Studying the Water Cycle in an Environmental Context: The "Blue Planet" Program.

ERIC Educational Resources Information Center

Ben-zvi-assaraf, Orit; Orion, Nir

The Blue Planet program aims to develop an understanding of and insight into the environment among students by introducing environmental problems such as pollution. This paper presents a study investigating junior high school students' previous knowledge and understanding of environmental issues and perceptions on the nature of the water cycle.…

Laminar flow effects in the coil planet centrifuge

NASA Technical Reports Server (NTRS)

Herrmann, F. T.

1984-01-01

The coil planet centrifuge designed by Ito employs flow of a single liquid phase, through a rotating coiled tube in a centrifugal force field, to provide a separation of particles based on sedimentation rates. Mathematical solutions are derived for the linear differential equations governing particle behavior in the coil planet centrifuge device. These solutions are then applied as the basis of a model for optimizing particle separations.

Measurements of 100 'Critical' Minor Planets from NEAT Archive

NASA Astrophysics Data System (ADS)

Deshmukh, Shishir

2017-07-01

Uncertainties associated with the orbits of minor planets can be reduced by analyzing archival imagery as attempted in the current investigation. Archival images from NEAT and NASA’s Skymorph database were analyzed using standard software to identify the minor planets listed in the critical list. Findings of each minor planet were submitted to Minor Planet Center (MPC) to offer better orbital solutions.

Influence on photosynthesis of starlight, moonlight, planetlight, and light pollution (reflections on photosynthetically active radiation in the universe).

PubMed

Raven, J A; Cockell, C S

2006-08-01

Photosynthesis on Earth can occur in a diversity of organisms in the photosynthetically active radiation (PAR) range of 10 nmol of photons m(-2) s(-1) to 8 mmol of photons m(-2) s(-1). Similar considerations would probably apply to photosynthetic organisms on Earth-like planets (ELPs) in the continuously habitable zone of other stars. On Earth, starlight PAR is inadequate for photosynthetically supported growth. An increase in starlight even to reach the minimum theoretical levels to allow for photosynthesis would require a universe that was approximately ten million times older, or with a ten million times greater density of stars, than is the case for the present universe. Photosynthesis on an ELP using PAR reflected from a natural satellite with the same size as our Moon, but at the Roche limit, could support a low rate of photosynthesis at full Moon. Photosynthesis on an ELP-like satellite of a Jupiter-sized planet using light reflected from the planet could be almost 1% of the rate in full sunlight on Earth when the planet was full. These potential contributions to photosynthesis require that the contribution is compared with the rate of photosynthesis driven by direct radiation from the star. Light pollution on Earth only energizes photosynthesis by organisms that are very close to the light source. However, effects of light pollution on photosynthesis can be more widespread if the photosynthetic canopy is retained for more of the year, caused by effects on photoperiodism, with implications for the influence of civilizations on photosynthesis.

On the classification of exoplanets according to Safronov number

NASA Astrophysics Data System (ADS)

Öztürk, O.; Erdem, A.

2018-02-01

We reexamine the classification of transiting exoplanets proposed by Hansen & Barman (2007) based on equilibrium temperatures and Safronov numbers. We used more sensitive data, namely, photometric and spectroscopic orbital solutions, of 263 well-known planets given in The Exoplanet Data Explorer, while Hansen & Barman (2007) used data on 18 transiting planets. Diagrams of the planet gravity vs. orbital period, planet gravity vs. equilibrium temperature, and Safronov number vs. equilibrium temperature of the 263 transiting planets show that the division of planets into two classes is indistinct.

So What's a Toxic Waste Site? Kids for Saving Earth News. Action Program #16.

ERIC Educational Resources Information Center

Kids for Saving Earth Worldwide, Minneapolis, MN.

This document provides ideas for activities on toxic waste sites. A toxic tour around the home accompanied by an adult is recommended to discover items that are dangerous for humans and the earth. Activities on understanding forests, pollution problems, recycling, and prevention of pollution for a healthy planet is included. (YDS)

Journey to Planet Earth: The Urban Explosion. The Public Television Series. [Videotape].

ERIC Educational Resources Information Center

1999

This videotape attempts to show students how the uncontrolled development of the world's major cities has led to a series of problems such as air pollution, water pollution, limited room for waste disposal, housing shortages, and loss of farmland. The videotape profiles four mega-cities: Mexico City, Shanghai, Istanbul, and New York City. Students…

Throwing Icebergs at White Dwarfs

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-08-01

Where do the metals come from that pollute the atmospheres of many white dwarfs? Close-in asteroids may not be the only culprits! A new study shows that distant planet-size and icy objects could share some of the blame.Pollution ProblemsArtists impression of rocky debris lying close around a white dwarf star. [NASA/ESA/STScI/G. Bacon]When a low- to intermediate-mass star reaches the end of its life, its outer layers are blown off, leaving behind its compact core. The strong gravity of this white dwarf causes elements heavier than hydrogen and helium to rapidly sink to its center in a process known as sedimentation, leaving an atmosphere that should be free of metallic elements.Therefore its perhaps surprising that roughly 2550% of all white dwarfs are observed to have atmospheric pollution by heavy elements. The short timescales for sedimentation suggest that these elements were added to the white dwarf recently but how did they get there?Bringing Ice InwardIn the generally accepted theory, pre-existing rocky bodies or an orbiting asteroid belt survive the stars evolution, later accreting onto the final white dwarf. But this scenario doesnt explain a few observations that suggest white dwarfs might be accreting larger planetary-size bodies and bodies with ices and volatile materials.Dynamical evolution of a Neptune-like planet (a) and a Kuiper belt analog object (b) in wide binary star systems. Both have large eccentricity excitations during the white dwarf phase. [Stephan et al. 2017]How might you get large or icy objects which would begin on very wide orbits close enough to a white dwarf to become disrupted and accrete? Led by Alexander Stephan, a team of scientists at UCLA now suggest that the key is for the white dwarf to be in a binary system.Influence of a CompanionIn the authors model, the white-dwarf progenitor is orbited by both a distant stellar companion (a common occurrence) and a number of large potential polluters, which could have masses between that of a large asteroid up to several times the mass of Jupiter. These potential polluters have very wide orbits that allow them to maintain ice and volatile materials.At the end of the progenitors lifetime it loses a significant amount of mass, causing the orbits of the surviving objects in the system to expand. After this stage, the stellar companion gravitationally perturbs the potential polluters onto extremely eccentric orbits, bringing these massive and long-period objects close enough accrete onto what is now the white dwarf.The Need for ObservationsThe likelihood distributions for orbital parameters of the systems that result in white dwarfs polluted by Neptune-like planets and Kuiper-belt-analog objects. The black arrows mark the parameters for one of the few observed systems, WD 1425+540, for comparison. [Stephan et al. 2017]By running large Monte Carlo simulations, Stephan and collaborators demonstrate that this scenario can successfully produce accretion of both Neptune-like planets and Kuiper-belt-analog objects. Their simulation results indicate that 1% of all white dwarfs should accrete Neptune-like planets, and 7.5% of all white dwarfs should accrete Kuiper-belt-analog objects.While these fractions are broadly consistent with observations, its hard to say with certainty whether this model is correct, as observations are scant. Only 200 polluted white dwarfs have been observed, and of these, only 15 have had detailed abundance measurements made. Next steps for understanding white-dwarf pollution certainly must includegathering more observations of polluted white dwarfs and establishing the statistics of what is polluting them.CitationAlexander P. Stephan et al 2017 ApJL 844 L16. doi:10.3847/2041-8213/aa7cf3

Locations of stationary/periodic solutions in mean motion resonances according to the properties of dust grains

NASA Astrophysics Data System (ADS)

Pástor, P.

2016-07-01

The equations of secular evolution for dust grains in mean motion resonances with a planet are solved for stationary points. Non-gravitational effects caused by stellar radiation (the Poynting-Robertson effect and the stellar wind) are taken into account. The solutions are stationary in the semimajor axis, eccentricity and resonant angle, but allow the pericentre to advance. The semimajor axis of stationary solutions can be slightly shifted from the exact resonant value. The periodicity of the stationary solutions in a reference frame orbiting with the planet is proved analytically. The existence of periodic solutions in mean motion resonances means that analytical theory enables infinitely long capture times for dust particles. The stationary solutions are periodic motions to which the eccentricity asymptotically approaches and around which the libration occurs. Initial conditions corresponding to the stationary solutions are successfully found by numerically integrating the equation of motion. Numerically and analytically determined shifts of the semimajor axis from the exact resonance for the stationary solutions are in excellent agreement. The stationary solutions can be plotted by the locations of pericentres in the reference frame orbiting with the planet. The pericentres are distributed in space according to the properties of the dust particles.

HAT-P-44b, HAT-P-45b, AND HAT-P-46b: Three transiting hot Jupiters in possible multi-planet systems

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

Hartman, J. D.; Bakos, G. Á.; Bhatti, W.

2014-06-01

We report the discovery by the HATNet survey of three new transiting extrasolar planets orbiting moderately bright (V = 13.2, 12.8, and 11.9) stars. The planets have orbital periods of 4.3012, 3.1290, and 4.4631 days, masses of 0.35, 0.89, and 0.49 M {sub J}, and radii of 1.24, 1.43, and 1.28 R {sub J}. The stellar hosts have masses of 0.94, 1.26, and 1.28 M {sub ☉}. Each system shows significant systematic variations in its residual radial velocities, indicating the possible presence of additional components. Based on its Bayesian evidence, the preferred model for HAT-P-44 consists of two planets, includingmore » the transiting component, with the outer planet having a period of 872 days, eccentricity of 0.494 ± 0.081, and a minimum mass of 4.0 M {sub J}. Due to aliasing we cannot rule out alternative solutions for the outer planet having a period of 220 days or 438 days. For HAT-P-45, at present there is not enough data to justify the additional free parameters included in a multi-planet model; in this case a single-planet solution is preferred, but the required jitter of 22.5 ± 6.3 m s{sup –1} is relatively high for a star of this type. For HAT-P-46 the preferred solution includes a second planet having a period of 78 days and a minimum mass of 2.0 M {sub J}, however the preference for this model over a single-planet model is not very strong. While substantial uncertainties remain as to the presence and/or properties of the outer planetary companions in these systems, the inner transiting planets are well characterized with measured properties that are fairly robust against changes in the assumed models for the outer planets. Continued radial velocity monitoring is necessary to fully characterize these three planetary systems, the properties of which may have important implications for understanding the formation of hot Jupiters.« less

Dynamics as a 'Red Flag' in Exoplanetary Science

NASA Astrophysics Data System (ADS)

Horner, Jonathan; Wittenmyer, Robert

2018-01-01

The great majority of exoplanets are discovered indirectly - by observing a star doing something unusual, and inferring the presence of planets from that behaviour. The nature of those planets - their mass and their orbital parameters - is typically somewhat unclear, with a variety of different scenarios offering equally good fits to the observational data.Typically, authors publish the solution that offers the best fit to the data, without considering the degree to which the planets propsed would interact with one another. This has led to the 'discovery' of planetary systems that are clearly unfeasible - and it is likely that a number of such systems are buried in the catalogue of 'confirmed' exoplanets.Fortunately, there is a solution to this problem. By carrying out suites of n-body integrations of proposed planetary systems, we can find solutions that both offer a good fit to the observational data and the long-term dynamical stability required to give confidence that the planets proposed are truly all they seem.Here, we present the results from a number of such dynamical studies, showing the importance of such simulations to the process of exoplanet discovery and characterisation.

The Pan-Pacific Planet Search. II. Confirmation of a Two-planet System around HD 121056

NASA Astrophysics Data System (ADS)

Wittenmyer, Robert A.; Wang, Liang; Liu, Fan; Horner, Jonathan; Endl, Michael; Johnson, John Asher; Tinney, C. G.; Carter, B. D.

2015-02-01

Precise radial velocities from the Anglo-Australian Telescope (AAT) confirm the presence of a rare short-period planet around the K0 giant HD 121056. An independent two-planet solution using the AAT data shows that the inner planet has P = 89.1 ± 0.1 days, and m sin i = 1.35 ± 0.17 MJup. These data also confirm the planetary nature of the outer companion, with m sin i = 3.9 ± 0.6 MJup and a = 2.96 ± 0.16 AU. HD 121056 is the most-evolved star to host a confirmed multiple-planet system, and is a valuable example of a giant star hosting both a short-period and a long-period planet.

Late stages of accumulation and early evolution of the planets

NASA Technical Reports Server (NTRS)

Vityazev, Andrey V.; Perchernikova, G. V.

1991-01-01

Recently developed solutions of problems are discussed that were traditionally considered fundamental in classical solar system cosmogony: determination of planetary orbit distribution patterns, values for mean eccentricity and orbital inclinations of the planets, and rotation periods and rotation axis inclinations of the planets. Two important cosmochemical aspects of accumulation are examined: the time scale for gas loss from the terrestrial planet zone, and the composition of the planets in terms of isotope data. It was concluded that the early beginning of planet differentiation is a function of the heating of protoplanets during collisions with large (thousands of kilometers) bodies. Energetics, heat mass transfer processes, and characteristic time scales of these processes at the early stages of planet evolution are considered.

Barnard’s Star: Planets or Pretense

NASA Astrophysics Data System (ADS)

Bartlett, Jennifer L.; Ianna, P. A.

2014-01-01

Barnard’s Star remains popular with planet hunters because it is not only an extremely near, high proper motion star, but also the object of early planet-detection claims. In 1963, van de Kamp explained perturbations in its proper motion by the presence of a planet. In 1969, he produced another single-planet solution and a two-planet solution to the astrometric wobbles detected. At least 19 studies have failed to confirm his results using a range of techniques, including radial velocity, direct imaging, and speckle interferometry. However, most of them lacked the sensitivity to detect the planets he described, including astrometric studies at the McCormick and Naval Observatories. However, radial-velocity monitoring of Barnard’s Star at Lick and Keck Observatories from 1987 through 2012 appears to have ruled out such planets. Based upon observations made at the Sproul Observatory between 1916 and 1962, van de Kamp claimed that Barnard’s Star had a planet with about 1.6 times the mass of Jupiter and an orbital period of 24 years. After accounting for instrumentation effects that might have been partially responsible for his initial results, he continued to assert that this red dwarf had two planets. In his 1982 analysis of ~20,000 exposures collected between 1938 and 1981, he calculated that two planets with 0.7- and 0.5-Jupiter masses in 12- and 20-year orbits, respectively, orbited the second-closest stellar system to our own. Starting in 1995, the dramatic successes of radial velocity searches for extrasolar planets drove van de Kamp’s unsubstantiated claims from popular consciousness. Although many low-mass stellar companions were discovered through astrometry, the technique has been less successful for planets: “The Extrasolar Planets Encyclopaedia” identifies one such discovery out of the 997 planets listed on 2013 September 23. Although Barnard’s Star has lost its pretensions to hosting the first extrasolar planets known, its intrinsic properties will keep it under observation. NSF grant AST 98-20711, Litton Marine Systems, Levinson Fund, University of Virginia, Hampden-Sydney College, and US Naval Observatory supported this research.

Flow of Planets, Not Weak Tidal Evolution, Produces the Short-Period Planet Distribution with More Planets than Expected

NASA Astrophysics Data System (ADS)

Taylor, Stuart F.

2013-01-01

The most unexpected planet finding is arguably the number of those with shorter periods than theorists had expected, because most such close planets had been expected to migrate into the star in shorter timescales than the ages of the stars. Subsequent effort has been made to show how tidal dissipation in stars due to planets could be weaker than expected, but we show how the occurrence distribution of differently-sized planets is more consistent with the explanation that these planets have more recently arrived as a flow of inwardly migrating planets, with giant planets more likely to be found while gradually going through a short period stage. This continual ``flow'' of new planets arriving from further out is presumably supplied by the flow likely responsible for the short period pileup of giant planets (Socrates+ 2011). We have previously shown that the shortest period region of the exoplanet occurrence distribution has a fall-off shaped by inward tidal migration due to stellar tides, that is, tides on the star caused by the planets (Taylor 2011, 2012). The power index of the fall-off of giant and intermediate radius planet candidates found from Kepler data (Howard+ 2011) is close to the index of 13/3 which is expected for planets in circular orbits undergoing tidal migration. However, there is a discrepancy of the strength of the tidal migration determined using fits to the giant and medium planets distributions. This discrepancy is best resolved by the explanation that more giant than medium radii planets migrate through these short period orbits. We also present a correlation between higher eccentricity of planetary orbits with higher Fe/H of host stars, which could be explained by high eccentricity planets being associated with recent episodes of other planets into stars. By the time these planets migrate to become hot Jupiters, the pollution may be mixed into the star. The clearing of other planets by migrating hot giant planets may result in hot Jupiters being anti-correlated with additional planets. We present results from our study of inward migration.

Rocky Planetary Debris Around Young WDs

NASA Astrophysics Data System (ADS)

Gaensicke, B.

2014-04-01

The vast majority of all known planet host stars, including the Sun, will eventually evolve into red giants and finally end their lives as white dwarfs: extremely dense Earth-sized stellar embers. Only close-in planets will be devoured during the red-giant phase. In the solar system, Mars, the asteroid belt, and all the giant planets will escape evaporation, and the same is true for many of the known exo-planets. It is hence certain that a significant fraction of the known white dwarfs were once host stars to planets, and it is very likely that many of them still have remnants of planetary systems. The detection of metals in the atmospheres of white dwarfs is the unmistakable signpost of such evolved planetary systems. The strong surface gravity of white dwarfs causes metals to sink out of the atmosphere on time-scales much shorter than their cooling ages, leading unavoidably to pristine H/He atmospheres. Therefore any metals detected in the atmosphere of a white dwarf imply recent or ongoing accretion of planetary debris. In fact, planetary debris is also detected as circumstellar dust and gas around a number of white dwarfs. These debris disks are formed from the tidal disruption of asteroids or Kuiper belt-like objects, stirred up by left-over planets, and are subsequently accreted onto the white dwarf, imprinting their abundance pattern into its atmosphere. Determining the photospheric abundances of debris-polluted white dwarfs is hence entirely analogue to the use of meteorites, "rocks that fell from the sky", for measuring the abundances of planetary material in the solar system. I will briefly review this new field of exo-planet science, and then focus on the results of a large, unbiased COS snapshot survey of relatively young ( 20-100Myr) white dwarfs that we carried out in Cycle 18/19. * At least 30% of all white dwarfs in our sample are accreting planetary debris, and that fraction may be as high as 50%. * In most cases where debris pollution is detected, the low C/Si ratio demonstrates that the planetary material is of rocky nature. * None of the 9 systems where we measure the C/O ratio shows evidence for carbon-dominated chemistry, implying that "carbon planets" are not common. * In the most polluted white dwarfs, we measure the debris abundances of up to 11 elements, enabling a detailed comparison between the chemistry of exo-planetary material with that of solar system meteorites. We find that the exo-planetary debris shares many characteristics of solar-system material, i.e. a wide spread in the relative abundances of Mg, Fe, Si, and O, a constant Al/Ca ratio, and evidence for differentiation in the form of Fe over-abundances All of the above is suggestive that thermal and collisional processing of planetary material in those systems might have been similar to that in the solar system.

ON THE NOTION OF WELL-DEFINED TECTONIC REGIMES FOR TERRESTRIAL PLANETS IN THIS SOLAR SYSTEM AND OTHERS

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

Lenardic, A.; Crowley, J. W., E-mail: ajns@rice.edu, E-mail: jwgcrowley@gmail.com

2012-08-20

A model of coupled mantle convection and planetary tectonics is used to demonstrate that history dependence can outweigh the effects of a planet's energy content and material parameters in determining its tectonic state. The mantle convection-surface tectonics system allows multiple tectonic modes to exist for equivalent planetary parameter values. The tectonic mode of the system is then determined by its specific geologic and climatic history. This implies that models of tectonics and mantle convection will not be able to uniquely determine the tectonic mode of a terrestrial planet without the addition of historical data. Historical data exists, to variable degrees,more » for all four terrestrial planets within our solar system. For the Earth, the planet with the largest amount of observational data, debate does still remain regarding the geologic and climatic history of Earth's deep past but constraints are available. For planets in other solar systems, no such constraints exist at present. The existence of multiple tectonic modes, for equivalent parameter values, points to a reason why different groups have reached different conclusions regarding the tectonic state of extrasolar terrestrial planets larger than Earth ({sup s}uper-Earths{sup )}. The region of multiple stable solutions is predicted to widen in parameter space for more energetic mantle convection (as would be expected for larger planets). This means that different groups can find different solutions, all potentially viable and stable, using identical models and identical system parameter values. At a more practical level, the results argue that the question of whether extrasolar terrestrial planets will have plate tectonics is unanswerable and will remain so until the temporal evolution of extrasolar planets can be constrained.« less

Secular dynamics of multiplanetary circumbinary systems: stationary solutions and binary-planet secular resonance

NASA Astrophysics Data System (ADS)

Andrade-Ines, Eduardo; Robutel, Philippe

2018-01-01

We present an analytical formalism to study the secular dynamics of a system consisting of N-2 planets orbiting a binary star in outer orbits. We introduce a canonical coordinate system and expand the disturbing function in terms of canonical elliptic elements, combining both Legendre polynomials and Laplace coefficients, to obtain a general formalism for the secular description of this type of configuration. With a quadratic approximation of the development, we present a simplified analytical solution for the planetary orbits for both the single planet and the two-planet cases. From the two-planet model, we show that the inner planet accelerates the precession rate of the binary pericenter, which, in turn, may enter in resonance with the secular frequency of the outer planet, characterizing a secular resonance. We calculate an analytical expression for the approximate location of this resonance and apply it to known circumbinary systems, where we show that it can occur at relatively close orbits, for example at 2.4 au for the Kepler-38 system. With a more refined model, we analyse the dynamics of this secular resonance and we show that a bifurcation of the corresponding fixed points can affect the long- term evolution and stability of planetary systems. By comparing our results with complete integrations of the exact equations of motion, we verified the accuracy of our analytical model.

Exoplanet Science with TMT

NASA Astrophysics Data System (ADS)

Crossfield, Ian

2014-07-01

TMT will have unparalleled capabilities for characterizing the composition of extrasolar planets and their atmospheres, and for probing the complex interplay between planet formation, evolution, and migration. In this plenary talk I will summarize these science cases and discuss their synergy with other observing facilities. High-resolution imaging with IRIS and PFI/SEIT will study young, hot planets in nearby star-forming regions, complementing JWST and WFIRST/AFTA coronagraphic efforts at larger semimajor axes. The same instruments will flesh out planets detected by radial velocity (RV) by measuring the albedos and bolometric radii of old, cold Jovian planets and a few ~300 K super-Earths. Complementing JWST and HST studies of short-period transiting planets, NIRES and IRMS spectroscopy will reveal atmospheric composition, dynamics, and thermal structure for dozens of hot Jupiters and Neptunes; NIRES will also produce 2D global maps and movies of a few exoplanets and dozens of brown dwarfs. HROS high-dispersion spectroscopy will precisely measure the composition of extrasolar planetesimals in polluted white dwarfs, and RV followup will continue to exploit the legacies of Kepler, K2, TESS, and PLATO to measure the masses, orbits, and bulk compositions of Earth analogues. Most exciting of all, TMT may facilitate the next major step in the study of exobiology by allowing the detection of biosignature gases around the closest habitable transiting planets.

The fates of Solar system analogues with one additional distant planet

NASA Astrophysics Data System (ADS)

Veras, Dimitri

2016-12-01

The potential existence of a distant planet (`Planet Nine') in the Solar system has prompted a re-think about the evolution of planetary systems. As the Sun transitions from a main-sequence star into a white dwarf, Jupiter, Saturn, Uranus and Neptune are currently assumed to survive in expanded but otherwise unchanged orbits. However, a sufficiently distant and sufficiently massive extra planet would alter this quiescent end scenario through the combined effects of Solar giant branch mass-loss and Galactic tides. Here, I estimate bounds for the mass and orbit of a distant extra planet that would incite future instability in systems with a Sun-like star and giant planets with masses and orbits equivalent to those of Jupiter, Saturn, Uranus and Neptune. I find that this boundary is diffuse and strongly dependent on each of the distant planet's orbital parameters. Nevertheless, I claim that instability occurs more often than not when the planet is as massive as Jupiter and harbours a semimajor axis exceeding about 300 au, or has a mass of a super-Earth and a semimajor axis exceeding about 3000 au. These results hold for orbital pericentres ranging from 100 to at least 400 au. This instability scenario might represent a common occurrence, as potentially evidenced by the ubiquity of metal pollution in white dwarf atmospheres throughout the Galaxy.

How Planet Nine could change the fate of the Solar system

NASA Astrophysics Data System (ADS)

Veras, D.

2017-09-01

The potential existence of a distant planet ('Planet Nine') in the Solar system has prompted a re-think about the evolution of planetary systems. As the Sun transitions from a main-sequence star into a white dwarf, Jupiter, Saturn, Uranus and Neptune are currently assumed to survive in expanded but otherwise unchanged orbits. However, a sufficiently distant and sufficiently massive extra planet would alter this quiescent end scenario through the combined effects of Solar giant branch mass-loss and Galactic tides. Here I estimate bounds for the mass and orbit of a distant extra planet that would incite future instability in systems with a Sun-like star and giant planets with masses and orbits equivalent to those of Jupiter, Saturn, Uranus and Neptune. I find that this boundary is diffuse and strongly dependent on each of the distant planet's orbital parameters. Nevertheless, I claim that instability occurs more often than not when the planet is as massive as Jupiter and harbours a semimajor axis exceeding about 300 au, or has a mass of a super-Earth and a semimajor axis exceeding about 3000 au. These results hold for orbital pericentres ranging from 100 to at least 400 au. This instability scenario might represent a common occurrence, as potentially evidenced by the ubiquity of metal pollution in white dwarf atmospheres throughout the Galaxy.

Origin of water in the inner Solar System: Planetesimals scattered inward during Jupiter and Saturn's rapid gas accretion

NASA Astrophysics Data System (ADS)

Raymond, Sean N.; Izidoro, Andre

2017-11-01

There is a long-standing debate regarding the origin of the terrestrial planets' water as well as the hydrated C-type asteroids. Here we show that the inner Solar System's water is a simple byproduct of the giant planets' formation. Giant planet cores accrete gas slowly until the conditions are met for a rapid phase of runaway growth. As a gas giant's mass rapidly increases, the orbits of nearby planetesimals are destabilized and gravitationally scattered in all directions. Under the action of aerodynamic gas drag, a fraction of scattered planetesimals are deposited onto stable orbits interior to Jupiter's. This process is effective in populating the outer main belt with C-type asteroids that originated from a broad (5-20 AU-wide) region of the disk. As the disk starts to dissipate, scattered planetesimals reach sufficiently eccentric orbits to cross the terrestrial planet region and deliver water to the growing Earth. This mechanism does not depend strongly on the giant planets' orbital migration history and is generic: whenever a giant planet forms it invariably pollutes its inner planetary system with water-rich bodies.

Children's Books in Review. Saving and Appreciating Our Planet.

ERIC Educational Resources Information Center

Winfield, Evelyn T.

1992-01-01

Reviews books for preschool through elementary school students, focusing on environmental issues in urban and rural areas. The literature examines such topics as saving the tropical rainforests, conserving energy and resources, decreasing pollution, and saving endangered species. (SM)

Planets migrating into stars: Rates and Signature

NASA Astrophysics Data System (ADS)

Taylor, Stuart F.

2015-01-01

New measurements of the occurrence distribution of planets (POD) make it possible to make the first determination of the rate of planet migration into stars as a function of the strength of stellar tidal dissipation. We show how the period at which there is falloff in the POD due to planets migrating into the star can be used to calculate this rate. We show that it does not take extremely weak tidal dissipation for this rate to be low enough to be supplied by a reasonable number of planets being scattered into the lowest period region. The presence of the shortest period giant planets can be better explained by the ongoing migration of giant planets into stars. The presence of giant planets in period on the order of a day and less had prompted some to conclude that tidal dissipation in stars must necessarily be much weaker for planet mass than for binary star mass companions. However, a flow of less than one planet per thousand stars per gigayear could explain their presence without requiring as much of a difference in tidal dissipation strength in stars for planetary than for stellar mass companions. We show several new analytical expressions describing the rate of evolution of the falloff in the POD, as well as the rate of planet. The question of how strong is the tidal dissipation (the quality factor 'Q') for planet-mass companions may be answered within a few years by a measurable time shift in the transit period. We show that the distribution of remaining planet lifetimes indicates a mass-dependence of the stellar tidal dissipation. The possibility of regular merger of planets with stars has led us to find several correlations of iron abundance in stars with planet parameters, starting with the iron-eccentricity correlation (Taylor 2012, Dawson & Murray-Clay 2013). These correlations change in the presence of a stellar companion. We show that the distribution of planets of iron-rich planets is significantly different from the distribution of iron poor stars in several ways which indicate that both formation and whole planet pollution play roles in producing several recently discovered planet-star correlations.

THE PAN-PACIFIC PLANET SEARCH. II. CONFIRMATION OF A TWO-PLANET SYSTEM AROUND HD 121056

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

Wittenmyer, Robert A.; Tinney, C. G.; Wang, Liang

2015-02-10

Precise radial velocities from the Anglo-Australian Telescope (AAT) confirm the presence of a rare short-period planet around the K0 giant HD 121056. An independent two-planet solution using the AAT data shows that the inner planet has P = 89.1 ± 0.1 days, and m sin i = 1.35 ± 0.17 M{sub Jup}. These data also confirm the planetary nature of the outer companion, with m sin i = 3.9 ± 0.6 M{sub Jup} and a = 2.96 ± 0.16 AU. HD 121056 is the most-evolved star to host a confirmed multiple-planet system, and is a valuable example of a giant star hosting both a short-period andmore » a long-period planet.« less

NASA's Hubble Space Telescope Finds Dead Stars 'Polluted with Planet Debris'

NASA Image and Video Library

2017-12-08

This is an artist’s impression of a white dwarf (burned-out) star accreting rocky debris left behind by the star’s surviving planetary system. It was observed by Hubble in the Hyades star cluster. At lower right, an asteroid can be seen falling toward a Saturn-like disk of dust that is encircling the dead star. Infalling asteroids pollute the white dwarf’s atmosphere with silicon. Credit: NASA, ESA, and G. Bacon (STScI) --- NASA's Hubble Space Telescope has found the building blocks for Earth-sized planets in an unlikely place-- the atmospheres of a pair of burned-out stars called white dwarfs. These dead stars are located 150 light-years from Earth in a relatively young star cluster, Hyades, in the constellation Taurus. The star cluster is only 625 million years old. The white dwarfs are being polluted by asteroid-like debris falling onto them. 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

14th Annual P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet

EPA Pesticide Factsheets

EPA as part of its People, Prosperity and the Planet (P3) Award Program – is seeking applications proposing to research, develop, and design solutions to real world challenges involving sustainability.

Planetary Engulfment as a Trigger for White Dwarf Pollution

NASA Astrophysics Data System (ADS)

Petrovich, Cristobal; Muñoz, Diego J.

2017-01-01

The presence of a planetary system can shield a planetesimal disk from the secular gravitational perturbations due to distant outer massive objects (planets or stellar companions). As the host star evolves off the main sequence to become a white dwarf, these planets can be engulfed during the giant phase, triggering secular instabilities and leading to the tidal disruptions of small rocky bodies. These disrupted bodies can feed the white dwarfs with rocky material and possibly explain the high-metallicity material in their atmospheres. We illustrate how this mechanism can operate when the gravitational perturbations are due to the KL mechanism from a stellar binary companion, a process that is activated only after the planet has been removed/engulfed. We show that this mechanism can explain the observed accretion rates if: (1) the planetary engulfment happens rapidly compared to the secular timescale, which is generally the case for wide binaries (> 100 au) and planetary engulfment during the asymptotic giant branch; (2) the planetesimal disk has a total mass of ˜ {10}-4-{10}-2{M}\\oplus . We show that this new mechanism can provide a steady supply of material throughout the entire life of the white dwarfs for all cooling ages and can account for a large fraction (up to nearly half) of the observed polluted white dwarfs.

Plants and their microbial assistants: Nature's answer to Earth's environmental pollution problems

NASA Technical Reports Server (NTRS)

Wolverton, B. C.

1990-01-01

The utilization of higher plants and their associated microorganisms to solve environmental pollution problems on Earth and in future space applications is briefly reviewed. If man is sealed inside closed facilities, he becomes a polluter of the environment. It is also common knowledge to most people that man cannot survive on Earth without green photosynthesizing plants and microorganisms. Therefore, it is vitally important to have a better understanding of the interactions of man with plants and microorganisms. Biosphere 2 and other related studies presently being conducted or planned, hopefully, will supply data that will help save planet Earth from impending environmental disaster. The development of means to utilize both air and water pollution as a nutrient source for growing green plants is examined.

The Anglo-Australian Planet Search. XXV. A Candidate Massive Saturn Analog Orbiting HD 30177

NASA Astrophysics Data System (ADS)

Wittenmyer, Robert A.; Horner, Jonathan; Mengel, M. W.; Butler, R. P.; Wright, D. J.; Tinney, C. G.; Carter, B. D.; Jones, H. R. A.; Anglada-Escudé, G.; Bailey, J.; O'Toole, Simon J.

2017-04-01

We report the discovery of a second long-period giant planet orbiting HD 30177, a star previously known to host a massive Jupiter analog (HD 30177b: a = 3.8 ± 0.1 au, m sin I = 9.7 ± 0.5 M Jup). HD 30177c can be regarded as a massive Saturn analog in this system, with a = 9.9 ± 1.0 au and m sin I = 7.6 ± 3.1 M Jup. The formal best-fit solution slightly favors a closer-in planet at a ˜ 7 au, but detailed n-body dynamical simulations show that configuration to be unstable. A shallow local minimum of longer period, lower eccentricity solutions was found to be dynamically stable, and hence we adopt the longer period in this work. The proposed ˜32 year orbit remains incomplete; further monitoring of this and other stars is necessary to reveal the population of distant gas giant planets with orbital separations a ˜ 10 au, analogous to that of Saturn.

Evidence for water in the rocky debris of a disrupted extrasolar minor planet.

PubMed

Farihi, J; Gänsicke, B T; Koester, D

2013-10-11

The existence of water in extrasolar planetary systems is of great interest because it constrains the potential for habitable planets and life. We have identified a circumstellar disk that resulted from the destruction of a water-rich and rocky extrasolar minor planet. The parent body formed and evolved around a star somewhat more massive than the Sun, and the debris now closely orbits the white dwarf remnant of the star. The stellar atmosphere is polluted with metals accreted from the disk, including oxygen in excess of that expected for oxide minerals, indicating that the parent body was originally composed of 26% water by mass. This finding demonstrates that water-bearing planetesimals exist around A- and F-type stars that end their lives as white dwarfs.

Climate change impacts on human exposures to air pollution ...

EPA Pesticide Factsheets

This is an abstract for a presentations at the Annual Conference of the International Society on Exposure Science and Environmental Epidemiology. This presentation will serve as an introduction to the symposium. As we consider the potential health impacts of a warming planet, the relationships between climate change and air pollutants become increasingly important to understand. These relationships are complex and highly variable, causing a variety of environmental impacts at local, regional and global scales. Human exposures and health impacts for air pollutants have the potential to be altered by changes in climate through multiple factors that drive population exposures to these pollutants. Research on this topic will provide both state and local governments with the tools and scientific knowledge base to undertake any necessary adaptation of the air pollution regulations and/or public health management systems in the face of climate change.

Seeing the Sky: 100 Projects, Activities, and Explorations in Astronomy.

ERIC Educational Resources Information Center

Schaaf, Fred

1990-01-01

Fourteen astronomy activities are presented including classroom procedures and questions. Topics include different investigations of the moon, planets, stars, sunsets, light pollution, and rainbows and halos. Additional information on measurements used for observations in astronomy, and rainbow characteristics is included. (CW)

Giant Planets around FGK Stars Probably Form through Core Accretion

NASA Astrophysics Data System (ADS)

Wang, Wei; Wang, Liang; Li, Xiang; Chen, Yuqin; Zhao, Gang

2018-06-01

We present a statistical study of the planet–metallicity (P–M) correlation by comparing the 744 stars with candidate planets (SWPs) in the Kepler field that have been observed with LAMOST, and a sample of distance-independent, fake “twin” stars in the Kepler field with no planet reported (CKSNPs) yet. With well-defined and carefully selected large samples, we find for the first time a turnoff P–M correlation of Δ[Fe/H]SWPs–SNPs, which on average increases from ∼0.00 ± 0.03 dex to 0.06 ± 0.03 dex, and to 0.12 ± 0.03 for stars with Earth-, Neptune-, and Jupiter-sized planets successively, and then declines to ∼‑0.01 ± 0.03 dex for more massive planets or brown dwarfs. Moreover, the percentage of those systems with positive Δ[Fe/H] has the same turnoff pattern. We also find that FG-type stars follow this general trend, but K-type stars are different. Moderate metal enhancement (∼0.1–0.2 dex) for K-type stars with planets of radii between 2 and 4 R ⊕, compared to CKSNPs is observed, which indicates much higher metallicities are required for Super-Earths and Neptune-sized planets to form around K-type stars. We point out that the P–M correlation is actually metallicity-dependent, i.e., the correlation is positive at solar and supersolar metallicities, and negative at subsolar metallicities. No steady increase of Δ[Fe/H] against planet sizes is observed for rocky planets, excluding the pollution scenario as a major mechanism for the P–M correlation. All these clues suggest that giant planets probably form differently from rocky planets or more massive planets/brown dwarfs, and the core accretion scenario is highly favored, and high metallicity is a prerequisite for massive planets to form.

Planet Press: an EGU initiative to bring geoscientific research to children

NASA Astrophysics Data System (ADS)

Ferreira, Bárbara

2016-04-01

Planet Press (http://www.egu.eu/education/planet-press/) is an EGU educational project that aims to get children (mainly 7-13 year olds), as well as their parents and educators, interested in and engaged with up-to-date scientific research and news. Planet Press articles are short versions of EGU press releases written in child-friendly language. Because EGU press releases cover research published in the various EGU scientific journals, Planet Press focuses on topics as varied as air pollution, glaciers, climate change, earthquakes, ocean sciences, droughts and floods, or space sciences. The texts are reviewed by both scientists and educators to make sure they are accurate and clear to their target audience. By sharing new and exciting geoscientific research with young kids, we hope to inspire them to develop an interest in the Earth, planetary and space sciences. In this presentation, we describe how the Planet Press idea came about, how the project is run, and the challenges and lessons learnt since the launch of this educational initiative in 2014. Planet Press, which has the support of the EGU Committee on Education, is made possible by the work of volunteer scientists and educators who review and translate the texts. We are grateful for the help of Jane Robb, former EGU Educational Fellow, with launching the project. Planet Press is inspired by Space Scoop (http://www.spacescoop.org/), an initiative by UNAWE, the EU-Universe Awareness organisation, that brings astronomy news to children every week.

15th Annual P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet

EPA Pesticide Factsheets

The U.S. Environmental Protection Agency (EPA) – as part of its People, Prosperity and the Planet (P3) Award Program – is seeking applications proposing to research, develop, design, and demonstrate solutions to real world challenges

Climate changes-What are the possible solutions?

NASA Astrophysics Data System (ADS)

Di Carlo, Caterina

2017-04-01

In this year, my school agreed to the Educational National Event "Week UNESCO DESS 2016-Education to the sustainable development". The proposal theme was "Climate changes-What can our cities do?" In November 2016 conferences, discussions, animations were organized in three second classrooms with 46 students of 16 age in total. During these activities, developed with the help of the curriculum teachers, the theme of the climate changes has been treated, in particular in the Mediterranean area with different evidences; one of them was the danger of the loss of the resources and biodiversity as concrete example. Then opinions, reflections were picked up on what solutions could be start up to limit the causes of the climate changes. All the work had the aim to sensitize the new generations to the problems and to stimulate a critical and responsible attitude in the sphere of the sustainable development. The opinions with the solutions were picked up and analysed. Results were the following: 15 students suggested as solution, to limit the use of the cars that consume hydrocarbons and to introduce electric cars in the big cities; to limit also the use of the electric energy in the houses and cities; 14 students thought it was important to project new technologies without hydrocarbons; 7 students suggested to develop more the renewable energies less polluting; 3 students thought it was important to manage better the waste with the recycle; 3 students suggested to increase the trees in the forest; 2 students thought it was important to form and to inform all the citizens of the Planet; 1 student suggested that world political leaders had to propose the solutions; 1 student thought it was important to use food produced locally. From that, is clear that the students are conscious of the solutions taken by the political leaders on the environment, but they also consider important the action of the single person that if observed by everyone can lead to a general improvement. Students solutions with higher range, as to limit the hydrocarbons cars and to project new technologies, probably have appeared because they live in an overcrowded city with intense road traffic. They perceive at the emotive level a trouble, a vexation in this situation. At this moment we think to realize a "brochure" with all the solutions as best practices more practicable by a single person, a sort of a "Vademecum"to be responsible citizens of the Planet in our time. In conclusion we believe this experience is also a didactic practice that permits to develop Science's curriculum giving back protagonists the students that can develop skills and competences for the solutions of the problems today and tomorrow.

Aerospace vehicle design, spacecraft section. Volume 2

NASA Technical Reports Server (NTRS)

1988-01-01

The next major step in the evolution of the space program is the exploration of the planet Mars. In preparation for this, much research is needed on the problem of surveying the planet surface. An aircraft appears to be a viable solution because it can carry men and equipment large distances in a short period of time as compared with ground transportation. The problems and design of an aircraft which would be able to survey the planet Mars are examined.

13th Annual P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet

EPA Pesticide Factsheets

The EPA, as part of the P3-People, Prosperity and the Planet Award Program, is seeking applications proposing to research, develop, and design solutions to real world challenges involving the overall sustainability of human society.

This Little Planet.

ERIC Educational Resources Information Center

Hamilton, Michael, Ed.

In six essays considering overpopulation, pollution, and food supply from the framework of the Judeo-Christian tradition and of world ecology, three theologians (Pollard, Shinn, and Bonifazi), an ecologist (Sears), a geographer (Glacken), and a medical scientist and administrator (Bennett), conclude that the control and preservation of the natural…

3D hydrodynamic simulations of tidal disruption of terrestrial planets around white dwarfs

NASA Astrophysics Data System (ADS)

Liu, Shangfei; Zhang, Jinsu; Lin, Douglas N. C.

2018-01-01

Recent K2 mission spotted striking variability due to a group of minor bodies transiting white dwarf WD 1145+017 with periods ranging from 4.5 hours to 4.9 hours. One of the formation scenarios is that those transiting objects are the debris of a tidally disrupted minor planet. This scenario is consistent with fact that the white dwarf also hosts a dusty disk and displays strong metal atmospheric pollution. In this work, we perform state-of-the-art three-dimensional hydrodynamic simulations to study the consequences of tidal disruption of planets with various differentiated compositions by a white dwarf. We study the general outcomes of tidal disruption including partially disruption and total disruption. We also apply our results to the WD 1145+017 system to infer the physical and orbital properties of the progenitor.

The Greenhouse Gases. UNEP/GEMS Environment Library No. 1.

ERIC Educational Resources Information Center

United Nations Environment Programme, Nairobi (Kenya).

Since the United Nations Environment Program (UNEP) was created, more than a dozen years ago, public understanding of the environmental issues confronting our planet has increased enormously. The Global Environment Monitoring System (GEMS) has provided several environmental assessments including urban air pollution, climate modification,…

Two cultures are better than one: Earth sciences and Art for a better planet sustainability

NASA Astrophysics Data System (ADS)

Lanza, Tiziana; Rubbia, Giuliana; Negrete, Aquiles

2015-04-01

Climate change, pollution, desertification, natural hazard, animals' extinction are some of the problems we face every day. Very often Science and Technology are charged of the solutions while Art is intended mainly for entertainment. Are we sure this is the right attitude? "Technology is a queer thing. It brings you gifts with one hand, and stabs you in the back with the other", says C.P.Snow, author of a milestone book on the Two Cultures, namely Sciences and Humanities. If Science can drive to a rigorous knowledge of the Earth speaking to people's mind, Technology is Science in action. When individuals act very often the reasons behind their actions are linked to their education, values, sense of beauty, presence or absence of feelings, all things pertaining to the emotional sphere of humans usually addressed by humanistic culture. But if in one hand, Science and Technology cannot be left alone to solve the impelling problems that are deteriorating not only our planet resources but also our quality of life, on the other hand the humanistic culture can find a powerful ally in scientific culture for re-awakening in everybody the sense of beauty, values and respect for the planet. To know Earth is to love Earth, since nature is in itself a work of Art. Earth sciences dig out all the secrets that make our planet a unique place in the Universe we know. Every single phenomena can be seen then in a double face value. An Aurora, for instance, can inspire poetry for its beauty and colors but always remains the result of the interaction between the solar wind and the Earth magnetic field. And, most important, an Aurora will never inspire negative feelings. To make our part in creating a common field between Art and Earth sciences, we have created a blog and a related FaceBook page to collect, browsing the web, all the experiences in this trend, to find out that many scientists and artists are already working in this direction as a final and enjoyable surprise.

Multi-layer hydrostatic equilibrium of planets and synchronous moons: theory and application to Ceres and to solar system moons

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

Tricarico, Pasquale

2014-02-20

The hydrostatic equilibrium of multi-layer bodies lacks a satisfactory theoretical treatment despite its wide range of applicability. Here we show that by using the exact analytical potential of homogeneous ellipsoids we can obtain recursive analytical solutions and an exact numerical method for the hydrostatic equilibrium shape problem of multi-layer planets and synchronous moons. The recursive solutions rely on the series expansion of the potential in terms of the polar and equatorial shape eccentricities, while the numerical method uses the exact potential expression. These solutions can be used to infer the interior structure of planets and synchronous moons from their observedmore » shape, rotation, and gravity. When applied to the dwarf planet Ceres, we show that it is most likely a differentiated body with an icy crust of equatorial thickness 30-90 km and a rocky core of density 2.4-3.1 g cm{sup –3}. For synchronous moons, we show that the J {sub 2}/C {sub 22} ≅ 10/3 and the (b – c)/(a – c) ≅ 1/4 ratios have significant corrections of order Ω{sup 2}/(πGρ), with important implications for how their gravitational coefficients are determined from fly-by radio science data and for how we assess their hydrostatic equilibrium state.« less

THE CALIFORNIA PLANET SURVEY IV: A PLANET ORBITING THE GIANT STAR HD 145934 AND UPDATES TO SEVEN SYSTEMS WITH LONG-PERIOD PLANETS

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

Katherina Feng, Y.; Wright, Jason T.; Nelson, Benjamin

2015-02-10

We present an update to seven stars with long-period planets or planetary candidates using new and archival radial velocities from Keck-HIRES and literature velocities from other telescopes. Our updated analysis better constrains orbital parameters for these planets, four of which are known multi-planet systems. HD 24040 b and HD 183263 c are super-Jupiters with circular orbits and periods longer than 8 yr. We present a previously unseen linear trend in the residuals of HD 66428 indicative of an additional planetary companion. We confirm that GJ 849 is a multi-planet system and find a good orbital solution for the c component: it is a 1more » M {sub Jup} planet in a 15 yr orbit (the longest known for a planet orbiting an M dwarf). We update the HD 74156 double-planet system. We also announce the detection of HD 145934 b, a 2 M {sub Jup} planet in a 7.5 yr orbit around a giant star. Two of our stars, HD 187123 and HD 217107, at present host the only known examples of systems comprising a hot Jupiter and a planet with a well constrained period greater than 5 yr, and with no evidence of giant planets in between. Our enlargement and improvement of long-period planet parameters will aid future analysis of origins, diversity, and evolution of planetary systems.« less

iSTEM: Celebrating Earth Day with Sustainability

ERIC Educational Resources Information Center

Sibley, Amanda; Kurz, Terri L.

2014-01-01

Earth Day is celebrated annually on April 22. Teachers often commemorate Earth Day with their classes by planting trees, discussing important conservation topics (such as recycling or preventing pollution), and encouraging students to take care of planet Earth. To promote observance of Earth Day in an intermediate elementary school classroom, this…

SOLSOURCE 3-IN-1: PROVIDING CLEAN ENERGY TO THE POOREST 2.5 BILLION AT A PRICE THEY CAN AFFORD

EPA Science Inventory

We expect this project to have the following impacts on people, prosperity, and the planet:

People: Decreased indoor air pollution exposures, decreased pathogen transmission, decreased injuries and miscarriages during fuel collection along mountain slopes, increased ...

Safe Planet. The Guide to Environmental Film and Video.

ERIC Educational Resources Information Center

Media Network, New York, NY.

Innovative and incisive films and videotapes exist which address the issues of toxic waste, agricultural pollutants, land and water use, energy production, and other important environmental topics. They provide in-depth analyses, alternative points of view, and specific suggestions for what ordinary citizens can do to help stop environmental…

Compositional Constraints on the Best Characterized Rocky Exoplanet, Kepler-36 b

NASA Astrophysics Data System (ADS)

Rogers, Leslie; Deck, Katherine; Lissauer, Jack J.; Carter, Joshua A.

2015-01-01

Kepler-36 is an extreme planetary system, consisting of two transiting sub-Neptune-size planets that revolve around a sub-giant star with orbital periods of 13.84 and 16.24 days. Mutual gravitational interactions between the two planets perturb the planets' transit times, allowing the planets' masses to be measured. Despite the similarity of their masses and orbital radii, the planets show a stark contrast in their mean densities; the inner planet (Kepler-36 b) is more than eight times as dense as its outer companion planet (Kepler-36 c). We perform a photo-dynamical analysis of the Kepler-36 system based on more than three years of Kepler photometry. With N-body integrations of initial conditions sampled from the photo-dynamical fits, we further refine the properties of the system by ruling out solutions that show large-scale instability within 5 Giga-days. Ultimately, we measure the planets' masses within 4.2% precision, and the planets' radii with 1.8% precision. Kepler-36 b is currently the rocky exoplanet with the most precisely measured mass and radius. Kepler-36 b's mass and radius are consistent with an Earth-like composition, and an iron-enhanced Mercury-like composition is ruled out.

Compositional Constraints on the Best Characterized Rocky Exoplanet, Kepler-36 b

NASA Astrophysics Data System (ADS)

Rogers, Leslie Anne; Deck, Katherine; Lissauer, Jack; Carter, Joshua

2015-08-01

Kepler-36 is an extreme planetary system, consisting of two transiting sub-Neptune-size planets that revolve around a sub-giant star with orbital periods of 13.84 and 16.24 days. Mutual gravitational interactions between the two planets perturb the planets' transit times, allowing the planets' masses to be measured. Despite the similarity of their masses and orbital radii, the planets show a stark contrast in their mean densities; the inner planet (Kepler-36 b) is more than eight times as dense as its outer companion planet (Kepler-36 c). We perform a photo-dynamical analysis of the Kepler-36 system based on more than three years of Kepler photometry. With N-body integrations of initial conditions sampled from the photo-dynamical fits, we further refine the properties of the system by ruling out solutions that show large scale instability within 5 Giga-days. Ultimately, we measure the planets' masses within 4.2% precision, and the planets' radii with 1.8% precision. Kepler-36 b is currently the rocky exoplanet with the most precisely measured mass and radius. Kepler-36 b’s mass and radius are consistent with a Earth-like composition, and an iron-enhanced Mercury-like composition is ruled out.

Compositional Constraints on the Best Characterized Rocky Exoplanet, Kepler-36 b

NASA Astrophysics Data System (ADS)

Rogers, L.; Deck, K.; Lissauer, J. J.; Carter, J.

2014-12-01

Kepler-36 is an extreme planetary system, consisting of two transiting sub-Neptune-size planets that revolve around a sub-giant star with orbital periods of 13.84 and 16.24 days. Mutual gravitational interactions between the two planets perturb the planets' transit times, allowing the planets' masses to be measured. Despite the similarity of their masses and orbital radii, the planets show a stark contrast in their mean densities; the inner planet (Kepler-36 b) is more than eight times as dense as its outer companion planet (Kepler-36 c). We perform a photo-dynamical analysis of the Kepler-36 system based on more than three years of Kepler photometry. With N-body integrations of initial conditions sampled from the photo-dynamical fits, we further refine the properties of the system by ruling out solutions that show large scale instability within 5 Giga-days. Ultimately, we measure the planets' masses within 4.2% precision, and the planets' radii with 1.8% precision. Kepler-36 b is currently the rocky exoplanet with the most precisely measured mass and radius. Kepler-36 b's mass and radius are consistent with a Earth-like composition, and an iron-enhanced Mercury-like composition is ruled out.

Secure Mass Measurements from Transit Timing: 10 Kepler Exoplanets between 3 and 8 M⊕ with Diverse Densities and Incident Fluxes

NASA Astrophysics Data System (ADS)

Jontof-Hutter, Daniel; Ford, Eric B.; Rowe, Jason F.; Lissauer, Jack J.; Fabrycky, Daniel C.; Van Laerhoven, Christa; Agol, Eric; Deck, Katherine M.; Holczer, Tomer; Mazeh, Tsevi

2016-03-01

We infer dynamical masses in eight multiplanet systems using transit times measured from Kepler's complete data set, including short-cadence data where available. Of the 18 dynamical masses that we infer, 10 pass multiple tests for robustness. These are in systems Kepler-26 (KOI-250), Kepler-29 (KOI-738), Kepler-60 (KOI-2086), Kepler-105 (KOI-115), and Kepler-307 (KOI-1576). Kepler-105 c has a radius of 1.3 R⊕ and a density consistent with an Earth-like composition. Strong transit timing variation (TTV) signals were detected from additional planets, but their inferred masses were sensitive to outliers or consistent solutions could not be found with independently measured transit times, including planets orbiting Kepler-49 (KOI-248), Kepler-57 (KOI-1270), Kepler-105 (KOI-115), and Kepler-177 (KOI-523). Nonetheless, strong upper limits on the mass of Kepler-177 c imply an extremely low density of ˜0.1 g cm-3. In most cases, individual orbital eccentricities were poorly constrained owing to degeneracies in TTV inversion. For five planet pairs in our sample, strong secular interactions imply a moderate to high likelihood of apsidal alignment over a wide range of possible eccentricities. We also find solutions for the three planets known to orbit Kepler-60 in a Laplace-like resonance chain. However, nonlibrating solutions also match the transit timing data. For six systems, we calculate more precise stellar parameters than previously known, enabling useful constraints on planetary densities where we have secure mass measurements. Placing these exoplanets on the mass-radius diagram, we find that a wide range of densities is observed among sub-Neptune-mass planets and that the range in observed densities is anticorrelated with incident flux.

The Robo-AO KOI Survey: Laser Adaptive Optics Imaging of Every Kepler Exoplanet Candidate

NASA Astrophysics Data System (ADS)

Ziegler, Carl; Law, Nicholas M.; Baranec, Christoph; Morton, Tim; Riddle, Reed L.

2016-01-01

The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star (KOI) with laser adaptive optics imaging to hunt for blended nearby stars which may be physically associated companions. With the unparalleled efficiency provided by the first fully robotic adaptive optics system, we perform the critical search for nearby stars (0.15" to 4.0" separation with contrasts up to 6 magnitudes) that pollute the observed planetary transit signal, contributing to inaccurate planetary characteristics or astrophysical false positives. We present approximately 3300 high resolution observations of Kepler planetary hosts from 2012-2015, with ~500 observed nearby stars. We measure an overall nearby star probability rate of 16.2±0.8%. With this large dataset, we are uniquely able to explore broad correlations between multiple star systems and the properties of the planets which they host. We then use these clues for insight into the formation and evolution of these exotic systems. Several KOIs of particular interest will be discussed, including possible quadruple star systems hosting planets and updated properties for possible rocky planets orbiting in the habitable zone.

Detectable close-in planets around white dwarfs through late unpacking

NASA Astrophysics Data System (ADS)

Veras, Dimitri; Gänsicke, Boris T.

2015-02-01

Although 25-50 per cent of white dwarfs (WDs) display evidence for remnant planetary systems, their orbital architectures and overall sizes remain unknown. Vibrant close-in (≃1 R⊙) circumstellar activity is detected at WDs spanning many Gyr in age, suggestive of planets further away. Here we demonstrate how systems with 4 and 10 closely packed planets that remain stable and ordered on the main sequence can become unpacked when the star evolves into a WD and experience pervasive inward planetary incursions throughout WD cooling. Our full-lifetime simulations run for the age of the Universe and adopt main-sequence stellar masses of 1.5, 2.0 and 2.5 M⊙, which correspond to the mass range occupied by the progenitors of typical present-day WDs. These results provide (i) a natural way to generate an ever-changing dynamical architecture in post-main-sequence planetary systems, (ii) an avenue for planets to achieve temporary close-in orbits that are potentially detectable by transit photometry and (iii) a dynamical explanation for how residual asteroids might pollute particularly old WDs.

The applications of chemical thermodynamics and chemical kinetics to planetary atmospheres research

NASA Technical Reports Server (NTRS)

Fegley, Bruce, Jr.

1990-01-01

A review of the applications of chemical thermodynamics and chemical kinetics to planetary atmospheres research during the past four decades is presented with an emphasis on chemical equilibrium models and thermochemical kinetics. Several current problems in planetary atmospheres research such as the origin of the atmospheres of the terrestrial planets, atmosphere-surface interactions on Venus and Mars, deep mixing in the atmospheres of the gas giant planets, and the origin of the atmospheres of outer planet satellites all require laboratory data on the kinetics of thermochemical reactions for their solution.

Teaching Sustainability in the Anthropocene

NASA Astrophysics Data System (ADS)

Ibarra, D. L.

2017-12-01

Human impact on our planet Earth and its ecosystems is well documented and a new epoch, Anthropocene, has been suggested within the scientific community. As educators in the 21st century we are tasked within our communities to teach both the impacts of mankind on our planet and help students to design solutions that will solve a multitude of life threatening challenges. At ISF Academy in Hong Kong, faculty are working collaboratively within the whole school community to educate students about the fundamental problems facing society today and give students to skills to creatively solve these problems locally, regionally, and globally. As a leading school in HK, the physical campus has been updated to provide students with hands-on opportunities to see the latest technologies used for sustainable development. Recently added infrastructure includes air pollution monitoring equipment, an energy management system, aerobic food waste composting, organic garden, bio-diverse landscaping, and photovoltaic renewable energy. The design of each of these systems allows for students to interact directly with the equipment, and conduct student-led research. The curriculum across the campus is designed for all students K-12 and there is an on-going effort to make cross-disciplinary links. The programs outside of the classroom include ecology trips in the Asia region, experiential learning programs that allow students to learn first hand the climate change challenges for communities in distress, and field trips where students work with local experts. Also within the context of the school, there is a new established maker-space that will allow students to work collaboratively together while testing and prototyping their solutions. Hong Kong will need to solve many pressing problems in the next few years and this will require expertise, new innovations, and behaviour changes on the part of all citizens. Our goal at ISF Academy is to equip our students with the required background knowledge to help solve these problems.

How can we make biofuels more climate friendly?

USDA-ARS?s Scientific Manuscript database

Wouldn’t it be great to find a fuel that powers our cars and planes without polluting the environment or warming up our planet? Fuels made from plants, like corn or sugarcane, called “biofuels,” appeared to be more climate-friendly than burning fossil fuels. Unfortunately, it turns out that many bi...

The impact of environmental Pollution on soil and climate change, and how to deal with.

NASA Astrophysics Data System (ADS)

Kaadan, M. Ihsan

2010-05-01

introduction: Every person on Earth contributes to the state of our planet, because we all use natural resources and produce waste materials. The more people there are, the more damage they do through pollution. results: Pollution can kill or sicken plants, animals, and people. Pollution can change the environment. Pollution can get into the air. Pollution can also get into soil and water. From there, pollutants can get into the food chain. methods: Laws can stop factories from dumping poisonous chemicals in lakes, rivers, and the ocean. Engineers can build cars that burn less gasoline. Scientists are looking for fuels to replace coal and oil. They are looking for ways to use the power in wind and in rays from the Sun. We can help cut down on the amount of garbage we make. We can recycle paper, plastic, glass bottles, and metal cans. Recycled material gets used over again. Recycling helps cut down on pollution. Discussion: Humans are very inventive and intelligent, as well as very destructive and careless. If we understand that our environment is fragile, then we can all help to save it, and the precious and life-giving resources that it provides.

The Origin of Systematic Errors in the GCM Simulation of ITCZ Precipitation

NASA Technical Reports Server (NTRS)

Chao, Winston C.; Suarez, M. J.; Bacmeister, J. T.; Chen, B.; Takacs, L. L.

2006-01-01

Previous GCM studies have found that the systematic errors in the GCM simulation of the seasonal mean ITCZ intensity and location could be substantially corrected by adding suitable amount of rain re-evaporation or cumulus momentum transport. However, the reason(s) for these systematic errors and solutions has remained a puzzle. In this work the knowledge gained from previous studies of the ITCZ in an aqua-planet model with zonally uniform SST is applied to solve this puzzle. The solution is supported by further aqua-planet and full model experiments using the latest version of the Goddard Earth Observing System GCM.

The chemical composition of the cores of the terrestrial planets and the moon

NASA Technical Reports Server (NTRS)

Kuskov, O. L.; Khitarov, N. I.

1977-01-01

Using models of the quasi-chemical theory of solutions, the activity coefficients of silicon are calculated in the melts Fe-Si, Ni-Si, and Fe-Ni-Si. The calculated free energies of solution of liquid nickel and silicon in liquid iron in the interval 0 to 1400 kbar and 1500 to 4000 K, shows that Fe-Ni-Si alloy is stable under the conditions of the outer core of the earth and the cores of the terrestrial planets. The oxidation-reduction conditions are studied, and the fugacity of oxygen in the mantles of the planets and at the core-mantle boundary are calculated. The mechanism of reduction of silicon is analyzed over a broad interval of p and T. The interaction between the matter of the core and mantle is studied, resulting in the extraction of silicon from the mantle and its solution in the material of the core. It is concluded that silicon can enter into the composition of the outer core of the earth and Venus, but probably does not enter into the composition of the cores of Mercury, Mars, and the moon, if in fact the latter possesses one.

Hydrodynamic escape from planetary atmospheres

NASA Astrophysics Data System (ADS)

Tian, Feng

Hydrodynamic escape is an important process in the formation and evolution of planetary atmospheres. Due to the existence of a singularity point near the transonic point, it is difficult to find transonic steady state solutions by solving the time-independent hydrodynamic equations. In addition to that, most previous works assume that all energy driving the escape flow is deposited in one narrow layer. This assumption not only results in less accurate solutions to the hydrodynamic escape problem, but also makes it difficult to include other chemical and physical processes in the hydrodynamic escape models. In this work, a numerical model describing the transonic hydrodynamic escape from planetary atmospheres is developed. A robust solution technique is used to solve the time dependent hydrodynamic equations. The method has been validated in an isothermal atmosphere where an analytical solution is available. The hydrodynamic model is applied to 3 cases: hydrogen escape from small orbit extrasolar planets, hydrogen escape from a hydrogen rich early Earth's atmosphere, and nitrogen/methane escape from Pluto's atmosphere. Results of simulations on extrasolar planets are in good agreement with the observations of the transiting extrasolar planet HD209458b. Hydrodynamic escape of hydrogen from other hypothetical close-in extrasolar planets are simulated and the influence of hydrogen escape on the long-term evolution of these extrasolar planets are discussed. Simulations on early Earth suggest that hydrodynamic escape of hydrogen from a hydrogen rich early Earth's atmosphere is about two orders magnitude slower than the diffusion limited escape rate. A hydrogen rich early Earth's atmosphere could have been maintained by the balance between the hydrogen escape and the supply of hydrogen into the atmosphere by volcanic outgassing. Origin of life may have occurred in the organic soup ocean created by the efficient formation of prebiotic molecules in the hydrogen rich early Earth's atmosphere. Simulations show that hydrodynamic escape of nitrogen from Pluto is able to remove a ~3 km layer of ice over the age of the solar system. The escape flux of neutral nitrogen may interact with the solar wind at Pluto's orbit and may be detected by the New Horizon mission.

Degradation of organic pollutants in/on snow and ice by singlet molecular oxygen (¹O₂*) and an organic triplet excited state.

PubMed

Bower, Jonathan P; Anastasio, Cort

2014-04-01

Singlet molecular oxygen (¹O₂*) can be a significant sink for a variety of electron-rich pollutants in surface waters and atmospheric drops. We recently found that ¹O₂* concentrations are enhanced by up to a factor of 10(4) on illuminated ice compared to in the equivalent liquid solution, suggesting that ¹O₂* could be an important oxidant for pollutants in snow. To examine this, here we study the degradation of three model organic pollutants: furfuryl alcohol (to represent furans), tryptophan (for aromatic amino acids), and bisphenol A (for phenols). Each compound was studied in illuminated aqueous solution and ice containing Rose Bengal (RB, a sensitizer for ¹O₂*) and sodium chloride (to adjust the concentration of total solutes). The RB-mediated loss of each organic compound is enhanced on illuminated ice compared to in solution, by factors of 6400 for furfuryl alcohol, 8300 for tryptophan, and 50 for bisphenol A for ice containing 0.065 mM total solutes. Rates of loss of furfuryl alcohol and tryptophan decrease at a higher total solute concentration, in qualitative agreement with predictions from freezing-point depression. In contrast, the loss of bisphenol A on ice is independent of total solute concentration. Relative to liquid tests, the enhanced loss of tryptophan on ice during control experiments made with deoxygenated solutions and solutions in D₂O show that the triplet excited state of Rose Bengal may also contribute to loss of pollutants on ice.

Influence of tides in viscoelastic bodies of planet and satellite on the satellite's orbital motion

NASA Astrophysics Data System (ADS)

Emelyanov, N. V.

2018-06-01

The problem of influence of tidal friction in both planetary and satellite bodies upon satellite's orbital motion is considered. Using the differential equations in satellite's rectangular planetocentric coordinates, the differential equations describing the changes in semimajor axis and eccentricity are derived. The equations in rectangular coordinates were taken from earlier works on the problem. The calcultations carried out for a number of test examples prove that the averaged solutions of equations in coordinates and precise solutions of averaged equations in the Keplerian elements are identical. For the problem of tides raised on planet's body, it was found that, if satellite's mean motion n is equal to 11/18 Ω, where Ω is the planet's angular rotation rate, the orbital eccentricity does not change. This conclusion is in agreement with the results of other authors. It was also found that there is essential discrepancy between the equations in the elements obtained in this paper and analogous equations published by earlier researchers.

Automated design of gravity-assist trajectories to Mars and the outer planets

NASA Technical Reports Server (NTRS)

Longuski, James M.; Williams, Steve N.

1991-01-01

In this paper, a new approach to planetary mission design is described which automates the search for gravity-assist trajectories. This method finds all conic solutions given a range of launch dates, a range of launch energies and a set of target planets. The new design tool is applied to the problems of finding multiple encounter trajectories to the outer planets and Venus gravity-assist trajectories to Mars. The last four-planet grand tour opportunity (until the year 2153) is identified. It requires an earth launch in 1996 and encounters Jupiter, Uranus, Neptune, and Pluto. Venus gravity-assist trajectories to Mars for the 30 year period 1995-2024 are examined. It is shown that in many cases these trajectories require less launch energy to reach Mars than direct ballistic trajectories.

The Fate of Unstable Circumbinary Planets

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2016-03-01

What happens to Tattooine-like planets that are instead in unstable orbits around their binary star system? A new study examines whether such planets will crash into a host star, get ejected from the system, or become captured into orbit around one of their hosts.Orbit Around a DuoAt this point we have unambiguously detected multiple circumbinary planets, raising questions about these planets formation and evolution. Current models suggest that it is unlikely that circumbinary planets would be able to form in the perturbed environment close their host stars. Instead, its thought that the planets formed at a distance and then migrated inwards.One danger such planets face when migrating is encountering ranges of radii where their orbits become unstable. Two scientists at the University of Chicago, Adam Sutherland and Daniel Fabrycky, have studied what happens when circumbinary planets migrate into such a region and develop unstable orbits.Producing Rogue PlanetsTime for planets to either be ejected or collide with one of the two stars, as a function of the planets starting distance (in AU) from the binary barycenter. Colors represent different planetary eccentricities. [Sutherland Fabrycky 2016]Sutherland and Fabrycky used N-body simulations to determine the fates of planets orbiting around a star system consisting of two stars a primary like our Sun and a secondary roughly a tenth of its size that are separated by 1 AU.The authors find that the most common fate for a circumbinary planet with an unstable orbit is ejection from the system; over 80% of unstable planets were ejected. This has interesting implications: if the formation of circumbinary planets is common, this mechanism could be filling the Milky Way with a population of free-floating, rogue planets that no longer are associated with their host star.The next most common outcome for unstable planets is collision with one of their host stars (most often the secondary), resulting inaccretion of the planet onto the star. Only rarely do unstable planets make it through the 10,000-yr integration without being removed from the system via ejection or collision.Tidal EffectsAs a final experiment, the authors also added the effects of tidal stripping, which occurs when the stars of the binary tear away some of the planets mass during close encounters. They found that this alters the orbit of the planets that have close encounters with one of the stars, making it slightly more likely that they can be captured around a star.How can we test these models? When a star tidally strips a planet or accretes a planet in a collision, this process leaves its mark on the star in the form of stellar pollution. By comparing the amount of planetary material in the two stars of a binary, it may be possible to confirm the rates predicted here thereby answering the question of what happens to unstable Tattooines.CitationAdam P. Sutherland and Daniel C. Fabrycky 2016 ApJ 818 6. doi:10.3847/0004-637X/818/1/6

Water Pollution. Project COMPSEP.

ERIC Educational Resources Information Center

Lantz, H. B., Jr.

This is an introductory program on water pollution. Examined are the cause and effect relationships of water pollution, sources of water pollution, and possible alternatives to effect solutions from our water pollution problems. Included is background information on water pollution, a glossary of pollution terminology, a script for a slide script…

First light of the Gemini Planet Imager

PubMed Central

Macintosh, Bruce; Graham, James R.; Ingraham, Patrick; Konopacky, Quinn; Marois, Christian; Perrin, Marshall; Poyneer, Lisa; Bauman, Brian; Barman, Travis; Burrows, Adam S.; Cardwell, Andrew; Chilcote, Jeffrey; De Rosa, Robert J.; Dillon, Daren; Doyon, Rene; Dunn, Jennifer; Erikson, Darren; Fitzgerald, Michael P.; Gavel, Donald; Goodsell, Stephen; Hartung, Markus; Hibon, Pascale; Kalas, Paul; Larkin, James; Maire, Jerome; Marchis, Franck; Marley, Mark S.; McBride, James; Millar-Blanchaer, Max; Morzinski, Katie; Norton, Andrew; Oppenheimer, B. R.; Palmer, David; Patience, Jennifer; Pueyo, Laurent; Rantakyro, Fredrik; Sadakuni, Naru; Saddlemyer, Leslie; Savransky, Dmitry; Serio, Andrew; Soummer, Remi; Sivaramakrishnan, Anand; Song, Inseok; Thomas, Sandrine; Wallace, J. Kent; Wiktorowicz, Sloane; Wolff, Schuyler

2014-01-01

The Gemini Planet Imager is a dedicated facility for directly imaging and spectroscopically characterizing extrasolar planets. It combines a very high-order adaptive optics system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution. Every aspect of the Gemini Planet Imager has been tuned for maximum sensitivity to faint planets near bright stars. During first-light observations, we achieved an estimated H band Strehl ratio of 0.89 and a 5-σ contrast of 106 at 0.75 arcseconds and 105 at 0.35 arcseconds. Observations of Beta Pictoris clearly detect the planet, Beta Pictoris b, in a single 60-s exposure with minimal postprocessing. Beta Pictoris b is observed at a separation of 434 ± 6 milliarcseconds (mas) and position angle 211.8 ± 0.5°. Fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of 3 improvement in most parameters over previous solutions. The planet orbits at a semimajor axis of 9.0−0.4+0.8 AU near the 3:2 resonance with the previously known 6-AU asteroidal belt and is aligned with the inner warped disk. The observations give a 4% probability of a transit of the planet in late 2017. PMID:24821792

First light of the Gemini Planet imager.

PubMed

Macintosh, Bruce; Graham, James R; Ingraham, Patrick; Konopacky, Quinn; Marois, Christian; Perrin, Marshall; Poyneer, Lisa; Bauman, Brian; Barman, Travis; Burrows, Adam S; Cardwell, Andrew; Chilcote, Jeffrey; De Rosa, Robert J; Dillon, Daren; Doyon, Rene; Dunn, Jennifer; Erikson, Darren; Fitzgerald, Michael P; Gavel, Donald; Goodsell, Stephen; Hartung, Markus; Hibon, Pascale; Kalas, Paul; Larkin, James; Maire, Jerome; Marchis, Franck; Marley, Mark S; McBride, James; Millar-Blanchaer, Max; Morzinski, Katie; Norton, Andrew; Oppenheimer, B R; Palmer, David; Patience, Jennifer; Pueyo, Laurent; Rantakyro, Fredrik; Sadakuni, Naru; Saddlemyer, Leslie; Savransky, Dmitry; Serio, Andrew; Soummer, Remi; Sivaramakrishnan, Anand; Song, Inseok; Thomas, Sandrine; Wallace, J Kent; Wiktorowicz, Sloane; Wolff, Schuyler

2014-09-02

The Gemini Planet Imager is a dedicated facility for directly imaging and spectroscopically characterizing extrasolar planets. It combines a very high-order adaptive optics system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution. Every aspect of the Gemini Planet Imager has been tuned for maximum sensitivity to faint planets near bright stars. During first-light observations, we achieved an estimated H band Strehl ratio of 0.89 and a 5-σ contrast of 10(6) at 0.75 arcseconds and 10(5) at 0.35 arcseconds. Observations of Beta Pictoris clearly detect the planet, Beta Pictoris b, in a single 60-s exposure with minimal postprocessing. Beta Pictoris b is observed at a separation of 434 ± 6 milliarcseconds (mas) and position angle 211.8 ± 0.5°. Fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of 3 improvement in most parameters over previous solutions. The planet orbits at a semimajor axis of [Formula: see text] near the 3:2 resonance with the previously known 6-AU asteroidal belt and is aligned with the inner warped disk. The observations give a 4% probability of a transit of the planet in late 2017.

Planet Formation in Binaries

NASA Astrophysics Data System (ADS)

Thebault, P.; Haghighipour, N.

Spurred by the discovery of numerous exoplanets in multiple systems, binaries have become in recent years one of the main topics in planet formation research. Numerous studies have investigated to what extent the presence of a stellar companion can affect the planet formation process. Such studies have implications that can reach beyond the sole context of binaries, as they allow to test certain aspects of the planet formation scenario by submitting them to extreme environments. We review here the current understanding on this complex problem. We show in particular how each of the different stages of the planet-formation process is affected differently by binary perturbations. We focus especially on the intermediate stage of kilometre-sized planetesimal accretion, which has proven to be the most sensitive to binarity and for which the presence of some exoplanets observed in tight binaries is difficult to explain by in-situ formation following the "standard" planet-formation scenario. Some tentative solutions to this apparent paradox are presented. The last part of our review presents a thorough description of the problem of planet habitability, for which the binary environment creates a complex situation because of the presence of two irradation sources of varying distance.

ORBITAL MOTION OF HR 8799 b, c, d USING HUBBLE SPACE TELESCOPE DATA FROM 1998: CONSTRAINTS ON INCLINATION, ECCENTRICITY, AND STABILITY

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

Soummer, Remi; Hagan, J. Brendan; Pueyo, Laurent

2011-11-01

HR 8799 is currently the only multiple-planet system that has been detected with direct imaging, with four giant planets of masses 7-10 M{sub Jup} orbiting at large separations (15-68 AU) from this young late A star. Orbital motion provides insight into the stability and possible formation mechanisms of this planetary system. Dynamical studies can also provide constraints on the planets' masses, which help calibrate evolutionary models, yet measuring the orbital motion is a very difficult task because the long-period orbits (50-500 yr) require long time baselines and high-precision astrometry. This paper studies the three planets HR 8799b, c, and dmore » in the archival data set of HR 8799 obtained with the Hubble Space Telescope (HST) NICMOS coronagraph in 1998. The detection of all three planets is made possible by a careful optimization of the Locally Optimized Combination of Images algorithm, and we used a statistical analysis of a large number of reduced images. This work confirms previous astrometry for planet b and presents new detections and astrometry for planets c and d. These HST images provide a ten-year baseline with the discovery images from 2008, and therefore offer a unique opportunity to constrain their orbital motion now. Recent dynamical studies of this system show the existence of a few possible stable solutions involving mean motion resonances (MMRs), where the interaction between c and d plays a major role. We study the compatibility of a few of these stable scenarios (1d:1c, 1d:2c, or 1d:2c:4d) with the new astrometric data from HST. In the hypothesis of a 1d:2c:4b MMR our best orbit fit is close to the stable solution previously identified for a three-planet system and involves low eccentricity for planet d (e{sub d} = 0.10) and moderate inclination of the system (i = 28.0 deg), assuming a coplanar system, circular orbits for b and c, and exact resonance with integer period ratios. Under these assumptions, we can place strong constraints on the inclination of the system (27.3-31.4 deg) and on the eccentricity for d e{sub d} < 0.46. Our results are robust to small departures from exact integer period ratios and consistent with previously published results based on dynamical studies for a three-planet system prior to the discovery of the fourth planet.« less

Orbital dynamics of multi-planet systems with eccentricity diversity

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

Kane, Stephen R.; Raymond, Sean N., E-mail: skane@sfsu.edu

2014-04-01

Since exoplanets were detected using the radial velocity method, they have revealed a diverse distribution of orbital configurations. Among these are planets in highly eccentric orbits (e > 0.5). Most of these systems consist of a single planet but several have been found to also contain a longer period planet in a near-circular orbit. Here we use the latest Keplerian orbital solutions to investigate four known systems which exhibit this extreme eccentricity diversity; HD 37605, HD 74156, HD 163607, and HD 168443. We place limits on the presence of additional planets in these systems based on the radial velocity residuals.more » We show that the two known planets in each system exchange angular momentum through secular oscillations of their eccentricities. We calculate the amplitude and timescale for these eccentricity oscillations and associated periastron precession. We further demonstrate the effect of mutual orbital inclinations on the amplitude of high-frequency eccentricity oscillations. Finally, we discuss the implications of these oscillations in the context of possible origin scenarios for unequal eccentricities.« less

EXOFIT: orbital parameters of extrasolar planets from radial velocities

NASA Astrophysics Data System (ADS)

Balan, Sreekumar T.; Lahav, Ofer

2009-04-01

Retrieval of orbital parameters of extrasolar planets poses considerable statistical challenges. Due to sparse sampling, measurement errors, parameters degeneracy and modelling limitations, there are no unique values of basic parameters, such as period and eccentricity. Here, we estimate the orbital parameters from radial velocity data in a Bayesian framework by utilizing Markov Chain Monte Carlo (MCMC) simulations with the Metropolis-Hastings algorithm. We follow a methodology recently proposed by Gregory and Ford. Our implementation of MCMC is based on the object-oriented approach outlined by Graves. We make our resulting code, EXOFIT, publicly available with this paper. It can search for either one or two planets as illustrated on mock data. As an example we re-analysed the orbital solution of companions to HD 187085 and HD 159868 from the published radial velocity data. We confirm the degeneracy reported for orbital parameters of the companion to HD 187085, and show that a low-eccentricity orbit is more probable for this planet. For HD 159868, we obtained slightly different orbital solution and a relatively high `noise' factor indicating the presence of an unaccounted signal in the radial velocity data. EXOFIT is designed in such a way that it can be extended for a variety of probability models, including different Bayesian priors.

Nitrate removal from polluted water by using a vegetated floating system.

PubMed

Bartucca, Maria Luce; Mimmo, Tanja; Cesco, Stefano; Del Buono, Daniele

2016-01-15

Nitrate (NO3(-)) water pollution is one of the most prevailing and relevant ecological issues. For instance, the wide presence of this pollutant in the environment is dramatically altering the quality of superficial and underground waters. Therefore, we set up a floating bed vegetated with a terrestrial herbaceous species (Italian ryegrass) with the aim to remediate hydroponic solutions polluted with NO3(-). The floating bed allowed the plants to grow and achieve an adequate development. Ryegrass was not affected by the treatments. On the contrary, plant biomass production and total nitrogen content (N-K) increased proportionally to the amount of NO3(-) applied. Regarding to the water cleaning experiments, the vegetated floating beds permitted to remove almost completely all the NO3(-) added from the hydroponic solutions with an initial concentration of 50, 100 and 150 mg L(-1). Furthermore, the calculation of the bioconcentration factor (BCF) indicated this species as successfully applicable for the remediation of solutions polluted by NO3(-). In conclusion, the results highlight that the combination of ryegrass and the floating bed system resulted to be effective in the remediation of aqueous solutions polluted by NO3(-). Copyright © 2015 Elsevier B.V. All rights reserved.

POST-MAIN SEQUENCE EVOLUTION OF ICY MINOR PLANETS: IMPLICATIONS FOR WATER RETENTION AND WHITE DWARF POLLUTION

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

Malamud, Uri; Perets, Hagai B., E-mail: uri.mal@tx.technion.ac.il, E-mail: hperets@physics.technion.ac.il

Most observations of polluted white dwarf atmospheres are consistent with accretion of water-depleted planetary material. Among tens of known cases, merely two involve accretion of objects that contain a considerable mass fraction of water. The purpose of this study is to investigate the relative scarcity of these detections. Based on a new and highly detailed model, we evaluate the retention of water inside icy minor planets during the high-luminosity stellar evolution that follows the main sequence. Our model fully considers the thermal, physical, and chemical evolution of icy bodies, following their internal differentiation as well as water depletion, from themore » moment of their birth and through all stellar evolution phases preceding the formation of the white dwarf. We also account for different initial compositions and formation times. Our results differ from previous studies, which have either underestimated or overestimated water retention. We show that water can survive in a variety of circumstances and in great quantities, and therefore other possibilities are discussed in order to explain the infrequency of water detection. We predict that the sequence of accretion is such that water accretes earlier, and more rapidly, than the rest of the silicate disk, considerably reducing the chance of its detection in H-dominated atmospheres. In He-dominated atmospheres, the scarcity of water detections could be observationally biased. It implies that the accreted material is typically intrinsically dry, which may be the result of the inside-out depopulation sequence of minor planets.« less

A Detailed Study of Rocky Planetary Material in the Hyades

NASA Astrophysics Data System (ADS)

Farihi, Jay

2017-08-01

The Hyades is the nearest open cluster, relatively young, and containing numerous A-type stars. Its youth, distance, and metallicity make it an ideal site to study planet formation around 2-3 Msun stars, and in a dynamically challenging environment.During our HST COS Snapshot, we discovered the ongoing accretion of Si-rich and C-deficient material in two white dwarf Hyads. The lower limit Si/C ratios determined from these 400s exposures indicate the material is more C-depleted than in chondritic meteorites, the most primitive rocks in the Solar System. Our 2013 Keck discovery of metal pollution in a third Hyades white dwarf indicates that planet formation is common in the cluster. Together, these three stars indicate that substantial minor bodies persist at several AU or more, and provide an unprecedented opportunity for a detailed study of rocky exoplanet precursors in a cluster environment.We propose to obtain detailed abundances of the planetary debris at these three polluted Hyads, which requires a modest investment of observatory time. The mass ratios between C, O, Mg, and Si are accurate indicators of the temperature and orbital regions where the parent bodies formed, their water and volatile contents. We will also detect Al and Fe, which are key indicators of differentiation and giant impacts among planetary embryos.Our proposed observations will provide legacy value for planet formation models, and especially those in cluster enviroments. These observations cannot be done from the ground or at optical or longer wavelengths, and must be carried out by HST in the ultraviolet.

Results of two multichord stellar occultations by dwarf planet (1) Ceres

NASA Astrophysics Data System (ADS)

Gomes-Júnior, A. R.; Giacchini, B. L.; Braga-Ribas, F.; Assafin, M.; Vieira-Martins, R.; Camargo, J. I. B.; Sicardy, B.; Timerson, B.; George, T.; Broughton, J.; Blank, T.; Benedetti-Rossi, G.; Brooks, J.; Dantowitz, R. F.; Dunham, D. W.; Dunham, J. B.; Ellington, C. K.; Emilio, M.; Herpich, F. R.; Jacques, C.; Maley, P. D.; Mehret, L.; Mello, A. J. T.; Milone, A. C.; Pimentel, E.; Schoenell, W.; Weber, N. S.

2015-08-01

We report the results of two multichord stellar occultations by the dwarf planet (1) Ceres that were observed from Brazil on 2010 August 17, and from the USA on 2013 October 25. Four positive detections were obtained for the 2010 occultation, and nine for the 2013 occultation. Elliptical models were adjusted to the observed chords to obtain Ceres' size and shape. Two limb-fitting solutions were studied for each event. The first one is a nominal solution with an indeterminate polar aspect angle. The second one was constrained by the pole coordinates as given by Drummond et al. Assuming a Maclaurin spheroid, we determine an equatorial diameter of 972 ± 6 km and an apparent oblateness of 0.08 ± 0.03 as our best solution. These results are compared to all available size and shape determinations for Ceres made so far, and shall be confirmed by the NASA's Dawn space mission.

40 CFR 467.35 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) 110 53 Subpart C Solution Heat Treatment Contact Cooling Water Pollutant or pollutant property PSES...) 69 35 Subpart C Press Heat Treatment Contact Cooling Water Pollutant or pollutant property PSES...

40 CFR 467.35 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) 110 53 Subpart C Solution Heat Treatment Contact Cooling Water Pollutant or pollutant property PSES...) 69 35 Subpart C Press Heat Treatment Contact Cooling Water Pollutant or pollutant property PSES...

40 CFR 467.35 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) 110 53 Subpart C Solution Heat Treatment Contact Cooling Water Pollutant or pollutant property PSES...) 69 35 Subpart C Press Heat Treatment Contact Cooling Water Pollutant or pollutant property PSES...

A New Climate: The Time is Now for Colleges to Rally around the Sustainability Movement

ERIC Educational Resources Information Center

Stephens, Rusty

2010-01-01

Environmentalist Lester Brown famously likened the declining natural environment to a global Ponzi scheme, where the decimation of the planet's natural asset base has yielded high, yet unsustainable economic returns. Brown cited a range of examples, from population growth to food security to air pollution. His claims took on new urgency this year…

Gravitational tides in the outer planets. I - Implications of classical tidal theory. II - Interior calculations and estimation of the tidal dissipation factor

NASA Technical Reports Server (NTRS)

Ioannou, Petros J.; Lindzen, Richard S.

1993-01-01

Classical tidal theory is applied to the atmospheres of the outer planets. The tidal geopotential due to satellites of the outer planets is discussed, and the solution of Laplace's tidal equation for Hough modes appropriate to tides on the outer planets is examined. The vertical structure of tidal modes is described, noting that only relatively high-order meridional mode numbers can propagate vertically with growing amplitude. Expected magnitudes for tides in the visible atmosphere of Jupiter are discussed. The classical theory is extended to planetary interiors taking the effects of spherically and self-gravity into account. The thermodynamic structure of Jupiter is described and the WKB theory of the vertical structure equation is presented. The regions for which inertial, gravity, and acoustic oscillations are possible are delineated. The case of a planet with a neutral interior is treated, discussing the various atmospheric boundary conditions and showing that the tidal response is small.

40 CFR 467.36 - Pretreatment standards for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) 20.37 20.37 Subpart C Solution Heat Treatment Contact Cooling Water Pollutant or pollutant property....29 13.29 Subpart C Press Heat Treatment Contact Cooling Water Pollutant or pollutant property PSNS...

40 CFR 467.36 - Pretreatment standards for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) 20.37 20.37 Subpart C Solution Heat Treatment Contact Cooling Water Pollutant or pollutant property....29 13.29 Subpart C Press Heat Treatment Contact Cooling Water Pollutant or pollutant property PSNS...

40 CFR 467.36 - Pretreatment standards for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) 20.37 20.37 Subpart C Solution Heat Treatment Contact Cooling Water Pollutant or pollutant property....29 13.29 Subpart C Press Heat Treatment Contact Cooling Water Pollutant or pollutant property PSNS...

Surface Modification of Graphene Oxides by Plasma Techniques and Their Application for Environmental Pollution Cleanup.

PubMed

Wang, Xiangxue; Fan, Qiaohui; Chen, Zhongshan; Wang, Qi; Li, Jiaxing; Hobiny, Aatef; Alsaedi, Ahmed; Wang, Xiangke

2016-02-01

Graphene oxides (GOs) have come under intense multidisciplinary study because of their unique physicochemical properties and possible applications. The large amount of oxygen-containing functional groups on GOs leads to a high sorption capacity for the removal of various kinds of organic and inorganic pollutants from aqueous solutions in environmental pollution cleanup. However, the lack of selectivity results in difficulty in the selective removal of target pollutants from aqueous solutions in the presence of other coexisting pollutants. Herein, the surface grafting of GOs with special oxygen-containing functional groups using low-temperature plasma techniques and the application of the surface-modified GOs for the efficient removal of organic and inorganic pollutants in environmental pollution are reviewed. This paper gives an account of our research on the application of GO-based nanomaterials in environmental pollution cleanup, including: (1) the synthesis and surface grafting of functional groups on GOs, summarizing various types of low-temperature plasma techniques for the synthesis of graphene/GOs; and (2) the application of graphene/GOs and their composites for the efficient removal of organic and inorganic pollutants from aqueous solutions, including the interaction mechanism according to recently published results. © 2015 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Polymer "Pollution Solution" Classroom Activity.

ERIC Educational Resources Information Center

Helser, Terry L.

1996-01-01

Explains an approach to presenting polymer chemistry to nonmajors that employs polystyrene foam, foam peanuts made from water soluble starch, and water soluble plastic bags. Students are presented with a pollution scenario and are guided to the discovery of solutions. (DDR)

Coupled Evolution with Tides of the Radius and Orbit of Transiting Giant Planets

NASA Astrophysics Data System (ADS)

Ibgui, Laurent; Burrows, A.

2009-12-01

Some transiting extrasolar giant planets have measured radii larger than predicted by the standard theory. We explore the possibility that an earlier episode of tidal heating can explain such radius anomalies and apply the formalism we develop to HD 209458b as an example. We find that for strong enough tides the planet's radius can undergo a transient phase of inflation that temporarily interrupts canonical, monotonic shrinking due to radiative losses. Importantly, an earlier episode of tidal heating can result in a planet with an inflated radius, even though its orbit has nearly circularized. Moreover, we confirm that at late times, and under some circumstances, by raising tides on the star itself a planet can spiral into its host. We note that a 3 to 10 solar planet atmospheric opacity with no tidal heating is sufficient to explain the observed radius of HD 209458b. However, our model demonstrates that with an earlier phase of episodic tidal heating we can fit the observed radius of HD 209458b even with lower (solar) atmospheric opacities. This work demonstrates that, if a planet is left with an appreciable eccentricity after early inward migration and/or dynamical interaction, coupling radius and orbit evolution in a consistent fashion that includes tidal heating, stellar irradiation, and detailed model atmospheres might offer a generic solution to the inflated radius puzzle for transiting extrasolar giant planets.

First light of the Gemini Planet Imager

DOE PAGES

Macintosh, Bruce; Graham, James R.; Ingraham, Patrick; ...

2014-05-12

The Gemini Planet Imager is a dedicated facility for directly imaging and spectroscopically characterizing extrasolar planets. It combines a very high-order adaptive optics system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution. Every aspect of the Gemini Planet Imager has been tuned for maximum sensitivity to faint planets near bright stars. During first-light observations, we achieved an estimated H band Strehl ratio of 0.89 and a 5-σ contrast of 10 6 at 0.75 arcseconds and 10 5 at 0.35 arcseconds. Observations of Beta Pictoris clearly detect the planet, Beta Pictoris b, inmore » a single 60-s exposure with minimal postprocessing. Beta Pictoris b is observed at a separation of 434 ± 6 milliarcseconds (mas) and position angle 211.8 ± 0.5°. Fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of 3 improvement in most parameters over previous solutions. The planet orbits at a semimajor axis of 9.0 +0.8 –0.4 AU near the 3:2 resonance with the previously known 6-AU asteroidal belt and is aligned with the inner warped disk. In conclusion, the observations give a 4% probability of a transit of the planet in late 2017.« less

Direct Detection and Orbit Analysis of the Exoplanets HR 8799 bcd from Archival 2005 Keck/NIRC2 Data

NASA Technical Reports Server (NTRS)

Currie, Thayne; Fukagawa, Misato; Thalmann, Christian; Matsumura, Soko; Plavchan, Peter

2012-01-01

We present previously unpublished July 2005 H-band coronagraphic data of the young, planet-hosting star HR 8799 from the newly-released Keck/NIRC2 archive. Despite poor observing conditions, we detect three of the planets (HR 8799 bcd), two of them (HR 8799 bc) without advanced image processing. Comparing these data with previously published 1998-2011 astrometry and that from re-reduced October 2010 Keck data constrains the orbits of the planets. Analyzing the planets' astrometry separately, HR 8799 d's orbit is likely inclined at least 25 deg from face-on and the others may be on in inclined orbits. For semimajor axis ratios consistent with a 4:2:1 mean-motion resonance our analysis yields precise values for HR 8799 bcd's orbital parameters and strictly constrains the planets' eccentricities to be less than 0.18-0.3. However, we find no acceptable orbital solutions with this resonance that place the planets in face-on orbits; HR 8799 d shows the largest deviation from such orbits. Moreover, few orbits make HR 8799 d coplanar with b and c, whereas dynamical stability analyses used to constrain the planets' masses typically assume coplanar and/or fare.on orbits. This paper illustrates the significant science gain enabled with the release of the NIRC2 archive.

Planet-disc interactions with Discontinuous Galerkin Methods using GPUs

NASA Astrophysics Data System (ADS)

Velasco Romero, David A.; Veiga, Maria Han; Teyssier, Romain; Masset, Frédéric S.

2018-05-01

We present a two-dimensional Cartesian code based on high order discontinuous Galerkin methods, implemented to run in parallel over multiple GPUs. A simple planet-disc setup is used to compare the behaviour of our code against the behaviour found using the FARGO3D code with a polar mesh. We make use of the time dependence of the torque exerted by the disc on the planet as a mean to quantify the numerical viscosity of the code. We find that the numerical viscosity of the Keplerian flow can be as low as a few 10-8r2Ω, r and Ω being respectively the local orbital radius and frequency, for fifth order schemes and resolution of ˜10-2r. Although for a single disc problem a solution of low numerical viscosity can be obtained at lower computational cost with FARGO3D (which is nearly an order of magnitude faster than a fifth order method), discontinuous Galerkin methods appear promising to obtain solutions of low numerical viscosity in more complex situations where the flow cannot be captured on a polar or spherical mesh concentric with the disc.

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.

Analytical Solutions for Radiative Transfer: Implications for Giant Planet Formation by Disk Instability

NASA Astrophysics Data System (ADS)

Boss, Alan P.

2009-03-01

The disk instability mechanism for giant planet formation is based on the formation of clumps in a marginally gravitationally unstable protoplanetary disk, which must lose thermal energy through a combination of convection and radiative cooling if they are to survive and contract to become giant protoplanets. While there is good observational support for forming at least some giant planets by disk instability, the mechanism has become theoretically contentious, with different three-dimensional radiative hydrodynamics codes often yielding different results. Rigorous code testing is required to make further progress. Here we present two new analytical solutions for radiative transfer in spherical coordinates, suitable for testing the code employed in all of the Boss disk instability calculations. The testing shows that the Boss code radiative transfer routines do an excellent job of relaxing to and maintaining the analytical results for the radial temperature and radiative flux profiles for a spherical cloud with high or moderate optical depths, including the transition from optically thick to optically thin regions. These radial test results are independent of whether the Eddington approximation, diffusion approximation, or flux-limited diffusion approximation routines are employed. The Boss code does an equally excellent job of relaxing to and maintaining the analytical results for the vertical (θ) temperature and radiative flux profiles for a disk with a height proportional to the radial distance. These tests strongly support the disk instability mechanism for forming giant planets.

Pollution Probe.

ERIC Educational Resources Information Center

Chant, Donald A.

This book is written as a statement of concern about pollution by members of Pollution Probe, a citizens' anti-pollution group in Canada. Its purpose is to create public awareness and pressure for the eventual solution to pollution problems. The need for effective government policies to control the population explosion, conserve natural resources,…

Computerized series solution of relativistic equations of motion.

NASA Technical Reports Server (NTRS)

Broucke, R.

1971-01-01

A method of solution of the equations of planetary motion is described. It consists of the use of numerical general perturbations in orbital elements and in rectangular coordinates. The solution is expanded in Fourier series in the mean anomaly with the aid of harmonic analysis and computerized series manipulation techniques. A detailed application to the relativistic motion of the planet Mercury is described both for Schwarzschild and isotropic coordinates.

Periodic solution for a stochastic non-autonomous competitive Lotka-Volterra model in a polluted environment

NASA Astrophysics Data System (ADS)

Jiang, Daqing; Zhang, Qiumei; Hayat, Tasawar; Alsaedi, Ahmed

2017-04-01

In this paper, we consider a stochastic non-autonomous competitive Lotka-Volterra model in a polluted environment. We derive sufficient criteria for the existence and global attractivity of the boundary periodic solutions. Furthermore, we obtain conditions for the existence and global attractivity of a nontrivial positive periodic solution. Finally we make simulations to illustrate our analytical results.

Global issues in environmental medicine.

PubMed

Goldstein, B D

1993-03-01

This overview will discuss a number of the issues posed by the challenge of international environmental health. The reasons that environmental problems occurring elsewhere in the world are of importance to occupational and environmental physicians in North America include the interconnectedness of the biosphere of our planet so that environmental alterations in one part of the globe can have an adverse outcome on our health and well-being; the often high levels of pollution and environmental degradation elsewhere provide an opportunity to determine and predict adverse consequences of environmental agents pertinent to protecting our own health; and, most importantly, our own ability to provide assistance in helping economic development occur in a setting of low risk of environmental pollution.

[Groundwater organic pollution source identification technology system research and application].

PubMed

Wang, Xiao-Hong; Wei, Jia-Hua; Cheng, Zhi-Neng; Liu, Pei-Bin; Ji, Yi-Qun; Zhang, Gan

2013-02-01

Groundwater organic pollutions are found in large amount of locations, and the pollutions are widely spread once onset; which is hard to identify and control. The key process to control and govern groundwater pollution is how to control the sources of pollution and reduce the danger to groundwater. This paper introduced typical contaminated sites as an example; then carried out the source identification studies and established groundwater organic pollution source identification system, finally applied the system to the identification of typical contaminated sites. First, grasp the basis of the contaminated sites of geological and hydrogeological conditions; determine the contaminated sites characteristics of pollutants as carbon tetrachloride, from the large numbers of groundwater analysis and test data; then find the solute transport model of contaminated sites and compound-specific isotope techniques. At last, through groundwater solute transport model and compound-specific isotope technology, determine the distribution of the typical site of organic sources of pollution and pollution status; invest identified potential sources of pollution and sample the soil to analysis. It turns out that the results of two identified historical pollution sources and pollutant concentration distribution are reliable. The results provided the basis for treatment of groundwater pollution.

Characterizing Young Giant Planets with the Gemini Planet Imager: An Iterative Approach to Planet Characterization

NASA Technical Reports Server (NTRS)

Marley, Mark

2015-01-01

After discovery, the first task of exoplanet science is characterization. However experience has shown that the limited spectral range and resolution of most directly imaged exoplanet data requires an iterative approach to spectral modeling. Simple, brown dwarf-like models, must first be tested to ascertain if they are both adequate to reproduce the available data and consistent with additional constraints, including the age of the system and available limits on the planet's mass and luminosity, if any. When agreement is lacking, progressively more complex solutions must be considered, including non-solar composition, partial cloudiness, and disequilibrium chemistry. Such additional complexity must be balanced against an understanding of the limitations of the atmospheric models themselves. For example while great strides have been made in improving the opacities of important molecules, particularly NH3 and CH4, at high temperatures, much more work is needed to understand the opacity of atomic Na and K. The highly pressure broadened fundamental band of Na and K in the optical stretches into the near-infrared, strongly influencing the spectral shape of Y and J spectral bands. Discerning gravity and atmospheric composition is difficult, if not impossible, without both good atomic opacities as well as an excellent understanding of the relevant atmospheric chemistry. I will present examples of the iterative process of directly imaged exoplanet characterization as applied to both known and potentially newly discovered exoplanets with a focus on constraints provided by GPI spectra. If a new GPI planet is lacking, as a case study I will discuss HR 8799 c and d will explain why some solutions, such as spatially inhomogeneous cloudiness, introduce their own additional layers of complexity. If spectra of new planets from GPI are available I will explain the modeling process in the context of understanding these new worlds.

Asteroid 'Bites the Dust' Around Dead Star

NASA Technical Reports Server (NTRS)

2009-01-01

NASA's Spitzer Space Telescope set its infrared eyes upon the dusty remains of shredded asteroids around several dead stars. This artist's concept illustrates one such dead star, or 'white dwarf,' surrounded by the bits and pieces of a disintegrating asteroid. These observations help astronomers better understand what rocky planets are made of around other stars.

Asteroids are leftover scraps of planetary material. They form early on in a star's history when planets are forming out of collisions between rocky bodies. When a star like our sun dies, shrinking down to a skeleton of its former self called a white dwarf, its asteroids get jostled about. If one of these asteroids gets too close to the white dwarf, the white dwarf's gravity will chew the asteroid up, leaving a cloud of dust.

Spitzer's infrared detectors can see these dusty clouds and their various constituents. So far, the telescope has identified silicate minerals in the clouds polluting eight white dwarfs. Because silicates are common in our Earth's crust, the results suggest that planets similar to ours might be common around other stars.

Our Mission to Planet Earth: A guide to teaching Earth system science

NASA Technical Reports Server (NTRS)

1994-01-01

Volcanic eruptions, hurricanes, floods, and El Nino are naturally occurring events over which humans have no control. But can human activities cause additional environmental change? Can scientists predict the global impacts of increased levels of pollutants in the atmosphere? Will the planet warm because increased levels of greenhouse gases, produced by the burning of fossil fuels, trap heat and prevent it from being radiated back into space? Will the polar ice cap melt, causing massive coastal flooding? Have humans initiated wholesale climatic change? These are difficult questions, with grave implications. Predicting global change and understanding the relationships among earth's components have increased in priority for the nation. The National Aeronautics and Space Administration (NASA), along with many other government agencies, has initiated long-term studies of earth's atmosphere, oceans, and land masses using observations from satellite, balloon, and aircraft-borne instruments. NASA calls its research program Mission to Planet Earth. Because NASA can place scientific instruments far above earth's surface, the program allows scientists to explore earth's components and their interactions on a global scale.

Twenty Years of Precise Radial Velocities at Keck and Lick Observatories

NASA Astrophysics Data System (ADS)

Wright, J. T.

2015-10-01

The precise radial velocity survey at Keck Observatory began over 20 years ago. Its survey of thousands of stars now has the time baseline to be sensitive to planets with decade-long orbits, including Jupiter analogs. I present several newly-finished orbital solutions for long-period giant planets. Although hot Jupiters are generally ``lonely'' (i.e. they are not part of multiplanet systems), those that are not appear to often have giant companions at 5 AU or beyond. I present two of the highest period-ratios among planets in a two-planet system, and some of the longest orbital periods ever measured for exoplanets. In many cases, combining Keck radial velocities from those from other long-term surveys at Lick Observatory, McDonald Observatory, HARPS, and, of course, OHP spectrographs, produces superior orbital fits, constraining both period and eccentricity better than could be possible with any single set alone. Stellar magnetic activity cycles can masquerade as long-period planets. In most cases this effect is very small, but a loud minority of stars, including, apparently, HD 154345, show very strong RV-activity correlations.

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

Winn, Joshua N.; Albrecht, Simon; Johnson, John Asher

We present new radial velocity (RV) measurements of HAT-P-13, a star with two previously known companions: a transiting giant planet 'b' with an orbital period of 3 days and a more massive object 'c' on a 1.2 yr, highly eccentric orbit. For this system, dynamical considerations would lead to constraints on planet b's interior structure, if it could be shown that the orbits are coplanar and apsidally locked. By modeling the Rossiter-McLaughlin effect, we show that planet b's orbital angular momentum vector and the stellar spin vector are well aligned on the sky ({lambda} = 1.9 {+-} 8.6 deg). Themore » refined orbital solution favors a slightly eccentric orbit for planet b (e = 0.0133 {+-} 0.0041), although it is not clear whether it is apsidally locked with c's orbit ({Delta}{omega} = 36{sup +27}{sub -36} deg). We find a long-term trend in the star's RV and interpret it as evidence for an additional body 'd', which may be another planet or a low-mass star. Predictions are given for the next few inferior conjunctions of c, when transits may happen.« less

An improved risk-explicit interval linear programming model for pollution load allocation for watershed management.

PubMed

Xia, Bisheng; Qian, Xin; Yao, Hong

2017-11-01

Although the risk-explicit interval linear programming (REILP) model has solved the problem of having interval solutions, it has an equity problem, which can lead to unbalanced allocation between different decision variables. Therefore, an improved REILP model is proposed. This model adds an equity objective function and three constraint conditions to overcome this equity problem. In this case, pollution reduction is in proportion to pollutant load, which supports balanced development between different regional economies. The model is used to solve the problem of pollution load allocation in a small transboundary watershed. Compared with the REILP original model result, our model achieves equity between the upstream and downstream pollutant loads; it also overcomes the problem of greatest pollution reduction, where sources are nearest to the control section. The model provides a better solution to the problem of pollution load allocation than previous versions.

40 CFR 471.32 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... powder atomized Chromium 0.970 0.393 Nickel 1.44 .970 Fluoride 156 69.2 (q) Annealing and solution heat... pollutants. (r) Wet air pollution control scrubber blowdown. Subpart C—BAT Pollutant or pollutant property...

OGLE-2013-BLG-1761Lb: A Massive Planet around an M/K Dwarf

NASA Astrophysics Data System (ADS)

Hirao, Y.; Udalski, A.; Sumi, T.; Bennett, D. P.; Koshimoto, N.; Bond, I. A.; Rattenbury, N. J.; Suzuki, D.; and; Abe, F.; Asakura, Y.; Barry, R. K.; Bhattacharya, A.; Donachie, M.; Evans, P.; Fukui, A.; Itow, Y.; Li, M. C. A.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Matsuo, T.; Muraki, Y.; Nagakane, M.; Ohnishi, K.; Ranc, C.; Saito, To.; Sharan, A.; Shibai, H.; Sullivan, D. J.; Tristram, P. J.; Yamada, T.; Yamada, T.; Yonehara, A.; MOA Collaboration; Poleski, R.; Skowron, J.; Mróz, P.; Szymański, M. K.; Kozłowski, S.; Pietrukowicz, P.; Soszyński, I.; Wyrzykowski, Ł.; Ulaczyk, K.; OGLE Collaboration

2017-07-01

We report the discovery and the analysis of the planetary microlensing event, OGLE-2013-BLG-1761. There are some degenerate solutions in this event because the planetary anomaly is only sparsely sampled. However, the detailed light-curve analysis ruled out all stellar binary models and shows the lens to be a planetary system. There is the so-called close/wide degeneracy in the solutions with the planet/host mass ratio of q ˜ (7.0 ± 2.0) × 10-3 and q ˜ (8.1 ± 2.6) × 10-3 with the projected separation in Einstein radius units of s = 0.95 (close) and s = 1.18 (wide), respectively. The microlens parallax effect is not detected, but the finite source effect is detected. Our Bayesian analysis indicates that the lens system is located DL=6.9-1.2+1.0 kpc away from us and the host star is an M/K dwarf with a mass of ML=0.33-0.19+0.32 M⊙ orbited by a super-Jupiter mass planet with a mass of mP=2.7-1.5+2.5 MJup at the projected separation of a\\perp=1.8-0.5+0.5 au. The preference of the large lens distance in the Bayesian analysis is due to the relatively large observed source star radius. The distance and other physical parameters may be constrained by the future high-resolution imaging by large ground telescopes or HST. If the estimated lens distance is correct, then this planet provides another sample for testing the claimed deficit of planets in the Galactic bulge.

Magnetospheric structure and atmospheric Joule heating of habitable planets orbiting M-dwarf stars

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

Cohen, O.; Drake, J. J.; Garraffo, C.

2014-07-20

We study the magnetospheric structure and the ionospheric Joule Heating of planets orbiting M-dwarf stars in the habitable zone using a set of magnetohydrodynamic models. The stellar wind solution is used to drive a model for the planetary magnetosphere, which is coupled with a model for the planetary ionosphere. Our simulations reveal that the space environment around close-in habitable planets is extreme, and the stellar wind plasma conditions change from sub- to super-Alfvénic along the planetary orbit. As a result, the magnetospheric structure changes dramatically with a bow shock forming in the super-Alfvénic sectors, while no bow shock forms inmore » the sub-Alfvénic sectors. The planets reside most of the time in the sub-Alfvénic sectors with poor atmospheric protection. A significant amount of Joule Heating is provided at the top of the atmosphere as a result of the intense stellar wind. For the steady-state solution, the heating is about 0.1%-3% of the total incoming stellar irradiation, and it is enhanced by 50% for the time-dependent case. The significant Joule Heating obtained here should be considered in models for the atmospheres of habitable planets in terms of the thickness of the atmosphere, the top-side temperature and density, the boundary conditions for the atmospheric pressure, and particle radiation and transport. Here we assume constant ionospheric Pedersen conductance similar to that of the Earth. The conductance could be greater due to the intense EUV radiation leading to smaller heating rates. We plan to quantify the ionospheric conductance in future study.« less

OGLE-2013-BLG-1761Lb: A Massive Planet around an MK Dwarf

NASA Technical Reports Server (NTRS)

Hirao, Y.; Udalski, A.; Sumi, T.; Bennett, D. P.; Koshimoto, N.; Bond, I. A.; Rattenbury, N. J.; Suzuki, D.; Abe, F.; Asakura, Y.;

The Pollution Solution.

ERIC Educational Resources Information Center

Stephens, Lillian

1981-01-01

Presented are methods to help teachers continue the environmental awareness programs they have already started by providing up-to-date information and activities dealing with air pollution, water pollution, and solid waste disposal. (Author/KC)

U.S. News Media Coverage of Pharmaceutical Pollution in the Aquatic Environment: A Content Analysis of the Problems and Solutions Presented by Actors.

PubMed

Blair, Benjamin; Zimny-Schmitt, Daniel; Rudd, Murray A

2017-08-01

Pharmaceutical pollution in the aquatic environment is an issue of concern that has attracted attention by the news media. Understanding the factors that contribute to media framing of pharmaceutical pollution may lead to a better understanding of the management and governance of this issue, including why these pollutants are generally unregulated at this time. This study conducted a content analysis of 405 newspaper articles (81 had substantive information on the topic) from 2007 to 2014, using the search terms "water" and "pharmaceuticals" in the Chicago Tribune, Denver Post, Los Angeles Times, New York Daily News, New York Times, USA Today, Wall Street Journal, and Washington Post. We sought to analyze the factors that contributed to the news media presentation of pharmaceutical pollution in the United States, including the presentation of the risks/safety and solutions by various actors. We found that the primary issues in the news media were uncertainty regarding public health and harm to the environment. The primary solutions recommended within the news media were implementing additional water treatment technologies, taking unused pharmaceuticals to predetermined sites for disposal (take-back programs), and trash disposal of unused pharmaceuticals. Water utilities and scientists presented improved water treatment technology, government actors presented take-back programs, and pharmaceutical representatives, while sparsely involved in the news media, presented trash disposal as their primary solutions. To advance the understanding of the management of pharmaceutical pollution, this article offers further insight into the debate and potential solutions within the news media presentation of this complex scientific topic.

U.S. News Media Coverage of Pharmaceutical Pollution in the Aquatic Environment: A Content Analysis of the Problems and Solutions Presented by Actors

NASA Astrophysics Data System (ADS)

Blair, Benjamin; Zimny-Schmitt, Daniel; Rudd, Murray A.

2017-08-01

Pharmaceutical pollution in the aquatic environment is an issue of concern that has attracted attention by the news media. Understanding the factors that contribute to media framing of pharmaceutical pollution may lead to a better understanding of the management and governance of this issue, including why these pollutants are generally unregulated at this time. This study conducted a content analysis of 405 newspaper articles (81 had substantive information on the topic) from 2007 to 2014, using the search terms "water" and "pharmaceuticals" in the Chicago Tribune, Denver Post, Los Angeles Times, New York Daily News, New York Times, USA Today, Wall Street Journal, and Washington Post. We sought to analyze the factors that contributed to the news media presentation of pharmaceutical pollution in the United States, including the presentation of the risks/safety and solutions by various actors. We found that the primary issues in the news media were uncertainty regarding public health and harm to the environment. The primary solutions recommended within the news media were implementing additional water treatment technologies, taking unused pharmaceuticals to predetermined sites for disposal (take-back programs), and trash disposal of unused pharmaceuticals. Water utilities and scientists presented improved water treatment technology, government actors presented take-back programs, and pharmaceutical representatives, while sparsely involved in the news media, presented trash disposal as their primary solutions. To advance the understanding of the management of pharmaceutical pollution, this article offers further insight into the debate and potential solutions within the news media presentation of this complex scientific topic.

An Introduction to the Solar System

NASA Astrophysics Data System (ADS)

McBride, Neil; Gilmour, Iain

2004-03-01

Compiled by a team of experts, this textbook has been designed for elementary university courses in planetary science. It starts with a tour of the Solar System and an overview of its formation that reviews in detail the terrestrial planets, giant planets and minor bodies. It concludes with a discussion of the origin of the Solar System. The text contains numerous useful learning features such as boxed summaries, student exercises with full solutions, and a glossary of terms. It is also supported by a website hosting further teaching materials.

A space telescope for infrared spectroscopy of earth-like planets

NASA Technical Reports Server (NTRS)

Angel, J. R. P.; Cheng, A. Y. S.; Woolf, N. J.

1986-01-01

It is shown here that a space telescope of 16 m diameter, apodized in a new way, could image and measure oxygen n in the thermal infrared spectral of earthlike planets up to 4 pc away. The problems of visible light imaging for this case are discussed, and it is argued that imaging the thermal emission, with greatly reduced requirements for gain and hence surface accuracy, is preferable. The requirements for such imaging are discussed, including the apodization solution.

Ammonia, phosphate, phenol, and copper(II) removal from aqueous solution by subsurface and surface flow constructed wetland.

PubMed

Mojiri, Amin; Ahmad, Zakiah; Tajuddin, Ramlah Mohd; Arshad, Mohd Fadzil; Gholami, Ali

2017-07-01

Water pollution is a global problem. During current study, ammonia, phosphate, phenol, and copper(II) were removed from aqueous solution by subsurface and surface flow constructed wetland. In current investigation, distilled water was polluted with four contaminants including ammonia, phosphate, copper (Cu), and phenol. Response surface methodology and central composite design were applied to optimize pollutant removal during treatment by subsurface flow constructed wetland (SSFCW). Contact time (12 to 80 h) and initial pollutant concentration (20 to 85 mg/L) were selected as independent factors; some upper and lower ranges were also monitored for accuracy. In SSFCW, water hyacinth transplanted in two substrate layers, namely zeolite and cockle shell. SSFCW removed 87.7, 81.4, 74.7, and 54.9% of ammonia, phosphate, Cu, and phenol, respectively, at optimum contact time (64.5 h) and initial pollutant concentration (69.2 mg/L). Aqueous solution was moved to a surface flow constructed wetland (SFCW) after treating via SSFCW at optimum conditions. In SFCW, Typha was transplanted to a fixed powdered substrate layer, including bentonite, zeolite, and cockle shell. SFCW could develop performance of this combined system and could improve elimination efficacy of the four contaminants to 99.99%. So this combined CW showed a good performance in removing pollutants. Graphical abstract Wetlands arrangement for treating aqueous solution in current study.

Planet Patrol. An Educational Unit on Solid Waste Solutions for Grades 4-6.

ERIC Educational Resources Information Center

Shively, Patti J.; And Others

This educational unit on solid waste solutions is intended to convey to students an understanding of the four methods of solid waste handling, in priority order, as recommended by the Environmental Protection Agency: (1) reduction in the volume of waste produced; (2) recycling and composting; (3) waste combustion, i.e., incineration of waste; and…

Computational techniques for solar wind flows past terrestrial planets: Theory and computer programs

NASA Technical Reports Server (NTRS)

Stahara, S. S.; Chaussee, D. S.; Trudinger, B. C.; Spreiter, J. R.

1977-01-01

The interaction of the solar wind with terrestrial planets can be predicted using a computer program based on a single fluid, steady, dissipationless, magnetohydrodynamic model to calculate the axisymmetric, supersonic, super-Alfvenic solar wind flow past both magnetic and nonmagnetic planets. The actual calculations are implemented by an assemblage of computer codes organized into one program. These include finite difference codes which determine the gas-dynamic solution, together with a variety of special purpose output codes for determining and automatically plotting both flow field and magnetic field results. Comparisons are made with previous results, and results are presented for a number of solar wind flows. The computational programs developed are documented and are presented in a general user's manual which is included.

A Possible Bifurcation in Atmospheres of Strongly Irradiated Stars and Planets

NASA Technical Reports Server (NTRS)

Hubeny, Ivan; Burrows, Adam; Sudarsky, David

2003-01-01

We show that under certain circumstances the differences between the absorption mean and Planck mean opacities can lead to multiple solutions for an LTE atmospheric structure. Since the absorption and Planck mean opacities are not expected to differ significantly in the usual case of radiative equilibrium, nonirradiated atmospheres, the most interesting situations in which the effect may play a role are strongly irradiated stars and planets, and also possibly structures in which there is a significant deposition of mechanical energy, such as stellar chromospheres and accretion disks. We have presented an illustrative example of a strongly irradiated giant planet in which the bifurcation effect is predicted to occur for a certain range of distances from the star.

Understanding International Environmental Security: A Strategic Military Perspective

DTIC Science & Technology

2000-11-01

remain one of the more fragile organisms on the planet, bound to a relatively constrained set of environmental conditions of landscape, temperature...series of interwoven phenomena including, but not limited to, deforestation, 30 burning of fossil fuels, and industrial pollution. Assessing each of...burning of fossil fuels is the cause. Figure 3-7 shows the trend in carbon dioxide con- centration over the past 300 years with an expanded view since

40 CFR 420.95 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Acid Pickling... for existing sources. (a) Sulfuric acid (spent acid solutions and rinse waters)—(1) Rod, wire, and... pickling (spent acid solutions and rinse waters)—(1) Rod, wire, and coil. Subpart I Pollutant or pollutant...

Reuse of hydroponic waste solution.

PubMed

Kumar, Ramasamy Rajesh; Cho, Jae Young

2014-01-01

Attaining sustainable agriculture is a key goal in many parts of the world. The increased environmental awareness and the ongoing attempts to execute agricultural practices that are economically feasible and environmentally safe promote the use of hydroponic cultivation. Hydroponics is a technology for growing plants in nutrient solutions with or without the use of artificial medium to provide mechanical support. Major problems for hydroponic cultivation are higher operational cost and the causing of pollution due to discharge of waste nutrient solution. The nutrient effluent released into the environment can have negative impacts on the surrounding ecosystems as well as the potential to contaminate the groundwater utilized by humans for drinking purposes. The reuse of non-recycled, nutrient-rich hydroponic waste solution for growing plants in greenhouses is the possible way to control environmental pollution. Many researchers have successfully grown several plant species in hydroponic waste solution with high yield. Hence, this review addresses the problems associated with the release of hydroponic waste solution into the environment and possible reuse of hydroponic waste solution as an alternative resource for agriculture development and to control environmental pollution.

Implications of pebble accretion on the composition of hot and cold Jupiters

NASA Astrophysics Data System (ADS)

Bitsch, Bertram; Johansen, Anders; Madhusudhan, Nikku

2016-10-01

The formation of the planetary cores of gas giants via the accretion of planetesimals takes very long and is not compatible with the lifetime of protoplanetary discs (Levison et al. 2010). This time-scale problem can be solved through the accretion of pebbles onto a planetary seed. Contrary to planetesimals, pebbles feel the headwind from the gas which robs them of angular momentum allowing an efficient growth from the entire Hill sphere, which reduces the growth time-scale by several orders of magnitude (Lambrechts & Johansen, 2012; 2014). However, pebble accretion self-terminates when the planets start to open a partial gap in the disc, which accelerates the gas outside of the planets orbit to super-Keplerian speeds and thus stops the flow of pebbles onto the planetary core (Lambrechts et al. 2014). Typically this mass is of the order of 10-20 Earth masses, depending on the local disc properties. The planet can then start to accrete a gaseous envelope without a pollution of pebbles. During its growth, the planet migrates through the disc, which evolves in time (Bitsch et al. 2015a,b).Different volatile species like CO2 or H2O have different condensation temperatures and are thus present in either solid or gaseous form at different locations in the disc. A pebble accreting planet can thus only accrete volatiles that are in solid form, while a gas accreting planet will only accrete volatiles which are in gaseous form. Therefore the final chemical composition of the planetary atmosphere of a giant planet is strongly influenced by the formation location of the initial planetary seed and its subsequent migration path through the disc. Additionally, the envelope can be enriched through the erosion of the planetary core.I will discuss the implications of the formation of planets via pebble accretion and their subsequent migration through the disc on the composition of gas giants. In particular I will focus on the carbon to oxygen ratio of hot Jupiters around other stars and on the carbon to oxygen ratio of Jupiter in our own solar system.

Are beryllium abundances anomalous in stars with giant planets?

NASA Astrophysics Data System (ADS)

Santos, N. C.; Israelian, G.; García López, R. J.; Mayor, M.; Rebolo, R.; Randich, S.; Ecuvillon, A.; Domínguez Cerdeña, C.

2004-12-01

In this paper we present beryllium (Be) abundances in a large sample of 41 extra-solar planet host stars, and for 29 stars without any known planetary-mass companion, spanning a large range of effective temperatures. The Be abundances were derived through spectral synthesis done in standard Local Thermodynamic Equilibrium, using spectra obtained with various instruments. The results seem to confirm that overall, planet-host stars have ``normal'' Be abundances, although a small, but not significant, difference might be present. This result is discussed, and we show that this difference is probably not due to any stellar ``pollution'' events. In other words, our results support the idea that the high-metal content of planet-host stars has, overall, a ``primordial'' origin. However, we also find a small subset of planet-host late-F and early-G dwarfs that might have higher than average Be abundances. The reason for the offset is not clear, and might be related either to the engulfment of planetary material, to galactic chemical evolution effects, or to stellar-mass differences for stars of similar temperature. Based on observations collected with the VLT/UT2 Kueyen telescope (Paranal Observatory, ESO, Chile) using the UVES spectrograph (Observing runs 66.C-0116 A, 66.D-0284 A, and 68.C-0058 A), and with the William Herschel and Nordic Optical Telescopes, operated on the island of La Palma by the Isaac Newton Group and jointly by Denmark, Finland, Iceland, and Norway, respectively, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

Optimal Planet Properties For Plate Tectonics Through Time And Space

NASA Astrophysics Data System (ADS)

Stamenkovic, Vlada; Seager, Sara

2014-11-01

Both the time and the location of planet formation shape a rocky planet’s mass, interior composition and structure, and hence also its tectonic mode. The tectonic mode of a planet can vary between two end-member solutions, plate tectonics and stagnant lid convection, and does significantly impact outgassing and biogeochemical cycles on any rocky planet. Therefore, estimating how the tectonic mode of a planet is affected by a planet’s age, mass, structure, and composition is a major step towards understanding habitability of exoplanets and geophysical false positives to biosignature gases. We connect geophysics to astronomy in order to understand how we could identify and where we could find planet candidates with optimal conditions for plate tectonics. To achieve this goal, we use thermal evolution models, account for the current wide range of uncertainties, and simulate various alien planets. Based on our best model estimates, we predict that the ideal targets for plate tectonics are oxygen-dominated (C/O<1) (solar system like) rocky planets of ~1 Earth mass with surface oceans, large metallic cores super-Mercury, rocky body densities of ~7000kgm-3), and with small mantle concentrations of iron 0%), water 0%), and radiogenic isotopes 10 times less than Earth). Super-Earths, undifferentiated planets, and especially hypothetical carbon planets, speculated to consist of SiC and C, are not optimal for the occurrence of plate tectonics. These results put Earth close to an ideal compositional and structural configuration for plate tectonics. Moreover, the results indicate that plate tectonics might have never existed on planets formed soon after the Big Bang—but instead is favored on planets formed from an evolved interstellar medium enriched in iron but depleted in silicon, oxygen, and especially in Th, K, and U relative to iron. This possibly sets a belated Galactic start for complex Earth-like surface life if plate tectonics significantly impacts the build up and regulation of gases relevant for life. This allows for the first time to discuss the tectonic mode of a rocky planet from a practical astrophysical perspective.

Smart urban design to reduce transportation impact in city centers

NASA Astrophysics Data System (ADS)

Fezzai, Soufiane; Mazouz, Said; Ahriz, Atef

2018-05-01

Air pollution is one of the most serious problems facing human being; urban wastes are in first range of energy consumption and emission of greenhouse gasses. Transportation or car traffic is one of the most consumer sectors of fuel, and most pollutant. Reducing energy consumption in transportation and the emission of pollutant gasses becomes an important objective for urban designers; many solutions may be proposed to help solving this problem in future designs, but it depend on other factors in existing urban space especially in city centers characterized with high occupation density. In this paper we investigate traffic rate in the city center of the case study, looking for the causes of the high traffic using gate count method and estimating fuel consumption. We try to propose some design solutions to reduce distances so fuel consumption and emission of pollutant gasses. We use space syntax techniques to evaluate urban configuration and verify the proposed solutions.

Introducing future engineers to sustainable ecology problems: a case study

NASA Astrophysics Data System (ADS)

Filipkowski, A.

2011-12-01

The problem of Earth environmental destruction by human activities is becoming dangerous. Engineers responsible for the production of any goods should be well aware of the negative influence of their activities on the state of the planet. This is why the understanding of ecological problems is essential for people responsible for production and industrial design. The energy, which they consume, is increasing the greenhouse effect and the waste poisons the environment. So far, most courses on ecology are offered to specialists in environmental engineering. These courses are filled with many details. The Warsaw Academy of Computer Science, Management and Administration teaches students in the direction of management and production engineering. Upon completion, the students receive the degree of 'engineer'. Their future work will mainly concern management of different types of industrial enterprises and they will be responsible for organising it in such a way as to avoid a dangerous contribution to environmental pollution and climate change. This is why it was decided to introduce a new course entitled 'Principles of Ecology and Environmental Management'. This course is quite broad, concerning almost all technical, law and organisational aspects of the problem. The presentation is made in a spectacular way, aiming to convince students that their future activity must be environmentally friendly. It contains information about international activities in ecology, legal aspects concerning pollution, technical and information methods of monitoring and, finally, the description of 'green' solutions. Altogether, 27 hours of lectures and 15 hours of discussions and students' presentations complete the course. Details of this course are described in this paper.

From Scientists to the Public: Communicating Science through Blogs on oceanbites.org and envirobites.org

NASA Astrophysics Data System (ADS)

Lemon, M. G.; McDonough, C. A.; Schifman, L. A.

2017-12-01

Science communication is increasingly important. Our world is facing difficult environmental challenges that can only be addressed if an understanding of the basic scientific principles exists. With this in mind, we founded oceanbites.org in 2013, and recently (August 2017) also started envirobites.org. For both blogs, graduate students, postdoctoral researchers, and science professionals come together to write and edit easy-to-read, compelling summaries of recent, cutting-edge research papers in environmental science or oceanography and make them accessible to non-experts. We want to share our passion for research with all non-scientists who are interested to learn more about the environment and our oceans: This ranges in scale from identifying science problems and solutions in cities to explaining the complex environmental challenges facing our planet as a whole. Because science is also about identifying and applying technologies to address these challenges, we also cover some success stories! For envirobites.org, topics of posts include science in and for cities, global transport of pollutants, toxic effects of pollution, climate change, and environmental remediation. Oceanbites.org covers topics ranging from chemical, to biological, and physical oceanography. Currently, oceanbites.org has 24 writers and publishes posts daily, whereas envirobites.org has 26 writers and we publish posts on our blog three times per week. We hope to recruit more members and editors, but most of all, increase our readership to make a big splash in the communication of science to the public, whether we reach K-12 classrooms or living rooms.

Greening Solutions Applicable in the Tailing Ponds Tăusani and Bosneag from Moldova Nouă

NASA Astrophysics Data System (ADS)

Burlacu, I. F.; Deak, G.; Raischi, M. C.; Daescu, A.; Zamfir, S.; Uritescu, B.; Cirstinoiu, C.; Olteanu, M. V.

2017-06-01

This study aims to propose solutions for greening of the tailings ponds resulted from mining activities with transboundary impacts. As case study, are proposed for greening the Boşneag and Tăuşani tailing ponds because they pollute Moldova Nouă, Danube and towns on the Serbian side of the Danube with particles in suspension. We analyzed four scenarios of modeling dispersion of particles in suspension (copper and other heavy metals) from the Tăuşani and Boşneag tailing ponds in the theoretical background where pollution has cross-border nature and require studying the transport of pollutants over a long distance from the source and modeling dispersion of particles in suspension in the atmosphere, these were performed using TAPM model, able to simulate the aspects mentioned. After running the software for modeling the dispersion of particles, was revealed that the pollution generated from the pollution sources taked into consideration is very high and significantly affects quality of life on considerable areas both in Romania and Serbia, thus amplifying the need to implement greening solutions of the analyzed area. Following the results obtained are presented three alternatives solutions for greening the area studied, aiming at minimizing the impact on the environmental and population.

Water cycling between ocean and mantle: Super-earths need not be waterworlds

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

Cowan, Nicolas B.; Abbot, Dorian S., E-mail: n-cowan@northwestern.edu

2014-01-20

Large terrestrial planets are expected to have muted topography and deep oceans, implying that most super-Earths should be entirely covered in water, so-called waterworlds. This is important because waterworlds lack a silicate weathering thermostat so their climate is predicted to be less stable than that of planets with exposed continents. In other words, the continuously habitable zone for waterworlds is much narrower than for Earth-like planets. A planet's water is partitioned, however, between a surface reservoir, the ocean, and an interior reservoir, the mantle. Plate tectonics transports water between these reservoirs on geological timescales. Degassing of melt at mid-ocean ridgesmore » and serpentinization of oceanic crust depend negatively and positively on seafloor pressure, respectively, providing a stabilizing feedback on long-term ocean volume. Motivated by Earth's approximately steady-state deep water cycle, we develop a two-box model of the hydrosphere and derive steady-state solutions to the water partitioning on terrestrial planets. Critically, hydrostatic seafloor pressure is proportional to surface gravity, so super-Earths with a deep water cycle will tend to store more water in the mantle. We conclude that a tectonically active terrestrial planet of any mass can maintain exposed continents if its water mass fraction is less than ∼0.2%, dramatically increasing the odds that super-Earths are habitable. The greatest source of uncertainty in our study is Earth's current mantle water inventory: the greater its value, the more robust planets are to inundation. Lastly, we discuss how future missions can test our hypothesis by mapping the oceans and continents of massive terrestrial planets.« less

Dwarf carbon stars are likely metal-poor binaries and unlikely hosts to carbon planets

NASA Astrophysics Data System (ADS)

Whitehouse, Lewis J.; Farihi, J.; Green, P. J.; Wilson, T. G.; Subasavage, J. P.

2018-06-01

Dwarf carbon stars make up the largest fraction of carbon stars in the Galaxy with ≈1200 candidates known to date primarily from the Sloan Digital Sky Survey. They either possess primordial carbon-enhancements, or are polluted by mass transfer from an evolved companion such that C/O is enhanced beyond unity. To directly test the binary hypothesis, a radial velocity monitoring survey has been carried out on 28 dwarf carbon stars, resulting in the detection of variations in 21 targets. Using Monte Carlo simulations,this detection fraction is found to be consistent with a 100% binary population and orbital periods on the order of hundreds of days. This result supports the post-mass transfer nature of dwarf carbon stars, and implies they are not likely hosts to carbon planets.

Wi-Fi technology--an uncontrolled global experiment on the health of mankind.

PubMed

Markov, Marko; Grigoriev, Yuri G

2013-06-01

The twenty-first century is marked with exponentially increasing development of technologies that provide wireless communications. To the pollution of the atmosphere with radio and TV signals, not only satellite communications but also any varieties of the Wi-Fi networks are added. By 2010 in the USA, 285 million mobile phone subscribers have been registered (for a little bit more than 300 million inhabitants). The estimate for the world is more than 5 billion mobile phone users at approximately 7 billion people living on this planet. Approximately 2 years ago, the International Agency of Research on Cancer (IARC) classified the electromagnetic fields used in mobile communication as a possible cancerogene. This paper discusses the potential health hazard and lack of scientific assessment and regulatory actions in protection of the life on the planet.

14th Annual P3 Awards: A National Student Design ...

EPA Pesticide Factsheets

2017-02-14

EPA as part of its People, Prosperity and the Planet (P3) Award Program – is seeking applications proposing to research, develop, and design solutions to real world challenges involving sustainability.

On the necessity of making geoethics a central concern in eduethics world-wide

NASA Astrophysics Data System (ADS)

Crookall, David; Promduangsri, Pimnutcha

2017-04-01

Our planet is in dire need of ethical behaviour by all its citizens. However, recent research has highlighted the increasingly dangerous impact of human activity on life systems of the planet. CO2 emissions continue to rise (400+ppm, end 2016), methane emissions are accelerating. The Arctic is about 28°C above the normal average. Average global temperature is reaching 1° above normal. Air, water and ground pollution levels are reaching devastating levels. Resource depletion is accelerating. Yet most governments still beat the drums of growth, while hypocritically humming the tune of sustainability. Humans are overshooting the carrying capacity of the planet; as attested by top scientists and organizations. Earth overshoot day in 2016 was 8 August; we need 5½ earths to live like Australians. Of course, efforts are being made globally and locally to combat impending disaster and to encourage more respectful behaviour towards the planet and its life. Individuals include scientists, writers, film makers, journalists. World-wide organizations include Climate Literacy and Energy Awareness Network (CLEAN), the Climate Change Education Partnership Alliance, the International Geoscience Education Organisation (IGEO), and the United Nations Environment Programme (UNEP). A key organization is the International Association for Promoting Geoethics (IAPG) because it focuses firmly and explicitly on the key issue of ethics, which few others appear to do. One might argue that the general lack of major progress in environmental care is rooted to a large degree in the world-wide lack of strong adherence to geoethical principles. Learning to behave ethically needs far more than knowledge about energy imbalance, pollution, acidity, ice melt, etc. It needs people to learn, and grow up learning, about what is right and wrong in regard to each aspect of our personal earth citizen lives. That needs nothing short of a revolution in educational practice for all schools across the globe - a tall order, and an intergenerational process. Our worry is: Can 'we' educate sufficient numbers of (younger) voyagers on our spaceship Earth in time - in order for a fully informed humanity to guide it towards becoming a healthy environment, fit for the wellbeing of humans, animals and plants. It seems to us that the IAPG is in a unique position to encourage this. The most powerful way to mitigate climate change, pollution, etc is to make geoethics the core of education across the globe. In our presentation, we will emphasize the need to boost strong eduethics, so that the positive effects are passed on from generation to generation. The presentation will outline this rationale and then suggest ways in which we might wish to make eduethics the companion of geoethics, to encourage them to advance hand in hand. We hope to start a process of reflecting on how the IAPG, its members, educational communities and society can together move towards education programmes that encourage ethically sound behaviour individually and collectively. The aim would be for informed and ethical citizens to vote for governments that put the planet and its citizens at the centre of their preoccupations.

Sustainable Development--Education, Business and Management--Architecture and Building Construction--Agriculture and Food Security

ERIC Educational Resources Information Center

Ghenai, Chaouki, Ed.

2012-01-01

Securing the future of the human race will require an improved understanding of the environment as well as of technological solutions, mindsets and behaviors in line with modes of development that the ecosphere of our planet can support. Some experts see the only solution in a global deflation of the currently unsustainable exploitation of…

Protected areas in the Atlantic facing the hazards of micro-plastic pollution: first diagnosis of three islands in the Canary Current.

PubMed

Baztan, Juan; Carrasco, Ana; Chouinard, Omer; Cleaud, Muriel; Gabaldon, Jesús E; Huck, Thierry; Jaffrès, Lionel; Jorgensen, Bethany; Miguelez, Aquilino; Paillard, Christine; Vanderlinden, Jean-Paul

2014-03-15

Coastal zones and the biosphere as a whole show signs of cumulative degradation due to the use and disposal of plastics. To better understand the manifestation of plastic pollution in the Atlantic Ocean, we partnered with local communities to determine the concentrations of micro-plastics in 125 beaches on three islands in the Canary Current: Lanzarote, La Graciosa, and Fuerteventura. We found that, in spite of being located in highly-protected natural areas, all beaches in our study area are exceedingly vulnerable to micro-plastic pollution, with pollution levels reaching concentrations greater than 100 g of plastic in 1l of sediment. This paper contributes to ongoing efforts to develop solutions to plastic pollution by addressing the questions: (i) Where does this pollution come from?; (ii) How much plastic pollution is in the world's oceans and coastal zones?; (iii) What are the consequences for the biosphere?; and (iv) What are possible solutions? Copyright © 2014 Elsevier Ltd. All rights reserved.

Understanding Environmental Security: A Military Perspective

DTIC Science & Technology

2000-06-14

rates, which humankind can impact only in minor percentages of total use. In the final analysis we remain one of the more fragile organisms on the planet...by. a series of interwoven phenomenon including but not limited to deforestation. burning of fossil ftiels. industrial pollution. and urbanization...burning of fossil fuels is the cause. Figure 1-7 shows the trend in carbon dioxide concentration over the past 300 years with an expanded view since 1960

Extreme coronagraphy with an adaptive hologram. Simulations of exo-planet imaging

NASA Astrophysics Data System (ADS)

Ricci, D.; Le Coroller, H.; Labeyrie, A.

2009-08-01

Aims: We present a solution to improve the performance of coronagraphs for the detection of exo-planets. Methods: We simulate numerically several kinds of coronagraphic systems, with the aim of evaluating the gain obtained with an adaptive hologram. Results: The detection limit in flux ratio between a star and a planet (F_s/F_p) observed with an apodized Lyot coronagraph characterized by wavefront bumpiness imperfections of λ/20 (resp. λ/100) turns out to be increased by a factor of 103.4 (resp. 105.1) when equipped with a hologram. Conclusions: This technique could provide direct imaging of an exo-Earth at a distance of 11 parsec with a 6.5 m space telescope such as the JWST with the optical quality of the HST.

Mussel-inspired polydopamine biopolymer decorated with magnetic nanoparticles for multiple pollutants removal.

PubMed

Zhang, Shengxiao; Zhang, Yuanyuan; Bi, Guoming; Liu, Junshen; Wang, Zhigang; Xu, Qiang; Xu, Hui; Li, Xiaoyan

2014-04-15

The polydopamine polymer decorated with magnetic nanoparticles (Fe3O4/PDA) was synthesized and applied for removal of multiple pollutants. The resulted Fe3O4/PDA was characterized with elemental analysis, thermo-gravimetric analyses, vibrating sample magnetometer, high resolution transmission electron microscope, Fourier transform infrared spectra, and X-ray photoelectron spectroscopy. The self-polymerization of dopamine could be completed within 8h, and Fe3O4 nanoparticles were embedded into PDA polymer. Superparamagnetism and large saturation magnetization facilitated collection of sorbents with a magnet. Based on the catechol and amine groups, the PDA polymer provided multiple interactions to combine with pollutants. To investigate the adsorption ability of Fe3O4/PDA, heavy metal ions and dyes were selected as target pollutants. The adsorption of pollutants was pH dependent due to the variation of surface charges at different solution pH. The removal efficiencies of cation pollutants enhanced with solution pH increasing, and that of anion pollutant was just the opposite. Under the optimal solution pH, the maximum adsorption capacity calculated from Langmuir adsorption isotherm for methylene blue, tartrazine, Cu(2+), Ag(+), and Hg(2+) were 204.1, 100.0, 112.9, 259.1, and 467.3 mg g(-1), respectively. The Fe3O4/PDA shows great potential for multiple pollutants removal, and this study is the first application of PDA polymer in environmental remediation. Copyright © 2014 Elsevier B.V. All rights reserved.

Modeling the secular evolution of migrating planet pairs

NASA Astrophysics Data System (ADS)

Michtchenko, T. A.; Rodríguez, A.

2011-10-01

The secular regime of motion of multi-planetary systems is universal; in contrast with the 'accidental' resonant motion, characteristic only for specific configurations of the planets, secular motion is present everywhere in phase space, even inside the resonant region. The secular behavior of a pair of planets evolving under dissipative forces is the principal subject of this study, particularly, the case when the dissipative forces affect the planetary semi-major axes and the planets move inward/outward the central star, the process known as planet migration. Based on the fundamental concepts of conservative and dissipative dynamics of the three-body problem, we develop a qualitative model of the secular evolution of the migrating planetary pair. Our approach is based on analysis of the energy and the orbital angular momentum exchange between the two-planet system and an external medium; thus no specific kind of dissipative forces is invoked. We show that, under assumption that dissipation is weak and slow, the evolutionary routes of the migrating planets are traced by the Mode I and Mode II stationary solutions of the conservative secular problem. The ultimate convergence and the evolution of the system along one of these secular modes of motion is determined uniquely by the condition that the dissipation rate is sufficiently smaller than the proper secular frequency of the system. We show that it is possible to reassemble the starting configurations and migration history of the systems on the basis of their final states and consequently to constrain the parameters of the physical processes involved.

Coupled Evolution with Tides of the Radius and Orbit of Transiting Giant Planets: General Results

NASA Astrophysics Data System (ADS)

Ibgui, Laurent; Burrows, Adam

2009-08-01

Some transiting extrasolar giant planets (EGPs) have measured radii larger than predicted by the standard theory. In this paper, we explore the possibility that an earlier episode of tidal heating can explain such radius anomalies and apply the formalism we develop to HD 209458b as an example. We find that for strong enough tides the planet's radius can undergo a transient phase of inflation that temporarily interrupts canonical, monotonic shrinking due to radiative losses. Importantly, an earlier episode of tidal heating can result in a planet with an inflated radius, even though its orbit has nearly circularized. Moreover, we confirm that at late times, and under some circumstances, by raising tides on the star itself a planet can spiral into its host. We note that a 3× to 10× solar planet atmospheric opacity with no tidal heating is sufficient to explain the observed radius of HD 209458b. However, our model demonstrates that with an earlier phase of episodic tidal heating, we can fit the observed radius of HD 209458b even with lower (solar) atmospheric opacities. This work demonstrates that, if a planet is left with an appreciable eccentricity after early inward migration and/or dynamical interaction, coupling radius and orbit evolution in a consistent fashion that includes tidal heating, stellar irradiation, and detailed model atmospheres might offer a generic solution to the inflated radius puzzle for transiting EGPs such as WASP-12b, TrES-4, and WASP-6b.

Searching For Infrared Excesses Around White Dwarf Stars

NASA Astrophysics Data System (ADS)

Deeb Wilson, Elin; Rebull, Luisa M.; Debes, John H.; Stark, Chris

2017-01-01

Many WDs have been found to be “polluted,” meaning they contain heavier elements in their atmospheres. Either an active process that counters gravitational settling is taking place, or an external mechanism is the cause. One proposed external mechanism for atmospheric pollution of WDs is the disintegration and accretion of rocky bodies, which would result in a circumstellar (CS) disk. As CS disks are heated, they emit excess infrared (IR) emission. WDs with IR excesses indicative of a CS disk are known as dusty WDs. Statistical studies are still needed to determine how numerous dusty, polluted WDs are, along with trends and correlations regarding rate of planetary accretion, the lifetimes of CS disks, and the structure and evolution of CS disks. These findings will allow for a better understanding of the fates of planets along with potential habitability of surviving planets.In this work, we are trying to confirm IR excesses around a sample of 69 WD stars selected as part of the WISE InfraRed Excesses around Degenerates (WIRED) Survey (Debes et al. 2011). We have archival data from WISE, Spitzer, 2MASS, DENIS, and SDSS. The targets were initially selected from the Sloan Digital Sky Survey (SDSS), and identified as containing IR excesses based on WISE data. We also have data from the Four Star Infrared Camera array, which is part of Carnegie Institution’s Magellan 6.5 meter Baade Telescope located at Las Campanas Observatory in Chile. These Four Star data are much higher spatial resolution than the WISE data that were used to determine if each WD has an IR excess. There are often not many bands delineating the IR excess portion of the SED; therefore, we are using the Four Star data to check if there is another source in the WISE beam affecting the IR excess.

Mapping the Pressure-radius Relationship of Exoplanets

NASA Astrophysics Data System (ADS)

Cubillos, Patricio; Fossati, Luca; Kubyshkina, Darya

2017-10-01

The radius of a planet is one of the most physically meaningful and readily accessible parameters of extra-solar planets. This parameter is extensively used in the literature to compare planets or study trends in the know population of exoplanets. However, in an atmosphere, the concept of a planet radius is inherently fuzzy. The atmospheric pressures probed by trasmission (transit) or emission (eclipse) spectra are not directly constrained by the observations, they vary as a function of the atmospheric properties and observing wavelengths, and further correlate with the atmospheric properties producing degenerate solutions.Here, we characterize the properties of exoplanet radii using a radiative-transfer model to compute clear- atmosphere transmission and emission spectra of gas-dominated planets. We explore a wide range of planetary temperatures, masses, and radii, sampling from 300 to 3000 K and Jupiter- to Earth-like values. We will discuss how transit and photospheric radii vary over the parameter space, and map the global trends in the atmospheric pressures associated with these radii. We will also highlight the biases introduced by the choice of an observing band, or the assumption of a clear/cloudy atmosphere, and the relevance that these biases take as better instrumentation improves the precision of photometric observations.

Migration of giant planets in a time-dependent planetesimal accretion disc

NASA Astrophysics Data System (ADS)

Del Popolo, A.; Ekşi, K. Y.

2002-05-01

In this paper we develop further the model for the migration of planets introduced in Del Popolo et al. We first model the protoplanetary nebula as a time-dependent accretion disc, and find self-similar solutions to the equations of the accretion disc that give us explicit formulae for the spatial structure and the temporal evolution of the nebula. These equations are then used to obtain the migration rate of the planet in the planetesimal disc, and to study how the migration rate depends on the disc mass, on its time evolution and on some values of the dimensionless viscosity parameter α . We find that planets that are embedded in planetesimal discs, having total mass of 10-4 -0.1Msolar , can migrate inward a large distance for low values of α (e.g., α ~=10-3 -10-2 ) and/or large disc mass, and can survive only if the inner disc is truncated or because of tidal interaction with the star. Orbits with larger a are obtained for smaller values of the disc mass and/or for larger values of α . This model may explain several orbital features of the recently discovered giant planets orbiting nearby stars.

Solutions Network Formulation Report. NASA's Potential Contributions for Using Solar Ultraviolet Radiation in Conjunction with Photocatalysis for Urban Air Pollution Mitigation and Increasing Air Quality

NASA Technical Reports Server (NTRS)

Underwood, Lauren; Ryan, Robert E.

2007-01-01

This Candidate Solution is based on using NASA Earth science research on atmospheric ozone and aerosols data as a means to predict and evaluate the effectiveness of photocatalytically created surfaces (building materials like glass, tile and cement) for air pollution mitigation purposes. When these surfaces are exposed to near UV light, organic molecules, like air pollutants and smog precursors, will degrade into environmentally friendly compounds. U.S. EPA (Environmental Protection Agency) is responsible for forecasting daily air quality by using the Air Quality Index (AQI) that is provided by AIRNow. EPA is partnered with AIRNow and is responsible for calculating the AQI for five major air pollutants that are regulated by the Clean Air Act. In this Solution, UV irradiance data acquired from the satellite mission Aura and the OMI Surface UV algorithm will be used to help understand both the efficacy and efficiency of the photocatalytic decomposition process these surfaces facilitate, and their ability to reduce air pollutants. Prediction models that estimate photocatalytic function do not exist. NASA UV irradiance data will enable this capability, so that air quality agencies that are run by state and local officials can develop and implement programs that utilize photocatalysis for urban air pollution control and, enable them to make effective decisions about air pollution protection programs.

Masses, Radii, and Cloud Properties of the HR 8799 Planets

NASA Technical Reports Server (NTRS)

Marley, Mark S.; Saumon, Didier; Cushing, Michael; Ackerman, Andrew S.; Fortney, Jonathan J.; Freedman, Richard

2012-01-01

The near-infrared colors of the planets directly imaged around the A star HR 8799 are much redder than most field brown dwarfs of the same effective temperature. Previous theoretical studies of these objects have compared the photometric and limited spectral data of the planets to the predictions of various atmosphere and evolution models and concluded that the atmospheres of planets b, c, and d are unusually cloudy or have unusual cloud properties. Most studies have also found that the inferred radii of some or all of the planets disagree with expectations of standard giant planet evolution models. Here we compare the available data to the predictions of our own set of atmospheric and evolution models that have been extensively tested against field L and T dwarfs, including the reddest L dwarfs. Unlike almost all previous studies we specify mutually self-consistent choices for effective temperature, gravity, cloud properties, and planetary radius. This procedure yields plausible and self-consistent values for the masses, effective temperatures, and cloud properties of all three planets. We find that the cloud properties of the HR 8799 planets are in fact not unusual but rather follow previously recognized trends including a gravity dependence on the temperature of the L to T spectral transition, some reasons for which we discuss. We find that the inferred mass of planet b is highly sensitive to the H and K band spectrum. Solutions for planets c and particularly d are less certain but are consistent with the generally accepted constraints on the age of the primary star and orbital dynamics. We also confirm that as for L and T dwarfs and solar system giant planets, non-equilibrium chemistry driven by atmospheric mixing is also important for these objects. Given the preponderance of data suggesting that the L to T spectral type transition is gravity dependent, we present a new evolution calculation that predicts cooling tracks on the near-infrared color-magnitude diagram. Finally we argue that the range of uncertainty conventionally quoted for the bolometric luminosity of all three planets is too small.

The Solutions Data Base Component of the Water Pollution Abatement Subsystem (WPAS) of the Pollution Abatement Management System. (PAMS).

DTIC Science & Technology

1981-04-01

Facilities EngineerATTN: DAEN-MPC Fitzs ;mons Amy Medical Center ATTN: DAEN-PE Army Instl. and Major Activities (CONuS; waiter Reed Army Medical center ATTN...S)St. Paul Fort Sheridan 21st Support ComandTulsa Fort Stewart4 Vicksburg Fort Wainmright AN: AREA (5) Walls Walla Vancouver Bks. Wilmington US Am...ABG/DEEE Patrick AFB, FL 32925 ATTN: XRQ ’ C Bandy, John T. The Solutions Data Base component of the Water Pollution Abatement Subsystem (WPAS) of the

China: A sleeping giant awakens to environment

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

Ni Shaoxiang

1995-07-01

This article discusses the approach the Chinese government is taking to environmental issues. Included are the following topics: pollution abatement; improved rural environment by curbing the production and use of highly toxic pesticides; limiting erosion; natural reserves. Problems awaiting solutions are also discussed: air pollution (particularly coal combustion); water pollution; solid-waste pollution; rural pollution; soil erosion; desertification; soil salinization; deforestation; grassland deterioration; natural disasters.

PERSONAL-PRACTICES POLLUTANTS: UBIETY, UBIQUITY, SIGNIFICANCE, SOLUTIONS, STEWARDSHIP

EPA Science Inventory

The occurrence of pharmaceuticals and personal care products (PPCPS) as environmental pollutants is a multifaceted issue whose scope continues to become better delineated with the escalation of attention that began in the 1980s. PPCPs typically occur as trace environmental pollut...

Numerical simulation the pollutants transport in the Lake base on remote sensing image with Lattice Boltzmann Method

NASA Astrophysics Data System (ADS)

Qiao, Y.

2013-12-01

As China's economic development, water pollution incidents happened frequently. For example, the cyanobacterial bloom events repeatedly occur in Taihu Lake. In this research, we investigate the pollutants solute transport start at different points, such as the eutrophication substances Nitrogen and Phosphorus et al, with the Lattice Boltzmann Method (LBM) performed on real pore geometries. The LBM has emerged as a powerful tool for simulating the behaviour of multi-component fluid systems in complex pore networks. We will build a quick response simulation system, which is base on the high resolution GIS figure, using the LBM numerical method.When the start two deferent points at the Meiliang Bay nearby the Wuxi City, it is shown that the pollutants solute can't transport out of the bay to influence the Taihu Lake and the diffusion areas are similar. On the other hand, when the start point at central region of the Taihu Lake, it is found that the pollutants solute covered the almost whole area of the lake and the cyanobacterial bloom with good condition. In the same way, if the cyanobacterial bloom transport in the central area, then it will pollute the whole Taihu Lake. Therefore, when we monitor and deal with the eutrophication substances, we need to focus on the central area of lake.

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.

Modelling the secular evolution of migrating planet pairs

NASA Astrophysics Data System (ADS)

Michtchenko, T. A.; Rodríguez, A.

2011-08-01

The subject of this paper is the secular behaviour of a pair of planets evolving under dissipative forces. In particular, we investigate the case when dissipative forces affect the planetary semimajor axes and the planets move inwards/outwards the central star, in a process known as planet migration. To perform this investigation, we introduce fundamental concepts of conservative and dissipative dynamics of the three-body problem. Based on these concepts, we develop a qualitative model of the secular evolution of the migrating planetary pair. Our approach is based on the analysis of the energy and the orbital angular momentum exchange between the two-planet system and an external medium; thus no specific kind of dissipative forces is invoked. We show that, under the assumption that dissipation is weak and slow, the evolutionary routes of the migrating planets are traced by the Mode I and Mode II stationary solutions of the conservative secular problem. The ultimate convergence and the evolution of the system along one of these secular modes of motion are determined uniquely by the condition that the dissipation rate is sufficiently smaller than the proper secular frequency of the system. We show that it is possible to reassemble the starting configurations and the migration history of the systems on the basis of their final states and consequently to constrain the parameters of the physical processes involved.

RESONANCES REQUIRED: DYNAMICAL ANALYSIS OF THE 24 Sex AND HD 200964 PLANETARY SYSTEMS

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

Wittenmyer, Robert A.; Horner, Jonathan; Tinney, C. G., E-mail: rob@phys.unsw.edu.au

We perform several suites of highly detailed dynamical simulations to investigate the architectures of the 24 Sextantis and HD 200964 planetary systems. The best-fit orbital solution for the two planets in the 24 Sex system places them on orbits with periods that lie very close to 2:1 commensurability, while that for the HD 200964 system places the two planets therein in orbits whose periods lie close to a 4:3 commensurability. In both cases, the proposed best-fit orbits are mutually crossing-a scenario that is only dynamically feasible if the planets are protected from close encounters by the effects of mutual mean-motionmore » resonance (MMR). Our simulations reveal that the best-fit orbits for both systems lie within narrow islands of dynamical stability, and are surrounded by much larger regions of extreme instability. As such, we show that the planets are only feasible if they are currently trapped in mutual MMR-the 2:1 resonance in the case of 24 Sex b and c, and the 4:3 resonance in the case of HD 200964 b and c. In both cases, the region of stability is strongest and most pronounced when the planetary orbits are mutually coplanar. As the inclination of planet c with respect to planet b is increased, the stability of both systems rapidly collapses.« less

Records of Migration in the Exoplanet Configurations

NASA Astrophysics Data System (ADS)

Michtchenko, Tatiana A.; Rodriguez Colucci, A.; Tadeu Dos Santos, M.

2013-05-01

Abstract (2,250 Maximum Characters): When compared to our Solar System, many exoplanet systems exhibit quite unusual planet configurations; some of these are hot Jupiters, which orbit their central stars with periods of a few days, others are resonant systems composed of two or more planets with commensurable orbital periods. It has been suggested that these configurations can be the result of a migration processes originated by tidal interactions of the planets with disks and central stars. The process known as planet migration occurs due to dissipative forces which affect the planetary semi-major axes and cause the planets to move towards to, or away from, the central star. In this talk, we present possible signatures of planet migration in the distribution of the hot Jupiters and resonant exoplanet pairs. For this task, we develop a semi-analytical model to describe the evolution of the migrating planetary pair, based on the fundamental concepts of conservative and dissipative dynamics of the three-body problem. Our approach is based on an analysis of the energy and the orbital angular momentum exchange between the two-planet system and an external medium; thus no specific kind of dissipative forces needs to be invoked. We show that, under assumption that dissipation is weak and slow, the evolutionary routes of the migrating planets are traced by the stationary solutions of the conservative problem (Birkhoff, Dynamical systems, 1966). The ultimate convergence and the evolution of the system along one of these modes of motion are determined uniquely by the condition that the dissipation rate is sufficiently smaller than the roper frequencies of the system. We show that it is possible to reassemble the starting configurations and migration history of the systems on the basis of their final states, and consequently to constrain the parameters of the physical processes involved.

Speckle Imaging and Spectroscopy of Kepler Exo-planet Transit Candidate Stars

NASA Astrophysics Data System (ADS)

Howell, Steve B.; Sherry, William; Horch, Elliott; Doyle, Laurance

2010-02-01

The NASA Kepler mission was successfully launched on 6 March 2009 and has begun science operations. Commissioning tests done early on in the mission have shown that for the bright sources, 10-15 ppm relative photometry can be achieved. This level assures we will detect Earth- like transits if they are present. ``Hot Jupiter" and similar large planet candidates have already been discovered and will be discussed at the Jan. AAS meeting as well as in a special issue of Science magazine to appear near years end. The plethora of variability observed is astounding and includes a number of eclipsing binaries which appear to have Jupiter and smaller size objects as an orbiting their body. Our proposal consists of three highly related objectives: 1) To continue our highly successful speckle imaging program which is a major component of defense to weed out false positive candidate transiting planets found by Kepler and move the rest to probable or certain exo-planet detections; 2) To obtain low resolution ``discovery" type spectra for planet candidate stars in order to provide spectral type and luminosity class indicators as well as a first look triage to eliminate binaries and rapid rotators; and 3) to obtain ~1Aresolution time ordered spectra of eclipsing binaries that are exo-planet candidates in order to obtain the velocity solution for the binary star, allowing its signal to be modeled and removed from the Keck or HET exo-planet velocity search. As of this writing, Kepler has produced a list of 227 exo-planet candidates which require false positive decision tree observations. Our proposed effort performs much of the first line of defense for the mission.

THE IMPRINT OF EXOPLANET FORMATION HISTORY ON OBSERVABLE PRESENT-DAY SPECTRA OF HOT JUPITERS

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

Mordasini, C.; Van Boekel, R.; Mollière, P.

The composition of a planet’s atmosphere is determined by its formation, evolution, and present-day insolation. A planet’s spectrum therefore may hold clues on its origins. We present a “chain” of models, linking the formation of a planet to its observable present-day spectrum. The chain links include (1) the planet’s formation and migration, (2) its long-term thermodynamic evolution, (3) a variety of disk chemistry models, (4) a non-gray atmospheric model, and (5) a radiometric model to obtain simulated spectroscopic observations with James Webb Space Telescope and ARIEL. In our standard chemistry model the inner disk is depleted in refractory carbon asmore » in the Solar System and in white dwarfs polluted by extrasolar planetesimals. Our main findings are: (1) envelope enrichment by planetesimal impacts during formation dominates the final planetary atmospheric composition of hot Jupiters. We investigate two, under this finding, prototypical formation pathways: a formation inside or outside the water iceline, called “dry” and “wet” planets, respectively. (2) Both the “dry” and “wet” planets are oxygen-rich (C/O < 1) due to the oxygen-rich nature of the solid building blocks. The “dry” planet’s C/O ratio is <0.2 for standard carbon depletion, while the “wet” planet has typical C/O values between 0.1 and 0.5 depending mainly on the clathrate formation efficiency. Only non-standard disk chemistries without carbon depletion lead to carbon-rich C/O ratios >1 for the “dry” planet. (3) While we consistently find C/O ratios <1, they still vary significantly. To link a formation history to a specific C/O, a better understanding of the disk chemistry is thus needed.« less

EPA Science Matters Newsletter: Volume 2, Number 6

EPA Pesticide Factsheets

EPA research has embraced sustainability as a necessary goal for the future of the planet, our economy, and our society. To achieve it will require asking different questions, thinking about challenges differently, and seeking innovative solutions.

The Space Infrared Interferometric Telescope (SPIRIT): The Mission Design Solution Space and the Art of the Possible

NASA Technical Reports Server (NTRS)

Leisawitz, David; Hyde, T. Tupper; Rinehart, Stephen A.; Weiss, Michael

2008-01-01

Although the Space Infrared Interferometric Telescope (SPIRIT) was studied as a candidate NASA Origins Probe mission, the real world presents a broader set of options, pressures, and constraints. Fundamentally, SPIRIT is a far-IR observatory for high-resolution imaging and spectroscopy designed to address a variety of compelling scientific questions. How do planetary systems form from protostellar disks, dousing some planets in water while leaving others dry? Where do planets form, and why are some ice giants while others are rocky? How did high-redshift galaxies form and merge to form the present-day population of galaxies? This paper takes a pragmatic look at the mission design solution space for SPIRIT, presents Probe-class and facility-class mission scenarios, and describes optional design changes. The costs and benefits of various mission design alternatives are roughly evaluated, giving a basis for further study and to serve as guidance to policy makers.

Dynamical Analysis of the Circumprimary Planet in the Eccentric Binary System HD 59686

NASA Astrophysics Data System (ADS)

Trifonov, Trifon; Lee, Man Hoi; Reffert, Sabine; Quirrenbach, Andreas

2018-04-01

We present a detailed orbital and stability analysis of the HD 59686 binary-star planet system. HD 59686 is a single-lined, moderately close (a B = 13.6 au) eccentric (e B = 0.73) binary, where the primary is an evolved K giant with mass M = 1.9 M ⊙ and the secondary is a star with a minimum mass of m B = 0.53 M ⊙. Additionally, on the basis of precise radial velocity (RV) data, a Jovian planet with a minimum mass of m p = 7 M Jup, orbiting the primary on a nearly circular S-type orbit with e p = 0.05 and a p = 1.09 au, has recently been announced. We investigate large sets of orbital fits consistent with HD 59686's RV data by applying bootstrap and systematic grid search techniques coupled with self-consistent dynamical fitting. We perform long-term dynamical integrations of these fits to constrain the permitted orbital configurations. We find that if the binary and the planet in this system have prograde and aligned coplanar orbits, there are narrow regions of stable orbital solutions locked in a secular apsidal alignment with the angle between the periapses, Δω, librating about 0°. We also test a large number of mutually inclined dynamical models in an attempt to constrain the three-dimensional orbital architecture. We find that for nearly coplanar and retrograde orbits with mutual inclination 145° ≲ Δi ≤ 180°, the system is fully stable for a large range of orbital solutions.

CHEMICAL ABUNDANCES IN THE EXTERNALLY POLLUTED WHITE DWARF GD 40: EVIDENCE OF A ROCKY EXTRASOLAR MINOR PLANET

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

Klein, B.; Jura, M.; Zuckerman, B.

2010-02-01

We present Keck/High Resolution Echelle Spectrometer data with model atmosphere analysis of the helium-dominated polluted white dwarf GD 40, in which we measure atmospheric abundances relative to helium of nine elements: H, O, Mg, Si, Ca, Ti, Cr, Mn, and Fe. Apart from hydrogen, whose association with the other contaminants is uncertain, this material most likely accreted from GD 40's circumstellar dust disk whose existence is demonstrated by excess infrared emission. The data are best explained by accretion of rocky planetary material, in which heavy elements are largely contained within oxides, derived from a tidally disrupted minor planet at leastmore » the mass of Juno, and probably as massive as Vesta. The relatively low hydrogen abundance sets an upper limit of 10% water by mass in the inferred parent body, and the relatively high abundances of refractory elements, Ca and Ti, may indicate high-temperature processing. While the overall constitution of the parent body is similar to the bulk Earth being over 85% by mass composed of oxygen, magnesium, silicon, and iron, we find n(Si)/n(Mg) = 0.30 +- 0.11, significantly smaller than the ratio near unity for the bulk Earth, chondrites, the Sun, and nearby stars. This result suggests that differentiation occurred within the parent body.« less

Desorption of 1,3,5-Trichlorobenzene from Multi-Walled Carbon Nanotubes: Impact of Solution Chemistry and Surface Chemistry

PubMed Central

Ma, Xingmao; Uddin, Sheikh

2013-01-01

The strong affinity of carbon nanotubes (CNTs) to environmental contaminants has raised serious concern that CNTs may function as a carrier of environmental pollutants and lead to contamination in places where the environmental pollutants are not expected. However, this concern will not be realized until the contaminants are desorbed from CNTs. It is well recognized that the desorption of environmental pollutants from pre-laden CNTs varies with the environmental conditions, such as the solution pH and ionic strength. However, comprehensive investigation on the influence of solution chemistry on the desorption process has not been carried out, even though numerous investigations have been conducted to investigate the impact of solution chemistry on the adsorption of environmental pollutants on CNTs. The main objective of this study was to determine the influence of solution chemistry (e.g., pH, ionic strength) and surface functionalization on the desorption of preloaded 1,3,5-trichlorobenzene (1,3,5-TCB) from multi-walled carbon nanotubes (MWNTs). The results suggested that higher pH, ionic strength and natural organic matter in solution generally led to higher desorption of 1,3,5-TCB from MWNTs. However, the extent of change varied at different values of the tested parameters (e.g., pH < 7 vs. pH > 7). In addition, the impact of these parameters varied with MWNTs possessing different surface functional groups, suggesting that surface functionalization could considerably alter the environmental behaviors and impact of MWNTs. PMID:28348336

Habitability of the TRAPPIST-1 System

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-04-01

The recent discovery of seven Earth-sized, terrestrial planets around an M dwarf star was met with excitement and optimism. But how habitable are these planets actually likely to be? A recent study of these planets likely climates may provide an answer to this question.An Optimistic OutlookIn February of this year, the TRAPPIST-1 system was announced: seven roughly Earth-sized, transiting, terrestrial planets all orbiting their host ultracool dwarf star within a distance the size of Mercurys orbit. Three of the planets were initially declared to be in the stars habitable zone and scientists speculated that even those outside the habitable zone could potentially still harbor liquid water making the system especially exciting.In Wolfs simulations, the surface temperature (solid lines) of TRAPPIST-1d grows to more than 380K in just 40 years. [Adapted from Wolf 2017]The planets were labeled as temperate because all seven have equilibrium temperatures that are under 400K. Since liquid water requires a surface temperature of 273-373K, this certainly seems promising!Finding Realistic TemperaturesBut theres a catch: equilibrium temperatures are not actual measurements of the planets surface temperature, theyre just very rudimentary estimates based on how much light the planet receives. To get a better estimate of the real temperature of the planet and therefore assess its habitability you need advanced climate modeling of the planet that include factors like the greenhouse effect and planetary albedo.In Wolfs simulations, the surface temperature of TRAPPIST-1f plummets rapidly even when modeled with dense carbon dioxide atmosphere (purple line). The bottom panel shows the corresponding rapid growth of sea-ice on the surface oceans for the different atmospheric models. [Wolf 2017]To that end, scientist Eric Wolf (University of Colorado Boulder) has conducted state-of-the-art 3D climate calculations for the three center-most planets planets d, e, and f in the TRAPPIST-1 system. Wolf assumed traditional terrestrial-planet atmospheres composed of nitrogen, carbon dioxide, and water, and he examined what would happen if these planets had large water supplies in the form of surface oceans.Runaway and Snowball PlanetsWolfs climate model indicates that the closest-in of the three planets, planet d, would undergo thermal runaway even in the best case scenario. In just 40 years of the simulation, the planets surface temperature exceeds 380K, suggesting it couldnt continue to sustain liquid water. Wolf argues that planet d and the two planets interior to it, b and c, all lie inside of the traditional liquid water habitable zone they are hot, dry, and uninhabitable.Next, Wolf models the outermost of the three center planets, planet f. Even when planet f is modeled with a dense carbon dioxide atmosphere, it cant avoid its fate of becoming completely ice-covered within roughly 60 years. Wolf concludes that planets f, g and h all lie outside of the traditional habitable zone defined by the maximum carbon dioxide greenhouse limit.Equilibrium solutions for TRAPPIST-1e with various atmospheric conditions. Top panel: mean surface temperature. Middle panel: sea-ice coverage. Bottom panel: habitable surface area. [Wolf 2017]Goldilocks?Lastly, Wolf turns to planet e, the central planet in the system. This planet, he finds, is the most viable candidate for a robustly habitable world. The simulations show that planet e can maintain habitable surface conditions for a variety of atmospheric compositions.While astrobiologists eyeing TRAPPIST-1 may be disappointed that at second glance the planets are not quite as inhabitable as they first seemed, it is promising to see that the habitability of the central planet holds up reasonably well to some more realistic testing. Either way, future examinations of all seven of these planets should help us learn more about terrestrial, Earth-sized planets.CitationEric T. Wolf 2017 ApJL 839 L1. doi:10.3847/2041-8213/aa693a

A geographic information system screening tool to tackle diffuse pollution through the use of sustainable drainage systems.

PubMed

Todorovic, Zorica; Breton, Neil P

2014-01-01

Sustainable drainage systems (SUDS) offer many benefits that traditional solutions do not. Traditional approaches are unable to offer a solution to problems of flood management and water quality. Holistic consideration of the wide range of benefits from SUDS can result in advantages such as improved flood resilience and water quality enhancement through consideration of diffuse pollution sources. Using a geographical information system (GIS) approach, diffuse pollutant sources and opportunities for SUDS are easily identified. Consideration of potential SUDS locations results in source, site and regional controls, leading to improved water quality (to meet Water Framework Directive targets). The paper will discuss two different applications of the tool, the first of which is where the pollutant of interest is known. In this case the outputs of the tool highlight and isolate the areas contributing the pollutants and suggest the adequate SUDS measures to meet the required criteria. The second application is where the tool identifies likely pollutants at a receiving location, and SUDS measures are proposed to reduce pollution with assessed efficiencies.

Activity and magnetic field structure of the Sun-like planet-hosting star HD 1237

NASA Astrophysics Data System (ADS)

Alvarado-Gómez, J. D.; Hussain, G. A. J.; Grunhut, J.; Fares, R.; Donati, J.-F.; Alecian, E.; Kochukhov, O.; Oksala, M.; Morin, J.; Redfield, S.; Cohen, O.; Drake, J. J.; Jardine, M.; Matt, S.; Petit, P.; Walter, F. M.

2015-10-01

We analyse the magnetic activity characteristics of the planet-hosting Sun-like star, HD 1237, using HARPS spectro-polarimetric time-series data. We find evidence of rotational modulation of the magnetic longitudinal field measurements that is consistent with our ZDI analysis with a period of 7 days. We investigate the effect of customising the LSD mask to the line depths of the observed spectrum and find that it has a minimal effect on the shape of the extracted Stokes V profile but does result in a small increase in the S/N (~7%). We find that using a Milne-Eddington solution to describe the local line profile provides a better fit to the LSD profiles in this slowly rotating star, which also affects the recovered ZDI field distribution. We also introduce a fit-stopping criterion based on the information content (entropy) of the ZDI map solution set. The recovered magnetic field maps show a strong (+90 G) ring-like azimuthal field distribution and a complex radial field dominating at mid latitudes (~45 degrees). Similar magnetic field maps are recovered from data acquired five months apart. Future work will investigate how this surface magnetic field distribution affeccts the coronal magnetic field and extended environment around this planet-hosting star.

Little Stars Don't Like Big Planets: An Astrometric Search for Super-Jupiters Around Red Dwarfs

NASA Astrophysics Data System (ADS)

Lurie, John C.; Henry, T. J.; Jao, W.; Koerner, D. W.; Riedel, A. R.; Subasavage, J.; RECONS

2013-01-01

The astrometric detection and characterization of extrasolar planets presents considerable technical challenges, but also promises to greatly enhance our understanding of these systems. Nearly all currently confirmed exoplanets have been discovered using transit or radial velocity techniques. The former is geometrically biased towards planets with small orbits, while the latter is biased towards massive planets with short periods that exert large gravitational accelerations on their host stars. Astrometric techniques are limited by the minimum detectable perturbation of a star's position due to a planet, but allow for the determination of orbit inclination and an accurate planetary mass. Here we present astrometric solutions for five nearby stars with known planets: four M dwarfs (GJ 317, GJ 581, GJ 849, and GJ 1214) and one K dwarf (BD -10 3166). Observations have baselines of three to thirteen years, and were made using the 0.9 m telescope at CTIO as part of the RECONS long-term astrometry program. We provide improved parallaxes for the stars and find that there are no planets of several Jupiter masses or brown dwarfs orbiting these stars with periods up to twice the length of the astrometric coverage. In the broader context, these results are consistent with the paucity of super-Jupiter and brown dwarf companions we find among the roughly 200 red dwarfs searched in our astrometric program. This effort has been supported by the National Science Foundation via grant AST 09-08402 and the long-term cooperative efforts of the National Optical Astronomy Observatories and the members of the SMARTS Consortium.

A Footprint Family extended MRIO model to support Europe's transition to a One Planet Economy.

PubMed

Galli, Alessandro; Weinzettel, Jan; Cranston, Gemma; Ercin, Ertug

2013-09-01

Currently, the European economy is using nearly three times the ecological assets that are locally available. This situation cannot be sustained indefinitely. Tools are needed that can help reverse the unsustainable trend. In 2010, an EC funded One Planet Economy Network: Europe (OPEN:EU) project was launched to develop the evidence and innovative practical tools that will allow policy-makers and civil society to identify policy interventions to transform Europe into a One Planet Economy, by 2050. Building on the premise that no indicator alone is able to comprehensively monitor (progress towards) sustainability, the project has drawn on the Ecological, Carbon and Water Footprints to define a Footprint Family suite of indicators, to track human pressure on the planet. An environmentally-extended multi-regional input-output (MRIO) model has then been developed to group the Footprint Family under a common framework and combine the indicators in the family with national economic accounts and trade statistics. Although unable to monitor the full spectrum of human pressures, once grouped within the MRIO model, the Footprint Family is able to assess the appropriation of ecological assets, GHG emissions as well as freshwater consumption and pollution associated with consumption of specific products and services within a specified country. Using MRIO models within the context of Footprint analyses also enables the Footprint Family to take into account full production chains with technologies specific to country of origin. Copyright © 2012 Elsevier B.V. All rights reserved.

Gas pollutants removal in a single- and two-stage ejector-venturi scrubber.

PubMed

Gamisans, Xavier; Sarrà, Montserrrat; Lafuente, F Javier

2002-03-29

The absorption of SO(2) and NH(3) from the flue gas into NaOH and H(2)SO(4) solutions, respectively has been studied using an industrial scale ejector-venturi scrubber. A statistical methodology is presented to characterise the performance of the scrubber by varying several factors such as gas pollutant concentration, air flowrate and absorbing solution flowrate. Some types of venturi tube constructions were assessed, including the use of a two-stage venturi tube. The results showed a strong influence of the liquid scrubbing flowrate on pollutant removal efficiency. The initial pollutant concentration and the gas flowrate had a slight influence. The use of a two-stage venturi tube considerably improved the absorption efficiency, although it increased energy consumption. The results of this study will be applicable to the optimal design of venturi-based absorbers for gaseous pollution control or chemical reactors.

Pollution in America: The Trouble with Trash. Series on Public Issues No. 7.

ERIC Educational Resources Information Center

Maurice, S. Charles; Smithson, Charles W.

Examined in this booklet, one of a series intended to apply economic principles to major social and political issues of the day, are such questions as the origins of interest in combating pollution, why people pollute, continuing interest in the issue, the social costs of pollution, and a possible solution to the problem, all considered from an…

Corrosion Behavior of Cu40Zn in Sulfide-Polluted 3.5% NaCl Solution

NASA Astrophysics Data System (ADS)

Song, Q. N.; Xu, N.; Bao, Y. F.; Jiang, Y. F.; Gu, W.; Yang, Z.; Zheng, Y. G.; Qiao, Y. X.

2017-10-01

The corrosion behavior of a duplex-phase brass Cu40Zn in clean and sulfide-polluted 3.5% NaCl solutions was investigated by conducting electrochemical and gravimetric measurements. The corrosion product films were analyzed by scanning electron microscopy, energy-dispersive spectroscopy and x-ray diffraction. The presence of sulfide shifted the corrosion potential of Cu40Zn toward a more negative value by 100 mV and increased the mass loss rate by a factor of 1.257 compared with the result in the clean solution. The corrosion product film in the clean solution was thin and compact; it mainly consisted of oxides, such as ZnO and Cu2O. By contrast, the film in the sulfide-polluted solution was thick and porous. It mainly contained sulfides and zinc hydroxide chloride (i.e., Zn5(OH)8Cl2·H2O). The presence of sulfide ions accelerated the corrosion damage of Cu40Zn by hindering the formation of protective oxides and promoting the formation of a defective film which consisted of sulfides and hydroxide chlorides.

Solar System Chaos and Orbital Solutions for Paleoclimate Studies: Limits and New Results

NASA Astrophysics Data System (ADS)

Zeebe, R. E.

2017-12-01

I report results from accurate numerical integrations of Solar System orbits over the past 100 Myr. The simulations used different integrator algorithms, step sizes, and initial conditions (NASA, INPOP), and included effects from general relativity, different models of the Moon, the Sun's quadrupole moment, and up to ten asteroids. In one simulation, I probed the potential effect of a hypothetical Planet 9 on the dynamics of the system. The most expensive integration required 4 months wall-clock time (Bulirsch-Stoer algorithm) and showed a maximum relative energy error < 2.5e{-13} over the past 100 Myr. The difference in Earth's eccentricity (DeE) was used to track the difference between two solutions, which were considered to diverge at time tau when DeE irreversibly crossed 10% of Earth's mean eccentricity ( 0.028 x 0.1). My results indicate that finding a unique orbital solution is limited by initial conditions from current ephemerides to 54 Myr. Bizarrely, the 4-month Bulirsch-Stoer integration and a different integration scheme that required only 5 hours wall-clock time (symplectic, 12-day time step, Moon as a simple quadrupole perturbation), agree to 63 Myr. Solutions including 3 and 10 asteroids diverge at tau 48 Myr. The effect of a hypothetical Planet 9 on DeE becomes discernible at 66 Myr. Using tau as a criterion, the current state-of-the-art solutions all differ from previously published results beyond 50 Myr. The current study provides new orbital solutions for application in geological studies. I will also comment on the prospect of constraining astronomical solutions by geologic data.

The Solar System and Its Origin

ERIC Educational Resources Information Center

Dormand, J. R.

1973-01-01

Presents a brief explanation of the solar system, including planets, asteroids, satellites, comets, planetary orbits, as well as, old and recent cosmogonic theories. Indicates that man is nearer a solution to the origin of the planetary system than ever before.

13th Annual P3 Awards: A National Student Design ...

EPA Pesticide Factsheets

2017-02-14

The EPA, as part of the P3-People, Prosperity and the Planet Award Program, is seeking applications proposing to research, develop, and design solutions to real world challenges involving the overall sustainability of human society.

A Preliminary Study on the Circulation of an ocean covering a Synchronously Rotating Planet

NASA Astrophysics Data System (ADS)

Matsuo, H.; Ishiwatari, M.; Takehiro, S.; Hayashi, Y.; Nakajima, K.

2012-12-01

Recently, nearly 800 extrasolar planets have been detected. It seems that some of them present into habitable zone, in which planets can have ocean, and such planets rotate synchronously with their central stars. Ocean is necessary for life, and the circulation makes climate mild by heat transport on the earth. The earth is the only planet that has ocean in the solar system so that it has not been understood what oceanic circulation is like in another planets. The purpose of this study is prediction of oceanic circulation on extrasolar planets by using numerical simulation. As a first step, elementary consideration is made. The planet is almost entirely covered with ocean and whose rotation period corresponds with its orbital period. On synchronously rotating planets, the thermal contrast between day-hemisphere and night-hemisphere would be extreme. However, it may be lessend if there is significant zonal heat transport. The circulation in such conditions has not been known well. We performed a numerical experiment based on the linear shallow water equation, assuming that both the evaporation and the precipitation occur only on day-hemisphere (Noda et al., 2011). With these distributions of the evaporation and the precipitation, one may anticipate the circulation occurs in only day-hemisphere. However, the resulting calculation is characterized with zonally uniform zonal flow, which also covers night hemisphere. In addition, the intensity of the flow increases with time. That behavior can be understood by constructing asymptotic solution which is first degree in time. The importance of Coriolis force, which bends meridional flow to zonal flow, is identified. It is implied that, even when only day-hemisphere has the evaporation and precipitation, there may be significant amount of heat can be transported from the day-hemisphere to the night-hemisphere by the strong zonal flow. The growth of zonal flow would be stopped when the evaporation and the precipitation are balanced with mass transport in the bottom Ekman layer.

CoRoT-2b: a Tidally Inflated, Young Exoplanet?

NASA Astrophysics Data System (ADS)

Guillot, Tristan; Havel, M.

2009-09-01

CoRoT-2b is among the most anomalously large transiting exoplanet known. Due to its large mass (3.3 Mjup), its large radius ( 1.5 Rjup) cannot be explained by standard evolution models. Recipes that work for other anomalously large exoplanets (e.g. HD209458b), such as invoking kinetic energy transport in the planetary interior or increased opacities, clearly fail for CoRoT-2b. Interestingly, the planet's parent star is an active star with a large fraction (7 to 20%) of spots and a rapid rotation (4.5 days). We first model the star's evolution to accurately constrain the planetary parameters. We find that the stellar activity has little influence on the star's evolution and inferred parameters. However, stellar evolution models point towards two kind of solutions for the star-planet system: (i) a very young system (20-40 Ma) with a star still undergoing pre-main sequence contraction, and a planet which could have a radius as low as 1.4 Rjup, or (ii) a young main-sequence star (40 to 500 Ma) with a planet that is slightly more inflated ( 1.5 Rjup). In either case, planetary evolution models require a significant added internal energy to explain the inferred planet size: from a minimum of 3x1028 erg/s in case (i), to up to 1.5x1029 erg/s in case (ii). We find that evolution models consistently including planet/star tides are able to reproduce the inferred radius but only for a short period of time ( 10 Ma). This points towards a young age for the star/planet system and dissipation by tides due to either circularization or synchronization of the planet. Additional observations of the star (infrared excess due to disk?) and of the planet (precise Rossiter effect, IR secondary eclispe) would be highly valuable to understand the early evolution of star-exoplanet systems.

ANALYTICAL SOLUTION FOR WAVES IN PLANETS WITH ATMOSPHERIC SUPERROTATION. II. LAMB, SURFACE, AND CENTRIFUGAL WAVES

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

Peralta, J.; López-Valverde, M. A.; Imamura, T.

2014-07-01

This paper is the second in a two-part study devoted to developing tools for a systematic classification of the wide variety of atmospheric waves expected on slowly rotating planets with atmospheric superrotation. Starting with the primitive equations for a cyclostrophic regime, we have deduced the analytical solution for the possible waves, simultaneously including the effect of the metric terms for the centrifugal force and the meridional shear of the background wind. In those cases where the conditions for the method of the multiple scales in height are met, these wave solutions are also valid when vertical shear of the backgroundmore » wind is present. A total of six types of waves have been found and their properties were characterized in terms of the corresponding dispersion relations and wave structures. In this second part, we study the waves' solutions when several atmospheric approximations are applied: Lamb, surface, and centrifugal waves. Lamb and surface waves are found to be quite similar to those in a geostrophic regime. By contrast, centrifugal waves turn out to be a special case of Rossby waves that arise in atmospheres in cyclostrophic balance. Finally, we use our results to identify the nature of the waves behind atmospheric periodicities found in polar and lower latitudes of Venus's atmosphere.« less

Community Solutions to Solid Waste Pollution. Operation Waste Watch: The New Three Rs for Elementary School. Grade 6. [Second Edition.

ERIC Educational Resources Information Center

Virginia State Dept. of Waste Management, Richmond. Div. of Litter & Recycling.

This publication, the last in a series of seven for elementary schools, is an environmental education curriculum guide with a focus on waste management issues. It contains a unit of exercises selected for sixth grade students focusing on community solutions to solid waste pollution. Waste management activities included in this unit seek to…

Steady-state solution of the semi-empirical diffusion equation for area sources. [air pollution studies

NASA Technical Reports Server (NTRS)

Lebedeff, S. A.; Hameed, S.

1975-01-01

The problem investigated can be solved exactly in a simple manner if the equations are written in terms of a similarity variable. The exact solution is used to explore two questions of interest in the modelling of urban air pollution, taking into account the distribution of surface concentration downwind of an area source and the distribution of concentration with height.

WFIRST Microlensing Exoplanet Characterization with HST Follow up

NASA Astrophysics Data System (ADS)

Bhattacharya, Aparna; David Bennett, Jay Anderson, J.P. Beaulieu.

2018-01-01

More than 50 planets are discovered with the different ground based telescopes available for microlensing. But the analysis of ground based data fails to provide a complete solution. To fulfill that gap, space based telescopes, like Hubble space telescope and Spitzer are used. My research work focuses on extracting the planet mass, host star mass, their separation and their distance in physical units from HST Follow-up observations. I will present the challenges faced in developing this method.This is the primary method to be used for NASA's top priority project (according to 2010 decadal survey) Wide Field InfraRed Survey Telescope (WFIRST) Exoplanet microlensing space observatory, to be launched in 2025. The unique ability of microlensing is that with WFIRST it can detect sub-earth- mass planets beyond the reach of Kepler at separation 1 AU to infinity. This will provide us the necessary statistics to study the formation and evolution of planetary systems. This will also provide us with necessary initial conditions to model the formation of planets and the habitable zones around M dwarf stars.

The final fate of planetary systems

NASA Astrophysics Data System (ADS)

Gaensicke, Boris

2015-12-01

The discovery of the first extra-solar planet around a main-sequence star in 1995 has changed the way we think about the Universe: our solar system is not unique. Twenty years later, we know that planetary systems are ubiquitous, orbit stars spanning a wide range in mass, and form in an astonishing variety of architectures. Yet, one fascinating aspect of planetary systems has received relatively little attention so far: their ultimate fate.Most planet hosts will eventually evolve into white dwarfs, Earth-sized stellar embers, and the outer parts of their planetary systems (in the solar system, Mars and beyond) can survive largely intact for billions of years. While scattered and tidally disrupted planetesimals are directly detected at a small number of white dwarfs in the form infrared excess, the most powerful probe for detecting evolved planetary systems is metal pollution of the otherwise pristine H/He atmospheres.I will present the results of a multi-cycle HST survey that has obtained COS observations of 136 white dwarfs. These ultraviolet spectra are exquisitely sensitive to the presence of metals contaminating the white atmosphere. Our sophisticated model atmosphere analysis demonstrates that at least 27% of all targets are currently accreting planetary debris, and an additional 29% have very likely done so in the past. These numbers suggest that planet formation around A-stars (the dominant progenitors of today's white dwarf population) is similarly efficient as around FGK stars.In addition to post-main sequence planetary system demographics, spectroscopy of the debris-polluted white dwarf atmospheres provides a direct window into the bulk composition of exo-planetesimals, analogous to the way we use of meteorites to determine solar-system abundances. Our ultraviolet spectroscopy is particularly sensitive to the detection of Si, a dominant rock-forming species, and we identify up to ten additional volatile and refractory elements in the most strongly contaminated white dwarfs. The derived bulk abundances unambiguously demonstrate the predominantly rocky nature of the accreted material, with two exceptions where we detect volatile-rich debris. The relative abundance ratios suggest a wide range of parent bodies, including both primitive asteroids and fragments from differentiated planetesimals. The growing number of detailed debris abundances can provide important observational constraints on planet formation models.

Consensus-Based Cooperative Control Based on Pollution Sensing and Traffic Information for Urban Traffic Networks

PubMed Central

Artuñedo, Antonio; del Toro, Raúl M.; Haber, Rodolfo E.

2017-01-01

Nowadays many studies are being conducted to develop solutions for improving the performance of urban traffic networks. One of the main challenges is the necessary cooperation among different entities such as vehicles or infrastructure systems and how to exploit the information available through networks of sensors deployed as infrastructures for smart cities. In this work an algorithm for cooperative control of urban subsystems is proposed to provide a solution for mobility problems in cities. The interconnected traffic lights controller (TLC) network adapts traffic lights cycles, based on traffic and air pollution sensory information, in order to improve the performance of urban traffic networks. The presence of air pollution in cities is not only caused by road traffic but there are other pollution sources that contribute to increase or decrease the pollution level. Due to the distributed and heterogeneous nature of the different components involved, a system of systems engineering approach is applied to design a consensus-based control algorithm. The designed control strategy contains a consensus-based component that uses the information shared in the network for reaching a consensus in the state of TLC network components. Discrete event systems specification is applied for modelling and simulation. The proposed solution is assessed by simulation studies with very promising results to deal with simultaneous responses to both pollution levels and traffic flows in urban traffic networks. PMID:28445398

Consensus-Based Cooperative Control Based on Pollution Sensing and Traffic Information for Urban Traffic Networks.

PubMed

Artuñedo, Antonio; Del Toro, Raúl M; Haber, Rodolfo E

2017-04-26

Nowadays many studies are being conducted to develop solutions for improving the performance of urban traffic networks. One of the main challenges is the necessary cooperation among different entities such as vehicles or infrastructure systems and how to exploit the information available through networks of sensors deployed as infrastructures for smart cities. In this work an algorithm for cooperative control of urban subsystems is proposed to provide a solution for mobility problems in cities. The interconnected traffic lights controller ( TLC ) network adapts traffic lights cycles, based on traffic and air pollution sensory information, in order to improve the performance of urban traffic networks. The presence of air pollution in cities is not only caused by road traffic but there are other pollution sources that contribute to increase or decrease the pollution level. Due to the distributed and heterogeneous nature of the different components involved, a system of systems engineering approach is applied to design a consensus-based control algorithm. The designed control strategy contains a consensus-based component that uses the information shared in the network for reaching a consensus in the state of TLC network components. Discrete event systems specification is applied for modelling and simulation. The proposed solution is assessed by simulation studies with very promising results to deal with simultaneous responses to both pollution levels and traffic flows in urban traffic networks.

Digging for substellar objects in the stellar graveyard

NASA Astrophysics Data System (ADS)

Debes, John H., IV

2005-11-01

White dwarfs, the endpoint of stellar evolution for stars with mass < 8 [Special characters omitted.] , possess several attributes favorable for studying planet and brown dwarf formation around stars with primordial masses 1 [Special characters omitted.] . This thesis explores the consequences of post-main-sequence evolution on the dynamics of a planetary system and the observational signatures that arise from such evolution. These signatures are then specifically tested with a direct imaging survey of nearby white dwarfs. Finally, new techniques for high contrast imaging are discussed and placed in the context of further searches for planets and brown dwarfs in the stellar graveyard. While planets closer than ~ 5 AU will most likely not survive the post-main sequence evolution of its parent star, any planet with semimajor axis > 5 AU will survive, and its semimajor axis will increase as the central star loses mass. The stability of adjacent orbits to mutual planet-planet perturbations depends on the ratio of the planet mass to the central star's mass, and I demonstrate that some planets in previously stable orbits around a star undergoing mass loss will become unstable. If pollution of a white dwarf's atmosphere is caused by relic planetary systems, any white dwarf with photospheric absorption due to metals can be searched for substellar companions. Hydrogen white dwarfs with metal absorption, so called DAZ white dwarfs, are hard to explain by simple ISM accretion, and present an opportunity to test the observational signatures of unstable planetary systems. Additionally, field white dwarfs can be searched for substellar companions as well. The search for planetary companions to stars requires further development of high contrast imaging techniques. This thesis studies Gaussian aperture pupil masks (GAPMs) which in theory can achieve the contrast requisite for directly imaging an extrasolar planet around a nearby solar type star. I outline the process of designing, fabricating, and testing a GAPM for use on current telescopes and specifically the Penn State near-IR Imager and Spectrograph (PIRIS) at the Mt. Wilson 100" telescope. I find that observations with a prototype are quite successful, achieving a contrast similar to a traditional Lyot coronagraph without blocking any light from a central object and useful for finding faint companions to nearby young solar analogues. In the lab I can reproduce the expected PSF reasonably well and with a single aperture design which achieves ~ 4 x 10 -5 contrast at 10l/ D . I find that small inaccuracies in the mask fabrication process and insufficient correction of the atmosphere contribute the most degradation to contrast at these levels. (Abstract shortened by UMI.)

A Likely Detection of a Two-planet System in a Low-magnification Microlensing Event

NASA Astrophysics Data System (ADS)

Suzuki, D.; Bennett, D. P.; Udalski, A.; Bond, I. A.; Sumi, T.; Han, C.; Kim, Ho-il.; Abe, F.; Asakura, Y.; Barry, R. K.; Bhattacharya, A.; Donachie, M.; Freeman, M.; Fukui, A.; Hirao, Y.; Itow, Y.; Koshimoto, N.; Li, M. C. A.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Muraki, Y.; Nagakane, M.; Onishi, K.; Oyokawa, H.; Ranc, C.; Rattenbury, N. J.; Saito, To.; Sharan, A.; Sullivan, D. J.; Tristram, P. J.; Yonehara, A.; MOA Collaboration; Poleski, R.; Mróz, P.; Skowron, J.; Szymański, M. K.; Soszyński, I.; Kozłowski, S.; Pietrukowicz, P.; Wyrzykowski, Ł.; Ulaczyk, K.; OGLE Collaboration

2018-06-01

We report on the analysis of a microlensing event, OGLE-2014-BLG-1722, that showed two distinct short-term anomalies. The best-fit model to the observed light curves shows that the two anomalies are explained with two planetary mass ratio companions to the primary lens. Although a binary-source model is also able to explain the second anomaly, it is marginally ruled out by 3.1σ. The two-planet model indicates that the first anomaly was caused by planet “b” with a mass ratio of q=({4.5}-0.6+0.7)× {10}-4 and projected separation in units of the Einstein radius, s = 0.753 ± 0.004. The second anomaly reveals planet “c” with a mass ratio of {q}2=({7.0}-1.7+2.3)× {10}-4 with Δχ 2 ∼ 170 compared to the single-planet model. Its separation has two degenerated solutions: the separation of planet c is s 2 = 0.84 ± 0.03 and 1.37 ± 0.04 for the close and wide models, respectively. Unfortunately, this event does not show clear finite-source and microlensing parallax effects; thus, we estimated the physical parameters of the lens system from Bayesian analysis. This gives the masses of planets b and c as {m}{{b}}={56}-33+51 and {m}{{c}}={85}-51+86 {M}\\oplus , respectively, and they orbit a late-type star with a mass of {M}host} ={0.40}-0.24+0.36 {M}ȯ located at {D}{{L}}={6.4}-1.8+1.3 {kpc} from us. The projected distances between the host and planets are {r}\\perp ,{{b}}=1.5+/- 0.6 {au} for planet b and {r}\\perp ,{{c}}={1.7}-0.6+0.7 {au} and {r}\\perp ,{{c}}={2.7}-1.0+1.1 {au} for the close and wide models of planet c. If the two-planet model is true, then this is the third multiple-planet system detected using the microlensing method and the first multiple-planet system detected in low-magnification events, which are dominant in the microlensing survey data. The occurrence rate of multiple cold gas giant systems is estimated using the two such detections and a simple extrapolation of the survey sensitivity of the 6 yr MOA microlensing survey combined with the 4 yr μFUN detection efficiency. It is estimated that 6% ± 2% of stars host two cold giant planets.

Accurate analytical periodic solution of the elliptical Kepler equation using the Adomian decomposition method

NASA Astrophysics Data System (ADS)

Alshaery, Aisha; Ebaid, Abdelhalim

2017-11-01

Kepler's equation is one of the fundamental equations in orbital mechanics. It is a transcendental equation in terms of the eccentric anomaly of a planet which orbits the Sun. Determining the position of a planet in its orbit around the Sun at a given time depends upon the solution of Kepler's equation, which we will solve in this paper by the Adomian decomposition method (ADM). Several properties of the periodicity of the obtained approximate solutions have been proved in lemmas. Our calculations demonstrated a rapid convergence of the obtained approximate solutions which are displayed in tables and graphs. Also, it has been shown in this paper that only a few terms of the Adomian decomposition series are sufficient to achieve highly accurate numerical results for any number of revolutions of the Earth around the Sun as a consequence of the periodicity property. Numerically, the four-term approximate solution coincides with the Bessel-Fourier series solution in the literature up to seven decimal places at some values of the time parameter and nine decimal places at other values. Moreover, the absolute error approaches zero using the nine term approximate Adomian solution. In addition, the approximate Adomian solutions for the eccentric anomaly have been used to show the convergence of the approximate radial distances of the Earth from the Sun for any number of revolutions. The minimal distance (perihelion) and maximal distance (aphelion) approach 147 million kilometers and 152.505 million kilometers, respectively, and these coincide with the well known results in astronomical physics. Therefore, the Adomian decomposition method is validated as an effective tool to solve Kepler's equation for elliptical orbits.

Our Pittsburgh Constellation

NASA Astrophysics Data System (ADS)

Turnshek, Diane

2015-08-01

Riding on the Pittsburgh mayor’s keen interest in astronomy and the ongoing change of 40,000 city lights from mercury and sodium vapor to shielded LEDs, we organized a series of city-wide celestial art projects to bring attention to the skies over Pittsburgh. Light pollution public talks were held at the University of Pittsburgh’s Allegheny Observatory and other colleges. Earth Hour celebrations kicked off an intensive year of astronomy outreach in the city. Lights went out on March 28, 2015 from 8:30 to 9:30 pm in over fifty buildings downtown and in Oakland (the “Eds and Meds” center, where many Pittsburgh universities and hospitals are located). Our art contest was announced at the De-Light Pittsburgh celebration at the Carnegie Science Center during Astronomy Weekend. “Our Pittsburgh Constellation” is an interactive Google map of all things astronomical in the city. Different colored stars mark locations of planetariums, star parties, classes, observatories, lecture series, museums, telescope manufacturers and participating art galleries. Contest entrants submitted artwork depicting their vision of the constellation figure that incorporates and connects all the “stars” in our custom city map. Throughout the year, over a dozen artists ran workshops on painting star clusters, galaxies, nebulae, comets, planets and aurorae with discussions of light pollution solutions and scientific explanations of what the patrons were painting, including demonstrations with emission tubes and diffraction grating glasses. We will display the celestial art created in this International Year of Light at an art gallery as part of the City’s Department of Innovation & Performance March 2016 Earth Hour gala. We are thankful for the Astronomical Footprint grant from the Heinz Endowments, which allowed us to bring the worlds of science and art together to enact social change.

Obesity Management: What Should We Do If Fat Gain Is Necessary to Maintain Body Homeostasis in a Modern World?

PubMed

Tremblay, Angelo

2018-01-01

The prevalence of overweight has substantially increased over the last decades despite the intent of health professionals and the general population to prevent this trend. Traditionally, this phenomenon has been attributed to unhealthy dietary macronutrient composition and/or to the decrease in physical activity participation. Beyond the influence of these factors, it is more than likely that other factors have influenced energy balance in a context of modernity. These include inadequate sleep, demanding cognitive effort, chemical pollution, and probably others which also have the potential to promote a positive energy balance but which are also part of the reality of success and productivity in a globalized world. As discussed in this paper, many individuals may become conflicted with themselves if they wish to prevent weight gain while influencing factors which are determinants of their socioeconomic success. In this regard, this paper reminds us of the contribution of adipose tissue gain in body homeostasis which is essential to permit energy balance, especially under lifestyle conditions promoting overfeeding. From a clinical standpoint, this imposes the consideration of a weight loss program as a search for compromise between what can be changed to promote a negative energy balance and what can be tolerated by the body in terms of fat loss. Furthermore, if we also consider the impact of pollution on energy balance for which we currently do not hold solutions of reversibility, we probably must accept that the mankind of today will have to be more corpulent than its ancestors. In this pessimistic environment, there are still possibilities to do better; however, this will probably require the revisiting of lifestyle practices according to what the human body and planet can tolerate as deviation from optimal functioning.

Developing the STS sound pollution unit for enhancing students' applying knowledge among science technology engineering and mathematics

NASA Astrophysics Data System (ADS)

Jumpatong, Sutthaya; Yuenyong, Chokchai

2018-01-01

STEM education suggested that students should be enhanced to learn science with integration between Science, Technology, Engineering and Mathematics. To help Thai students make sense of relationship between Science, Technology, Engineering and Mathematics, this paper presents learning activities of STS Sound Pollution. The developing of STS Sound Pollution is a part of research that aimed to enhance students' perception of the relationship between Science Technology Engineering and Mathematics. This paper will discuss how to develop Sound Pollution through STS approach in framework of Yuenyong (2006) where learning activities were provided based on 5 stages. These included (1) identification of social issues, (2) identification of potential solutions, (3) need for knowledge, (4) decisionmaking, and (5) socialization stage. The learning activities could be highlighted as following. First stage, we use video clip of `Problem of people about Sound Pollution'. Second stage, students will need to identification of potential solutions by design Home/Factory without noisy. The need of scientific and other knowledge will be proposed for various alternative solutions. Third stage, students will gain their scientific knowledge through laboratory and demonstration of sound wave. Fourth stage, students have to make decision for the best solution of designing safety Home/Factory based on their scientific knowledge and others (e.g. mathematics, economics, art, value, and so on). Finally, students will present and share their Design Safety Home/Factory in society (e.g. social media or exhibition) in order to validate their ideas and redesigning. The paper, then, will discuss how those activities would allow students' applying knowledge of science technology engineering, mathematics and others (art, culture and value) for their possible solution of the STS issues.

One-dimensional analytical solution for hydraulic head and numerical solution for solute transport through a horizontal fracture for submarine groundwater discharge.

PubMed

He, Cairong; Wang, Tongke; Zhao, Zhixue; Hao, Yonghong; Yeh, Tian-Chyi J; Zhan, Hongbin

2017-11-01

Submarine groundwater discharge (SGD) has been recognized as a major pathway of groundwater flow to coastal oceanic environments. It could affect water quality and marine ecosystems due to pollutants and trace elements transported through groundwater. Relations between different characteristics of aquifers and SGD have been investigated extensively before, but the role of fractures in SGD still remains unknown. In order to better understand the mechanism of groundwater flow and solute transport through fractures in SGD, one-dimensional analytical solutions of groundwater hydraulic head and velocity through a synthetic horizontal fracture with periodic boundary conditions were derived using a Laplace transform technique. Then, numerical solutions of solute transport associated with the given groundwater velocity were developed using a finite-difference method. The results indicated that SGD associated with groundwater flow and solute transport was mainly controlled by sea level periodic fluctuations, which altered the hydraulic head and the hydraulic head gradient in the fracture. As a result, the velocity of groundwater flow associated with SGD also fluctuated periodically. We found that the pollutant concentration associated with SGD oscillated around a constant value, and could not reach a steady state. This was particularly true at locations close to the seashore. This finding of the role of fracture in SGD will assist pollution remediation and marine conservation in coastal regions. Copyright © 2017 Elsevier B.V. All rights reserved.

One-dimensional analytical solution for hydraulic head and numerical solution for solute transport through a horizontal fracture for submarine groundwater discharge

NASA Astrophysics Data System (ADS)

He, Cairong; Wang, Tongke; Zhao, Zhixue; Hao, Yonghong; Yeh, Tian-Chyi J.; Zhan, Hongbin

2017-11-01

Submarine groundwater discharge (SGD) has been recognized as a major pathway of groundwater flow to coastal oceanic environments. It could affect water quality and marine ecosystems due to pollutants and trace elements transported through groundwater. Relations between different characteristics of aquifers and SGD have been investigated extensively before, but the role of fractures in SGD still remains unknown. In order to better understand the mechanism of groundwater flow and solute transport through fractures in SGD, one-dimensional analytical solutions of groundwater hydraulic head and velocity through a synthetic horizontal fracture with periodic boundary conditions were derived using a Laplace transform technique. Then, numerical solutions of solute transport associated with the given groundwater velocity were developed using a finite-difference method. The results indicated that SGD associated with groundwater flow and solute transport was mainly controlled by sea level periodic fluctuations, which altered the hydraulic head and the hydraulic head gradient in the fracture. As a result, the velocity of groundwater flow associated with SGD also fluctuated periodically. We found that the pollutant concentration associated with SGD oscillated around a constant value, and could not reach a steady state. This was particularly true at locations close to the seashore. This finding of the role of fracture in SGD will assist pollution remediation and marine conservation in coastal regions.

VLT/SPHERE robust astrometry of the HR8799 planets at milliarcsecond-level accuracy. Orbital architecture analysis with PyAstrOFit

NASA Astrophysics Data System (ADS)

Wertz, O.; Absil, O.; Gómez González, C. A.; Milli, J.; Girard, J. H.; Mawet, D.; Pueyo, L.

2017-02-01

Context. HR8799 is orbited by at least four giant planets, making it a prime target for the recently commissioned Spectro-Polarimetric High-contrast Exoplanet REsearch (VLT/SPHERE). As such, it was observed on five consecutive nights during the SPHERE science verification in December 2014. Aims: We aim to take full advantage of the SPHERE capabilities to derive accurate astrometric measurements based on H-band images acquired with the Infra-Red Dual-band Imaging and Spectroscopy (IRDIS) subsystem, and to explore the ultimate astrometric performance of SPHERE in this observing mode. We also aim to present a detailed analysis of the orbital parameters for the four planets. Methods: We performed thorough post-processing of the IRDIS images with the Vortex Imaging Processing (VIP) package to derive a robust astrometric measurement for the four planets. This includes the identification and careful evaluation of the different contributions to the error budget, including systematic errors. Combining our astrometric measurements with the ones previously published in the literature, we constrain the orbital parameters of the four planets using PyAstrOFit, our new open-source python package dedicated to orbital fitting using Bayesian inference with Monte-Carlo Markov Chain sampling. Results: We report the astrometric positions for epoch 2014.93 with an accuracy down to 2.0 mas, mainly limited by the astrometric calibration of IRDIS. For each planet, we derive the posterior probability density functions for the six Keplerian elements and identify sets of highly probable orbits. For planet d, there is clear evidence for nonzero eccentricity (e 0.35), without completely excluding solutions with smaller eccentricities. The three other planets are consistent with circular orbits, although their probability distributions spread beyond e = 0.2, and show a peak at e ≃ 0.1 for planet e. The four planets have consistent inclinations of approximately 30° with respect to the sky plane, but the confidence intervals for the longitude of the ascending node are disjointed for planets b and c, and we find tentative evidence for non-coplanarity between planets b and c at the 2σ level. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 60.A-9352.

76 FR 72403 - Access to Confidential Business Information by Primus Solutions, Inc.

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-23

...), Office of Pollution Prevention and Toxics, Environmental Protection Agency, 1200 Pennsylvania Ave., NW... Primus of 6303 Ivy Lane, Suite 130, Greenbelt, MD, will assist the Office of Pollution Prevention and... Director, Information Management Division, Office of Pollution Prevention and Toxics. [FR Doc. 2011-30143...

Creating a Star: The Science of Fusion--Fusion Power Would Not Contribute to Global Warming, Acid Rain, or Other Forms of Air Pollution, nor Would It Create Long-Lived Radioactive Waste

ERIC Educational Resources Information Center

Baird, Stephen L.

2005-01-01

Fusion is the process that powers the sun and the stars. Since the 1950s, scientists and engineers in the United States and around the world have been conducting fusion research in pursuit of the creation of a new energy source for our planet and to further our understanding and control of plasma, the fourth state of matter that dominates the…

Surface motion of a fluid planet induced by impacts

NASA Astrophysics Data System (ADS)

Ni, Sidao; Ahrens, Thomas J.

2006-10-01

In order to approximate the free-surface motion of an Earth-sized planet subjected to a giant impact, we have described the excitation of body and surface waves in a spherical compressible fluid planet without gravity or intrinsic material attenuation for a buried explosion source. Using the mode summation method, we obtained an analytical solution for the surface motion of the fluid planet in terms of an infinite series involving the products of spherical Bessel functions and Legendre polynomials. We established a closed form expression for the mode summation excitation coefficient for a spherical buried explosion source, and then calculated the surface motion for different spherical explosion source radii a (for cases of a/R = 0.001 to 0.035, R is the radius of the Earth) We also studied the effect of placing the explosion source at different radii r0 (for cases of r0/R = 0.90 to 0.96) from the centre of the planet. The amplitude of the quasi-surface waves depends substantially on a/R, and slightly on r0/R. For example, in our base-line case, a/R = 0.03, r0/R = 0.96, the free-surface velocity above the source is 0.26c, whereas antipodal to the source, the peak free surface velocity is 0.19c. Here c is the acoustic velocity of the fluid planet. These results can then be applied to studies of atmosphere erosion via blow-off caused by asteroid impacts.

ngVLA Key Science Goal 1: Unveiling the Formation of Solar System Analogues

NASA Astrophysics Data System (ADS)

Liu, Shangfei; Ricci, Luca; Isella, Andrea; Li, Hui; Li, Shengtai

2018-01-01

The annular gaps and other substructures discovered in several protoplanetary disks by ALMA and optical/NIR telescopes are reminiscent of the interaction between newborn planets and the circumstellar material. The comparison with theoretical models indicates that these structures might indeed result from the gravitational interaction between the circumstellar disk and Saturn-mass planets orbiting at tens of AU from the parent star. The same observations also revealed that the submm-wave dust continuum emission arising within 10-30 AU from the star is optically thick. The large optical depth prevents us from accurately measuring the dust density and, therefore, image planet-driven density perturbations. A natural solution to this problem consists in imaging disks at wavelengths of 3mm and longer, where the dust continuum emission from the innermost disk regions is optically thin, but still bright enough to be detected. These wavelengths are covered by the VLA, which, however, lacks the angular resolution and sensitivity to efficiently search for signatures of planets orbiting in the innermost and densest disk regions. Thanks to its much larger collecting area, resolving power, and image quality the Next Generation VLA (ngVLA) will transform the study of planet formation. we present the results of a recent study aimed at investigating the potential of the ngVLA of discovering disk sub-structures, such as gaps and azimuthal asymmetries, generated by the interaction with low-mass forming planets at < 10 au from the star.

Air pollution, deprivation and health: understanding relationships to add value to local air quality management policy and practice in Wales, UK.

PubMed

Brunt, H; Barnes, J; Jones, S J; Longhurst, J W S; Scally, G; Hayes, E

2017-09-01

Air pollution exposure reduces life expectancy. Air pollution, deprivation and poor-health status combinations can create increased and disproportionate disease burdens. Problems and solutions are rarely considered in a broad public health context, but doing so can add value to air quality management efforts by reducing air pollution risks, impacts and inequalities. An ecological study assessed small-area associations between air pollution (nitrogen dioxide and particulate matter), deprivation status and health outcomes in Wales, UK. Air pollution concentrations were highest in 'most' deprived areas. When considered separately, deprivation-health associations were stronger than air pollution-health associations. Considered simultaneously, air pollution added to deprivation-health associations; interactions between air pollution and deprivation modified and strengthened associations with all-cause and respiratory disease mortality, especially in 'most' deprived areas where most-vulnerable people lived and where health needs were greatest. There is a need to reduce air pollution-related risks for all. However, it is also the case that greater health gains can result from considering local air pollution problems and solutions in the context of wider health-determinants and acting on a better understanding of relationships. Informed and co-ordinated air pollution mitigation and public health action in high deprivation and pollution areas can reduce risks and inequalities. To achieve this, greater public health integration and collaboration in local air quality management policy and practice is needed. © The Author 2016. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The pulsar planet production process

NASA Technical Reports Server (NTRS)

Phinney, E. S.; Hansen, B. M. S.

1993-01-01

Most plausible scenarios for the formation of planets around pulsars end with a disk of gas around the pulsar. The supplicant author then points to the solar system to bolster faith in the miraculous transfiguration of gas into planets. We here investigate this process of transfiguration. We derive analytic sequences of quasi-static disks which give good approximations to exact solutions of the disk diffusion equation with realistic opacity tables. These allow quick and efficient surveys of parameter space. We discuss the outward transfer of mass in accretion disks and the resulting timescale constraints, the effects of illumination by the central source on the disk and dust within it, and the effects of the widely different elemental compositions of the disks in the various scenarios, and their extensions to globular clusters. We point out where significant uncertainties exist in the appropriate grain opacities, and in the effect of illumination and winds from the neutron star.

Air Pollution and Climate Change Effects on Allergies in the Anthropocene: Abundance, Interaction, and Modification of Allergens and Adjuvants.

PubMed

Reinmuth-Selzle, Kathrin; Kampf, Christopher J; Lucas, Kurt; Lang-Yona, Naama; Fröhlich-Nowoisky, Janine; Shiraiwa, Manabu; Lakey, Pascale S J; Lai, Senchao; Liu, Fobang; Kunert, Anna T; Ziegler, Kira; Shen, Fangxia; Sgarbanti, Rossella; Weber, Bettina; Bellinghausen, Iris; Saloga, Joachim; Weller, Michael G; Duschl, Albert; Schuppan, Detlef; Pöschl, Ulrich

2017-04-18

Air pollution and climate change are potential drivers for the increasing burden of allergic diseases. The molecular mechanisms by which air pollutants and climate parameters may influence allergic diseases, however, are complex and elusive. This article provides an overview of physical, chemical and biological interactions between air pollution, climate change, allergens, adjuvants and the immune system, addressing how these interactions may promote the development of allergies. We reviewed and synthesized key findings from atmospheric, climate, and biomedical research. The current state of knowledge, open questions, and future research perspectives are outlined and discussed. The Anthropocene, as the present era of globally pervasive anthropogenic influence on planet Earth and, thus, on the human environment, is characterized by a strong increase of carbon dioxide, ozone, nitrogen oxides, and combustion- or traffic-related particulate matter in the atmosphere. These environmental factors can enhance the abundance and induce chemical modifications of allergens, increase oxidative stress in the human body, and skew the immune system toward allergic reactions. In particular, air pollutants can act as adjuvants and alter the immunogenicity of allergenic proteins, while climate change affects the atmospheric abundance and human exposure to bioaerosols and aeroallergens. To fully understand and effectively mitigate the adverse effects of air pollution and climate change on allergic diseases, several challenges remain to be resolved. Among these are the identification and quantification of immunochemical reaction pathways involving allergens and adjuvants under relevant environmental and physiological conditions.

Air Pollution and Climate Change Effects on Allergies in the Anthropocene: Abundance, Interaction, and Modification of Allergens and Adjuvants

PubMed Central

2017-01-01

Air pollution and climate change are potential drivers for the increasing burden of allergic diseases. The molecular mechanisms by which air pollutants and climate parameters may influence allergic diseases, however, are complex and elusive. This article provides an overview of physical, chemical and biological interactions between air pollution, climate change, allergens, adjuvants and the immune system, addressing how these interactions may promote the development of allergies. We reviewed and synthesized key findings from atmospheric, climate, and biomedical research. The current state of knowledge, open questions, and future research perspectives are outlined and discussed. The Anthropocene, as the present era of globally pervasive anthropogenic influence on planet Earth and, thus, on the human environment, is characterized by a strong increase of carbon dioxide, ozone, nitrogen oxides, and combustion- or traffic-related particulate matter in the atmosphere. These environmental factors can enhance the abundance and induce chemical modifications of allergens, increase oxidative stress in the human body, and skew the immune system toward allergic reactions. In particular, air pollutants can act as adjuvants and alter the immunogenicity of allergenic proteins, while climate change affects the atmospheric abundance and human exposure to bioaerosols and aeroallergens. To fully understand and effectively mitigate the adverse effects of air pollution and climate change on allergic diseases, several challenges remain to be resolved. Among these are the identification and quantification of immunochemical reaction pathways involving allergens and adjuvants under relevant environmental and physiological conditions. PMID:28326768

Initialization of distributed spacecraft for precision formation flying

NASA Technical Reports Server (NTRS)

Hadaegh, F. Y.; Scharf, D. P.; Ploen, S. R.

2003-01-01

In this paper we present a solution to the formation initialization problem for N distributed spacecraft located in deep space. Our solution to the FI problem is based on a three-stage sky search procedure that reduces the FI problem for N spacecraft to the simpler problem of initializing a set of sub-formations. We demonstrate our FI algorithm in simulation using NASA's five spacecraft Terrestrial Planet Finder mission as an example.

The conjectured S-type retrograde planet in ν Octantis: more evidence including four years of iodine-cell radial velocities

NASA Astrophysics Data System (ADS)

Ramm, D. J.; Nelson, B. E.; Endl, M.; Hearnshaw, J. B.; Wittenmyer, R. A.; Gunn, F.; Bergmann, C.; Kilmartin, P.; Brogt, E.

2016-08-01

We report 1212 radial-velocity (RV) measurements obtained in the years 2009-2013 using an iodine cell for the spectroscopic binary ν Octantis (K1 III/IV). This system (a_{bin} ˜ 2.6 au, P ˜ 1050 d) is conjectured to have a Jovian planet with a semimajor axis half that of the binary host. The extreme geometry only permits long-term stability if the planet is in a retrograde orbit. Whilst the reality of the planet (P ˜ 415 d) remains uncertain, other scenarios (stellar variability or apsidal motion caused by a yet unobserved third star) continue to appear substantially less credible based on cross-correlation function bisectors, line-depth ratios and many other independent details. If this evidence is validated but the planet is disproved, the claims of other planets using RVs will be seriously challenged. We also describe a significant revision to the previously published RVs and the full set of 1437 RVs now encompasses nearly 13 yr. The sensitive orbital dynamics allow us to constrain the 3D architecture with a broad prior probability distribution on the mutual inclination, which with posterior samples obtained from an N-body Markov chain Monte Carlo is found to be 152.5°±^{0.7}_{0.6}. None of these samples are dynamically stable beyond 106 yr. However, a grid search around the best-fitting solution finds a region that has many models stable for 107 yr, and includes one model within 1σ that is stable for at least 108 yr. The planet's exceptional nature demands robust independent verification and makes the theoretical understanding of its formation a worthy challenge.

Characterization of the KOI-273 Planetary System with HARPS-N

NASA Astrophysics Data System (ADS)

Gettel, Sara; Charbonneau, David; Harps-N Collaboration

2015-01-01

The NASA Kepler mission detected thousands of planets with radii between 1 and 3 Earth radii, a population with no analog in our own solar system. The composition of these objects is not yet well understood; some of these may be planets that are predominantly rocky and others may be planets with a large fractional composition of volatiles or a substantial hydrogen envelope. There are only seven planets smaller than 2.5 Re with published mass estimates with a precision better than 20%, the minimum required to distinguish between different compositional models.HARPS-N is an ultra-stable, fiber-fed, high-resolution spectrograph optimized for the measurement of very precise radial velocities. A primary goal of the HARPS-N collaboration is to measure precisely the masses of small transiting planets and so constrain their individual compositions.KOI-273 is a solar-like star (Teff = 5783, log(g) = 4.43, V = 11.68) with a 1.8 Earth-radius planet candidate in a 10.5-d orbit. During the 2014 Kepler observing season, we obtained 50 observations of this star, with a median photon-limited radial velocity precision of 1.9 m/s. Our data indicated the presence of an outer, massive companion. We present the orbital solution of this system and measure the bulk density and inferred composition of the inner planet.HARPS-N was funded by the Swiss Space Office, the Harvard Origin of Life Initiative, the Scottish Universities Physics Alliance, the University of Geneva, the Smithsonian Astrophysical Observatory, and the Italian National Astrophysical Institute, University of St. Andrews, Queens University Belfast, and University of Edinburgh. This work was made possible through a grant from the John Templeton Foundation.

Evaluation of groundwater pollution in a mining area using analytical solution: a case study of the Yimin open-pit mine in China.

PubMed

Li, Tianxin; Li, Li; Song, Hongqing; Meng, Linglong; Zhang, Shuli; Huang, Gang

2016-01-01

This study focused on using analytical and numerical models to develop and manage groundwater resources, and predict the effects of management measurements in the groundwater system. Movement of contaminants can be studied based on groundwater flow characteristics. This study can be used for prediction of ion concentration and evaluation of groundwater pollution as the theoretical basis. The Yimin open-pit mine is located in the northern part of the Inner Mongolia Autonomous Region of China. High concentrations of iron and manganese are observed in Yimin open-pit mine because of exploitation and pumping that have increased the concentration of the ions in groundwater. In this study, iron was considered as an index of contamination, and the solute model was calibrated using concentration observations from 14 wells in 2014. The groundwater flow model and analytical solutions were used in this study to forecast pollution concentration and variation trend after calibration. With continuous pumping, contaminants will migrate, and become enriched, towards the wellhead in the flow direction. The concentration of the contaminants and the range of pollution increase with the flow rate increased. The suitable flow rate of single well should be <380 m/day at Yimin open-pit for the standard value of pollution concentration.

Sounds and Noises. A Position Paper on Noise Pollution.

ERIC Educational Resources Information Center

Chapman, Thomas L.

This position paper focuses on noise pollution and the problems and solutions associated with this form of pollution. The paper is divided into the following five sections: Noise and the Ear, Noise Measurement, III Effects of Noise, Acoustics and Action, and Programs and Activities. The first section identifies noise and sound, the beginnings of…

Quebec's Toxic Pollution Concern.

ERIC Educational Resources Information Center

Mingie, Walter

The best solution to the problems of increased pollution of Quebec lakes and rivers with toxic wastes and increased incidence of pollution related diseases is to educate children, to make them aware of the environment and man's interrelationship with it. Attitudes of concern, based on knowledge, must be developed so that as adults, they will take…

Water Pollution (Causes, Mechanisms, Solution).

ERIC Educational Resources Information Center

Strandberg, Carl

Written for the general public, this book illustrates the causes, status, problem areas, and prediction and control of water pollution. Water pollution is one of the most pressing issues of our time and the author communicates the complexities of this problem to the reader in common language. The purpose of the introductory chapter is to show what…

Transportation, Air Pollution, and Climate Change

EPA Pesticide Factsheets

Learn how emissions reductions, advancements in fuels and fuel economy, and working with industry to find solutions to air pollution problems benefit human and environmental health, create consumer savings and are cost effective.

STS-68 Mission Insignia

NASA Technical Reports Server (NTRS)

1994-01-01

This STS-68 patch was designed by artist Sean Collins. Exploration of Earth from space is the focus of the design of the insignia, the second flight of the Space Radar Laboratory (SRL-2). SRL-2 was part of NASA's Mission to Planet Earth (MTPE) project. The world's land masses and oceans dominate the center field, with the Space Shuttle Endeavour circling the globe. The SRL-2 letters span the width and breadth of planet Earth, symbolizing worldwide coverage of the two prime experiments of STS-68: The Shuttle Imaging Radar-C and X-Band Synthetic Aperture Radar (SIR-C/X-SAR) instruments; and the Measurement of Air Pollution from Satellites (MAPS) sensor. The red, blue, and black colors of the insignia represent the three operating wavelengths of SIR-C/X-SAR, and the gold band surrounding the globe symbolizes the atmospheric envelope examined by MAPS. The flags of international partners Germany and Italy are shown opposite Endeavour. The relationship of the Orbiter to Earth highlights the usefulness of human space flights in understanding Earth's environment, and the monitoring of its changing surface and atmosphere. In the words of the crew members, the soaring Orbiter also typifies the excellence of the NASA team in exploring our own world, using the tools which the Space Program developed to explore the other planets in the solar system.

The ocean planet.

PubMed

Hinrichsen, D

1998-01-01

The Blue Planet is 70% water, and all but 3% of it is salt water. Life on earth first evolved in the primordial soup of ancient seas, and though today's seas provide 99% of all living space on the planet, little is known about the world's oceans. However, the fact that the greatest threats to the integrity of our oceans come from land-based activities is becoming clear. Humankind is in the process of annihilating the coastal and ocean ecosystems and the wealth of biodiversity they harbor. Mounting population and development pressures have taken a grim toll on coastal and ocean resources. The trend arising from such growth is the chronic overexploitation of marine resources, whereby rapidly expanding coastal populations and the growth of cities have contributed to a rising tide of pollution in nearly all of the world's seas. This crisis is made worse by government inaction and a frustrating inability to enforce existing coastal and ocean management regulations. Such inability is mainly because concerned areas contain so many different types of regulations and involve so many levels of government, that rational planning and coordination of efforts are rendered impossible. Concerted efforts are needed by national governments and the international community to start preserving the ultimate source of all life on earth.

STS-59 crew insignia

NASA Image and Video Library

1993-11-01

STS059-S-001 (November 1993) --- Designed by the crew members, the STS-59 insignia is dominated by Earth, reflecting the focus of the first Space Radar Laboratory (SRL-1) mission upon our planet's surface and atmosphere. The golden symbol of the astronaut corps emblem sweeps over Earth's surface from the space shuttle Endeavour, representing the operation of the SIR-C/Synthetic Aperture Radar (X-SAR) and the Measurement of Air Pollution from Space (MAPS) sensors. The astronaut emblem also signals the importance of the human element in space exploration and in the study of our planet. Using the unique vantage point of space, Endeavour and its crew -- along with scientists from around the world -- will study Earth and its environment. The starfield visible below Earth represents the many talents and skills of the international (SRL-1) team in working to make this "Mission to Planet Earth" (MTPE) a scientific and operational success. The NASA insignia design for space shuttle flights is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the forms of illustrations by the various news media. When and if there is any change in this policy, which is not anticipated, the change will be publicly announced. Photo credit: NASA

Space Shuttle Projects

NASA Image and Video Library

1994-02-25

This STS-68 patch was designed by artist Sean Collins. Exploration of Earth from space is the focus of the design of the insignia, the second flight of the Space Radar Laboratory (SRL-2). SRL-2 was part of NASA's Mission to Planet Earth (MTPE) project. The world's land masses and oceans dominate the center field, with the Space Shuttle Endeavour circling the globe. The SRL-2 letters span the width and breadth of planet Earth, symbolizing worldwide coverage of the two prime experiments of STS-68: The Shuttle Imaging Radar-C and X-Band Synthetic Aperture Radar (SIR-C/X-SAR) instruments; and the Measurement of Air Pollution from Satellites (MAPS) sensor. The red, blue, and black colors of the insignia represent the three operating wavelengths of SIR-C/X-SAR, and the gold band surrounding the globe symbolizes the atmospheric envelope examined by MAPS. The flags of international partners Germany and Italy are shown opposite Endeavour. The relationship of the Orbiter to Earth highlights the usefulness of human space flights in understanding Earth's environment, and the monitoring of its changing surface and atmosphere. In the words of the crew members, the soaring Orbiter also typifies the excellence of the NASA team in exploring our own world, using the tools which the Space Program developed to explore the other planets in the solar system.

Elliptical multi-sun-synchronous orbits for Mars exploration

NASA Astrophysics Data System (ADS)

Circi, Christian; Ortore, Emiliano; Bunkheila, Federico; Ulivieri, Carlo

2012-11-01

The multi-sun-synchronous orbits allow cycles of observation of the same area in which solar illumination repetitively changes according to the value of the orbit elements and returns to the initial condition after a temporal interval multiple of the repetition of observation. This paper generalizes the concept of multi-sun-synchronous orbits, whose classical sun-synchronous orbits represent particular solutions, taking into consideration the elliptical case. The feasibility of using this typology of orbits, referred to as elliptical periodic multi-sun-synchronous orbits, has been investigated for the exploration of Mars and particular solutions have been selected. Such solutions considerably reduce the manoeuvre of velocity variation at the end of the interplanetary transfer with respect to the case of a target circular orbit around Mars. They are based on the use of quasi-critical inclinations in order to minimize the apsidal line motion and thus reduce orbit maintenance costs. Moreover, in the case of high eccentricities, the argument of pericentre may be set in order to obtain, around the apocentre, a condition of quasi-synchronism with the planet (the footprint of the probe on the surface presents a small shift with respect to a fixed point on the Martian surface). The low altitude of pericentre allows observation of the planet at a higher spatial resolution, while the orbit arc around the apocentre may be used to observe Mars with a wide spatial coverage in quasi-stationary conditions. This latter characteristic is useful for analysing atmospheric and meteorological phenomena and it allows for most of the orbital period a link between a rover on the surface of Mars and a probe orbiting around the planet.

Pathologic Analysis of Control Plans for Air Pollution Management in Tehran Metropolis: A Cross-Sectional Study

PubMed Central

Salehi Shahrabi, Narges; Pourezzat, Aliasghar; Mobaraki, Hossein; Mafimoradi, Shiva

2013-01-01

Abstract Background The centralization of human activities is associated with different pollutants which enter into environment easily and cause the urban environment more vulnerable. Regarding the importance of air pollution issue for Tehran metropolis, many plans and regulations have been developed. However, most of them failed to decline the pollution. The purpose of this study was to pathologically analyze air-pollution control plans to offer effective solutions for Tehran metropolis. Methods A Qualitative content analysis in addition to a semi-structured interview with 14 practicing professional were used to identify 1) key sources of Tehran’s air pollution, 2) recognize challenges towards effective performance of pertinent plans and 3), offer effective solutions. Results Related challenges to air-pollution control plans can be divided into two major categories including lack of integrated and organized stewardship and PEST challenges. Conclusion For controlling the air pollution of Tehran effectively, various controlling alternatives were identified as systematization of plan preparation process, standardization and utilization of new technologies & experts, infrastructural development, realization of social justice, developing coordination mechanisms, improving citizens’ participatory capacity and focusing on effective management of fuel and energy. Controlling air pollution in Tehran needs a serious attention of policymakers to make enforcements through applying a systemic cycle of preparation comprehensive plans. Further, implement the enforcements and evaluate the environmental impact of the plans through involving all stakeholders. PMID:26171340

The SOLUTIONS project: challenges and responses for present and future emerging pollutants in land and water resources management.

PubMed

Brack, Werner; Altenburger, Rolf; Schüürmann, Gerrit; Krauss, Martin; López Herráez, David; van Gils, Jos; Slobodnik, Jaroslav; Munthe, John; Gawlik, Bernd Manfred; van Wezel, Annemarie; Schriks, Merijn; Hollender, Juliane; Tollefsen, Knut Erik; Mekenyan, Ovanes; Dimitrov, Saby; Bunke, Dirk; Cousins, Ian; Posthuma, Leo; van den Brink, Paul J; López de Alda, Miren; Barceló, Damià; Faust, Michael; Kortenkamp, Andreas; Scrimshaw, Mark; Ignatova, Svetlana; Engelen, Guy; Massmann, Gudrun; Lemkine, Gregory; Teodorovic, Ivana; Walz, Karl-Heinz; Dulio, Valeria; Jonker, Michiel T O; Jäger, Felix; Chipman, Kevin; Falciani, Francesco; Liska, Igor; Rooke, David; Zhang, Xiaowei; Hollert, Henner; Vrana, Branislav; Hilscherova, Klara; Kramer, Kees; Neumann, Steffen; Hammerbacher, Ruth; Backhaus, Thomas; Mack, Juliane; Segner, Helmut; Escher, Beate; de Aragão Umbuzeiro, Gisela

2015-01-15

SOLUTIONS (2013 to 2018) is a European Union Seventh Framework Programme Project (EU-FP7). The project aims to deliver a conceptual framework to support the evidence-based development of environmental policies with regard to water quality. SOLUTIONS will develop the tools for the identification, prioritisation and assessment of those water contaminants that may pose a risk to ecosystems and human health. To this end, a new generation of chemical and effect-based monitoring tools is developed and integrated with a full set of exposure, effect and risk assessment models. SOLUTIONS attempts to address legacy, present and future contamination by integrating monitoring and modelling based approaches with scenarios on future developments in society, economy and technology and thus in contamination. The project follows a solutions-oriented approach by addressing major problems of water and chemicals management and by assessing abatement options. SOLUTIONS takes advantage of the access to the infrastructure necessary to investigate the large basins of the Danube and Rhine as well as relevant Mediterranean basins as case studies, and puts major efforts on stakeholder dialogue and support. Particularly, the EU Water Framework Directive (WFD) Common Implementation Strategy (CIS) working groups, International River Commissions, and water works associations are directly supported with consistent guidance for the early detection, identification, prioritisation, and abatement of chemicals in the water cycle. SOLUTIONS will give a specific emphasis on concepts and tools for the impact and risk assessment of complex mixtures of emerging pollutants, their metabolites and transformation products. Analytical and effect-based screening tools will be applied together with ecological assessment tools for the identification of toxicants and their impacts. The SOLUTIONS approach is expected to provide transparent and evidence-based candidates or River Basin Specific Pollutants in the case study basins and to assist future review of priority pollutants under the WFD as well as potential abatement options. Copyright © 2014 Elsevier B.V. All rights reserved.

QUEST: Qualifying Environmentally Sustainable Technologies

NASA Technical Reports Server (NTRS)

2006-01-01

Over the years, pollution prevention has proven to be a means to comply with environmental regulations, improve product performance and reduce costs. The NASA Acquisition Pollution Prevention (AP2) Program was created to help individual NASA Centers and programs work together to evaluate and adopt environmentally preferable technologies and practices. The AP2 Program accomplishes its mission using a variety of tools such as networking, information/technology exchange and partnering. Due to its extensive network of contacts, the AP2 Program is an excellent resource for finding existing solutions to problems. If no solution is readily known, the AP2 Program works to identify potential solutions and partners for demonstration/ validation projects. Partnering to prevent pollution is a cornerstone of NASA's prime mission and the One NASA Initiative. This annual newsletter highlights some of our program's collaborative efforts. I believe you will discover how the AP2 Program is responsive in meeting the Agency's environmental management strategic plans.

Particulate Matter (Environmental Health Student Portal)

MedlinePlus

... on a charcoal or gas grill, or burning fossil fuels in a power plant. How can PM ... and understand the health effects associated with this form of pollution. Air Pollution: What's the Solution? (U.S. ...

FY 2013 Pollution Prevention Grant Program Request for Proposals

EPA Pesticide Factsheets

The Pollution Prevention (P2) grant program funds state and tribal technical assistance projects to help businesses identify better environmental strategies and solutions for reducing or eliminating waste at the source.

Classroom Activities about Water and Climate Change

NASA Astrophysics Data System (ADS)

Rodriguez, M.

2012-04-01

The purpose of this activity is to demonstrate practical work and experiments in the classroom, with students on Water: Water is the most neccesary Earth's resource, although it is decreasing because many human activities are changing its quality and its availability. The activity is designed in order to recreate experiments, simulations, and determine the aspects of the problematic environment currently plaguing our planet, especially those related to water and climate change. The selected activities have to be easy to make, and easy to understand. Each activity will be illustrated, explained and described using pictures and short texts, so teachers could replay them in their classroom. 1. Simulation of the Ocean Water Currents Convection to understand the heat distribution in our planet. 2. Ocean Water Stratification According to Water Salinity. We can understand the behaviour of water when we mix water from different densities 3. Melting of the Arctic and Antarctic Polar Caps. In this experiment, we can see the consequences of changing environment and climate conditions as it pertains to ice and our polar ice caps. We want to show the different behaviours of continental and floating ice and to evaluate the consequences of their melting. 4. Detecting water pollution. Here, we can analyse some water patterns and get to know the existence or absence of pollutants in the water, as well as learning how to determine its pH level, hardness, nitrogen composition, bacteria content and more. 5. Creating a home treatment. We show the necessity to preserve the water quality through a suitable treatment.

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

Rose, Brian E. J.; Cronin, Timothy W.; Bitz, Cecilia M., E-mail: brose@albany.edu

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

Vortex coronagraphs for the Habitable Exoplanet Imaging Mission concept: theoretical performance and telescope requirements

NASA Astrophysics Data System (ADS)

Ruane, Garreth; Mawet, Dimitri; Mennesson, Bertrand; Jewell, Jeffrey; Shaklan, Stuart

2018-01-01

The Habitable Exoplanet Imaging Mission concept requires an optical coronagraph that provides deep starlight suppression over a broad spectral bandwidth, high throughput for point sources at small angular separation, and insensitivity to temporally varying, low-order aberrations. Vortex coronagraphs are a promising solution that performs optimally on off-axis, monolithic telescopes and may also be designed for segmented telescopes with minor losses in performance. We describe the key advantages of vortex coronagraphs on off-axis telescopes such as (1) unwanted diffraction due to aberrations is passively rejected in several low-order Zernike modes relaxing the wavefront stability requirements for imaging Earth-like planets from <10 to >100 pm rms, (2) stars with angular diameters >0.1 λ / D may be sufficiently suppressed, (3) the absolute planet throughput is >10 % , even for unfavorable telescope architectures, and (4) broadband solutions (Δλ / λ > 0.1) are readily available for both monolithic and segmented apertures. The latter make use of grayscale apodizers in an upstream pupil plane to provide suppression of diffracted light from amplitude discontinuities in the telescope pupil without inducing additional stroke on the deformable mirrors. We set wavefront stability requirements on the telescope, based on a stellar irradiance threshold set at an angular separation of 3 ± 0.5λ / D from the star, and discuss how some requirements may be relaxed by trading robustness to aberrations for planet throughput.

New insights into asteroid 3200 Phaethon's meteor complex

NASA Astrophysics Data System (ADS)

Jakubik, Marian; Neslusan, Lubos

2015-11-01

In this work, we study the meteor complex originating from asteroid 3200 Phaethon. Using a modeling of variety of meteoroid streams and following their dynamical evolution, we confirm the presence of two filaments crossing the Earth observed as Geminid and Daytime Sextantid meteor showers. We use numerical integrations of modeled particles performed for several past perihelion passages of the asteroid considering (i) only the gravity of planets and (2) gravity of planets and the Poynting-Robertson effect. We present the results of comparing our models (predicted showers) with observed showers. We also point out discrepancies, their possible solutions and/or new hypothesis concerning the examined meteor complex.

The turbulent formation of stars

NASA Astrophysics Data System (ADS)

Federrath, Christoph

2018-06-01

How stars are born from clouds of gas is a rich physics problem whose solution will inform our understanding of not just stars but also planets, galaxies, and the universe itself. Star formation is stupendously inefficient. Take the Milky Way. Our galaxy contains about a billion solar masses of fresh gas available to form stars-and yet it produces only one solar mass of new stars a year. Accounting for that inefficiency is one of the biggest challenges of modern astrophysics. Why should we care about star formation? Because the process powers the evolution of galaxies and sets the initial conditions for planet formation and thus, ultimately, for life.

Feasibility of infrared Earth tracking for deep-space optical communications.

PubMed

Chen, Yijiang; Hemmati, Hamid; Ortiz, Gerry G

2012-01-01

Infrared (IR) Earth thermal tracking is a viable option for optical communications to distant planet and outer-planetary missions. However, blurring due to finite receiver aperture size distorts IR Earth images in the presence of Earth's nonuniform thermal emission and limits its applicability. We demonstrate a deconvolution algorithm that can overcome this limitation and reduce the error from blurring to a negligible level. The algorithm is applied successfully to Earth thermal images taken by the Mars Odyssey spacecraft. With the solution to this critical issue, IR Earth tracking is established as a viable means for distant planet and outer-planetary optical communications. © 2012 Optical Society of America

Soil mineralogy and chemistry on Mars - Possible clues from salts and clays in SNC meteorites

NASA Technical Reports Server (NTRS)

Gooding, James L.

1992-01-01

If the shergottite, nakhlite, and chassignite (SNC) meteorites' parent planet is Mars, then the aqueous precipitates found in them imply that oxidizing, water-based solutions may have been chemically active on that planet over the past 200-1300 million yrs. It is suggested that the mixture of aqueous precipitates found in the SNCs furnish a self-consistent model for the bulk elemental composition of surface sediments at the Viking Lander sites. Further mineralogical and stable-isotope studies of the secondary minerals may establish the limits for biological activity over the last 1300 million years of Mars' water-based chemistry.

Surviving Armageddon - Solutions for a Threatened Planet

NASA Astrophysics Data System (ADS)

McGuire, Bill

2005-07-01

What do earthquakes, magma, asteroid 1950DA, and global warming have in common? All are very real natural disasters, already under way; all are also the focus of intensive work by scientists, aimed at preventing, predicting, or at least limiting their impact on civilization. Using the latest chilling data and taking care to draw a clear line between scientific fact and fiction, McGuire discusses the various ways that scientists have already started to prepare for survival. Solutions on earth range from 'space reflectors' to prevent global warming, to pressure-relieving 'robot excavators' to stop volcanic eruptions. In space, NASA is developing rocket motors to gently nudge asteroids out of Earth's path, and plans to have all threatening asteroids larger than 1km detected by 2008, thereby enabling us to predict possible collisions up to 2880. The book provides the strategies to the problems we face, and concludes optimistically with ways in which we can use technology to protect our society and planet from global catastrophe.

Silica metal-oxide vesicles catalyze comprehensive prebiotic chemistry.

PubMed

Bizzarri, Bruno Mattia; Botta, Lorenzo; Pérez-Valverde, Maritza Iveth; Saladino, Raffaele; Di Mauro, Ernesto; Garcia Ruiz, Juan Manuel

2018-03-30

It has recently been demonstrated that mineral self-assembled structures catalyzing prebiotic chemical reactions may form in natural waters derived from serpentinization, a geological process widespread in the early stages of Earth-like planets. We have synthesized self-assembled membranes by mixing microdrops of metal solutions with alkaline silicate solutions in the presence of formamide (NH2CHO), a single carbon molecule, at 80ºC. We found that these bilayer membranes, made of amorphous silica and metal oxide-hydroxide nanocrystals, catalyze the condensation of formamide, yielding the four nucleobases of RNA, three aminoacids and several carboxylic acids in a single pot experiment. Besides manganese, iron and magnesium, two abundant elements in the earliest Earth crust that are key in serpentinization reactions, are enough to produce all these biochemical compounds. These results suggest that the transition from inorganic geochemistry to prebiotic organic chemistry is common on a universal scale and, most probably, earlier than ever thought for our planet. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The HARPS-N Rocky Planet Search. I. HD 219134 b: A transiting rocky planet in a multi-planet system at 6.5 pc from the Sun

NASA Astrophysics Data System (ADS)

Motalebi, F.; Udry, S.; Gillon, M.; Lovis, C.; Ségransan, D.; Buchhave, L. A.; Demory, B. O.; Malavolta, L.; Dressing, C. D.; Sasselov, D.; Rice, K.; Charbonneau, D.; Collier Cameron, A.; Latham, D.; Molinari, E.; Pepe, F.; Affer, L.; Bonomo, A. S.; Cosentino, R.; Dumusque, X.; Figueira, P.; Fiorenzano, A. F. M.; Gettel, S.; Harutyunyan, A.; Haywood, R. D.; Johnson, J.; Lopez, E.; Lopez-Morales, M.; Mayor, M.; Micela, G.; Mortier, A.; Nascimbeni, V.; Philips, D.; Piotto, G.; Pollacco, D.; Queloz, D.; Sozzetti, A.; Vanderburg, A.; Watson, C. A.

2015-12-01

We know now from radial velocity surveys and transit space missions that planets only a few times more massive than our Earth are frequent around solar-type stars. Fundamental questions about their formation history, physical properties, internal structure, and atmosphere composition are, however, still to be solved. We present here the detection of a system of four low-mass planets around the bright (V = 5.5) and close-by (6.5 pc) star HD 219134. This is the first result of the Rocky Planet Search programme with HARPS-N on the Telescopio Nazionale Galileo in La Palma. The inner planet orbits the star in 3.0935 ± 0.0003 days, on a quasi-circular orbit with a semi-major axis of 0.0382 ± 0.0003 AU. Spitzer observations allowed us to detect the transit of the planet in front of the star making HD 219134 b the nearest known transiting planet to date. From the amplitude of the radial velocity variation (2.25 ± 0.22 ms-1) and observed depth of the transit (359 ± 38 ppm), the planet mass and radius are estimated to be 4.36 ± 0.44 M⊕ and 1.606 ± 0.086 R⊕, leading to a mean density of 5.76 ± 1.09 g cm-3, suggesting a rocky composition. One additional planet with minimum-mass of 2.78 ± 0.65 M⊕ moves on a close-in, quasi-circular orbit with a period of 6.767 ± 0.004 days. The third planet in the system has a period of 46.66 ± 0.08 days and a minimum-mass of 8.94 ± 1.13 M⊕, at 0.233 ± 0.002 AU from the star. Its eccentricity is 0.46 ± 0.11. The period of this planet is close to the rotational period of the star estimated from variations of activity indicators (42.3 ± 0.1 days). The planetary origin of the signal is, however, thepreferred solution as no indication of variation at the corresponding frequency is observed for activity-sensitive parameters. Finally, a fourth additional longer-period planet of mass of 71 M⊕ orbits the star in 1842 days, on an eccentric orbit (e = 0.34 ± 0.17) at a distance of 2.56 AU. The photometric time series and radial velocities used in this work are available in electronic form at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/584/A72

Singularity free N-body simulations called 'Dynamic Universe Model' don't require dark matter

NASA Astrophysics Data System (ADS)

Naga Parameswara Gupta, Satyavarapu

For finding trajectories of Pioneer satellite (Anomaly), New Horizons satellite going to Pluto, the Calculations of Dynamic Universe model can be successfully applied. No dark matter is assumed within solar system radius. The effect on the masses around SUN shows as though there is extra gravitation pull toward SUN. It solves the Dynamics of Extra-solar planets like Planet X, satellite like Pioneer and NH for 3-Position, 3-velocity 3-accelaration for their masses, considering the complex situation of Multiple planets, Stars, Galaxy parts and Galaxy centre and other Galaxies Using simple Newtonian Physics. It already solved problems Missing mass in Galaxies observed by galaxy circular velocity curves successfully. Singularity free Newtonian N-body simulations Historically, King Oscar II of Sweden an-nounced a prize to a solution of N-body problem with advice given by Güsta Mittag-Leffler in 1887. He announced `Given a system of arbitrarily many mass points that attract each according to Newton's law, under the assumption that no two points ever collide, try to find a representation of the coordinates of each point as a series in a variable that is some known function of time and for all of whose values the series converges uniformly.'[This is taken from Wikipedia]. The announced dead line that time was1st June 1888. And after that dead line, on 21st January 1889, Great mathematician Poincaré claimed that prize. Later he himself sent a telegram to journal Acta Mathematica to stop printing the special issue after finding the error in his solution. Yet for such a man of science reputation is important than money. [ Ref Book `Celestial mechanics: the waltz of the planets' By Alessandra Celletti, Ettore Perozzi, page 27]. He realized that he has been wrong in his general stability result! But till now nobody could solve that problem or claimed that prize. Later all solutions resulted in singularities and collisions of masses, given by many people . . . . . . . . . . . . . . . . . . . . . . . . .. Now I can say that the Dynamic Universe Model solves this classical N-body problem where only Newtonian Gravi-tation law and classical Physics were used. The solution converges at all points. There are no multiple values, diverging solutions or divided by zero singularities. Collisions of masses depend on physical values of masses and their space distribution only. These collisions do not happen due to internal inherent problems of Dynamic universe Model. If the mass distribution is homogeneous and isotropic, the masses will colloid. If the mass distribution is heterogeneous and anisotropic, they do not colloid. This approach solves many problems which otherwise can not be solved by General relativity, Steady state universe model etc. . .

Forming Giant Planet Cores by Pebble Accretion -- Why Slow and Steady wins the Race

NASA Astrophysics Data System (ADS)

Kretke, Katherine A.; Levison, Harold F.

2014-05-01

In recent years there has been a radical new solution proposed to solve the problem of giant planet core formation. "Pebbles", particles ranging from centimeters to meters in size, have been shown to accrete extremely efficiently due to aerodynamic drag. Large capture cross-sections combined with fast pebble drift rates can allow a single planetesimal to grow from Ceres size to 10s of Earth masses well within the lifetime of gaseous circumstellar disks. However, at large sizes, the the capture-cross section of pebbles goes with the Hill sphere, forcing pebble accretion to becomes a fundamentally "oligarchic-like" process. This makes it difficult to form a few giant planet cores; instead a more generic result is many 10s to 100s of competing oligarchs. In this work, we present a way to get around this oligarchic dilemma If pebbles are assumed to form slowly over a long period of time, then the planetesimal growth rates are slow enough for the planetesimals to dynamically excite each other. As the larger planetisimals/proto-planets stir their smaller companions, these smaller bodies are excited to such a degree that they spend only a small fraction of their orbits embedded in the cooler pebble disk. This allows the larger bodies to starve their neighbors and maintain a relative runaway growth rate to high mass, effectively forming the cores of giant planets.

Detection of Intermediate-Period Transiting Planets with a Network of Small Telescopes: transitsearch.org

NASA Astrophysics Data System (ADS)

Seagroves, Scott; Harker, Justin; Laughlin, Gregory; Lacy, Justin; Castellano, Tim

2003-12-01

We describe a project (transitsearch.org) currently attempting to discover transiting intermediate-period planets orbiting bright parent stars, and we simulate that project's performance. The discovery of such a transit would be an important astronomical advance, bridging the critical gap in understanding between HD 209458b and Jupiter. However, the task is made difficult by intrinsically low transit probabilities and small transit duty cycles. This project's efficient and economical strategy is to photometrically monitor stars that are known (from radial velocity surveys) to bear planets, using a network of widely spaced observers with small telescopes. These observers, each individually capable of precision (1%) differential photometry, monitor candidates during the time windows in which the radial velocity solution predicts a transit if the orbital inclination is close to 90°. We use Monte Carlo techniques to simulate the performance of this network, performing simulations with different configurations of observers in order to optimize coordination of an actual campaign. Our results indicate that transitsearch.org can reliably rule out or detect planetary transits within the current catalog of known planet-bearing stars. A distributed network of skilled amateur astronomers and small college observatories is a cost-effective method for discovering the small number of transiting planets with periods in the range 10 days

About Tidal Evolution of Quasi-Periodic Orbits of Satellites

NASA Astrophysics Data System (ADS)

Ershkov, Sergey V.

2017-06-01

Tidal interactions between Planet and its satellites are known to be the main phenomena, which are determining the orbital evolution of the satellites. The modern ansatz in the theory of tidal dissipation in Saturn was developed previously by the international team of scientists from various countries in the field of celestial mechanics. Our applying to the theory of tidal dissipation concerns the investigating of the system of ODE-equations (ordinary differential equations) that govern the orbital evolution of the satellites; such an extremely non-linear system of 2 ordinary differential equations describes the mutual internal dynamics for the eccentricity of the orbit along with involving the semi-major axis of the proper satellite into such a monstrous equations. In our derivation, we have presented the elegant analytical solutions to the system above; so, the motivation of our ansatz is to transform the previously presented system of equations to the convenient form, in which the minimum of numerical calculations are required to obtain the final solutions. Preferably, it should be the analytical solutions; we have presented the solution as a set of quasi- periodic cycles via re-inversing of the proper ultra- elliptical integral. It means a quasi-periodic character of the evolution of the eccentricity, of the semi-major axis for the satellite orbit as well as of the quasi-periodic character of the tidal dissipation in the Planet.

Environmental microbiology to the rescue of planet earth.

PubMed

de Lorenzo, Víctor

2018-03-24

Environmental Microbiology has undergone a dramatic transition from being a somewhat marginal branch of Life Sciences to becoming one of the most vibrant and visible areas of contemporary research. The homonymous journal has not only borne witness of the growing interest in environmental microbes that bloomed since the mid-1980s but it has helped also to give visibility to the field and nucleate an active and influential community of authors and readers. During the past 20 years the focus has shifted from individual isolates to communities and microbiomes, from single genomes to metagenomes and from small/medium-scale experimental systems to large/very large scenarios. New challenges that were somewhat marginal when the journal was founded have acquired an unanticipated relevance owing to their impact on the global Earth's homeostasis. They include the unacceptably high atmospheric levels of greenhouse gases, the worrying pollution of the oceans with very recalcitrant plastics and microplastics and the noxious effects of micropollutants on many ecosystems. Global problems ask for global solutions and the environmental microbiome - because of its dimension and its amazing activities - may end up being out best instrument to both counter the impact of industrial development and enable a new, sustainable partnership with Nature. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

The impact of (mega)-cities on the earth's gravity

NASA Astrophysics Data System (ADS)

Schnitzer, S.; Estrella, N.; Güntner, A.; Matiu, M.; Peterseim, N.; Menzel, A.

2013-12-01

The world population is constantly growing; today over 7 billion people populate the planet. This development has led to a strong urbanization and expanding cities. According to the United Nations, since 2007 more human beings have lived in urban areas than in rural areas, and by 2030 the urban share will be more than 60%. The challenges of fast growing cities lie in urban management, supply to inhabitants of resources (e.g. water, power, food), and strong environmental problems (e.g. pollution), i.e. their ecological footprint. In our study we address the question of another footprint, whether (mega)-cities have an impact on the earth's gravity field. Analyzing the possible triggers will help to understand the multiple footprints of big cities in various regions. We analyze several data sources. The main data sets are a) monthly solutions of the gravity satellite mission GRACE, detecting changes in the earth's gravity field over time, b) data of the hydrological model WGHM, estimating mass changes in terrestrial and ground water storage, c) urban population data of the United Nations, d) land cover information of the European Space Agency, e) different climate data sets and other auxiliary data. The results suggest a non-uniform pattern of gravity changes with variations in trends related to different clustering parameters.

40 CFR 471.34 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 156 69.2 (q) Annealing and solution heat treatment contact cooling water—Subpart C—PSES. There shall be no allowance for the discharge of wastewater pollutants. (r) Wet air pollution control scrubber...

Water Pollution. Environmental Education Curriculum. Revised.

ERIC Educational Resources Information Center

Topeka Public Schools, KS.

Water is one of the most polluted resources in our environment. Since everyone has the same basic need for pure water, it follows that all people should have a basic knowledge of the causes, results and solutions to the water pollution problem. This unit is designed for use with Level II and III educable mentally retarded students to present…

Toward Detection of Exoplanetary Rings via Transit Photometry: Methodology and a Possible Candidate

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

Aizawa, Masataka; Masuda, Kento; Suto, Yasushi

The detection of a planetary ring of exoplanets remains one of the most attractive, but challenging, goals in the field of exoplanetary science. We present a methodology that implements a systematic search for exoplanetary rings via transit photometry of long-period planets. This methodology relies on a precise integration scheme that we develop to compute a transit light curve of a ringed planet. We apply the methodology to 89 long-period planet candidates from the Kepler data so as to estimate, and/or set upper limits on, the parameters of possible rings. While the majority of our samples do not have sufficient signal-to-noise ratios (S/Ns) to place meaningfulmore » constraints on ring parameters, we find that six systems with higher S/Ns are inconsistent with the presence of a ring larger than 1.5 times the planetary radius, assuming a grazing orbit and a tilted ring. Furthermore, we identify five preliminary candidate systems whose light curves exhibit ring-like features. After removing four false positives due to the contamination from nearby stars, we identify KIC 10403228 as a reasonable candidate for a ringed planet. A systematic parameter fit of its light curve with a ringed planet model indicates two possible solutions corresponding to a Saturn-like planet with a tilted ring. There also remain two other possible scenarios accounting for the data; a circumstellar disk and a hierarchical triple. Due to large uncertain factors, we cannot choose one specific model among the three.« less

On the Variation of Zonal Gravity Coefficients of a Giant Planet Caused by Its Deep Zonal Flows

NASA Astrophysics Data System (ADS)

Kong, Dali; Zhang, Keke; Schubert, Gerald

2012-04-01

Rapidly rotating giant planets are usually marked by the existence of strong zonal flows at the cloud level. If the zonal flow is sufficiently deep and strong, it can produce hydrostatic-related gravitational anomalies through distortion of the planet's shape. This paper determines the zonal gravity coefficients, J 2n , n = 1, 2, 3, ..., via an analytical method taking into account rotation-induced shape changes by assuming that a planet has an effective uniform density and that the zonal flows arise from deep convection and extend along cylinders parallel to the rotation axis. Two different but related hydrostatic models are considered. When a giant planet is in rigid-body rotation, the exact solution of the problem using oblate spheroidal coordinates is derived, allowing us to compute the value of its zonal gravity coefficients \\bar{J}_{2n}, n=1,2,3, \\dots, without making any approximation. When the deep zonal flow is sufficiently strong, we develop a general perturbation theory for estimating the variation of the zonal gravity coefficients, \\Delta {J}_{2n}={J}_{2n}-\\bar{J}_{2n}, n=1,2,3, \\dots, caused by the effect of the deep zonal flows for an arbitrarily rapidly rotating planet. Applying the general theory to Jupiter, we find that the deep zonal flow could contribute up to 0.3% of the J 2 coefficient and 0.7% of J 4. It is also found that the shape-driven harmonics at the 10th zonal gravity coefficient become dominant, i.e., \\Delta {J}_{2n} \\,{\\ge}\\, \\bar{J}_{2n} for n >= 5.

OGLE-2016-BLG-1190Lb: The First Spitzer Bulge Planet Lies Near the Planet/Brown-dwarf Boundary

NASA Astrophysics Data System (ADS)

Ryu, Y.-H.; Yee, J. C.; Udalski, A.; Bond, I. A.; Shvartzvald, Y.; Zang, W.; Figuera Jaimes, R.; Jørgensen, U. G.; Zhu, W.; Huang, C. X.; Jung, Y. K.; Albrow, M. D.; Chung, S.-J.; Gould, A.; Han, C.; Hwang, K.-H.; Shin, I.-G.; Cha, S.-M.; Kim, D.-J.; Kim, H.-W.; Kim, S.-L.; Lee, C.-U.; Lee, D.-J.; Lee, Y.; Park, B.-G.; Pogge, R. W.; KMTNet Collaboration; Calchi Novati, S.; Carey, S.; Henderson, C. B.; Beichman, C.; Gaudi, B. S.; Spitzer team; Mróz, P.; Poleski, R.; Skowron, J.; Szymański, M. K.; Soszyński, I.; Kozłowski, S.; Pietrukowicz, P.; Ulaczyk, K.; Pawlak, M.; OGLE Collaboration; Abe, F.; Asakura, Y.; Barry, R.; Bennett, D. P.; Bhattacharya, A.; Donachie, M.; Evans, P.; Fukui, A.; Hirao, Y.; Itow, Y.; Kawasaki, K.; Koshimoto, N.; Li, M. C. A.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Miyazaki, S.; Muraki, Y.; Nagakane, M.; Ohnishi, K.; Ranc, C.; Rattenbury, N. J.; Saito, To.; Sharan, A.; Sullivan, D. J.; Sumi, T.; Suzuki, D.; Tristram, P. J.; Yamada, T.; Yamada, T.; Yonehara, A.; MOA Collaboration; Bryden, G.; Howell, S. B.; Jacklin, S.; UKIRT Microlensing Team; Penny, M. T.; Mao, S.; Fouqué, Pascal; Wang, T.; CFHT-K2C9 Microlensing Survey group; Street, R. A.; Tsapras, Y.; Hundertmark, M.; Bachelet, E.; Dominik, M.; Li, Z.; Cross, S.; Cassan, A.; Horne, K.; Schmidt, R.; Wambsganss, J.; Ment, S. K.; Maoz, D.; Snodgrass, C.; Steele, I. A.; RoboNet Team; Bozza, V.; Burgdorf, M. J.; Ciceri, S.; D’Ago, G.; Evans, D. F.; Hinse, T. C.; Kerins, E.; Kokotanekova, R.; Longa, P.; MacKenzie, J.; Popovas, A.; Rabus, M.; Rahvar, S.; Sajadian, S.; Skottfelt, J.; Southworth, J.; von Essen, C.; MiNDSTEp Team

2018-01-01

We report the discovery of OGLE-2016-BLG-1190Lb, which is likely to be the first Spitzer microlensing planet in the Galactic bulge/bar, an assignation that can be confirmed by two epochs of high-resolution imaging of the combined source–lens baseline object. The planet’s mass, M p = 13.4 ± 0.9 M J , places it right at the deuterium-burning limit, i.e., the conventional boundary between “planets” and “brown dwarfs.” Its existence raises the question of whether such objects are really “planets” (formed within the disks of their hosts) or “failed stars” (low-mass objects formed by gas fragmentation). This question may ultimately be addressed by comparing disk and bulge/bar planets, which is a goal of the Spitzer microlens program. The host is a G dwarf, M host = 0.89 ± 0.07 M ⊙, and the planet has a semimajor axis a ∼ 2.0 au. We use Kepler K2 Campaign 9 microlensing data to break the lens-mass degeneracy that generically impacts parallax solutions from Earth–Spitzer observations alone, which is the first successful application of this approach. The microlensing data, derived primarily from near-continuous, ultradense survey observations from OGLE, MOA, and three KMTNet telescopes, contain more orbital information than for any previous microlensing planet, but not quite enough to accurately specify the full orbit. However, these data do permit the first rigorous test of microlensing orbital-motion measurements, which are typically derived from data taken over <1% of an orbital period.

IMPACT OF η{sub Earth} ON THE CAPABILITIES OF AFFORDABLE SPACE MISSIONS TO DETECT BIOSIGNATURES ON EXTRASOLAR PLANETS

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

Léger, Alain; Defrère, Denis; Malbet, Fabien

2015-08-01

We present an analytic model to estimate the capabilities of space missions dedicated to the search for biosignatures in the atmosphere of rocky planets located in the habitable zone of nearby stars. Relations between performance and mission parameters, such as mirror diameter, distance to targets, and radius of planets, are obtained. Two types of instruments are considered: coronagraphs observing in the visible, and nulling interferometers in the thermal infrared. Missions considered are: single-pupil coronagraphs with a 2.4 m primary mirror, and formation-flying interferometers with 4 × 0.75 m collecting mirrors. The numbers of accessible planets are calculated as a functionmore » of η{sub Earth}. When Kepler gives its final estimation for η{sub Earth}, the model will permit a precise assessment of the potential of each instrument. Based on current estimations, η{sub Earth} = 10% around FGK stars and 50% around M stars, the coronagraph could study in spectroscopy only ∼1.5 relevant planets, and the interferometer ∼14.0. These numbers are obtained under the major hypothesis that the exozodiacal light around the target stars is low enough for each instrument. In both cases, a prior detection of planets is assumed and a target list established. For the long-term future, building both types of spectroscopic instruments, and using them on the same targets, will be the optimal solution because they provide complementary information. But as a first affordable space mission, the interferometer looks the more promising in terms of biosignature harvest.« less

OGLE-2017-BLG-0373Lb: A Jovian Mass-Ratio Planet Exposes A New Accidental Microlensing Degeneracy

NASA Astrophysics Data System (ADS)

Skowron, J.; Ryu, Y.-H.; Hwang, K.-H.; Udalski, A.; Mrǎłz, P.; Kozłowski, S.; Soszyński, I.; Pietrukowicz, P.; Szymański, P. K.; Poleski, R.; Ulaczyk, K.; Pawlak, M.; Rybicki, K.; Iwanek, P.; Albrow, M. D.; Chung, S.-J.; Gould, A.; Han, C.; Jung, Y. K.; Shin, I.-G.; Shvartzvald, Y.; Yee, J. C.; Zang, W.; Zhu, W.; Cha, S.-M.; Kim, D.-J.; Kim, H.-W.; Kim, S.-L.; Lee, C.-U.; Lee, D.-J.; Lee, Y.; Park, B.-G.; Pogge, R. W.

2018-03-01

We report the discovery of microlensing planet OGLE-2017-BLG-0373Lb. We show that while the planet-host system has an unambiguous microlens topology, there are two geometries within this topology that fit the data equally well, which leads to a factor 2.5 difference in planet-host mass ratio, i.e., q=1.5×10-3 vs. q=0.6×10-3. We show that this is an "accidental degeneracy" in the sense that it is due to a gap in the data. We dub it "the caustic-chirality degeneracy". We trace the mathematical origins of this degeneracy, which should enable similar degenerate solutions to be easily located in the future. A Bayesian estimate, based on a Galactic model, yields a host mass M=0.25+0.30-0.15 M⊙ at a distance DL=5.9+1.3-1.95 kpc. The lens-source relative proper motion is relatively fast, μ=9 mas/yr, which implies that the host mass and distance can be determined by high-resolution imaging after about 10 years. The same observations could in principle resolve the discrete degeneracy in q, but this will be more challenging.

Affordable spectroscopy for 1m-class telescopes: recent developments and applications

NASA Astrophysics Data System (ADS)

Csák, B.; Kovács, J.; Szabó, Gy. M.; Kiss, L. L.; Dózsa, Á.; Sódor, Á.; Jankovics, I.

2014-03-01

Doppler observations of exoplanet systems have been a very expensive technique, mainly due to the high costs of high-resolution stable spectrographs. Recent advances in instrumentation enable affordable Doppler planet detections with surprisingly small optical telescopes. We investigate the possibility of measuring Doppler reflex motion of planet hosting stars with small-aperture telescopes that have traditionally been neglected for this kind of studies. After thoroughly testing the recently developed and commercially available Shelyak eShel echelle spectrograph, we demonstrated that it is routinely possible to achieve velocity precision at the 100 m s-1 level, reaching down to ¬± 50 m s-1 for the best cases. We describe our off-the-shelf instrumentation, including a new 0.5m RC telescope at the Gothard Astrophysical Observatory of Loránd E&ötv&ös University equipped with an intermediate resolution fiber-fed echelle spectrograph. We present some follow-up radial velocity measurements of planet hosting stars and point out that updating the orbital solution of Doppler-planets is a very important task that can be fulfilled with sub-meter sized optical telescopes without requesting very expensive telescope times on 2—4 m (or larger) class telescopes.

CHARACTERIZATION OF THE K2-19 MULTIPLE-TRANSITING PLANETARY SYSTEM VIA HIGH-DISPERSION SPECTROSCOPY, AO IMAGING, AND TRANSIT TIMING VARIATIONS

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

Narita, Norio; Hori, Yasunori; Kusakabe, Nobuhiko

2015-12-10

K2-19 (EPIC201505350) is an interesting planetary system in which two transiting planets with radii ∼7 R{sub ⊕} (inner planet b) and ∼4 R{sub ⊕} (outer planet c) have orbits that are nearly in a 3:2 mean-motion resonance. Here, we present results of ground-based follow-up observations for the K2-19 planetary system. We have performed high-dispersion spectroscopy and high-contrast adaptive-optics imaging of the host star with the HDS and HiCIAO on the Subaru 8.2 m telescope. We find that the host star is a relatively old (≥8 Gyr) late G-type star (T{sub eff} ∼ 5350 K, M{sub s} ∼ 0.9 M{sub ⊙}, and R{sub s} ∼ 0.9 R{submore » ⊙}). We do not find any contaminating faint objects near the host star that could be responsible for (or dilute) the transit signals. We have also conducted transit follow-up photometry for the inner planet with KeplerCam on the FLWO 1.2 m telescope, TRAPPISTCAM on the TRAPPIST 0.6 m telescope, and MuSCAT on the OAO 1.88 m telescope. We confirm the presence of transit timing variations (TTVs), as previously reported by Armstrong and coworkers. We model the observed TTVs of the inner planet using the synodic chopping formulae given by Deck and Agol. We find two statistically indistinguishable solutions for which the period ratios (P{sub c}/P{sub b}) are located slightly above and below the exact 3:2 commensurability. Despite the degeneracy, we derive the orbital period of the inner planet P{sub b} ∼ 7.921 days and the mass of the outer planet M{sub c} ∼ 20 M{sub ⊕}. Additional transit photometry (especially for the outer planet) as well as precise radial-velocity measurements would be helpful to break the degeneracy and to determine the mass of the inner planet.« less

[Chemical pollution and breast milk: Taking positions].

PubMed

Díaz-Gómez, N M; Ares, S; Hernández-Aguilar, M T; Ortega-García, J A; Paricio-Talayero, J M; Landa-Rivera, L

2013-12-01

Chemical pollution affects all ecosystems of our planet. Human milk has been used as a biomarker of environmental pollution as, due to bioaccumulation processes in fat tissue, many chemical compounds reach measurable concentrations that can be readily tested in breast milk. Quite frequently information about the presence of contaminants in breast milk appears in the media, leading to misunderstanding among parents and health professionals, and in some cases breastfeeding the child is stopped. In this article, the Breastfeeding Committee of the Spanish Association of Paediatrics stresses the importance of promoting breastfeeding as the healthiest option, because its benefits clearly outweigh any health risks associated with chemical contaminants in breast milk. Breast milk contains protective factors that counteract the potential effects related to prenatal exposure to environmental pollutants. This article summarises the key recommendations to reduce the level of chemical contaminants in breast milk. It also highlights the importance of government involvement in the development of programs to eliminate or reduce chemical contamination of food and the environment. In this way, the negative effects on child health resulting from exposure to these toxic compounds through the placenta and breast milk may be prevented. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Air pollution effects on the leaf structure of two injury resistant species: Eucalyptus camaldulensis and Olea europaea L

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

Christodoulakis, N.S.; Koutsogeorgopoulou, L.

1991-09-01

The release of toxic gases as well as of particulate pollutants into the atmosphere is a major side effect of the human industrial, agricultural and domestic activities. The impact of these compounds on the various life forms of our planet seems to be very serious. Investigations of plant species resistant to pollution-induced injuries do have a meaning. The introduction of these species will improve air quality and establish a moderate rate of primary productivity in the handicapped regions. That is why data concerning an evergreen sclerophyllous species which does not present structural modifications and organelle destruction although forced to bemore » a dweller of a partition isle in a heavily polluted, traffic-loaded main street of the smog-suffering city of Athens, Greece, seemed very interesting. In this paper, further investigation is presented. Two common, species were studied. The first, Eucalyptus camaldulensis, a huge tree once imported to Europe from Australia as a marsh-drier in an effort to control malaria, is a drought enduring species mostly known for the essential oils accumulated in its leaves. The second, Olea europaea L. var oleaster Brot, is a sclerophyllous tree growing wild in chaparall formations in Greece.« less

Planet Ocean

NASA Astrophysics Data System (ADS)

Afonso, Isabel

2014-05-01

A more adequate name for Planet Earth could be Planet Ocean, seeing that ocean water covers more than seventy percent of the planet's surface and plays a fundamental role in the survival of almost all living species. Actually, oceans are aqueous solutions of extraordinary importance due to its direct implications in the current living conditions of our planet and its potential role on the continuity of life as well, as long as we know how to respect the limits of its immense but finite capacities. We may therefore state that natural aqueous solutions are excellent contexts for the approach and further understanding of many important chemical concepts, whether they be of chemical equilibrium, acid-base reactions, solubility and oxidation-reduction reactions. The topic of the 2014 edition of GIFT ('Our Changing Planet') will explore some of the recent complex changes of our environment, subjects that have been lately included in Chemistry teaching programs. This is particularly relevant on high school programs, with themes such as 'Earth Atmosphere: radiation, matter and structure', 'From Atmosphere to the Ocean: solutions on Earth and to Earth', 'Spring Waters and Public Water Supply: Water acidity and alkalinity'. These are the subjects that I want to develop on my school project with my pupils. Geographically, our school is located near the sea in a region where a stream flows into the sea. Besides that, our school water comes from a borehole which shows that the quality of the water we use is of significant importance. This project will establish and implement several procedures that, supported by physical and chemical analysis, will monitor the quality of water - not only the water used in our school, but also the surrounding waters (stream and beach water). The samples will be collected in the borehole of the school, in the stream near the school and in the beach of Carcavelos. Several physical-chemical characteristics related to the quality of the water will be taken into consideration, for instance, the value of the pH, using universal indicator paper, color, through visual evaluation and the temperature with the help of a thermometer. There will be also registered some existent chemical parameters as chloride, alkalinity, total hardness (Ca2+ and Mg2+), nitrate, nitrite, ammonia and phosphate. Two methods will be used for analysis, the titration and the kit of semi-quantitative chemical analyses. This kit is composed by biocompatible substances, which means they are not harmful for the environment and can be disposed of by domestic sewage systems. The results will be subsequently analyzed bearing in mind the maximum and recommended standards values for each one of the parameters. After this, the results achieved will be discussed. I believe this project contains characteristics that will be of interest to our students, thus enabling them to participate actively and effectively develop their knowledge and enhance their scientific curiosity.

Atmospheric pollution in a coal mine region of Romania and solutions to assure sustainable development

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

Irimie, I.I.; Tulbure, I.

1996-12-31

The present paper presents the following subjects regarding the atmospheric pollution in the Jiu-Valley coal mining region of Romania: identifying polluting sources, pointing out the pollution favoring conditions, the pollution impacts, and measures for short, middle, and long time, which could be taken in order to obtain a sustainable future development of this region. The importance of the problems presented in this paper is emphasized by the fact, that beside coking and fuel coal reserves, this region has a high touristic potential the year round.

Simultaneous pollutant removal and electricity generation in denitrifying microbial fuel cell with boric acid-borate buffer solution.

PubMed

Chen, Gang; Zhang, Shaohui; Li, Meng; Wei, Yan

2015-01-01

A double-chamber denitrifying microbial fuel cell (MFC), using boric acid-borate buffer solution as an alternative to phosphate buffer solution, was set up to investigate the influence of buffer solution concentration, temperature and external resistance on electricity generation and pollutant removal efficiency. The result revealed that the denitrifying MFC with boric acid-borate buffer solution was successfully started up in 51 days, with a stable cell voltage of 205.1 ± 1.96 mV at an external resistance of 50 Ω. Higher concentration of buffer solution favored nitrogen removal and electricity generation. The maximum power density of 8.27 W/m(3) net cathodic chamber was obtained at a buffer solution concentration of 100 mmol/L. An increase in temperature benefitted electricity generation and nitrogen removal. A suitable temperature for this denitrifying MFC was suggested to be 25 °C. Decreasing the external resistance favored nitrogen removal and organic matter consumption by exoelectrogens.

Distributed Water Pollution Source Localization with Mobile UV-Visible Spectrometer Probes in Wireless Sensor Networks.

PubMed

Ma, Junjie; Meng, Fansheng; Zhou, Yuexi; Wang, Yeyao; Shi, Ping

2018-02-16

Pollution accidents that occur in surface waters, especially in drinking water source areas, greatly threaten the urban water supply system. During water pollution source localization, there are complicated pollutant spreading conditions and pollutant concentrations vary in a wide range. This paper provides a scalable total solution, investigating a distributed localization method in wireless sensor networks equipped with mobile ultraviolet-visible (UV-visible) spectrometer probes. A wireless sensor network is defined for water quality monitoring, where unmanned surface vehicles and buoys serve as mobile and stationary nodes, respectively. Both types of nodes carry UV-visible spectrometer probes to acquire in-situ multiple water quality parameter measurements, in which a self-adaptive optical path mechanism is designed to flexibly adjust the measurement range. A novel distributed algorithm, called Dual-PSO, is proposed to search for the water pollution source, where one particle swarm optimization (PSO) procedure computes the water quality multi-parameter measurements on each node, utilizing UV-visible absorption spectra, and another one finds the global solution of the pollution source position, regarding mobile nodes as particles. Besides, this algorithm uses entropy to dynamically recognize the most sensitive parameter during searching. Experimental results demonstrate that online multi-parameter monitoring of a drinking water source area with a wide dynamic range is achieved by this wireless sensor network and water pollution sources are localized efficiently with low-cost mobile node paths.

Distributed Water Pollution Source Localization with Mobile UV-Visible Spectrometer Probes in Wireless Sensor Networks

PubMed Central

Zhou, Yuexi; Wang, Yeyao; Shi, Ping

2018-01-01

Pollution accidents that occur in surface waters, especially in drinking water source areas, greatly threaten the urban water supply system. During water pollution source localization, there are complicated pollutant spreading conditions and pollutant concentrations vary in a wide range. This paper provides a scalable total solution, investigating a distributed localization method in wireless sensor networks equipped with mobile ultraviolet-visible (UV-visible) spectrometer probes. A wireless sensor network is defined for water quality monitoring, where unmanned surface vehicles and buoys serve as mobile and stationary nodes, respectively. Both types of nodes carry UV-visible spectrometer probes to acquire in-situ multiple water quality parameter measurements, in which a self-adaptive optical path mechanism is designed to flexibly adjust the measurement range. A novel distributed algorithm, called Dual-PSO, is proposed to search for the water pollution source, where one particle swarm optimization (PSO) procedure computes the water quality multi-parameter measurements on each node, utilizing UV-visible absorption spectra, and another one finds the global solution of the pollution source position, regarding mobile nodes as particles. Besides, this algorithm uses entropy to dynamically recognize the most sensitive parameter during searching. Experimental results demonstrate that online multi-parameter monitoring of a drinking water source area with a wide dynamic range is achieved by this wireless sensor network and water pollution sources are localized efficiently with low-cost mobile node paths. PMID:29462929

Exploring Fifth-Grade Turkish Children's Solutions and Future Plans for Environmental Pollution through Their Drawings

ERIC Educational Resources Information Center

Saglam, Murat

2016-01-01

The pollution of land, water, air, noise, light etc. threatens people, plants, animals and ecosystems. Environmental literacy is at the heart of environmental education, and environmentally literate people are expected to be aware of how to help solve environmental problems such as pollution. The purpose of the present study is to explore 5th…

Farmers, Trust, and the Market Solution to Water Pollution: The Role of Social Embeddedness in Water Quality Trading

ERIC Educational Resources Information Center

Mariola, Matt J.

2012-01-01

Water quality trading (WQT) is a market arrangement in which a point-source water polluter pays farmers to implement conservation practices and claims the resulting benefits as credits toward meeting a pollution permit. Success rates of WQT programs nationwide are highly variable. Most of the literature on WQT is from an economic perspective…

The role of hydrothermally prepared supported photocatalytic composite in organic micro-pollutants removal from the water.

PubMed

Shivaraju, H P; Byrappa, K

2012-07-01

This work deals with the non-biodegradable micro-pollutants degradation by supported photocatalyst based heterogeneous photocatalytic reaction. TiO2 based supported photocatalyst was prepared by the hydrothermal technique to improve the photocatalytic performance along with easy recovery of suspended photocatalyst from aqueous medium after photoreaction. TO2 deposited calcium alumino-silicate beads (CASB) supports were prepared under mild hydrothermal conditions (Temparature-200 degrees C, Duration-24 h). In the present study, industrial dyes such as Amaranth and Brilliant Yellow were used as model micro-pollutants in aqueous solution. A real time pesticide industrial effluent was tested for its photocatalytic removal of organic pollutants using TO2 deposited CASB supported photocatalytic composite as an effective photocatalyst. Photocatalytic degradation of micro-pollutants present in aqueous medium was carried out in a batch photoreactor, at atmospheric pressure and temperature (28 degrees C). The influence of different light sources, irradiation time, catalyst load and catalytic performance is discussed. The photocatalytic degradation of micro-pollutants in aqueous medium was evaluated by determination of COD and %T. Easy separation and recovery of suspended photocatalysts from aqueous solution is the major advantage of hydrothermally prepared supported photocatalytic composite.

Photolysis of aromatic pollutants in clean and dirty ice

NASA Astrophysics Data System (ADS)

Kahan, T.; Malley, P.; Stathis, A.

2015-12-01

Anthropogenic aromatic pollutants such as polycyclic aromatic hydrocarbons (PAHs) and substituted benzenes often become more toxic following atmospheric oxidation. Photolysis of these pollutants in ice can be much faster than that in aqueous solution, which might lead to higher carcinogenic loadings in snow-covered regions. In this work we investigate two things. First, we investigate whether toluene, which has been detected at very elevated concentrations near hydraulic fracturing operations, can undergo photolysis at ice surfaces. Toluene in aqueous solution does not absorb sunlight, so photolysis has not been considered a potential atmospheric fate. However, benzene was recently demonstrated to undergo a significant red shift in its absorbance at ice surfaces, leading to photolysis under environmentally-relevant conditions. Here we show that toluene also undergoes photolysis at ice surfaces. In a second set of experiments, we have investigated the effects of organic matter on the photolysis kinetics ofPAHs in ice and at ice surfaces. We found that very small loadings of hydrophobic organics such as octanol can significantly suppress PAH photolysis kinetics in ice, but that the primary effect of the more soluble fulvic acid is competitive photon absorption. Our results show that photochemistry of anthropogenic pollutants can follow very different mechanisms and kinetics in ice than in aqueous solution, and that the photochemical fate of these pollutants depends strongly on the composition of the snow. These results have implications for pollutant fate and human health in a wide range of snow-covered environments including remote areas, cities, and regions near gas and oil extraction operations.

Environmental microbiology

NASA Astrophysics Data System (ADS)

Briški, Felicita; Vuković Domanovac, Marija

2017-10-01

For most people, microorganisms are out of sight and therefore out of mind but they are large, extremely diverse group of organisms, they are everywhere and are the dominant form of life on planet Earth. Almost every surface is colonized by microorganisms, including our skin; however most of them are harmless to humans. Some microorganisms can live in boiling hot springs, whereas others form microbial communities in frozen sea ice. Among their many roles, microorganisms are necessary for biogeochemical cycling, soil fertility, decomposition of dead plants and animals and biodegradation of many complex organic compounds present in the environment. Environmental microbiology is concerned with the study of microorganisms in the soil, water and air and their application in bioremediation to reduce environmental pollution through the biological degradation of pollutants into non-toxic or less toxic substances. Field of environmental microbiology also covers the topics such as microbially induced biocorrosion, biodeterioration of constructing materials and microbiological quality of outdoor and indoor air.

Treatability Aspects of Urban Stormwater Stressors

EPA Science Inventory

Eleven years into the 21st century, pollution from diffuse sources (pollution from contaminants picked up and carried into surface waters by stormwater runoff) remains the nation's largest source of water quality problems. Scientists and engineers still seek solutions that will ...

One Hundred Thousand Eyes: Analysis of Kepler Archival Data

NASA Astrophysics Data System (ADS)

Fischer, Debra

We are using a powerful resource, more than 100,000 eyes of users on the successful Planet Hunters Web project, who will identify the best follow-up science targets for this ADAP proposal among the Kepler public archive light curves. Planet Hunters is a Citizen Science program with a user base of more than 50,000 individuals who have already contributed the 24/7 cumulative equivalent of 200 human years assessing Kepler data. They independently identified most of the Kepler candidates with radii greater than 3-4 REARTH and they detected ten transiting planet candidates that were missed by the Kepler pipeline algorithms, including two circumbinary transiting planet candidates. These detections have provided important feedback for the Kepler algorithms about possible leaks where candidates might be lost. Our scientific follow up program will use Planet Hunter classifications of archival data from the Kepler Mission to: "Detect and model new transiting planets: for radii greater than 3 4 REARTH and orbital periods longer than one year, the Planet Hunters should be quite competitive with automated pipelines that require at least 3 transits for a detection and fill in the parameter space for Neptune-size planets over a wide range of orbital periods. For stars where a single transit can be modeled as a long period planet, we will establish a watch list for future transits. We will carry out checks for false positives (pixel centroiding analysis, AO observations, Doppler measurements where appropriate). "Analyze the completeness statistics for Kepler transits and independently determine a corrected planet occurrence rate as a function of planet radius and orbital period. This will be done by injecting synthetic transits into real Kepler light curves and calculating the efficiency with which the transits are detected by Planet Hunters. "Model the full spectroscopic and photometric orbital solutions for a set of ~60 detached eclipsing binary systems with low mass K and M dwarf components- quadrupling the number of fully characterized eclipsing systems with low-mass stars. We will revise the spectral synthesis modeling code, SME, to handle double line spectroscopic binaries (including velocity offets and relative intensity as free parameters). Our data, coupled with the sparse data currently available on late-type stellar radii, will allow us to explore the long-standing discrepancy between theory and observation in the sense that directly determined radii exceed theory predictions by ~10%. As such, host star radii are often the limiting factor in extracting the planetary radii from Kepler transiting systems since model approaches appear currently flawed. Thus, an empirical calibration to radius relationships for low-mass stars will be fundamentally enabling for the Kepler mission. "Carry out a search for transiting circumbinary planets; Planet Hunters has already detected two of four known eclipsing binary systems with transiting planets. "Develop a guest scientist program so that the larger community can tap into Planet Hunters with special programs. "Further develop our in-house software analysis tools for modeling light curves, analyzing pixel centroid offsets and measuring Doppler shifts in eclipsing binaries; we will make these programs available in the public domain (Astrophysics Source Code Library).

Removal of triazine-based pollutants from water by carbon nanotubes: Impact of dissolved organic matter (DOM) and solution chemistry.

PubMed

Engel, Maya; Chefetz, Benny

2016-12-01

Adsorption of organic pollutants by carbon nanotubes (CNTs) in the environment or removal of pollutants during water purification require deep understanding of the impacts of the presence of dissolved organic matter (DOM). DOM is an integral part of environmental systems and plays a key role affecting the behavior of organic pollutants. In this study, the effects of solution chemistry (pH and ionic strength) and the presence of DOM on the removal of atrazine and lamotrigine by single-walled CNTs (SWCNTs) was investigated. The solubility of atrazine slightly decreased (∼5%) in the presence of DOM, whereas that of lamotrigine was significantly enhanced (by up to ∼70%). Simultaneous introduction of DOM and pollutant resulted in suppression of removal of both atrazine and lamotrigine, which was attributed to DOM-pollutant competition or blockage of adsorption sites by DOM. However the decrease in removal of lamotrigine was also a result of its complexation with DOM. Pre-introduction of DOM significantly reduced pollutant adsorption by the SWCNTs, whereas introduction of DOM after the pollutant resulted in the release of adsorbed atrazine and lamotrigine from the SWCNTs. These data imply that DOM exhibits higher affinity for the adsorption sites than the triazine-based pollutants. In the absence of DOM atrazine was a more effective competitor than lamotrigine for adsorption sites in SWCNTs. However, competition between pollutants in the presence of DOM revealed lamotrigine as the better competitor. Our findings help unravel the complex DOM-organic pollutant-CNT system and will aid in CNT-implementation in water-purification technologies. Copyright © 2016 Elsevier Ltd. All rights reserved.

A 23.2:1 ratio, 300-watt, 26 N-m output torque, planetary roller-gear robotic transmission: Design and evaluation

NASA Technical Reports Server (NTRS)

Newman, Wyatt S.; Anderson, William J.; Shipitalo, William; Rohn, Douglas

1992-01-01

The design philosophy and measurements performed on a new roller-gear transmission prototype for a robotic manipulator are described. The design incorporates smooth rollers in a planetary configuration integrated with conventional toothed gears. The rollers were designed to handle low torque with low backlash and friction while the complementary gears support higher torques and prevent accumulated creep or slip of the rollers. The introduction of gears with finite numbers of teeth to function in parallel with the rollers imposes severe limits on available designs. Solutions for two-planet row designs are discussed. A two-planet row, four-planet design was conceived, fabricated, and tested. Detailed calculations of cluster geometry, gear stresses, and gear geometry are given. Measurement data reported here include transmission linearity, static and dynamic friction, inertia, backlash, stiffness, and forward and reverse efficiency. Initial test results are reported describing performance of the transmission in a servomechanism with torque feedback.

A linked simulation-optimization model for solving the unknown groundwater pollution source identification problems.

PubMed

Ayvaz, M Tamer

2010-09-20

This study proposes a linked simulation-optimization model for solving the unknown groundwater pollution source identification problems. In the proposed model, MODFLOW and MT3DMS packages are used to simulate the flow and transport processes in the groundwater system. These models are then integrated with an optimization model which is based on the heuristic harmony search (HS) algorithm. In the proposed simulation-optimization model, the locations and release histories of the pollution sources are treated as the explicit decision variables and determined through the optimization model. Also, an implicit solution procedure is proposed to determine the optimum number of pollution sources which is an advantage of this model. The performance of the proposed model is evaluated on two hypothetical examples for simple and complex aquifer geometries, measurement error conditions, and different HS solution parameter sets. Identified results indicated that the proposed simulation-optimization model is an effective way and may be used to solve the inverse pollution source identification problems. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Radiation pressure dynamics in planetary exospheres - A 'natural' framework

NASA Technical Reports Server (NTRS)

Bishop, James; Chamberlain, Joseph W.

1989-01-01

Exospheric theory is reformulated to provide for the analysis of dynamical underpinning of exospheric features. The formulation is based on the parabolic-cylindrical separability of the Hamiltonian that describes particle motions in the combined fields of planetary gravity and solar radiation pressure. An approximate solution for trajectory evolution in terms of orbital elements is derived and the role of the exopause in the tail phenomenon is discussed. Also, an expression is obtained for the bound constituent atom densities at outer planetocoronal positions along the planet-sun axis for the case of an evaporative, uniform exobase. This expression is used to estimate midnight density enhancements as a function of radial distance for the terrestrial planets.

Simulations of coronagraphy with a dynamic hologram for the direct detection of exo-planets

NASA Astrophysics Data System (ADS)

Ricci, Davide; Le Coroller, Hervé; Labeyrie, Antoine; Piron, Pierre

2010-07-01

In a previous paper,1 we discussed an original solution to improve the performances of coronagraphs by adding, in the optical scheme, an adaptive hologram removing most of the residual speckle starlight. In our simulations, the detection limit in the flux ratio between a host star and a very near planet (5λ/D) improves over a factor 1000 (resp. 10000) when equipped with a hologram for cases of wavefront bumpiness imperfections of λ/20 (resp. λ/100). We derive, in this paper, the transmission accuracy required on the hologram pixels to achieve such goals. We show that preliminary tests could be performed on the basis of existing technologies.

A primer on motor vehicle air pollution.

DOT National Transportation Integrated Search

1973-01-01

This primer presents a brief state-of-the art review of motor vehicle air pollution. Its purpose is to aid highway personnel in understanding the nature of this environmental problem on our highways and to present possible solutions for its abatement...

Treatability Aspects of Urban Stormwater Stressors - journal

EPA Science Inventory

Eleven years into the 21st century, pollution from diffuse sources (pollution from contaminants picked up and carried into surface waters by stormwater runoff) remains the nation's largest source of water quality problems. Scientists and engineers still seek solutions that will a...

Treatability Aspects of Urban Stormwater Stressors - paper

EPA Science Inventory

Eleven years into the 21st century, pollution from diffuse sources (pollution from contaminants picked up and carried into surface waters by stormwater runoff) remains the nation's largest source of water quality problems. Scientists and engineers still seek solutions that will a...

THREE-DIMENSIONAL GAS DYNAMIC SIMULATION OF THE INTERACTION BETWEEN THE EXOPLANET WASP-12b AND ITS HOST STAR

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

Bisikalo, D.; Kaygorodov, P.; Ionov, D.

2013-02-10

Hubble Space Telescope transit observations in the near-UV performed in 2009 made WASP-12b one of the most 'mysterious' exoplanets; the system presents an early ingress, which can be explained by the presence of optically thick matter located ahead of the planet at a distance of {approx}4-5 planet radii. This work follows previous attempts to explain this asymmetry with an exospheric outflow or a bow shock, induced by a planetary magnetic field, and provides a numerical solution of the early ingress, though we did not perform any radiative transfer calculation. We performed pure 3D gas dynamic simulations of the plasma interactionmore » between WASP-12b and its host star and describe the flow pattern in the system. In particular, we show that the overfilling of the planet's Roche lobe leads to a noticeable outflow from the upper atmosphere in the direction of the L{sub 1} and L{sub 2} points. Due to the conservation of the angular momentum, the flow to the L{sub 1} point is deflected in the direction of the planet's orbital motion, while the flow toward L{sub 2} is deflected in the opposite direction, resulting in a non-axisymmetric envelope, surrounding the planet. The supersonic motion of the planet inside the stellar wind leads to the formation of a bow shock with a complex shape. The existence of the bow shock slows down the outflow through the L{sub 1} and L{sub 2} points, allowing us to consider a long-living flow structure that is in the steady state.« less

The contamination impact of human exploration to a subterranean environment and the implications for further crewed space exploration

NASA Astrophysics Data System (ADS)

Leuko, Stefan; Rettberg, Petra; De Waele, Jo; Sanna, Laura; Koskinen, Kaisa

2016-07-01

The quest of exploring and looking for life in new places is a human desire since centuries. Nowadays, we are not only looking on planet Earth any more, but our endeavours focus on nearby planets in our solar system. It is therefore of great importance to preserve the extra-terrestrial environment and not to contaminate it with terrestrial / human associated bacteria. At this point in time we are not able to send crewed missions to other planets; however, analysing the impact of human exploration on environments is of great planetary protection concern. This can be achieved by obtaining samples from a subterranean environment, where only expert speleologists have access and the human impact is considered very low. For this study, astronauts participating in the 2014 ESA CAVES (Cooperative Adventure for Valuing and Exercising human behaviour and performance Skills) training course, obtained samples from deep within a subterranean environment and returned them to the laboratory for molecular microbial analysis. The diversity of the returned soil samples was analysed by molecular means such as clone library and next-generation sequencing (NGS). It was found that humans have an immense impact on the microbial diversity in the environment. Although the cave system is sparsely entered by humans, a high relative abundance of Staphylococcus spp. and Propionibacteria spp., organisms that are characteristic for human skin, have been recovered. Some samples even showed the presence of human gut associated methanogenic archaea, Methanomassiliicoccus spp. The obtained data from this investigation indicate that human exploration is strongly polluting an environment and may lead to false-positive sign of life on other planets. It is therefore imperative to increase our awareness to this problem as well as work towards new protocols to protect a pristine extraterrestrial environment during exploration.

The contribution of the ARIEL space mission to the study of planetary formation

NASA Astrophysics Data System (ADS)

Turrini, D.; Miguel, Y.; Zingales, T.; Piccialli, A.; Helled, R.; Vazan, A.; Oliva, F.; Sindoni, G.; Panić, O.; Leconte, J.; Min, M.; Pirani, S.; Selsis, F.; Coudé du Foresto, V.; Mura, A.; Wolkenberg, P.

2018-01-01

The study of extrasolar planets and of the Solar System provides complementary pieces of the mosaic represented by the process of planetary formation. Exoplanets are essential to fully grasp the huge diversity of outcomes that planetary formation and the subsequent evolution of the planetary systems can produce. The orbital and basic physical data we currently possess for the bulk of the exoplanetary population, however, do not provide enough information to break the intrinsic degeneracy of their histories, as different evolutionary tracks can result in the same final configurations. The lessons learned from the Solar System indicate us that the solution to this problem lies in the information contained in the composition of planets. The goal of the Atmospheric Remote-Sensing Infrared Exoplanet Large-survey (ARIEL), one of the three candidates as ESA M4 space mission, is to observe a large and diversified population of transiting planets around a range of host star types to collect information on their atmospheric composition. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres, which should show minimal condensation and sequestration of high-Z materials and thus reveal their bulk composition across all main cosmochemical elements. In this work we will review the most outstanding open questions concerning the way planets form and the mechanisms that contribute to create habitable environments that the compositional information gathered by ARIEL will allow to tackle.

Pollution attenuation by soils receiving cattle slurry after passage of a slurry-like feed solution. Column experiments.

PubMed

Núñez-Delgado, Avelino; López-Períago, Eugenio; Diaz-Fierros-Viqueira, Francisco

2002-09-01

Designing soil filtration systems or vegetated filter strips as a means of attenuating water pollution should take into account soil purging capacity. Here we report data on laboratory column trials used to investigate the capacity of a Hortic Anthrosol to attenuate contamination due to downward leaching from cattle slurry applied at the surface. The columns comprised 900 g of soil to a depth of about 20-25 cm, and had been used previously in an experiment involving passage of at least 5 pore volumes of an ion-containing cattle slurry-like feed solution. For the present experiments, the columns were first washed through with distilled water (simulating resting and rain falling after passage of the feed solution), and then received a single slurry dose equivalent to about 300 m3 ha(-1). The columns were then leached with distilled water, with monitoring of chemical oxygen demand (COD) and ion contents in outflow. The results indicated that the pollution-neutralising capacity of the soil was still high but clearly lower than in the earlier experiments with the feed solution. Furthermore, the time-course of COD showed that organic acids were leached through the column even more rapidly than chloride (often viewed as an inert tracer) enhancing the risk of heavy metals leaching and subsequent water pollution. Resting and alternate use of different soil-plant buffer zones would increase the lifespan of purging systems that use soil like the here studied one.

Searching for Extrasolar Trojan Planets: A Status Report

NASA Astrophysics Data System (ADS)

Caton, D. B.; Davis, S. A.; Kluttz, K. A.; Stamilio, R. J.; Wohlman, K. D.

2001-05-01

We are exploring the light curves of eclipsing binaries for the photometric signature of planets that may exist at the L4 and L5 Lagrange points of the stellar system. While no binaries are known to exist that strictly satisfy the stellar mass ratio constraint for the restricted three-body problem, the general solution would allow a planet formed at the L-point to remain there if there are no major perturbing bodies such as an additional planet. We have coined such objects "Trojan planets." The advantage of this approach is that the phases of the planetary eclipses are known. We picked systems with deep primary eclipses, to maximize the amount of system light eclipsed by the planet when in front of the hotter star. We also scanned the Finding List for Observers of Interactive Binary Stars, for G dwarf systems, but found only a few that were high inclination and detached. The target list includes QY Aql, YZ Aql, V442 Cas, SS Cet, S Cnc, VW Cyg, WW Cyg, RR Dra, RX Gem, RY Gem, VW Hya, Y Leo, TV Mon, BN Sct, UW Vir, AC UMa, and GSC 1657. We have concentrated on V442 Cas and YZ Aql, based on initial results that show anomalies in the light curves near the phases where a Trojan planet eclipse is expected. New work is being done on brighter systems by using a "spot filter," similar to that developed by Castellano (PASP 112, 821-6),2000), to allow longer exposures that provide brighter comparison stars. We will report on the observations made to date on several systems. We gratefully acknowledge the support of the National Science Foundation, through grants AST-9731062 and AST-0089248. We also appreciate the support of the Fund for Astrophysical Research. Gregory Shelton and Brenda Corbin, at the U.S. naval Observatory Library, have been indispensable in providing references for these binary systems. This research has made use of the Simbad database, operated at CDS, Strasbourg, France

Planet Earth: Its Past, Our Present, A Future (?)

NASA Astrophysics Data System (ADS)

Kieffer, S. W.

2012-04-01

We who have lived through the second half of the 20th century into the 21st century have witnessed a profound transition in the biological and physical relationship between humans and the rest of the planet. In the middle of the last century, our planet still had undeveloped islands: there were frontiers that held new lands, mysteries, adventures, cultures, and resources. However, these islands have merged into a relatively seamless planet by a mobile and expanding population, science and technology, and global communication. We are subject to stealth as well as natural disasters. Natural disasters result from the ongoing geological and meteorological processes on our planet, increasingly exacerbated by human presence and behavior. Stealth disasters, on the other hand, are caused by humans, but involve the natural systems that support us. Examples of stealth disasters are climate change, loss of soils, acidification of the oceans, desertification, and loss of groundwater resources. Civilization is a complex system. It has emergent properties, and a tuning parameter--a parameter that is "tuned" until the unexpected happens. The tuning parameter for populations is the number of members relative to the capacities that support them. Because of our sheer numbers, we are driving the stealth disasters, and we will be affected more severely by natural disasters than we have been in the past on a less densely populated planet. To guide our thinking about geoethical issues, we propose a (hypothetical) world organization modeled after the Centers for Disease Control (CDC) in the U.S., and call it the Center for Disaster Control for Planet Earth (CDCPE). This center would have a scientific body to provide impartial facts and uncertainties, an engineering body to propose and implement technical solutions, a negotiating body to balance the realities of political, economic, religious and cultural values, and an enforcement body that is responsive to all of the inputs. How shall we start?

Planet Formation in Stellar Binaries: How Disk Gravity Can Lower theFragmentation Barrier

NASA Astrophysics Data System (ADS)

Silsbee, Kedron; Rafikov, Roman R.

2014-11-01

Binary star systems present a challenge to current theories of planet formation. Perturbations from the companion star dynamically excite the protoplanetary disk, which can lead to destructive collisions between planetesimals, and prevent growth from 1 km to 100 km sized planetesimals. Despite this apparent barrier to coagulation, planets have been discovered within several small-separation (<20 AU), eccentric (eb 0.4) binaries, such as alpha Cen and gamma Cep. We address this problem by analytically exploring planetesimal dynamics under the simultaneous action of (1) binary perturbation, (2) gas drag (which tends to align planetesimal orbits), and (3), the gravity of an eccentric protoplanetary disk. We then use our dynamical solutions to assess the outcomes of planetesimal collisions (growth, destruction, erosion) for a variety of disk models. We find that planets in small-separation binaries can form at their present locations if the primordial protoplanetary disks were massive (>0.01M⊙) and not very eccentric (eccentricity of order several per cent at the location of planet). This constraint on the disk mass is compatible with the high masses of the giant planets in known gamma Cep-like binaries, which require a large mass reservoir for their formation. We show that for these massive disks, disk gravity is dominant over the gravity of the binary companion at the location of the observed planets. Therefore, planetesimal growth is highly sensitive to disk properties. The requirement of low disk eccentricity is in line with the recent hydrodynamic simulations that tend to show gaseous disks in eccentric binaries developing very low eccentricity, at the level of a few percent. A massive purely axisymmetric disk makes for a friendlier environment for planetesimal growth by driving rapid apsidal precession of planetesimals, and averaging out the eccentricity excitation from the binary companion. When the protoplanetary disk is eccentric we find that the most favorable conditions for planetesimal growth emerge when the disk is non-precessing and is apsidally aligned with the orbit of the binary.

Exploring the diversity of Jupiter-class planets

PubMed Central

Fletcher, Leigh N.; Irwin, Patrick G. J.; Barstow, Joanna K.; de Kok, Remco J.; Lee, Jae-Min; Aigrain, Suzanne

2014-01-01

Of the 900+ confirmed exoplanets discovered since 1995 for which we have constraints on their mass (i.e. not including Kepler candidates), 75% have masses larger than Saturn (0.3 MJ), 53% are more massive than Jupiter and 67% are within 1 AU of their host stars. When Kepler candidates are included, Neptune-sized giant planets could form the majority of the planetary population. And yet the term ‘hot Jupiter’ fails to account for the incredible diversity of this class of astrophysical object, which exists on a continuum of giant planets from the cool jovians of our own Solar System to the highly irradiated, tidally locked hot roasters. We review theoretical expectations for the temperatures, molecular composition and cloud properties of hydrogen-dominated Jupiter-class objects under a variety of different conditions. We discuss the classification schemes for these Jupiter-class planets proposed to date, including the implications for our own Solar System giant planets and the pitfalls associated with compositional classification at this early stage of exoplanetary spectroscopy. We discuss the range of planetary types described by previous authors, accounting for (i) thermochemical equilibrium expectations for cloud condensation and favoured chemical stability fields; (ii) the metallicity and formation mechanism for these giant planets; (iii) the importance of optical absorbers for energy partitioning and the generation of a temperature inversion; (iv) the favoured photochemical pathways and expectations for minor species (e.g. saturated hydrocarbons and nitriles); (v) the unexpected presence of molecules owing to vertical mixing of species above their quench levels; and (vi) methods for energy and material redistribution throughout the atmosphere (e.g. away from the highly irradiated daysides of close-in giants). Finally, we discuss the benefits and potential flaws of retrieval techniques for establishing a family of atmospheric solutions that reproduce the available data, and the requirements for future spectroscopic characterization of a set of Jupiter-class objects to test our physical and chemical understanding of these planets. PMID:24664910

Exploring the diversity of Jupiter-class planets.

PubMed

Fletcher, Leigh N; Irwin, Patrick G J; Barstow, Joanna K; de Kok, Remco J; Lee, Jae-Min; Aigrain, Suzanne

2014-04-28

Of the 900+ confirmed exoplanets discovered since 1995 for which we have constraints on their mass (i.e. not including Kepler candidates), 75% have masses larger than Saturn (0.3 MJ), 53% are more massive than Jupiter and 67% are within 1 AU of their host stars. When Kepler candidates are included, Neptune-sized giant planets could form the majority of the planetary population. And yet the term 'hot Jupiter' fails to account for the incredible diversity of this class of astrophysical object, which exists on a continuum of giant planets from the cool jovians of our own Solar System to the highly irradiated, tidally locked hot roasters. We review theoretical expectations for the temperatures, molecular composition and cloud properties of hydrogen-dominated Jupiter-class objects under a variety of different conditions. We discuss the classification schemes for these Jupiter-class planets proposed to date, including the implications for our own Solar System giant planets and the pitfalls associated with compositional classification at this early stage of exoplanetary spectroscopy. We discuss the range of planetary types described by previous authors, accounting for (i) thermochemical equilibrium expectations for cloud condensation and favoured chemical stability fields; (ii) the metallicity and formation mechanism for these giant planets; (iii) the importance of optical absorbers for energy partitioning and the generation of a temperature inversion; (iv) the favoured photochemical pathways and expectations for minor species (e.g. saturated hydrocarbons and nitriles); (v) the unexpected presence of molecules owing to vertical mixing of species above their quench levels; and (vi) methods for energy and material redistribution throughout the atmosphere (e.g. away from the highly irradiated daysides of close-in giants). Finally, we discuss the benefits and potential flaws of retrieval techniques for establishing a family of atmospheric solutions that reproduce the available data, and the requirements for future spectroscopic characterization of a set of Jupiter-class objects to test our physical and chemical understanding of these planets.

Pre-conditioned backward Monte Carlo solutions to radiative transport in planetary atmospheres. Fundamentals: Sampling of propagation directions in polarising media

NASA Astrophysics Data System (ADS)

García Muñoz, A.; Mills, F. P.

2015-01-01

Context. The interpretation of polarised radiation emerging from a planetary atmosphere must rely on solutions to the vector radiative transport equation (VRTE). Monte Carlo integration of the VRTE is a valuable approach for its flexible treatment of complex viewing and/or illumination geometries, and it can intuitively incorporate elaborate physics. Aims: We present a novel pre-conditioned backward Monte Carlo (PBMC) algorithm for solving the VRTE and apply it to planetary atmospheres irradiated from above. As classical BMC methods, our PBMC algorithm builds the solution by simulating the photon trajectories from the detector towards the radiation source, i.e. in the reverse order of the actual photon displacements. Methods: We show that the neglect of polarisation in the sampling of photon propagation directions in classical BMC algorithms leads to unstable and biased solutions for conservative, optically-thick, strongly polarising media such as Rayleigh atmospheres. The numerical difficulty is avoided by pre-conditioning the scattering matrix with information from the scattering matrices of prior (in the BMC integration order) photon collisions. Pre-conditioning introduces a sense of history in the photon polarisation states through the simulated trajectories. Results: The PBMC algorithm is robust, and its accuracy is extensively demonstrated via comparisons with examples drawn from the literature for scattering in diverse media. Since the convergence rate for MC integration is independent of the integral's dimension, the scheme is a valuable option for estimating the disk-integrated signal of stellar radiation reflected from planets. Such a tool is relevant in the prospective investigation of exoplanetary phase curves. We lay out two frameworks for disk integration and, as an application, explore the impact of atmospheric stratification on planetary phase curves for large star-planet-observer phase angles. By construction, backward integration provides a better control than forward integration over the planet region contributing to the solution, and this presents a clear advantage when estimating the disk-integrated signal at moderate and large phase angles. A one-slab, plane-parallel version of the PBMC algorithm is available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/573/A72

Linking long-term planetary N-body simulations with periodic orbits: application to white dwarf pollution

NASA Astrophysics Data System (ADS)

Antoniadou, Kyriaki I.; Veras, Dimitri

2016-12-01

Mounting discoveries of debris discs orbiting newly formed stars and white dwarfs (WDs) showcase the importance of modelling the long-term evolution of small bodies in exosystems. WD debris discs are, in particular, thought to form from very long-term (0.1-5.0 Gyr) instability between planets and asteroids. However, the time-consuming nature of N-body integrators which accurately simulate motion over Gyrs necessitates a judicious choice of initial conditions. The analytical tools known as periodic orbits can circumvent the guesswork. Here, we begin a comprehensive analysis directly linking periodic orbits with N-body integration outcomes with an extensive exploration of the planar circular restricted three-body problem (CRTBP) with an outer planet and inner asteroid near or inside of the 2:1 mean motion resonance. We run nearly 1000 focused simulations for the entire age of the Universe (14 Gyr) with initial conditions mapped to the phase space locations surrounding the unstable and stable periodic orbits for that commensurability. In none of our simulations did the planar CRTBP architecture yield a long-time-scale (≳0.25 per cent of the age of the Universe) asteroid-star collision. The pericentre distance of asteroids which survived beyond this time-scale (≈35 Myr) varied by at most about 60 per cent. These results help affirm that collisions occur too quickly to explain WD pollution in the planar CRTBP 2:1 regime, and highlight the need for further periodic orbit studies with the eccentric and inclined TBP architectures and other significant orbital period commensurabilities.

A disintegrating minor planet transiting a white dwarf.

PubMed

Vanderburg, Andrew; Johnson, John Asher; Rappaport, Saul; Bieryla, Allyson; Irwin, Jonathan; Lewis, John Arban; Kipping, David; Brown, Warren R; Dufour, Patrick; Ciardi, David R; Angus, Ruth; Schaefer, Laura; Latham, David W; Charbonneau, David; Beichman, Charles; Eastman, Jason; McCrady, Nate; Wittenmyer, Robert A; Wright, Jason T

2015-10-22

Most stars become white dwarfs after they have exhausted their nuclear fuel (the Sun will be one such). Between one-quarter and one-half of white dwarfs have elements heavier than helium in their atmospheres, even though these elements ought to sink rapidly into the stellar interiors (unless they are occasionally replenished). The abundance ratios of heavy elements in the atmospheres of white dwarfs are similar to the ratios in rocky bodies in the Solar System. This fact, together with the existence of warm, dusty debris disks surrounding about four per cent of white dwarfs, suggests that rocky debris from the planetary systems of white-dwarf progenitors occasionally pollutes the atmospheres of the stars. The total accreted mass of this debris is sometimes comparable to the mass of large asteroids in the Solar System. However, rocky, disintegrating bodies around a white dwarf have not yet been observed. Here we report observations of a white dwarf--WD 1145+017--being transited by at least one, and probably several, disintegrating planetesimals, with periods ranging from 4.5 hours to 4.9 hours. The strongest transit signals occur every 4.5 hours and exhibit varying depths (blocking up to 40 per cent of the star's brightness) and asymmetric profiles, indicative of a small object with a cometary tail of dusty effluent material. The star has a dusty debris disk, and the star's spectrum shows prominent lines from heavy elements such as magnesium, aluminium, silicon, calcium, iron, and nickel. This system provides further evidence that the pollution of white dwarfs by heavy elements might originate from disrupted rocky bodies such as asteroids and minor planets.

PHARMACEUTICALS AS UBIQUITOUS POLLUTANTS: SIGNIFICANCE, CONCERNS, SOLUTIONS

EPA Science Inventory

Those chemical pollutants that are regulated under various international, federal, and state programs represent but a small fraction of the universe of chemicals that occur in the environment as a result of both natural processes and human influence. Although this galaxy of targe...

NATIONAL RISK MANAGEMENT RESEARCH LABORATORY: PROVIDING SOLUTIONS FOR A BETTER TOMORROW

EPA Science Inventory

This small, two-fold flyer contains general information introducing EPA's National Risk Management Research Laboratory and its research program. The key overarching areas of research described are: Protection of drinking water; control of air pollution; pollution prevention and e...

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

Zhu Zhaohuan; Dong Ruobing; Nelson, Richard P.

By carrying out two-dimensional two-fluid global simulations, we have studied the response of dust to gap formation by a single planet in the gaseous component of a protoplanetary disk-the so-called dust filtration mechanism. We have found that a gap opened by a giant planet at 20 AU in an {alpha} = 0.01, M-dot =10{sup -8} M{sub Sun} yr{sup -1} disk can effectively stop dust particles larger than 0.1 mm drifting inward, leaving a submillimeter (submm) dust cavity/hole. However, smaller particles are difficult to filter by a gap induced by a several M{sub J} planet due to (1) dust diffusion andmore » (2) a high gas accretion velocity at the gap edge. Based on these simulations, an analytic model is derived to understand what size particles can be filtered by the planet-induced gap edge. We show that a dimensionless parameter T{sub s} /{alpha}, which is the ratio between the dimensionless dust stopping time and the disk viscosity parameter, is important for the dust filtration process. Finally, with our updated understanding of dust filtration, we have computed Monte Carlo radiative transfer models with variable dust size distributions to generate the spectral energy distributions of disks with gaps. By comparing with transitional disk observations (e.g., GM Aur), we have found that dust filtration alone has difficulties depleting small particles sufficiently to explain the near-IR deficit of moderate M-dot transitional disks, except under some extreme circumstances. The scenario of gap opening by multiple planets studied previously suffers the same difficulty. One possible solution is to invoke both dust filtration and dust growth in the inner disk. In this scenario, a planet-induced gap filters large dust particles in the disk, and the remaining small dust particles passing to the inner disk can grow efficiently without replenishment from fragmentation of large grains. Predictions for ALMA have also been made based on all these scenarios. We conclude that dust filtration with planet(s) in the disk is a promising mechanism to explain submm observations of transitional disks but it may need to be combined with other processes (e.g., dust growth) to explain the near-IR deficit of some systems.« less

Soil solution dynamics of Cu and Zn in a Cu- and Zn-polluted soil as influenced by gamma-irradiation and Cu-Zn interaction.

PubMed

Luo, Y M; Yan, W D; Christie, P

2001-01-01

A pot experiment was conducted to study soil solution dynamics of Cu and Zn in a Cu/Zn-polluted soil as influenced by gamma-irradiation and Cu-Zn interaction. A slightly acid sandy loam was amended with Cu and Zn (as nitrates) either singly or in combination (100 mg Cu and 150 mg Zn kg(-1) soil) and was then gamma-irradiated (10 kGy). Unamended and unirradiated controls were included, and spring barley (Hordeum vulgare L. cv. Forrester) was grown for 50 days. Soil solution samples obtained using soil moisture samplers immediately before transplantation and every ten days thereafter were used directly for determination of Cu, Zn, pH and absorbance at 360 nm (A360). Cu and Zn concentrations in the solution of metal-polluted soil changed with time and were affected by gamma-irradiation and metal interaction. gamma-Irradiation raised soil solution Cu substantially but generally decreased soil solution Zn. These trends were consistent with increased dissolved organic matter (A360) and solution pH after gamma-irradiation. Combined addition of Cu and Zn usually gave higher soil solution concentrations of Cu or Zn compared with single addition of Cu or Zn in gamma-irradiated and non-irradiated soils, indicating an interaction between Cu and Zn. Cu would have been organically complexed and consequently maintained a relatively high concentration in the soil solution under higher pH conditions. Zn tends to occur mainly as free ion forms in the soil solution and is therefore sensitive to changes in pH. The extent to which gamma-irradiation and metal interaction affected solubility and bioavailability of Cu and Zn was a function of time during plant growth. Studies on soil solution metal dynamics provide very useful information for understanding metal mobility and bioavailability.

A Spitzer Infrared Radius for the Transiting Extrasolar Planet HD 209458 b

NASA Technical Reports Server (NTRS)

Richardson, L. Jeremy; Harrington, Joseph; Seager, Sara; Deming, Drake

2007-01-01

We have measured the infrared transit of the extrasolar planet HD 209458 b using the Spitzer Space Telescope. We observed two primary eclipse events (one partial and one complete transit) using the 24 micrometer array of the Multiband Imaging Photometer for Spitzer (MIPS). We analyzed a total of 2392 individual images (10-second integrations) of the planetary system, recorded before, during, and after transit. We perform optimal photometry on the images and use the local zodiacal light as a short-term flux reference. At this long wavelength, the transit curve has a simple box-like shape, allowing robust solutions for the stellar and planetary radii independent of stellar limb darkening, which is negligible at 24 micrometers. We derive a stellar radius of R(sub *) = 1.06 plus or minus 0.07 solar radius, a planetary radius of R(sub p) = 1.26 plus or minus 0.08 R(sub J), and a stellar mass of 1.17 solar mass. Within the errors, our results agree with the measurements at visible wavelengths. The 24 micrometer radius of the planet therefore does not differ significantly compared to the visible result. We point out the potential for deriving extrasolar transiting planet radii to high accuracy using transit photometry at slightly shorter IR wavelengths where greater photometric precision is possible.

PHOTOMETRIC ORBITS OF EXTRASOLAR PLANETS

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

Brown, Robert A.

We define and analyze the photometric orbit (PhO) of an extrasolar planet observed in reflected light. In our definition, the PhO is a Keplerian entity with six parameters: semimajor axis, eccentricity, mean anomaly at some particular time, argument of periastron, inclination angle, and effective radius, which is the square root of the geometric albedo times the planetary radius. Preliminarily, we assume a Lambertian phase function. We study in detail the case of short-period giant planets (SPGPs) and observational parameters relevant to the Kepler mission: 20 ppm photometry with normal errors, 6.5 hr cadence, and three-year duration. We define a relevantmore » 'planetary population of interest' in terms of probability distributions of the PhO parameters. We perform Monte Carlo experiments to estimate the ability to detect planets and to recover PhO parameters from light curves. We calibrate the completeness of a periodogram search technique, and find structure caused by degeneracy. We recover full orbital solutions from synthetic Kepler data sets and estimate the median errors in recovered PhO parameters. We treat in depth a case of a Jupiter body-double. For the stated assumptions, we find that Kepler should obtain orbital solutions for many of the 100-760 SPGP that Jenkins and Doyle estimate Kepler will discover. Because most or all of these discoveries will be followed up by ground-based radial velocity observations, the estimates of inclination angle from the PhO may enable the calculation of true companion masses: Kepler photometry may break the 'msin i' degeneracy. PhO observations may be difficult. There is uncertainty about how low the albedos of SPGPs actually are, about their phase functions, and about a possible noise floor due to systematic errors from instrumental and stellar sources. Nevertheless, simple detection of SPGPs in reflected light should be robust in the regime of Kepler photometry, and estimates of all six orbital parameters may be feasible in at least a subset of cases.« less

Two-step extraction method for lead isotope fractionation to reveal anthropogenic lead pollution.

PubMed

Katahira, Kenshi; Moriwaki, Hiroshi; Kamura, Kazuo; Yamazaki, Hideo

2018-05-28

This study developed the 2-step extraction method which eluted the Pb adsorbing on the surface of sediments in the first solution by aqua regia and extracted the Pb absorbed inside particles into the second solution by mixed acid of nitric acid, hydrofluoric acid and hydrogen peroxide solution. We applied the method to sediments in the enclosed water area and found out that the isotope ratios of Pb in the second solution represented those of natural origin. This advantage of the method makes it possible to distinguish the Pb between natural origin and anthropogenic source on the basis of the isotope ratios. The results showed that the method was useful to discuss the Pb sources and that anthropogenic Pb in the sediment samples analysed was mainly derived from China because of transboundary air pollution.

Applied Physics Lab Kennedy Space Center: Recent Contributions

NASA Technical Reports Server (NTRS)

Starr, Stan; Youngquist, Robert

2006-01-01

The mission of the Applied Physics Lab is: (1) Develop and deliver novel sensors and devices to support KSC mission operations. (2) Analyze operational issues and recommend or deliver practical solutions. (3) Apply physics to the resolution of long term space flight issues that affect space port operation on Earth or on other planets.

Investigation on the efficiency of treated Palm Tree waste for removal of organic pollutants

NASA Astrophysics Data System (ADS)

Azoulay, Karima; El HajjajiI, Souad; Dahchour, Abdelmalek

2017-04-01

Development of the industrial sector generates several problems of environmental pollution. This issue rises concern among scientific community and decision makers, in this work; we e interested in water resources polluted by the chemical substances, which can cause various problems of health. As an example, dyes generated by different industrial activities such as textile, cosmetic, metal plating, leather, paper and plastic sectors, constitute an important source of pollution. In this work, we aim at investigating the efficiency of palm tree waste for removal of dyes from polluted solution. Our work presents a double environmental aspect, on one hand it constitutes an attempt for valorization of Palm Tree waste, and on the other hand it provides natural adsorbent. The study focuses on the effectiveness of the waste in removing Methylene Bleu and Methyl Orange taken as models of pollutants from aqueous solution. Kinetics and isotherm experiments were conducted in order to determine the sorption behavior of the examined dye. The effects of initial dye and adsorbent concentrations are considered. The results indicate that the correlation coefficient calculated from pseudo-second order equation was higher than the other kinetic equations, indicating that equilibrium data fitted well with pseudo-second order model where adsorption process was chemisorption. The adsorption equilibrium was well described by Langmuir isotherm model.

NASA's Potential Contributions for Remediation of Retention Ponds Using Solar Ultraviolet Radiation and Photocatalysis

NASA Technical Reports Server (NTRS)

Underwood, Lauren W.; Ryan, Robert E.

2007-01-01

This Candidate Solution uses NASA Earth science research on atmospheric ozone and aerosols data (1) to help improve the prediction capabilities of water runoff models that are used to estimate runoff pollution from retention ponds, and (2) to understand the pollutant removal contribution and potential of photocatalytically coated materials that could be used in these ponds. Models (the EPA's SWMM and the USGS SLAMM) exist that estimate the release of pollutants into the environment from storm-water-related retention pond runoff. UV irradiance data acquired from the satellite mission Aura and from the OMI Surface UV algorithm will be incorporated into these models to enhance their capabilities, not only by increasing the general understanding of retention pond function (both the efficacy and efficiency) but additionally by adding photocatalytic materials to these retention ponds, augmenting their performance. State and local officials who run pollution protection programs could then develop and implement photocatalytic technologies for water pollution control in retention ponds and use them in conjunction with existing runoff models. More effective decisions about water pollution protection programs could be made, the persistence and toxicity of waste generated could be minimized, and subsequently our natural water resources would be improved. This Candidate Solution is in alignment with the Water Management and Public Health National Applications.

Biosorption: a solution to pollution?

PubMed

Vieira, R H; Volesky, B

2000-03-01

To solve the water pollution problem by toxic heavy metal contamination resulting from humans technological activities has for long presented a challenge. Biosorption can be a part of the solution. Some types of biosorbents such as seaweeds, molds, yeasts, bacteria or crab shells are examples of biomass tested for metal biosorption with very encouraging results. The uptake of heavy metals by biomass can in some cases reach up to 50% of the biomass dry weight. New biosorbents can be manipulated for better efficiency and multiple re-use to increase their economic attractiveness.

Theoretical validation of potential habitability via analytical and boosted tree methods: An optimistic study on recently discovered exoplanets

NASA Astrophysics Data System (ADS)

Saha, S.; Basak, S.; Safonova, M.; Bora, K.; Agrawal, S.; Sarkar, P.; Murthy, J.

2018-04-01

Seven Earth-sized planets, known as the TRAPPIST-1 system, was discovered with great fanfare in the last week of February 2017. Three of these planets are in the habitable zone of their star, making them potentially habitable planets (PHPs) a mere 40 light years away. The discovery of the closest potentially habitable planet to us just a year before - Proxima b and a realization that Earth-type planets in circumstellar habitable zones are a common occurrence provides the impetus to the existing pursuit for life outside the Solar System. The search for life has two goals essentially: looking for planets with Earth-like conditions (Earth similarity) and looking for the possibility of life in some form (habitability). An index was recently developed, the Cobb-Douglas Habitability Score (CDHS), based on Cobb-Douglas habitability production function (CD-HPF), which computes the habitability score by using measured and estimated planetary parameters. As an initial set, radius, density, escape velocity and surface temperature of a planet were used. The proposed metric, with exponents accounting for metric elasticity, is endowed with analytical properties that ensure global optima and can be scaled to accommodate a finite number of input parameters. We show here that the model is elastic, and the conditions on elasticity to ensure global maxima can scale as the number of predictor parameters increase. K-NN (K-Nearest Neighbor) classification algorithm, embellished with probabilistic herding and thresholding restriction, utilizes CDHS scores and labels exoplanets into appropriate classes via feature-learning methods yielding granular clusters of habitability. The algorithm works on top of a decision-theoretical model using the power of convex optimization and machine learning. The goal is to characterize the recently discovered exoplanets into an "Earth League" and several other classes based on their CDHS values. A second approach, based on a novel feature-learning and tree-building method classifies the same planets without computing the CDHS of the planets and produces a similar outcome. For this, we use XGBoosted trees. The convergence of the outcome of the two different approaches indicates the strength of the proposed solution scheme and the likelihood of the potential habitability of the recently announced discoveries.

Pollution Solution

ERIC Educational Resources Information Center

Vannan, Donald A.

1972-01-01

Stresses briefly the need for individuals' actions for controlling the environmental pollution. A number of projects are suggested for teachers to involve children in this area. Simulated discussion groups of sellers'' and consumers, use of pictures, onion juice, and a water filtration contest are a few of the sources used. (PS)

40 CFR 467.26 - Pretreatment standards for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... 467.26 Section 467.26 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ALUMINUM FORMING POINT SOURCE CATEGORY Rolling With Emulsions Subcategory § 467.26... parameter) 13.29 13.29 Subpart B Solution Heat Treatment Contact Cooling Water Pollutant or pollutant...

Environmental Impact of Alkyl Lead(IV) Derivatives: Perspective after Their Phase-out.

PubMed

Filella, Montserrat; Bonet, Josep

2017-04-10

The use of alkyl lead derivatives as antiknock agents in gasoline can be considered as one of the main pollution disasters of the 20th century because of both the global character of the pollution emitted and the seriousness of the impact on human health. Alkyl lead derivatives in themselves cannot be considered to be persistent pollutants because they readily degrade either before being released from the tailpipes or soon afterwards in the atmosphere. However, the inorganic lead they produced has been deposited in soils all over the planet, largely, but not exclusively in urban areas and along motorways, since the direct emission of lead into the atmosphere favored its dispersal over great distances: The signal of the massive use of alkyl lead derivatives has been found all over the world, including in remote sites such as polar areas. The short residence time of lead in the atmosphere implies that this compartment is highly responsive to changes in emissions. This was demonstrated when leaded gasoline was phased-out and is in striking contrast to the very long permanence of inorganic lead in soils, where resuspension is a permanent source of toxic lead.

Long-term motion of resonant satellites with arbitrary eccentricity and inclination

NASA Technical Reports Server (NTRS)

Nacozy, P. E.; Diehl, R. E.

1982-01-01

A first-order, semi-analytical method for the long-term motion of resonant satellites is introduced. The method provides long-term solutions, valid for nearly all eccentricities and inclinations, and for all commensurability ratios. The method allows the inclusion of all zonal and tesseral harmonics of a nonspherical planet. We present here an application of the method to a synchronous satellite including J2 and J22 harmonics. Global, long-term solutions for this problem are given for arbitrary values of eccentricity, argument of perigee and inclination.

iGlobe Interactive Visualization and Analysis of Spatial Data

NASA Technical Reports Server (NTRS)

Hogan, Patrick

2012-01-01

iGlobe is open-source software built on NASA World Wind virtual globe technology. iGlobe provides a growing set of tools for weather science, climate research, and agricultural analysis. Up until now, these types of sophisticated tools have been developed in isolation by national agencies, academic institutions, and research organizations. By providing an open-source solution to analyze and visualize weather, climate, and agricultural data, the scientific and research communities can more readily advance solutions needed to understand better the dynamics of our home planet, Earth

UBIQUITOUS POLLUTION FROM HEALTH AND COSMETIC CARE: SIGNIFICANCE, CONCERN, SOLUTIONS, STEWARDSHIP

EPA Science Inventory

Those chemical pollutants that are regulated under various international, federal, and state programs represent but a small fraction of the universe of chemicals that occur in the environment as a result of both natural processses and human influence. Although this galaxy of ta...

40 CFR 467.02 - General definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... includes air pollution control scrubbers which are sometimes used to control fumes from chemical solution... cool. (s) Wet scrubbers are air pollution control devices used to remove particulates and fumes from... every plant in a subcategory, but when present is an integral part of the aluminum forming process. (c...

40 CFR 467.02 - General definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... includes air pollution control scrubbers which are sometimes used to control fumes from chemical solution... cool. (s) Wet scrubbers are air pollution control devices used to remove particulates and fumes from... every plant in a subcategory, but when present is an integral part of the aluminum forming process. (c...

40 CFR 467.02 - General definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... includes air pollution control scrubbers which are sometimes used to control fumes from chemical solution... cool. (s) Wet scrubbers are air pollution control devices used to remove particulates and fumes from... every plant in a subcategory, but when present is an integral part of the aluminum forming process. (c...

CONCRETE BLOCKS' ADVERSE EFFECTS ON INDOOR AIR AND RECOMMENDED SOLUTIONS

EPA Science Inventory

Air infiltration through highly permeable concrete blocks can allow entry of various serious indoor air pollutants. An easy approach to avoiding these pollutants is to select a less–air-permeable concrete block. Tests show that air permeability of concrete blocks can vary by a fa...

Joint Group on Pollution Prevention: Partnering for Progress

NASA Technical Reports Server (NTRS)

Hill, R.

2001-01-01

This viewgraph presentation outlines the Joint Group on Pollution Prevention (JG-PP) partnership. Details are given on what groups comprise JG-PP, the proven methodology for what JG-PP can accomplish, the common problems, joint solutions, and shared efforts, and some of the JG-PP projects.

Spatial interactions in a modified Daisyworld model: Heat diffusivity and greenhouse effects

NASA Astrophysics Data System (ADS)

Alberti, T.; Primavera, L.; Vecchio, A.; Lepreti, F.; Carbone, V.

2015-11-01

In this work we investigate a modified version of the Daisyworld model, originally introduced by Lovelock and Watson to describe in a simple way the interactions between an Earth-like planet, its biosphere, and the incoming solar radiation. Here a spatial dependency on latitude is included, and both a variable heat diffusivity along latitudes and a simple greenhouse effect description are introduced in the model. We show that the spatial interactions between the variables of the system can locally stabilize the coexistence of the two vegetation types. The feedback on albedo is able to generate equilibrium solutions which can efficiently self-regulate the planet climate, even for values of the solar luminosity relatively far from the current Earth conditions.

Comment on “Identification of the subsurface sulfide bodies responsible for acidity in Río Tinto source water, Spain” by Gómez-Ortiz et al. (Earth Planet. Sci. Lett. 391 (2014) 36-41)

NASA Astrophysics Data System (ADS)

Olías, Manuel; Nieto, José Miguel

2014-10-01

The source of the Río Tinto (SW Spain) is currently located close to the Peña de Hierro mine, where it receives the first acidic waters. A few kilometers south, the river crosses the Río Tinto mines, a supergiant massive sulfide deposit that is much more important than those of Peña de Hierro, and the acid pollutant contributions to the river increase by orders of magnitude.

Measurements and Modeling of The Air Pollution and The Meteorology On A Complex Topography Region: Case Study Grenoble 1998/1999

NASA Astrophysics Data System (ADS)

Couach, O.; Balin, I.; Jimenez, R.; Quaglia, P.; Kirchner, F.; Ristori, P.; Simeonov, V.; Clappier, A.; van den Bergh, H.; Calpini, B.

In order to understand, to predict and to elaborate solutions concerning the photo- chemical and meteorological processes, which occur often in the summer time over the Grenoble city and its three surroundings valleys, both modeling and measurement approaches were considered. Two intensive air pollution and meteorological measure- ments campaigns were performed in 1998 and 1999. Ozone (O3) and other pollutants (NOx, CH2O, SO2, etc) as well as wind, temperature, solar radiation and relative hu- midity were intensively measured at surface level combined with 3D measurements range by using: an instrumented aircraft (Metair), two ozone lidars (e.g. EPFL ozone dial lidar) and wind profilers (e.g.Degreane). This poster will focus on the main results of these measurements like the 3D ozone distribution, the mixing height/planetary boundary layer evolution, the meteorological behavior, and the other pollutants evalu- ation. The paper also highlights the use of these measurements as a necessary database for comparison and checking (validation) of the model performances and thus to allow modeling solutions in predicting the air pollution events and thus permitting to build the right abatement strategies.

Women's Ideas about the Health Effects of Household Air Pollution, Developed through Focus Group Discussions and Artwork in Southern Nepal.

PubMed

Devakumar, Delan; Qureshi, Zeshan; Mannell, Jenevieve; Baruwal, Manju; Sharma, Neha; Rehfuess, Eva; Saville, Naomi M; Manandhar, Dharma S; Osrin, David

2018-02-01

Household air pollution is a major cause of ill health, but few solutions have been effective to date. While many quantitative studies have been conducted, few have explored the lived experiences and perceptions of women who do the cooking, and as a result are those most exposed to household air pollution. In this study, we worked with groups of home cooks, and sought to use art as a means of engaging them in discussions of how household air pollution from cooking affects their lives. In the Terai district of southern Nepal, we held four focus groups that included 26 local women from urban and peri-urban areas, as well as six local artists. The women then met approximately weekly over four months, and produced images related to air pollution. Transcripts from the focus groups were reviewed independently by two authors, who initially categorised data deductively to pre-defined nodes, and subsequently inductively reviewed emergent themes. Women identified a number of health effects from air pollution. The main physical effects related to the eye and the respiratory system, and women and young children were seen as most vulnerable. The psychosocial effects of air pollution included reduced food intake by women and lethargy. Suggested solutions included modifications to the cooking process, changing the location of stoves, and increasing ventilation. The main barriers were financial. The lived experiences of women in southern Nepal around the problem of air pollution offers a more nuanced and context-specific understanding of the perceptions and challenges of addressing air pollution, which can be used to inform future interventions.

Women’s Ideas about the Health Effects of Household Air Pollution, Developed through Focus Group Discussions and Artwork in Southern Nepal

PubMed Central

Qureshi, Zeshan; Mannell, Jenevieve; Baruwal, Manju; Sharma, Neha; Rehfuess, Eva; Manandhar, Dharma S.; Osrin, David

2018-01-01

Household air pollution is a major cause of ill health, but few solutions have been effective to date. While many quantitative studies have been conducted, few have explored the lived experiences and perceptions of women who do the cooking, and as a result are those most exposed to household air pollution. In this study, we worked with groups of home cooks, and sought to use art as a means of engaging them in discussions of how household air pollution from cooking affects their lives. In the Terai district of southern Nepal, we held four focus groups that included 26 local women from urban and peri-urban areas, as well as six local artists. The women then met approximately weekly over four months, and produced images related to air pollution. Transcripts from the focus groups were reviewed independently by two authors, who initially categorised data deductively to pre-defined nodes, and subsequently inductively reviewed emergent themes. Women identified a number of health effects from air pollution. The main physical effects related to the eye and the respiratory system, and women and young children were seen as most vulnerable. The psychosocial effects of air pollution included reduced food intake by women and lethargy. Suggested solutions included modifications to the cooking process, changing the location of stoves, and increasing ventilation. The main barriers were financial. The lived experiences of women in southern Nepal around the problem of air pollution offers a more nuanced and context-specific understanding of the perceptions and challenges of addressing air pollution, which can be used to inform future interventions. PMID:29389909

Melting-induced crustal production helps plate tectonics on Earth-like planets

NASA Astrophysics Data System (ADS)

Lourenço, Diogo L.; Rozel, Antoine; Tackley, Paul J.

2016-04-01

Within our Solar System, Earth is the only planet to be in a mobile-lid regime. It is generally accepted that the other terrestrial planets are currently in a stagnant-lid regime, with the possible exception of Venus that may be in an episodic-lid regime (Armann and Tackley, JGR 2012). Using plastic yielding to self-consistently generate plate tectonics on an Earth-like planet with strongly temperature-dependent viscosity is now well-established, but such models typically focus on purely thermal convection, whereas compositional variations in the lithosphere can alter the stress state and greatly influence the likelihood of plate tectonics. For example, Rolf and Tackley (GRL, 2011) showed that the addition of a continent can reduce the critical yield stress for mobile-lid behaviour by a factor of around two. Moreover, it has been shown that the final tectonic state of the system can depend on the initial condition (Tackley, G3 2000 - part 2). Weller and Lenardic (GRL, 2012) found that the parameter range in which two solutions are obtained increases with viscosity contrast. We can also say that partial melting has a major role in the long-term evolution of rocky planets: (1) partial melting causes differentiation in both major elements and trace elements, which are generally incompatible (Hofmann, Nature 1997). Trace elements may contain heat-producing isotopes, which contribute to the heat loss from the interior; (2) melting and volcanism are an important heat loss mechanism at early times that act as a strong thermostat, buffering mantle temperatures and preventing it from getting too hot (Xie and Tackley, JGR 2004b); (3) mantle melting dehydrates and hardens the shallow part of the mantle (Hirth and Kohlstedt, EPSL 1996) and introduces viscosity and compositional stratifications in the shallow mantle due to viscosity variations with the loss of hydrogen upon melting (Faul and Jackson, JGR 2007; Korenaga and Karato, JGR 2008). We present a set of 2D spherical annulus simulations (Hernlund and Tackley, PEPI 2008) using StagYY (Tackley, PEPI 2008), which uses a finite-volume scheme for advection of temperature, a multigrid solver to obtain a velocity-pressure solution at each timestep, tracers to track composition, and a treatment of partial melting and crustal formation. We address the question of whether melting-induced crustal production changes the critical yield stress needed to obtain mobile-lid behaviour (plate tectonics). Our results show that melting-induced crustal production strongly influences plate tectonics on Earth-like planets by strongly enhancing the mobility of the lid, replacing a stagnant lid with an episodic lid, or greatly extending the time in which a smoothly evolving mobile lid is present in a planet. Finally, we show that our results are consistent with analytically predicted critical yield stress obtained with boundary layer theory, whether melting-induced crustal production is considered or not.

Saving the environment: women at the wheel.

PubMed

Domoto, A

1999-01-01

The article discusses the role of women in environmental conservation and in the promotion of the "green revolution" movement. Environmental degradation and pollution arises with the occurrence of industrial revolution and modernization. Women's vulnerability to these environmental problems results in a greater awareness of the links between the environment and human health. Women are in a strong position to develop integrated responses to the problems surrounding them. With the many barriers women faced, more and more women are educators, scientist, doctors, politicians, and business leaders. These women have a special responsibility to ensure that agricultural chemical and genetic engineering do not endanger the health of the food supply or the environment as a whole; that high quality reproductive health services are made available to those in need; that girls receive decent education; that business decisions are made with a firm eye on their environmental and social consequences; and that this planet fits for human habitation. By virtue of women's powerful position as consumers and educators, and their rising strength as business and political leaders, they have the opportunity to implement holistic solutions to environmental problems. Since the well being of the environment is a prerequisite to human well being, a true "green revolution" is called for. It necessitates the drafting and implementation of holistic legislation, the creation of accounting systems that account for the environment, and the inclusion of people across the social spectrum.

Review of Understanding of Earth's Hydrological Cycle: Observations, Theory and Modelling

NASA Astrophysics Data System (ADS)

Rast, Michael; Johannessen, Johnny; Mauser, Wolfram

2014-05-01

Water is our most precious and arguably most undervalued natural resource. It is essential for life on our planet, for food production and economic development. Moreover, water plays a fundamental role in shaping weather and climate. However, with the growing global population, the planet's water resources are constantly under threat from overuse and pollution. In addition, the effects of a changing climate are thought to be leading to an increased frequency of extreme weather causing floods, landslides and drought. The need to understand and monitor our environment and its resources, including advancing our knowledge of the hydrological cycle, has never been more important and apparent. The best approach to do so on a global scale is from space. This paper provides an overview of the major components of the hydrological cycle, the status of their observations from space and related data products and models for hydrological variable retrievals. It also lists the current and planned satellite missions contributing to advancing our understanding of the hydrological cycle on a global scale. Further details of the hydrological cycle are substantiated in several of the other papers in this Special Issue.

Measurements of Carbon Monoxide with the MOPITT Instrument 1999-2009

NASA Astrophysics Data System (ADS)

Drummond, J. R.; Gille, J. C.; Edwards, D. P.; Deeter, M. N.; Zou, J.; Nichitiu, F.

2009-12-01

The Measurements Of Pollution In The Troposphere (MOPITT) instrument on the Terra spacecraft is completing ten years of operation measuring carbon monoxide (CO) over the planet. These measurements have demonstrated the changes of CO in both space and time and shown a planet with very large variations in concentrations depending upon events and circumstances. This talk will review the MOPITT dataset and discuss how experience with the MOPITT instrument and with data processing have led to significant improvements in our understanding of the nature of the measurements and their strengths and limitations. These studies have led to improvements in our ability to understand the sensitivity of the measurements to boundary-layer CO (to cite a single example). This presentation leads naturally into a discussion of the future improvements of both of MOPITT instrument datasets and future instruments using similar techniques. MOPITT was provided to the Terra spacecraft by the Canadian Space Agency and was built by COMDEV of Cambridge, Ontario. Data processing is performed by the MOPITT team at the National Center for Atmospheric Research, Boulder, CO. Instrument control is by the team at the University of Toronto.

The Paper River: A Demonstration of Externalities and Coase's Theorem.

ERIC Educational Resources Information Center

Hoyt, Gail M.; Ryan, Patricia L.; Houston, Robert G., Jr.

1999-01-01

Presents a classroom simulation in which one firm pollutes the water used by another. Includes a detailed outline and discussion of the preparations and materials required, and the procedure for running the simulation. Argues that students learn how property rights provide a market solution to pollution costs. (DSK)

Recycle/Reuse: Utilizing New Technology.

ERIC Educational Resources Information Center

Vaglia, John S.

In the early 1990s, efforts were initiated to help countries move toward a solution of the global pollution problem. Technology education classrooms and laboratories are among the best places for bring the concepts of recycling/reuse and waste management to students' attention. Important concepts about pollution, waste prevention, and recycling…

Evidence-Based Integrated Environmental Solutions For Secondary Lead Smelters: Pollution Prevention And Waste Minimization Technologies And Practices

EPA Science Inventory

An evidence-based methodology was adopted in this research to establish strategies to increase lead recovery and recycling via a systematic review and critical appraisal of the published literature. In particular, the research examines pollution prevention and waste minimization...

Lake Pollution in the Yahara Watershed.

ERIC Educational Resources Information Center

Madison Public Schools, WI.

Audio-visual media are utilized in this teacher's guide for an interdisciplinary unit in the middle grades. A filmstrip is employed to increase the student's understanding of how pollution problems develop, and some of the steps necessary in working out solutions, as interpretation of historical changes, scientific analysis, and government…

Students As Environmental Consultants Simulating Life Science Problems

ERIC Educational Resources Information Center

Roberts, Megan; Zydney, Janet Mannheimer

2004-01-01

This article describes a project in which eighth graders at East Side Middle School in New York City used an interactive multimedia program called "Pollution Solution" in a science unit on environmental pollution. Students assumed the role of environmental consultants working at fictional corporations which were being investigated for…

METHOD OF ESTIMATING THE TRAVEL TIME OF NONINTERACTING SOLUTES THROUGH COMPACTED SOIL MATERIAL

EPA Science Inventory

The pollutant travel time through compacted soil material (i.e., when a pollutant introduced at the top first appears at the bottom) cannot be accurately predicted from the permeability (saturated hydraulic conductivity) alone. The travel time is also dependent on the effective p...

Air Pollution Primer.

ERIC Educational Resources Information Center

National Tuberculosis and Respiratory Disease Association, New York, NY.

As the dangers of polluted air to the health and welfare of all individuals became increasingly evident and as the complexity of the causes made responsibility for solutions even more difficult to fix, the National Tuberculosis and Respiratory Disease Association felt obligated to give greater emphasis to its clean air program. To this end they…

Proposed Pathophysiologic Framework to Explain Some Excess Cardiovascular Death Associated with Ambient Air Particle Pollution: Insights for Public Health Translation

EPA Science Inventory

The paper proposes a pathophysiologic framework to explain the well-established epidemiological association between exposure to ambient air particle pollution and premature cardiovascular mortality, and offers insights into public health solutions that extend beyond regularory en...

Development of a multiobjective optimization tool for the selection and placement of best management practices for nonpoint source pollution control

NASA Astrophysics Data System (ADS)

Maringanti, Chetan; Chaubey, Indrajeet; Popp, Jennie

2009-06-01

Best management practices (BMPs) are effective in reducing the transport of agricultural nonpoint source pollutants to receiving water bodies. However, selection of BMPs for placement in a watershed requires optimization of the available resources to obtain maximum possible pollution reduction. In this study, an optimization methodology is developed to select and place BMPs in a watershed to provide solutions that are both economically and ecologically effective. This novel approach develops and utilizes a BMP tool, a database that stores the pollution reduction and cost information of different BMPs under consideration. The BMP tool replaces the dynamic linkage of the distributed parameter watershed model during optimization and therefore reduces the computation time considerably. Total pollutant load from the watershed, and net cost increase from the baseline, were the two objective functions minimized during the optimization process. The optimization model, consisting of a multiobjective genetic algorithm (NSGA-II) in combination with a watershed simulation tool (Soil Water and Assessment Tool (SWAT)), was developed and tested for nonpoint source pollution control in the L'Anguille River watershed located in eastern Arkansas. The optimized solutions provided a trade-off between the two objective functions for sediment, phosphorus, and nitrogen reduction. The results indicated that buffer strips were very effective in controlling the nonpoint source pollutants from leaving the croplands. The optimized BMP plans resulted in potential reductions of 33%, 32%, and 13% in sediment, phosphorus, and nitrogen loads, respectively, from the watershed.

Revolutionary advances in medical waste management. The Sanitec system.

PubMed

Edlich, Richard F; Borel, Lise; Jensen, H Gordon; Winters, Kathryne L; Long, William B; Gubler, K Dean; Buschbacher, Ralph M; Becker, Daniel G; Chang, Dillon E; Korngold, Jonathan; Chitwood, W Randolph; Lin, Kant Y; Nichter, Larry S; Berenson, Susan; Britt, L D; Tafel, John A

2006-01-01

It is the purpose of this collective review to provide a detailed outline of a revolutionary medical waste disposal system that should be used in all medical centers in the world to prevent pollution of our planet from medical waste. The Sanitec medical waste disposal system consists of the following seven components: (1) an all-weather steel enclosure of the waste management system, allowing it to be used inside or outside of the hospital center; (2) an automatic mechanical lift-and-load system that protects the workers from devastating back injuries; (3) a sophisticated shredding system designed for medical waste; (4) a series of air filters including the High Efficiency Particulate Air (HEPA) filter; (5) microwave disinfection of the medical waste material; (6) a waste compactor or dumpster; and (7) an onboard microprocessor. It must be emphasized that this waste management system can be used either inside or outside the hospital. From start to finish, the Sanitec Microwave Disinfection system is designed to provide process and engineering controls that assure complete disinfection and destruction, while minimizing the operator's exposure to risk. There are numerous technologic benefits to the Sanitec systems, including environmental, operational, physical, and disinfection efficiency as well as waste residue disinfection. Wastes treated through the Sanitec system are thoroughly disinfected, unrecognizable, and reduced in volume by approximately 80% (saving valuable landfill space and reducing hauling requirements and costs). They are acceptable in any municipal solid waste program. Sanitec's Zero Pollution Advantage is augmented by a complete range of services, including installation, startup, testing, training, maintenance, and repair, over the life of this system. The Sanitec waste management system has essentially been designed to provide the best overall solution to the customer, when that customer actually looks at the total cost of dealing with the medical waste issue. The Sanitec system is the right choice for healthcare and medical waste professionals around the world.

An improved gravity model for Mars: Goddard Mars Model 1

NASA Technical Reports Server (NTRS)

Smith, D. E.; Lerch, F. J.; Nerem, R. S.; Zuber, M. T.; Patel, G. B.; Fricke, S. K.; Lemoine, F. G.

1993-01-01

Doppler tracking data of three orbiting spacecraft have been reanalyzed to develop a new gravitational field model for the planet Mars, Goddard Mars Model 1 (GMM-1). This model employs nearly all available data, consisting of approximately 1100 days of S band tracking data collected by NASA's Deep Space Network from the Mariner 9 and Viking 1 and Viking 2 spacecraft, in seven different orbits, between 1971 and 1979. GMM-1 is complete to spherical harmonic degree and order 50, which corresponds to a half-wavelength spatial resolution of 200-300 km where the data permit. GMM-1 represents satellite orbits with considerably better accuracy than previous Mars gravity models and shows greater resolution of identifiable geological structures. The notable improvement in GMM-1 over previous models is a consequence of several factors: improved computational capabilities, the use of otpimum weighting and least squares collocation solution techniques which stabilized the behavior of the solution at high degree and order, and the use of longer satellite arcs than employed in previous solutions that were made possible by improved force and measurement models. The inclusion of X band tracking data from the 379-km altitude, nnear-polar orbiting Mars Observer spacecraft should provide a significant improvement over GMM-1, particularly at high latitudes where current data poorly resolve the gravitational signature of the planet.

An improved gravity model for Mars: Goddard Mars Model-1 (GMM-1)

NASA Technical Reports Server (NTRS)

Smith, D. E.; Lerch, F. J.; Nerem, R. S.; Zuber, M. T.; Patel, G. B.; Fricke, S. K.; Lemoine, F. G.

1993-01-01

Doppler tracking data of three orbiting spacecraft have been reanalyzed to develop a new gravitational field model for the planet Mars, GMM-1 (Goddard Mars Model-1). This model employs nearly all available data, consisting of approximately 1100 days of S-bank tracking data collected by NASA's Deep Space Network from the Mariner 9, and Viking 1 and Viking 2 spacecraft, in seven different orbits, between 1971 and 1979. GMM-1 is complete to spherical harmonic degree and order 50, which corresponds to a half-wavelength spatial resolution of 200-300 km where the data permit. GMM-1 represents satellite orbits with considerably better accuracy than previous Mars gravity models and shows greater resolution of identifiable geological structures. The notable improvement in GMM-1 over previous models is a consequence of several factors: improved computational capabilities, the use of optimum weighting and least-squares collocation solution techniques which stabilized the behavior of the solution at high degree and order, and the use of longer satellite arcs than employed in previous solutions that were made possible by improved force and measurement models. The inclusion of X-band tracking data from the 379-km altitude, near-polar orbiting Mars Observer spacecraft should provide a significant improvement over GMM-1, particularly at high latitudes where current data poorly resolves the gravitational signature of the planet.

Rotation of the planet mercury.

PubMed

Jefferys, W H

1966-04-08

The equations of motion for the rotation of Mercury are solved for the general case by an asymptotic expansion. The findings of Liu and O'Keefe, obtained by numerical integration of a special case, that it is possible for Mercury's rotation to be locked into a 2:3 resonance with its revolution, are confirmed in detail. The general solution has further applications.

Environment and Development--Key Concepts for a New Approach to Education.

ERIC Educational Resources Information Center

Sachs, Ignacy

1978-01-01

Development and environment are two interconnected concepts and solutions to the problems of both can be found through "ecodevelopment." Inherent in this planning approach is an effort to meet the basic needs of a community while establishing true symbiosis between man and the planet. Educational effort at every level is necessary to make this…

Planetary System Physics

NASA Technical Reports Server (NTRS)

Peale, S. J.

2002-01-01

Contents include a summary of publications followed by their abstracts titeled: 1. On microlensing rates and optical depth toward the Galactic center. 2. Newly discovered brown dwarfs not seen in microlensing timescale frequency distribution? 3. Origin and evolution of the natural satellites. 4. Probing the structure of the galaxy with microlensing. 5. Tides, Encyclopedia of Astronomy and Astrophysics. 6. The Puzzle of the Titan-Hyperion 4:3 Orbital Resonance. 7. On the Validity of the Coagulation Equation and the Nature of Runaway Growth. 8. Making Hyperion. 9. The MESSENGER mission to Mercury: Scientific objectives and implementation. 10. A Survey of Numerical Solutions to the Coagulation. 11. Probability of detecting a planetary companion during a microlensing event. 12. Dynamics and origin of the 2:l orbital resonances of the GJ876 planets. 13. Planetary Interior Structure Revealed by Spin Dynamics. 14. A primordial origin of the Laplace relation among the Galilean Satellites. 15. A procedure for determining the nature of Mercury's core. 16. Secular evolution of hierarchical planetary systems. 17. Tidally induced volcanism. 18. Extrasolar planets and mean motion resonances. 19. Comparison of a ground-based microlensing search for planets with a search from space.

Evidence for a Dayside Thermal Inversion and High Metallicity for the Hot Jupiter WASP-18b

NASA Astrophysics Data System (ADS)

Sheppard, Kyle B.; Mandell, Avi M.; Tamburo, Patrick; Gandhi, Siddharth; Pinhas, Arazi; Madhusudhan, Nikku; Deming, Drake

2017-12-01

We find evidence for a strong thermal inversion in the dayside atmosphere of the highly irradiated hot Jupiter WASP-18b ({T}{eq}=2411 {{K}}, M=10.3 {M}J) based on emission spectroscopy from Hubble Space Telescope secondary eclipse observations and Spitzer eclipse photometry. We demonstrate a lack of water vapor in either absorption or emission at 1.4 μm. However, we infer emission at 4.5 μm and absorption at 1.6 μm that we attribute to CO, as well as a non-detection of all other relevant species (e.g., TiO, VO). The most probable atmospheric retrieval solution indicates a C/O ratio of 1 and a high metallicity ({{C}}/{{H}}={283}-138+395× solar). The derived composition and T/P profile suggest that WASP-18b is the first example of both a planet with a non-oxide driven thermal inversion and a planet with an atmospheric metallicity inconsistent with that predicted for Jupiter-mass planets at > 2σ . Future observations are necessary to confirm the unusual planetary properties implied by these results.

Habitability of super-Earth planets around other suns: models including Red Giant Branch evolution.

PubMed

von Bloh, W; Cuntz, M; Schröder, K-P; Bounama, C; Franck, S

2009-01-01

The unexpected diversity of exoplanets includes a growing number of super-Earth planets, i.e., exoplanets with masses of up to several Earth masses and a similar chemical and mineralogical composition as Earth. We present a thermal evolution model for a 10 Earth-mass planet orbiting a star like the Sun. Our model is based on the integrated system approach, which describes the photosynthetic biomass production and takes into account a variety of climatological, biogeochemical, and geodynamical processes. This allows us to identify a so-called photosynthesis-sustaining habitable zone (pHZ), as determined by the limits of biological productivity on the planetary surface. Our model considers solar evolution during the main-sequence stage and along the Red Giant Branch as described by the most recent solar model. We obtain a large set of solutions consistent with the principal possibility of life. The highest likelihood of habitability is found for "water worlds." Only mass-rich water worlds are able to realize pHZ-type habitability beyond the stellar main sequence on the Red Giant Branch.

Vital signs of life on distant worlds

NASA Astrophysics Data System (ADS)

2003-01-01

Ozone in a planet's spectrum may indicate the presence of life hi-res Size hi-res: 673 kb Credits: ESA 2001. Illustration by Medialab Ozone in a planet's spectrum may indicate the presence of life Darwin will most probably look for the spectral signature of ozone, which is unlikely to exist in any quantity for any length of time in the atmosphere of a planet that is not home to life. The background image is a view of Earth seen by the Apollo 17 crew as they traveled toward the Moon. The white patch at the bottom is Antarctica. Unobscured by clouds, Africa and the Arabian Peninsula are visible at the top of this image. The large island off the coast of Africa is the Malagasy Republic. Looking for Earth-like planets hi-res Size hi-res: 2106 Kb Credits: ESA 2002. Illustration by Medialab Looking for Earth-like planets Darwin has six telescopes that analyse the atmospheres of Earth-like planets Darwin's flotilla hi-res Size hi-res: 902 Kb Credits: ESA 2002. Illustration by Medialab Darwin's flotilla Darwin's six telescopes, a central view-combining spacecraft, and communication satellite (shown bottom left) Our radio and television broadcasts have been leaking into space since the 1930s, when the first powerful emitters were constructed. However, you can do things the other way around as well. The Search for Extraterrestrial Intelligence (SETI) has used radio telescopes to listen to the cosmos for similar signals. Nowadays, astrobiologists are pinpointing more subtle signs that all life, not just intelligent life, might radiate into space. They call these telltale signatures 'biomarkers'. When ESA's Darwin mission begins sending back data in the next decade, biomarkers will help indicate whether neighbouring planets are inhabited. If we only used radio waves as markers of life, this would exclude all forms of life that have not yet developed the means to emit radio waves. Life has been around for thousands of millions of years, but human beings have used radio waves for less than a century. Malcolm Fridlund, Project Scientist for ESA's Darwin mission says, "If other planets follow the Earth's pattern, it is much more likely that they will be inhabited by dinosaurs or even bacteria than by something that can count." In the 1970s, the British scientist James Lovelock pointed out that, just by breathing, life affects the composition of the Earth's atmosphere. He suggested looking for similar effects as a way to search with telescopes for life on other planets. You can study the composition of an atmosphere by splitting a planet's light into a rainbow of colours. This 'spectrum' will contain dark lines made by various chemicals in the planet's atmosphere. Darwin's strategy is to look for oxygen because oxygen is used by some life forms and produced as waste by others. Scientists believe that without life, all free oxygen in a planet's atmosphere would disappear within just four million years, because it reacts so easily with other chemicals. "The best estimates suggest that Darwin will be able to detect the build-up of oxygen caused within a few hundred million years of life's origin," says Fridlund. Although Darwin will not detect oxygen directly, it will 'see' ozone, a form of oxygen. It will also see carbon dioxide, water, and, in certain cases, methane. Fridlund says, "The general consensus is that if we find ozone, liquid water, and carbon dioxide simultaneously, it will be a very strong indicator of life's presence." The work will not stop once Darwin completes its survey of the nearest several thousand star-planet systems. Once it finds a living planet, the race will be on to understand the nature of its life forms. That means searching for more specific biomarkers. In future space missions, for example, scientists may use chlorophyll as a biomarker. This molecule allows plants and certain bacteria to use light as an energy source. "Finding the next generation of biomarkers is a very active field of research at the moment," says Fridlund. He can see a future in which space telescopes look for intelligent civilisations by searching for industrial pollution in a planet's atmosphere. This may sound like science fiction but for now, oxygen, carbon dioxide, and water will be good enough as indicators of life.

Adsorption of ciprofloxacin, bisphenol and 2-chlorophenol on electrospun carbon nanofibers: in comparison with powder activated carbon.

PubMed

Li, Xiaona; Chen, Shuo; Fan, Xinfei; Quan, Xie; Tan, Feng; Zhang, Yaobin; Gao, Jinsuo

2015-06-01

Carbon nanofibers (CNFs) were prepared by electrospun polyacrylonitrile (PAN) polymer solutions followed by thermal treatment. For the first time, the influence of stabilization procedure on the structure properties of CNFs was explored to improve the adsorption capacity of CNFs towards the environmental pollutants from aqueous solution. The adsorption of three organic chemicals including ciprofloxacin (CIP), bisphenol (BPA) and 2-chlorophenol (2-CP) on electrospun CNFs with high surface area of 2326m(2)/g and micro/mesoporous structure characteristics were investigated. The adsorption affinities were compared with that of the commercial powder activated carbon (PAC). The adsorption kinetics and isotherms showed that the maximum adsorption capacities (qm) of CNFs towards the three pollutants are sequenced in the order of CIP>BPA>2-CP, which are 2.6-fold (CIP), 1.6-fold (BPA) and 1.1-fold (2-CP) increase respectively in comparison with that of PAC adsorption. It was assumed that the micro/mesoporous structure of CNFs, molecular size of the pollutants and the π electron interaction play important roles on the high adsorption capacity exhibited by CNFs. In addition, electrostatic interaction and hydrophobic interaction also contribute to the adsorption of CNFs. This study demonstrates that the electrospun CNFs are promising adsorbents for the removal of pollutants from aqueous solutions. Copyright © 2015 Elsevier Inc. All rights reserved.

Selection and placement of best management practices used to reduce water quality degradation in Lincoln Lake watershed

NASA Astrophysics Data System (ADS)

Rodriguez, Hector German; Popp, Jennie; Maringanti, Chetan; Chaubey, Indrajeet

2011-01-01

An increased loss of agricultural nutrients is a growing concern for water quality in Arkansas. Several studies have shown that best management practices (BMPs) are effective in controlling water pollution. However, those affected with water quality issues need water management plans that take into consideration BMPs selection, placement, and affordability. This study used a nondominated sorting genetic algorithm (NSGA-II). This multiobjective algorithm selects and locates BMPs that minimize nutrients pollution cost-effectively by providing trade-off curves (optimal fronts) between pollutant reduction and total net cost increase. The usefulness of this optimization framework was evaluated in the Lincoln Lake watershed. The final NSGA-II optimization model generated a number of near-optimal solutions by selecting from 35 BMPs (combinations of pasture management, buffer zones, and poultry litter application practices). Selection and placement of BMPs were analyzed under various cost solutions. The NSGA-II provides multiple solutions that could fit the water management plan for the watershed. For instance, by implementing all the BMP combinations recommended in the lowest-cost solution, total phosphorous (TP) could be reduced by at least 76% while increasing cost by less than 2% in the entire watershed. This value represents an increase in cost of 5.49 ha-1 when compared to the baseline. Implementing all the BMP combinations proposed with the medium- and the highest-cost solutions could decrease TP drastically but will increase cost by 24,282 (7%) and $82,306 (25%), respectively.

Johnson Space Center's Role in a Sustainable Future

NASA Technical Reports Server (NTRS)

Ewert, Michael K.

2004-01-01

NASA scientists and many others are contributing to the growing knowledge of our Earth and its ecosystems. Satellites measure sea level rise, and changes in vegetation and air pollutants that travel between countries and continents. The U.S. federal government seeks to be a leader in environmental sustainability efforts through various Executive Orders and policies that save energy, reduce waste, and encourage less reliance on oil as an energy source. NASA, as an agency that is by nature focused on the future, has much to contribute to these efforts. The NASA mission is 'To understand and protect our home planet, to explore the universe and search for life, to inspire the next generation of explorers as only NASA can.' Pollution prevention, affirmative procurement and sustainable design are all programs that are under way at NASA. But more can be done. By sharing ideas and learning from other organizations as well as from the talented workforce we are a part of, JSC can improve its sustainability performance and spread the benefits to our community.

Environmental Activities, Junior High School.

ERIC Educational Resources Information Center

Edwards, William C.; Larson, Robert J.

This guide, for use at the junior high level, is aimed at helping our youth become more knowledgeable concerning the environment and associated problems, thus making them aware of how to solve these problems and motivating them to work toward their solution. Among the subjects discussed are art in nature, erosion, body pollution, water pollution,…

40 CFR 467.33 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... achievable. 467.33 Section 467.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ALUMINUM FORMING POINT SOURCE CATEGORY Extrusion Subcategory § 467.33....25 Aluminum 13.10 6.52 Subpart C Solution Heat Treatment Contact Cooling Water Pollutant or pollutant...

Water solubility enhancement of some organic pollutants and pesticides by dissolved humic and fulvic acids

USGS Publications Warehouse

Chiou, C.T.; Malcolm, R.L.; Brinton, T.I.; Kile, D.E.

1986-01-01

Water solubility enhancements by dissolved humic and fulvic acids from soil and aquatic origins and by synthetic organic polymers have been determined for selected organic pollutants and pesticides (p,p???-DDT, 2,4,5,2???,5???-PCB, 2,4,4???-PCB, 1,2,3-trichlorobenzene, and lindane). Significant solubility enhancements of relatively water-insoluble solutes by dissolved organic matter (DOM) of soil and aquatic origins may be described in terms of a partition-like interaction of the the solutes with the microscopic organic environment of the high-molecular-weight DOM species; the apparent solute solubilities increase linearly with DOM concentration and show no competitive effect between solutes. With a given DOM sample, the solute partition coefficient (Kdom) increases with a decrease of solute solubility (Sw) or with an increase of the solute's octanol-water partition coefficient (Kow). The Kdom values of solutes with soil-derived humic acid are approximately 4 times greater than with soil fulvic acid and 5-7 times greater than with aquatic humic and fulvic acids. The effectiveness of DOM in enhancing solute solubility appears to be largely controlled by the DOM molecular size and polarity. The relative inability of high-molecular-weight poly(acrylic acids) to enhance solute solubility is attributed to their high polarities and extended chain structures that do not permit the formation of a sizable intramolecular nonpolar environment.

Pollutant Transport and Fate: Relations Between Flow-paths and Downstream Impacts of Human Activities

NASA Astrophysics Data System (ADS)

Thorslund, J.; Jarsjo, J.; Destouni, G.

2017-12-01

The quality of freshwater resources is increasingly impacted by human activities. Humans also extensively change the structure of landscapes, which may alter natural hydrological processes. To manage and maintain freshwater of good water quality, it is critical to understand how pollutants are released into, transported and transformed within the hydrological system. Some key scientific questions include: What are net downstream impacts of pollutants across different hydroclimatic and human disturbance conditions, and on different scales? What are the functions within and between components of the landscape, such as wetlands, on mitigating pollutant load delivery to downstream recipients? We explore these questions by synthesizing results from several relevant case study examples of intensely human-impacted hydrological systems. These case study sites have been specifically evaluated in terms of net impact of human activities on pollutant input to the aquatic system, as well as flow-path distributions trough wetlands as a potential ecosystem service of pollutant mitigation. Results shows that although individual wetlands have high retention capacity, efficient net retention effects were not always achieved at a larger landscape scale. Evidence suggests that the function of wetlands as mitigation solutions to pollutant loads is largely controlled by large-scale parallel and circular flow-paths, through which multiple wetlands are interconnected in the landscape. To achieve net mitigation effects at large scale, a large fraction of the polluted large-scale flows must be transported through multiple connected wetlands. Although such large-scale flow interactions are critical for assessing water pollution spreading and fate through the landscape, our synthesis shows a frequent lack of knowledge at such scales. We suggest ways forward for addressing the mismatch between the large scales at which key pollutant pressures and water quality changes take place and the relatively scale at which most studies and implementations are currently made. These suggestions can help bridge critical knowledge gaps, as needed for improving water quality predictions and mitigation solutions under human and environmental changes.

Rapid population growth and environmental degradation: ultimate versus proximate factors.

PubMed

Shaw, R P

1989-01-01

This philosophical review of 2 arguments about responsibility for and solutions to environmental degradation concludes that both sides are correct: the ultimate and the proximal causes. Ultimate causes of pollution are defined as the technology responsible for a given type of pollution, such as burning fossil fuel; proximate causes are defined as situation-specific factors confounding the problem, such as population density or rate of growth. Commoner and others argue that developed countries with low or negative population growth rates are responsible for 80% of world pollution, primarily in polluting technologies such as automobiles, power generation, plastics, pesticides, toxic wastes, garbage, warfaring, and nuclear weapons wastes. Distortionary policies also contribute; examples are agricultural trade protection, land mismanagement, urban bias in expenditures, and institutional rigidity., Poor nations are responsible for very little pollution because poverty allows little waste or expenditures for polluting, synthetic technologies. The proximal causes of pollution include numbers and rate of growth of populations responsible for the pollution. Since change in the ultimate cause of pollution remains out of reach, altering the numbers of polluters can make a difference. Predictions are made for proportions of the world's total waste production, assuming current 1.6 tons/capita for developed countries and 0.17 tons/capita for developing countries. If developing countries grow at current rates and become more wealthy, they will be emitting half the world's waste by 2025. ON the other hand, unsustainable population growth goes along with inadequate investment in human capital: education, health, employment, infrastructure. The solution is to improve farming technologies in the 117 non-self-sufficient countries, fund development in the most unsustainable enclaves of growing countries, break institutionalized socio-political rigidity in these enclaves, and focus on educating and empowering women in these enclaves. Women are in charge of birth spacing and all aspects of management of energy, food, water and the local environment, more so than men, in most countries.

Geodesy at Mercury with MESSENGER

NASA Technical Reports Server (NTRS)

Smith, David E.; Zuber, Maria t.; Peale, Stanley J.; Phillips, Roger J.; Solomon, Sean C.

2006-01-01

In 2011 the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft will enter Mercury orbit and begin the mapping phase of the mission. As part of its science objectives the MESSENGER mission will determine the shape and gravity field of Mercury. These observations will enable the topography and the crustal thickness to be derived for the planet and will determine the small libration of the planet about its axis, the latter critical to constraining the state of the core. These measurements require very precise positioning of the MESSENGER spacecraft in its eccentric orbit, which has a periapsis altitude as low as 200 km, an apoapsis altitude near 15,000 km, and a closest approach to the surface varying from latitude 60 to about 70 N. The X-band tracking of MESSENGER and the laser altimetry are the primary data that will be used to measure the planetary shape and gravity field. The laser altimeter, which has an expected range of 1000 to 1200 km, is expected to provide significant data only over the northern hemisphere because of MESSENGER's eccentric orbit. For the southern hemisphere, radio occultation measurements obtained as the spacecraft passes behind the planet as seen from Earth and images obtained with the imaging system will be used to provide the long-wavelength shape of the planet. Gravity, derived from the tracking data, will also have greater resolution in the northern hemisphere, but full global models for both topography and gravity will be obtained at low harmonic order and degree. The limiting factor for both gravity and topography is expected to be knowledge of the spacecraft location. Present estimations are that in a combined tracking, altimetry, and occultation solution the spacecraft position uncertainty is likely to be of order 10 m. This accuracy should be adequate for establishing an initial geodetic coordinate system for Mercury that will enable positioning of imaged features on the surface, determination of the planet's obliquity, and detection of the librational motion of the planet about its axis.

Cooperative observation data center for planets: starting with the Mars 2009-2010 observation

NASA Astrophysics Data System (ADS)

Nakakushi, T.; Okyudo, M.; Tomita, A.

2009-12-01

We propose in this paper a plan to construct a planetary image data center on the internet, which links professional researchers and amateur observers all over the world. Such data archive projects have worked, at least for Mars. Since 2003, one of the authors (T. N.) have started a project to summarize Mars observations using such cooperative network observation data archives and to publish the summary as professional research papers (Nakakushi et al., 2004, 2005, and 2008). Planetary atmosphere varies in various timescales, which requires temporarily continuous observations. Cooperative observation which amateur observers join can keep the observation continuous and sustainable, so that it can be a strong weapon to reveal planetary climate and meteorology. For outer planets, in particular, we don't know synoptic "seasonal" variations because of their long periods of revolution. We need steady and persistent effort to accumulate observations. That is why we need amateur observers' high-level observation techniques. To do so, we also needs systems to provide (and reproduce) data for users in an appropriate manner. We start from Mars with our own new date archive website, because we have much experience in terms of Mars. Next, we will expand the system for all the planets. Roughly said, there will be 3 steps to expand the project to all the planets: (1) to construct our own Mars cooperative observation data center, (2) to link it with professional studies, (3) to construct cooperative observation data center for all planets. And 4 problems to tackle: (1) to develop web interfaces for users to submit data, (2) to develop interfaces for managers, (3) to secure finances, (4) to secure professional researchers. 2009 and 2010 are a good apparition for Mars observation. We manage the Mars image data website, find problems and solutions in detail, and search for ways to expand it to all the planet and to enable sustainable management.

Proposed pathophysiologic framework to explain some excess cardiovascular death associated with ambient air particle pollution: Insights for public health translation.

PubMed

Cascio, Wayne E

2016-12-01

The paper proposes a pathophysiologic framework to explain the well-established epidemiological association between exposure to ambient air particle pollution and premature cardiovascular mortality, and offers insights into public health solutions that extend beyond regulatory environmental protections to actions that can be taken by individuals, public health officials, healthcare professionals, city and regional planners, local and state governmental officials and all those who possess the capacity to improve cardiovascular health within the population. The foundation of the framework rests on the contribution of traditional cardiovascular risk factors acting alone and in concert with long-term exposures to air pollutants to create a conditional susceptibility for clinical vascular events, such as myocardial ischemia and infarction; stroke and lethal ventricular arrhythmias. The conceptual framework focuses on the fact that short-term exposures to ambient air particulate matter (PM) are associated with vascular thrombosis (acute coronary syndrome, stroke, deep venous thrombosis, and pulmonary embolism) and electrical dysfunction (ventricular arrhythmia); and that individuals having prevalent heart disease are at greatest risk. Moreover, exposure is concomitant with changes in autonomic nervous system balance, systemic inflammation, and prothrombotic/anti-thrombotic and profibrinolytic-antifibrinolytic balance. Thus, a comprehensive solution to the problem of premature mortality triggered by air pollutant exposure will require compliance with regulations to control ambient air particle pollution levels, minimize exposures to air pollutants, as well as a concerted effort to decrease the number of people at-risk for serious clinical cardiovascular events triggered by air pollutant exposure by improving the overall state of cardiovascular health in the population. This article is part of a Special Issue entitled Air Pollution, edited by Wenjun Ding, Andrew J. Ghio and Weidong Wu. Published by Elsevier B.V.

A gravity assist primer

NASA Astrophysics Data System (ADS)

Cesarone, R. J.

An account is given of the method by which the 'energy gain' accruing to a spacecraft as a result of its 'gravity-assist', parabolic-trajectory flyby of a massive body, such as a planet. The procedure begins with the solution of the two-body portion of the problem, and the results thus obtained are used to calculate changes with respect to the other massive body in the overall scenario, namely the sun. Attention is given to the 'vector diagram' often used to display the gravity-assist effect. The present procedure is noted to be reasonably accurate for flybys in which the plane of the spacecraft's trajectory is approximately the same as that of the planet's orbit around the sun, or the ecliptic plane; this reduces the problem to one in two dimensions.

VizieR Online Data Catalog: 231 transiting planets eccentricity and mass (Bonomo+, 2017)

NASA Astrophysics Data System (ADS)

Bonomo, A. S.; Desidera, S.; Benatti, S.; Borsa, F.; Crespi, S.; Damasso, M.; Lanza, A. F.; Sozzetti, A.; Lodato, G.; Marzari, F.; Boccato, C.; Claudi, R. U.; Cosentino, R.; Covino, E.; Gratton, R.; Maggio, A.; Micela, G.; Molinari, E.; Pagano, I.; Piotto, G.; Poretti, E.; Smareglia, R.; Affer, L.; Biazzo, K.; Bignamini, A.; Esposito, M.; Giacobbe, P.; Hebrard, G.; Malavolta, L.; Maldonado, J.; Mancini, L.; Martinez Fiorenzano, A.; Masiero, S.; Nascimbeni, V.; Pedani, M.; Rainer, M.; Scandariato, G.

2017-04-01

We carried out a homogeneous determination of the orbital parameters of 231 TGPs by analysing with our Bayesian DEMCMC tool both the literature RVs and the new high-accuracy and high-precision HARPS-N data we acquired for 45 TGPs orbiting relatively bright stars over ~3 years. We thus produced the largest uniform catalogue of giant planet orbital and physical parameters. For several systems we combined for the first time RV datasets collected with different spectrographs by different groups thus improving the orbital solution. In general, we fitted a separate jitter term for each dataset by allowing for different values of extra noise caused by instrumental effects and/or changing levels of stellar activity in different observing seasons. This way, we uniformly derived the orbital eccentricities of (8 data files).

Optimal solar sail planetocentric trajectories

NASA Technical Reports Server (NTRS)

Sackett, L. L.

1977-01-01

The analysis of solar sail planetocentric optimal trajectory problem is described. A computer program was produced to calculate optimal trajectories for a limited performance analysis. A square sail model is included and some consideration is given to a heliogyro sail model. Orbit to a subescape point and orbit to orbit transfer are considered. Trajectories about the four inner planets can be calculated and shadowing, oblateness, and solar motion may be included. Equinoctial orbital elements are used to avoid the classical singularities, and the method of averaging is applied to increase computational speed. Solution of the two-point boundary value problem which arises from the application of optimization theory is accomplished with a Newton procedure. Time optimal trajectories are emphasized, but a penalty function has been considered to prevent trajectories which intersect a planet's surface.

Tehran Air Pollutants Prediction Based on Random Forest Feature Selection Method

NASA Astrophysics Data System (ADS)

Shamsoddini, A.; Aboodi, M. R.; Karami, J.

2017-09-01

Air pollution as one of the most serious forms of environmental pollutions poses huge threat to human life. Air pollution leads to environmental instability, and has harmful and undesirable effects on the environment. Modern prediction methods of the pollutant concentration are able to improve decision making and provide appropriate solutions. This study examines the performance of the Random Forest feature selection in combination with multiple-linear regression and Multilayer Perceptron Artificial Neural Networks methods, in order to achieve an efficient model to estimate carbon monoxide and nitrogen dioxide, sulfur dioxide and PM2.5 contents in the air. The results indicated that Artificial Neural Networks fed by the attributes selected by Random Forest feature selection method performed more accurate than other models for the modeling of all pollutants. The estimation accuracy of sulfur dioxide emissions was lower than the other air contaminants whereas the nitrogen dioxide was predicted more accurate than the other pollutants.

[Light pollution. A connection between ecology and health].

PubMed

Jedidi, H; Depierreux, F; Jedidi, Z; Beckers, A

2015-11-01

Light pollution is defined as the abnormal and disturbing nocturnal presence of light, its adverse consequences on flora, fauna, and, ecosystems, and its suspected or proven effects on human health. Light pollution is a quite recent and increasing phenomenon within our society; it leads to a major environmental damage not only on wildlife, but also on human health (cancers, obesity, fatigue, depression...). The solutions to this problem are however simple, efficient and, de facto, inexpensive because they involve a substantial energy saving.

The biosphere: Problems and solutions; Proceedings of the Miami International Symposium on the Biosphere, Miami Beach, FL, April 23, 24, 1984

NASA Astrophysics Data System (ADS)

Veziroglu, T. N.

The objective of the Miami International Symposium on the Biosphere was to provide a forum for the presentation of the latest research findings on the environmental effects of human activities. The topics discussed are related to biosphere reserves, environmental aspects of hydrocarbon fuels, radioactivity and nuclear waste, land management, acid rains, water quality, water resources, coastal resources management, the pollution of rivers, industrial waste, economic development and the environment, health hazards and solutions, endangered species, environmentally compatible systems, space pollution, and global considerations. Attention is given to questions regarding global security and sustainable development, environethics as a global strategy for environmental quality, a gestalt approach to the environment, potential indicators for monitoring biosphere reserves, a review of regional impacts associated with the development of U.S. synthetic fuel resources, water resources in the Soviet Union, and pollution-free pesticides.

Nano-adsorbents for the removal of metallic pollutants from water and wastewater.

PubMed

Sharma, Y C; Srivastava, V; Singh, V K; Kaul, S N; Weng, C H

2009-05-01

Of the variety of adsorbents available for the removal of heavy and toxic metals, activated carbon has been the most popular. A number of minerals, clays and waste materials have been regularly used for the removal of metallic pollutants from water and industrial effluents. Recently there has been emphasis on the application of nanoparticles and nanostructured materials as efficient and viable alternatives to activated carbon. Carbon nanotubes also have been proved effective alternatives for the removal of metallic pollutants from aqueous solutions. Because of their importance from an environmental viewpoint, special emphasis has been given to the removal of the metals Cr, Cd, Hg, Zn, As, and Cu. Separation of the used nanoparticles from aqueous solutions and the health aspects of the separated nanoparticles have also been discussed. A significant number of the latest articles have been critically scanned for the present review to give a vivid picture of these exotic materials for water remediation.

Analytical solutions to compartmental indoor air quality models with application to environmental tobacco smoke concentrations measured in a house.

PubMed

Ott, Wayne R; Klepeis, Neil E; Switzer, Paul

2003-08-01

This paper derives the analytical solutions to multi-compartment indoor air quality models for predicting indoor air pollutant concentrations in the home and evaluates the solutions using experimental measurements in the rooms of a single-story residence. The model uses Laplace transform methods to solve the mass balance equations for two interconnected compartments, obtaining analytical solutions that can be applied without a computer. Environmental tobacco smoke (ETS) sources such as the cigarette typically emit pollutants for relatively short times (7-11 min) and are represented mathematically by a "rectangular" source emission time function, or approximated by a short-duration source called an "impulse" time function. Other time-varying indoor sources also can be represented by Laplace transforms. The two-compartment model is more complicated than the single-compartment model and has more parameters, including the cigarette or combustion source emission rate as a function of time, room volumes, compartmental air change rates, and interzonal air flow factors expressed as dimensionless ratios. This paper provides analytical solutions for the impulse, step (Heaviside), and rectangular source emission time functions. It evaluates the indoor model in an unoccupied two-bedroom home using cigars and cigarettes as sources with continuous measurements of carbon monoxide (CO), respirable suspended particles (RSP), and particulate polycyclic aromatic hydrocarbons (PPAH). Fine particle mass concentrations (RSP or PM3.5) are measured using real-time monitors. In our experiments, simultaneous measurements of concentrations at three heights in a bedroom confirm an important assumption of the model-spatial uniformity of mixing. The parameter values of the two-compartment model were obtained using a "grid search" optimization method, and the predicted solutions agreed well with the measured concentration time series in the rooms of the home. The door and window positions in each room had considerable effect on the pollutant concentrations observed in the home. Because of the small volumes and low air change rates of most homes, indoor pollutant concentrations from smoking activity in a home can be very high and can persist at measurable levels indoors for many hours.

Application of oil spill model to marine pollution and risk control problems

NASA Astrophysics Data System (ADS)

Aseev, Nikita; Agoshkov, Valery; Sheloput, Tatyana

2017-04-01

Oil transportation by sea induces challenging problems of environmental control. Millions of tonnes of oil are yearly released during routine ship operations, not to mention vast spills due to different accidents (e.g. tanker collisions, grounding, etc.). Oil pollution is dangerous to marine organisms such as plants, fish and mammals, leading to widespread damage to our planet. In turn, fishery and travel agencies can lose money and clients, and ship operators are obliged to pay huge penalties for environmental pollution. In this work we present the method of accessing oil pollution of marine environment using recently developed oil spill model. The model describes basic processes of the oil slick evolution: oil transport due to currents, drift under the action of wind, spreading on the surface, evaporation, emulsification and dispersion. Such parameters as slick location, mass, density of oil, water content, viscosity and density of "water-in-oil" emulsion can be calculated. We demonstrate how to apply the model to damage calculation problems using a concept of average damage to particular marine area. We also formulate the problem of oil spill risk control, when some accident parameters are not known, but their probability distribution is given. We propose a new algorithm to solve such problems and show results of our model simulations. The work can be interesting to broad environmental, physics and mathematics community. The work is supported by Russian Foundation for Basic Research grant 16-31-00510.

What We Need to Learn to Save the Planet

ERIC Educational Resources Information Center

Gadotti, Moacir

2008-01-01

The author argues that education, as we see it today, is more a part of sustainable development's (SD) problem than a part of its solution because it reinforces the principles and values of an unsustainable lifestyle and economy. He argues for an economy that is not centred on free market and profit, and which circulates wealth with a logic of…

Planet Patrol. An Environmental Unit on Solid Waste Solutions for Grades 4-6.

ERIC Educational Resources Information Center

Procter and Gamble Educational Services, Cincinnati, OH.

This classroom unit was developed for use in grades 4-6 to help teach the concept of solid waste management. The teacher's guide provides an overview of the issue of solid waste disposal, a description of government, industry, and consumer roles in resolving the solid waste issue, and four lessons involving sanitary landfills, the reduction of…

Saving the Planet, Stretching Their Skills: Using Environmental Science Investigations to Challenge Gifted Children

ERIC Educational Resources Information Center

Schroth, Stephen T.

2018-01-01

Gifted children are often highly sensitive to their surroundings and are able to readily identify potential solutions to challenges that imperil the environment in which they live. Many gifted children are strong advocates of sustainable living, caring deeply about the world around them and its health in the future. For this reason, parents and…

Influence of pollution control on lead inhalation bioaccessibility in PM2.5: A case study of 2014 Youth Olympic Games in Nanjing.

PubMed

Li, Shi-Wei; Li, Hong-Bo; Luo, Jun; Li, Hui-Ming; Qian, Xin; Liu, Miao-Miao; Bi, Jun; Cui, Xin-Yi; Ma, Lena Q

2016-09-01

Pollution controls were implemented to improve the air quality for the 2014 Youth Olympic Games (YOG) in Nanjing. To investigate the influence of pollution control on Pb inhalation bioaccessibility in PM2.5, samples were collected before, during, and after YOG. The objectives were to identify Pb sources in PM2.5 using stable isotope fingerprinting technique and compare Pb inhalation bioaccessibility in PM2.5 using two simulated lung fluids. While artificial lysosomal fluid (ALF) simulates interstitial fluid at pH 7.4, Gamble's solution simulates fluid in alveolar macrophages at pH 4.5. The Pb concentration in PM2.5 samples during YOG (88.2ngm(-3)) was 44-48% lower than that in non-YOG samples. Based on stable Pb isotope ratios, Pb in YOG samples was mainly from coal combustion while Pb in non-YOG samples was from coal combustion and smelting activities. While Pb bioaccessibility in YOG samples was lower than those in non-YOG samples (59-79% vs. 55-87%) by ALF, it was higher than those in non-YOG samples (11-29% vs. 5.3-21%) based on Gamble's solution, attributing to the lower pH and organic acids in ALF. Different Pb bioaccessibility in PM2.5 between samples resulted from changes in Pb species due to pollution control. PbSO4 was the main Pb species in PM2.5 from coal combustion, which was less soluble in ALF than PbO from smelting activities, but more soluble in Gamble's solution. This study showed it is important to consider Pb bioaccessibility during pollution control as source control not only reduced Pb contamination in PM2.5 but also influenced Pb bioaccessibility. Published by Elsevier Ltd.

Removal of organic micro-pollutants (phenol, aniline and nitrobenzene) via forward osmosis (FO) process: Evaluation of FO as an alternative method to reverse osmosis (RO).

PubMed

Cui, Yue; Liu, Xiang-Yang; Chung, Tai-Shung; Weber, Martin; Staudt, Claudia; Maletzko, Christian

2016-03-15

In this study, we have explored and compared the effectiveness of using (1) lab-fabricated forward osmosis (FO) membranes under both FO and reverse osmosis (RO) modes and (2) commercially available RO membranes under the RO mode for the removal of organic micro-pollutants. The lab-fabricated FO membranes are thin film composite (TFC) membranes consisting of a polyamide layer and a porous substrate cast from three different materials; namely, Matrimid, polyethersulfone (PESU) and sulfonated polyphenylene sulfone (sPPSU). The results show that the FO mode is superior to the RO mode in the removal of phenol, aniline and nitrobenzene from wastewater. The rejections of all three TFC membranes to all the three organic micro-pollutants under the FO processes are higher than 72% and can be even higher than 90% for aniline when a 1000 ppm aromatic aqueous solution and 1 M NaCl are employed as feeds. These performances outperform the results obtained from themselves and commercially available RO membranes under the RO mode. In addition, the rejection can be maintained even when treating a more concentrated feed solution (2000 ppm). The removal performance can be further enhanced by using a more concentrated draw solution (2 M). The water flux is almost doubled, and the rejection increment can reach up to 17%. Moreover, it was observed that annealing as a post-treatment would help compact the membrane selective layer and further enhance the separating efficiency. The obtained organic micro-pollutant rejections and water fluxes under various feasible operating conditions indicate that the FO process has potential to be a viable treatment for wastewater containing organic micro-pollutants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Leaching behaviour of low level organic pollutants contained in cement-based materials: experimental methodology and modelling approach.

PubMed

Tiruta-Barna, Ligia; Fantozzi-Merle, Catherine; de Brauer, Christine; Barna, Radu

2006-11-16

The aim of this paper is the investigation of the leaching behaviour of different porous materials containing organic pollutants (PAH: naphthalene and phenanthrene). The assessment methodology of long term leaching behaviour of inorganic materials was extended to cement solidified organic pollutants. Based on a scenario-approach considering environmental factors, matrix and pollutants specificities, the applied methodology is composed of adapted equilibrium and dynamic leaching tests. The contributions of different physical and chemical mechanisms were identified and the leaching behaviour was modelled. The physical parameters of the analysed reference and polluted materials are similar. A difference in the pore size distribution appears for higher naphthalene content. The solubility of the PAH contained in the material is affected by the ionic strength and by the presence of a co-solvent; the solution pH does not influence PAH solubility. The solubility of the major mineral species is not influenced by the presence of the two PAH nor by the presence of the methanol as co-solvent in the range of the tested material compositions. In the case of the leaching of a monolith material the main transport mechanism is the diffusion in the porous system. For both mineral and organic species we observed at least two dynamic domains. At the beginning of the leaching process the released flux is due to the surface dissolution and to the diffusion of the main quantity dissolved in the initial pore solution. The second period is governed by a stationary regime between dissolution in pore water and diffusion. The model, coupling transport and chemical phenomena in the pore solution, at the monolith surface and in the leachate simulates satisfactory the release for both mineral and organic species.

Dust-trapping Vortices and a Potentially Planet-triggered Spiral Wake in the Pre-transitional Disk of V1247 Orionis

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

Kraus, Stefan; Kreplin, Alexander; Young, Alison K.

The radial drift problem constitutes one of the most fundamental problems in planet formation theory, as it predicts particles to drift into the star before they are able to grow to planetesimal size. Dust-trapping vortices have been proposed as a possible solution to this problem, as they might be able to trap particles over millions of years, allowing them to grow beyond the radial drift barrier. Here, we present ALMA 0.″04 resolution imaging of the pre-transitional disk of V1247 Orionis that reveals an asymmetric ring as well as a sharply confined crescent structure, resembling morphologies seen in theoretical models ofmore » vortex formation. The asymmetric ring (at 0.″17 = 54 au separation from the star) and the crescent (at 0.″38 = 120 au) seem smoothly connected through a one-armed spiral-arm structure that has been found previously in scattered light. We propose a physical scenario with a planet orbiting at ∼0.″3 ≈ 100 au, where the one-armed spiral arm detected in polarized light traces the accretion stream feeding the protoplanet. The dynamical influence of the planet clears the gap between the ring and the crescent and triggers two vortices that trap millimeter-sized particles, namely, the crescent and the bright asymmetry seen in the ring. We conducted dedicated hydrodynamics simulations of a disk with an embedded planet, which results in similar spiral-arm morphologies as seen in our scattered-light images. At the position of the spiral wake and the crescent we also observe {sup 12}CO(3-2) and H{sup 12}CO{sup +} (4-3) excess line emission, likely tracing the increased scale-height in these disk regions.« less

MOA-2012-BLG-505Lb: A Super-Earth-mass Planet That Probably Resides in the Galactic Bulge

NASA Astrophysics Data System (ADS)

Nagakane, M.; Sumi, T.; Koshimoto, N.; Bennett, D. P.; Bond, I. A.; Rattenbury, N.; Suzuki, D.; Abe, F.; Asakura, Y.; Barry, R.; Bhattacharya, A.; Donachie, M.; Fukui, A.; Hirao, Y.; Itow, Y.; Li, M. C. A.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Matsuo, T.; Muraki, Y.; Ohnishi, K.; Ranc, C.; Saito, To.; Sharan, A.; Shibai, H.; Sullivan, D. J.; Tristram, P. J.; Yamada, T.; Yonehara, A.; MOA Collaboration

2017-07-01

We report the discovery of a super-Earth-mass planet in the microlensing event MOA-2012-BLG-505. This event has the second shortest event timescale of t E = 10 ± 1 days where the observed data show evidence of a planetary companion. Our 15 minute high cadence survey observation schedule revealed the short subtle planetary signature. The system shows the well known close/wide degeneracy. The planet/host-star mass ratio is q = 2.1 × 10-4 and the projected separation normalized by the Einstein radius is s = 1.1 or 0.9 for the wide and close solutions, respectively. We estimate the physical parameters of the system by using a Bayesian analysis and find that the lens consists of a super-Earth with a mass of {6.7}-3.6+10.7 {M}\\oplus orbiting around a brown dwarf or late-M-dwarf host with a mass of {0.10}-0.05+0.16 {M}⊙ with a projected star-planet separation of {0.9}-0.2+0.3 {au}. The system is at a distance of 7.2 ± 1.1 kpc, I.e., it is likely to be in the Galactic bulge. The small angular Einstein radius (θ E = 0.12 ± 0.02 mas) and short event timescale are typical for a low-mass lens in the Galactic bulge. Such low-mass planetary systems in the Bulge are rare because the detection efficiency of planets in short microlensing events is relatively low. This discovery may suggest that such low-mass planetary systems are abundant in the Bulge and currently on-going high cadence survey programs will detect more such events and may reveal an abundance of such planetary systems.

Tidal Barrier and the Asymptotic Mass of Proto-Gas Giant Planets

NASA Astrophysics Data System (ADS)

Dobbs-Dixon, Ian; Li, Shu Lin; Lin, D. N. C.

2007-05-01

According to the conventional sequential accretion scenario, observed extrasolar planets acquired their current masses via efficient gas accretion onto super-Earth cores with accretion timescales that rapidly increase with mass. Gas accretion in weak-line T Tauri disks may be quenched by global depletion of gas, but such a mechanism is unlikely to have stalled the growth in planetary systems that contain relatively low-mass, close-in planets together with more massive, longer period companions. Here, we suggest a potential solution for this conundrum. In general, supersonic infall of surrounding gas onto a protoplanet is only possible interior to both its Bondi and Roche radii. Above the critical mass where the Roche and Bondi radii are equal to the disk thickness, the protoplanet's tidal perturbation induces the formation of a gap. However, despite continued diffusion into the gap, the azimuthal flux across the protoplanet's Roche lobe will be quenched. Using two different schemes, we present the results of numerical simulations and analysis to show that the accretion rate increases rapidly with the ratio of the protoplanet's Roche to Bondi radii or equivalently to the disk thickness. Gas accretion is quenched, yielding relatively low protoplanetary masses, in regions with low aspect ratios. This becomes important for determining the gas giant planet's mass function, the distribution of their masses within multiple-planet systems, and for suppressing the emergence of gas giants around low-mass stars. Finally, we find that accretion rates onto protoplanets declines gradually on a characteristic timescale of a few Myr, during which the protracted accretion timescale onto circumplanetary disks may allow for the formation and retention of regular satellites.

A SEMI-ANALYTICAL MODEL OF VISIBLE-WAVELENGTH PHASE CURVES OF EXOPLANETS AND APPLICATIONS TO KEPLER- 7 B AND KEPLER- 10 B

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

Hu, Renyu; Demory, Brice-Olivier; Seager, Sara

2015-03-20

Kepler has detected numerous exoplanet transits by measuring stellar light in a single visible-wavelength band. In addition to detection, the precise photometry provides phase curves of exoplanets, which can be used to study the dynamic processes on these planets. However, the interpretation of these observations can be complicated by the fact that visible-wavelength phase curves can represent both thermal emission and scattering from the planets. Here we present a semi-analytical model framework that can be applied to study Kepler and future visible-wavelength phase curve observations of exoplanets. The model efficiently computes reflection and thermal emission components for both rocky andmore » gaseous planets, considering both homogeneous and inhomogeneous surfaces or atmospheres. We analyze the phase curves of the gaseous planet Kepler- 7 b and the rocky planet Kepler- 10 b using the model. In general, we find that a hot exoplanet’s visible-wavelength phase curve having a significant phase offset can usually be explained by two classes of solutions: one class requires a thermal hot spot shifted to one side of the substellar point, and the other class requires reflective clouds concentrated on the same side of the substellar point. Particularly for Kepler- 7 b, reflective clouds located on the west side of the substellar point can best explain its phase curve. The reflectivity of the clear part of the atmosphere should be less than 7% and that of the cloudy part should be greater than 80%, and the cloud boundary should be located at 11° ± 3° to the west of the substellar point. We suggest single-band photometry surveys could yield valuable information on exoplanet atmospheres and surfaces.« less

Dust-trapping Vortices and a Potentially Planet-triggered Spiral Wake in the Pre-transitional Disk of V1247 Orionis

NASA Astrophysics Data System (ADS)

Kraus, Stefan; Kreplin, Alexander; Fukugawa, Misato; Muto, Takayuki; Sitko, Michael L.; Young, Alison K.; Bate, Matthew R.; Grady, Carol; Harries, Tim T.; Monnier, John D.; Willson, Matthew; Wisniewski, John

2017-10-01

The radial drift problem constitutes one of the most fundamental problems in planet formation theory, as it predicts particles to drift into the star before they are able to grow to planetesimal size. Dust-trapping vortices have been proposed as a possible solution to this problem, as they might be able to trap particles over millions of years, allowing them to grow beyond the radial drift barrier. Here, we present ALMA 0.″04 resolution imaging of the pre-transitional disk of V1247 Orionis that reveals an asymmetric ring as well as a sharply confined crescent structure, resembling morphologies seen in theoretical models of vortex formation. The asymmetric ring (at 0.″17 = 54 au separation from the star) and the crescent (at 0.″38 = 120 au) seem smoothly connected through a one-armed spiral-arm structure that has been found previously in scattered light. We propose a physical scenario with a planet orbiting at ˜0.″3 ≈ 100 au, where the one-armed spiral arm detected in polarized light traces the accretion stream feeding the protoplanet. The dynamical influence of the planet clears the gap between the ring and the crescent and triggers two vortices that trap millimeter-sized particles, namely, the crescent and the bright asymmetry seen in the ring. We conducted dedicated hydrodynamics simulations of a disk with an embedded planet, which results in similar spiral-arm morphologies as seen in our scattered-light images. At the position of the spiral wake and the crescent we also observe 12CO(3-2) and H12CO+ (4-3) excess line emission, likely tracing the increased scale-height in these disk regions.

Reducing the need for surgeons by reducing pollution-derived workload: is there a role for surgeons?

PubMed

Talati, Jamsheer J; Agha, Riaz; Agha, Maliha; Rosin, Richard David

2011-01-01

The need for additional surgical workforce personnel is likely to increase dramatically at a rate beyond our capacity to train them. As surgical training programmes cannot be rapidly expanded, this paper explores an alternative solution to the quandary, a reduction of the disease burden by a war on pollution. Highlighting the role of pollutants in increasing the surgical workload, it identifies potential roles for surgeons in the battle against pollution and draws attention to the need to research out agents which could protect humans against their carcinogenic effects. Copyright © 2011 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Application of zinc isotope tracer technology in tracing soil heavy metal pollution

NASA Astrophysics Data System (ADS)

Norbu, Namkha; Wang, Shuguang; Xu, Yan; Yang, Jianqiang; Liu, Qiang

2017-08-01

Recent years the soil heavy metal pollution has become increasingly serious, especially the zinc pollution. Due to the complexity of this problem, in order to prevent and treat the soil pollution, it's crucial to accurately and quickly find out the pollution sources and control them. With the development of stable isotope tracer technology, it's able to determine the composition of zinc isotope. Based on the theory of zinc isotope tracer technique, and by means of doing some latest domestic and overseas literature research about the zinc isotope multi-receiving cups of inductively coupled plasma mass spectrometer (MC-ICP-MS) testing technology, this paper summarized the latest research results about the pollution tracer of zinc isotope, and according to the deficiencies and existing problems of previous research, made outlooks of zinc isotope fractionation mechanism, repository establishment and tracer multiple solutions.

Into the Eye

NASA Technical Reports Server (NTRS)

Ewers, Richard G.

2011-01-01

NASA's aeronautical research not only encompasses advancing aircraft technology and aviation safety for today and the future, but it also has a branch that deals with Airborne Science. This Airborne Science branch possesses unique airborne flight vehicles (manned and unmanned) whose sole purpose is to take scientists and their experiments anywhere in the world, into nearly any climatic condition, to gather the data they need for their research. This research spans such fields as; global warming, weather analysis, air and water pollution, mineral and archaeology search, earthquake damage and prediction, and yes, hurricanes. The data we obtain will hopefully, one day, allow us to better understand our planet, its natural forces and man's interaction with them.

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

Biscaye, P.E.

The goal of govern project is to understand and quantify the processes that the transport and dispersal of energy-related pollutants introduced to the waters of the continental shelf and slope. The report is divided into sections dealing with processes associated with suspended solids; processes associated with sediments sinks for radionuclides and other pollutants; and spreading of water characteristics and species in solution. (ACR)

Some Strategies for Environmental Remediation

ERIC Educational Resources Information Center

Peterson, Jerrold M.

1975-01-01

Analyzed are three strategies for reducing or eliminating environmental pollution: private market, legal, and effluent tax. Since private market solutions function well only with small numbers of parties and legal solutions oscillate too much, the author recommends effluent taxes. This strategy optimizes the abatement benefits and implementation…

The location of planetary bow shocks: A critical overview of theory and observations

NASA Technical Reports Server (NTRS)

Spreiter, J. R.; Stahara, S. S.

1995-01-01

A bow shock (BS has been observed in the collisionless solar wind upstream of every planet except Pluto, which has yet to be visited by a spacecraft. They are all of similar character, but their size relative to the planet varies widely, e.g., the planeto-centric distance to the BS nose ranges from about 1.4 R(sub V) for Venus to 88 R(sub J) or more for Jupiter. Comparisons are reviewed that show its location may be represented satisfactorily by a gasdynamic (GD) model, provided the properties of the solar wind and planetary magnetic field and ionosphere are known and used as input in the application. Factors that determine the location are discussed, and examples are presented to illustrate effects of their variation, including which part of a BS is influenced by a local variation of the magneto/ionopause (MIP) shape. The interplanetary magnetic field (IMF) has no influence on the BS location in the GD model, but is shown to have a small effect in corresponding solutions of the basic MHD model from which the GD model is derived as the limit for weak IMF. Nearly all GD and MHD solutions are for steady flow, but a solution for unsteady flow associated with the passage of an interplanetary shock is also presented. It shows that the BS moves rapidly from its initial to final location, e.g., in about minute for the earth. Since many changes in the solar wind occur over longer intervals, these results help explain the success of quasi-stationary solutions in modeling the BS in time-varying solar wind flows.

Debris Disk Structure and Morphology as Revealed by Aggressive STIS Multi-Roll Coronagraphy: A New Look at Some Old Friends

NASA Technical Reports Server (NTRS)

Grady, Carol A; Kuchner, Marc; Woodgate, Bruce E.

2012-01-01

We present new imaging results from a well-selected sample of II circumstellar debris disks, all with HST pedigree, using STIS visible-light 6-roll PSF-template subtracted coronagraphy (PSFTSC). These new observations, pushing HST to its highest levels of coronagraphic performance, simultaneously probe both the interior regions of these debris systems, with inner working distances < app 8 AU for half the stars in this sample (corresponding to the giant planet and Kuiper belt regions within our own solar system), and the exterior regions far beyond. These new images enable direct inter-comparison of the architectures of these exoplanetary debris systems in the context of our own Solar System: These observations also permit us, for the first time, to characterize material in these regions at high spatial resolution and identify disk sub-structures that are signposts of planet formation and evolution; in particular, asymmetries and non-uniform debris structures that signal the presence of co-orbiting perturbing planets, and dynamical interactions (e.g., resulting in posited small grain stripping and disk "pollution") with the ISM. We focus here on recently acquired and reduced images of he circumstellar debris systems about: AU Mic (edge-on, and @ 10 pc the closest star in our sample), HD 61005, HD 32297 and HD 15115 (all with morphologies strongly suggestive of ISM wind interactions), HD 181327 & HDI07146 (close to face-on with respectively narrow and broad debris rings), and MP Mus (a "mature" proto-planetary disk hosted by a cTTS). All of our objects were previously observed in the near-IR with inferior spatial resolution and imaging efficacy, but with NICMOS r = 0.3" inner working angle (IWA) comparable to STIS multi-roll coronagraphy. The combination of new optical and existing near-IR imaging can strongly constrain the dust properties, thus enabling an assessment of grain processing and planetesimal populations. These results will directly inform upon the posited planet formation mechanisms that occur after the approximately 10 My epoch of gas depletion, a time in our solar system when giant planets were migrating and terrestrial planets were forming, and directly test theoretical models of these processes. These observations lmiquely probe both into the interior regions of these systems and are sensitive to and spatially resolve low surface-brightness (SB) material at large stellocentric distances with spatial resolution comparable to ACS and with augmenting NICMOS near-IR disk photometry in hand.

Application of matched asymptotic expansions to lunar and interplanetary trajectories. Volume 2: Derivations of second-order asymptotic boundary value solutions

NASA Technical Reports Server (NTRS)

Lancaster, J. E.

1973-01-01

Previously published asymptotic solutions for lunar and interplanetery trajectories have been modified and combined to formulate a general analytical solution to the problem of N-bodies. The earlier first-order solutions, derived by the method of matched asymptotic expansions, have been extended to second order for the purpose of obtaining increased accuracy. The complete derivation of the second-order solution, including the application of a regorous matching principle, is given. It is shown that the outer and inner expansions can be matched in a region of order mu to the alpha power, where 2/5 alpha 1/2, and mu (the moon/earth or planet/sun mass ratio) is much less than one. The second-order asymptotic solution has been used as a basis for formulating a number of analytical two-point boundary value solutions. These include earth-to-moon, one- and two-impulse moon-to-Earth, and interplanetary solutions. Each is presented as an explicit analytical solution which does not require iterative steps to satisfy the boundary conditions. The complete derivation of each solution is shown, as well as instructions for numerical evaluation. For Vol. 1, see N73-27738.

Planetary Defense

DTIC Science & Technology

2016-05-01

is very likely that they may develop a solution for planetary defense. 8 United States is leading in space private investments. SpaceX , for...technology, with the ultimate goal of enabling people to live on other planets.5 SpaceX is the only private company ever to return a spacecraft from low...a technically challenging feat previously accomplished only by governments.6 Contracted by NASA and commercial companies, SpaceX already did 50

Same Planet, Different Worlds: Why Projects Continue to Fail. A Generalist Review of Project Management with Special Reference to Electronic Research Administration

ERIC Educational Resources Information Center

McCormick, Ian

2006-01-01

Implementation of IT "solutions" in the context of changes to business processes and efficiency is a common trigger for using formalised project management techniques. The trigger may include topical activities such as job evaluation schemes or quality assurance accreditation. This has led to a blurring of the boundary between projects and…

Resonant Capture and Tidal Evolution in Circumbinary Systems: Testing the Case of Kepler-38

NASA Astrophysics Data System (ADS)

Zoppetti, F. A.; Beaugé, C.; Leiva, A. M.

2018-04-01

Circumbinary planets are thought to form far from the central binary and migrate inwards by interactions with the circumbinary disk, ultimately stopping near their present location either by a planetary trap near the disk inner edge or by resonance capture. Here, we analyze the second possibility, presenting a detailed numerical study on the capture process, resonant dynamics and tidal evolution of circumbinary planets in high-order mean-motion resonances (MMRs). Planetary migration was modeled as an external acceleration in an N-body code, while tidal effects were incorporated with a weak-friction equilibrium tide model. As a working example we chose Kepler-38, a highly evolved system with a planet in the vicinity of the 5/1 MMR. Our simulations show that resonance capture is a high-probability event under a large range of system parameters, although several different resonant configuration are possible. We identified three possible outcomes: aligned librations, anti-aligned librations and chaotic solutions. All were found to be dynamically stable, even after the dissipation of the disk, for time-spans of the order of the system's age. We found that while tidal evolution decreases the binary's separation, the semimajor axis of the planet is driven outwards. Although the net effect is a secular increase in the mean-motion ratio, the system requires a planetary tidal parameter of the order of unity to reproduce the observed orbital configuration. The results presented here open an interesting outlook into the complex dynamics of high-order resonances in circumbinary systems.

Resonant capture and tidal evolution in circumbinary systems: testing the case of Kepler-38

NASA Astrophysics Data System (ADS)

Zoppetti, F. A.; Beaugé, C.; Leiva, A. M.

2018-07-01

Circumbinary planets are thought to form far from the central binary and migrate inwards by interactions with the circumbinary disc, ultimately stopping near their present location either by a planetary trap near the disc inner edge or by resonance capture. Here, we analyse the second possibility, presenting a detailed numerical study on the capture process, resonant dynamics, and tidal evolution of circumbinary planets in high-order mean-motion resonances (MMRs). Planetary migration was modelled as an external acceleration in an N-body code, while tidal effects were incorporated with a weak-friction equilibrium tide model. As a working example, we chose Kepler-38, a highly evolved system with a planet in the vicinity of the 5/1 MMR. Our simulations show that resonance capture is a high-probability event under a large range of system parameters, although several different resonant configuration are possible. We identified three possible outcomes: aligned librations, anti-aligned librations, and chaotic solutions. All were found to be dynamically stable, even after the dissipation of the disc, for time spans of the order of the system's age. We found that while tidal evolution decreases the binary's separation, the semimajor axis of the planet is driven outwards. Although the net effect is a secular increase in the mean-motion ratio, the system requires a planetary tidal parameter of the order of unity to reproduce the observed orbital configuration. The results presented here open an interesting outlook into the complex dynamics of high-order resonances in circumbinary systems.

Do planets remember how they formed?

NASA Astrophysics Data System (ADS)

Kipping, David

2018-01-01

One of the most directly observable features of a transiting multiplanet system is their size-ordering when ranked in orbital separation. Kepler has revealed a rich diversity of outcomes, from perfectly ordered systems, like Kepler-80, to ostensibly disordered systems, like Kepler-20. Under the hypothesis that systems are born via preferred formation pathways, one might reasonably expect non-random size-orderings reflecting these processes. However, subsequent dynamical evolution, often chaotic and turbulent in nature, may erode this information and so here we ask - do systems remember how they formed? To address this, we devise a model to define the entropy of a planetary system's size-ordering, by first comparing differences between neighbouring planets and then extending to accommodate differences across the chain. We derive closed-form solutions for many of the microstate occupancies and provide public code with look-up tables to compute entropy for up to 10-planet systems. All three proposed entropy definitions exhibit the expected property that their credible interval increases with respect to a proxy for time. We find that the observed Kepler multis display a highly significant deficit in entropy compared to a randomly generated population. Incorporating a filter for systems deemed likely to be dynamically packed, we show that this result is robust against the possibility of missing planets too. Put together, our work establishes that Kepler systems do indeed remember something of their younger years and highlights the value of information theory for exoplanetary science.

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

On the Minimum Core Mass for Giant Planet Formation

NASA Astrophysics Data System (ADS)

Piso, Ana-Maria; Youdin, Andrew; Murray-Clay, Ruth

2013-07-01

The core accretion model proposes that giant planets form by the accretion of gas onto a solid protoplanetary core. Previous studies have found that there exists a "critical core mass" past which hydrostatic solutions can no longer be found and unstable atmosphere collapse occurs. This core mass is typically quoted to be around 10Me. In standard calculations of the critical core mass, planetesimal accretion deposits enough heat to alter the luminosity of the atmosphere, increasing the core mass required for the atmosphere to collapse. In this study we consider the limiting case in which planetesimal accretion is negligible and Kelvin-Helmholtz contraction dominates the luminosity evolution of the planet. We develop a two-layer atmosphere model with an inner convective region and an outer radiative zone that matches onto the protoplanetary disk, and we determine the minimum core mass for a giant planet to form within the typical disk lifetime for a variety of disk conditions. We denote this mass as critical core mass. The absolute minimum core mass required to nucleate atmosphere collapse is ˜ 8Me at 5 AU and steadily decreases to ˜ 3.5Me at 100 AU, for an ideal diatomic gas with a solar composition and a standard ISM opacity law. Lower opacity and disk temperature significantly reduce the critical core mass, while a decrease in the mean molecular weight of the nebular gas results in a larger critical core mass. Our results yield lower mass cores than corresponding studies for large planetesimal accretion rates.

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

Geier, S.; Edelmann, H.; Heber, U.

Substellar objects, like planets and brown dwarfs orbiting stars, are by-products of the star formation process. The evolution of their host stars may have an enormous impact on these small companions. Vice versa a planet might also influence stellar evolution as has recently been argued. Here, we report the discovery of an 8-23 Jupiter-mass substellar object orbiting the hot subdwarf HD 149382 in 2.391 d at a distance of only about five solar radii. Obviously, the companion must have survived engulfment in the red giant envelope. Moreover, the substellar companion has triggered envelope ejection and enabled the sdB star tomore » form. Hot subdwarf stars have been identified as the sources of the unexpected ultraviolet (UV) emission in elliptical galaxies, but the formation of these stars is not fully understood. Being the brightest star of its class, HD 149382 offers the best conditions to detect the substellar companion. Hence, undisclosed substellar companions offer a natural solution for the long-standing formation problem of apparently single hot subdwarf stars. Planets and brown dwarfs may therefore alter the evolution of old stellar populations and may also significantly affect the UV emission of elliptical galaxies.« less

Design and optimal control of multi-spacecraft interferometric imaging systems

NASA Astrophysics Data System (ADS)

Chakravorty, Suman

The objective of the proposed NASA Origins mission, Planet Imager, is the high-resolution imaging of exo-solar planets and similar high resolution astronomical imaging applications. The imaging is to be accomplished through the design of multi-spacecraft interferometric imaging systems (MSIIS). In this dissertation, we study the design of MSIIS. Assuming that the ultimate goal of imaging is the correct classification of the formed images, we formulate the design problem as minimization of some resource utilization of the system subject to the constraint that the probability of misclassification of any given image is below a pre-specified level. We model the process of image formation in an MSIIS and show that the Modulation Transfer function of and the noise corrupting the synthesized optical instrument are dependent on the trajectories of the constituent spacecraft. Assuming that the final goal of imaging is the correct classification of the formed image based on a given feature (a real valued function of the image variable), and a threshold on the feature, we find conditions on the noise corrupting the measurements such that the probability of misclassification is below some pre-specified level. These conditions translate into constraints on the trajectories of the constituent spacecraft. Thus, the design problem reduces to minimizing some resource utilization of the system, while satisfying the constraints placed on the system by the imaging requirements. We study the problem of designing minimum time maneuvers for MSIIS. We transform the time minimization problem into a "painting problem". The painting problem involves painting a large disk with smaller paintbrushes (coverage disks). We show that spirals form the dominant set for the solution to the painting problem. We frame the time minimization in the subspace of spirals and obtain a bilinear program, the double pantograph problem, in the design parameters of the spiral, the spiraling rate and the angular rate. We show that the solution of this problem is given by the solution to two associated linear programs. We illustrate our results through a simulation where the banded appearance of a fictitious exo-solar planet at a distance of 8 parsecs is detected.

The Bactericidal Effect of Shock Waves

NASA Astrophysics Data System (ADS)

Leighs, James; Appleby-Thomas, Gareth; Wood, David; Goff, Michael; Hameed, Amer; Hazell, Paul

2013-06-01

There are a variety of theories relating to the origins of life on our home planet, some of which discuss the possibility that life may have been spread via inter-planetary impacts. There have been a number of investigations into the ability of life to withstand the likely conditions generated by asteroid impact (both contained in the impactor and buried beneath the planet surface). Previously published data regarding the ability of bacteria to survive such applied shock waves has produced conflicting conclusions. The work presented here used an established technique, in combination with a single stage gas gun to shock load and subsequently recover Escherichia coli populations suspended in a phosphate buffered saline solution. Peak pressure across the sample region was calculated via numerical modelling, validated via Heterodyne velocimetry measurements. Survival data against peak sample pressure for recovered samples is presented alongside control tests.

Introducing and evaluating a knowledge transfer approach to support problem solving in and around protected areas.

PubMed

Mattsson, Brady J; Fischborn, Marie; Brunson, Mark; Vacik, Harald

2018-03-30

Protected areas (PAs) can generate many benefits inside and outside their borders, and achieving objectives for diverse stakeholders raises many challenges. There are many examples of successful PA management around the globe, although a systematic and comprehensive approach to developing and sharing these solutions has been lacking. We present "solutioning" as a structured process of peer-learning, which can inform management strategies in and around protected areas. We explain how the PANORAMA-Solutions for a Healthy Planet initiative has put solutioning into practice through an interactive community and web portal to learn about protected area solutions around the globe. Unlike other web platforms and initiatives reviewed, PANORAMA facilitates adaptation of solution elements (i.e., building blocks) for novel implementation. Supported by theories of resilience and peer-learning, PANORAMA appears to have potential to promote efficiency and equitable benefits for PAs and associated stakeholders focused on nature conservation and sustainable development, although further research is needed to assess whether this learning leads to better solutions or more effective PA management.

The Effects of Computer-Aided Concept Cartoons and Outdoor Science Activities on Light Pollution

ERIC Educational Resources Information Center

Aydin, Güliz

2015-01-01

The purpose of this study is to create an awareness of light pollution on seventh grade students via computer aided concept cartoon applications and outdoor science activities and to help them develop solutions; and to determine student opinions on the practices carried out. The study was carried out at a middle school in Mugla province of Aegean…

Environmental and economic solutions: Pollution prevention technical assistance and the City of Los Angeles Hazardous and Toxic Materials Office

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

Toy-Chen, D.; Joyce, M.M.

1994-12-31

The City of Los Angeles faces a challenge to assist industrial facilities to minimize and manage hazardous materials in order to sustain the local economy and natural environment. Industrial facilities in Los Angeles County released into the environment or transferred off-site 103,442,074 tons of hazardous materials and waste in 1988. This enormous quantity of hazardous waste requires generators to be in compliance with several environmental regulatory agencies. The City of Los Angeles Hazardous and Toxic Materials (HTM) Office has increased the awareness, commitments, and implementation of hazardous waste at the source, the amount of toxic pollutants discharged into the City`smore » publicly owned treatment works, surface and groundwaters, soils and atmosphere can be substantially reduced. Quantifying hazardous waste minimization progress is extremely difficult and complex. However, the HTM Office anticipates that if the challenge of pollution prevention is successful, more businesses will decide to remain in the region and Los Angeles residents will feel convinced that industry is making good faith efforts to protect the environment. Pollution prevention is a long term solution for the hazardous waste crisis that society has only recently recognized.« less

The possibility of biomasses and coal co-firing in the Czech Republic

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

Juchelkova, D.

1998-07-01

The present state of the environment in the Czech Republic is influenced by many factors and one of them is the quality of fuel used in energetic sources. The greatest share is created by coal, burned with a low capacity, big power station blocks without a significant effort to reduce the emission of pollutants. It is possible to use other provisions for improving the environment: (1) primary--changing the burning fuel, the minimization of pollutant formation resulting in a burning process, the reconstruction of a significant part of burning equipment, and others; (2) or secondary--trapping pollutants. Changing the fuel must bemore » done, however, with minimization of outgoing pollutants. It should not burden surroundings with other undesirable influences and must provide the necessary output. One of the possibilities which is getting attention in the world today is the burning of biomasses. This solution itself has great investment cost (the necessity to build special burning equipment), but an attempt to burn suitable forms of biomass together with coal directly in the existing burning equipment has been discovered as a possible solution to this problem.« less

The real problem.

PubMed

Godfrey, M

1997-01-01

I really was dismayed to see the basic cause of all our planet's problems buried in the September/October 96 issue: "...religious zealots might wreck the family planning needs of a billion people...." Let's face hard facts: all these problems would go away if the planet's population were small enough. What we really need to establish is what the population of the earth should be, and then set out to achieve that population as soon as possible. All of our efforts to reduce automobile pollution, the amount of reactor waste, the number of species being obliterated, etc., are just postponing the inevitable. What we need to look at, and keep track of, are those factors that encourage expanding population and discourage population control. For example, most businesses like to see the population expand so they can have a growing customer base. I truly appreciate your efforts. But if we are going to get anywhere we have to clearly identify the real problem. And then we have to break it down into manageable pieces and go to work on them. Otherwise we are going to keep looking at the graphs and wringing our hands as this accumulation of problems builds until it sweeps over us like a giant tsunami. full text

Solution of the exact equations for three-dimensional atmospheric entry using directly matched asymptotic expansions

NASA Technical Reports Server (NTRS)

Busemann, A.; Vinh, N. X.; Culp, R. D.

1976-01-01

The problem of determining the trajectories, partially or wholly contained in the atmosphere of a spherical, nonrotating planet, is considered. The exact equations of motion for three-dimensional, aerodynamically affected flight are derived. Modified Chapman variables are introduced and the equations are transformed into a set suitable for analytic integration using asymptotic expansions. The trajectory is solved in two regions: the outer region, where the force may be considered a gravitational field with aerodynamic perturbations, and the inner region, where the force is predominantly aerodynamic, with gravity as a perturbation. The two solutions are matched directly. A composite solution, valid everywhere, is constructed by additive composition. This approach of directly matched asymptotic expansions applied to the exact equations of motion couched in terms of modified Chapman variables yields an analytical solution which should prove to be a powerful tool for aerodynamic orbit calculations.

Opportunities and constraints for improved water resources management under increasing hydrological extremes

NASA Astrophysics Data System (ADS)

Wada, Y.

2017-12-01

Increased occurrence of extreme climate events is one of the most damaging consequences of global climate change today and in the future. Estimating the impacts of such extreme events on global and regional water resources is therefore crucial for quantifying increasing risks from climate change. The quest for water security has been a struggle throughout human history. Only in recent years has the scale of this quest moved beyond the local, to the national and regional scales and to the planet itself. Absent or unreliable water supply, sanitation and irrigation services, unmitigated floods and droughts, and degraded water environments severely impact half of the planet's population. The scale and complexity of the water challenges faced by society, particularly but not only in the world's poorest regions, are now recognized, as is the imperative of overcoming these challenges for a stable and equitable world. IIASA's Water Futures and Solutions Initiative (WFAS) is an unprecedented inter-disciplinary scientific initiative to identify robust and adaptive portfolios of optional solutions across different economic sectors, including agriculture, energy and industry, and to test these solution-portfolios with multi-model ensembles of hydrologic and sector models to obtain a clearer picture of the trade-offs, risks, and opportunities. The results of WFaS scenarios and models provide a basis for long-term strategic planning of water resource development under changing environments and increasing climate extremes. And given the complexity of the water system, WFaS uniquely provides policy makers with optional sets of solutions that work together and that can be easily adapted as circumstances change in the future. As WFaS progresses, it will establish a network involving information exchange, mutual learning and horizontal cooperation across teams of researchers, public and private decision makers and practitioners exploring solutions at regional, national and local scales. The initiative includes a major stakeholder consultation component, to inform and guide the science and to test and refine policy and business outcome.

40 CFR 415.162 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT... from which the process brine solution was originally withdrawn, provided no additional pollutants are... through 125.32, any existing point source subject to this subpart and using the solution brine mining...

40 CFR 420.96 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Acid Pickling...) Sulfuric acid pickling (spent acid solutions and rinse waters)—(1) Rod, wire, coil. Subpart I Pollutant or... operations. (b) Hydrochloric acid pickling (spent acid solutions and rinse waters)—(1) Rod, wire, coil...

Average pollutant concentration in soil profile simulated with Convective-Dispersive Equation. Model and Manual

USDA-ARS?s Scientific Manuscript database

Different parts of soil solution move with different velocities, and therefore chemicals are leached gradually from soil with infiltrating water. Solute dispersivity is the soil parameter characterizing this phenomenon. To characterize the dispersivity of soil profile at field scale, it is desirable...

Oil pollution: cleaning up the legal mess. [Liability for pollution

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

Maloof, D.L.

1976-10-01

The legal background of various laws and judicial decisions relative to oil-spill responsibility is reviewed. The positions of the maritime industry, the Federal Government, and coastal state governments are all presented. The Askew Decision and the Florida Oil Spill Prevention and Pollution Control Act of 1970 are discussed. The Federal law purported to be the solution to the problems incurred by the various state legislation acts was presented to both houses of Congress in July, 1975. Until this new act is passed, maritime trade is subject to various state regulations. The furor over liability for oil pollution as controlled bymore » the state regulations is discussed in detail. (BLM)« less

Meteorological conditions, climate change, new emerging factors, and asthma and related allergic disorders. A statement of the World Allergy Organization.

PubMed

D'Amato, Gennaro; Holgate, Stephen T; Pawankar, Ruby; Ledford, Dennis K; Cecchi, Lorenzo; Al-Ahmad, Mona; Al-Enezi, Fatma; Al-Muhsen, Saleh; Ansotegui, Ignacio; Baena-Cagnani, Carlos E; Baker, David J; Bayram, Hasan; Bergmann, Karl Christian; Boulet, Louis-Philippe; Buters, Jeroen T M; D'Amato, Maria; Dorsano, Sofia; Douwes, Jeroen; Finlay, Sarah Elise; Garrasi, Donata; Gómez, Maximiliano; Haahtela, Tari; Halwani, Rabih; Hassani, Youssouf; Mahboub, Basam; Marks, Guy; Michelozzi, Paola; Montagni, Marcello; Nunes, Carlos; Oh, Jay Jae-Won; Popov, Todor A; Portnoy, Jay; Ridolo, Erminia; Rosário, Nelson; Rottem, Menachem; Sánchez-Borges, Mario; Sibanda, Elopy; Sienra-Monge, Juan José; Vitale, Carolina; Annesi-Maesano, Isabella

2015-01-01

The prevalence of allergic airway diseases such as asthma and rhinitis has increased dramatically to epidemic proportions worldwide. Besides air pollution from industry derived emissions and motor vehicles, the rising trend can only be explained by gross changes in the environments where we live. The world economy has been transformed over the last 25 years with developing countries being at the core of these changes. Around the planet, in both developed and developing countries, environments are undergoing profound changes. Many of these changes are considered to have negative effects on respiratory health and to enhance the frequency and severity of respiratory diseases such as asthma in the general population. Increased concentrations of greenhouse gases, and especially carbon dioxide (CO2), in the atmosphere have already warmed the planet substantially, causing more severe and prolonged heat waves, variability in temperature, increased air pollution, forest fires, droughts, and floods - all of which can put the respiratory health of the public at risk. These changes in climate and air quality have a measurable impact not only on the morbidity but also the mortality of patients with asthma and other respiratory diseases. The massive increase in emissions of air pollutants due to economic and industrial growth in the last century has made air quality an environmental problem of the first order in a large number of regions of the world. A body of evidence suggests that major changes to our world are occurring and involve the atmosphere and its associated climate. These changes, including global warming induced by human activity, have an impact on the biosphere, biodiversity, and the human environment. Mitigating this huge health impact and reversing the effects of these changes are major challenges. This statement of the World Allergy Organization (WAO) raises the importance of this health hazard and highlights the facts on climate-related health impacts, including: deaths and acute morbidity due to heat waves and extreme meteorological events; increased frequency of acute cardio-respiratory events due to higher concentrations of ground level ozone; changes in the frequency of respiratory diseases due to trans-boundary particle pollution; altered spatial and temporal distribution of allergens (pollens, molds, and mites); and some infectious disease vectors. According to this report, these impacts will not only affect those with current asthma but also increase the incidence and prevalence of allergic respiratory conditions and of asthma. The effects of climate change on respiratory allergy are still not well defined, and more studies addressing this topic are needed. Global warming is expected to affect the start, duration, and intensity of the pollen season on the one hand, and the rate of asthma exacerbations due to air pollution, respiratory infections, and/or cold air inhalation, and other conditions on the other hand.

Economic evaluation of health losses from air pollution in Beijing, China.

PubMed

Zhao, Xiaoli; Yu, Xueying; Wang, Ying; Fan, Chunyang

2016-06-01

Aggravated air pollution in Beijing, China has caused serious health concern. This paper comprehensively evaluates the health losses from illness and premature death caused by air pollution in monetary terms. We use the concentration of PM10 as an indicator of the pollution since it constitutes the primary pollutant in Beijing. By our estimation, air pollution in Beijing caused a health loss equivalent to Ұ583.02 million or 0.03 % of its GDP. Most of the losses took the form of depreciation in human capital that resulted from premature death. The losses from premature deaths were most salient for people of either old or young ages, with the former group suffering from the highest mortality rates and the latter group the highest per capital losses of human capitals from premature death. Policies that target on PM10 emission reduction, urban vegetation expansion, and protection of vulnerable groups are all proposed as possible solutions to air pollution risks in Beijing.

Can we model solute transfer in heterogeneous soils with MIM model?

NASA Astrophysics Data System (ADS)

Ben Slimene, Erij; Lassabatere, Laurent; Winiarski, Thierry; Gourdon, Remy

2017-04-01

The fate of pollutants in the vadose zone must be understood, in particular, underneath infiltration basins for an optimum management of these plants. Stormwaters carry pollutants (heavy metals, organics, emerging pollutant like nanoparticles, etc.) and thus constitute a risk for groundwater and soil quality. Most infiltration basins are settled over highly permeable soils that exhibit a strong lithological heterogeneity. The impact of such lithological heterogeneity on flow and solute transfer has already been questioned. Previous studies have already proved that lithological heterogeneity was prone to the establishment of preferential flows. In more details, the concomitance of several materials with contrasting hydraulic properties induces funneled flow at the interfaces between less permeable and more permeable lithofacies. Solutes are then carried by water fluxes quickly along preferential flow pathways and have restricted access to zones far from these pathways. It can clearly be imagined that such pattern could be modeled by a MIM model postulating water fraction into two fractions, one mobile and the other immobile, with solute transport by convection and dispersion in mobile water fraction and solute diffusion at the interface between mobile and immobile water fractions. The application of MIM approach to the case of solute transport in strongly heterogeneous soils may be quite advantageous: simplification of the problem, fewer parameters, ease of modeling, numerical computation, gain in computation time, etc. However, such consistency has never been investigated in details. In this paper, we focus on the possibility to model solute transport in a strongly heterogeneous deposit using MIM model. The deposit has been the subject of intensive campaigns of characterization of its lithology and the hydraulic and hydrodispersive properties of its lithofacies. Numerical computations were performed for a section of deposit 13.5 m wide and 2.5 m deep. Numerical results clearly showed the establishment of preferential flows with funneling mostly under unsaturated conditions. Solute elution at 2.5 m depth was characterized and discussed as a function of solute reactivity. Solutes breakthrough curves show clear evidence of MIM like pattern. In this paper, we clearly demonstrate that MIM model accurately reproduces solute elution at 2.5m depths but also at different depths. MIM approach accuracy is ensured provided that related parameters are optimized as a function of depth, hydric and hydraulic conditions and the contrast in hydraulic parameters of the lithofacies that constitute the deposit.

Are Giant Planet Satellites Mini-solar Systems?

NASA Astrophysics Data System (ADS)

Mosqueira, I.; Estrada, P. R.

2003-12-01

The regular satellites of Jupiter and Saturn exhibit a number of characteristics strongly suggestive of formation in a thin (aspect ratio H/r ˜ 0.1) circumplanetary gas disk (Mosqueira and Estrada 2003a). Also, the mass ratio of the largest satellites to the primary μ ˜ 10-4 lead one to think of these satellite systems as scaled-down solar systems. Yet, the larger mass ratio for the giant planets to the primary μ ˜ 10-3 appears to limit the usefulness of the planet-satellite analogy. If gap-opening determines the final size of at least Jupiter (Lin and Papaloizou 1993), then significantly smaller objects would be unable to truncate the disk. There are, however, at least two significant difficulties with this point of view. First, the non-linear or thermal gap-opening criterion (Lin and Papaloizou 1993) does not yield a Jupiter mass. Second, the migration timescale due to planet-disk interactions (Ward 1997) is too fast for the formation of giant planets through the core accretion process (Pollack et. al 1996) despite recent work which has lengthened it by up to an order of magnitude (Tanaka et al. 2002, D'Angelo et al. 2002, Bate et al. 2003). An alternative viewpoint has accretion taking place in a weakly turbulent disk, and the survival of both planets and satellites a direct consequence of gap-opening. In this view at least the largest satellites (Mosqueira and Estrada 2003b) and planetary cores ( ˜ 10 M⊕ ; Rafikov 2002) were able to open gaps in the disk. However, because the waves launched by such pertubers do not become non-linear immediately, the gap begins to form a distance away from the perturber given by the shocking length of acoustic waves (Goodman and Rafikov 2001; Rafikov 2002). Estrada and Mosqueira (2003) have suggested that the annulus of material adjacent to the proto-planet that immediately precedes the runaway gas accretion phase (Pollack et al. 1996) can be used to provide the mass needed to lead to the formation of a giant planet. If so, the dilemma posed by Type I migration (Ward 1997) is mitigated, and the analogy between satellites and planets gains currency. It is possible to argue that an alternative solution to this issue may involve lowering the migration rate even further, but one should keep in mind that slower migration might allow even smaller objects to open gaps. Here we look into the issues raised by this annulus of material in the satellite context, and argue that it may not prevent satellite survival. This work was supported by a NASA PGG grant and the NRC.

Semi-analytical integration of the Earth's precession-nutation based on the GCRS coordinates of the CIP unit vector

NASA Astrophysics Data System (ADS)

Capitaine, N.; Folgueira, M.

2012-12-01

In a previous paper (Capitaine et al. 2006), referred here as Paper I, we demonstrated the possibility of integrating the Earth's rotational motion in terms of the coordinates (X, Y ) of the celestial intermediate pole (CIP) unit vector in the Geocentric celestial reference system (GCRS). Here, we report on the approach that has been followed for solving the equations in the case of an axially symmetric rigid Earth and the semi-analytical (X, Y ) solution obtained from the expression of the external torque acting on the Earth derived from the most complete semi-analytical solutions for the Earth, Moon and planets.

Musica Universalis or the Music of the Spheres

NASA Astrophysics Data System (ADS)

Birat, Jean-Pierre

2018-06-01

The Music of the Spheres was a model of the universe proposed by Pythagoras and Aristotle, which explained cosmology in terms of spheres to which the sun, the moon and the planets were pinned, while their motion was driven by something akin to music. Modern thinking, related to ecology and industrial ecology, has metaphorically breathed life back into this old model by speaking about spheres again: biosphere, geosphere, anthroposphere, technosphere, hydrosphere, cryosphere, atmosphere, etc. Sustainable development also speaks about its three pillars (economy, environment, society) represented in a Venn diagram as intersecting circles (or spheres). All these models differ from the models of physicists, as they are more conceptual diagrams than a representation of the world as it is. Thus, they remind us of the old Music of the Spheres model. They also stress connections, exchanges, equilibria between the spheres - or the lack of them -, like Pythagoras' music. The presentation will discuss these various approaches, see how they match to some extent, but also how they do not show a perfect fit. Analyzing what happens at the boundaries of the spheres, where they overlap or penetrate into each other, is a powerful way to analyze the connection between technology, society, life and ecosystems. It can also help discuss pollution, ecotoxicology and explore global solutions. This article was given as a keynote lecture at the EMERC 2017 (First International Conference on Energy and Material Efficiency), organized by ISIJ in Kobe, Japan, 11-13 October, 2017.

Decontamination of electronic waste-polluted soil by ultrasound-assisted soil washing.

PubMed

Chen, Fu; Yang, Baodan; Ma, Jing; Qu, Junfeng; Liu, Gangjun

2016-10-01

Laboratorial scale experiments were performed to evaluate the efficacy of a washing process using the combination of methyl-β-cyclodextrin (MCD) and tea saponin (TS) for simultaneous desorption of hydrophobic organic contaminants (HOCs) and heavy metals from an electronic waste (e-waste) site. Ultrasonically aided mixing of the field contaminated soil with a combination of MCD and TS solutions simultaneously mobilizes most of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and the analyte metal (Pb, Cu, and Ni) burdens. It is found that 15 g/L MCD and 10 g/L TS is an efficient reagent combination reconciling extraction performance and reagent costs. Under these conditions, the removal efficiencies of HOCs and heavy metals are 93.5 and 91.2 %, respectively, after 2 cycles of 60-min ultrasound-assisted washing cycles. By contrast, 86.3 % of HOCs and 88.4 % of metals are removed from the soil in the absence of ultrasound after 3 cycles of 120-min washing. The ultrasound-assisted soil washing could generate high removal efficiency and decrease the operating time significantly. Finally, the feasibility of regenerating and reusing the spent washing solution in extracting pollutants from the soil is also demonstrated. By application of this integrated technology, it is possible to recycle the washing solution for a purpose to reduce the consumption of surfactant solutions. Collectively, it has provided an effective and economic treatment of e-waste-polluted soil.

Residual Explosives Criteria for Treatment of Area P Soil, Louisiana Army Ammunition Plant

DTIC Science & Technology

1988-03-11

sorbed explosive in soil and water held in soil pores (called the soil solution ). Moreover, equilibrium is presumed to exist between soil slut’rion and...at a soil concentration of a pollutant equal to the product, water o’lub-iiLy*KKd. The soil solution could not become more saturated if the soil...to real behavior. More likely, as the soil solution approaches saturation, the relation between soil and soil solution concentration becomes non-linear

Discovery of a warm, dusty giant planet around HIP 65426

NASA Astrophysics Data System (ADS)

Chauvin, G.; Desidera, S.; Lagrange, A.-M.; Vigan, A.; Gratton, R.; Langlois, M.; Bonnefoy, M.; Beuzit, J.-L.; Feldt, M.; Mouillet, D.; Meyer, M.; Cheetham, A.; Biller, B.; Boccaletti, A.; D'Orazi, V.; Galicher, R.; Hagelberg, J.; Maire, A.-L.; Mesa, D.; Olofsson, J.; Samland, M.; Schmidt, T. O. B.; Sissa, E.; Bonavita, M.; Charnay, B.; Cudel, M.; Daemgen, S.; Delorme, P.; Janin-Potiron, P.; Janson, M.; Keppler, M.; Le Coroller, H.; Ligi, R.; Marleau, G. D.; Messina, S.; Mollière, P.; Mordasini, C.; Müller, A.; Peretti, S.; Perrot, C.; Rodet, L.; Rouan, D.; Zurlo, A.; Dominik, C.; Henning, T.; Menard, F.; Schmid, H.-M.; Turatto, M.; Udry, S.; Vakili, F.; Abe, L.; Antichi, J.; Baruffolo, A.; Baudoz, P.; Baudrand, J.; Blanchard, P.; Bazzon, A.; Buey, T.; Carbillet, M.; Carle, M.; Charton, J.; Cascone, E.; Claudi, R.; Costille, A.; Deboulbe, A.; De Caprio, V.; Dohlen, K.; Fantinel, D.; Feautrier, P.; Fusco, T.; Gigan, P.; Giro, E.; Gisler, D.; Gluck, L.; Hubin, N.; Hugot, E.; Jaquet, M.; Kasper, M.; Madec, F.; Magnard, Y.; Martinez, P.; Maurel, D.; Le Mignant, D.; Möller-Nilsson, O.; Llored, M.; Moulin, T.; Origné, A.; Pavlov, A.; Perret, D.; Petit, C.; Pragt, J.; Puget, P.; Rabou, P.; Ramos, J.; Rigal, R.; Rochat, S.; Roelfsema, R.; Rousset, G.; Roux, A.; Salasnich, B.; Sauvage, J.-F.; Sevin, A.; Soenke, C.; Stadler, E.; Suarez, M.; Weber, L.; Wildi, F.; Antoniucci, S.; Augereau, J.-C.; Baudino, J.-L.; Brandner, W.; Engler, N.; Girard, J.; Gry, C.; Kral, Q.; Kopytova, T.; Lagadec, E.; Milli, J.; Moutou, C.; Schlieder, J.; Szulágyi, J.; Thalmann, C.; Wahhaj, Z.

2017-09-01

Aims: The SHINE program is a high-contrast near-infrared survey of 600 young, nearby stars aimed at searching for and characterizing new planetary systems using VLT/SPHERE's unprecedented high-contrast and high-angular-resolution imaging capabilities. It is also intended to place statistical constraints on the rate, mass and orbital distributions of the giant planet population at large orbits as a function of the stellar host mass and age to test planet-formation theories. Methods: We used the IRDIS dual-band imager and the IFS integral field spectrograph of SPHERE to acquire high-contrast coronagraphic differential near-infrared images and spectra of the young A2 star HIP 65426. It is a member of the 17 Myr old Lower Centaurus-Crux association. Results: At a separation of 830 mas (92 au projected) from the star, we detect a faint red companion. Multi-epoch observations confirm that it shares common proper motion with HIP 65426. Spectro-photometric measurements extracted with IFS and IRDIS between 0.95 and 2.2 μm indicate a warm, dusty atmosphere characteristic of young low-surface-gravity L5-L7 dwarfs. Hot-start evolutionary models predict a luminosity consistent with a 6-12 MJup, Teff = 1300-1600 K and R = 1.5 ± 0.1 RJup giant planet. Finally, the comparison with Exo-REM and PHOENIX BT-Settl synthetic atmosphere models gives consistent effective temperatures but with slightly higher surface gravity solutions of log (g) = 4.0-5.0 with smaller radii (1.0-1.3 RJup). Conclusions: Given its physical and spectral properties, HIP 65426 b occupies a rather unique placement in terms of age, mass, and spectral-type among the currently known imaged planets. It represents a particularly interesting case to study the presence of clouds as a function of particle size, composition, and location in the atmosphere, to search for signatures of non-equilibrium chemistry, and finally to test the theory of planet formation and evolution. Based on observations collected at La Silla and Paranal Observatory, ESO (Chile) Program ID: 097.C-0865 and 098.C-0209 (SPHERE).The planet spectrum is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/605/L9

Terraforming planet Dune: Climate-vegetation interactions on a sandy planet

NASA Astrophysics Data System (ADS)

Cresto Aleina, F.; Baudena, M.; D'Andrea, F.; Provenzale, A.

2012-04-01

The climate and the biosphere of planet Earth interact in multiple, complicated ways and on many spatial and temporal scales. Some of these processes can be studied with the help of simple mathematical models, as done for the effects of vegetation on albedo in desert areas and for the mechanisms by which terrestrial vegetation affects water fluxes in arid environments. Conceptual models of this kind do not attempt at providing quantitative descriptions of the climate-biosphere interaction, but rather to explore avenues and mechanisms which can play a role in the real system, providing inspiration for further research. In this work, we develop a simple conceptual box model in the spirit illustrated above, to explore whether and how vegetation affects the planetary hydrologic cycle. We imagine a planet with no oceans and whose surface is entirely covered with sand, quite similar to planet Dune of the science-fiction series by Frank Herbert (1965). We suppose that water is entirely in the sand, below the surface. Without vegetation, only evaporation takes place, affecting the upper sand layer for a maximum depth of a few cm. The amount of water that is evaporated in the atmosphere is relatively small, and not sufficient to trigger a full hydrologic cycle. The question is what happens to this planet when vegetation is introduced: the root depth can reach a meter or more, and plant transpiration can then transfer a much larger amount of water to the atmosphere. One may wonder whether the presence of vegetation is sufficient to trigger a hydrologic cycle with enough precipitation to sustain the vegetation itself and, if the answer is positive, what is the minimum vegetation cover that is required to maintain the cycle active. In more precise terms, we want to know whether the introduction of vegetation and of the evapotranspiration feedback allows for the existence of multiple equilibria (or solutions) in the soil-vegetation-atmosphere system. Although the box model introduced here is best formulated in terms of a hypothetical sandy planet, the results can be used to study the hydrologic cycle on wide continental regions of the Earth. On the other hand, our findings show how the definition of a habitable climate may also depend on surface characteristics, and in particular on biosphere and climate interactions.

Exchanges across land-water-scape boundaries in urban systems: strategies for reducing nitrate pollution.

PubMed

Cadenasso, M L; Pickett, S T A; Groffman, P M; Band, L E; Brush, G S; Galvin, M F; Grove, J M; Hagar, G; Marshall, V; McGrath, B P; O'Neil-Dunne, J P M; Stack, W P; Troy, A R

2008-01-01

Conservation in urban areas typically focuses on biodiversity and large green spaces. However, opportunities exist throughout urban areas to enhance ecological functions. An important function of urban landscapes is retaining nitrogen thereby reducing nitrate pollution to streams and coastal waters. Control of nonpoint nitrate pollution in urban areas was originally based on the documented importance of riparian zones in agricultural and forested ecosystems. The watershed and boundary frameworks have been used to guide stream research and a riparian conservation strategy to reduce nitrate pollution in urban streams. But is stream restoration and riparian-zone conservation enough? Data from the Baltimore Ecosystem Study and other urban stream research indicate that urban riparian zones do not necessarily prevent nitrate from entering, nor remove nitrate from, streams. Based on this insight, policy makers in Baltimore extended the conservation strategy throughout larger watersheds, attempting to restore functions that no longer took place in riparian boundaries. Two urban revitalization projects are presented as examples aimed at reducing nitrate pollution to stormwater, streams, and the Chesapeake Bay. An adaptive cycle of ecological urban design synthesizes the insights from the watershed and boundary frameworks, from new data, and from the conservation concerns of agencies and local communities. This urban example of conservation based on ameliorating nitrate water pollution extends the initial watershed-boundary approach along three dimensions: 1) from riparian to urban land-water-scapes; 2) from discrete engineering solutions to ecological design approaches; and 3) from structural solutions to inclusion of individual, household, and institutional behavior.

Grassed swales for stormwater pollution control during rain and snowmelt.

PubMed

Bäckström, M

2003-01-01

The retention of suspended solids, particles and heavy metals in different grassed swales during rain events and snowmelt is discussed. The experimental results derived from investigations performed in existing grassed swales in the Luleå region, Northern Sweden. During high pollutant loading rates, grassed swales retain significant amounts of pollutants, mainly due to sedimentation of particulate matter. Low to moderate removal efficiencies could be expected for heavy metals, especially metals in solution (i.e. the dissolved phase). When grassed swales receive urban runoff with low pollutant concentrations, they may release rather than retain pollutants. Swales are important snow deposit areas in the city and particle bound pollutants do to a large extent remain in the swale after snowmelt. However, dissolved pollutants (i.e. dissolved heavy metals) are likely to escape the swale with the melt water. Grassed swales may be regarded as facilities that even out the peaks in pollutant loads without being capable of producing consistent high removal rates. This suggests that swales should be considered as primary treatment devices. Possible design parameters for grassed swales are mean hydraulic detention time, surface loading rate or specific swale area.

Nutritional Solutions to Reduce Risks of Negative Health Impacts of Air Pollution

PubMed Central

Péter, Szabolcs; Holguin, Fernando; Wood, Lisa G.; Clougherty, Jane E.; Raederstorff, Daniel; Antal, Magda; Weber, Peter; Eggersdorfer, Manfred

2015-01-01

Air pollution worldwide has been associated with cardiovascular and respiratory morbidity and mortality, particularly in urban settings with elevated concentrations of primary pollutants. Air pollution is a very complex mixture of primary and secondary gases and particles, and its potential to cause harm can depend on multiple factors—including physical and chemical characteristics of pollutants, which varies with fine-scale location (e.g., by proximity to local emission sources)—as well as local meteorology, topography, and population susceptibility. It has been hypothesized that the intake of anti-oxidant and anti-inflammatory nutrients may ameliorate various respiratory and cardiovascular effects of air pollution through reductions in oxidative stress and inflammation. To date, several studies have suggested that some harmful effects of air pollution may be modified by intake of essential micronutrients (such as B vitamins, and vitamins C, D, and E) and long-chain polyunsaturated fatty acids. Here, we review the existing literature related to the potential for nutrition to modify the health impacts of air pollution, and offer a framework for examining these interactions. PMID:26690474

Nutritional Solutions to Reduce Risks of Negative Health Impacts of Air Pollution.

PubMed

Péter, Szabolcs; Holguin, Fernando; Wood, Lisa G; Clougherty, Jane E; Raederstorff, Daniel; Antal, Magda; Weber, Peter; Eggersdorfer, Manfred

2015-12-10

Air pollution worldwide has been associated with cardiovascular and respiratory morbidity and mortality, particularly in urban settings with elevated concentrations of primary pollutants. Air pollution is a very complex mixture of primary and secondary gases and particles, and its potential to cause harm can depend on multiple factors-including physical and chemical characteristics of pollutants, which varies with fine-scale location (e.g., by proximity to local emission sources)-as well as local meteorology, topography, and population susceptibility. It has been hypothesized that the intake of anti-oxidant and anti-inflammatory nutrients may ameliorate various respiratory and cardiovascular effects of air pollution through reductions in oxidative stress and inflammation. To date, several studies have suggested that some harmful effects of air pollution may be modified by intake of essential micronutrients (such as B vitamins, and vitamins C, D, and E) and long-chain polyunsaturated fatty acids. Here, we review the existing literature related to the potential for nutrition to modify the health impacts of air pollution, and offer a framework for examining these interactions.

Effects of industrial effluents, heavy metals, and organic solvents on mallard embryo development.

PubMed

Hoffman, D J; Eastin, W C

1981-09-01

Mallard eggs were externally exposed at 3 and 8 days of incubation to 7 different industrial effluents and to 7 different heavy metal, organic solvent, and petroleum solutions to screen for potential embryo-toxic effects. This route of exposure was chosen in order to simulate the transfer of pollutant from the plumage of aquatic birds to their eggs. Five of the effluents including mineral pigment, scouring effluent, sludge, and tannery effluent resulted in small but significant reductions in embryonic growth. Treatment with methyl mercury chloride solution of 50 ppm (Hg) impaired embryonic growth but much higher concentrations were required to affect survival and cause teratogenic effects. Oil used to suppress road dust was the most toxic of the pollutants tested and only 0.5 microliter/egg caused 60% mortality by 18 days of development. These findings, in combination with other studies suggest that petroleum pollutants, or effluents in combination with petroleum, may pose a hazard to birds' eggs when exposure is by this route.

Effects of industrial effluents, heavy metals, and organic solvents on mallard embryo development

USGS Publications Warehouse

Hoffman, D.J.; Eastin, W.C.

1981-01-01

Mallard eggs were externally exposed at 3 and 8 days of incubation to 7 different industrial effluents and to 7 different heavy metal, organic solvent, and petroleum solutions to screen for potential embryo-toxic effects. This route of exposure was chosen in order to simulate the transfer of pollutant from the plumage of aquatic birds to their eggs. Five of the effluents including mineral pigment, scouring effluent, sludge, and tannery effluent resulted in small but significant reductions in embryonic growth. Treatment with methyl mercury chloride solution of 50 ppm (Hg) impaired embryonic growth but much higher concentrations were required to affect survival and cause teratogenic effects. Oil used to suppress road dust was the most toxic of the pollutants tested and only 0.5 microliter/egg caused 60% mortality by 18 days of development. These findings, in combination with other studies suggest that petroleum pollutants, or effluents in combination with petroleum, may pose a hazard to birds' eggs when exposure is by this route.

Zeolite A synthesized from alkaline assisted pre-activated halloysite for efficient heavy metal removal in polluted river water and industrial wastewater.

PubMed

Meng, Qingpeng; Chen, Hong; Lin, Junzhong; Lin, Zhang; Sun, Junliang

2017-06-01

High quality zeolite A was synthesized through a hydrothermal process using alkaline-assisted pre-activated halloysite mineral as the alumina and silica source. The synthesis conditions employed in this study were finely tuned by varying the activating temperature, sodium hydroxide content, water content and Si/Al ratio. The obtained zeolite A showed excellent adsorption properties for both single metal cation solutions and mixed cation solutions when the concentrations of the mixed cations were comparable with those in polluted natural river water and industrial wastewater. High adsorptive capacities for Ag + (123.05mg/g) and Pb 2+ (227.70mg/g) were achieved using the synthesized zeolite A. This observation indicates that the zeolite A synthesized from alkaline-assisted pre-activated halloysite can be used as a low-cost and relatively effective adsorbent to purify heavy metal cation polluted natural river water and industrial wastewater. Copyright © 2016. Published by Elsevier B.V.

An auto-adaptive optimization approach for targeting nonpoint source pollution control practices.

PubMed

Chen, Lei; Wei, Guoyuan; Shen, Zhenyao

2015-10-21

To solve computationally intensive and technically complex control of nonpoint source pollution, the traditional genetic algorithm was modified into an auto-adaptive pattern, and a new framework was proposed by integrating this new algorithm with a watershed model and an economic module. Although conceptually simple and comprehensive, the proposed algorithm would search automatically for those Pareto-optimality solutions without a complex calibration of optimization parameters. The model was applied in a case study in a typical watershed of the Three Gorges Reservoir area, China. The results indicated that the evolutionary process of optimization was improved due to the incorporation of auto-adaptive parameters. In addition, the proposed algorithm outperformed the state-of-the-art existing algorithms in terms of convergence ability and computational efficiency. At the same cost level, solutions with greater pollutant reductions could be identified. From a scientific viewpoint, the proposed algorithm could be extended to other watersheds to provide cost-effective configurations of BMPs.

A comprehensive one-dimensional numerical model for solute transport in rivers

NASA Astrophysics Data System (ADS)

Barati Moghaddam, Maryam; Mazaheri, Mehdi; MohammadVali Samani, Jamal

2017-01-01

One of the mechanisms that greatly affect the pollutant transport in rivers, especially in mountain streams, is the effect of transient storage zones. The main effect of these zones is to retain pollutants temporarily and then release them gradually. Transient storage zones indirectly influence all phenomena related to mass transport in rivers. This paper presents the TOASTS (third-order accuracy simulation of transient storage) model to simulate 1-D pollutant transport in rivers with irregular cross-sections under unsteady flow and transient storage zones. The proposed model was verified versus some analytical solutions and a 2-D hydrodynamic model. In addition, in order to demonstrate the model applicability, two hypothetical examples were designed and four sets of well-established frequently cited tracer study data were used. These cases cover different processes governing transport, cross-section types and flow regimes. The results of the TOASTS model, in comparison with two common contaminant transport models, shows better accuracy and numerical stability.

Special Advanced Studies for Pollution Prevention. Delivery Order 0058: The Monitor - Spring 2000

DTIC Science & Technology

2001-04-01

Process complexity ➨ Strippability ➨ Maturity ➨ Process type and chemistry ➨ Licensing requirements ➨ Vendor information ➨ Niplate 700 (Surface...Courses of Action 4 Identify & Evaluate Potential Alternatives 5 Select Best Alternative & Develop Project 6 Prioritize Projects by Commodity 7 Rank...Burden CS Priority Process Specific P2 OASolution Selection Solution Planning Solution Implementation Solution Evaluation Phase 2 Phase 3 Phase 1

Bioavailable cadmium during the bioremediation of phenanthrene-contaminated soils using the diffusive gradients in thin-film technique.

PubMed

Amezcua-Allieri, M A; Rodríguez-Vázquez, R

2006-03-01

To study the impact of fungal bioremediation of phenanthrene on trace cadmium solid-solution fluxes and solution phase concentration. The bioremediation of phenanthrene in soils was performed using the fungus Penicillium frequentans. Metal behaviour was evaluated by the techniques of diffusive gradient in thin-films (DGT) and filtration. Fluxes of cadmium (Cd) show a significant (P < 0.002) increase after the start of bioremediation, indicating that the bioremediation process itself releases significant amount of Cd into solution from the soil solid-phase. Unlike DGT devices, the solution concentration from filtration shows a clear bimodal distribution. We postulate that the initial action of the fungi is most likely to breakdown the surface of the solid phase to smaller, 'solution-phase' material (<0.45 microm) leading to a peak in Cd concentration in solution. Phenanthrene removal from soils by bioremediation ironically results in the mobilization of another toxic pollutant (Cd). Bioremediation of organic pollutants in contaminated soil will likely lead to large increases in the mobilization of toxic metals, increasing metal bio-uptake and incorporation into the wider food chain. Bioremediation strategies need to account for this behaviour and further research is required both to understand the generality of this behaviour and the operative mechanisms.

Stream Management

DTIC Science & Technology

2000-03-01

from coconut husks bound within a woven mesh rope either made from polyethylene or coir rope. The CGR incorporates wetland plants (usually as rooted...Process 6-1 Nonrestoration Alternative Considerations 6-3 Stormwater ponds 6-4 Infiltration (exfiltration) devices 6-6 Oil and grease trap devices 6-8... Oil and Grease Trap Pollutant Removal 6-9 Table 6.4. Sand Filter Pollutant Removal 6-11 Table 6.5. Selection of Appropriate Structural Solutions

40 CFR 421.252 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/troy ounce of gold and... monthly average mg/troy ounce of silver reduced in solution Lead 0.168 0.080 Mercury 0.100 0.040 Silver 0... property Maximum for any 1 day Maximum for monthly average mg/troy ounce of gold refined electrolytically...

Laboratory Reactor for Processing Carbon-Containing Sludge

NASA Astrophysics Data System (ADS)

Korovin, I. O.; Medvedev, A. V.

2016-10-01

The paper describes a reactor for high-temperature pyrolysis of carbon-containing sludge with the possibility of further development of environmentally safe technology of hydrocarbon waste disposal to produce secondary products. A solution of the urgent problem has been found: prevention of environmental pollution resulting from oil pollution of soils using the pyrolysis process as a method of disposal of hydrocarbon waste to produce secondary products.

What Do Israeli High School Students Understand about Biodiversity? An Evaluation of the High School Biology Programme, "Nature in a World of Change"

ERIC Educational Resources Information Center

Dor-Haim, Shayli; Amir, Ruth; Dodick, Jeff

2011-01-01

One of the most serious problems facing our planet is the biodiversity crisis. As a solution to this problem, both scientists and educators have emphasised the need for educating people about how to conserve the Earth's biodiversity. As a small contribution to this effort, we have designed a learning unit about biodiversity, "Nature in a…

Existence of collisional trajectories of Mercury, Mars and Venus with the Earth.

PubMed

Laskar, J; Gastineau, M

2009-06-11

It has been established that, owing to the proximity of a resonance with Jupiter, Mercury's eccentricity can be pumped to values large enough to allow collision with Venus within 5 Gyr (refs 1-3). This conclusion, however, was established either with averaged equations that are not appropriate near the collisions or with non-relativistic models in which the resonance effect is greatly enhanced by a decrease of the perihelion velocity of Mercury. In these previous studies, the Earth's orbit was essentially unaffected. Here we report numerical simulations of the evolution of the Solar System over 5 Gyr, including contributions from the Moon and general relativity. In a set of 2,501 orbits with initial conditions that are in agreement with our present knowledge of the parameters of the Solar System, we found, as in previous studies, that one per cent of the solutions lead to a large increase in Mercury's eccentricity-an increase large enough to allow collisions with Venus or the Sun. More surprisingly, in one of these high-eccentricity solutions, a subsequent decrease in Mercury's eccentricity induces a transfer of angular momentum from the giant planets that destabilizes all the terrestrial planets approximately 3.34 Gyr from now, with possible collisions of Mercury, Mars or Venus with the Earth.

An Introduction to the Solar System

NASA Astrophysics Data System (ADS)

McBride, Neil; Gilmour, Iain

2004-02-01

Compiled by a team of experts, this textbook has been designed for introductory university courses in planetary science. It starts with a tour of the Solar System and an overview of its formation. The composition, internal structure, surface morphology and atmospheres of the terrestrial planets are then described. This leads naturally to a discussion of the giant planets and why they are compositionally different. Minor bodies are reviewed and the book concludes with a discussion of the origin of the Solar System and the evidence from meteorites. Written in an accessible style that avoids complex mathematics, and illustrated in colour throughout, this book is suitable for self-study and will appeal to amateur enthusiasts as well as undergraduate students. It contains numerous helpful learning features such as boxed summaries, student exercises with full solutions, and a glossary of terms. The book is also supported by a website hosting further teaching materials. Written by a team of experts in an accessible style that avoids complex mathematics, and illustrated in colour throughout Contains numerous pedagogical features including boxed summaries, brief biographies of pioneering astronomers, bulleted questions and answers throughout, over 90 exercises with full solutions, and a glossary of terms Supported by a website hosting additional teaching materials including illustrations, further exercises and links to other Internet resources

An Infrared Telescope for Planet Detection and General Astrophysics

NASA Technical Reports Server (NTRS)

Lillie, C. F.; Atkinson, C. B.; Casement, L. S.; Flannery, M. R.; Kroening, K. V.; Moses, S. L.

2004-01-01

NASA plans to launch a Terrestrial Planet Finder (TPF) mission in 2014 to detect and characterize Earth-like planets around nearby stars, perform comparative planetology studies, and obtain general astrophysics observations. During our recently completed a TPF Mission Architecture study for NASA/JPL we developed the conceptual design for a 28-meter telescope with an IR Coronagraph that meets these mission objectives. This telescope and the technology it embodies are directly applicable to future Far-IR and Submillimeter space missions. The detection of a 30th magnitude planet located within 50 milli-arc-seconds of a 5th (Visual) magnitude star is an exceptionally challenging objective. Observations in the thermal infrared (7-17 microns) are somewhat easier since the planet is "only" 15(sup m) fainter than the star at these wavelengths, but many severe challenges must still be overcome. These challenges include: 1. Designing a coronagraph for star:planet separations less than or equal to lambda/D. 2. Developing the deployment scheme for a 28m space telescope that can fit in an existing launch vehicle payload fairing. 3. Generating configuration layouts for the IR telescope, coronagraph, spacecraft bus, sunshade, solar array, and high-gain antenna. 4. Providing: Structural stability to within 10 microns to support the optics. Thermal control to achieve the necessary structural stability, as well as providing a stable (approx. 30K) thermal environment for the optics. Dynamics isolation from potential jitter sources. 5. Minimizing launch mass to provide the maximum payload for the science mission Interfacing to an EELV Heavy launch vehicle, including acoustic and stress loads for the launch environment. 6. Identifying the key technologies (which can be developed by 2009) that will enable TPF mission to be performed. 7. Generating a manufacturing plan that will permit TPF to be developed at a reasonable cost and schedule. Many of these design challenges result in inherently conflicting requirements on the design of TPF. Drawing on our experience with large space telescopes such as the Chandra X-ray Observatory and the Next Generation Space Telescope, we have created a conceptual design for TPF that successfully meets these challenging requirements. This paper describes our solution to these challenges.

The Demonology of Pollution.

ERIC Educational Resources Information Center

Landsberg, Hans H.

This paper offers a fresh perspective on causes of and solutions to environmental problems, and would be useful as an initiator of classroom discussions. The author argues that in our pursuit of a society based on environmentally sound principles, we have perhaps misidentified the villains, and have latched into solutions that may be either naive,…

A Pollutant Transformation Laboratory Exercise for Environmental Chemistry: The Reduction of Nitrobenzenes by Anaerobic Solutions of Humic Acid

ERIC Educational Resources Information Center

Dunnivant, Frank M.; Reynolds, Mark-Cody

2007-01-01

The laboratory experiment, which acts as a capstone, integrated lecture-laboratory exercise involving solution preparation, pH buffers, [E[subscript]H] (reduction potential) buffers, organic reaction mechanisms, reaction kinetics, and instrumental analysis is presented. The students completing the lecture and laboratory exercises could gain a…

A model for managing sources of groundwater pollution

USGS Publications Warehouse

Gorelick, Steven M.

1982-01-01

The waste disposal capacity of a groundwater system can be maximized while maintaining water quality at specified locations by using a groundwater pollutant source management model that is based upon linear programing and numerical simulation. The decision variables of the management model are solute waste disposal rates at various facilities distributed over space. A concentration response matrix is used in the management model to describe transient solute transport and is developed using the U.S. Geological Survey solute transport simulation model. The management model was applied to a complex hypothetical groundwater system. Large-scale management models were formulated as dual linear programing problems to reduce numerical difficulties and computation time. Linear programing problems were solved using a numerically stable, available code. Optimal solutions to problems with successively longer management time horizons indicated that disposal schedules at some sites are relatively independent of the number of disposal periods. Optimal waste disposal schedules exhibited pulsing rather than constant disposal rates. Sensitivity analysis using parametric linear programing showed that a sharp reduction in total waste disposal potential occurs if disposal rates at any site are increased beyond their optimal values.

Statistically based sustainable re-design of stormwater overflow control systems in urban catchments

NASA Astrophysics Data System (ADS)

Ganora, Daniele; Isacco, Silvia; Claps, Pierluigi

2017-04-01

Control and reduction of pollution from stormwater overflow is a major concern for municipalities to manage the quality of the receiving water bodies according to the Framework Water Directive 2000/60/CE. In this regard, assessment studies of the potential pollution load from sewer networks recognize the need for adaptation and upgrade of existing drainage systems, which can be achieved with either traditional water works (detention tanks, increase of wastewater treatment plant capacity, etc.) or even Nature-based solutions (constructed wetlands, restored floodplains, etc.) sometimes used in combination. Nature-based solutions are recently receiving consistent attentions as they are able to enhance urban and degraded environments being, in the same time, more resilient and adaptable to climatic and anthropic changes than most traditional engineering works. On the other hand, restoration of the urban environment using natural absorbing surfaces requires diffuse interventions, high costs and a considerable amount of time. In this work we investigate how simple, economically-sustainable and quick solutions to the problem at hand can be addressed by changes in the management rules when pumping stations play a role in sewer systems. In particular, we provide a statistically-based framework to be used in the calibration of the management rules, facing improved quality of overflows from sewer systems. Typical pumping rules favor a massive delivery of stormwater volumes to the wastewater treatment plans, requiring large storage tanks in the sewer network, heavy pumping power and reducing the efficiency of the treatment plant due to pollutant dilution. In this study we show that it is possible to optimize the pumping rule in order to reduce pumped volumes to the plant (thus saving energy), while simultaneously keeping high pollutant concentration. On the other hand, larger low-concentration overflow volumes are released outside the sewer network with respect to the standard pumping rules. Such released volumes could be efficiently processed by nature-based solutions, like for instance constructed wetlands, to reduce the final pollutant impact on the environment. The proposed procedure is based on the previous knowledge of the precipitation forcing and of a quantity/quality model of the sewer network. The method provides marginal and joint probability distributions of water volumes and pollutant concentration (or mass) delivered toward the wastewater treatment plant and the Nature-based system, with the aim of supporting a more efficient design of the whole sewer system. A practical example of application is provided for illustrative purposes.

Monitoring of pyrocatechol indoor air pollution

NASA Astrophysics Data System (ADS)

Eškinja, I.; Grabarić, Z.; Grabarić, B. S.

Spectrophotometric and electrochemical methods for monitoring of pyrocatechol (PC) indoor air pollution have been investigated. Spectrophotometric determination was performed using Fe(III) and iodine methods. The adherence to Beer's law was found in the concentration range between 0 and 12 μg ml - for iodine method at pH = 5.7 measuring absorbance at 725 nm, and in the range 0-30 μg ml - for Fe(III) method at pH = 9.5 measuring absorbance at 510 nm. The former method showed greater sensitivity than the latter one. Differential pulse voltammetry (DPV) and chronoamperometric (CA) detection in flow injection analysis (FIA) using carbon paste electrode in phosphate buffer solution of pH = 6.5 was also used for pyrocatechol determination. The electrochemical methods allowed pyrocatechol quantitation in submicromolar concentration level with an overall reproducibility of ± 1%. The efficiency of pyrocatechol sampling collection was investigated at two temperatures (27 and 40°C) in water, 0.1 M NaOH and 0.1 M HCl solutions. Solution of 0.1 M HCl gave the best collection efficiency (95.5-98.5%). A chamber testing simulating the indoor pollution has been performed. In order to check the reliability of the proposed methods for monitoring of the indoor pyrocatechol pollution, the air in working premises with pyrocatechol released from meteorological charts during mapping and paper drying was analyzed using proposed methods. The concentration of pyrocatechol in the air during mapping was found to be 1.8 mg m -3 which is below the hygienic standard of permissible exposure of 20 mg m -3 (≈ 5 ppm). The release of pyrocatechol from the paper impregnated with pyrocatechol standing at room temperature during one year was also measured. The proposed methods can be used for indoor pyrocatechol pollution monitoring in working premises of photographic, rubber, oil and dye industries, fur and furniture dyeing and cosmetic or pharmaceutical premises where pyrocatechol and related compounds are in use.

Experientally guided robots. [for planet exploration

NASA Technical Reports Server (NTRS)

Merriam, E. W.; Becker, J. D.

1974-01-01

This paper argues that an experientally guided robot is necessary to successfully explore far-away planets. Such a robot is characterized as having sense organs which receive sensory information from its environment and motor systems which allow it to interact with that environment. The sensori-motor information which it receives is organized into an experiential knowledge structure and this knowledge in turn is used to guide the robot's future actions. A summary is presented of a problem solving system which is being used as a test bed for developing such a robot. The robot currently engages in the behaviors of visual tracking, focusing down, and looking around in a simulated Martian landscape. Finally, some unsolved problems are outlined whose solutions are necessary before an experientally guided robot can be produced. These problems center around organizing the motivational and memory structure of the robot and understanding its high-level control mechanisms.

Candidate Nearby, Young Stars in Gaia's First Data Release

NASA Astrophysics Data System (ADS)

Chalifour, Matthieu; Kastner, Joel H.; Binks, Alex; Rodriguez, David; Punzi, Kristina; Zuckerman, Ben; Sacco, Germano

2018-01-01

The nearest examples of young stars are essential subjects for the study of planet and star formation. The recent data release from Gaia, which contains accurate parallax distances for ~2.5 million stars, allows age determinations via isochronal analysis for thousands of stars within ~100 pc. We have selected nearly 400 candidates nearby, young, late-type stars in the approximate mass range 0.5-1.0 Msun from the Tycho Gaia Astrometric Solution catalog on the basis of (a) D < 100 pc, (b) Galex UV detection, and (c) isochronal age <~ 80 Myr. Approximately 10% of these candidates lie within 50 pc of Earth and, hence, may represent excellent targets for direct-imaging searches for young, self-luminous planets. We discuss our ongoing efforts to assess the accuracy of these stars' isochronal ages via various diagnostic tools, including galactic kinematics, UV excess, relative X-ray luminosity, andoptical spectroscopic indicators of youth.

The bactericidal effect of shock waves

NASA Astrophysics Data System (ADS)

Leighs, J. A.; Appleby-Thomas, G. J.; Wood, D. C.; Goff, M. J.; Hameed, A.; Hazell, P. J.

2014-05-01

There are a variety of theories relating to the origins of life on our home planet, some of which discuss the possibility that life may have been spread via inter-planetary bodies. There have been a number of investigations into the ability of life to withstand the likely conditions generated by asteroid impact (both contained in the impactor and buried beneath the planet surface). Previously published data regarding the ability of bacteria to survive such applied shockwaves has produced conflicting conclusions. The work presented here used an established and published technique in combination with a single stage gas gun, to shock and subsequently recover Escherichia coli populations suspended in a phosphate buffered saline solution. Peak pressure across the sample region was calculated via numerical modelling. Survival data against peak sample pressure for recovered samples is presented alongside control tests. SEM micrographs of shocked samples are presented alongside control sets to highlight key differences between cells in each case.

Bayesian planet searches in radial velocity data

NASA Astrophysics Data System (ADS)

Gregory, Phil

2015-08-01

Intrinsic stellar variability caused by magnetic activity and convection has become the main limiting factor for planet searches in both transit and radial velocity (RV) data. New spectrographs are under development like ESPRESSO and EXPRES that aim to improve RV precision by a factor of approximately 100 over the current best spectrographs, HARPS and HARPS-N. This will greatly exacerbate the challenge of distinguishing planetary signals from stellar activity induced RV signals. At the same time good progress has been made in simulating stellar activity signals. At the Porto 2014 meeting, “Towards Other Earths II,” Xavier Dumusque challenged the community to a large scale blind test using the simulated RV data to understand the limitations of present solutions to deal with stellar signals and to select the best approach. My talk will focus on some of the statistical lesson learned from this challenge with an emphasis on Bayesian methodology.

Photometric investigation of hot exoplanets: TrES-3b and Qatar-1b

NASA Astrophysics Data System (ADS)

Püsküllü, Ç.; Soydugan, F.; Erdem, A.; Budding, E.

2017-08-01

New photometric follow-up observations of transitting 'hot Jupiters' TrES-3b and Qatar-1b are presented. Weighted mean values of the solutions of light curves in R-filter for both planetary systems are reported and compared with the previous results. The transit light curves were analysed using the WINFITTER code. The physical properties of the planets were estimated. The planet radii are found to be Rp = 1.381 ± 0.033RJ for TrES-3b and Rp = 1.142 ± 0.025RJ for Qatar-1b. Transit times and their uncertainties were also determined and a new linear ephemeris was computed for both systems. Analysis of transit times showed that a significant signal could not be determined for TrES-3b, while weak evidence was found for Qatar-1b, which might be tested using more precise future transit times.

Reaction-induced rheological weakening enables oceanic plate subduction.

PubMed

Hirauchi, Ken-Ichi; Fukushima, Kumi; Kido, Masanori; Muto, Jun; Okamoto, Atsushi

2016-08-26

Earth is the only terrestrial planet in our solar system where an oceanic plate subducts beneath an overriding plate. Although the initiation of plate subduction requires extremely weak boundaries between strong plates, the way in which oceanic mantle rheologically weakens remains unknown. Here we show that shear-enhanced hydration reactions contribute to the generation and maintenance of weak mantle shear zones at mid-lithospheric depths. High-pressure friction experiments on peridotite gouge reveal that in the presence of hydrothermal water, increasing strain and reactions lead to an order-of-magnitude reduction in strength. The rate of deformation is controlled by pressure-solution-accommodated frictional sliding on weak hydrous phyllosilicate (talc), providing a mechanism for the 'cutoff' of the high peak strength at the brittle-plastic transition. Our findings suggest that infiltration of seawater into transform faults with long lengths and low slip rates is an important controlling factor on the initiation of plate tectonics on terrestrial planets.

Large space-based systems for dealing with global environment change

NASA Technical Reports Server (NTRS)

Jenkins, Lyle M.

1992-01-01

Increased concern over the effects of global climate change and depletion of the ozone layer has resulted in support for the Global Change Research Program and the Mission to Planet Earth. Research to understand Earth system processes is critical, but it falls short of providing ways of mitigating the effects of change. Geoengineering options and alternatives to interactively manage change need to be developed. Space-based concepts for dealing with changes to the environment should be considered in addition to Earth-based actions. 'Mission for Planet Earth' describes those space-based geoengineering solutions that may combine with an international global change program to stabilize the Global environment. Large space systems that may be needed for this response challenge guidance and control engineering and technology. Definition, analysis, demonstration, and preparation of geoengineering technology will provide a basis for policy response if global change consequences are severe.

The First Planetary Microlensing Event with Two Microlensed Source Stars

NASA Astrophysics Data System (ADS)

Bennett, D. P.; Udalski, A.; Han, C.; Bond, I. A.; Beaulieu, J.-P.; Skowron, J.; Gaudi, B. S.; Koshimoto, N.; Abe, F.; Asakura, Y.; Barry, R. K.; Bhattacharya, A.; Donachie, M.; Evans, P.; Fukui, A.; Hirao, Y.; Itow, Y.; Li, M. C. A.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Muraki, Y.; Nagakane, M.; Ohnishi, K.; Oyokawa, H.; Ranc, C.; Rattenbury, N. J.; Rosenthal, M. M.; Saito, To.; Sharan, A.; Sullivan, D. J.; Sumi, T.; Suzuki, D.; Tristram, P. J.; Yonehara, A.; The MOA Collaboration; Szymański, M. K.; Poleski, R.; Soszyński, I.; Ulaczyk, K.; Wyrzykowski, Ł.; The OGLE Collaboration; DePoy, D.; Gould, A.; Pogge, R. W.; Yee, J. C.; The μFUN Collaboration; Albrow, M. D.; Bachelet, E.; Batista, V.; Bowens-Rubin, R.; Brillant, S.; Caldwell, J. A. R.; Cole, A.; Coutures, C.; Dieters, S.; Dominis Prester, D.; Donatowicz, J.; Fouqué, P.; Horne, K.; Hundertmark, M.; Kains, N.; Kane, S. R.; Marquette, J.-B.; Menzies, J.; Pollard, K. R.; Ranc, C.; Sahu, K. C.; Wambsganss, J.; Williams, A.; Zub, M.; The PLANET Collaboration

2018-03-01

We present the analysis of the microlensing event MOA-2010-BLG-117, and show that the light curve can only be explained by the gravitational lensing of a binary source star system by a star with a Jupiter-mass ratio planet. It was necessary to modify standard microlensing modeling methods to find the correct light curve solution for this binary source, binary-lens event. We are able to measure a strong microlensing parallax signal, which yields the masses of the host star, M * = 0.58 ± 0.11 M ⊙, and planet, m p = 0.54 ± 0.10M Jup, at a projected star–planet separation of a ⊥ = 2.42 ± 0.26 au, corresponding to a semimajor axis of a=2.9≥nfrac{}{}{0em}{}{+1.6}{-0.6} au. Thus, the system resembles a half-scale model of the Sun–Jupiter system with a half-Jupiter0mass planet orbiting a half-solar-mass star at very roughly half of Jupiter’s orbital distance from the Sun. The source stars are slightly evolved, and by requiring them to lie on the same isochrone, we can constrain the source to lie in the near side of the bulge at a distance of D S = 6.9 ± 0.7 kpc, which implies a distance to the planetary lens system of D L = 3.5 ± 0.4 kpc. The ability to model unusual planetary microlensing events, like this one, will be necessary to extract precise statistical information from the planned large exoplanet microlensing surveys, such as the WFIRST microlensing survey.

Ecotoxicological characteristic of a soil polluted by radioactive elements and heavy metals before and after its bioremediation

NASA Astrophysics Data System (ADS)

Georgiev, P.; Groudev, S.; Spasova, I.; Nikolova, M.

2012-04-01

Cinnamon soils from southeastern Bulgaria are heavily polluted with radionuclides (uranium, radium) and toxic heavy metals (copper and lead) due to the winds transportation of fine particles from flotation dumps to the soil surface. As a result of this, the polluted soils are characterized by a slightly alkaline pH (7.82) and positive net neutralization potential (+136.8 kg CaCO3/t). A fresh sample of cinnamon soil was subjected to remediation under laboratory conditions in four lysimeters each containing 70 kg of soil. The preliminary study revealed that most of the pollutants were presented as carbonate, reducible and oxidisable mobility fractions, i.e. pollutants ions were specifically adsorbed by carbonate and ferric iron minerals or were capsulated in sulfides. The applied soil treatment was connected with leaching of the pollutants located mainly in the horizon A, their transportation through the soil profile as soluble forms, and their precipitation in the rich-in-clay subhorizon B3. The efficiency of leaching depended on the activity of the indigenous microflora and on the chemical processes connected with solubilization of pollutants and formation of stable complexes with some organic compounds, chloride and hydrocarbonate ions. These processes were considerably enhanced by adding hay to the horizon A and irrigating the soil with water solutions containing the above-mentioned ions and some nutrients. After 18 months of treatment, each of the soil profiles in the different lysimeters was divided into five sections reflecting the different soil layers. The soil in these sections was subjected to a detailed chemical analysis and the data obtained were compared with the relevant data obtained before the start of the experiment. The best leaching of pollutants from horizon A was measured in the variants where soil mulching was applied. For example, the best leaching of lead (54.5 %) was found in the variant combining this technique and irrigation with solutions containing only nutrients. The best leaching of uranium (66.3 %), radium (62.5 %), and copper (15.1 %) were measured in the variant in which the soil was subjected to mulching and irrigation with alkaline solutions containing hydocarbonate ions. Despite the higher removal of these pollutants from the soil, the acute soil toxicity towards earthworms (Lumbricus terrestris) was higher in comparison to the toxicity of soil that had been treated in the other variant. Furthermore, the highly alkaline soil pH (10.47) that was determined due to the applied alkaline leaching resulted in an acute soil toxicity to oats (Avena sativa) and clover (Trifolium repens) that was even higher in comparison to the toxicity of the non-treated soil. These data revealed that the soil detoxification was depended not only on the decrease of the total concentration and on the bioavailable forms of above-mentioned pollutants but also on the changes that had taken place in chemical and geotechnical properties of the treated soil.

Science and Society Test for Scientists: Transportation

ERIC Educational Resources Information Center

Hafemeister, David

1976-01-01

Presents numerous questions concerning transportation systems, energy consumption, noise, air pollution and other transportation oriented topics. Solutions are provided using undergraduate pre-calculus mathematics. (CP)

Fast adsorption kinetics of highly dispersed ultrafine nickel/carbon nanoparticles for organic dye removal

NASA Astrophysics Data System (ADS)

Kim, Taek-Seung; Song, Hee Jo; Dar, Mushtaq Ahmad; Lee, Hack-Jun; Kim, Dong-Wan

2018-05-01

Magnetic metal/carbon nano-materials are attractive for pollutant adsorption and removal. In this study, ultrafine nickel/carbon nanoparticles are successfully prepared via electrical wire explosion processing in ethanol media for the elimination of pollutant organic dyes such as Rhodamine B and methylene blue in aqueous solutions. High specific surface areas originating from both the nano-sized particles and the existence of carbon on the surface of Ni nanoparticles enhance dye adsorption capacity. In addition to this, the excellent dispersity of Ni/C nanoparticles in aqueous dye solutions leads to superior adsorption rates. The adsorption kinetics for the removal of organic dyes by Ni/C nanoparticles agree with a pseudo-second-order model and follow Freundlich adsorption isotherm behavior.

Washing as a remediation technology applicable in soils heavily polluted by mining-metallurgical activities.

PubMed

Moutsatsou, A; Gregou, M; Matsas, D; Protonotarios, V

2006-06-01

A permanent solution in order to remediate a heavily contaminated soil is washing it utilizing the appropriate reagents. The study presented in this paper deals with the washing of a soil highly polluted by mining and metallurgical activities. Pollution consists of slags, sulphur compound waste and various low grade lead condensates, all rich in heavy metals and metalloids (Pb, As, Cu, Zn, Mn and Fe). Soil was washed with deionized water, 6, 3, 2 and 1 M HCl, 6 M H(2)SO(4), 6 M HNO(3) and 0.1 M Na(2)EDTA. High extraction efficiency was achieved with respect to hydrochloric acid even at the lowest concentration; the solubility of pollutants in nitric acid was low, while sulphuric acid was proven to be problematic with respect to lead. Mobilization of metals and metalloids under DI water effect was minimal indicating that the elements fraction that is weakly bound to soil particles is insignificant. Furthermore, a kinetic study was undertaken, utilizing 1 M HCl and 0.1 M Na(2)EDTA. Results illustrated that 1 M HCl was more effective for intermediate mixing times (up to 4 h) while 0.1 M Na(2)EDTA was better applicable to short mixing times (<1 h) and low pH values (pH < 7.1). 1 M HCl was proven to be very effective for the removal of pollutants from contaminated soil but the high metal content of the resulting solution necessitates further treatment for the retention of metals.

Organic pollution of rivers: Combined threats of urbanization, livestock farming and global climate change

NASA Astrophysics Data System (ADS)

Wen, Yingrong; Schoups, Gerrit; van de Giesen, Nick

2017-02-01

Organic pollution of rivers by wastewater discharge from human activities negatively impacts people and ecosystems. Without treatment, pollution control relies on a combination of natural degradation and dilution by natural runoff to reduce downstream effects. We quantify here for the first time the global sanitation crisis through its impact on organic river pollution from the threats of (1) increasing wastewater discharge due to urbanization and intensification of livestock farming, and (2) reductions in river dilution capacity due to climate change and water extractions. Using in-stream Biochemical Oxygen Demand (BOD) as an overall indicator of organic river pollution, we calculate historical (2000) and future (2050) BOD concentrations in global river networks. Despite significant self-cleaning capacities of rivers, the number of people affected by organic pollution (BOD >5 mg/l) is projected to increase from 1.1 billion in 2000 to 2.5 billion in 2050. With developing countries disproportionately affected, our results point to a growing need for affordable wastewater solutions.

Using biochar for remediation of soils contaminated with heavy metals and organic pollutants.

PubMed

Zhang, Xiaokai; Wang, Hailong; He, Lizhi; Lu, Kouping; Sarmah, Ajit; Li, Jianwu; Bolan, Nanthi S; Pei, Jianchuan; Huang, Huagang

2013-12-01

Soil contamination with heavy metals and organic pollutants has increasingly become a serious global environmental issue in recent years. Considerable efforts have been made to remediate contaminated soils. Biochar has a large surface area, and high capacity to adsorb heavy metals and organic pollutants. Biochar can potentially be used to reduce the bioavailability and leachability of heavy metals and organic pollutants in soils through adsorption and other physicochemical reactions. Biochar is typically an alkaline material which can increase soil pH and contribute to stabilization of heavy metals. Application of biochar for remediation of contaminated soils may provide a new solution to the soil pollution problem. This paper provides an overview on the impact of biochar on the environmental fate and mobility of heavy metals and organic pollutants in contaminated soils and its implication for remediation of contaminated soils. Further research directions are identified to ensure a safe and sustainable use of biochar as a soil amendment for remediation of contaminated soils.

Organic pollution of rivers: Combined threats of urbanization, livestock farming and global climate change.

PubMed

Wen, Yingrong; Schoups, Gerrit; van de Giesen, Nick

2017-02-23

Organic pollution of rivers by wastewater discharge from human activities negatively impacts people and ecosystems. Without treatment, pollution control relies on a combination of natural degradation and dilution by natural runoff to reduce downstream effects. We quantify here for the first time the global sanitation crisis through its impact on organic river pollution from the threats of (1) increasing wastewater discharge due to urbanization and intensification of livestock farming, and (2) reductions in river dilution capacity due to climate change and water extractions. Using in-stream Biochemical Oxygen Demand (BOD) as an overall indicator of organic river pollution, we calculate historical (2000) and future (2050) BOD concentrations in global river networks. Despite significant self-cleaning capacities of rivers, the number of people affected by organic pollution (BOD >5 mg/l) is projected to increase from 1.1 billion in 2000 to 2.5 billion in 2050. With developing countries disproportionately affected, our results point to a growing need for affordable wastewater solutions.

Organic pollution of rivers: Combined threats of urbanization, livestock farming and global climate change

PubMed Central

Wen, Yingrong; Schoups, Gerrit; van de Giesen, Nick

2017-01-01

Organic pollution of rivers by wastewater discharge from human activities negatively impacts people and ecosystems. Without treatment, pollution control relies on a combination of natural degradation and dilution by natural runoff to reduce downstream effects. We quantify here for the first time the global sanitation crisis through its impact on organic river pollution from the threats of (1) increasing wastewater discharge due to urbanization and intensification of livestock farming, and (2) reductions in river dilution capacity due to climate change and water extractions. Using in-stream Biochemical Oxygen Demand (BOD) as an overall indicator of organic river pollution, we calculate historical (2000) and future (2050) BOD concentrations in global river networks. Despite significant self-cleaning capacities of rivers, the number of people affected by organic pollution (BOD >5 mg/l) is projected to increase from 1.1 billion in 2000 to 2.5 billion in 2050. With developing countries disproportionately affected, our results point to a growing need for affordable wastewater solutions. PMID:28230079

On the Coplanar Integrable Case of the Twice-Averaged Hill Problem with Central Body Oblateness

NASA Astrophysics Data System (ADS)

Vashkov'yak, M. A.

2018-01-01

The twice-averaged Hill problem with the oblateness of the central planet is considered in the case where its equatorial plane coincides with the plane of its orbital motion relative to the perturbing body. A qualitative study of this so-called coplanar integrable case was begun by Y. Kozai in 1963 and continued by M.L. Lidov and M.V. Yarskaya in 1974. However, no rigorous analytical solution of the problem can be obtained due to the complexity of the integrals. In this paper we obtain some quantitative evolution characteristics and propose an approximate constructive-analytical solution of the evolution system in the form of explicit time dependences of satellite orbit elements. The methodical accuracy has been estimated for several orbits of artificial lunar satellites by comparison with the numerical solution of the evolution system.

Efficient Removal of Cationic and Anionic Radioactive Pollutants from Water Using Hydrotalcite-Based Getters.

PubMed

Bo, Arixin; Sarina, Sarina; Liu, Hongwei; Zheng, Zhanfeng; Xiao, Qi; Gu, Yuantong; Ayoko, Godwin A; Zhu, Huaiyong

2016-06-29

Hydrotalcite (HT)-based materials are usually applied to capture anionic pollutants in aqueous solutions. Generally considered anion exchangers, their ability to capture radioactive cations is rarely exploited. In the present work, we explored the ability of pristine and calcined HT getters to effectively capture radioactive cations (Sr(2+) and Ba(2+)) which can be securely stabilized at the getter surface. It is found that calcined HT outperforms its pristine counterpart in cation removal ability. Meanwhile, a novel anion removal mechanism targeting radioactive I(-) is demonstrated. This approach involves HT surface modification with silver species, namely, Ag2CO3 nanoparticles, which can attach firmly on HT surface by forming coherent interface. This HT-based anion getter can be further used to capture I(-) in aqueous solution. The observed I(-) uptake mechanism is distinctly different from the widely reported ion exchange mechanism of HT and much more efficient. As a result of the high local concentrations of precipitants on the getters, radioactive ions in water can be readily immobilized onto the getter surface by forming precipitates. The secured ionic pollutants can be subsequently removed from water by filtration or sedimentation for safe disposal. Overall, these stable, inexpensive getters are the materials of choice for removal of trace ionic pollutants from bulk radioactive liquids, especially during episodic environmental crisis.

Coupling Light Emitting Diodes with Photocatalyst-Coated Optical Fibers Improves Quantum Yield of Pollutant Oxidation.

PubMed

Ling, Li; Tugaoen, Heather; Brame, Jonathon; Sinha, Shahnawaz; Li, Chuanhao; Schoepf, Jared; Hristovski, Kiril; Kim, Jae-Hong; Shang, Chii; Westerhoff, Paul

2017-11-21

A photocatalyst-coated optical fiber was coupled with a 318 nm ultraviolet-A light emitting diode, which activated the photocatalysts by interfacial photon-electron excitation while minimizing photonic energy losses due to conventional photocatalytic barriers. The light delivery mechanism was explored via modeling of evanescent wave energy produced upon total internal reflection and photon refraction into the TiO 2 surface coating. This work explores aqueous phase LED-irradiated optical fibers for treating organic pollutants and for the first time proposes a dual-mechanistic approach to light delivery and photocatalytic performance. Degradation of a probe organic pollutant was evaluated as a function of optical fiber coating thickness, fiber length, and photocatalyst attachment method and compared against the performance of an equivalent catalyst mass in a completely mixed slurry reactor. Measured and simulated photon fluence through the optical fibers decreased as a function of fiber length, coating thickness, or TiO 2 mass externally coated on the fiber. Thinner TiO 2 coatings achieved faster pollutant removal rates from solution, and dip coating performed better than sol-gel attachment methods. TiO 2 attached to optical fibers achieved a 5-fold higher quantum yield compared against an equivalent mass of TiO 2 suspended in a slurry solution.

Decontaminating soil organic pollutants with manufactured nanoparticles.

PubMed

Li, Qi; Chen, Xijuan; Zhuang, Jie; Chen, Xin

2016-06-01

Organic pollutants in soils might threaten the environmental and human health. Manufactured nanoparticles are capable to reduce this risk efficiently due to their relatively large capacity of sorption and degradation of organic pollutants. Stability, mobility, and reactivity of nanoparticles are prerequisites for their efficacy in soil remediation. On the basis of a brief introduction of these issues, this review provides a comprehensive summary of the application and effectiveness of various types of manufactured nanoparticles for removing organic pollutants from soil. The main categories of nanoparticles include iron (oxides), titanium dioxide, carbonaceous, palladium, and amphiphilic polymeric nanoparticles. Their advantages (e.g., unique properties and high sorption capacity) and disadvantages (e.g., high cost and low recovery) for soil remediation are discussed with respect to the characteristics of organic pollutants. The factors that influence the decontamination effects, such as properties, surfactants, solution chemistry, and soil organic matter, are addressed.

A new database on urban runoff pollution: comparison of separate and combined sewer systems.

PubMed

Brombach, H; Weiss, G; Fuchs, S

2005-01-01

For a long time people have questioned what the "best" sewer system is for limiting the pollution load released into the receiving waters. In this paper the traditional separate and combined sewer systems are compared using a pollution load balance. The investigation is based on measured concentration data for a range of pollutant parameters in the sewer from the new database "ATV-DVWK Datenpool 2001". The approach also accounted for the wastewater treatment plant outflow which contributes to the total pollutant load considerably. In spite of a number of neglected effects, the results show that the separate system is superior to the combined for some parameters only, such as nutrients, whereas for other parameters, e.g. heavy metals and COD, the combined system yields less total loads. Any uncritical preference of the separate system as a particularly advantageous solution is thus questionable. Individual investigations case by case are recommended.

Remote Sensing of Environmental Pollution

NASA Technical Reports Server (NTRS)

North, G. W.

1971-01-01

Environmental pollution is a problem of international scope and concern. It can be subdivided into problems relating to water, air, or land pollution. Many of the problems in these three categories lend themselves to study and possible solution by remote sensing. Through the use of remote sensing systems and techniques, it is possible to detect and monitor, and in some cases, identify, measure, and study the effects of various environmental pollutants. As a guide for making decisions regarding the use of remote sensors for pollution studies, a special five-dimensional sensor/applications matrix has been designed. The matrix defines an environmental goal, ranks the various remote sensing objectives in terms of their ability to assist in solving environmental problems, lists the environmental problems, ranks the sensors that can be used for collecting data on each problem, and finally ranks the sensor platform options that are currently available.

Research on the negative externality of breeding wastewater in rural construction—Taking the large-scale breeding project of Tongnan in Chongqing as an example

NASA Astrophysics Data System (ADS)

Yin, Mingqiang; Hu, Wen; Wu, Haonan

2018-03-01

The country vigorously promotes the collective operation of traditional culture, which brings a lot of negative externalities of environmental pollution. Environmental pollution causes the difference between social cost and private cost. The cost of pollution is not borne by private enterprises, it is an external cost for the polluters. This paper attempts to take the Chongqing pig farm as an example to select the COD and TN indicators in the wastewater as the focus point of the analysis. We explore the equilibrium point based on the personal cost of Party A and the public welfare cost brought by environmental pollution, and test the rationality and accuracy of the existing norms. On the basis of existing research, the end of the paper tries to explore the better solution according to the law of Pigou and the property rights delimitation.

ERCA 2008 - From the Human Dimensions of Global Environmental Change to the Observation of the Earth from Space

NASA Astrophysics Data System (ADS)

Boutron, Claude

2009-02-01

This book is the eighth volume in the series of books published within the framework of the European Research Course on Atmospheres ("ERCA"). ERCA was initiated in 1993 by the University Joseph Fourier of Grenoble, in order to provide PhD students and scientists from Europe and the rest of the world with a multidisciplinary course, which covers especially: the climate system and climate change; the physics and chemistry of the Earth's atmosphere; the human dimensions of environmental change; the other planets and satellites in the solar system and beyond. Since 1993, sixteen sessions have been attended by more 800 participants from 50 countries. The seventeenth session will take place from 12 January to 13 February 2009. This new volume contains twenty two chapters dealing with a wide range of topics. The following subjects are covered: the human dimensions of global environmental change; climate change and cryospheric evolution in China; the projections of twenty-first century climate over Europe; the understanding of the health impacts of air pollutants; air quality and human welfare; photocatalytic self-cleaning materials; radiative transfer in the cloudy atmosphere; laboratory modelling of atmospheric dynamical processes; stratospheric ozone; the applications of stable isotope analysis to atmospheric trace gas budgets; nitrogen oxides in the troposphere; the observation of the solid Earth, the oceans and land waters; the surface mass balance of the Greenland ice sheet; sea surface salinity reconstruction as seen with foraminifera shells; sources markers in aerosols, oceanic particles and sediments; the nucleation of atmospheric particles; the characterization of atmospheric aerosol episodes in China; the solar magnetic activity; the present and past climates of planet Mars; the outer solar system; Titan as an analog of Earth's past and future; the detection and characterization of extrasolar planets.

STS-68 crew insignia

NASA Image and Video Library

1994-03-01

STS068-S-001 (March 1994) --- Exploration of Earth from space is the focus of the design of the STS-68 insignia, the second flight of the Space Radar Laboratory (SRL-2). SRL-2 is part of NASA's Mission to Planet Earth (MTPE) *project. The world's land masses and oceans dominate the center field, with the space shuttle Endeavour circling the globe. The SRL-2 letters span the width and breadth of planet Earth, symbolizing worldwide coverage of the two prime experiments of STS-68 - The Shuttle Imaging Radar-C and X-Band Synthetic Aperture Radar (SIR-C/X-SAR) instruments, and the Measurement of Air Pollution from Satellites (MAPS) sensor. The red, blue and black colors of the insignia represent the three operating wavelengths of SIR-C/X-SAR, and the gold band surrounding the globe symbolizes the atmospheric envelope examined by MAPS. The flags of international partners Germany and Italy are shown opposite Endeavour. The relationship of the orbiter to Earth highlights the usefulness of human spaceflights in understanding Earth's environment, and the monitoring its changing surface and atmosphere. In the words of the crew members, "the soaring orbiter also typifies the excellence of the NASA team in exploring our own world, using the tools which the Space Program developed to explore the other planets in the solar system". This STS-68 patch was designed by artist Sean Collins. The NASA insignia design for space shuttle flights is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the forms of illustrations by the various news media. When and if there is any change in this policy, which is not anticipated, the change will be publicly announced. Photo credit: NASA

Functionalized paper--A readily accessible adsorbent for removal of dissolved heavy metal salts and nanoparticles from water.

PubMed

Setyono, Daisy; Valiyaveettil, Suresh

2016-01-25

Paper, a readily available renewable resource, comprises of interwoven cellulosic fibers, which can be functionalized to develop interesting low-cost adsorbent material for water purification. In this study, polyethyleneimine (PEI)-functionalized paper was used for the removal of hazardous pollutants such as Au and Ag nanoparticles, Cr(VI) anions, Ni(2+), Cd(2+), and Cu(2+) cations from spiked water samples. Compared to untreated paper, the PEI-coated paper showed significant improvement in adsorption capacities toward the pollutants investigated in this study. Kinetics, isotherm models, pH, and desorption studies were carried out to study the adsorption mechanism of pollutants on the adsorbent surface. Adsorption of pollutants was better described by pseudo-second order kinetics and Langmuir isotherm model. Maximum adsorption of anionic pollutants was achieved at pH 5 while that of cations was at pH>6. Overall, the PEI-functionalized paper showed interesting Langmuir adsorption capacities for heavy metal ions such as Cr(VI) (68 mg/g), Ni(2+) (208 mg/g), Cd(2+) (370 mg/g), and Cu(2+) (435 mg/g) ions at neutral pH. In addition, the modified paper was also used to remove Ag-citrate (79 mg/g), Ag-PVP (46 mg/g), Au-citrate (30 mg/g), Au-PVP (17 mg/g) nanoparticles from water. Desorption of NPs from the adsorbent was done by washing with 2 M HCl or thiourea solution, while heavy metal ions were desorbed using 1 M NaOH or HNO3 solution. The modified paper retained its extraction efficiencies upon desorption of pollutants. Copyright © 2015 Elsevier B.V. All rights reserved.

Linkage of iron elution and dissolved oxygen consumption with removal of organic pollutants by nanoscale zero-valent iron: Effects of pH on iron dissolution and formation of iron oxide/hydroxide layer.

PubMed

Fujioka, Nanae; Suzuki, Moe; Kurosu, Shunji; Kawase, Yoshinori

2016-02-01

The iron elution and dissolved oxygen (DO) consumption in organic pollutant removal by nanoscale zero-valent iron (nZVI) was examined in the range of solution pH from 3.0 to 9.0. Their behaviors were linked with the removal of organic pollutant through the dissolution of iron and the formation of iron oxide/hydroxide layer affected strongly by solution pH and DO. As an example of organic pollutants, azo-dye Orange II was chosen in this study. The chemical composition analyses before and after reaction confirmed the corrosion of nZVI into ions, the formation of iron oxide/hydroxide layer on nZVI surface and the adsorption of the pollutant and its intermediates. The complete decolorization of Orange II with nZVI was accomplished very quickly. On the other hand, the total organic carbon (TOC) removal was considerably slow and the maximum TOC removal was around 40% obtained at pH 9.0. The reductive cleavage of azo-bond by emitted electrons more readily took place as compared with the cleavage of aromatic rings of Orange II leading to the degradation to smaller molecules and subsequently the mineralization. A reaction kinetic model based on the Langmuir-Hinshelwood/Eley-Rideal approach was developed to elucidate mechanisms for organic pollutant removal controlled by the formation of iron oxide/hydroxide layer, the progress of which could be characterized by considering the dynamic concentration changes in Fe(2+) and DO. The dynamic profiles of Orange II removal linked with Fe(2+) and DO could be reasonably simulated in the range of pH from 3.0 to 9.0. Copyright © 2015 Elsevier Ltd. All rights reserved.

A cyclostrophic transformed Eulerian zonal mean model for the middle atmosphere of slowly rotating planets

NASA Astrophysics Data System (ADS)

Li, K. F.; Yao, K.; Taketa, C.; Zhang, X.; Liang, M. C.; Jiang, X.; Newman, C. E.; Tung, K. K.; Yung, Y. L.

2015-12-01

With the advance of modern computers, studies of planetary atmospheres have heavily relied on general circulation models (GCMs). Because these GCMs are usually very complicated, the simulations are sometimes difficult to understand. Here we develop a semi-analytic zonally averaged, cyclostrophic residual Eulerian model to illustrate how some of the large-scale structures of the middle atmospheric circulation can be explained qualitatively in terms of simple thermal (e.g. solar heating) and mechanical (the Eliassen-Palm flux divergence) forcings. This model is a generalization of that for fast rotating planets such as the Earth, where geostrophy dominates (Andrews and McIntyre 1987). The solution to this semi-analytic model consists of a set of modified Hough functions of the generalized Laplace's tidal equation with the cyclostrohpic terms. As examples, we apply this model to Titan and Venus. We show that the seasonal variations of the temperature and the circulation of these slowly-rotating planets can be well reproduced by adjusting only three parameters in the model: the Brunt-Väisälä bouyancy frequency, the Newtonian radiative cooling rate, and the Rayleigh friction damping rate. We will also discuss the application of this model to study the meridional transport of photochemically produced tracers that can be observed by space instruments.

Some matters relating to the documentary evidence of the discovery of Neptune

NASA Astrophysics Data System (ADS)

Foster, N.

2014-04-01

The discovery of the planet Neptune was regarded as one of the greatest discoveries of the nineteenth century. Its existence was first detected, not by eye or with telescope, but by the mathematical analysis of the orbit of the planet Uranus. The perturbations of Uranus were under investigation by John Couch Adams (1819-92) in Cambridge, and Urban Le Verrier (1811-77) in Paris. Both these astronomers believed that the irregularities in the motion of Uranus could only be attributed to the action of an unknown planet of the Solar System. However, the circumstances of the discovery have once again become a matter of dispute and contention by some recent historians. My aim is to review the essential facts and the interpretation placed on them and to examine the conspiracy theories that have arisen from an examination of the documentary evidence. These conspiracy theories have detracted from Adams, the true merit of his early researches and his place in the history of the discovery. There has also been speculative allegations made of the character of Adams based on selected documentary evidence, which I believe is not necessarily a true representation of the facts. In presenting a fair portrayal of Adams's researches, I have reconstructed his 1845 October solution in a way that has not been done before.

A cyclostrophic transformed Eulerian zonal mean model for the middle atmosphere of slowly rotating planets

NASA Astrophysics Data System (ADS)

Li, King-Fai; Yao, Kaixuan; Taketa, Cameron; Zhang, Xi; Liang, Mao-Chang; Jiang, Xun; Newman, Claire; Tung, Ka-Kit; Yung, Yuk L.

2016-04-01

With the advance of modern computers, studies of planetary atmospheres have heavily relied on general circulation models (GCMs). Because these GCMs are usually very complicated, the simulations are sometimes difficult to understand. Here we develop a semi-analytic zonally averaged, cyclostrophic residual Eulerian model to illustrate how some of the large-scale structures of the middle atmospheric circulation can be explained qualitatively in terms of simple thermal (e.g. solar heating) and mechanical (the Eliassen-Palm flux divergence) forcings. This model is a generalization of that for fast rotating planets such as the Earth, where geostrophy dominates (Andrews and McIntyre 1987). The solution to this semi-analytic model consists of a set of modified Hough functions of the generalized Laplace's tidal equation with the cyclostrohpic terms. As an example, we apply this model to Titan. We show that the seasonal variations of the temperature and the circulation of these slowly-rotating planets can be well reproduced by adjusting only three parameters in the model: the Brunt-Väisälä bouyancy frequency, the Newtonian radiative cooling rate, and the Rayleigh friction damping rate. We will also discuss an application of this model to study the meridional transport of photochemically produced tracers that can be observed by space instruments.

A novel orbiter mission concept for venus with the EnVision proposal

NASA Astrophysics Data System (ADS)

de Oliveira, Marta R. R.; Gil, Paulo J. S.; Ghail, Richard

2018-07-01

In space exploration, planetary orbiter missions are essential to gain insight into planets as a whole, and to help uncover unanswered scientific questions. In particular, the planets closest to the Earth have been a privileged target of the world's leading space agencies. EnVision is a mission proposal designed for Venus and competing for ESA's next launch opportunity with the objective of studying Earth's closest neighbor. The main goal is to study geological and atmospheric processes, namely surface processes, interior dynamics and atmosphere, to determine the reasons behind Venus and Earth's radically different evolution despite the planets' similarities. To achieve these goals, the operational orbit selection is a fundamental element of the mission design process. The design of an orbit around Venus faces specific challenges, such as the impossibility of choosing Sun-synchronous orbits. In this paper, an innovative genetic algorithm optimization was applied to select the optimal orbit based on the parameters with more influence in the mission planning, in particular the mission duration and the coverage of sites of interest on the Venusian surface. The solution obtained is a near-polar circular orbit with an altitude of 259 km that enables the coverage of all priority targets almost two times faster than with the parameters considered before this study.

Evidence for a Dayside Thermal Inversion and High Metallicity for the Hot Jupiter WASP-18b

NASA Astrophysics Data System (ADS)

Sheppard, Kyle; Mandell, Avi M.; Tamburo, Patrick; Gandhi, Siddarth; Pinhas, Arazi; Madhusudhan, Nikku; Deming, Drake

2018-01-01

Hot Jupiters have been vital in revealing the structural and atmospheric diversity of gas-rich planets. Since they are exposed to extreme conditions and relatively easy to observe through transit and eclipse spectroscopy, hot Jupiters provide a window into a unique part of parameter space, allowing us to better understand both atmospheric physics and planetary structure. Additionally, constraints on the structure and composition of exoplanetary atmospheres allow us to test and generalize planetary formation models. We find evidence for a strong thermal inversion in the dayside atmosphere of the highly irradiated hot Jupiter WASP-18b (Teq=2400K, M=10MJ) based on Hubble Space Telescope secondary eclipse observations and Spitzer eclipse photometry. We report a 4.7σ detection of CO, and a non-detection of water vapor as well as all other relevant species (e.g., TiO, VO). The most probable atmospheric retrieval solution indicates a C/O ratio of 1 and an extremely high metallicity (C/H=~283x solar). If confirmed with future observations, WASP-18b would be the first example of a planet with a non-oxide driven thermal inversion and an atmospheric metallicity inconsistent with that predicted for Jupiter-mass planets.

Exospheric perturbations by radiation pressure. 2: Solution for orbits in the ecliptic plane

NASA Technical Reports Server (NTRS)

Chamberlain, J. W.

1980-01-01

The instantaneous rates of change for the orbital elements eccentricity, longitude of perigee from the Sun, and longitude from the Sun of the ascending node are integrated simultaneously for the case of the inclination i = 0. The results confirm the validity of using mean rates when the orbits are tightly bound to the planet and serve as examples to be reproduced by the complicated numerical solutions required for arbitrary inclination. Strongly bound hydrogen atoms escaping from Earth due to radiation pressure do not seem a likely cause of the geotail extending in the anti-sun direction. Instead, radiation pressure will cause those particles' orbits to deteriorate into the Earth's atmosphere.

Model of the vertical structure of the optical parameters of the Neptune atmosphere.

NASA Astrophysics Data System (ADS)

Morozhenko, A. V.

Analyzes the wavelength dependence of the geometric albedo of Neptune's disk and estimates some parameters of the planet's atmosphere by the method based on the determination of deviations of the vertical structure of the cloud layer from the homogeneity condition. The ratio between the methane and gas scale heights is found to be about 0.4. For the upper atmosphere, components of methane, aerosol, the mean geometric radius of particles, the turbulent mixing coefficient are determined. Two solutions were found for deeper atmospheric layers. The first one suggests a rather dense cloud; in the second solution the lower cloud layer is an extension of the upper aerosol layer.

Phosphate removal by refined aspen wood fiber treated with carboxymethyl cellulose and ferrous chloride

Treesearch

Thomas L. Eberhardt; Soo-Hong Min; James S. Han

2006-01-01

Biomass-based filtration media are of interest as an economical means to remove pollutants and nutrients found in stormwater runoff. Refined aspen wood fiber samples treated with iron salt solutions demonstrated limited capacities to remove (ortho)phosphate from test solutions. To provide additional sites for iron complex formation, and thereby impart a greater...

Photocatalytic Solutions Create Self-Cleaning Surfaces

NASA Technical Reports Server (NTRS)

2013-01-01

A Stennis Space Center researcher investigating the effectiveness of photocatalytic materials for keeping the Center's buildings free of grime turned to a solution created by PURETi Inc. of New York City. Testing proved successful, and NASA and the company now share a Dual Use Technology partnership. PURETi's coatings keep surfaces clean and purify surrounding air, eliminating pollution, odors, and microbes.

Building a Comprehensive Mill-Level Database for the Industrial Sectors Integrated Solutions (ISIS) Model of the U.S. Pulp and Paper Sector

EPA Science Inventory

The Industrial Sectors Integrated Solutions (ISIS) model for the pulp and paper sector is currently under development at the U.S. Environmental Protection Agency (EPA), and can be utilized to facilitate multi-pollutant sector-based analyses that are performed in conjunction with ...

Taking Advantage of a Corrosion Problem to Solve a Pollution Problem

ERIC Educational Resources Information Center

Palomar-Ramirez, Carlos F.; Bazan-Martinez, Jose A.; Palomar-Pardave, Manuel E.; Romero-Romo, Mario A.; Ramirez-Silva, Maria Teresa

2011-01-01

Some simple chemistry is used to demonstrate how Fe(II) ions, formed during iron corrosion in acid aqueous solution, can reduce toxic Cr(VI) species, forming soluble Cr(III) and Fe(III) ions. These ions, in turn, can be precipitated by neutralizing the solution. The procedure provides a treatment for industrial wastewaters commonly found in…

Investment in Green Technologies

NASA Astrophysics Data System (ADS)

Das Gupta, Supratim

Since the middle of the 1970's, there has been considerable research about how to deal with exhaustible natural resources which are essential to production. In the absence of substitution possibilities, the finite stock of these resources acts as a limiting factor to continued growth of output and hence consumption possibilities. In our first chapter, we combine a finite natural resource and human capital in the production function and look at the possibility of maintaining a non-declining or sustainable level of consumption for an infinite horizon. Our results show that the return to human capital accumulation plays a key role in ensuring this objective. In our model without physical capital, we obtain a similar result where this return must be such that the fraction of time devoted to acquiring human capital each period is at least as much as the share of natural resources in output. Our second chapter focuses on the transition from a relatively cheap exhaustible natural resource (coal, gasoline) to an expensive alternative technology assumed to be in nearly unlimited supply (wind, solar). Due to significant cost differences between fossil-fuel based energy sources and these alternative (backstop) technologies, their use is not as widespread. Public subsidies to research can however bring about innovation through cheaper production techniques which would significantly reduce the operating costs of these backstop technologies. But without sufficient incentives for investment and patent protections, individual firms typically underinvest in backstop technologies relative to the socially optimal level. In our paper, we find that this underinvestment in the backstop also leads to an under-extraction of the exhaustible natural resource. This imply firms would conserve the natural resource for too long and switch later to the alternative technology relative to the socially optimal solution. We extend the chapter to include pollution as a flow variable. Pollution from aggregate use of the natural resource is seen to not affect the behavior of an individual firm whereas it significantly affects that of the social planner. For relatively low pollution cost values, the socially optimal solution involves less investment in the backstop and conserving the natural resource for a longer period compared to the case without pollution. For higher values of the pollution cost, the social planner invests more in the backstop each period and switches sooner to the backstop compared to the case without pollution. In some situations, this may involve leaving behind some stock of the natural resource in the ground. The third chapter introduces pollution (a stock variable) through a deterioration of environmental quality. The structure of the second chapter is maintained here. Comparing the true pollution cost of the resource (in terms of a poor environmental quality) and the cost of the backstop technology, it is possible for the natural resource to be relatively more expensive. This arises in a situation of a very dirty environmental quality where the additional benefit from a slightly better environment exceeds the cost of the alternative cleaner technology. In this case, the optimal solution involves using the backstop at first for a few periods before making a discrete jump to a constant mix of using both the resource and the backstop technology. Here the economy settles at a steady state of environmental quality. It similarly follows that when the quality of the environment is relatively clean to begin with, the optimal solution involves starting with the cheaper but polluting natural resource before switching to a constant mix of using both the energy sources.

Studying the Sky/Planets Can Drown You in Images: Machine Learning Solutions at JPL/Caltech

NASA Technical Reports Server (NTRS)

Fayyad, U. M.

1995-01-01

JPL is working to develop a domain-independent system capable of small-scale object recognition in large image databases for science analysis. Two applications discussed are the cataloging of three billion sky objects in the Sky Image Cataloging and Analysis Tool (SKICAT) and the detection of possibly one million small volcanoes visible in the Magellan synthetic aperture radar images of Venus (JPL Adaptive Recognition Tool, JARTool).

Evaluation of Proposed Solutions to Global Warming, Air Pollution, and Energy Security

NASA Astrophysics Data System (ADS)

Jacobson, M. Z.

2008-12-01

This study reviews and ranks major proposed solutions to global warming, air pollution mortality, and energy security while considering other impacts of the proposed solutions, such as on water supply, land use, wildlife, resource availability, thermal pollution, water chemical pollution, nuclear proliferation, and undernutrition. Nine electric power sources and two liquid fuel options are considered. The electricity sources include solar-photovoltaics (PV), concentrated solar power (CSP), wind, geothermal, hydroelectric, wave, tidal, nuclear, and coal with carbon capture and storage (CCS) technology. The liquid fuel options include corn-E85 and cellulosic E85. To place the electric and liquid fuel sources on an equal footing, we examine their comparative abilities to address the problems mentioned by powering new-technology vehicles, including battery-electric vehicles (BEVs), hydrogen fuel cell vehicles (HFCVs), and flex-fuel vehicles run on E85. Twelve combinations of energy source-vehicle type are considered. Upon ranking and weighting each combination with respect to each of 11 impact categories, four clear divisions of ranking, or tiers, emerge. Tier 1 (highest-ranked) includes wind-BEVs and wind-HFCVs. Tier 2 includes CSP-BEVs, geothermal-BEVs, PV-BEVs, tidal-BEVs, and wave-BEVs. Tier 3 includes hydro-BEVs, nuclear-BEVs, and CCS-BEVs. Tier 4 includes corn- and cellulosic-E85. Wind-BEVs ranked first in six out of 11 categories, including the two most important, mortality and climate damage reduction. Although HFCVs are less efficient than BEVs, wind- HFCVs ranked second among all combinations. Tier 2 options provide significant benefits and are recommended. Tier 3 options are less desirable. However, hydroelectricity, which was ranked ahead of coal- CCS and nuclear with respect to climate and health, is an excellent load balancer, thus strongly recommended. The Tier-4 combinations (cellulosic- and corn-E85) were ranked lowest overall and with respect to climate, air pollution, land use, wildlife damage, and chemical waste. Cellulosic-E85 ranked lower than corn-E85 overall, primarily due to its potentially larger land footprint based on recent data and its higher upstream air pollution emissions than corn-E85. Whereas cellulosic-E85 may cause the greatest average human mortality, nuclear-BEVs cause the greatest upper-limit mortality risk due to the expansion of plutonium separation and uranium enrichment in nuclear energy facilities worldwide. Wind-BEVs and CSP-BEVs cause the least mortality. The footprint area of wind-BEVs is 2-6 orders of magnitude less than that of any other option. Because of their low footprint and pollution, wind-BEVs cause the least wildlife loss. The largest consumer of water is corn-E85. The smallest are wind-, tidal-, and wave-BEVs. In sum, use of wind, CSP, geothermal, tidal, PV, wave, and hydro to power electricity for BEVs and HFCVs and for general use in the residential, industrial, and commercial sectors will result in the most benefit among the options considered. The combination of these technologies should be advanced as a solution to global warming, air pollution, and energy security. Coal-CCS and nuclear offer less benefit, and the biofuel options provide little or no benefit and greater negative impacts.

Desorption of 137Cs from Brachythecium mildeanum moss using acid solutions with pH 4.60-6.50

NASA Astrophysics Data System (ADS)

Čučulović, Ana; Veselinović, Dragan

2015-12-01

The desorption of 137Cs from the moss Brachythecium mildeanum (Schimp.) was performed using the following solutions: H2SO4 ( I), HNO3 ( II), H2SO4 + HNO3 ( III) with pH values of 4.60, 5.15, and 5.75, respectively, as well as distilled water (D) with pH 6.50. After five successive desorptions, each lasting 24 h, 20.5-37.6% 137Cs was desorbed from the moss using these solutions, while 30.7% of the starting content was desorbed using distilled water. The first desorption removed the highest percent of the original content of 137Cs in the moss (11.3-18.4%). This was determined by measuring 137Cs activity. If the current results are compared with those obtained earlier it may be concluded that 137Cs desorption from mosses is not species-dependent. The obtained results indicate the necessity of investigating the influence of acid rain, or rather, of H+ ions, on desorption of other ions from biological systems, i.e., the role of H+ ions in spreading other polluting compounds and thus producing secondary environmental pollution. From the results of this study it follows that acid rain will lead, through H+ ion action, to a similar increasing pollution of fallout waters with other ionic compounds which may not be present in the water before the contact with the plants and thus enable the pollution spreading. In the investigated system, the replacement of H+ ions from acid rains by more dangerous radioactive ions occured, increasing the concentration of the radioactive ions in the water, which demonstrates that the same process takes place in fallout water.

Integrated solutions for urban runoff pollution control in Brazilian metropolitan regions.

PubMed

Morihama, A C D; Amaro, C; Tominaga, E N S; Yazaki, L F O L; Pereira, M C S; Porto, M F A; Mukai, P; Lucci, R M

2012-01-01

One of the most important causes for poor water quality in urban rivers in Brazil is the low collection efficiency of the sewer system due to unforeseen interconnections with the stormwater drainage system. Since the beginning of the 20th century, Brazilian cities have adopted separate systems for sanitary sewers and stormwater runoff. Gradually these two systems became interconnected. A major challenge faced today by water managers in Brazil is to find efficient and low cost solutions to deal with this mixed system. The current situation poses an important threat to the improvement of the water quality in urban rivers and lakes. This article presents an evaluation of the water quality parameters and the diffuse pollution loads during rain events in the Pinheiros River, a tributary of the Tietê River in São Paulo. It also presents different types of integrated solutions for reducing the pollution impact of combined systems, based on the European experience in urban water management. An evaluation of their performance and a comparison with the separate system used in most Brazilian cities is also presented. The study is based on an extensive water quality monitoring program that was developed for a special investigation in the Pinheiros River and lasted 2.5 years. Samples were collected on a daily basis and water quality variables were analyzed on a daily, weekly or monthly basis. Two hundred water quality variables were monitored at 53 sampling points. During rain events, additional monitoring was carried out using an automated sampler. Pinheiros River is one of the most important rivers in the São Paulo Metropolitan Region and it is also a heavily polluted one.

Mind the Gap

NASA Astrophysics Data System (ADS)

2008-09-01

Astronomers have been able to study planet-forming discs around young Sun-like stars in unsurpassed detail, clearly revealing the motion and distribution of the gas in the inner parts of the disc. This result, which possibly implies the presence of giant planets, was made possible by the combination of a very clever method enabled by ESO's Very Large Telescope. Uncovering the disc ESO PR Photo 27a/08 Planet-forming Disc Planets could be home to other forms of life, so the study of exoplanets ranks very high in contemporary astronomy. More than 300 planets are already known to orbit stars other than the Sun, and these new worlds show an amazing diversity in their characteristics. But astronomers don't just look at systems where planets have already formed - they can also get great insights by studying the discs around young stars where planets may currently be forming. "This is like going 4.6 billion years back in time to watch how the planets of our own Solar System formed," says Klaus Pontoppidan from Caltech, who led the research. Pontoppidan and colleagues have analysed three young analogues of our Sun that are each surrounded by a disc of gas and dust from which planets could form. These three discs are just a few million years old and were known to have gaps or holes in them, indicating regions where the dust has been cleared and the possible presence of young planets. The new results not only confirm that gas is present in the gaps in the dust, but also enable astronomers to measure how the gas is distributed in the disc and how the disc is oriented. In regions where the dust appears to have been cleared out, molecular gas is still highly abundant. This can either mean that the dust has clumped together to form planetary embryos, or that a planet has already formed and is in the process of clearing the gas in the disc. For one of the stars, SR 21, a likely explanation is the presence of a massive giant planet orbiting at less than 3.5 times the distance between the Earth and the Sun, while for the second star, HD 135344B, a possible planet could be orbiting at 10 to 20 times the Earth-Sun distance. The observations of the third star, TW Hydrae, may also require the presence of one or two planets. "Our observations with the CRIRES instrument on ESO's Very Large Telescope clearly reveal that the discs around these three young, Sun-like stars are all very different and will most likely result in very different planetary systems," concludes Pontoppidan. "Nature certainly does not like to repeat herself" [1]. "These kinds of observations complement the future work of the ALMA observatory, which will be imaging these discs in great detail and on a larger scale," adds Ewine van Dishoeck, from Leiden Observatory, who works with Pontoppidan. To study the gaps in dust discs that are the size of the Solar System around stars that are located up to 400 light-years away is a daunting challenge that requires a clever solution and the best possible instruments [2]. "Traditional imaging cannot hope to see details on the scale of planetary distances for objects located so far away," explains van Dishoeck. "Interferometry can do better but won't allow us to follow the motion of the gas." Astronomers used a technique known as 'spectro-astrometric imaging' to give them a window into the inner regions of the discs where Earth-like planets may be forming. They were able not only to measure distances as small as one-tenth the Earth-Sun distance, but to measure the velocity of the gas at the same time [3]. "The particular configuration of the instrument and the use of adaptive optics allows astronomers to carry out observations with this technique in a very user-friendly way: as a consequence, spectro-astrometric imaging with CRIRES can now be routinely performed," says team member Alain Smette, from ESO [4].

Removal of copper from aqueous solution using perlite

NASA Astrophysics Data System (ADS)

Tanaydin, Mehmet Kayra; Tanaydin, Zümra Bakici; Ince, Muharrem; Demırkiran, Nizamettin

2017-04-01

The wastewaters containing organic and inorganic pollutants after many industrial processes such as metal plating, mining, textile, alloy, battery and industrial chemicals, are often discharged to environment. Heavy metals among these pollutants have highly stable, toxic, non-degradable and carcinogenic characters. They affect not only ecological system, but also human health and many life forms. Therefore, these contaminants should be eliminated or reduced to allowable levels before releasing to environment. Most of heavy metals have toxic character even at low concentrations of about 0.1-0.3 ppm. Treatment technologies such as filtration, ion exchange, precipitation, electrodeposition, reverse osmosis, sedimentation, and adsorption have been applied for removal of heavy metals from aqueous solutions. Adsorption is one of the most common and widely applied methods to eliminate the metal ions from waste solutions because of its simplicity and cost effectiveness. Activated carbon, clay minerals, ion exchange resins and various agricultural residues can be used as adsorbent materials in this process [1-3].

Phytodegradation potential of bisphenolA from aqueous solution by Azolla Filiculoides

PubMed Central

2014-01-01

Many organic hazardous pollutants such as bisphenolA (BPA) which are toxic and not easily biodegradable can concerns for environmental pollution worldwide. The objective of this study was to examine whether Azolla Filiculoides is able to remove BPA from aqueous solutions. In this study, the Azolla with different biomass (0.3, 0.6, 0.9, 1.2 g) has been cultured in solution that was contained 5, 10, 25 and 50 ppm BPA. Samples were collected every 2 days from all of containers. The analytical determination of BPA was performed by using of DR4000 uv-visible at λmax = 276 nm. The results indicated that Azolla has high ability to remove BPA from aqueous solutions. The BPA removal was 60-90%. The removal efficiency is increasing with decreasing of BPA concentration and increasing of biomass amount and vice versa. The removal efficiency was more than 90% when BPA concentration was 5 ppm and amount of biomass was 0.9gr. It is concluded that Azolla able remove BPA by Phytodegradation from the aqueous solutions. Since conventional methods of BPA removal need to high cost and energy, phytoremediation by Azolla as a natural treatment system can decrease those issues and it can be a useful and beneficial method to removal of BPA. PMID:24693863

Phytodegradation potential of bisphenolA from aqueous solution by Azolla Filiculoides.

PubMed

Zazouli, Mohammad Ali; Mahdavi, Yousef; Bazrafshan, Edris; Balarak, Davoud

2014-01-01

Many organic hazardous pollutants such as bisphenolA (BPA) which are toxic and not easily biodegradable can concerns for environmental pollution worldwide. The objective of this study was to examine whether Azolla Filiculoides is able to remove BPA from aqueous solutions. In this study, the Azolla with different biomass (0.3, 0.6, 0.9, 1.2 g) has been cultured in solution that was contained 5, 10, 25 and 50 ppm BPA. Samples were collected every 2 days from all of containers. The analytical determination of BPA was performed by using of DR4000 uv-visible at λmax = 276 nm. The results indicated that Azolla has high ability to remove BPA from aqueous solutions. The BPA removal was 60-90%. The removal efficiency is increasing with decreasing of BPA concentration and increasing of biomass amount and vice versa. The removal efficiency was more than 90% when BPA concentration was 5 ppm and amount of biomass was 0.9gr. It is concluded that Azolla able remove BPA by Phytodegradation from the aqueous solutions. Since conventional methods of BPA removal need to high cost and energy, phytoremediation by Azolla as a natural treatment system can decrease those issues and it can be a useful and beneficial method to removal of BPA.

Water pollution risk simulation and prediction in the main canal of the South-to-North Water Transfer Project

NASA Astrophysics Data System (ADS)

Tang, Caihong; Yi, Yujun; Yang, Zhifeng; Cheng, Xi

2014-11-01

The middle route of the South-to-North Water Transfer Project (MRP) will divert water to Beijing Tuancheng Lake from Taocha in the Danjiangkou reservoir located in the Hubei province of China. The MRP is composed of a long canal and complex hydraulic structures and will transfer water in open channel areas to provide drinking water for Beijing, Shijiazhuang and other cities under extremely strict water quality requirements. A large number of vehicular accidents, occurred on the many highway bridges across the main canal would cause significant water pollution in the main canal. To ensure that water quality is maintained during the diversion process, the effects of pollutants on water quality due to sudden pollution accidents were simulated and analyzed in this paper. The MIKE11 HD module was used to calculate the hydraulic characteristics of the 42-km Xishi-to-Beijuma River channel of the MRP. Six types of hydraulic structures, including inverted siphons, gates, highway bridges, culverts and tunnels, were included in this model. Based on the hydrodynamic model, the MIKE11 AD module, which is one-dimensional advection dispersion model, was built for TP, NH3-N, CODMn and F. The validated results showed that the computed values agreed well with the measured values. In accordance with transportation data across the Dianbei Highway Bridge, the effects of traffic accidents on the bridge on water quality were analyzed. Based on simulated scenarios with three discharge rates (ranged from 12 m3/s to 17 m3/s, 40 m3/s, and 60 m3/s) and three pollution loading concentration levels (5 t, 10 t and 20 t) when trucks spill their contents (i.e., phosphate fertilizer, cyanide, oil and chromium solution) into the channel, emergency measures were proposed. Reasonable solutions to ensure the water quality with regard to the various types of pollutants were proposed, including treating polluted water, maintaining materials, and personnel reserves.

Application of the powder of porous titanium carbide ceramics to a reusable adsorbent for environmental pollutants.

PubMed

Moriwaki, Hiroshi; Kitajima, Shiori; Shirai, Koji; Kiguchi, Kenji; Yamada, Osamu

2011-01-30

The aim of this study is to investigate the utilization of the powder of porous titanium carbide (TiC) ceramics as a novel adsorbent or a material for solid-phase extraction (SPE). The adsorption and elution of inorganic and organic pollutants, Pb(II), 2,4,6-trichlorophenol (TCP), perfluorooctane sulfonate (PFOS), and perfluorooctanoic acid (PFOA), to the material were evaluated. The cartridge packed with TiC ceramics powder was used for the extraction test of pollutants. The solution containing pollutants at 1.0 μg mL(-1) was passed through the TiC cartridge, and the substances were almost quantitatively removed. Furthermore, the pollutants retained in the cartridge were eluted with 3N HCl for Pb(II) and with methanol for organic pollutants. The recoveries of pollutants were over 80%. In addition, we used the TiC cartridge for the solid-phase extraction of water samples (500 mL each of the distilled water and the river water) by adding pollutants at determined concentrations. Every pollutant was adsorbed almost quantitatively, and eluted by 3N HCl or methanol. From these results, we concluded that the powder of porous TiC ceramics is a useful reusable adsorbent for the water cleanup and solid-phase extraction. Copyright © 2010 Elsevier B.V. All rights reserved.

Partial degradation of five pesticides and an industrial pollutant by ozonation in a pilot-plant scale reactor.

PubMed

Maldonado, M I; Malato, S; Pérez-Estrada, L A; Gernjak, W; Oller, I; Doménech, Xavier; Peral, José

2006-11-16

Aqueous solutions of a mixture of several pesticides (alachlor, atrazine, chlorfenvinphos, diuron and isoproturon), considered PS (priority substances) by the European Commission, and an intermediate product of the pharmaceutical industry (alpha-methylphenylglycine, MPG) chosen as a model industrial pollutant, have been degraded at pilot-plant scale using ozonation. This study is part of a large research project [CADOX Project, A Coupled Advanced Oxidation-Biological Process for Recycling of Industrial Wastewater Containing Persistent Organic Contaminants, Contract No.: EVK1-CT-2002-00122, European Commission, http://www.psa.es/webeng/projects/cadox/index.html] founded by the European Union that inquires into the potential coupling between chemical and biological oxidations for the removal of toxic or non-biodegradable contaminants from water. The evolution of pollutant concentration, TOC mineralization, generation of inorganic species and consumption of O3 have been followed in order to visualize the chemical treatment effectiveness. Although complete mineralization is hard to accomplish, and large amounts of the oxidant are required to lower the organic content of the solutions, the possibility of ozonation cannot be ruled out if partial degradation is the final goal wanted. In this sense, Zahn-Wellens biodegradability tests of the ozonated MPG solutions have been performed, and the possibility of a further coupling with a secondary biological treatment for complete organic removal is envisaged.

Transport behaviors of anionic azo dyes at interface between surfactant-modified flax shives and aqueous solution: Synchrotron infrared and adsorption studies

NASA Astrophysics Data System (ADS)

Wang, Wenxia; Huang, Guohe; An, Chunjiang; Xin, Xiaying; Zhang, Yan; Liu, Xia

2017-05-01

From the viewpoint of sustainability, biomass adsorbent has a high potential in pollution control and there is an emerging interest to investigate the behaviors of pollutants at the interface between biomass adsorbent and solution. This study investigated the performance of cetyltrimethylammonium bromide surfactant-modified flax shives (MFS) for removal of anionic azo dyes from aqueous solution. The equilibrium and kinetic analysis for the adsorption of Acid Orange 7 (AO-7), Acid Red 18 (AR-18) and Acid Black 1 (AB-1) on MFS were conducted. The surface of MFS was characterized by synchrotron infrared and SEM analysis. The absorbed amount of three anionic azo dyes varied with the change of adsorbent dosage, pH and ionic strength. The adsorption isotherm data well fit to the Langmuir model. The adsorption process followed the pseudo-second-order kinetics and the liquid film diffusion models. Thermodynamic studies indicated that the adsorption of three anionic azo dyes was spontaneous. The adsorption of AR-18 and AB-1 onto MFS was endothermic while the adsorption of AO-7 was exothermic. The results can help better understand the behaviors of organic pollutants at biomass adsorbent-water interface. They also present the potential of using MFS as a suitable adsorbent for the removal of anionic azo dyes from wastewater.

Study on Contaminant Transportation of a Typical Chemical Industry Park Based on GMS Software

NASA Astrophysics Data System (ADS)

Huang, LinXian; Liu, GuoZhen; Xing, LiTing; Liu, BenHua; Xu, ZhengHe; Yang, LiZhi; Zhu, HebgHua

2018-03-01

The groundwater solute transport model can effectively simulated the transport path, the transport scope, and the concentration of contaminant which can provide quantitative data for groundwater pollution repair and groundwater resource management. In this study, we selected biological modern technology research base of Shandong province as research objective and simulated the pollution characteristic of typicalcontaminant cis-1, 3-dichloropropene under different operating conditions by using GMS software.

The persistent and pernicious myth of the early CO2-N2 atmospheres of terrestrial planets

NASA Astrophysics Data System (ADS)

Shaw, G. H.

2009-12-01

The accepted model for early atmospheres of terrestrial planets has settled on a CO2-N2 composition. Unfortunately, while it is largely based on a brilliant geological analysis by Rubey, there is no compelling evidence whatsoever for such a composition as the first “permanent” atmosphere for Earth or any other planet. In fact, geological discoveries of the past 50+ years reveal several problems with a CO2-N2 atmosphere, some of which Rubey recognized in his own analysis. He clearly addressed the problem of timing of degassing, concluding that early massive degassing of CO2 would produce readily observed and profound effects, which are not evident. Modeling and constraints on the timing of planetary accretion and core formation indicate massive early degassing. If early degassing emitted CO2-N2, the effects are concealed. Plate tectonic recycling is not a solution, as conditions would have persisted beyond the time of the earliest rocks, which do not show the effects. Attempts to return degassed CO2 to the mantle are not only ad hoc, but inconsistent with early thermal structure of the Earth. Second, production of prebiotic organic compounds from a CO2-N2 atmosphere has been a nagging problem. At best this has been addressed by invoking hydrogen production from the mantle to provide reducing capacity. While hydrogen may be emitted in volcanic eruptions, it is exceedingly difficult to imagine this process generating enough organics to yield high concentrations in a global ocean. The recent fashion of invoking organic synthesis at deep-sea vents suffers from the same problem: how to achieve sufficient concentrations of organics in a global ocean by abiotic synthesis when hydrothermal activity stirs the solution and carries the prebiotic products off to great dilution? Suggesting life began at deep-sea vents, and continues to carry on chemosynthesis there, begs the question. Unless you get high enough concentrations of prebiotics by abiotic processes, you simply don’t get life. Third, solutions invoking high atmospheric CO2 as the answer to the faint young sun problem encounter exactly the same problems associated with prompt degassing of CO2. Fourth, the carbon isotope record, in which early carbonaceous deposits show signs of photosynthetic fractionation of carbon are problematical if most of the primary surface and near-surface carbon was CO2. Finally, the delay in oxidation of Earth’s surface following oxygenic photosynthesis is problematical if early photosynthesizers had a vast CO2 source from early degassing. Given an abundant food supply, what prevented early cyanobacteria from rapidly oxidizing the surface? Although discovery of CO2-rich atmospheres on Venus and Mars seem to support CO2 as the primary surface carbon reservoir, these atmospheres are the result of atmospheric evolution, particularly loss of H to space. ALL of these problems disappear with early degassing of reduced gases such as CH4 and NH3. Considerations of meteoritic compositions, accretionary processes, and early atmosphere/hydrosphere chemical processing all support reduced gases as dominant in the early atmospheres of the terrestrial planets. The time has come to revert to any earlier idea of strongly reducing conditions on early terrestrial planet surfaces, followed by long-term evolutionary trends toward oxidation.

Competitive sorption of persistent organic pollutants onto microplastics in the marine environment.

PubMed

Bakir, Adil; Rowland, Steven J; Thompson, Richard C

2012-12-01

Plastics are known to sorb persistent organic pollutants from seawater. However, studies to quantify sorption rates have only considered the affinity of chemicals in isolation, unlike the conditions in the environment where contaminants are present as complex mixtures. Here we examine whether phenanthrene and 4,4'-DDT, in a mixture, compete for sorption sites onto PVC with no added additives (unplasticised PVC or uPVC) and Ultra-High Molecular Weight polyethylene. Interactions were investigated by exposing particles of uPVC and UHMW PE to mixtures of 3H and 14C radiolabelled Phe and DDT. Changes in sorption capacity were modelled by applying a Freundlich binding sorption isotherms. An Extended Langmuir Model and an Interaction Factor Model were also applied to predict equilibrium concentrations of pollutants onto plastic. This study showed that in a bi-solute system, DDT exhibited no significantly different sorption behaviour than in single solute systems. However, DDT did appear to interfere with the sorption of Phe onto plastic, indicating an antagonistic effect. Copyright © 2012 Elsevier Ltd. All rights reserved.

Two novel two-dimensional copper(II) coordination polymers with 1-(4-aminobenzyl)-1,2,4-triazole: Synthesis, crystal structure, magnetic characterization and absorption of anion pollutants

NASA Astrophysics Data System (ADS)

Zhang, Xin; Wu, Xiang Xia; Guo, Jian-Hua; Huo, Jian-Zhong; Ding, Bin

2017-01-01

In this work a flexible multi-dentate 1-(4-aminobenzyl)-1,2,4-triazole (abtz) ligand has been employed, two novel triazole-Cu(II) coordination polymers {[Cu(abtz)2(Br)2]·(H2O)2}n (1) and {[Cu(abtz)2]·(SiF6)·(H2O)2}n (2) have been isolated under solvo-thermal conditions. 1 is a 2D neutral CuII coordination polymer while 2 is 2D cation micro-porous CuII coordination polymer with the channel dimensionalities of 11.852(1) Å × 11.852(1) Å (metal-metal distances). Variable-temperature magnetic susceptibility data of 1 and 2 have been recorded in the 2-300 K temperature range indicating weak anti-ferromagnetic interactions. Further absorption properties of anion pollutants for 2 also have been investigated. 2 presents the novel example of cationic triazole-copper(II) coordination framework for effectively capturing anion pollutants Cr2O72- in the water solutions and selectively capturing Congo Red in the methanol solutions.

Sister Earth, Our Common Home: Toward a Sustainable, Planet Friendly Approach to Dialysis, a Paradigm of High Technology Medicine.

PubMed

Piccoli, Giorgina Barbara; Mery, David

2017-11-01

In our high-technology, highly polluted world, medicine plays an important role balancing saving lives with the expenses of growing amounts of waste products, not only biologically dangerous (the potentially "contaminated" or "hazardous" waste) but also potentially harmful for the planet (nonrecyclable, plastic waste). Dialysis, the prototype of high-technology medicine, is central to these problems, as the present treatment of about 2 million patients produces an enormous quantity of waste (considering hazardous waste only about 2 kg per session, with 160 sessions per year, that is 320 kg per patient, or about 640,000 tons of hazardous waste per year for 2 million patients, roughly corresponding to 6 nuclear aircraft carriers). Furthermore, obsolete dialysis machines, and water treatments are discharged, adding to the "technological waste." Water produced by the reverse osmosis is also discharged; this is the only nonhazardous, nonpolluting waste, but in particular in dry areas, wasting water is a great ecologic concern. The present review is aimed at discussing strategies already in place and to be further implemented for reducing this particular "uremic toxin" for the earth: dialysis waste, including dialysis disposables, water, and dialysis machines. Copyright © 2017 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

MGA trajectory planning with an ACO-inspired algorithm

NASA Astrophysics Data System (ADS)

Ceriotti, Matteo; Vasile, Massimiliano

2010-11-01

Given a set of celestial bodies, the problem of finding an optimal sequence of swing-bys, deep space manoeuvres (DSM) and transfer arcs connecting the elements of the set is combinatorial in nature. The number of possible paths grows exponentially with the number of celestial bodies. Therefore, the design of an optimal multiple gravity assist (MGA) trajectory is a NP-hard mixed combinatorial-continuous problem. Its automated solution would greatly improve the design of future space missions, allowing the assessment of a large number of alternative mission options in a short time. This work proposes to formulate the complete automated design of a multiple gravity assist trajectory as an autonomous planning and scheduling problem. The resulting scheduled plan will provide the optimal planetary sequence and a good estimation of the set of associated optimal trajectories. The trajectory model consists of a sequence of celestial bodies connected by two-dimensional transfer arcs containing one DSM. For each transfer arc, the position of the planet and the spacecraft, at the time of arrival, are matched by varying the pericentre of the preceding swing-by, or the magnitude of the launch excess velocity, for the first arc. For each departure date, this model generates a full tree of possible transfers from the departure to the destination planet. Each leaf of the tree represents a planetary encounter and a possible way to reach that planet. An algorithm inspired by ant colony optimization (ACO) is devised to explore the space of possible plans. The ants explore the tree from departure to destination adding one node at the time: every time an ant is at a node, a probability function is used to select a feasible direction. This approach to automatic trajectory planning is applied to the design of optimal transfers to Saturn and among the Galilean moons of Jupiter. Solutions are compared to those found through more traditional genetic-algorithm techniques.

A model for interprovincial air pollution control based on futures prices.

PubMed

Zhao, Laijun; Xue, Jian; Gao, Huaizhu Oliver; Li, Changmin; Huang, Rongbing

2014-05-01

Based on the current status of research on tradable emission rights futures, this paper introduces basic market-related assumptions for China's interprovincial air pollution control problem. The authors construct an interprovincial air pollution control model based on futures prices: the model calculated the spot price of emission rights using a classic futures pricing formula, and determined the identities of buyers and sellers for various provinces according to a partitioning criterion, thereby revealing five trading markets. To ensure interprovincial cooperation, a rational allocation result for the benefits from this model was achieved using the Shapley value method to construct an optimal reduction program and to determine the optimal annual decisions for each province. Finally, the Beijing-Tianjin-Hebei region was used as a case study, as this region has recently experienced serious pollution. It was found that the model reduced the overall cost of reducing SO2 pollution. Moreover, each province can lower its cost for air pollution reduction, resulting in a win-win solution. Adopting the model would therefore enhance regional cooperation and promote the control of China's air pollution. The authors construct an interprovincial air pollution control model based on futures prices. The Shapley value method is used to rationally allocate the cooperation benefit. Interprovincial pollution control reduces the overall reduction cost of SO2. Each province can lower its cost for air pollution reduction by cooperation.

Potential and Actual Health Hazards in the Dense Urban Operational Environment: Critical Gaps and Solutions for Military Occupational Health.

PubMed

Patterson, Steven L; Dancy, Blair C R; Ippolito, Danielle L; Stallings, Jonathan D

2017-11-01

: This paper presents environmental health risks which are prevalent in dense urban environments.We review the current literature and recommendations proposed by environmental medicine experts in a 2-day symposium sponsored by the Department of Defense and supported by the Johns Hopkins University Applied Physics Laboratory.Key hazards in the dense urban operational environment include toxic industrial chemicals and materials, water pollution and sewage, and air pollution. Four critical gaps in environmental medicine were identified: prioritizing chemical and environmental concerns, developing mobile decision aids, personalized health assessments, and better real-time health biomonitoring.As populations continue to concentrate in cities, civilian and military leaders will need to meet emerging environmental health concerns by developing and delivering adequate technology and policy solutions.

Discovery of KPS-1b, a Transiting Hot-Jupiter, with an Amateur Telescope Setup (Abstract)

NASA Astrophysics Data System (ADS)

Benni, P.; Burdanov, A.; Krushinsky, V.; Sokov, E.

2018-06-01

(Abstract only) Using readily available amateur equipment, a wide-field telescope (Celestron RASA, 279 mm f/2.2) coupled with a SBIG ST-8300M camera was set up at a private residence in a fairly light polluted suburban town thirty miles outside of Boston, Massachusetts. This telescope participated in the Kourovka Planet Search (KPS) prototype survey, along with a MASTER-II Ural wide field telescope near Yekaterinburg, Russia. One goal was to determine if higher resolution imaging ( 2 arcsec/pixel) with much lower sky coverage can practically detect exoplanet transits compared to the successful very wide-field exoplanet surveys (KELT, XO, WASP, HATnet, TrES, Qatar, etc.) which used an array of small aperture telescopes coupled to CCDs.

A PILOT SEARCH FOR EVIDENCE OF EXTRASOLAR EARTH-ANALOG PLATE TECTONICS

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

Jura, M.; Klein, B.; Xu, S.

Relative to calcium, both strontium and barium are markedly enriched in Earth's continental crust compared to the basaltic crusts of other differentiated rocky bodies within the solar system. Here, we both re-examine available archived Keck spectra to place upper bounds on n(Ba)/n(Ca) and revisit published results for n(Sr)/n(Ca) in two white dwarfs that have accreted rocky planetesimals. We find that at most only a small fraction of the pollution is from crustal material that has experienced the distinctive elemental enhancements induced by Earth-analog plate tectonics. In view of the intense theoretical interest in the physical structure of extrasolar rocky planets,more » this search should be extended to additional targets.« less

Leaching of Metal Pollutants from Four Well Casings Used for Ground-Water Monitoring

DTIC Science & Technology

1989-09-01

Atomic Spectroscopy, 4:126-128. 10 APPENDIX A : LEVELS OF CD, PB, CR, BA AND CU DETERMINED IN GROUND-WATER SOLUTIONS (MG/L). Time Pqle R:ph’itc (day1s...7 Conclusion ................................................... 9 Literature cited ................................................ 9 Appendix A ... Levels of Cd, Pb, Cr, Ba and Cu determined in ground-water solutions .................................................. 11 ILLUSTRATIONS Figure 1. Ground

A Telescope at the Solar Gravitational Lens: Problems and Solutions

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.

2017-01-01

Due to the bending of light by gravity, the gravity of sun forms a lens. In principle, a spacecraft sent to the distance of the solar gravitational focus could be used as a gravitational lens telescope. One example of such a mission would be to use the gravitational lens to image an extrasolar planet around a nearby star. The practical difficulties with this concept are discussed, and some approaches to mitigating these difficulties suggested.

OGLE-2015-BLG-1459L: The Challenges of Exo-moon Microlensing

NASA Astrophysics Data System (ADS)

Hwang, K.-H.; Udalski, A.; Bond, I. A.; Albrow, M. D.; Chung, S.-J.; Gould, A.; Han, C.; Jung, Y. K.; Ryu, Y.-H.; Shin, I.-G.; Yee, J. C.; Zhu, W.; Cha, S.-M.; Kim, D.-J.; Kim, H.-W.; Kim, S.-L.; Lee, C.-U.; Lee, D.-J.; Lee, Y.; Park, B.-G.; Pogge, R. W.; KMTNet Collaboration; Pawlak, M.; Poleski, R.; Szymański, M. K.; Skowron, J.; Soszyński, I.; Mróz, P.; Kozłowski, S.; Pietrukowicz, P.; Ulaczyk, K.; OGLE Collaboration; Abe, F.; Asakura, Y.; Barry, R.; Bennett, D. P.; Bhattacharya, A.; Donachie, M.; Evans, P.; Fukui, A.; Hirao, Y.; Itow, Y.; Kawasaki, K.; Koshimoto, N.; Li, M. C. A.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Miyazaki, S.; Muraki, Y.; Nagakane, M.; Ohnishi, K.; Ranc, C.; Rattenbury, N. J.; Saito, To.; Sharan, A.; Sullivan, D. J.; Sumi, T.; Suzuki, D.; Tristram, P. J.; Yamada, T.; Yamada, T.; Yonehara, A.; MOA Collaboration

2018-06-01

We show that dense OGLE and KMTNet I-band survey data require four bodies (sources plus lenses) to explain the microlensing light curve of OGLE-2015-BLG-1459. However, these can equally well consist of three lenses and one source (3L1S), two lenses and two sources (2L2S), or one lens and three sources (1L3S). In the 3L1S and 2L2S interpretations, the host is a brown dwarf and the dominant companion is a Neptune-class planet, with the third body (in the 3L1S case) being a Mars-class object that could have been a moon of the planet. In the 1L3S solution, the light curve anomalies are explained by a tight (five stellar radii) low-luminosity binary source that is offset from the principal source of the event by ∼ 0.17 {au}. These degeneracies are resolved in favor of the 1L3S solution by color effects derived from comparison to MOA data, which are taken in a slightly different (R/I) passband. To enable current and future (WFIRST) surveys to routinely characterize exo-moons and distinguish among such exotic systems requires an observing strategy that includes both a cadence faster than 9 minute‑1 and observations in a second band on a similar timescale.

Kinetic Effect on the Freezing of Ammonium-Sodium-Carbonate-Chloride Brines and Implications for Origin of Ceres' Bright Spots

NASA Astrophysics Data System (ADS)

Hodyss, R. P.; Thomas, E. C.; Vu, T. H.; Johnson, P. V.; Choukroun, M.

2017-12-01

Subsurface brines on Ceres containing natrite (Na2CO3) and smaller amounts of NH4Cl or NH4HCO3 have been proposed to reach the dwarf planet's surface from an internal reservoir, where the brines freeze and result in bright spots across Ceres. Kinetically frozen solutions containing the likely constituents of Ceres' subsurface brines (ammonium, sodium, carbonate, and chloride ions) were studied via infrared and micro-Raman spectroscopy, where the flash-frozen mixtures were found to preferentially form ammonium chloride and ammonium bicarbonate, even in sodium-dominated solutions. Additionally, sodium chloride only formed when sodium or chloride (or both) were present in excess in the brine solutions. Raman spectroscopy was further employed to analyze the effect of vacuum exposure on these frozen brines over longer periods of time to simulate the surface conditions of Ceres.