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Sample records for leo medium earth

  1. Operation of commercial R3000 processors in the Low Earth Orbit (LEO) space environment

    Energy Technology Data Exchange (ETDEWEB)

    Kaschmitter, J.L.; Shaeffer, D.L.; Colella, N.J. [Lawrence Livermore National Lab., CA (United States); McKnett, C.L.; Coakley, P.G. [JAYCOR, Santa Monica, CA (United States)

    1990-08-09

    Spacecraft processors must operate with minimal degradation of performance in the Low Earth Orbit (LEO) radiation environment, which includes the effects of total accumulated ionizing dose and Single Event Phenomena (SEP) caused by protons and cosmic rays. Commercially available microprocessors can offer a number of advantages relative to radiation-hardened devices, including lower cost, reduced development and procurement time, extensive software support, higher density and performance. However, commercially available systems are not normally designed to tolerate effects induced by the LEO environment. Lawrence Livermore National Laboratory (LLNL) and others have extensively tested the MIPS R3000 Reduced Instruction Set Computer (RISC) microprocessor family for operation in LEO environments. We have characterized total dose and SEP effects for altitudes and inclinations of interest to systems operating in LEO, and we postulate techniques for detection and alleviation of SEP effects based on experimental results. 12 refs.

  2. Operation of commercial R3000 processors in the low earth orbit (LEO) space environment

    Energy Technology Data Exchange (ETDEWEB)

    Kaschmitter, J.L.; Shaeffer, D.L.; Colella, N.J. (Lawrence Livermore National Lab., CA (United States)); McKnett, C.L.; Coakley, P.G. (JAYCOR, Santa Monica, CA (United States))

    1991-12-01

    Spacecraft processors must operate with minimal degradation of performance in the Low Earth Orbit (LEO) radiation environment, which includes the effects of total accumulated ionizing dose and Single Event Phenomena (SEP) caused by protons and cosmic rays. Commercially available microprocessors can offer a number of advantages relative to radiation-hardened devices, including lower cost, reduced development and procurement time, extensive software support, higher density and performance. However, commercially available systems are not normally designed to tolerate effects induced by the LEO environments. Lawrence Livermore National Laboratory (LLNL) and others have extensively tested the MIPS R3000 Reduced Instruction Set Computer (RISC) microprocessor family for operation in LEO environments. In this paper the authors characterize total dose and SEP effects for altitudes and inclinations of interest to systems operating in LEO, and the authors postulate techniques for detection and alleviation of SEP effects based on experimental results.

  3. Leo F. Laporte: Professor of Earth Sciences, Recollections of UCSC, 1971-1996

    OpenAIRE

    Laporte, Leo F.; Jarrell, Randall; Regional History Project, UCSC Library

    1998-01-01

    Randall Jarrell conducted an oral history with Leo Laporte on August 15, 1994, as a part of the Project's interviews with retiring senior faculty. Laporte served as department chairman of Earth Sciences from 1972 to 1975, and dean as the Natural Sciences Division from 1975-1976. In 1980 he received the UC Santa Cruz Alumni Distinguished Teaching Award. In his narration, Laporte discusses the building of the earth sciences department at UC Santa Cruz, how and why certain specialties were empha...

  4. A Dynamic/Anisotropic Low Earth Orbit (LEO) Ionizing Radiation Model

    Science.gov (United States)

    Badavi, Francis F.; West, Katie J.; Nealy, John E.; Wilson, John W.; Abrahms, Briana L.; Luetke, Nathan J.

    2006-01-01

    The International Space Station (ISS) provides the proving ground for future long duration human activities in space. Ionizing radiation measurements in ISS form the ideal tool for the experimental validation of ionizing radiation environmental models, nuclear transport code algorithms, and nuclear reaction cross sections. Indeed, prior measurements on the Space Transportation System (STS; Shuttle) have provided vital information impacting both the environmental models and the nuclear transport code development by requiring dynamic models of the Low Earth Orbit (LEO) environment. Previous studies using Computer Aided Design (CAD) models of the evolving ISS configurations with Thermo Luminescent Detector (TLD) area monitors, demonstrated that computational dosimetry requires environmental models with accurate non-isotropic as well as dynamic behavior, detailed information on rack loading, and an accurate 6 degree of freedom (DOF) description of ISS trajectory and orientation.

  5. Spectroscopy of the earth's atmosphere and interstellar medium

    CERN Document Server

    Rao, KN

    1992-01-01

    Spectroscopy of the Earth's Atmosphere and Interstellar Medium focuses on the characteristics of the electromagnetic spectrum of the Earth's atmosphere in the far-infrared and microwave regions. It discusses the modes of observation in field measurements and reviews the two techniques used in the spectral region. Organized into six chapters, this volume begins with an overview of the effect of water-vapor absorption, followed by a discussion on the two frequently used method for deriving atmospheric parameters from high-resolution infrared atmospheric spectra, namely, the equivalent width

  6. Hierarchical Supervisor and Agent Routing Algorithm in LEO/MEO Double-layered Optical Satellite Network

    Science.gov (United States)

    Li, Yongjun; Zhao, Shanghong

    2016-09-01

    A novel routing algorithm (Hierarchical Supervisor and Agent Routing Algorithm, HSARA) for LEO/MEO (low earth orbit/medium earth orbit) double-layered optical satellite network is brought forward. The so-called supervisor (MEO satellite) is designed for failure recovery and network management. LEO satellites are grouped according to the virtual managed field of MEO which is different from coverage area of MEO satellite in RF satellite network. In each LEO group, one LEO satellite which has maximal persistent link with its supervisor is called the agent. A LEO group is updated when this optical inter-orbit links between agent LEO satellite and the corresponding MEO satellite supervisor cuts off. In this way, computations of topology changes and LEO group updating can be decreased. Expense of routing is integration of delay and wavelength utilization. HSARA algorithm simulations are implemented and the results are as follows: average network delay of HSARA can reduce 21 ms and 31.2 ms compared with traditional multilayered satellite routing and single-layer LEO satellite respectively; LEO/MEO double-layered optical satellite network can cover polar region which cannot be covered by single-layered LEO satellite and throughput is 1% more than that of single-layered LEO satellite averagely. Therefore, exact global coverage can be achieved with this double-layered optical satellite network.

  7. Material interactions with the Low Earth Orbital (LEO) environment: Accurate reaction rate measurements

    Science.gov (United States)

    Visentine, James T.; Leger, Lubert J.

    1987-01-01

    To resolve uncertainties in estimated LEO atomic oxygen fluence and provide reaction product composition data for comparison to data obtained in ground-based simulation laboratories, a flight experiment has been proposed for the space shuttle which utilizes an ion-neutral mass spectrometer to obtain in-situ ambient density measurements and identify reaction products from modeled polymers exposed to the atomic oxygen environment. An overview of this experiment is presented and the methodology of calibrating the flight mass spectrometer in a neutral beam facility prior to its use on the space shuttle is established. The experiment, designated EOIM-3 (Evaluation of Oxygen Interactions with Materials, third series), will provide a reliable materials interaction data base for future spacecraft design and will furnish insight into the basic chemical mechanisms leading to atomic oxygen interactions with surfaces.

  8. Construction of a Matched Global Cloud and Radiance Product from LEO/GEO and EPIC Observations to Estimate Daytime Earth Radiation Budget from DSCOVR

    Science.gov (United States)

    Duda, David P.; Khlopenkov, Konstantin V.; Thiemann, Mandana; Palikonda, Rabindra; Sun-Mack, Sunny; Minnis, Patrick; Su, Wenying

    2016-01-01

    With the launch of the Deep Space Climate Observatory (DSCOVR), new estimates of the daytime Earth radiation budget can be computed from a combination of measurements from the two Earth-observing sensors onboard the spacecraft, the Earth Polychromatic Imaging Camera (EPIC) and the National Institute of Standards and Technology Advanced Radiometer (NISTAR). Although these instruments can provide accurate top-of-atmosphere (TOA) radiance measurements, they lack sufficient resolution to provide details on small-scale surface and cloud properties. Previous studies have shown that these properties have a strong influence on the anisotropy of the radiation at the TOA, and ignoring such effects can result in large TOA-flux errors. To overcome these effects, high-resolution scene identification is needed for accurate Earth radiation budget estimation. Selected radiance and cloud property data measured and derived from several low earth orbit (LEO, including NASA Terra and Aqua MODIS, NOAA AVHRR) and geosynchronous (GEO, including GOES (east and west), METEOSAT, INSAT-3D, MTSAT-2, and HIMAWARI-8) satellite imagers were collected to create hourly 5-km resolution global composites of data necessary to compute angular distribution models (ADM) for reflected shortwave (SW) and longwave (LW) radiation. The satellite data provide an independent source of radiance measurements and scene identification information necessary to construct ADMs that are used to determine the daytime Earth radiation budget. To optimize spatial matching between EPIC measurements and the high-resolution composite cloud properties, LEO/GEO retrievals within the EPIC fields of view (FOV) are convolved to the EPIC point spread function (PSF) in a similar manner to the Clouds and the Earth's Radiant Energy System (CERES) Single Scanner Footprint TOA/Surface Fluxes and Clouds (SSF) product. Examples of the merged LEO/GEO/EPIC product will be presented, describing the chosen radiance and cloud properties and

  9. Managing big, linked, and open earth-observation data: Using the TELEIOS/LEO software stack

    NARCIS (Netherlands)

    M. Koubarakis (Manolis); K. Kyzirakos (Konstantinos); C. Nikolaou (Charalampos); G. Garbis (George); K. Bereta (Konstantina); R. Dogani (Roi); S. Giannakopoulou (Stella); P. Smeros (Panayiotis); D. Savva (Dimitrianos); G. Stamoulis (Georgios); G. Vlachopoulos (Giannis); S. Manegold (Stefan); C. Kontoes (Charalampos); T. Herekakis (Themistocles); I. Papoutsis (Ioannis); D. Michail (Dimitrios)

    2016-01-01

    textabstractBig Earth-observation (EO) data that are made freely available by space agencies come from various archives. Therefore, users trying to develop an application need to search within these archives, discover the needed data, and integrate them into their application. In this article, we

  10. Sustainable Systems for exploration, stays with increased duration in LEO and Earth application -an overview about life support activities

    Science.gov (United States)

    Slenzka, Klaus; Duenne, Matthias

    Solar system exploration with extended stays in totally closed habitats far away from Earth as well as longer stays in LEO requires intensive preparatory activities. Activities supporting life in a more or less close meaning are essential in this context -on a scientific as well as on a technical level. These needed activities are supporting life by e.g.: i) increasing knowledge about the impact of single and combined effects of different exploration related environmental conditions (e. g. microgravity, radiation, reduced pressure and temperature, lunar soil etc.) on biological systems. This is needed to enable safe life of humans itself as well as safe operating of required bioregenerative life support systems. Thus, different human cell types as well as representatives of bioregenerative life support system protagonists (algae, bacteria as well as higher organisms) needs to be addressed. ii) provision of required consumables (oxygen, food, energy equivalents etc.) on site, mainly via bioregenerative life support systems, Bio-ISRU-units etc. Preparation is needed on a scientific as well as technological level. iii) ensuring reduced negative effects on humans (and partially also equipment), which could be caused by living in a closed habitat in general (and thus being not space related per se): E. g. detection systems for the quality of water and air, antimicrobial and selfhealing as well as anti-icing materials without dangerous hazard substances, psychological health enhancing components etc. Referring payloads for above mentioned investigations (scientific evaluation and technology demonstration) must be developed. Extended stays and extended closure in habitats without the possibility of material transport into and out of the system are leading to the necessity of more autonomous technologies and sustainable processes. Latter one will rely mainly on biological processes and structures, which increases additionally the necessity of an intensive scientific and

  11. Rare earth ions in the glass amplifying medium

    International Nuclear Information System (INIS)

    Auzel, F.

    1998-01-01

    Full text: Though one of the recent major application breakthrough in the rare-earth (RE) field, is the general use of Erbium Doped Fibre Amplifiers (EDFA) for optical communications, such amplifiers are still bulky and expensive which limits them to terrestrial long trunk and under sea cable applications. In order to obtain compact amplifiers for the distribution network, doping concentration has to be increased up to the chemical and physical limits. In this paper, a basic limitation linked with the existence of the so-called clustering of rare earths (RE) ions is addressed. It is first shown that the 'clusters' of RE dopant, as found in literature from fibre amplification experiments, are related to what could be called 'interaction clusters' with size much larger than for 'chemical clusters'. Such interaction clusters could have spatial extension of more than 20 to 100e for non radiative interaction clusters and up to millimetres for radiative ones. Clearly such 'clusters' have nothing to do with 'chemical clusters' which are the only ones depending on the chemical processes of the glass preparation. The existence of 'chemical clusters' of spatial extension of a few e, would increased tremendously ion-ion interactions of all kinds. One needs to obtain signature of such clusters which are the only ones that chemistry could eventually modify. It has been recently proposed that the physical process of cooperative luminescence be closely related to chemical clustering and that using this effect with Yb 3+ as a probing ion, clear signatures of RE clusters could be obtained for different glass compositions and RE concentrations. Developing this approach, a new doping principle is proposed. It is based on the recognition that during crystal growing, the various atomic forces at the atomic scale are able to define atomic positions of atoms with the crystal cells regularity. In particular, in the case of a crystal with RE as constituents, the RE-RE distances are

  12. NASA STD-4005: The LEO Spacecraft Charging Design Standard

    Science.gov (United States)

    Ferguson, Dale C.

    2006-01-01

    Power systems with voltages higher than about 55 volts may charge in Low Earth Orbit (LEO) enough to cause destructive arcing. The NASA STD-4005 LEO Spacecraft Charging Design Standard will help spacecraft designers prevent arcing and other deleterious effects on LEO spacecraft. The Appendices, an Information Handbook based on the popular LEO Spacecraft Charging Design Guidelines by Ferguson and Hillard, serve as a useful explanation and accompaniment to the Standard.

  13. The International Space Station: A Low-Earth Orbit (LEO) Test Bed for Advancements in Space and Environmental Medicine

    Science.gov (United States)

    Ruttley, Tara M.; Robinson, Julie A.

    2010-01-01

    Ground-based space analog projects such as the NASA Extreme Environment Mission Operations (NEEMO) can be valuable test beds for evaluation of experimental design and hardware feasibility before actually being implemented on orbit. The International Space Station (ISS) is an closed-system laboratory that orbits 240 miles above the Earth, and is the ultimate extreme environment. Its inhabitants spend hours performing research that spans from fluid physics to human physiology, yielding results that have implications for Earth-based improvements in medicine and health, as well as those that will help facilitate the mitigation of risks to the human body associated with exploration-class space missions. ISS health and medical experiments focus on pre-flight and in-flight prevention, in-flight treatment, and postflight recovery of health problems associated with space flight. Such experiments include those on enhanced medical monitoring, bone and muscle loss prevention, cardiovascular health, immunology, radiation and behavior. Lessons learned from ISS experiments may not only be applicable to other extreme environments that face similar capability limitations, but also serve to enhance standards of care for everyday use on Earth.

  14. Wave Optics Based LEO-LEO Radio Occultation Retrieval

    DEFF Research Database (Denmark)

    von Benzon, Hans-Henrik; Høeg, Per

    2016-01-01

    optics based retrieval chain is used on a number of examples and the retrieved atmospheric parameters are compared to the parameters from a global ECMWF analysis model. This model is used in a forward propagator that simulates the electromagnetic field amplitudes and phases at the receiver on board...... receiver on board a Low Earth Orbit (LEO) satellite. The technique is based on the Doppler shift imposed, by the atmosphere, on the signal emitted from the GPS satellite. Two LEO satellites are assumed in the occultations discussed in this paper and the retrieval is also dependent on the decrease...

  15. IMPREGNATION OF 2-MERCAPTOBENZOTHIAZOLE ON DIATOMACEOUS EARTH AND ITS APPLICATION AS MERCURY(II) ADSORBEN IN AQUEOUS MEDIUM

    OpenAIRE

    Purwanto, Agung; Narsito, Narsito

    2010-01-01

    An adsorbent was prepared by impregnating 2-mercaptobenzo-thiazole onto polystirene treated diatomaceous earth support. This adsorbent was then applied to adsorb mercury(II) in aqueous medium. The mercury(II) adsorption characteristics of the adsorbent was studied by the use of the original diatomaceous earth as reference. Interaction of mercury(II) and both of diatomaceous earth as well as MBT-diatomaceous were performed in a aqueous batch system to include the following parameters: (a)...

  16. Cosmic Carbon Chemistry: From the Interstellar Medium to the Early Earth

    Science.gov (United States)

    Ehrenfreund, Pascale; Cami, Jan

    2010-01-01

    Astronomical observations have shown that carbonaceous compounds in the gas and solid state, refractory and icy are ubiquitous in our and distant galaxies. Interstellar molecular clouds and circumstellar envelopes are factories of complex molecular synthesis. A surprisingly large number of molecules that are used in contemporary biochemistry on Earth are found in the interstellar medium, planetary atmospheres and surfaces, comets, asteroids and meteorites, and interplanetary dust particles. In this article we review the current knowledge of abundant organic material in different space environments and investigate the connection between presolar and solar system material, based on observations of interstellar dust and gas, cometary volatiles, simulation experiments, and the analysis of extraterrestrial matter. Current challenges in astrochemistry are discussed and future research directions are proposed. PMID:20554702

  17. Trapped Proton Environment in Medium-Earth Orbit (2000-2010)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yue [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Friedel, Reinhard Hans [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kippen, Richard Marc [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-31

    This report describes the method used to derive fluxes of the trapped proton belt along the GPS orbit (i.e., a Medium-Earth Orbit) during 2000 – 2010, a period almost covering a solar cycle. This method utilizes a newly developed empirical proton radiation-belt model, with the model output scaled by GPS in-situ measurements, to generate proton fluxes that cover a wide range of energies (50keV- 6MeV) and keep temporal features as well. The new proton radiation-belt model is developed based upon CEPPAD proton measurements from the Polar mission (1996 – 2007). Comparing to the de-facto standard empirical model of AP8, this model is not only based upon a new data set representative of the proton belt during the same period covered by GPS, but can also provide statistical information of flux values such as worst cases and occurrence percentiles instead of solely the mean values. The comparison shows quite different results from the two models and suggests that the commonly accepted error factor of 2 on the AP8 flux output over-simplifies and thus underestimates variations of the proton belt. Output fluxes from this new model along the GPS orbit are further scaled by the ns41 in-situ data so as to reflect the dynamic nature of protons in the outer radiation belt at geomagnetically active times. Derived daily proton fluxes along the GPS ns41 orbit, whose data files are delivered along with this report, are depicted to illustrate the trapped proton environment in the Medium-Earth Orbit. Uncertainties on those daily proton fluxes from two sources are evaluated: One is from the new proton-belt model that has error factors < ~3; the other is from the in-situ measurements and the error factors could be ~ 5.

  18. Orbital Lifetime Analysis for Nanosatellites at LEO

    Science.gov (United States)

    Cubillos Jara, D. J.; Soliz Torrico, J. A.; Ramírez Suárez, O. L.

    2018-01-01

    Nanosatellites at low earth orbit (LEO) have multiple applications such as monitoring environmental conditions, measuring ionosphere properties, improving communications, among others. These applications have lead to increase the effort of estimating orbital lifetimes for nanosatellites because they define the maximum operational time of a mission. In this report, we estimate orbital lifetimes of nanosatellites at LEO taking into account the gravitational interaction, Earth deformations, atmospheric drag and satellite initial conditions. Highest, mean and lowest lifetimes for nanosatellites of 1U, 2U and 3U in an equatorial orbit are computed by assuming a density profile according to literature and hypothetical uncertainties.

  19. Medium Resolution Global Earth Observations with Landsat: Looking 35 Years Back and 50 Years Forward

    Science.gov (United States)

    Williams, D. L.; Irons, J. R.; Goward, S. N.

    2007-12-01

    The modern era of global medium resolution satellite remote sensing was inaugurated 35 years ago, in July 1972, with the launch of the first Landsat satellite carrying the Multispectral Scanner (MSS) sensor. Ten years after that first launch, Landsat 4 carried a much-improved sensor aloft, the Thematic Mapper. The TM provided better spatial resolution (30 m versus 79 m) than the MSS, as well as additional spectral bands in the mid- infrared (IR) and thermal IR regions. Roughly another decade later, in April 1999, the Enhanced Thematic Mapper Plus (ETM+) instrument was placed in orbit on Landsat 7. The ETM+ provided a new 15 m panchromatic band and a much-improved thermal band resolution (60 m versus 120 m). Through a combination of planning and good luck, the various Landsat missions have delivered a continuous set of calibrated, multispectral images of the Earth's surface spanning this entire 35-year time period. This imagery database has been used in agricultural evaluations, forest management inventories, geological surveys, water resource estimates, coastal zone appraisals, and a host of other applications to meet the needs of a very broad user community, including business, government, science, education, national security, and now -- even the casual observer -- as Landsat imagery provides the skeletal backbone of Google Earth. Landsat established the U.S. as the world leader in terrestrial remote sensing, contributed significantly to the understanding of the Earth's environment, spawned revolutionary uses of space-based data by the commercial value-added industry, and encouraged a new generation of commercial satellites that provide regional, high-resolution spatial images. In spite of the overall success of the Landsat series of satellites, the first 35 years of the Landsat legacy have been extremely challenging as the push to embrace new technologies was often questioned by those who simply wanted to maintain whatever the current capability was at that

  20. Application of higher harmonics in protection against single-phase earth faults in resonant grounded cable networks of medium voltage

    OpenAIRE

    Vinokurova, T. Yu.; Dobryagina, O. A.; Shagurina, E. S.; Shuin, V. A.

    2015-01-01

    Protections based by higher harmonics absolute measurements the zero sequence currents of the protected object connections against single-phase earth faults in resonant grounded cable networks of medium voltage industrial and urban energy supply systems have been widely applied in Russia since the late 60s of the 20th century. However, some operational problems connected with sufficient selectivity and sensitivity of these protection devices appeared with time. Sensitivity and selectivity of ...

  1. Global recovery process of thorium and rare earths in a nitrate medium

    International Nuclear Information System (INIS)

    Cailly, F.; Mottot, Y.

    1993-01-01

    The aqueous solution of thorium and rare earth nitrates, obtained by leaching the ore with nitric acid, is extracted by an organic phosphorous compound (phosphate, phosphonate, phosphinate or phosphine oxide) and a cationic extractant chosen among phosphoric acid di-esters. Extraction of thorium and rare earths is possible even in presence of phosphate ions in the aqueous solution. Thorium and rare earths are separated by liquid-liquid extraction of the organic phase

  2. IMPREGNATION OF 2-MERCAPTOBENZOTHIAZOLE ON DIATOMACEOUS EARTH AND ITS APPLICATION AS MERCURY(II ADSORBEN IN AQUEOUS MEDIUM

    Directory of Open Access Journals (Sweden)

    Agung Purwanto

    2010-06-01

    Full Text Available An adsorbent was prepared by impregnating 2-mercaptobenzo-thiazole onto polystirene treated diatomaceous earth support. This adsorbent was then applied to adsorb mercury(II in aqueous medium. The mercury(II adsorption characteristics of the adsorbent was studied by the use of the original diatomaceous earth as reference. Interaction of mercury(II and both of diatomaceous earth as well as MBT-diatomaceous were performed in a aqueous batch system to include the following parameters: (a medium acidity and (b mercury(II adsorption characteristic on MBT-diatomaceous with and without the present of other metal ions. In the present work quantification of mercury(II adsorption was done by determining the mercury concentration left in the solution after adsorption. A cold vapour-generation atomic absorption spectroscopy technic was used in this determination.The experiment results show, that the adsorption affinity of MBT-diatomaceous is higher than the original diatomaceous earth. The total adsorption energy of mercury(II for diatomaceous earth (24.702 kJ/mol and MBT-diatomaceous (46.942 kJ/mol suggest that the interaction is chemisorption. The mercury(II maximum adsorption on diatomaceous earth is obtained at pH 6, while similar adsorption on MBT-diatomaceous practically was not influenced by pH changes. The present of other metals, i.e. Fe(III, Co(II, Ni(II, Cu(II, Cd(II and Zn(II in solution does not give any appreciable influence to the adsorption affinity of MBT-diatomaceous to mercury(II; the total sum of the mercury(II adsorbed is constantly high, almost 100 %. Keyword: Impregnation, MBT-diatomaceous, adsorption, mercury(II

  3. Fabrication process of a rare earth compound colloidal dispersion in an aqueous medium and product obtained

    International Nuclear Information System (INIS)

    David, C.; Seon, F.

    1989-01-01

    A rare earth oxide is reacted with a controlled amount of a water soluble monovalent acid with a pK a between 2.5 and 5.0 then, the whole is heated. The invention is well suited for the preparation of yttric rare earth compound colloidal dispersion [fr

  4. Impact of LEO satellites on global GPS solutions

    Science.gov (United States)

    Rothacher, M.; Svehla, D.

    2003-04-01

    Already at present quite a few Low Earth Orbiting (LEO) satellites (SAC-C, CHAMP, JASON-1, GRACE-1 and GRACE-2) are equipped with one or more GPS receivers for precise orbit determination or other applications (atmospheric sounding, gravity field recovery, ...). This trend will continue in the near future (e.g., with the GOCE and COSMIC missions) and we will soon have an entire``constellation´´ of LEO satellites tracked by GPS at our disposal. In this contribution we study the impact of LEO GPS measurements (from a single LEO satellite or from a LEO constellation) on global GPS solutions, where GPS satellite orbits and clocks, Earth rotation parameters (ERPs), station coordinates and troposphere zenith delays are determined simultaneously. In order to assess the impact of the LEO GPS data on global IGS results, we perform a combined analysis of the space-borne and the ground-based GPS data. Such a combination may benefit on one hand from the differences between a ground station and a LEO, namely, (1) the different tracking geometry (coverage of isolated geographical areas by LEOs, rapidly changing geometry, ...); (2) that LEOs connect all ground stations within 1-2 hours; (3) that baselines between LEO and ground stations may be longer than station-station baselines; (4) that no tropospheric delays have to be estimated for LEOs; and (5) that LEOs orbit the Earth within the ionosphere and may therefore contribute to global ionosphere models. On the other hand we have to deal with difficult aspects of precise orbit determination for the LEOs: only if we succeed to obtain very accurate dynamic or reduced-dynamic orbits for the LEOs, we will have a chance to improve the global GPS results at all. We present first results concerning the influence of LEO data on GPS orbits, ERPs, site coordinates, and troposphere zenith delays using both, variance-covariance analyses based on simulated data and combined global solutions based on real CHAMP and JASON data and the data

  5. Possible mechanism of the interplanetary medium effect on the diurnal rotation rate of the Earth

    International Nuclear Information System (INIS)

    Krymskij, P.F.

    1993-01-01

    Mechanism is proposed for effect of the solar wind and interplanetary magnetic field on the Earth rotation. In the mechanism base is Hall current generation in the plasma layer of the magnetosphere tail

  6. Contribution to the study of molybdic medium and of rare earth molybdates in solution

    International Nuclear Information System (INIS)

    Bouih, A.

    1989-01-01

    On one hand,a potentiometric study of molybdic medium is done, and on the other hand, trivalent Europium behaviour in this medium is investigated The using of potentiometric data resulting from the molybdic medium study has permited to determine, with the help of a calculation program based on the electroneutrality equations and on the mass conservation, the equilibrium constants corresponding to the polymerization of molybdic acid. The behaviour of trivalent Europium in molybdic medium has been investigated using solvent extraction and potentiometry methods. Both methods have permited to identify two complexes: EuHMo7O24(2-); EuHMo7O24(2-) and to calculate their equilibrium constants. 11 figs., 12 tabs., 29 refs.(author)

  7. Sensitivities of surface wave velocities to the medium parameters in a radially anisotropic spherical Earth and inversion strategies

    Directory of Open Access Journals (Sweden)

    Sankar N. Bhattacharya

    2015-11-01

    Full Text Available Sensitivity kernels or partial derivatives of phase velocity (c and group velocity (U with respect to medium parameters are useful to interpret a given set of observed surface wave velocity data. In addition to phase velocities, group velocities are also being observed to find the radial anisotropy of the crust and mantle. However, sensitivities of group velocity for a radially anisotropic Earth have rarely been studied. Here we show sensitivities of group velocity along with those of phase velocity to the medium parameters VSV, VSH , VPV, VPH , h and density in a radially anisotropic spherical Earth. The peak sensitivities for U are generally twice of those for c; thus U is more efficient than c to explore anisotropic nature of the medium. Love waves mainly depends on VSH while Rayleigh waves is nearly independent of VSH . The sensitivities show that there are trade-offs among these parameters during inversion and there is a need to reduce the number of parameters to be evaluated independently. It is suggested to use a nonlinear inversion jointly for Rayleigh and Love waves; in such a nonlinear inversion best solutions are obtained among the model parameters within prescribed limits for each parameter. We first choose VSH, VSV and VPH within their corresponding limits; VPV and h can be evaluated from empirical relations among the parameters. The density has small effect on surface wave velocities and it can be considered from other studies or from empirical relation of density to average P-wave velocity.

  8. High Earth Orbit Design for Lunar-Assisted Medium Class Explorer Missions

    Science.gov (United States)

    McGiffin, Daniel A.; Mathews, Michael; Cooley, Steven

    2001-01-01

    This study investigates the application of high-Earth orbit (HEO) trajectories to missions requiring long on-target integration times, avoidance of the Earth's radiation belt, and minimal effects of Earth and Lunar shadow periods which could cause thermal/mechanical stresses on the science instruments. As used here, a HEO trajectory is a particular solution to the restricted three-body problem in the Earth-Moon system with the orbit period being either 1/2 of, or 1/4 of, the lunar sidereal period. A primary mission design goal is to find HEO trajectories where, for a five-year mission duration, the minimum perigee radius is greater than seven Earth radii (R(sub E)). This minimum perigee radius is chosen so that, for the duration of the mission, the perigee is always above the relatively heavily populated geosynchronous radius of 6.6 R(sub E). A secondary goal is to maintain as high an ecliptic inclination as possible for the duration of the mission to keep the apsis points well out of the Ecliptic plane. Mission design analysis was completed for launch dates in the month of June 2003, using both direct transfer and phasing loop transfer techniques, to a lunar swingby for final insertion into a HEO. Also provided are analysis results of eclipse patterns for the trajectories studied, as well as the effects of launch vehicle errors and launch delays.

  9. Stability of rare earth complexes with 2-(o-hydroxyphenyl)benzimidazole in aqueous-dioxane medium

    International Nuclear Information System (INIS)

    Akhrimenko, Z.M.; Panyushkin, V.T.; Fedorova, M.V.

    1990-01-01

    Method of potentiometric titration was used to determine protonation constants of 2-(-hydroxyphenyl)benzimidazole (pK 1 =4.5; pK 2 =11.30) and stability constants of Pr,Nd,Sm,Eu,Tb,Dy complexes with this ligand. Nonmonotonous change of lgK 1 with increase of ordinal number of rare earth element was revealed

  10. Leo II PC

    Data.gov (United States)

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

  11. Preliminary study for the separation of rare earth group elements in medium and heavy fractions by solvent extraction

    International Nuclear Information System (INIS)

    Soares, P.S.M.

    1994-01-01

    The objective of the study is the definition of a solvent extraction system suitable to achieve the separation of Rare Earth group elements, contained in hydrochloric acid media, into two fractions, medium and heavy rare earth groups. The experimental programme is proposed and developed in two parts, batch and continuous tests, with phosphonic acid, in an aliphatic diluent. In these tests, extraction and stripping behaviour of Y, Dy, Sm and Gd are examined, as they are the most concentrated elements in the solution feed. Y is the most extracted element and Dy is extracted along with Y due to the low separation factor Y/Dy = 3.64, identified for the system studied. Sm and Gd practically are not extracted into the organic phase and under the same conditions are easily scrubbed from it. Results obtained in batch were confirmed in continuous tests performed in laboratory scale mixer settlers assembly. It is proposed and successfully tested a solvent extraction circuit suitable to achieve the separation of the rare earth mixture studied in two concentrates one rich in Sm, Gd and the other rich in Dy, Y respectively. The point of fractioning of this mixture for the experimental conditions studied is located between the elements Gd and Dy. (author). 135 refs., 36 figs., 14 tabs

  12. Separation of uranium from rare earths in chloride medium using Alamine 336

    International Nuclear Information System (INIS)

    Mondal, S.; Giriyalkar, A.B.; Singh, A.K.; Hubli, R.C.

    2014-01-01

    Present work was carried out to optimize a process to separate uranium from rare earths using Alamine-336 (tri-n-octyl amine). This paper describes the process of extraction of uranium from chloride liquor generated after dissolution of impure SDU cake in hydrochloric acid. The solvent used in this study is Alamine-336 which was procured from M/s. Chemical Centre, Mumbai. Dodecane was used as diluent and isodecanol as phase modifier. The extraction and stripping experiments were carried out in separating funnels shaken manually at room temperature. The contact time was fixed at five minutes for all the experiments. Following contact, the aqueous phase and the organic phase were separated and the aqueous phase was taken up for analysis. Analysis of uranium and rare earths were done by ICP-AES. Metal extraction by amines depends on the capacity of the metallic ions to form anionic/neutral species in the aqueous media; these species are then extracted by anion exchange mechanism or by adduct formation respectively

  13. Leo Satellite Communication through a LEO Constellation using TCP/IP Over ATM

    Science.gov (United States)

    Foore, Lawrence R.; Konangi, Vijay K.; Wallett, Thomas M.

    1999-01-01

    The simulated performance characteristics for communication between a terrestrial client and a Low Earth Orbit (LEO) satellite server are presented. The client and server nodes consist of a Transmission Control Protocol /Internet Protocol (TCP/IP) over ATM configuration. The ATM cells from the client or the server are transmitted to a gateway, packaged with some header information and transferred to a commercial LEO satellite constellation. These cells are then routed through the constellation to a gateway on the globe that allows the client/server communication to take place. Unspecified Bit Rate (UBR) is specified as the quality of service (QoS). Various data rates are considered.

  14. Medium-range order of magnetic amorphous alloys containing rare earth metals

    International Nuclear Information System (INIS)

    Boucher, B.

    1989-01-01

    The influence of nuclear order and surface layers on the magnetic order and the existence of two characteristic lengths (ξ=2π/k∼10 3 A or 10 A) have been established. The principal conclusions of theorists: concerning the abscence of infinite ferromagnetic clusters and the correlated spin glass or ferromagnet with wandering axis models are verified. The published results seem to indicate the existence of a critical temperature. The role of 3d ions in the magnetic ordering has not been extensively studied; it seems that the presence of 3d ions leads smaller correlation lengths. The Lorentzian scattering term correspond not only to spin waves but also to a static order. The origin of the L 3/2 scattering term observed in severals cases is discussed. It would be very useful to carry out measurements at lower q values so as to obtain more detailed informations concerning the nuclear or magnetic medium range order

  15. Nickel metal hydride LEO cycle testing

    Science.gov (United States)

    Lowery, Eric

    1995-01-01

    The George C. Marshall Space Flight Center is working to characterize aerospace AB5 Nickel Metal Hydride (NiMH) cells. The cells are being evaluated in terms of storage, low earth orbit (LEO) cycling, and response to parametric testing (high rate charge and discharge, charge retention, pulse current ability, etc.). Cells manufactured by Eagle Picher are the subjects of the evaluation. There is speculation that NiMH cells may become direct replacements for current Nickel Cadmium cells in the near future.

  16. Regional positioning using a low Earth orbit satellite constellation

    Science.gov (United States)

    Shtark, Tomer; Gurfil, Pini

    2018-02-01

    Global and regional satellite navigation systems are constellations orbiting the Earth and transmitting radio signals for determining position and velocity of users around the globe. The state-of-the-art navigation satellite systems are located in medium Earth orbits and geosynchronous Earth orbits and are characterized by high launching, building and maintenance costs. For applications that require only regional coverage, the continuous and global coverage that existing systems provide may be unnecessary. Thus, a nano-satellites-based regional navigation satellite system in Low Earth Orbit (LEO), with significantly reduced launching, building and maintenance costs, can be considered. Thus, this paper is aimed at developing a LEO constellation optimization and design method, using genetic algorithms and gradient-based optimization. The preliminary results of this study include 268 LEO constellations, aimed at regional navigation in an approximately 1000 km × 1000 km area centered at the geographic coordinates [30, 30] degrees. The constellations performance is examined using simulations, and the figures of merit include total coverage time, revisit time, and geometric dilution of precision (GDOP) percentiles. The GDOP is a quantity that determines the positioning solution accuracy and solely depends on the spatial geometry of the satellites. Whereas the optimization method takes into account only the Earth's second zonal harmonic coefficient, the simulations include the Earth's gravitational field with zonal and tesseral harmonics up to degree 10 and order 10, Solar radiation pressure, drag, and the lunisolar gravitational perturbation.

  17. Short- and Medium-Term Induced Ionization in the Earth Atmosphere by Galactic and Solar Cosmic Rays

    Directory of Open Access Journals (Sweden)

    Alexander Mishev

    2013-01-01

    Full Text Available The galactic cosmic rays are the main source of ionization in the troposphere of the Earth. Solar energetic particles of MeV energies cause an excess of ionization in the atmosphere, specifically over polar caps. The ionization effect during the major ground level enhancement 69 on January 20, 2005 is studied at various time scales. The estimation of ion rate is based on a recent numerical model for cosmic-ray-induced ionization. The ionization effect in the Earth atmosphere is obtained on the basis of solar proton energy spectra, reconstructed from GOES 11 measurements and subsequent full Monte Carlo simulation of cosmic-ray-induced atmospheric cascade. The evolution of atmospheric cascade is performed with CORSIKA 6.990 code using FLUKA 2011 and QGSJET II hadron interaction models. The atmospheric ion rate is explicitly obtained for various latitudes, namely, 40°N, 60°N and 80°N. The time evolution of obtained ion rates is presented. The short- and medium-term ionization effect is compared with the average effect due to galactic cosmic rays. It is demonstrated that ionization effect is significant only in subpolar and polar atmosphere during the major ground level enhancement of January 20, 2005. It is negative in troposphere at midlatitude, because of the accompanying Forbush effect.

  18. Remembering Leo Kadanoff

    Indian Academy of Sciences (India)

    Everyone gathered at the Monday bag-lunch seminar series Leo started. He was already a celebrity with ... the world and presented bag-lunch seminars in addition to their more formal lecture-duties at the institute ... The emergence of the now famous Chicago school in statistical and soft matter physics took place after I left ...

  19. Leo Meyer / Villem Reiman

    Index Scriptorium Estoniae

    Reiman, Villem

    2008-01-01

    Prof. dr. phil. Leo Meyer (03.07.1830-24.05.1910), keeleteadlane, Tartu ja Göttingeni ülikooli ja võrdleva keeleteaduse õppejõud, Eesti Kirjanduse Seltsi kauaaegne esimees ja esimene auliige. Varem ilm.: Eesti Kirjandus, 1910, nr. 9, lk. 389-393

  20. What Happened to Leo P's Metals?

    Science.gov (United States)

    Kohler, Susanna

    2015-12-01

    Hubble observations to reconstruct Leo Ps star formation history. McQuinn and collaborators use this history to determine the dwarf galaxys total oxygen production used as a tracer of its metal production over its lifetime. They then compare this to the abundance of oxygen currently observed within Leo P.In non-isolated dwarf-spheroidal galaxies of similar mass to Leo P, 99% of their expected metals are missing. In comparison, the authors find that Leo P is missing 95% of its expected metals. From these results, it seems that expulsion of enriched material by stellar feedback alone can explain most of the missing metals in such galaxies; external factors only remove an additional few percent.This explanation is further supported by the fact that, of the oxygen remaining in Leo P, 25% is locked up in stars, whereas 75% is found to be in gas form in the galaxys interstellar medium. If this 75% were stripped away by external processes, Leo Ps measurements would become consistent with those of the non-isolated dwarf galaxies.CitationKristen B. W. McQuinn et al 2015 ApJ 815 L17. doi:10.1088/2041-8205/815/2/L17

  1. Petróleo

    Directory of Open Access Journals (Sweden)

    Celso Fernando Lucchesi

    1998-08-01

    Full Text Available COM MENOS DE 50 anos de atividade empresarialmente organizada a exploração de petróleo no Brasil encontra-se em fase de mudança com a aprovação, em 1997, da nova legislação do setor de petróleo. Descreve-se neste trabalho o período pré-Petrobras (1858 a 1953 e a exclusividade da Petrobras (1954 a 1997 que resultou no expressivo volume de reservas de petróleo no país, da ordem de 17 bilhões de barris de óleo equivalente no final de 1997. Projetos de produção já iniciados elevarão a produção a mais de 1,5 milhão de barris de óleo por dia no início do novo século. O gás natural crescerá rapidamente sua participação na matriz energética a partir de 1999. Com a instalação da Agência Nacional de Petróleo (ANP inicia-se uma nova fase, sendo esta responsável pela atração de novos investimentos na busca de novas reservas nas bacias sedimentares brasileiras, cujo potencial é ainda significativo. Diversas empresas internacionais deverão estar operando no país no curto prazo, inicialmente associadas à Petrobras. O modelo adotado para as atividades de exploração e produção no país é o de concessão. A atividade no Brasil nesta área dependerá do regime fiscal que vier a ser implantado.THE APPROVAL OF the new Petroleum Law in 1997 proposed a dramatic change in the activities of petroleum exploration in Brazil after almost fifty years of its initial entrepreneurual organization, represented by the creation of Petrobras, in 1953. In this work two important periods are described: the pre-Petrobras period (1858 to 1953 and the period when Petrobras acted alone in the oil business (1954 to 1997. During the last one, significant results were achieved. The amount of reserves reached 17 billion barrels of oil equivalent and were made available to the country at the end of 1997. Production projects already in place or under development will raise Brazilian daily production to levels of 1.5 million barrels of oil per day

  2. Impact of GPS tracking data of LEO satellites on global GPS solutions

    Science.gov (United States)

    Rothacher, M.; Svehla, D.

    Already at present quite a few Low Earth Orbiting (LEO) satellites (SAC-C, CHAMP, JASON-1, GRACE-1 and GRACE-2) are equipped with one or more GPS receivers for precise orbit determination or other applications (atmospheric sounding, gravity field recovery, . . . ). This trend will continue in the near future (e.g., with the GOCE and COSMIC missions) and we will soon have an entire "constellation" of LEO satellites tracked by GPS at our disposal. In this contribution we want to study the impact of LEO GPS measurements (from a single LEO satellite or from a LEO constellation) on global GPS solutions, where GPS satellite orbits and clocks, Earth rotation parameters (ERPs), station coordinates and troposphere zenith delays are determined simultaneously using the data of the global network of the International GPS Service (IGS). In order to assess the impact of the LEO GPS data on global IGS results, we have to perform a combined analysis of the space-borne and the ground-based GPS data. Such a combination may benefit on one hand from the differences between a ground station and a LEO, e.g., (1) the different tracking geometry (coverage of isolated geographical areas by LEOs, rapidly changing geometry, . . . ), (2) that LEOs connect all ground stations within 1-2 hours, (3) that baselines between LEO and ground stations may be longer than station-station baselines, (4) that no tropospheric delays have to be estimated for LEOs, and (5) that LEOs orbit the Earth within the ionosphere and may therefore contribute to global ionosphere models. On the other hand we have to deal with difficult aspects of precise orbit determination for the LEOs: only if we succeed to obtain very accurate dynamic or reduced-dynamic orbits for the LEOs, we will have a chance at all to improve the global GPS results. We present first results concerning the influence of LEO data on GPS orbits, ERPs, site coordinates, and troposphere zenith delays using both, variance-covariance analyses based on

  3. Earth

    CERN Document Server

    Carter, Jason

    2017-01-01

    This curriculum-based, easy-to-follow book teaches young readers about Earth as one of the eight planets in our solar system in astronomical terms. With accessible text, it provides the fundamental information any student needs to begin their studies in astronomy, such as how Earth spins and revolves around the Sun, why it's uniquely suitable for life, its physical features, atmosphere, biosphere, moon, its past, future, and more. To enhance the learning experience, many of the images come directly from NASA. This straightforward title offers the fundamental information any student needs to sp

  4. Specialized Finite Set Statistics (FISST)-Based Estimation Methods to Enhance Space Situational Awareness in Medium Earth Orbit (MEO) and Geostationary Earth Orbit (GEO)

    Science.gov (United States)

    2016-08-17

    component. Included in the state propagation were perturbing accelerations due to an 8 x 8 Earth gravity field, Solar and Lunar gravity, and Solar ...21 Earth gravity field, Solar gravity, Lunar gravity, and solar radiation pressure. Two days of truth data were generated and saved in both ECI...Track Management Scheme for the Gaussian-Mixture Probability Hypothesis Density Tracker ," in Proceedings of the Fourth International Conference on

  5. Geocenter variations derived from a combined processing of LEO- and ground-based GPS observations

    Science.gov (United States)

    Männel, Benjamin; Rothacher, Markus

    2017-08-01

    GNSS observations provided by the global tracking network of the International GNSS Service (IGS, Dow et al. in J Geod 83(3):191-198, 2009) play an important role in the realization of a unique terrestrial reference frame that is accurate enough to allow a detailed monitoring of the Earth's system. Combining these ground-based data with GPS observations tracked by high-quality dual-frequency receivers on-board low earth orbiters (LEOs) is a promising way to further improve the realization of the terrestrial reference frame and the estimation of geocenter coordinates, GPS satellite orbits and Earth rotation parameters. To assess the scope of the improvement on the geocenter coordinates, we processed a network of 53 globally distributed and stable IGS stations together with four LEOs (GRACE-A, GRACE-B, OSTM/Jason-2 and GOCE) over a time interval of 3 years (2010-2012). To ensure fully consistent solutions, the zero-difference phase observations of the ground stations and LEOs were processed in a common least-squares adjustment, estimating all the relevant parameters such as GPS and LEO orbits, station coordinates, Earth rotation parameters and geocenter motion. We present the significant impact of the individual LEO and a combination of all four LEOs on the geocenter coordinates. The formal errors are reduced by around 20% due to the inclusion of one LEO into the ground-only solution, while in a solution with four LEOs LEO-specific characteristics are significantly reduced. We compare the derived geocenter coordinates w.r.t. LAGEOS results and external solutions based on GPS and SLR data. We found good agreement in the amplitudes of all components; however, the phases in x- and z-direction do not agree well.

  6. Íleo biliar

    OpenAIRE

    Allan Pérez-Baltodano; Marcela Bermúdez-Coto; Madelein Centeno-Rodríguez; William Vargas-Alpízar

    2005-01-01

    El íleo biliar es una entidad clínica difícil de diagnosticar que se produce como resultado de una comunicación anormal entre la vía biliar y el tubo digestivo, con la consiguiente evacuación del cálculo e impactación del mismo distalmente hasta que se presenta como un cuadro de obstrucción intestinal. Reportamos el caso de un paciente de 47 años de edad, sin antecedentes médicos ni quirúrgicos de importancia, que ingresó al servicio de emergencias quirúrgicas con un abdomen agudo, caracteriz...

  7. Mitochondrial genome of the African lion Panthera leo leo.

    Science.gov (United States)

    Ma, Yue-ping; Wang, Shuo

    2015-01-01

    In this study, the complete mitochondrial genome sequence of the African lion P. leo leo was reported. The total length of the mitogenome was 17,054 bp. It contained the typical mitochondrial structure, including 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and 1 control region; 21 of the tRNA genes folded into typical cloverleaf secondary structure except for tRNASe. The overall composition of the mitogenome was A (32.0%), G (14.5%), C (26.5%) and T (27.0%). The new sequence will provide molecular genetic information for conservation genetics study of this important large carnivore.

  8. What does it take to build a medium scale scientific cloud to process significant amounts of Earth observation data?

    Science.gov (United States)

    Hollstein, André; Diedrich, Hannes; Spengler, Daniel

    2017-04-01

    The installment of the operational fleet of Sentinels by Copernicus offers an unprecedented influx of freely available Earth Observation data with Sentinel-2 being a great example. It offers a broad range of land applications due to its high spatial sampling from 10 m to 20 m and its multi-spectral imaging capabilities with 13 spectral bands. The open access policy allows unrestricted use by everybody and provides data downloads for on the respective sites. For a small area of interest and shorter time series, data processing, and exploitation can easily be done manually. However, for multi-temporal analysis of larger areas, the data size can quickly increase such that it is not manageable in practice on a personal computer which leads to an increasing interest in central data exploitation platforms. Prominent examples are GoogleEarth Engine, NASA Earth Exchange (NEX) or current developments such as CODE-DE in Germany. Open standards are still evolving, and the choice of a platform may create lock-in scenarios and a situation where scientists are not anymore in full control of all aspects of their analysis. Securing intellectual properties of researchers can become a major issue in the future. Partnering with a startup company that is dedicated to providing tools for farm management and precision farming, GFZ builds a small-scale science cloud named GTS2 for processing and distribution of Sentinel-2 data. The service includes a sophisticated atmospheric correction algorithm, spatial co-registration of time series data, as well as a web API for data distribution. This approach is different from the drag to centralized research using infrastructures controlled by others. By keeping the full licensing rights, it allows developing new business models independent from the initially chosen processing provider. Currently, data is held for the greater German area but is extendable to larger areas on short notice due to a scalable distributed network file system. For a

  9. Leo Tolstoy the Spiritual Educator

    Science.gov (United States)

    Moulin, Dan

    2008-01-01

    This paper considers the often overlooked religious and educational works of the Russian novelist Leo Tolstoy (1828-1910). After outlining Tolstoy's life, religious and educational views, it is argued that Tolstoy has much to offer spiritual educators today. In particular, it suggests Tolstoy's insistence on the absolute and eternal nature of…

  10. Space Power Theory: Controlling the Medium Without Weapons in Space

    National Research Council Canada - National Science Library

    Wilkerson, Don L

    2008-01-01

    .... strategic space assets and the ability to negate enemy space systems is essential to U.S. space strategy in controlling the geographical environment of space, predominately in the Lower Earth Orbit (LEO...

  11. Analysis of the Accuracy of Beidou Combined Orbit Determination Enhanced by LEO and ISL

    Directory of Open Access Journals (Sweden)

    FENG Laiping

    2017-05-01

    Full Text Available In order to improve the precision of BeiDou orbit determination under the conditions of regional ground monitoring station and make good use of increasingly rich on-board data and upcoming ISL technology, a method of BeiDou precision orbit determination is proposed which combines the use of ground monitoring stations data, low earth orbit satellite(LEOs data and Inter-Satellite Link(ISL data. The effects of assisting data of LEOs and ISL on the precision orbit determination of navigation satellite are discussed. Simulation analysis is carried out mainly from the number of LEOs, orbit slot configuration and ISL. The results show that the orbit precision of BeiDou will greatly improve about 73% with a small number of LEOs, while improvement of clock bias is not remarkable; the uniform orbit slot configuration of the same number of LEOs has a modest effect on the accuracy of combined orbit determination; compared with LEOs, the increase of ISL will significantly improve the accuracy of orbit determination with a higher efficiency.

  12. PCVs Estimation and their Impacts on Precise Orbit Determination of LEOs

    Science.gov (United States)

    Chunmei, Z.; WANG, X.

    2017-12-01

    In the last decade the precise orbit determination (POD) based on GNSS, such as GPS, has been considered as one of the efficient methods to derive orbits of Low Earth Orbiters (LEOs) that demand accuracy requirements. The Earth gravity field recovery and its related researches require precise dynamic orbits of LEOs. With the improvements of GNSS satellites' orbit and clock accuracy, the algorithm optimization and the refinement of perturbation force models, the antenna phase-center variations (PCVs) of space-borne GNSS receiver have become an increasingly important factor that affects POD accuracy. A series of LEOs such as HY-2, ZY-3 and FY-3 with homebred space-borne GNSS receivers have been launched in the past several years in China. Some of these LEOs load dual-mode GNSS receivers of GPS and BDS signals. The reliable performance of these space-borne receivers has been establishing an important foundation for the future launches of China gravity satellites. Therefore, we first evaluate the data quality of on-board GNSS measurement by examining integrity, multipath error, cycle slip ratio and other quality indices. Then we determine the orbits of several LEOs at different altitudes by the reduced dynamic orbit determination method. The corresponding ionosphere-free carrier phase post-fit residual time series are obtained. And then we establish the PCVs model by the ionosphere-free residual approach and analyze the effects of antenna phase-center variation on orbits. It is shown that orbit accuracy of LEO satellites is greatly improved after in-flight PCV calibration. Finally, focus on the dual-mode receiver of FY-3 satellite we analyze the quality of onboard BDS data and then evaluate the accuracy of the FY-3 orbit determined using only BDS measurement onboard. The accuracy of LEO satellites orbit based on BDS would be well improved with the global completion of BDS by 2020.

  13. The resolved stellar population of Leo A

    NARCIS (Netherlands)

    Tolstoy, E

    1996-01-01

    New observations of the resolved stellar population of the extremely metal-poor Magellanic dwarf irregular galaxy Leo A in Thuan-Gunn r, g, i, and narrowband Ha filters are presented. Using the recent Cepheid variable star distance determination to Leo A by Hoessel et al., we are able to create an

  14. Creation of Leo LT postponed yet again

    Index Scriptorium Estoniae

    2008-01-01

    Valitsusega koos investeerimisfirmat Leo LT loova ettevõtte NDX Energija esindaja Ignas Staskevicius ei välista ka projektist loobumist, kuna lepingute tegemine on jäänud venima. Investeerimisfirma Leo LT ülesandeks on ehitada Leedu uus tuumajaam

  15. Geocenter Coordinates from a Combined Processing of LEO and Ground-based GPS Observations

    Science.gov (United States)

    Männel, Benjamin; Rothacher, Markus

    2017-04-01

    The GPS observations provided by the global IGS (International GNSS Service) tracking network play an important role for the realization of a unique terrestrial reference frame that is accurate enough to allow the monitoring of the Earth's system. Combining these ground-based data with GPS observations tracked by high-quality dual-frequency receivers on-board Low Earth Orbiters (LEO) might help to further improve the realization of the terrestrial reference frame and the estimation of the geocenter coordinates, GPS satellite orbits and Earth rotation parameters (ERP). To assess the scope of improvement, we processed a network of 50 globally distributed and stable IGS-stations together with four LEOs (GRACE-A, GRACE-B, OSTM/Jason-2 and GOCE) over a time interval of three years (2010-2012). To ensure fully consistent solutions the zero-difference phase observations of the ground stations and LEOs were processed in a common least-square adjustment, estimating GPS orbits, LEO orbits, station coordinates, ERPs, site-specific tropospheric delays, satellite and receiver clocks and ambiguities. We present the significant impact of the individual LEOs and a combination of all four LEOs on geocenter coordinates derived by using a translational approach (also called network shift approach). In addition, we present geocenter coordinates derived from the same set of GPS observations by using a unified approach. This approach combines the translational and the degree-one approach by estimating translations and surface deformations simultaneously. Based on comparisons against each other and against geocenter time series derived by other techniques the effect of the selected approach is assessed.

  16. Deep neutral hydrogen observations of Leo T with the Westerbork Synthesis Radio Telescope

    Science.gov (United States)

    Adams, Elizabeth A. K.; Oosterloo, Tom A.

    2018-04-01

    Leo T is the lowest mass gas-rich galaxy currently known and studies of its gas content help us understand how such marginal galaxies survive and form stars. We present deep neutral hydrogen (H I) observations from the Westerbork Synthesis Radio Telescope in order to understand its H I distribution and potential for star formation. We find a larger H I line flux than the previously accepted value, resulting in a 50% larger H I mass of 4.1 × 105 M⊙. The additional H I flux is from low surface brightness emission that was previously missed; with careful masking this emission can be recovered even in shallower data. We perform a Gaussian spectral decomposition to find a cool neutral medium component (CNM) with a mass of 3.7 × 104 M⊙, or almost 10% of the total H I mass. Leo T has no H I emission extending from the main H I body, but there is evidence of interaction with the Milky Way circumgalactic medium in both a potential truncation of the H I body and the offset of the peak H I distribution from the optical center. The CNM component of Leo T is large when compared to other dwarf galaxies, even though Leo T is not currently forming stars and has a lower star formation efficiency than other gas-rich dwarf galaxies. However, the H I column density associated with the CNM component in Leo T is low. One possible explanation is the large CNM component is not related to star formation potential but rather a recent, transient phenomenon related to the interaction of Leo T with the Milky Way circumgalactic medium. The reduced datacube (FITS file) 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/612/A26

  17. Combining terrestrial and LEO data to extend the GPS satellite antenna patterns to nadir angles beyond 14°

    Science.gov (United States)

    Dach, R.; Jaeggi, A.; Bock, H.; Beutler, G.; Montenbruck, O.; Schmid, R.; Andres, Y.

    2011-12-01

    The absolute phase center model igs08.atx adopted by the International GNSS Service (IGS) in 2011 is based on robot calibrations for a number of terrestrial GNSS receiver antennas and consistent correction values for the GNSS transmitter antennas estimated from data of the global IGS tracking network. As the calibration of the satellite antennas is solely based on terrestrial measurements, the estimation of their phase patterns is limited to a nadir angle of 14°. This is not sufficient for the analysis of spaceborne GPS data collected by low Earth orbiting (LEO) satellites that record observations at nadir angles of up to 17°. We use GPS tracking data from the LEO missions Jason-2, MetOp-A, GRACE, and GOCE to extend the IGS satellite antenna patterns to nadir angles beyond 14° in a combined analysis with terrestrial measurements. In order to achieve estimates that are consistent with the PCVs currently used within the IGS, GPS and LEO orbits are fixed to reprocessed solutions obtained by adopting the IGS conventional values from igs08.atx. Due to significant near-field multipath effects in the LEO spacecraft environment, it is necessary to solve for GPS (nadir-dependent only) and LEO (azimuth- and elevation-dependent) antenna patterns simultaneously. We assess the contribution of the different LEO missions to a combined solution and analyze the impact of the extended PCVs on LEO precise orbit determination results.

  18. Maneuver optimization for collision avoidance of LEO objects

    Science.gov (United States)

    Peterson, G.

    Consideration of a maneuver might be warranted when a dangerous conjunction between a primary satellite and a secondary object is identified as part of the collision avoidance (COLA) process. Efficient yet accurate numerical solutions to the maneuver problem have been developed and are implemented in The Aerospace Corporation program DVOPT (DeltaV OPTimization) for objects in geosynchronous orbit. However, achieving an accurate solution for satellites in low Earth (LEO) orbits can be problematic. DVOPT utilizes a two-body backwards/forwards propagation technique to determine the effect a proposed burn has on the probability computation. For high altitude, near-circular orbits such as geosynchronous and semisynchronous (i.e., Global Positioning System), the two-body assumption produces sufficient accuracy. The current research determines the validity of the backwards-forwards two-body propagation and identifies the perturbations that are necessary for regimes other than GEO. It is found that LEO orbits experience a significant effect due to other perturbations, which can disrupt the two -body assumption producing an unacceptable reduction in the accuracy of the probability computation. Earth oblateness and drag influence LEOs. Improvement is made to the DVOPT method by allowing for higher order perturbations in the backwards-forwards propagation. An approximate method is utilized that captures the dominant perturbation characteristics without slowing the solution process significantly. The last point is crucial. During operations, determining viable burn solutions can be time critical. The development of the solution shows that the relative error due to the perturbations can be minimized thereby significantly widening the applicability of the maneuver optimization process to other orbit classes without causing a major increase in the s lutiono runtime.

  19. Telemetry Tracking & Control (TT&C) - First TDRSS, then Commercial GEO & Big LEO and Now Through LEO

    Science.gov (United States)

    Morgan, Dwayne R.; Streich, Ron G.; Bull, Barton; Grant, Chuck; Power, Edward I. (Technical Monitor)

    2001-01-01

    The advent of low earth orbit (LEO) commercial communication satellites provides an opportunity to dramatically reduce Telemetry, Tracking and Control (TT&C) costs of launch vehicles, Unpiloted Aerial Vehicles (UAVs), Research Balloons and spacecraft by reducing or eliminating ground infrastructure. Personnel from the Goddard Space Flight Center's Wallops Flight Facility (GSFC\\WFF) have successfully used commercial Geostationary Earth Orbit (GEO) and Big LEO communications satellites for Long Duration Balloon Flight TT&C. The Flight Modem is a GSFC\\WFF Advanced Range Technology initiative (ARTI) designed to streamline TT&C capability in the user community of these scientific data gathering platforms at low cost. Making use of existing LEO satellites and adapting and ruggedized commercially available components; two-way, over the horizon communications may be established with these vehicles at great savings due to reduced infrastructure. Initially planned as a means for permitting GPS data for tracking and recovery of sounding rocket and balloon payloads, expectations are that the bandwidth can soon be expanded to allow more comprehensive data transfer. The system architecture which integrates antennas, GPS receiver, commercial satellite packet data modem and a single board computer with custom software is described and technical challenges are discussed along with the plan for their resolution. A three-phase testing and development plan is outlined and the current results are reported. Results and status of ongoing flight tests on aircraft and sounding rockets are reported. Future applications on these platforms and the potential for satellite support are discussed along with an analysis of cost effectiveness of this method vs. other tracking and data transmission schemes.

  20. An Assessment of the Current LEO Debris Environment and the Need for Active Debris Removal

    Science.gov (United States)

    Liou, Jer-Chyi

    2010-01-01

    The anti-satellite test on the Fengun-1 C weather satellite in early 2007 and the collision between Iridium 33 and Cosmos 2251 in 2009 dramatically altered the landscape of the human-made orbital debris environment in the low Earth orbit (LEO). The two events generated approximately 5500 fragments large enough to be tracked by the U.S. Space Surveillance Network. Those fragments account for more than 60% increase to the debris population in LEO. However, even before the ASAT test, model analyses already indicated that the debris population (for those larger than 10 cm) in LEO had reached a point where the population would continue to increase, due to collisions among existing objects, even without any future launches. The conclusion implies that as satellites continue to be launched and unexpected breakup events continue to occur, commonly-adopted mitigation measures will not be able to stop the collision-driven population growth. To remediate the debris environment in LEO, active debris removal must be considered. This presentation will provide an updated assessment of the debris environment after the Iridium 33/Cosmos 2251 collision, an analysis of several future environment projections based on different scenarios, and a projection of collision activities in LEO in the near future. The need to use active debris removal to stabilize future debris environment will be demonstrated and the effectiveness of various active debris removal strategies will be quantified.

  1. Leo Tolstoy's theory of sleep.

    Science.gov (United States)

    Vein, Alla A

    2008-03-01

    Throughout his life, Leo Tolstoy was fascinated by the phenomena of sleep and dreams. He composed a series of observations and judgements that were brought together under "my theory of sleep". Tolstoy was constantly preoccupied with the basic principles of "the theory". It is hard to name a work by him where a description of sleep and/or a dream does not play a vital role in the unfolding of the plot. They testify to Tolstoy's interest in the mechanism of sleep and in the processes of falling asleep and waking up. Tolstoy viewed sleep as a specific state of consciousness, and he subsequently linked the concept of sleep with the concept of death. For him sleep and awakening were experiences emblematic of life and death.

  2. Meie poliitikute seitse viga / Leo Kunnas

    Index Scriptorium Estoniae

    Kunnas, Leo, 1967-

    2008-01-01

    Artikkel põhineb reservkolonelleitnant Leo Kunnase mõttepäeval "Isemõtlejad iseolemisest" peetud ettekandel, kus ta toob välja 1930-ndatele aastatele ja tänapäevale iseloomulikud poliitkute eksimused

  3. Eestikeelseid filosoofiaraamatuid oodates / Leo Luks, Margus Ott

    Index Scriptorium Estoniae

    Luks, Leo, 1976-

    2016-01-01

    Möödunud aastal ilmus kaks algupärast eestikeelset filosoofiamonograafiat - Margus Oti "Vägi" ja Leo Luksi "Nihilism ja kirjandus". Nende autorid arutlevad vestluses, miks on filosoofiaraamatuid nii vähe

  4. The Star Formation History of Leo P

    Science.gov (United States)

    McQuinn, Kristen

    2013-10-01

    The nearby {D = 1.7+/-0.3 Mpc}, very low luminosity {M_V = -9.3+/-0.4mag}, gas-rich star forming galaxy Leo P was discovered by its HI 21cm emission in the Arecibo ALFALFA survey. Follow-up optical spectroscopy of its single HII region revealed an oxygen abundance of 12+log{O/H}=7.16+/-0.04, making it the lowest metallicity star forming galaxy in the Local Volume {D history with reasonable time resolution.The star formation history will answer two vital questions: {1} Did Leo P experience suppressed star formation during its early evolution like another isolated dwarf galaxy Leo A? and {2} What fraction of all newly created metals has Leo P been able to retain during its lifetime?

  5. The Resolved Stellar Population of Leo A

    Science.gov (United States)

    Tolstoy, Eline

    1996-05-01

    New observations of the resolved stellar population of the extremely metal-poor Magellanic dwarf irregular galaxy Leo A in Thuan-Gunn r, g, i, and narrowband Hα filters are presented. Using the recent Cepheid variable star distance determination to Leo A by Hoessel et al., we are able to create an accurate color-magnitude diagram (CMD). We have used the Bavesian inference method described by Tolstoy & Saha to calculate the likelihood of a Monte Carlo simulation of the stellar population of Leo A being a good match to the data within the well understood errors in the data. The magnitude limits on our data are sensitive enough to look back at ~1 Gyr of star formation history at the distance of Leo A. To explain the observed ratio of red to blue stars in the observed CMD, it is necessary to invoke either a steadily decreasing star formation rate toward the present time or gaps in the star formation history. We also compare the properties of the observed stellar population with the known spatial distribution of the H I gas and H II regions to support the conclusions from CMD modeling. We consider the possibility that currently there is a period of diminished star formation in Leo A, as evidenced by the lack of very young stars in the CMD and the faint H II regions. How the chaotic H I distribution, with no observable rotation, fits into our picture of the evolution of Leo A is as yet unclear.

  6. Establishing a Robotic, LEO-to-GEO Satellite Servicing Infrastructure as an Economic Foundation for Exploration

    Science.gov (United States)

    Horsham, Gary A. P.; Schmidt, George R.; Gilland, James H.

    2010-01-01

    The strategy for accomplishing civilian exploration goals and objectives is in the process of a fundamental shift towards a potential new approach called Flexible Path. This paper suggests that a government-industry or public-private partnership in the commercial development of low Earth orbit to geostationary orbit (LEO-to-GEO (LTG)) space, following or in parallel with the commercialization of Earth-to-LEO and International Space Station (ISS) operations, could serve as a necessary, logical step that can be incorporated into the flexible path approach. A LTG satellite-servicing infrastructure and architecture concept is discussed within this new strategic context. The concept consists of a space harbor that serves as a transport facility for a fleet of specialized, fully- or semi-autonomous robotic servicing spacecraft. The baseline, conceptual system architecture is composed of a space harbor equipped with specialized servicer spacecraft; a satellite command, communication, and control system; a parts station; a fuel station or depot; and a fuel/parts replenishment transport. The commercial servicer fleet would consist of several types of spacecraft, each designed with specialized robotic manipulation subsystems to provide services such as refueling, upgrade, repair, inspection, relocation, and removal. The space harbor is conceptualized as an ISS-type, octagonal truss structure equipped with radiation tolerant subsystems. This space harbor would be primarily capable of serving as an operational platform for various commercially owned and operated servicer spacecraft positioned and docked symmetrically on four of the eight sides. Several aspects of this concept are discussed, such as: system-level feasibility in terms of ISS-truss-type infrastructure and subsystems emplacement and maintenance between LEO and GEO; infrastructure components assembly in LEO, derived from ISS assembly experience, and transfer to various higher orbital locations; the evolving Earth

  7. Effect of KOH concentration on LEO cycle life of IPV nickel-hydrogen flight battery cells

    Science.gov (United States)

    Smithrick, John J.; Hall, Stephen W.

    1990-01-01

    A breakthrough in the low-earth-orbit (LEO) cycle life of individual pressure vessel (IPV) nickel hydrogen battery cells is reported. The cycle life of boiler plate cells containing 26 percent potassium hydroxide (KOH) electrolyte was about 40,000 LEO cycles compared to 3500 cycles for cells containing 31 percent KOH. The effect of KOH concentration on cycle life was studied. The cycle regime was a stressful accelerated LEO, which consisted of a 27.5 min charge followed by a 17.5 min charge (2 x normal rate). The depth of discharge (DOD) was 80 percent. The cell temperature was maintained at 23 C. The next step is to validate these results using flight hardware and real time LEO test. NASA Lewis has a contract with the Naval Weapons Support Center (NWSC), Crane, Indiana to validate the boiler plate test results. Six 48 A-hr Hughes recirculation design IPV nickel-hydrogen flight battery cells are being evaluated. Three of the cells contain 26 percent KOH (test cells) and three contain 31 percent KOH (control cells). They are undergoing real time LEO cycle life testing. The cycle regime is a 90-min LEO orbit consisting of a 54-min charge followed by a 36-min discharge. The depth-of-discharge is 80 percent. The cell temperature is maintained at 10 C. The cells were cycled for over 8000 cycles in the continuing test. There were no failures for the cells containing 26 percent KOH. There were two failures, however, for the cells containing 31 percent KOH.

  8. Nimbus-3 Medium-Resolution Infrared Radiometer (MRIR) Imagery of the Earth and Atmosphere at Daytime on 4" x 5" Film Sheets V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The MRIRN3IM data product consists of 4 x 5 inch photographic film sheets from the Nimbus-3 Medium Resolution Infrared Radiometer. Each film sheet contains an entire...

  9. Nimbus-2 Medium-Resolution Infrared Radiometer (MRIR) Imagery of the Earth and Atmosphere at Daytime on 4" x 5" Film Sheets V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The MRIRN2IM data product consists of 4 x 5 inch photographic film sheets from the Nimbus-2 Medium Resolution Infrared Radiometer. Each film sheet contains an entire...

  10. MEMS Reaction Control and Maneuvering for Picosat Beyond LEO

    Science.gov (United States)

    Alexeenko, Alina

    2016-01-01

    The MEMS Reaction Control and Maneuvering for Picosat Beyond LEO project will further develop a multi-functional small satellite technology for low-power attitude control, or orientation, of picosatellites beyond low Earth orbit (LEO). The Film-Evaporation MEMS Tunable Array (FEMTA) concept initially developed in 2013, is a thermal valving system which utilizes capillary forces in a microchannel to offset internal pressures in a bulk fluid. The local vapor pressure is increased by resistive film heating until it exceeds meniscus strength in a nozzle which induces vacuum boiling and provides a stagnation pressure equal to vapor pressure at that point which is used for propulsion. Interplanetary CubeSats can utilize FEMTA for high slew rate attitude corrections in addition to desaturating reaction wheels. The FEMTA in cooling mode can be used for thermal control during high-power communication events, which are likely to accompany the attitude correction. Current small satellite propulsion options are limited to orbit correction whereas picosatellites are lacking attitude control thrusters. The available attitude control systems are either quickly saturated reaction wheels or movable high drag surfaces with long response times.

  11. Leo Metsari tõlkepärl / Aivar Kull

    Index Scriptorium Estoniae

    Kull, Aivar, 1955-

    2002-01-01

    Arvustus: Mann, Thomas. Lotte Weimaris / tlk. Leo Metsar. Tln. : Eesti Raamat, 2001. (Nobeli laureaat). Vaata ka: Kull, Aivar. Kulli pilk. - Tartu : Ilmamaa, 2005, lk. 68-69, pealkirjaga "Goethe, Thomas Mann ja Leo Metsar"

  12. Ion transport under the effect of an electric field in porous medium: application to the separation of rare earths by focalization electrophoresis

    International Nuclear Information System (INIS)

    Vieira-Nunes, A.I.

    1999-01-01

    Trivalent ions of rare earth elements have very similar properties and their difficult separation each from another is usually carried out by liquid-liquid extraction or ion exchange. Focalization electrophoresis represents an alternative route to the usual techniques. The purpose of this work consisted of the fundamental investigation of ion transport phenomena in electrophoretic processes. Focalization electrophoresis is suitable for separation of amphoteric species such as rare earth ions, using a pH gradient in the cell and upon addition of a complexed agent e. g. EDTA. This technique relies upon the difference in iso-electrical points of the considered species, being under the form of free cation near the anode, and in the form of anionic complexed species closer to the cathode. Rare earth species are submitted to the antagonist effects of diffusion and migration, enabling their focalization to occur at the iso-electrical point, corresponding to nil value of their effective mobility. Following a literature survey on rare earth elements and electrophoresis processes, the document describes theoretical and experimental investigations of complexation equilibria of some rare earth elements, namely lanthanum, neodymium, praseodymium and cerium, depending on pH. Values for the iso-electrical points could be estimated. Transport and focalization phenomena in view of rare earth separation, are dealt in the last chapter. Investigations were first carried out without forced circulation of the electrolyte solution and the transient behavior of the system allowed operating conditions to be design and built-up of a continuous device, more suitable to separation, and provided with 42 potential and 42 temperature sensors: the results of the preliminary runs, in form of variable profiles, are presented and discussed. (author)

  13. LEGEND, a LEO-to-GEO Environment Debris Model

    Science.gov (United States)

    Liou, Jer Chyi; Hall, Doyle T.

    2013-01-01

    LEGEND (LEO-to-GEO Environment Debris model) is a three-dimensional orbital debris evolutionary model that is capable of simulating the historical and future debris populations in the near-Earth environment. The historical component in LEGEND adopts a deterministic approach to mimic the known historical populations. Launched rocket bodies, spacecraft, and mission-related debris (rings, bolts, etc.) are added to the simulated environment. Known historical breakup events are reproduced, and fragments down to 1 mm in size are created. The LEGEND future projection component adopts a Monte Carlo approach and uses an innovative pair-wise collision probability evaluation algorithm to simulate the future breakups and the growth of the debris populations. This algorithm is based on a new "random sampling in time" approach that preserves characteristics of the traditional approach and captures the rapidly changing nature of the orbital debris environment. LEGEND is a Fortran 90-based numerical simulation program. It operates in a UNIX/Linux environment.

  14. A LEO concept for millimeter wave satellite communication

    Science.gov (United States)

    Jackson, A. H.; Christopher, P.

    1995-01-01

    A conceptual 60 satellite LEO constellation for millimeter wave communication is discussed. It could be launched in segments, with the first 30 satellites providing high elevation angles for all time in the Northern latitudes between Miami and Thule. The second set of 30 satellites would complete the worldwide coverage with emphasis on high ground elevation angles in the densely populated temperate zones. Full earth searches for all time are used to generate probability density functions for elevation angle. The density functions are used to derive optimum frequencies for random elevation systems. The 55 degree average elevation angle and 14 degree standard deviation are seen to be acceptable for 0.997 rain availability in Washington, DC for the 40 to 47 GHz region. The 40 to 47 GHz region is nearly optimum, if 0.99 rain availability is acceptable.

  15. Association of alkali and alkaline earth metal cations with radical-anions of 9-fluorenone and 9.10-anthraquinone in dimethyl formamide medium

    International Nuclear Information System (INIS)

    Karpinets, A.P.; Bezuglyj, V.D.; Svetlichnaya, T.M.

    1988-01-01

    The polarographic method is used to estimate the stability of associates formed in dimethyl formamide by the products of one-electron reduction of 9-fluorenone and 9.10-anthraquinone with cations of alkali and alkali earth metals. It is shown that the strength of 9-fluorenone and 9.10-anthraquinone radical anion associates studied increases with cation charge increase and decrease of its crystallographic radius

  16. Challenging Christianity: Leo Tolstoy and Religious Education

    Science.gov (United States)

    Moulin, Dan

    2009-01-01

    The religious thought of Russian novelist Leo Tolstoy is a well documented but often overlooked example of unorthodox Christianity. This paper uses the example of Tolstoy's religious thinking to question the integrity of the current representation of Christianity in UK schools. It also uses Tolstoy's criticism of orthodox Christianity to suggest a…

  17. The Ancient stellar population of Leo A.

    NARCIS (Netherlands)

    Saha, Abhijit; Fiorentino, Giuliana; Tolstoy, Eline; Cole, Andrew

    The primary goal of our proposal is the characterisation of the oldest stellar populations in Leo A using the properties of ancient RR Lyrae variable stars as tracers. Well known and long established correlations exist between the periods and luminosities of RR Lyrae variable stars and their ages

  18. In Memory of Leo P. Kadanoff

    Science.gov (United States)

    Wegner, Franz J.

    2017-05-01

    Leo Kadanoff has worked in many fields of statistical mechanics. His contributions had an enormous impact. This holds in particular for critical phenomena, where he explained Widom's homogeneity laws by means of block-spin transformations and laid the basis for Wilson's renormalization group equation. I had the pleasure to work in his group for 1 year. A short historical account is given.

  19. Effect of KOH concentration on LEO cycle life of IPV nickel-hydrogen flight cells-update 2

    Science.gov (United States)

    Smithrick, John J.; Hall, Stephen W.

    1991-01-01

    An update of validation test results confirming the breakthrough in low earth orbit (LEO) cycle life of nickel-hydrogen cells containing 26 percent KOH electrolyte is presented. A breakthrough in the LEO cycle life of individual pressure vessel (IPV nickel-hydrogen cells has been previously reported. The cycle life of boiler plate cells containing 26 percent potassium hydroxide (KOH) electrolyte was about 40 000 LEO cycles compared to 3500 cycles for cells containing 31 percent KOH. This test was conducted at Hughes Aircraft Company under a NASA Lewis contract. The purpose was to investigate the effect of KOH concentration on cycle life. The cycle regime was a stressful accelerated LEO, which consisted of a 27.5 min charge followed by a 17.5 min discharge (2x normal rate). The depth of discharge (DOD) was 80 percent. The cell temperature was maintained at 23 C. The boiler plate test results are in the process of being validated using flight hardware and real time LEO test at the Naval Weapons Support Center (NWSC), Crane, Indiana under a NASA Lewis Contract. Six 48 Ah Hughes recirculation design IPV nickel-hydrogen flight battery cells are being evaluated. Three of the cells contain 26 percent KOH (test cells), and three contain 31 percent KOH (control cells). They are undergoing real time LEO cycle life testing. The cycle regime is a 90-min LEO orbit consisting of a 54-min charge followed by a 36-min discharge. The depth-of-discharge is 80 percent. The cell temperature is maintained at 10 C. The three 31 percent KOH cells failed (cycles 3729, 4165, and 11355). One of the 26 percent KOH cells failed at cycle 15314. The other two 26 percent KOH cells were cycled for over 16600 cycles during the continuing test.

  20. Cross-calibration of Medium Resolution Earth Observing Satellites by Using EO-1 Hyperion-derived Spectral Surface Reflectance from "Lunar Cal Sites"

    Science.gov (United States)

    Ungar, S.

    2017-12-01

    Over the past 3 years, the Earth Observing-one (EO-1) Hyperion imaging spectrometer was used to slowly scan the lunar surface at a rate which results in up to 32X oversampling to effectively increase the SNR. Several strategies, including comparison against the USGS RObotic Lunar Observatory (ROLO) mode,l are being employed to estimate the absolute and relative accuracy of the measurement set. There is an existing need to resolve discrepancies as high as 10% between ROLO and solar based calibration of current NASA EOS assets. Although the EO-1 mission was decommissioned at the end of March 2017, the development of a well-characterized exoatmospheric spectral radiometric database, for a range of lunar phase angles surrounding the fully illuminated moon, continues. Initial studies include a comprehensive analysis of the existing 17-year collection of more than 200 monthly lunar acquisitions. Specific lunar surface areas, such as a lunar mare, are being characterized as potential "lunar calibration sites" in terms of their radiometric stability in the presence of lunar nutation and libration. Site specific Hyperion-derived lunar spectral reflectance are being compared against spectrographic measurements made during the Apollo program. Techniques developed through this activity can be employed by future high-quality orbiting imaging spectrometers (such as HyspIRI and EnMap) to further refine calibration accuracies. These techniques will enable the consistent cross calibration of existing and future earth observing systems (spectral and multi-spectral) including those that do not have lunar viewing capability. When direct lunar viewing is not an option for an earth observing asset, orbiting imaging spectrometers can serve as transfer radiometers relating that asset's sensor response to lunar values through near contemporaneous observations of well characterized stable CEOS test sites. Analysis of this dataset will lead to the development of strategies to ensure more

  1. Low Earth Orbit satellite/terrestrial mobile service compatibility

    Science.gov (United States)

    Sheriff, Ray E.; Gardiner, John G.

    1993-01-01

    Currently the geostationary type of satellite is the only one used to provide commercial mobile-satellite communication services. Low earth orbit (LEO) satellite systems are now being proposed as a future alternative. By the implementation of LEO satellite systems, predicted at between 5 and 8 years time, mobile space/terrestrial technology will have progressed to the third generation stage of development. This paper considers the system issues that will need to be addressed when developing a dual mode terminal, enabling access to both terrestrial and LEO satellite systems.

  2. The Oldest Stars of the Extremely Metal-Poor Local Group Dwarf Irregular Galaxy Leo A

    Science.gov (United States)

    Schulte-Ladbeck, Regina E.; Hopp, Ulrich; Drozdovsky, Igor O.; Greggio, Laura; Crone, Mary M.

    2002-08-01

    We present deep Hubble Space Telescope (HST) single-star photometry of Leo A in B, V, and I. Our new field of view is offset from the centrally located field observed by Tolstoy et al. in order to expose the halo population of this galaxy. We report the detection of metal-poor red horizontal branch stars, which demonstrate that Leo A is not a young galaxy. In fact, Leo A is as least as old as metal-poor Galactic Globular Clusters that exhibit red horizontal branches and are considered to have a minimum age of about 9 Gyr. We discuss the distance to Leo A and perform an extensive comparison of the data with stellar isochrones. For a distance modulus of 24.5, the data are better than 50% complete down to absolute magnitudes of 2 or more. We can easily identify stars with metallicities between 0.0001 and 0.0004, and ages between about 5 and 10 Gyr, in their post-main-sequence phases, but we lack the detection of main-sequence turnoffs that would provide unambiguous proof of ancient (>10 Gyr) stellar generations. Blue horizontal branch stars are above the detection limits but difficult to distinguish from young stars with similar colors and magnitudes. Synthetic color-magnitude diagrams show it is possible to populate the blue horizontal branch in the halo of Leo A. The models also suggest ~50% of the total astrated mass in our pointing to be attributed to an ancient (>10 Gyr) stellar population. We conclude that Leo A started to form stars at least about 9 Gyr ago. Leo A exhibits an extremely low oxygen abundance, only 3% of solar, in its ionized interstellar medium. The existence of old stars in this very oxygen-deficient galaxy illustrates that a low oxygen abundance does not preclude a history of early star formation. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  3. Time Serial Analysis of the Induced LEO Environment within the ISS 6A

    Science.gov (United States)

    Wilson, John W.; Nealy, John E.; Tomov, B. T.; Cucinotta, Francis A.; Badavi, Frank F.; DeAngelis, Giovanni; Atwell, William; Leutke, N.

    2006-01-01

    Anisotropies in the low Earth orbit (LEO) radiation environment were found to influence the thermoluminescence detectors (TLD) dose within the (International Space Station) ISS 7A Service Module. Subsequently, anisotropic environmental models with improved dynamic time extrapolation have been developed including westward and northern drifts using AP8 Min & Max as estimates of the historic spatial distribution of trapped protons in the 1965 and 1970 era, respectively. In addition, a directional dependent geomagnetic cutoff model was derived for geomagnetic field configurations from the 1945 to 2020 time frame. A dynamic neutron albedo model based on our atmospheric radiation studies has likewise been required to explain LEO neutron measurements. The simultaneous measurements of dose and dose rate using four Liulin instruments at various locations in the US LAB and Node 1 has experimentally demonstrated anisotropic effects in ISS 6A and are used herein to evaluate the adequacy of these revised environmental models.

  4. Earth-to-Satellite Quantum Key Distribution with Noise Reduction via Entangled Photon Time Correlation

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this proposal is to establish a provably secure communication link between ground and low-earth-orbit (LEO). Current communication technologies rely...

  5. Geocenter Motion Derived from GNSS and SLR Tracking Data of LEO

    Science.gov (United States)

    Li, Y. S.; Ning, F. S.; Tseng, K. H.; Tseng, T. P.; Wu, J. M.; Chen, K. L.

    2017-12-01

    Space geodesy techniques can provide the monitoring data of global variations with high precision and large coverage through the satellites. Geocenter motion (GM) describes the difference of CF (Center of Figure) respect to CM (Center of Mass of the Earth System) due to the re-distribution and deformation of the earth system. Because satellite tracking data between ground stations and satellites orbit around the CM, geocenter motion is related to the realization of the ITRF (International Terrestrial Reference Frame) origin. In this study, GPS (Global Positioning System) observation data of IGS (International GNSS Service) and SLR (Satellite Laser Ranging) tracking data are applied to estimate the coordinates of observing sites on Earth's surface. The GPS observing sites are distributed deliberately and globally by 15° ×15° grids. Meanwhile, two different global ocean tide models are applied here. The model used in ITRF comparison and combination is parameter transformation, which is a mathematical formula allowing to transform the different frames between ITRF and CM system. Following the parameter transformation, the results of geocenter motion can be determined. The FORMOSAT-7/COSMIC-2 (F7C2) mission is a constellation of LEO (Low-Earth-Orbit) satellites, which will be launched in 2018. Besides the observing system for Meteorology, Ionosphere, and Climate, the F7C2 will be equipped with LRR (Laser Ranging Retroreflector). This work is a pilot survey to study the application of LEO SLR data in Taiwan.

  6. Optimization of Return Trajectories for Orbital Transfer Vehicle between Earth and Moon

    Science.gov (United States)

    Funase, Ryu; Tsuda, Yuichi; Kawaguchi, Jun'ichiro

    2007-01-01

    In this paper, optimum trajectories in Earth Transfer Orbit (ETO) for a lunar transportation system are proposed. This paper aims at improving the payload ratio of the reusable orbital transfer vehicle (OTV), which transports the payload from Low Earth Orbit (LEO) to Lunar Low Orbit (LLO) and returns to LEO. In ETO, we discuss ballistic flight using chemical propulsion, multi-impulse flight using electrical propulsion, and aero-assisted flight using aero-brake. The feasibility of the OTV is considered.

  7. A Spatio-Temporal Enhancement Method for medium resolution LAI (STEM-LAI), International Journal of Applied Earth Observation and Geoinformation

    KAUST Repository

    Houborg, Rasmus

    2015-12-12

    Satellite remote sensing has been used successfully to map leaf area index (LAI) across landscapes, but advances are still needed to exploit multi-scale data streams for producing LAI at both high spatial and temporal resolution. A multi-scale Spatio-Temporal Enhancement Method for medium resolution LAI (STEM-LAI) has been developed to generate 4-day time-series of Landsat-scale LAI from existing medium resolution LAI products. STEM-LAI has been designed to meet the demands of applications requiring frequent and spatially explicit information, such as effectively resolving rapidly evolving vegetation dynamics at sub-field (30 m) scales. In this study, STEM-LAI is applied to Moderate Resolution Imaging Spectroradiometer (MODIS) based LAI data and utilizes a reference-based regression tree approach for producing MODIS-consistent, but Landsat-based, LAI. The Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) is used to interpolate the downscaled LAI between Landsat acquisition dates, providing a high spatial and temporal resolution improvement over existing LAI products. STARFM predicts high resolution LAI by blending MODIS and Landsat based information from a common acquisition date, with MODIS data from a prediction date. To demonstrate its capacity to reproduce fine-scale spatial features observed in actual Landsat LAI, the STEM-LAI approach is tested over an agricultural region in Nebraska. The implementation of a 250 m resolution LAI product, derived from MODIS 1 km data and using a scale consistent approach based on the Normalized Difference Vegetation Index (NDVI), is found to significantly improve accuracies of spatial pattern prediction, with the coefficient of efficiency (E) ranging from 0.77–0.94 compared to 0.01–0.85 when using 1 km LAI inputs alone. Comparisons against an 11-year record of in-situ measured LAI over maize and soybean highlight the utility of STEM-LAI in reproducing observed LAI dynamics (both characterized by r2 = 0

  8. Leo P: An Unquenched Very Low-Mass Galaxy

    OpenAIRE

    McQuinn, Kristen B. W.; Skillman, Evan D.; Dolphin, Andrew; Cannon, John M.; Salzer, John J.; Rhode, Katherine L.; Adams, Elizabeth A. K.; Berg, Danielle; Giovanelli, Riccardo; Girardi, Léo; Haynes, Martha P.

    2015-01-01

    Leo P is a low-luminosity dwarf galaxy discovered through the blind HI Arecibo Legacy Fast ALFA (ALFALFA) survey. The HI and follow-up optical observations have shown that Leo P is a gas-rich dwarf galaxy with active star formation, an underlying older population, and an extremely low oxygen abundance. We have obtained optical imaging with the Hubble Space Telescope to two magnitudes below the red clump in order to study the evolution of Leo P. We refine the distance measurement to Leo P to b...

  9. Optimal trajectories for aeroassisted, noncoplanar orbital transfer. II - LEO-to-LEO transfer

    Science.gov (United States)

    Miele, A.; Mease, K. D.; Lee, W. Y.

    1987-01-01

    Both classical and minimax problems of optimal control arising in the study of noncoplanar, aeroassisted orbital transfer are considered and are illustrated with the example of LEO-to-LEO transfer. Trajectory control is achieved by modulation of the lift coefficient and the angle of bank. Problems considered include the minimization of the energy required for orbital transfer, maximization of the flight time during the atmospheric portion of the trajectory, and minimization of the peak heating rate. The near-grazing solution is found to be a good compromise between energy and heating requirements.

  10. Alfalfa discovery of the nearby gas-rich dwarf galaxy LEO P. V. Neutral gas dynamics and kinematics

    International Nuclear Information System (INIS)

    Bernstein-Cooper, Elijah Z.; Pardy, Stephen A.; Cannon, John M.

    2014-01-01

    We present new H I spectral line imaging of the extremely metal-poor, star-forming dwarf irregular galaxy Leo P. Our H I images probe the global neutral gas properties and the local conditions of the interstellar medium (ISM). The H I morphology is slightly elongated along the optical major axis. We do not find obvious signatures of interaction or infalling gas at large spatial scales. The neutral gas disk shows obvious rotation, although the velocity dispersion is comparable to the rotation velocity. The rotation amplitude is estimated to be V c =15 ± 5 km s –1 . Within the H I radius probed by these observations, the mass ratio of gas to stars is roughly 2:1, while the ratio of the total mass to the baryonic mass is ≳15:1. We use this information to place Leo P on the baryonic Tully-Fisher relation, testing the baryonic content of cosmic structures in a sparsely populated portion of parameter space that has hitherto been occupied primarily by dwarf spheroidal galaxies. We detect the signature of two temperature components in the neutral ISM of Leo P; the cold and warm components have characteristic velocity widths of 4.2 ± 0.9 km s –1 and 10.1 ± 1.2 km s –1 , corresponding to kinetic temperature upper limits of ∼1100 K and ∼6200 K, respectively. The cold H I component is unresolved at a physical resolution of 200 pc. The highest H I surface densities are observed in close physical proximity to the single H II region. A comparison of the neutral gas properties of Leo P with other extremely metal-deficient (XMD) galaxies reveals that Leo P has the lowest neutral gas mass of any known XMD, and that the dynamical mass of Leo P is more than two orders of magnitude smaller than any known XMD with comparable metallicity.

  11. The impact of GPS ephemeris on the accuracy of precise orbit determination for LEO using GPS

    Science.gov (United States)

    Peng, D. J.; Wu, B.

    2008-10-01

    Today more and more Low Earth orbiting satellites (LEOs) of new scientific missions are equipped with a GPS receiver for precise orbit determination (POD), on-board GPS has become one of the main POD approaches. However, the on-board GPS POD accuracy obviously relies on the accuracy of GPS orbit and clock products. Based on the zero-difference dynamic POD approach of SHORDE-III program, this paper shows the influence of GPS orbit and clock on the POD accuracy of LEO using real GRACE data and three types of IGS orbit products between 1 Aug. and 7 Aug. The results indicate that IGS final precise orbit product (igs) and rapid orbit product (igr) have the equal POD accuracy which is about 9.5cm, the POD accuracy using ultra-rapid orbit product (igu) is about 10.5cm which is a little worse than igs and igr; High-rate GPS clock products have an impact of about 1--6 cm on the POD accuracy of LEO.

  12. Development of flexible LEO-resistant PI films for space applications using a self-healing mechanism by surface-directed phase separation of block copolymers

    NARCIS (Netherlands)

    Fischer, H.R.; Tempelaars, K.; Kerpershoek, A.M.; Dingemans, T.; Iqbal, M.; Lonkhuyzen, H.; Iwanowsky, B.; Semprimoschnig, C.

    2010-01-01

    Polimide-block-polydimethylsiloxane (PI-b-PDMS) block copolymers have been synthesized from commercially available amino-terminated polysiloxanes with different molecular weights, for use as polymeric materials resistant to the low earth orbit (LEO) space environment. A structural optimization with

  13. Materials selection for long life in low earth orbit - A critical evaluation of atomic oxygen testing with thermal atom systems

    Science.gov (United States)

    Koontz, S. L.; Albyn, K.; Leger, L.

    1990-01-01

    The use of thermal atom test methods as a materials selection and screening technique for low-earth orbit (LEO) spacecraft is critically evaluated. The chemistry and physics of thermal atom environments are compared with the LEO environment. The relative reactivities of a number of materials determined in thermal atom environments are compared with those observed in LEO and in high-quality LEO simulations. Reaction efficiencies (cu cm/atom) measured in a new type of thermal atom apparatus are one-thousandth to one ten-thousandth those observed in LEO, and many materials showing nearly identical reactivities in LEO show relative reactivities differing by as much as a factor of eight in thermal atom systems. A simple phenomenological kinetic model for the reaction of oxygen atoms with organic materials can be used to explain the differences in reactivity in different environments. Certain speciic thermal atom test environments can be used as reliable materials screening tools.

  14. Leo Kunnas : triibuline särk kuuli ei peata / Leo Kunnas ; interv. Jaanus Piirsalu

    Index Scriptorium Estoniae

    Kunnas, Leo, 1967-

    2006-01-01

    2005. aastal koalitsioonijõudude koosseisus Iraagis teeninud Leo Kunnas selgitab intervjuus, mida on Eesti kaitsevägi Iraagi missioonist õppinud, millist mõju on Eesti sõdurite osalemine välismissioonides avaldanud ühiskonnale, lisaks võrdleb Iraagi ja Afganistani missioone ning põhjendab, miks on palgaarmee loomise idee Eestis sõjaliselt mitterelevantne

  15. Sling-on-a-Ring: Structure for an elevator to LEO

    OpenAIRE

    Meulenberg, Andrew; Poston, Timothy

    2015-01-01

    Various proposed space elevators may bypass the financial and environmental limits on rocket technology, but all have their own problems. A Low-Earth-Orbit, LEO, rotovator-based space-elevator version called 'sling-on-a-ring' may overcome them. This mass-lifting system uses the spatial stability of an orbital ring, accessorized for transfer and storage of momentum and electrical power. A high-tensile-strength equatorial circum-terra loop of colossal-carbon tube, CCT, fiber has solar-power and...

  16. Re-Entry Point Targeting for LEO Spacecraft using Aerodynamic Drag

    Science.gov (United States)

    Omar, Sanny; Bevilacqua, Riccardo; Fineberg, Laurence; Treptow, Justin; Johnson, Yusef; Clark, Scott

    2016-01-01

    Most Low Earth Orbit (LEO) spacecraft do not have thrusters and re-enter atmosphere in random locations at uncertain times. Objects pose a risk to persons, property, or other satellites. Has become a larger concern with the recent increase in small satellites. Working on a NASA funded project to design a retractable drag device to expedite de-orbit and target a re-entry location through modulation of the drag area. Will be discussing the re-entry point targeting algorithm here.

  17. Petróleo, Royalties e Pobreza

    Directory of Open Access Journals (Sweden)

    Gicélia Mendes da Silva

    2009-08-01

    Full Text Available A exploração do petróleo se constitui num elemento significativo para a economia sergipana. A contradição existente entre o subsolo rico e a população pobre levanta indagações a respeito da gestão destes recursos e as condições de vida da população. Tais condições, aliadas à entrada de novos atores na exploração do petróleo em Sergipe e à gestão dos recursos advindos da exploração, vêm incutindo relações peculiares à política neoliberal na região e em Sergipe. O estudo foi desenvolvido a partir da análise e cruzamento de informações disponíveis na Agência Nacional do Petróleo (ANP, Instituto Brasileiro de Geografia e Estatística (IBGE, Tribunal de Contas da União (TCU e PETROBRAS, dentre outros setores. A carência de políticas sociais que ofereçam às populações condições de inserção nas questões política, econômica e social da região produtora de petróleo tem impedido o desenvolvimento efetivo e mudança no padrão de vida das populações, evidenciando a incoerência entre os altos valores depositados nos cofres públicos municipais decorrentes dos royalties e os elevados índices de pobreza apresentados na região. Tal constatação reforça a ideia de que as políticas públicas devem primar pela redução da desigualdade a partir da gestão responsável dos recursos públicos.

  18. Viiv enne kojuminekut / Leo Kunnas ; interv. Helen Arak

    Index Scriptorium Estoniae

    Kunnas, Leo, 1967-

    2006-01-01

    Kaitsejõudude Peastaabi operatiivosakonna ülem kolonelleitnant Leo Kunnas oma perekonnast, lapsepõlvekodust Põlvamaal ja praegusest elamisest Tallinnas, missioonil viibivate sõjaväelaste probleemidest ning eluolust Iraagis. Lisa: Katkend Leo Kunnase raamatust "Viiv pikas sõjas"

  19. Introducing Leo LT - the "three-headed lion"

    Index Scriptorium Estoniae

    2008-01-01

    Leedu valitsus kiitis heaks seaduseparandused, mille tulemusena saab võtta tuumajaama ehitaja, investeerimis- ja energiafirma Leo LT strateegilise tähtsusega firmade hulka. Kui parlament valitsuse ettepanekud heaks kiidab, saab riik 61,7% Leo LT ja 38,3% NDX Energija aktsiatest

  20. Leo Kunnas, sõdurjumala teener / Leo Kunnas ; interv. Eve Jaakson

    Index Scriptorium Estoniae

    Kunnas, Leo, 1967-

    2006-01-01

    Kaitsejõudude peastaabi operatiivosakonna ülem kolonelleitnant Leo Kunnas räägib Iraagi sõja kogemustest ja oma raamatust "Viiv pikas sõjas. Märkmeid Iraagi sõjast", riigikaitsest, kaitseväeteenistusest, kaitseminister Jürgen Ligist, kaitsepoliitikast, NATO-st, sõjalisest koostööst, perekonnast. Kommenteerivad Sten Reimann ja Venno Loosaar

  1. Petróleo, Royalties e Pobreza

    Directory of Open Access Journals (Sweden)

    Gicélia Mendes da Silva

    2009-08-01

    Full Text Available A exploração do petróleo se constitui num elemento significativo para a economia sergipana. A contradição existente entre o subsolo rico e a população pobre levanta indagações a respeito da gestão destes recursos e as condições de vida da população. Tais condições, aliadas à entrada de novos atores na exploração do petróleo em Sergipe e à gestão dos recursos advindos da exploração, vêm incutindo relações peculiares à política neoliberal na região e em Sergipe. O estudo foi desenvolvido a partir da análise e cruzamento de informações disponíveis na Agência Nacional do Petróleo (ANP, Instituto Brasileiro de Geografia e Estatística (IBGE, Tribunal de Contas da União (TCU e PETROBRAS, dentre outros setores. A carência de políticas sociais que ofereçam às populações condições de inserção nas questões política, econômica e social da região produtora de petróleo tem impedido o desenvolvimento efetivo e mudança no padrão de vida das populações, evidenciando a incoerência entre os altos valores depositados nos cofres públicos municipais decorrentes dos royalties e os elevados índices de pobreza apresentados na região. Tal constatação reforça a ideia de que as políticas públicas devem primar pela redução da desigualdade a partir da gestão responsável dos recursos públicos. Abstract OIL, ROYALTIES AND POVERTY The exploitation of oil has significant element for the Sergipe´s economy. However, the contradiction between the subsoils rich and poor people raises key questions about the management of these resources and the living conditions of the population. Such conditions, the entry of new actors in the scenery for the exploration of oil in Sergipe and the management of resources of exploration, instilling relations peculiar to neo-liberal policy in the region and in Sergipe. The study was developed from the analysis and crossing of information available in the national agency oil (ANP

  2. Particle flows to shape and voltage surface discontinuities in the electron sheath surrounding a high voltage solar array in LEO

    Science.gov (United States)

    Metz, Roger N.

    1991-01-01

    This paper discusses the numerical modeling of electron flows from the sheath surrounding high positively biased objects in LEO (Low Earth Orbit) to regions of voltage or shape discontinuity on the biased surfaces. The sheath equations are derived from the Two-fluid, Warm Plasma Model. An equipotential corner and a plane containing strips of alternating voltage bias are treated in two dimensions. A self-consistent field solution of the sheath equations is outlined and is pursued through one cycle. The electron density field is determined by numerical solution of Poisson's equation for the electrostatic potential in the sheath using the NASCAP-LEO relation between electrostatic potential and charge density. Electron flows are calculated numerically from the electron continuity equation. Magnetic field effects are not treated.

  3. On the feasibility of phase only PPP for kinematic LEO orbits

    Science.gov (United States)

    Wallat, Christoph; Schön, Steffen

    2016-04-01

    Low Earth Orbiters (LEO) are satellites in altitudes up to 1000 kilometers. From the sensor data collected on board the Earth's gravity field can be recovered. Over the last 15 years several satellite missions were brought into space and the orbit determination improved over the years. To process the sensor data, precise positioning and timing of the satellite is mandatory. There are two approaches for precise orbit determination (POD) of LEO satellites. Kinematic orbits are based on GNSS observations and star camera data measured on board of the LEO. With a Precise Point Positioning (PPP) known from the terrestrial case, using ionospheric-free linear combinations P3 and L3 three-dimensional coordinates of the LEO can be estimated for every observation epoch. To counteract the challenges in kinematic orbit determination our approach is based on a technique called GNSS receiver clock modeling (RCM). Here the frequency stability of an external oscillator is used to model the behavior of the GNSS receiver clock with piecewise linear polynomials instead of estimating epoch-wise the receiver clock time offset as an unknown parameter. When using RCM the observation geometry is stabilized and the orbit coordinates and the receiver clock error can be estimated with a better precision. The satellites of the Gravity Recovery And Climate Experiment (GRACE) mission are equipped with Ultra Stable quartz Oscillators (USO). The USO frequency stability is used to correct the GRACE GPS receiver clock. Therefore, receiver clock modeling is feasible for polynomials with a length up to 60 seconds, leading to improved mean PDOP values of 30 % and smaller formal mean standard deviations of the coordinates between 6 and 33 %. We developed a new approach for GRACE orbits using kinematic PPP with clock modeling and tested our approach with simulated and real GPS data. The idea to use only carrier phase observations in the final processing and no code measurements leads to a reduced number

  4. Low cost Earth attitude sensor

    Science.gov (United States)

    Liberati, Fabrizio; Perrotta, Giorgio; Verzegnassi, Fulvia

    2017-11-01

    A patent-pending, low-cost, moderate performance, Earth Attitude Sensor for LEO satellites is described in this paper. The paper deals with the system concepts, the technology adopted and the simulation results. The sensor comprises three or four narrow field of view mini telescopes pointed towards the Earth edge to detect and measure the variation of the off-nadir angle of the Earth-to-black sky transition using thermopile detectors suitably placed in the foci of the optical min telescopes. The system's innovation consists in the opto-mechanical configuration adopted that is sturdy and has no moving parts being , thus, inherently reliable. In addition, with a view to reducing production costs, the sensor does without hi-rel and is instead mainly based on COTS parts suitably chosen. Besides it is flexible and can be adapted to perform attitude measurement onboard spacecraft flying in orbits other than LEO with a minimum of modifications to the basic design. At present the sensor is under development by IMT and OptoService.

  5. Fluxgate magnetometry for precise mapping of the Earth's field

    DEFF Research Database (Denmark)

    Primdahl, Fritz; Merayo, José M.G.; Brauer, Peter

    2007-01-01

    The requirements for precise global mapping of the Earth's vector magnetic field from a high inclination LEO satellite needs a stable and precise vector magnetometer. Equally important are the measurement of the stellar attitude of the vector sensor and establishment of the calibration by onboard...

  6. Some results regarding the comparison of the Earth's atmospheric models

    Directory of Open Access Journals (Sweden)

    Šegan S.

    2005-01-01

    Full Text Available In this paper we examine air densities derived from our realization of aeronomic atmosphere models based on accelerometer measurements from satellites in a low Earth's orbit (LEO. Using the adapted algorithms we derive comparison parameters. The first results concerning the adjustment of the aeronomic models to the total-density model are given.

  7. Earth-Mars transfers through Moon Distant Retrograde Orbits

    Science.gov (United States)

    Conte, Davide; Di Carlo, Marilena; Ho, Koki; Spencer, David B.; Vasile, Massimiliano

    2018-02-01

    This paper focuses on the trajectory design which is relevant for missions that would exploit the use of asteroid mining in stable cis-lunar orbits to facilitate deep space missions, specifically human Mars exploration. Assuming that a refueling "gas station" is present at a given lunar Distant Retrograde Orbit (DRO), ways of departing from the Earth to Mars via that DRO are analyzed. Thus, the analysis and results presented in this paper add a new cis-lunar departure orbit for Earth-Mars missions. Porkchop plots depicting the required C3 at launch, v∞ at arrival, Time of Flight (TOF), and total Δ V for various DRO departure and Mars arrival dates are created and compared with results obtained for low Δ V Low Earth Orbit (LEO) to Mars trajectories. The results show that propellant-optimal trajectories from LEO to Mars through a DRO have higher overall mission Δ V due to the additional stop at the DRO. However, they have lower Initial Mass in LEO (IMLEO) and thus lower gear ratio as well as lower TOF than direct LEO to Mars transfers. This results in a lower overall spacecraft dry mass that needs to be launched into space from Earth's surface.

  8. Bioatividade de óleos essenciais no controle de Botrytis cinerea isolado de morangueiro Essential oils bioactivity in strawberry grey mould control

    Directory of Open Access Journals (Sweden)

    E.R. Lorenzetti

    2011-01-01

    Full Text Available Objetivou-se avaliar o uso de óleos essenciais sobre isolados de Botrytis cinerea, causador do mofo cinzento em morangueiro. Foram testados óleos essenciais de capim-limão, palmarosa, citronela, cravo, canela, menta, lavanda, tangerina, eucalipto, melaleuca, alecrim e laranja, todos estes analisados em cromatógrafo a gás acoplado a detector de massas, para identificação dos principais componentes dos óleos. Foram avaliados o crescimento micelial, produção e germinação de conídios de B. cinerea, com a incorporação do óleo no meio de cultura. Realizou-se ainda uma avaliação de voláteis e a eficiência de óleos em isolado resistente a fungicida. Para cada teste, diferentes óleos apresentaram eficiência, contudo capim limão, palmarosa, canela e menta demonstraram os melhores efeitos em todos os testes realizados. Todos os tratamentos a base de óleos demonstraram efeito semelhante a um fungicida recomendado para a cultura, a base de tiofanato metílico. Dois tratamentos mostraram-se efetivos no caso de isolado resistente (óleo de capim limão e de canela. Óleos essenciais mostram-se como opção promissora para o desenvolvimento de possíveis produtos fitossanitários para o manejo de doenças em plantas.This study aimed evaluates essential oils in Botrytis cinerea isolates growth, which causes gray mould on strawberry. Were tested essential oils of lemon grass, palmrose, citronella, clove, cinnamon, mint, lavender, tangerine, eucalyptus, tea tree, rosemary and orange. The oils were analyzed in gas chromatograph attached to mass detector for identifying the mainly oils components. Were evaluated mycelial growth, conidia production and conidia germination of B. cinerea, with oil incorporation in culture medium. Were conducted an evaluation of oils volatile components and the efficiency of oils in fungicide-resistant isolate. For each test, different oils showed efficiency, however lemongrass, palmarosa, cinnamon and mint

  9. LEO P: AN UNQUENCHED VERY LOW-MASS GALAXY

    Energy Technology Data Exchange (ETDEWEB)

    McQuinn, Kristen B. W.; Skillman, Evan D.; Berg, Danielle [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, S.E., University of Minnesota, Minneapolis, MN 55455 (United States); Dolphin, Andrew [Raytheon Company, 1151 E. Hermans Road, Tucson, AZ 85756 (United States); Cannon, John M. [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Salzer, John J.; Rhode, Katherine L. [Department of Astronomy, Indiana University, 727 East 3rd Street, Bloomington, IN 47405 (United States); Adams, Elizabeth A. K. [ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA, Dwingeloo (Netherlands); Giovanelli, Riccardo; Haynes, Martha P. [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Girardi, Léo, E-mail: kmcquinn@astro.umn.edu [Osservatorio Astronomico di Padova, INAF, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy)

    2015-10-20

    Leo P is a low-luminosity dwarf galaxy discovered through the blind H i Arecibo Legacy Fast ALFA survey. The H i and follow-up optical observations have shown that Leo P is a gas-rich dwarf galaxy with active star formation, an underlying older population, and an extremely low oxygen abundance. We have obtained optical imaging with the Hubble Space Telescope to two magnitudes below the red clump in order to study the evolution of Leo P. We refine the distance measurement to Leo P to be 1.62 ± 0.15 Mpc, based on the luminosity of the horizontal branch stars and 10 newly identified RR Lyrae candidates. This places the galaxy at the edge of the Local Group, ∼0.4 Mpc from Sextans B, the nearest galaxy in the NGC 3109 association of dwarf galaxies of which Leo P is clearly a member. The star responsible for ionizing the H ii region is most likely an O7V or O8V spectral type, with a stellar mass ≳25 M{sub ⊙}. The presence of this star provides observational evidence that massive stars at the upper end of the initial mass function are capable of being formed at star formation rates as low as ∼10{sup −5} M{sub ⊙} yr{sup −1}. The best-fitting star formation history (SFH) derived from the resolved stellar populations of Leo P using the latest PARSEC models shows a relatively constant star formation rate over the lifetime of the galaxy. The modeled luminosity characteristics of Leo P at early times are consistent with low-luminosity dSph Milky Way satellites, suggesting that Leo P is what a low-mass dSph would look like if it evolved in isolation and retained its gas. Despite the very low mass of Leo P, the imprint of reionization on its SFH is subtle at best, and consistent with being totally negligible. The isolation of Leo P, and the total quenching of star formation of Milky Way satellites of similar mass, implies that the local environment dominates the quenching of the Milky Way satellites.

  10. Minimum Number of Observation Points for LEO Satellite Orbit Estimation by OWL Network

    Directory of Open Access Journals (Sweden)

    Maru Park

    2015-12-01

    Full Text Available By using the Optical Wide-field Patrol (OWL network developed by the Korea Astronomy and Space Science Institute (KASI we generated the right ascension and declination angle data from optical observation of Low Earth Orbit (LEO satellites. We performed an analysis to verify the optimum number of observations needed per arc for successful estimation of orbit. The currently functioning OWL observatories are located in Daejeon (South Korea, Songino (Mongolia, and Oukaïmeden (Morocco. The Daejeon Observatory is functioning as a test bed. In this study, the observed targets were Gravity Probe B, COSMOS 1455, COSMOS 1726, COSMOS 2428, SEASAT 1, ATV-5, and CryoSat-2 (all in LEO. These satellites were observed from the test bed and the Songino Observatory of the OWL network during 21 nights in 2014 and 2015. After we estimated the orbit from systematically selected sets of observation points (20, 50, 100, and 150 for each pass, we compared the difference between the orbit estimates for each case, and the Two Line Element set (TLE from the Joint Space Operation Center (JSpOC. Then, we determined the average of the difference and selected the optimal observation points by comparing the average values.

  11. A Parametric Study on Using Active Debris Removal to Stabilize the Future LEO Debris Environment

    Science.gov (United States)

    Liou, J.C.

    2010-01-01

    Recent analyses of the instability of the orbital debris population in the low Earth orbit (LEO) region and the collision between Iridium 33 and Cosmos 2251 have reignited the interest in using active debris removal (ADR) to remediate the environment. There are; however, monumental technical, resources, operational, legal, and political challenges in making economically viable ADR a reality. Before a consensus on the need for ADR can be reached, a careful analysis of the effectiveness of ADR must be conducted. The goal is to demonstrate the feasibility of using ADR to preserve the future environment and to guide its implementation to maximize the benefit-cost ratio. This paper describes a comprehensive sensitivity study on using ADR to stabilize the future LEO debris environment. The NASA long-term, orbital debris evolutionary model, LEGEND, is used to quantify the effects of many key parameters. These parameters include (1) the starting epoch of ADR implementation, (2) various target selection criteria, (3) the benefits of collision avoidance maneuvers, (4) the consequence of targeting specific inclination or altitude regimes, (5) the consequence of targeting specific classes of vehicles, and (6) the timescale of removal. Additional analyses on the importance of postmission disposal and how future launches might affect the requirements to stabilize the environment are also included.

  12. A Parametric Study on Using Active Debris Removal for LEO Environment Remediation

    Science.gov (United States)

    2010-01-01

    Recent analyses on the instability of the orbital debris population in the low Earth orbit (LEO) region and the collision between Iridium 33 and Cosmos 2251 have reignited the interest in using active debris removal (ADR) to remediate the environment. There are; however, monumental technical, resource, operational, legal, and political challenges in making economically viable ADR a reality. Before a consensus on the need for ADR can be reached, a careful analysis of its effectiveness must be conducted. The goal is to demonstrate the need and feasibility of using ADR to better preserve the future environment and to guide its implementation to maximize the benefit-to-cost ratio. This paper describes a new sensitivity study on using ADR to stabilize the future LEO debris environment. The NASA long-term orbital debris evolutionary model, LEGEND, is used to quantify the effects of several key parameters, including target selection criteria/constraints and the starting epoch of ADR implementation. Additional analyses on potential ADR targets among the currently existing satellites and the benefits of collision avoidance maneuvers are also included.

  13. Leishmania infantum infection in two captive barbary lions (Panthera leo leo).

    Science.gov (United States)

    Libert, Cédric; Ravel, Christophe; Pratlong, Francine; Lami, Patrick; Dereure, Jacques; Keck, Nicolas

    2012-09-01

    A female barbary lion (Panthera leo leo) from the Montpellier Zoological Park (France) showing colitis, epistaxis, and lameness with pad ulcers was positive by polymerase chain reaction (PCR) for Leishmania infantum. Further indirect immunofluorescence (IFAT) tests on the banked sera from all lions of the park detected another infected but asymptomatic female, which was confirmed by PCR on ethylenediaminetetraacetic acid (EDTA) blood sample. Leishmania infantum zymodeme MON-1 was cultured from EDTA bone marrow samples sampled from this second animal. The first female was successfully treated with marbofloxacine at 2 mg/kg s.i.d. for 28 days (Marbocyl, Vetoquinol 70204 Lure, France) and allopurinol at 30 mg/kg s.i.d. for 3 mo (Allopurinol Mylan, Mylan SAS, 69800 Saint-Priest, France) and then 1 wk/mo. Both positive animals were born at the Rabat Zoological Park, Morocco, and arrived together at Montpellier in 2003. The chronicity and source of this current infection are unknown since Morocco and southern France are well-known to be enzootic for leishmaniasis.

  14. Alfalfa discovery of the nearby gas-rich dwarf galaxy LEO P. V. Neutral gas dynamics and kinematics

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein-Cooper, Elijah Z.; Pardy, Stephen A. [Department of Astronomy, University of Wisconsin, 475 N Charter Street, Madison, WI 53706 (United States); Cannon, John M., E-mail: ezbc@astro.wisc.edu, E-mail: spardy@astro.wisc.edu, E-mail: jcannon@macalester.edu [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); and others

    2014-08-01

    We present new H I spectral line imaging of the extremely metal-poor, star-forming dwarf irregular galaxy Leo P. Our H I images probe the global neutral gas properties and the local conditions of the interstellar medium (ISM). The H I morphology is slightly elongated along the optical major axis. We do not find obvious signatures of interaction or infalling gas at large spatial scales. The neutral gas disk shows obvious rotation, although the velocity dispersion is comparable to the rotation velocity. The rotation amplitude is estimated to be V {sub c} =15 ± 5 km s{sup –1}. Within the H I radius probed by these observations, the mass ratio of gas to stars is roughly 2:1, while the ratio of the total mass to the baryonic mass is ≳15:1. We use this information to place Leo P on the baryonic Tully-Fisher relation, testing the baryonic content of cosmic structures in a sparsely populated portion of parameter space that has hitherto been occupied primarily by dwarf spheroidal galaxies. We detect the signature of two temperature components in the neutral ISM of Leo P; the cold and warm components have characteristic velocity widths of 4.2 ± 0.9 km s{sup –1} and 10.1 ± 1.2 km s{sup –1}, corresponding to kinetic temperature upper limits of ∼1100 K and ∼6200 K, respectively. The cold H I component is unresolved at a physical resolution of 200 pc. The highest H I surface densities are observed in close physical proximity to the single H II region. A comparison of the neutral gas properties of Leo P with other extremely metal-deficient (XMD) galaxies reveals that Leo P has the lowest neutral gas mass of any known XMD, and that the dynamical mass of Leo P is more than two orders of magnitude smaller than any known XMD with comparable metallicity.

  15. Human Exploration Beyond LEO by the End of the Decade: Designs for Long-Duration "Gateway" Habitats

    Science.gov (United States)

    Thronson, Harley; Barr, Jonathan; Budinoff, Jason; Dorsey, John; Gold, Michael; Kutter, Bernard; Lester, Daniel; Moe, Rud; Sauls, Bobby; Spampinato, Phillip; hide

    2010-01-01

    For the past few years, designs have been developed that are intended to demonstrate that a long-duration habitation system beyond LEO is plausible within several years. Here we summarize a pair of designs with the overriding goal of development and operation beyond LEO before the end of the decade that also build upon experiments and lessons learned from ISS. Both concepts here have the goal of an expandable long-duration habitat at Earth- Moon L1 and/or L2. Both options require subsequent launches for the astronauts. If a heavy-lift launch vehicle is available this decade, an expandable 30.5 mt habitat and departure-stage propulsion system may be launched to E-M L1,2 in a single launch and will offer 575 cubic meter (roughly half the habitable volume of ISS) If existing (or near-future) EELVs are the available launch vehicles this decade, a 16 mt, 170 cubic meter design that uses a pair of launches of Delta IV H and LEO rendezvous/fuel transfer to reach E-M L1,2.

  16. Malignant lymphoma in african lions (panthera leo).

    Science.gov (United States)

    Harrison, T M; McKnight, C A; Sikarskie, J G; Kitchell, B E; Garner, M M; Raymond, J T; Fitzgerald, S D; Valli, V E; Agnew, D; Kiupel, M

    2010-09-01

    Malignant lymphoma has become an increasingly recognized problem in African lions (Panthera leo). Eleven African lions (9 male and 2 female) with clinical signs and gross and microscopic lesions of malignant lymphoma were evaluated in this study. All animals were older adults, ranging in age from 14 to 19 years. Immunohistochemically, 10 of the 11 lions had T-cell lymphomas (CD3(+), CD79a(-)), and 1 lion was diagnosed with a B-cell lymphoma (CD3(-), CD79a(+)). The spleen appeared to be the primary site of neoplastic growth in all T-cell lymphomas, with involvement of the liver (6/11) and regional lymph nodes (5/11) also commonly observed. The B-cell lymphoma affected the peripheral lymph nodes, liver, and spleen. According to the current veterinary and human World Health Organization classification of hematopoietic neoplasms, T-cell lymphoma subtypes included peripheral T-cell lymphoma (4/11), precursor (acute) T-cell lymphoblastic lymphoma/leukemia (2/11), chronic T-cell lymphocytic lymphoma/leukemia (3/11), and T-zone lymphoma (1/11). The single B-cell lymphoma subtype was consistent with diffuse large B-cell lymphoma. Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) testing by immunohistochemistry on sections of malignant lymphoma was negative for all 11 lions. One lion was seropositive for FeLV. In contrast to domestic and exotic cats, in which B-cell lymphomas are more common than T-cell lymphomas, African lions in this study had malignant lymphomas that were primarily of T-cell origin. Neither FeLV nor FIV, important causes of malignant lymphoma in domestic cats, seems to be significant in the pathogenesis of malignant lymphoma in African lions.

  17. Sizing of "Mother Ship and Catcher" Missions for LEO Small Debris and for GEO Large Object Capture

    Science.gov (United States)

    Bacon, John B.

    2009-01-01

    Most LEO debris lies in a limited number of inclination "bands" associated with specific useful orbits. Objects in such narrow inclination bands have all possible Right Ascensions of Ascending Node (RAANs), creating a different orbit plane for nearly every piece of debris. However, a low-orbiting satellite will always phase in RAAN faster than debris objects in higher orbits at the same inclination, potentially solving the problem. Such a low-orbiting base can serve as a "mother ship" that can tend and then send small, disposable common individual catcher/deboost devices--one for each debris object--as the facility drifts into the same RAAN as each higher object. The dV necessary to catch highly-eccentric orbit debris in the center of the band alternatively allows the capture of less-eccentric debris in a wider inclination range around the center. It is demonstrated that most LEO hazardous debris can be removed from orbit in three years, using a single LEO launch of one mother ship--with its onboard magazine of freeflying low-tech catchers--into each of ten identified bands, with second or potentially third launches into only the three highest-inclination bands. The nearly 1000 objects near the geostationary orbit present special challenges in mass, maneuverability, and ultimate disposal options, leading to a dramatically different architecture and technology suite than the LEO solution. It is shown that the entire population of near-GEO derelict objects can be gathered and tethered together within a 3 year period for future scrap-yard operations using achievable technologies and only two earth launches.

  18. Real time prediction and correction of ADCS problems in LEO satellites using fuzzy logic

    Directory of Open Access Journals (Sweden)

    Yassin Mounir Yassin

    2017-06-01

    Full Text Available This approach is concerned with adapting the operations of attitude determination and control subsystem (ADCS of low earth orbit LEO satellites through analyzing the telemetry readings received by mission control center, and then responding to ADCS off-nominal situations. This can be achieved by sending corrective operational Tele-commands within real time. Our approach is related to the fuzzy membership of off-nominal telemetry readings of corrective actions through a set of fuzzy rules based on understanding the ADCS modes resulted from the satellite telemetry readings. Response in real time gives us a chance to avoid risky situations. The approach is tested on the EgyptSat-1 engineering model, which is our method to simulate the results.

  19. Aspects of scintillation modelling in LEO-ground free-space optical communications

    Science.gov (United States)

    Moll, Florian

    2017-10-01

    Free-space optical communications can be used to transmit data from low Earth orbit satellites to ground with very high data rate. In the last section of the downlink, the electro-magnetic wave propagates through the turbulent atmosphere which is characterized by random index of refraction fluctuations. The propagating wave experiences phase distortions that lead to intensity scintillation in the aperture plane of the receiving telescope. For quantification, an appropriate scintillation model is needed. Approaches to analytically model the scintillation exist. Parameterization of the underlying turbulence profile (Cn2 profile) is however difficult. The Cn2 profiles are often site-specific and thus inappropriate or generic and thus too complex for a feasible deployment. An approach that directly models the scintillation effect based on measurements without claiming to be generic is therefore more feasible. Since measurements are sparse, a combination with existing theoretical framework is feasible to develop a new scintillation model that focuses on low earth orbit to ground free-space optical communications link design with direct detection. The paper addresses several questions one has to answer while analyzing the measurements data and selection of the theoretical models for the LEO downlink scenario. The first is the question of a suitable yet ease to use simple Cn2 profile. The HAP model is analyzed for its feasibility in this scenario since it includes a more realistic boundary layer profile decay than the HV model. It is found that the HAP model needs to be modified for a feasible deployment in the LEO downlink scenario for night time. The validity of the plane wave assumption in the downlink is discussed by model calculations of the scintillation index for a plane and Gaussian beam wave. Inaccuracies when using the plane earth model instead of the spherical earth model are investigated by analyzing the Rytov index. Impact of beam wander and non

  20. Passivation Strategies on Board Airbus ds Leo Pcdus

    Directory of Open Access Journals (Sweden)

    Lapeña Emilio

    2017-01-01

    This paper deals with the different strategies followed in the Airbus DS LEO PCDUs regarding the implementation of the passivation function in several LEO missions with different architectures (DET and MPPT solar array power conditioning. In the selection of the solution implemented in the frame of every mission, a key driver is the degree of advance in the test performed over flight representative battery modules regarding their safe behavior when deeply depleted after a long period in orbit with the passivation applied over the spacecraft.

  1. El petróleo como repelente de Phlebotomus

    Directory of Open Access Journals (Sweden)

    Marshall Hertig

    1943-09-01

    Full Text Available Se ha probado el repelente del petróleo contra el Phlebotomus verrucarum. Se echó varias veces petróleo en las paredes exteriores y en el suelo alrededor de casas en la zona verrucógena del Rímac, donde son abundantes las titiras. Inmediatamente después de cada petrolización se redujeron a números insignificantes las titiras dentro de las casas, efecto que duró aproximadamente una semana.

  2. Evaluating the environmental criticality of massive objects in LEO for debris mitigation and remediation

    Science.gov (United States)

    Pardini, Carmen; Anselmo, Luciano

    2018-04-01

    Approximately 95% of the mass in Earth orbit is currently concentrated in about 6700 intact objects, of which nearly 80% are abandoned and more than 90% cannot be maneuvered. The intact objects abandoned in low Earth orbit (LEO) above 650 km, i.e. with an average residual lifetime of more than 25 years, represent the main potential mass reservoir for the generation of new detrimental orbital debris in case of mutual collisions with the existing debris environment, taking into account that an 800 g impactor may be sufficient, in principle, to shatter a 1000 kg spacecraft or rocket stage. Since the 1980's, several mitigation measures were promoted and agreed at the international level in order to prevent the occurrence of new breakups in space and put under control the accumulation of mass abandoned in orbit, but unfortunately the level of compliance with such guidelines, requirements or standards is still far from satisfactory. Moreover, the appearance on the scene of space activity of new private and government actors from a growing number of countries makes the proper management of the circumterrestrial space a task of increasing complexity, taking also into account the rapid emerging of new potential applications, disrupting technologies and operational approaches quite different from the past. In this rapidly evolving environment, it might be useful to have a simple and flexible instrument for evaluating the potential criticality for the environment of massive objects placed or abandoned in LEO. With this goal, in the last few years, a particular effort was devoted to the development of various "criticality indexes", then applied for evaluating many families of rocket bodies and selected spacecraft. In this paper, with the underlining ambition to be simple, intuitive and relevant, from an environmental point of view, a couple of the most complete indexes were coherently applied in order to assess the potential criticality of the most massive objects abandoned in

  3. The Clouds and the Earth's Radiant Energy System Elevation Bearing Assembly Life Test

    Science.gov (United States)

    Brown, Phillip L.; Miller, James B.; Jones, William R., Jr.; Rasmussen, Kent; Wheeler, Donald R.; Rana, Mauro; Peri, Frank

    1999-01-01

    The Clouds and the Earth's Radiant Energy System (CERES) elevation scan bearings lubricated with Pennzane SHF X2000 and 2% lead naphthenate (PbNp) were life tested for a seven-year equivalent Low Earth Orbit (LEO) operation. The bearing life assembly was tested continuously at an accelerated and normal rate using the scanning patterns developed for the CERES Earth Observing System AM-1 mission. A post-life-test analysis was performed on the collected data, bearing wear, and lubricant behavior.

  4. The influence of the interstellar medium on climate and life

    International Nuclear Information System (INIS)

    Talbot, R.J. Jr.

    1980-01-01

    Recent studies of the gas and dust between the stars, the interstellar medium, reveal a complex chemistry which indicates that prebiotic organic chemistry is ubiquitous. The relationship between this interstellar chemistry and the organic chemistry of the early solar system and the Earth is explored. The interstellar medium is also considered as likely to have a continuing influence upon the climate of the Earth and other planets. Life forms as known are not only descendants of the organic evolution begun in the interstellar medium, but their continuing evolution is also molded through occasional interactions between the interstellar medium, the Sun and the climate on Earth. (author)

  5. Sulfur Earth

    Science.gov (United States)

    de Jong, B. H.

    2007-12-01

    Variations in surface tension affect the buoyancy of objects floating in a liquid. Thus an object floating in water will sink deeper in the presence of dishwater fluid. This is a very minor but measurable effect. It causes for instance ducks to drown in aqueous solutions with added surfactant. The surface tension of liquid iron is very strongly affected by the presence of sulfur which acts as a surfactant in this system varying between 1.9 and 0.4 N/m at 10 mass percent Sulfur (Lee & Morita (2002), This last value is inferred to be the maximum value for Sulfur inferred to be present in the liquid outer core. Venting of Sulfur from the liquid core manifests itself on the Earth surface by the 105 to 106 ton of sulfur vented into the atmosphere annually (Wedepohl, 1984). Inspection of surface Sulfur emission indicates that venting is non-homogeneously distributed over the Earth's surface. The implication of such large variation in surface tension in the liquid outer core are that at locally low Sulfur concentration, the liquid outer core does not wet the predominantly MgSiO3 matrix with which it is in contact. However at a local high in Sulfur, the liquid outer core wets this matrix which in the fluid state has a surface tension of 0.4 N/m (Bansal & Doremus, 1986), couples with it, and causes it to sink. This differential and diapiric movement is transmitted through the essentially brittle mantle (1024 Pa.s, Lambeck & Johnson, 1998; the maximum value for ice being about 1030 Pa.s at 0 K, in all likely hood representing an upper bound of viscosity for all materials) and manifests itself on the surface by the roughly 20 km differentiation, about 0.1 % of the total mantle thickness, between topographical heights and lows with concomitant lateral movement in the crust and upper mantle resulting in thin skin tectonics. The brittle nature of the medium though which this movement is transmitted suggests that the extremes in topography of the D" layer are similar in range to

  6. [Leo Bormans. Õnn on] / Krista Kivisalu

    Index Scriptorium Estoniae

    Kivisalu, Krista, 1968-

    2015-01-01

    Tutvustus: Õnn on : kogu maailma õnneraamat : teadmisi ja tarkusi enam kui sajalt õnneasjatundjalt kogu maailmast / toimetanud Leo Bormans ; [inglise keelest tõlkinud Triin Aimla-Laid ; toimetanud Violetta Riidas ; originaali kujundus: Kris Demey] Ilmunud [Tallinn] : Pegasus, c2015

  7. Complete mitochondrial genome of a Asian lion (Panthera leo goojratensis).

    Science.gov (United States)

    Li, Yu-Fei; Wang, Qiang; Zhao, Jian-ning

    2016-01-01

    The entire mitochondrial genome of this Asian lion (Panthera leo goojratensis) was 17,183 bp in length, gene composition and arrangement conformed to other lions, which contained the typical structure of 22 tRNAs, 2 rRNAs, 13 protein-coding genes and a non-coding region. The characteristic of the mitochondrial genome was analyzed in detail.

  8. Haemangiosarcoma in a captive Asiatic lion ( Panthera leo persica ...

    African Journals Online (AJOL)

    A 2.7-year-old male captive Asiatic lion (Panthera leo persica) died unexpectedly without preceding symptoms. Gross necropsy revealed liver and lung tumours, which proved to be haemangiosarcomas by histopathology. Some of the liver tumours were ruptured, leading to massive intra-abdominal haemorrhage and death.

  9. Estimation of the lion ( Panthera leo ) population in the southwestern ...

    African Journals Online (AJOL)

    A previous estimate of the lion (Panthera leo) population in the southwestern Kgalagadi Transfrontier Park (KTP) was made over 20 years ago. This together with increased fears regarding the viability of the population as a result of recent killings of roaming animals, an observed increase in non-violent mortalities during ...

  10. In memoriam Prof. Dr. Leo Daniel Brongersma (1907-1994)

    NARCIS (Netherlands)

    Hoogmoed, M.S.

    1995-01-01

    A biography of Leo Daniel Brongersma is given, highlighting his significance for herpetology worldwide, and especially for snake anatomy, sea turtle distribution, faunistics of New Guinea and IndoAustralia. Lists of patronyms, of species named by Brongersma and of his publications are given. Also

  11. Telelegend Leo Karpin : ETV uus juhtkond teeb vaid lammutustööd / Leo Karpin ; interv. Verni Leivak

    Index Scriptorium Estoniae

    Karpin, Leo, 1946-2014

    2004-01-01

    Pea 40 aastat Eesti Televisioonis töötanud telerežissöör oma teletöölt lahkumise põhjustest. Lisaks kommentaar "ETV juhatuse esimees Ilmar Raag, miks tunnustatud telemees Leo Karpin ametist vabastati?"

  12. SSC Tenant Meeting: NASA Near Earth Network (NEN) Overview

    Science.gov (United States)

    Carter, David; Larsen, David; Baldwin, Philip; Wilson, Cristy; Ruley, LaMont

    2018-01-01

    The Near Earth Network (NEN) consists of globally distributed tracking stations that are strategically located throughout the world which provide Telemetry, Tracking, and Commanding (TTC) services support to a variety of orbital and suborbital flight missions, including Low Earth Orbit (LEO), Geosynchronous Earth Orbit (GEO), highly elliptical, and lunar orbits. Swedish Space Corporation (SSC), which is one of the NEN Commercial Service Provider, has provided the NEN with TTC services support from its Alaska, Hawaii, Chile and Sweden. The presentation will give an overview of the NEN and its support from SSC.

  13. Earth as art three

    Science.gov (United States)

    ,

    2010-01-01

    For most of us, deserts, mountains, river valleys, coastlines even dry lakebeds are relatively familiar features of the Earth's terrestrial environment. For earth scientists, they are the focus of considerable scientific research. Viewed from a unique and unconventional perspective, Earth's geographic attributes can also be a surprising source of awe-inspiring art. That unique perspective is space. The artists for the Earth as Art Three exhibit are the Landsat 5 and Landsat 7 satellites, which orbit approximately 705 kilometers (438 miles) above the Earth's surface. While studying the images these satellites beam down daily, researchers are often struck by the sheer beauty of the scenes. Such images inspire the imagination and go beyond scientific value to remind us how stunning, intricate, and simply amazing our planet's features can be. Instead of paint, the medium for these works of art is light. But Landsat satellite sensors don't see light as human eyes do; instead, they see radiant energy reflected from Earth's surface in certain wavelengths, or bands, of red, green, blue, and infrared light. When these different bands are combined into a single image, remarkable patterns, colors, and shapes emerge. The Earth as Art Three exhibit provides fresh and inspiring glimpses of different parts of our planet's complex surface. The images in this collection were chosen solely based on their aesthetic appeal. Many of the images have been manipulated to enhance color variations or details. They are not intended for scientific interpretation only for your viewing pleasure. Enjoy!

  14. Modeling of LEO Orbital Debris Populations in Centimeter and Millimeter Size Regimes

    Science.gov (United States)

    Xu, Y.-L.; Hill, . M.; Horstman, M.; Krisko, P. H.; Liou, J.-C.; Matney, M.; Stansbery, E. G.

    2010-01-01

    The building of the NASA Orbital Debris Engineering Model, whether ORDEM2000 or its recently updated version ORDEM2010, uses as its foundation a number of model debris populations, each truncated at a minimum object-size ranging from 10 micron to 1 m. This paper discusses the development of the ORDEM2010 model debris populations in LEO (low Earth orbit), focusing on centimeter (smaller than 10 cm) and millimeter size regimes. Primary data sets used in the statistical derivation of the cm- and mm-size model populations are from the Haystack radar operated in a staring mode. Unlike cataloged objects of sizes greater than approximately 10 cm, ground-based radars monitor smaller-size debris only in a statistical manner instead of tracking every piece. The mono-static Haystack radar can detect debris as small as approximately 5 mm at moderate LEO altitudes. Estimation of millimeter debris populations (for objects smaller than approximately 6 mm) rests largely on Goldstone radar measurements. The bi-static Goldstone radar can detect 2- to 3-mm objects. The modeling of the cm- and mm-debris populations follows the general approach to developing other ORDEM2010-required model populations for various components and types of debris. It relies on appropriate reference populations to provide necessary prior information on the orbital structures and other important characteristics of the debris objects. NASA's LEO-to-GEO Environment Debris (LEGEND) model is capable of furnishing such reference populations in the desired size range. A Bayesian statistical inference process, commonly adopted in ORDEM2010 model-population derivations, changes a priori distribution into a posteriori distribution and thus refines the reference populations in terms of data. This paper describes key elements and major steps in the statistical derivations of the cm- and mm-size debris populations and presents results. Due to lack of data for near 1-mm sizes, the model populations of 1- to 3.16-mm

  15. Solar Power Beaming: From Space to Earth

    Energy Technology Data Exchange (ETDEWEB)

    Rubenchik, A M; Parker, J M; Beach, R J; Yamamoto, R M

    2009-04-14

    Harvesting solar energy in space and power beaming the collected energy to a receiver station on Earth is a very attractive way to help solve mankind's current energy and environmental problems. However, the colossal and expensive 'first step' required in achieving this goal has to-date stifled its initiation. In this paper, we will demonstrate that recent advance advances in laser and optical technology now make it possible to deploy a space-based system capable of delivering 1 MW of energy to a terrestrial receiver station, via a single unmanned commercial launch into Low Earth Orbit (LEO). Figure 1 depicts the overall concept of our solar power beaming system, showing a large solar collector in space, beaming a coherent laser beam to a receiving station on Earth. We will describe all major subsystems and provide technical and economic discussion to support our conclusions.

  16. POLIURETANOS BASEADOS EM ÓLEO DE MAMONA

    Directory of Open Access Journals (Sweden)

    Heliberto José Limberger

    2013-12-01

    Full Text Available Neste trabalho de revisão foram apresentadas as principais características do óleo de mamona e de poliuretanos (PUs obtidos a partir deste, descrevendo os métodos de síntese e obtenção empregados. Buscou-se reunir informações sobre novas tendências na área, bem como possíveis aplicações para este tipo de polímero considerando as diferentes propriedades que pode apresentar. PUs obtidos a partir de óleo de mamona podem ser aplicados nas áreas de construção civil, medicina, de materiais e de adesivos, apresentando a vantagem de serem oriundos de fonte renovável e muitas vezes serem biodegradáveis.

  17. Fuel Optimization for Low Earth Orbit Maintenance

    Directory of Open Access Journals (Sweden)

    Yong Jae Park

    2008-06-01

    Full Text Available The resolution of Earth images taken from a satellite has close relation with satellite's altitude. If a satellite has lower altitude, it gets a picture having better resolution. However the satellite will be exposed to heavier air drag and will spend more fuel to maintain its altitude for a desired mission. Therefore, in this study, the required fuel to maintain very low earth orbit(LEO with severe air drag is analyzed using optimization method such as collocation method. The required fuel to maintain the low altitude has significantly increased as the mission altitude is lowered and the solar activity is maximized. This study also shows that the fuel reduced by increasing the period of the satellite maneuver is very small, and that slightly increasing the satellite's mission altitude is much effective in reducing the amount of fuel to maintain its altitude. The calculated fuel to maintain very low earth orbit in this study would give useful information in planning the budget of fuel and cost for LEO satellites.

  18. Jean Leo Testut (1849-1925): anatomist and anthropologist

    OpenAIRE

    Reverón, Rafael Romero

    2014-01-01

    Leo Testut (1849–1925), professor of human anatomy of the Faculty of Medicine of Lyon, wrote more than 90 publicationson anatomy, anthropology and history, the most outstanding of which was his treatise on human anatomy published in1887. He founded and directed the International Journal of Anatomy and Histology. He was a member of the FrenchAcademy of Medicine and president of the World Association of Anatomists

  19. Integration of 5G Technologies in LEO Mega-Constellations

    OpenAIRE

    Guidotti, Alessandro; Vanelli-Coralli, Alessandro; Kodheli, Oltjon; Colavolpe, Giulio; Foggi, Tommaso

    2017-01-01

    3GPP is finalising the first release of the 5G New Radio physical layer. To cope with the demanding 5G requirements on global connectivity and large throughput, Satellite Communications might be a valuable resource to extend and complement terrestrial networks. In this context, we introduce an integrated architecture for 5G-based LEO mega-constellations and assess the impact of large Doppler shifts and delays on both the 5G waveform and the PHY/MAC layer procedures.

  20. Integration of Satellites in 5G through LEO Constellations

    OpenAIRE

    Kodheli, Oltjon; Guidotti, Alessandro; Vanelli-Coralli, Alessandro

    2017-01-01

    The standardization of 5G systems is entering in its critical phase, with 3GPP that will publish the PHY standard by June 2017. In order to meet the demanding 5G requirements both in terms of large throughput and global connectivity, Satellite Communications provide a valuable resource to extend and complement terrestrial networks. In this context, we consider a heterogeneous architecture in which a LEO mega-constellation satellite system provides backhaul connectivity to terrestrial 5G Relay...

  1. LTE-based Satellite Communications in LEO Mega-Constellations

    OpenAIRE

    Guidotti, A.; Vanelli-Coralli, A.; Foggi, T.; Colavolpe, G.; Caus, M.; Bas, J.; Cioni, S.; Modenini, A.

    2017-01-01

    The integration of satellite and terrestrial networks is a promising solution for extending broadband coverage to areas not connected to a terrestrial infrastructure, as also demonstrated by recent commercial and standardisation endeavours. However, the large delays and Doppler shifts over the satellite channel pose severe technical challenges to traditional terrestrial systems, as LTE or 5G. In this paper, two architectures are proposed for a LEO mega-constellation realising a satellite-enab...

  2. Earth Orbiting Support Systems for commercial low Earth orbit data relay: Assessing architectures through tradespace exploration

    Science.gov (United States)

    Palermo, Gianluca; Golkar, Alessandro; Gaudenzi, Paolo

    2015-06-01

    As small satellites and Sun Synchronous Earth Observation systems are assuming an increased role in nowadays space activities, including commercial investments, it is of interest to assess how infrastructures could be developed to support the development of such systems and other spacecraft that could benefit from having a data relay service in Low Earth Orbit (LEO), as opposed to traditional Geostationary relays. This paper presents a tradespace exploration study of the architecture of such LEO commercial satellite data relay systems, here defined as Earth Orbiting Support Systems (EOSS). The paper proposes a methodology to formulate architectural decisions for EOSS constellations, and enumerate the corresponding tradespace of feasible architectures. Evaluation metrics are proposed to measure benefits and costs of architectures; lastly, a multicriteria Pareto criterion is used to downselect optimal architectures for subsequent analysis. The methodology is applied to two case studies for a set of 30 and 100 customer-spacecraft respectively, representing potential markets for LEO services in Exploration, Earth Observation, Science, and CubeSats. Pareto analysis shows how increased performance of the constellation is always achieved by an increased node size, as measured by the gain of the communications antenna mounted on EOSS spacecraft. On the other hand, nonlinear trends in optimal orbital altitude, number of satellites per plane, and number of orbital planes, are found in both cases. An upward trend in individual node memory capacity is found, although never exceeding 256 Gbits of onboard memory for both cases that have been considered, assuming the availability of a polar ground station for EOSS data downlink. System architects can use the proposed methodology to identify optimal EOSS constellations for a given service pricing strategy and customer target, thus identifying alternatives for selection by decision makers.

  3. Técnica do aproveitamento da papila íleo-cecal naileostomia definitiva e na anastomose íleo-retal

    OpenAIRE

    Silva,Alcino Lázaro da

    2011-01-01

    INTRODUÇÃO: Quando se faz ileostomia com a papila, a perda líquida é bem menor e a irritação local às vezes é nula, podendo o paciente viver sem o uso da bolsa. OBJETIVO: Mostrar uma técnica operatória em que se preserva a papila na ileostomia ou na anastomose íleo-retal. Ela consta da preservação da vasculatura do ceco e íleo terminal e secção do ceco deixando-se 1 cm de orla na papila ileal que é fixada na pele por contra-abertura para ileostomia definitiva. Quando se resseca o cólon, a pap...

  4. NASA-STD-4005 and NASA-HDBK-4006, LEO Spacecraft Solar Array Charging Design Standard

    Science.gov (United States)

    Ferguson, Dale C.

    2007-01-01

    Two new NASA Standards are now official. They are the NASA LEO Spacecraft Charging Design Standard (NASA-STD-4005) and the NASA LEO Spacecraft Charging Design Handbook (NASA-HDBK-4006). They give the background and techniques for controlling solar array-induced charging and arcing in LEO. In this paper, a brief overview of the new standards is given, along with where they can be obtained and who should be using them.

  5. Hinnangud võtmeesinejatele / Leo Voogt ; inglise keelest tõlkinud Kristina Pai

    Index Scriptorium Estoniae

    Voogt, Leo

    2012-01-01

    Euroopa teadusraamatukogude organisatsiooni LIBER-i tegevdirektori Leo Voogti seisukohad Tartus 27.-30. juunil 2012 peetud konverentsi ettekandjate kohta, lisaks konverentsi ankeetides tagasisidena kajastunu

  6. Effects of Low Earth Orbit on Docking Seal Materials

    Science.gov (United States)

    Imka, Emily C.; Asmar, Olivia C.; deGroh, Henry C., III; Banks, Bruce A.

    2014-01-01

    Spacecraft docking seals are typically made of silicone elastomers. When such seals are exposed to low Earth orbit (LEO) conditions, they can suffer damage from ultraviolet (UV) radiation and atomic oxygen (AO, or monoatomic oxygen, the predominant oxygen species in LEO). An experiment flew on the International Space Station (ISS) to measure the effects of LEO on seal materials S0383-70 and ELA-SA-401 and various mating counterface materials which included anodized aluminum. Samples flown in different orientations received different amounts of UV and AO. The hypotheses were that most of the damage would be from UV, and 10 days or more of exposure in LEO would badly damage the seals. Eighteen seals were exposed for 543 days in ram (windward), zenith (away from Earth), or wake (leeward) orientations, and 15 control samples (not flown) provided undamaged baseline leakage. To determine post-flight leak rates, each of the 33 seals were placed in an O-ring groove of a leak test fixture and pressure tested over time. Resistance temperature detectors (RTDs), pressure transducers, and LabVIEW (National Instruments) programs were used to measure and analyze the temperature and pressure and calculate leakage. Average leakage of control samples was 2.6 x 10(exp -7) lbs/day. LEO exposure did not considerably damage ELA-SA-401. The S0383-70 flight samples leaked at least 10 times more than ELA-SA-401 in all cases except one, demonstrating that ELA-SA-401 may be a more suitable sealing material in LEO. AO caused greater damage than UV; samples in ram orientation (receiving an AO fluence of 4.3 x 10(exp 21) atoms/(sq cm) and in wake (2.9x 10(exp 20) atoms/(sq cm)) leaked more than those in zenith orientation (1.58 x 10(exp 20) atoms/(sq cm)), whereas variations in UV exposure did not seem to affect the samples. Exposure to LEO did less damage to the seals than hypothesized, and the data did not support the conjecture that UV causes more damage than AO.

  7. Pursuing atmospheric water vapor retrieval through NDSA measurements between two LEO satellites: evaluation of estimation errors in spectral sensitivity measurements

    Science.gov (United States)

    Facheris, L.; Cuccoli, F.; Argenti, F.

    2008-10-01

    NDSA (Normalized Differential Spectral Absorption) is a novel differential measurement method to estimate the total content of water vapor (IWV, Integrated Water Vapor) along a tropospheric propagation path between two Low Earth Orbit (LEO) satellites. A transmitter onboard the first LEO satellite and a receiver onboard the second one are required. The NDSA approach is based on the simultaneous estimate of the total attenuations at two relatively close frequencies in the Ku/K bands and of a "spectral sensitivity parameter" that can be directly converted into IWV. The spectral sensitivity has the potential to emphasize the water vapor contribution, to cancel out all spectrally flat unwanted contributions and to limit the impairments due to tropospheric scintillation. Based on a previous Monte Carlo simulation approach, through which we analyzed the measurement accuracy of the spectral sensitivity parameter at three different and complementary frequencies, in this work we examine such accuracy for a particularly critical atmospheric status as simulated through the pressure, temperature and water vapor profiles measured by a high resolution radiosonde. We confirm the validity of an approximate expression of the accuracy and discuss the problems that may arise when tropospheric water vapor concentration is lower than expected.

  8. Updating the NASA LEO Orbital Debris Environment Model with Recent Radar and Optical Observations and in Situ Measurements

    Science.gov (United States)

    Liou, J.-C.; Anz-Meador, P.; Matney, M. J.; Kessler, D. J.; Theall, J.; Johnson, N. L.

    2000-01-01

    The Low Earth Orbit (LEO, between 200 and 2000 km altitudes) debris environment has been constantly measured by NASA Johnson Space Center's Liquid Mirror Telescope (LMT) since 1996 (Africano et al. 1999, NASA JSC-28826) and by Haystack and Haystack Auxiliary radars at MIT Lincoln Laboratory since 1990 (Settecerri et al. 1999, NASA JSC-28744). Debris particles as small as 3 mm can be detected by the radars and as small as 3 cm can be measured by LMT. Objects about 10 cm in diameter and greater are tracked and catalogued by the US Space Surveillance Network. Much smaller (down to several micrometers) natural and debris particle populations can be estimated based on in situ measurements, such as Long Duration Exposure Facility, and based on analyses of returned surfaces, such as Hubble Space Telescope solar arrays, European Retrievable Carrier, and Space Shuttles. To increase our understanding of the current LEO debris environment, the Orbital Debris Program Office at NASA JSC has initiated an effort to improve and update the ORDEM96 model (Kessler et al. 1996, NASA TM-104825) utilizing the recently available data. This paper gives an overview of the new NASA orbital debris engineering model, ORDEM2000.

  9. Space base laser torque applied on LEO satellites of various geometries at satellite’s closest approach

    Directory of Open Access Journals (Sweden)

    N.S. Khalifa

    2013-12-01

    Full Text Available In light of using laser power in space applications, the motivation of this paper is to use a space based solar pumped laser to produce a torque on LEO satellites of various shapes. It is assumed that there is a space station that fires laser beam toward the satellite so the beam spreading due to diffraction is considered to be the dominant effect on the laser beam propagation. The laser torque is calculated at the point of closest approach between the space station and some sun synchronous low Earth orbit cubesats. The numerical application shows that space based laser torque has a significant contribution on the LEO cubesats. It has a maximum value in the order of 10−8 Nm which is comparable with the residual magnetic moment. However, it has a minimum value in the order 10−11 Nm which is comparable with the aerodynamic and gravity gradient torque. Consequently, space based laser torque can be used as an active attitude control system.

  10. Technology for monitoring global change. [NASA Technology Initiative for space based observations of Earth

    Science.gov (United States)

    Johnston, Gordon I.; Hudson, Wayne R.

    1989-01-01

    Multiinstrumented earth-science platforms currently being planned for both LEO and GEO positions will furnish data for the compilation of systematic and intercorrelated information that is suitable for the treatment of interdisciplinary questions concerning atmospheric, oceanic, hydrological, geological, and biological changes of an either natural or anthropogenic nature. Attention will be given in these observational campaigns to such essential earth variables as atmospheric pressure, rainfall/snowfall, vegetation cover, soil nutrient cycles, sea surface temperatures, ocean circulation, and ocean biological productivity.

  11. EcAMSat and BioSentinel: Autonomous Bio Nanosatellites Addressing Strategic Knowledge Gaps for Manned Spaceflight Beyond LEO

    Science.gov (United States)

    Padgen, Mike

    2017-01-01

    Manned missions beyond low Earth orbit (LEO) require that several strategic knowledge gaps about the effects of space travel on the human body be addressed. NASA Ames Research Center has been the leader in developing autonomous bio nanosatellites, including past successful missions for GeneSat, PharmaSat, and OOREOS, that tackled some of these issues. These nanosatellites provide in situ measurements, which deliver insight into the dynamic changes in cell behavior in microgravity. In this talk, two upcoming bio nanosatellites developed at Ames, the E. coli Antimicrobial Satellite (EcAMSat) and BioSentinel, will be discussed. Both satellites contain microfluidic systems that precisely deliver nutrients to the microorganisms stored within wells of fluidic cards. Each well, in turn, has its own 3-color LED and detector system which is used to monitor changes in metabolic activity with alamarBlue, a redox indicator, and the optical density of the cells. EcAMSat investigates the effects of microgravity on bacterial resistance to antimicrobial drugs, vital knowledge for understanding how to maintain the health of astronauts in long-term and beyond LEO spaceflight. The behavior of wild type and mutant uropathic E. coli will be compared in microgravity and with ground data to help understand the molecular mechanisms behind antibiotic resistance and how these phenotypes might change in space. BioSentinel seeks to directly measure the effects of space radiation on budding yeast S. cerevisiae, particularly double strand breaks (DSB). While hitching a ride on the SLS EM-1 mission (Orions first unmanned mission to the moon) in 2018, BioSentinel will be kicked off and enter into a heliocentric orbit, becoming the first study of the effects of radiation on living organisms outside LEO since the Apollo program. The yeast are stored in eighteen independent 16-well microfluidic cards, which will be individually activated over the 12 month mission duration. In addition to the wild

  12. Effects of space weather on the ionosphere and LEO satellites' orbital trajectory in equatorial, low and middle latitude

    Science.gov (United States)

    Nwankwo, Victor U. J.; Chakrabarti, Sandip K.

    2018-04-01

    We study the effects of space weather on the ionosphere and low Earth orbit (LEO) satellites' orbital trajectory in equatorial, low- and mid-latitude (EQL, LLT and MLT) regions during (and around) the notable storms of October/November, 2003. We briefly review space weather effects on the thermosphere and ionosphere to demonstrate that such effects are also latitude-dependent and well established. Following the review we simulate the trend in variation of satellite's orbital radius (r), mean height (h) and orbit decay rate (ODR) during 15 October-14 November 2003 in EQL, LLT and MLT. Nominal atmospheric drag on LEO satellite is usually enhanced by space weather or solar-induced variations in thermospheric temperature and density profile. To separate nominal orbit decay from solar-induced accelerated orbit decay, we compute r, h and ODR in three regimes viz. (i) excluding solar indices (or effect), where r =r0, h =h0 and ODR =ODR0 (ii) with mean value of solar indices for the interval, where r =rm, h =hm and ODR =ODRm and (iii) with actual daily values of solar indices for the interval (r, h and ODR). For a typical LEO satellite at h = 450 km, we show that the total decay in r during the period is about 4.20 km, 3.90 km and 3.20 km in EQL, LLT and MLT respectively; the respective nominal decay (r0) is 0.40 km, 0.34 km and 0.22 km, while solar-induced orbital decay (rm) is about 3.80 km, 3.55 km and 2.95 km. h also varied in like manner. The respective nominal ODR0 is about 13.5 m/day, 11.2 m/day and 7.2 m/day, while solar-induced ODRm is about 124.3 m/day, 116.9 m/day and 97.3 m/day. We also show that severe geomagnetic storms can increase ODR by up to 117% (from daily mean value). However, the extent of space weather effects on LEO Satellite's trajectory significantly depends on the ballistic co-efficient and orbit of the satellite, and phase of solar cycles, intensity and duration of driving (or influencing) solar event.

  13. Experimental Final IGS Product from ESA Based on GPS Measurements from a Network of LEO Satellites

    Science.gov (United States)

    Svehla, D.; Springer, T.; Flohrer, C.; Enderle, W.; Dow, J. M.; Rothacher, M.

    2011-12-01

    One of the main objectives of the former Working Group on LEO POD, organized in parallel by IAG and IGS, was inclusion of GPS measurements from LEO satellites in the generation of Final IGS Products. Thanks to the several gravity field missions over the last 10 years, gravity field models have been significantly improved, allowing for very accurate modeling of LEO satellite dynamics. On the other hand, the number of LEO satellites carrying GPS receiver have considerably increased over the years and we are now for the first time in the position to form a network of LEO satellites in space. In the similar way we form a network of IGS stations on the ground, we can form a network of satellites carrying GPS receiver in the LEO orbit. In the case of formation-flying of GRACE mission we have already demonstrated that ambiguity resolution plays a key role in order to improve quality of the relative orbit information between LEO satellites. Improvements of up to one order of magnitude in the relative orbit information can be expected when GRACE satellites are processed together. Here, we extend this approach to a network of LEO satellites and investigate combined ambiguity resolution for ground and LEO networks based on a new ambiguity resolution strategy. We show the first results and discuss performance of the new experimental IGS Final Products from ESA, making use of GPS measurements from several LEO missions, such as GRACE-A/B, JASON-2, GOCE, TerraSAR, Metop, etc. There is more LEO satellites to come in the near future carrying GNSS receivers, such as Swarm constellation, Sentinels and a number of altimetry satellites.

  14. Massive star formation within the Leo 'primordial' ring.

    Science.gov (United States)

    Thilker, David A; Donovan, Jennifer; Schiminovich, David; Bianchi, Luciana; Boissier, Samuel; de Paz, Armando Gil; Madore, Barry F; Martin, D Christopher; Seibert, Mark

    2009-02-19

    Few intergalactic, plausibly primordial clouds of neutral atomic hydrogen (H(i)) have been found in the local Universe, suggesting that such structures have either dispersed, become ionized or produced a stellar population on gigayear timescales. The Leo ring, a massive (M(H(i)) approximately 1.8 x 10(9)M[symbol: see text], M[symbol: see text] denoting the solar mass), 200-kpc-wide structure orbiting the galaxies M105 and NGC 3384 with a 4-Gyr period, is a candidate primordial cloud. Despite repeated atttempts, it has previously been seen only from H i emission, suggesting the absence of a stellar population. Here we report the detection of ultraviolet light from gaseous substructures of the Leo ring, which we attribute to recent massive star formation. The ultraviolet colour of the detected complexes is blue, implying the onset of a burst of star formation or continuous star formation of moderate (approximately 10(8)-yr) duration. Measured ultraviolet-visible photometry favours models with low metallicity (Z approximately Z[symbol: see text]/50-Z[symbol: see text]/5, Z[symbol: see text] denoting the solar metallicity), that is, a low proportion of elements heavier than helium, although spectroscopic confirmation is needed. We speculate that the complexes are dwarf galaxies observed during their formation, but distinguished by their lack of a dark matter component. In this regard, they resemble tidal dwarf galaxies, although without the enrichment preceding tidal stripping. If structures like the Leo ring were common in the early Universe, they may have produced a large, yet undetected, population of faint, metal-poor, halo-lacking dwarf galaxies.

  15. Theory, Practice, and Modernity: Leo Strauss on Rousseau's Epicureanism.

    Science.gov (United States)

    Holley, Jared

    2017-01-01

    This article reconstructs Leo Strauss's reading of Rousseau's Epicureanism to argue that his work is unified by an abiding concern with the problem of theory and practice. Strauss sought to clarify the distinction between theory and practice he considered a fundamental precondition of any properly philosophical reflection on political life, and he explained the pernicious obscuring of that distinction through a narrative tracing the modern modifications of classical Epicureanism. Strauss's critical history of modern political thought is thus part of his attempt to restore the classical distinction between theory and practice to the status of a philosophical problem in modernity.

  16. Los derrames de petróleo : Su impacto ambiental

    OpenAIRE

    Zlatar, Yerko

    1994-01-01

    Los yacimientos de hidrocarburos se localizan, en su mayoría, en lugares alejados de los centros de consumo o de las industrias de procesamiento (destilerías), por tanto el petróleo y sus derivados se transportan mediante embarcaciones de gran tonelaje. Casi el 50% de la flota mundial, que navega a través de las vías marítimas y fluviales, está compuesta por barcos cisternas (tanqueros) que trasladan miles de millones de metros cúbicos de hidrocarburos. Durante las operaciones de carga y desc...

  17. The Tectonics of Love in Leo Tolstoy’s Resurrection

    Directory of Open Access Journals (Sweden)

    Głąb Anna

    2016-09-01

    Full Text Available The text analyzes Leo Tolstoy’s Resurrection focusing on the feelings expressed in the novel. It focuses on: (I the ways in which the content of the novel is expressed through artistic means; (II Tolstoy’s anthropology; (III the notion of love presented by Ronald de Sousa in his last book Love. A Very Short Introduction: the difference between love and mood or emotion; the classification of love (philia, storge, agape, eros; the distinction between love and lust; love as a reason-free desire; and the notion of the historicity of love.

  18. Haemangiosarcoma in a captive Asiatic lion (Panthera leo persica

    Directory of Open Access Journals (Sweden)

    F. Vercammen

    2015-05-01

    Full Text Available A 2.7-year-old male captive Asiatic lion (Panthera leo persica died unexpectedly without preceding symptoms. Gross necropsy revealed liver and lung tumours, which proved to be haemangiosarcomas by histopathology. Some of the liver tumours were ruptured, leading to massive intra-abdominal haemorrhage and death. Haemangiosarcomas are rare in domestic and exotic felids, occurring in skin, thoracic-abdominal cavity and bones. Although these tumours mainly appear to be occurring in older cats, they are sometimes observed in younger animals, as in the present case. This is the first description of haemangiosarcoma in a young Asiatic lion.

  19. Reading Claude Lefort: Following the Footprints of Leo Strauss

    Directory of Open Access Journals (Sweden)

    Claudia Hilb

    2015-12-01

    Full Text Available It might seem outlandish to examine the theoretical links between the work of Claude Lefort, a left-wing French student of democracy, and Leo Strauss, the radical critic of modern mass democracy, usually associated with conservativism in North American political thought. Nonetheless, every reader of Lefort is certainly aware of his respect for Strauss’s reading of Machiavelli and for the Straussian insights into modern political thought. This article tries to make sense of Lefort’s dialogue with Strauss, both in its explicit and implicit aspects, focusing on the fundamental points of agreement and on the most relevant differences between the two authors.

  20. Can Telescopes Help Leo Satellites Dodge Most Lethal Impacts?

    Science.gov (United States)

    GUDIEL, ANDREA; Carroll, Joseph; Rowe, David

    2018-01-01

    Authors: Joseph Carroll and David RoweABSTRACT LEO objects are tracked by radar because it works day and night, in all weather. This fits military interest in potentially hostile objects. There is less interest in objects too small to be credible active threats. But accidental hypervelocity impact by even 5-10 mm objects can disable most LEO satellites. Such “cm-class” objects greatly outnumber objects of military interest, and will cause most accidental impact losses.Under good viewing conditions, a sunlit 5mm sphere with 0.15 albedo at 800 km altitude is a 19th magnitude object. A ground-based 0.5m telescope tracking it against a 20 mag/arcsec2 sky can see it in seconds, and provide population can be tracked frequently, accurately, and affordably enough to be avoided. The value of a conjunction warning service should scale with the number of lethal objects in its catalog. This should motivate a commercial service to find and catalog most lethal objects. There may already be >1 million such objects in LEO, nearly all debris fragments, mostly cm-class and at 600-1200 km altitude.Maintaining a ~million-item catalog requires a world-wide network of several dozen telescope sites with several telescopes at each site. Each telescope needs a mount capable of ~1,000,000 fast slews/year without wearing out.The paper discusses recent advances that make such a service far more feasible:1. Automated tasking and remote control of distributed telescope networks,2. Direct-drive mounts that can make millions of fast slews without wearing out,3. Telescope optics with low focal curvature that are in focus across large imagers,4. CMOS imagers with 95% peak QE and 1.5e- noise at 2E8 pix/sec readout rates,5. Methods for uncued detection of most lethal LEO debris (eg., >5 mm at 800 km),6. Initial orbit determination using 3 alt-az fixes made during the discovery pass,7. High-speed photometry to infer debris spin axis, to predict drag area changes,8. Better conjunction predictions

  1. ESEM modifications to LEO SUPRA 35 VP FESEM.

    Science.gov (United States)

    Dracopoulos, Vassileios; Danilatos, Gerasimos

    2013-01-01

    A LEO SUPRA 35 VP FESEM has been modified to significantly improve image quality in the low pressure mode of operation. It is further shown that the same conversion can allow the machine to operate also as a fully fledged environmental scanning electron microscope with specimen chamber pressures in excess of 2000 Pa. This is achieved by a diamagnetic insert with a thin pressure limiting aperture at the bottom of the pole-piece. The insert allows the use of various size apertures in addition to the existing 1 mm differential diaphragm. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Zwingli en Leo Jud se Zürichse Doopformulier | Storm | HTS ...

    African Journals Online (AJOL)

    The Zurich Baptismal Formulary of Zwingli and Leo Jud. The author expands on Zwingli and Leo Jud's Zurich order of baptism now to be discussed. The sacrament of baptism does not ensure salvation for the pious. All sinners can only be saved by the grace of God. The baptismal ceremony does not entitle the cleansing of ...

  3. Akadeemik Leo Jürgenson 100 / Avo Suurvärav

    Index Scriptorium Estoniae

    Suurvärav, Avo

    2001-01-01

    Eesti Teaduste Akadeemia, Tallinna Tehnikaülikool ja Tallinna Teadlaste Maja tähistasid tehnikateadlase, õppejõu, ehitusspetsialisti akadeemik Leo Jürgensoni 100. sünniaastapäeva. Tallinna Tehnikaülikoolis on avatud näitus "Akadeemik Leo Jürgenson 100"

  4. LeoA, B and C from Enterotoxigenic Escherichia coli (ETEC) Are Bacterial Dynamins

    DEFF Research Database (Denmark)

    Michie, Katharine A; Boysen, Anders; Low, Harry H

    2014-01-01

    Escherichia coli (ETEC) strain H10407 contains a GTPase virulence factor, LeoA, which is encoded on a pathogenicity island and has been shown to enhance toxin release, potentially through vesicle secretion. By sequence comparisons and X-ray structure determination we now identify LeoA as a bacter...

  5. Near-infrared Stellar Populations in the Metal-poor, Dwarf Irregular Galaxies Sextans A and Leo A

    Science.gov (United States)

    Jones, Olivia C.; Maclay, Matthew T.; Boyer, Martha L.; Meixner, Margaret; McDonald, Iain; Meskhidze, Helen

    2018-02-01

    We present JHK s observations of the metal-poor ([Fe/H] {10}-11 {M}ȯ {yr}}-1, confirming that metal-poor stars can form substantial amounts of dust. We also find tentative evidence for oxygen-rich dust formation at low metallicity, contradicting previous models that suggest oxygen-rich dust production is inhibited in metal-poor environments. The total rates of dust injection into the interstellar medium of Leo A and Sextans A are (8.2+/- 1.8)× {10}-9 {M}ȯ {yr}}-1 and (6.2+/- 0.2)× {10}-7 {M}ȯ {yr}}-1, respectively. The majority of this dust is produced by a few very dusty evolved stars and does not vary strongly with metallicity.

  6. Mass driver reaction engine characteristics and performance in earth orbital transfer missions

    Science.gov (United States)

    Snow, W. R.; Dunbar, R. S.

    1982-01-01

    Configurations of a typical mass driver reaction engine (MDRE) are presented and its use for delivery of payloads to geosynchronous orbit (GEO) from low earth orbit (LEO) is discussed. Basic rocket equations are developed for LEO to GEO round-trip missions using a single exhaust velocity. It is shown that exhaust velocities in the 5-10 km/sec range (specific impulse of 500-1000 sec) are well suited for mass drivers, minimizing the overall cost of missions. Payload delivery rate fractions show that there is little to be gained by stretching out LEO to GEO transfer times from 90 to 180 days. It therefore pays to use the shorter trip time, approximately doubling the amount of delivered payload during any fixed time of use of the MDRE.

  7. Model-Based GN and C Simulation and Flight Software Development for Orion Missions beyond LEO

    Science.gov (United States)

    Odegard, Ryan; Milenkovic, Zoran; Henry, Joel; Buttacoli, Michael

    2014-01-01

    For Orion missions beyond low Earth orbit (LEO), the Guidance, Navigation, and Control (GN&C) system is being developed using a model-based approach for simulation and flight software. Lessons learned from the development of GN&C algorithms and flight software for the Orion Exploration Flight Test One (EFT-1) vehicle have been applied to the development of further capabilities for Orion GN&C beyond EFT-1. Continuing the use of a Model-Based Development (MBD) approach with the Matlab®/Simulink® tool suite, the process for GN&C development and analysis has been largely improved. Furthermore, a model-based simulation environment in Simulink, rather than an external C-based simulation, greatly eases the process for development of flight algorithms. The benefits seen by employing lessons learned from EFT-1 are described, as well as the approach for implementing additional MBD techniques. Also detailed are the key enablers for improvements to the MBD process, including enhanced configuration management techniques for model-based software systems, automated code and artifact generation, and automated testing and integration.

  8. Radiated EMC& EMI Management During Design Qualification and Test Phases on LEO Satellites Constellation

    Science.gov (United States)

    Blondeaux, H.; Terral, M.; Gutierrez-Galvan, R.; Baud, C.

    2016-05-01

    The aim of the proposed paper is to present the global radiated EMC/EMI approach applied by Thales Alenia Space in the frame of a telecommunication Low Earth Orbit (LEO) satellites constellation program. The paper will present this approach in term of analyses, of specific characterisation and of sub-system and satellite tests since first design reviews up-to satellite qualification tests on Prototype Flight Model (PFM) and to production tests on reduced FMs. The global aim is : 1 - to reduce risk and cost (units EMC delta qualification, EMC tests at satellite level for the 81 Space Vehicles (SV) through appropriated EMC analyses (in term of methodologies and contours) provided in the frame of design reviews.2 - to early anticipate potential critical case to reduce the impact in term of engineering/qualification/test extra cost and of schedule.3 - to secure/assure the payload and SV design/layout.4 - to define and optimize the EMC/EMI test campaigns to be performed on Prototype Flight Model (PFM) for complete qualification and on some FMs for industrial qualification/validation.The last part of the paper is dedicated to system Bite Error Rate (BER) functional test performed on PFM SV to demonstrate the final compatibility between the three on-board payloads and to the Internal EMC tests performed on PFM and some FMs to demonstrate the SV panel RF shielding efficiency before and after environmental tests and the Thales Alenia Space (TAS) and Orbital AKT (OATK) workmanships reproducibility.

  9. PREACHER AS A CHARACTER IN THE CREATIVE WORK OF LEO TOLSTOY AND GEORGE ELIOT

    Directory of Open Access Journals (Sweden)

    Irina Fedorovna Gnyusova

    2014-11-01

    Full Text Available The article analyzes characters of clergymen and the process of creating a specifi c type of a preacher in Leo Tolstoy’s works. The researcher tries to prove that this process was strongly infl uenced by Tolstoy’s close attention to the preacher characters in George Eliot’s works. This can be proved by Tolstoy’s letters, diary and notes in the books from the writer’s personal library. The main features of Tolstoy’s preacher character are demonstrated by the example of Prince Nekhlyudov (Resurrection. Proclaiming evangelical truth, he is not a member of any confession; he does not promulgate his views, but he proves his case by his actions and his way of life. He rejects earthly comfort and goods and voluntarily becomes integrated into people’s life. Having walked his way of repentance of former sins, he cultivates the ability to forgive and have mercy. George Eliot also accents these features in the key characters of her books, analyzed in this article (Janet’s repentance, Adam Bede and Felix Holt, the Radical. Eliot’s version of preaching becomes a certain guide for Tolstoy in the process of shaping a new type of character in his late works.

  10. Analysis of MIR-18 results for physical and biological dosimetry: radiation shielding effectiveness in LEO

    Science.gov (United States)

    Cucinotta, F. A.; Wilson, J. W.; Williams, J. R.; Dicello, J. F.

    2000-01-01

    We compare models of radiation transport and biological response to physical and biological dosimetry results from astronauts on the Mir space station. Transport models are shown to be in good agreement with physical measurements and indicate that the ratio of equivalent dose from the Galactic Cosmic Rays (GCR) to protons is about 3/2:1 and that this ratio will increase for exposures to internal organs. Two biological response models are used to compare to the Mir biodosimetry for chromosome aberration in lymphocyte cells; a track-structure model and the linear-quadratic model with linear energy transfer (LET) dependent weighting coefficients. These models are fit to in vitro data for aberration formation in human lymphocytes by photons and charged particles. Both models are found to be in reasonable agreement with data for aberrations in lymphocytes of Mir crew members: however there are differences between the use of LET dependent weighting factors and track structure models for assigning radiation quality factors. The major difference in the models is the increased effectiveness predicted by the track model for low charge and energy ions with LET near 10 keV/micrometers. The results of our calculations indicate that aluminum shielding, although providing important mitigation of the effects of trapped radiation, provides no protective effect from the galactic cosmic rays (GCR) in low-earth orbit (LEO) using either equivalent dose or the number of chromosome aberrations as a measure until about 100 g/cm 2 of material is used.

  11. Influence of the ionospheric model on DCB computation and added value of LEO satellites

    Science.gov (United States)

    Wautelet, Gilles; Lestarquit, Laurent; Loyer, Sylvain; Mercier, Flavien; Perosanz, Félix

    2016-04-01

    In order to compute inter-frequency Differential Code Biases (DCBs), the Geometry-Free combination of a GNSS signal pair needs to be corrected from the ionospheric refraction effect. Such information is obtained using either Global Ionospheric Maps (GIMs) or local models. In this work we investigate the influence of GIMs on the final value and precision of DCB solution. The study covers different ionospheric conditions, ranging from very quiet ionospheric background up to a severe ionospheric storm. In a first step, the Slant Total Electron Content (STEC) between GIMs is assessed as a function of receiver latitude, elevation mask and ionospheric conditions. Then, daily DCBs are estimated using these different GIMs, receiver and satellite contributions being separated using a zero-mean constraint. If the precision of satellite DCBs is clearly dependent on ionospheric conditions and of the observing network, the choice of the GIM seems also to have a non negligible impact. At last, an independent estimation of DCBs is performed using Low Earth Orbit (LEO) observations (such as JASON's GPS data). This solution is compared with our ground network solution and with DCBs coming from the International GNSS Service.

  12. Growth and characterization of AlxGa1-xN LEO substrates

    International Nuclear Information System (INIS)

    Paek, H.S.; Sakong, T.; Lee, S.N.; Son, J.K.; Ryu, H.Y.; Nam, O.H.; Park, Y.

    2006-01-01

    We have studied the effect of Al composition on the properties of Al x Ga 1-x N LEO substrates. Al x Ga 1-x N LEO substrates were prepared on stripe-patterned 2μm-thick undoped GaN/sapphire substrates by metalorganic chemical vapor deposition. To investigate the dislocation and crack density, and the surface morphology of Al x Ga 1-x N LEO substrates with different Al compositions, photoluminescence and optical microscope were used. At a 1% of Al composition, we obtained crack-free and mirror-like substrates having a low dislocation density of ∼1E6cm -2 . We expect considerable reduction in threshold current density to be achieved from blue-violet laser diodes grown on Al x Ga 1-x N LEO substrates because of the increased optical gain, as compared to the laser diodes grown on Al-free LEO substrates

  13. Uncontrolled re-entry of satellite parts after finishing their mission in LEO: Titanium alloy degradation by thermite reaction energy

    Science.gov (United States)

    Monogarov, K. A.; Pivkina, A. N.; Grishin, L. I.; Frolov, Yu. V.; Dilhan, D.

    2017-06-01

    Analytical and experimental studies conducted at Semenov Institute of Chemical Physics for investigating the use of pyrotechnic compositions, i.e., thermites, to reduce the risk of the fall of thermally stable parts of deorbiting end-of-life LEO satellites on the Earth are described. The main idea was the use of passive heating during uncontrolled re-entry to ignite thermite composition, fixed on the titanium surface, with the subsequent combustion energy release to be sufficient to perforate the titanium cover. It is supposed, that thus destructed satellite parts will lose their streamline shape, and will burn out being aerodynamically heated during further descending in atmosphere (patent FR2975080). On the base of thermodynamic calculations the most promising thermite compositions have been selected for the experimental phase. The unique test facilities have been developed for the testing of the efficiency of thermite charges to perforate the titanium TA6V cover of 0.8 mm thickness under temperature/pressure conditions duplicated the uncontrolled re-entry of titanium tank after its mission on LEO. Experiments with the programmed laser heating inside the vacuum chamber revealed the only efficient thermite composition among preliminary selected ones to be Al/Co3O4. Experimental searching of the optimal aluminum powder between spherical and flaked nano- and micron-sized ones revealed the possibility to adjust the necessary ignition delay time, according to the titanium cover temperature dependency on deorbiting time. For the titanium tank the maximum temperature is 1100 °C at altitude 68 km and pressure 60 Pa. Under these conditions Al/Co3O4 formulations with nano-Al spherical particles provide the ignition time to be 13.3 s, and ignition temperature as low as 592±5 °C, whereas compositions with the micron-sized spherical Al powder reveal these values to be much higher, i.e., 26.3 s and 869±5 °C, respectively. The analytical and experimental studies described

  14. Environmental Durability Issues for Solar Power Systems in Low Earth Orbit

    Science.gov (United States)

    Degroh, Kim K.; Banks, Bruce A.; Smith, Daniela C.

    1994-01-01

    Space solar power systems for use in the low Earth orbit (LEO) environment experience a variety of harsh environmental conditions. Materials used for solar power generation in LEO need to be durable to environmental threats such as atomic oxygen, ultraviolet (UV) radiation, thermal cycling, and micrometeoroid and debris impact. Another threat to LEO solar power performance is due to contamination from other spacecraft components. This paper gives an overview of these LEO environmental issues as they relate to space solar power system materials. Issues addressed include atomic oxygen erosion of organic materials, atomic oxygen undercutting of protective coatings, UV darkening of ceramics, UV embrittlement of Teflon, effects of thermal cycling on organic composites, and contamination due to silicone and organic materials. Specific examples of samples from the Long Duration Exposure Facility (LDEF) and materials returned from the first servicing mission of the Hubble Space Telescope (HST) are presented. Issues concerning ground laboratory facilities which simulate the LEO environment are discussed along with ground-to-space correlation issues.

  15. New Conditions for a Total Neutrino Conversion in a Medium

    OpenAIRE

    Chizhov, M. V.; Petcov, S. T.

    1999-01-01

    A new effect of total neutrino conversion is possible when neutrino propagates through multi-layer medium of nonperiodic constant density layers. The effect can take place in the oscillations in the Earth of the Earth-core-crossing solar and atmospheric neutrinos.

  16. THE LOCAL LEO COLD CLOUD AND NEW LIMITS ON A LOCAL HOT BUBBLE

    International Nuclear Information System (INIS)

    Peek, J. E. G.; Heiles, Carl; Peek, Kathryn M. G.; Meyer, David M.; Lauroesch, J. T.

    2011-01-01

    We present a multi-wavelength study of the local Leo cold cloud (LLCC), a very nearby, very cold cloud in the interstellar medium (ISM). Through stellar absorption studies we find that the LLCC is between 11.3 pc and 24.3 pc away, making it the closest known cold neutral medium cloud and well within the boundaries of the local cavity. Observations of the cloud in the 21 cm H I line reveal that the LLCC is very cold, with temperatures ranging from 15 K to 30 K, and is best fit with a model composed of two colliding components. The cloud has associated 100 μm thermal dust emission, pointing to a somewhat low dust-to-gas ratio of 48 x10 -22 MJy sr -1 cm 2 . We find that the LLCC is too far away to be generated by the collision among the nearby complex of local interstellar clouds but that the small relative velocities indicate that the LLCC is somehow related to these clouds. We use the LLCC to conduct a shadowing experiment in 1/4 keV X-rays, allowing us to differentiate between different possible origins for the observed soft X-ray background (SXRB). We find that a local hot bubble model alone cannot account for the low-latitude SXRB, but that isotropic emission from solar wind charge exchange (SWCX) does reproduce our data. In a combined local hot bubble and SWCX scenario, we rule out emission from a local hot bubble with an 1/4 keV emissivity greater than 1.1 Snowdens pc -1 at 3σ, four times lower than previous estimates. This result dramatically changes our perspective on our local ISM.

  17. Rare earths

    International Nuclear Information System (INIS)

    Cranstone, D.A.

    1980-01-01

    There has been no Canadian production of the rare earth oxides since 1977. World production in 1978, the last year for which figures are available, is estimated to have been about 41000 tonnes, mostly from Australia and the United States. The United States Bureau of Mines estimates that world reserves contain about 7 million tonnes of rare earth oxides and 35 million tonnes of yttrium. The largest yttrium reserves are in India, while China is believed to have the world's largest reserves of rare earth oxides. World consumption of rare aarths increased slightly in 1980, but is still only a small fraction of known reserves. Rare earths are used mainly in high-strength magnets, automobile exhaust systems, fluorescent tube and television screen phosphors, metallurgical applications, petroleum cracking catalysts, and glass polishing

  18. Earth Sciences

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    The following papers were presented at the earth science session: earth science developments in support of water isolation; development of models and parameters for ground-water flow in fractured rock masses; isotope geochemistry as a tool for determining regional ground-water flow; natural analogs of radionuclide migration; nuclide retardation data: its use in the NWTS program; and ground-water geochemistry and interaction with basalt at Hanford

  19. Earth materials and earth dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, K; Shankland, T. [and others

    2000-11-01

    In the project ''Earth Materials and Earth Dynamics'' we linked fundamental and exploratory, experimental, theoretical, and computational research programs to shed light on the current and past states of the dynamic Earth. Our objective was to combine different geological, geochemical, geophysical, and materials science analyses with numerical techniques to illuminate active processes in the Earth. These processes include fluid-rock interactions that form and modify the lithosphere, non-linear wave attenuations in rocks that drive plate tectonics and perturb the earth's surface, dynamic recrystallization of olivine that deforms the upper mantle, development of texture in high-pressure olivine polymorphs that create anisotropic velocity regions in the convecting upper mantle and transition zone, and the intense chemical reactions between the mantle and core. We measured physical properties such as texture and nonlinear elasticity, equation of states at simultaneous pressures and temperatures, magnetic spins and bonding, chemical permeability, and thermal-chemical feedback to better characterize earth materials. We artificially generated seismic waves, numerically modeled fluid flow and transport in rock systems and modified polycrystal plasticity theory to interpret measured physical properties and integrate them into our understanding of the Earth. This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL).

  20. RITD - Adapting Mars Entry, Descent and Landing System for Earth

    Science.gov (United States)

    Haukka, H.; Heilimo, J.; Harri, A.-M.; Aleksashkin, S.; Koryanov, V.; Arruego, I.; Schmidt, W.; Finchenko, V.; Martynov, M.; Ponomarenko, A.; Kazakovtsev, V.; Martin, S.

    2015-10-01

    We have developed an atmospheric re-entry and descent system concept based on inflatable hypersonic decelerator techniques that were originally developed for Mars. The ultimate goal of this EU-funded RITD-project (Re-entry: Inflatable Technology Development) was to assess the benefits of this technology when deploying small payloads from low Earth orbits to the surface of the Earth with modest costs. The principal goal was to assess and develop a preliminary EDLS design for the entire relevant range of aerodynamic regimes expected to be encountered in Earth's atmosphere during entry, descent and landing. Low Earth Orbit (LEO) and even Lunar applications envisaged include the use of the EDLS approach in returning payloads of 4-8 kg down to the surface.

  1. Might electrical earthing affect convection of light

    International Nuclear Information System (INIS)

    Budrikis, Z.L.

    1982-01-01

    Partial convection of light by moving media was predicted by Fresnel and verified by Fizeau, Zeeman and others. It is accepted as an important argument in favour of the Special Theory of Relativity. The suggestion is made here that the convection is partial only when the propagating medium is moved with respect to its electrically earthed surroundings and that it would be total if an earthed shield was co-moving with the medium. This is based on a reinterpretation of Maxwell's equations wherein they are seen as macroscopic relationships that are in each case valid only in respect of a particular inertial frame of reference, the local electrical earth frame. (Auth.)

  2. THE ARECIBO LEGACY FAST ALFA SURVEY. IX. THE LEO REGION H I CATALOG, GROUP MEMBERSHIP, AND THE H I MASS FUNCTION FOR THE LEO I GROUP

    International Nuclear Information System (INIS)

    Stierwalt, Sabrina; Haynes, Martha P.; Giovanelli, Riccardo; Martin, Ann M.; Kent, Brian R.; Saintonge, Amelie; Karachentsev, Igor D.; Karachentseva, Valentina E.

    2009-01-01

    We present the catalog of H I sources extracted from the ongoing Arecibo Legacy Fast ALFA (ALFALFA) extragalactic H I line survey, found within the sky region bounded by 9 h 36 m h 36 m and +08 0 0 . The H I catalog presented here for this 118 deg 2 region is combined with the ones derived from surrounding regions also covered by the ALFALFA survey to examine the large-scale structure in the complex Leo region. Because of the combination of wide sky coverage and superior sensitivity, spatial and spectral resolution, the ALFALFA H I catalog of the Leo region improves significantly on the numbers of low H I mass sources as compared with those found in previous H I surveys. The H I mass function of the Leo I group presented here is dominated by low-mass objects: 45 of the 65 Leo I members have M H I 8 M-odot, yielding tight constraints on the low-mass slope of the Leo I H I mass function. The best-fit slope is α ≅ -1.41 + 0.2 - 0.1. A direct comparison between the ALFALFA H I line detections and an optical search of the Leo I region proves the advantage of the ALFALFA strategy in finding low-mass, gas-rich dwarfs. These results suggest the existence of a significant population of low surface brightness, gas-rich, yet still very low H I mass galaxies, and may reflect the same type of morphological segregation as is seen in the Local Group. While the low-mass end slope of the Leo I H I mass function is steeper than that determined for luminosity functions of the group, the slope still falls short of the values predicted by simulations of structure formation in the lambda cold dark matter paradigm.

  3. Assessing the Impact of Earth Radiation Pressure Acceleration on Low-Earth Orbit Satellites

    Science.gov (United States)

    Vielberg, Kristin; Forootan, Ehsan; Lück, Christina; Kusche, Jürgen; Börger, Klaus

    2017-04-01

    The orbits of satellites are influenced by several external forces. The main non-gravitational forces besides thermospheric drag, acting on the surface of satellites, are accelerations due to the Earth and Solar Radiation Pres- sure (SRP and ERP, respectively). The sun radiates visible and infrared light reaching the satellite directly, which causes the SRP. Earth also emits and reflects the sunlight back into space, where it acts on satellites. This is known as ERP acceleration. The influence of ERP increases with decreasing distance to the Earth, and for low-earth orbit (LEO) satellites ERP must be taken into account in orbit and gravity computations. Estimating acceler- ations requires knowledge about energy emitted from the Earth, which can be derived from satellite remote sensing data, and also by considering the shape and surface material of a satellite. In this sensitivity study, we assess ERP accelerations based on different input albedo and emission fields and their modelling for the satellite missions Challenging Mini-Satellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE). As input fields, monthly 1°x1° products of Clouds and the Earth's Radiant En- ergy System (CERES), L3 are considered. Albedo and emission models are generated as latitude-dependent, as well as in terms of spherical harmonics. The impact of different albedo and emission models as well as the macro model and the altitude of satellites on ERP accelerations will be discussed.

  4. Os Óleos Essenciais de Piper reticulatum L. e P. crassinervium H. B. K.

    OpenAIRE

    LUZ,Arnaldo Iran R.; ZOGHBI,Maria das Graças B.; MAIA,José Guilherme S.

    2003-01-01

    Os óleos essenciais das folhas e galhos finos de Piper reticulatum e de P. crassinervium, coletados na região norte do Brasil, foram obtidos por arraste à vapor e analisados através de GC/MS. O óleo de P. reticulatum é constituido principalmente por β-elemeno (24,6%) e β-cariofileno (16,7%). Os principais compostos identificados no óleo de P. crassinervium foramβ-cariofileno (17,7%), γ-elemeno (14,4%) e β-elemeno (10,9%).

  5. Cranial malformations in related white lions (Panthera leo krugeri).

    Science.gov (United States)

    Scaglione, F E; Schröder, C; Degiorgi, G; Zeira, O; Bollo, E

    2010-11-01

    White lions (Panthera leo krugeri) have never been common in the wild, and at present, the greatest population is kept in zoos where they are bred for biological and biodiversity conservation. During the years 2003 to 2008 in a zoological garden in northern Italy, 19 white lions were born to the same parents, who were in turn paternally consanguineous. Out of the 19 lions, 4 (21%) were stillborn, 13 (69%) died within 1 month, and 1 (5%) was euthanatized after 6 months because of difficulty with prehension of food. Six lions (32%) showed malformations involving the head (jaw, tongue, throat, teeth, and cranial bones). One lion (5%) still alive at 30 months revealed an Arnold-Chiari malformation upon submission for neurological evaluation of postural and gait abnormalities. Paternal consanguinity of the parents, along with inbreeding among white lions in general, could account for the high incidence of congenital malformations of the head in this pride of white lions.

  6. Blood platelet counts, morphology and morphometry in lions, Panthera leo.

    Science.gov (United States)

    Du Plessis, L

    2009-09-01

    Due to logistical problems in obtaining sufficient blood samples from apparently healthy animals in the wild in order to establish normal haematological reference values, only limited information regarding the blood platelet count and morphology of free-living lions (Panthera leo) is available. This study provides information on platelet counts and describes their morphology with particular reference to size in two normal, healthy and free-ranging lion populations. Blood samples were collected from a total of 16 lions. Platelet counts, determined manually, ranged between 218 and 358 x 10(9)/l. Light microscopy showed mostly activated platelets of various sizes with prominent granules. At the ultrastructural level the platelets revealed typical mammalian platelet morphology. However, morphometric analysis revealed a significant difference (P < 0.001) in platelet size between the two groups of animals. Basic haematological information obtained in this study may be helpful in future comparative studies between animals of the same species as well as in other felids.

  7. Doramectin toxicity in a group of lions (Panthera leo).

    Science.gov (United States)

    Lobetti, Remo G; Caldwell, Peter

    2012-10-15

    Ten lions (Panthera leo) that were treated with a single injection of doramectin at a dose ranging between 0.2 mg/kg and 0.5 mg/kg showed clinical signs consistent with avermectin toxicity, namely ataxia, hallucinations, and mydriasis. Two subsequently died whereas the other eight lions recovered after 4-5 days with symptomatic therapy. Post-mortem examinations of the two that died showed cyanosis, severe pulmonary oedema, pleural effusion, and pericardial effusion, with histopathology not revealing any abnormalities. In both these lions, doramectin brain and liver tissue concentrations were elevated. Although doramectin is regularly used in wild felids, to date there have been no reports of avermectin toxicity in the literature. This article highlights the potential for doramectin toxicity in this species.

  8. CLINICOPATHOLOGIC FEATURES OF MAMMARY MASSES IN CAPTIVE LIONS (PANTHERA LEO).

    Science.gov (United States)

    Sadler, Ryan A; Craig, Linden E; Ramsay, Edward C; Helmick, Kelly; Collins, Darin; Garner, Michael M

    2016-03-01

    A multi-institutional retrospective analysis of 330 pathology accessions from 285 different lions found 15 captive, female African lions (Panthera leo) with confirmed mammary masses. Aside from the presence of a mammary mass, the most common initial clinical sign was inappetence. Histologic diagnoses were predominantly adenocarcinoma (n = 12), though two benign masses (mammary hyperplasia and a mammary cyst) and one squamous cell carcinoma were identified. Nine of 13 malignant tumors had metastasized to lymph nodes or viscera at the time of necropsy. Six lions with adenocarcinoma and two lions with benign mammary masses had received hormonal contraception, though little evidence of mammary lobular hyperplasia was seen in association with the adenocarcinomas. The most common concurrent disease processes found at necropsy were chronic urinary tract disease and other malignancies. These cases demonstrate that mammary malignancies occur in captive lions and frequently metastasize.

  9. Hadrons in medium

    Indian Academy of Sciences (India)

    medium properties of hadrons. I discuss the relevant symmetries of QCD and how they might affect the observed hadron properties. I then discuss at length the observable consequences of in-medium changes of hadronic properties in reactions with ...

  10. Medium is the message

    NARCIS (Netherlands)

    Kuipers, G.; Ritzer, G.

    2012-01-01

    "The medium is the message" is a phrase coined by Canadian media theorist Marshall McLuhan (1911-1980), in his book Understanding Media: The Extensions of Man (1964). In this book, McLuhan examines the impact of media on societies and human relations, arguing for the primacy of the medium -

  11. Simulation of Earth-Moon-Mars Environments for the Assessment of Organ Doses

    Science.gov (United States)

    Kim, Myung-Hee; Schwadron, Nathan; Townsend, Lawrence W.; Cucinotta, Francis A.

    2010-01-01

    Space radiation environments for historically large solar particle events (SPE) and galactic cosmic rays (GCR) at solar minimum and solar maximum are simulated in order to characterize exposures to radio-sensitive organs for missions to low-Earth orbit (LEO), moon, and Mars. Primary and secondary particles for SPE and GCR are transported through the respective atmosphere of Earth or Mars, space vehicle, and astronaut s body tissues using the HZETRN/QMSFRG computer code. In LEO, exposures are reduced compared to deep space because particles are deflected by the Earth s magnetic field and absorbed by the solid body of the Earth. Geomagnetic transmission function as a function of altitude was applied for the particle flux of charged particles, and the shift or the organ exposures to higher velocity or lower stopping powers compared to those in deep space were analyzed. In the transport through Mars atmosphere, a vertical distribution of atmospheric thickness was calculated from the temperature and pressure data of Mars Global Surveyor, and the directional cosine distribution was implemented to describe the spherically distributed atmospheric distance along the slant path at each altitude. The resultant directional shielding by Mars atmosphere at solar minimum and solar maximum was used for the particle flux simulation at various altitudes on the Martian surface. Finally, atmospheric shielding was coupled with vehicle and body shielding for organ dose estimates. We made predictions of radiation dose equivalents and evaluated acute symptoms at LEO, moon, and Mars at solar minimum and solar maximum.

  12. Digital Earth - A sustainable Earth

    Science.gov (United States)

    Mahavir

    2014-02-01

    All life, particularly human, cannot be sustainable, unless complimented with shelter, poverty reduction, provision of basic infrastructure and services, equal opportunities and social justice. Yet, in the context of cities, it is believed that they can accommodate more and more people, endlessly, regardless to their carrying capacity and increasing ecological footprint. The 'inclusion', for bringing more and more people in the purview of development is often limited to social and economic inclusion rather than spatial and ecological inclusion. Economic investment decisions are also not always supported with spatial planning decisions. Most planning for a sustainable Earth, be at a level of rural settlement, city, region, national or Global, fail on the capacity and capability fronts. In India, for example, out of some 8,000 towns and cities, Master Plans exist for only about 1,800. A chapter on sustainability or environment is neither statutorily compulsory nor a norm for these Master Plans. Geospatial technologies including Remote Sensing, GIS, Indian National Spatial Data Infrastructure (NSDI), Indian National Urban Information Systems (NUIS), Indian Environmental Information System (ENVIS), and Indian National GIS (NGIS), etc. have potential to map, analyse, visualize and take sustainable developmental decisions based on participatory social, economic and social inclusion. Sustainable Earth, at all scales, is a logical and natural outcome of a digitally mapped, conceived and planned Earth. Digital Earth, in fact, itself offers a platform to dovetail the ecological, social and economic considerations in transforming it into a sustainable Earth.

  13. Added value of online satellite data transmission for flood forecasting: warning systems in medium-size catchments.

    Science.gov (United States)

    Ruch, C; Stadler, H

    2009-01-01

    The present paper deals with the implementation of online data transferred via LEO satellite communication in a flood forecasting system. Although the project is ongoing, it is already recognised that the information chain: "measurement-transmission-forecast-alert" can be shortened, i.e., the flood danger can be more rapidly communicated to the population at risk. This gain is particularly valuable for medium size catchments where the concentration time (basin time of response to rainfall) is short.

  14. A new system to quantify uncertainties in LEO satellite position determination due to space weather events

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a new system for quantitative assessment of uncertainties in LEO satellite position caused by storm time changes in space environmental...

  15. Narratiivsuse probleem kaasaaegses arhitektuurihistoriograafias : Mõned võimalused Leo Gensi arhitektuurikirjutuse lugemiseks / Epp Lankots

    Index Scriptorium Estoniae

    Lankots, Epp, 1976-

    2010-01-01

    Käsitletakse 20. sajandi moodsa arhitektuuri ajaloo tekstide lugemisvõimalusi kriitilise historiograafia valguses. Vaadeldakse Leo Gensi kui peamise nõukogudeaegsest arhitektuurist kirjutanud ajaloolase ja kriitiku tekstistrateegiaid. Ka tema ajalootekstide võrdlusi tunduvalt teravamate ajakirjanduslike tekstidega

  16. Composição do óleo essencial de Sinningia aggregata

    Directory of Open Access Journals (Sweden)

    M.E.A. Stefanello

    Full Text Available O óleo essencial de Sinningia aggregata (Ker. Gawl. Wiehler (Gesneriaceae foi extraído por hidrodestilação e analisado por CG e CG/EM. Foram identificados 17 compostos, representando 91,8% do óleo. O óleo é constituído principalmente por compostos alifáticos de cadeia longa (49,8% e sesquiterpenos oxigenados (40,2%. Os principais componentes foram: linoleato de metila (28,4%, 1-octadecanol (16,9%, acetato de (Z-nerolidila (8,8%, espatulenol (7,8% e (E-nerolidol (6,7%. Monoterpenos e fenilpropanóides não foram encontrados. Este é o primeiro relato de estudo de óleo essencial na família Gesneriaceae.

  17. Efeito fungitóxico in vitro do óleo resina e do óleo essencial de copaíba (Copaifera multijuga Hayne)

    OpenAIRE

    Deus,R.J.A.; Carvalho,A.S.C.; Banna,D.A.D.S.; Arruda,M.S.P.; Alves,C.N.; Santos,A.S.

    2009-01-01

    Óleo de Copaifera multijuga Hayne, in natura e as frações foram avaliadas quanto às atividades fungitóxicas in vitro, frente a cinco espécies de fungos filamentosos do gênero Aspergillus e três espécies de leveduras do gênero Candida. Concentrações de óleo resina e de óleo essencial na faixa de 0,08 mg mL-1 a 1,6 mg mL-1 foram usadas para as análises qualitativa e quantitativas. As amostras foram dispostas sobre discos de papel de 5 mm de diâmetro e distribuídos sobre o meio Saboraud em placa...

  18. Local interstellar medium

    International Nuclear Information System (INIS)

    Crutcher, R.M.; and Radio Astronomy Laboratory, University of California, Berkeley)

    1982-01-01

    Analysis of the velocities of optical interstellar lines shows that the Sun is immersed in a coherently moving local interstellar medium whose velocity vector agrees with that of the interstellar wind observed through backscatter of solar H Lyα and He lambda584 photons. The local interstellar medium consists of both cool clouds and warm intercloud medium gas, has a mass of perhaps approx.30 M/sub sun/, does not have severe depletion of trace elements from the gas phase, and appears to be material which has been shocked and accelerated by stellar winds and supernovae associated with the Sco-Oph OB association

  19. A DEEPER LOOK AT LEO IV: STAR FORMATION HISTORY AND EXTENDED STRUCTURE

    International Nuclear Information System (INIS)

    Sand, David J.; Seth, Anil; Olszewski, Edward W.; Zaritsky, Dennis; Willman, Beth; Kallivayalil, Nitya

    2010-01-01

    We present MMT/Megacam imaging of the Leo IV dwarf galaxy in order to investigate its structure and star formation history, and to search for signs of association with the recently discovered Leo V satellite. Based on parameterized fits, we find that Leo IV is round, with ε h ≅ 130 pc. Additionally, we perform a thorough search for extended structures in the plane of the sky and along the line of sight. We derive our surface brightness detection limit by implanting fake structures into our catalog with stellar populations identical to that of Leo IV. We show that we are sensitive to stream-like structures with surface brightness μ r ∼ -2 , and at this limit we find no stellar bridge between Leo IV (out to a radius of ∼0.5 kpc) and the recently discovered, nearby satellite Leo V. Using the color-magnitude fitting package StarFISH, we determine that Leo IV is consistent with a single age (∼14 Gyr), single metallicity ([Fe/H] ∼ -2.3) stellar population, although we cannot rule out a significant spread in these values. We derive a luminosity of M V = -5.5 ± 0.3. Studying both the spatial distribution and frequency of Leo IV's 'blue plume' stars reveals evidence for a young (∼2 Gyr) stellar population which makes up ∼2% of its stellar mass. This sprinkling of star formation, only detectable in this deep study, highlights the need for further imaging of the new Milky Way satellites along with theoretical work on the expected, detailed properties of these possible 'reionization fossils'.

  20. LEO to GEO (and Beyond) Transfers Using High Power Solar Electric Propulsion (HP-SEP)

    Science.gov (United States)

    Loghry, Christopher S.; Oleson, Steven R.; Woytach, Jeffrey M.; Martini, Michael C.; Smith, David A.; Fittje, James E.; Gyekenyesi, John Z.; Colozza, Anthony J.; Fincannon, James; Bogner, Aimee; hide

    2017-01-01

    Rideshare, or Multi-Payload launch configurations, are becoming more and more commonplace but access to space is only one part of the overall mission needs. The ability for payloads to achieve their target orbits or destinations can still be difficult and potentially not feasible with on-board propulsion limitations. The High Power Solar Electric Propulsion (HP-SEP) Orbital Maneuvering Vehicle (OMV) provides transfer capabilities for both large and small payload in excess of what is possible with chemical propulsion. Leveraging existing secondary payload adapter technology like the ESPA provides a platform to support Multi-Payload launch and missions. When coupled with HP-SEP, meaning greater than 30 kW system power, very large delta-V maneuvers can be accomplished. The HP-SEP OMV concept is designed to perform a Low Earth Orbit to Geosynchronous Orbit (LEO-GEO) transfer of up to six payloads each with 300kg mass. The OMV has enough capability to perform this 6 kms maneuver and have residual capacity to extend an additional transfer from GEO to Lunar orbit. This high deltaV capability is achieved using state of the art 12.5kW Hall Effect Thrusters (HET) coupled with high power roll up solar arrays. The HP-SEP OMV also provides a demonstration platform for other SEP technologies such as advanced Power Processing Units (PPU), Xenon Feed Systems (XFS), and other HET technologies. The HP-SEP OMV platform can be leveraged for other missions as well such as interplanetary science missions and applications for resilient space architectures.

  1. HIRENASD medium unstructured

    Data.gov (United States)

    National Aeronautics and Space Administration — Unstructured HIRENASD mesh: - medium size (16 million nodes, 39 million elements) - for node centered solvers - 31.05.2011 - caution: dimensions in mm

  2. Concept medium programme

    DEFF Research Database (Denmark)

    Bjerrum, Peter

    2005-01-01

    The present essay is an attempt to determine the architectural project of the 21st century in relation to a modern conception of space as the medium of architecture, and of sociality as its program...

  3. Concept medium programme

    DEFF Research Database (Denmark)

    Bjerrum, Peter

    2005-01-01

    The present essay is an attempt to determine the architectural project of the 21st century in relation to a modern conception of space as the medium of architecture, and of sociality as its program......The present essay is an attempt to determine the architectural project of the 21st century in relation to a modern conception of space as the medium of architecture, and of sociality as its program...

  4. Simulation of the synergistic low Earth orbit effects of vacuum thermal cycling, vacuum UV radiation, and atomic oxygen

    Science.gov (United States)

    Dever, Joyce A.; Degroh, Kim K.; Stidham, Curtis R.; Stueber, Thomas J.; Dever, Therese M.; Rodriguez, Elvin; Terlep, Judith A.

    1992-01-01

    In order to assess the low Earth orbit (LEO) durability of candidate space materials, it is necessary to use ground laboratory facilities which provide LEO environmental effects. A facility combining vacuum thermal cycling and vacuum ultraviolet (VUV) radiation has been designed and constructed at NASA Lewis Research Center for this purpose. This facility can also be operated without the VUV lamps. An additional facility can be used to provide VUV exposure only. By utilizing these facilities, followed by atomic oxygen exposure in an RF plasma asher, the effects of the individual vacuum thermal cycling and VUV environments can be compared to the effect of the combined vacuum thermal cycling/VUV environment on the atomic oxygen durability of materials. The synergistic effects of simulated LEO environmental conditions on materials were evaluated by first exposing materials to vacuum thermal cycling, VUV, and vacuum thermal cycling/VUV environments followed by exposure to atomic oxygen in an RP plasma asher. Candidate space power materials such as atomic oxygen protected polyimides and solar concentrator mirrors were evaluated using these facilities. Characteristics of the Vacuum Thermal Cycling/VUV Exposure Facility which simulates the temperature sequences and solar ultraviolet radiation exposure that would be experienced by a spacecraft surface in LEO are discussed. Results of durability evaluations of some candidate space power materials to the simulated LEO environmental conditions will also be discussed. Such results have indicated that for some materials, atomic oxygen durability is affected by previous exposure to thermal cycling and/or VUV exposure.

  5. The Many Worlds of Leo Szilard: Physicist, Peacemaker, Provocateur

    Science.gov (United States)

    Lanouette, William

    2014-03-01

    Best known for being the first to conceive and patent the nuclear chain reaction in the 1930s, Leo Szilard should also be remembered for other insights in both physics and biology, and for historical initiatives to control the A-bomb he helped create. In physics, Szilard applied entropy to data in a seminal 1929 paper that laid the basis for ``information theory.'' Szilard co-designed an electromagnetic refrigerator pump with Einstein in the 1920s, in 1939 he co-designed the first nuclear reactor with Enrico Fermi, and he later thought up and named the nuclear ``breeder'' reactor. Biologist Francois Jacob called Szilard an ``intellectual bumblebee'' for the many novel ideas he shared, including one that earned Jacob and others the Nobel Prize. James D. Watson said that for intellectual stimulation he liked being around Szilard because ``Leo got excited about something before it was true.'' A political activist, Szilard proposed and drafted the 1939 letter Einstein sent to President Franklin Roosevelt that warned of German A-bomb work and led to the Manhattan Project - where Szilard was ``Chief Physicist.'' Yet Szilard then worked tirelessly to curb nuclear weapons, organizing a scientists' petition to President Truman and lobbying Congress for civilian control of the atom. Szilard loved dreaming up new institutions. He helped to create the Pugwash Conferences on Science and World Affairs, and founded the Council for a Livable World - the first political action committee for arms control. In biology, Szilard proposed the European Molecular Biology Organization modeled on CERN, and helped create the Salk Institute for Biological Studies, where he was one of the first fellows. Shy, witty, and eccentric, Szilard wrote a political satire in 1960 that predicted when the US-Soviet nuclear arms race would end in the late 1980s. Another satire, ``My Trial as a War Criminal'' about scientists' responsibilities for weapons of mass destruction, is credited with prompting

  6. TRIFLE DIFFERENCE APPROACH TO LOW EARTH ORBITER PRECISION ORBIT DETERMINATION

    OpenAIRE

    Jay Hyoun Kwon; Dorota A. Grejner-Brezinska; Jae Hong Yom; Dong Cheon Lee

    2003-01-01

    A precise kinematic orbit determination (P-KOD) procedure for Low Earth Orbiter(LEO) using the GPS ion-free triple differenced carrier phases is presented. Because the triple differenced observables provide only relative information, the first epoch`s positions of the orbit should be held fixed. Then, both forward and backward filtering was executed to mitigate the effect of biases of the first epoch`s position. p-KOD utilizes the precise GPS orbits and ground stations data from International...

  7. Defined medium for Moraxella bovis.

    OpenAIRE

    Juni, E; Heym, G A

    1986-01-01

    A defined medium (medium MB) for Moraxella bovis was formulated. Nineteen strains grew well on medium MB. One strain was auxotrophic for asparagine, and another was auxotrophic for methionine. Strains of M. equi and M. lacunata also grew on medium MB. All strains had an absolute requirement for thiamine and were stimulated by or actually required the other growth factors in the medium.

  8. Exploring the challenges of habitation design for extended human presence beyond low-earth orbit: Are new requirements and processes needed?

    NARCIS (Netherlands)

    Robinson, D.K.R.; Sterenborg, Glenn; Häuplik, Sandra; Aguzzi, Manuela

    2008-01-01

    With the renewed interest in a sustained human presence beyond low-earth orbit, habitation in space, on planets and on moons is an area that requires re-evaluation in terms of mission and habitat design—there is a need for a paradigmatic move from a design focus on short-term LEO missions to that of

  9. Effect of KOH concentration on LEO cycle life of IPV nickel-hydrogen flight cells - An update

    Science.gov (United States)

    Smithrick, John J.; Hall, Stephen W.

    1991-01-01

    An update of validation test results confirming the breakthrough in LEO cycle life of nickel-hydrogen cells containing 26 percent potassium hydroxide (KOH) electrolyte is presented. A breakthrough in the LEO cycle life of individual pressure vessel nickel-hydrogen cells is reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 LEO cycles compared to 3500 cycles for cells containing 31 percent KOH.

  10. Effect of KOH concentration on LEO cycle life of IPV nickel-hydrogen flight cells. An update

    Science.gov (United States)

    Smithrick, John J.; Hall, Stephen W.

    1991-01-01

    An update of validation test results confirming the breakthrough in LEO cycle life of nickel-hydrogen cells containing 26 percent potassium hydroxide (KOH) electrolyte is presented. A breakthrough in the LEO cycle life of individual pressure vessel nickel-hydrogen cells is reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 LEO cycles compared to 3500 cycles for cells containing 31 percent KOH.

  11. A metapopulation approach to African lion (Panthera leo) conservation.

    Science.gov (United States)

    Dolrenry, Stephanie; Stenglein, Jennifer; Hazzah, Leela; Lutz, R Scott; Frank, Laurence

    2014-01-01

    Due to anthropogenic pressures, African lion (Panthera leo) populations in Kenya and Tanzania are increasingly limited to fragmented populations. Lions living on isolated habitat patches exist in a matrix of less-preferred habitat. A framework of habitat patches within a less-suitable matrix describes a metapopulation. Metapopulation analysis can provide insight into the dynamics of each population patch in reference to the system as a whole, and these analyses often guide conservation planning. We present the first metapopulation analysis of African lions. We use a spatially-realistic model to investigate how sex-biased dispersal abilities of lions affect patch occupancy and also examine whether human densities surrounding the remaining lion populations affect the metapopulation as a whole. Our results indicate that male lion dispersal ability strongly contributes to population connectivity while the lesser dispersal ability of females could be a limiting factor. When populations go extinct, recolonization will not occur if distances between patches exceed female dispersal ability or if females are not able to survive moving across the matrix. This has profound implications for the overall metapopulation; the female models showed an intrinsic extinction rate from five-fold to a hundred-fold higher than the male models. Patch isolation is a consideration for even the largest lion populations. As lion populations continue to decline and with local extinctions occurring, female dispersal ability and the proximity to the nearest lion population are serious considerations for the recolonization of individual populations and for broader conservation efforts.

  12. Cistos peribiliares em leão-africano (Panthera leo

    Directory of Open Access Journals (Sweden)

    Ricardo B. Lucena

    2011-02-01

    Full Text Available São descritos os achados macroscópicos e histopatológicos de cistos peribiliares em uma fêmea adulta de leão-africano (Panthera leo. Macroscopicamente, todos os lobos hepáticos continham numerosos cistos preenchidos por líquido translúcido. Histologicamente, os cistos estavam localizados no hilo hepático e nos tratos portais. Os cistos eram revestidos internamente por epitélio simples, constituído por células colunares ou cuboidais e não mucinosas, de acordo com avaliação para ácido periódico de Schiff/azul alciano. Na imuno-histiquímica, todas as células desse epitélio foram positivas para citoceratina. O leão morreu de complicações relacionadas a um carcinoma pulmonar e não foram observadas alterações clínicas associadas à lesão hepática, comprovando que cistos peribiliares em leões também ocorrem não associados a sinais clínicos.

  13. Leo Esakia on duality in modal and intuitionistic logics

    CERN Document Server

    Bezhanishvili, Guram

    2014-01-01

    This volume is dedicated to Leo Esakia's contributions to the theory of modal and intuitionistic systems. Consisting of 10 chapters, written by leading experts, this volume discusses Esakia's original contributions and consequent developments that have helped to shape duality theory for modal and intuitionistic logics and to utilize it to obtain some major results in the area. Beginning with a chapter which explores Esakia duality for S4-algebras, the volume goes on to explore Esakia duality for Heyting algebras and its generalizations to weak Heyting algebras and implicative semilattices. The book also dives into the Blok-Esakia theorem and provides an outline of the intuitionistic modal logic KM which is closely related to the Gödel-Löb provability logic GL. One chapter scrutinizes Esakia's work interpreting modal diamond as the derivative of a topological space within the setting of point-free topology. The final chapter in the volume is dedicated to the derivational semantics of modal logic and other re...

  14. Analysis of received AIS data from a LEO Cubesat

    DEFF Research Database (Denmark)

    Larsen, Jesper Abildgaard; Mortensen, Hans Peter; Tausen, Mathias

    2014-01-01

    using their AIS broadcast signals as an indication of position by means of a simple dipole antenna. The SDR based receiver used on board the satellite is using a single chip front-end solution, which downconverts the AIS signal located around 162 MHz to an intermediate frequency at 200 kHz. This I....../Q signal is sampled with a 750 kSPS A/D converter and further processed by an Analog De- vices DSP. The algorithm first analyses the stream to identify possible AIS transmissions on the two different AIS channels. If likely transmissions are identified, the center frequency of the transmission is estimated...... of the satellite was to perform a feasibility study about the possibility of detecting AIS signals from a 1U cubesat in LEO. However, soon after launch it was found, that the AIS receiver performed very well and an improved algorithm which samples and decodes real-time was developed and uploaded to the satellite...

  15. Mems Reaction Control and Maneuvering for Picosat beyond LEO

    Data.gov (United States)

    National Aeronautics and Space Administration — This project further develops a multi-functional SmallSat technology for low-power attitude control of picosatellites beyond low Earth orbit. The film-evaporation...

  16. The Spatial Distribution of the Leo II dSph Galaxy

    Science.gov (United States)

    Siegel, M.; Majewski, S.; Patterson, R.

    2000-12-01

    We report preliminary results of a >4 degrees2 survey of the Leo II dwarf spheroidal (dSph) galaxy using the Washington M and T2 filters and the stellar gravity-sensitive DDO51 filter. Using the technique outlined by Majewski et al. (2000, AJ, 119, 760), we map the spatial distribution of potential Leo II giant stars. The distribution of candidate Leo II giants shows several intruiging features, including a small outcropping from the main body of the dSph that extends to the tidal radius. This outcropping is also apparent on the starcount contour maps of Irwin & Hatzidimitriou (1995). We have revised Leo II's structural parameters from a deep UBV survey using both classical starcount methods and an analysis of the surface brightness profile of unresolved stars in a star-subtracted image of the dSph. The outcropping appears to be aligned with this revised major axis. A few potential Leo II RGB stars lie outside of its tidal radius. However, the signal is not much greater than the statistical noise. Spectroscopic follow-up will be needed to determine if these extra-tidal stars are indeed associated with Leo II. The small signal, however, suggests that Leo II has either undergone little tidal disruption by the Milky Way or that any tidal debris has drifted away from the dSph during what is speculated to be a very long orbital period along a very eccentric orbit. We acknowledge support for this research from NSF CAREER Award grant AST 97-02521, the David and Lucile Packard Foundation, and the Research Corporation.

  17. PROPRIEDADES DE ÓLEOS EMPREGADOS EM FLOTAÇÃO

    Directory of Open Access Journals (Sweden)

    José Aurélio Medeiros da Luz

    2014-07-01

    Full Text Available Neste trabalho se buscou a sistematização das características de quatro amostras de óleos vegetais e uma amostra de sebo bovino, no que concerne a suas propriedades físico-químicas como com o fito de estabelecer padrões de comportamento e de desempenho em sistemas de flotação. Os óleos vegetais estudados foram: de arroz refinado, de rícino, de semente de uva e de soja refinado, usualmente empregados em operações de tecnologia mineral, com ênfase em seu uso em sistemas de flotação em espuma. As massas específicas determinadas foram: 930 kg/m³ para o óleo de semente de uva; 950 kg/m³ para o óleo de rícino; 910 kg/m³ para o óleo de arroz refinado; e 920 kg/m³ para o óleo de soja. Quanto à tensão superficial foram realizados 26 ensaios para cada amostra de óleo vegetal sendo que os valores variam de 0,0323 N/m a 0,0334 N/m. Viscosidade dinâmica aparente, tensão superficial, índice de refração e valores de umidade também foram levantados. Os resultados permitiram aceder às propriedades das amostras e confrontá-las com as que se descrevem na literatura, servindo, assim, como subsidio ao entendimento da influência destas propriedades na flotação.

  18. Óleo de melaleuca (Melaleuca alternifolia Maiden & Betche, Cheel no controle de cercosporiose em beterraba

    Directory of Open Access Journals (Sweden)

    A.D. SOUZA

    2015-01-01

    Full Text Available RESUMO O óleo volátil da melaleuca (Melaleuca alternifolia Maiden & Betche, Cheel possui atividade antimicrobiana podendo causar efeitos sobre as plantas. Avaliou-se a inibição do óleo em Cercospora beticolaSacc., e seu efeito no aumento da produção e qualidade de raízes de beterraba. As doses foram de 0,13; 0,67; 0,80 e 1,00% do óleo, além das testemunhas composta pelo meio de cultura Batata Dextrose Ágar (BDA no experimento in vitro, e água no experimento in vivo. As plantas foram pulverizadas duas vezes por semana. O delineamento foi inteiramente casualizado, com 4 repetições, e as médias foram comparadas pelo teste Tukey a 5% de probabilidade. O índice de infecção das folhas foi determinado por escala diagramática além do peso e diâmetro das raízes. Os resultados de inibição do crescimento micelial para as doses do óleo foram 0; 56; 87; 83 e 99%, e os índices de infecção: 77,08; 35,62; 21,04; 19,37 e 20,00%, respectivamente, para a testemunha e as doses 0,13; 0,67; 0,80 e 1,00% do óleo. Somente na concentração de 0,80% o óleo proporcionou relação positiva entre o ganho de peso e o diâmetro das raízes. O óleo de Melaleuca foi eficaz no controle de C. beticola e, como consequência, houve produção de raízes de beterraba com melhor desenvolvimento.

  19. Spiegel. Medium. Kunst

    DEFF Research Database (Denmark)

    Kacunko, Slavko

    and cultural perspective. From 1800 on, the great incentive was to push forward the material-physical and optical-mechanical and especially the media ‘exploitation’ of the mirror. The significance of the mirror as a central meta-medium of the visual emerged in a particularly striking way in the late 1830s....... That ricochets through media theory, theories of art and culture and through cultural historiography. A repository is one thing, a transmitter another: the distinction will act crucially on the quest for appropriate perspectives and classifications of what in terms of disciplines would rather appear...... or as synaesthesia gone mute. It stands in contrast with the mirror, which assumes the status of a medium facility or meta-medium of visual transference, encountering its only medial and operative limitation within the analogue or digital repository media. The present proposal for an artistic and cultural history...

  20. Rare earth ferrosilicon alloy

    International Nuclear Information System (INIS)

    Caiquan, L.; Zeguang, T.; Zaizhang, L.

    1985-01-01

    In order to obtain RE ferrosilicon alloy with good quality and competitive price, it is essential that proper choice of raw materials, processing technology and equipments should be made based on the characteristics of Bai-Yun-Ebo mineral deposits. Experimental work and actual production practice indicate that pyrometallurgical method is suitable for the extraction and isolation of the rare earths and comprehensive utilization of the metal values contained in the feed material is capable of reducing cost of production of RE ferrosilicon alloy. In the Bai-Yun-Ebo deposit, the fluorite type medium lean ore (with respect to iron content) makes a reserve of considerable size. The average content of the chief constituents are given

  1. Use of negotiated rulemaking in developing technical rules for low-Earth orbit mobile satellite systems

    Science.gov (United States)

    Taylor, Leslie A.

    Technical innovations have converged with the exploding market demand for mobile telecommunications to create the impetus for low-earth orbit (LEO) communications satellite systems. The so-called 'Little LEO's' propose use of VHF and UHF spectrum to provide position - location and data messaging services. The so-called 'Big LEO's' propose to utilize the RDSS bands to provide voice and data services. In the United States, several applications were filed with the U.S. Federal Communications Commission (FCC) to construct and operate these mobile satellite systems. To enable the prompt introduction of such new technology services, the FCC is using innovative approaches to process the applications. Traditionally, when the FCC is faced with 'mutually exclusive' applications, e.g. a grant of one would preclude a grant of the others, it uses selection mechanisms such as comparative hearings or lotteries. In the case of the LEO systems, the FCC has sought to avoid these time-consuming approaches by using negotiated rulemakings. The FCC's objective is to enable the multiple applicants and other interested parties to agree on technical and service rules which will enable the grant of all qualified applications. With regard to the VHF/UHF systems, the Advisory Committee submitted a consensus report to the FCC. The process for the systems operating in the bands above 1 GHz involved more parties and more issues but still provided the FCC useful technical information to guide the adoption of rules for the new mobile satellite service.

  2. Efeito de óleos essenciais como alternativa no controle de Colletotrichum gloeosporioides, em pimenta

    Directory of Open Access Journals (Sweden)

    Rosa Maria Souto de Sousa

    2012-03-01

    Full Text Available Fungos do gênero Colletotrichum causam doenças conhecidas como antracnose. Métodos alternativos que sejam eficientes e menos agressivos vêm sendo amplamente testados. Dentre estes, surge o interesse pela utilização de óleos essenciais extraídos de vegetais. O presente trabalho teve como objetivo avaliar o efeito de óleos essenciais de eucalipto, copaíba, andiroba, babaçu, coco, neem, semente de uva, amêndoa, hortelã e pau rosa, em diferentes concentrações sobre o fungo Colletotrichum gloeosporioides, in vitro e em frutos de pimenta em pós colheita. O experimento in vitro foi realizado utilizando-se cinco concentrações (0,2; 0,4; 0,6; 0,8 e 1,0% dos dez óleos misturados ao meio de cultura BDA. As variáveis analisadas foram a taxa de crescimento micelial e o índice de velocidade de crescimento micelial (IVCM. O ensaio em pós-colheita foi feito com imersão dos frutos de pimenta por 5 minutos, nos mesmos óleos utilizados no experimento anterior, usando-se a maior concentração. O fungo C. gloeosporioides foi inoculado, através de ferimento, logo após a imersão dos frutos. As avaliações foram realizadas diariamente através de medição do diâmetro das colônias e das lesões, tomando-se duas medições em sentidos diametralmente opostos. Pode-se observar que no experimento in vitro todos os óleos, com exceção dos óleos de babaçu, semente de uva e amêndoa, tiveram excelentes resultados inibindo o crescimento do fungo. No resultado obtido em pós-colheita foi observado que apenas o óleo de babaçu não foi eficiente em reduzir o desenvolvimento da lesão de antracnose. Dados relevantes foram observados para os óleos de semente de uva e amêndoa, que não apresentaram efeito direto sobre o fungo in vitro, porém no tratamento pós-colheita apresentaram bons resultados, reduzindo a lesão causada por C. gloeosporioides, sugerindo assim que estes óleos possam ser utilizados como indutores de resistência em frutos

  3. Concept medium program

    DEFF Research Database (Denmark)

    Bjerrum, Peter

    2003-01-01

    The present essays is an attempt to dertermine the architecural project of the 21st century in realation to a modern conception of space as the medium of architecture, and of society as its program. This attempt adopts the internal point of view of an architect in describing a modern architectura...

  4. Radon in geological medium

    International Nuclear Information System (INIS)

    Hricko, J.

    1995-01-01

    The paper presented deals with behavior of the radon in geological medium and with some results of the radon survey in Bratislava and Kosice regions. 1) The a v has been detected in the holes 0.80 m deep. The density of observations - 3 reference areas (one represents 20 stations) per 1 km 2 . The radon risk maps in 1:25000 and 1:50000 scales have been compiled. The 56.8% of the project area lies in low radon risk, 37.6% in medium radon risk and 5.6% in high radon risk. Follow-up monitoring of the equivalent volume radon activity (EVRA) at the flats, located in the areas with high radon risk of the surface layer, has showed values several times higher than Slovak limits (Marianka, Raca, Vajnory). The evidence that neotectonic is excellent medium for rising up emanation to the subsurface layer, is shown on the map. The tectonic zone of Liscie udolie in Bratislava-Karlova Ves area has been clearly detected by profile radon survey (a v > 50 kBq/m 3 ). 2) At present, northern half of the area of Kosice in question was covered by radon survey. The low and medium radon risks have been observed here, while localities with high radon risk are small in extent. The part of radon risk and soil permeability map from northern Kosice area is shown. (J.K.) 3 figs., 2 refs

  5. Efeito fungitóxico in vitro do óleo resina e do óleo essencial de copaíba (Copaifera multijuga Hayne In vitro fungitoxic effect of the oil-resin and the essential oil of copaiba (Copaifera multijuga Hayne

    Directory of Open Access Journals (Sweden)

    R.J.A. Deus

    2009-01-01

    Full Text Available Óleo de Copaifera multijuga Hayne, in natura e as frações foram avaliadas quanto às atividades fungitóxicas in vitro, frente a cinco espécies de fungos filamentosos do gênero Aspergillus e três espécies de leveduras do gênero Candida. Concentrações de óleo resina e de óleo essencial na faixa de 0,08 mg mL-1 a 1,6 mg mL-1 foram usadas para as análises qualitativa e quantitativas. As amostras foram dispostas sobre discos de papel de 5 mm de diâmetro e distribuídos sobre o meio Saboraud em placas de Petri, inoculadas com esporos dos microorganismos e incubadas a 28ºC durante 10 dias. Utilizou-se solução com 1,6 mg mL-1 de nitrato de miconazol como controle positivo. Os resultados qualitativos mostraram que o óleo resina apresentou boa atividade fungistática, porém uma das frações do óleo essencial se mostrou altamente efetiva contra Candida parapsilosis IOC-2882, Aspergillus flavus IOC-3874 e A tamarii IOC-187 com halos de inibição de 16,0±1,4 mm, 19,5±2,1 mm e 12,5±3,5 mm, respectivamente. Já a avaliação quantitativa mostrou que 0,3 mg mL-1 do óleo resina inibiu o crescimento de A. flavus e C. parapsilosis, enquanto que 0,08 mg mL-1 da fração do óleo essencial atingiu esta mesma atividade.Copaifera multijuga Hayne oil, crude and fractions, was evaluated for its in vitro fungitoxic activities against five species of filamentous fungi belonging to the genus Aspergillus and three yeast species of the genus Candida. Oil-resin and essential oil concentrations ranging from 0.008 mg mL-1 to 1.6 mg mL-1 were used in qualitative and quantitative analyses. Samples were placed onto 5mm-diameter paper disks and distributed on Saboraud culture medium in Petri dishes inoculated with conidia and incubated at 28ºC during 10 days. A solution with 1.6 mg mL-1 of miconazole nitrate was used as positive control. Qualitative results indicated that the oil-resin presented good fungistatic activity; however, one of the essential

  6. Avaliação do efeito antifúngico do óleo resina e do óleo essencial de copaíba (Copaifera multijuga Hayne Evaluation of the antifungal effect of oleoresin and essential oil of copaiba (Copaifera multijuga Hayne

    Directory of Open Access Journals (Sweden)

    R.J.A Deus

    2011-01-01

    Full Text Available Óleo de Copaifera multijuga Hayne, in natura e as frações foram avaliados quanto às suas atividades fungitóxicas, frente a cinco espécies de fungos filamentosos do gênero Aspergillus e três espécies de leveduras do gênero Candida. Concentrações de óleo resina e de óleo essencial na faixa de 0,08 mg mL-1a 1,6 mg mL-1 foram usadas para as análises qualitativa e quantitativas. As amostras foram dispostas sobre discos de papel de 5 mm de diâmetro e distribuídos sobre o meio Saboraud em placas de Petri, inoculadas com esporos dos microrganismos e incubadas a 28ºC durante 10 dias. Utilizou-se uma solução com 1,6 mg mL-1 de nitrato de miconazol como controle positivo. Os resultados qualitativos mostraram que o óleo resina apresentou boa atividade, porém uma das frações do óleo essencial se mostrou altamente efetivo contra C. parapsilosis IOC - 2882, A.flavus IOC-3874 e A. tamarii IOC-187 com halos de inibição de 16,0±1,4 mm, 19,5±2,1 mm e 12,5±3,5 mm, respectivamente. Já a avaliação quantitativa mostrou que 0,3 mg mL-1 do óleo resina inibiu o crescimento de A. flavus e C. parapsilosis, enquanto que 0,08 mg mL-1 da fração do óleo essencial atingiu esta mesma atividade.Copaifera multijuga Hayne oil in natura and its fractions were evaluated as to their fungitoxic activities against five filamentous fungus species belonging to the genus Aspergillus and three yeast species of the genus Candida. Oleoresin and essential oil concentrations ranging from 0.08 mg mL-1 to 1.6 mg mL-1 were used for qualitative and quantitative analyses. The samples were placed onto 5mm-diameter paper discs distributed on Sabouraud's medium in Petri dishes inoculated with spores of the microorganisms and incubated at 28ºC for 10 days. A solution containing 1.6 mg mL-1 miconazole nitrate was used as positive control. Qualitative results showed that the oleoresin presented good activity, while a fraction of the essential oil was highly effective

  7. Efeito fungitóxico do óleo essencial de aroeira da praia (Schinus terebinthifolius RADDI sobre Colletotrichum gloeosporioides Fungitoxic effect of essential oil from aroeira (Schinus terebinthifolius RADDI on Colletotrichum gloeosporioides

    Directory of Open Access Journals (Sweden)

    L.F.G Oliveira Junior

    2013-01-01

    Full Text Available Neste trabalho foi avaliado o efeito do óleo essencial do fruto de Schinus terebinthifolius sobre o crescimento micelial do fungo Colletotrichum gloeosporioides in vitro, e no desenvolvimento da antracnose no período de pós-colheita em mamões. As diferentes concentrações de óleo foram diluídas em Tween 80 a 8%. No experimento in vitro foram preparados meios de cultura BDA nas concentrações de 0,05; 0,10; 0,25 e 0,50% do óleo essencial. O controle negativo foi realizado apenas com meio BDA e o controle solvente com meio BDA e Tween 80 a 8%. A inibição do crescimento do fungo foi diretamente proporcional à quantidade do óleo e a maior inibição encontrada foi de 79,07% na concentração de óleo de 0,50%. No experimento in vivo os frutos do mamoeiro foram inoculados com o fungo em quatro tratamentos: com biofilme; com biofilme mais 0,50% do óleo; com fungicida Prochloraz e frutos controle. Embora o tratamento com óleo tenha sido eficiente contra o fungo, não foi indicado comercialmente, pois apresentou valores elevados de perda de massa fresca, de firmeza, e também sintomas de fitotoxidade. O óleo tem propriedade antifúngica contra C. gloeosporioides in vitro e in vivo, contudo, não é recomendado para o mamão em função da fitotoxidezThis study evaluated the effect of essential oil from Schinus terebinthifolius fruit on the mycelial growth of the fungus Colletotrichum gloeosporioides in vitro and on the anthracnose development during the postharvest period of papaya fruits. The different oil concentrations were diluted in 8% Tween 80. For the in vitro experiment, PDA culture media were prepared at the concentrations of 0.05, 0.10, 0.25 and 0.50% essential oil. Negative control was prepared with PDA medium alone, while solvent control was prepared with PDA medium and 8% Tween 80. Fungal growth inhibition was directly proportional to the oil amount and the greatest inhibition was 79.07% at 0.50% oil concentration. For the

  8. The Oxygen and Nitrogen Abundance of Leo A and GR 8

    Science.gov (United States)

    van Zee, L.; Skillman, E. D.; Haynes, M. P.

    1999-05-01

    Gas phase abundances are one of the best measures of the intrinsic metallicity of low mass galaxies. We recently obtained low resolution long slit optical spectra of several HII regions in Leo A and GR 8 with the Palomar 5m telescope. Previous studies of the resolved stellar population of Leo A indicated that the stars have metallicities approximately 2% of solar (Tolstoy et al. 1998). Preliminary analysis of the HII region spectra, and that of a planetary nebula, indicates that the gas phase oxygen abundance of Leo A is approximately 3% of solar. This confirms the result of Skillman et al. (1989), who also derived an oxygen abundance for Leo A from a planetary nebula. Similarly, for GR 8 we find a mean oxygen abundance of 5% of solar. For all the HII regions, the derived log(N/O) is -1.5 +/- 0.1, as has been found for other low metallicity systems. These new observations of multiple HII regions in Leo A and GR 8 confirm that metals in low mass galaxies are well mixed.

  9. Utilizing Earth Observations for Societal Issues

    Science.gov (United States)

    Habib, Shahid

    2010-01-01

    Over the last four decades a tremendous progress has been made in the Earth science space-based remote sensing observations, technologies and algorithms. Such advancements have improved the predictability by providing lead-time and accuracy of forecast in weather, climate, natural hazards, and natural resources. It has further reduced or bounded the overall uncertainties by partially improving our understanding of planet Earth as an integrated system that is governed by non-linear and chaotic behavior. Many countries such as the US, European Community, Japan, China, Russia, India has and others have invested billions of dollars in developing and launching space-based assets in the low earth (LEO) and geostationary (GEO) orbits. However, the wealth of this scientific knowledge that has potential of extracting monumental socio-economic benefits from such large investments have been slow in reaching the public and decision makers. For instance, there are a number of areas such as water resources and availability, energy forecasting, aviation safety, agricultural competitiveness, disaster management, air quality and public health, which can directly take advantage. Nevertheless, we all live in a global economy that depends on access to the best available Earth Science information for all inhabitants of this planet. This presentation discusses a process to transition Earth science data and products for societal needs including NASA's experience in achieving such objectives. It is important to mention that there are many challenges and issues that pertain to a number of areas such as: (1) difficulties in making a speedy transition of data and information from observations and models to relevant Decision Support Systems (DSS) or tools, (2) data and models inter-operability issues, (3) limitations of spatial, spectral and temporal resolution, (4) communication limitations as dictated by the availability of image processing and data compression techniques. Additionally, the

  10. Atividade antifúngica, in vitro, do óleo de café verde

    OpenAIRE

    Elizei,Virgínia Guerra; Chalfoun,Sara Maria; Botelho,Deila Magna dos Santos; Rebelles,Pedro Paulo Reis

    2016-01-01

    RESUMO: O objetivo deste trabalho foi avaliar o efeito do contato direto e da fração volátildo óleo de café verde, testado nas concentrações de 500, 1.000, 1.500 e 2.000 µL L-1, sobre o crescimento micelial e a esporulação dos fungos Penicillium roqueforti e Rhizopus stolonifer. O óleo essencial de cravo-da-índia na concentração de 800 µL L-1 foi utilizado para comparação. Nas concentrações de 1.500 e 2.000 µL L-1, o óleo de café verde em contato direto proporcionou redução da esporulação do ...

  11. Reações químicas em óleo de soja utilizando celadonita

    OpenAIRE

    Cíntia Salomão Zarth

    2008-01-01

    Neste trabalho foi realizado o estudo de transformações de óleo de soja com o catalisador VO(acac)2 em meio homogêneo e heterogêneo. Estes processos catalíticos estão de acordo com os conceitos de química limpa, no sentido de economia de reagentes e diminuição de subprodutos, enquanto que a matéria-prima, óleo vegetal, foi escolhida por ser de fonte renovável, sustentável e abundante no Rio Grande do Sul e no Brasil. A reação de transesterificação do óleo de soja foi realizada através do sist...

  12. POLIMEROS COMO METODOS PARA RECUPERAÇÃO AVANÇADA DE PETRÓLEO

    OpenAIRE

    Marques, Landson S.; UFBA; Quintella, Cristina M.; UFBA; Neto, Guilherme João Musse; UFBA; Cavalcanti, David Falcão; UFBA; Santos, Lauro Tiago Souza; UFBA

    2014-01-01

    A recuperação terciária ou avançada de petróleo (EOR) com a injeção de soluções diluídas de um polímero nos reservatórios ajuda a deslocar o óleo dos poros atuando na viscosidade do fluido injetado e na molhabilidade. EOR é utilizada especialmente quando aumenta a demanda por petróleo e seus derivados. EOR com polímeros tem sido patenteada desde 1967 e continua até aos dias de hoje em pequenas ondas. Os EUA têm o maior número de patentes. A grandes depositantes são as maiores empresas de p...

  13. Organic chemistry and biology of the interstellar medium

    Science.gov (United States)

    Sagan, C.

    1973-01-01

    Interstellar organic chemistry is discussed as the field of study emerging from the discovery of microwave lines of formaldehyde and of hydrogen cyanide in the interstellar medium. The reliability of molecular identifications and comparisons of interstellar and cometary compounds are considered, along with the degradational origin of simple organics. It is pointed out that the contribution of interstellar organic chemistry to problems in biology is not substantive but analogical. The interstellar medium reveals the operation of chemical processes which, on earth and perhaps on vast numbers of planets throughout the universe, led to the origin of life, but the actual molecules of the interstellar medium are unlikely to play any significant biological role.

  14. El íleo biliar: una revisión de la literatura médica

    Directory of Open Access Journals (Sweden)

    C.F. Ploneda-Valencia

    2017-07-01

    Conclusiones: El objetivo del tratamiento del íleo biliar es liberar la obstrucción, obtenido a través de la enterolitotomía. Esta es la técnica recomendada para el manejo del íleo biliar debido a su morbimortalidad menor, comparada con las otras técnicas.

  15. EPOXI EARTH OBS - MRI CALIBRATED IMAGES V2.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset contains calibrated, 750-nm filter images of Earth acquired by the Deep Impact Medium Resolution Visible CCD (MRI) during the EPOCh and Cruise 2 phases...

  16. EPOXI EARTH OBS - MRI RAW IMAGES V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set set contains version 1.0 of raw 750-nm filter images of Earth acquired by the Deep Impact Medium Resolution Visible CCD during the EPOCh phase of the...

  17. EPOXI EARTH OBS - MRI CALIBRATED IMAGES V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set set contains version 1.0 of calibrated 750-nm filter images of Earth acquired by the Deep Impact Medium Resolution Visible CCD during the EPOCh phase...

  18. Medium-energy physics

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    One of the basic challenges of medium-energy physics is the development of a clear picure of the manner in which pions propagate in nuclear matter. Since the pion is a basic quantum of the nuclear force, understanding its propagation in nuclei contributes to our understanding of the basic nature of nuclear forces. Key to such understanding is a comprehensive and precise experimental description of pion interactions both with complex nuclei and few nucleon systems. This is a major objective of the ANL effort in medium-energy physics. Experiments are carried out as a part of a comprehensive nuclear program, and, because of this perspective, the pion studies are expected to give new insights into the nature of nuclear forces. At the present time, almost all experimental activity is concentrated on measurements using various pion beams of the Los Alamos Meson Physics Facility

  19. Kulturmorphologie und Neopaganismus. Der Glaube des Leo Frobenius - Kulturmorphologie and Neopaganism. The beliefs of des Leo Frobenius

    Directory of Open Access Journals (Sweden)

    Bernhard Streck

    2015-11-01

    Full Text Available Anthropologists are used to describing the religions of others, nut not their own beliefs. In the human sciences we rarely find information about the religious beliefs of researchers. But carefully examining published and unpublished writings, we can still find some indications regarding the authors’ values, which they may not have always intended to disclose to the public. This is in spite of the fact or perhaps, more correctly, because they are closely related to the theory and practice of their science. To illustrate this rather apocryphal relationship between an author’s basic convictions and his published opinions, in this essay we take the example of Leo Frobenius (1873-1938, a researcher who remained on the fringes of the academic world. As an autodidact ethnologist he was already very enthusiastic about the mythologies of the world at a very young age, but instead of a “global myth” he published a catalogue of mythological themes or “mythologems”, which he considered as universal (Die Weltanschauung der Naturvölker – “the worldview of primitive peoples”, 1898; Das Zeitalter des Sonnengottes – “In the era of the Sun God”, 1904. Unlike the mythologies written much later (1964-1971 by Claude Lévi-Strauss (1908-2009, they do not deal with formal structures of thought, but rather with an archaic cosmology similar to the archetypes we find in the later works of Carl Gustav Jung (1875-1961 or Mircea Eliade (1907-1986. In search of these archetypal images of cosmic evolution, Frobenius collected folk tales and later rock paintings, which he copied by hand during his field research (12 expeditions to Africa between 1904 and 1935. The birth in death, the ritual murder of the Holy King or High Priest, the complementarity of the sexes (for example the numbers 3 and 4 in the sum 7, the law that a culture's rise must inevitably be followed by its decline – these all are ideas that have determined the work of this researcher

  20. Liquid chromatographic extraction medium

    Science.gov (United States)

    Horwitz, E. Philip; Dietz, Mark L.

    1994-01-01

    A method and apparatus for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column is described. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water.

  1. Atividade antifúngica do óleo essencial de Origanum vulgare frente a Malassezia pachydermatis

    Directory of Open Access Journals (Sweden)

    R. Santin

    2014-04-01

    Full Text Available Objetivou-se com este estudo avaliar a atividade antifúngica in vitro do óleo essencial de Origanum vulgare frente a isolados clínicos de Malassezia pachydermatis. As folhas secas de O. vulgare foram adquiridas de distribuidor comercial com certificado de qualidade e origem e encaminhadas para extração do óleo essencial e cromatografia. Para realização do teste in vitro, foi utilizada a técnica de microdiluição em caldo (CLSI M27A3 com modificações para fitofármacos e M. pachydermatis. O óleo essencial de orégano foi testado nas concentrações de 28 a 0,87mg/mL diluído em caldo Sabouraud com 1% de tween 80. Todos os isolados foram testados em duplicata. Na análise cromatográfica do óleo essencial, foram identificados 12 compostos, sendo timol, a-terpineno e 4-terpineol os compostos majoritários. A CIM e a CFM dos 42 isolados de M. pachydermatis variaram de <0,87 a 7mg/mL, com valores de CIM50 e CIM90 de 1,18 e 3,28mg/mL, respectivamente. Com este estudo foi possível concluir que M. pachydermatis é sensível ao óleo essencial de orégano mesmo em concentrações baixas. Dessa maneira, o óleo essencial de orégano apresenta-se como promissor na bioprospecção de novos fármacos para o tratamento das otites e dermatites na clínica de pequenos animais.

  2. Óleos essenciais e vegetais no controle in vitro de Colletotrichum gloeosporioides

    Directory of Open Access Journals (Sweden)

    K. RAMOS

    Full Text Available RESUMO O objetivo deste trabalho foi avaliar a atividade antifúngica de óleos essenciais e vegetais no controle in vitro de Colletotrichum gloeosporioides, agente causal da antracnose em pós-colheita de frutíferas. Treze óleos essenciais foram utilizados em concentrações de 0,00%, 0,40%, 0,80%, 1,70%, 3,20%, 6,25%, 12,50%, 25,00%, 50,00% e 100,00%, e uma linhagem padrão de Colletotrichum gloeosporioides. Foram avaliadas a concentração inibitória mínima e a concentração mínima fungicida a fim de caracterizar o potencial de cada um dos óleos essenciais avaliados. Verificou-se que os óleos utilizados apresentaram atividade fungicida em diferentes concentrações, as quais variaram de 0,80% (melaleuca, 3,20%, (eucalipto, 6,25% (limão, capim limão, cravo da índia, canela e nim, 12,5% (hortelã e citronela, 25% (copaíba, 50% (coco e gengibre e 100% (manjericão. O óleo de nim apresentou maior redução da carga microbiana em função do tempo de exposição, sendo necessários 30 minutos para anulação da contagem microbiana. O efeito antifúngico dos óleos essenciais, para controle de Colletotrichum gloeosporioides, depende da planta e da concentração empregada.

  3. Potencial inseticida de óleos de origem vegetal sobre Grapholita molesta (Busck (Lepidoptera: Tortricidae

    Directory of Open Access Journals (Sweden)

    J.F. Colpo

    2014-06-01

    Full Text Available Em decorrência do estudo das interações químicas entre insetos e herbívoros, e do avanço da pesquisa fitoquímica, é conhecida ampla variedade de produtos naturais com potencial inseticida. Grapholita molesta (Busck (Lepidoptera: Tortricidae, mariposa-oriental, é uma das principais pragas do pessegueiro, danificando brotações e frutos. O objetivo do presente estudo foi verificar a mortalidade, atratividade e deterrência de óleos vegetais em G. molesta. Ovos e pupas de insetos provindos de criação artificial foram imersos nos óleos essenciais de Elionurus muticus (Spreng. Kuntze e Cymbopogon winterianus Jowitt ex Bor nas concentrações de 0,25%, 0,5%, 1% e 0,5%, 1%, 5%. Os testes de atratividade foram realizados em olfatômetro do tipo "Y". A deterrência à oviposição foi testada em gaiolas sem escolha e de dupla escolha. O óleo de E. muticus aplicado em ovos de G. molesta nas três concentrações causou mortalidades maiores que 30%, diferindo significativamente dos controles (p<0,05. A mortalidade causada pelo óleo de citronela foi em torno de 70%, significativamente superior ao controle (p<0,01. O óleo de citronela aplicado a 1% em pupas causou mortalidade de 99,8%. No teste com o olfatômetro, não houve atratividade dos adultos para nenhum dos óleos. A média de ovos no substrato com o tratamento (0,33±0,33, foi significativamente menor que no controle (7,3±0,88 (p<0,01, indicando deterrência à oviposição.

  4. Hadrons in the medium

    International Nuclear Information System (INIS)

    Leupold, Stefan

    2005-01-01

    QCD, the theory of the strong interaction, has a non-trivial vacuum structure. One way to characterize this structure is by means of non-vanishing matrix elements of quark or gluon operators, the condensates. In hot and/or dense enough strongly interacting media, QCD is subject to phase transitions or rapid crossovers. Consequently, the condensates typically change with density and temperature. An exciting aspect of hadron physics is the question how these changes affect the properties of hadrons which are put in a strongly interacting environment. Here vector mesons deserve special attention as they couple directly to (virtual) photons. The latter can decay into dileptons which leave the strongly interacting system untouched. Via that process information about possible in-medium modifications of the vector mesons can be carried to the detectors. With the ω-meson as an example I will review our current understanding of the connections between in-medium changes of condensates and the in-medium changes of the properties of hadrons. (author)

  5. Skylon; potentially the new big thing in LEO transport

    NARCIS (Netherlands)

    Van der Peijl, I.; Veraart, M.

    2013-01-01

    Space planes could very well be the ultimate aerospace engineering machine. These space planes are vehicles that function both as an aircraft when flying or gliding through the atmosphere, and as a spacecraft when orbiting around the earth. Well known examples of space planes are NASA’s space

  6. Uso de óleo essencial de tomilho (Thymus vulgaris) na dieta de ovinos

    OpenAIRE

    Angelo Dias Brito Ribeiro

    2015-01-01

    Três experimentos foram conduzidos com o objetivo de avaliar o efeito do óleo essencial de tomilho nos parâmetros ruminais, metabolismo e desempenho. O experimento I teve por objetivo avaliar se o óleo essencial de tomilho exerce efeito sofre a fermentação ruminal e consequentemente no metabolismo de ovinos confinados, bem como avaliar o consumo e digestibilidade aparente dos nutrientes em dietas com 90% concentrado e 10% de volumoso. Foram utilizados 20 ovinos ½ Dorper x ½ Santa Inês, machos...

  7. Long-term behavior of stellar flare activity in AD Leo

    International Nuclear Information System (INIS)

    Pettersen, B.R.

    1984-01-01

    AD Leo is a dM4e solar neighborhood red dwarf on the main sequence. It has an effective temperature of 3500 0 K, radius of 0.44 R/sub solar/ and a bolomeric luminosity of 0.024 L/sub solar/. The mass-luminosity relation implies a mass of 0.44 M/sub solar/. Photometry of starspots indicates a rotation period of 2.7 days implying that the rotation axis of AD Leo is inclined 38 0 to the line of sight

  8. Actividad anticaries de una crema dental con propóleos

    OpenAIRE

    Estela Gispert Abreu; Elena Cantillo Estrada; Aracelys Rivero López; Marela Padrón Illance

    2000-01-01

    Por muestreo aleatorio simple se seleccionaron 50 escolares con antecedentes de alta infección por Streptococcus mutans, para verificar la actividad anticaries de una crema dental que contiene 0,8 de extracto de propóleo blando. Se perdieron del estudio a 7 escolares por inasistencia y traslados. Se crearon 2 grupos: uno control (n=19) que se cepilló con una crema dental placebo y otro tratamiento (n=24) que se cepilló con la crema dental de propóleo. Entre ambos grupos no había diferencia si...

  9. Atividades biol?gicas de terpenos de ?leos de copa?ba (Copaifera spp. ? Fabaceae)

    OpenAIRE

    Vargas, Fabiano de Sousa

    2013-01-01

    A copa?ba (Copaifera L.) ? uma das plantas amaz?nicas mais conhecidas e utilizadas por popula??es tradicionais como medicamento natural. O ?leo-resina de copa?ba ? fonte de compostos terp?nicos. O fracionamento pr?vio dos ?cidos terp?nicos contidos ?leo de copa?ba para o isolamento de metab?litos de interesse ? um m?todo ?til na celeridade dos processos fitoqu?micos posteriores. A utiliza??o da cromatografia de troca i?nica ? uma alternativa que minimiza o inconveniente da forma??o de emuls?e...

  10. Ileostomia continente com preservação da papila íleo-cecal

    OpenAIRE

    FORMIGA,GJS

    2000-01-01

    Seis doentes foram submetidos a ileostomia continente com preservação da papila íleo-cecal, como tempo cirúrgico complementar à proctocolectomia e à colectomia totais, para tratamento de doença inflamatória intestinal e polipose adenomatosa familiar, associada a pólipo degenerado no reto inferior. A técnica utilizada de ileostomia continente preserva a papila íleo-cecal e uma pequena borda circular de parede cecal exteriorizados na parede abdominal. O débito ileal, na primeira semana pós-oper...

  11. Integrated Ideas of a Life Warrior ~ An Interview with Leo Fong

    Directory of Open Access Journals (Sweden)

    Peter Hobart

    2012-07-01

    Full Text Available Mr. Leo Fong is the architect and founder of a system of martial arts known as Wei Kuen Do (man. Hui Quan Dao—the Way of the Integrated Fist. Leo Fong trained in a variety of Chinese disciplines, including Shaolin, Choy Lay Fut and Tiger Claw, and was a close associate of Bruce Lee. Over the course of his studies, Master Fong combined many of the aspects of Chinese martial arts with principles of western boxing, to produce his own, unique and devastating system of self-defense.

  12. Effectiveness of Space Debris Mitigation Guidelines: Economic Potential of LEO and Traffic Management Issues

    Science.gov (United States)

    Belviso, Luciano

    implementation of international technical standards concerning traffic control systems. Applicability of regulatory regime to satellite tracking systems. Even considering the effectiveness of traffic control systems, the most part of accident will be caused by part of operating system floating without guidance. In this case, both the Outer Space Treaty[5] and the Liability Convention[6] only apply if the space object, or part of it, is identifiable. The improvement of tracking system will empower recognition capabilities and will allow to predict with a certain precision to what space object the debris belongs and, also considering the growing number of space objects, it will be possible to identify the fatherhood of a single debris with a certain confidence. The question concerning international law is whether an information relying on simulated and algorithm-based interpretation can be considered like an observed dataset. In other words, in the case one could identify a debris responsible for a damage using simulation, a standard for the whole identification procedure is needed in order to ensure a minimum requirement in terms of accuracy of the model used. These implications will be considered in our paper. References [1] Greenberg, Economic Implications of Orbital Debris Mitigation [LEO Missions], Proceedings of the 48th International Astronautical Congress, IAA-97-IAA-6.5.08, 1997 [2] Art. 33 of the International Telecommunication Convention (ITC) considers that the Geostationary Orbit is a "limited natural resource (which) must be used efficiently and economically so that countries or groups of countries may have equitable access [...]". [3] Collins and Williams, Towards traffic control systems for near-earth space, Proceedings of the 29th colloqium on the law of Outer Space, IISL, 1986, p.166. [4] Dittberner, Fudge, Huth, Johnson, McKnight, Examining siclifying assumption of probability of collisions in LEO, Proceedings of the first European conference on Space Debris

  13. The Internal Kinematics of the Leo I Dwarf Spheroidal Galaxy: Dark Matter at the Fringe of the Milky Way

    Science.gov (United States)

    Mateo, Mario; Olszewski, Edward W.; Vogt, Steven S.; Keane, Michael J.

    1998-11-01

    We present radial velocities of 33 red giants in the Leo I dwarf spheroidal galaxy (dSph) obtained from spectra taken with the HIRES echelle spectrograph on the Keck Telescope. These data have a mean precision of 2.2 km s^-1 and lead to estimates of the central velocity dispersion and systemic velocity of Leo I of 8.8 +/- 1.3 km s^-1 and 287.0 +/- 1.9 km s^-1, respectively. The systemic velocity confirms past results that Leo I has an unusually large galactocentric velocity, implying the presence of a massive dark halo in the Milky Way or an extended dark component pervading the Local Group. The V-band M/L ratio of Leo I is in the range 3.5-5.6. We have produced a set of models that accounts for the effects of stellar evolution on the global mass-to-light ratio of a composite population. Because Leo I contains a dominant intermediate-age population, we find that the V-band mass-to-light ratio of Leo I would be in the range 6-13 if it were composed exclusively of old stars such as those found in globular clusters. This suggests that Leo I probably does contain a significant dark halo. The mass of this halo is approximately 2 x 10^7 M_⊙, similar to the dark halo masses inferred for all other galactic dSph galaxies. Because Leo I is isolated and has passed the Milky Way at most once in the past, external tides could not plausibly have inflated its central dispersion to the observed value. We also considered whether modified Newtonian dynamics (MOND) could account for the internal kinematics of Leo I and conclude that this alternative gravitational model can account for the Leo I kinematics adequately without requiring a dark halo.

  14. Reciclo-óleo: do óleo de cozinha ao sabão ecológico, um projeto de educação ambiental

    OpenAIRE

    Maria Isabel Morgan Martins; Fábio Renê Klagenberg Mesdes; Caroline Soster; Eliane Fraga; Ana Maria Pujol Vieira dos Santos; Nadia Teresinha Schoreder

    2016-01-01

    O consumo de óleo faz parte do dia-a-dia das famílias, restaurantes, indústrias e com ele o descarte incorreto do óleo de cozinha usado (OCU) se torna um grave problema ambiental. Quando despejado no lixo comum impermeabiliza e contamina o solo, porque a decomposição aumenta o efeito estufa, na rede de esgoto compromete as tubulações das residências e das cidades e ao atingir os rios forma uma película na água que impede a passagem de luz e oxigênio a flora e a fauna aquática. Objetivo: é pro...

  15. Estruturação de óleo de palma e emulsões utilizando óleo de palma totalmente hidrogenado e lecitina de soja

    OpenAIRE

    Valéria da Silva Santos

    2014-01-01

    Resumo: O óleo de palma (PO) destaca-se por ser uma matéria-prima com grande potencial de aplicação em diversos produtos. Porém, quando aplicado de maneira isolada, apresenta cristalização lenta, gerando problemas para a indústria de alimentos. A fim de acelerar a cristalização utilizam-se compostos que podem, além de contribuir para a redução do período de indução, atuar como agentes estruturantes, atual foco em desenvolvimento na área de óleos e gorduras. Este estudo tem por objetivos avali...

  16. Refinação de óleos vegetais e fracionamento contínuo de óleo de Palma

    OpenAIRE

    Mota, Daniel Santos

    2016-01-01

    Este relatório enquadra-se na unidade de formação de estágio profissionalizante, do Mestrado em Engenharia Alimentar da Escola Superior Agrária de Coimbra e traduz algumas partes do trabalho realizado ao longo de 6 meses de estágio, na empresa Rogério Leal. O estágio consistiu na observação, e posterior participação, dos métodos de refinação, hidrogenação, interestereficação e fracionamento do óleo de palma. Neste relatório descreve-se o método de refinação físico e hidrogenação do óleo...

  17. Wave propagation in a general anisotropic poroelastic medium ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 116; Issue 4. Wave propagation in a general anisotropic poroelastic medium: Biot's theories and homogenisation theory. M D Sharma. Volume 116 Issue 4 August ... Keywords. Anisotropic poroelastic (APE) solid; Biot's theory; homogenisation theory; phase velocity.

  18. Ever Ready to Go: The Multiple Exiles of Leo Szilard

    Science.gov (United States)

    Frank, Tibor

    2005-06-01

    I argue that to understand the life and work of Leo Szilard (1898 1964) we have to understand, first, that he was driven by events to numerous departures, escapes, and exiles, changing his religion, his language, his country of residence, and his scientific disciplines; second, that he was a man haunted by major moral dilemmas throughout his life, burdened by a sincere and grave sense of responsibility for the fate of the world; and third, that he experienced a terrible sense of déjà vu: his excessive sensitivity and constant alertness were products of his experiences as a young student in Budapest in 1919. The mature Szilard in Berlin of 1933, and forever after, was always ready to move. I proceed as follows:After a brief introduction to his family background, youth, and education in Budapest, I discuss the impact of his army service in the Great War and of the tumultous events in Hungary in 1918 1919 on his life and psyche, forcing him to leave Budapest for Berlin in late 1919. He completed his doctoral degree under Max von Laue (1879 1960) at the University of Berlin in 1922 and his Habilitationsschrift in 1925. During the 1920s and early 1930s, he filed a number of patents, several of them jointly with Albert Einstein (1879 1955). He left Berlin in March 1933 for London where he played a leading role in the rescue operations for refugee scientists and scholars from Nazi Germany. He also carried out notable research in nuclear physics in London and Oxford before immigrating to the United States at the end of 1938. He drafted Einstein’s famous letter of August 2, 1939, to President Franklin D. Roosevelt, worked in the Manhattan Project during World War II, initiated a petition to President Harry S. Truman not to use the bomb on Japan, and immediately after the war was a leader in the scientists’ movement that resulted in civilian control of nuclear energy. In 1946 he turned to biology, in which his most significant contribution was to formulate a theory of

  19. Spiegel. Medium. Kunst

    DEFF Research Database (Denmark)

    Kacunko, Slavko

    to human talent, came the millennia of untiring labours and the play of art and science and thought. The human love-affair with reflection (to cite Mark Pendergast’s subtitle - Mirror/Mirror: A History of the Human Love Affair with Reflection [New York 2003]) has always been a platonic one and I hold...... and cultural perspective. From 1800 on, the great incentive was to push forward the material-physical and optical-mechanical and especially the media ‘exploitation’ of the mirror. The significance of the mirror as a central meta-medium of the visual emerged in a particularly striking way in the late 1830s...

  20. Resonant Orbital Dynamics in LEO Region: Space Debris in Focus

    Directory of Open Access Journals (Sweden)

    J. C. Sampaio

    2014-01-01

    Full Text Available The increasing number of objects orbiting the earth justifies the great attention and interest in the observation, spacecraft protection, and collision avoidance. These studies involve different disturbances and resonances in the orbital motions of these objects distributed by the distinct altitudes. In this work, objects in resonant orbital motions are studied in low earth orbits. Using the two-line elements (TLE of the NORAD, resonant angles and resonant periods associated with real motions are described, providing more accurate information to develop an analytical model that describes a certain resonance. The time behaviors of the semimajor axis, eccentricity, and inclination of some space debris are studied. Possible irregular motions are observed by the frequency analysis and by the presence of different resonant angles describing the orbital dynamics of these objects.

  1. Nimbus-2 Level 2 Medium Resolution Infrared Radiometer (MRIR) V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The Nimbus II Medium Resolution Infrared Radiometer (MRIR) was designed to measure electromagnetic radiation emitted and reflected from the earth and its atmosphere...

  2. A theory of ionospheric dynamo for complete model of terrestrial space at high and medium latitudes

    International Nuclear Information System (INIS)

    Vardanyan, Yu.S.

    1992-01-01

    A multi-layer model of terrestrial cosmic space at high and medium latitudes is considered in the approximation of infinite conductivity of the Earth taking into account the ambipolar diffusion processes in upper layers of ionosphere. 14 refs

  3. DENSE MEDIUM CYCLONE OPTIMIZATON

    Energy Technology Data Exchange (ETDEWEB)

    Gerald H. Luttrell; Chris J. Barbee; Peter J. Bethell; Chris J. Wood

    2005-06-30

    Dense medium cyclones (DMCs) are known to be efficient, high-tonnage devices suitable for upgrading particles in the 50 to 0.5 mm size range. This versatile separator, which uses centrifugal forces to enhance the separation of fine particles that cannot be upgraded in static dense medium separators, can be found in most modern coal plants and in a variety of mineral plants treating iron ore, dolomite, diamonds, potash and lead-zinc ores. Due to the high tonnage, a small increase in DMC efficiency can have a large impact on plant profitability. Unfortunately, the knowledge base required to properly design and operate DMCs has been seriously eroded during the past several decades. In an attempt to correct this problem, a set of engineering tools have been developed to allow producers to improve the efficiency of their DMC circuits. These tools include (1) low-cost density tracers that can be used by plant operators to rapidly assess DMC performance, (2) mathematical process models that can be used to predict the influence of changes in operating and design variables on DMC performance, and (3) an expert advisor system that provides plant operators with a user-friendly interface for evaluating, optimizing and trouble-shooting DMC circuits. The field data required to develop these tools was collected by conducting detailed sampling and evaluation programs at several industrial plant sites. These data were used to demonstrate the technical, economic and environmental benefits that can be realized through the application of these engineering tools.

  4. GPS Based Reduced-Dynamic Orbit Determination for Low Earth Orbiters with Ambiguity Fixing

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2015-01-01

    Full Text Available With the ever-increasing number of satellites in Low Earth Orbit (LEO for scientific missions, the precise determination of the position and velocity of the satellite is a necessity. GPS (Global Positioning System based reduced-dynamic orbit determination (RPOD method is commonly used in the post processing with high precision. This paper presents a sequential RPOD strategy for LEO satellite in the framework of Extended Kalman Filter (EKF. Precise Point Positioning (PPP technique is used to process the GPS observations, with carrier phase ambiguity resolution using Integer Phase Clocks (IPCs products. A set of GRACE (Gravity Recovery And Climate Experiment mission data is used to test and validate the RPOD performance. Results indicate that orbit determination accuracy could be improved by 15% in terms of 3D RMS error in comparison with traditional RPOD method with float ambiguity solutions.

  5. CALIDAD MICROBIOLÓGICA DE PROPÓLEO CRUDO Y SÓLIDOS SOLUBLES DE EXTRACTOS DE PROPÓLEOS DE Apis mellifera EN COLOMBIA

    Directory of Open Access Journals (Sweden)

    C. Talero

    2012-01-01

    Full Text Available Se tomaron cincuenta y nueve muestras de propóleo crudo recolectadas en tres orígenes geográficos de Colombia, a las cuales se les realizó control de la calidad microbiológica, y se determinó el porcentaje de extracto seco obtenido de las extracciones etanólicas de propóleo ( ee P al 70 y 96%. s e cuantificaron los grupos indicadores mesófilos aerobios, coliformes totales, coliformes fecales, Staphylococcus sp., mohos y levaduras, y se encontraron conteos en promedio de 93x10 3 ; 79x10 2 ; <1; 94; 10x10 4 UFC/g, res - pectivamente. La detección de patógenos se realizó para Escherichia coli y Staphylococcus aureus , los cuales estuvieron presentes en el 4 y 2% de las muestras, respectivamente. Los hallazgos microbiológicos se compararon con normas de calidad de Japón, Perú y e l s alvador; se encontró que el grupo indicador mohos y levaduras fue el más crítico, donde 92 a 94% de las muestras evaluadas estuvieron por fuera de los límites exigidos por estas normas. Los resultados indican que las extracciones con etanol al 70 y 96% de propóleos colombianos, en promedio obtuvieron 93,0 y 175,3 mg/ml de extracto seco, respectivamente. La concentración de extracto seco se comparó con la normatividad existente en Brasil, a rgentina y Japón. Para la norma más exigente, que corresponde a la brasileña, se hallaron porcentajes de cumplimiento del 53,4 y 56,1% para ee P 70 y 96%, respectivamente, y para la norma de Japón se encontraron aceptables 75,9 y 69,7% de los ee P 70 y 96%, respectivamente. Los resultados están asociados al origen fitogeo - gráfico y a la producción no especializada de propóleos. e n este estudio se incluyeron muestras de propóleo crudo de países como Bélgica, Chile, Cuba y Nueva Zelanda.

  6. The science of 'man-eating' among lions Panthera Leo with a ...

    African Journals Online (AJOL)

    The story of the 'Man-eaters of Tsavo' has been retold through script, cinema, and oral tradition in the 100+ years since their infamous 'reign of terror'. Despite their predictably broad popular appeal, the details pertaining to the natural history of these lions Panthera leo have never been reviewed. The skulls and skins of ...

  7. Changes in lion (Panthera leo) home range size in Waza National Park, Cameroon

    NARCIS (Netherlands)

    Tumenta, P.N.; Van't Zelfde, M.; Croes, B.M.; Buij, R.; Funston, P.J.; Haes, de H.A.U.; longh, De H.H.

    2013-01-01

    The spatial ecology of Africa lions (Panthera leo) was studied from 2007 to 2009 in Waza National Park, Cameroon, by equipping individual lions with GPS/VHF radio-collars. Mean home range estimates using 100% minimum convex polygons (MCP) and 95% kernel-density estimation (KDE) were respectively

  8. Leo Kanner's Mention of 1938 in His Report on Autism Refers to His First Patient

    Science.gov (United States)

    Olmsted, Dan; Blaxill, Mark

    2016-01-01

    Leo Kanner begins his landmark 1943 case series on autistic children by stating the condition was first brought to his attention in 1938. Recent letters to "JADD" have described this reference as "mysterious" and speculated it refers to papers published that year by Despert or Asperger. In fact, as Kanner goes on to state, 1938…

  9. The ACS LCID Project - VIII. The short-period Cepheids of Leo A

    NARCIS (Netherlands)

    Bernard, Edouard J.; Monelli, Matteo; Gallart, Carme; Fiorentino, Giuliana; Cassisi, Santi; Aparicio, Antonio; Cole, Andrew A.; Drozdovsky, Igor; Hidalgo, Sebastian L.; Skillman, Evan D.; Stetson, Peter B.; Tolstoy, Eline

    We present the results of a new search for variable stars in the Local Group dwarf galaxy Leo A, based on deep photometry from the Advanced Camera for Surveys onboard the Hubble Space Telescope. We detected 166 bona fide variables in our field, of which about 60 per cent are new discoveries and 33

  10. The ACS LCID Project : VIII. The short-period Cepheids of Leo A

    NARCIS (Netherlands)

    Bernard, Edouard J.; Monelli, Matteo; Gallart, Carme; Fiorentino, Giuliana; Cassisi, Santi; Aparicio, Antonio; Cole, Andrew A.; Drozdovsky, Igor; Hidalgo, Sebastian L.; Skillman, Evan D.; Stetson, Peter B.; Tolstoy, Eline

    2013-01-01

    We present the results of a new search for variable stars in the Local Group dwarf galaxy Leo A, based on deep photometry from the Advanced Camera for Surveys onboard the Hubble Space Telescope. We detected 166 bona fide variables in our field, of which about 60 per cent are new discoveries and 33

  11. Leo Burnett wins agency of the year title in Estonia and Lithuania

    Index Scriptorium Estoniae

    2004-01-01

    Eesti Kuldmuna reklaamikonkursil, Leedu reklaamifestivalil Adrenalinas aasta reklaamiagentuuri tiitli pälvinud ettevõttest Kontuur Leo Burnett. Madis Laas, Tomas Ramanauskas ja Marius Petrukaitis vastavad küsimustele firma edu võimalike põhjuste ja tulevikuplaanide kohta

  12. COMPONENTES MINORITÁRIOS DO ÓLEO DE MAMONA (Ricinus comunnis L.

    Directory of Open Access Journals (Sweden)

    Elina Bastos Caramão

    2007-12-01

    Full Text Available O óleo extraído de sementes de Ricinnus communis L., conhecida como mamona, foi analisado neste trabalho quanto a presença decomponentes minoritários extraídos na fase insaponificável. A extração de insaponificáveis foi realizada conforme o método AOCS(Ca 6a-40 e a análise das amostras de óleo foi realizada por Cromatografia gasosa acoplada a espectrometria de massas (CG-DEMapós derivatização com BSA. Entre as substâncias identificadas encontrou-se o D-tocoferol, g- tocoferol, D5-ergostenol, stigmasterol,obtusifoliol, g-sitosterol, fucosterol e cicloartenol. As amostras de óleo de diferentes variedades de mamona, obtidas por prensagem afrio e por solvente em extrator soxhlet apresentaram diferenças quanto as substâncias separadas. O método empregado para extração eanálise foi apropriado para identificar a presença de componentes minoritários no óleo de mamona.

  13. ALFALFA and WSRT Imaging of Extended H I Features in the Leo Cloud of Galaxies

    NARCIS (Netherlands)

    Leisman, Lukas; Haynes, Martha P.; Giovanelli, Riccardo; Józsa, Gyula; Adams, Elizabeth A. K.; Hess, Kelley M.

    2016-01-01

    We present Arecibo Legacy Fast ALFA (ALFALFA) H I observations of a well-studied region of the Leo Cloud, which includes the NGC 3227 group and the NGC 3190 group. We detect optically dark H I tails and plumes with extents potentially exceeding 600 kpc, well beyond the field of view of previous

  14. Tagakiusamine ja kirjutamiskunst / Leo Strauss ; järelsõna Jüri Lipping

    Index Scriptorium Estoniae

    Strauss, Leo, 1899-1973

    2000-01-01

    Ajalooliste tekstide ridade vahele peidetud sõnumi lugemisest. Tsensuuri mõjust filosoofilistele tekstidele. Peidetud sõnumi lugemisest lähtuvast erinevusest eelmoodsate ja uusaegsete filosoofide teostes. Jüri Lipping'u järelsõna Leo Straussi filosoofilistest vaadetest.

  15. Leo A : A late-blooming survivor of the epoch of reionization in the local group

    NARCIS (Netherlands)

    Cole, Andrew A.; Skillman, Evan D.; Tolstoy, Eline; Gallagher, John S.; Aparicio, Antonio; Dolphin, Andrew E.; Gallart, Carme; Hidalgo, Sebastian L.; Saha, Abhijit; Stetson, Peter B.; Weisz, Daniel R.

    2007-01-01

    As part of a major program to use isolated Local Group dwarf galaxies as near-field probes of cosmology, we have obtained deep images of the dwarf irregular galaxy Leo A with the Advanced Camera for Surveys aboard the Hubble Space Telescope. From these images we have constructed a color-magnitude

  16. EC-Earth V2.2: description and validation of a new seamless earth system prediction model

    NARCIS (Netherlands)

    Hazeleger, W.; Wang, X.; Severijns, C.; Linden, van der E.C.

    2012-01-01

    EC-Earth, a new Earth system model based on the operational seasonal forecast system of the European Centre for Medium-Range Weather Forecasts (ECMWF), is presented. The performance of version 2.2 (V2.2) of the model is compared to observations, reanalysis data and other coupled atmosphere–ocean-sea

  17. Availability of Earth resources data

    Science.gov (United States)

    ,

    1976-01-01

    The purpose of this booklet is to help the reader to become aware of the volume of Earth resources data that have been collected by agencies of the United States Government and to find out where and how these data may be obtained. Earth resources data as discussed here are those obtained by remote-sensing instruments, including aerial cameras, multispectral cameras, multispectral scanners, and radar. They are obtained by spacecraft and high-altitude aircraft. Also, various agencies have been acquiring vast quantities of conventional aerial mapping photography from low and medium altitudes for more than 50 years. There is also brief information to assist the reader in locating published references and identifying research projects relating to application of Earth resources data to a variety of purposes. In all cases, it is not the intent to say what data are needed or how the data are to be used, but to describe where an interested person can begin to locate Earth resources data.

  18. Leo Sgouros – Tyrant and Patriot. The Ruler of the Northeastern Peloponnese in the Early 13th Century

    Directory of Open Access Journals (Sweden)

    Viktor N. Chkhaidze

    2017-11-01

    Full Text Available Leo Sgouros is one of the Byzantine magnates who ruled in the northeastern Peloponnese in the late 12th – early 13th centuries. The paper discusses the separatist activity of the Leo Sgouros which allowed him in a short time to create ephemeral ‘state’ in the South of Thessaly, Boeotia, Attica, Corinth and the Argolid. In order to give legitimacy to his authority Leo Sgouros married the daughter of the deposed Emperor Alexios III. But his way from separatism to Imperial idea was interrupted by the clash with the knights of the Latin Empire who have predetermined his defeat. Among the reasons for the defeat we can name the enmity with the clergy and nonpossibility of joining with other governors in fighting the crusaders. According to later legend, Leo Sgouros died, throwing himself with his horse from the cliff of the Acrocorinth fortress, besieged by the crusaders. According to another version, Leo Sgouros died under the walls of his native city Nauplius. The study examined the seal of the Leo Sgouros with a rare title of sebastohypertatos (higher sebastos, and similar seal which was reused by John Branas. Data analysis suggests that such a contradictory personality as Leo Sgouros’ may be characterized not only as an ambitious tyrant and the defender of Byzantine Hellenism. The Annex contains information about the seven of Sgouros names that have become known in recent years by virtue of the monuments of sphragistics.

  19. Precision Assessment of Near Real Time Precise Orbit Determination for Low Earth Orbiter

    Science.gov (United States)

    Choi, Jong-Yeoun; Lee, Sang-Jeong

    2011-03-01

    The precise orbit determination (POD) of low earth orbiter (LEO) has complied with its required positioning accuracy by the double-differencing of observations between International GNSS Service (IGS) and LEO to eliminate the common clock error of the global positioning system (GPS) satellites and receiver. Using this method, we also have achieved the 1 m positioning accuracy of Korea Multi-Purpose Satellite (KOMPSAT)-2. However double-differencing POD has huge load of processing the global network of lots of ground stations because LEO turns around the Earth with rapid velocity. And both the centimeter accuracy and the near real time (NRT) processing have been needed in the LEO POD applications--atmospheric sounding or urgent image processing--as well as the surveying. An alternative to differential GPS for high accuracy NRT POD is precise point positioning (PPP) to use measurements from one satellite receiver only, to replace the broadcast navigation message with precise post processed values from IGS, and to have phase measurements of dual frequency GPS receiver. PPP can obtain positioning accuracy comparable to that of differential positioning. KOMPSAT-5 has a precise dual frequency GPS flight receiver (integrated GPS and occultation receiver, IGOR) to satisfy the accuracy requirements of 20 cm positioning accuracy for highly precise synthetic aperture radar image processing and to collect GPS radio occultation measurements for atmospheric sounding. In this paper we obtained about 3-5 cm positioning accuracies using the real GPS data of the Gravity Recover and Climate Experiment (GRACE) satellites loaded the Blackjack receiver, a predecessor of IGOR. And it is important to reduce the latency of orbit determination processing in the NRT POD. This latency is determined as the volume of GPS measurements. Thus changing the sampling intervals, we show their latency to able to reduce without the precision degradation as the assessment of their precision.

  20. Alfalfa discovery of the nearby gas-rich dwarf galaxy Leo P. IV. Distance measurement from LBT optical imaging

    Energy Technology Data Exchange (ETDEWEB)

    McQuinn, Kristen B. W.; Skillman, Evan D.; Berg, Danielle [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, S.E., University of Minnesota, Minneapolis, MN 55455 (United States); Cannon, John M. [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Salzer, John J.; Rhode, Katherine L. [Department of Astronomy, Indiana University, 727 East 3rd Street, Bloomington, IN 47405 (United States); Adams, Elizabeth A. K.; Giovanelli, Riccardo; Haynes, Martha P. [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Dolphin, Andrew, E-mail: kmcquinn@astro.umn.edu, E-mail: skillman@astro.umn.edu, E-mail: berg@astro.umn.edu, E-mail: jcannon@macalester.edu, E-mail: rhode@astro.indiana.edu, E-mail: slaz@astro.indiana.edu, E-mail: betsey@astro.cornell.edu, E-mail: riccardo@astro.cornell.edu, E-mail: haynes@astro.cornell.edu [Raytheon Company, 1151 E. Hermans Road, Tucson, AZ 85756 (United States)

    2013-12-01

    Leo P is a low-luminosity dwarf galaxy discovered through the blind H I Arecibo Legacy Fast ALFA survey. The H I and follow-up optical observations have shown that Leo P is a gas-rich dwarf galaxy with both active star formation and an underlying older population, as well as an extremely low oxygen abundance. Here, we measure the distance to Leo P by applying the tip of the red giant branch (TRGB) distance method to photometry of the resolved stellar population from new Large Binocular Telescope V and I band imaging. We measure a distance modulus of 26.19{sub −0.50}{sup +0.17} mag corresponding to a distance of 1.72{sub −0.40}{sup +0.14} Mpc. Although our photometry reaches 3 mag below the TRGB, the sparseness of the red giant branch yields higher uncertainties on the lower limit of the distance. Leo P is outside the Local Group with a distance and velocity consistent with the local Hubble flow. While located in a very low-density environment, Leo P lies within ∼0.5 Mpc of a loose association of dwarf galaxies which include NGC 3109, Antlia, Sextans A, and Sextans B, and 1.1 Mpc away from its next nearest neighbor, Leo A. Leo P is one of the lowest metallicity star-forming galaxies known in the nearby universe, comparable in metallicity to I Zw 18 and DDO 68, but with stellar characteristics similar to dwarf spheriodals (dSphs) in the Local Volume such as Carina, Sextans, and Leo II. Given its physical properties and isolation, Leo P may provide an evolutionary link between gas-rich dwarf irregular galaxies and dSphs that have fallen into a Local Group environment and been stripped of their gas.

  1. CARACTERIZAÇÃO QUÍMICA DE ÓLEOS ESSENCIAIS DE PLANTAS MEDICINAIS

    Directory of Open Access Journals (Sweden)

    Ranieli Paiva Lopes

    2017-01-01

    Full Text Available Os óleos essenciais são substâncias naturais de grande importância econômica, sendo utilizados como medicamentos, perfumarias, alimentos e cosméticos. São obtidos por diferentes métodos de extração e encontrados em diferentes partes das plantas. Desta forma o trabalho teve como objetivo a coleta, preparação e a extração do óleo essencial de várias espécies realizada através de hidrodestilação durante 4 horas utilizando o aparelho Clevenger. Foi avaliado o rendimento de extração do óleo essencial e a sua composição química por cromatografia a gás com detectores FID e Espectrometria de Massas. A identificação dos constituintes dos óleos essênciais foi realizada através de comparação com dados da biblioteca do equipamento de Espectrometria de Massas e os cálculos do Índice de Kovats. Os teores em % (massa/massa dos óleo essenciais foram: alecrim 1,13%, levante 0,58%, manjericão 0,24%, hortelã 0,25% e hortelã pimenta 0,75%. Foram identificados vários compostos majoritários tais como:alfa-pineno, o-cimene, germacreno-D, Linalol, Acetato de linalila e cariofileno.

  2. The Binary Fraction of Stars in Dwarf Galaxies: The Case of Leo II

    Science.gov (United States)

    Spencer, Meghin E.; Mateo, Mario; Walker, Matthew G.; Olszewski, Edward W.; McConnachie, Alan W.; Kirby, Evan N.; Koch, Andreas

    2017-06-01

    We combine precision radial velocity data from four different published works of the stars in the Leo II dwarf spheroidal galaxy. This yields a data set that spans 19 years, has 14 different epochs of observation, and contains 372 unique red giant branch stars, 196 of which have repeat observations. Using this multi-epoch data set, we constrain the binary fraction for Leo II. We generate a suite of Monte Carlo simulations that test different binary fractions using Bayesian analysis and determine that the binary fraction for Leo II ranges from {0.30}-0.10+0.09 to {0.34}-0.11+0.11, depending on the distributions of binary orbital parameters assumed. This value is smaller than what has been found for the solar neighborhood (˜0.4-0.6) but falls within the wide range of values that have been inferred for other dwarf spheroidals (0.14-0.69). The distribution of orbital periods has the greatest impact on the binary fraction results. If the fraction we find in Leo II is present in low-mass ultra-faints, it can artificially inflate the velocity dispersion of those systems and cause them to appear more dark matter rich than in actuality. For a galaxy with an intrinsic dispersion of 1 km s-1 and an observational sample of 100 stars, the dispersion can be increased by a factor of 1.5-2 for Leo II-like binary fractions or by a factor of three for binary fractions on the higher end of what has been seen in other dwarf spheroidals.

  3. LEO P: HOW MANY METALS CAN A VERY LOW MASS, ISOLATED GALAXY RETAIN?

    Energy Technology Data Exchange (ETDEWEB)

    McQuinn, Kristen B. W.; Skillman, Evan D. [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, S.E., University of Minnesota, Minneapolis, MN 55455 (United States); Dolphin, Andrew [Raytheon Company, 1151 E. Hermans Road, Tucson, AZ 85756 (United States); Cannon, John M. [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Salzer, John J.; Rhode, Katherine L. [Department of Astronomy, Indiana University, 727 East 3rd Street, Bloomington, IN 47405 (United States); Adams, Elizabeth A. K. [ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA, Dwingeloo (Netherlands); Berg, Danielle [Center for Gravitation, Cosmology and Astrophysics, Department of Physics, University of Wisconsin Milwaukee, 1900 East Kenwood Boulevard, Milwaukee, WI 53211 (United States); Giovanelli, Riccardo; Haynes, Martha P., E-mail: kmcquinn@astro.as.utexas.edu [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States)

    2015-12-20

    Leo P is a gas-rich dwarf galaxy with an extremely low gas-phase oxygen abundance (3% solar). The isolated nature of Leo P enables a quantitative measurement of metals lost solely due to star formation feedback. We present an inventory of the oxygen atoms in Leo P based on the gas-phase oxygen abundance measurement, the star formation history (SFH), and the chemical enrichment evolution derived from resolved stellar populations. The SFH also provides the total amount of oxygen produced. Overall, Leo P has retained 5% of its oxygen; 25% of the retained oxygen is in the stars while 75% is in the gas phase. This is considerably lower than the 20%–25% calculated for massive galaxies, supporting the trend for less efficient metal retention for lower-mass galaxies. The retention fraction is higher than that calculated for other alpha elements (Mg, Si, Ca) in dSph Milky Way satellites of similar stellar mass and metallicity. Accounting only for the oxygen retained in stars, our results are consistent with those derived for the alpha elements in dSph galaxies. Thus, under the assumption that the dSph galaxies lost the bulk of their gas mass through an environmental process such as tidal stripping, the estimates of retained metal fractions represent underestimates by roughly a factor of four. Because of its isolation, Leo P provides an important datum for the fraction of metals lost as a function of galaxy mass due to star formation.

  4. Semen cryopreservation and radical reduction capacity of seminal fluid in captive African lion (Panthera leo).

    Science.gov (United States)

    Luther, I; Jakop, U; Lueders, I; Tordiffe, A; Franz, C; Schiller, J; Kotze, A; Müller, K

    2017-02-01

    Optimizing cryopreservation protocols for nondomestic felids contributes to the successful development of assisted reproduction techniques and genetic resource banking. In this study, we describe a simple cryopreservation procedure for African lion (Panthera leo) ejaculates, which was tested with different packaging options and different sperm numbers per dose. By applying urethral catheterization and electroejaculation, 17 ejaculates with greater than 20% motile and greater than 5% progressively motile sperm were collected. A lyophilized extender (a modified egg yolk-Tes-Tris-fructose-glycerol medium) was rehydrated and added in one step at ambient temperature (∼25 °C) to semen, which was prediluted in cell culture medium M199. After slow cooling of insulated samples to 15 °C in a refrigerator (4 °C), the samples were fast frozen over the surface of liquid nitrogen or in a dry shipper. Aliquots of 300 μL containing 20 × 10 6 sperm were frozen in cryovials and in 0.5-mL straws. Differences were observed in the total motility after thawing between vial (31.5 ± 14.1%) and straw freezing (20.1 ± 8.6%). However, the subpopulations of vital (22.7 ± 7.8% for vial and 19.8 ± 8.5% for straw) and progressively motile (10.0 ± 7.9% for vial and 10.0 ± 6.4% for straw) sperm after washing and 1 hour incubation at 38 °C were of similar magnitude, velocity, and linearity for both packaging options. After freezing of five ejaculates with 20, 60, and 100 × 10 6 sperm per dose, best results were achieved at the lowest concentration. In general, post-thaw results were highly variable (2.2% and 56.5% total motility) and not correlated to motility or morphology of the fresh semen. To further characterize semen quality, we assessed the protective potential of seminal fluid against oxidative stress, which might be challenged on freeze thawing. The capacity of seminal fluid to reduce radicals was measured in 10 semen samples by electron spin resonance

  5. Controle fitopatológico do Fusarium subglutinans pelo óleo essencial do capim-citronela (Cymbopogon nardus L. e do composto citronelal Fungitoxic activity of essential oil of citronella grass (Cymbopogon nardus L. and compound citronellal

    Directory of Open Access Journals (Sweden)

    P.T.L. Seixas

    2011-01-01

    Full Text Available Este trabalho teve como objetivo avaliar o efeito fungitóxico do óleo essencial de capim-citronela e do seu constituinte majoritário citronelal sobre a inibição micelial do fitopatógeno Fusarium subglutinans, agente causal da fusariose da cultura do abacaxi (Ananas comosus. Para avaliar o efeito do óleo essencial no crescimento micelial do fungo, foram utilizadas seis alíquotas (0, 5, 10, 15, 20 e 25 ìL do óleo e do citronelal que foram distribuídas na superfície do meio BDA (batata-dextrose-ágar antes da repicagem do fungo. O crescimento micelial foi medido após 48 h de instalação do experimento e em cinco épocas de avaliação (2, 4, 6, 8 e 10 dias após repicagem. Os resultados indicaram que o óleo essencial do capim-citronela demonstrou maior efeito inibitório do crescimento micelial do fungo F. subglutinans do que o composto citronelal. Em todas as alíquotas utilizadas o óleo essencial proporcionou menor taxa de crescimento micelial do que o citronelal.This study aimed to evaluate the fungitoxic effect of the essential oil of citronella grass and its major constituent citronellal on the inhibition of mycelial pathogen Fusarium subglutinans, the causal agent of Fusarium culture of pineapple (Ananas comosus. To evaluate the effect of essential oil in the mycelial growth of the fungus were used six rates (0, 5, 10, 15, 20 and 25 mL of oil that were distributed on the surface of PDA medium (potato dextrose agar before subculturing of the fungus. Mycelial growth was measured after 48 h of the experiment and five times of assessment (2, 4, 6, 8 and 10 days after subculturing. The results indicated that the essential oil of citronella grass showed higher inhibitory effect of mycelial growth of the fungus F. subglutinans than compound citronellal. In all rates used of the essential oil gave lower growth rate than the mycelial citronellal.

  6. Atividade repelente do óleo essencial de Ocimum selloi Benth. (variedade eugenol) contra o anopheles braziliensis chagas

    OpenAIRE

    Paula, Josiane P.; Farago, Paulo V.; Checchia, Lizianne E. M.; Hirose, Karla M.; Ribas, Joao L.

    2004-01-01

    Ocimum selloi Benth. (Lamiaceae) é uma planta herbácea nativa do Brasil. Seu óleo essencial tem sido utilizado como flavorizante em comidas e em produtos orais e como componente de fragrâncias. O objetivo do presente trabalho foi avaliar a atividade repelente de mosquitos do óleo essencial de O. selloi (variedade eugenol) em humanos. O óleo essencial foi obtido por hidrodestilação das folhas da espécie. Em estudo de campo, no qual seis voluntários (cada qual como seu próprio contr...

  7. Criação de valor sustentável e o óleo de palma no Brasil

    OpenAIRE

    Almeida, Julio Ribeiro

    2012-01-01

    A produção de óleo de palma expandiu-se consideravelmente nas últimas décadas e atualmente o óleo de palma é o óleo vegetal mais comercializado do mundo. Dentre outros fatores, a maior produtividade da cultura e os menores custos de produção explicam o crescimento. Os grandes produtores mundiais, contudo, destruíram grandes áreas de floresta para acomodar o crescimento da plantação e se utilizaram de técnicas de cultivo que trouxeram severos impactos ambientais. Campanhas lider...

  8. O preço do petróleo como factor global: análise sectorial

    OpenAIRE

    Martinho, Isabel Rodrigues

    2010-01-01

    Mestrado em Finanças/ G12; Q40 Nos últimos anos tornou-se bastante popular o investimento em commodities, nomeadamente, em petróleo. Entre as várias possibilidades que existem, uma delas é o investimento em acções de empresas do sector petrolífero. Esta tese emprega um modelo multifactorial para identificar, no período 2000-2009, os principais determinantes da rendibilidade dos sectores de produtores de petróleo e gás; equipamentos, serviços e distribuição de petróleo;...

  9. Guilda de abelhas coletoras de óleo (APOIDEA) associada à Byrsonima sericea e Byrsonima cydoniifolia (Malpighiaceae)

    OpenAIRE

    Lua, Shantala

    2013-01-01

    As abelhas coletoras de óleos florais apresentam relações bastante estreitas com espécies de Malpighiaceae. Este estudo tem como objetivo caracterizar a guilda de abelhas que visitam duas espécies de Byrsonima (Malpighiaceae) e investigar se a variação na oferta de óleo floral influencia na riqueza e abundância local destas abelhas, em uma área na Chapada Diamantina. As abelhas foram coletadas com redes entomológicas durante a visita às flores de Byrsonima e a oferta de óleo floral foi estima...

  10. Performance evaluation of propulsion systems as LEO deorbiting devices

    Directory of Open Access Journals (Sweden)

    Alexandru IONEL

    2017-09-01

    Full Text Available This paper evaluates the possibility of deorbiting a launch vehicle upper-stage at end-of-mission from low Earth orbit, by using an additional propulsion system as a means of achieving deorbiting and complying with the “25 years” mitigation regulation. The deorbiting performances of chemical and electrical propulsion are analyzed through a MATLAB code which integrates orbital perturbations such as gravitational acceleration, atmospheric drag and rocket engine/motor thrust. Additionally, the research is placed within a body of similar papers concerned with deorbiting by means of propulsion, by performing a state of the art study.

  11. The Space Mission Design Example Using LEO Bolos

    Directory of Open Access Journals (Sweden)

    Oleg Nizhnik

    2013-12-01

    Full Text Available Four sample space launch missions were designed using rotating momentum transfer tethers (bolos within low Earth orbit and a previously unknown phenomenon of “aerospinning” was identified and simulated. The momentum transfer tethers were found to be only marginally more efficient than the use of chemical rocket boosters. Insufficient power density of modern spacecrafts was identified as the principal inhibitory factor for tether usage as a means of launch-assistance, with power densities at least 10 W/kg required for effective bolos operation.

  12. Geolocation applications of the Gonets LEO messaging satellites

    Science.gov (United States)

    Vlasov, Vladimir N.; Ashjaee, Javad M.

    Geostationary satellites carry a majority of the international telecommunications traffic not carried by transoceanic cable. However, because the radio path links to and from geostationary satellites total at least 70,000 km and because of inherent on-board spacecraft power limitations, earth stations used in conjunction with geostationary satellites are usually large and expensive. This limits their installation to areas with a well-developed industrial and economic infrastructure. This reality helps perpetuate a chicken egg dilemma for the developing countries and isolated regions. Economic integration with the developed world requires being 'networked'. But for many developing entities, even the initial price of entry exceeds their modest resources. Exclusion from the global information highways virtually assures retardation of economic growth for developing nations, remote and isolated areas. Very Small Aperture Terminal (VSAT) earth stations are often thought of as a solution for networking developing regions. But economic considerations often forecloses this option. If VSAT size and cost is to be minimized, powerful spot beams from the satellite need to be focused on relatively small regions. This is not often feasible because of the high cost of the satellite itself. To dedicate a high power spot beam to a small region is usually not economically feasible.

  13. Earth mortars and earth-lime renders

    Directory of Open Access Journals (Sweden)

    Maria Fernandes

    2008-01-01

    Full Text Available Earth surface coatings play a decorative architectural role, apart from their function as wall protection. In Portuguese vernacular architecture, earth mortars were usually applied on stone masonry, while earth renders and plasters were used on indoors surface coatings. Limestone exists only in certain areas of the country and consequently lime was not easily available everywhere, especially on granite and schist regions where stone masonry was a current building technique. In the central west coast of Portugal, the lime slaking procedure entailed slaking the quicklime mixed with earth (sandy soil, in a pit; the resulting mixture would then be combined in a mortar or plaster. This was also the procedure for manufactured adobes stabilized with lime. Adobe buildings with earth-lime renderings and plasters were also traditional in the same region, using lime putty and lime wash for final coat and decoration. Classic decoration on earth architecture from the 18th-19th century was in many countries a consequence of the François Cointeraux (1740-1830 manuals - Les Cahiers d'Architecture Rurale" (1793 - a French guide for earth architecture and building construction. This manual arrived to Portugal in the beginning of XIX century, but was never translated to Portuguese. References about decoration for earth houses were explained on this manual, as well as procedures about earth-lime renders and ornamentation of earth walls; in fact, these procedures are exactly the same as the ones used in adobe buildings in this Portuguese region. The specific purpose of the present paper is to show some cases of earth mortars, renders and plasters on stone buildings in Portugal and to explain the methods of producing earth-lime renders, and also to show some examples of rendering and coating with earth-lime in Portuguese adobe vernacular architecture.

  14. Near Earth Objects

    DEFF Research Database (Denmark)

    Wolff, Stefan

    2006-01-01

    , Near Earth Objects: Asteroids and comets following paths that bring them near the Earth. NEOs have collided with the Earth since its formation, some causing local devastation, some causing global climate changes, yet the threat from a collision with a near Earth object has only recently been recognised...

  15. Desenvolvimento de uma unidade virtual para desasfaltação de resíduos pesados de petróleo para maximização de óleo desasfaltado e daí óleo lubrificante

    OpenAIRE

    Ayda Karina León Ayala

    2011-01-01

    Resumo: O aumento mundial na demanda de energia e o descobrimento de óleo pesado e viscoso por parte da PETROBRAS nos últimos anos têm incrementado o desenvolvimento de novas tecnologias no Brasil para o processamento deste tipo de petróleo, assim como a adequação dos processos já existentes nas refinarias, visando atingir os requerimentos do mercado ao se obter produtos leves de alto valor comercial. No caso da produção de óleos lubrificantes tem se aumentado a necessidade de se conhecer o p...

  16. Propriedade antibacteriana de óleos essenciais de especiarias sobre bactérias contaminantes de alimentos Antibacterial property of spice essential oils on food contaminating bacteria

    Directory of Open Access Journals (Sweden)

    Vinicius Nogueira Trajano

    2009-09-01

    Full Text Available As especiarias são conhecidas por exercerem uma estabilidade frente à ação de microrganismos, estando inseridas no grupo dos alimentos estáveis. Esta propriedade conservante das especiarias está relacionada com a presença de compostos antibacterianos na sua composição. Tais compostos podem ser usados no combate a bactérias deteriorantes de alimentos, por esse motivo, este trabalho visa à investigação da propriedade antimicrobiana dos óleos essenciais de Cinnamomum zeylanicum Blume, Coriandrum sativum L., Cuminum cyminum L., Mentha. piperita L., Ocimum basilicum L., Origanum majorana L., Pimpinella anisum L., Piper nigrum L., Rosmarinus officinalis L. e Zingiber officinalis Rosc. frente a bactérias contaminantes de alimentos. Para esse estudo, foram selecionadas 10 cepas bacterianas deteriorantes de alimentos. Para a realização dos ensaios antibacterianos, foi utilizado o método de difusão em meio sólido. Os resultados mostram que os óleos essenciais das folhas do E. caryophyllata e da C. zeylanicum mostraram uma eficiência na inibição de todas as cepas bacterianas ensaiadas. Os outros óleos produziram atividade antibacteriana, porém com menor espectro de ação. A pesquisa de tais produtos mostra-se bastante promissora, sendo essa uma boa alternativa para a substituição de aditivos químicos em alimentos.Spices are known for their stability against microbial action; that being so, they are included in the group of stable foods. This preservative property of spices is related to the presence of antibacterial compounds in their composition. Such compounds could be used to control the food contaminating bacteria. This study aimed to assess the antimicrobial property of the essential oils from Cinnamomum zeylanicum Blume, Coriandrum sativum L., Cuminum cyminum L., Mentha. piperita L., Ocimum basilicum L., Origanum majorana L., Pimpinella anisum L., Piper nigrum L., Rosmarinus officinalis L., and Zingiber officinalis Rosc

  17. Earth Observation Missions at OHB System

    Science.gov (United States)

    Tobehn, C.; Penné, B.; Kassebom, M.; Ziegler, B.; Mahal, S.; Greinacher, R.; Holsten, S.; Borowy, C.

    2008-08-01

    This paper covers the current OHB-System AG activities in the field of Earth Observation with small satellites ranging from science and research towards commercial and security missions. Very highresolution, multi-spectral, hyperspectral, as well as very high resolution SAR mission concepts are presented including the following projects: The SAR-Lupe constellation generates very high resolution SAR images for military reconnaissance purposes. It is developed by OHB-System and reaches full in-orbit deployment in 2008. EnMAP - featuring an innovative hyperspectral sensor systems for the detailed and global analysis of eco-system parameters. Very high resolution SAR and Optical Constellations of 1m resolution are currently investigated for emergency response and disaster management, which require a fast system response-time. Data Relay from GEO relaxes the typical EO bottle-neck in downloading data. Therefore it enables an increase of LEO observation time and reduces image ageing as well as system response time by direct EO satellite tasking. Ocean-Colour from GEO shall be a sustainable source for intra-daily observations of coastal zones for environment monitoring, fishery management and coastal water pollution. Next Generation very high resolution missions below 1m resolution are proposed for reconnaissance and dual-use applications for commercial customers. New services and products are under development for a range of applications, including hyperspectral data exploitation, data fusion with in-situ systems for maritime environment, security as well as for air quality services. The realisation of an end-user oriented infrastructure - including space and ground segment - for commercial Earth observation is a key element of OHB-System's Earth observation activities.

  18. Uma contribuição à logística da indústria do petróleo

    OpenAIRE

    Borsani, Angelo João

    2001-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de Produção. No campo da Logística Inbound na indústria do petróleo, a função de maior impacto econômico é a aquisição (operações de trading) de matéria prima sob a forma de óleo bruto para posterior processamento e transformação em derivados. Os preços dos petróleos, no cenário internacional, estão em geral vinculados às cotações de dois óleos referenciais, West Tex...

  19. Seismic anisotropy inside the Earth from a model space search approach

    NARCIS (Netherlands)

    Beghein, Caroline

    2003-01-01

    For theoretical and computational convenience, the Earth has long been modelled as an isotropic medium for wave propagation. There is, however, considerable evidence of seismic anisotropy at different depths and different scales throughout the Earth, which can provide insight into Earth's dynamic

  20. Reciclo-óleo: do óleo de cozinha ao sabão ecológico, um projeto de educação ambiental

    Directory of Open Access Journals (Sweden)

    Maria Isabel Morgan Martins

    2016-10-01

    Full Text Available O consumo de óleo faz parte do dia-a-dia das famílias, restaurantes, indústrias e com ele o descarte incorreto do óleo de cozinha usado (OCU se torna um grave problema ambiental. Quando despejado no lixo comum impermeabiliza e contamina o solo, porque a decomposição aumenta o efeito estufa, na rede de esgoto compromete as tubulações das residências e das cidades e ao atingir os rios forma uma película na água que impede a passagem de luz e oxigênio a flora e a fauna aquática. Objetivo: é promover a educação ambiental para o descarte correto e a reciclagem do óleo de cozinha usado, transformando-o em sabão em barra ecológico, gerando renda e sustentabilidade. Método/ atividades de extensão: o projeto apresenta duas linhas bem definidas à educação ambiental e o desenvolvimento de receitas que transformam do OCU em sabão em barra ecológico. O projeto educa para a consciência e responsabilidade ambiental a diferentes grupos da comunidade, ensina e orienta a importância de dar o destino correto ao OCU, bem como, a reciclagem com sustentabilidade, criando alternativa de geração de renda. Desde 2010, as oficinas foram realizadas em diferentes bairros, escolas e empresas dos municípios da grande Porto Alegre, RS. As receitas foram desenvolvidas no laboratório do campus da ULBRA Gravataí, e apresentam baixo custo, para a fabricação “caseira” do sabão ecológico. O primeiro processo é educar com consciência ambiental. Considerações finais: o reciclo-óleo contribui para o combate à poluição e manutenção dos recursos naturais. Portanto, com ações de educação em saúde é possível refletir positivamente na preservação do meio ambiente, contribuindo, dessa forma, para o desenvolvimento sustentável e para a promoção da saúde das cidades.

  1. TRIFLE DIFFERENCE APPROACH TO LOW EARTH ORBITER PRECISION ORBIT DETERMINATION

    Directory of Open Access Journals (Sweden)

    Jay Hyoun Kwon

    2003-03-01

    Full Text Available A precise kinematic orbit determination (P-KOD procedure for Low Earth Orbiter(LEO using the GPS ion-free triple differenced carrier phases is presented. Because the triple differenced observables provide only relative information, the first epoch`s positions of the orbit should be held fixed. Then, both forward and backward filtering was executed to mitigate the effect of biases of the first epoch`s position. p-KOD utilizes the precise GPS orbits and ground stations data from International GPS Service (IGS so that the only unknown parameters to be solved are positions of the satellite at each epoch. Currently, the 3-D accuracy off-KOD applied to CHAMP (CHAllenging Min-isatellite Payload shows better than 35 cm compared to the published rapid scientific orbit (RSO solution from GFZ (GeoForschungsZentrum Potsdam. The data screening for cycle slips is a particularly challenging procedure for LEO, which moves very fast in the middle of the ionospheric layer. It was found that data screening using SNR (signal to noise ratio generates best results based on the residual analysis using RSO. It is expected that much better accuracy are achievable with refined prescreening procedure and optimized geometry of the satellites and ground stations.

  2. Triple Difference Approach to Low Earth Orbiter Precision Orbit Determination

    Science.gov (United States)

    Kwon, Jay-Hyoun; Grejner-Brzezinska, Dorota A.; Yom, Jae-Hong; Cheon, Lee-Dong

    2003-03-01

    A precise kinematic orbit determination (P-KOD) procedure for Low Earth Orbiter(LEO) using the GPS ion-free triple differenced carrier phases is presented. Because the triple differenced observables provide only relative information, the first epoch's positions of the orbit should be held fixed. Then, both forward and backward filtering was executed to mitigate the effect of biases of the first epoch's position. P-KOD utilizes the precise GPS orbits and ground stations data from International GPS Service (IGS) so that the only unknown parameters to be solved are positions of the satellite at each epoch. Currently, the 3-D accuracy of P-KOD applied to CHAMP (CHAllenging Minisatellite Payload) shows better than 35 cm compared to the published rapid scientific orbit (RSO) solution from GFZ (GeoForschungsZentrum Potsdam). The data screening for cycle slips is a particularly challenging procedure for LEO, which moves very fast in the middle of the ionospheric layer. It was found that data screening using SNR (signal to noise ratio) generates best results based on the residual analysis using RSO. It is expected that much better accuracy are achievable with refined prescreening procedure and optimized geometry of the satellites and ground stations.

  3. Orbit Propagation and Determination of Low Earth Orbit Satellites

    Directory of Open Access Journals (Sweden)

    Ho-Nien Shou

    2014-01-01

    Full Text Available This paper represents orbit propagation and determination of low Earth orbit (LEO satellites. Satellite global positioning system (GPS configured receiver provides position and velocity measures by navigating filter to get the coordinates of the orbit propagation (OP. The main contradictions in real-time orbit which is determined by the problem are orbit positioning accuracy and the amount of calculating two indicators. This paper is dedicated to solving the problem of tradeoffs. To plan to use a nonlinear filtering method for immediate orbit tasks requires more precise satellite orbit state parameters in a short time. Although the traditional extended Kalman filter (EKF method is widely used, its linear approximation of the drawbacks in dealing with nonlinear problems was especially evident, without compromising Kalman filter (unscented Kalman Filter, UKF. As a new nonlinear estimation method, it is measured at the estimated measurements on more and more applications. This paper will be the first study on UKF microsatellites in LEO orbit in real time, trying to explore the real-time precision orbit determination techniques. Through the preliminary simulation results, they show that, based on orbit mission requirements and conditions using UKF, they can satisfy the positioning accuracy and compute two indicators.

  4. Nickel-hydrogen cell low-Earth life test update

    Science.gov (United States)

    Frate, David T.

    When individual pressure vessel (IPV) nickel-hydrogen (Ni/H2) cells were selected as the energy storage system for the Space Station Freedom in March of 1986, a limited database existed on life and performance characteristics of these cells in a low earth orbit (LEO) regime. Therefore, NASA LeRC initiated a Ni/H2 cell test program with the primary objectives of building a test facility, procuring cells from existing NASA contracts, and screening several cell designs by life testing in a LEO 35 percent depth of discharge (DOD) scenario. A total of 40 cells incorporating 13 designs were purchased from Yardney, Hughes, and Eagle-Picher. Thirty-two of the cells purchased were 65 A-hr nameplate capacity and eight cells were 50 A-hr. Yardney and Eagle-Picher cells were built with both the Air Force recirculating and the advanced back-to-back electrode stack configurations and incorporated 31 and 26 percent KOH. Acceptance testing of the first delivered cells began in March of 1988, with life testing following in September of that year.Performance comparisons of these cells are made here while specifically addressing life test data relative to the design differences.

  5. Advanced Exo-Brake Development: Parachuting Small Payloads in a Single-Stage from Low Earth Orbit (LEO)

    Data.gov (United States)

    National Aeronautics and Space Administration — What is an Exo-Brake/How Does it Work?: The Exo-Brake is a Exo-Atmopsheric drag device that dramatically reduces the ballistic coefficient (above) such that de-orbit...

  6. Low earth orbit satellite/terrestrial mobile service compatibility

    Science.gov (United States)

    Sheriff, R. E.; Gardiner, J. G.

    Digital cellular mobile 'second generation' systems are now gradually being introduced into service; one such example is GSM, which will provide a digital voice and data service throughout Europe. Total coverage is not expected to be achieved until the mid '90's, which has resulted in several proposals for the integration of GSM with a geostationary satellite service. Unfortunately, because terrestrial and space systems have been designed to optimize their performance for their particular environment, integration between a satellite and terrestrial system is unlikely to develop further than the satellite providing a back-up service. This lack of system compatibility is now being addressed by system designers of third generation systems. The next generation of mobile systems, referred to as FPLMTS (future public land mobile telecommunication systems) by CCIR and UMTS (universal mobile telecommunication system) in European research programs, are intended to provide inexpensive, hand-held terminals that can operate in either satellite, cellular, or cordless environments. This poses several challenges for system designers, not least in terms of the choice of multiple access technique and power requirements. Satellite mobile services have been dominated by the geostationary orbital type. Recently, however, a number of low earth orbit configurations have been proposed, for example Iridium. These systems are likely to be fully operational by the turn of the century, in time for the implementation of FPLMTS. The developments in LEO mobile satellite service technology were recognized at WARC-92 with the allocation of specific frequency bands for 'big' LEO's, as well as a frequency allocation for FPLMTS which included a specific satellite allocation. When considering integrating a space service into the terrestrial network, LEO's certainly appear to have their attractions: they can provide global coverage, the round trip delay is of the order of tens of milliseconds, and

  7. Effect of KOH concentration on LEO cycle life of IPV nickel-hydrogen flight cell - Update II

    Science.gov (United States)

    Smithrick, John J.; Hall, Stephen W.

    1992-01-01

    An update of validation test results confirming the breakthrough in LEO cycle life of nickel-hydrogen cells containing 26 percent KOH electrolyte is presented. A breakthrough in the LEO cycle life of individual pressure vessel (IPV) nickel-hydrogen cells has been previously reported. The cycle life of boiler plate cells containing 26 percent potassium hydroxide (KOH) electrolyte was about 40,000 LEO cycles, compared to 3500 cycles for cells containing 31 percent KOH. The cycle regime was a stressful accelerated LEO, which consisted of a 27.5 min charge followed by a 17.5 min discharge (2X normal rate). The depth-of-discharge was 80 percent. Six 48-Ah Hughes recirculation design IPV nickel-hydrogen flight battery cells are being evaluated. Three of the cells contain 26 percent KOH (test cells), and three contain 31 percent KOH (control cells). They are undergoing real time LEO cycle life testing. The cycle regime is a 90-min LEO orbit consisting of a 54-min charge followed by a 36-min discharge. The depth-of-discharge is 80 percent. The cell temperature is maintained at 10 C. The three 31 percent KOH cells failed (cycles 3729, 4165, and 11355). One of the 26 percent KOH cells failed at cycle 15314. The other two 26 percent KOH cells were cycled for over 16,000 cycles during the continuing test.

  8. Features of rare earth element (3) complexing

    International Nuclear Information System (INIS)

    Martynenko, L.I.

    1991-01-01

    Reasons for nonobeyance to the regularity of tetrad ''W'' effect of rare earth chelate complex compounds are discussed in the review. The concept of metal-ligand ionic bond in rare earth complexes is put in the basis of the consideration. From this viewpoint mutual influence of ligands in lower, higher, polynuclear and different-ligand complexes, formed by the ligands of low, medium and high denticity, is discussed. Problems of intermolecular interaction of complexes with different structure are considered in relation to problems of variation of chelate volatility and selectivity in the processes of sublimation and precipitation

  9. Leo den Store: Prædiken på st. Laurentius' dag

    DEFF Research Database (Denmark)

    Willert, Niels

    1992-01-01

    Oversættelse af prædiken holdt af den kendte pave Leo den store i 400-tallet. Prædikenen forholder sig til Sankt Laurentius og hans martyrdød.Oversættelsen er et bidrag i en samling af prædikener fra oldkirken. Bogen har en indledning ved professor dr.theol. Christian Thodberg.......Oversættelse af prædiken holdt af den kendte pave Leo den store i 400-tallet. Prædikenen forholder sig til Sankt Laurentius og hans martyrdød.Oversættelsen er et bidrag i en samling af prædikener fra oldkirken. Bogen har en indledning ved professor dr.theol. Christian Thodberg....

  10. Federalismo Fiscal e Petróleo No Brasil e no Mundo

    OpenAIRE

    Sérgio Wulff Gobetti

    2011-01-01

    Este texto busca contribuir com o debate atual sobre as regras de distribuição dos royalties no Brasil a partir de reflexões teóricas e empíricas sobre o federalismo fiscal e de uma análise comparativa das experiências dos diversos países produtores de petróleo que, a exemplo do nosso, se organizam como federações. A análise se baseia nos estudos reunidos em um projeto internacional denominado Petróleo e Gás em Sistemas Federativos e mostra que o modo como as federações lidam com a propriedad...

  11. \\"Biodegradação de poliuretano derivado do óleo de mamona\\"

    OpenAIRE

    José Marcelo Cangemi

    2006-01-01

    O meio ambiente requer polímeros que possam ser degradados e desapareçam por completo pela atuação de vários fatores ambientais, incluindo microrganismos. No presente trabalho estudou-se a biodegradação de espumas de poliuretano obtidas a partir do óleo de mamona, um material renovável e de origem natural, se constituindo em uma alternativa viável para a substituição das tradicionais espumas de PU. O acompanhamento da biodegradação foi realizado para a espuma PU-vegetal e PU-petróleo, através...

  12. América Latina: petróleo y conflicto

    Directory of Open Access Journals (Sweden)

    Luis Humberto Hernández

    2008-01-01

    Full Text Available En el actual escenario conflictivo mundial energético presentamos la siguiente reflexión sobre la situación petrolera de América Latina a partir de su discurrir pasado y la situación actual. Se ubica inicialmente una breve historia regional del petróleo en el mundo a partir de los hechos fundamentales que le dan razón a cada una de las ocho regiones petroleras existentes, concentrando la reseña en América Latina, acompañada de un balance del estado económico y político actual del petróleo en América Latina.

  13. The Design and Analysis Program for the Development of LEO Satellite Electrical Power Subsystem

    Directory of Open Access Journals (Sweden)

    Sang-Kon Lee

    2007-06-01

    Full Text Available The design and analysis of satellite power subsystem is an important driver for the mass, size, and capability of the satellite. Every other satellite subsystem is affected by the power subsystem, and in particular, important issues such as launch vehicle selection, thermal design, and structural design are largely influenced by the capabilities and limitations of the power system. This paper introduces a new electrical power subsystem design program for the rapid development of LEO satellite and shows an example of design results using other LEO satellite design data. The results shows that the proposed design program can be used the optimum sizing and the analytical prediction of the on-orbit performance of satellite electrical power subsystem.

  14. The Lifeworld Earth and a Modelled Earth

    Science.gov (United States)

    Juuti, Kalle

    2014-01-01

    The goal of this paper is to study the question of whether a phenomenological view of the Earth could be empirically endorsed. The phenomenological way of thinking considers the Earth as a material entity, but not as an object as viewed in science. In the learning science tradition, tracking the process of the conceptual change of the shape of the…

  15. Rare earths in iron and steelmaking and gaseous desulphurisation

    International Nuclear Information System (INIS)

    Kay, D.A.R.; Subramanian, S.V.; Meng, V.; Kumar, R.V.

    1985-01-01

    Rare earth (RE) additions, either as mischmetal or rare earth silicide, are used in many ladle treatment processes in modern ferrous metallurgy. In ironmaking they provide the basis for the control of graphite morphology in cast irons and in steelmaking additions are made to aluminum-killed steels for desulphurisation and the control of inclusion composition and morphology. Rare earth oxides may also be used in the desulphurisation of medium calorific value gaseous fuels and stack gases. In this paper, Ce-S-O and La-S-O phase stability diagrams are used to determine the role of the rare earths in the external processing of iron and steel, and gaseous desulphurisation

  16. Rare earth sulfates

    International Nuclear Information System (INIS)

    Komissarova, L.N.; Shatskij, V.M.; Pokrovskij, A.N.; Chizhov, S.M.; Bal'kina, T.I.; Suponitskij, Yu.L.

    1986-01-01

    Results of experimental works on the study of synthesis conditions, structure and physico-chemical properties of rare earth, scandium and yttrium sulfates, have been generalized. Phase diagrams of solubility and fusibility, thermodynamic and crystallochemical characteristics, thermal stability of hydrates and anhydrous sulfates of rare earths, including normal, double (with cations of alkali and alkaline-earth metals), ternary and anion-mixed sulfates of rare earths, as well as their adducts, are considered. The state of ions of rare earths, scandium and yttrium in aqueous sulfuric acid solutions is discussed. Data on the use of rare earth sulfates are given

  17. Positive immunolabelling for feline infectious peritonitis in an African lion (Panthera leo) with bilateral panuveitis.

    Science.gov (United States)

    Mwase, M; Shimada, K; Mumba, C; Yabe, J; Squarre, D; Madarame, H

    2015-01-01

    A 15-year-old male African lion (Panthera leo) was presented with blindness due to bilateral panuveitis with retinal detachment. Feline coronavirus (FCoV) antigen was identified immunohistochemically in ocular macrophages, consistent with a diagnosis of feline infectious peritonitis (FIP) infection. This is the first report of FIP in an African lion and the first report of ocular FIP in a non-domestic felid. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Serum biochemical study of major elements of captive Asiatic Lions Panthera leo persica

    Directory of Open Access Journals (Sweden)

    R.G. Jani

    2010-02-01

    Full Text Available The serum biochemistry of captive Asiatic Lions Panthera leo persica in India has not been studied in depths. We report here the results of an analysis of a large number of individuals with the aim of providing reference ranges for major serological parameters in male and female Asiatic lions in health and diseases. This information will be of use to zoo veterinarians and pathologists.

  19. Natural law Judaism? The genesis of bioethics in Hans Jonas, Leo Strauss, and Leon Kass.

    Science.gov (United States)

    Vogel, Lawrence

    2006-01-01

    Leon Kass is much misunderstood. He is not simply a Republican ideologue who tailored his ideas to break out of the ivory tower and into the halls of power. Nor does he look simply to use human nature as a moral guide. When the full range of his writings is considered and set in the tradition of his teachers, Hans Jonas and Leo Strauss, what emerges is a natural law position colored by religious revelation.

  20. Personality assessment and feline–keepers relationship in lions (Panthera leo)

    OpenAIRE

    Quintavalle Pastorino, Giovanni; Soares, Nuno; Mazzola, Silvia Michela; Preziosi, Richard; Albertini, Mariangela

    2016-01-01

    Animal personality is a growing research area due to the increasing evidence of the impact that it has on welfare, health and management of animals in captivity (Freeman and Gosling, 2010). Testing and improving existent methodologies, as well as develop new ones, to outline animal personality is an important step towards welfare, health and longevity of captive animals (Phillips, 2007; Whitham and Wielebnowski, 2013). Lions (Panthera leo) were chosen for this study because the species is und...

  1. Obchod s trofejemi lva (Panthera leo) ve vztahu k ochraně druhu

    OpenAIRE

    HRDLIČKOVÁ, Lucie

    2014-01-01

    In addition to other causes of threats to the lion (Panthera leo), such as the loss of habitat, disease and conflict with humans, the largest subject of discussion is the trophy hunting. The growing threat to populations divides scientists, participants in hunting industry, various welfare and conservation organizations and now also a part of the general public into two camps. Some believe that it is possible sustainable trophy hunting and trading with other commodities originating from lions...

  2. Effects of DeOrbitSail as applied to Lifetime predictions of Low Earth Orbit Satellites

    Science.gov (United States)

    Afful, Andoh; Opperman, Ben; Steyn, Herman

    2016-07-01

    Orbit lifetime prediction is an important component of satellite mission design and post-launch space operations. Throughout its lifetime in space, a spacecraft is exposed to risk of collision with orbital debris or operational satellites. This risk is especially high within the Low Earth Orbit (LEO) region where the highest density of space debris is accumulated. This paper investigates orbital decay of some LEO micro-satellites and accelerating orbit decay by using a deorbitsail. The Semi-Analytical Liu Theory (SALT) and the Satellite Toolkit was employed to determine the mean elements and expressions for the time rates of change. Test cases of observed decayed satellites (Iridium-85 and Starshine-1) are used to evaluate the predicted theory. Results for the test cases indicated that the theory fitted observational data well within acceptable limits. Orbit decay progress of the SUNSAT micro-satellite was analysed using relevant orbital parameters derived from historic Two Line Element (TLE) sets and comparing with decay and lifetime prediction models. This paper also explored the deorbit date and time for a 1U CubeSat (ZACUBE-01). The use of solar sails as devices to speed up the deorbiting of LEO satellites is considered. In a drag sail mode, the deorbitsail technique significantly increases the effective cross-sectional area of a satellite, subsequently increasing atmospheric drag and accelerating orbit decay. The concept proposed in this study introduced a very useful technique of orbit decay as well as deorbiting of spacecraft.

  3. Óleos e gosduras vegetais: composição e tecnologia

    Directory of Open Access Journals (Sweden)

    Luiz Antonio Gioielli

    Full Text Available O trabalho apresenta revisão bibliográfica sobre a composição química de óleos e gorduras vegetais, incluindo a classificação de lipídeos, as notações empregadas, os principais ácidos graxos saturados e insaturados e o teor em óleo de matérias-primas vegetais. São ainda enfocados aspectos de produção comercial mundial e brasileira. São apresentados esquemas básicos de processamento industrial, incluindo a preparação da matérias-primas vegetais. São ainda enfocados aspectos de produção comercial mundial e brasileira. São apresentados esquemas básicos de processamento industrial, incluindo a preparação da matéria-prima, a extração do óleo bruto e os métodos de refinação e modificação.

  4. Petróleo y cambio social como programa de investigación en Venezuela

    Directory of Open Access Journals (Sweden)

    Luis J. González Oquendo

    2006-01-01

    Full Text Available Alo largo del siglo xx, el petróleo ha sido el elemento estructural que ha explicado la estructuración de la sociedad venezolana. Es una idea extendida que Venezuela es lo que la actividad petrolera le ha permitido ser. El presente trabajo se está interesado en estudiar cómo la construcción de la sociedad venezolana ha sido posible desde la óptica de productos intelectuales científico sociales. No interesa sólo una lectura teórica sino hacer una aproximación epistemológica que determine la existencia de un programa de investigación. Se utilizó el modelo VIE de José Padrón para analizar la obra de cinco científicos sociales clave que han estudiado el impacto social del petróleo en Venezuela: Rodolfo Quintero, Carmen Vallarino de Bracho, Roberto Briceño León, María Sol Pérez Schael y Fernando Coronil. Finalmente, se pudo demostrar que el único elemento en común entre estos estudios de investigación es el objeto, aunque cada uno de ellos tiene diferentes construcciones teóricas acerca de éste. De este modo, «petróleo y cambio social en Venezuela» no es todavía un programa de investigación

  5. Orbital period variations of the eclipsing binaries TU Cnc, VZ Leo, and OS Ori

    Science.gov (United States)

    Khaliullina, A. I.

    2017-10-01

    Variations of the orbital periods of the eclipsing binaries TU Cnc, VZ Leo, and OS Ori are analyzed. Secular period decreases were earlier believed to occur in these systems. It is demonstrated that the period variations of TU Cnc can be represented using the light-time effect corresponding to the orbital motion of the eclipsing binary with a period of 78.6 years around the center ofmass of the triple system, with the mass of the third body being M 3 > 0.82 M ⊙. With the same accuracy, the period variations of VZ Leo and OS Ori can be represented either solely using the light-time effect, or a superposition of a secular period decrease and the light-time effect. For VZ Leo, the period of the long-term orbit is 63.8 years in the former case and 67.9 years in the latter case. Similar masses for the third body are indicated in both cases: M 3 > 0.55 M ⊙ and M 3 > 0.61 M ⊙. For OS Ori, the period of the long-term orbit is 46 years and M 3 > 0.5 M ⊙ in the former case, and the period is 36 years and M 3 > 0.6 M ⊙ in the latter case.

  6. Assessment of active methods for removal of LEO debris

    Science.gov (United States)

    Hakima, Houman; Emami, M. Reza

    2018-03-01

    This paper investigates the applicability of five active methods for removal of large low Earth orbit debris. The removal methods, namely net, laser, electrodynamic tether, ion beam shepherd, and robotic arm, are selected based on a set of high-level space mission constraints. Mission level criteria are then utilized to assess the performance of each redirection method in light of the results obtained from a Monte Carlo simulation. The simulation provides an insight into the removal time, performance robustness, and propellant mass criteria for the targeted debris range. The remaining attributes are quantified based on the models provided in the literature, which take into account several important parameters pertaining to each removal method. The means of assigning attributes to each assessment criterion is discussed in detail. A systematic comparison is performed using two different assessment schemes: Analytical Hierarchy Process and utility-based approach. A third assessment technique, namely the potential-loss analysis, is utilized to highlight the effect of risks in each removal methods.

  7. A LEO Hyperspectral Mission Implementation for Global Carbon Cycle Observations

    Science.gov (United States)

    Gervin, Janette C.; Esper, Jaime; McClain, Charles R.; Hall, Forrest G.; Middleton, Elizabeth M.; Gregg, Watson W.; Mannino, Antonio; Knox, Robert G.; Huemmrich, K. Fred

    2004-01-01

    For both terrestrial and ocean carbon cycle science objectives, high resolution (less than l0 nm) imaging spectrometers capable of acquiring multiple regional to global scale observations per day should enable the development of new remote sensing measurements for important but as yet unobservable variables, with the overall goal of linking both terrestrial and ocean carbon cycle processes to climate variability. For terrestrial research, accurate estimates of carbon, water and energy (CWE) exchange between the terrestrial biosphere and atmosphere a needed to id- the geographical locations and temporal dynamics of carbon sources/sinks and to improve regional climate models and climate change assessments. It is an enormous challenge to estimate CWE exchange from the infrequent temporal coverage and sparse spectral information provided by most single polar-orbiting, earth-looking satellite. The available satellite observations lack a sufficient number of well-placed narrow bands from which to derive spectral indices that capture vegetation responses to stress conditions associated with down-regulation of photosynthesis. Physiological status can best be assessed with spectral indices based on continuous, narrow bands in the visible/near infrared spectra, as can seasonal and annual terrestrial productivity. For coastal and ocean constituents, narrow-band observations in the ultraviolet and visible are essential to investigate the variability, dynamics and biogeochemical cycles of the world's coastal and open ocean regions, which will in turn help in measuring ocean productivity and predicting the variability of ocean carbon uptake and its role in climate change.

  8. Ion transport under the effect of an electric field in porous medium: application to the separation of rare earths by focalization electrophoresis; Transport d'ions sous l'effet d'un champ electrique en milieu poreux: Application a la separation de terres rares par electrophorese a focalisation

    Energy Technology Data Exchange (ETDEWEB)

    Vieira-Nunes, A.I

    1999-01-15

    Trivalent ions of rare earth elements have very similar properties and their difficult separation each from another is usually carried out by liquid-liquid extraction or ion exchange. Focalization electrophoresis represents an alternative route to the usual techniques. The purpose of this work consisted of the fundamental investigation of ion transport phenomena in electrophoretic processes. Focalization electrophoresis is suitable for separation of amphoteric species such as rare earth ions, using a pH gradient in the cell and upon addition of a complexed agent e. g. EDTA. This technique relies upon the difference in iso-electrical points of the considered species, being under the form of free cation near the anode, and in the form of anionic complexed species closer to the cathode. Rare earth species are submitted to the antagonist effects of diffusion and migration, enabling their focalization to occur at the iso-electrical point, corresponding to nil value of their effective mobility. Following a literature survey on rare earth elements and electrophoresis processes, the document describes theoretical and experimental investigations of complexation equilibria of some rare earth elements, namely lanthanum, neodymium, praseodymium and cerium, depending on pH. Values for the iso-electrical points could be estimated. Transport and focalization phenomena in view of rare earth separation, are dealt in the last chapter. Investigations were first carried out without forced circulation of the electrolyte solution and the transient behavior of the system allowed operating conditions to be design and built-up of a continuous device, more suitable to separation, and provided with 42 potential and 42 temperature sensors: the results of the preliminary runs, in form of variable profiles, are presented and discussed. (author)

  9. Space Gravity Spectroscopy - determination of the Earth’s gravitational field by means of Newton interpolated LEO ephemeris Case studies on dynamic (CHAMP Rapid Science Orbit and kinematic orbits

    Directory of Open Access Journals (Sweden)

    T. Reubelt

    2003-01-01

    Full Text Available An algorithm for the (kinematic orbit analysis of a Low Earth Orbiting (LEO GPS tracked satellite to determine the spherical harmonic coefficients of the terrestrial gravitational field is presented. A contribution to existing long wavelength gravity field models is expected since the kinematic orbit of a LEO satellite can nowadays be determined with very high accuracy in the range of a few centimeters. To demonstrate the applicability of the proposed method, first results from the analysis of real CHAMP Rapid Science (dynamic Orbits (RSO and kinematic orbits are illustrated. In particular, we take advantage of Newton’s Law of Motion which balances the acceleration vector and the gradient of the gravitational potential with respect to an Inertial Frame of Reference (IRF. The satellite’s acceleration vector is determined by means of the second order functional of Newton’s Interpolation Formula from relative satellite ephemeris (baselines with respect to the IRF. Therefore the satellite ephemeris, which are normally given in a Body fixed Frame of Reference (BRF have to be transformed into the IRF. Subsequently the Newton interpolated accelerations have to be reduced for disturbing gravitational and non-gravitational accelerations in order to obtain the accelerations caused by the Earth’s gravitational field. For a first insight in real data processing these reductions have been neglected. The gradient of the gravitational potential, conventionally expressed in vector-valued spherical harmonics and given in a Body Fixed Frame of Reference, must be transformed from BRF to IRF by means of the polar motion matrix, the precession-nutation matrices and the Greenwich Siderial Time Angle (GAST. The resulting linear system of equations is solved by means of a least squares adjustment in terms of a Gauss-Markov model in order to estimate the spherical harmonics coefficients of the Earth’s gravitational field.Key words. space gravity spectroscopy

  10. NASA Earth Exchange (NEX)

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA Earth Exchange (NEX) represents a new platform for the Earth science community that provides a mechanism for scientific collaboration and knowledge sharing....

  11. EarthKAM

    Data.gov (United States)

    National Aeronautics and Space Administration — Sponsored by NASA, EarthKAM (Earth Knowledge Acquired by Middle School Students) is an educational outreach program allowing middle school students to take pictures...

  12. The Near-Earth Orbital Debris Problem and the Challenges for Environment Remediation

    Science.gov (United States)

    Liou, Jer-Chyi

    2012-01-01

    The near-Earth space environment has been gradually polluted with orbital debris (OD) since the beginning of space activities 55 years ago. Although this problem has been known to the research community for decades, the public was, in general, unaware of the issue until the anti-satellite test conducted by China in 2007 and the collision between Cosmos 2251 and the operational Iridium 33 in 2009. The latter also underlined the potential of an ongoing collision cascade effect (the "Kessler Syndrome") in the low Earth orbit (LEO, the region below 2000 km altitude). Recent modeling results have indicated that mitigation measures commonly adopted by the international space community will be insufficient to stabilize the LEO debris population. To better limit the OD population increase, more aggressive actions must be considered. There are three options for OD environment remediation-removal of large/massive intact objects to address the root cause of the OD population growth problem, removal of 5-mm-to-1 cm debris to mitigate the main mission-ending threats for the majority of operational spacecraft, and prevention of major debris-generating collisions as a temporary means to slow down the OD population increase. The technology, engineering, and cost challenges to carry out any of these three options are monumental. It will require innovative ideas, game-changing technologies, and major collaborations at the international level to address the OD problem and preserve the near-Earth environment for future generations.

  13. The WEBERSAT camera - An inexpensive earth imaging system

    Science.gov (United States)

    Jackson, Stephen; Raetzke, Jeffrey

    WEBERSAT is a 27 pound LEO satellite launched in 1990 into a 500 mile polar orbit. One of its payloads is a low cost CCD color camera system developed by engineering students at Weber State University. The camera is a modified Canon CI-10 with a 25 mm lens, automatic iris, and 780 x 490 pixel resolution. The iris range control potentiometer was made programmable; a 10.7 MHz digitization clock, fixed focus support, and solid tantalum capacitors were added. Camera output signals, composite video, red, green, blue, and the digitization clock are fed to a flash digitizer, where they are processed for storage in RAM. Camera control commands are stored and executed via the onboard computer. The CCD camera has successfully imaged meteorological features of the earth, land masses, and a number of astronomical objects.

  14. Cost-effective and robust mitigation of space debris in low earth orbit

    Science.gov (United States)

    Walker, R.; Martin, C. E.

    2004-01-01

    For the wide acceptance of space debris mitigation measures throughout government agencies and industry, their cost-effectiveness must be demonstrated. The selected measures must not only be effective at controlling the future growth of the debris population, but they should also aim to minimise the collision risk to spacecraft at a minimal cost of implementation. Furthermore, the selected measures must be sufficiently robust to retain their effectiveness if unexpected increases in space activity were to occur. In this paper, clear criteria are established in order to assess numerous different Low Earth Orbit (LEO) debris mitigation scenarios for their cost-effectiveness and robustness. The ESA DELTA debris model is used to provide long-term debris environment projections for these scenarios as an input to the effectiveness/robustness element. Manoeuvre requirements for the different post-mission disposal scenarios are calculated in order to define the cost-related element. A 25-year post-mission lifetime de-orbit policy, combined with explosion prevention and mission-related object limitation, was found to be the most cost-effective solution to the space debris problem in LEO. This package would also be robust enough to retain its effectiveness even after a significant increase in future launch traffic. It was found that the re-orbiting of space systems above the LEO region would not lead to significant collision activity there over the next century. However, above-LEO disposal should be used sparingly because the disposal region could become unstable after a limited number of localised explosion or collision-induced breakup events due to a lack of air drag to remove the resulting fragments.

  15. PRODUÇÃO DE PETRÓLEO E IMPACTOS AMBIENTAIS: ALGUMAS CONSIDERAÇÕES

    Directory of Open Access Journals (Sweden)

    Silas Sarkiz da Silva Martins

    2015-12-01

    Full Text Available O petróleo está a cada dia sendo mais explorado e tem sido um recurso energético gerador de divisas para a economia de países e nações, a exemplo do Brasil, mas, também, difusor de impactos ambientais negativos. As etapas que envolvem a produção de petróleo desde a perfuração de poços até o refino, direta ou indiretamente, têm causado alterações ao meio ambiente. O objetivo deste estudo foi o de compreender os principais impactos ambientais gerados pelas etapas de produção de petróleo, considerando estudos de impacto ambiental (EIAs e seus respectivos relatórios de impacto ambiental (RIMAs. A avaliação dos impactos ambientais se dá através do diagnóstico ambiental da área de influência do empreendimento, o qual é feito para se conhecer os componentes dos meios físico, biológico e socioeconômico da área e, posteriormente, avaliar os efeitos das atividades do empreendimento sobre os mesmos. Pela complexidade da composição química do petróleo, o risco quanto as suas atividades e seu manuseio é, na maioria dos casos, de grande potencial, pois pode haver acidentes, que, por sua vez, podem interferir negativamente no meio ambiente. Ao término do estudo, concluiu-se que a fase de produção de petróleo apresenta diversos aspectos ambientais, os quais geram impactos. Viu-se que os impactos não são apenas de caráter negativo. E, por fim, sugere-se a aplicação de medidas mitigadoras e de um sistema de gestão ambiental eficaz para a minimização e/ou eliminação de tais impactos.

  16. Rare earth optogalvanic spectroscopy: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Destro, Marcelo G.; Neri, Jose W.; Rodrigues, Nicolau A.S.; Silveira, Carlos A.B.; Riva, Rudimar [Instituto de Estudos Avancados (IEAv/EFO), Sao Jose dos Campos, SP (Brazil). Div. de Fotonica]. E-mail: destro@ieav.cta.br; Victor, Alessandro R. [Instituto Tecnologico de Aeronautica (ITA), Sao Jose dos Campos, SP (Brazil)

    2008-07-01

    The IEAv has special interest in the studies of rare earth isotope applications in laser medium and integrated optics as well as aerospace research. We are starting to work with Ytterbium, Erbium, Dysprosium and Neodymium laser selective photoionization research. This paper describes the preliminary results of emission and optogalvanic spectroscopy obtained from a Neodymium hollow cathode lamps. Furthermore these results were used to setup our laser systems to work to leads a Nd isotopes selective laser photoionization. (author)

  17. Ação antioxidante de alfa-tocoferol e extrato de alecrim em óleo de soja submetido à termoxidação

    OpenAIRE

    Ramalho, Valéria Cristina [UNESP

    2005-01-01

    O presente trabalho teve como objetivos avaliar, em condições de termoxidação, o compor tamento e a atividade antioxidante do a- tocoferol naturalmente presente em óleo de soja e adicionado em óleo de soja pur ificado, o compor tamento e a atividade antioxidante do extrato de alecr im adicionado em óleo de soja com seus tocoferóis or iginais e pur ificado e, ainda, ver ificar a influência do alecr im na res is tência do a- tocoferol natural ou adicionado em óleo de soja. Para is so foram real...

  18. The Performance of Silicon Solar Cells Exposed to a Simulated Low Earth Orbit Plasma Environment: Laboratory Ground Tests

    Science.gov (United States)

    Abd El-Hameed, Afaf M.; Sabry, M.; Ghitas, Ahmed; El-Tokhy, Fatma S.; Schlosser, Viktor

    2015-12-01

    We have studied the effects of a low earth orbit (LEO) plasma environment on the performance of solar cells. Laboratory ground tests were used to simulate the properties of a low-energy LEO plasma. A Penning plasma source was used to generate plasma from an argon (Ar) gas flow at low pressure (˜10-5 torr) through a vacuum chamber. Diagnostic tools were used to investigate the plasma conditions and their effects on six silicon (Si) solar cells located in the chamber. Alternating current conditions for both biased and unbiased monocrystalline Si solar cells produced from n/ p terrestrial cells with deep junctions were investigated after exposure to plasma fluence for different times up to 14 h. The results obtained confirmed variation of the performance of the cells samples as a consequence of exposure to the plasma.

  19. CARACTERIZAÇÃO QUÍMICA E ATIVIDADE MUTAGÊNICA DO ÓLEO ESSENCIAL DE Lippia alba

    Directory of Open Access Journals (Sweden)

    Thammyres de Assis Alves

    2017-01-01

    Full Text Available Os óleos essenciais são substâncias voláteis que vêm despertando interesse no setor agrícola, devido o grande potencial que possuem no controle de pragas. Assim, objetivo deste trabalho foi determinar a composição química do óleo essencial de folhas de Lippia alba e avaliar o seu potencial mutagênico. Para isso, o óleo essencial foi obtido por hidrodestilação, utilizando um aparelho do tipo Clevenger, seus constituintes químicos foram analisados por meio da cromatografia em fase gasosa com detector de ionização de chama (CG-DIC e de espectrometria de massas (CG-EM. Os compostos majoritários encontrados foram: geranial (29,83%, neral (20,71% e óxido de cariofileno (19,26%. A toxicidade do óleo essencial de L. alba foi avaliado em sementes de Lactuca sativa. O óleo essencial de L. alba inibiu 100% o crescimento radicular das sementes de L. sativa nas concentrações de 0,720% e 0,360% (m v-1. Nas outras concentrações testadas (0,180%, 0,090%, 0,045%, o óleo essencial apresentou um decréscimo no efeito de inibição conforme diminuição de sua concentração. Logo, o óleo essencial de L. alba possui potencial a ser usado como bioherbicida.

  20. Environmental degradation of nano enhanced polymers in low earth orbit

    Science.gov (United States)

    Jaradat, Mohammed

    Polymers are widely used in space shuttles and systems due to the unique properties they possess. However, the extremely harsh conditions in the low earth orbit (LEO), which ranges from 200-1800 km above the earth, have a degrading effect on those polymers. The predominant component of the LEO atmosphere is Atomic Oxygen (AO), which is a single O atom formed through the dissociation of molecular oxygen by ultra violet radiation from the sun. AO particles collide with a kinetic energy of approximately 5 eV, this energy is enough to facilitate the degradation of most polymers. An organic/inorganic hybrid material approach is used in this study through the incorporation of polyhedral oligomeric silsesquixanes (POSS) into traditional polymer systems. Several materials with different POSS percentages and exposure times to oxygen plasma (glassification process) are considered for this research. Following a pre-testing process only selected specimens are sent to the atomic oxygen testing facility at Marshall Space and Flight Center to be tested and evaluated. The specimens were assessed using the dynamic mechanical analysis and atomic force microscopy techniques to characterize the surface and obtain different mechanical and physical properties. A computational approach in the form of Molecular Dynamics (MD) simulations are performed on a polyimide and polyimide/POSS systems and elastic properties are determined. The selected materials with higher POSS percentages generally performed better in terms of mass loss of the tested systems due to the rapid and more complete formation of an oxidized protective layer that significantly limits further degradation once it formed. The glassification process doesn't seem to improve the resistance against AO attacks greatly at such small exposure times, never the less a slight improvement is noticed.

  1. Pions in the nuclear medium

    International Nuclear Information System (INIS)

    Chanfray, G.

    1996-07-01

    We discuss various aspects of pion physics in the nuclear medium. We first study s-wave pion-nucleus interaction in connection with chiral symmetry restoration and quark condensate in the nuclear medium. We then address the question of p-wave pion-nucleus interaction and collective pionic modes in nuclei and draw the consequences for in medium ππ correlations especially in the scalar-isoscalar channel. We finally discuss the modification of the rho meson mass spectrum at finite density and/or temperature in connection with relativistic heavy ion collisions

  2. Mission to Planet Earth

    Science.gov (United States)

    Tilford, Shelby G.; Asrar, Ghassem; Backlund, Peter W.

    1994-01-01

    Mission to Planet Earth (MTPE) is NASA's concept for an international science program to produce the understanding needed to predict changes in the Earth's environment. NASA and its interagency and international partners will place satellites carrying advanced sensors in strategic Earth orbits to gather multidisciplinary data. A sophisticated data system will process and archive an unprecedented amount of information about the Earth and how it works as a system. Increased understanding of the Earth system is a basic human responsibility, a prerequisite to informed management of the planet's resources and to the preservation of the global environment.

  3. Mission to Planet Earth

    International Nuclear Information System (INIS)

    Wilson, G.S.; Backlund, P.W.

    1992-01-01

    Mission to Planet Earth (MTPE) is NASA's concept for an international science program to produce the understanding needed to predict changes in the earth's environment. NASA and its interagency and international partners will place satellites carrying advanced sensors in strategic earth orbits to gather multidisciplinary data. A sophisticated data system will process and archive an unprecedented amount of information about the earth and how it works as a system. Increased understanding of the earth system is a basic human responsibility, a prerequisite to informed management of the planet's resources and to the preservation of the global environment. 8 refs

  4. Tratamento de água produzida de petróleo para remoção de óleo por processos de separação por membranas: revisão Produced water treatment for oil removal by membrane separation process: review

    Directory of Open Access Journals (Sweden)

    Albérico Ricardo Passos da Motta

    2013-03-01

    Full Text Available O gerenciamento da água produzida (AP de petróleo se constitui em um enorme desafio para as empresas petrolíferas. As alternativas usualmente adotadas para o seu destino são o descarte, injeção e o reúso. Em todos os casos é necessário tratamento da AP, a fim de evitar danos ao meio ambiente e às instalações de produção ou a fim de permitir o seu reúso sem causar prejuízos aos processos nos quais a AP será utilizada. Os processos de separação por membranas (PSM têm se mostrado capazes de tratar efluentes que apresentam elevados teores de óleo em emulsão e de partículas com tamanhos médios e pequenos, competindo, assim, com tecnologias de tratamento mais complexas, tais como flotação. O objetivo deste artigo foi apresentar uma revisão sobre o tratamento de AP utilizando os PSM discutindo os principais aspectos da AP e os aspectos conceituais dos PSM, com ênfase para sua aplicação para remoção de óleo da AP.The management of oil produced water (PW constitutes a major challenge to oil companies. The options usually adopted for PW are disposal, injection and reuse. In all cases, a PW treatment is required in order to avoid damages to the environment and to production facilities or to allow its reuse without causing damage to processes in which the PW is used. The membrane separation processes (MSP has been shown to be capable of treating effluent with high content of emulsified oil and with medium and small sizes particle, competing well with more complex treatment technologies such as flotation. The aim of this paper was to present a review of the PW treatment by MSP, discussing the main aspects of the PW and the conceptual aspects of the MSP, with emphasis on their application for removal of oil from the PW.

  5. Rapid analysis of some rare earth magnets

    International Nuclear Information System (INIS)

    Raoot, K.N.; Raoot, Sarala; Rukmani Desikan, N.

    1978-01-01

    A simple complexometric method for the quick analysis of the constituent elements in some quaternary rare earth magnets of the type RE-Co-Cu-Fe and RE-Ni-Cu-Fe is described. The technique is based on a total titration, subsequent release of EDTA from rare earth with ammonium fluoride and that from copper (II) with ascorbic acid and thiourea followed by determination of the excess and liberated EDTA by lead nitrate in a weak acid medium using xylenol orange indicator. In another, aliquot iron (III) and rare earth are first masked with sodium fluoride, and copper (II) with ascorbic acid and thiourea before cobalt (II) or nickel (II) is estimated by back titration. Iron is calculated by difference. The new method yields accurate and reproducible results with error not exceeding 1%. A set of three samples can conveniently be analysed in two hours. (author)

  6. Differential Medium for Vibrio cholerae

    Science.gov (United States)

    Schrank, Gordon D.; Stager, Charles E.; Verwey, W. F.

    1973-01-01

    A differential medium designed for rapid presumptive identification of Vibrio cholerae was described and shown to be useful for enumeration of viable cholera vibrios in the presence of other intestinal bacteria. Images PMID:4764406

  7. Medium effects in direct reactions

    International Nuclear Information System (INIS)

    Karakoc, M; Bertulani, C

    2013-01-01

    We discuss medium corrections of the nucleon-nucleon (NN) cross sections and their influence on direct reactions at intermediate energies ≳50 MeV/nucleon. The results obtained with free NN cross sections are compared with those obtained with a geometrical treatment of Pauli-blocking and Dirac-Bruecker methods. We show that medium corrections may lead to sizable modifications for collisions at intermediate energies and that they are more pronounced in reactions involving weakly bound nuclei.

  8. Avaliação de óleo essencial de Eucalyptus urograndis(Myrtaceae no controle de Pentatomidae

    Directory of Open Access Journals (Sweden)

    Taciany Ferreira de Souza

    Full Text Available O objetivo dessa pesquisa foi avaliar o potencial inseticida do óleo essencial de Eucalyptus urograndis para o controle de ninfas e adultos de Euschistus heros (Fabricius, 1794 em bioensaios de laboratório. Foram avaliados quatro parâmetros em ninfas e adultos dessa espécie: exposição por aplicação tópica, exposição em superfície de contato, fagoinibição sem chance de escolha e fagoinibição com dupla chance de escolha. A avaliação, observando-se o número de indivíduos vivos e mortos, foi feita no período de 24 e 48 horas. Constatou-se que óleo essencial de E. urograndis é tóxico para ninfas e adultos de E. heros. Tanto as Doses Letais (DL como as Concentrações Letais (CL determinadas para o óleo diminuíram à medida que aumentou o tempo de exposição dos insetos e a dose aplicada do óleo essencial, indicando uma dependência com o tempo de exposição. Verificou-se que as sementes tratadas com óleo essencial provocaram ação fagoinibidora reduzindo os pontos de alimentação, mostrando-se promissor para o controle alternativo desse inseto.

  9. Avaliação do efeito antifúngico do óleo resina e do óleo essencial de copaíba (Copaifera multijuga Hayne)

    OpenAIRE

    Deus,R.J.A; Alves,C.N; Arruda,M.S.P

    2011-01-01

    Óleo de Copaifera multijuga Hayne, in natura e as frações foram avaliados quanto às suas atividades fungitóxicas, frente a cinco espécies de fungos filamentosos do gênero Aspergillus e três espécies de leveduras do gênero Candida. Concentrações de óleo resina e de óleo essencial na faixa de 0,08 mg mL-1a 1,6 mg mL-1 foram usadas para as análises qualitativa e quantitativas. As amostras foram dispostas sobre discos de papel de 5 mm de diâmetro e distribuídos sobre o meio Saboraud em placas de ...

  10. Óleos vegetais e óleo mineral na mortalidade da Bemisia tabaci biótipo B e na transmissão do vírus do mosaico dourado no feijoeiro

    OpenAIRE

    Marques, Míriam de Almeida

    2011-01-01

    Como alternativa aos inseticidas sintéticos, óleos vegetais e óleos minerais têm se revelado promissores no controle da Bemisia tabaci biótipo B. Esse trabalho teve como objetivo avaliar o efeito de óleos vegetais e mineral sobre ovos, ninfas e adultos da B. tabaci biótipo B e sobre a transmissão do vírus do mosaico dourado no feijoeiro e na sua produtividade. Os experimentos foram conduzidos em casa telada na Embrapa Arroz e Feijão, Santo Antônio de Goiás, Goiás. Utilizaram-se...

  11. Biodegradability of commercial and weathered diesel oils Biodegradabilidade de óleos diesel comercial e intemperizado

    Directory of Open Access Journals (Sweden)

    Adriano Pinto Mariano

    2008-03-01

    Full Text Available This work aimed to evaluate the capability of different microorganisms to degrade commercial diesel oil in comparison to a weathered diesel oil collected from the groundwater at a petrol station. Two microbiological methods were used for the biodegradability assessment: the technique based on the redox indicator 2,6 - dichlorophenol indophenol (DCPIP and soil respirometric experiments using biometer flasks. In the former we tested the bacterial cultures Staphylococcus hominis, Kocuria palustris, Pseudomonas aeruginosa LBI, Ochrobactrum anthropi and Bacillus cereus, a commercial inoculum, consortia obtained from soil and groundwater contaminated with hydrocarbons and a consortium from an uncontaminated area. In the respirometric experiments it was evaluated the capability of the native microorganisms present in the soil from a petrol station to biodegrade the diesel oils. The redox indicator experiments showed that only the consortia, even that from an uncontaminated area, were able to biodegrade the weathered diesel. In 48 days, the removal of the total petroleum hydrocarbons (TPH in the respirometric experiments was approximately 2.5 times greater when the commercial diesel oil was used. This difference was caused by the consumption of labile hydrocarbons, present in greater quantities in the commercial diesel oil, as demonstrated by gas chromatographic analyses. Thus, results indicate that biodegradability studies that do not consider the weathering effect of the pollutants may over estimate biodegradation rates and when the bioaugmentation is necessary, the best strategy would be that one based on injection of consortia, because even cultures with recognised capability of biodegrading hydrocarbons may fail when applied isolated.Este trabalho objetivou avaliar a capacidade de diferentes microrganismos em degradar óleo diesel comercial em comparação com um óleo diesel intemperizado coletado da água subterrânea em um posto de combust

  12. Digital Earth – A sustainable Earth

    International Nuclear Information System (INIS)

    Mahavir

    2014-01-01

    All life, particularly human, cannot be sustainable, unless complimented with shelter, poverty reduction, provision of basic infrastructure and services, equal opportunities and social justice. Yet, in the context of cities, it is believed that they can accommodate more and more people, endlessly, regardless to their carrying capacity and increasing ecological footprint. The 'inclusion', for bringing more and more people in the purview of development is often limited to social and economic inclusion rather than spatial and ecological inclusion. Economic investment decisions are also not always supported with spatial planning decisions. Most planning for a sustainable Earth, be at a level of rural settlement, city, region, national or Global, fail on the capacity and capability fronts. In India, for example, out of some 8,000 towns and cities, Master Plans exist for only about 1,800. A chapter on sustainability or environment is neither statutorily compulsory nor a norm for these Master Plans. Geospatial technologies including Remote Sensing, GIS, Indian National Spatial Data Infrastructure (NSDI), Indian National Urban Information Systems (NUIS), Indian Environmental Information System (ENVIS), and Indian National GIS (NGIS), etc. have potential to map, analyse, visualize and take sustainable developmental decisions based on participatory social, economic and social inclusion. Sustainable Earth, at all scales, is a logical and natural outcome of a digitally mapped, conceived and planned Earth. Digital Earth, in fact, itself offers a platform to dovetail the ecological, social and economic considerations in transforming it into a sustainable Earth

  13. Atividade antimicrobiana de óleos essenciais no controle de alguns fitopatógenos fúngicos in vitro e no tratamento de sementes Antimicrobial activity of essential oils on the in vitro control of some fungal phytopathogens and on seed treatment

    Directory of Open Access Journals (Sweden)

    T. Hillen

    2012-01-01

    Full Text Available Este trabalho verificou o efeito dos óleos essenciais (OE extraídos de Eremanthus erythropappus (candeia, Cymbopogon martinii (palmarosa e de Rosmarinus officinalis (alecrim no crescimento micelial de alguns fitopatógenos fúngicos e no tratamento de sementes de milho, soja e feijão. No teste in vitro, alíquotas de 20, 40, 60, 100, 200, 500 e 1000 μL de cada um dos óleos essenciais foram distribuídas na superfície do meio de cultura. Posteriormente, discos de meio de cultura com micélio de Alternaria carthami, Alternaria sp. e Rhizoctonia solani foram transferidos para o centro de cada placa. O crescimento foi mensurado e calculada a taxa de inibição do crescimento micelial (ICM. Para verificar o efeito dos OE na germinação das sementes utilizou-se a aplicação deles por fumigação. Foi avaliada a percentagem de sementes germinadas e a incidência de patógenos nas sementes. Sobre o crescimento micelial, o óleo de palmarosa inibiu completamente todos os patógenos fúngicos, independentemente da concentração. Já os óleos de candeia e alecrim foram melhores quando foram adicionadas alíquotas superiores a 200 μL. Os óleos influenciaram diferentemente a germinação e a sanidade das sementes de milho, soja e feijão.This study aimed to verify the effect of essential oils (EO extracted from Eremanthus erythropappus ("candeia" Cymbopogon martinii ("palmarosa" and Rosmarinus officinalis (rosemary on the mycelial growth of some fungal phytopathogens, as well as on the treatment of corn, soybean and bean seeds. In the in vitro test, aliquots of 20, 40, 60, 100, 200, 500 and 1000 μL of each essential oil were distributed on the surface of the culture medium. Then, discs of culture medium with mycelium of Alternaria carthami, Alternaria sp and Rhizoctonia solani were transferred to the center of each plate. Growth was measured and the mycelial growth inhibition rate (MGI was calculated. To verify the effect of EO on seed

  14. Atividade antimicrobiana do óleo-resina produzido pela copaiba - Copaifera multijuga Hayne (Leguminosae

    Directory of Open Access Journals (Sweden)

    Davidy Eduardo Mendonça

    Full Text Available A pesquisa de plantas com fins medicinais tem grande importância para a comunidade médica, uma destas é o óleo-resina extraído da copaíba, Copaifera multijuga Hayne, o qual é natural da região Amazônica onde é encontrado uma grande diversidade dessa espécies. Seu uso medicinal, tão difundido o torna o fitofármaco mais usado e conhecido pelas populações mais pobres da região Norte do Brasil, sendo utilizado como diurético, laxativo, antitetânico, antiblenorrágico, anti-reumático, anti-séptico do aparelho urinário, antiinflamatório, antitussígeno, cicatrizante e remédio para o combate ao câncer. O presente trabalho apresenta os resultados da avaliação da atividade antimicrobiana deste óleo, onde foi avaliado pela a técnica de difusão em ágar em meio Muller-Hinton. As cepas avaliadas foram: Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 e Pseudomonas aeruginosa ATCC 9027. As placas forma incubadas em estufas por 24 h em temperatura de 35 ºC. Como padrões foram utilizados os antibióticos amoxicilina (AMO-10 mg/disco, cloranfenicol (CLO-30 mg/disco e tetraciclina (TET-30 mg/disco. Os resultados mostraram que o óleo de copaíba possui capacidade de inibir o crescimento das três bactérias avaliadas, apresentando com isso uma concentração inibitória mínima de 1,56, 3,12 e 12,5% para E. coli, S. aureus e P. aeruginosa, respectivamente.

  15. Biochemical parameters of wild felids (Panthera leo and Panthera tigris altaica kept in captivity

    Directory of Open Access Journals (Sweden)

    Maria Helena Matiko Akao Larsson

    2017-05-01

    Full Text Available A maioria das populações de felinos selvagens é considerada ameaçada ou em extinção devido à caça indiscriminada e à redução de seu habitat natural causada pelo homem. Devido ao número limitado de animais, essas espécies são vulneráveis às doenças e endogamia, além das alterações metabólicas e comportamentais relacionadas à mudança das condições naturais, habitat e alimentação e, ainda, à condição de cativeiro. Há poucos relatos na literatura sobre a bioquímica sérica em leões e tigres. Este estudo apresenta os parâmetros bioquímicos de 23 leões de cativeiro (Panthera leo e 10 tigres siberianos de cativeiro (Panthera tigris altaica do Fundação Parque Zoológico de São Paulo. Ureia; creatinina; AST; ALT; ALP; GGT; bilirrubinas totais, diretos e indiretos; proteína total; albumina; CK; lactato desidrogenase; os níveis de triglicérides, de colesterol e de glicose séricas foram determinados; e também os eletrólitos cálcio, fósforo, cloro, sódio e potássio. Não foram encontradas diferenças de parâmetros bioquímicos relacionados ao sexo de Panthera leo, mas para Panthera tigris altaica foram observados valores mais elevados de albumina em machos. Os valores obtidos neste estudo podem ser usados como referência para os indivíduos em cativeiro de Panthera leo e Panthera tigris altaica.

  16. Atividade insetistática de óleo essencial de Pothomorphe umbellata sobre Sitophilus zeamais

    Directory of Open Access Journals (Sweden)

    Carolina F. Pauliquevis

    2015-12-01

    Full Text Available RESUMO Sitophilus zeamais (Motschulsky, 1885 (Coleoptera: Curculionidae é um dos principais insetos que atacam e comprometem severamente a qualidade de grãos armazenados cujo controle é feito através de inseticidas químicos que nem sempre são eficazes, ocasionam a seleção de insetos resistentes, eliminam populações de inimigos naturais, deixam resíduos nos alimentos e contaminam o meio ambiente. Na tentativa de minimizar o problema com a possibilidade de uma alternativa agroecológica, pesquisas com óleos essenciais têm-se mostrado promissoras. Neste contexto, o objetivo da pesquisa foi identificar o potencial insetistático do óleo essencial da pariparoba no controle do gorgulho-do-milho para o que foram realizados bioensaios para verificar o efeito fumigante, exposição em superfície de contato e repelência. Houve efeito fumigante, os valores da CL50 e CL99 para as 24 h de confinamento dos insetos foram, respectivamente, 0,95 e 6,73 µL g-1. Os valores da CL50 e CL99 para as 24 h de exposição em superfície de contato foram, respectivamente, 0,34 e 4,91 µL cm-2; a repelência ocorreu na primeira hora; desta forma, o óleo essencial de Pothomorphe umbellata apresenta efeito insetistático para o controle de S. zeamais.

  17. Desenvolvimento de metodologias para análise direta de óleos vegetais empregando microemulsões de água em óleo e meios não aquosos

    OpenAIRE

    Carla Rosane Barboza Mendonça

    2005-01-01

    Amostras de óleo vegetal foram preparadas na forma de microemulsão de água em óleo (w/o) utilizando dodecil sulfato de sódio (SDS) como surfactante e um álcool como co-surfactante. As microemulsões foram caracterizadas através de medidas de viscosidade, índice de refração, condutividade elétrica, espalhamento de luz dinâmico e voltametria. Ensaios preliminares para a quantificação de analitos por análise direta foram realizados por voltametria linear e eletroforese capilar. As microemulsões d...

  18. Avaliação do desempenho de embarcações recolhedoras de óleo, em áreas de exploração e produção de petróleo

    OpenAIRE

    Carvalho, José Augusto de

    2013-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Ambiental, Florianópolis, 2013. Sabe-se que a necessidade mundial de consumo do Petróleo vem aumentando, consecutivamente também cresce o processo de pesquisa e sua produção. Vivemos um momento especial, onde estamos presenciando a exploração de Petróleo no chamado Pré Sal, caracterizado por estar em grande profundidade. Esta tecnologia ainda não está completamente ...

  19. Óleos essenciais: aspectos gerais e usos em terapias naturais

    OpenAIRE

    Murbach Teles Machado, Bruna Fernanda; Fernandes Junior, Ary

    2011-01-01

    O conhecimento tradicional atualmente é uma fonte para pesquisas na busca por novos compostos biologicamente ativos e como terapêutica efetiva que contemple os cuidados atuais para a saúde. Políticas de saúde utilizando estas fontes têm sido incentivadas por organizações internacionais e nacionais, como a Organização Mundial da Saúde e o Ministério da Saúde do Brasil. A Aromaterapia e os óleos essenciais são uma destas vertentes que estão em ascensão comercial e como objeto de estudo. O prese...

  20. Entendendo governança internacional: estudo de caso no setor de petróleo

    OpenAIRE

    Guedes, Ana Lucia; Faria, Alexandre

    2004-01-01

    Este artigo apresenta resultados preliminares de uma investigação sobre um processo de internacionalização de uma empresa brasileira do setor de petróleo. Com base na literatura de economia política internacional, os autores demonstram a importância de desenvolvimento de abordagens em gestão internacional que reconheçam as interfaces entre público e privado, mais particularmente entre governo e corporações transnacionais, e entre matriz e subsidiárias. O artigo sugere que esse tipo de abordag...

  1. Genius in the shadows a biography of Leo Szilard, the man behind the bomb

    CERN Document Server

    Lanouette, William

    2013-01-01

    Well-known names such as Albert Einstein, Enrico Fermi, J. Robert Oppenheimer, and Edward Teller are usually those that surround the creation of the atom bomb. One name that is rarely mentioned is Leo Szilard, known in scientific circles as "father of the atom bomb." The man who first developed the idea of harnessing energy from nuclear chain reactions, he is curiously buried with barely a trace in the history of this well-known and controversial topic.Born in Hungary and educated in Berlin, he escaped Hitler's Germany in 1933 and that first year developed his concept of nucle

  2. Reservsõjaväelasele Leo Kunnasele anti Stalkeri romaaniauhind / Kalev Kask, Kaarel Kressa

    Index Scriptorium Estoniae

    Kask, Kalev

    2009-01-01

    Eesti Ulmeühingu Stalkeri-nimelised auhinnad jaotusid järgmiselt: algupärase romaani auhind - Leo Kunnas (romaani "Gort Ashryn" 1. osa "Enne viimast sõda"), algupärase jutu auhind - Indrek Hargla ("Minu päevad Liinaga", ilm. Looming, 2008, nr. 8), algupärase lühijutu auhind - Laur Kraft ("Ultima Cthule", ilm. võrguajakirjas Algernon), tõlkeromaani auhind - Sergei Lukjanenko ("Öine Vahtkond"), kogumiku auhind - Poul Anderson ("Taevarahvas"), tõlkejutu auhind - Paolo Bacigalup ("Flööditüdruk")

  3. Parasites and parasite stages of free-ranging wild lions (Panthera leo) of northern Tanzania.

    Science.gov (United States)

    Bjork, K E; Averbeck, G A; Stromberg, B E

    2000-03-01

    Fecal samples from 33 lions (Panthera leo) in Serengeti National Park and Ngorongoro Crater Conservation Area in northern Tanzania contained 19 different parasites, 12 of which, including Aelurostrongylus sp., a species of Acanthocephala, a species of Anoplocephalidae, Capillaria sp., Demodex sp., Eimeria sp., Habronema sp., Isospora felis, Isospora rivolta, one species of Isospora that was previously undescribed from lions, one species of Trematoda that was previously undescribed from lions, and Trichuris sp., were new reports for lions. Seven other species had been previously reported from lions.

  4. Geopolítica del petróleo en América Latina

    OpenAIRE

    Fontaine, Guillaume

    2003-01-01

    El presente artículo analiza la industria petrolera como un sector globalizado y ubica al Ecuador en el marco de la geopolítica del petróleo en América Latina, recalcando cual ha sido la evolución de la industria petrolera en la región hasta la fecha. En una primera parte, exponemos que desde la década del cincuenta se diseñó un escenario de dependencia económica y tecnología externa, con la prepotencia de las empresas multinacionales estadounidenses como telón de fondo. En una segunda parte,...

  5. VizieR Online Data Catalog: Kinematic study of the Leo II dwarf galaxy (Spencer+, 2017)

    Science.gov (United States)

    Spencer, M. E.; Mateo, M.; Walker, M. G.; Olszewski, E. W.

    2017-10-01

    We used the 90prime imager on the 2.3m Bok telescope at Steward Observatory in Arizona to collect photometry of Leo II. Stars were observed in the Washington M and I filters during 2006 February. We calibrated these instrumental M and I magnitudes by transposing them to apparent g and i magnitudes of the Sloan Digital Sky Survey (SDSS). Spectroscopic observations were obtained with the Multiple Mirror Telescope (MMT) using Hectochelle. Spectra were taken on five different runs between 2006 and 2013. (2 data files).

  6. Estudo da biotividade de óleos essenciais de tomilhos de Portugal

    OpenAIRE

    Correia, Mariana Roxo Martins Caril

    2014-01-01

    Dissertação de mestrado em Biodiversidade e Biotecnologia Vegetal, apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra. O género Thymus L. compreende espécies aromáticas de grande relevo etnobotânico e industrial, essencialmente devido aos seus óleos essenciais que possuem múltiplas utilizações na medicina tradicional dos povos do Mediterrâneo e aplicações nas indústrias de perfumes, cosméticos, produtos farmacêuticos e ...

  7. Bioremediación de suelos contaminados con hidrocarburos derivados del petróleo

    OpenAIRE

    López de Mesa, Joaquín Benavides; Quintero, Gladis; Guevara Vizcaíno, Andrea Liliana; Jaimes Cáceres, Diana Carolina; Gutiérrez Riaño, Sandra Milena; Miranda García, Johanna

    2006-01-01

    El manejo inadecuado de los materiales y residuos peligrosos ha generado a escala mundial, un problema de contaminación de suelos, aire y agua. Entre las más severas contaminaciones se destacan las que se produjeron y todavía se producen a causa de la extracción y el manejo del petróleo en todos los países productores de hidrocarburos. En nuestro país, el transporte de crudo y sus derivados se ha visto afectado considerablemente durante los últimos 18 años, por una permanente actividad terror...

  8. CONSISTÊNCIA DE MISTURA DE GORDURAS HIDROGENADAS E ÓLEO DE SOJA

    Directory of Open Access Journals (Sweden)

    SIMÕES Ilka Sumiyoshi

    1998-01-01

    Full Text Available A consistência é um aspecto funcional importante das gorduras plásticas, que são misturas de cristais de gordura sólida e óleo líquido. A relação entre as duas fases e o caracter cristalino da fase sólida determinam a consistência e a firmeza das amostras. O objetivo do trabalho foi determinar a consistência de duas gorduras vegetais hidrogenadas e suas misturas binárias e ternárias, com a presença ou não de óleo de soja, a partir dos resultados do analisador de textura (TA XT2, variando as profundidades de penetração e o ângulo dos cones. Aplicou-se um modelo de regressão múltipla, do tipo cúbico especial para as misturas de óleo e gorduras, utilizando o aplicativo MIXPLOT para a construção de diagrama triangular. A força de compressão variou de 0,0080 a 5,459 kg, dependendo da amostra e da profundidade de penetração do cone. Para os cones de ângulos 30, 40 e 45º, as consistências foram todas estatisticamente semelhantes, a p< 0,05. Para algumas amostras, os resultados empregando o cone de 20º foram estatisticamente diferentes. Tais diferenças de resultados podem ser justificadas pelo fato da geometria do cone de 20º ser diferente, em função do truncamento de sua ponta. A análise do diagrama triangular mostra que o componente óleo de soja não contribuiu estatisticamente para a consistência. Os coeficientes relativos às interações foram sempre negativos, demonstrando efeito antagônico para a consistência, característico das interações eutéticas entre gorduras. Este efeito eutético ocorre devido à incompatibilidade no estado sólido entre os componentes da mistura.

  9. The structure of nearby clusters of galaxies Hierarchical clustering and an application to the Leo region

    CERN Document Server

    Materne, J

    1978-01-01

    A new method of classifying groups of galaxies, called hierarchical clustering, is presented as a tool for the investigation of nearby groups of galaxies. The method is free from model assumptions about the groups. The scaling of the different coordinates is necessary, and the level from which one accepts the groups as real has to be determined. Hierarchical clustering is applied to an unbiased sample of galaxies in the Leo region. Five distinct groups result which have reasonable physical properties, such as low crossing times and conservative mass-to-light ratios, and which follow a radial velocity- luminosity relation. Only 4 out of 39 galaxies were adopted as field galaxies. (27 refs).

  10. Atividade antifúngica do óleo essencial da Calendula officinalis cultivada no Brasil

    OpenAIRE

    Gazim, Zilda Cristiane; Rezende, Claudia Moraes; Fraga, Sandra Regina; Svidzinski, Terezinha Inez Estivaleti; Cortez, Diógenes Aparicio Garcia

    2008-01-01

    This study tested in vitro activity of the essential oil from flowers of Calendula officinalis using disk-diffusion techniques. The antifungal assay results showed for the first time that the essential oil has good potential antifungal activity: it was effective against all 23 clinical fungi strains tested.Neste estudo foi avaliada a atividade antifúngica do óleo essencial, obtido das flores de Calendula officinalis utilizando-se técnica de difusão em discos. Os resultados dos ensaios antifún...

  11. LA ECO-EFICACIA DE LA PLATAFORMA LOGÍSTICA DE PETRÓLEO EN CUBA

    OpenAIRE

    José Antonio Acevedo Suárez; Martha Inés Gómez Acosta; Alejandro César Pons Salabarría; Roberto González González

    2003-01-01

    La perspectiva integradora de la gestión ambiental proactiva con las decisiones básicas del sistema de combustible cubano se considera una oportunidad rentable y efectiva. En consecuencia, la plataforma logística de petróleo como modelo para la innovación tecnológica en la gestión de la distribución debe demostrar la compatibilidad con ambas estrategias, permitiendo así obtener las oportunidades amb...

  12. PRIMA Platform capability for satellite missions in LEO and MEO (SAR, Optical, GNSS, TLC, etc.)

    Science.gov (United States)

    Logue, T.; L'Abbate, M.

    2016-12-01

    PRIMA (Piattaforma Riconfigurabile Italiana Multi Applicativa) is a multi-mission 3-axis stabilized Platform developed by Thales Alenia Space Italia under ASI contract.PRIMA is designed to operate for a wide variety of applications from LEO, MEO up to GEO and for different classes of satellites Platform Family. It has an extensive heritage in flight heritage (LEO and MEO Satellites already fully operational) in which it has successfully demonstrated the flexibility of use, low management costs and the ability to adapt to changing operational conditions.The flexibility and modularity of PRIMA provides unique capability to satisfy different Payload design and mission requirements, thanks to the utilization of recurrent adaptable modules (Service Module-SVM, Propulsion Module-PPM, Payload Module-PLM) to obtain mission dependent configuration. PRIMA product line development is continuously progressing, and is based on state of art technology, modular architecture and an Integrated Avionics. The aim is to maintain and extent multi-mission capabilities to operate in different environments (LEO to GEO) with different payloads (SAR, Optical, GNSS, TLC, etc.). The design is compatible with a wide range of European and US equipment suppliers, thus maximising cooperation opportunity. Evolution activities are mainly focused on the following areas: Structure: to enable Spacecraft configurations for multiple launch; Thermal Control: to guarantee thermal limits for new missions, more demanding in terms of environment and payload; Electrical: to cope with higher power demand (e.g. electrical propulsion, wide range of payloads, etc.) considering orbital environment (e.g. lighting condition); Avionics : AOCS solutions optimized on mission (LEO observation driven by agility and pointing, agility not a driver for GEO). Use of sensors and actuators tailored for specific mission and related environments. Optimised Propulsion control. Data Handling, SW and FDIR mission customization

  13. Acción antimicrobiana de extracto etanólico de propóleos sobre estreptococos mutans

    Directory of Open Access Journals (Sweden)

    Patricia Alejandra Vaculik

    2014-12-01

    Full Text Available El propóleo es un producto natural, posee una amplia variedad de propiedades vinculadas a las ciencias de la salud. De acuerdo al lugar de origen, condiciones climatológicas y tipo de especies botánicas circundantes, son las características que va a reunir. Por ello la particularidad de conocer el tipo de propóleos de nuestra zona geográfica y las propiedades que posee de acuerdo a sus compuestos químicos. La caries dental es una enfermedad infecciosa, que se origina por la interacción de múltiples factores, la dieta, el diente susceptible, los microorganismos, tiempo y la edad. Entre los microorganismos implicados en la formación de caries encontramos al Estreptococos mutans. El objetivo de este trabajo es conocer el propóleo de nuestra región y sus efectos antimicrobianos sobre los Estreptococos mutans.

  14. Nano emulsões aplicadas a recuperação avançada de petróleo

    OpenAIRE

    Souza, Tamyris Thaise Costa de

    2013-01-01

    A exploração de petróleo está a cada dia em circunstâncias mais adversas, no que diz respeito à profundidade dos poços como também, em relação à fluidez do óleo. Os reservatórios de descobertas recentes não possuem energia própria para produzir ou os métodos convencionais não são eficientes para fazer com que esses reservatórios tenham uma vida útil elevada, devido a alterações das propriedades físico-químicas, como por exemplo a viscosidade, que torna o deslocamento do óleo pe...

  15. O mercado internacional de petróleo: a influência da OPEP e o poder de mercado

    OpenAIRE

    Henrique dos Santos Maxir

    2016-01-01

    A criação da Organização dos Países Exportadores de Petróleo (OPEP) foi um marco para o mercado internacional de petróleo. Para a opinião pública a OPEP é um cartel devido aos choques do petróleo ocorridos na década de 1970, porém na literatura econômica não existe consenso sobre a OPEP ser ou não um cartel. Sob a ótica da teoria dos cartéis, esta pesquisa tem como objetivo evidenciar o papel da OPEP e verificar se a mesma exerce poder de mercado, demonstrando aspectos históricos que desencad...

  16. Commentary: Science, Technology, and Society in Guidelines for Using Technology to Prepare Social Studies Teachers--A Reply to Hicks et al. and Crocco and Leo

    Science.gov (United States)

    Mason, Lance

    2015-01-01

    This essay is a response to both the "Guidelines for Using Technology to Prepare Social Studies Teachers" published in this journal by Hicks, Lee, Berson, Bolick, and Diem (2014) and the rejoinder by Crocco and Leo (2015). The author agrees with Crocco and Leo's assessment that removing the principal regarding science, technology, and…

  17. Factores de riesgo asociados a íleo posquirúrgico prolongado en pacientes sometidos a resección electiva de colon

    Directory of Open Access Journals (Sweden)

    M.A. Juárez-Parra

    2015-10-01

    Conclusiones: La presencia de estos factores de riesgo pueden servir como alertas para un seguimiento más cercano en pacientes de alto riesgo de íleo postoperatorio. El uso de anestesia peridural pudiera disminuir la incidencia de íleo.

  18. Earth as a Tool for Astrobiology—A European Perspective

    Science.gov (United States)

    Martins, Zita; Cottin, Hervé; Kotler, Julia Michelle; Carrasco, Nathalie; Cockell, Charles S.; de la Torre Noetzel, Rosa; Demets, René; de Vera, Jean-Pierre; d'Hendecourt, Louis; Ehrenfreund, Pascale; Elsaesser, Andreas; Foing, Bernard; Onofri, Silvano; Quinn, Richard; Rabbow, Elke; Rettberg, Petra; Ricco, Antonio J.; Slenzka, Klaus; Stalport, Fabien; ten Kate, Inge L.; van Loon, Jack J. W. A.; Westall, Frances

    2017-07-01

    Scientists use the Earth as a tool for astrobiology by analyzing planetary field analogues (i.e. terrestrial samples and field sites that resemble planetary bodies in our Solar System). In addition, they expose the selected planetary field analogues in simulation chambers to conditions that mimic the ones of planets, moons and Low Earth Orbit (LEO) space conditions, as well as the chemistry occurring in interstellar and cometary ices. This paper reviews the ways the Earth is used by astrobiologists: (i) by conducting planetary field analogue studies to investigate extant life from extreme environments, its metabolisms, adaptation strategies and modern biosignatures; (ii) by conducting planetary field analogue studies to investigate extinct life from the oldest rocks on our planet and its biosignatures; (iii) by exposing terrestrial samples to simulated space or planetary environments and producing a sample analogue to investigate changes in minerals, biosignatures and microorganisms. The European Space Agency (ESA) created a topical team in 2011 to investigate recent activities using the Earth as a tool for astrobiology and to formulate recommendations and scientific needs to improve ground-based astrobiological research. Space is an important tool for astrobiology (see Horneck et al. in Astrobiology, 16:201-243, 2016; Cottin et al., 2017), but access to space is limited. Complementing research on Earth provides fast access, more replications and higher sample throughput. The major conclusions of the topical team and suggestions for the future include more scientifically qualified calls for field campaigns with planetary analogy, and a centralized point of contact at ESA or the EU for the organization of a survey of such expeditions. An improvement of the coordinated logistics, infrastructures and funding system supporting the combination of field work with planetary simulation investigations, as well as an optimization of the scientific return and data processing

  19. Capturing near-Earth asteroids around Earth

    Science.gov (United States)

    Hasnain, Zaki; Lamb, Christopher A.; Ross, Shane D.

    2012-12-01

    The list of detected near-Earth asteroids (NEAs) is constantly growing. NEAs are likely targets for resources to support space industrialization, as they may be the least expensive source of certain needed raw materials. The limited supply of precious metals and semiconducting elements on Earth may be supplemented or even replaced by the reserves floating in the form of asteroids around the solar system. Precious metals make up a significant fraction NEAs by mass, and even one metallic asteroid of ˜1km size and fair enrichment in platinum-group metals would contain twice the tonnage of such metals already harvested on Earth. There are ˜1000 NEAs with a diameter of greater than 1 km. Capturing these asteroids around the Earth would expand the mining industry into an entirely new dimension. Having such resources within easy reach in Earth's orbit could provide an off-world environmentally friendly remedy for impending terrestrial shortages, especially given the need for raw materials in developing nations. In this paper, we develop and implement a conceptually simple algorithm to determine trajectory characteristics necessary to move NEAs into capture orbits around the Earth. Altered trajectories of asteroids are calculated using an ephemeris model. Only asteroids of eccentricity less than 0.1 have been studied and the model is restricted to the ecliptic plane for simplicity. We constrain the time of retrieval to be 10 years or less, based on considerations of the time to return on investment. For the heliocentric phase, constant acceleration is assumed. The acceleration required for transporting these asteroids from their undisturbed orbits to the sphere of influence of the Earth is the primary output, along with the impulse or acceleration necessary to effect capture to a bound orbit once the Earth's sphere of influence is reached. The initial guess for the constant acceleration is provided by a new estimation method, similar in spirit to Edelbaum's. Based on the

  20. Avaliação da atividade larvicida do óleo essencial do Zingiber officinale Roscoe (gengibre) frente ao mosquito Aedes aegypti

    OpenAIRE

    GOMES, P.R.B.; SILVA, A.L.S.; PINHEIRO, H.A.; CARVALHO, L.L.; LIMA, H.S.; SILVA, E.F.; SILVA, R.P.; LOUZEIRO, C.H.; OLIVEIRA, M.B.; FILHO, V.E.M.

    2016-01-01

    RESUMO Este trabalho analisa o efeito larvicida do óleo Zingiber officinale Roscoe contra larvas em terceiro estágio do mosquito Aedes aegypti. Extraiu-se quantitativamente o óleo essencial por hidrodestilação e calculou-se a CL50 do óleo, a partir dos métodos de Reed-Muench e Pizzi, respectivamente. O óleo essencial obteve CL50 de 76,07 (±2,24) μg mL-1 e rendimento de 0,52% m/v. Os resultados indicam que o óleo essencial avaliado é composto por substâncias que propiciam efeito larvicida cont...

  1. Calibração multivariada de misturas de óleos vegetais utilizando espectroscopia no infravermelho médio

    OpenAIRE

    Pereira, Wesley de Assis

    2012-01-01

    Os óleos vegetais são muito importantes para a saúde humana pois são excelentes fontes de ácidos graxos mono e polinsaturados que são benéficos a nossa saúde. E o Brasil é um grande produtor de óleo vegetal, principalmente do óleo de soja, seja como matéria-prima para a indústria de alimentos, seja para a produção de biodiesel, onde o óleo de soja corresponde a cerca de 90% da matéria prima desse combustível. Esses óleos vegetais possuem características que influenciam nas suas...

  2. Avaliação da atividade larvicida do óleo essencial do Zingiber officinale Roscoe (gengibre frente ao mosquito Aedes aegypti

    Directory of Open Access Journals (Sweden)

    P.R.B. GOMES

    Full Text Available RESUMO Este trabalho analisa o efeito larvicida do óleo Zingiber officinale Roscoe contra larvas em terceiro estágio do mosquito Aedes aegypti. Extraiu-se quantitativamente o óleo essencial por hidrodestilação e calculou-se a CL50 do óleo, a partir dos métodos de Reed-Muench e Pizzi, respectivamente. O óleo essencial obteve CL50 de 76,07 (±2,24 μg mL-1 e rendimento de 0,52% m/v. Os resultados indicam que o óleo essencial avaliado é composto por substâncias que propiciam efeito larvicida contra Aedes aegypti.

  3. Uso de óleo essencial de copaíba sobre o desempenho produtivo de frangos de corte

    OpenAIRE

    SOUZA, Vanessa Pereira de

    2010-01-01

    As recentes restrições ao uso de antibióticos melhoradores do desempenho na produção de frangos de cortes têm incentivado a busca por aditivos alternativos. Entre os produtos naturais, o óleo de copaíba tem uma grande representação social e econômica, especialmente na região amazônica, onde é nativo e largamente empregado. Os objetivos deste estudo foram avaliar os efeitos da inclusão do óleo de Copaíba (Copaifera reticulata), sobre o desempenho produtivo de frangos de corte. Foram utilizados...

  4. Estudo comparativo dos óleos voláteis de algumas espécies de Piperaceae

    OpenAIRE

    Mesquita,J.M.O.; Cavaleiro,C.; Cunha,A.P.; Lombardi,J.A.; Oliveira,A.B.

    2005-01-01

    O presente trabalho teve por objetivo a análise comparativa dos óleos voláteis de espécies da família Piperaceae. As espécies estudadas foram as seguintes: Piper aduncum, P. amalago, P. arboreum, P. cernuum, P. hispidum, P. regnelii, P. submarginalum, P. vicosanum e Pothomorphe umbellata. A análise dos óleos voláteis foi efetuada pela combinação de técnicas de Cromatografia de Fase Gasosa (CG) e de Cromatografia de Fase Gasosa acoplada a Espectrometria de Massa (CG/EM). A porcentagem de ident...

  5. Uma imersão no tabuleiro da baiana: o estudo do óleo de palma.

    OpenAIRE

    Curvelo, Fabiana Martins

    2010-01-01

    p. 1-105 O Objetivo do presente trabalho foi avaliar a qualidade do óleo de palma bruto e daquele empregado na fritura de acarajés, consumidos na cidade de Salvador-Bahia. Metodologia: para avaliação das técnicas de fritura aplicou-se questionário semi estruturado a 149 baianas de acarajé distribuídas pelos 12 distritos sanitários da referida cidade. Com base nestes, foram coletados os 15 principais óleos empregados na fritura dos bolinhos e 149 amostras daquele empregado na fritura. A ava...

  6. Actividad antiurolítica del extracto etanólico de propóleo ayacuchano en ratas

    OpenAIRE

    López-Cabanillas, Rita; Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Sociedad Científica de San Fernando. Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Estudiante de Medicina.; Huayanay-Conde, Ronal; Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Estudiante de Medicina; Gonzales, Cinthya; Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Sociedad Científica de San Fernando. Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Estudiante de Medicina.; Maguiña, Mahli; Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Sociedad Científica de San Fernando. Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Estudiante de Medicina.; Granados, Italo; Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Sociedad Científica de San Fernando. Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Estudiante de Medicina.; Ccasani, Mila; Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Sociedad Científica de San Fernando. Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Estudiante de Medicina.; Laguna, Astrid; Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Estudiante de Medicina.; León, Ernesto; Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Estudiante de Medicina.; Romero-Caballero, Nuria; Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Estudiante de Medicina.; Chacón, Jessenia; Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Estudiante de Medicina.

    2017-01-01

    Objetivos. Determinar la actividad antiurolítica del extracto etanólico de propóleo ayacuchano en un modelo preventivo de urolitiasis inducido en ratas. Materiales y métodos. Se estudiaron 45 ratas albinas macho Sprague-Dawley. El efecto antiurolítico se analizó en cinco grupos de seis animales: blanco, control (1 mL de etilenglicol al 5% y 1 mL cloruro de amonio al 5%) y tres grupos tratados con el extracto etanólico de propóleo a dosis diaria de 250, 350 y 500 mg/Kg. Las sustancias fueron a...

  7. Chemistry of the interstellar medium

    International Nuclear Information System (INIS)

    Umanskij, S.Ya.

    1979-01-01

    Some aspects of chemistry of interstellar gas-dust clouds are considered. The specific attention is paid to the molecule formation in the interstellar medium. Discussed are the process of hydrogen atom recombination on interstellar specks of dust as well as the formation of double-atom molecules. An ion-molecular mechanism plays the main role in the origination of multiatom molecules. It is noted, that the real progress in chemistry of the interstellar medium will be determined by the development of laboratory investigations at ultralow temperatures and study of the processes proceeding on solid surfaces

  8. Linhaça marrom e dourada: propriedades químicas e funcionais das sementes e dos óleos prensados a frio

    Directory of Open Access Journals (Sweden)

    Ana Karina Mauro Barroso

    2014-01-01

    Full Text Available O objetivo do estudo foi comparar a composição química e a capacidade antioxidante das sementes e dos óleos de linhaça marrom e dourada, e avaliar a estabilidade oxidativa dos óleos. Nas sementes, foram determinados: composição centesimal, capacidade antioxidante total e compostos fenólicos totais. Nos óleos, foram determinados: índice de acidez e peróxido, matéria insaponificável, composição em ácidos graxos, tocoferóis, capacidade antioxidante, compostos fenólicos totais e estabilidade oxidativa em quatro condições de estocagem por até um ano. Não houve diferenças significativas entre os tipos de sementes quanto às variáveis investigadas, e ainda entre os óleos quanto ao rendimento da prensagem, composição em ácidos graxos insaturados, índice de acidez, teores de insaponificáveis e compostos fenólicos totais. Apesar do declínio da estabilidade oxidativa de ambos os óleos durante o armazenamento, o óleo de linhaça marrom e os óleos estocados sob refrigeração apresentaram-se mais estáveis. O índice de peróxido foi maior no óleo de linhaça dourada. O teor de tocoferol total e capacidade antioxidante total foram maiores no óleo de linhaça marrom. Contudo, observou-se uma igualdade entre as sementes de ambas as variedades de linhaça e uma superioridade do óleo de linhaça marrom.

  9. Atmospheric influences on infrared-laser signals used for occultation measurements between Low Earth Orbit satellites

    Directory of Open Access Journals (Sweden)

    S. Schweitzer

    2011-10-01

    Full Text Available LEO-LEO infrared-laser occultation (LIO is a new occultation technique between Low Earth Orbit (LEO satellites, which applies signals in the short wave infrared spectral range (SWIR within 2 μm to 2.5 μm. It is part of the LEO-LEO microwave and infrared-laser occultation (LMIO method that enables to retrieve thermodynamic profiles (pressure, temperature, humidity and altitude levels from microwave signals and profiles of greenhouse gases and further variables such as line-of-sight wind speed from simultaneously measured LIO signals. Due to the novelty of the LMIO method, detailed knowledge of atmospheric influences on LIO signals and of their suitability for accurate trace species retrieval did not yet exist. Here we discuss these influences, assessing effects from refraction, trace species absorption, aerosol extinction and Rayleigh scattering in detail, and addressing clouds, turbulence, wind, scattered solar radiation and terrestrial thermal radiation as well. We show that the influence of refractive defocusing, foreign species absorption, aerosols and turbulence is observable, but can be rendered small to negligible by use of the differential transmission principle with a close frequency spacing of LIO absorption and reference signals within 0.5%. The influences of Rayleigh scattering and terrestrial thermal radiation are found negligible. Cloud-scattered solar radiation can be observable under bright-day conditions, but this influence can be made negligible by a close time spacing (within 5 ms of interleaved laser-pulse and background signals. Cloud extinction loss generally blocks SWIR signals, except very thin or sub-visible cirrus clouds, which can be addressed by retrieving a cloud layering profile and exploiting it in the trace species retrieval. Wind can have a small influence on the trace species absorption, which can be made negligible by using a simultaneously retrieved or a moderately accurate background wind speed profile. We

  10. Low Earth orbit assessment of proton anisotropy using AP8 and AP9 trapped proton models.

    Science.gov (United States)

    Badavi, Francis F; Walker, Steven A; Santos Koos, Lindsey M

    2015-04-01

    The completion of the International Space Station (ISS) in 2011 has provided the space research community with an ideal evaluation and testing facility for future long duration human activities in space. Ionized and secondary neutral particles radiation measurements inside ISS form the ideal tool for validation of radiation environmental models, nuclear reaction cross sections and transport codes. Studies using thermo-luminescent detectors (TLD), tissue equivalent proportional counter (TPEC), and computer aided design (CAD) models of early ISS configurations confirmed that, as input, computational dosimetry at low Earth orbit (LEO) requires an environmental model with directional (anisotropic) capability to properly describe the exposure of trapped protons within ISS. At LEO, ISS encounters exposure from trapped electrons, protons and geomagnetically attenuated galactic cosmic rays (GCR). For short duration studies at LEO, one can ignore trapped electrons and ever present GCR exposure contributions during quiet times. However, within the trapped proton field, a challenge arises from properly estimating the amount of proton exposure acquired. There exist a number of models to define the intensity of trapped particles. Among the established trapped models are the historic AE8/AP8, dating back to the 1980s and the recently released AE9/AP9/SPM. Since at LEO electrons have minimal exposure contribution to ISS, this work ignores the AE8 and AE9 components of the models and couples a measurement derived anisotropic trapped proton formalism to omnidirectional output from the AP8 and AP9 models, allowing the assessment of the differences between the two proton models. The assessment is done at a target point within the ISS-11A configuration (circa 2003) crew quarter (CQ) of Russian Zvezda service module (SM), during its ascending and descending nodes passes through the south Atlantic anomaly (SAA). The anisotropic formalism incorporates the contributions of proton narrow

  11. Time and Energy, Exploring Trajectory Options Between Nodes in Earth-Moon Space

    Science.gov (United States)

    Martinez, Roland; Condon, Gerald; Williams, Jacob

    2012-01-01

    The Global Exploration Roadmap (GER) was released by the International Space Exploration Coordination Group (ISECG) in September of 2011. It describes mission scenarios that begin with the International Space Station and utilize it to demonstrate necessary technologies and capabilities prior to deployment of systems into Earth-Moon space. Deployment of these systems is an intermediate step in preparation for more complex deep space missions to near-Earth asteroids and eventually Mars. In one of the scenarios described in the GER, "Asteroid Next", there are activities that occur in Earth-Moon space at one of the Earth-Moon Lagrange (libration) points. In this regard, the authors examine the possible role of an intermediate staging point in an effort to illuminate potential trajectory options for conducting missions in Earth-Moon space of increasing duration, ultimately leading to deep space missions. This paper will describe several options for transits between Low Earth Orbit (LEO) and the libration points, transits between libration points, and transits between the libration points and interplanetary trajectories. The solution space provided will be constrained by selected orbital mechanics design techniques and physical characteristics of hardware to be used in both crewed missions and uncrewed missions. The relationships between time and energy required to transfer hardware between these locations will provide a better understanding of the potential trade-offs mission planners could consider in the development of capabilities, individual missions, and mission series in the context of the ISECG GER.

  12. Operational specification and forecasting advances for Dst, LEO thermospheric densities, and aviation radiation dose and dose rate

    Science.gov (United States)

    Tobiska, W. Kent

    Space weather’s effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun’s photons, particles, and fields. Of the space environment domains that are affected by space weather, the magnetosphere, thermosphere, and even troposphere are key regions that are affected. Space Environment Technologies (SET) has developed and is producing innovative space weather applications. Key operational systems for providing timely information about the effects of space weather on these domains are SET’s Magnetosphere Alert and Prediction System (MAPS), LEO Alert and Prediction System (LAPS), and Automated Radiation Measurements for Aviation Safety (ARMAS) system. MAPS provides a forecast Dst index out to 6 days through the data-driven, redundant data stream Anemomilos algorithm. Anemomilos uses observational proxies for the magnitude, location, and velocity of solar ejecta events. This forecast index is used by satellite operations to characterize upcoming geomagnetic storms, for example. In addition, an ENLIL/Rice Dst prediction out to several days has also been developed and will be described. LAPS is the SET fully redundant operational system providing recent history, current epoch, and forecast solar and geomagnetic indices for use in operational versions of the JB2008 thermospheric density model. The thermospheric densities produced by that system, driven by the LAPS data, are forecast to 72-hours to provide the global mass densities for satellite operators. ARMAS is a project that has successfully demonstrated the operation of a micro dosimeter on aircraft to capture the real-time radiation environment due to Galactic Cosmic Rays and Solar Energetic Particles. The dose and dose-rates are captured on aircraft, downlinked in real-time via the Iridium satellites, processed on the ground, incorporated into the most recent NAIRAS global radiation climatology data runs, and made available to end users via the web and

  13. Hands On Earth Science.

    Science.gov (United States)

    Weisgarber, Sherry L.; Van Doren, Lisa; Hackathorn, Merrianne; Hannibal, Joseph T.; Hansgen, Richard

    This publication is a collection of 13 hands-on activities that focus on earth science-related activities and involve students in learning about growing crystals, tectonics, fossils, rock and minerals, modeling Ohio geology, geologic time, determining true north, and constructing scale-models of the Earth-moon system. Each activity contains…

  14. EARTH FROM SPACE

    Indian Academy of Sciences (India)

    Table of contents. EARTH FROM SPACE · Slide 2 · Earth System · Slide 4 · Global water cycle · Slide 6 · Slide 7 · Direct Observations of Recent Climate Change · Slide 9 · Slide 10 · Snow cover and Arctic sea ice are decreasing · Polar Melting & Global Heat Transport · Antarctica: Melting and Thickening · Slide 14 · Slide 15.

  15. Introducing Earth's Orbital Eccentricity

    Science.gov (United States)

    Oostra, Benjamin

    2015-01-01

    Most students know that planetary orbits, including Earth's, are elliptical; that is Kepler's first law, and it is found in many science textbooks. But quite a few are mistaken about the details, thinking that the orbit is very eccentric, or that this effect is somehow responsible for the seasons. In fact, the Earth's orbital eccentricity is…

  16. Earth Flyby Anomalies

    OpenAIRE

    Nieto, Michael Martin; Anderson, John D.

    2009-01-01

    In a reference frame fixed to the solar system's center of mass, a satellite's energy will change as it is deflected by a planet. But a number of satellites flying by Earth have also experienced energy changes in the Earth-centered frame -- and that's a mystery.

  17. Bioleaching of rare earth elements from monazite sand.

    Science.gov (United States)

    Brisson, Vanessa L; Zhuang, Wei-Qin; Alvarez-Cohen, Lisa

    2016-02-01

    Three fungal strains were found to be capable of bioleaching rare earth elements from monazite, a rare earth phosphate mineral, utilizing the monazite as a phosphate source and releasing rare earth cations into solution. These organisms include one known phosphate solubilizing fungus, Aspergillus niger ATCC 1015, as well as two newly isolated fungi: an Aspergillus terreus strain ML3-1 and a Paecilomyces spp. strain WE3-F. Although monazite also contains the radioactive element Thorium, bioleaching by these fungi preferentially solubilized rare earth elements over Thorium, leaving the Thorium in the solid residual. Adjustments in growth media composition improved bioleaching performance measured as rare earth release. Cell-free spent medium generated during growth of A. terreus strain ML3-1 and Paecilomyces spp. strain WE3-F in the presence of monazite leached rare earths to concentrations 1.7-3.8 times those of HCl solutions of comparable pH, indicating that compounds exogenously released by these organisms contribute substantially to leaching. Organic acids released by the organisms included acetic, citric, gluconic, itaconic, oxalic, and succinic acids. Abiotic leaching with laboratory prepared solutions of these acids was not as effective as bioleaching or leaching with cell-free spent medium at releasing rare earths from monazite, indicating that compounds other than the identified organic acids contribute to leaching performance. © 2015 Wiley Periodicals, Inc.

  18. A Multi-epoch Kinematic Study of the Remote Dwarf Spheroidal Galaxy Leo II

    Science.gov (United States)

    Spencer, Meghin E.; Mateo, Mario; Walker, Matthew G.; Olszewski, Edward W.

    2017-02-01

    We conducted a large spectroscopic survey of 336 red giants in the direction of the Leo II dwarf galaxy using Hectochelle on the Multiple Mirror Telescope, and we conclude that 175 of them are members based on their radial velocities and surface gravities. Of this set, 40 stars have never before been observed spectroscopically. The systemic velocity of the dwarf is 78.3 ± 0.6 km s-1 with a velocity dispersion of 7.4 ± 0.4 km s-1. We identify one star beyond the tidal radius of Leo II but find no signatures of uniform rotation, kinematic asymmetries, or streams. The stars show a strong metallicity gradient of -1.53 ± 0.10 dex kpc-1 and have a mean metallicity of -1.70 ± 0.02 dex. There is also evidence of two different chemodynamic populations, but the signal is weak. A larger sample of stars would be necessary to verify this feature. Observations reported here were obtained at the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution.

  19. FRACIONAMENTO DE ÓLEOS DE CITROS UTILIZANDO FLUIDOS SUPERCRÍTICOS

    Directory of Open Access Journals (Sweden)

    Marisa MENDES

    1997-12-01

    Full Text Available O objetivo deste trabalho é o estudo sobre o fracionamento do óleo de laranja. Neste sentido, o limoneno e o linalol foram considerados os componentes-chaves do óleo de laranja, representando os terpenos e compostos oxigenados, respectivamente. Para modelar os dados de equilíbrio de fases foi usada a equação de estado de Peng-Robinson, juntamente com as regras de mistura de van der Waals, uni e biparamétrica, e de Panagiotopoulos e Reid. O uso desses modelos termodinâmicos permitiu determinar as condições de temperatura e pressão que levaram aos melhores valores do par seletividade-capacidade.The objective of this work is to study the fractionation of the citrus oils, especially orange oil. The orange oil is considered to be a mixture of two main components, limonene and linalool, which represent the terpenes and oxygenated group fractions, respectively. The Peng-Robinson equation of state using the van der Waals, with one or two parameters, and Panagiotopoulos and Reid mixing rules, were used to correlate and predict the binary and ternary high pressure phase equilibria of CO2 containing systems . The use of thermodynamic models to predict the phase equilibria allowed to establish the conditions of temperature and pressure, which led to the best results of selectivities and capacities of the extraction.

  20. A Multi-epoch Kinematic Study of the Remote Dwarf Spheroidal Galaxy Leo II

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, Meghin E.; Mateo, Mario [Department of Astronomy, University of Michigan, Ann Arbor, MI (United States); Walker, Matthew G. [McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, Pittsburgh, PA (United States); Olszewski, Edward W., E-mail: meghins@umich.edu [Steward Observatory, The University of Arizona, Tucson, AZ (United States)

    2017-02-20

    We conducted a large spectroscopic survey of 336 red giants in the direction of the Leo II dwarf galaxy using Hectochelle on the Multiple Mirror Telescope, and we conclude that 175 of them are members based on their radial velocities and surface gravities. Of this set, 40 stars have never before been observed spectroscopically. The systemic velocity of the dwarf is 78.3 ± 0.6 km s{sup −1} with a velocity dispersion of 7.4 ± 0.4 km s{sup −1}. We identify one star beyond the tidal radius of Leo II but find no signatures of uniform rotation, kinematic asymmetries, or streams. The stars show a strong metallicity gradient of −1.53 ± 0.10 dex kpc{sup −1} and have a mean metallicity of −1.70 ± 0.02 dex. There is also evidence of two different chemodynamic populations, but the signal is weak. A larger sample of stars would be necessary to verify this feature.

  1. Micropropagation of dahlia in static liquid medium using slow-release tools of medium ingredients

    NARCIS (Netherlands)

    Klerk, de G.J.M.; Brugge, ter J.

    2011-01-01

    Growth of dahlia shoots in vitro was ca. 4 times faster in liquid medium than on solidified medium. In liquid standard medium (3% sucrose, macroelements according to Driver–Kuniyuki Walnut medium, microelements according to Murashige–Skoog medium, 0.44 µM benzylaminopurine), the major medium

  2. Animal Locomotion in Different Mediums

    Indian Academy of Sciences (India)

    Wetlands are repositories of unique biodiversity. Wetlandorganisms are well adapted to their habitat, lying at theinterface of aquatic and terrestrial environments. In order tounderstand their adaptations in a better way, it is essential tograsp the basic properties of the medium in which variousorganisms live. This is attempted ...

  3. Animal Locomotion in Different Mediums

    Indian Academy of Sciences (India)

    IAS Admin

    Fishes, moving in water encounter drag forces, which can be of considerable magnitude. If sudden movement is required to catch prey or escape predators in a viscous medium, it is only possible by the contraction of fast, white muscle fibres, which rely on anaerobic glycolysis pathways. Therefore, it is not surprising that.

  4. Molecular spectroscopy of interstellar medium

    International Nuclear Information System (INIS)

    Varshalovich, D.A.; Khersonskij, V.K.

    1980-01-01

    Experimental data obtained in the investigation into molecules of interstellar medium by molecular-spectroscopic methods are discussed generally. Ion-molecule reactions play a significant part in the formation of multiatom molecules in the interstellar medium as well as reactions proceeding on the surface of interstellar dust. More than 50 types of molecules have been detected in the interstellar medium at present. In a wide range of wave lengths over 500 spectral lines belonging to various molecules and molecular fragments have been recorded. Interstellar molecules permit to investigate interstellar gas from all the sides. They are a suitable indicator of the isotope composition of interstellar gas. Radio observations of interstellar molecules make it possible to effectively investigate kinematics and space structure both separate gas-dust complexes and total gas distribution in Galaxy. It is noted that achievements of molecular spectroscopy of the interstellar medium radically change representations of the chemical composition of interstellar gas, of isotope abundance and organic substance in the Universe

  5. Hadron photoproduction at medium energy

    International Nuclear Information System (INIS)

    Dainton, J.B.

    1985-04-01

    Results from measurements of multibody photoproduction at medium incident photon energy (2.8 to 4.8 GeV) are presented and discussed. Particular emphasis is placed on topics which are not well understood and which therefore motivate experiments with the upgraded electron accelerator and storage ring ELSA at the University of Bonn, FR Germany. (author)

  6. Google Earth and Geo Applications: A Toolset for Viewing Earth's Geospatial Information

    Science.gov (United States)

    Tuxen-Bettman, K.

    2016-12-01

    Earth scientists measure and derive fundamental data that can be of broad general interest to the public and policy makers. Yet, one of the challenges that has always faced the Earth science community is how to present their data and findings in an easy-to-use and compelling manner. Google's Geo Tools offer an efficient and dynamic way for scientists, educators, journalists and others to both access data and view or tell stories in a dynamic three-dimensional geospatial context. Google Earth in particular provides a dense canvas of satellite imagery on which can be viewed rich vector and raster datasets using the medium of Keyhole Markup Language (KML). Through KML, Google Earth can combine the analytical capabilities of Earth Engine, collaborative mapping of My Maps, and storytelling of Tour Builder and more to make Google's Geo Applications a coherent suite of tools for exploring our planet.https://earth.google.com/https://earthengine.google.com/https://mymaps.google.com/https://tourbuilder.withgoogle.com/https://www.google.com/streetview/

  7. NEUDOSE: A CubeSat Mission for Dosimetry of Charged Particles and Neutrons in Low-Earth Orbit.

    Science.gov (United States)

    Hanu, A R; Barberiz, J; Bonneville, D; Byun, S H; Chen, L; Ciambella, C; Dao, E; Deshpande, V; Garnett, R; Hunter, S D; Jhirad, A; Johnston, E M; Kordic, M; Kurnell, M; Lopera, L; McFadden, M; Melnichuk, A; Nguyen, J; Otto, A; Scott, R; Wagner, D L; Wiendels, M

    2017-01-01

    During space missions, astronauts are exposed to a stream of energetic and highly ionizing radiation particles that can suppress immune system function, increase cancer risks and even induce acute radiation syndrome if the exposure is large enough. As human exploration goals shift from missions in low-Earth orbit (LEO) to long-duration interplanetary missions, radiation protection remains one of the key technological issues that must be resolved. In this work, we introduce the NEUtron DOSimetry & Exploration (NEUDOSE) CubeSat mission, which will provide new measurements of dose and space radiation quality factors to improve the accuracy of cancer risk projections for current and future space missions. The primary objective of the NEUDOSE CubeSat is to map the in situ lineal energy spectra produced by charged particles and neutrons in LEO where most of the preparatory activities for future interplanetary missions are currently taking place. To perform these measurements, the NEUDOSE CubeSat is equipped with the Charged & Neutral Particle Tissue Equivalent Proportional Counter (CNP-TEPC), an advanced radiation monitoring instrument that uses active coincidence techniques to separate the interactions of charged particles and neutrons in real time. The NEUDOSE CubeSat, currently under development at McMaster University, provides a modern approach to test the CNP-TEPC instrument directly in the unique environment of outer space while simultaneously collecting new georeferenced lineal energy spectra of the radiation environment in LEO.

  8. Óleos essenciais no controle da ferrugem asiática da soja Phakopsora pachyrhizi Syd. & P. Syd. Essential oils used in the control of asian soybean rust Phakopsora pachyrhizi Syd. & P. Syd.

    Directory of Open Access Journals (Sweden)

    Regiane Medice

    2007-02-01

    Full Text Available Objetivou-se com este trabalho avaliar o potencial de óleos essenciais na inibição da germinação de urediniósporos de Phakopsora pachyrhizi e na redução da severidade dos sintomas da ferrugem asiática em casa-de-vegetação. O experimento foi conduzido em duas etapas. Na primeira, foram adicionados em placas de Petri contendo 10 mL de meio de cultura agar-água óleos essenciais de Corymbia citriodora (eucalipto citriodora,Cymbopogon nardus (citronela,Azadirachta indica (nim e Thymus vulgaris L (tomilho nas concentrações 1%, 0,5%, 1% e 0,3%, respectivamente para cada óleo. Em placas controles foi adicionado 1mL de água. Sobre as placas foram adicionados 100µL de urediniósporos na concentração de 5 mg/mL de água. As placas foram incubadas por 4 horas a 25ºC e logo depois avaliada a porcentagem de germinação. Na segunda etapa, em casa-de-vegetação, os óleos foram aplicados nas mesmas concentrações em plantas de soja, cultivares MG/BR46 (Conquista e Suprema, aos 7 dias antes, 15 e 30 dias depois da inoculação. Os parâmetros avaliados foram incidência e número de pústulas por cm² de área foliar. Foram também coletadas folhas para preparação de amostras para microscopia eletrônica de varredura (MEV. Constatou-se que os óleos nas concentrações utilizadas inibiram 100% a germinação dos urediniósporos em meio ágar-água. Em casa-de-vegetação observou-se que todos os óleos retardaram a evolução da doença quando comparado com o controle, sendo que a severidade foi reduzida em média de 34,6 a 60,7% na cultivar MG/BR46 (Conquista e de 45,7 a 62, 3% na cultivar Suprema, em relação ao controle. Nas observações em MEV observou-se que houve murchamento dos urediniósporos, quando tratados com óleo de tomilho. Para os demais tratamentos observou-se apenas redução no tamanho das urédias. Com isso podemos inferir que os óleos essenciais utilizados têm potencial para reduzir o ataque do fungo em plantas

  9. Trade Study for Neutron Transport at Low Earth Orbit: Adding Fidelity to DIORAMA

    Energy Technology Data Exchange (ETDEWEB)

    McClanahan, Tucker Caden [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wakeford, Daniel Tyler [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-22

    The Distributed Infrastructure Offering Real-Time Access to Modeling and Analysis (DIORAMA) software provides performance modeling capabilities of the United States Nuclear Detonation Detection System (USNDS) with a focus on the characterization of Space-Based Nuclear Detonation Detection (SNDD) instrument performance [1]. A case study was done to add the neutron propagation capabilities of DIORAMA to low earth orbit (LEO), and compare the back-calculated incident energy from the time-of- ight (TOF) spectrum with the scored incident energy spectrum. As the scoring altitude lowers, the time increase due to scattering takes up much more of the fraction of total TOF; whereas at geosynchronous earth orbit (GEO), the time increase due to scattering is a negligible fraction of the total TOF [2]. The scattering smears out the TOF enough to make the back-calculation of the initial energy spectrum from the TOF spectrum very convoluted.

  10. The BioSentinel Bioanalytical Microsystem: Characterizing DNA Radiation Damage in Living Organisms Beyond Earth Orbit

    Science.gov (United States)

    Ricco, A. J.; Hanel, R.; Bhattacharya, S.; Boone, T.; Tan, M.; Mousavi, A.; Rademacher, A.; Schooley, A.; Klamm, B.; Benton, J.; hide

    2016-01-01

    We will present details and initial lab test results from an integrated bioanalytical microsystem designed to conduct the first biology experiments beyond low Earth orbit (LEO) since Apollo 17 (1972). The 14-kg, 12x24x37-cm BioSentinel spacecraft (Figure 1) assays radiation-responsive yeast in its science payload by measuring DNA double-strand breaks (DSBs) repaired via homologous recombination, a mechanism common to all eukaryotes including humans. S. cerevisiae (brewer's yeast) in 288 microwells are provided with nutrient and optically assayed for growth and metabolism via 3-color absorptimetry monthly during the 18-month mission. BioSentinel is one of several secondary payloads to be deployed by NASA's Exploration Mission 1 (EM-1) launch vehicle into approximately 0.95 AU heliocentric orbit in July 2018; it will communicate with Earth from up to 100 million km.

  11. Operation of the computer model for direct atomic oxygen exposure of Earth satellites

    Science.gov (United States)

    Bourassa, R. J.; Gruenbaum, P. E.; Gillis, J. R.; Hargraves, C. R.

    1995-01-01

    One of the primary causes of material degradation in low Earth orbit (LEO) is exposure to atomic oxygen. When atomic oxygen molecules collide with an orbiting spacecraft, the relative velocity is 7 to 8 km/sec and the collision energy is 4 to 5 eV per atom. Under these conditions, atomic oxygen may initiate a number of chemical and physical reactions with exposed materials. These reactions contribute to material degradation, surface erosion, and contamination. Interpretation of these effects on materials and the design of space hardware to withstand on-orbit conditions requires quantitative knowledge of the atomic oxygen exposure environment. Atomic oxygen flux is a function of orbit altitude, the orientation of the orbit plan to the Sun, solar and geomagnetic activity, and the angle between exposed surfaces and the spacecraft heading. We have developed a computer model to predict the atomic oxygen exposure of spacecraft in low Earth orbit. The application of this computer model is discussed.

  12. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 120; Issue 1. Experimental real-time multi-model ensemble (MME) prediction of rainfall during Monsoon 2008: Large-scale medium-range aspects. A K Mitra G R Iyengar V R Durai J Sanjay T N Krishnamurti A Mishra D R Sikka. Volume 120 Issue 1 February 2011 ...

  13. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    ... Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Journal of Earth System Science; Volume 121; Issue 2. Development of multimodel ensemble based district level medium range rainfall forecast system for Indian region. S K Roy Bhowmik V R Durai. Volume 121 Issue 2 April 2012 pp 273-285 ...

  14. Crystallization of mixed rare earth (didymium) molybdates in silica gel

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Experiments on the growth of mixed rare earth (didymium—a combination of La, Nd, Pr and Sm) molybdates in silica gel medium are reported. The optimum conditions conducive for the growth of these crystals are described and discussed. Concentration programming is reported to enhance the size of crystals by.

  15. Crystallization of mixed rare earth (didymium) molybdates in silica gel

    Indian Academy of Sciences (India)

    Experiments on the growth of mixed rare earth (didymium—a combination of La, Nd, Pr and Sm) molybdates in silica gel medium are reported. The optimum conditions conducive for the growth of these crystals are described and discussed. Concentration programming is reported to enhance the size of crystals by two-fold; ...

  16. Desempenho na barra de tração de um trator agrícola de pneus, alimentado com misturas de óleo diesel e óleo de soja reutilizado

    Directory of Open Access Journals (Sweden)

    Wagner da Cunha Siqueira

    2013-12-01

    Full Text Available O petróleo é a principal fonte de energia para motores de combustão interna, possibilitando sua transformação em energia mecânica. A dependência do petróleo conduz à necessidade de alternativas, mediante o cultivo de matérias-primas renováveis. Os problemas atuais são os custos dos biocombustíveis, que são maiores que dos derivados do petróleo, e o fato de que não existem muitos motores de combustão adequados ao uso de óleos vegetais. Em vista disso, são necessárias mais investigações quanto às técnicas de produção e de refino dos biocombustíveis e, ainda, à adequação de motores ao uso de óleos vegetais, para que estes possam ser uma alternativa viável. O objetivo deste trabalho foi caracterizar as diferentes misturas e avaliar o desempenho de um trator agrícola de pneus, utilizando misturas de óleo Diesel (OD com óleo de soja reutilizável (OSR. Primeiramente, foi realizado um estudo de densidade, viscosidade das misturas e comportamento da temperatura do OD no sistema de alimentação de combustível no motor. Após as análises, verificou-se, por meio de ensaios na barra de tração, o desempenho das misturas de OD e OSR. As principais conclusões deste trabalho foram: a densidade e viscosidade das misturas sofrem variações com o aumento da quantidade de OSR e com a variação da temperatura. Para as avaliações na barra de tração, os melhores resultados observados no rendimento do trator foram verificados com o aumento das percentagens de mistura (25% OSR, para carga N, 25, 75 e 100% OSR, para a quarta marcha, como carga, e 75 e 100% OSR, para a terceira, segunda e primeira marcha, como carga.

  17. Consumo e Descarte do Óleo Comestível em um Município do sul de Minas Gerais/ Consumption and Disposal of Edible Oil in a city of Southern Minas Gerais

    OpenAIRE

    Patricia Calixto Novaes; Alexandre Magno Batista Machado; Fábio Vieira Lacerda

    2014-01-01

    Objetivo: Estimar a quantidade de óleo residual comercializado na cidade, tendo como amostras os grandes revendedores do produto, e estimar a quantidade de óleo destinada por meio dos ecopontos de coleta de óleo no município. Métodos: Foi coletada, em cinco estabelecimentos de referência na cidade, a quantidade de óleo que foi comercializada no ano de 2013, juntamente com a quantidade de óleo destinada para reaproveitamento. Os dados foram confrontados e discutidos seguindo as diretrizes da l...

  18. Sun-Earth Days

    Science.gov (United States)

    Thieman, J.; Ng, C.; Lewis, E.; Cline, T.

    2010-08-01

    Sun-Earth Day is a well-coordinated series of programs, resources and events under a unique yearly theme highlighting the fundamentals of heliophysics research and missions. A menu of activities, conducted throughout the year, inspire and educate participants. Sun-Earth Day itself can vary in date, but usually is identified by a celebration on or near the spring equinox. Through the Sun-Earth Day framework we have been able to offer a series of coordinated events that promote and highlight the Sun, its connection to Earth and the other planets. Sun-Earth Day events are hosted by educators, museums, amateur astronomers and scientists and occur at schools, community groups, parks, planetaria and science centers around the globe. Sun-Earth Day raises the awareness and knowledge of formal and informal education audiences concerning space weather and heliophysics. By building on the success of Sun-Earth Day yearly celebrations, we seek to affect people of all backgrounds and ages with the wonders of heliophysics science, discovery, and exploration in ways that are both tangible and meaningful to their lives.

  19. Design Concepts for a Small Space-Based GEO Relay Satellite for Missions Between Low Earth and near Earth Orbits

    Science.gov (United States)

    Bhasin, Kul B.; Warner, Joseph D.; Oleson, Steven; Schier, James

    2014-01-01

    the number of links looking above and below GEO; the detailed design of a GEO SSBS spacecraft bus and its accommodation of the communication payload, and a summary of the trade study that resulted in the selection of the Falcon 9 launch vehicle to deploy the SSBS and its impact on cost reductions per satellite. ======================================================================== Several initiatives have taken place within NASA1 and international space agencies2 to create a human exploration strategy for expanding human presence into the solar system; these initiatives have been driven by multiple factors to benefit Earth. Of the many elements in the strategy one stands out: to send robotic and human missions to destinations beyond Low Earth Orbit (LEO), including cis-lunar space, Near-Earth Asteroids (NEAs), the Moon, and Mars and its moons.3, 4 The time frame for human exploration to various destinations, based on the public information available,1,4 is shown in Figure 1. Advance planning is needed to define how future space communications services will be provided in the new budget environment to meet future space communications needs. The spacecraft for these missions can be dispersed anywhere from below LEO to beyond GEO, and to various destinations within the solar system. NASA's Space Communications and Navigation (SCaN) program office provides communication and tracking services to space missions during launch, in-orbit testing, and operation phases. Currently, SCaN's space networking relay satellites mainly provide services to users below GEO, at Near Earth Orbit (NEO), below LEO, and in deep space. The potential exists for using a space-based relay satellite, located in the vicinity of various solar system destinations, to provide communication space links to missions both below and above its orbit. Such relays can meet the needs of human exploration missions for maximum connectivity to Earth locations and for reduced latency. In the past, several studies

  20. Earth Science Informatics - Overview

    Science.gov (United States)

    Ramapriyan, H. K.

    2017-01-01

    Over the last 10-15 years, significant advances have been made in information management, there are an increasing number of individuals entering the field of information management as it applies to Geoscience and Remote Sensing data, and the field of informatics has come to its own. Informatics is the science and technology of applying computers and computational methods to the systematic analysis, management, interchange, and representation of science data, information, and knowledge. Informatics also includes the use of computers and computational methods to support decision making and applications. Earth Science Informatics (ESI, a.k.a. geoinformatics) is the application of informatics in the Earth science domain. ESI is a rapidly developing discipline integrating computer science, information science, and Earth science. Major national and international research and infrastructure projects in ESI have been carried out or are on-going. Notable among these are: the Global Earth Observation System of Systems (GEOSS), the European Commissions INSPIRE, the U.S. NSDI and Geospatial One-Stop, the NASA EOSDIS, and the NSF DataONE, EarthCube and Cyberinfrastructure for Geoinformatics. More than 18 departments and agencies in the U.S. federal government have been active in Earth science informatics. All major space agencies in the world, have been involved in ESI research and application activities. In the United States, the Federation of Earth Science Information Partners (ESIP), whose membership includes over 180 organizations (government, academic and commercial) dedicated to managing, delivering and applying Earth science data, has been working on many ESI topics since 1998. The Committee on Earth Observation Satellites (CEOS)s Working Group on Information Systems and Services (WGISS) has been actively coordinating the ESI activities among the space agencies.The talk will present an overview of current efforts in ESI, the role members of IEEE GRSS play, and discuss

  1. Sample Return: What Happens to the Samples on Earth?

    Science.gov (United States)

    McNamara, Karen

    2010-01-01

    As space agencies throughout the world turn their attention toward human exploration of the Moon, Mars, and the solar system beyond, there has been an increase in the number of robotic sample return missions proposed as precursors to these human endeavors. In reality, however, we, as a global community, have very little experience with robotic sample return missions: 3 of the Russian Luna Missions successfully returned lunar material in the 1970s; 28 years later, in 2004, NASA s Genesis Mission returned material from the solar wind; and in 2006, NASA s Stardust Mission returned material from the Comet Wild2. [Note: The Japanese Hyabusa mission continues in space with the hope of returning material from the asteroid 25143 Itokawa.] We launch many spacecraft to LEO and return them to Earth. We also launch spacecraft beyond LEO to explore the planets, our solar system, and beyond. Some even land on these bodies. But these do not return. So as we begin to contemplate the sample return missions of the future, some common questions arise: "What really happens when the capsule returns?" "Where does it land?" "Who retrieves it and just how do they do that?" "Where does it go after that?" "How do the scientists get the samples?" "Do they keep them?" "Who is in charge?" The questions are nearly endless. The goal of this paper/presentation is to uncover many of the mysteries of the post-return phase of a mission - from the time the return body enters the atmosphere until the mission ends and the samples become part of a long term collection. The discussion will be based largely on the author s own experience with both the Genesis and Stardust missions. Of course, these two missions have a great deal in common, being funded by the same NASA Program (Discovery) and having similar team composition. The intent, however, is to use these missions as examples in order to highlight the general requirements and the challenges in defining and meeting those requirements for the final

  2. Near Earth Network (NEN) CubeSat Communications

    Science.gov (United States)

    Schaire, Scott

    2017-01-01

    The NASA Near Earth Network (NEN) consists of globally distributed tracking stations, including NASA, commercial, and partner ground stations, that are strategically located to maximize the coverage provided to a variety of orbital and suborbital missions, including those in LEO (Low Earth Orbit), GEO (Geosynchronous Earth Orbit), HEO (Highly Elliptical Orbit), lunar and L1-L2 orbits. The NEN's future mission set includes and will continue to include CubeSat missions. The first NEN-supported CubeSat mission will be the Cubesat Proximity Operations Demonstration (CPOD) launching into LEO in 2017. The majority of the CubeSat missions destined to fly on EM-1, launching in late 2018, many in a lunar orbit, will communicate with ground-based stations via X-band and will utilize the NASA Jet Propulsion Laboratory (JPL)-developed IRIS (Satellite Communication for Air Traffic Management) radio. The NEN recognizes the important role CubeSats are beginning to play in carrying out NASAs mission and is therefore investigating the modifications needed to provide IRIS radio compatibility. With modification, the NEN could potentially expand support to the EM-1 (Exploration Mission-1) lunar CubeSats. The NEN could begin providing significant coverage to lunar CubeSat missions utilizing three to four of the NEN's mid-latitude sites. This coverage would supplement coverage provided by the JPL Deep Space Network (DSN). The NEN, with smaller apertures than DSN, provides the benefit of a larger beamwidth that could be beneficial in the event of uncertain ephemeris data. In order to realize these benefits the NEN would need to upgrade stations targeted based on coverage ability and current configuration ease of upgrade, to ensure compatibility with the IRIS radio. In addition, the NEN is working with CubeSat radio developers to ensure NEN compatibility with alternative CubeSat radios for Lunar and L1-L2 CubeSats. The NEN has provided NEN compatibility requirements to several radio

  3. Interference of heating on the antimicrobial activity and chemical composition of Origanum vulgare L. (Lamiaceae essential oil Interferência do aquecimento sobre a atividade antimicrobiana e composição química do óleo essencial de Origanum vulgare L. (Lamiaceae

    Directory of Open Access Journals (Sweden)

    Evandro Leite de Souza

    2008-06-01

    Full Text Available Origanum vulgare L. (oregano, Lamiaceae, essential oil has a variety of biological properties and its antimicrobial activity has received a renewed interest for use in food conservation. The aim of this study was to evaluate the interference of heating on the antimicrobial activity and chemical composition of O. vulgare essential oil. The antimicrobial activity of the essential oil kept at room temperature and exposed to different heating temperatures (60, 80, 100 and 120 °C during 1 hour was evaluated by observing antimicrobial effectiveness at absolute concentration and determining MIC values by the solid medium diffusion procedure. The essential oil chemical composition analysis was performed by GC-MS. O. vulgare essential oil showed interesting antimicrobial activity on all assayed microbial strains (Candida albicans, C.krusei, C. tropicalis, Bacillus cereus, Escherichia coli, Staphylococcus aureus, Yersinia enterocolitica, Salmonella enterica, Serratia marcencens, noted by large growth inhibition zones (30-42 mm. Heating treatment showed no significant interference (p O óleo essencial de Origanum vulgare L. Lamiaceae (orégano apresenta variadas propriedades biológicas, de modo que seu potencial antimicrobiano tem despertado interesse para uso na conservação de alimentos. Este estudo objetivou avaliar a interferência de diferentes tratamentos térmicos (60, 80, 100 e 120 °C/1 hora sobre a efetividade antimicrobiana e composição química do óleo essencial de O. vulgare. A efetividade antimicrobiana do óleo essencial exposto aos diferentes tratamentos térmicos foi avaliada através da observação de sua atividade antimicrobiana em concentração absoluta e através da determinação da sua CIM utilizando-se a técnica de difusão em meio sólido. O estudo da composição do óleo essencial foi realizado através de GC-MS. O óleo essencial apresentou intensa atividade antimicrobiana sobre todas as amostras microbianas ensaiadas

  4. 95 päeva sõjatandril, päevik tagataskus / Leo Kunnas ; interv. Erkki Bahovski

    Index Scriptorium Estoniae

    Kunnas, Leo, 1967-

    2006-01-01

    Kolonelleitnant Leo Kunnas räägib Iraagi sissisõjast ja oma raamatust "Viiv pikas sõjas. Märkmeid Iraagi sõjast", mis põhineb tema Iraagi-kogemustel. Vt. samas: Sõda, kus eestlane on sisside vastu

  5. Genetic diversity, evolutionary history and implications for conservation of the lion (Panthera leo) in West and Central Africa

    NARCIS (Netherlands)

    Bertola, L.D.; Hooft, van W.F.; Vrieling, K.; Weerd, de D.R.U.; York, D.S.; Bauer, H.; Prins, H.H.T.; Funston, P.J.; Haes, de H.A.U.; Leirs, H.; Haeringen, van W.A.; Sogbohossou, E.; Tumenta, P.N.; Iongh, de H.H.

    2011-01-01

    Aim In recent decades there has been a marked decline in the numbers of African lions (Panthera leo), especially in West Africa where the species is regionally endangered. Based on the climatological history of western Africa, we hypothesize that West and Central African lions have a unique

  6. Aktuální pohled na folkloristickou činnost Leoše Janáčka

    Czech Academy of Sciences Publication Activity Database

    Procházková, Jarmila

    H 42-43, - (2007-2008), s. 97-103 ISSN 0231-522X R&D Projects: GA ČR GA408/08/1330 Institutional research plan: CEZ:AV0Z90580513 Keywords : Janáček Leoš (1854-1928) * folkloric activities * folksong and folk dance * ethnomusicology Subject RIV: AC - Archeology, Anthropology, Ethnology

  7. Variable stars in Leo A : RR Lyrae stars, short-period cepheids, and implications for stellar content

    NARCIS (Netherlands)

    Dolphin, AE; Saha, A; Claver, J; Skillman, ED; Cole, AA; Gallagher, JS; Tolstoy, E; Dohm-Palmer, RC; Mateo, M

    We present the results of a search for short-period variable stars in Leo A. We have found 92 candidate variables, including eight candidate RR Lyrae stars. From the RR Lyrae stars, we measure a distance modulus of (m - M)(0) = 24.51 +/- 0.12, or 0.80 +/- 0.04 Mpc. This discovery of RR Lyrae stars

  8. Heategu läbi minu silmade / Mikko Leo Selg ; toimetaja Juhani Püttsepp ; kommenteerija Uudo Timm

    Index Scriptorium Estoniae

    Selg, Mikko Leo

    2011-01-01

    Lions klubi ja haridusministeeriumi korraldatud kirjandusvõistluse "Heategu läbi minu silmade" keskmises vanuserühmas (11-14 aastat) kolmanda koha saavutanud Tartu Forseliuse gümnaasiumi õpilase Mikko Leo Selja võistlustöö, mis kirjeldab ohustatud lendorava liigi uurimiseks ja kaitsmiseks tehtud korjandust

  9. ATIVIDADE DE DETERRÊNCIA ALIMENTAR DO ÓLEO ESSENCIAL DE LARANJA AMARGA SOBRE Helicoverpa armigera HÜBNER

    Directory of Open Access Journals (Sweden)

    Victor Luiz de Souza Lima

    2017-01-01

    Full Text Available Diversas plantas possuem compostos secundários com propriedades inseticidas e o óleo essencial de laranja amarga mostra-se com grande potencial para o controle de pragas. Recentemente, foi registrada no Brasil a espécie Helicoverpa armigera, uma das maiores pragas da agricultura mundial. Tendo em vista a falta de métodos alternativos aos inseticidas para o controle dessa praga, o objetivo desse trabalho foi avaliar os efeitos do óleo essencial de laranja amarga sobre H. armigera. Foi realizado um teste de escolha para avaliar a atividade deterrente. Folhas de tomate foram imersas em soluções contendo óleo de laranja amarga em três concentrações (1, 10 e 100 mg L-1. As folhas tratadas com óleo e folhas não tratadas foram oferecidas à lagartas de segunda instar e após 24h foi calculado o índice de deterrência alimentar (IDA. A concentração de 1 mg L-1 apresentou 71% de deterrência alimentar. Porém as concentrações de 10 e 100 mg L-1 causaram fitotoxidez às folhas de tomate, inviabilizando o consumo pelas lagartas e a estimativa do IDA. Novos testes devem ser realizados com concentrações menores para evitar a fitotoxidez.

  10. Rare earth germanates

    International Nuclear Information System (INIS)

    Bondar', I.A.; Vinogradova, N.V.; Dem'yanets, L.N.

    1983-01-01

    From the viewpoint of structural chemistry and general regularities controlling formation reactions of compounds and phases in melts, solid and gaseous states, recent achievements in the chemistry of rare earth germanates are generalized. Methods of synthesizing germanates, systems on the base of germanium oxides and rare earths are considered. The data on crystallochemical characteristics are tabulated. Individual compounds of scandium germanate are also characterized. Processes of germanate formation using the data of IR-spectroscopy, X-ray phase analysis are studied. The structure and morphotropic series of rare earth germanates and silicates are determined. Fields of their present and possible future application are considered

  11. Rare earth oxychalcogenides

    International Nuclear Information System (INIS)

    Eliseev, A.A.; Grizik, A.A.

    1977-01-01

    Considered are oxychalcogenides of rare earth elements: their nomenclature, general physico-chemical characteristics, methods of preparation. Considered in detail are chemistry and crystal chemistry of oxychalcogenides of Ln 2 O 2 S, Ln 2 O 2 Se, Ln 4 O 4 Se 3 , Ln 2 O 2 Te types, where Ln=La-Lu. Given are parameters of crystal lattices, elementary cells, interatomic distances and dependences of lattice periods on ion radii of rare earth elements. Described are the prospects of the practical application of rare-earth element oxychalcogenides as various luminophores

  12. Earth before life.

    Science.gov (United States)

    Marzban, Caren; Viswanathan, Raju; Yurtsever, Ulvi

    2014-01-09

    A recent study argued, based on data on functional genome size of major phyla, that there is evidence life may have originated significantly prior to the formation of the Earth. Here a more refined regression analysis is performed in which 1) measurement error is systematically taken into account, and 2) interval estimates (e.g., confidence or prediction intervals) are produced. It is shown that such models for which the interval estimate for the time origin of the genome includes the age of the Earth are consistent with observed data. The appearance of life after the formation of the Earth is consistent with the data set under examination.

  13. Earth from Above

    Science.gov (United States)

    Parkinson, Claire L.

    Earth from Above provides an easy introduction to understanding and interpreting satellite images, using illustrative examples to instruct on the fantastically informative new global data sets. Beginning with two short chapters on visible satellite images and radiation, the book then covers six key Earth-atmosphere variables on such environmentally important topics as the Antarctic ozone hole, El Nino, deforestation, the missing carbon dilemma, and the effects of sea ice, snow cover, and volcanoes on atmospheric temperatures. A final chapter broadens the discussion to consider satellite Earth observations in general.

  14. Earth System Chemistry integrated Modelling (ESCiMo) with the Modular Earth Submodel System (MESSy) version 2.51

    NARCIS (Netherlands)

    Jockel, P.; Tost, H.; Pozzer, A.; Kunze, M.; Kirner, O.; Brenninkmeijer, C.A.M.; Brinkop, S.; Cai, D.S.; Dyroff, C.; Eckstein, J.; Frank, F.; Garny, H.; Gottschald, K.D.; Graf, P.; Grewe, V.; Kerkweg, A.; Kern, B.; Matthes, S; Mertens, M; Meul, S.; Neumaier, M.; Nützel, M; Oberländer-Hayn, S; Ruhnke, R.; Runde, T.; Sander, R.; Scharffe, D; Zahn, A.

    2016-01-01

    Three types of reference simulations, as recommended by the Chemistry–Climate Model Initiative (CCMI), have been performed with version 2.51 of the European Centre for Medium-Range Weather Forecasts – Hamburg (ECHAM)/Modular Earth Submodel System (MESSy) Atmospheric Chemistry (EMAC) model: hindcast

  15. Actividade antimicrobiana do óleo essencial do Foeniculum vulgare Miller Antimicrobial activity of Foeniculum vulgare Miller essential oil

    Directory of Open Access Journals (Sweden)

    M. T. Tinoco

    2007-01-01

    Full Text Available O Foeniculum vulgare Mill. subsp. vulgare é uma planta espontânea da região mediterrânea, pertencente à família Apiaceae. O seu óleo essencial, principalmente o dos frutos secos, é amplamente utilizado nas indústrias alimentar, farmacêutica, cosmética e perfumaria. Neste trabalho, pretendeu-se avaliar a actividade antimicrobiana do óleo essencial dos frutos verdes e das folhas da variedade de funcho doce colhido no Alentejo, na região de Évora, e relacionar essa actividade com a respectiva composição química. A extracção dos óleos essenciais foi efectuada por hidrodestilação e a sua análise foi feita por GC-FID e GC-MS. No óleo das folhas foram identificados como componentes maioritários os fenilpropanóides anetol, fenchona e estragol e o monoterpeno a-felandreno, enquanto que o óleo dos frutos apresentou como constituintes predominantes anetol e fenchona. A actividade antimicrobiana dos óleos foi avaliada face às estirpes Staphylococcus aureus, Escherichia coli, Saccharomyces spp., Fusarium oxysporum e Penicillium sp.. Os óleos essenciais apresentaram actividade antimicrobiana contra S. aureus, Saccharomyces spp. e Fusarium oxysporum.Foeniculum vulgare Mill. ssp. vulgare is a spontaneous plant of Mediterranean region that belongs to the Apiaceae family. Its essential oil is used as additives in food, pharmaceutical, cosmetic and perfume industries mainly that one obtained from dried seeds. The main goal of this work were to evaluate the antimicrobial activity of essential oils obtained from fresh leaves and unripe seeds of sweet fennel, collected in Évora-Alentejo, in face of their chemical composition. The extraction of the essentials oils was made by hydrodistillation. Chemical analyses were carried out by GC-FID and GCMS. Phenylpropanoides anethole, fenchone, estragole and the monoterpene aphellandrene were the most abundant compounds of leaves essential oil. Seeds essential oil showed as main components

  16. Análise térmica do óleo de linhaça natural e oxidado

    Directory of Open Access Journals (Sweden)

    Marcelo Marques da Fonseca

    2010-05-01

    Full Text Available O óleo de Linhaça é um óleo natural constituído basicamente de triacilglicerol contendo alta porcentagem de ácidos graxos poliinsaturados que têm suas propriedades físico-químicas alteradas durante o processo de oxidação. Muitos estudos têm sido realizados para compreender o processo oxidativo que ocorre em óleos vegetais e para determinar os compostos formados durante a auto-oxidação destes materiais. A Termogravimetria (TG, a Análise Térmica Diferencial (DTA e a Calorimetria Exploratória Diferencial (DSC têm sido utilizadas principalmente no estudo da estabilidade térmica de materiais combustíveis e ainda são escassas no estudo do comportamento térmico do óleo de linhaça, por ser amplamente utilizado na fabricação de materiais pictóricos. Assim, avaliou-se o comportamento térmico do óleo de linhaça natural e envelhecido artificialmente por TG/DTG e por DTA, em atmosfera dinâmica de ar sintético e nitrogênio. Os resultados mostraram que, em atmosfera de nitrogênio, as amostras se decompõem em um estágio entre 30°C e 490°C, com perda de aproximadamente 95% da massa inicial. Em atmosfera dinâmica de ar sintético, as amostras reagem com o gás oxigênio e se decompõem em três estágios entre 30°C e 550°C formando 4,5% (massa de resíduo. A diferença no processo de decomposição está relacionada com a complexidade da matriz e dos mecanismos envolvidos na auto-oxidação do óleo. Os espectros Infravermelhos (IV destas amostras revelam que vários compostos oxigenados são formados durante o envelhecimento do óleo.

  17. Rendimento e Características Físicas dos Óleos de Nim (Azadirachta indica e Mamona (Ricinus communis

    Directory of Open Access Journals (Sweden)

    Juarez Benigno Paes

    Full Text Available A pesquisa objetivou avaliar o rendimento e a viscosidade de óleos de nim (Azadirachta indica e mamona (Ricinus communis. Os frutos de nim foram coletados no Núcleo de Pesquisa do Semiárido, em Patos, Paraíba, e os de mamona, às margens do Rio Espinharas, Patos e em Igaracy, Paraíba. Os frutos foram beneficiados no Laboratório de Tecnologia de Produtos Florestais, em Patos. Foram retiradas amostras de sementes para a determinação do teor de umidade e do rendimento em óleos. Os óleos foram extraídos com álcool etílico absoluto e empregados no preparo de soluções com os óleos de nim e mamona. Determinaram-se a densidade e a viscosidade das soluções. A mamona teve menor teor de umidade e rendimento em óleo que o nim. A densidade e a viscosidade do óleo de nim foram menores que o da mamona. Uma maior quantidade de óleos de mamona proporcionou aumento na densidade e na viscosidade das soluções preparadas.

  18. The Canadian Space Agency, Space Station, Strategic Technologies for Automation and Robotics Program technology development activity in protection of materials from the low Earth orbit space environment

    Science.gov (United States)

    Francoeur, J. R.

    1992-01-01

    The Strategic Technologies in Automation and Robotics (STEAR) program is managing a number of development contracts to improve the protection of spacecraft materials from the Low Earth Orbit (LEO) space environment. The project is structured in two phases over a 3 to 4 year period with a budget of 3 to 4 million dollars. Phase 1 is designed to demonstrate the technical feasibility and commercial potential of a coating/substrate system and its associated application process. The objective is to demonstrate a prototype fabrication capability using a full scale component of a commercially viable process for the protection of materials and surface finishes from the LEO space environment, and to demonstrate compliance with a set of performance requirements. Only phase 1 will be discussed in this paper.

  19. Studies of Geomagnetic Pulsations Using Magnetometer Data from the CHAMP Low-Earth-Orbit Satellite and Ground-Based Stations: a Review

    Directory of Open Access Journals (Sweden)

    P R Sutcliffe

    2011-06-01

    Full Text Available We review research on geomagnetic pulsations carried out using magnetic field measurements from the CHAMP low-Earth-orbit (LEO satellite and ground-based stations in South Africa and Hungary. The high quality magnetic field measurements from CHAMP made it possible to extract and clearly resolve Pi2 and Pc3 pulsations in LEO satellite data. Our analyses for nighttime Pi2 pulsations are indicative of a cavity mode resonance. However, observations of daytime Pi2 pulsation events identified in ground station data show no convincing evidence of their occurrence in CHAMP data. We also studied low-latitude Pc3 pulsations and found that different types of field line resonant structure occur, namely discrete frequencies driven by a narrow band source and L-dependent frequencies driven by a broad band source.

  20. Medium modifications with recoil polarization

    Energy Technology Data Exchange (ETDEWEB)

    Brand, J.F.J. van den [Nationaal Instituut voor Kernfysica en Hoge Energiefysica, Amsterdam (Netherlands); Ent, R. [CEBAF, Newport News, VA (United States)

    1994-04-01

    The authors show that the virtual Compton scattering process allows for a precise study of the off-shell electron-nucleon vertex. In a separable model, they show the sensitivity to new unconstrained structure functions of the nucleon, beyond the usual Dirac and Pauli form factors. In addition, they show the sensitivity to bound nucleon form factors using the reaction 4He({rvec e},e{prime},{rvec p}){sup 3}H. A nucleon embedded in a nucleus represents a complex system. Firstly, the bound nucleon is necessarily off-shell and in principle a complete understanding of the dynamical structure of the nucleon is required in order to calculate its off-shell electromagnetic interaction. Secondly, one faces the possibility of genuine medium effects, such as for example quark-exchange contributions. Furthermore, the electromagnetic coupling to the bound nucleon is dependent on the nuclear dynamics through the self-energy of the nucleon in the nuclear medium.

  1. Medium modifications with recoil polarization

    International Nuclear Information System (INIS)

    Brand, J.F.J. van den; Ent, R.

    1994-01-01

    The authors show that the virtual Compton scattering process allows for a precise study of the off-shell electron-nucleon vertex. In a separable model, they show the sensitivity to new unconstrained structure functions of the nucleon, beyond the usual Dirac and Pauli form factors. In addition, they show the sensitivity to bound nucleon form factors using the reaction 4He(rvec e,e',rvec p) 3 H. A nucleon embedded in a nucleus represents a complex system. Firstly, the bound nucleon is necessarily off-shell and in principle a complete understanding of the dynamical structure of the nucleon is required in order to calculate its off-shell electromagnetic interaction. Secondly, one faces the possibility of genuine medium effects, such as for example quark-exchange contributions. Furthermore, the electromagnetic coupling to the bound nucleon is dependent on the nuclear dynamics through the self-energy of the nucleon in the nuclear medium

  2. Whole-Earth Decompression Dynamics

    OpenAIRE

    Herndon, J. Marvin

    2005-01-01

    The principles of Whole-Earth Decompression Dynamics are disclosed leading to a new way to interpret whole-Earth dynamics. Whole-Earth Decompression Dynamics incorporates elements of and unifies the two seemingly divergent dominant theories of continential displacement, plate tectonics theory and Earth expansion theory. Whole-Earth decompression is the consequence of Earth formation from within a Jupiter-like protoplanet with subsequent loss of gases and ices and concomitant rebounding. The i...

  3. Probing the local interstellar medium

    International Nuclear Information System (INIS)

    Suess, S.T.; Dessler, A.J.

    1985-01-01

    The paper concerns the location of the heliospheric shock, in view of the discrepancy between the theoretical and experimental values. To determine whether the discrepancy may be attributed to parameters used to describe the local interstellar medium [LISM], the authors applied a sophisticated model of solar-wind expansion to deduce a range of parameters for the LISM. Both the interstellar magnetic field and the pressure due to galactic cosmic rays are considered. (U.K.)

  4. Mars, earth, and ice

    International Nuclear Information System (INIS)

    Cordell, B.M.

    1986-01-01

    Possible mechanisms to explain the global ice covering of Mars, and previous ice ages on the earth, are considered. Evidence for the Milankovitch effect is found in the close correspondence of earth's past climate with its orbital variations, as recorded principally in ocean sediments, and the role of CO 2 is discussed. Mars' range of obliquity, 10 times that of the earth, and orbital eccentricity, fluctuating over a range 2 1/2 times that of the earth, could produce an important climate-driving cycle. Mathematical models of the Martian surface and atmosphere based on Viking data suggest that escaped CO 2 could create a surface pressure of 1-3 bars. Other factors such as the effect of continental drift, the increased brightness of the sun, and planetary reversals of magnetic field polarity are discussed, and the questions of where Martian water and CO 2 have gone are considered

  5. Near Earth Asteroid Scout

    Data.gov (United States)

    National Aeronautics and Space Administration — Near-Earth Asteroid Scout, or NEA Scout, is a 6U CubeSat developed jointly between NASA’s Marshall Space Flight Center and the Jet Propulsion Laboratory. NASA...

  6. Earliest life on earth

    CERN Document Server

    Golding, Suzanne D

    2010-01-01

    This volume integrates the latest findings on earliest life forms, identified and characterized in some of the oldest rocks on Earth. It places emphasis on the integration of analytical methods with observational techniques and experimental simulations.

  7. Gambling with the earth

    CERN Multimedia

    Muir, H

    2000-01-01

    The probability that dangerous Earth-devouring particles will be born at a new accelerator in the US may be tiny, but scientists have played down the devastating potential costs in their risk assessments according to a physicist (1 page).

  8. Earth's variable rotation

    Science.gov (United States)

    Hide, Raymond; Dickey, Jean O.

    1991-01-01

    Recent improvements in geodetic data and practical meteorology have advanced research on fluctuations in the earth's rotation. The interpretation of these fluctuations is inextricably linked with studies of the dynamics of the earth-moon system and dynamical processes in the liquid metallic core of the earth (where the geomagnetic field originates), other parts of the earth's interior, and the hydrosphere and atmosphere. Fluctuations in the length of the day occurring on decadal time scales have implications for the topographay of the core-mantle boundary and the electrical, magnetic, ande other properties of the core and lower mantle. Investigations of more rapid fluctuations bear on meteorological studies of interannual, seasonal, and intraseasonal variations in the general circulation of the atmosphere and the response of the oceans to such variations.

  9. Earth's electric field

    International Nuclear Information System (INIS)

    Kelley, M.C.

    1978-01-01

    The earth becomes charged during thunderstorm activity and discharges through the weak conducting atmosphere. Balloon and rocket studies infer that a high altitude electric field penetrates virtually unattenuated through the atmosphere, at least as far as balloon heights. The field has two primary sources. At low and mid latitudes, interaction between the earth's magnetic field and the neutral wind creates electric fields. At latitudes above 60 0 , the high altitude electrical structure is dominated by the interaction between the solar wind and the earth's magnetic field. The auroral light is emitted by atmospheric atoms and molecules excited by electrons with potentials of many thousands volts. The potentials are induced by the solar wind. Recent satellite data shows that the electrons get this energy by passing through a localized electric field about 6000 km above the auroral zone. Several rocket and satellite experiments used to study the earth's electric field are discussed

  10. Down to earth relativity

    Science.gov (United States)

    Shapiro, I. I.

    1978-01-01

    The basic concepts of the special and general theories of relativity are described. Simple examples are given to illustrate the effect of relativity on measurements of time and frequency in the near-earth environment.

  11. Earth retaining structures manual

    Science.gov (United States)

    2009-10-29

    The objectives of this policy are to obtain statewide uniformity, establish standard : procedures and delineate responsibility for the preparation and review of plans, : design and construction control of earth retaining structures. In addition, it i...

  12. Alterações oxidativas em óleos de algodão, girassol e palma utilizados em frituras de mandioca palito congelada

    Directory of Open Access Journals (Sweden)

    M. S. CORSINI

    2008-10-01

    Full Text Available

    O presente trabalho teve como objetivo avaliar as alterações oxidativas produzidas nos óleos de algodão, girassol e palma, durante o processo de fritura descontínua de mandioca palito congelada. As frituras foram conduzidas em uma fritadeira elétrica doméstica, onde o óleo foi aquecido, à temperatura de 180°C, por 25 horas, com reposição de óleo fresco. Os resultados obtidos das determinações analíticas foram submetidos às análises de variância, em esquema fatorial, no delineamento inteiramente casualizado, de modo a determinar a influência dos fatores óleos e tempos de fritura sobre as alterações nos óleos e no produto. Os resultados mostraram que as menores alterações ocorreram para o óleo de palma, mais saturado. Para os óleos de algodão e girassol, mais insaturados, verificou-se que ao longo dos tempos de frituras ocorreu um aumento da formação dos compostos de degradação e diminuiu a estabilidade oxidativa. Apesar das diferenças na composição em ácidos graxos, os óleos estudados não apresentaram, em nenhuma análise, valores acima dos limites recomendados, independentemente do tempo de aquecimento. PALAVRAS-CHAVE: Óleos vegetais; alterações oxidativas; estabilidade oxidativa; frituras.

  13. Extraction of uranium from alkaline medium by organic extractants

    International Nuclear Information System (INIS)

    El - nadi, Y.A.M.

    1996-01-01

    A recent possible route for treatment of small amounts of neutron irradiated uranium from alkaline medium was addressed. This have some advantages related to the isolation of many troublesome fission products which forms insoluble carbonates or hydroxides upon alkaline carbonate dissolution of uranium oxide. In alkaline solution containing sodium carbonate and hydroxide, hexavalent uranium is expected to be dissolved in solution whereby most of the fission products transition elements exemplified by zirconium and niobium as well as trivalent lanthanides and actinides will be precipitated. Therefore, in this medium the solution will contain mainly alkali and alkaline earth metal such as Cs + and Sr 2+ and anionic fission products such as pertechnetates and antimonates, Which can be easily separted from uranium. Therefore, The present thesis is directed to investigate the following; 1 - solubility of uranium oxide in alkaline medium consists of sodium carbonate and sodium hydroxide in presence of oxidizing agent. 2 - Extraction of uranium from the aforementioned alkaline medium by immiscible organic diluent containing different amine extractants. 3 - Extraction behaviour of uranium by the macroporous anion exchanger, amberlite IRA - 410, from alkaline solution

  14. Seismic anisotropy inside the Earth from a model space search approach

    OpenAIRE

    Beghein, Caroline

    2003-01-01

    For theoretical and computational convenience, the Earth has long been modelled as an isotropic medium for wave propagation. There is, however, considerable evidence of seismic anisotropy at different depths and different scales throughout the Earth, which can provide insight into Earth's dynamic processes. Since computational power has greatly increased during the last decades, it has now become possible to account for seismic anisotropy in tomographic modelling. Current methods to map seism...

  15. Rare earths crystal chemistry

    International Nuclear Information System (INIS)

    Wells, A.F.

    1988-01-01

    From the viewpoint of general crystal chemistry principles and on the basis of modern data the structural chemistry of rare earth compounds in different oxidation degrees (2,3,4) is briefly presented. The change of the structure type of oxides, halides and some other compounds of rare earths, as well as the coordination number of the central atom from lanthanide ionic radius is considered

  16. Large Diffractive Optics for GEo-Based Earth Surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Hyde, R A

    2003-09-11

    The natural vantage point for performing Earth-centric operations from space is geosynchronous orbit (GEO); a platform there moves at the same rate as the Earth's surface, so appears to continually ''hover'' over a fixed site on the Earth. Unlike spacecraft in other orbits, which rapidly fly-over targets, a GEO-based platform remains in-position all the time. In order to insure continual access to sites using low earth orbit (LEO) platforms, one needs a large enough constellation ({approx} 50) of spacecraft so that one is always overhead; in contrast, a single GEO platform provides continuous coverage over sites throughout Euro-Asia. This permanent coverage comes, unfortunately, with a stiff price-tag; geosynchronous orbit is 36,000 km high, so space platforms there must operate at ranges roughly 100 times greater than ones located in LEO. For optical-based applications, this extreme range is difficult to deal with; for surveillance the price is a 100-fold loss of resolution, for laser weapons it is a 10,000-fold loss in flux-on-target. These huge performance penalties are almost always unacceptable, preventing us from successfully using GEO-based platforms. In practice, we are forced to either settle for brief, infrequent access to targets, or, if we demand continuous coverage, to invest in large, many-satellite, constellations. There is, fortunately, a way to use GEO-based optical platforms without incurring the huge, range-dependent, performance penalties; one must simply use bigger optics. As long as the aperture of a platform's optics increases as much as its operating range, then its performance (resolution and/or flux) does not suffer; the price for operating from GEO is simply 100-fold larger optics. This is, of course, a very stiff price; while meter-class optics may suffice for many low-earth-orbit applications, 100 meter apertures are needed in order to achieve similar performance from GEO. Since even the largest Earth

  17. Medium Theory and Social Systems

    DEFF Research Database (Denmark)

    Tække, Jesper

    The  paper  first  gives  a  tentative  theoretical  explanation  of  the  concept  of media,  based  on  the  dichotomies  of  actual/potential  (meaning),  form/medium  (appearance),  and  substratum/material  content  (extension  in  time  and  space).  This  theoretical  explanation  presents......  seen as medium  for  formation. Finally  the  paper  takes  the micro  level  perspective  by  applying  the  theory  to  newsgroups,  interpreting  them as self-organizing interactive systems giving a differentiated and diversified scope for social  inclusion.  ......The  paper  first  gives  a  tentative  theoretical  explanation  of  the  concept  of media,  based  on  the  dichotomies  of  actual/potential  (meaning),  form/medium  (appearance),  and  substratum/material  content  (extension  in  time  and  space).  This  theoretical  explanation  presents......  the  possibility  for  observation both of a social micro and a social macro level from a medium perspective. In the next  section  the paper  frames  the macro  level by  a  tentative  synthesis of  the medium  theory  and  the  sociological systems theory briefly describing a socio...

  18. Earth Observation from Space - The Issue of Environmental Sustainability

    Science.gov (United States)

    Durrieu, Sylvie; Nelson, Ross F.

    2013-01-01

    Remote sensing scientists work under assumptions that should not be taken for granted and should, therefore, be challenged. These assumptions include the following: 1. Space, especially Low Earth Orbit (LEO), will always be available to governmental and commercial space entities that launch Earth remote sensing missions. 2. Space launches are benign with respect to environmental impacts. 3. Minimization of Type 1 error, which provides increased confidence in the experimental outcome, is the best way to assess the significance of environmental change. 4. Large-area remote sensing investigations, i.e. national, continental, global studies, are best done from space. 5. National space missions should trump international, cooperative space missions to ensure national control and distribution of the data products. At best, all of these points are arguable, and in some cases, they're wrong. Development of observational space systems that are compatible with sustainability principles should be a primary concern when Earth remote sensing space systems are envisioned, designed, and launched. The discussion is based on the hypothesis that reducing the environmental impacts of thedata acquisition step,which is at the very beginning of the information streamleading to decision and action, will enhance coherence in the information streamand strengthen the capacity of measurement processes to meet their stated functional goal, i.e. sustainable management of Earth resources. We suggest that unconventional points of view should be adopted and when appropriate, remedial measures considered that could help to reduce the environmental footprint of space remote sensing and of Earth observation and monitoring systems in general. This article discusses these five assumptions inthe contextof sustainablemanagementof Earth's resources. Takingeachassumptioninturn,we find the following: (1) Space debris may limit access to Low Earth Orbit over the next decades. (2) Relatively speaking, given

  19. Composição química e variação sazonal dos óleos essenciais de Eugenia pyriformis (Myrtaceae)

    OpenAIRE

    Stefanello, Maria É.A.; Wisniewski Jr., Alberto; Simionatto, Edésio L.; Cervi, Armando C.

    2009-01-01

    A composição química dos óleos essenciais obtidos por hidrodestilação de folhas (coletadas entre outubro/2005 e dezembro/2006), flores e frutos de Eugenia pyriformis Camb. (Myrtaceae), foi analisada por CG e CG/EM. Os óleos foram caracterizados pela presença de monoterpenos e sesquiterpenos em quantidades variáveis durante o ano. Nos óleos das folhas os principais componentes foram β-pineno, limoneno, 1,8-cineol e óxido de cariofileno. O teor destes compostos mostrou grande variação sazo...

  20. COMPOSIÇÃO QUÍMICA E AVALIAÇÃO DA ATIVIDADE CARRAPATICIDA DO ÓLEO ESSENCIAL DE Cinnamomun zeylanicum NO CONTROLE DE Rhipicephalus microplus

    OpenAIRE

    ILDENICE NOGUEIRA MONTEIRO

    2013-01-01

    Os constituintes do óleo de Cinnamomum zeylanicum foram identificados por cromatografia gasosa acoplada à espectrometria de massas (CG-EM). Também foi avaliada a atividade deste óleo essencial contra larvas e fêmeas de Rhipicephalus microplus (carrapato bovino). O óleo das folhas mostrou um rendimento de 1,03% e seus principais constituintes foram Benzoato de Benzila (65,39%), Linalol (5,37%), E-Cinamaldeido (3,97%), α-Pineno (3,95%), β-Felandreno (3,42%), Eugenol (3,36%) e Benzalde...

  1. Utilização da Energia de Dietas para Frangos de Corte Formuladas com Óleo Ácido de Soja

    Directory of Open Access Journals (Sweden)

    Vieira SL

    2002-01-01

    Full Text Available O produto comercialmente chamado "óleo ácido de soja", resulta da acidificação da borra residual do processo de refino do óleo de soja. Este tem sido muito utilizado na indústria de rações animais, ainda que com vários questinamentos a cerca de sua eficiência, tais como a adulteração com outros ácidos graxos de baixo valor nutricional, nível de peroxidação, presença de impurezas, e valores energéticos não confiáveis. Neste estudo, foi avaliado o desempenho de frangos de corte consumindo dietas contendo óleo de soja ou óleo ácido de soja nos níveis de 4 e 8% ou a mistura das duas fontes em partes iguais de 2 e 4% cada. Essas dietas foram fornecidas para frangos de corte alojados em baterias climatizadas a partir dos 7 dias de idade. As aves que receberam misturas equivalentes de óleo ácido de soja e óleo de soja apresentaram menor peso corporal no final do experimento (aos 42 dias quando comparadas com aquelas que consumiram apenas óleo ou óleo ácido de soja, independentemente do nível adicionado. O nível de inclusão de óleo de soja ou óleo ácido de soja não influenciou o peso final das aves. Foi verificado maior consumo de ração pelos animais que receberam dietas de menor nível de inclusão, o que contribuiu para piorar a conversão alimentar dos mesmos. O óleo ácido de soja demonstrou ser uma fonte energética alternativa de alto potencial econômico para uso em dietas comerciais para frangos de corte, apresentando valor energético de 8.114 kcal EMAn/kg de MS, valor 5% inferior ao determinado para o óleo de soja degomado.

  2. Viabilidade de sementes de feijão caupi após o tratamento com óleo essencial de citronela (Cymbopogon winterianus Jowitt)

    OpenAIRE

    Xavier,M.V.A.; Oliveira,C.R.F.; Brito,S.S.S.; Matos,C.H.C.; Pinto,M.A.D.S.C.

    2012-01-01

    O tratamento de sementes com óleos essenciais é um método alternativo que auxilia o manejo integrado de pragas. O objetivo deste trabalho foi avaliar a influência do tratamento de sementes de feijão Vigna unguiculata (L.) Walp. com o óleo essencial de citronela (Cymbopogon winterianus Jowitt). Foi avaliado o efeito do óleo essencial de C. winterianus sobre V. unguiculata nas dosagens 20 μL, 15 μL, 10 μL, 5 μL e testemunha. A qualidade fisiológica das sementes foi determina...

  3. Linhaça marrom e dourada: propriedades químicas e funcionais das sementes e dos óleos prensados a frio

    OpenAIRE

    Barroso,Ana Karina Mauro; Torres,Alexandre Guedes; Branco,Vanessa Naciuk Castelo; Ferreira,Andrea; Finotelli,Priscilla Vanessa; Freitas,Suely Pereira; Leão,Maria Helena Miguez da Rocha

    2014-01-01

    O objetivo do estudo foi comparar a composição química e a capacidade antioxidante das sementes e dos óleos de linhaça marrom e dourada, e avaliar a estabilidade oxidativa dos óleos. Nas sementes, foram determinados: composição centesimal, capacidade antioxidante total e compostos fenólicos totais. Nos óleos, foram determinados: índice de acidez e peróxido, matéria insaponificável, composição em ácidos graxos, tocoferóis, capacidade antioxidante, compostos fenólicos totais e estabilidade oxid...

  4. CARACTERIZAÇÃO E AVALIAÇÃO DA ATIVIDADE LARVICIDA DO ÓLEO ESSENCIAL DO Zingiber officinale Roscoe (GENGIBRE) FRENTE AO MOSQUITO Aedes aegypti

    OpenAIRE

    ANDRESON LEANDRO SANTANA SILVA

    2012-01-01

    Na procura pelo controle químico alternativo contra o mosquito Aedes aegypti, diversas pesquisas são desenvolvidas e estimuladas no intuito de descobrirem novas substâncias inseticidas de origem vegetal. Neste trabalho a partir da extração e do estudo analítico do óleo essencial dos rizomas do Zingiber officinale Roscoe, foi analisado o efeito larvicida do óleo contra larvas em terceiro estágio do mosquito Aedes aegypti (Linnaeus, 1792). Extraiu-se quantitativamente o óleo essencial por hidro...

  5. Caracterización de propóleos provenientes del municipio de Caldas obtenido por dos métodos de recolección

    OpenAIRE

    Martínez G, Julián; Garcia P, Carlos; Durango R, Diego; Gil G, Jesús

    2012-01-01

    RESUMENObjetivo. Determinar las características fisicoquímicas y la actividad antimicrobiana de propóleos de Apis mellifera, provenientes del municipio de Caldas, obtenidos por dos métodos de recolección. Materiales y métodos. Se utilizaron dos métodos de recolección: de raspado y trampa plastica. Se estableció el contenido de cera, ceniza, material insoluble y resina de los propóleos crudos. Al extracto etanólico de los propóleos se les determinó el perfil cromatográfico (GC-MS) y el espectr...

  6. Cefovecin (Convenia) for the treatment of septic peritonitis in a female lion (Panthera leo).

    Science.gov (United States)

    Steeil, James; Schumacher, Juergen; Seibert, Rachel; Tobias, Karen

    2012-09-01

    An 8-yr-old intact female African lion (Panthera leo) presented with a 3-day history of lethargy, anorexia, and vomiting. Hematologic and biochemical abnormalities included a leukocytosis, 41,700/microl (4,700-15,300) with a neutrophilia (37,530/microl; 2,000-9,200) and a left shift (1,250/microl bands; 0-300), and mild hypokalemia of 2.1 mEq/L (2.8-4.8). Abdominal radiographs revealed evidence of intestinal ileus, peritonitis, and the presence of effusion. An exploratory laparotomy was performed, and septic peritonitis due to a pyometra was diagnosed. The lion was treated with an ovariohysterectomy, abdominal lavage, fluid therapy, and a subcutaneous injection of cefovecin. The lion recovered, and clinical signs associated with septic peritonitis resolved within 36 hr. It was returned to conspecifics 3 wk later. Three months postoperatively, the lion showed no residual signs of septic peritonitis.

  7. Cholangiocarcinoma of intrahepatic bile ducts with disseminated metastases in an African lion (Panthera leo).

    Science.gov (United States)

    Lepri, Elvio; Sforna, Monica; Brachelente, Chiara; Chiara, Brachelente; Vitellozzi, Giovanni; Giovanni, Vitellozzi

    2013-06-01

    A cholangiocarcinoma is reported in an 18-yr-old, female African lion (Panthera leo). The primary tumor consisted of multifocal to coalescing, hepatic, white-yellow masses distributed throughout the liver lobes. Metastases were present in regional lymph nodes, peritoneal surface, and lungs. Histologically, the tumor was characterized by a tubular pattern with alcian- and periodic acid-Schiff-positive secretory material in cystic spaces. The neoplastic cells were positive to broad-spectrum cytokeratins. Histochemical and immunohistochemical stains were consistent with bile duct carcinoma. Biliary tumors arising from the gallbladder have been reported in lions. However, to the authors' knowledge, this is the first case of intrahepatic bile duct carcinoma reported in an African lion.

  8. Age Estimation of African Lions Panthera leo by Ratio of Tooth Areas.

    Directory of Open Access Journals (Sweden)

    Paula A White

    Full Text Available Improved age estimation of African lions Panthera leo is needed to address a number of pressing conservation issues. Here we present a formula for estimating lion age to within six months of known age based on measuring the extent of pulp closure from X-rays, or Ratio Of tooth AReas (ROAR. Derived from measurements taken from lions aged 3-13 years for which exact ages were known, the formula explains 92% of the total variance. The method of calculating the pulp/tooth area ratio, which has been used extensively in forensic science, is novel in the study of lion aging. As a quantifiable measure, ROAR offers improved lion age estimates for population modeling and investigations of age-related mortality, and may assist national and international wildlife authorities in judging compliance with regulatory measures involving age.

  9. Age Estimation of African Lions Panthera leo by Ratio of Tooth Areas.

    Science.gov (United States)

    White, Paula A; Ikanda, Dennis; Ferrante, Luigi; Chardonnet, Philippe; Mesochina, Pascal; Cameriere, Roberto

    2016-01-01

    Improved age estimation of African lions Panthera leo is needed to address a number of pressing conservation issues. Here we present a formula for estimating lion age to within six months of known age based on measuring the extent of pulp closure from X-rays, or Ratio Of tooth AReas (ROAR). Derived from measurements taken from lions aged 3-13 years for which exact ages were known, the formula explains 92% of the total variance. The method of calculating the pulp/tooth area ratio, which has been used extensively in forensic science, is novel in the study of lion aging. As a quantifiable measure, ROAR offers improved lion age estimates for population modeling and investigations of age-related mortality, and may assist national and international wildlife authorities in judging compliance with regulatory measures involving age.

  10. Performance Bounds of DPSK and OOK for Low Elevation Optical LEO Downlinks

    Directory of Open Access Journals (Sweden)

    H. Henniger

    2010-12-01

    Full Text Available Optical wireless LEO downlinks are seen as an emerging solution to increase available bandwidth to multigigabits per second. One of the biggest challenges is the impact of the atmosphere on the optical signal. The atmosphere causes time-varying link degradation due to index of refraction turbulence, especially at low elevation angles. Since the influence of the turbulence for low elevation downlinks is hardly investigated we perform numerical propagation simulations in order to achieve reliable received signal statistics. These results are further utilized to evaluate performance bounds of optical wireless systems from an information theory perspective. We focus on the two most common optical wireless systems, i.e. NRZ-DPSK and NRZ-OOK. This work shows that under low elevation angles acceptable quality of service can only be reached with high code rates.

  11. Íleo biliar, causa poco frecuente de obstrucción intestinal

    OpenAIRE

    García-Marín, A.; Pérez-López, M.; Pérez-Bru, S.; Compañ-Rosique, A.

    2014-01-01

    El íleo biliar, rara complicación de la colelitiasis, se caracteriza por la oclusión intestinal secundaria a la impactación de un lito biliar en algún punto del tracto digestivo debido a la existencia de una fístula bilioentérica. El objetivo del trabajo es analizar nuestra experiencia mediante un estudio retrospectivo durante un período de 12 años. Se incluyeron 14 casos (10 mujeres y 4 varones) con una mediana de edad de 81 años y comorbilidades en 11. La principal alteración analítica fue ...

  12. Estudo do comportamento de solos contaminados com óleo de isolamento de transformadores.

    OpenAIRE

    Lauro Massao Wada

    2012-01-01

    Com a finalidade de estudar o comportamento de fluidos aquosos não miscíveis em água no solo, foram executados ensaios de laboratório, a construção de um modelo físico e a comparação dos dados com a simulação numérica com o programa HSSM. Os ensaios de laboratório tiveram a finalidade de obter os parâmetros do solo utilizado no modelo físico e numérico. Foram obtidas curvas de retenção do solo com concentrações de 2, 5, 10 e 15% de óleo e somente c...

  13. Fatal infection with feline panleukopenia virus in two captive wild carnivores (Panthera tigris and Panthera leo).

    Science.gov (United States)

    Duarte, Margarida D; Barros, Sílvia C; Henriques, Margarida; Fernandes, Teresa Lobo; Bernardino, Rui; Monteiro, Madalena; Fevereiro, Miguel

    2009-06-01

    Two cases of fatal infection caused by parvovirus in a white tiger (Panthera tigris) and an African lion (Panthera leo) at the Lisbon Zoo (Portugal) are described. Gross findings at necropsy were catharral enteritis in the tiger and severe hemorrhagic enteritis in the lion. Histopathologic examination revealed, in both animals, intestinal crypt necrosis and lymphocyte depletion in the germinal centers of the mesenteric lymph nodes. Bacteriologic examination was negative for common bacterial pathogens, including Salmonella. Amplification of the parvovirus VP2 complete gene was achieved in both cases and sequencing analysis identified these isolates as feline panleukopenia virus (FPLV). The nucleotide sequences obtained from these two viruses were genetically indistinguishable. The phylogenetic analysis of FPLV strains from domestic cats obtained in the Lisbon area revealed the circulation of FPLV strains highly similar to those isolated from the tiger and lion, which strongly suggests that stray cats may have been the source of infection.

  14. ¿Adictos al petróleo? : una perspectiva latinoamericana

    Directory of Open Access Journals (Sweden)

    Mauricio Medinaceli Monrroy

    2013-10-01

    Full Text Available Una de las preocupaciones centrales en la política energética hoy en día es la elevada dependencia energética en los combustibles fósiles. Esto no sólo por los problemas ambientales asociados a su exploración y explotación, sino también por el reciente incremento en los precios internaciones del petróleo que, en países importadores, incrementa la llamada “factura petrolera” y, en países productores, genera rentas económicas que muchas veces alteran la estabilidad política de un país.

  15. The Making of a Hemispheric Intellectual-Statesman: Leo S. Rowe in Argentina (1906–1919

    Directory of Open Access Journals (Sweden)

    Ricardo D. Salvatore

    2010-03-01

    Full Text Available

    Leo S. Rowe, before becoming director of the Pan-American Union, came to Argentina to gather information, connect with local intellectuals, and disseminate the basic ideas of an emerging inter-American system of cultural and intellectual cooperation that would be the backbone of Pan-Americanism. This paper deals with the interaction and communication between the Hemispheric Intellectual-Statesman and its local counterparts, focusing on the dynamic of the imperial hegemonic process. Argentine intellectuals failed to accept Rowe’s progressive ideas about modern corporations, government by public opinion, and social reform. But they were quite ready to entertain ideas of inter-American cooperation with the powerful Northern Neighbor, vindicating at the same time their affinity with and belonging to “European culture.”

  16. Hematologic and serum chemistry reference intervals for free-ranging lions (Panthera leo).

    Science.gov (United States)

    Maas, Miriam; Keet, Dewald F; Nielen, Mirjam

    2013-08-01

    Hematologic and serum chemistry values are used by veterinarians and wildlife researchers to assess health status and to identify abnormally high or low levels of a particular blood parameter in a target species. For free-ranging lions (Panthera leo) information about these values is scarce. In this study 7 hematologic and 11 serum biochemistry values were evaluated from 485 lions from the Kruger National Park, South Africa. Significant differences between sexes and sub-adult (≤ 36 months) and adult (>36 months) lions were found for most of the blood parameters and separate reference intervals were made for those values. The obtained reference intervals include the means of the various blood parameter values measured in captive lions, except for alkaline phosphatase in the subadult group. These reference intervals can be utilized for free-ranging lions, and may likely also be used as reference intervals for captive lions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Location and removal of deslorelin acetate implants in female African lions (Panthera leo).

    Science.gov (United States)

    Moresco, Anneke; Dadone, Liza; Arble, Jason; Klaphake, Eric; Agnew, Dalen W

    2014-06-01

    Contraception is necessary to manage zoo animal populations and to be able to house animals in groups without producing additional unwanted offspring. In felids and canids, an association between exposure to progestins and the occurrence of endometrial and mammary gland pathology has been documented. Therefore, the Association of Zoos and Aquariums (AZA) Wildlife Contraceptive Center recommends the use of deslorelin acetate for long-term contraception in carnivores. Return to cyclicity after deslorelin treatment has been variable; some individuals show ovarian suppression for long periods after the expected end of the deslorelin efficacy. In an attempt to reduce the time to reversal, techniques to locate and remove previous implants are being developed. This report documents the successful implementation of high-frequency ultrasonography in lions (Panthera leo) to locate and direct surgical removal of multiple deslorelin implants placed at least 2 yr previously as well as the return of follicular activity in both females at 7 months post-removal of implants.

  18. NGSLR's Measurement of the Retro-Reflector Array Response of Various LEO to GNSS Satellites

    Science.gov (United States)

    McGarry, Jan; Clarke, Christopher; Degnan, John; Donovan, Howard; Hall, Benjamin; Hovarth, Julie; Zagwodzki, Thomas

    2012-01-01

    "NASA's Next Generation Satellite Laser Ranging System (NGSLR) has successfully demonstrated daylight and nighttime tracking this year to s atellites from LEO to GNSS orbits, using a 7-8 arcsecond beam divergence, a 43% QE Hamamatsu MCP-PMT with single photon detection, a narrow field of view (11 arcseconds), and a 1 mJ per pulse 2kHz repetition rate laser. We have compared the actual return rates we are getting against the theoretical link calculations, using the known system confi guration parameters, an estimate of the sky transmission using locall y measured visibility, and signal processing to extract the signal from the background noise. We can achieve good agreement between theory and measurement in most passes by using an estimated pOinting error. We will s.()w the results of this comparison along with our conclusio ns."

  19. Dynamic and reduced-dynamic precise orbit determination of satellites in low earth orbits

    International Nuclear Information System (INIS)

    Swatschina, P.

    2009-01-01

    The precise positioning of satellites in Low Earth Orbits (LEO) has become a key technology for advanced space missions. Dedicated satellite missions, such as CHAMP, GRACE and GOCE, that aim to map the Earths gravity field and its variation over time with unprecedented accuracy, initiated the demand for highly precise orbit solutions of LEO satellites. Furthermore, a wide range of additional science opportunities opens up with the capability to generate accurate LEO orbits. For all considered satellite missions, the primary measurement system for navigation is a spaceborne GPS receiver. The goal of this thesis is to establish and implement methods for Precise Orbit Determination (POD) of LEO satellites using GPS. Striving for highest precision using yet efficient orbit generation strategies, the attained orbit solutions are aimed to be competitive with the most advanced solutions of other institutions. Dynamic and reduced-dynamic orbit models provide the basic concepts of this work. These orbit models are subsequently adjusted to the highly accurate GPS measurements. The GPS measurements are introduced at the zero difference level in the ionosphere free linear combination. Appropriate procedures for GPS data screening and editing are established to detect erroneous data and to employ measurements of good quality only. For the dynamic orbit model a sophisticated force model, especially designed for LEO satellites, has been developed. In order to overcome the limitations that are induced by the deficiencies of the purely dynamical model, two different types of empirical parameters are introduced into the force model. These reduced-dynamic orbit models allow for the generation of much longer orbital arcs while preserving the spacecraft dynamics to the most possible extent. The two methods for reduced-dynamic orbit modeling are instantaneous velocity changes (pulses) or piecewise constant accelerations. For both techniques highly efficient modeling algorithms are

  20. ASCHFLOW - A dynamic landslide run-out model for medium scale hazard analysis

    Czech Academy of Sciences Publication Activity Database

    Quan Luna, B.; Blahůt, Jan; van Asch, T.W.J.; van Westen, C.J.; Kappes, M.

    2016-01-01

    Roč. 3, 12 December (2016), č. článku 29. E-ISSN 2197-8670 Institutional support: RVO:67985891 Keywords : landslides * run-out models * medium scale hazard analysis * quantitative risk assessment Subject RIV: DE - Earth Magnetism, Geodesy, Geography

  1. LA ECO-EFICACIA DE LA PLATAFORMA LOGÍSTICA DE PETRÓLEO EN CUBA

    Directory of Open Access Journals (Sweden)

    José Antonio Acevedo Suárez

    2003-04-01

    Full Text Available

    La perspectiva integradora de la gestión ambiental proactiva con las decisiones básicas del sistema de combustible cubano se considera una oportunidad rentable y efectiva. En consecuencia, la plataforma logística de petróleo como modelo para la innovación tecnológica en la gestión de la distribución debe demostrar la compatibilidad con ambas estrategias, permitiendo así obtener las oportunidades ambientales mediante los procedimientos para el desarrollo del modelo. Además se seleccionan los medidores del desempeño ambiental para la cuantificación del efecto sobre la carga ambiental. El modelo plataforma logística de petróleo asegura la compatibilidad con la gestión ambiental proactiva a través de diferentes etapas de desarrollo, que proporcionan un conducto natural para integrar las preocupaciones ambientales de las actividades logísticas con la cadena de suministro del canal de distribución. También se identifican los indicadores de eco-eficacia como la forma más generalizadora para medir el desempeño ambiental en el ámbito empresarial, demostrando con su aplicación un uso más racional de la energía, los materiales y el agua por metros cúbicos de combustibles vendidos.

  2. Actividad anticaries de una crema dental con propóleos

    Directory of Open Access Journals (Sweden)

    Estela Gispert Abreu

    2000-12-01

    Full Text Available Por muestreo aleatorio simple se seleccionaron 50 escolares con antecedentes de alta infección por Streptococcus mutans, para verificar la actividad anticaries de una crema dental que contiene 0,8 de extracto de propóleo blando. Se perdieron del estudio a 7 escolares por inasistencia y traslados. Se crearon 2 grupos: uno control (n=19 que se cepilló con una crema dental placebo y otro tratamiento (n=24 que se cepilló con la crema dental de propóleo. Entre ambos grupos no había diferencia significativa en el índice de caries COP-D ni en el porcentaje de afectados. Luego de los 10 ciclos de cepillado durante 18 meses, dentro del grupo tratamiento se redujo significativamente en índice de caries y el porcentaje de afectados (Q = p50 students with history of high infection caused by Streptococcus mutans were selected by simple random sampling aimed at verifying the anticaries activity of a tooth paste containing 0.8 of soft propolis extract. 7 students did not conclude the study due to absences and transfers. 2 groups were created: a control group (n = 19 that brushed its teeth with a placebo tooth paste and the other under treatment (n = 24 that used a tooth paste with propolis. There was no significant difference between both groups as regards the COP-D caries index and the percentage of affection. A significant reduction of the caries index and of the percentage of affected individuals (Q = p

  3. Optimal Safety EarthingEarth Electrode Sizing Using A ...

    African Journals Online (AJOL)

    In this paper a deterministic approach in the sizing of earth electrode using the permissible touch voltage criteria is presented. The deterministic approach is effectively applied in the sizing of the length of earth rod required for the safe earthing of residential and facility buildings. This approach ensures that the earthing ...

  4. Óleos essenciais e extratos vegetais no controle da podridão mole em alface crespa Essential oils and plant extracts on the control of soft rot of crispy lettuce

    Directory of Open Access Journals (Sweden)

    Cristiane L Silva

    2012-12-01

    Full Text Available Avaliou-se o efeito de óleos essenciais e extratos vegetais no controle da podridão mole em alface, bem como, a influência desses produtos nas características físico-químicas desta hortaliça. Nos testes in vitro, discos de papel de filtro foram embebidos em 11 óleos essenciais e 20 extratos vegetais nas concentrações 0,0; 0,25; 0,50; 0,75 e 1% e 0,0; 10, 40, 70 e 100%, respectivamente, e depositados sobre meio de cultura contendo Pectobacterium carotovorum subsp. carotovorum (Pcc A1. Os halos de inibição foram mensurados após 24 e 48 h de incubação. Em casa de vegetação, plantas de alface cv. Veneranda foram tratadas com 11 óleos nas concentrações de 0,5 e 1%, 20 extratos na concentração de 10% e Mycoshield® (3 g L-1, sendo inoculadas com o isolado Pcc A1 após 72 h. A severidade da doença foi avaliada a intervalos de seis até 48 h, calculando-se a área abaixo da curva de progresso da doença (AACPD. Em experimento similar, plantas tratadas com óleo de Corymbia citriodora, sete extratos e Mycoshield® foram analisadas quanto aos teores de sólidos solúveis, vitamina C, acidez titulável e pH. Pcc A1 não foi inibido in vitro. Dois óleos (C. citriodora e Citrus sinensis e sete extratos (Parkinsonia aculeata, Chamaecrista cytisoides, Sida galherensis, Polygala violaceae, Chamaecrista desvauxii e Pityrocarpa moniliformis reduziram significativamente a severidade da doença em relação à testemunha, não diferindo do controle Mycoshield®. Já a AACPD foi reduzida por oito óleos e dez extratos. Destacaram-se com eficiência similar ao Mycoshield® e diferindo da testemunha (7,5 e 132,3 nas duas variáveis analisadas, o óleo de C. citriodora a 0,5% e o extrato de S. galherensis a 10% com severidades de 3,6 e 3,5 e AACPD de 83,35 e 88,25, respectivamente. Os teores de vitamina C, acidez titulável e pH não foram alterados em folhas de alface tratadas com óleo de C. citriodora e extratos de P. aculeata e C. cytisoides

  5. EarthCache as a Tool to Promote Earth-Science in Public School Classrooms

    Science.gov (United States)

    Gochis, E. E.; Rose, W. I.; Klawiter, M.; Vye, E. C.; Engelmann, C. A.

    2011-12-01

    Geoscientists often find it difficult to bridge the gap in communication between university research and what is learned in the public schools. Today's schools operate in a high stakes environment that only allow instruction based on State and National Earth Science curriculum standards. These standards are often unknown by academics or are written in a style that obfuscates the transfer of emerging scientific research to students in the classroom. Earth Science teachers are in an ideal position to make this link because they have a background in science as well as a solid understanding of the required curriculum standards for their grade and the pedagogical expertise to pass on new information to their students. As part of the Michigan Teacher Excellence Program (MiTEP), teachers from Grand Rapids, Kalamazoo, and Jackson school districts participate in 2 week field courses with Michigan Tech University to learn from earth science experts about how the earth works. This course connects Earth Science Literacy Principles' Big Ideas and common student misconceptions with standards-based education. During the 2011 field course, we developed and began to implement a three-phase EarthCache model that will provide a geospatial interactive medium for teachers to translate the material they learn in the field to the students in their standards based classrooms. MiTEP participants use GPS and Google Earth to navigate to Michigan sites of geo-significance. At each location academic experts aide participants in making scientific observations about the locations' geologic features, and "reading the rocks" methodology to interpret the area's geologic history. The participants are then expected to develop their own EarthCache site to be used as pedagogical tool bridging the gap between standards-based classroom learning, contemporary research and unique outdoor field experiences. The final phase supports teachers in integrating inquiry based, higher-level learning student

  6. Grid for Earth Science Applications

    Science.gov (United States)

    Petitdidier, Monique; Schwichtenberg, Horst

    2013-04-01

    The civil society at large has addressed to the Earth Science community many strong requirements related in particular to natural and industrial risks, climate changes, new energies. The main critical point is that on one hand the civil society and all public ask for certainties i.e. precise values with small error range as it concerns prediction at short, medium and long term in all domains; on the other hand Science can mainly answer only in terms of probability of occurrence. To improve the answer or/and decrease the uncertainties, (1) new observational networks have been deployed in order to have a better geographical coverage and more accurate measurements have been carried out in key locations and aboard satellites. Following the OECD recommendations on the openness of research and public sector data, more and more data are available for Academic organisation and SMEs; (2) New algorithms and methodologies have been developed to face the huge data processing and assimilation into simulations using new technologies and compute resources. Finally, our total knowledge about the complex Earth system is contained in models and measurements, how we put them together has to be managed cleverly. The technical challenge is to put together databases and computing resources to answer the ES challenges. However all the applications are very intensive computing. Different compute solutions are available and depend on the characteristics of the applications. One of them is Grid especially efficient for independent or embarrassingly parallel jobs related to statistical and parametric studies. Numerous applications in atmospheric chemistry, meteorology, seismology, hydrology, pollution, climate and biodiversity have been deployed successfully on Grid. In order to fulfill requirements of risk management, several prototype applications have been deployed using OGC (Open geospatial Consortium) components with Grid middleware. The Grid has permitted via a huge number of runs to

  7. Experimental Tests of UltraFlex Array Designs in Low Earth Orbital and Geosynchronous Charging Environments

    Science.gov (United States)

    Galofaro, Joel T.; Vayner, Boris V.; Hillard, Grover B.

    2011-01-01

    The present ground based investigations give the first definitive look describing the expected on-orbit charging behavior of Orion UltraFlex array coupons in the Low Earth Orbital and Geosynchronous Environments. Furthermore, it is important to note that the LEO charging environment also applies to the International Space Station as well as to the lunar mission charging environments. The GEO charging environment includes the bounding case for all lunar orbital and lunar surface mission environments. The UltraFlex thin film photovoltaic array technology has been targeted to become the sole power system for life support and on-orbit power for the manned Aires Crew Exploration Vehicle. It is therefore, crucial to gain an understanding of the complex charging behavior to answer some of the basic performance and survivability issues in an attempt to ascertain that a single UltraFlex array design will be able to cope with the projected worst case LEO and GEO charging environments. Testing was limited to four array coupons, two coupons each from two different array manufactures, Emcore and Spectrolab. The layout of each array design is identical and varies only in the actual cell technology used. The individual array cells from each manufacturer have an antireflection layered coating and come in two different varieties either uncoated (only AR coating) or coated with a thin conducting ITO layer. The LEO Plasma tests revealed that all four coupons passed the arc threshold -120 V bias tests. GEO electron gun charging tests revealed that only front side area of ITO coated coupons passed tests. Only the Emcore AR array passed backside Stage 2 GEO Tests.

  8. A Validation Method of ESA's MASTER 1 cm Population in Low Earth Orbit

    Science.gov (United States)

    Horstmann, A.; Stoll, E.; Krag, H.

    This paper explains the validation phase within ESA's Meteoroid And Space Debris Terrestrial Environment Reference (MASTER) model for the large object population in Low Earth Orbit (LEO) (diameter less than 1 cm). It answers three questions: 1) How is the MASTER population calibrated against observation results 2) Do recent fragmentation events affect the validation phase and 3) Does the space debris model represent reality suffciently? Since all on-orbit fragments are modeled event-based, one of the main calibration parameters for each fragmentation is the number of objects that are tracked by the Space Surveillance Network (SSN). However, to further calibrate the LEO population, radar surveys such as the Tracking and Imaging Radar (TIRA) Beam park experiments (Fraunhofer Institute/FHR, Germany) and European Incoherent SCATter Radar systems (EISCAT) observations (three radar systems in northern Scandinavia) are performed within dedicated observation campaigns. These space debris observation campaigns can detect objects in LEO down to 1 cm in diameter. For the validation, the observation campaigns are simulated with the Program for Radar and Optical Observation Forecasting (PROOF-2009) using the MASTER population. The results are compared against those from the observation campaigns. One important aspect during the validation is that observation campaigns can be susceptible to recent fragmentation events due to the sensors' detection sensitivity. This is shown by comparing radar observations, which were performed shortly after a fragmentation event, and a state-of-the-art MASTER population snapshot at the same epoch. Evaluations are based on the Fengyun-1C fragmentation event and the contemporary radar observations.

  9. "Winterização" de óleo de pescado via solvente Winterization of fish oil with solvent

    Directory of Open Access Journals (Sweden)

    Daniele Colembergue Cunha

    2009-03-01

    Full Text Available O fracionamento de óleos via "winterização" consiste numa cristalização fracionada, na qual os triacilgliceróis de óleos e gorduras são separados pela cristalização parcial na fase líquida. O objetivo deste trabalho consistiu na determinação das variáveis significativas e das condições operacionais do processo de "winterização" via solvente do óleo de pescado. Como matéria-prima empregou-se o óleo de pescado bruto de indústrias pesqueiras, o qual foi branqueado. Na etapa de "winterização", o óleo branqueado foi resfriado progressivamente em três estágios, de 30 ºC até -5 ºC. Foram estudados os seguintes fatores: tipo de solvente, proporção de solvente e agitação no segundo estágio do resfriamento. As composições de ácidos graxos dos óleos de pescado foram determinadas através de cromatografia gasosa. Foram analisadas as variações percentuais dos ácidos graxos insaturados e dos ácidos graxos saturados. As condições recomendadas para o processo foram o emprego de hexano como solvente, na proporção de 40% em relação à massa de óleo, e sem o emprego de agitação no segundo estágio do resfriamento. Sob tais condições, obteve-se um óleo com teor de ácidos graxos poli-insaturados (PUFA de 64,3%, sendo observado um aumento no percentual dos ácidos graxos insaturados de aproximadamente 9,2% e uma redução de 13,4% dos saturados, em relação ao óleo branqueado de pescado.The process of winterization consists of fractional crystallization, in which the triglycerides of oils and fats are separate by the partial crystallization in the liquid phase. The objective of this work was to evaluate significant variables and the operational conditions in the solvent winterization process of the fish oil. The crude fish oil from fishery industries was bleached and used as raw material. During the winterization step, the bleached oil was cooled progressively from 30 ºC to 5 ºC in three phases. The solvent

  10. Essential oils for rust control on coffee plants Óleos essenciais no controle da ferrugem em cafeeiro

    Directory of Open Access Journals (Sweden)

    Ricardo Borges Pereira

    2012-02-01

    Full Text Available Rust is considered the most important disease in coffee because it causes severe defoliation in plants and, consequently, reduction in productivity. This study evaluated the in vitro effect of essential oils of cinnamon, citronella, lemongrass, clove, tea tree, thyme, neem and eucalyptus on the germination of urediniospores of Hemileia vastatrix; the effectiveness of these oils to control rust on seedlings of coffee cultivars Catucaí 2SL, Catuaí IAC 62 and Mundo Novo 379/19 in the greenhouse; and the effect of more promising oils on urediniospores of H. vastatrix by transmission electron microscopy (TEM. All the essential oils inhibited the germination of urediniospores with increasing concentrations. All oils promoted partial control of the disease in the greenhouse. However, the oils of thyme, clove and citronella, at a concentration of 1000 µL L-1, were most effective in controlling the disease on cultivars Catucaí 2SL, Catuaí IAC 62 and Mundo Novo 379/19, respectively. The images generated in TEM showed that urediniospores exposed to oils of clove, citronella and thyme promoted cellular disorganization and cytoplasmic vacuolization, which was more pronounced in urediniospores exposed to citronella oil. The oils of thyme, clove and citronella are promising for the control of rust in coffee.A ferrugem é considerada a doença de maior importância no cafeeiro, pois causa acentuada desfolha nas plantas e, consequentemente, redução na produtividade. Este trabalho avaliou o efeito in vitro de óleos essenciais de canela, citronela, capim-limão, cravo-da-índia, árvore-de-chá, tomilho, nim e eucalipto na germinação de urediniósporos de Hemileia vastatrix; a eficácia desses óleos no controle da ferrugem em mudas de cafeeiro das cultivares Catucaí 2SL, Catuaí IAC 62 e Mundo Novo 379/19 em casa de vegetação; e o efeito dos óleos mais promissores sobre urediniósporos de H. vastatrix por meio de microscopia eletrônica de transmiss

  11. Development of brachytherapy medium doserate

    International Nuclear Information System (INIS)

    Atang Susila; Ari Satmoko; Ahmad Rifai; Kristiyanti

    2010-01-01

    Brachytherapy has proven to be an effective treatment for different types of cancers and it become a common treatment modality in most radiotherapy clinics. PRPN has had experience in development of Low Dose Rate Brachytherapy for cervix cancer treatment. However the treatment process using LDR device needs 5 hours in time that the patient feel uncomfort. Therefore PRPN develops Medium Dose Rate Brachytherapy with radiation activity not more than 5 Currie. The project is divided into two stages. Purchasing of TPS software and TDS design are held in 2010, and the construction will be in 2011. (author)

  12. A Heterogeneous Medium Analytical Benchmark

    International Nuclear Information System (INIS)

    Ganapol, B.D.

    1999-01-01

    A benchmark, called benchmark BLUE, has been developed for one-group neutral particle (neutron or photon) transport in a one-dimensional sub-critical heterogeneous plane parallel medium with surface illumination. General anisotropic scattering is accommodated through the Green's Function Method (GFM). Numerical Fourier transform inversion is used to generate the required Green's functions which are kernels to coupled integral equations that give the exiting angular fluxes. The interior scalar flux is then obtained through quadrature. A compound iterative procedure for quadrature order and slab surface source convergence provides highly accurate benchmark qualities (4- to 5- places of accuracy) results

  13. Charmed hadrons in nuclear medium

    International Nuclear Information System (INIS)

    Tolos, L.; Gamermann, D.; Molina, R.; Nieves, J.; Oset, E.; Garcia-Recio, C.; Ramos, A.

    2010-01-01

    We study the properties of charmed hadrons in dense matter within a coupled-channel approach which accounts for Pauli blocking effects and meson self-energies in a self-consistent manner. We analyze the behaviour in this dense environment of dynamically-generated baryonic resonances as well as the open-charm meson spectral functions. We discuss the implications of the in-medium properties of open-charm mesons on the D s0 (2317) and the predicted X(3700) scalar resonances. (authors)

  14. Advanced transportation system study: Manned launch vehicle concepts for two way transportation system payloads to LEO

    Science.gov (United States)

    Duffy, James B.

    1993-01-01

    The purpose of the Advanced Transportation System Study (ATSS) task area 1 study effort is to examine manned launch vehicle booster concepts and two-way cargo transfer and return vehicle concepts to determine which of the many proposed concepts best meets NASA's needs for two-way transportation to low earth orbit. The study identified specific configurations of the normally unmanned, expendable launch vehicles (such as the National Launch System family) necessary to fly manned payloads. These launch vehicle configurations were then analyzed to determine the integrated booster/spacecraft performance, operations, reliability, and cost characteristics for the payload delivery and return mission. Design impacts to the expendable launch vehicles which would be required to perform the manned payload delivery mission were also identified. These impacts included the implications of applying NASA's man-rating requirements, as well as any mission or payload unique impacts. The booster concepts evaluated included the National Launch System (NLS) family of expendable vehicles and several variations of the NLS reference configurations to deliver larger manned payload concepts (such as the crew logistics vehicle (CLV) proposed by NASA JSC). Advanced, clean sheet concepts such as an F-1A engine derived liquid rocket booster (LRB), the single stage to orbit rocket, and a NASP-derived aerospace plane were also included in the study effort. Existing expendable launch vehicles such as the Titan 4, Ariane 5, Energia, and Proton were also examined. Although several manned payload concepts were considered in the analyses, the reference manned payload was the NASA Langley Research Center's HL-20 version of the personnel launch system (PLS). A scaled up version of the PLS for combined crew/cargo delivery capability, the HL-42 configuration, was also included in the analyses of cargo transfer and return vehicle (CTRV) booster concepts. In addition to strictly manned payloads, two-way cargo

  15. The Sun and Earth

    Science.gov (United States)

    Gopalswamy, Natchimuthuk

    2012-01-01

    Thus the Sun forms the basis for life on Earth via the black body radiation it emits. The Sun also emits mass in the form of the solar wind and the coronal mass ejections (CMEs). Mass emission also occurs in the form of solar energetic particles (SEPs), which happens during CMEs and solar flares. Both the mass and electromagnetic energy output of the Sun vary over a wide range of time scales, thus introducing disturbances on the space environment that extends from the Sun through the entire heliosphere including the magnetospheres and ionospheres of planets and moons of the solar system. Although our habitat is located in the neutral atmosphere of Earth, we are intimately connected to the non-neutral space environment starting from the ionosphere to the magnetosphere and to the vast interplanetary space. The variability of the solar mass emissions results in the interaction between the solar wind plasma and the magnetospheric plasma leading to huge disturbances in the geospace. The Sun ionizes our atmosphere and creates the ionosphere. The ionosphere can be severely disturbed by the transient energy input from solar flares and the solar wind during geomagnetic storms. The complex interplay between Earth's magnetic field and the solar magnetic field carried by the solar wind presents varying conditions that are both beneficial and hazardous to life on earth. This seminar presents some of the key aspects of this Sun-Earth connection that we have learned since the birth of space science as a scientific discipline some half a century ago.

  16. Monitoring the Earth

    Science.gov (United States)

    Vita-Finzi, Claudio

    2003-02-01

    Monitoring the Earth is the first book to review the recent advances in satellite technology, computing and mass spectrometry that are opening up completely new avenues of enquiry to Earth scientists. Among the geological changes that were previously considered too slow or too extensive for direct measurements and that can now be monitored directly are continental displacements, mountain uplift, the growth and decay of icesheets and glaciers, the faulting and folding of rocks, the progress of weathering and sedimentation, and the growth of coral reefs. In addition to these developments, the book assesses progress in fields not normally considered part of physical geology, such as the shape and orbit of the gravity and the terrestrial magnetic field. The results from the new findings are already helping Earth scientists analyze and explain the underlying mechanisms, notably with regard to the storage and release of strain during earthquakes and the interaction of glacial history with the Earth's rate of rotation. The outcoe is a foretaste of the physical geology of the space age.^Fully illustrated with line drawings and photographs, and with a bibliography that encompasses the scattered and disparate litarature, Monitoring the Earth is intended for undergraduates in geology, geomorphology, geomatic engineering and planetary science, but it should also be of interest to astronomers and historians of science.

  17. Crescent Earth and Moon

    Science.gov (United States)

    1977-01-01

    This picture of a crescent-shaped Earth and Moon -- the first of its kind ever taken by a spacecraft -- was recorded Sept. 18, 1977, by NASA's Voyager 1 when it was 7.25 million miles (11.66 million kilometers) from Earth. The Moon is at the top of the picture and beyond the Earth as viewed by Voyager. In the picture are eastern Asia, the western Pacific Ocean and part of the Arctic. Voyager 1 was directly above Mt. Everest (on the night side of the planet at 25 degrees north latitude) when the picture was taken. The photo was made from three images taken through color filters, then processed by the Jet Propulsion Laboratory's Image Processing Lab. Because the Earth is many times brighter than the Moon, the Moon was artificially brightened by a factor of three relative to the Earth by computer enhancement so that both bodies would show clearly in the print. Voyager 2 was launched Aug. 20, 1977, followed by Voyager 1 on Sept. 5, 1977, en route to encounters at Jupiter in 1979 and Saturn in 1980 and 1981. JPL manages the Voyager mission for NASA's Office of Space Science.

  18. The earth's hydrological cycle

    CERN Document Server

    Bonnet, R-M; Calisto, M; Destouni, G; Gurney, R; Johannessen, J; Kerr, Y; Lahoz, WA; Rast, M

    2014-01-01

    This book gives a comprehensive presentation of our present understanding of the Earth's Hydrological cycle and the problems, consequences and impacts that go with this topic. Water is a central component in the Earth's system. It is indispensable for life on Earth in its present form and influences virtually every aspect of our planet's life support system. On relatively short time scales, atmospheric water vapor interacts with the atmospheric circulation and is crucial in forming the Earth's climate zones. Water vapor is the most powerful of the greenhouse gases and serves to enhance the tropospheric temperature. The dominant part of available water on Earth resides in the oceans. Parts are locked up in the land ice on Greenland and Antarctica and a smaller part is estimated to exist as groundwater. If all the ice over the land and all the glaciers were to melt, the sea level would rise by some 80 m. In comparison, the total amount of water vapor in the atmosphere is small; it amounts to ~ 25 kg/m2, or the ...

  19. Modeling the earth system

    Energy Technology Data Exchange (ETDEWEB)

    Ojima, D. [ed.

    1992-12-31

    The 1990 Global Change Institute (GCI) on Earth System Modeling is the third of a series organized by the Office for Interdisciplinary Earth Studies to look in depth at particular issues critical to developing a better understanding of the earth system. The 1990 GCI on Earth System Modeling was organized around three themes: defining critical gaps in the knowledge of the earth system, developing simplified working models, and validating comprehensive system models. This book is divided into three sections that reflect these themes. Each section begins with a set of background papers offering a brief tutorial on the subject, followed by working group reports developed during the institute. These reports summarize the joint ideas and recommendations of the participants and bring to bear the interdisciplinary perspective that imbued the institute. Since the conclusion of the 1990 Global Change Institute, research programs, nationally and internationally, have moved forward to implement a number of the recommendations made at the institute, and many of the participants have maintained collegial interactions to develop research projects addressing the needs identified during the two weeks in Snowmass.

  20. Óleo de cravo como anestésico em adultos de tilápia-do-nilo

    Directory of Open Access Journals (Sweden)

    Larissa Novaes Simões

    2010-12-01

    Full Text Available O objetivo deste trabalho foi testar a eficiência do óleo de cravo como anestésico em adultos de tilápia-do-nilo (Oreochromis niloticus e avaliar, sensorialmente, o aroma e o sabor do filé, após a anestesia. No primeiro experimento, os peixes foram expostos a banhos anestésicos em diferentes concentrações de óleo de cravo (0, 100, 150, 200, 250 e 350 mg L-1. No segundo experimento, avaliaram-se diferentes tempos (10, 20 e 30 minutos de exposição à anestesia. Finalmente, o aroma e o sabor dos filés de tilápia foram testados, em diferentes tempos de exposição à concentração adequada de óleo de cravo. A concentração de 250 mg L-1 de óleo de cravo foi adequada para a indução de parada dos batimentos operculares em adultos de tilápia, e para a anestesia voltada para biometria e breve manejo, a concentração recomendada é 100 mg L-1. Os filés de tilápias previamente anestesiadas com óleo de cravo apresentaram diferença moderada no aroma e no sabor logo após a anestesia. O óleo de cravo é um anestésico eficaz no manejo de adultos de tilápia em procedimentos de rotina na piscicultura, porém o abate de tilápias deve ser realizado a partir de 12 horas após a exposição a este anestésico, para não induzir alteração nas características organolépticas dos filés de peixes anestesiados