth's deep volatile cycles and bears on the long-term evolution of the atmosphere. Existing data on the melting curves of calcium carbonate (CaCO3) and sodium carbonate (Na2CO3) are limited to 7 GPa and therefore do not allow a full understanding of carbon storage and cycling in deep Earth. We determined the melting curves of CaCO3 and Na2CO3 to the pressures of Earth's transition zone using a multi-anvil apparatus. Melting was detected in situ by monitoring a steep and large increase in ionic conductivity, or inferred from sunken platinum markers in recovered samples. The melting point of CaCO3 rises from 1870 K at 3 GPa to ∼2000 K at 6 GPa and then stays within 50 K of 2000 K between 6 and 21 GPa. In contrast, the melting point of Na2CO3 increases continuously from ∼1123 K at 3 GPa to ∼1950 K at 17 GPa. A pre-melting peak in the alternating current through solid CaCO3 is attributed to the transition from aragonite to calcite V. Accordingly the calcite V-aragonite-liquid invariant point is placed at 13 ± 1 GPa and 1970 ± 40 K, with the Clapeyron slope of the calcite V to aragonite transition constrained at ∼70 K/GPa. The experiments on CaCO3 suggest a slight decrease in the melting temperature from 8 to 13 GPa, followed by a slight increase from 14 to 21 GPa. The negative melting slope is consistent with the prediction from our ab initio simulations that the liquid may be more compressible and become denser than calcite V at sufficiently high pressure. The positive melting slope at higher pressures is supported by the ab initio prediction that aragonite is denser than the liquid at pressures up to 30 GPa. At transition zone pressures the melting points of CaCO3 are comparable to that of Na2CO3 but nearly 400 K and 500 K lower than that of MgCO3. The fusible nature of compressed CaCO3 may be partially responsible for the majority of carbonatitic melts found on Earth's surface

High-pressure phase of brucite stable at Earth's mantle transition zone and lower mantle conditions.

PubMed

Hermann, Andreas; Mookherjee, Mainak

2016-12-06

We investigate the high-pressure phase diagram of the hydrous mineral brucite, Mg(OH) 2 , using structure search algorithms and ab initio simulations. We predict a high-pressure phase stable at pressure and temperature conditions found in cold subducting slabs in Earth's mantle transition zone and lower mantle. This prediction implies that brucite can play a much more important role in water transport and storage in Earth's interior than hitherto thought. The predicted high-pressure phase, stable in calculations between 20 and 35 GPa and up to 800 K, features MgO 6 octahedral units arranged in the anatase-TiO 2 structure. Our findings suggest that brucite will transform from a layered to a compact 3D network structure before eventual decomposition into periclase and ice. We show that the high-pressure phase has unique spectroscopic fingerprints that should allow for straightforward detection in experiments. The phase also has distinct elastic properties that might make its direct detection in the deep Earth possible with geophysical methods.

Migration transition in small Northern and Eastern Caribbean states.

PubMed

Mcelroy, J L; De Albuquerque, K

1988-01-01

1 area of intra-Caribbean migration that has been overlooked is the "migration transition"--the transformation of rapidly modernizing societies from net labor exporters to net labor importers. This article assembles 8 case studies to 1) briefly present a spectrum of migration experiences in the Caribbean, 2) uncover some transitions under way, 3) pinpoint the forces that underlie the migration transition, and 4) point out some of the more important policy implications of labor migration reversals. The 8 island societies sampled for illustration purposes include 1) the Bahamas and the US Virgin Islands as post-migration transition societies (Zelinsky's advanced society), 2) the British Virgin Islands and the Cayman Islands as undergoing transition (Zelinsky's late transitional society), and 3) Anguilla, St. Kitts-Nevis, Turks and Caicos, and Montserrat as premigration transition societies (Zelinsky's early transitional society). Population data for the islands were derived primarily from the West Indian censuses and government statistics. These 8 historical sketches reveal certain commonalities. All are at various stages in a long-term economic restructuring to displace traditional staple crops with more income elastic, high value export services. In such societies, population growth and progress along the migration transition is an increasing function of this kind of successful export substitution. In addition, along the migration and economic transitions, such insular economies exhibit a relatively large public sector (20-30% of all activity), declining unemployment, increasing fiscal autonomy, and are committed to a development strategy remarkably similar to the "successful" model of the Bahamas and the US Virgin Islands. Cursory evidence suggests that, because of intersectoral competition for land and labor, there is an inverse relationship between farm effort/manufacturing employment and tourism intensity. This review suggests that small islands undergoing

A cloaking device for transiting planets

NASA Astrophysics Data System (ADS)

Kipping, David M.; Teachey, Alex

2016-06-01

The transit method is presently the most successful planet discovery and characterization tool at our disposal. Other advanced civilizations would surely be aware of this technique and appreciate that their home planet's existence and habitability is essentially broadcast to all stars lying along their ecliptic plane. We suggest that advanced civilizations could cloak their presence, or deliberately broadcast it, through controlled laser emission. Such emission could distort the apparent shape of their transit light curves with relatively little energy, due to the collimated beam and relatively infrequent nature of transits. We estimate that humanity could cloak the Earth from Kepler-like broad-band surveys using an optical monochromatic laser array emitting a peak power of ˜30 MW for ˜10 hours per year. A chromatic cloak, effective at all wavelengths, is more challenging requiring a large array of tunable lasers with a total power of ˜250 MW. Alternatively, a civilization could cloak only the atmospheric signatures associated with biological activity on their world, such as oxygen, which is achievable with a peak laser power of just ˜160 kW per transit. Finally, we suggest that the time of transit for optical Search for Extraterrestrial Intelligence (SETI) is analogous to the water-hole in radio SETI, providing a clear window in which observers may expect to communicate. Accordingly, we propose that a civilization may deliberately broadcast their technological capabilities by distorting their transit to an artificial shape, which serves as both a SETI beacon and a medium for data transmission. Such signatures could be readily searched in the archival data of transit surveys.

Evaluation of an Innovative Interest-Based Post-School Transition Programme for Young People with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Ashburner, Jill K.; Bobir, Natasha I.; van Dooren, Kate

2018-01-01

After leaving school, young people with autism spectrum disorder often struggle with social, educational and employment participation. A post-school transition programme underpinned by individualised case management, where mentees are guided to complete self-selected projects by mentors with multimedia skills, was evaluated using a qualitative…

Effects of Composition and Iron Spin State on the Structural Transition of (Mg,Fe)CO3 in the Earth's Lower Mantle

NASA Astrophysics Data System (ADS)

Hsu, H.; Huang, S. C.; Wei, C. M.; Hsing, C. R.

2015-12-01

Iron-bearing magnesium carbonates (Mg,Fe)CO3 are believed the major carbon carriers in the Earth's deep lower mantle; they may play a crucial role in the Earth's deep carbon cycle. Knowledge of the physical and chemical properties of these carbonates is thus essential for our understanding of the mantle's role in global carbon cycle. Experiments have shown that (Mg,Fe)CO3 ferromagnesite (calcite structure) can be stable up to 80-100 GPa. At 45-50 GPa, ferromangsite undergoes a high-spin to low-spin transition, accompanied by a volume reduction and elastic anomalies. Starting ~100 GPa, ferromagnesite goes through a complicated structural transition. The detail of this transition and the atomic structures of high-pressure (Mg,Fe)CO3 phases are still highly debated. Experimental observations and theoretical results are inconsistent so far. In experiments, several distinct high-pressure (Mg,Fe)CO3 structures have been reported, including a P21/c phase [1] and a Pmm2 phase [2]. In theory, a C2/m phase [3] and a P-1 phase [4] have been suggested, while the Pmm2 phase is not found. One possible reason for such a discrepancy is that all available theoretical calculations so far are based on pure MgCO3, while experimental works are performed using (Mg,Fe)CO3 with high iron concentration ( > 50%). Clearly, the concentration of iron and the possible iron spin crossover can significantly affect the stability of these high-pressure (Mg,Fe)CO3 phases. Here, we use density functional theory + self-consistent Hubbard U (DFT+Usc) calculations to study this structural transition. The effects of composition and iron spin state on these (Mg,Fe)CO3 phases are also discussed. Our results can be expected to provide insightful information for better understanding the Earth's deep carbon cycle.[1] E. Boulard et al., Proc. Natl. Acad. Sci. USA 108, 5184 (2011).[2] J. Liu et al., Sci. Rep. 5, 7640 (2015). [3] A. R. Oganov et al., Earth Planet. Sci. Lett. 273, 38 (2008). [4] C. J. Pickard and

Debunking Myths: The B.C. Student Transitions Project

ERIC Educational Resources Information Center

Gaber, Devron; Heslop, Joanne

2009-01-01

British Colombia's Student Transitions Project (STP) is challenging long-held myths about the movement of students through the education system in that province and may become a catalyst for re-examining commonly held ideas about students' transition to post-secondary education across the country. The STP is a collaborative effort among B.C.'s…

Abnormal Elasticity of Single-Crystal Magnesiosiderite across the Spin Transition in Earth's Lower Mantle

NASA Astrophysics Data System (ADS)

Fu, S.; Yang, J.; Lin, J. F.

2016-12-01

Carbon can be transported into deep Earth's interior via subduction of carbonated oceanic crust, hosted as Mg-Fe bearing carbonates. The existence of stable carbonate can significantly affect our understanding on geochemical and geophysical properties of the planet. Early studies have shown that iron spin-pairing transition could occur in the iron-enriched carbonates, generally called magnesiosiderite, under lower mantle conditions. The pressure-induced spin state change is accompanied by a sudden volume collaps. However, the effects of the spin-pairing transition on single-crystal elasticity of magnesiosiderite under high pressure conditions are still unclear. Understanding the elasticity of single-crystal magnesiosiderite at relevant lower mantle conditions plays an important role in better understanding the seismic signatures in the carbon-enriched region, and to constrain carbon storage and recycling in the mantle. In order to solve all individual elastic constants (C11, C22, C33, C44, C55, C66, C12, C23, and C13) of magnesiosiderite at high pressures via Christoffel's equations, we employed Brillouin Light Scattering (BLS) to measure shear wave (Vs) and compressional wave velocities (Vp) as a function of the azimuthal angle under lower mantle pressures, accompanied by Impulsive Stimulate Light Scattering (ISS) to measure the Vp when pressures are too high to measure it by BLS. A general thermoelastic modelling was developed to fit the elastic softening within the spin transition. We will further discuss the effects of pressures, as well as iron spin states, on the single-crystal elasticity and seismic parameters (Vp and Vs anisotropy AVp, AVs, etc) at lower mantle conditions. These results could provide clues in explaining regional seismic heterogeneities in deep mantle.

Post-Soviet transition: improving health services delivery and management.

PubMed

Antoun, Joseph; Phillips, Frank; Johnson, Tricia

2011-01-01

During the post-Soviet transition of the last 2 decades, ex-Communist countries of the Eastern Bloc, including eastern and central Europe, the Soviet Union, and its satellite and aligned states, have undergone major health system reforms. Many health systems of those countries--previously adopting a Soviet-type Semashko model--are currently called "in transition," as reform agendas, such as shifting to a Bismarck, Beveridge, or mixed financing scheme or adopting new health delivery management policies, are still in development. In this article, we first review common characteristics of Semashko health systems (the predominant health system of Communist countries during the Soviet era) and then discuss the "new public management" principles that ex-Communist countries have recently started to adopt with various degrees of success. We then illustrate experiences with these principles using 2 case studies, from Russia and Albania, and propose health policy options for both cases. Based on a review of the literature and on the our work experience in Russia and Albania, we found that the 2 ex-Semashko systems have not fully capitalized on expected positive outcomes of new public management principles due to low local healthcare financing levels, depreciated healthcare infrastructure and operational capacities, overlapping and contradicting ideology and policies of the former and newer health systems, and finally, lack of leadership that has successful experience with these principles. In the case of pharmaceutical pricing, reimbursement, and access in Russia, we show how a well-intentioned but suboptimally designed and managed pharmaceutical coverage scheme has suffered moral hazard and adverse selection and has adversely impacted the new public management promise of efficient medicine coverage. In the case of Albania, the delayed investment in human resource reform within a depreciated and underfinanced delivery system has adversely affected the implementation of new

The 2004 Transit of Venus as a Space Science Education Opportunity

NASA Astrophysics Data System (ADS)

Odenwald, S.; Mayo, L.; Vondrak, R.; Thieman, J.; Hawkins, I.; Schultz, G.

2003-12-01

We will present some of the programs and activities that NASA and its missions are preparing in order to support public and K12 education in space science and astronomy using the 2004 transit of Venus as a focal event. The upcoming transit of Venus on June 8 offers a unique opportunity to educate students and the general public about the scale of the solar system and the universe, as well as basic issues in comparative planetology. NASA's Sun-Earth Connection Education Forum is offering a number of programs to take advantage of this rare event. Among these are a live web cast from Spain of the entire transit, a series of radio and TV programs directed at students and the general public, a web cast describing extra-solar planet searches using the transit geometry, and archived observations produced by public observatories and student-operated solar viewers. The NASA/OSS Education Forums will also partner with science museums, planetaria and teachers across the country to bring the transit of Venus 'down to Earth'. In addition to offering enrichment activities in mathematics and space science, we also describe collaborations that have yielded unique historical resources including online archives of newspaper articles from the 1874 and 1882 transits. In addition, in collaboration with the Library of Congress Music Division, we have supported a modern re-orchestration of John Philip Sousa's Transit of Venus March which has not been performed since 1883. We anticipate that the transit of Venus will be a significant event of considerable public interest and curiosity, if the newspaper headlines from the transit seen in 1882 are any indication.

A new interpretation of the Besnus transition in monoclinic pyrrhotite

NASA Astrophysics Data System (ADS)

Gehring, Andreas

2016-04-01

Non-stoichiometric monoclinic 4C pyrrhotite (ideal formula: Fe7S8) is a major magnetic remanence carrier in the Earth's crust and in extraterrestrial materials. Because of its low-temperature magnetic transition around 30 K also known as Besnus transition, this mineral phase is easily detectable in natural samples. Considering the rock magnetic literature, an intrinsic origin of the Besnus transition similar to that of the Verwey transition has generally been assumed. Although the physical properties of pyrrhotite have intensively been studied, the mechanism behind the pronounced change in magnetization at the low-temperature transition is still debated. To address this question we performed magnetization experiments on a natural pyrrhotite crystal (Fe6.6S8) that consists of an epitaxial intergrowth of a commensurate 4C and an incommensurate 5C* superstructure that are different in their defect structure (1,2). The occurrence of two monoclinic superstructures detected by X-ray diffractometry is magnetically confirmed by symmetric inflection points in hysteresis measurements above the transition at about 30 K. The disappearance of the inflection points and the associated change of the hysteresis parameters indicate that the two superstructures become strongly coupled to form a unitary magnetic anisotropy system at the transition. From this it follows that the Besnus transition in monoclinic pyrrhotite is an extrinsic magnetic phenomenon with respect to the 4C superstructure and therefore the physics behind it is in fact different from that of the well-known Verwey transition. Finally, this novel interpretation explains the rock magnetic data for the low-temperature transition that has been reported for monoclinic pyrrhotite. It will also provide deeper understanding of magnetism in monoclinic pyrrhotite, which in turn will enable a more profound insight to the magnetization properties of the Earth's crust. 1.) Charilaou, M., Kind, J., Koulialias, D., Weidler, P

A Pilot Study for Antimicrobial Stewardship Post-Discharge: Avoiding Pitfalls at the Transitions of Care.

PubMed

Jones, Justin M; Leedahl, Nathan D; Losing, Ashley; Carson, Paul J; Leedahl, David D

2018-04-01

Lack of patient follow-up is a major concern during care transitions, and the role of an antimicrobial stewardship program (ASP) in assessing antimicrobial regimens after hospital discharge is not well described. We implemented an expanded ASP to include patients recently discharged from the hospital and measured its impact on inappropriate antimicrobial therapy 72 hours after inpatient culture data were finalized. A prospective cohort study was conducted at a 583-bed tertiary care center in the Upper Midwest of America. All patients discharged from our facility on antimicrobial therapy with pending culture results between February 3, 2016, and March 2, 2016, were included for review. If a pathogen nonsusceptible to all prescribed antimicrobials was identified post-discharge, a recommendation for therapy modification was communicated to the prescriber. Thirty-eight patients discharged from our hospital on antimicrobial therapy with pending culture results were evaluated for intervention. When final culture susceptibilities were considered, 5 of 38 patients had been prescribed an inappropriate antimicrobial agent. An ASP pharmacist intervened on 4 of 5 patients, resulting in 3 of 5 patients transitioning to appropriate antimicrobial therapy. When compared to a historical cohort, our transitions-of-care ASP yielded a 3.6-fold increase in antimicrobial-related interventions among discharged patients while reducing inappropriate outpatient antimicrobial therapy by 39%. We believe this is the first pharmacist-driven ASP represented in the medical literature which evaluated all available inpatient culture data to serve patients discharged from the hospital. Antimicrobial stewardship for patients in care transitions may provide an opportunity to increase ASP interventions and reduce inappropriate antimicrobial therapy.

Analyses of some exoplanets' transits and transit timing variations

NASA Astrophysics Data System (ADS)

Püsküllü, ćaǧlar; Soydugan, Faruk

2017-02-01

We present solutions of the transit light curves and transit timing variations (TTVs) analyses of the exoplanets HAT-P-5b, HAT-P-9b and HAT-P-25b. Transit light curves were collected at Çanakkale Onsekiz Mart University Observatory and TUBITAK National Observatory. The models were produced by WINFITTER program and stellar, planetary and orbital properties were obtained and discussed. We gave new transit times and generated TTVs with them by appending additional data based on Exoplanet Transit Database (ETD). Significant signals at the TTVs were also investigated.

COMPARATIVE HABITABILITY OF TRANSITING EXOPLANETS

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

Barnes, Rory; Meadows, Victoria S.; Evans, Nicole, E-mail: rory@astro.washington.edu

2015-12-01

Exoplanet habitability is traditionally assessed by comparing a planet’s semimajor axis to the location of its host star’s “habitable zone,” the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler space telescope has discovered numerous planet candidates near the habitable zone, and many more are expected from missions such as K2, TESS, and PLATO. These candidates often require significant follow-up observations for validation, so prioritizing planets for habitability from transit data has become an important aspect of the search for life in the universe. We propose a method to compare transiting planets for theirmore » potential to support life based on transit data, stellar properties and previously reported limits on planetary emitted flux. For a planet in radiative equilibrium, the emitted flux increases with eccentricity, but decreases with albedo. As these parameters are often unconstrained, there is an “eccentricity-albedo degeneracy” for the habitability of transiting exoplanets. Our method mitigates this degeneracy, includes a penalty for large-radius planets, uses terrestrial mass–radius relationships, and, when available, constraints on eccentricity to compute a number we call the “habitability index for transiting exoplanets” that represents the relative probability that an exoplanet could support liquid surface water. We calculate it for Kepler objects of interest and find that planets that receive between 60% and 90% of the Earth’s incident radiation, assuming circular orbits, are most likely to be habitable. Finally, we make predictions for the upcoming TESS and James Webb Space Telescope missions.« less

Phase transitions in single macromolecules: Loop-stretch transition versus loop adsorption transition in end-grafted polymer chains

NASA Astrophysics Data System (ADS)

Zhang, Shuangshuang; Qi, Shuanhu; Klushin, Leonid I.; Skvortsov, Alexander M.; Yan, Dadong; Schmid, Friederike

2018-01-01

We use Brownian dynamics simulations and analytical theory to compare two prominent types of single molecule transitions. One is the adsorption transition of a loop (a chain with two ends bound to an attractive substrate) driven by an attraction parameter ɛ and the other is the loop-stretch transition in a chain with one end attached to a repulsive substrate, driven by an external end-force F applied to the free end. Specifically, we compare the behavior of the respective order parameters of the transitions, i.e., the mean number of surface contacts in the case of the adsorption transition and the mean position of the chain end in the case of the loop-stretch transition. Close to the transition points, both the static behavior and the dynamic behavior of chains with different length N are very well described by a scaling ansatz with the scaling parameters (ɛ - ɛ*)Nϕ (adsorption transition) and (F - F*)Nν (loop-stretch transition), respectively, where ϕ is the crossover exponent of the adsorption transition and ν is the Flory exponent. We show that both the loop-stretch and the loop adsorption transitions provide an exceptional opportunity to construct explicit analytical expressions for the crossover functions which perfectly describe all simulation results on static properties in the finite-size scaling regime. Explicit crossover functions are based on the ansatz for the analytical form of the order parameter distributions at the respective transition points. In contrast to the close similarity in equilibrium static behavior, the dynamic relaxation at the two transitions shows qualitative differences, especially in the strongly ordered regimes. This is attributed to the fact that the surface contact dynamics in a strongly adsorbed chain is governed by local processes, whereas the end height relaxation of a strongly stretched chain involves the full spectrum of Rouse modes.

Biotic transitions in global marine diversity

NASA Technical Reports Server (NTRS)

Miller, A. I.

1998-01-01

Long-term transitions in the composition of Earth's marine biota during the Phanerozoic have historically been explained in two different ways. One view is that they were mediated through biotic interactions among organisms played out over geologic time. The other is that mass extinctions transcended any such interactions and governed diversity over the long term by resetting the relative diversities of higher taxa. However, a growing body of evidence suggests that macroevolutionary processes effecting biotic transitions during background times were not fundamentally different from those operating during mass extinctions. Physical perturbations at many geographic scales combined to produce the long-term trajectory of Phanerozoic diversity.

"In Transition": Choice and the Children of New Zealand's Economic Reforms

ERIC Educational Resources Information Center

Higgins, Jane; Nairn, Karen

2006-01-01

New Zealand's rapid emergence as a late-modern, neo-liberal society following 1984 led to a transformation in the institutional infrastructure for youth transitions from school to post-school worlds. Our research focuses on the ways that young people born after 1984 craft identities in transition. We investigate their perspectives on transition in…

Independent Living Transition Assistance for Young Adults Who Have Special Needs

ERIC Educational Resources Information Center

Russell, Rhonda L.

2016-01-01

This research focused on young adults who have disabilities and their transition and career planning for post-secondary life. The study sought to identify best practices in transition planning, transition planning services, and to determine the types of resources and support needed by young adults who have disabilities. For youth who have…

Impact of Legislation on Post-School Transition Practice for Young People with Additional Support Needs in Scotland

ERIC Educational Resources Information Center

Richardson, Thomas D.; Jindal-Snape, Divya; Hannah, Elizabeth F. S.

2017-01-01

A longitudinal study was conducted to understand post-school transition practice for young people with additional support needs (ASN) before and after the implementation of key legislation, the Education (Additional Support for Learning) (Scotland) Act 2004, amended in 2009. Primary data were collected from one local authority in Scotland. Twelve…

Youth and administrator perspectives on transition in Kentucky's state agency schools.

PubMed

Marshall, Amy; Powell, Norman; Pierce, Doris; Nolan, Ronnie; Fehringer, Elaine

2012-01-01

Students, a large percentage with disabilities, are at high risk for poor post-secondary outcomes in state agency education programs. This mixed-methods study describes the understandings of student transitions in state agency education programs from the perspectives of youth and administrators. Results indicated that: transition is more narrowly defined within alternative education programs; key strengths of transition practice are present in nontraditional schools; and the coordination barriers within this fluid inter-agency transition system are most apparent in students' frequent inter-setting transitions between nontraditional and home schools.

Transiting Exoplanet Survey Satellite (TESS)

NASA Technical Reports Server (NTRS)

Ricker, G. R.; Clampin, M.; Latham, D. W.; Seager, S.; Vanderspek, R. K.; Villasenor, J. S.; Winn, J. N.

2012-01-01

The Transiting Exoplanet Survey Satellite (TESS) will discover thousands of exoplanets in orbit around the brightest stars in the sky. In a two-year survey, TESS will monitor more than 500,000 stars for temporary drops in brightness caused by planetary transits. This first-ever spaceborne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances. No ground-based survey can achieve this feat. A large fraction of TESS target stars will be 30-100 times brighter than those observed by Kepler satellite, and therefore TESS . planets will be far easier to characterize with follow-up observations. TESS will make it possible to study the masses, sizes, densities, orbits, and atmospheres of a large cohort of small planets, including a sample of rocky worlds in the habitable zones of their host stars. TESS will provide prime targets for observation with the James Webb Space Telescope (JWST), as well as other large ground-based and space-based telescopes of the future. TESS data will be released with minimal delay (no proprietary period), inviting immediate community-wide efforts to study the new planets. The TESS legacy will be a catalog of the very nearest and brightest main-sequence stars hosting transiting exoplanets, thus providing future observers with the most favorable targets for detailed investigations.

Transitions.

ERIC Educational Resources Information Center

Field, David; And Others

1992-01-01

Includes four articles: "Career Aspirations" (Field); "Making the Transition to a New Curriculum" (Baker, Householder); "How about a 'Work to School' Transition?" (Glasberg); and "Technological Improvisation: Bringing CNC to Woodworking" (Charles, McDuffie). (SK)

Transitions of Adoptive Parents: A Longitudinal Mixed Methods Analysis.

PubMed

Foli, Karen J; Hebdon, Megan; Lim, Eunjung; South, Susan C

2017-10-01

As adoptive parents create a new family, they face myriad changes both pre-and post-placement of their child. The aim of this study was to describe parent perceptions and depressive symptoms during this transition via reports collected with an online survey. Using content analysis, we analyzed a total of 110 responses from 64 parents at three time points: 4-6weeks pre-placement, and 4-6weeks and 5-6months post-placement. Five main themes were revealed: Transition from uncertainty to a new normal; unique experiences related to adoption; rest/fatigue: out of balance; life stressors; and faith/spirituality. Two subthemes were also identified: previous losses (pre-placement) and joy and love (post-placement). During the transition from pre-to post-placement, adoptive parents experience a unique passage, with both challenges and strengths exclusive to this group of parents. While acknowledging the commonalities of some parenting experiences, healthcare and adoption professionals should recognize the unique dynamics that adoption brings to families. Copyright © 2017 Elsevier Inc. All rights reserved.

The detection and characterization of a nontransiting planet by transit timing variations.

PubMed

Nesvorný, David; Kipping, David M; Buchhave, Lars A; Bakos, Gáspár Á; Hartman, Joel; Schmitt, Allan R

2012-06-01

The Kepler mission is monitoring the brightness of ~150,000 stars, searching for evidence of planetary transits. As part of the Hunt for Exomoons with Kepler (HEK) project, we report a planetary system with two confirmed planets and one candidate planet discovered with the publicly available data for KOI-872. Planet b transits the host star with a period P(b) = 33.6 days and exhibits large transit timing variations indicative of a perturber. Dynamical modeling uniquely detects an outer nontransiting planet c near the 5:3 resonance (P(c) = 57.0 days) with a mass 0.37 times that of Jupiter. Transits of a third planetary candidate are also found: a 1.7-Earth radius super-Earth with a 6.8-day period. Our analysis indicates a system with nearly coplanar and circular orbits, reminiscent of the orderly arrangement within the solar system.

NASA's SDO Satellite Captures Venus Transit Approach

NASA Image and Video Library

2012-06-05

NASA image captured June 5, 2012 at 212357 UTC (about 5:24 p.m. EDT). On June 5-6 2012, SDO is collecting images of one of the rarest predictable solar events: the transit of Venus across the face of the sun. This event happens in pairs eight years apart that are separated from each other by 105 or 121 years. The last transit was in 2004 and the next will not happen until 2117. This image was captured by SDO's AIA instrument at 193 Angstroms. Credit: NASA/SDO, AIA To read more about the 2012 Venus Transit go to: sunearthday.nasa.gov/transitofvenus Add your photos of the Transit of Venus to our Flickr Group here: www.flickr.com/groups/venustransit/ NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Interplay of rare-earth and transition-metal subsystems in C u3Yb (SeO3) 2O2Cl

NASA Astrophysics Data System (ADS)

Markina, M. M.; Zakharov, K. V.; Ovchenkov, E. A.; Berdonosov, P. S.; Dolgikh, V. A.; Kuznetsova, E. S.; Olenev, A. V.; Klimin, S. A.; Kashchenko, M. A.; Budkin, I. V.; Yatsyk, I. V.; Demidov, A. A.; Zvereva, E. A.; Vasiliev, A. N.

2017-10-01

We present the synthesis and the experimental and theoretical study of the new member of the francisite family, C u3Yb (SeO3) 2O2Cl . The compound reaches an antiferromagnetic order at TN=36.7 K and experiences first-order spin-reorientation transition to weakly ferromagnetic phase at TR=8.7 K evidenced in specific heat Cp and magnetic susceptibility χ measurements. Distinctly different magnetization loops in T earth and transition-metal subsystems. At low temperatures, the saturation magnetization Ms˜5.2 μB is reached in pulsed magnetic-field measurements. The electron spin resonance data reveal the complicated character of the absorption line attributed to response from both copper and ytterbium ions. Critical broadening of the linewidth at the phase transitions points to quasi-two-dimensional character of the magnetic correlations. The spectroscopy of Y b3 + ions evidences splitting of the lowest-energy Kramers doublet of 2F5 /2 excited multiplet at TRtransition in the framework of a unified approach based on the mean-field approximation and crystal-field calculations.

Transition from the spouse dementia caregiver role: A change for the better?

PubMed

Brown, Lynsey J; Bond, Malcolm J

2016-07-01

One in 15 Australians over 65 experience dementia, and are commonly supported by spouses. Evidence demonstrates declining wellbeing for these caregivers as their role continues. There are indications of improvement once caregivers transition out of the role (recovery) but alternate suggestions that caregiving stress may be too damaging to be appeased (wear and tear). It seems plausible that reason for transition (care recipient's move into residential care or death) will affect caregivers' outcomes. A synthetic cohort method compared caregivers' stress and wellbeing prior to, and one and two years post-transition. There was evidence of wear and tear for physical wellbeing but recovery for psychological wellbeing over time; with little difference based on reason for transition. Caregiver outcomes seem to be a function of the action rather than the reason for transition, but factors such as age must be considered when designing methods to support post-transition wellbeing. © The Author(s) 2014.

Chinese records of the 1874 transit of Venus

NASA Astrophysics Data System (ADS)

Lu, Lingfeng; Li, Huifang

2013-03-01

Before the advent of radar, transits of Venus were very important for measuring the distance between the Earth and the Sun. A transit occurred in 1874, and was visible from China, other parts of east and southeast Asia and from India, Australia and New Zealand and certain islands in the Indian and Pacific Oceans. As a result, many astronomers from Western countries came to China to observe it. According to traditional Chinese astrology, the Sun represented the Emperor, and if the Sun was invaded by other astronomical bodies it meant that the Emperor and the country faced some ominous disaster. In the late nineteenth century, Western astronomical knowledge was widely translated into Chinese and spread among Chinese intellectuals, so the 1874 transit supposedly was easily understood by Chinese intellectuals. Before the transit took place, various Chinese publications introduced this kind of celestial event as science news, but at the same time other influential newspapers and journals discussed the astrological connection between the transit and the fortunes of the nation. In this paper we review these interesting Chinese records and discuss the different attitudes towards the transit exhibited by Chinese intellectuals and officials, during a period when Western learning was being widely disseminated throughout China.

Variations of physicochemical properties in Kalpakkam coastal waters, east coast of India, during southwest to northeast monsoon transition period.

PubMed

Satpathy, Kamala Kanta; Mohanty, Ajit K; Sahu, Gouri; Sarkar, Santosh K; Natesan, Usha; Venkatesan, R; Prasad, M V R

2010-12-01

A significant variation in physicochemical properties of the Kalpakkam coastal waters, eastern part of India, was observed during the event of southwest to northeast monsoon transition. Increase in nitrate, total nitrogen, and silicate concentrations were noticed during post-transition period. Ammonia concentration was at peak during transition period as compared to pre- and post-transition periods. Hypo-saline condition (~23 psu) was observed during post-transition as the surface water salinity decreased by ~10 psu from the pre-transitional values. Turbidity, suspended particulate matter, phosphate and total phosphorous values decreased marginally, coinciding with northward to southward current reversal. A drastic decrease (eightfold) in chlorophyll-a concentration was observed in the coastal water during post-transition period.

Transitioning Earth Remote Sensing Data to Benefit Society: A Paradigm for a Center of Excellence

NASA Technical Reports Server (NTRS)

Jedlovec, Gary; Bjorgo, Einar; Burn, Anthony

2015-01-01

Over the past decade there has been a substantial increase in the number of Earth remote sensing satellites launched for research and operational usage and numerous others planned by the international community. These satellites have been used to varying degrees by their supporting agencies for weather and environmental monitoring, climate studies, disaster monitoring and response, and other humanitarian activities. While there are success stories on useful applications of remote sensing data, the broader use of these satellite assets by other organizations and entities has been limited for a number of reasons including lack of data services, data dissemination issues, and a general failure to engage the broader end user community with useful data access and knowledge of how to use the data and products. This paper describes some of these current limitations on the broader use of Earth remote sensing data by the international community and describes the concept of a general "Center of Excellence" to facilitate the development, transition, and utilization of these Earth remote sensing observations by the broader international community.

Global seismic data reveal little water in the mantle transition zone

NASA Astrophysics Data System (ADS)

Houser, C.

2016-08-01

Knowledge of the Earth's present water content is necessary to constrain the amount of water and other volatiles the Earth acquired during its formation and the amount that is cycled back into the interior from the surface. This study compares 410 and 660 km discontinuity depth with shear wave tomography within the mantle transition zone to identify regions with seismic signals consistent with water. The depth of the 410 and 660 km discontinuities is determined from a large updated dataset of SS-S410S and SS-S660S differential travel times, known as SS precursors. The discontinuity depths measured from binning and stacking the SS precursor data are then compared to the shear velocity model HMSL-S06 in the transition zone. Mapping all the possible combinations, very few locations match the predictions from mineral physics for the effects of water on discontinuity depth and shear velocity. The predictions, although not yet measured at actual transition zone temperatures and pressures, are a shallow 410 km discontinuity, a deep 660 km discontinuity, and a slow shear velocity. Only 8% of the bins with high-quality data are consistent with these predictions, and the calculated average water content within these bins is around 0.6 wt.%. A few isolated locations have patterns of velocity/topography that are consistent with water, while there are large regional-scale patterns consistent with cold/hot temperature anomalies. Combining this global analysis of long period seismic data and the current mineral physics predictions for water in transition zone minerals, I find that the mantle transition zone is generally dry, containing less than one Earth ocean of water. Although subduction zones could be locally hydrated, the combined discontinuity and velocity data show no evidence that wadsleyite or ringwoodite have been globally hydrated by subduction or initial Earth conditions.

Factors Related to Successful Transition Planning for Adolescents on the Autism Spectrum

ERIC Educational Resources Information Center

Hatfield, Megan; Ciccarelli, Marina; Falkmer, Torbjörn; Falkmer, Marita

2018-01-01

Adolescents on the autism spectrum often have difficulties with the transition from high school to post-school activities. Despite this, little is known about the transition planning processes for this group. This study explored predisposing, reinforcing and enabling factors related to the transition planning processes for adolescents on the…

75 FR 67751 - Medicare Program: Community-Based Care Transitions Program (CCTP) Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-03

...] Medicare Program: Community-Based Care Transitions Program (CCTP) Meeting AGENCY: Centers for Medicare... guidance and ask questions about the upcoming Community-based Care Transitions Program. The meeting is open... registration information will be posted on the CMS Care Transitions Web site at http://www.cms.gov/DemoProjects...

Transition of Students with Autistic Spectrum Disorders from Primary to Post-Primary School: A Framework for Success

ERIC Educational Resources Information Center

Deacy, Evelyn; Jennings, Fiona; O'Halloran, Ailbhe

2015-01-01

The purpose of this research was to investigate best practice in relation to the planning, process and strategies that support the transition of students with ASD from primary to post-primary school. A questionnaire survey was sent to graduates of a postgraduate Certificate/Diploma in SEN (ASD) in Ireland who were working in primary and…

"Show me your impact": evaluating transitional justice in contested spaces.

PubMed

Duggan, Colleen

2012-02-01

This paper discusses some of the most significant challenges and opportunities for evaluating the effects of programs in support of transitional justice - the field that addresses how post-conflict or post authoritarian societies deal with legacies of wide spread human rights violations. The discussion is empirically grounded in a case study that assesses the efforts of the International Development Research Centre (IDRC) and one of its Guatemalan partners to evaluate the effects of a museum exposition that is attempting to recast historic memory and challenge racist attitudes in post-conflict Guatemala. The paper argues that despite the increasing trend to fund transitional justice programs, many international aid donors are stuck in traditional and arguably orthodox paradigms of program evaluation. This is having a negative effect not only upon the administration of aid but also upon how transitional justice research is perceived and valued by local populations. The case study experience indicates that there is no perfect evaluation model or approach for evaluating transitional justice programming - only choices to be made by commissioners of evaluation, evaluators, and those being evaluated. These are profoundly influenced by the extreme politics and moral values that define transitional justice settings as contested spaces in which calls to remember the tragic past must be balanced with aspirations to re-build a hopeful future. Copyright © 2010. Published by Elsevier Ltd.

Supporting Transition

ERIC Educational Resources Information Center

Qureshi, Asima; Petrucco, James

2018-01-01

Meadowbrook Primary School has explored the use of The Teacher Assessment in Primary Science (TAPS) to support transition, initially for transfer to secondary school and now for transition from Early Years Foundation Stage (EYFS) into Key Stage 1 (ages 5-7). This article will consider an example of a secondary transition project and discuss the…

Mass transit : bus rapid transit shows promise

DOT National Transportation Integrated Search

2001-09-17

The U. S. General Accounting Office (GAO) was asked to (1) examine the federal role in supporting Bus Rapid Transit; (2) compare the capital costs, operating costs, and performance characteristics of Bus Rapid Transit and Light Rail systems; and (3) ...

Presidential Transitions during Capital Campaigns

ERIC Educational Resources Information Center

Nehls, Kimberly

2008-01-01

In the past few decades, capital campaigns at institutions of higher education have increased in duration, while collegiate presidential tenures have been doing just the opposite. Turnover in the top post was frequent, even during major fundraising campaigns. Before this study, presidential transitions during campaigns had not been previously…

Harnessing Post-Conflict Transitions: A Conceptual Primer

DTIC Science & Technology

2010-09-01

aid community uses transition as a key indi- cator of success for development and aid programs (Cliffe et al., 2003; Crane et al., 2009; Crichton ...3, pp. 345-365. Barnett, M ., (2006), “Building a republican peace: Stabilizing states after war,” International Security, Vol. 30, No. 4, pp. 87-112...Security, Vol. 29, No. 4, pp. 157-195. Berdal, M . R., (2009), Building Peace After War, Abingdon, UK; New York; London, UK: Routledge: International

Phase transitions in tumor growth VI: Epithelial-Mesenchymal transition

NASA Astrophysics Data System (ADS)

Guerra, A.; Rodriguez, D. J.; Montero, S.; Betancourt-Mar, J. A.; Martin, R. R.; Silva, E.; Bizzarri, M.; Cocho, G.; Mansilla, R.; Nieto-Villar, J. M.

2018-06-01

Herewith we discuss a network model of the epithelial-mesenchymal transition (EMT) based on our previous proposed framework. The EMT appears as a "first order" phase transition process, analogous to the transitions observed in the chemical-physical field. Chiefly, EMT should be considered a transition characterized by a supercritical Andronov-Hopf bifurcation, with the emergence of limit cycle and, consequently, a cascade of saddle-foci Shilnikov's bifurcations. We eventually show that the entropy production rate is an EMT-dependent function and, as such, its formalism reminds the van der Waals equation.

Transit of Venus Culture: A Celestial Phenomenon Intrigues the Public

NASA Astrophysics Data System (ADS)

Bueter, Chuck

2012-01-01

When Jeremiah Horrocks first observed it in 1639, the transit of Venus was a desirable telescopic target because of its scientific value. By the next transit of Venus in 1761, though, the enlightened public also embraced it as a popular celestial phenomenon. Its stature elevated over the centuries, the transit of Venus has been featured in music, poetry, stamps, plays, books, and art. The June 2004 transit emerged as a surprising global sensation, as suggested by the search queries it generated. Google's Zeitgeist deemed Venus Transit to be the #1 Most Popular Event in the world for that month. New priorities, technologies, and media have brought new audiences to the rare alignment. As the 2012 transit of Venus approaches, the trend continues with publicly accessible capabilities that did not exist only eight years prior. For example, sites from which historic observations have been made are plotted and readily available on Google Earth. A transit of Venus phone app in development will, if fully funded, facilitate a global effort to recreate historic expeditions by allowing smartphone users to submit their observed transit timings to a database for quantifying the Astronomical Unit. While maintaining relevance in modern scientific applications, the transit of Venus has emerged as a cultural attraction that briefly intrigues the mainstream public and inspires their active participation in the spectacle.

Skills in Motion: Boys' Trail Motorbiking Activities as Transitions into Working-Class Masculinity in a Post-Industrial Locale

ERIC Educational Resources Information Center

Ivinson, Gabrielle Mary

2014-01-01

During an ethnographic research project exploring young people's perceptions of living in a post-industrial semi-rural place, boys aged 13/14 years revealed their semi-clandestine motorbiking activities across mountains trails. It was found that riding motorbikes and fixing engines were potential resources for young boys' transitions into adult…

Scatterometer Observes Extratropical Transition of Pacific Typhoons

NASA Technical Reports Server (NTRS)

Liu, W. Timothy; Tang, Wenqing; Dunbar, R. Scott

1997-01-01

From September 15 to 25, 1996, NASA's scatterometer (NSCAT) monitored the evolution of twin typhoons, Violet and Tom, as they moved north from the western tropical Pacific, acquiring features of mid-latitude storms. The typhoons developed frontal structures, increased asymmetry, and dry air was introduced into their cores. Violet hit Japan, causing death and destruction (Figure 1), and Tom merged with a mid-latitude trough and evolved into a large extratropical storm with gale-force winds (Figure 2). We understand relatively little about the extratropical transition of tropical cyclones because of the complex thermodynamics involved [e.g., Sinclair, 1993], but we do know that the mid-latitude storms resulting from tropical cyclones usually generate strong winds and heavy precipitation. Since the transition usually occurs over the ocean, few measurements have been made. The transition is a fascinating science problem, but it also has important economic consequences. The transition occurs over the busiest trans-ocean shipping lanes, and when the resulting storms hit land, they usually devastate populated areas. NSCAT was successfully launched into a near-polar, sun-synchronous orbit on the Japanese Advanced Earth Observing Satellite (ADEOS) in August 1996 from Tanegashima Space Center in Japan. NSCAT's six antennas send microwave pulses at a frequency of 14 GHz to the Earth's surface and measure the backscatter. The antennas scan two 600-km bands of the ocean, which are separated by a 330-km data gap. From NSCAT observations, surface wind vectors can be derived at 25-km spatial resolution, covering 77% of the ice-free ocean in one day and 97% of the ocean in two days, under both clear and cloudy conditions.

Relationship between covalence and displacive phase transition temperature in RAO{sub 4} and LiAO{sub 3} (R = rare-earth element and A = Nb and Ta)

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

Tsunekawa, S.; Fukuda, T.; Kimiyama, T.

Crystal structure analyses by TOF neutron powder diffraction are performed for R TaO{sub 4} (R = rare-earth element) and the Ta-O interatomic distances are determined. The relationship between the covalency of A-O bonds (A = Nb and Ta), which show the most shortening upon phase transition, and the transition temperature is discussed for RAO{sub 4} and LiAO{sub 3}, and the parameters of Ta-O covalence are determined.

Alameda-Contra Costa Transit District (AC Transit) Fuel Cell Transit Buses: Preliminary Evaluation Results

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

Chandler, K.; Eudy, L.

2007-03-01

This report provides an evaluation of three prototype fuel cell-powered transit buses operating at AC Transit in Oakland, California, and six baseline diesel buses similar in design to the fuel cell buses.

Coordination of IVI and transit signal priority on transit evacuations.

DOT National Transportation Integrated Search

2011-02-01

During an emergency evacuation, execution time is always critical to the evacuees who are : transit dependent. Transit Signal Priority (TSP) can speed up the transit services by prioritizing : the approaching bus at a signalized intersection. With th...

A cloudiness transition in a marine boundary layer

NASA Technical Reports Server (NTRS)

Betts, Alan K.; Boers, Reinout

1990-01-01

Boundary layer cloudiness plays several important roles in the energy budget of the earth. Low level stratocumulus are highly reflective clouds which reduce the net incoming shortwave radiation at the earth's surface. Climatically, the transition to a small area fraction of scattered cumulus clouds occurs as the air flows over warmer water. Although these clouds reflect less sunlight, they still play an important role in the boundary layer equilibrium by transporting water vapor upwards, and enhancing the surface evaporation. The First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment (FIRE) included a marine stratocumulus experiment off the southern California coast from June 29 to July 19, 1987. The objectives of this experiment were to study the controls on fractional cloudiness, and to assess the role of cloud-top entrainment instability (CTEI) and mesoscale structure in determining cloud type. The focus is one research day, July 7, 1987, when coordinated aircraft missions were flown by four research aircraft, centered on a LANDSAT scene at 1830 UTC. The remarkable feature of this LANDSAT scene is the transition from a clear sky in the west through broken cumulus to solid stratocumulus in the east. The dynamic and thermodynamic structure of this transition in cloudiness is analyzed using data from the NCAR Electra. By averaging the aircraft data, the internal structure of the different cloud regimes is documented, and it is shown that the transition between broken cumulus and stratocumulus is associated with a change in structure with respect to the CTEI condition. However, this results not from sea surface temperature changes, but mostly from a transition in the air above the inversion, and the breakup appears to be at a structure on the unstable side of the wet virtual adiabat.

Coercivity of domain wall motion in thin films of amorphous rare earth-transition metal alloys

NASA Technical Reports Server (NTRS)

Mansuripur, M.; Giles, R. C.; Patterson, G.

1991-01-01

Computer simulations of a two dimensional lattice of magnetic dipoles are performed on the Connection Machine. The lattice is a discrete model for thin films of amorphous rare-earth transition metal alloys, which have application as the storage media in erasable optical data storage systems. In these simulations, the dipoles follow the dynamic Landau-Lifshitz-Gilbert equation under the influence of an effective field arising from local anisotropy, near-neighbor exchange, classical dipole-dipole interactions, and an externally applied field. Various sources of coercivity, such as defects and/or inhomogeneities in the lattice, are introduced and the subsequent motion of domain walls in response to external fields is investigated.

Personality and Relationship Quality During the Transition From High School to Early Adulthood

PubMed Central

Parker, Philip D.; Lüdtke, Oliver; Trautwein, Ulrich; Roberts, Brent W.

2013-01-01

The post–high school transition period is believed to be associated with considerable changes in social networks, yet longitudinal studies documenting these changes are scarce. To address this gap, the current research explored 3 relevant issues. First, changes in participants’ relationship characteristics during the transition from high school were examined. Second, the roles of personality traits as antecedents of these changes were studied. Third, the association between change in relationship characteristics and personality during the transition was explored. A sample of over 2,000 German emerging adults, surveyed before leaving school and then 2 years after the transition from high school, was assessed on personality traits and a multidimensional assessment of the quality of their relationships. Findings indicated that participants experienced mostly positive changes in relationship quality during the transition from high school and that antecedent personality at school was an important predictor of the nature of this change. Finally, change in relationship quality was found to be associated with personality change during the post-school transition. Findings indicated that personality traits may influence transition success and that change in relationships during this transition may influence personality development. The implications of the research for post-school transition success are discussed. PMID:22224909

Stuck in a Mismatch? The Persistence of Overeducation during Twenty Years of the Post-Communist Transition in Poland

ERIC Educational Resources Information Center

Kiersztyn, Anna

2013-01-01

This paper examines long-term changes in the persistence of overeducation among individual workers, focusing on the relationship between the rate of those changes and the general economic situation. All analyses are based on data from the Polish Panel Survey (POLPAN) conducted throughout the post-communist transition period, 1988-2008. The results…

Framing Young People's Educational Transitions: The Role of Local and Contemporary Economic Contexts

ERIC Educational Resources Information Center

Evans, Ceryn

2017-01-01

Despite rates of participation in post-compulsory full-time education reaching approximately 84% in Wales, social class inequalities continue to shape young people's transitions from compulsory to post-compulsory education. This article draws upon data from a project which explored how young people's educational decisions and transitions in Wales,…

Sun Earth Day 2012, The Transit of Venus: From Mauna Kea to the World

NASA Astrophysics Data System (ADS)

Mayo, Louis

2012-10-01

For 2012, NASA’s Sun Earth Day program ( http://sunearthday.nasa.gov/ and http://venustransit.nasa.gov/ ), now in its 13th year, featured the transit of Venus as well as other close celestial encounters. A NASA sponsored team of scientists, social media experts, telescope technicians, students, and the NASA EDGE webcasting team journeyed to the 14,000 foot summit of Mauna Kea in Hawaii to view and share with the world this wondrous last in a lifetime show. Fifteen NASA missions participated providing educational resources and science content. And when it was all over, it was the biggest education event NASA ever held, bigger than the Super Bowl, the last shuttle flight, or Prince William’s wedding. Over 600 million web hits, 7.7 million web streams, and an estimated 500 million to 1 billion people reached. This presentation will highlight this phenomenal education program, discuss best practices, and show how we are replicating the Sun Earth Day approach and methods for other event based education programs.

Alameda-Contra Costa Transit District (AC Transit) Fuel Cell Transit Buses : Evaluation Results Update

DOT National Transportation Integrated Search

2007-10-01

In early 2007, the National Renewable Energy Laboratory (NREL) published a preliminary evaluation results report1 (April through November 2006) on hydrogen fuel cell and diesel buses operating at Alameda-Contra Costa Transit District (AC Transit) in ...

Kepler Transit Depths Contaminated By a Phantom Star

NASA Astrophysics Data System (ADS)

Dalba, Paul A.; Muirhead, Philip S.; Croll, Bryce; Kempton, Eliza M.-R.

2017-02-01

We present ground-based observations from the Discovery Channel Telescope (DCT) of three transits of Kepler-445c—a supposed super-Earth exoplanet with properties resembling GJ 1214b—and demonstrate that the transit depth is ˜50% shallower than the depth previously inferred from Kepler spacecraft data. The resulting decrease in planetary radius significantly alters the interpretation of the exoplanet’s bulk composition. Despite the faintness of the M4 dwarf host star, our ground-based photometry clearly recovers each transit and achieves repeatable 1σ precision of ˜0.2% (2 millimags). The transit parameters estimated from the DCT data are discrepant with those inferred from the Kepler data to at least 17σ confidence. This inconsistency is due to a subtle miscalculation of the stellar crowding metric during the Kepler pre-search data conditioning (PDC). The crowding metric, or CROWDSAP, is contaminated by a non-existent phantom star originating in the USNO-B1 catalog and inherited by the Kepler Input Catalog (KIC). Phantom stars in the KIC are likely rare, but they have the potential to affect statistical studies of Kepler targets that use the PDC transit depths for a large number of exoplanets where an individual follow-up observation of each is not possible. The miscalculation of Kepler-445c’s transit depth emphasizes the importance of stellar crowding in the Kepler data, and provides a cautionary tale for the analysis of data from the Transiting Exoplanet Survey Satellite, which will have even larger pixels than Kepler.

Eigenstate Phase Transitions

NASA Astrophysics Data System (ADS)

Zhao, Bo

Phase transitions are one of the most exciting physical phenomena ever discovered. The understanding of phase transitions has long been of interest. Recently eigenstate phase transitions have been discovered and studied; they are drastically different from traditional thermal phase transitions. In eigenstate phase transitions, a sharp change is exhibited in properties of the many-body eigenstates of the Hamiltonian of a quantum system, but not the thermal equilibrium properties of the same system. In this thesis, we study two different types of eigenstate phase transitions. The first is the eigenstate phase transition within the ferromagnetic phase of an infinite-range spin model. By studying the interplay of the eigenstate thermalization hypothesis and Ising symmetry breaking, we find two eigenstate phase transitions within the ferromagnetic phase: In the lowest-temperature phase the magnetization can macroscopically oscillate by quantum tunneling between up and down. The relaxation of the magnetization is always overdamped in the remainder of the ferromagnetic phase, which is further divided into phases where the system thermally activates itself over the barrier between the up and down states, and where it quantum tunnels. The second is the many-body localization phase transition. The eigenstates on one side of the transition obey the eigenstate thermalization hypothesis; the eigenstates on the other side are many-body localized, and thus thermal equilibrium need not be achieved for an initial state even after evolving for an arbitrary long time. We study this many-body localization phase transition in the strong disorder renormalization group framework. After setting up a set of coarse-graining rules for a general one dimensional chain, we get a simple "toy model'' and obtain an almost purely analytical solution to the infinite-randomness critical fixed point renormalization group equation. We also get an estimate of the correlation length critical exponent nu

Transitions from hospital to community care: the role of patient-provider language concordance.

PubMed

Rayan, Nosaiba; Admi, Hanna; Shadmi, Efrat

2014-01-01

Cultural and language discordance between patients and providers constitutes a significant challenge to provision of quality healthcare. This study aims to evaluate minority patients' discharge from hospital to community care, specifically examining the relationship between patient-provider language concordance and the quality of transitional care. This was a multi-method prospective study of care transitions of 92 patients: native Hebrew, Russian or Arabic speakers, with a pre-discharge questionnaire and structured observations examining discharge preparation from a large Israeli teaching hospital. Two weeks post-discharge patients were surveyed by phone, on the transition from hospital to community care (the Care Transition Measure (CTM-15, 0-100 scale)) and on the primary-care post-discharge visit. Overall, ratings on the CTM indicated fair quality of the transition process (scores of 51.8 to 58.8). Patient-provider language concordance was present in 49% of minority patients' discharge briefings. Language concordance was associated with higher CTM scores among minority groups (64.1 in language-concordant versus 49.8 in non-language-concordant discharges, P <0.001). Other aspects significantly associated with CTM scores: extent of discharge explanations (P <0.05), quality of discharge briefing (P <0.001), and post-discharge explanations by the primary care physician (P <0.01). Language-concordant care, coupled with extensive discharge briefings and post-discharge explanations for ongoing care, are important contributors to the quality of care transitions of ethnic minority patients.

Transitions from hospital to community care: the role of patient–provider language concordance

PubMed Central

2014-01-01

Background Cultural and language discordance between patients and providers constitutes a significant challenge to provision of quality healthcare. This study aims to evaluate minority patients’ discharge from hospital to community care, specifically examining the relationship between patient–provider language concordance and the quality of transitional care. Methods This was a multi-method prospective study of care transitions of 92 patients: native Hebrew, Russian or Arabic speakers, with a pre-discharge questionnaire and structured observations examining discharge preparation from a large Israeli teaching hospital. Two weeks post-discharge patients were surveyed by phone, on the transition from hospital to community care (the Care Transition Measure (CTM-15, 0–100 scale)) and on the primary-care post-discharge visit. Results Overall, ratings on the CTM indicated fair quality of the transition process (scores of 51.8 to 58.8). Patient–provider language concordance was present in 49% of minority patients’ discharge briefings. Language concordance was associated with higher CTM scores among minority groups (64.1 in language-concordant versus 49.8 in non-language-concordant discharges, P <0.001). Other aspects significantly associated with CTM scores: extent of discharge explanations (P <0.05), quality of discharge briefing (P <0.001), and post-discharge explanations by the primary care physician (P <0.01). Conclusion Language-concordant care, coupled with extensive discharge briefings and post-discharge explanations for ongoing care, are important contributors to the quality of care transitions of ethnic minority patients. PMID:25075273

Alameda-Contra Costa Transit District (AC Transit) Fuel Cell Transit Buses : Third Evaluation Report

DOT National Transportation Integrated Search

2008-07-04

This report describes operations at Alameda-Contra Costa Transit District (AC Transit) for three prototype fuel cell buses and six diesel buses operating from the same location. This is the third evaluation report for this site, and it describes new ...

Understanding age-based transition needs: Perspectives from adolescents and adults with congenital heart disease

USDA-ARS?s Scientific Manuscript database

The purpose of this study was to explore the transition process in congenital heart disease (CHD) care through the perceived needs and concerns of adolescents (pretransition) and the experiential insight from adults (post-transition), in order to inform future transition initiatives and information ...

NASA's SDO Satellite Captures Venus Transit Approach -- Bigger, Better!

NASA Image and Video Library

2017-12-08

NASA image captured June 5, 2012. On June 5-6 2012, SDO is collecting images of one of the rarest predictable solar events: the transit of Venus across the face of the sun. This event happens in pairs eight years apart that are separated from each other by 105 or 121 years. The last transit was in 2004 and the next will not happen until 2117. Credit: NASA/SDO, AIA To read more about the 2012 Venus Transit go to: sunearthday.nasa.gov/transitofvenus Add your photos of the Transit of Venus to our Flickr Group here: www.flickr.com/groups/venustransit/ NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

NASA's SDO Satellite Captures 2012 Venus Transit [Close-Up

NASA Image and Video Library

2017-12-08

NASA image captured June 5, 2012. On June 5-6 2012, SDO is collecting images of one of the rarest predictable solar events: the transit of Venus across the face of the sun. This event happens in pairs eight years apart that are separated from each other by 105 or 121 years. The last transit was in 2004 and the next will not happen until 2117. Credit: NASA/SDO, HMI To read more about the 2012 Venus Transit go to: sunearthday.nasa.gov/transitofvenus Add your photos of the Transit of Venus to our Flickr Group here: www.flickr.com/groups/venustransit/ NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Transition boiling heat transfer and the film transition regime

NASA Technical Reports Server (NTRS)

Ramilison, J. M.; Lienhard, J. H.

1987-01-01

The Berenson (1960) flat-plate transition-boiling experiment has been recreated with a reduced thermal resistance in the heater, and an improved access to those portions of the transition boiling regime that have a steep negative slope. Tests have been made in Freon-113, acetone, benzene, and n-pentane boiling on horizontal flat copper heaters that have been mirror-polished, 'roughened', or teflon-coated. The resulting data reproduce and clarify certain features observed by Berenson: the modest surface finish dependence of boiling burnout, and the influence of surface chemistry on both the minimum heat flux and the mode of transition boiling, for example. A rational scheme of correlation yields a prediction of the heat flux in what Witte and Lienhard (1982) previously identified as the 'film-transition boiling' region. It is also shown how to calculate the heat flux at the boundary between the pure-film, and the film-transition, boiling regimes, as a function of the advancing contact angle.

Transitions: A Guide to Teens Getting Older and Changing Health Care Providers

MedlinePlus

... Transitions: A Guide to Getting Older and Changing Health Care Providers (HCP’s) Posted under Health Guides . Updated 11 ... can help me plan my transition to adult health care? Your pediatrician or other health care provider Your ...

Agile Port System Transition Support Transition Plan Development

DTIC Science & Technology

2013-07-29

Operational Needs addressed • Proposed Solutions • Current Status • Risk • A Business Case for transition • Appropriate Funding Sources • Transition...13  3.1.6  Risk  Table...18  3.2.6  Risk  Table

Introductory Physics Gender Gaps: Pre- and Post-Studio Transition

NASA Astrophysics Data System (ADS)

Kohl, Patrick B.; Kuo, H. Vincent

2009-11-01

Prior work has characterized the gender gaps present in college-level introductory physics courses. Such work has also shown that research-based interactive engagement techniques can reduce or eliminate these gender gaps. In this paper, we study the gender gaps (and lack thereof) in the introductory calculus-based electricity and magnetism course at the Colorado School of Mines. We present eight semesters' worth of data, totaling 2577 students, with four semesters preceding a transition to Studio physics, and four following. We examine gender gaps in course grades, DFW (D grade, fail, or withdrawal) rates, and normalized gains on the Conceptual Survey of Electricity and Magnetism (CSEM), and consider factors such as student ACT scores and grades in prior math classes. We find little or no gap in male/female course grades and DFW rates, but substantial gaps in CSEM gains that are reduced somewhat by the transition to Studio physics.

Transition Specialists Partner with Students to Turn Dreams into Reality

ERIC Educational Resources Information Center

Flannery, Ann

2013-01-01

Ann Flannery is one of two transition specialists who serve youth and families statewide through the Post-Secondary Transition Program of the Idaho Educational Services for the Deaf and the Blind. In this article she writes that too often her office was seeing graduates coming back to school after failing to find a path to success. They returned…

Evidence for a universal localization transition underlying the glass transition

NASA Astrophysics Data System (ADS)

Simmons, David; Hung, Jui-Hsiang; Patra, Tarak; Meenakshisundaram, Venkatesh; Mangalara, Jayachandra Hari

The glass transition is a ubiquitous pathway to the development of solid-like character, occurring in materials ranging from polymers to metals. Despite its technological and fundamental importance across diverse materials, the underlying nature of the glass transition remains a durable open question. Here we describe results from high-throughput simulations of the glass transition in metals, polymers, small organic molecules, and organics, indicating that a universal particle localization transition underlies the dynamic glass transition. We find that a single adjustable parameter is sufficient to describe the nonuniversal growth in relaxation time resulting from this localization event. These results point to an opportunity to advance the modern understanding of the glass transition by refocusing attention on the onset of localization rather than the growth in relaxation time as the key experimental observable. This work was made possible by generous support from the W. M. Keck Foundation. This material is based in part on work sup-ported by the National Science Foundation NSF Career Award Grant Number DMR1554920.

Saturn's magnetosheath transition layer

NASA Astrophysics Data System (ADS)

Masters, A.; Hasegawa, H.; Phan, T. D.; Badman, S. V.; Fujimoto, M.; Coates, A. J.; Dougherty, M. K.

2012-09-01

The interaction between the solar wind and a magnetised planet produces a cavity around the planet known as a magnetosphere. Although this cavity effectively shields near-planet space from the solar wind, the occurrence of magnetic reconnection at the manetopause boundary of the magnetosphere allows solar wind energy to enter the system. In the case of Earth's magnetosphere a region of reduced plasma pressure and enhanced magnetic pressure can form in the solar wind immediately adjacent to the magnetopause (which also can form around other planetary magnetospheres). This layer is often referred to as the Magnetosheath Transition Layer (MTL), and Earth's MTL responds strongly to magnetopause reconnection. The nature of magnetopause reconnection at Saturn is unclear. We study Saturn's MTL using data taken by the Cassini spacecraft. We examine the reponse of the layer to local magnetised plasma conditions, compare this response to that of Earth's MTL, and assess whether our results are in agreement with current, limited understanding of magnetopause reconnection at Saturn.

Esophageal Transit, Contraction and Perception of Transit After Swallows of Two Viscous Boluses

PubMed Central

Dalmazo, Jucileia; Aprile, Lilian Rose Otoboni; Dantas, Roberto Oliveira

2015-01-01

Background There have been results showing the influence of bolus viscosities and consistency on esophageal motility and transit. However, there is no description about the influence of two different viscous boluses on esophageal contractions, bolus transit and perception of transit. Our objective in this investigation was to evaluate the esophageal transit and contraction after swallows of two viscous boluses. Methods By impedance and manometric methods, we measured the esophageal transit and contraction after swallows of two viscous boluses of 5 mL volume, 100% barium sulfate and yogurt, swallowed in duplicate in the supine and upright positions. The bolus transit, esophageal contractions and the perception of bolus transit through the esophagus were evaluated in both positions. Impedance and contraction were measured at 5, 10, 15 and 20 cm from the lower esophageal sphincter. After each swallow, the volunteers were asked about the sensation of bolus transit through the esophagus. Results In supine position, the yogurt had a less frequent complete bolus transit than barium. Also in the supine position, the esophageal transit was longer with yogurt than with barium. Esophageal contractions after swallows were similar between barium and yogurt boluses. There was no difference in perception of transit between the two boluses. Conclusion Although both 100% barium sulfate and yogurt are viscous boluses and have similar viscosities, the transit through the esophagus is slower with yogurt bolus than with barium bolus, which suggests that viscosity may be not the sole factor to determine transit. PMID:27785308

Transition Goals for Youth with Social, Emotional, and Behavioral Problems: Parent and Student Knowledge

ERIC Educational Resources Information Center

Harrison, Judith R.; State, Talida M.; Wills, Howard P.; Custer, Beth A.; Miller, Elaine

2017-01-01

Transition planning is a mandated component of individualized education plans (IEPs) designed to ensure successful transition to adult life for students with disabilities. Students with social, emotional, and behavioral (SEB) needs experience poor post-school outcomes, suggesting a need for more effective transition planning. This study evaluated…

Transit manager's handbook.

DOT National Transportation Integrated Search

2011-09-01

This handbook provides an overview of public transit in Iowa and how to do business with the Iowa Department of Transportation (Iowa DOT) Office of Public Transit (OPT). It is intended to be a tool to assist transit managers navigate through the many...

Transition path time distribution and the transition path free energy barrier.

PubMed

Pollak, Eli

2016-10-19

The recent experimental measurement of the transition path time distributions of proteins presents several challenges to theory. Firstly, why do the fits of the experimental data to a theoretical expression lead to barrier heights which are much lower than the free energies of activation of the observed transitions? Secondly, there is the theoretical question of determining the transition path time distribution, without invoking the Smoluchowski limit. In this paper, we derive an exact expression for a transition path time distribution which is valid for arbitrary memory friction using the normal mode transformation which underlies Kramers' rate theory. We then recall that for low barriers, there is a noticeable difference between the transition path time distribution obtained with absorbing boundary conditions and free boundary conditions. For the former, the transition times are shorter, since recrossings of the boundaries are disallowed. As a result, if one uses the distribution based on absorbing boundary conditions to fit the experimental data, one will find that the transition path barrier will be larger than the values found based on a theory with free boundary conditions. We then introduce the paradigm of a transition path barrier height, and show that one should always expect it to be much smaller than the activation energy.

Youth in Transition: A Description of Selected Transition Programs Serving Adolescents with Emotional Disabilities. Youth in Transition Project.

ERIC Educational Resources Information Center

Modrcin, Matthew J.; And Others

This monograph addresses the transition needs of adolescents with serious emotional disabilities, describing programs in various settings and states. An introductory chapter discusses the concept of transition and outlines service components. Findings from a national survey of 53 transition programs are then presented. Findings indicated that 60%…

Transition Metal Switchable Mirror

ScienceCinema

None

2017-12-09

The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft.

Transition Metal Switchable Mirror

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

None

2009-08-21

The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft.

Patients' perceptions of implant placement surgery, the post-surgical healing and the transitional implant prostheses: a qualitative study.

PubMed

Kashbour, Wafa A; Rousseau, Nikki; Thomason, J Mark; Ellis, Janice S

2017-07-01

This study aimed to explore patients' thoughts, feelings about, and experiences of, implant placement surgery (IPS), the post-surgical healing stage and the immediate post-surgical transitional implant prosthesis (TIP) (fixed and removable). A qualitative study design was chosen and 38 semi-structured telephone and face-to-face interviews were conducted with 34 patients at different stages of implant treatment. The interviews were transcribed verbatim; the data collection and coding process followed the principles of thematic analysis, which was facilitated through the use of NVivo10. Patients anticipated that surgery would be painful and unpleasant but were prepared to accept this temporary discomfort for the expected benefits of implant treatment. However, a key finding was that patients felt they had overestimated the trauma of surgery but underestimated the discomfort and difficulties of the healing phase. A number of difficulties were also identified with the TIP phase following implant surgery. Existing research has tended to focus on the longer term benefits of dental implant treatment. This qualitative study has investigated in-depth patients' perceptions of dental implant surgery, including their experiences related to sedation, and of transitional implant restoration. While patients felt their concerns were overestimated in relation to the implant surgery, they experienced greater morbidity than they expected in the healing phase. Recommendations are made for relatively small changes in care provision which might improve the overall patient experience. Partial dentate patients treated with a fixed transitional prosthesis experienced advantages more quickly than patients with an overdenture. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

What causes the Besnus transition in monoclinic pyrrhotite?

NASA Astrophysics Data System (ADS)

Gehring, A. U.; Koulialias, D.; Löffler, J. F.; Charilaou, M.

2016-12-01

Monoclinic 4C pyrrhotite (ideal formula Fe7S8) is a major magnetic remanence carrier in the Earth's crust and in extraterrestrial materials. Because of its low-temperature magnetic transition around 30 K also known as Besnus transition, this mineral phase is easily detectable in rock samples. An intrinsic origin of the Besnus transition due to a crystallographic change similar to that in the Verwey transition has generally been postulated (1). Although the physical properties of pyrrhotite have intensively been studied, the physics behind the pronounced change in magnetization at the low-temperature transition is still unresolved. To address this question we performed structural and magnetic analyses on a natural pyrrhotite single crystal (Fe6.6S8) from Auerbach, Germany (2,3). Chemical analysis, X-ray diffractometry and transmission electron microscopy show that this pyrrhotite consists of an intergrowth of 4C and an incommensurate 5C* superstructure that are polymorphs with different vacancy distributions. The occurrence of two superstructures is magnetically confirmed by symmetric inflection points in the hysteresis measurements above the transition at about 30 K. The disappearance of the inflection points and the associated change of the hysteresis parameters indicate that the two superstructures become embedded to form a unitary magnetic anisotropy system at the transition. This embedding of the 5C* into the 4C pyrrhotite at about 30 K is directly visible by the occurrence of additional 4-fold and 12-fold symmetry terms in magnetic anisotropy and anisotropic magnetic resistivity mesarurements, respectively. From this it follows that the Besnus transition in monoclinic pyrrhotite is an extrinsic magnetic phenomenon with respect to the 4C superstructure, i.e., a coupling effect, and therefore the physics behind it is in fact different from that of the well-known Verwey transition. (1) Rochette et al., The IRM Quarterly, 21, 1 (2011); (2) Charilaou et al., J

Transition to Adulthood

MedlinePlus

... page. To connect with info and examples on writing transition goal statements: Visit Transition Goals in the IEP . You’ll find the examples there illuminating, we hope. They’re drawn from the work of the National Technical Assistance Center on Transition . Back to top The ...

Buoyancy Effects on Flow Transition in Low-Density Inertial Gas Jets

NASA Technical Reports Server (NTRS)

Pasumarthi, Kasyap S.; Agrawal, Ajay K.

2005-01-01

Effects of buoyancy on transition from laminar to turbulent flow are presented for momentum-dominated helium jet injected into ambient air. The buoyancy was varied in a 2.2-sec drop tower facility without affecting the remaining operating parameters. The jet flow in Earth gravity and microgravity was visualized using the rainbow schlieren deflectometry apparatus. Results show significant changes in the flow structure and transition behavior in the absence of buoyancy.

The mass of the Mars-sized exoplanet Kepler-138 b from transit timing.

PubMed

Jontof-Hutter, Daniel; Rowe, Jason F; Lissauer, Jack J; Fabrycky, Daniel C; Ford, Eric B

2015-06-18

Extrasolar planets that pass in front of their host star (transit) cause a temporary decrease in the apparent brightness of the star, providing a direct measure of the planet's size and orbital period. In some systems with multiple transiting planets, the times of the transits are measurably affected by the gravitational interactions between neighbouring planets. In favourable cases, the departures from Keplerian orbits (that is, unaffected by gravitational effects) implied by the observed transit times permit the planetary masses to be measured, which is key to determining their bulk densities. Characterizing rocky planets is particularly difficult, because they are generally smaller and less massive than gaseous planets. Therefore, few exoplanets near the size of Earth have had their masses measured. Here we report the sizes and masses of three planets orbiting Kepler-138, a star much fainter and cooler than the Sun. We determine that the mass of the Mars-sized inner planet, Kepler-138 b, is 0.066(+0.059)(-0.037) Earth masses. Its density is 2.6(+2.4)(-1.5) grams per cubic centimetre. The middle and outer planets are both slightly larger than Earth. The middle planet's density (6.2(+5.8)(-3.4) grams per cubic centimetre) is similar to that of Earth, and the outer planet is less than half as dense at 2.1(+2.2)(-1.2) grams per cubic centimetre, implying that it contains a greater portion of low-density components such as water and hydrogen.

Transition in Turbines

NASA Technical Reports Server (NTRS)

1985-01-01

The concept of a large disturbance bypass mechanism for the initiation of transition is reviewed and studied. This mechanism, or some manifestation thereof, is suspected to be at work in the boundary layers present in a turbine flow passage. Discussion is presented on four relevant subtopics: (1) the effect of upstream disturbances and wakes on transition; (2) transition prediction models, code development, and verification; (3) transition and turbulence measurement techniques; and (4) the hydrodynamic condition of low Reynolds number boundary layers.

TWO SMALL PLANETS TRANSITING HD 3167

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

Vanderburg, Andrew; Bieryla, Allyson; Latham, David W.

2016-09-20

We report the discovery of two super-Earth-sized planets transiting the bright (V = 8.94, K = 7.07) nearby late G-dwarf HD 3167, using data collected by the K2 mission. The inner planet, HD 3167 b, has a radius of 1.6 R {sub ⊕} and an ultra-short orbital period of only 0.96 days. The outer planet, HD 3167 c, has a radius of 2.9 R {sub ⊕} and orbits its host star every 29.85 days. At a distance of just 45.8 ± 2.2 pc, HD 3167 is one of the closest and brightest stars hosting multiple transiting planets, making HD 3167more » b and c well suited for follow-up observations. The star is chromospherically inactive with low rotational line-broadening, ideal for radial velocity observations to measure the planets’ masses. The outer planet is large enough that it likely has a thick gaseous envelope that could be studied via transmission spectroscopy. Planets transiting bright, nearby stars like HD 3167 are valuable objects to study leading up to the launch of the James Webb Space Telescope .« less

REVIEWS OF TOPICAL PROBLEMS: Transition radiation in media with random inhomogeneities

NASA Astrophysics Data System (ADS)

Platonov, Konstantin Yu; Fleishman, G. D.

2002-03-01

This review analyzes radiation produced by randomly inhomogeneous media excited by fast particles — i.e., polarization bremsstrahlung for thermodynamically equilibrium inhomogeneities or transition radiation for nonthermal ones — taking into account all the effects important for natural sources. Magnetic field effects on both the motion of fast particles and the dispersion of background plasma are considered, and the multiple scattering of fast particles in the medium is examined. Various resonant effects occurring under the conditions of Cherenkov (or cyclotron) emission for a particular eigenmode are discussed. The transition radiation intensity and absorption (amplification) coefficients are calculated for ensembles of fast particles with realistic distributions over momentum and angles. The value of the developed theory of transition radiation is illustrated by applying it to astrophysical objects. Transition radiation is shown to contribute significantly to the radio emission of the Sun, planets (including Earth), and interplanetary and interstellar media. Possible further applications of transition radiation (particularly stimulated) are discussed.

The Emergence of Life as a First-Order Phase Transition

NASA Astrophysics Data System (ADS)

Mathis, Cole; Bhattacharya, Tanmoy; Imari Walker, Sara

2017-03-01

It is well known that life on Earth alters its environment over evolutionary and geological timescales. An important open question is whether this is a result of evolutionary optimization or a universal feature of life. In the latter case, the origin of life would be coincident with a shift in environmental conditions. Here we present a model for the emergence of life in which replicators are explicitly coupled to their environment through the recycling of a finite supply of resources. The model exhibits a dynamic, first-order phase transition from nonlife to life, where the life phase is distinguished by selection on replicators. We show that environmental coupling plays an important role in the dynamics of the transition. The transition corresponds to a redistribution of matter in replicators and their environment, driven by selection on replicators, exhibiting an explosive growth in diversity as replicators are selected. The transition is accurately tracked by the mutual information shared between replicators and their environment. In the absence of successfully repartitioning system resources, the transition fails to complete, leading to the possibility of many frustrated trials before life first emerges. Often, the replicators that initiate the transition are not those that are ultimately selected. The results are consistent with the view that life's propensity to shape its environment is indeed a universal feature of replicators, characteristic of the transition from nonlife to life. We discuss the implications of these results for understanding life's emergence and evolutionary transitions more broadly.

Small City Transit : Xenia, Ohio : Transit Service for a Rebuilding Community

DOT National Transportation Integrated Search

1976-03-01

Xenia, Ohio is an illustration of a transit service which evolved from a freefare emergency service to a demonstration of para-transit services. This case study is one of thirteen examples of a transit service in a small community. The background of ...

The effects of economic and political integration on power plants’ carbon emissions in the post-soviet transition nations

NASA Astrophysics Data System (ADS)

Jorgenson, Andrew K.; Longhofer, Wesley; Grant, Don; Sie, Amanda; Giedraitis, Vincentas

2017-04-01

The combustion of fossil fuels for electricity generation, which accounts for a significant share of the world’s CO2 emissions, varies by macro-regional context. Here we use multilevel regression modeling techniques to analyze CO2 emissions levels in the year 2009 for 1360 fossil-fuel power plants in the 25 post-Soviet transition nations in Central and Eastern Europe and Eurasia. We find that various facility-level factors are positively associated with plant-level emissions, including plant size, age, heat rate, capacity utilization rate, and coal as the primary fuel source. Results further indicate that plant-level emissions are lower, on average, in the transition nations that joined the European Union (EU), whose market reforms and environmental directives are relevant for emissions reductions. These negative associations between plant-level emissions and EU accession are larger for the nations that joined the EU in 2004 relative to those that joined in 2007. The findings also suggest that export-oriented development is positively associated with plant-level CO2 emissions in the transition nations. Our results highlight the importance in macro-regional assessments of the conjoint effects of political and economic integration for facility-level emissions.

Social Media Planning for the June 5, 2012 transit of Venus

NASA Astrophysics Data System (ADS)

Young, C.; Wawro, M.; Cline, T. D.; Schenk, L. C.; Durscher, R.

2012-12-01

On June 5, 2012 at sunset on the East Coast of North America and earlier for other parts of the U.S., the planet Venus made its final trek across the face of the sun as seen from Earth until the year 2117! The NASA Goddard Sun-Earth Day and Solar Dynamics Observatory EPO teams developed a social media strategy to support NASAs Transit of Venus event and webcast from Mauna Kea, Hawaii, on June 5, 2012. Our goal was to connect our contacts with a growing and vibrant social media community during all phases of this celestial event! We also wanted to help spread the word about the Transit of Venus by sharing content, facts, videos, images and links about the transit with our networks. Although social media events occurred throughout the world, our strategy was to provide an additional focus on NASA related events in key locations including those events happening in Hawaii, Alaska, and NASA Ames thereby amplifying our outreach efforts while ensuring that a strong connection existed across geographical and cultural borders. We also wanted to provide the public with information that would help them understand the importance of staying connected via social media even if viewing the transit was possible from their own locations. The social media strategy and the transit of Venus events were a great success and well as a learning experience for future social media events. We present the results of our plan as well as ways to improve and expand for future events. In addition, we present our social media template developed for the transit and now used by other heliophysics EPO teams.

Interplanetary Transit Simulations Using the International Space Station

NASA Technical Reports Server (NTRS)

Charles, John B.; Arya, M.; Kundrot, C. E.

2010-01-01

We evaluated the space life sciences utility of the International Space Station (ISS) to simulate the outbound transit portion of missions to Mars and Near Earth Asteroids (NEA) to investigate biomedical and psychological aspects of such transits, to develop and test space operation procedures compatible with communication delays and outages, and to demonstrate and validate technologies and countermeasures. Two major categories of space life sciences activities can capitalize on ISS capabilities. The first includes studies that require ISS (or a comparable facility), typically for access to prolonged weightlessness. The second includes studies that do not strictly require ISS but can exploit it to maximize their scientific return more efficiently and productively than in ground-based simulations. For these studies, ISS offers a high fidelity analog for fundamental factors on future missions, such as crew composition, mission control personnel, operational tasks and workload, real-world risk, and isolation, and can mimic the effects of distance and limited accessibility. In addition to conducting Mars- and NEA-transit simulations on 6-month ISS increments, extending the current ISS increment duration from 6 months to 9 or even 12 months will provide opportunities for enhanced and focused research relevant to long duration Mars and NEA missions. Increasing the crew duration may pose little additional risk to crewmembers beyond that currently accepted on 6-month increments, but additional medical monitoring capabilities will be required beyond those currently used for ISS operations. Finally, while presenting major logistical challenges, such a simulation followed by a post-landing simulation of Mars exploration could provide quantitative evidence of capabilities in an actual mission. Thus, the use of ISS to simulate aspects of Mars and NEA missions seems practical. If it were to be implemented without major disruption of on-going ISS activities, then planning should

Biomass transition metal hydrogen-evolution electrocatalysts and electrodes

DOEpatents

Chen, Wei-Fu; Iyer, Shweta; Iyer, Shilpa; Sasaki, Kotaro; Muckerman, James T.; Fujita, Etsuko

2017-02-28

A catalytic composition from earth-abundant transition metal salts and biomass is disclosed. A calcined catalytic composition formed from soybean powder and ammonium molybdate is specifically exemplified herein. Methods for making the catalytic composition are disclosed as are electrodes for hydrogen evolution reactions comprising the catalytic composition.

Thermoelastic effects across the post-perovskite transition in (Al,Fe)-bearing bridgmanite

NASA Astrophysics Data System (ADS)

Valencia-Cardona, J. J.; Shukla, G.; Sarkar, K.; Wentzcovitch, R. M. M.

2017-12-01

The post-perovskite (PPv) transition in (Al,Fe)-bearing bridgmanite has been intensively investigated by experiments and ab initio calculations. However, there are still important aspects of this transformation to be clarified from the atomistic point of view, especially because of the extreme conditions of pressure and temperature in which it takes place, P=125 GPa and T = 2500 K. Here we systematically address this question in (Al,Fe3+)-, (Fe2+)- and (Fe3+)-bearing bridgmanite using ab initio calculations. We particularly address the effect of velocity changes across this transformation in these systems. Our results are important to further understand and constrain the composition of the D" region, believed to be a thermal and/or compositional boundary layer between the solid mantle and molten outer core.

Americans in transit : a profile of public transit passengers

DOT National Transportation Integrated Search

1992-12-01

This report explores the socio-economic characteristics of the transit-riding population; it describes the gender, age, race. ethnicity, income and trip purpose of the average public transit rider and searches for future trends.

Transition to Employment. PRO-ED Series on Transition.

ERIC Educational Resources Information Center

Michaels, Craig A.

Part of a series designed to provide practical resources for transition personnel on a variety of topics critical to the process of preparing individuals with disabilities for adulthood, this guide focuses on transition to employment. Chapter 1, "Employment and Students with Disabilities," discusses the meaning of work in American…

Transition-Metal Decorated Aluminum Nanocrystals.

PubMed

Swearer, Dayne F; Leary, Rowan K; Newell, Ryan; Yazdi, Sadegh; Robatjazi, Hossein; Zhang, Yue; Renard, David; Nordlander, Peter; Midgley, Paul A; Halas, Naomi J; Ringe, Emilie

2017-10-24

Recently, aluminum has been established as an earth-abundant alternative to gold and silver for plasmonic applications. Particularly, aluminum nanocrystals have shown to be promising plasmonic photocatalysts, especially when coupled with catalytic metals or oxides into "antenna-reactor" heterostructures. Here, a simple polyol synthesis is presented as a flexible route to produce aluminum nanocrystals decorated with eight varieties of size-tunable transition-metal nanoparticle islands, many of which have precedence as heterogeneous catalysts. High-resolution and three-dimensional structural analysis using scanning transmission electron microscopy and electron tomography shows that abundant nanoparticle island decoration in the catalytically relevant few-nanometer size range can be achieved, with many islands spaced closely to their neighbors. When coupled with the Al nanocrystal plasmonic antenna, these small decorating islands will experience increased light absorption and strong hot-spot generation. This combination makes transition-metal decorated aluminum nanocrystals a promising material platform to develop plasmonic photocatalysis, surface-enhanced spectroscopies, and quantum plasmonics.

Gas turbine combustor transition

DOEpatents

Coslow, Billy Joe; Whidden, Graydon Lane

1999-01-01

A method of converting a steam cooled transition to an air cooled transition in a gas turbine having a compressor in fluid communication with a combustor, a turbine section in fluid communication with the combustor, the transition disposed in a combustor shell and having a cooling circuit connecting a steam outlet and a steam inlet and wherein hot gas flows from the combustor through the transition and to the turbine section, includes forming an air outlet in the transition in fluid communication with the cooling circuit and providing for an air inlet in the transition in fluid communication with the cooling circuit.

Effect of post-prandial posture on orocecal transit time and digestion of milk lactose in humans.

PubMed

Hirota, Naoko; Sone, Yoshiaki; Tokura, Hiromi

2004-05-01

We examined the effect of post-prandial body posture on orocecal transit time and absorption of milk lactose using the breath hydrogen test. In this experiment, subjects ingested a cup of commercially available milk to which we had added a small amount of lactosucrose (an indigestible trisaccharide), and then they lay on their backs or sat on a chair for the first 4 hr (from 08:00 to 12:00). After four hours lying or sitting, they remained sedentary on a sofa for the second six hr (from 12:00 to 18:00). Participants' end alveolar breath samples were collected every 15 min from 08:00 to 12:30, then every 30 min from 13:00 to 18:00. The experiment was conducted on two consecutive days using a randomized, crossover study design. Examination showed that the orocecal transit time of the oligosaccharides (lactosucrose and milk lactose) under the post-prandial supine condition was significantly longer than that under the sitting condition. In addition, the amount of breath hydrogen excretion under the supine condition was significantly lower than under the sitting condition, indicating that the unabsorbed milk lactose moved into cecum under the supine condition is smaller than that under the sitting condition. These findings provide evidence that postprandial supine posture works more beneficially to digest and absorb milk lactose when compared to the sitting posture.

Characterising the Atmospheres of Transiting Planets with a Dedicated Space Telescope

NASA Astrophysics Data System (ADS)

Tessenyi, M.; Ollivier, M.; Tinetti, G.; Beaulieu, J. P.; Coudé du Foresto, V.; Encrenaz, T.; Micela, G.; Swinyard, B.; Ribas, I.; Aylward, A.; Tennyson, J.; Swain, M. R.; Sozzetti, A.; Vasisht, G.; Deroo, P.

2011-10-01

Transiting super-Earths orbiting M dwarfs are excellent targets for the prospect of studying potentially habitable extrasolar planets. While most of the currently known Exoplanets are of the Hot Jupiter and Neptune type, attention is now turning to these super- Earths. Two recent examples are GJ 1214b, found by Charbonneau et al. in 2009, and Cancri 55 e, found by Winn et al. in 2011. These candidates offer the opportunity of obtaining spectral signatures of their atmospheres in transiting scenarios, via data obtained by ground based and space observatories, compared to simulated climate scenarios. With the recent selection of the Exoplanet Characterisation Observatory (EChO) mission by ESA for further studies, I present observational strategies and time requirements for a range of targets characterisable by EChO, with a view to super-Earths orbiting M dwarfs.

Transit Project Planning Guidance : Estimation of Transit Supply Parameters

DOT National Transportation Integrated Search

1984-04-01

This report discusses techniques applicable to the estimation of transit vehicle fleet requirements, vehicle-hours and vehicle-miles, and other related transit supply parameters. These parameters are used for estimating operating costs and certain ca...

Uranium redox transition pathways in acetate-amended sediments

USGS Publications Warehouse

Bargar, John R.; Williams, Kenneth H.; Campbell, Kate M.; Long, Philip E.; Stubbs, Joanne E.; Suvorova, Elenal I.; Lezama-Pacheco, Juan S.; Alessi, Daniel S.; Stylo, Malgorzata; Webb, Samuel M.; Davis, James A.; Giammar, Daniel E.; Blue, Lisa Y.; Bernier-Latmani, Rizlan

2013-01-01

Redox transitions of uranium [from U(VI) to U(IV)] in low-temperature sediments govern the mobility of uranium in the environment and the accumulation of uranium in ore bodies, and inform our understanding of Earth’s geochemical history. The molecular-scale mechanistic pathways of these transitions determine the U(IV) products formed, thus influencing uranium isotope fractionation, reoxidation, and transport in sediments. Studies that improve our understanding of these pathways have the potential to substantially advance process understanding across a number of earth sciences disciplines. Detailed mechanistic information regarding uranium redox transitions in field sediments is largely nonexistent, owing to the difficulty of directly observing molecular-scale processes in the subsurface and the compositional/physical complexity of subsurface systems. Here, we present results from an in situ study of uranium redox transitions occurring in aquifer sediments under sulfate-reducing conditions. Based on molecular-scale spectroscopic, pore-scale geochemical, and macroscale aqueous evidence, we propose a biotic–abiotic transition pathway in which biomass-hosted mackinawite (FeS) is an electron source to reduce U(VI) to U(IV), which subsequently reacts with biomass to produce monomeric U(IV) species. A species resembling nanoscale uraninite is also present, implying the operation of at least two redox transition pathways. The presence of multiple pathways in low-temperature sediments unifies apparently contrasting prior observations and helps to explain sustained uranium reduction under disparate biogeochemical conditions. These findings have direct implications for our understanding of uranium bioremediation, ore formation, and global geochemical processes.

Promoting Multicultural Competence: Diversity Training for Transition Professionals

ERIC Educational Resources Information Center

Lichtenstein, David; Lindstrom, Lauren; Povenmire-Kirk, Tiana

2008-01-01

As post-school outcomes for diverse students with disabilities continue to fall short of those of their majority-culture peers, there is an increasingly urgent need to increase multicultural competence among transition professionals. This study used a pre-/post-test measure to assess changes in multicultural competence for a statewide group of…

NASA's SDO Shows Moon Transiting the Sun

NASA Image and Video Library

2017-12-08

On Nov. 22, 2014 from 5:29 to 6:04 p.m. EST., the moon partially obscured the view of the sun from NASA's Solar Dynamics Observatory. This phenomenon, which is called a lunar transit, could only be seen from SDO's point of view. In 2014, SDO captured four such transits -- including its longest ever recorded, which occurred on Jan. 30, and lasted two and a half hours. SDO imagery during a lunar transit always shows a crisp horizon on the moon -- a reflection of the fact that the moon has no atmosphere around it to distort the light from the sun. The horizon is so clear in these images that mountains and valleys in the terrain can be seen. Credit: NASA/SDO NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Transition Analysis for the Mars Science Laboratory Entry Vehicle

NASA Technical Reports Server (NTRS)

Chang, Chau-Lyan; Choudhari, Meelan M.; Hollis, Brian R.; Li, Fei

2009-01-01

Viscous Laminar-turbulent transition plays an important role in the design of the Mars Science Laboratory (MSL) entry vehicle. The lift-to-drag ratio required for the precision landing trajectory will be achieved via an angle of attack equal to 16 degrees. At this relatively high angle of attack, the boundary layer flow near the leeward meridian is expected to transition early in the trajectory, resulting in substantially increased heating loads. This paper presents stability calculations and transition correlations for a series of wind tunnel models of the MSL vehicle. Experimentally measured transition onset locations are used to correlate with the N-factor calculations for various wind tunnel conditions. Due to relatively low post-shock Mach numbers near the edge of the boundary layer, the dominant instability waves are found to be of the first mode type. The N-factor values correlating with measured transition onset at selected test points from the Mach 6 conventional facility experiments fall between 3.5 and 4.5 and apparently vary linearly with the wind tunnel unit Reynolds number, indicating strong receptivity effect. The small transition N value is consistent with previous correlations for second-mode dominant transition in the same wind tunnel facility. Stability calculations for stationary and traveling crossflow instability waves in selected configurations indicate that an N value of 4 and 6, respectively, correlates reasonably well with transition onset discerned from one experimentally measured thermographic image.

Gifts from Exoplanetary Transits

NASA Astrophysics Data System (ADS)

Narita, Norio

2009-08-01

The discovery of transiting extrasolar planets has enabled us to do a number of interesting studies. Transit photometry reveals the radius and the orbital inclination of transiting planets, which allows us to learn the true mass and density of the respective planets by the combined information from radial velocity (RV) measurements. In addition, follow-up observations of transiting planets, looking at such things as secondary eclipses, transit timing variations, transmission spectroscopy, and the Rossiter-McLaughlin effect, provide us information about their dayside temperatures, unseen bodies in systems, planetary atmospheres, and the obliquity of planetary orbits. Such observational information, which will provide us a greater understanding of extrasolar planets, is available only for transiting planets. Here, I briefly summarize what we can learn from transiting planets and introduce previous studies.

Photometric Follow-up Transit (Primary Eclipse) Observations of WASP-43 b and TrES-3b and A Study on Their Transit Timing Variations

NASA Astrophysics Data System (ADS)

Zhao, Sun; Jiang-hui, Ji; Yao, Dong

2018-01-01

Two photometric follow-up transit (primary eclipse) observations on WASP-43 b and four observations on TrES-3 b are performed using the Xuyi Near-Earth Object Survey Telescope. After differential photometry and light curve analysis, the physical parameters of the two systems are obtained and are in good match with the literature. Combining with transit data from a lot of literature, the residuals (O - C) of transit observations of both systems are fitted with the linear and quadratic functions. With the linear fitting, the periods and transit timing variations (TTVs) of the planets are obtained, and no obvious periodic TTV signal is found in both systems after an analysis. The maximum mass of a perturbing planet located at the 1:2 mean motion resonance (MMR) for WASP-43 b and TrES-3 b is estimated to be 1.826 and 1.504 Earth mass, respectively. By quadratic fitting, it is confirmed that WASP-43 b may have a long-term TTV which means an orbital decay. The decay rate is shown to be Ṗ = (-0.005248 ± 0.001714) s·yr-1, and compared with the previous results. Based on this, the lower limit of the stellar tidal quality parameter of WASP-43 is calculated to be Q‧* ≥ 1.5 × 105 , and the remaining lifetimes of the planets are presented for the different Q‧* values of the two systems, correspondingly.

Transitional Experiences of Post-16 Sports Education: Jack's Story

ERIC Educational Resources Information Center

Aldous, David C. R.; Sparkes, Andrew C.; Brown, David H. K.

2014-01-01

This paper explores the layered transitional experiences of a semi-professional athlete named Jack (a pseudonym) between the fields of professional sport and further and higher education. Our analysis is framed by the quadripartite framework of structuration and focuses on Jack's "in-situ" practices at his college and university in order…

Gas turbine combustor transition

DOEpatents

Coslow, B.J.; Whidden, G.L.

1999-05-25

A method is described for converting a steam cooled transition to an air cooled transition in a gas turbine having a compressor in fluid communication with a combustor, a turbine section in fluid communication with the combustor, the transition disposed in a combustor shell and having a cooling circuit connecting a steam outlet and a steam inlet and wherein hot gas flows from the combustor through the transition and to the turbine section, includes forming an air outlet in the transition in fluid communication with the cooling circuit and providing for an air inlet in the transition in fluid communication with the cooling circuit. 7 figs.

POLARIMETRIC DETECTION OF EXOPLANETS TRANSITING T AND L BROWN DWARFS

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

Sengupta, Sujan, E-mail: sujan@iiap.res.in

While scattering of light by atoms and molecules yields large amounts of polarization at the B-band of both T and L dwarfs, scattering by dust grains in the cloudy atmosphere of L dwarfs gives rise to significant polarization at the far-optical and infrared wavelengths where these objects are much brighter. However, the observable disk-averaged polarization should be zero if the clouds are uniformly distributed and the object is spherically symmetric. Therefore, in order to explain the observed large polarization of several L dwarfs, rotation-induced oblateness or horizontally inhomogeneous cloud distribution in the atmosphere is invoked. On the other hand, whenmore » an extra-solar planet of Earth-size or larger transits the brown dwarf along the line of sight, the asymmetry induced during the transit gives rise to a net non-zero, time-dependent polarization. Employing atmospheric models for a range of effective temperature and surface gravity appropriate for T and L dwarfs, I derive the time-dependent polarization profiles of these objects during the transit phase and estimate the peak amplitude of polarization that occurs during the inner contact points of the transit ingress/egress phase. It is found that peak polarization in the range of 0.2%–1.0% at I and J band may arise of cloudy L dwarfs occulted by Earth-size or larger exoplanets. Such an amount of polarization is higher than what can be produced by rotation-induced oblateness of even rapidly rotating L dwarfs. Hence, I suggest that time-resolved imaging polarization could be a potential technique for detecting transiting exoplanets around L dwarfs.« less

Compositional dependence of elastic moduli for transition-metal oxide spinels

NASA Astrophysics Data System (ADS)

Reichmann, H. J.; Jacobsen, S. D.; Boffa Ballaran, T.

2012-12-01

Spinel phases (AB2O4) are common non-silicate oxides in the Earth's crust and upper mantle. A characteristic of this mineral group is the ability to host a wide range of transition metals. Here we summarize the influence of transition metals (Fe, Zn, and Mn) on the pressure dependence of elastic moduli of related spinels (magnetite, gahnite, and franklinite) using GHz-ultrasonic interferometry. Measurements were carried out up to 10 GPa in diamond-anvil cells using hydrostatic pressure media. Transition metals with unfilled 3d orbitals strongly influence the elastic properties of spinels. Franklinite (Zn,Mn)Fe2O4 and magnetite Fe3O4 with transition metals on both A and B cation sites exhibit pressure-induced mode softening of C44, whereas C44 of gahnite(ZnAl2O4) and spinel (MgAl2O4) exhibit positive pressure derivatives of the shear moduli. Spinels with two transition elements tend to undergo phase changes at a lower pressure than those with none or only one transition metal. Along the Mn-Zn solid solution, the variation of moduli with composition is non-linear, and a mid-range franklinite composition studied here shows a minimum in C44 compared with either end-member: MnFe2O 4 or ZnFe2O4. In general, the linear variation of sound velocity with density (Birch's Law) is followed by spinels, however spinels containing only one or no transition metals follow a distinct slope from those containing transition metals on both A and B sites. The Cauchy relation, 0.5(C12 - C44) = P is fulfilled by spinels with only one or no transition metals, suggesting that that Coulomb interactions dominate. Spinels with two transition metals fail to meet the Cauchy relation, indicating strong directional dependence and covalent character of bonding. The bonding character of transition metals is crucial to understanding the elastic behavior of natural and synthetic spinel solid solutions containing transition metals.

Formal Valence, 3 d Occupation, and Charge Ordering Transitions

NASA Astrophysics Data System (ADS)

Pickett, Warren

2014-03-01

The metal-insulator transition (MIT), discovered by Verwey in the late 1930s, has been thought to be one of the best understood of MITs, the other ones being named after Wigner, Peierls, Mott, and Anderson. Continuing work on these transitions finds in some cases less and less charge to order, raising the fundamental question of just where the entropy is coming from, and just what is ordering. To provide insight into the mechanism of charge-ordering transitions, which conventionally are pictured as a disproportionation, I will (1) review and reconsider the charge state (or oxidation number) picture itself, (2) introduce new theoretical results for the rare earth nickelates (viz. YNiO3), the putative charge ordering compound AgNiO2, and the dual charge state insulator AgO, and (3) analyze cationic occupations of actual (not formal) charge, and work to reconcile the conundrums that arise. Several of the clearest cases of charge ordering transitions involve no disproportion; moreover, the experimental data used to support charge ordering can be accounted for within density functional based calculations that contain no charge transfer The challenge of modeling charge ordering transitions with model Hamiltonians will be discussed. Acknowledgment: Y. Quan, V. Pardo. Supported by NSF award DMR-1207622-0.

Matter in transition

DOE PAGES

Anderson, Lara B.; Gray, James; Raghuram, Nikhil; ...

2016-04-13

In this study, we explore a novel type of transition in certain 6D and 4D quantum field theories, in which the matter content of the theory changes while the gauge group and other parts of the spectrum remain invariant. Such transitions can occur, for example, for SU(6) and SU(7) gauge groups, where matter fields in a three-index antisymmetric representation and the fundamental representation are exchanged in the transition for matter in the two-index antisymmetric representation. These matter transitions are realized by passing through superconformal theories at the transition point. We explore these transitions in dual F-theory and heterotic descriptions, wheremore » a number of novel features arise. For example, in the heterotic description the relevant 6D SU(7) theories are described by bundles on K3 surfaces where the geometry of the K3 is constrained in addition to the bundle structure. On the F-theory side, non-standard representations such as the three-index antisymmetric representation of SU(N) require Weierstrass models that cannot be realized from the standard SU(N) Tate form. We also briefly describe some other situations, with groups such as Sp(3), SO(12), and SU(3), where analogous matter transitions can occur between different representations. For SU(3), in particular, we find a matter transition between adjoint matter and matter in the symmetric representation, giving an explicit Weierstrass model for the F-theory description of the symmetric representation that complements another recent analogous construction.« less

Predictors of substance use among young adults transitioning away from high school: a narrative review.

PubMed

Kirst, Maritt; Mecredy, Graham; Borland, Tracey; Chaiton, Michael

2014-11-01

Young adulthood has been shown to be a time of increased substance use. Yet, not enough is known about which factors contribute to initiation and progression of substance use among young adults specifically during the transition year away from high school. A narrative review was undertaken to increase understanding of the predictors of changes in use of tobacco, alcohol, cannabis, other illicit drugs, and mental health problems among young adults during the transition period after high school. A review of academic literature examining predictors of the use of tobacco, alcohol and cannabis, and co-morbidities (e.g., co-occurring substance use and/or mental health issues) among young adults transitioning from high school to post-secondary education or the workforce. Twenty six studies were included in the review. The majority of the studies (19) examined substance use during the transition from high school to post-secondary settings. Seven studies examined substance use in post-secondary settings. The studies consistently found that substance use increases among young adults as they transition away from high school. During the transition away from high school, common predictors of substance use include substance use in high school, and peer influence. Common predictors of substance use in post-secondary education include previous substance use, peer influence, psychological factors and mental health issues. Conclusions/Importance: Further research on social contextual influences on substance use, mental health issues, gender differences and availability of substances during the transition period is needed to inform the development of new preventive interventions for this age group.

Mercury Transit (Composite Image)

NASA Image and Video Library

2017-12-08

On May 9, 2016, Mercury passed directly between the sun and Earth. This event – which happens about 13 times each century – is called a transit. NASA’s Solar Dynamics Observatory, or SDO, studies the sun 24/7 and captured the entire seven-and-a-half-hour event. This composite image of Mercury’s journey across the sun was created with visible-light images from the Helioseismic and Magnetic Imager on SDO. Image Credit: NASA's Goddard Space Flight Center/SDO/Genna Duberstein NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

A Catalog of Transit Timing Posterior Distributions for all Kepler Planet Candidate Transit Events

NASA Astrophysics Data System (ADS)

Montet, Benjamin Tyler; Becker, Juliette C.; Johnson, John Asher

2015-12-01

Kepler has ushered in a new era of planetary dynamics, enabling the detection of interactions between multiple planets in transiting systems for hundreds of systems. These interactions, observed as transit timing variations (TTVs), have been used to find non-transiting companions to transiting systems and to measure masses, eccentricities, and inclinations of transiting planets. Often, physical parameters are inferred by comparing the observed light curve to the result of a photodynamical model, a time-intensive process that often ignores the effects of correlated noise in the light curve. Catalogs of transit timing observations have previously neglected non-Gaussian uncertainties in the times of transit, uncertainties in the transit shape, and short cadence data. Here, I present a catalog of not only times of transit centers, but also posterior distributions on the time of transit for every planet candidate transit event in the Kepler data, developed through importance sampling of each transit. This catalog allows one to marginalize over uncertainties in the transit shape and incorporate short cadence data, the effects of correlated noise, and non-Gaussian posteriors. Our catalog will enable dynamical studies that reflect accurately the precision of Kepler and its limitations without requiring the computational power to model the light curve completely with every integration. I will also present our open-source N-body photodynamical modeling code, which integrates planetary and stellar orbits accounting for the effects of GR, tidal effects, and Doppler beaming.

STP Research Results: An Annual Research Update on the First Transitions of B.C. Grade 12 Graduates into B.C. Public Post-Secondary Education

ERIC Educational Resources Information Center

Heslop, Joanne

2017-01-01

Every year, the Student Transitions Project (STP) collects post-secondary enrollment and credential completion data from the twenty-five British Columbia (B.C.) public post-secondary institutions and links this data to secondary enrollment information via encrypted personal education numbers (PENs). Now comprising fourteen full years of…

The Emergence of Life as a First-Order Phase Transition

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

Mathis, Cole; Bhattacharya, Tanmoy; Walker, Sara Imari

It is well known that life on Earth alters its environment over evolutionary and geological timescales. An important open question is whether this is a result of evolutionary optimization or a universal feature of life. In the latter case, the origin of life would be coincident with a shift in environmental conditions. Here in this paper we present a model for the emergence of life in which replicators are explicitly coupled to their environment through the recycling of a finite supply of resources. The model exhibits a dynamic, first-order phase transition from nonlife to life, where the life phase ismore » distinguished by selection on replicators. We show that environmental coupling plays an important role in the dynamics of the transition. The transition corresponds to a redistribution of matter in replicators and their environment, driven by selection on replicators, exhibiting an explosive growth in diversity as replicators are selected. The transition is accurately tracked by the mutual information shared between replicators and their environment. In the absence of successfully repartitioning system resources, the transition fails to complete, leading to the possibility of many frustrated trials before life first emerges. Often, the replicators that initiate the transition are not those that are ultimately selected. The results are consistent with the view that life's propensity to shape its environment is indeed a universal feature of replicators, characteristic of the transition from nonlife to life. We discuss the implications of these results for understanding life's emergence and evolutionary transitions more broadly.« less

The Emergence of Life as a First-Order Phase Transition

DOE PAGES

Mathis, Cole; Bhattacharya, Tanmoy; Walker, Sara Imari

2017-03-01

It is well known that life on Earth alters its environment over evolutionary and geological timescales. An important open question is whether this is a result of evolutionary optimization or a universal feature of life. In the latter case, the origin of life would be coincident with a shift in environmental conditions. Here in this paper we present a model for the emergence of life in which replicators are explicitly coupled to their environment through the recycling of a finite supply of resources. The model exhibits a dynamic, first-order phase transition from nonlife to life, where the life phase ismore » distinguished by selection on replicators. We show that environmental coupling plays an important role in the dynamics of the transition. The transition corresponds to a redistribution of matter in replicators and their environment, driven by selection on replicators, exhibiting an explosive growth in diversity as replicators are selected. The transition is accurately tracked by the mutual information shared between replicators and their environment. In the absence of successfully repartitioning system resources, the transition fails to complete, leading to the possibility of many frustrated trials before life first emerges. Often, the replicators that initiate the transition are not those that are ultimately selected. The results are consistent with the view that life's propensity to shape its environment is indeed a universal feature of replicators, characteristic of the transition from nonlife to life. We discuss the implications of these results for understanding life's emergence and evolutionary transitions more broadly.« less

Modeling the transition region

NASA Technical Reports Server (NTRS)

Singer, Bart A.

1993-01-01

The current status of transition-region models is reviewed in this report. To understand modeling problems, various flow features that influence the transition process are discussed first. Then an overview of the different approaches to transition-region modeling is given. This is followed by a detailed discussion of turbulence models and the specific modifications that are needed to predict flows undergoing laminar-turbulent transition. Methods for determining the usefulness of the models are presented, and an outlook for the future of transition-region modeling is suggested.

Pressure induced structural phase transition in IB transition metal nitrides compounds

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

Soni, Shubhangi; Kaurav, Netram, E-mail: netramkaurav@yahoo.co.uk; Jain, A.

2015-06-24

Transition metal mononitrides are known as refractory compounds, and they have, relatively, high hardness, brittleness, melting point, and superconducting transition temperature, and they also have interesting optical, electronic, catalytic, and magnetic properties. Evolution of structural properties would be an important step towards realizing the potential technological scenario of this material of class. In the present study, an effective interionic interaction potential (EIOP) is developed to investigate the pressure induced phase transitions in IB transition metal nitrides TMN [TM = Cu, Ag, and Au] compounds. The long range Coulomb, van der Waals (vdW) interaction and the short-range repulsive interaction upto second-neighbormore » ions within the Hafemeister and Flygare approach with modified ionic charge are properly incorporated in the EIOP. The vdW coefficients are computed following the Slater-Kirkwood variational method, as both the ions are polarizable. The estimated value of the phase transition pressure (Pt) and the magnitude of the discontinuity in volume at the transition pressure are consistent as compared to the reported data.« less

Rationale and design of TRANSITION: a randomized trial of pre-discharge vs. post-discharge initiation of sacubitril/valsartan.

PubMed

Pascual-Figal, Domingo; Wachter, Rolf; Senni, Michele; Belohlavek, Jan; Noè, Adele; Carr, David; Butylin, Dmytro

2018-04-01

The prognosis after hospitalization for acute decompensated heart failure (ADHF) remains poor, especially <30 days post-discharge. Evidence-based medications with prognostic impact administered at discharge improve survival and hospital readmission, but robust studies comparing pre-discharge with post-discharge initiation are rare. The PARADIGM-HF trial established sacubitril/valsartan as a new evidence-based therapy in patients with heart failure (HF) and reduced left ventricular ejection fraction (<40%) (rEF). In common with other landmark studies, it enrolled patients who were ambulatory at the time of inclusion. In addition, there is also still limited knowledge of initiation and up-titration of sacubitril/valsartan in ACEi/ARB- naïve patients and in de novo HF with rEF patients. TRANSITION is a multicentre, open-label study in which ~1000 adults hospitalized for ADHF with rEF are randomized to start sacubitril/valsartan in a pre-discharge arm (initiated ≥24 h after haemodynamic stabilization) or a post-discharge arm (initiated within Days 1-14 after discharge). The protocol allows investigators to select the appropriate starting dose and dose adjustments according to clinical circumstances. Over a 10 week treatment period, the primary and secondary objectives assess the feasibility and safety of starting sacubitril/valsartan in-hospital, early after haemodynamic stabilization. Exploratory objectives also include assessment of HF signs and symptoms, readmissions, N-terminal pro-B-type natriuretic peptide and high-sensitivity troponin T levels, and health resource utilization parameters. TRANSITION will provide new evidence about initiating sacubitril/valsartan following hospitalization for ADHF, occurring either as de novo ADHF or as deterioration of chronic HF, and in patients with or without prior ACEI/ARB therapy. The results of TRANSITION will thus be highly relevant to the management of patients hospitalized for ADHF with rEF. © 2017 The Authors

Simulating the Seismic Signal of Phase Transitions in the Deepest Mantle (Invited)

NASA Astrophysics Data System (ADS)

Walker, A.; Dobson, D. P.; Nowacki, A.; Wookey, J. M.; Forte, A. M.; Kendall, J. M.

2013-12-01

The discovery of the perovskite to post-perovskite phase transition in (Mg,Fe)SiO3 explains many of the seismic observations of the lowermost mantle including the presence of multiple seismic discontinuities and significant seismic anisotropy. However, the explanations of many detailed features remain elusive. The recent discovery of a topotactic relationship between the orientation of perovskite and post-perovskite crystals in a partially transformed analogue opens the possibility of texture inheritance through the phase transition [1]. This must be captured in simulations designed to explain the anisotropy of the lowermost mantle, especially those which link mantle dynamics with seismic observations. We have extended our previous work linking models of flow in the lowermost mantle with simulations of texture development and predictions of seismic anisotropy [2] to account for the topotaxy between perovskite and post-perovskite. In particular, we compare four cases: (1) As in [2], anisotropy is only generated in post-perovskite by dislocation mediated deformation dominated by one of a number of slip systems, phase transitions destroy texture and ferropericlase and perovskite dominated rocks are isotropic. (2) Although phase transitions destroy texture, ferropericlase and/or perovskite deform by dislocation motion permitting the generation of seismic anisotropy in warmer regions of the mantle where post-perovskite is unstable. We account for the possibility of the inversion of slip-system activities in ferropericlase at high pressure as suggested by models of dislocation motion based on atomic scale simulations [3]. (3) Allow texture development by dislocation motion in perovskite and post-perovskite and texture inheritance through phase transitions by the mechanism described in [1]. However, we assume that the bulk of the lower mantle deforms by a mechanism that does not lead to the development of texture and so begin the simulation from a random distribution of

An analysis of the transit times of TrES-1b

NASA Astrophysics Data System (ADS)

Steffen, Jason H.; Agol, Eric

2005-11-01

The presence of a second planet in a known, transiting-planet system will cause the time between transits to vary. These variations can be used to constrain the orbital elements and mass of the perturbing planet. We analyse the set of transit times of the TrES-1 system given in Charbonneau et al. We find no convincing evidence for a second planet in the TrES-1 system from those data. By further analysis, we constrain the mass that a perturbing planet could have as a function of the semi-major axis ratio of the two planets and the eccentricity of the perturbing planet. Near low-order, mean-motion resonances (within ~1 per cent fractional deviation), we find that a secondary planet must generally have a mass comparable to or less than the mass of the Earth - showing that these data are the first to have sensitivity to sub-Earth-mass planets. We compare the sensitivity of this technique to the mass of the perturbing planet with future, high-precision radial velocity measurements.

Role of thermal heating on the voltage induced insulator-metal transition in VO2.

PubMed

Zimmers, A; Aigouy, L; Mortier, M; Sharoni, A; Wang, Siming; West, K G; Ramirez, J G; Schuller, Ivan K

2013-02-01

We show that the main mechanism for the dc voltage or dc current induced insulator-metal transition in vanadium dioxide VO(2) is due to local Joule heating and not a purely electronic effect. This "tour de force" experiment was accomplished by using the fluorescence spectra of rare-earth doped micron sized particles as local temperature sensors. As the insulator-metal transition is induced by a dc voltage or dc current, the local temperature reaches the transition temperature indicating that Joule heating plays a predominant role. This has critical implications for the understanding of the dc voltage or dc current induced insulator-metal transition and has a direct impact on applications which use dc voltage or dc current to externally drive the transition.

Fast therapeutic hypothermia prevents post-cardiac arrest syndrome through cyclophilin D-mediated mitochondrial permeability transition inhibition.

PubMed

Jahandiez, Vincent; Cour, Martin; Bochaton, Thomas; Abrial, Maryline; Loufouat, Joseph; Gharib, Abdallah; Varennes, Annie; Ovize, Michel; Argaud, Laurent

2017-07-01

The opening of the mitochondrial permeability transition pore (PTP), which is regulated by the matrix protein cyclophilin D (CypD), plays a key role in the pathophysiology of post-cardiac arrest (CA) syndrome. We hypothesized that therapeutic hypothermia could prevent post-CA syndrome through a CypD-mediated PTP inhibition in both heart and brain. In addition, we investigated whether specific pharmacological PTP inhibition would confer additive protection to cooling. Adult male New Zealand White rabbits underwent 15 min of CA followed by 120 min of reperfusion. Five groups (n = 10-15/group) were studied: control group (CA only), hypothermia group (HT, hypothermia at 32-34 °C induced by external cooling at reperfusion), NIM group (injection at reperfusion of 2.5 mg/kg NIM811, a specific CypD inhibitor), HT + NIM, and sham group. The following measurements were taken: hemodynamics, echocardiography, and cellular damage markers (including S100β protein and troponin Ic). Oxidative phosphorylation and PTP opening were assessed on mitochondria isolated from both brain and heart. Acetylation of CypD was measured by immunoprecipitation in both the cerebral cortex and myocardium. Hypothermia and NIM811 significantly prevented cardiovascular dysfunction, pupillary areflexia, and early tissue damage. Hypothermia and NIM811 preserved oxidative phosphorylation, limited PTP opening in both brain and heart mitochondria and prevented increase in CypD acetylation in brain. There were no additive beneficial effects in the combination of NIM811 and therapeutic hypothermia. In conclusion, therapeutic hypothermia limited post-CA syndrome by preventing mitochondrial permeability transition mainly through a CypD-dependent mechanism.

Transition Metal Switchable Mirror

ScienceCinema

None

2017-12-29

The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft. More information at: http://windows.lbl.gov/materials/chromogenics/default.htm

Transition Metal Switchable Mirror

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

None

2009-08-21

The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft. More information at: http://windows.lbl.gov/materials/chromogenics/default.htm

Transit-oriented development: an examination of America's transit precincts in 2000 & 2010.

DOT National Transportation Integrated Search

2013-06-01

This study creates a typology of all fixed transit precincts across the United States to categorize all stations as either a Transit Oriented Development (TOD), Transit Adjacent Development (TAD) or hybrid. This typology is based on an index that acc...

Cosmic Genes in the Cretaceous-Tertiary transition

NASA Astrophysics Data System (ADS)

Wallis, M. K.

2003-07-01

It is proposed that genes coding for Aib-polypeptides arose early on in the K/T transition, presumed from the Earth's accretion of interplanetary (comet) dust. Aib-fungi flourished because of the evolutionary advantage of novel antibiotics. The stress on Cretaceous biology led directly and indirectly to mass species extinctions, including many dinosaur species, in the epoch preceding the Chicxulub impact.

Neutron diffraction studies of some rare earth-transition metal deuterides

NASA Astrophysics Data System (ADS)

James, W. J.

1984-04-01

Neutron diffraction studies of the ternary alloy system Y6(Fel-xMnx)23 reveal that the unusual magnetic behavior upon substitution of Mn or Fe into the end members, is a consequence of atomic ordering wherein there is strong site preference of Mn for the f sub 2 sites and of Fe for the f sub 1 sites. In the Mn-rich compositions, Fe is found to have no spontaneous moments. Therefore, the long range magnetic ordering arises solely from Mn-Mn interactions. Upon substitution of Mn into the Fe-rich ternaries, the Fe moments are considerably reduced. Neutron diffraction studies of Y6Mn23D23 show that a transition occurs below 180K from a fcc structure to a primitive tetragonal structure, space group P4/mmm with the onset of antiferromagnetic ordering. The Mn moments are directed along the c-axis. The transition probably results from atomic ordering of the D atoms at low temperature which induces c axis magnetic ordering. The question of the appropriate space group of LaNi4.5Al0.5D4.5, P6/mmm or P3/m has been resolved by a careful refinement and analysis of neutron diffraction data. The preferred space group is P6/mmm. Neutron powder diffraction and thermal magnetization measurements on small single crystals of ErNi3, ErCo3, and ErFe3 (space group R3m) show that the magnetocrystalline properties are a consequence of competing local site anisotropies between the two non-equivalent crystallographic sites of Er and two of the three non-equivalent sites of the 3d-transition metal.

Developments in Earth observation for the assessment and monitoring of inland, transitional, coastal and shelf-sea waters.

PubMed

Tyler, Andrew N; Hunter, Peter D; Spyrakos, Evangelos; Groom, Steve; Constantinescu, Adriana Maria; Kitchen, Jonathan

2016-12-01

The Earth's surface waters are a fundamental resource and encompass a broad range of ecosystems that are core to global biogeochemical cycling and food and energy production. Despite this, the Earth's surface waters are impacted by multiple natural and anthropogenic pressures and drivers of environmental change. The complex interaction between physical, chemical and biological processes in surface waters poses significant challenges for in situ monitoring and assessment and often limits our ability to adequately capture the dynamics of aquatic systems and our understanding of their status, functioning and response to pressures. Here we explore the opportunities that Earth observation (EO) has to offer to basin-scale monitoring of water quality over the surface water continuum comprising inland, transition and coastal water bodies, with a particular focus on the Danube and Black Sea region. This review summarises the technological advances in EO and the opportunities that the next generation satellites offer for water quality monitoring. We provide an overview of algorithms for the retrieval of water quality parameters and demonstrate how such models have been used for the assessment and monitoring of inland, transitional, coastal and shelf-sea systems. Further, we argue that very few studies have investigated the connectivity between these systems especially in large river-sea systems such as the Danube-Black Sea. Subsequently, we describe current capability in operational processing of archive and near real-time satellite data. We conclude that while the operational use of satellites for the assessment and monitoring of surface waters is still developing for inland and coastal waters and more work is required on the development and validation of remote sensing algorithms for these optically complex waters, the potential that these data streams offer for developing an improved, potentially paradigm-shifting understanding of physical and biogeochemical processes

Transition path time distributions

NASA Astrophysics Data System (ADS)

Laleman, M.; Carlon, E.; Orland, H.

2017-12-01

Biomolecular folding, at least in simple systems, can be described as a two state transition in a free energy landscape with two deep wells separated by a high barrier. Transition paths are the short part of the trajectories that cross the barrier. Average transition path times and, recently, their full probability distribution have been measured for several biomolecular systems, e.g., in the folding of nucleic acids or proteins. Motivated by these experiments, we have calculated the full transition path time distribution for a single stochastic particle crossing a parabolic barrier, including inertial terms which were neglected in previous studies. These terms influence the short time scale dynamics of a stochastic system and can be of experimental relevance in view of the short duration of transition paths. We derive the full transition path time distribution as well as the average transition path times and discuss the similarities and differences with the high friction limit.

In Pursuit of New Worlds: Searches for and Studies of Transiting Exoplanets from Three Space-Based Observatories

NASA Astrophysics Data System (ADS)

Ballard, Sarah Ashley

2012-01-01

This thesis presents studies of transiting exoplanets using observations gathered in large part from space, with the NASA EPOXI Mission, the Spitzer Space Telescope, and the Kepler Mission. The first part of this thesis describes searches for additional transiting planets in known exoplanet systems, using time series photometry gathered as part of the NASA EPOXI Mission. Using the EPOXI light curves spanning weeks for each star, we searched six exoplanetary systems for signatures of additional transiting planets. These six systems include five hosts to hot Jupiters: HAT-P-4, TrES-3, TrES-2, WASP-3, and HAT-P-7, and one host to a hot Neptune: GJ 436. We place upper limits on the presence of additional transiting planets in the super-Earth radius range for GJ 436 in Chapter 2, and in the Neptune-to-Saturn radius range for the other five systems in Chapter 4. Chapter 3 details a search for additional transits of a hypothesized planet smaller than the Earth, whose presence was suggested by the EPOXI observations of GJ 436. In that study, we demonstrate the sensitivity of Warm Spitzer observations to transits of a sub-Earth-sized planet. The fifth chapter details the characterization and validation of the Kepler-19 system, which hosts a transiting 2.2 R⊕ planet, Kepler-19b. We demonstrate the planetary nature of the transit signal with an analysis that combines information from high-resolution spectroscopy, the shape of the transit light curve, adaptive optics imaging, and near-infrared transits of the planet. The sinusoidal variation in the transit times of Kepler-19b indicates the presence of an additional perturbing body, and comprises the first definitive detection of a planet using the transit timing variation method. While we cannot uniquely determine the mass and orbital period of Kepler-19c, we establish that its mass must be less than 6 times the mass of Jupiter. The sixth chapter presents evidence for the validation of a 2.0 R ⊕ planet residing in the

Mesenchymal-endothelial-transition contributes to cardiac neovascularization

PubMed Central

Ubil, Eric; Duan, Jinzhu; Pillai, Indulekha C.L.; Rosa-Garrido, Manuel; Wu, Yong; Bargiacchi, Francesca; Lu, Yan; Stanbouly, Seta; Huang, Jie; Rojas, Mauricio; Vondriska, Thomas M.; Stefani, Enrico; Deb, Arjun

2014-01-01

Endothelial cells contribute to a subset of cardiac fibroblasts by undergoing endothelial-to-mesenchymal-transition, but whether cardiac fibroblasts can adopt an endothelial cell fate and directly contribute to neovascularization after cardiac injury is not known. Here, using genetic fate map techniques, we demonstrate that cardiac fibroblasts rapidly adopt an endothelial cell like phenotype after acute ischemic cardiac injury. Fibroblast derived endothelial cells exhibit anatomical and functional characteristics of native endothelial cells. We show that the transcription factor p53 regulates such a switch in cardiac fibroblast fate. Loss of p53 in cardiac fibroblasts severely decreases the formation of fibroblast derived endothelial cells, reduces post infarct vascular density and worsens cardiac function. Conversely, stimulation of the p53 pathway in cardiac fibroblasts augments mesenchymal to endothelial transition, enhances vascularity and improves cardiac function. These observations demonstrate that mesenchymal-to-endothelial-transition contributes to neovascularization of the injured heart and represents a potential therapeutic target for enhancing cardiac repair. PMID:25317562

A rocky planet transiting a nearby low-mass star.

PubMed

Berta-Thompson, Zachory K; Irwin, Jonathan; Charbonneau, David; Newton, Elisabeth R; Dittmann, Jason A; Astudillo-Defru, Nicola; Bonfils, Xavier; Gillon, Michaël; Jehin, Emmanuël; Stark, Antony A; Stalder, Brian; Bouchy, Francois; Delfosse, Xavier; Forveille, Thierry; Lovis, Christophe; Mayor, Michel; Neves, Vasco; Pepe, Francesco; Santos, Nuno C; Udry, Stéphane; Wünsche, Anaël

2015-11-12

M-dwarf stars--hydrogen-burning stars that are smaller than 60 per cent of the size of the Sun--are the most common class of star in our Galaxy and outnumber Sun-like stars by a ratio of 12:1. Recent results have shown that M dwarfs host Earth-sized planets in great numbers: the average number of M-dwarf planets that are between 0.5 to 1.5 times the size of Earth is at least 1.4 per star. The nearest such planets known to transit their star are 39 parsecs away, too distant for detailed follow-up observations to measure the planetary masses or to study their atmospheres. Here we report observations of GJ 1132b, a planet with a size of 1.2 Earth radii that is transiting a small star 12 parsecs away. Our Doppler mass measurement of GJ 1132b yields a density consistent with an Earth-like bulk composition, similar to the compositions of the six known exoplanets with masses less than six times that of the Earth and precisely measured densities. Receiving 19 times more stellar radiation than the Earth, the planet is too hot to be habitable but is cool enough to support a substantial atmosphere, one that has probably been considerably depleted of hydrogen. Because the host star is nearby and only 21 per cent the radius of the Sun, existing and upcoming telescopes will be able to observe the composition and dynamics of the planetary atmosphere.

Immigration transition and sleep-related symptoms experienced during menopausal transition

PubMed Central

Im, Eun-Ok; Ko, Young; Chee, Eunice; Chee, Wonshik

2018-01-01

The transition due to immigration from one country to another country (referred to as immigration transition henceforth) is inherently stressful, placing an additional dimension of stress to midlife women in the menopausal transition. However, few studies have examined the association of immigration to sleep-related symptoms experienced by midlife women in the menopausal transition. The purpose of this study was to explore the associations of immigration to sleep-related symptoms among four major racial/ethnic groups of 1,054 midlife women in the U.S. This was a secondary analysis of data from two national surveys that were collected from 2005 to 2013. The instruments included questions on background characteristics, health and menopausal status, immigration transition and the Sleep Index for Midlife Women. The data were analyzed using t-tests, chi-square tests, correlation analyses, and hierarchical multiple regression analyses. Immigrants reported fewer total numbers of and lower total severity scores of sleep-related symptoms than non-immigrants (p < .01). Yet, when background characteristics and health and menopausal status were controlled, self-reported racial/ethnic identity was the only significant factor associated with sleep-related symptoms (Δ R2=0.02, p<0.01). Health care providers need to consider self-reported racial/ethnic identity as a factor significantly related to sleep-related symptoms during the menopausal transition. PMID:26881786

Immigration transition and sleep-related symptoms experienced during menopausal transition.

PubMed

Im, Eun-Ok; Ko, Young; Chee, Eunice; Chee, Wonshik

2017-01-01

The transition due to immigration from one country to another country (referred to as immigration transition henceforth) is inherently stressful, placing an additional dimension of stress to midlife women in the menopausal transition. However, few studies have examined the association of immigration to sleep-related symptoms experienced by midlife women in the menopausal transition. The authors' purpose for this study was to explore the associations of immigration to sleep-related symptoms among four major racial/ethnic groups of 1,054 midlife women in the United States. This was a secondary analysis of data from two national surveys that were collected from 2005 to 2013. The instruments included questions on background characteristics, health and menopausal status, immigration transition, and the Sleep Index for Midlife Women. The data were analyzed using t-tests, chi-square tests, correlation analyses, and hierarchical multiple regression analyses. Immigrants reported fewer total numbers of and lower total severity scores of sleep-related symptoms than non-immigrants (p < .01). Yet, when background characteristics and health and menopausal status were controlled, self-reported racial/ethnic identity was the only significant factor associated with sleep-related symptoms (ΔR 2  = 0.02, p < .01). Health-care providers need to consider self-reported racial/ethnic identity as a factor significantly related to sleep-related symptoms during the menopausal transition.

Microgravity Studies of Liquid-Liquid Phase Transitions in Alumina-Yttria Melts

NASA Technical Reports Server (NTRS)

Guynes, Buddy (Technical Monitor); Weber, Richard; Nordine, Paul

2004-01-01

The scientific objective of this research is to increase the fundamental knowledge base for liquid- phase processing of technologically important oxide materials. The experimental objective is to define conditions and hardware requirements for microgravity flight experiments to test and expand the experimental hypotheses that: 1. Liquid phase transitions can occur in undercooled melts by a diffusionless process. 2. Onset of the liquid phase transition is accompanied by a large change in the temperature dependence of melt viscosity. Experiments on undercooled YAG (Y3A15012)- and rare earth oxide aluminate composition liquids demonstrated a large departure from an Arrhenian temperature dependence of viscosity. Liquid YAG is nearly inviscid at its 2240 K melting point. Glass fibers were pulled from melts undercooled by ca. 600 K indicating that the viscosity is on the order of 100 Pans (1000 Poise) at 1600 K. This value of viscosity is 500 times greater than that obtained by extrapolation of data for temperatures above the melting point of YAG. These results show that the liquids are extremely fragile and that the onset of the highly non-Arrhenian viscosity-temperature relationship occurs at a temperature considerably below the equilibrium melting point of the solid phases. Further results on undercooled alumina-yttria melts containing 23-42 mole % yttrium oxide indicate that a congruent liquid-liquid phase transition occurs in the undercooled liquids. The rates of transition are inconsistent with a diffusion-limited process. This research is directed to investigation of the scientifically interesting phenomena of polyamorphism and fragility in undercooled rare earth oxide aluminum oxide liquids. The results bear on the technologically important problem of producing high value rare earth-based optical materials.

Transition Dipole Moments and Transition Probabilities of the CN Radical

NASA Astrophysics Data System (ADS)

Yin, Yuan; Shi, Deheng; Sun, Jinfeng; Zhu, Zunlue

2018-04-01

This paper studies the transition probabilities of electric dipole transitions between 10 low-lying states of the CN radical. These states are X2Σ+, A2Π, B2Σ+, a4Σ+, b4Π, 14Σ‑, 24Π, 14Δ, 16Σ+, and 16Π. The potential energy curves are calculated using the CASSCF method, which is followed by the icMRCI approach with the Davidson correction. The transition dipole moments between different states are calculated. To improve the accuracy of potential energy curves, core–valence correlation and scalar relativistic corrections, as well as the extrapolation of potential energies to the complete basis set limit are included. The Franck–Condon factors and Einstein coefficients of emissions are calculated. The radiative lifetimes are determined for the vibrational levels of the A2Π, B2Σ+, b4Π, 14Σ‑, 24Π, 14Δ, and 16Π states. According to the transition probabilities and radiative lifetimes, some guidelines for detecting these states spectroscopically are proposed. The spin–orbit coupling effect on the spectroscopic and vibrational properties is evaluated. The splitting energy in the A2Π state is determined to be 50.99 cm‑1, which compares well with the experimental ones. The potential energy curves, transition dipole moments, spectroscopic parameters, and transition probabilities reported in this paper can be considered to be very reliable. The results obtained here can be used as guidelines for detecting these transitions, in particular those that have not been measured in previous experiments or have not been observed in the Sun, comets, stellar atmospheres, dark interstellar clouds, and diffuse interstellar clouds.

Transitioning from parenteral to inhaled prostacyclin therapy in pulmonary arterial hypertension.

PubMed

Ataya, Ali; Somoracki, Angelina; Cope, Jessica; Alnuaimat, Hassan

2016-10-01

Parenteral prostacyclin therapy for PAH has allowed for improvements in functional status, quality of life and mortality. Parenteral therapies however carry an increased risk of line-associated complications. Inhaled prostacyclins are an attractive alternative therapy; however, limited data exists supporting the safety and outcomes after transition. We describe a retrospective observational analysis of adults with PAH who were transitioned from a parenteral prostacyclin to inhaled treprostinil at our institution. Endpoints include duration of transition, hospital length of stay, adverse effects during transition, and cardiopulmonary function post transition. Eight patients were included, all of which were on triple therapy. Seven patients receiving intravenous prostacyclin therapy were transitioned in an ICU setting, while one patient was transitioned from subcutaneous treprostinil as an outpatient. The average ICU and hospital length of stay was 4.1 ± 0.7 days. Patient preference was the most common reason for transition (n = 5), followed by line complication (n = 2), and intolerance to parenteral therapy (n = 1). One adverse event was observed while initiating inhaled treprostinil that only required slowing of the transition process. On follow-up (19.6 ± 11.1 months) functional class did not change, and non-parametric test showed no change in 6MWD after transition (p = 0.62). One patient failed inhaled therapy necessitating transition back to intravenous therapy. Transitioning patients from parenteral to inhaled prostacyclin therapy can be safely accomplished in specialized centers over a 48-72 h period. Patient preference was overwhelming the most prevalent reason for transition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Transit emergency planning guidance.

DOT National Transportation Integrated Search

2007-07-01

Providing safe, reliable transportation has long been a priority at all levels of : the transit industry including the Federal Transit Administration (FTA), : state Departments of Transportation and individual transit providers. Over the : last decad...

Transitional Gas Jet Diffusion Flames in Microgravity

NASA Technical Reports Server (NTRS)

Agrawal, Ajay K.; Alammar, Khalid; Gollahalli, S. R.; Griffin, DeVon (Technical Monitor)

2000-01-01

Drop tower experiments were performed to identify buoyancy effects in transitional hydrogen gas jet diffusion flames. Quantitative rainbow schlieren deflectometry was utilized to optically visualize the flame and to measure oxygen concentration in the laminar portion of the flame. Test conditions consisted of atmospheric pressure flames burning in quiescent air. Fuel from a 0.3mm inside diameter tube injector was issued at jet exit Reynolds numbers (Re) of 1300 to 1700. Helium mole percentage in the fuel was varied from 0 to 40%. Significant effects of buoyancy were observed in near field of the flame even-though the fuel jets were momentum-dominated. Results show an increase of breakpoint length in microgravity. Data suggest that transitional flames in earth-gravity at Re<1300 might become laminar in microgravity.

Detection of Extrasolar Planets by Transit Photometry

NASA Technical Reports Server (NTRS)

Borucki, William; Koch, David; Webster, Larry; Dunham, Edward; Witteborn, Fred; Jenkins, Jon; Caldwell, Douglas; Showen, Robert; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

A knowledge of other planetary systems that includes information on the number, size, mass, and spacing of the planets around a variety of star types is needed to deepen our understanding of planetary system formation and processes that give rise to their final configurations. Recent discoveries show that many planetary systems are quite different from the solar system in that they often possess giant planets in short period orbits. The inferred evolution of these planets and their orbital characteristics imply the absence of Earth-like planets near the habitable zone. Information on the properties of the giant-inner planets is now being obtained by both the Doppler velocity and the transit photometry techniques. The combination of the two techniques provides the mass, size, and density of the planets. For the planet orbiting star HD209458, transit photometry provided the first independent confirmation and measurement of the diameter of an extrasolar planet. The observations indicate a planet 1.27 the diameter of Jupiter with 0.63 of its mass (Charbonneau et al. 1999). The results are in excellent agreement with the theory of planetary atmospheres for a planet of the indicated mass and distance from a solar-like star. The observation of the November 23, 1999 transit of that planet made by the Ames Vulcan photometer at Lick Observatory is presented. In the future, the combination of the two techniques will greatly increase the number of discoveries and the richness of the science yield. Small rocky planets at orbital distances from 0.9 to 1.2 AU are more likely to harbor life than the gas giant planets that are now being discovered. However, new technology is needed to find smaller, Earth-like planets, which are about three hundred times less massive than Jupiter-like planets. The Kepler project is a space craft mission designed to discover hundreds of Earth-size planets in and near the habitable zone around a wide variety of stars. To demonstrate that the

Transit Security Procedures Guide

DOT National Transportation Integrated Search

1994-12-01

To protect passenger, employees, revenue, and property, transit systems are encouraged to take a proactive, prevention-oriented systems approach to transit security. This guide is a compilation of materials for planning and improving transit security...

REVISITING {rho}{sup 1} CANCRI e: A NEW MASS DETERMINATION OF THE TRANSITING SUPER-EARTH

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

Endl, Michael; Cochran, William D.; MacQueen, Phillip J.

2012-11-01

We present a mass determination for the transiting super-Earth {rho}{sup 1} Cancri e based on nearly 700 precise radial velocity (RV) measurements. This extensive RV data set consists of data collected by the McDonald Observatory planet search and published data from Lick and Keck observatories. We obtained 212 RV measurements with the Tull Coude Spectrograph at the Harlan J. Smith 2.7 m Telescope and combined them with a new Doppler reduction of the 131 spectra that we have taken in 2003-2004 with the High-Resolution Spectrograph (HRS) at the Hobby-Eberly Telescope for the original discovery of {rho}{sup 1} Cancri e. Usingmore » this large data set we obtain a five-planet Keplerian orbital solution for the system and measure an RV semi-amplitude of K = 6.29 {+-} 0.21 m s{sup -1} for {rho}{sup 1} Cnc e and determine a mass of 8.37 {+-} 0.38 M {sub Circled-Plus }. The uncertainty in mass is thus less than 5%. This planet was previously found to transit its parent star, which allowed them to estimate its radius. Combined with the latest radius estimate from Gillon et al., we obtain a mean density of {rho} = 4.50 {+-} 0.20 g cm{sup -3}. The location of {rho}{sup 1} Cnc e in the mass-radius diagram suggests that the planet contains a significant amount of volatiles, possibly a water-rich envelope surrounding a rocky core.« less

Transitional Care

ERIC Educational Resources Information Center

Naylor, Mary; Keating, Stacen A.

2008-01-01

Transitional care encompasses a broad range of services and environments designed to promote the safe and timely passage of patients between levels of health care and across care settings. High-quality transitional care is especially important for older adults with multiple chronic conditions and complex therapeutic regimens, as well as for their…

Colorado transit resource directory

DOT National Transportation Integrated Search

2003-11-01

The Colorado Transit Resource Directory is a joint publication of the Colorado Association of Transit Agencies (CASTA), the Colorado Department of Transportation (CDOT) and the Federal Transit Administration (FTA). It is intended as a resource and ha...

Subsidence transition during the post-rift stage of the Dongpu Sag, Bohai Bay Basin, NE China: A new geodynamic model

NASA Astrophysics Data System (ADS)

Xu, Han; Wang, Xin-Wen; Yan, Dan-Ping; Qiu, Liang

2018-06-01

The Dongpu Sag, located in the Bohai Bay Basin, NE China, is a Cenozoic continental rift basin. The post-rift evolution of the Dongpu Sag is associated with the development of petroleum reservoirs and has implications for Neogene-Quaternary basin evolution along the eastern margin of Eurasia. To determine the nature and origin of post-rift subsidence in the Dongpu Sag, we apply backstripping, modified strain-rate inversion, and revised finite extension modelling techniques, using data from 14 real and synthetic wells that are intersected by three seismic lines. Our results reveal discrepancies by subsidence based on backstripping of well data (the observed subsidence) minus that predicted by modified strain-rate inversion and revised finite extension modelling (the predicted subsidence). During the Miocene, the observed subsidence was smaller than the predicted subsidence, leaving negative discrepancies referred to here as "insufficient subsidence" ranging from -343 to -96 m. In contrast, during the Pliocene-Quaternary the observed subsidence was greater than the predicted subsidence by +123 to +407 m, which left positive discrepancies referred to as "over-sufficient subsidence". Therefore, we infer a transition from insufficient to over-sufficient subsidence during the post-rift stage. Normal faulting that started at ca. 5.3 Ma is estimated to have produced only ∼20% of the over-sufficient subsidence. Therefore, the remaining over-sufficient subsidence, as well as the preceding insufficient subsidence and the transition between the two, were likely controlled by lithosphere processes. We propose a new tectonic model in which variations in the conditions (e.g. rate, direction, and angle) associated with subduction of the Pacific plate resulted in a change of heat flow decreasing from a linear to a curvilinear pattern, leading to a transition from insufficient to over-sufficient subsidence.

Decaying shock studies of phase transitions in MgO-SiO2 systems: implications for the Super-Earths' interiors

NASA Astrophysics Data System (ADS)

Bolis, R.; Morard, G.; Vinci, T.; Ravasio, A.; Bambrink, E.; Guarguaglini, M.; Koenig, M.; Musella, R.; Françoise, R.; Bouchet, J.; Ozaki, N.; Miyanishi, K.; Sekine, T.; Sakawa, Y.; Sano, T.; Kodama, R.; Guyot, F. J.; Benuzzi, A.

2016-12-01

Mantles of telluric exoplanets, so-called Earth-like and Super-Earths, are expected to be mainly composed of different type of oxides, such as periclase (MgO), enstatite (MgSiO3) and forsterite (Mg2SiO4). Determining the phase diagrams, melting curves and liquid properties of these compounds under extreme pressure (0.2-1 TPa) is crucial to model the internal dynamic of these exoplanets, as the melting of mantle components controls planetary temperature profiles [6]. Experimentally, these planetary thermodynamic states can be achieved with laser-shock compression. Here we present laser-driven decaying shock experiments on MgO, MgSiO3 and Mg2SiO4 samples performed at LULI and GEKKO laser facilities, where we focused 1.2-2.5 ns laser pulses with an intensity between 3-8 1013 W/cm2 exploring pressures between 0.2 and 1 TPa and temperature between 5000 and 30000 K. We determined the thermodynamic states using rear side optical diagnostics. We observed a single transition for MgO associated to melting (at 0.47 TPa ± 0.04 and 9863 ± 812 K) and no evidence of a liquid-liquid transition, dissociation or melting for all the other compounds in the range 150-500 Gpa and 200-800 Gpa respectively for MgSiO3 and Mg2SiO4. Some implications are presented comparing our data experimental and theoretical data found in literature [1, 2, 3, 4, 5]. In particular these results represent a key input to solve the controversy on a possible MgSiO3 liquid-liquid phase transition. Moreover we propose a revision of the phase diagram of MgO, with a lower melting line which results in a lower temperature profile for super-Earths. Finally our data evidence the presence of a poor electrically conducting liquid in the phase diagram of all the studied material, with implications for the modelling of magnetic field generation via dynamo mechanism.[1] McWilliams et al., Science 338 (2012): 1330-1333. [2] Spaulding et al., Physical Review Letters108 (2012): 065701. [3] Root et al., Physical Review

Best practice intervention for post-traumatic stress disorder among transit workers.

PubMed

Bender, Ash; Eynan, Rahel; O'Grady, John; Nisenbaum, Rosane; Shah, Ravi; Links, Paul S

2016-03-09

Transportation industry workers are at high risk for exposure to traumatic incidents in the workplace. A considerable number of those exposed to such incidents will develop post-traumatic stress disorder (PTSD) symptoms, which leads to high rates of absenteeism and are costly to the public transit corporation and workplace safety compensation insurance. To determine whether the newly implemented Best Practice Intervention (BPI) provides superior outcomeswhen compared with Treatment-as-Usual (TAU) interventions in improving workers' rates of return to work (RTW), decreasing duration of time lost from work and overall reduction in severity of PTSD symptoms 6 months after exposure. A sequential mixed methods approach was used with qualitative analysis followed by a pre-post intervention design. Sixty-two participants were recruited to the (TAU) phase of the study and 79 to the (BPI) phase. Significant differences were observed between the TAU and BPI groups in number of lost work days (TAU: 20 days vs. BPI: 52 days, p = 0.02). PTSD symptoms decreased with time (MPPS score: 51.3 vs. 24.35; p < 0.001). One-fifth of the participants (21 %) did not return to work by the end of the 6 months follow-up period. The study demonstrated the value of workplace interventions in improving awareness of psychological symptoms after exposure to a traumatic incident and the value of screening for PTSD symptoms.

The Effect of the Transit of Venus on ACRIM's Total Solar Irradiance Measurements: Implications for Transit Studies of Extrasolar Planets

NASA Astrophysics Data System (ADS)

Schneider, G.; Pasachoff, J. M.; Willson, Richard C.

2006-04-01

We have used the 2004 June 8 transit of Venus (ToV) as a surrogate to test observing methods, strategies, and techniques that are being contemplated for future space missions to detect and characterize extrasolar terrestrial planets (ETPs) as they transit their host stars, notably NASA's Kepler mission, planned for 2008. As an analog to ``Kepler-like'' photometric transit observations, we obtained (spatially unresolved) radiometric observations with the ACRIM 3 instrument on ACRIMSAT at a sampling cadence of 131 s to follow the effect of the ToV on the total solar irradiance (TSI). Contemporaneous high-resolution broadband imagery with NASA's TRACE spacecraft provided, directly, measures of the stellar (solar) astrophysical noise that can intrinsically limit such transit observations. During the Venus transit, which lasted ~5.5 hr, the planet's angular diameter was approximately 1/32 the solar diameter, thus covering ~0.1% of the stellar surface. With our ACRIM 3 data, we measure temporal changes in TSI with a 1 σ per sample (unbinned) uncertainty of approximately 100 mW m-2 (0.007%). A diminution in TSI of ~1.4 W m-2 (~0.1%, closely corresponding to the geometrically occulted area of the photosphere) was measured at mid-transit compared with a mean pre-/post-transit TSI of ~1365.9 W m-2. The radiometric light curve is complex because of the parallactic motion of Venus induced by ACRIMSAT's near-polar orbit, but exhibits the characteristic signature of photospheric limb darkening. These observations serve as a surrogate for future photometric observations of ETPs, such as Kepler will deliver. Detailed analysis of the ToV, a rare event within our own solar system, with time-resolved radiometry augmented with high-resolution imagery, provides a useful analog for investigating the detectability and characterization of ETPs from observations that are anticipated in the near future.

Online transit trip planner for small agencies using Google Transit : final deployment package.

DOT National Transportation Integrated Search

2011-09-01

Google Transit is a public transportation trip planner that enables travelers to obtain information regarding available transit services between a : given origin and given destination. While transit agencies can publish their service information onto...

Transitions: A Personal Perspective.

ERIC Educational Resources Information Center

Wood, Ann Stace

1995-01-01

Distinguishes between unchosen transitions (children maturing and leaving, parents aging, companies downsizing) and chosen ones (moving, divorce, marriage, career changes). Describes the steps one goes through: uneasiness, renewed energy, complaining, exploration, partial transition, and the completed transition. (JOW)

Caltrans : transit funding manual : managing the delivery of transit projects

DOT National Transportation Integrated Search

2001-05-01

This manual attempts to provide a step by step transit funding process. Included in this manual : is an overview of Caltrans Division of Mass Transportation, roles and responsibilities in : assisting local agencies to deliver transit projects. Transi...

Easing the Transition to School: Administrators' Descriptions of Transition to School Activities

ERIC Educational Resources Information Center

Noel, Andrea

2011-01-01

This paper details the early childhood transition activities of three schools in southern Queensland, Australia, as reported by school administrators. The transition programs were analysed using the categories of the Transition to School Matrix of the New South Wales (NSW) Department of Education. Activities fell into the first four categories…

Phase Transitions in Geomorphology

NASA Astrophysics Data System (ADS)

Ortiz, C. P.; Jerolmack, D. J.

2015-12-01

Landscapes are patterns in a dynamic steady-state, due to competing processes that smooth or sharpen features over large distances and times. Geomorphic transport laws have been developed to model the mass-flux due to different processes, but are unreasonably effective at recovering the scaling relations of landscape features. Using a continuum approximation to compare experimental landscapes and the observed landscapes of the earth, one finds they share similar morphodynamics despite a breakdown of classical dynamical similarity between the two. We propose the origin of this effectiveness is a different kind of dynamic similarity in the statistics of initiation and cessation of motion of groups of grains, which is common to disordered systems of grains under external driving. We will show how the existing data of sediment transport points to common signatures with dynamical phase transitions between "mobile" and "immobile" phases in other disordered systems, particularly granular materials, colloids, and foams. Viewing landscape evolution from the lens of non-equilibrium statistical physics of disordered systems leads to predictions that the transition of bulk measurements such as particle flux is continuous from one phase to another, that the collective nature of the particle dynamics leads to very slow aging of bulk properties, and that the dynamics are history-dependent. Recent results from sediment transport experiments support these predictions, suggesting that existing geomorphic transport laws may need to be replaced by a new generation of stochastic models with ingredients based on the physics of disordered phase transitions. We discuss possible strategies for extracting the necessary information to develop these models from measurements of geomorphic transport noise by connecting particle-scale collective dynamics and space-time fluctuations over landscape features.

Temperature and magnetic field induced multiple magnetic transitions in DyAg(2).

PubMed

Arora, Parul; Chattopadhyay, M K; Sharath Chandra, L S; Sharma, V K; Roy, S B

2011-02-09

The magnetic properties of the rare-earth intermetallic compound DyAg(2) are studied in detail with the help of magnetization and heat capacity measurements. It is shown that the multiple magnetic phase transitions can be induced in DyAg(2) both by temperature and magnetic field. The detailed magnetic phase diagram of DyAg(2) is determined experimentally. It was already known that DyAg(2) undergoes an incommensurate to commensurate antiferromagnetic phase transition close to 10 K. The present experimental results highlight the first order nature of this phase transition, and show that this transition can be induced by magnetic field as well. It is further shown that another isothermal magnetic field induced transition or metamagnetic transition exhibited by DyAg(2) at still lower temperatures is also of first order nature. The multiple magnetic phase transitions in DyAg(2) give rise to large peaks in the temperature dependence of the heat capacity below 17 K, which indicates its potential as a magnetic regenerator material for cryocooler related applications. In addition it is found that because of the presence of the temperature and field induced magnetic phase transitions, and because of short range magnetic correlations deep inside the paramagnetic regime, DyAg(2) exhibits a fairly large magnetocaloric effect over a wide temperature window, e.g., between 10 and 60 K.

Out-of-transit Refracted Light in the Atmospheres of Transiting and Non-transiting Exoplanets

NASA Astrophysics Data System (ADS)

Dalba, Paul A.

2017-10-01

Before an exoplanet transit, atmospheric refraction bends light into the line of sight of an observer. The refracted light forms a stellar mirage—a distorted secondary image of the host star. I model this phenomenon and the resultant out-of-transit flux increase across a comprehensive exoplanetary parameter space. At visible wavelengths, Rayleigh scattering limits the detectability of stellar mirages in most exoplanetary systems with semimajor axes ≲ 6 {au}. A notable exception is almost any planet orbiting a late M or ultra-cool dwarf star at ≳ 0.5 {au}, where the maximum relative flux increase is >50 parts per million. Based partly on previous work, I propose that the importance of refraction in an exoplanet system is governed by two angles: the orbital distance divided by the stellar radius and the total deflection achieved by a ray in the optically thin portion of the atmosphere. Atmospheric lensing events caused by non-transiting exoplanets, which allow for exoplanet detection and atmospheric characterization, are also investigated. I derive the basic formalism to determine the total signal-to-noise ratio of an atmospheric lensing event, with application to Kepler data. It is unlikely that out-of-transit refracted light signals are clearly present in Kepler data due to Rayleigh scattering and the bias toward short-period exoplanets. However, observations at long wavelengths (e.g., the near-infrared) are significantly more likely to detect stellar mirages. Lastly, I discuss the potential for the Transiting Exoplanet Survey Satellite to detect refracted light and consider novel science cases enabled by refracted light spectra from the James Webb Space Telescope.

An evaluation of the accuracy of the Federal Transit Administration approved, groundborne noise and vibration prediction model for rail transit systems; a case study for a new subway line using post construction, transit operation measurements

NASA Astrophysics Data System (ADS)

Carman, Richard A.; Reyes, Carlos H.

2005-09-01

The groundborne noise and vibration model developed by Nelson and Saurenman in 1984, now recognized by the Federal Transit Administration as the approved model for new transit system facilities, is entering its third decade of use by engineers and consultants in the transit industry. The accuracy of the model has been explored in the past (e.g., Carman and Wolfe). New data obtained for a recently completed extension to a major heavy rail transit system provides an opportunity to evaluate the accuracy of the model once more. During the engineering design phase of the project, noise and vibration predictions were performed for numerous buildings adjacent to the new subway line. The values predicted by the model were used to determine the need for and type of noise and/or vibration control measures. After the start of transit operations on the new line, noise and vibration measurements were made inside several of the buildings to determine whether the criteria were in fact achieved. The measurement results are compared with the values predicted by the model. The predicted and measured, overall noise and vibration levels show very good agreement, whereas the spectral comparisons indicate some differences. Possible reasons for these differences are offered.

The CaCl2 transition in Stishovite

NASA Astrophysics Data System (ADS)

Cohen, R. E.

2001-12-01

Rutile-structured SiO2, or stishovite, has been the subject of intense theoretical study for the development and testing of theoretical methods.1 The pressure induced phase transition of stishovite to the CaCl2 structure is one of the few cases of phase transitions predicted from first-principles electronic structure theory before being proven experimentally. Such tests are important, because one does not know to what level to trust theoretical predictions unless there are test predictions that are fulfilled. There were some indications of a phase transition from earlier ionic model calculations,3 but confidence in the predicted pressure was low because the model was not sufficiently accurate for the equation of state. Then, Linearized Augmented Plane Wave (LAPW) calculations, which make no assumptions abouyt ionicity, were performed for SiO2, and clearly showed an elastic instability at about 45 GPa.2 Non-hydrostatic experiments showed evidence for a transition, but at about 100 GPa.4 Raman experiments showed softening of the B1g Raman mode frequency, which, if extrapolated, would vanish at about 100 GPa.5 Theory predicted an transition, where the elastic anomaly c11-c12=0, at which point the Raman mode would begin to increase in frequency. A hydrostatic single crystal Raman experiment was done to higher pressures, and the transition was found at about 45-50 GPa, and the Raman spectra were in good agreement with the theoretical predictions.5 Single crystal hydrostatic x-ray studies have verified the transition, and showed that the transition is weakly first-order, with some hysteresis.7 Progress in theoretical studies of stishovite and the transition will be reviewed. 1 Cohen, R. E. In: Silica: Physical Behavior, Geochemistry, and Materials Applications. P. Heaney, C. T. Prewitt and G. V. Gibbs. Washington, D.C., Mineralogical Society of America. 29: 369-402, 1994. 2 Cohen, R. E., In: High Pressure Research in Mineral Physics: Application to Earth and Planetary

Transit labor relations guide

DOT National Transportation Integrated Search

2001-09-01

This report is designed as a guide for those involved in labor relations in the transit industry. It begins with a history of transit labor relations. The economic, political, and legal environment of transit relations is then discussed. A section fo...

Transit detection of a `starshade' at the inner lagrange point of an exoplanet

NASA Astrophysics Data System (ADS)

Gaidos, E.

2017-08-01

All water-covered rocky planets in the inner habitable zones of solar-type stars will inevitably experience a catastrophic runaway climate due to increasing stellar luminosity and limits to outgoing infrared radiation from wet greenhouse atmospheres. Reflectors or scatterers placed near Earth's inner Lagrange point (L_1) have been proposed as a "geoengineering' solution to anthropogenic climate change and an advanced version of this could modulate incident irradiation over many Gyr or `rescue' a planet from the interior of the habitable zone. The distance of the starshade from the planet that minimizes its mass is 1.6 times the Earth-L_1 distance. Such a starshade would have to be similar in size to the planet and the mutual occultations during planetary transits could produce a characteristic maximum at mid-transit in the light curve. Because of a fortuitous ratio of densities, Earth-size planets around G dwarf stars present the best opportunity to detect such an artefact. The signal would be persistent and is potentially detectable by a future space photometry mission to characterize transiting planets. The signal could be distinguished from natural phenomenon, I.e. starspots or cometary dust clouds, by its shape, persistence and transmission spectrum.

Independet Component Analyses of Ground-based Exoplanetary Transits

NASA Astrophysics Data System (ADS)

Silva Martins-Filho, Walter; Griffith, Caitlin Ann; Pearson, Kyle; Waldmann, Ingo; Biddle, Lauren; Zellem, Robert Thomas; Alvarez-Candal, Alvaro

2016-10-01

Most observations of exoplanetary atmospheres are conducted when a "Hot Jupiter" exoplanet transits in front of its host star. These Jovian-sized planets have small orbital periods, on the order of days, and therefore a short transit time, making them more ameanable to observations. Measurements of Hot Jupiter transits must achieve a 10-4 level of accuracy in the flux to determine the spectral modulations of the exoplanetary atmosphere. In order to accomplish this level of precision, we need to extract systematic errors, and, for ground-based measurements, the effects of Earth's atmosphere, from the signal due to the exoplanet, which is several orders of magnitudes smaller. Currently, the effects of the terrestrial atmosphere and the some of the time-dependent systematic errors are treated by dividing the host star by a reference star at each wavelength and time step of the transit. More recently, Independent Component Analyses (ICA) have been used to remove systematic effects from the raw data of space-based observations (Waldmann 2014,2012; Morello et al.,2015,2016). ICA is a statistical method born from the ideas of the blind-source separation studies, which can be used to de-trend several independent source signals of a data set (Hyvarinen and Oja, 2000). One strength of this method is that it requires no additional prior knowledge of the system. Here, we present a study of the application of ICA to ground-based transit observations of extrasolar planets, which are affected by Earth's atmosphere. We analyze photometric data of two extrasolar planets, WASP-1b and GJ3470b, recorded by the 61" Kuiper Telescope at Stewart Observatory using the Harris B and U filters. The presentation will compare the light curve depths and their dispersions as derived from the ICA analysis to those derived by analyses that ratio of the host star to nearby reference stars.References: Waldmann, I.P. 2012 ApJ, 747, 12, Waldamann, I. P. 2014 ApJ, 780, 23; Morello G. 2015 ApJ, 806

Essentials of Transition Planning. Brookes Transition to Adulthood Series

ERIC Educational Resources Information Center

Wehman, Paul

2011-01-01

For young people with disabilities, crossing the bridge to adulthood will be empowering instead of intimidating--when their support teams know the essentials of effective transition planning. Now all the fundamentals of well-crafted transition plans are collected in one concise quick-guide, straight from one of the top authorities on helping young…

Exploring the role of knowledge of condition and psycho-social profiles of young people with epilepsy during transition.

PubMed

Gray, Victoria; Palmer, Lucy; Whelby, Kayleigh; Vinten, Jacqui; Gait, Lucy

2017-08-01

Transitioning from paediatric to adult care can be a particularly challenging time for young people with epilepsy and research has shown that there are a range of factors which may influence a young person's ability to successfully cope with this difficult time. The following study aimed to explore the psychosocial characteristics of this transitioning population, as well as investigate how knowledgeable the young person and their parent/carer are of their own condition throughout transition. Young people with epilepsy were recruited from two specialist epilepsy clinics in the North West and allocated to one of three groups; Group 1 pre-transition, Group 2 transitioning, and Group 3 post-transition. Results found that the young person's knowledge increased significantly throughout transition, whilst parent/carer's knowledge decreased. In addition, anxiety was found to be significantly lower in Group 2 (transitioning group) compared to Group 1 (pre-transition) and Group 3 (post-transition) and a number of significant gender differences were also identified across the groups. The study highlights the importance of considering all relevant psychosocial factors, such as anxiety, gender and the degree of knowledge the individual holds of their own condition during the transition process in order to develop psycho-educational programmes and transition pathways. Copyright © 2017 Elsevier Inc. All rights reserved.

Advances in the Kepler Transit Search Engine

NASA Astrophysics Data System (ADS)

Jenkins, Jon M.

2016-10-01

Twenty years ago, no planets were known outside our own solar system. Since then, the discoveries of ~1500 exoplanets have radically altered our views of planets and planetary systems. This revolution is due in no small part to the Kepler Mission, which has discovered >1000 of these planets and >4000 planet candidates. While Kepler has shown that small rocky planets and planetary systems are quite common, the quest to find Earth's closest cousins and characterize their atmospheres presses forward with missions such as NASA Explorer Program's Transiting Exoplanet Survey Satellite (TESS) slated for launch in 2017 and ESA's PLATO mission scheduled for launch in 2024. These future missions pose daunting data processing challenges in terms of the number of stars, the amount of data, and the difficulties in detecting weak signatures of transiting small planets against a roaring background. These complications include instrument noise and systematic effects as well as the intrinsic stellar variability of the subjects under scrutiny. In this paper we review recent developments in the Kepler transit search pipeline improving both the yield and reliability of detected transit signatures. Many of the phenomena in light curves that represent noise can also trigger transit detection algorithms. The Kepler Mission has expended great effort in suppressing false positives from its planetary candidate catalogs. Over 18,000 transit-like signatures can be identified for a search across 4 years of data. Most of these signatures are artifacts, not planets. Vetting all such signatures historically takes several months' effort by many individuals. We describe the application of machine learning approaches for the automated vetting and production of planet candidate catalogs. These algorithms can improve the efficiency of the human vetting effort as well as quantifying the likelihood that each candidate is truly a planet. This information is crucial for obtaining valid planet occurrence

National transit summaries and trends for the 1995 National Transit Database report year

DOT National Transportation Integrated Search

1996-12-01

The 1995 National Transit Summaries and Trends (NTST) provides an overview of the national mass transit industry. The NTST highlights the aggregate financial and operational characteristics and trends of mass transit for the 5-year period 1991-1995. ...

Metal-insulator transitions

NASA Astrophysics Data System (ADS)

Imada, Masatoshi; Fujimori, Atsushi; Tokura, Yoshinori

1998-10-01

Metal-insulator transitions are accompanied by huge resistivity changes, even over tens of orders of magnitude, and are widely observed in condensed-matter systems. This article presents the observations and current understanding of the metal-insulator transition with a pedagogical introduction to the subject. Especially important are the transitions driven by correlation effects associated with the electron-electron interaction. The insulating phase caused by the correlation effects is categorized as the Mott Insulator. Near the transition point the metallic state shows fluctuations and orderings in the spin, charge, and orbital degrees of freedom. The properties of these metals are frequently quite different from those of ordinary metals, as measured by transport, optical, and magnetic probes. The review first describes theoretical approaches to the unusual metallic states and to the metal-insulator transition. The Fermi-liquid theory treats the correlations that can be adiabatically connected with the noninteracting picture. Strong-coupling models that do not require Fermi-liquid behavior have also been developed. Much work has also been done on the scaling theory of the transition. A central issue for this review is the evaluation of these approaches in simple theoretical systems such as the Hubbard model and t-J models. Another key issue is strong competition among various orderings as in the interplay of spin and orbital fluctuations. Experimentally, the unusual properties of the metallic state near the insulating transition have been most extensively studied in d-electron systems. In particular, there is revived interest in transition-metal oxides, motivated by the epoch-making findings of high-temperature superconductivity in cuprates and colossal magnetoresistance in manganites. The article reviews the rich phenomena of anomalous metallicity, taking as examples Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Ru compounds. The diverse phenomena include strong spin and

Gardner Transition in Physical Dimensions

NASA Astrophysics Data System (ADS)

Hicks, C. L.; Wheatley, M. J.; Godfrey, M. J.; Moore, M. A.

2018-06-01

The Gardner transition is the transition that at mean-field level separates a stable glass phase from a marginally stable phase. This transition has similarities with the de Almeida-Thouless transition of spin glasses. We have studied a well-understood problem, that of disks moving in a narrow channel, which shows many features usually associated with the Gardner transition. We show that some of these features are artifacts that arise when a disk escapes its local cage during the quench to higher densities. There is evidence that the Gardner transition becomes an avoided transition, in that the correlation length becomes quite large, of order 15 particle diameters, even in our quasi-one-dimensional system.

Transitional Leadership: Leadership During Times of Transition, Key Principles, and Considerations for Success.

PubMed

Norbash, Alexander

2017-06-01

To suggest a methodical approach for refining transitional management abilities, including empowerment of a growing leader, leading in an unfamiliar organization or leading in an organization that is changing. Management approaches based on the body of work dealing with leadership studies and transitions and dealing with leadership during times of transition and change management were consolidated and categorized. Transitional leaders can benefit from effective leadership training including defining and prospectively accruing necessary experiences and skills; strengthening information gathering skills; effectively self-assessing; valuing and implementing mentoring; formulating strategy; and communicating. A categorical approach to transitional leadership may be implemented through a systems-based and methodical approach to gaining the definable, and distinct sets of skills and abilities necessary for transitional leadership success. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

SDO's Ultra-high Definition View of 2012 Venus Transit - 304 Angstrom

NASA Image and Video Library

2017-12-08

NASA image captured June 5, 2012. On June 5-6 2012, SDO is collecting images of one of the rarest predictable solar events: the transit of Venus across the face of the sun. This event happens in pairs eight years apart that are separated from each other by 105 or 121 years. The last transit was in 2004 and the next will not happen until 2117. Credit: NASA/SDO, AIA To read more about the 2012 Venus Transit go to: sunearthday.nasa.gov/transitofvenus Add your photos of the Transit of Venus to our Flickr Group here: www.flickr.com/groups/venustransit/ NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

SDO's Ultra-high Definition View of 2012 Venus Transit - 171 Angstrom

NASA Image and Video Library

2017-12-08

NASA image captured June 6, 2012. On June 5-6 2012, SDO is collecting images of one of the rarest predictable solar events: the transit of Venus across the face of the sun. This event happens in pairs eight years apart that are separated from each other by 105 or 121 years. The last transit was in 2004 and the next will not happen until 2117. Credit: NASA/SDO, AIA To read more about the 2012 Venus Transit go to: sunearthday.nasa.gov/transitofvenus Add your photos of the Transit of Venus to our Flickr Group here: www.flickr.com/groups/venustransit/ NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

SDO's Ultra-high Definition View of 2012 Venus Transit - HMI Instrument

NASA Image and Video Library

2012-06-06

NASA image captured June 6, 2012. On June 5-6 2012, SDO is collecting images of one of the rarest predictable solar events: the transit of Venus across the face of the sun. This event happens in pairs eight years apart that are separated from each other by 105 or 121 years. The last transit was in 2004 and the next will not happen until 2117. Credit: NASA/SDO, HMI To read more about the 2012 Venus Transit go to: sunearthday.nasa.gov/transitofvenus Add your photos of the Transit of Venus to our Flickr Group here: www.flickr.com/groups/venustransit/ NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

SDO's Ultra-high Definition View of 2012 Venus Transit - 304 Angstrom

NASA Image and Video Library

2017-12-08

NASA image captured June 6, 2012. On June 5-6 2012, SDO is collecting images of one of the rarest predictable solar events: the transit of Venus across the face of the sun. This event happens in pairs eight years apart that are separated from each other by 105 or 121 years. The last transit was in 2004 and the next will not happen until 2117. Credit: NASA/SDO, AIA To read more about the 2012 Venus Transit go to: sunearthday.nasa.gov/transitofvenus Add your photos of the Transit of Venus to our Flickr Group here: www.flickr.com/groups/venustransit/ NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

SDO's Ultra-high Definition View of 2012 Venus Transit - 193 Angstrom

NASA Image and Video Library

2017-12-08

NASA image captured June 6, 2012. On June 5-6 2012, SDO is collecting images of one of the rarest predictable solar events: the transit of Venus across the face of the sun. This event happens in pairs eight years apart that are separated from each other by 105 or 121 years. The last transit was in 2004 and the next will not happen until 2117. Credit: NASA/SDO, AIA To read more about the 2012 Venus Transit go to: sunearthday.nasa.gov/transitofvenus Add your photos of the Transit of Venus to our Flickr Group here: www.flickr.com/groups/venustransit/ NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

SDO's Ultra-high Definition View of 2012 Venus Transit -- Path Sequence

NASA Image and Video Library

2017-12-08

NASA image captured June 5-6, 2012. On June 5-6 2012, SDO is collecting images of one of the rarest predictable solar events: the transit of Venus across the face of the sun. This event happens in pairs eight years apart that are separated from each other by 105 or 121 years. The last transit was in 2004 and the next will not happen until 2117. Credit: NASA/SDO, AIA To read more about the 2012 Venus Transit go to: sunearthday.nasa.gov/transitofvenus Add your photos of the Transit of Venus to our Flickr Group here: www.flickr.com/groups/venustransit/ NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

SDO's Ultra-high Definition View of 2012 Venus Transit - 171 Angstrom

NASA Image and Video Library

2017-12-08

NASA image captured June 5, 2012. On June 5-6 2012, SDO is collecting images of one of the rarest predictable solar events: the transit of Venus across the face of the sun. This event happens in pairs eight years apart that are separated from each other by 105 or 121 years. The last transit was in 2004 and the next will not happen until 2117. Credit: NASA/SDO, AIA To read more about the 2012 Venus Transit go to: sunearthday.nasa.gov/transitofvenus Add your photos of the Transit of Venus to our Flickr Group here: www.flickr.com/groups/venustransit/ NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Career Development Programming Strategies for Transitioning Incarcerated Adolescents to the World of Work

ERIC Educational Resources Information Center

Waintrup, Miriam G.; Unruh, Deanne K.

2008-01-01

Formerly incarcerated adolescents with disabilities face additional barriers to a successful transition to adulthood when released from the youth correctional facility often with societal expectations of transitioning directly to adulthood. Employment and post-secondary enrollment may serve as protective factors and reduce the likelihood of future…

National transit summaries and trends for the 1994 National Transit Database report year

DOT National Transportation Integrated Search

1996-04-01

The 1994 National Transit Summaries and Trends (NTST) provides an overview of the national mass transit industry. The NTST highlights the aggregate financial and operational characteristics and trends of mass transit for the 5-year period 1990-1994 a...

Noise Assessment of the Greater Cleveland Regional Transit Authority Heavy Rail Transit Authority

DOT National Transportation Integrated Search

1978-10-01

The report describes the noise climate on and near the Greater Cleveland Regional Transit Authority (RTA), formerly the Cleveland Transit System (CTS), Airport Line. The RTA urban rail transit line has approximately 19 miles of two-way revenue track ...

Preparing for TESS: Precision Ground-based Light-curves of Newly Discovered Transiting Exoplanets

NASA Astrophysics Data System (ADS)

Li, Yiting; Stefansson, Gudmundur; Mahadevan, Suvrath; Monson, Andy; Hebb, Leslie; Wisniewski, John; Huehnerhoff, Joseph

2018-01-01

NASA’s Transiting Exoplanet Survey Satellite (TESS), to be launched in early 2018, is expected to catalog a myriad of transiting exoplanet candidates ranging from Earth-sized to gas giants, orbiting a diverse range of stellar types in the solar neighborhood. In particular, TESS will find small planets orbiting the closest and brightest stars, and will enable detailed atmospheric characterizations of planets with current and future telescopes. In the TESS era, ground-based follow-up resources will play a critical role in validating and confirming the planetary nature of the candidates TESS will discover. Along with confirming the planetary nature of exoplanet transits, high precision ground-based transit observations allow us to put further constraints on exoplanet orbital parameters and transit timing variations. In this talk, we present new observations of transiting exoplanets recently discovered by the K2 mission, using the optical diffuser on the 3.5m ARC Telescope at Apache Point Observatory. These include observations of the mini-Neptunes K2-28b and K2-104b orbiting early-to-mid M-dwarfs. In addition, other recent transit observations performed using the robotic 30cm telescope at Las Campanas Observatory in Chile will be presented.

Examining hydrogen transitions.

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

Plotkin, S. E.; Energy Systems

2007-03-01

This report describes the results of an effort to identify key analytic issues associated with modeling a transition to hydrogen as a fuel for light duty vehicles, and using insights gained from this effort to suggest ways to improve ongoing modeling efforts. The study reported on here examined multiple hydrogen scenarios reported in the literature, identified modeling issues associated with those scenario analyses, and examined three DOE-sponsored hydrogen transition models in the context of those modeling issues. The three hydrogen transition models are HyTrans (contractor: Oak Ridge National Laboratory), MARKAL/DOE* (Brookhaven National Laboratory), and NEMS-H2 (OnLocation, Inc). The goals ofmore » these models are (1) to help DOE improve its R&D effort by identifying key technology and other roadblocks to a transition and testing its technical program goals to determine whether they are likely to lead to the market success of hydrogen technologies, (2) to evaluate alternative policies to promote a transition, and (3) to estimate the costs and benefits of alternative pathways to hydrogen development.« less

Isothermal lipid phase transitions.

PubMed

Cevc, G

1991-03-01

In liotropic lipid systems phase transitions can be induced isothermally by changing the solvent concentration or composition; alternatively, lipid composition can be modified by (bio)chemical means. The probability for isothermal phase transitions increases with the decreasing transition entropy; it is proportional to the magnitude of the transition temperature shift caused by transformation-inducing system variation. Manipulations causing large thermodynamic effects, such as lipid (de)hydration, binding of protons or divalent ions and macromolecular adsorption, but also close bilayer approach are, therefore, likely to cause structural lipid change(s) at a constant temperature. Net lipid charges enhance the membrane susceptibility to salt-induced isothermal phase transitions; a large proportion of this effect is due to the bilayer dehydration, however, rather than being a consequence of the decreased Coulombic electrostatic interactions. Membrane propensity for isothermal phase transitions, consequently, always increases with the hydrophilicity of the lipid heads, as well as with the desaturation and shortening of the lipid chains. Upon a phase change at a constant temperature, some of the interfacially bound solutes (e.g. protons or calcium) are released in the solution. Membrane permeability and fusogenicity simultaneously increase. In mixed systems, isothermal phase transitions, moreover, may result in lateral phase separation. All this opens up ways for the involvement of isothermal phase transitions in the regulation of biological processes.

Cyclotron transitions of bound ions

NASA Astrophysics Data System (ADS)

Bezchastnov, Victor G.; Pavlov, George G.

2017-06-01

A charged particle in a magnetic field possesses discrete energy levels associated with particle rotation around the field lines. The radiative transitions between these levels are the well-known cyclotron transitions. We show that a bound complex of particles with a nonzero net charge displays analogous transitions between the states of confined motion of the entire complex in the field. The latter bound-ion cyclotron transitions are affected by a coupling between the collective and internal motions of the complex and, as a result, differ from the transitions of a "reference" bare ion with the same mass and charge. We analyze the cyclotron transitions for complex ions by including the coupling within a rigorous quantum approach. Particular attention is paid to comparison of the transition energies and oscillator strengths to those of the bare ion. Selection rules based on integrals of collective motion are derived for the bound-ion cyclotron transitions analytically, and the perturbation and coupled-channel approaches are developed to study the transitions quantitatively. Representative examples are considered and discussed for positive and negative atomic and cluster ions.

Small City Transit : Evansville, Indiana : A Low Subsidy Transit Service

DOT National Transportation Integrated Search

1976-03-01

Evansville, Indiana, is an illustration of a transit service in which a large percentage of operating costs are obtained from fare-box revenues. This case study is one of thirteen examples of a transit service in a small community. The background of ...

Public transit risk management : a handbook for public transit executives

DOT National Transportation Integrated Search

1978-12-01

Transit is seen by insurers as a risk with high loss potential. Since people are transported in large numbers, a single accident may yield many claims. One solution to this insurance situation that has been employed by transit system operators is to ...

Nonlinear Dynamics of the Superfluid Transition: What may We learn on orbit?

NASA Technical Reports Server (NTRS)

Duncan, Rob

2003-01-01

Linear response (specifically, Fourier's Law) in He-4 has been observed to fail in heat flow experiments near the superfluid transition. A detailed analysis of the data suggests that the hydrostatic pressure gradient across the helium column limits the divergence of the correlation length in our earth-based experiments. This is consistent with other observations, such as the surprising lack of mutual friction and hysteresis near the superfluid transition, and a 'rounding' of the transition that appears to be independent of heat flux in the low heat flux limit. I will discuss these unusual results from earth-based measurements, and will show predictions for the very different results that may result when we make our measurements on orbit as part of the M1 Mission of the Low- Temperature, Microgravity Physics Facility. This work has been funded by the Fundamental Physics Discipline within the Physical Sciences Research Office of NASA, and is conducted by the DYNAMX (UNM) and CQ (Caltech) Groups, with assistance from the Low Temperature Science and Quantum Sensors Group at JPL.

The Kepler-19 System: A Thick-envelope Super-Earth with Two Neptune-mass Companions Characterized Using Radial Velocities and Transit Timing Variations

NASA Astrophysics Data System (ADS)

Malavolta, Luca; Borsato, Luca; Granata, Valentina; Piotto, Giampaolo; Lopez, Eric; Vanderburg, Andrew; Figueira, Pedro; Mortier, Annelies; Nascimbeni, Valerio; Affer, Laura; Bonomo, Aldo S.; Bouchy, Francois; Buchhave, Lars A.; Charbonneau, David; Collier Cameron, Andrew; Cosentino, Rosario; Dressing, Courtney D.; Dumusque, Xavier; Fiorenzano, Aldo F. M.; Harutyunyan, Avet; Haywood, Raphaëlle D.; Johnson, John Asher; Latham, David W.; Lopez-Morales, Mercedes; Lovis, Christophe; Mayor, Michel; Micela, Giusi; Molinari, Emilio; Motalebi, Fatemeh; Pepe, Francesco; Phillips, David F.; Pollacco, Don; Queloz, Didier; Rice, Ken; Sasselov, Dimitar; Ségransan, Damien; Sozzetti, Alessandro; Udry, Stéphane; Watson, Chris

2017-05-01

We report a detailed characterization of the Kepler-19 system. This star was previously known to host a transiting planet with a period of 9.29 days, a radius of 2.2 R ⊕, and an upper limit on the mass of 20 M ⊕. The presence of a second, non-transiting planet was inferred from the transit time variations (TTVs) of Kepler-19b over eight quarters of Kepler photometry, although neither the mass nor period could be determined. By combining new TTVs measurements from all the Kepler quarters and 91 high-precision radial velocities obtained with the HARPS-N spectrograph, using dynamical simulations we obtained a mass of 8.4 ± 1.6 M ⊕ for Kepler-19b. From the same data, assuming system coplanarity, we determined an orbital period of 28.7 days and a mass of 13.1 ± 2.7 M ⊕ for Kepler-19c and discovered a Neptune-like planet with a mass of 20.3 ± 3.4 M ⊕ on a 63-day orbit. By comparing dynamical simulations with non-interacting Keplerian orbits, we concluded that neglecting interactions between planets may lead to systematic errors that can hamper the precision in the orbital parameters when the data set spans several years. With a density of 4.32 ± 0.87 g cm-3 (0.78 ± 0.16 ρ ⊕) Kepler-19b belongs to the group of planets with a rocky core and a significant fraction of volatiles, in opposition to low-density planets characterized only by transit time variations and an increasing number of rocky planets with Earth-like density. Kepler-19 joins the small number of systems that reconcile transit timing variation and radial velocity measurements.

Boundary Layer Transition Results From STS-114

NASA Technical Reports Server (NTRS)

Berry, Scott A.; Horvath, Thomas J.; Cassady, Amy M.; Kirk, Benjamin S.; Wang, K. C.; Hyatt, Andrew J.

2006-01-01

The tool for predicting the onset of boundary layer transition from damage to and/or repair of the thermal protection system developed in support of Shuttle Return to Flight is compared to the STS-114 flight results. The Boundary Layer Transition (BLT) Tool is part of a suite of tools that analyze the aerothermodynamic environment of the local thermal protection system to allow informed disposition of damage for making recommendations to fly as is or to repair. Using mission specific trajectory information and details of each damage site or repair, the expected time of transition onset is predicted to help determine the proper aerothermodynamic environment to use in the subsequent thermal and stress analysis of the local structure. The boundary layer transition criteria utilized for the tool was developed from ground-based measurements to account for the effect of both protuberances and cavities and has been calibrated against flight data. Computed local boundary layer edge conditions provided the means to correlate the experimental results and then to extrapolate to flight. During STS-114, the BLT Tool was utilized and was part of the decision making process to perform an extravehicular activity to remove the large gap fillers. The role of the BLT Tool during this mission, along with the supporting information that was acquired for the on-orbit analysis, is reviewed. Once the large gap fillers were removed, all remaining damage sites were cleared for reentry as is. Post-flight analysis of the transition onset time revealed excellent agreement with BLT Tool predictions.

Evaluation of Achieving a College Education Plus: A Credit-Based Transition Program

ERIC Educational Resources Information Center

Luna, Gaye; Fowler, Michael

2011-01-01

This ex post facto study evaluated Achieving a College Education (ACE) Plus program, a credit-based transition program between a high school district and a community college. Achieving a College Education Plus is an early outreach program. It is designed to aid at-risk students in graduating from high school and making a smooth transition to…

Chinese-Born International Students' Transition Experiences from Study to Work in New Zealand

ERIC Educational Resources Information Center

Dyer, Suzette; Lu, Fen

2010-01-01

A growing number of Chinese-born international students are seeking permanent residency and paid employment in New Zealand after graduation. As yet, little is known about their post-study transitions to permanent residency and paid employment. This article reports on research investigating the transition experiences of 10 Chinese-born…

Transition in Physical Recreation and Students with Cognitive Disabilities: Graduate and Parent Perspectives

ERIC Educational Resources Information Center

Roth, Kristi; Pyfer, Jean; Huettig, Carol

2007-01-01

The purpose of this study was to investigate the perceived impact of physical recreation transition programming on individuals with cognitive disabilities and generate strategies for improved transition. Interviews were completed with 17 young adults who were one to three years post graduation. Interviews determined graduate's perception of their…

Resonant Two-Photon Transitions

NASA Astrophysics Data System (ADS)

Apanasevich, P. A.; Timofeeva, G. I.

2018-05-01

We have developed a theory for a two-photon transition when the frequencies of the absorbed or emitted radiation are in resonance with transitions to the same intermediate level in the medium. We have determined the conditions under which such resonant two-photon transitions can play an important role.

Structural phases arising from reconstructive and isostructural transitions in high-melting-point oxides under hydrostatic pressure: A first-principles study

NASA Astrophysics Data System (ADS)

Tian, Hao; Kuang, Xiao-Yu; Mao, Ai-Jie; Yang, Yurong; Xu, Changsong; Sayedaghaee, S. Omid; Bellaiche, L.

2018-01-01

High-melting-point oxides of chemical formula A B O3 with A =Ca , Sr, Ba and B =Zr , Hf are investigated as a function of hydrostatic pressure up to 200 GPa by combining first-principles calculations with a particle swarm optimization method. Ca- and Sr-based systems: (1) first undergo a reconstructive phase transition from a perovskite state to a novel structure that belongs to the post-post-perovskite family and (2) then experience an isostructural transition to a second, also new post-post-perovskite state at higher pressures, via the sudden formation of a specific out-of-plane B -O bond. In contrast, the studied Ba compounds evolve from a perovskite phase to a third novel post-post-perovskite structure via another reconstructive phase transition. The original characteristics of these three different post-post-perovskite states are emphasized. Unusual electronic properties, including significant piezochromic effects and an insulator-metal transition, are also reported and explained.

Post-School Horizons: New Zealand's Neo-Liberal Generation in Transition

ERIC Educational Resources Information Center

Nairn, Karen; Higgins, Jane; Ormond, Adreanne

2007-01-01

Dominant conceptions of the world infuse educational experiences for young people in implicit rather than explicit ways--through becoming, as Stuart Hall argues, "the horizon of the taken-for-granted". In this article we explore these horizons as experienced by New Zealand's neo-liberal generation, currently "in transition"…

Mantle transition zone structure beneath the Canadian Shield

NASA Astrophysics Data System (ADS)

Thompson, D. A.; Helffrich, G. R.; Bastow, I. D.; Kendall, J. M.; Wookey, J.; Eaton, D. W.; Snyder, D. B.

2010-12-01

The Canadian Shield is underlain by one of the deepest and most laterally extensive continental roots on the planet. Seismological constraints on the mantle structure beneath the region are presently lacking due to the paucity of stations in this remote area. Presented here is a receiver function study on transition zone structure using data from recently deployed seismic networks from the Hudson Bay region. High resolution images based on high signal-to-noise ratio data show clear arrivals from the 410 km and 660 km discontinuities, revealing remarkably little variation in transition zone structure. Transition zone thickness is close to the global average (averaging 245 km across the study area), and any deviations in Pds arrival time from reference Earth models can be readily explained by upper-mantle velocity structure. The 520 km discontinuity is not a ubiquitous feature, and is only weakly observed in localised areas. These results imply that the Laurentian root is likely confined to the upper-mantle and if any mantle downwelling exists, possibly explaining the existence of Hudson Bay, it is also confined to the upper 400 km. Any thermal perturbations at transition zone depths associated with the existence of the root, whether they be cold downwellings or elevated temperatures due to the insulating effect of the root, are thus either non-existent or below the resolution of the study.

Theory of Valence Transition

NASA Astrophysics Data System (ADS)

Misawa, S.; Takano, F.

1981-01-01

The valence transition phenomena occurring in rare-earth compounds are studied by using the periodic Anderson model with the electron-phonon coupling. This electron-phonon interaction G is treated in the Hartree-Fock approximation. The Coulomb repulsion U between f-electrons on the same site is taken to be ∞, and the decoupling method of Roth is used for the higher order Green function considering the mixing interaction to be small. We put the condition that the total number of electrons is a constant, and calculate the numbers of f- and d-electrons as functions of the original energy of f-electron by using the Green functions. The first order transition is shown to occur if G ≳ (1/2)W, where W is the width of the original d-band. The energy of f-electron at which the insulator and the metallic phase have the same ground state energy is calculated asɛc ≃ (1/2)(G-(1/2)W) + (2V^2/W) log |(G-W/2)/(G+W/2)|- (V^2/8W) log | (G-W/2)(G-(3/2)W) |. The magnetic susceptibilities of both phases are also calculated, but the result is not good, showing the decoupling method used here is not appropriate for the calculation of magnetic properties.

Dependence of transition width on current and critical current in transition-edge sensors

NASA Astrophysics Data System (ADS)

Morgan, K. M.; Pappas, C. G.; Bennett, D. A.; Gard, J. D.; Hays-Wehle, J. P.; Hilton, G. C.; Reintsema, C. D.; Schmidt, D. R.; Ullom, J. N.; Swetz, D. S.

2017-05-01

In superconducting transition-edge sensor X-ray detectors, we observe that as the thermal conductance (G) to the heat bath increases, the resistive transition broadens. Consequently, the sensitivity of films to deposited energy worsens. Using a two-fluid model for the superconducting-to-normal transition in a thin film, we show that this broadening can be attributed to the larger current (I0) necessary for biasing the film at a given point in the transition for higher-G devices, resulting in a higher Ic0/I0 ratio (Ic0 is the film's critical current at zero temperature). To recover a sharper transition, we fabricated rectangular films with varying numbers of internal normal-metal structures while keeping G constant, allowing the independent variation of both I0 and Ic0. We show that it is possible to manipulate the transition width and G independently, thus enabling fast thermal sensors with an excellent energy resolution.

Wetting transition on patterned surfaces: transition states and energy barriers.

PubMed

Ren, Weiqing

2014-03-18

We study the wetting transition on microstructured hydrophobic surfaces. We use the string method [J. Chem. Phys. 2007, 126, 164103; J. Chem. Phys. 2013, 138, 134105] to accurately compute the transition states, the energy barriers, and the minimum energy paths for the wetting transition from the Cassie-Baxter state to the Wenzel state. Numerical results are obtained for the wetting of a hydrophobic surface textured with a square lattice of pillars. It is found that the wetting of the solid substrate occurs via infiltration of the liquid in a single groove, followed by lateral propagation of the liquid front. The propagation of the liquid front proceeds in a stepwise manner, and a zipping mechanism is observed during the infiltration of each layer. The minimum energy path for the wetting transition goes through a sequence of intermediate metastable states, whose wetted areas reflect the microstructure of the patterned surface. We also study the dependence of the energy barrier on the drop size and the gap between the pillars.

Early Earth slab stagnation

NASA Astrophysics Data System (ADS)

Agrusta, R.; Van Hunen, J.

2016-12-01

At present day, the Earth's mantle exhibits a combination of stagnant and penetrating slabs within the transition zone, indicating a intermittent convection mode between layered and whole-mantle convection. Isoviscous thermal convection calculations show that in a hotter Earth, the natural mode of convection was dominated by double-layered convection, which may imply that slabs were more prone to stagnate in the transition zone. Today, slab penetration is to a large extent controlled by trench mobility for a plausible range of lower mantle viscosity and Clapeyron slope of the mantle phase transitions. Trench mobility is, in turn, governed by slab strength and density and upper plate forcing. In this study, we systematically investigate the slab-transition zone internation in the Early Earth, using 2D self-consistent numerical subduction models. Early Earth's higher mantle temperature facilitates decoupling between the plates and the underlying asthenosphere, and may result in slab sinking almost without trench retreat. Such behaviour together with a low resistance of a weak lower mantle may allow slabs to penetrate. The ability of slab to sink into the lower mantle throughout Earth's history may have important implications for Earth's evolution: it would provide efficient mass and heat flux through the transition zone therefore provide an efficient way to cool and mix the Earth's mantle.

Transit operator absenteeism.

DOT National Transportation Integrated Search

1985-01-01

A nationwide survey of transit operators indicated that absenteeism among transit operators is a significant problem and that the associated costs are substantial. The objective of the research reported here was to determine the scope of operator abs...

High Precision Photometry of Bright Transiting Exoplanet Hosts

NASA Astrophysics Data System (ADS)

Wilson, Maurice; Eastman, Jason; Johnson, John A.

2016-01-01

Within the past two decades, the successful search for exoplanets and the characterization of their physical properties have shown the immense progress that has been made towards finding planets with characteristics similar to Earth. For most exoplanets with a radius about the size of Earth, evaluating their physical properties, such as the mass, radius and equilibrium temperature, cannot be determined with satisfactory precision. The MINiature Exoplanet Radial Velocity Array (MINERVA) was recently built to obtain spectroscopic and photometric measurements to find, confirm, and characterize Earth-like exoplanets. MINERVA's spectroscopic survey targets the brightest, nearby stars which are well-suited to the array's capabilities, while its primary photometric goal is to search for transits around these bright targets. Typically, it is difficult to find satisfactory comparison stars within a telescope's field of view when the primary target is very bright. This issue is resolved by using one of MINERVA's telescopes to observe the primary bright star while the other telescopes observe a distinct field of view that contains satisfactory bright comparison stars. We describe the code used to identify nearby comparison stars, schedule the four telescopes, produce differential photometry from multiple telescopes, and show the first results from this effort.This work has been funded by the Ronald E. McNair Post-Baccalaureate Achievement Program, the ERAU Honors Program, the ERAU Undergraduate Research Spark Fund, and the Banneker Institute at the Harvard-Smithsonian Center for Astrophysics.

The transition to modernity and chronic disease: mismatch and natural selection.

PubMed

Corbett, Stephen; Courtiol, Alexandre; Lummaa, Virpi; Moorad, Jacob; Stearns, Stephen

2018-05-09

The Industrial Revolution and the accompanying nutritional, epidemiological and demographic transitions have profoundly changed human ecology and biology, leading to major shifts in life history traits, which include age and size at maturity, age-specific fertility and lifespan. Mismatch between past adaptations and the current environment means that gene variants linked to higher fitness in the past may now, through antagonistic pleiotropic effects, predispose post-transition populations to non-communicable diseases, such as Alzheimer disease, cancer and coronary artery disease. Increasing evidence suggests that the transition to modernity has also altered the direction and intensity of natural selection acting on many traits, with important implications for public and global health.

Perspectives of school-work transitions among youth with spina bifida, their parents and health care providers.

PubMed

Lindsay, Sally; McPherson, Amy C; Maxwell, Joanne

2017-04-01

Purpose Youth with disabilities encounter many challenges in finding employment and transitioning to post-secondary education. In this article, we explore the nature of school-work transitions for youth with spina bifida, which few studies have previously addressed. Method We conducted in-depth interviews with 44 participants (nine youth and 12 young adults with spina bifida, 11 parents and 12 clinicians). We analyzed our data using a qualitative content analysis approach. Results We identified several enablers to school-work transitions, including professional support, social support and school accommodations. Lacking such support created several challenges for youth with spina bifida. We also identified several barriers to school-work transitions, including lack of education and information on finances, housing and transportation; discrimination and stigma; and challenges coping with spina bifida at school and work. Conclusions Although some supports are available, youth with spina bifida encounter many challenges in transitioning to post-secondary education and employment. With clinicians at the helm, efforts should be put in place within the health and social services system to better prepare youth, as they transition to adulthood, to become connected to appropriate information and resources to help them to succeed in their school and employment goals. Implications for Rehabilitation Youth with spina bifida encounter many challenges in transitioning to post-secondary education or work. Clinicians, educators and parents should continue to support youth with spina bifida in choosing their vocations, setting career goals and developing career plans. Starting from a young age, parents, clinicians and educators should help youth with spina bifida prepare for school work transitions by fostering their independence, life skills and self-management of spina bifida-related symptoms. Clinicians and educators should help connect youth with spina bifida to appropriate

International Space Station: Transitional Platform for Moon and Mars

NASA Technical Reports Server (NTRS)

Greeniesen, Michael C.

2006-01-01

Humans on the path to Mars are employing the Space Station to better understand the Life Sciences issues during long duration space flight. In this phase the problems, for example, of bone loss, skeletal muscle atrophy and radiation will be prioritized for countermeasure development. This presentation will feature NASA's critical path to the Moon and Mars as the initial blueprint for addressing these Human Life Sciences challenges necessary to accomplish a successful Mars transit, surface exploration and return to Earth. A Moon base will be the test bed for resolving the engineering obstacles for later establishment of the Mars Crew Habitat. Current engineering concept scenarios for Moon and Mars bases plus Mars transit vehicles will receive the final focus.

Earthscape: Transitions toward World Order. The Whole Earth Papers, No. 12.

ERIC Educational Resources Information Center

Mische, Patricia; And Others

The five articles in this booklet focus on positive social, political, and economic responses to world problems. The first article, "Earthscape: Transitions Toward World Order," by Patricia Mische, outlines major biological, historical, and cultural transformations which the world has undergone since the beginnings of recorded history and…

Correlation-based Transition Modeling for External Aerodynamic Flows

NASA Astrophysics Data System (ADS)

Medida, Shivaji

Conventional turbulence models calibrated for fully turbulent boundary layers often over-predict drag and heat transfer on aerodynamic surfaces with partially laminar boundary layers. A robust correlation-based model is developed for use in Reynolds-Averaged Navier-Stokes simulations to predict laminar-to-turbulent transition onset of boundary layers on external aerodynamic surfaces. The new model is derived from an existing transition model for the two-equation k-omega Shear Stress Transport (SST) turbulence model, and is coupled with the one-equation Spalart-Allmaras (SA) turbulence model. The transition model solves two transport equations for intermittency and transition momentum thickness Reynolds number. Experimental correlations and local mean flow quantities are used in the model to account for effects of freestream turbulence level and pressure gradients on transition onset location. Transition onset is triggered by activating intermittency production using a vorticity Reynolds number criterion. In the new model, production and destruction terms of the intermittency equation are modified to improve consistency in the fully turbulent boundary layer post-transition onset, as well as ensure insensitivity to freestream eddy viscosity value specified in the SA model. In the original model, intermittency was used to control production and destruction of turbulent kinetic energy. Whereas, in the new model, only the production of eddy viscosity in SA model is controlled, and the destruction term is not altered. Unlike the original model, the new model does not use an additional correction to intermittency for separation-induced transition. Accuracy of drag predictions are improved significantly with the use of the transition model for several two-dimensional single- and multi-element airfoil cases over a wide range of Reynolds numbers. The new model is able to predict the formation of stable and long laminar separation bubbles on low-Reynolds number airfoils that

2D Micro-XAS mapping in Diamond Anvil Cell: Application for Post-Spinel Transition

NASA Astrophysics Data System (ADS)

Leonid, D.; Narygina, O.; Kantor, I.; Pascarelli, S.; Aquilanti, G.; Munoz, M.

2007-12-01

Energy Dispersive X-ray Absorption Spectroscopy (EDXAS) is a now a well-established method which has been applied to a broad range of applications. The advantages of an energy dispersive spectrometer, that features no movement of optics during acquisition leading to an enhanced stability of energy scale, spot size and position, combined with a micron sized spot and the option of fluorescence detection, has made it possible to address 2- dimensional mapping with micron resolution on heterogeneous samples, providing full XAS information on each pixel. It is worth noting that due to the absence of mechanical scanning of the monochromator, the spatial resolution is not affected by the energy scan and remains fixed to the dimensions of the probe. In addition, the energy scale is preserved. Moreover, the dwell time per pixel is short enough to make it practically possible to acquire 100 x 100 pixel images in a few hours. We tested 2D mapping in transmission mode to perform "in-situ" investigations in the diamond anvil cell. Maps of redox and speciation at extreme conditions of pressure and temperature yield information on possible phase transitions and/or chemical reactions that occur at P and T conditions in the Earth interiors. As test sample, we chose a major component of Earth's transition zone, ringwoodite [γ-(Mg,Fe)2SiO4]. Sample synthesized in large-volume press at 19 GPa and 1700 C from natural olivine (Mg0.88,Fe0.12)2SiO4 was polished, loaded into the DAC, compressed to desire pressure, and laser-heated. We aquired Fe K-edge XANES maps at different pressures, up to ~ 40 GPa, before and after laser heating, covering for each map an area of 200 x 200 m2 at 5 m resolution. We found that laser heating does not result in re-distribution of iron between heated and non-heated areas. Within precision of measurements there are no detectable changes in iron oxidation state upon decomposition of ringwoodite in to silicate perovskite and magnesowüstite. We also

Metal–insulator transition in a transition metal dichalcogenide: Dependence on metal contacts

NASA Astrophysics Data System (ADS)

Shimazu, Y.; Arai, K.; Iwabuchi, T.

2018-03-01

Transition metal dichalcogenides are promising layered materials for realizing novel nanoelectronic and nano-optoelectronic devices. Molybdenum disulfide (MoS2), a typical transition metal dichalcogenide, has been extensively investigated due to the presence of a sizable band gap, which enables the use of MoS2 as a channel material in field-effect transistors (FET). The gate-voltage-tunable metal–insulator transition and superconductivity using MoS2 have been demonstrated in previous studies. These interesting phenomena can be considered as quantum phase transitions in two-dimensional systems. In this study, we observed that the transport properties of thin MoS2 flakes in FET geometry significantly depend on metal contacts. On comparing Ti/Au with Al contacts, it was found that the threshold voltages for FET switching and metal–insulator transition were considerably lower for the device with Al contacts. This result indicated the significant influence of the Al contacts on the properties of MoS2 devices.

A systematic review of mentorship programs to facilitate transition to post-secondary education and employment for youth and young adults with disabilities.

PubMed

Lindsay, Sally; R Hartman, Laura; Fellin, Melissa

2016-07-01

Youth with disabilities experience barriers in transitioning to Post-Secondary Education (PSE) and employment. Mentorship programs provide a promising approach to supporting youth through those transitions. This paper aims to identify the effective components of mentorship programs and describe participants' experiences. We undertook a systematic review of mentorship interventions for youth and young adults with disabilities. We searched seven electronic databases for peer-reviewed articles published in English between 1980 and 2014. We included articles that examined mentorship interventions focused on PSE or employment outcomes among youth, aged thirty or younger, with physical, developmental, or cognitive disabilities. Of the 5068 articles identified, 22 met the inclusion criteria. For seven mentorship interventions, at least one significant improvement was reported in school- or work-related outcomes. Mentorship programs with significant outcomes were often structured, delivered in group-based or mixed formats, and longer in duration (>6 months). Mentors acted as role models, offered advice, and provided mentees with social and emotional support. Evidence suggests that mentorship programs may be effective for helping youth with disabilities transition to PSE or employment. More rigorously designed studies are needed to document the impact of mentorship programs on school and vocational outcomes for youth with disabilities. Implications for Rehabilitation Mentorship interventions have the potential to effectively support youth with disabilities as they transition to post-secondary education and employment. Youth should consider participating in formal mentorship interventions, and clinicians and educators should encourage them to do so, to enhance social, educational, and vocational outcomes. When developing interventions, clinicians should consider incorporating the effective components (i.e. duration, content, format) of mentorship interventions identified in

Conservation in the involvement of heterochronic genes and hormones during developmental transitions.

PubMed

Faunes, Fernando; Larraín, Juan

2016-08-01

Developmental transitions include molting in some invertebrates and the metamorphosis of insects and amphibians. While the study of Caenorhabditis elegans larval transitions was crucial to determine the genetic control of these transitions, Drosophila melanogaster and Xenopus laevis have been classic models to study the role of hormones in metamorphosis. Here we review how heterochronic genes (lin-4, let-7, lin-28, lin-41), hormones (dafachronic acid, ecdysone, thyroid hormone) and the environment regulate developmental transitions. Recent evidence suggests that some heterochronic genes also regulate transitions in higher organisms that they are controlled by hormones involved in metamorphosis. We also discuss evidence demonstrating that heterochronic genes and hormones regulate the proliferation and differentiation of embryonic and neural stem cells. We propose the hypothesis that developmental transitions are regulated by an evolutionary conserved mechanism in which heterochronic genes and hormones interact to control stem/progenitor cells proliferation, cell cycle exit, quiescence and differentiation and determine the proper timing of developmental transitions. Finally, we discuss the relevance of these studies to understand post-embryonic development, puberty and regeneration in humans. Copyright © 2016 Elsevier Inc. All rights reserved.

Transition: Preschool to Kindergarten

ERIC Educational Resources Information Center

Arizona Department of Education, 2007

2007-01-01

Transition is movement or change without interruption. It should be a smooth flow from one place or condition to another. While the transition plan for a student receiving special education services is designed to prepare him or her for life after high school, transition can start when a child enters preschool. The second of six distinct stages of…

EXTRASOLAR BINARY PLANETS. II. DETECTABILITY BY TRANSIT OBSERVATIONS

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

Lewis, K. M.; Ida, S.; Ochiai, H.

2015-05-20

We discuss the detectability of gravitationally bound pairs of gas-giant planets (which we call “binary planets”) in extrasolar planetary systems that are formed through orbital instability followed by planet–planet dynamical tides during their close encounters, based on the results of N-body simulations by Ochiai et al. (Paper I). Paper I showed that the formation probability of a binary is as much as ∼10% for three giant planet systems that undergo orbital instability, and after post-capture long-term tidal evolution, the typical binary separation is three to five times the sum of the physical radii of the planets. The binary planets aremore » stable during the main-sequence lifetime of solar-type stars, if the stellarcentric semimajor axis of the binary is larger than 0.3 AU. We show that detecting modulations of transit light curves is the most promising observational method to detect binary planets. Since the likely binary separations are comparable to the stellar diameter, the shape of the transit light curve is different from transit to transit, depending on the phase of the binary’s orbit. The transit durations and depth for binary planet transits are generally longer and deeper than those for the single planet case. We point out that binary planets could exist among the known inflated gas-giant planets or objects classified as false positive detections at orbital radii ≳0.3 AU, propose a binary planet explanation for the CoRoT candidate SRc01 E2 1066, and show that binary planets are likely to be present in, and could be detected using, Kepler-quality data.« less

Research to Operations: The Critical Transition

NASA Technical Reports Server (NTRS)

Fogarty, Jennifer A.

2009-01-01

Space Life Sciences Directorate (SLSD) specializes in transitioning technology and knowledge to medical operations. This activity encompasses funding a spectrum of research and technology efforts, such as understanding fundamental biological mechanisms altered by microgravity and executing technology watches for state of the art diagnostic imaging equipment. This broad spectrum approach to fulfilling the need to protect crewmember health and performance during long and short duration missions to the International Space Station, moon and Mars is made possible by having a line of site between research and operations. Currently, SLSD's line of site is articulated in a transition to medical practice (TMP) process. This process is designed to shepherd information and knowledge gained through fundamental and mechanistic research toward the development of an operational solution such as a pre-flight selection criteria; an in-flight countermeasure, monitoring capability or treatment; or a post-flight reconditioning program. The TMP process is also designed to assist with the customization of mature hardware or technology for NASA specific use. The benefits of this process are that the concept of operational usability is interjected early in the research, design, or acquisition phase, and stakeholders are involved early to identify requirements and also periodically asked to assess requirements compliance of research or technology development project. Currently a device known as the actiwatch is being assessed for the final transition to operational use. Specific examples of research to operations transition success help to illustrate the process and bolster communication between the research and medical operations communities.

Mars Polar Cap During Transition Phase Instrument Checkout

NASA Technical Reports Server (NTRS)

2006-01-01

During the last week of September and the first week or so of October 2006, scientific instruments on NASA's Mars Reconnaissance Orbiter were turned on to acquire test information during the transition phase leading up to full science operations. The mission's primary science phase will begin the first week of November 2006, following superior conjunction. (Superior conjunction is where a planet goes behind the sun as viewed from Earth.) Since it is very difficult to communicate with a spacecraft when it is close to the sun as seen from Earth, this checkout of the instruments was crucial to being ready for the primary science phase of the mission.

Throughout the transition-phase testing, the Mars Color Imager (MARCI) acquired terminator (transition between nighttime and daytime) to terminator swaths of color images on every dayside orbit, as the spacecraft moved northward in its orbit. The south polar region was deep in winter shadow, but the north polar region was illuminated the entire Martian day. During the primary mission, such swaths will be assembled into global maps that portray the state of the Martian atmosphere -- its weather -- as seen every day and at every place at about 3 p.m. local solar time. After the transition phase completed, most of the instruments were turned off, but the Mars Climate Sounder and MARCI have been left on. Their data will be recorded and played back to Earth following the communications blackout associated with conjunction.

Combined with wide-angle image mosaics taken by the Mars Orbiter Camera on NASA's Mars Global Surveyor at 2 p.m. local solar time, the MARCI maps will be used to track motions of clouds.

This image is a composite mosaic of four polar views of Mars, taken at midnight, 6 a.m., noon, and 6 p.m. local Martian time. This is possible because during summer the sun is always shining in the polar region. It shows the mostly water-ice perennial cap (white area), sitting atop the north polar layered

Predictors of Supported Employment for Transitioning Youth with Developmental Disabilities

ERIC Educational Resources Information Center

Simonsen, Monica Lynn

2010-01-01

The Individuals with Disabilities Education Act of 2004 requires school systems to plan systematically for the transition from school to post-secondary education and/or employment and include measurable post-school goals in students' IEPs. Schools are required to coordinate activities, such as work experiences, to assist students in meeting their…

Pediatric Renal Transplantation: Focus on Current Transition Care and Proposal of the "RISE to Transition" Protocol.

PubMed

Raina, Rupesh; Wang, Joseph; Krishnappa, Vinod; Ferris, Maria

2018-01-16

The transition from pediatric to adult medical services is an important time in the life of an adolescent or young adult with a renal transplant. Failure of proper transition can lead to medical non-adherence and subsequent loss of graft and/or return to dialysis. The aim of this study was to conduct a systematic review and survey to assess the challenges and existing practices in transition of renal transplant recipient children to adult services, and to develop a transition protocol. We conducted a literature review and performed a survey of pediatric nephrologists across the United States to examine the current state of transition care. A structured transition protocol was developed based on these results. Our literature review revealed that a transition program has a positive impact on decline in renal function and acute rejection episodes, and may improve long-term graft outcomes in pediatric kidney transplant patients. With a response rate of 40% (60/150) from nephrologists in 56% (49/87) of centers, our survey shows inconsistent use of validated tools despite their availability, inefficient communication between teams, and lack of use of dedicated clinics. To address these issues, we developed the "RISE to Transition" protocol, which relies on 4 competency areas: Recognition, Insight, Self-reliance, and Establishment of healthy habits. The transition program decreases acute graft rejection episodes, and the main challenges in transition care are the communication gap between health care providers and inconsistent use of transition tools. Our RISE to transition protocol incorporates transition tools, defines personnel, and aims to improve communication between teams.

QATS: Quasiperiodic Automated Transit Search

NASA Astrophysics Data System (ADS)

Carter, Joshua A.; Agol, Eric

2017-12-01

QATS detects transiting extrasolar planets in time-series photometry. It relaxes the usual assumption of strictly periodic transits by permitting a variable, but bounded, interval between successive transits.

Political commitment for vulnerable populations during donor transition.

PubMed

Rodríguez, Daniela C; Whiteside, Alan; Bennett, Sara

2017-02-01

The responsibilities for the programmatic, technical and financial support of health programmes are increasingly being passed from external donors to governments. Programmes for family planning, human immunodeficiency virus, immunization, malaria and tuberculosis have already faced such donor transition, which is a difficult and often political process. Wherever programmes and services aimed at vulnerable populations are primarily supported by donors, the post-transition future is uncertain. Overreliance on donor support is often a reflection of limited domestic political commitment. Limited commitment, which is frequently expressed as the persecution of vulnerable groups, poses a risk to individuals as well as to the effectiveness and sustainability of health programmes. We argue that, for reasons linked to human rights, the social contract and the cost-effectiveness of health promotion, prevention and treatment programmes, it is critical that governments sustain health services for vulnerable populations during and after donor transition. Although civil society organizations could help by engaging with government stakeholders, pushing to change social norms and supporting mechanisms that demand accountability, they may be constrained by economic, political and social factors. Vulnerable populations need to be actively involved in the planning and implementation of donor transition - to ensure that their voice and needs are taken into account and to establish a platform that improves visibility and accountability. As transitions spread across all aspects of global health, transparent conversations about the building and sustainment of political commitment for health services for vulnerable populations become a critical human rights issue.

Columbus State University Global Observation and Outreach for the 2012 Transit of Venus

NASA Astrophysics Data System (ADS)

Perry, Matthew; McCarty, C.; Bartow, M.; Hood, J. C.; Lodder, K.; Johnson, M.; Cruzen, S. T.; Williams, R. N.

2013-01-01

Faculty, staff and students from Columbus State University’s (CSU’s) Coca-Cola Space Science Center presented a webcast of the 2012 Transit of Venus from three continents to a global audience of 1.4 million unique viewers. Team members imaged the transit with telescopes using white-light, hydrogen-alpha, and calcium filters, from Alice Springs, Australia; the Gobi Desert, Mongolia; Bryce Canyon, UT; and Columbus, GA. Images were webcast live during the transit in partnership with NASA’s Sun-Earth Day program, and Science Center staff members were featured on NASA TV. Local members of the public were brought in for a series of outreach initiatives, in both Georgia and Australia, before and during the transit. The data recorded from the various locations have been archived for use in demonstrating principles such as the historical measurement of the astronomical unit.

A 1.9 Earth Radius Rocky Planet and the Discovery of a Non-transiting Planet in the Kepler-20 System

NASA Astrophysics Data System (ADS)

Buchhave, Lars A.; Dressing, Courtney D.; Dumusque, Xavier; Rice, Ken; Vanderburg, Andrew; Mortier, Annelies; Lopez-Morales, Mercedes; Lopez, Eric; Lundkvist, Mia S.; Kjeldsen, Hans; Affer, Laura; Bonomo, Aldo S.; Charbonneau, David; Collier Cameron, Andrew; Cosentino, Rosario; Figueira, Pedro; Fiorenzano, Aldo F. M.; Harutyunyan, Avet; Haywood, Raphaëlle D.; Johnson, John Asher; Latham, David W.; Lovis, Christophe; Malavolta, Luca; Mayor, Michel; Micela, Giusi; Molinari, Emilio; Motalebi, Fatemeh; Nascimbeni, Valerio; Pepe, Francesco; Phillips, David F.; Piotto, Giampaolo; Pollacco, Don; Queloz, Didier; Sasselov, Dimitar; Ségransan, Damien; Sozzetti, Alessandro; Udry, Stéphane; Watson, Chris

2016-12-01

Kepler-20 is a solar-type star (V = 12.5) hosting a compact system of five transiting planets, all packed within the orbital distance of Mercury in our own solar system. A transition from rocky to gaseous planets with a planetary transition radius of ˜1.6 {R}\\oplus has recently been proposed by several articles in the literature. Kepler-20b ({R}p ˜ 1.9 {R}\\oplus ) has a size beyond this transition radius; however, previous mass measurements were not sufficiently precise to allow definite conclusions to be drawn regarding its composition. We present new mass measurements of three of the planets in the Kepler-20 system that are facilitated by 104 radial velocity measurements from the HARPS-N spectrograph and 30 archival Keck/HIRES observations, as well as an updated photometric analysis of the Kepler data and an asteroseismic analysis of the host star ({M}\\star = 0.948+/- 0.051 {M}⊙ and {R}\\star = 0.964+/- 0.018 {R}⊙ ). Kepler-20b is a {1.868}-0.034+0.066 {R}\\oplus planet in a 3.7 day period with a mass of {9.70}-1.44+1.41 {M}\\oplus , resulting in a mean density of {8.2}-1.3+1.5 {{g}} {{cm}}-3, indicating a rocky composition with an iron-to-silicate ratio consistent with that of the Earth. This makes Kepler-20b the most massive planet with a rocky composition found to date. Furthermore, we report the discovery of an additional non-transiting planet with a minimum mass of {19.96}-3.61+3.08 {M}\\oplus and an orbital period of ˜34 days in the gap between Kepler-20f (P ˜ 11 days) and Kepler-20d (P ˜ 78 days). Based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofísica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

Revisiting ρ1 Cancri e: A New Mass Determination of the Transiting Super-Earth

NASA Astrophysics Data System (ADS)

Endl, Michael; Robertson, Paul; Cochran, William D.; MacQueen, Phillip J.; Brugamyer, Erik J.; Caldwell, Caroline; Wittenmyer, Robert A.; Barnes, Stuart I.; Gullikson, Kevin

2012-11-01

We present a mass determination for the transiting super-Earth ρ1 Cancri e based on nearly 700 precise radial velocity (RV) measurements. This extensive RV data set consists of data collected by the McDonald Observatory planet search and published data from Lick and Keck observatories. We obtained 212 RV measurements with the Tull Coudé Spectrograph at the Harlan J. Smith 2.7 m Telescope and combined them with a new Doppler reduction of the 131 spectra that we have taken in 2003-2004 with the High-Resolution Spectrograph (HRS) at the Hobby-Eberly Telescope for the original discovery of ρ1 Cancri e. Using this large data set we obtain a five-planet Keplerian orbital solution for the system and measure an RV semi-amplitude of K = 6.29 ± 0.21 m s-1 for ρ1 Cnc e and determine a mass of 8.37 ± 0.38 M ⊕. The uncertainty in mass is thus less than 5%. This planet was previously found to transit its parent star, which allowed them to estimate its radius. Combined with the latest radius estimate from Gillon et al., we obtain a mean density of ρ = 4.50 ± 0.20 g cm-3. The location of ρ1 Cnc e in the mass-radius diagram suggests that the planet contains a significant amount of volatiles, possibly a water-rich envelope surrounding a rocky core. Based partly on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen.

Small City Transit : Sudbury, Massachusetts : A Short-Lived Suburban Transit Service.

DOT National Transportation Integrated Search

1976-03-01

Sudbury, Massachusetts, is an illustration of a over-extended fixed-route transit service which was rather short-lived. This case study is one of thirteen examples of a transit service in a small community. The background of the community is discusse...

Small City Transit : Eugene/Springfield, Oregon : Extensive County-Wide Transit Coverage

DOT National Transportation Integrated Search

1976-03-01

Eugene/Springfield, Oregon is an illustration of a fixed-route transit service with extensive county-wide coverage. This case study is one of thirteen examples of a transit service in a small community. The background of the community is discussed al...

Land use impacts of rapid transit: implications of recent experience. Final report

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

Knight, R.L.; Trygg, L.L.

Evidence of land use impacts of recent major rapid transit improvements are reviewed and conclusions drawn concerning the extent and nature of such impacts and the conditions under which they have occurred. Transit improvements studied are primarily post-World War II in origin. American and Canadian examples are stressed, although European experience is teated briefly. Virtually all major modern American and Canadian rapid transit investments are included, covering conventional rapid rail, commuter rail, light rail and bus/busway. In addition to conclusions on general patterns of land use impact and causes, research recommendations and Federal policy implications are drawn.

Transitivity of Preferences

ERIC Educational Resources Information Center

Regenwetter, Michel; Dana, Jason; Davis-Stober, Clintin P.

2011-01-01

Transitivity of preferences is a fundamental principle shared by most major contemporary rational, prescriptive, and descriptive models of decision making. To have transitive preferences, a person, group, or society that prefers choice option "x" to "y" and "y" to "z" must prefer "x" to…

Evidence for pleural epithelial-mesenchymal transition in murine compensatory lung growth

PubMed Central

Ysasi, Alexandra B.; Wagner, Willi L.; Valenzuela, Cristian D.; Kienzle, Arne; Servais, Andrew B.; Bennett, Robert D.; Tsuda, Akira; Ackermann, Maximilian; Mentzer, Steven J.

2017-01-01

In many mammals, including rodents and humans, removal of one lung results in the compensatory growth of the remaining lung; however, the mechanism of compensatory lung growth is unknown. Here, we investigated the changes in morphology and phenotype of pleural cells after pneumonectomy. Between days 1 and 3 after pneumonectomy, cells expressing α-smooth muscle actin (SMA), a cytoplasmic marker of myofibroblasts, were significantly increased in the pleura compared to surgical controls (p < .01). Scanning electron microscopy of the pleural surface 3 days post-pneumonectomy demonstrated regions of the pleura with morphologic features consistent with epithelial-mesenchymal transition (EMT); namely, cells with disrupted intercellular junctions and an acquired mesenchymal (rounded and fusiform) morphotype. To detect the migration of the transitional pleural cells into the lung, a biotin tracer was used to label the pleural mesothelial cells at the time of surgery. By post-operative day 3, image cytometry of post-pneumonectomy subpleural alveoli demonstrated a 40-fold increase in biotin+ cells relative to pneumonectomy-plus-plombage controls (p < .01). Suggesting a similar origin in space and time, the distribution of cells expressing biotin, SMA, or vimentin demonstrated a strong spatial autocorrelation in the subpleural lung (p < .001). We conclude that post-pneumonectomy compensatory lung growth involves EMT with the migration of transitional mesothelial cells into subpleural alveoli. PMID:28542402

Integration of transit and land use : a study of Los Angeles rail transit stations

DOT National Transportation Integrated Search

2003-01-01

This study focuses on transit-oriented development at rail transit stations in Los Angeles. It reviews the development of rail transit and land use in Los Angeles and looks at four specific station sites to see what is contributing to or hindering tr...

M2K Planet Search: Spectroscopic Screening and Transit Photometry

NASA Astrophysics Data System (ADS)

Mann, Andrew; Gaidos, E.; Fischer, D.; Lepine, S.

2010-10-01

The M2K project is a search for planets orbiting nearby early M and late K dwarf drawn from the SUPERBLINK catalog. M and K dwarfs are highly attractive targets for finding low-mass and habitable planets because (1) close-in planets are more likely to orbit within their habitable zone, (2) planets orbiting them induce a larger Doppler signal and have deeper transits than similar planets around F, G, and early K type stars, (3) planet formation models predict they hold an abundance of super-Earth sized planets, and (4) they represent the vast majority of the stars close enough for direct imaging techniques. In spite of this, only 10% of late K and early M dwarfs are being monitored by current Doppler surveys. As part of the M2K project we have obtained low-resolution spectra for more than 2000 of our sample of 10,000 M and K dwarfs. We vet our sample by screening these stars for high metallicity and low chromospheric activity. We search for transits on targets showing high RMS Doppler signal and photometry candidates provided by SuperWASP project. By using "snapshot” photometry have been able to achieve sub-millimag photometry on numerous transit targets in the same night. With further follow-up observations we will be able to detect planets smaller than 10 Earth masses.

Design of personal rapid transit networks for transit-oriented development cities.

DOT National Transportation Integrated Search

2014-04-01

Personal rapid transit (PRT) is an automated transit system in which vehicles are sized to transport a batch of passengers on demand to their destinations, by means of nonstop and non-transfer on its own right-of-way. PRT vehicles run exclusively on ...

Enhanced Air Stability in REPb3 (RE = Rare Earths) by Dimensional Reduction Mediated Valence Transition.

PubMed

Subbarao, Udumula; Sarkar, Sumanta; Jana, Rajkumar; Bera, Sourav S; Peter, Sebastian C

2016-06-06

We conceptually selected the compounds REPb3 (RE = Eu, Yb), which are unstable in air, and converted them to the stable materials in ambient conditions by the chemical processes of "nanoparticle formation" and "dimensional reduction". The nanoparticles and the bulk counterparts were synthesized by the solvothermal and high-frequency induction furnace heating methods, respectively. The reduction of the particle size led to the valence transition of the rare earth atom, which was monitored through magnetic susceptibility and X-ray absorption near edge spectroscopy (XANES) measurements. The stability was checked by X-ray diffraction and thermogravimetric analysis over a period of seven months in oxygen and argon atmospheres and confirmed by XANES. The nanoparticles showed outstanding stability toward aerial oxidation over a period of seven months compared to the bulk counterpart, as the latter one is more prone to the oxidation within a few days.

Rural transit emergency planning guidance.

DOT National Transportation Integrated Search

2008-07-01

Providing safe, reliable transportation has long been a priority at all levels of the transit industry including the Federal Transit Administration (FTA), California Department of Transportation (Caltrans) and individual transit providers. Over the l...

Numerical simulations of the optical gain of crystalline fiber doped by rare earth and transition ion

NASA Astrophysics Data System (ADS)

Daoui, A. K.; Boubir, B.; Adouane, A.; Demagh, N.; Ghoumazi, M.

2015-02-01

A fiber laser is a laser whose gain medium is a doped fiber, although lasers whose cavity is made wholly of fibers have also been called fiber lasers. The gain media in a fiber laser is usually fiber doped with rare-earth ions, such as erbium (Er), neodymium (Nd), ytterbium (Yb), thulium (Tm), or praseodymium (Pr), which is doped into the core of the optical fiber, similar to those used to transmit telecommunications signals. Fiber lasers find many applications in materials processing, including cutting, welding, drilling, and marking metal. To maximize their market penetration, it is necessary to increase their output power. In this work, we present a detailed study based on the numerical simulation using MATLAB, of one of the principal characteristics of a fiber laser doped with rare earth ions and transition ion. The gain depends on several parameters such as the length of the doped fiber, the density, the pump power, noise, etc.). The used program resolves the state equations in this context together with those governing the light propagation phenomena. The developed code can also be used to study the dynamic operating modes of a doped fiber laser.

22 CFR 41.71 - Transit aliens.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is satisfied...

22 CFR 41.71 - Transit aliens.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is satisfied...

22 CFR 41.71 - Transit aliens.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is satisfied...

22 CFR 41.71 - Transit aliens.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is satisfied...

22 CFR 41.71 - Transit aliens.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is satisfied...

Band gap tuning in transition metal oxides by site-specific substitution

DOEpatents

Lee, Ho Nyung; Chisholm, Jr., Matthew F; Jellison, Jr., Gerald Earle; Singh, David J; Choi, Woo Seok

2013-12-24

A transition metal oxide insulator composition having a tuned band gap includes a transition metal oxide having a perovskite or a perovskite-like crystalline structure. The transition metal oxide includes at least one first element selected form the group of Bi, Ca, Ba, Sr, Li, Na, Mg, K, Pb, and Pr; and at least one second element selected from the group of Ti, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Hf, Ta, W, Re, Os, Ir, and Pt. At least one correlated insulator is integrated into the crystalline structure, including REMO.sub.3, wherein RE is at least one Rare Earth element, and wherein M is at least one element selected from the group of Co, V, Cr, Ni, Mn, and Fe. The composition is characterized by a band gap of less of 4.5 eV.

High pressure phase transitions in the rare earth metal erbium to 151 GPa.

PubMed

Samudrala, Gopi K; Thomas, Sarah A; Montgomery, Jeffrey M; Vohra, Yogesh K

2011-08-10

High pressure x-ray diffraction studies have been performed on the heavy rare earth metal erbium (Er) in a diamond anvil cell at room temperature to a pressure of 151 GPa and Er has been compressed to 40% of its initial volume. The rare earth crystal structure sequence hcp → Sm type → dhcp → distorted fcc (hcp: hexagonal close packed; fcc: face centered cubic; dhcp: double hcp) is observed in Er below 58 GPa. We have carried out Rietveld refinement of crystal structures in the pressure range between 58 GPa and 151 GPa. We have examined various crystal structures that have been proposed for the distorted fcc (dfcc) phase and the post-dfcc phase in rare earth metals. We find that the hexagonal hR 24 structure is the best fit between 58 and 118 GPa. Above 118 GPa, a structural transformation from hR 24 phase to a monoclinic C 2/m phase is observed with a volume change of - 1.9%. We have also established a clear trend for the pressure at which a post-dfcc phase is formed in rare earth metals and show that there is a monotonic increase in this pressure with the filling of 4f shell.

High pressure phase transitions in the rare earth metal erbium to 151 GPa

NASA Astrophysics Data System (ADS)

Samudrala, Gopi K.; Thomas, Sarah A.; Montgomery, Jeffrey M.; Vohra, Yogesh K.

2011-08-01

High pressure x-ray diffraction studies have been performed on the heavy rare earth metal erbium (Er) in a diamond anvil cell at room temperature to a pressure of 151 GPa and Er has been compressed to 40% of its initial volume. The rare earth crystal structure sequence {hcp} \\to {Sm}~ {type} \\to {dhcp} \\to {distorted} fcc (hcp: hexagonal close packed; fcc: face centered cubic; dhcp: double hcp) is observed in Er below 58 GPa. We have carried out Rietveld refinement of crystal structures in the pressure range between 58 GPa and 151 GPa. We have examined various crystal structures that have been proposed for the distorted fcc (dfcc) phase and the post-dfcc phase in rare earth metals. We find that the hexagonal hR 24 structure is the best fit between 58 and 118 GPa. Above 118 GPa, a structural transformation from hR 24 phase to a monoclinic C 2/m phase is observed with a volume change of - 1.9%. We have also established a clear trend for the pressure at which a post-dfcc phase is formed in rare earth metals and show that there is a monotonic increase in this pressure with the filling of 4f shell.